iptables plugin: Adds a plugin to collect iptables'-counters.
authorSjoerd van der Berg <harekiet@gmail.com>
Sat, 3 Mar 2007 09:35:35 +0000 (10:35 +0100)
committerFlorian Forster <octo@leeloo.lan.home.verplant.org>
Sat, 3 Mar 2007 09:35:35 +0000 (10:35 +0100)
My first attempt at a module for this is an iptables modules This will try to
read out the rules from iptables for a specific table and chain.
It will go through the rules looking for ones with "comment" matches and will
use the comment as a base for the generated filename.

So basically looking for lines like
 $ iptables -t mangle -A incoming -p tcp -m comment --comment "tcp"
will generate a iptables-incoming/tcp.rrd file from the byte counters

There used to also be an account iptables module but that seems to have been
neglected, which would generate /proc entries for specific rules, don't know
what would work better. Either way, this seems to work somewhat.

12 files changed:
configure.in
contrib/iptables/accounting.sh [new file with mode: 0755]
src/Makefile.am
src/iptables.c [new file with mode: 0644]
src/libiptc/Makefile.am [new file with mode: 0644]
src/libiptc/ipt_kernel_headers.h [new file with mode: 0644]
src/libiptc/libip4tc.c [new file with mode: 0644]
src/libiptc/libip6tc.c [new file with mode: 0644]
src/libiptc/libiptc.c [new file with mode: 0644]
src/libiptc/libiptc.h [new file with mode: 0644]
src/libiptc/linux_list.h [new file with mode: 0644]
src/libiptc/linux_stddef.h [new file with mode: 0644]

index 602d0fa..49f6ac3 100644 (file)
@@ -1046,6 +1046,7 @@ AC_COLLECTD([dns],       [disable], [module], [dns statistics])
 AC_COLLECTD([email],     [disable], [module], [email statistics])
 AC_COLLECTD([quota],     [enable],  [module], [quota statistics (experimental)])
 AC_COLLECTD([hddtemp],   [disable], [module], [hdd temperature statistics])
+AC_COLLECTD([iptables],  [disable], [module], [IPtables statistics])
 AC_COLLECTD([load],      [disable], [module], [system load statistics])
 AC_COLLECTD([mbmon],     [disable], [module], [motherboard monitor statistics])
 AC_COLLECTD([memory],    [disable], [module], [memory statistics])
@@ -1064,7 +1065,7 @@ AC_COLLECTD([users],     [disable], [module], [user count statistics])
 AC_COLLECTD([vserver],   [disable], [module], [vserver statistics])
 AC_COLLECTD([wireless],  [disable], [module], [wireless link statistics])
 
-AC_OUTPUT(Makefile src/Makefile src/collectd.conf src/libconfig/Makefile src/liboping/Makefile)
+AC_OUTPUT(Makefile src/Makefile src/collectd.conf src/libconfig/Makefile src/liboping/Makefile src/libiptc/Makefile )
 
 cat <<EOF;
 
diff --git a/contrib/iptables/accounting.sh b/contrib/iptables/accounting.sh
new file mode 100755 (executable)
index 0000000..71032f0
--- /dev/null
@@ -0,0 +1,29 @@
+#/bin/bash
+#Simple script that sets up some chains in mangle table to do global logging of all 
+#traffic going in and out of an interface
+#Could also use the regular input/output tree but this also catches the forwarded nat traffic
+
+IT="iptables -t mangle"
+
+#First clear the old stuff
+$IT -F incoming
+$IT -F outgoing
+$IT -N incoming
+$IT -N outgoing
+
+$IT -D PREROUTING -i eth0 -j incoming
+$IT -D POSTROUTING -o eth0 -j outgoing
+
+#should add some arg == stop exit here...
+
+$IT -A PREROUTING -i eth0 -j incoming
+$IT -A POSTROUTING -o eth0 -j outgoing
+
+$IT -A incoming -p tcp -m comment --comment "tcp"
+$IT -A incoming -p udp -m comment --comment "udp"
+$IT -A incoming -p icmp -m comment --comment "icmp"
+
+$IT -A outgoing -p tcp -m comment --comment "tcp"
+$IT -A outgoing -p udp -m comment --comment "udp"
+$IT -A outgoing -p icmp -m comment --comment "icmp"
+
index 58cc0fe..f1bcd77 100644 (file)
@@ -2,6 +2,7 @@ SUBDIRS = libconfig
 if BUILD_WITH_OWN_LIBOPING
 SUBDIRS += liboping
 endif
+SUBDIRS += libiptc
 
 if COMPILER_IS_GCC
 AM_CFLAGS = -Wall -Werror
@@ -208,6 +209,16 @@ collectd_LDADD += "-dlopen" hddtemp.la
 collectd_DEPENDENCIES += hddtemp.la
 endif
 
+if BUILD_MODULE_IPTABLES
+pkglib_LTLIBRARIES += iptables.la
+iptables_la_SOURCES = iptables.c
+iptables_la_LDFLAGS = -module -avoid-version
+iptables_la_LIBADD  = libiptc/libiptc.la
+iptables_la_DEPENDENCIES = libiptc/libiptc.la
+collectd_LDADD += "-dlopen" iptables.la
+collectd_DEPENDENCIES += iptables.la
+endif
+
 if BUILD_MODULE_LOAD
 pkglib_LTLIBRARIES += load.la
 load_la_SOURCES = load.c
diff --git a/src/iptables.c b/src/iptables.c
new file mode 100644 (file)
index 0000000..a8cdb3a
--- /dev/null
@@ -0,0 +1,214 @@
+/**
+ * collectd - src/iptables.c
+ * Copyright (C) 2007 Sjoerd van der Berg
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
+ *
+ * Authors:
+ *  Sjoerd van der Berg <harekiet at users.sourceforge.net>
+ **/
+
+#include "collectd.h"
+#include "common.h"
+#include "plugin.h"
+#include "configfile.h"
+#include "libiptc/libiptc.h"
+
+#define MODULE_NAME "iptables"
+#define BUFSIZE 512
+
+/*
+ * (Module-)Global variables
+ */
+
+/*
+    Files will go into iptables-chain/comment.rrd files
+*/
+static char *file_template   = "iptables-%s.rrd";
+/*
+    Config format should be Chain table chainname 
+    So "Chain mangle incoming"
+*/
+static char *config_keys[] =
+{
+       "Chain",
+       NULL
+};
+static int config_keys_num = 1;
+/*
+    Removed packet count for now, should have config option if you want to save them
+    Although other collectd models don't seem to care much for options eitherway for what to log
+*/
+static char *ds_def[] =
+{
+//     "DS:packets:COUNTER:"COLLECTD_HEARTBEAT":0:U",
+       "DS:bytes:DERIVE:"COLLECTD_HEARTBEAT":0:U",
+       NULL
+};
+static int ds_num = 1;
+
+/*
+    Each table/chain combo that will be queried goes into this list
+*/
+typedef struct {
+    char table[16];
+    char name[32];
+} ip_chain_t;
+
+static ip_chain_t **chain_list = NULL;
+static int chain_num = 0;
+
+static int iptables_config (char *key, char *value)
+{
+       if (strcasecmp (key, "Chain") == 0)
+       {
+               ip_chain_t temp, *final, **list;
+               char *chain;
+               int tLen;
+               
+               memset( &temp, 0, sizeof( temp ));
+       
+               /* simple parsing, only allow a space... */
+               chain = rindex(value, ' ' );
+               if (!chain) 
+               {
+                       syslog (LOG_EMERG, "missing chain." );
+                       return (1);
+               }
+               tLen = (int)(chain - value);
+               if ( tLen > sizeof( temp.table ))
+               {
+                       syslog (LOG_EMERG, "table too long." );
+                       return (1);
+               }
+               memcpy( temp.table, value, tLen );
+               temp.table[tLen] = 0; 
+               chain++;
+               strncpy( temp.name, chain, sizeof( temp.name ));
+                       
+               list = (ip_chain_t **) realloc (chain_list, (chain_num + 1) * sizeof (ip_chain_t *));
+               if ( list == NULL )
+               {
+                       syslog (LOG_EMERG, "Cannot allocate more memory.");
+                       return (1);
+               }
+               chain_list = list;
+               final = (ip_chain_t *) malloc( sizeof(temp) );
+               if (final == NULL) 
+               {
+                       syslog (LOG_EMERG, "Cannot allocate memory.");
+                       return (1);
+               }
+               *final = temp;
+               chain_list[chain_num++] = final;
+       } else 
+       {
+               return (-1);
+       }
+
+       return (0);
+}
+
+static void iptables_init (void)
+{      
+    return;
+}
+
+static void iptables_write (char *host, char *inst, char *val) 
+{
+       char file[BUFSIZE];
+       int status;
+
+       status = snprintf (file, BUFSIZE, file_template, inst);
+       if (status < 1)
+               return;
+       else if (status >= BUFSIZE)
+               return;
+
+       rrd_update_file (host, file, val, ds_def, ds_num);
+}
+
+
+static int submit_match( const struct ipt_entry_match *match, const struct ipt_entry *entry, const ip_chain_t *chain ) 
+{
+    char name[BUFSIZE];
+    char buf[BUFSIZE];
+    int status;
+
+    /* Only log rules that have a comment, although could probably also do numerical targets sometime */
+    if ( strcmp( match->u.user.name, "comment" ) )
+       return 0;
+
+/*
+    This would also add the table name to the name, but seems a bit overkill
+    status = snprintf (name, BUFSIZE, "%s-%s/%s",
+       table->table, table->chain, match->data );
+*/
+    status = snprintf (name, BUFSIZE, "%s/%s", chain->name, match->data );
+
+    if ((status >= BUFSIZE) || (status < 1))
+       return 0;
+
+    status = snprintf (buf, BUFSIZE, "%u:%lld",// ":lld",
+                               (unsigned int) curtime,
+//                             entry->counters.pcnt,
+                                entry->counters.bcnt );
+    if ((status >= BUFSIZE) || (status < 1))
+       return 0;
+
+    plugin_submit (MODULE_NAME, name, buf);
+
+    return 0;
+}
+
+static void submit_chain( iptc_handle_t *handle, ip_chain_t *chain ) {
+    const struct ipt_entry *entry;
+
+    /* Find first rule for chain and use the iterate macro */    
+    entry = iptc_first_rule( chain->name, handle );
+    while ( entry ) {
+        IPT_MATCH_ITERATE( entry, submit_match, entry, chain );
+       entry = iptc_next_rule( entry, handle );
+    }
+}
+
+
+static void iptables_read (void) {
+    int i;
+
+    /* Init the iptc handle structure and query the correct table */    
+    for( i = 0; i < chain_num; i++) {
+       iptc_handle_t handle;
+       ip_chain_t *chain;
+       
+       chain = chain_list[i];
+       if (!chain)
+           continue;
+       handle = iptc_init( chain->table );
+       if (!handle)
+           continue;
+       submit_chain( &handle, chain );
+       iptc_free( &handle );
+    }
+}
+
+void module_register (void)
+{
+       plugin_register (MODULE_NAME, iptables_init, iptables_read, iptables_write);
+       cf_register (MODULE_NAME, iptables_config, config_keys, config_keys_num);
+}
+
+#undef BUFSIZE
+#undef MODULE_NAME
diff --git a/src/libiptc/Makefile.am b/src/libiptc/Makefile.am
new file mode 100644 (file)
index 0000000..0774f6f
--- /dev/null
@@ -0,0 +1,13 @@
+AUTOMAKE_OPTIONS = foreign no-dependencies
+
+if COMPILER_IS_GCC
+AM_CFLAGS = -Wall
+endif
+
+EXTRA_DIST = libiptc.c
+
+noinst_LTLIBRARIES = libiptc.la
+
+#libiptc_la_CFLAGS = 
+libiptc_la_LDFLAGS = -avoid-version
+libiptc_la_SOURCES = libip4tc.c
\ No newline at end of file
diff --git a/src/libiptc/ipt_kernel_headers.h b/src/libiptc/ipt_kernel_headers.h
new file mode 100644 (file)
index 0000000..18861fe
--- /dev/null
@@ -0,0 +1,27 @@
+/* This is the userspace/kernel interface for Generic IP Chains,
+   required for libc6. */
+#ifndef _FWCHAINS_KERNEL_HEADERS_H
+#define _FWCHAINS_KERNEL_HEADERS_H
+
+#include <limits.h>
+
+#if defined(__GLIBC__) && __GLIBC__ == 2
+#include <netinet/ip.h>
+#include <netinet/in.h>
+#include <netinet/ip_icmp.h>
+#include <netinet/tcp.h>
+#include <netinet/udp.h>
+#include <net/if.h>
+#include <sys/types.h>
+#else /* libc5 */
+#include <sys/socket.h>
+#include <linux/ip.h>
+#include <linux/in.h>
+#include <linux/if.h>
+#include <linux/icmp.h>
+#include <linux/tcp.h>
+#include <linux/udp.h>
+#include <linux/types.h>
+#include <linux/in6.h>
+#endif
+#endif
diff --git a/src/libiptc/libip4tc.c b/src/libiptc/libip4tc.c
new file mode 100644 (file)
index 0000000..a0cdc2f
--- /dev/null
@@ -0,0 +1,502 @@
+/* Library which manipulates firewall rules.  Version 0.1. */
+
+/* Architecture of firewall rules is as follows:
+ *
+ * Chains go INPUT, FORWARD, OUTPUT then user chains.
+ * Each user chain starts with an ERROR node.
+ * Every chain ends with an unconditional jump: a RETURN for user chains,
+ * and a POLICY for built-ins.
+ */
+
+/* (C)1999 Paul ``Rusty'' Russell - Placed under the GNU GPL (See
+   COPYING for details). */
+
+#include <assert.h>
+#include <string.h>
+#include <errno.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <unistd.h>
+
+#ifdef DEBUG_CONNTRACK
+#define inline
+#endif
+
+#if !defined(__GLIBC__) || (__GLIBC__ < 2)
+typedef unsigned int socklen_t;
+#endif
+
+#include "libiptc/libiptc.h"
+
+#define IP_VERSION     4
+#define IP_OFFSET      0x1FFF
+
+#define HOOK_PRE_ROUTING       NF_IP_PRE_ROUTING
+#define HOOK_LOCAL_IN          NF_IP_LOCAL_IN
+#define HOOK_FORWARD           NF_IP_FORWARD
+#define HOOK_LOCAL_OUT         NF_IP_LOCAL_OUT
+#define HOOK_POST_ROUTING      NF_IP_POST_ROUTING
+#ifdef NF_IP_DROPPING
+#define HOOK_DROPPING          NF_IP_DROPPING
+#endif
+
+#define STRUCT_ENTRY_TARGET    struct ipt_entry_target
+#define STRUCT_ENTRY           struct ipt_entry
+#define STRUCT_ENTRY_MATCH     struct ipt_entry_match
+#define STRUCT_GETINFO         struct ipt_getinfo
+#define STRUCT_GET_ENTRIES     struct ipt_get_entries
+#define STRUCT_COUNTERS                struct ipt_counters
+#define STRUCT_COUNTERS_INFO   struct ipt_counters_info
+#define STRUCT_STANDARD_TARGET struct ipt_standard_target
+#define STRUCT_REPLACE         struct ipt_replace
+
+#define STRUCT_TC_HANDLE       struct iptc_handle
+#define TC_HANDLE_T            iptc_handle_t
+
+#define ENTRY_ITERATE          IPT_ENTRY_ITERATE
+#define TABLE_MAXNAMELEN       IPT_TABLE_MAXNAMELEN
+#define FUNCTION_MAXNAMELEN    IPT_FUNCTION_MAXNAMELEN
+
+#define GET_TARGET             ipt_get_target
+
+#define ERROR_TARGET           IPT_ERROR_TARGET
+#define NUMHOOKS               NF_IP_NUMHOOKS
+
+#define IPT_CHAINLABEL         ipt_chainlabel
+
+#define TC_DUMP_ENTRIES                dump_entries
+#define TC_IS_CHAIN            iptc_is_chain
+#define TC_FIRST_CHAIN         iptc_first_chain
+#define TC_NEXT_CHAIN          iptc_next_chain
+#define TC_FIRST_RULE          iptc_first_rule
+#define TC_NEXT_RULE           iptc_next_rule
+#define TC_GET_TARGET          iptc_get_target
+#define TC_BUILTIN             iptc_builtin
+#define TC_GET_POLICY          iptc_get_policy
+#define TC_INSERT_ENTRY                iptc_insert_entry
+#define TC_REPLACE_ENTRY       iptc_replace_entry
+#define TC_APPEND_ENTRY                iptc_append_entry
+#define TC_DELETE_ENTRY                iptc_delete_entry
+#define TC_DELETE_NUM_ENTRY    iptc_delete_num_entry
+#define TC_CHECK_PACKET                iptc_check_packet
+#define TC_FLUSH_ENTRIES       iptc_flush_entries
+#define TC_ZERO_ENTRIES                iptc_zero_entries
+#define TC_READ_COUNTER                iptc_read_counter
+#define TC_ZERO_COUNTER                iptc_zero_counter
+#define TC_SET_COUNTER         iptc_set_counter
+#define TC_CREATE_CHAIN                iptc_create_chain
+#define TC_GET_REFERENCES      iptc_get_references
+#define TC_DELETE_CHAIN                iptc_delete_chain
+#define TC_RENAME_CHAIN                iptc_rename_chain
+#define TC_SET_POLICY          iptc_set_policy
+#define TC_GET_RAW_SOCKET      iptc_get_raw_socket
+#define TC_INIT                        iptc_init
+#define TC_FREE                        iptc_free
+#define TC_COMMIT              iptc_commit
+#define TC_STRERROR            iptc_strerror
+#define TC_NUM_RULES           iptc_num_rules
+#define TC_GET_RULE            iptc_get_rule
+
+#define TC_AF                  AF_INET
+#define TC_IPPROTO             IPPROTO_IP
+
+#define SO_SET_REPLACE         IPT_SO_SET_REPLACE
+#define SO_SET_ADD_COUNTERS    IPT_SO_SET_ADD_COUNTERS
+#define SO_GET_INFO            IPT_SO_GET_INFO
+#define SO_GET_ENTRIES         IPT_SO_GET_ENTRIES
+#define SO_GET_VERSION         IPT_SO_GET_VERSION
+
+#define STANDARD_TARGET                IPT_STANDARD_TARGET
+#define LABEL_RETURN           IPTC_LABEL_RETURN
+#define LABEL_ACCEPT           IPTC_LABEL_ACCEPT
+#define LABEL_DROP             IPTC_LABEL_DROP
+#define LABEL_QUEUE            IPTC_LABEL_QUEUE
+
+#define ALIGN                  IPT_ALIGN
+#define RETURN                 IPT_RETURN
+
+#include "libiptc.c"
+
+#define IP_PARTS_NATIVE(n)                     \
+(unsigned int)((n)>>24)&0xFF,                  \
+(unsigned int)((n)>>16)&0xFF,                  \
+(unsigned int)((n)>>8)&0xFF,                   \
+(unsigned int)((n)&0xFF)
+
+#define IP_PARTS(n) IP_PARTS_NATIVE(ntohl(n))
+
+int
+dump_entry(STRUCT_ENTRY *e, const TC_HANDLE_T handle)
+{
+       size_t i;
+       STRUCT_ENTRY_TARGET *t;
+
+       printf("Entry %u (%lu):\n", iptcb_entry2index(handle, e),
+              iptcb_entry2offset(handle, e));
+       printf("SRC IP: %u.%u.%u.%u/%u.%u.%u.%u\n",
+              IP_PARTS(e->ip.src.s_addr),IP_PARTS(e->ip.smsk.s_addr));
+       printf("DST IP: %u.%u.%u.%u/%u.%u.%u.%u\n",
+              IP_PARTS(e->ip.dst.s_addr),IP_PARTS(e->ip.dmsk.s_addr));
+       printf("Interface: `%s'/", e->ip.iniface);
+       for (i = 0; i < IFNAMSIZ; i++)
+               printf("%c", e->ip.iniface_mask[i] ? 'X' : '.');
+       printf("to `%s'/", e->ip.outiface);
+       for (i = 0; i < IFNAMSIZ; i++)
+               printf("%c", e->ip.outiface_mask[i] ? 'X' : '.');
+       printf("\nProtocol: %u\n", e->ip.proto);
+       printf("Flags: %02X\n", e->ip.flags);
+       printf("Invflags: %02X\n", e->ip.invflags);
+       printf("Counters: %llu packets, %llu bytes\n",
+              (unsigned long long)e->counters.pcnt, (unsigned long long)e->counters.bcnt);
+       printf("Cache: %08X ", e->nfcache);
+       if (e->nfcache & NFC_ALTERED) printf("ALTERED ");
+       if (e->nfcache & NFC_UNKNOWN) printf("UNKNOWN ");
+       printf("\n");
+
+       IPT_MATCH_ITERATE(e, print_match);
+
+       t = GET_TARGET(e);
+       printf("Target name: `%s' [%u]\n", t->u.user.name, t->u.target_size);
+       if (strcmp(t->u.user.name, STANDARD_TARGET) == 0) {
+               int pos = *(int *)t->data;
+               if (pos < 0)
+                       printf("verdict=%s\n",
+                              pos == -NF_ACCEPT-1 ? "NF_ACCEPT"
+                              : pos == -NF_DROP-1 ? "NF_DROP"
+                              : pos == -NF_QUEUE-1 ? "NF_QUEUE"
+                              : pos == RETURN ? "RETURN"
+                              : "UNKNOWN");
+               else
+                       printf("verdict=%u\n", pos);
+       } else if (strcmp(t->u.user.name, IPT_ERROR_TARGET) == 0)
+               printf("error=`%s'\n", t->data);
+
+       printf("\n");
+       return 0;
+}
+
+static unsigned char *
+is_same(const STRUCT_ENTRY *a, const STRUCT_ENTRY *b, unsigned char *matchmask)
+{
+       unsigned int i;
+       unsigned char *mptr;
+
+       /* Always compare head structures: ignore mask here. */
+       if (a->ip.src.s_addr != b->ip.src.s_addr
+           || a->ip.dst.s_addr != b->ip.dst.s_addr
+           || a->ip.smsk.s_addr != b->ip.smsk.s_addr
+           || a->ip.dmsk.s_addr != b->ip.dmsk.s_addr
+           || a->ip.proto != b->ip.proto
+           || a->ip.flags != b->ip.flags
+           || a->ip.invflags != b->ip.invflags)
+               return NULL;
+
+       for (i = 0; i < IFNAMSIZ; i++) {
+               if (a->ip.iniface_mask[i] != b->ip.iniface_mask[i])
+                       return NULL;
+               if ((a->ip.iniface[i] & a->ip.iniface_mask[i])
+                   != (b->ip.iniface[i] & b->ip.iniface_mask[i]))
+                       return NULL;
+               if (a->ip.outiface_mask[i] != b->ip.outiface_mask[i])
+                       return NULL;
+               if ((a->ip.outiface[i] & a->ip.outiface_mask[i])
+                   != (b->ip.outiface[i] & b->ip.outiface_mask[i]))
+                       return NULL;
+       }
+
+       if (a->nfcache != b->nfcache
+           || a->target_offset != b->target_offset
+           || a->next_offset != b->next_offset)
+               return NULL;
+
+       mptr = matchmask + sizeof(STRUCT_ENTRY);
+       if (IPT_MATCH_ITERATE(a, match_different, a->elems, b->elems, &mptr))
+               return NULL;
+       mptr += IPT_ALIGN(sizeof(struct ipt_entry_target));
+
+       return mptr;
+}
+
+#if 0
+/***************************** DEBUGGING ********************************/
+static inline int
+unconditional(const struct ipt_ip *ip)
+{
+       unsigned int i;
+
+       for (i = 0; i < sizeof(*ip)/sizeof(u_int32_t); i++)
+               if (((u_int32_t *)ip)[i])
+                       return 0;
+
+       return 1;
+}
+
+static inline int
+check_match(const STRUCT_ENTRY_MATCH *m, unsigned int *off)
+{
+       assert(m->u.match_size >= sizeof(STRUCT_ENTRY_MATCH));
+       assert(ALIGN(m->u.match_size) == m->u.match_size);
+
+       (*off) += m->u.match_size;
+       return 0;
+}
+
+static inline int
+check_entry(const STRUCT_ENTRY *e, unsigned int *i, unsigned int *off,
+           unsigned int user_offset, int *was_return,
+           TC_HANDLE_T h)
+{
+       unsigned int toff;
+       STRUCT_STANDARD_TARGET *t;
+
+       assert(e->target_offset >= sizeof(STRUCT_ENTRY));
+       assert(e->next_offset >= e->target_offset
+              + sizeof(STRUCT_ENTRY_TARGET));
+       toff = sizeof(STRUCT_ENTRY);
+       IPT_MATCH_ITERATE(e, check_match, &toff);
+
+       assert(toff == e->target_offset);
+
+       t = (STRUCT_STANDARD_TARGET *)
+               GET_TARGET((STRUCT_ENTRY *)e);
+       /* next_offset will have to be multiple of entry alignment. */
+       assert(e->next_offset == ALIGN(e->next_offset));
+       assert(e->target_offset == ALIGN(e->target_offset));
+       assert(t->target.u.target_size == ALIGN(t->target.u.target_size));
+       assert(!TC_IS_CHAIN(t->target.u.user.name, h));
+
+       if (strcmp(t->target.u.user.name, STANDARD_TARGET) == 0) {
+               assert(t->target.u.target_size
+                      == ALIGN(sizeof(STRUCT_STANDARD_TARGET)));
+
+               assert(t->verdict == -NF_DROP-1
+                      || t->verdict == -NF_ACCEPT-1
+                      || t->verdict == RETURN
+                      || t->verdict < (int)h->entries->size);
+
+               if (t->verdict >= 0) {
+                       STRUCT_ENTRY *te = get_entry(h, t->verdict);
+                       int idx;
+
+                       idx = iptcb_entry2index(h, te);
+                       assert(strcmp(GET_TARGET(te)->u.user.name,
+                                     IPT_ERROR_TARGET)
+                              != 0);
+                       assert(te != e);
+
+                       /* Prior node must be error node, or this node. */
+                       assert(t->verdict == iptcb_entry2offset(h, e)+e->next_offset
+                              || strcmp(GET_TARGET(index2entry(h, idx-1))
+                                        ->u.user.name, IPT_ERROR_TARGET)
+                              == 0);
+               }
+
+               if (t->verdict == RETURN
+                   && unconditional(&e->ip)
+                   && e->target_offset == sizeof(*e))
+                       *was_return = 1;
+               else
+                       *was_return = 0;
+       } else if (strcmp(t->target.u.user.name, IPT_ERROR_TARGET) == 0) {
+               assert(t->target.u.target_size
+                      == ALIGN(sizeof(struct ipt_error_target)));
+
+               /* If this is in user area, previous must have been return */
+               if (*off > user_offset)
+                       assert(*was_return);
+
+               *was_return = 0;
+       }
+       else *was_return = 0;
+
+       if (*off == user_offset)
+               assert(strcmp(t->target.u.user.name, IPT_ERROR_TARGET) == 0);
+
+       (*off) += e->next_offset;
+       (*i)++;
+       return 0;
+}
+
+#ifdef IPTC_DEBUG
+/* Do every conceivable sanity check on the handle */
+static void
+do_check(TC_HANDLE_T h, unsigned int line)
+{
+       unsigned int i, n;
+       unsigned int user_offset; /* Offset of first user chain */
+       int was_return;
+
+       assert(h->changed == 0 || h->changed == 1);
+       if (strcmp(h->info.name, "filter") == 0) {
+               assert(h->info.valid_hooks
+                      == (1 << NF_IP_LOCAL_IN
+                          | 1 << NF_IP_FORWARD
+                          | 1 << NF_IP_LOCAL_OUT));
+
+               /* Hooks should be first three */
+               assert(h->info.hook_entry[NF_IP_LOCAL_IN] == 0);
+
+               n = get_chain_end(h, 0);
+               n += get_entry(h, n)->next_offset;
+               assert(h->info.hook_entry[NF_IP_FORWARD] == n);
+
+               n = get_chain_end(h, n);
+               n += get_entry(h, n)->next_offset;
+               assert(h->info.hook_entry[NF_IP_LOCAL_OUT] == n);
+
+               user_offset = h->info.hook_entry[NF_IP_LOCAL_OUT];
+       } else if (strcmp(h->info.name, "nat") == 0) {
+               assert((h->info.valid_hooks
+                       == (1 << NF_IP_PRE_ROUTING
+                           | 1 << NF_IP_POST_ROUTING
+                           | 1 << NF_IP_LOCAL_OUT)) ||
+                      (h->info.valid_hooks
+                       == (1 << NF_IP_PRE_ROUTING
+                           | 1 << NF_IP_LOCAL_IN
+                           | 1 << NF_IP_POST_ROUTING
+                           | 1 << NF_IP_LOCAL_OUT)));
+
+               assert(h->info.hook_entry[NF_IP_PRE_ROUTING] == 0);
+
+               n = get_chain_end(h, 0);
+
+               n += get_entry(h, n)->next_offset;
+               assert(h->info.hook_entry[NF_IP_POST_ROUTING] == n);
+               n = get_chain_end(h, n);
+
+               n += get_entry(h, n)->next_offset;
+               assert(h->info.hook_entry[NF_IP_LOCAL_OUT] == n);
+               user_offset = h->info.hook_entry[NF_IP_LOCAL_OUT];
+
+               if (h->info.valid_hooks & (1 << NF_IP_LOCAL_IN)) {
+                       n = get_chain_end(h, n);
+                       n += get_entry(h, n)->next_offset;
+                       assert(h->info.hook_entry[NF_IP_LOCAL_IN] == n);
+                       user_offset = h->info.hook_entry[NF_IP_LOCAL_IN];
+               }
+
+       } else if (strcmp(h->info.name, "mangle") == 0) {
+               /* This code is getting ugly because linux < 2.4.18-pre6 had
+                * two mangle hooks, linux >= 2.4.18-pre6 has five mangle hooks
+                * */
+               assert((h->info.valid_hooks
+                       == (1 << NF_IP_PRE_ROUTING
+                           | 1 << NF_IP_LOCAL_OUT)) || 
+                      (h->info.valid_hooks
+                       == (1 << NF_IP_PRE_ROUTING
+                           | 1 << NF_IP_LOCAL_IN
+                           | 1 << NF_IP_FORWARD
+                           | 1 << NF_IP_LOCAL_OUT
+                           | 1 << NF_IP_POST_ROUTING)));
+
+               /* Hooks should be first five */
+               assert(h->info.hook_entry[NF_IP_PRE_ROUTING] == 0);
+
+               n = get_chain_end(h, 0);
+
+               if (h->info.valid_hooks & (1 << NF_IP_LOCAL_IN)) {
+                       n += get_entry(h, n)->next_offset;
+                       assert(h->info.hook_entry[NF_IP_LOCAL_IN] == n);
+                       n = get_chain_end(h, n);
+               }
+
+               if (h->info.valid_hooks & (1 << NF_IP_FORWARD)) {
+                       n += get_entry(h, n)->next_offset;
+                       assert(h->info.hook_entry[NF_IP_FORWARD] == n);
+                       n = get_chain_end(h, n);
+               }
+
+               n += get_entry(h, n)->next_offset;
+               assert(h->info.hook_entry[NF_IP_LOCAL_OUT] == n);
+               user_offset = h->info.hook_entry[NF_IP_LOCAL_OUT];
+
+               if (h->info.valid_hooks & (1 << NF_IP_POST_ROUTING)) {
+                       n = get_chain_end(h, n);
+                       n += get_entry(h, n)->next_offset;
+                       assert(h->info.hook_entry[NF_IP_POST_ROUTING] == n);
+                       user_offset = h->info.hook_entry[NF_IP_POST_ROUTING];
+               }
+       } else if (strcmp(h->info.name, "raw") == 0) {
+               assert(h->info.valid_hooks
+                      == (1 << NF_IP_PRE_ROUTING
+                          | 1 << NF_IP_LOCAL_OUT));
+
+               /* Hooks should be first three */
+               assert(h->info.hook_entry[NF_IP_PRE_ROUTING] == 0);
+
+               n = get_chain_end(h, n);
+               n += get_entry(h, n)->next_offset;
+               assert(h->info.hook_entry[NF_IP_LOCAL_OUT] == n);
+
+               user_offset = h->info.hook_entry[NF_IP_LOCAL_OUT];
+
+#ifdef NF_IP_DROPPING
+       } else if (strcmp(h->info.name, "drop") == 0) {
+               assert(h->info.valid_hooks == (1 << NF_IP_DROPPING));
+
+               /* Hook should be first */
+               assert(h->info.hook_entry[NF_IP_DROPPING] == 0);
+               user_offset = 0;
+#endif
+       } else {
+               fprintf(stderr, "Unknown table `%s'\n", h->info.name);
+               abort();
+       }
+
+       /* User chain == end of last builtin + policy entry */
+       user_offset = get_chain_end(h, user_offset);
+       user_offset += get_entry(h, user_offset)->next_offset;
+
+       /* Overflows should be end of entry chains, and unconditional
+           policy nodes. */
+       for (i = 0; i < NUMHOOKS; i++) {
+               STRUCT_ENTRY *e;
+               STRUCT_STANDARD_TARGET *t;
+
+               if (!(h->info.valid_hooks & (1 << i)))
+                       continue;
+               assert(h->info.underflow[i]
+                      == get_chain_end(h, h->info.hook_entry[i]));
+
+               e = get_entry(h, get_chain_end(h, h->info.hook_entry[i]));
+               assert(unconditional(&e->ip));
+               assert(e->target_offset == sizeof(*e));
+               t = (STRUCT_STANDARD_TARGET *)GET_TARGET(e);
+               assert(t->target.u.target_size == ALIGN(sizeof(*t)));
+               assert(e->next_offset == sizeof(*e) + ALIGN(sizeof(*t)));
+
+               assert(strcmp(t->target.u.user.name, STANDARD_TARGET)==0);
+               assert(t->verdict == -NF_DROP-1 || t->verdict == -NF_ACCEPT-1);
+
+               /* Hooks and underflows must be valid entries */
+               entry2index(h, get_entry(h, h->info.hook_entry[i]));
+               entry2index(h, get_entry(h, h->info.underflow[i]));
+       }
+
+       assert(h->info.size
+              >= h->info.num_entries * (sizeof(STRUCT_ENTRY)
+                                        +sizeof(STRUCT_STANDARD_TARGET)));
+
+       assert(h->entries.size
+              >= (h->new_number
+                  * (sizeof(STRUCT_ENTRY)
+                     + sizeof(STRUCT_STANDARD_TARGET))));
+       assert(strcmp(h->info.name, h->entries.name) == 0);
+
+       i = 0; n = 0;
+       was_return = 0;
+       /* Check all the entries. */
+       ENTRY_ITERATE(h->entries.entrytable, h->entries.size,
+                     check_entry, &i, &n, user_offset, &was_return, h);
+
+       assert(i == h->new_number);
+       assert(n == h->entries.size);
+
+       /* Final entry must be error node */
+       assert(strcmp(GET_TARGET(index2entry(h, h->new_number-1))
+                     ->u.user.name,
+                     ERROR_TARGET) == 0);
+}
+#endif /*IPTC_DEBUG*/
+
+#endif
diff --git a/src/libiptc/libip6tc.c b/src/libiptc/libip6tc.c
new file mode 100644 (file)
index 0000000..5b3ae0b
--- /dev/null
@@ -0,0 +1,441 @@
+/* Library which manipulates firewall rules.  Version 0.1. */
+
+/* Architecture of firewall rules is as follows:
+ *
+ * Chains go INPUT, FORWARD, OUTPUT then user chains.
+ * Each user chain starts with an ERROR node.
+ * Every chain ends with an unconditional jump: a RETURN for user chains,
+ * and a POLICY for built-ins.
+ */
+
+/* (C)1999 Paul ``Rusty'' Russell - Placed under the GNU GPL (See
+   COPYING for details). */
+
+#include <assert.h>
+#include <string.h>
+#include <errno.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <arpa/inet.h>
+
+#ifdef DEBUG_CONNTRACK
+#define inline
+#endif
+
+#if !defined(__GLIBC__) || (__GLIBC__ < 2)
+typedef unsigned int socklen_t;
+#endif
+
+#include "libiptc/libip6tc.h"
+
+#define HOOK_PRE_ROUTING       NF_IP6_PRE_ROUTING
+#define HOOK_LOCAL_IN          NF_IP6_LOCAL_IN
+#define HOOK_FORWARD           NF_IP6_FORWARD
+#define HOOK_LOCAL_OUT         NF_IP6_LOCAL_OUT
+#define HOOK_POST_ROUTING      NF_IP6_POST_ROUTING
+
+#define STRUCT_ENTRY_TARGET    struct ip6t_entry_target
+#define STRUCT_ENTRY           struct ip6t_entry
+#define STRUCT_ENTRY_MATCH     struct ip6t_entry_match
+#define STRUCT_GETINFO         struct ip6t_getinfo
+#define STRUCT_GET_ENTRIES     struct ip6t_get_entries
+#define STRUCT_COUNTERS                struct ip6t_counters
+#define STRUCT_COUNTERS_INFO   struct ip6t_counters_info
+#define STRUCT_STANDARD_TARGET struct ip6t_standard_target
+#define STRUCT_REPLACE         struct ip6t_replace
+
+#define STRUCT_TC_HANDLE       struct ip6tc_handle
+#define TC_HANDLE_T            ip6tc_handle_t
+
+#define ENTRY_ITERATE          IP6T_ENTRY_ITERATE
+#define TABLE_MAXNAMELEN       IP6T_TABLE_MAXNAMELEN
+#define FUNCTION_MAXNAMELEN    IP6T_FUNCTION_MAXNAMELEN
+
+#define GET_TARGET             ip6t_get_target
+
+#define ERROR_TARGET           IP6T_ERROR_TARGET
+#define NUMHOOKS               NF_IP6_NUMHOOKS
+
+#define IPT_CHAINLABEL         ip6t_chainlabel
+
+#define TC_DUMP_ENTRIES                dump_entries6
+#define TC_IS_CHAIN            ip6tc_is_chain
+#define TC_FIRST_CHAIN         ip6tc_first_chain
+#define TC_NEXT_CHAIN          ip6tc_next_chain
+#define TC_FIRST_RULE          ip6tc_first_rule
+#define TC_NEXT_RULE           ip6tc_next_rule
+#define TC_GET_TARGET          ip6tc_get_target
+#define TC_BUILTIN             ip6tc_builtin
+#define TC_GET_POLICY          ip6tc_get_policy
+#define TC_INSERT_ENTRY                ip6tc_insert_entry
+#define TC_REPLACE_ENTRY       ip6tc_replace_entry
+#define TC_APPEND_ENTRY                ip6tc_append_entry
+#define TC_DELETE_ENTRY                ip6tc_delete_entry
+#define TC_DELETE_NUM_ENTRY    ip6tc_delete_num_entry
+#define TC_CHECK_PACKET                ip6tc_check_packet
+#define TC_FLUSH_ENTRIES       ip6tc_flush_entries
+#define TC_ZERO_ENTRIES                ip6tc_zero_entries
+#define TC_ZERO_COUNTER                ip6tc_zero_counter
+#define TC_READ_COUNTER                ip6tc_read_counter
+#define TC_SET_COUNTER         ip6tc_set_counter
+#define TC_CREATE_CHAIN                ip6tc_create_chain
+#define TC_GET_REFERENCES      ip6tc_get_references
+#define TC_DELETE_CHAIN                ip6tc_delete_chain
+#define TC_RENAME_CHAIN                ip6tc_rename_chain
+#define TC_SET_POLICY          ip6tc_set_policy
+#define TC_GET_RAW_SOCKET      ip6tc_get_raw_socket
+#define TC_INIT                        ip6tc_init
+#define TC_FREE                        ip6tc_free
+#define TC_COMMIT              ip6tc_commit
+#define TC_STRERROR            ip6tc_strerror
+#define TC_NUM_RULES           ip6tc_num_rules
+#define TC_GET_RULE            ip6tc_get_rule
+
+#define TC_AF                  AF_INET6
+#define TC_IPPROTO             IPPROTO_IPV6
+
+#define SO_SET_REPLACE         IP6T_SO_SET_REPLACE
+#define SO_SET_ADD_COUNTERS    IP6T_SO_SET_ADD_COUNTERS
+#define SO_GET_INFO            IP6T_SO_GET_INFO
+#define SO_GET_ENTRIES         IP6T_SO_GET_ENTRIES
+#define SO_GET_VERSION         IP6T_SO_GET_VERSION
+
+#define STANDARD_TARGET                IP6T_STANDARD_TARGET
+#define LABEL_RETURN           IP6TC_LABEL_RETURN
+#define LABEL_ACCEPT           IP6TC_LABEL_ACCEPT
+#define LABEL_DROP             IP6TC_LABEL_DROP
+#define LABEL_QUEUE            IP6TC_LABEL_QUEUE
+
+#define ALIGN                  IP6T_ALIGN
+#define RETURN                 IP6T_RETURN
+
+#include "libiptc.c"
+
+#define BIT6(a, l) \
+ ((ntohl(a->in6_u.u6_addr32[(l) / 32]) >> (31 - ((l) & 31))) & 1)
+
+int
+ipv6_prefix_length(const struct in6_addr *a)
+{
+       int l, i;
+       for (l = 0; l < 128; l++) {
+               if (BIT6(a, l) == 0)
+                       break;
+       }
+       for (i = l + 1; i < 128; i++) {
+               if (BIT6(a, i) == 1)
+                       return -1;
+       }
+       return l;
+}
+
+static int
+dump_entry(struct ip6t_entry *e, const ip6tc_handle_t handle)
+{
+       size_t i;
+       char buf[40];
+       int len;
+       struct ip6t_entry_target *t;
+       
+       printf("Entry %u (%lu):\n", iptcb_entry2index(handle, e),
+              iptcb_entry2offset(handle, e));
+       puts("SRC IP: ");
+       inet_ntop(AF_INET6, &e->ipv6.src, buf, sizeof buf);
+       puts(buf);
+       putchar('/');
+       len = ipv6_prefix_length(&e->ipv6.smsk);
+       if (len != -1)
+               printf("%d", len);
+       else {
+               inet_ntop(AF_INET6, &e->ipv6.smsk, buf, sizeof buf);
+               puts(buf);
+       }
+       putchar('\n');
+       
+       puts("DST IP: ");
+       inet_ntop(AF_INET6, &e->ipv6.dst, buf, sizeof buf);
+       puts(buf);
+       putchar('/');
+       len = ipv6_prefix_length(&e->ipv6.dmsk);
+       if (len != -1)
+               printf("%d", len);
+       else {
+               inet_ntop(AF_INET6, &e->ipv6.dmsk, buf, sizeof buf);
+               puts(buf);
+       }
+       putchar('\n');
+       
+       printf("Interface: `%s'/", e->ipv6.iniface);
+       for (i = 0; i < IFNAMSIZ; i++)
+               printf("%c", e->ipv6.iniface_mask[i] ? 'X' : '.');
+       printf("to `%s'/", e->ipv6.outiface);
+       for (i = 0; i < IFNAMSIZ; i++)
+               printf("%c", e->ipv6.outiface_mask[i] ? 'X' : '.');
+       printf("\nProtocol: %u\n", e->ipv6.proto);
+       if (e->ipv6.flags & IP6T_F_TOS)
+               printf("TOS: %u\n", e->ipv6.tos);
+       printf("Flags: %02X\n", e->ipv6.flags);
+       printf("Invflags: %02X\n", e->ipv6.invflags);
+       printf("Counters: %llu packets, %llu bytes\n",
+              (unsigned long long)e->counters.pcnt, (unsigned long long)e->counters.bcnt);
+       printf("Cache: %08X ", e->nfcache);
+       if (e->nfcache & NFC_ALTERED) printf("ALTERED ");
+       if (e->nfcache & NFC_UNKNOWN) printf("UNKNOWN ");
+       printf("\n");
+       
+       IP6T_MATCH_ITERATE(e, print_match);
+
+       t = ip6t_get_target(e);
+       printf("Target name: `%s' [%u]\n", t->u.user.name, t->u.target_size);
+       if (strcmp(t->u.user.name, IP6T_STANDARD_TARGET) == 0) {
+               int pos = *(int *)t->data;
+               if (pos < 0)
+                       printf("verdict=%s\n",
+                              pos == -NF_ACCEPT-1 ? "NF_ACCEPT"
+                              : pos == -NF_DROP-1 ? "NF_DROP"
+                              : pos == IP6T_RETURN ? "RETURN"
+                              : "UNKNOWN");
+               else
+                       printf("verdict=%u\n", pos);
+       } else if (strcmp(t->u.user.name, IP6T_ERROR_TARGET) == 0)
+               printf("error=`%s'\n", t->data);
+
+       printf("\n");
+       return 0;
+}
+
+static unsigned char *
+is_same(const STRUCT_ENTRY *a, const STRUCT_ENTRY *b,
+       unsigned char *matchmask)
+{
+       unsigned int i;
+       unsigned char *mptr;
+
+       /* Always compare head structures: ignore mask here. */
+       if (memcmp(&a->ipv6.src, &b->ipv6.src, sizeof(struct in6_addr))
+           || memcmp(&a->ipv6.dst, &b->ipv6.dst, sizeof(struct in6_addr))
+           || memcmp(&a->ipv6.smsk, &b->ipv6.smsk, sizeof(struct in6_addr))
+           || memcmp(&a->ipv6.dmsk, &b->ipv6.dmsk, sizeof(struct in6_addr))
+           || a->ipv6.proto != b->ipv6.proto
+           || a->ipv6.tos != b->ipv6.tos
+           || a->ipv6.flags != b->ipv6.flags
+           || a->ipv6.invflags != b->ipv6.invflags)
+               return NULL;
+
+       for (i = 0; i < IFNAMSIZ; i++) {
+               if (a->ipv6.iniface_mask[i] != b->ipv6.iniface_mask[i])
+                       return NULL;
+               if ((a->ipv6.iniface[i] & a->ipv6.iniface_mask[i])
+                   != (b->ipv6.iniface[i] & b->ipv6.iniface_mask[i]))
+                       return NULL;
+               if (a->ipv6.outiface_mask[i] != b->ipv6.outiface_mask[i])
+                       return NULL;
+               if ((a->ipv6.outiface[i] & a->ipv6.outiface_mask[i])
+                   != (b->ipv6.outiface[i] & b->ipv6.outiface_mask[i]))
+                       return NULL;
+       }
+
+       if (a->nfcache != b->nfcache
+           || a->target_offset != b->target_offset
+           || a->next_offset != b->next_offset)
+               return NULL;
+
+       mptr = matchmask + sizeof(STRUCT_ENTRY);
+       if (IP6T_MATCH_ITERATE(a, match_different, a->elems, b->elems, &mptr))
+               return NULL;
+       mptr += IP6T_ALIGN(sizeof(struct ip6t_entry_target));
+
+       return mptr;
+}
+
+/* All zeroes == unconditional rule. */
+static inline int
+unconditional(const struct ip6t_ip6 *ipv6)
+{
+       unsigned int i;
+
+       for (i = 0; i < sizeof(*ipv6); i++)
+               if (((char *)ipv6)[i])
+                       break;
+
+       return (i == sizeof(*ipv6));
+}
+
+#ifdef IPTC_DEBUG
+/* Do every conceivable sanity check on the handle */
+static void
+do_check(TC_HANDLE_T h, unsigned int line)
+{
+       unsigned int i, n;
+       unsigned int user_offset; /* Offset of first user chain */
+       int was_return;
+
+       assert(h->changed == 0 || h->changed == 1);
+       if (strcmp(h->info.name, "filter") == 0) {
+               assert(h->info.valid_hooks
+                      == (1 << NF_IP6_LOCAL_IN
+                          | 1 << NF_IP6_FORWARD
+                          | 1 << NF_IP6_LOCAL_OUT));
+
+               /* Hooks should be first three */
+               assert(h->info.hook_entry[NF_IP6_LOCAL_IN] == 0);
+
+               n = get_chain_end(h, 0);
+               n += get_entry(h, n)->next_offset;
+               assert(h->info.hook_entry[NF_IP6_FORWARD] == n);
+
+               n = get_chain_end(h, n);
+               n += get_entry(h, n)->next_offset;
+               assert(h->info.hook_entry[NF_IP6_LOCAL_OUT] == n);
+
+               user_offset = h->info.hook_entry[NF_IP6_LOCAL_OUT];
+       } else if (strcmp(h->info.name, "nat") == 0) {
+               assert((h->info.valid_hooks
+                       == (1 << NF_IP6_PRE_ROUTING
+                           | 1 << NF_IP6_LOCAL_OUT
+                           | 1 << NF_IP6_POST_ROUTING)) ||
+                      (h->info.valid_hooks
+                       == (1 << NF_IP6_PRE_ROUTING
+                           | 1 << NF_IP6_LOCAL_IN
+                           | 1 << NF_IP6_LOCAL_OUT
+                           | 1 << NF_IP6_POST_ROUTING)));
+
+               assert(h->info.hook_entry[NF_IP6_PRE_ROUTING] == 0);
+
+               n = get_chain_end(h, 0);
+
+               n += get_entry(h, n)->next_offset;
+               assert(h->info.hook_entry[NF_IP6_POST_ROUTING] == n);
+               n = get_chain_end(h, n);
+
+               n += get_entry(h, n)->next_offset;
+               assert(h->info.hook_entry[NF_IP6_LOCAL_OUT] == n);
+               user_offset = h->info.hook_entry[NF_IP6_LOCAL_OUT];
+
+               if (h->info.valid_hooks & (1 << NF_IP6_LOCAL_IN)) {
+                       n = get_chain_end(h, n);
+                       n += get_entry(h, n)->next_offset;
+                       assert(h->info.hook_entry[NF_IP6_LOCAL_IN] == n);
+                       user_offset = h->info.hook_entry[NF_IP6_LOCAL_IN];
+               }
+
+       } else if (strcmp(h->info.name, "mangle") == 0) {
+               /* This code is getting ugly because linux < 2.4.18-pre6 had
+                * two mangle hooks, linux >= 2.4.18-pre6 has five mangle hooks
+                * */
+               assert((h->info.valid_hooks
+                       == (1 << NF_IP6_PRE_ROUTING
+                           | 1 << NF_IP6_LOCAL_OUT)) ||
+                      (h->info.valid_hooks
+                       == (1 << NF_IP6_PRE_ROUTING
+                           | 1 << NF_IP6_LOCAL_IN
+                           | 1 << NF_IP6_FORWARD
+                           | 1 << NF_IP6_LOCAL_OUT
+                           | 1 << NF_IP6_POST_ROUTING)));
+
+               /* Hooks should be first five */
+               assert(h->info.hook_entry[NF_IP6_PRE_ROUTING] == 0);
+
+               n = get_chain_end(h, 0);
+
+               if (h->info.valid_hooks & (1 << NF_IP6_LOCAL_IN)) {
+                       n += get_entry(h, n)->next_offset;
+                       assert(h->info.hook_entry[NF_IP6_LOCAL_IN] == n);
+                       n = get_chain_end(h, n);
+               }
+
+               if (h->info.valid_hooks & (1 << NF_IP6_FORWARD)) {
+                       n += get_entry(h, n)->next_offset;
+                       assert(h->info.hook_entry[NF_IP6_FORWARD] == n);
+                       n = get_chain_end(h, n);
+               }
+
+               n += get_entry(h, n)->next_offset;
+               assert(h->info.hook_entry[NF_IP6_LOCAL_OUT] == n);
+               user_offset = h->info.hook_entry[NF_IP6_LOCAL_OUT];
+
+               if (h->info.valid_hooks & (1 << NF_IP6_POST_ROUTING)) {
+                       n = get_chain_end(h, n);
+                       n += get_entry(h, n)->next_offset;
+                       assert(h->info.hook_entry[NF_IP6_POST_ROUTING] == n);
+                       user_offset = h->info.hook_entry[NF_IP6_POST_ROUTING];
+               }
+       } else if (strcmp(h->info.name, "raw") == 0) {
+               assert(h->info.valid_hooks
+                      == (1 << NF_IP6_PRE_ROUTING
+                          | 1 << NF_IP6_LOCAL_OUT));
+
+               /* Hooks should be first three */
+               assert(h->info.hook_entry[NF_IP6_PRE_ROUTING] == 0);
+
+               n = get_chain_end(h, n);
+               n += get_entry(h, n)->next_offset;
+               assert(h->info.hook_entry[NF_IP6_LOCAL_OUT] == n);
+
+               user_offset = h->info.hook_entry[NF_IP6_LOCAL_OUT];
+       } else {
+                fprintf(stderr, "Unknown table `%s'\n", h->info.name);
+               abort();
+       }
+
+       /* User chain == end of last builtin + policy entry */
+       user_offset = get_chain_end(h, user_offset);
+       user_offset += get_entry(h, user_offset)->next_offset;
+
+       /* Overflows should be end of entry chains, and unconditional
+           policy nodes. */
+       for (i = 0; i < NUMHOOKS; i++) {
+               STRUCT_ENTRY *e;
+               STRUCT_STANDARD_TARGET *t;
+
+               if (!(h->info.valid_hooks & (1 << i)))
+                       continue;
+               assert(h->info.underflow[i]
+                      == get_chain_end(h, h->info.hook_entry[i]));
+
+               e = get_entry(h, get_chain_end(h, h->info.hook_entry[i]));
+               assert(unconditional(&e->ipv6));
+               assert(e->target_offset == sizeof(*e));
+               t = (STRUCT_STANDARD_TARGET *)GET_TARGET(e);
+               printf("target_size=%u, align=%u\n",
+                       t->target.u.target_size, ALIGN(sizeof(*t)));
+               assert(t->target.u.target_size == ALIGN(sizeof(*t)));
+               assert(e->next_offset == sizeof(*e) + ALIGN(sizeof(*t)));
+
+               assert(strcmp(t->target.u.user.name, STANDARD_TARGET)==0);
+               assert(t->verdict == -NF_DROP-1 || t->verdict == -NF_ACCEPT-1);
+
+               /* Hooks and underflows must be valid entries */
+               iptcb_entry2index(h, get_entry(h, h->info.hook_entry[i]));
+               iptcb_entry2index(h, get_entry(h, h->info.underflow[i]));
+       }
+
+       assert(h->info.size
+              >= h->info.num_entries * (sizeof(STRUCT_ENTRY)
+                                        +sizeof(STRUCT_STANDARD_TARGET)));
+
+       assert(h->entries.size
+              >= (h->new_number
+                  * (sizeof(STRUCT_ENTRY)
+                     + sizeof(STRUCT_STANDARD_TARGET))));
+       assert(strcmp(h->info.name, h->entries.name) == 0);
+
+       i = 0; n = 0;
+       was_return = 0;
+
+#if 0
+       /* Check all the entries. */
+       ENTRY_ITERATE(h->entries.entrytable, h->entries.size,
+                     check_entry, &i, &n, user_offset, &was_return, h);
+
+       assert(i == h->new_number);
+       assert(n == h->entries.size);
+
+       /* Final entry must be error node */
+       assert(strcmp(GET_TARGET(index2entry(h, h->new_number-1))
+                     ->u.user.name,
+                     ERROR_TARGET) == 0);
+#endif
+}
+#endif /*IPTC_DEBUG*/
diff --git a/src/libiptc/libiptc.c b/src/libiptc/libiptc.c
new file mode 100644 (file)
index 0000000..1c17480
--- /dev/null
@@ -0,0 +1,2283 @@
+/* Library which manipulates firewall rules.  Version $Revision: 6665 $ */
+
+/* Architecture of firewall rules is as follows:
+ *
+ * Chains go INPUT, FORWARD, OUTPUT then user chains.
+ * Each user chain starts with an ERROR node.
+ * Every chain ends with an unconditional jump: a RETURN for user chains,
+ * and a POLICY for built-ins.
+ */
+
+/* (C) 1999 Paul ``Rusty'' Russell - Placed under the GNU GPL (See
+ * COPYING for details). 
+ * (C) 2000-2004 by the Netfilter Core Team <coreteam@netfilter.org>
+ *
+ * 2003-Jun-20: Harald Welte <laforge@netfilter.org>:
+ *     - Reimplementation of chain cache to use offsets instead of entries
+ * 2003-Jun-23: Harald Welte <laforge@netfilter.org>:
+ *     - performance optimization, sponsored by Astaro AG (http://www.astaro.com/)
+ *       don't rebuild the chain cache after every operation, instead fix it
+ *       up after a ruleset change.  
+ * 2004-Aug-18: Harald Welte <laforge@netfilter.org>:
+ *     - futher performance work: total reimplementation of libiptc.
+ *     - libiptc now has a real internal (linked-list) represntation of the
+ *       ruleset and a parser/compiler from/to this internal representation
+ *     - again sponsored by Astaro AG (http://www.astaro.com/)
+ */
+#include <sys/types.h>
+#include <sys/socket.h>
+
+#include "linux_list.h"
+
+//#define IPTC_DEBUG2 1
+
+#ifdef IPTC_DEBUG2
+#include <fcntl.h>
+#define DEBUGP(x, args...)     fprintf(stderr, "%s: " x, __FUNCTION__, ## args)
+#define DEBUGP_C(x, args...)   fprintf(stderr, x, ## args)
+#else
+#define DEBUGP(x, args...)
+#define DEBUGP_C(x, args...)
+#endif
+
+#ifndef IPT_LIB_DIR
+#define IPT_LIB_DIR "/usr/local/lib/iptables"
+#endif
+
+static int sockfd = -1;
+static int sockfd_use = 0;
+static void *iptc_fn = NULL;
+
+static const char *hooknames[]
+= { [HOOK_PRE_ROUTING]  "PREROUTING",
+    [HOOK_LOCAL_IN]     "INPUT",
+    [HOOK_FORWARD]      "FORWARD",
+    [HOOK_LOCAL_OUT]    "OUTPUT",
+    [HOOK_POST_ROUTING] "POSTROUTING",
+#ifdef HOOK_DROPPING
+    [HOOK_DROPPING]    "DROPPING"
+#endif
+};
+
+/* Convenience structures */
+struct ipt_error_target
+{
+       STRUCT_ENTRY_TARGET t;
+       char error[TABLE_MAXNAMELEN];
+};
+
+struct chain_head;
+struct rule_head;
+
+struct counter_map
+{
+       enum {
+               COUNTER_MAP_NOMAP,
+               COUNTER_MAP_NORMAL_MAP,
+               COUNTER_MAP_ZEROED,
+               COUNTER_MAP_SET
+       } maptype;
+       unsigned int mappos;
+};
+
+enum iptcc_rule_type {
+       IPTCC_R_STANDARD,               /* standard target (ACCEPT, ...) */
+       IPTCC_R_MODULE,                 /* extension module (SNAT, ...) */
+       IPTCC_R_FALLTHROUGH,            /* fallthrough rule */
+       IPTCC_R_JUMP,                   /* jump to other chain */
+};
+
+struct rule_head
+{
+       struct list_head list;
+       struct chain_head *chain;
+       struct counter_map counter_map;
+
+       unsigned int index;             /* index (needed for counter_map) */
+       unsigned int offset;            /* offset in rule blob */
+
+       enum iptcc_rule_type type;
+       struct chain_head *jump;        /* jump target, if IPTCC_R_JUMP */
+
+       unsigned int size;              /* size of entry data */
+       STRUCT_ENTRY entry[0];
+};
+
+struct chain_head
+{
+       struct list_head list;
+       char name[TABLE_MAXNAMELEN];
+       unsigned int hooknum;           /* hook number+1 if builtin */
+       unsigned int references;        /* how many jumps reference us */
+       int verdict;                    /* verdict if builtin */
+
+       STRUCT_COUNTERS counters;       /* per-chain counters */
+       struct counter_map counter_map;
+
+       unsigned int num_rules;         /* number of rules in list */
+       struct list_head rules;         /* list of rules */
+
+       unsigned int index;             /* index (needed for jump resolval) */
+       unsigned int head_offset;       /* offset in rule blob */
+       unsigned int foot_index;        /* index (needed for counter_map) */
+       unsigned int foot_offset;       /* offset in rule blob */
+};
+
+STRUCT_TC_HANDLE
+{
+       int changed;                     /* Have changes been made? */
+
+       struct list_head chains;
+       
+       struct chain_head *chain_iterator_cur;
+       struct rule_head *rule_iterator_cur;
+
+       STRUCT_GETINFO info;
+       STRUCT_GET_ENTRIES *entries;
+};
+
+/* allocate a new chain head for the cache */
+static struct chain_head *iptcc_alloc_chain_head(const char *name, int hooknum)
+{
+       struct chain_head *c = malloc(sizeof(*c));
+       if (!c)
+               return NULL;
+       memset(c, 0, sizeof(*c));
+
+       strncpy(c->name, name, TABLE_MAXNAMELEN);
+       c->hooknum = hooknum;
+       INIT_LIST_HEAD(&c->rules);
+
+       return c;
+}
+
+/* allocate and initialize a new rule for the cache */
+static struct rule_head *iptcc_alloc_rule(struct chain_head *c, unsigned int size)
+{
+       struct rule_head *r = malloc(sizeof(*r)+size);
+       if (!r)
+               return NULL;
+       memset(r, 0, sizeof(*r));
+
+       r->chain = c;
+       r->size = size;
+
+       return r;
+}
+
+/* notify us that the ruleset has been modified by the user */
+static void
+set_changed(TC_HANDLE_T h)
+{
+       h->changed = 1;
+}
+
+#ifdef IPTC_DEBUG
+static void do_check(TC_HANDLE_T h, unsigned int line);
+#define CHECK(h) do { if (!getenv("IPTC_NO_CHECK")) do_check((h), __LINE__); } while(0)
+#else
+#define CHECK(h)
+#endif
+
+
+/**********************************************************************
+ * iptc blob utility functions (iptcb_*)
+ **********************************************************************/
+
+static inline int
+iptcb_get_number(const STRUCT_ENTRY *i,
+          const STRUCT_ENTRY *seek,
+          unsigned int *pos)
+{
+       if (i == seek)
+               return 1;
+       (*pos)++;
+       return 0;
+}
+
+static inline int
+iptcb_get_entry_n(STRUCT_ENTRY *i,
+           unsigned int number,
+           unsigned int *pos,
+           STRUCT_ENTRY **pe)
+{
+       if (*pos == number) {
+               *pe = i;
+               return 1;
+       }
+       (*pos)++;
+       return 0;
+}
+
+static inline STRUCT_ENTRY *
+iptcb_get_entry(TC_HANDLE_T h, unsigned int offset)
+{
+       return (STRUCT_ENTRY *)((char *)h->entries->entrytable + offset);
+}
+
+static unsigned int
+iptcb_entry2index(const TC_HANDLE_T h, const STRUCT_ENTRY *seek)
+{
+       unsigned int pos = 0;
+
+       if (ENTRY_ITERATE(h->entries->entrytable, h->entries->size,
+                         iptcb_get_number, seek, &pos) == 0) {
+               fprintf(stderr, "ERROR: offset %u not an entry!\n",
+                       (unsigned int)((char *)seek - (char *)h->entries->entrytable));
+               abort();
+       }
+       return pos;
+}
+
+static inline STRUCT_ENTRY *
+iptcb_offset2entry(TC_HANDLE_T h, unsigned int offset)
+{
+       return (STRUCT_ENTRY *) ((void *)h->entries->entrytable+offset);
+}
+
+
+static inline unsigned long
+iptcb_entry2offset(const TC_HANDLE_T h, const STRUCT_ENTRY *e)
+{
+       return (void *)e - (void *)h->entries->entrytable;
+}
+
+static inline unsigned int
+iptcb_offset2index(const TC_HANDLE_T h, unsigned int offset)
+{
+       return iptcb_entry2index(h, iptcb_offset2entry(h, offset));
+}
+
+/* Returns 0 if not hook entry, else hooknumber + 1 */
+static inline unsigned int
+iptcb_ent_is_hook_entry(STRUCT_ENTRY *e, TC_HANDLE_T h)
+{
+       unsigned int i;
+
+       for (i = 0; i < NUMHOOKS; i++) {
+               if ((h->info.valid_hooks & (1 << i))
+                   && iptcb_get_entry(h, h->info.hook_entry[i]) == e)
+                       return i+1;
+       }
+       return 0;
+}
+
+
+/**********************************************************************
+ * iptc cache utility functions (iptcc_*)
+ **********************************************************************/
+
+/* Is the given chain builtin (1) or user-defined (0) */
+static unsigned int iptcc_is_builtin(struct chain_head *c)
+{
+       return (c->hooknum ? 1 : 0);
+}
+
+/* Get a specific rule within a chain */
+static struct rule_head *iptcc_get_rule_num(struct chain_head *c,
+                                           unsigned int rulenum)
+{
+       struct rule_head *r;
+       unsigned int num = 0;
+
+       list_for_each_entry(r, &c->rules, list) {
+               num++;
+               if (num == rulenum)
+                       return r;
+       }
+       return NULL;
+}
+
+/* Get a specific rule within a chain backwards */
+static struct rule_head *iptcc_get_rule_num_reverse(struct chain_head *c,
+                                           unsigned int rulenum)
+{
+       struct rule_head *r;
+       unsigned int num = 0;
+
+       list_for_each_entry_reverse(r, &c->rules, list) {
+               num++;
+               if (num == rulenum)
+                       return r;
+       }
+       return NULL;
+}
+
+/* Returns chain head if found, otherwise NULL. */
+static struct chain_head *
+iptcc_find_chain_by_offset(TC_HANDLE_T handle, unsigned int offset)
+{
+       struct list_head *pos;
+
+       if (list_empty(&handle->chains))
+               return NULL;
+
+       list_for_each(pos, &handle->chains) {
+               struct chain_head *c = list_entry(pos, struct chain_head, list);
+               if (offset >= c->head_offset && offset <= c->foot_offset)
+                       return c;
+       }
+
+       return NULL;
+}
+/* Returns chain head if found, otherwise NULL. */
+static struct chain_head *
+iptcc_find_label(const char *name, TC_HANDLE_T handle)
+{
+       struct list_head *pos;
+
+       if (list_empty(&handle->chains))
+               return NULL;
+
+       list_for_each(pos, &handle->chains) {
+               struct chain_head *c = list_entry(pos, struct chain_head, list);
+               if (!strcmp(c->name, name))
+                       return c;
+       }
+
+       return NULL;
+}
+
+/* called when rule is to be removed from cache */
+static void iptcc_delete_rule(struct rule_head *r)
+{
+       DEBUGP("deleting rule %p (offset %u)\n", r, r->offset);
+       /* clean up reference count of called chain */
+       if (r->type == IPTCC_R_JUMP
+           && r->jump)
+               r->jump->references--;
+
+       list_del(&r->list);
+       free(r);
+}
+
+
+/**********************************************************************
+ * RULESET PARSER (blob -> cache)
+ **********************************************************************/
+
+/* Delete policy rule of previous chain, since cache doesn't contain
+ * chain policy rules.
+ * WARNING: This function has ugly design and relies on a lot of context, only
+ * to be called from specific places within the parser */
+static int __iptcc_p_del_policy(TC_HANDLE_T h, unsigned int num)
+{
+       if (h->chain_iterator_cur) {
+               /* policy rule is last rule */
+               struct rule_head *pr = (struct rule_head *)
+                       h->chain_iterator_cur->rules.prev;
+
+               /* save verdict */
+               h->chain_iterator_cur->verdict = 
+                       *(int *)GET_TARGET(pr->entry)->data;
+
+               /* save counter and counter_map information */
+               h->chain_iterator_cur->counter_map.maptype = 
+                                               COUNTER_MAP_NORMAL_MAP;
+               h->chain_iterator_cur->counter_map.mappos = num-1;
+               memcpy(&h->chain_iterator_cur->counters, &pr->entry->counters, 
+                       sizeof(h->chain_iterator_cur->counters));
+
+               /* foot_offset points to verdict rule */
+               h->chain_iterator_cur->foot_index = num;
+               h->chain_iterator_cur->foot_offset = pr->offset;
+
+               /* delete rule from cache */
+               iptcc_delete_rule(pr);
+               h->chain_iterator_cur->num_rules--;
+
+               return 1;
+       }
+       return 0;
+}
+
+/* alphabetically insert a chain into the list */
+static inline void iptc_insert_chain(TC_HANDLE_T h, struct chain_head *c)
+{
+       struct chain_head *tmp;
+
+       /* sort only user defined chains */
+       if (!c->hooknum) {
+               list_for_each_entry(tmp, &h->chains, list) {
+                       if (!tmp->hooknum && strcmp(c->name, tmp->name) <= 0) {
+                               list_add(&c->list, tmp->list.prev);
+                               return;
+                       }
+               }
+       }
+
+       /* survived till end of list: add at tail */
+       list_add_tail(&c->list, &h->chains);
+}
+
+/* Another ugly helper function split out of cache_add_entry to make it less
+ * spaghetti code */
+static void __iptcc_p_add_chain(TC_HANDLE_T h, struct chain_head *c,
+                               unsigned int offset, unsigned int *num)
+{
+       __iptcc_p_del_policy(h, *num);
+
+       c->head_offset = offset;
+       c->index = *num;
+
+       iptc_insert_chain(h, c);
+       
+       h->chain_iterator_cur = c;
+}
+
+/* main parser function: add an entry from the blob to the cache */
+static int cache_add_entry(STRUCT_ENTRY *e, 
+                          TC_HANDLE_T h, 
+                          STRUCT_ENTRY **prev,
+                          unsigned int *num)
+{
+       unsigned int builtin;
+       unsigned int offset = (char *)e - (char *)h->entries->entrytable;
+
+       DEBUGP("entering...");
+
+       /* Last entry ("policy rule"). End it.*/
+       if (iptcb_entry2offset(h,e) + e->next_offset == h->entries->size) {
+               /* This is the ERROR node at the end of the chain */
+               DEBUGP_C("%u:%u: end of table:\n", *num, offset);
+
+               __iptcc_p_del_policy(h, *num);
+
+               h->chain_iterator_cur = NULL;
+               goto out_inc;
+       }
+
+       /* We know this is the start of a new chain if it's an ERROR
+        * target, or a hook entry point */
+
+       if (strcmp(GET_TARGET(e)->u.user.name, ERROR_TARGET) == 0) {
+               struct chain_head *c = 
+                       iptcc_alloc_chain_head((const char *)GET_TARGET(e)->data, 0);
+               DEBUGP_C("%u:%u:new userdefined chain %s: %p\n", *num, offset, 
+                       (char *)c->name, c);
+               if (!c) {
+                       errno = -ENOMEM;
+                       return -1;
+               }
+
+               __iptcc_p_add_chain(h, c, offset, num);
+
+       } else if ((builtin = iptcb_ent_is_hook_entry(e, h)) != 0) {
+               struct chain_head *c =
+                       iptcc_alloc_chain_head((char *)hooknames[builtin-1], 
+                                               builtin);
+               DEBUGP_C("%u:%u new builtin chain: %p (rules=%p)\n", 
+                       *num, offset, c, &c->rules);
+               if (!c) {
+                       errno = -ENOMEM;
+                       return -1;
+               }
+
+               c->hooknum = builtin;
+
+               __iptcc_p_add_chain(h, c, offset, num);
+
+               /* FIXME: this is ugly. */
+               goto new_rule;
+       } else {
+               /* has to be normal rule */
+               struct rule_head *r;
+new_rule:
+
+               if (!(r = iptcc_alloc_rule(h->chain_iterator_cur, 
+                                          e->next_offset))) {
+                       errno = ENOMEM;
+                       return -1;
+               }
+               DEBUGP_C("%u:%u normal rule: %p: ", *num, offset, r);
+
+               r->index = *num;
+               r->offset = offset;
+               memcpy(r->entry, e, e->next_offset);
+               r->counter_map.maptype = COUNTER_MAP_NORMAL_MAP;
+               r->counter_map.mappos = r->index;
+
+               /* handling of jumps, etc. */
+               if (!strcmp(GET_TARGET(e)->u.user.name, STANDARD_TARGET)) {
+                       STRUCT_STANDARD_TARGET *t;
+
+                       t = (STRUCT_STANDARD_TARGET *)GET_TARGET(e);
+                       if (t->target.u.target_size
+                           != ALIGN(sizeof(STRUCT_STANDARD_TARGET))) {
+                               errno = EINVAL;
+                               return -1;
+                       }
+
+                       if (t->verdict < 0) {
+                               DEBUGP_C("standard, verdict=%d\n", t->verdict);
+                               r->type = IPTCC_R_STANDARD;
+                       } else if (t->verdict == r->offset+e->next_offset) {
+                               DEBUGP_C("fallthrough\n");
+                               r->type = IPTCC_R_FALLTHROUGH;
+                       } else {
+                               DEBUGP_C("jump, target=%u\n", t->verdict);
+                               r->type = IPTCC_R_JUMP;
+                               /* Jump target fixup has to be deferred
+                                * until second pass, since we migh not
+                                * yet have parsed the target */
+                       }
+               } else {
+                       DEBUGP_C("module, target=%s\n", GET_TARGET(e)->u.user.name);
+                       r->type = IPTCC_R_MODULE;
+               }
+
+               list_add_tail(&r->list, &h->chain_iterator_cur->rules);
+               h->chain_iterator_cur->num_rules++;
+       }
+out_inc:
+       (*num)++;
+       return 0;
+}
+
+
+/* parse an iptables blob into it's pieces */
+static int parse_table(TC_HANDLE_T h)
+{
+       STRUCT_ENTRY *prev;
+       unsigned int num = 0;
+       struct chain_head *c;
+
+       /* First pass: over ruleset blob */
+       ENTRY_ITERATE(h->entries->entrytable, h->entries->size,
+                       cache_add_entry, h, &prev, &num);
+
+       /* Second pass: fixup parsed data from first pass */
+       list_for_each_entry(c, &h->chains, list) {
+               struct rule_head *r;
+               list_for_each_entry(r, &c->rules, list) {
+                       struct chain_head *c;
+                       STRUCT_STANDARD_TARGET *t;
+
+                       if (r->type != IPTCC_R_JUMP)
+                               continue;
+
+                       t = (STRUCT_STANDARD_TARGET *)GET_TARGET(r->entry);
+                       c = iptcc_find_chain_by_offset(h, t->verdict);
+                       if (!c)
+                               return -1;
+                       r->jump = c;
+                       c->references++;
+               }
+       }
+
+       /* FIXME: sort chains */
+
+       return 1;
+}
+
+
+/**********************************************************************
+ * RULESET COMPILATION (cache -> blob)
+ **********************************************************************/
+
+/* Convenience structures */
+struct iptcb_chain_start{
+       STRUCT_ENTRY e;
+       struct ipt_error_target name;
+};
+#define IPTCB_CHAIN_START_SIZE (sizeof(STRUCT_ENTRY) +                 \
+                                ALIGN(sizeof(struct ipt_error_target)))
+
+struct iptcb_chain_foot {
+       STRUCT_ENTRY e;
+       STRUCT_STANDARD_TARGET target;
+};
+#define IPTCB_CHAIN_FOOT_SIZE  (sizeof(STRUCT_ENTRY) +                 \
+                                ALIGN(sizeof(STRUCT_STANDARD_TARGET)))
+
+struct iptcb_chain_error {
+       STRUCT_ENTRY entry;
+       struct ipt_error_target target;
+};
+#define IPTCB_CHAIN_ERROR_SIZE (sizeof(STRUCT_ENTRY) +                 \
+                                ALIGN(sizeof(struct ipt_error_target)))
+
+
+
+/* compile rule from cache into blob */
+static inline int iptcc_compile_rule (TC_HANDLE_T h, STRUCT_REPLACE *repl, struct rule_head *r)
+{
+       /* handle jumps */
+       if (r->type == IPTCC_R_JUMP) {
+               STRUCT_STANDARD_TARGET *t;
+               t = (STRUCT_STANDARD_TARGET *)GET_TARGET(r->entry);
+               /* memset for memcmp convenience on delete/replace */
+               memset(t->target.u.user.name, 0, FUNCTION_MAXNAMELEN);
+               strcpy(t->target.u.user.name, STANDARD_TARGET);
+               /* Jumps can only happen to builtin chains, so we
+                * can safely assume that they always have a header */
+               t->verdict = r->jump->head_offset + IPTCB_CHAIN_START_SIZE;
+       } else if (r->type == IPTCC_R_FALLTHROUGH) {
+               STRUCT_STANDARD_TARGET *t;
+               t = (STRUCT_STANDARD_TARGET *)GET_TARGET(r->entry);
+               t->verdict = r->offset + r->size;
+       }
+       
+       /* copy entry from cache to blob */
+       memcpy((char *)repl->entries+r->offset, r->entry, r->size);
+
+       return 1;
+}
+
+/* compile chain from cache into blob */
+static int iptcc_compile_chain(TC_HANDLE_T h, STRUCT_REPLACE *repl, struct chain_head *c)
+{
+       int ret;
+       struct rule_head *r;
+       struct iptcb_chain_start *head;
+       struct iptcb_chain_foot *foot;
+
+       /* only user-defined chains have heaer */
+       if (!iptcc_is_builtin(c)) {
+               /* put chain header in place */
+               head = (void *)repl->entries + c->head_offset;
+               head->e.target_offset = sizeof(STRUCT_ENTRY);
+               head->e.next_offset = IPTCB_CHAIN_START_SIZE;
+               strcpy(head->name.t.u.user.name, ERROR_TARGET);
+               head->name.t.u.target_size = 
+                               ALIGN(sizeof(struct ipt_error_target));
+               strcpy(head->name.error, c->name);
+       } else {
+               repl->hook_entry[c->hooknum-1] = c->head_offset;        
+               repl->underflow[c->hooknum-1] = c->foot_offset;
+       }
+
+       /* iterate over rules */
+       list_for_each_entry(r, &c->rules, list) {
+               ret = iptcc_compile_rule(h, repl, r);
+               if (ret < 0)
+                       return ret;
+       }
+
+       /* put chain footer in place */
+       foot = (void *)repl->entries + c->foot_offset;
+       foot->e.target_offset = sizeof(STRUCT_ENTRY);
+       foot->e.next_offset = IPTCB_CHAIN_FOOT_SIZE;
+       strcpy(foot->target.target.u.user.name, STANDARD_TARGET);
+       foot->target.target.u.target_size =
+                               ALIGN(sizeof(STRUCT_STANDARD_TARGET));
+       /* builtin targets have verdict, others return */
+       if (iptcc_is_builtin(c))
+               foot->target.verdict = c->verdict;
+       else
+               foot->target.verdict = RETURN;
+       /* set policy-counters */
+       memcpy(&foot->e.counters, &c->counters, sizeof(STRUCT_COUNTERS));
+
+       return 0;
+}
+
+/* calculate offset and number for every rule in the cache */
+static int iptcc_compile_chain_offsets(TC_HANDLE_T h, struct chain_head *c,
+                                      unsigned int *offset, unsigned int *num)
+{
+       struct rule_head *r;
+
+       c->head_offset = *offset;
+       DEBUGP("%s: chain_head %u, offset=%u\n", c->name, *num, *offset);
+
+       if (!iptcc_is_builtin(c))  {
+               /* Chain has header */
+               *offset += sizeof(STRUCT_ENTRY) 
+                            + ALIGN(sizeof(struct ipt_error_target));
+               (*num)++;
+       }
+
+       list_for_each_entry(r, &c->rules, list) {
+               DEBUGP("rule %u, offset=%u, index=%u\n", *num, *offset, *num);
+               r->offset = *offset;
+               r->index = *num;
+               *offset += r->size;
+               (*num)++;
+       }
+
+       DEBUGP("%s; chain_foot %u, offset=%u, index=%u\n", c->name, *num, 
+               *offset, *num);
+       c->foot_offset = *offset;
+       c->foot_index = *num;
+       *offset += sizeof(STRUCT_ENTRY)
+                  + ALIGN(sizeof(STRUCT_STANDARD_TARGET));
+       (*num)++;
+
+       return 1;
+}
+
+/* put the pieces back together again */
+static int iptcc_compile_table_prep(TC_HANDLE_T h, unsigned int *size)
+{
+       struct chain_head *c;
+       unsigned int offset = 0, num = 0;
+       int ret = 0;
+
+       /* First pass: calculate offset for every rule */
+       list_for_each_entry(c, &h->chains, list) {
+               ret = iptcc_compile_chain_offsets(h, c, &offset, &num);
+               if (ret < 0)
+                       return ret;
+       }
+
+       /* Append one error rule at end of chain */
+       num++;
+       offset += sizeof(STRUCT_ENTRY)
+                 + ALIGN(sizeof(struct ipt_error_target));
+
+       /* ruleset size is now in offset */
+       *size = offset;
+       return num;
+}
+
+static int iptcc_compile_table(TC_HANDLE_T h, STRUCT_REPLACE *repl)
+{
+       struct chain_head *c;
+       struct iptcb_chain_error *error;
+
+       /* Second pass: copy from cache to offsets, fill in jumps */
+       list_for_each_entry(c, &h->chains, list) {
+               int ret = iptcc_compile_chain(h, repl, c);
+               if (ret < 0)
+                       return ret;
+       }
+
+       /* Append error rule at end of chain */
+       error = (void *)repl->entries + repl->size - IPTCB_CHAIN_ERROR_SIZE;
+       error->entry.target_offset = sizeof(STRUCT_ENTRY);
+       error->entry.next_offset = IPTCB_CHAIN_ERROR_SIZE;
+       error->target.t.u.user.target_size = 
+               ALIGN(sizeof(struct ipt_error_target));
+       strcpy((char *)&error->target.t.u.user.name, ERROR_TARGET);
+       strcpy((char *)&error->target.error, "ERROR");
+
+       return 1;
+}
+
+/**********************************************************************
+ * EXTERNAL API (operates on cache only)
+ **********************************************************************/
+
+/* Allocate handle of given size */
+static TC_HANDLE_T
+alloc_handle(const char *tablename, unsigned int size, unsigned int num_rules)
+{
+       size_t len;
+       TC_HANDLE_T h;
+
+       len = sizeof(STRUCT_TC_HANDLE) + size;
+
+       h = malloc(sizeof(STRUCT_TC_HANDLE));
+       if (!h) {
+               errno = ENOMEM;
+               return NULL;
+       }
+       memset(h, 0, sizeof(*h));
+       INIT_LIST_HEAD(&h->chains);
+       strcpy(h->info.name, tablename);
+
+       h->entries = malloc(sizeof(STRUCT_GET_ENTRIES) + size);
+       if (!h->entries)
+               goto out_free_handle;
+
+       strcpy(h->entries->name, tablename);
+       h->entries->size = size;
+
+       return h;
+
+out_free_handle:
+       free(h);
+
+       return NULL;
+}
+
+
+TC_HANDLE_T
+TC_INIT(const char *tablename)
+{
+       TC_HANDLE_T h;
+       STRUCT_GETINFO info;
+       unsigned int tmp;
+       socklen_t s;
+
+       iptc_fn = TC_INIT;
+
+       if (strlen(tablename) >= TABLE_MAXNAMELEN) {
+               errno = EINVAL;
+               return NULL;
+       }
+       
+       if (sockfd_use == 0) {
+               sockfd = socket(TC_AF, SOCK_RAW, IPPROTO_RAW);
+               if (sockfd < 0)
+                       return NULL;
+       }
+       sockfd_use++;
+
+       s = sizeof(info);
+
+       strcpy(info.name, tablename);
+       if (getsockopt(sockfd, TC_IPPROTO, SO_GET_INFO, &info, &s) < 0) {
+               if (--sockfd_use == 0) {
+                       close(sockfd);
+                       sockfd = -1;
+               }
+               return NULL;
+       }
+
+       DEBUGP("valid_hooks=0x%08x, num_entries=%u, size=%u\n",
+               info.valid_hooks, info.num_entries, info.size);
+
+       if ((h = alloc_handle(info.name, info.size, info.num_entries))
+           == NULL) {
+               if (--sockfd_use == 0) {
+                       close(sockfd);
+                       sockfd = -1;
+               }
+               return NULL;
+       }
+
+       /* Initialize current state */
+       h->info = info;
+
+       h->entries->size = h->info.size;
+
+       tmp = sizeof(STRUCT_GET_ENTRIES) + h->info.size;
+
+       if (getsockopt(sockfd, TC_IPPROTO, SO_GET_ENTRIES, h->entries,
+                      &tmp) < 0)
+               goto error;
+
+#ifdef IPTC_DEBUG2
+       {
+               int fd = open("/tmp/libiptc-so_get_entries.blob", 
+                               O_CREAT|O_WRONLY);
+               if (fd >= 0) {
+                       write(fd, h->entries, tmp);
+                       close(fd);
+               }
+       }
+#endif
+
+       if (parse_table(h) < 0)
+               goto error;
+
+       CHECK(h);
+       return h;
+error:
+       if (--sockfd_use == 0) {
+               close(sockfd);
+               sockfd = -1;
+       }
+       TC_FREE(&h);
+       return NULL;
+}
+
+void
+TC_FREE(TC_HANDLE_T *h)
+{
+       struct chain_head *c, *tmp;
+
+       iptc_fn = TC_FREE;
+       if (--sockfd_use == 0) {
+               close(sockfd);
+               sockfd = -1;
+       }
+
+       list_for_each_entry_safe(c, tmp, &(*h)->chains, list) {
+               struct rule_head *r, *rtmp;
+
+               list_for_each_entry_safe(r, rtmp, &c->rules, list) {
+                       free(r);
+               }
+
+               free(c);
+       }
+
+       free((*h)->entries);
+       free(*h);
+
+       *h = NULL;
+}
+
+static inline int
+print_match(const STRUCT_ENTRY_MATCH *m)
+{
+       printf("Match name: `%s'\n", m->u.user.name);
+       return 0;
+}
+
+static int dump_entry(STRUCT_ENTRY *e, const TC_HANDLE_T handle);
+void
+TC_DUMP_ENTRIES(const TC_HANDLE_T handle)
+{
+       iptc_fn = TC_DUMP_ENTRIES;
+       CHECK(handle);
+#if 0
+       printf("libiptc v%s. %u bytes.\n",
+              IPTABLES_VERSION, handle->entries->size);
+       printf("Table `%s'\n", handle->info.name);
+       printf("Hooks: pre/in/fwd/out/post = %u/%u/%u/%u/%u\n",
+              handle->info.hook_entry[HOOK_PRE_ROUTING],
+              handle->info.hook_entry[HOOK_LOCAL_IN],
+              handle->info.hook_entry[HOOK_FORWARD],
+              handle->info.hook_entry[HOOK_LOCAL_OUT],
+              handle->info.hook_entry[HOOK_POST_ROUTING]);
+       printf("Underflows: pre/in/fwd/out/post = %u/%u/%u/%u/%u\n",
+              handle->info.underflow[HOOK_PRE_ROUTING],
+              handle->info.underflow[HOOK_LOCAL_IN],
+              handle->info.underflow[HOOK_FORWARD],
+              handle->info.underflow[HOOK_LOCAL_OUT],
+              handle->info.underflow[HOOK_POST_ROUTING]);
+
+       ENTRY_ITERATE(handle->entries->entrytable, handle->entries->size,
+                     dump_entry, handle);
+#endif
+}
+
+/* Does this chain exist? */
+int TC_IS_CHAIN(const char *chain, const TC_HANDLE_T handle)
+{
+       iptc_fn = TC_IS_CHAIN;
+       return iptcc_find_label(chain, handle) != NULL;
+}
+
+static void iptcc_chain_iterator_advance(TC_HANDLE_T handle)
+{
+       struct chain_head *c = handle->chain_iterator_cur;
+
+       if (c->list.next == &handle->chains)
+               handle->chain_iterator_cur = NULL;
+       else
+               handle->chain_iterator_cur = 
+                       list_entry(c->list.next, struct chain_head, list);
+}
+
+/* Iterator functions to run through the chains. */
+const char *
+TC_FIRST_CHAIN(TC_HANDLE_T *handle)
+{
+       struct chain_head *c = list_entry((*handle)->chains.next,
+                                         struct chain_head, list);
+
+       iptc_fn = TC_FIRST_CHAIN;
+
+
+       if (list_empty(&(*handle)->chains)) {
+               DEBUGP(": no chains\n");
+               return NULL;
+       }
+
+       (*handle)->chain_iterator_cur = c;
+       iptcc_chain_iterator_advance(*handle);
+
+       DEBUGP(": returning `%s'\n", c->name);
+       return c->name;
+}
+
+/* Iterator functions to run through the chains.  Returns NULL at end. */
+const char *
+TC_NEXT_CHAIN(TC_HANDLE_T *handle)
+{
+       struct chain_head *c = (*handle)->chain_iterator_cur;
+
+       iptc_fn = TC_NEXT_CHAIN;
+
+       if (!c) {
+               DEBUGP(": no more chains\n");
+               return NULL;
+       }
+
+       iptcc_chain_iterator_advance(*handle);
+       
+       DEBUGP(": returning `%s'\n", c->name);
+       return c->name;
+}
+
+/* Get first rule in the given chain: NULL for empty chain. */
+const STRUCT_ENTRY *
+TC_FIRST_RULE(const char *chain, TC_HANDLE_T *handle)
+{
+       struct chain_head *c;
+       struct rule_head *r;
+
+       iptc_fn = TC_FIRST_RULE;
+
+       DEBUGP("first rule(%s): ", chain);
+
+       c = iptcc_find_label(chain, *handle);
+       if (!c) {
+               errno = ENOENT;
+               return NULL;
+       }
+
+       /* Empty chain: single return/policy rule */
+       if (list_empty(&c->rules)) {
+               DEBUGP_C("no rules, returning NULL\n");
+               return NULL;
+       }
+
+       r = list_entry(c->rules.next, struct rule_head, list);
+       (*handle)->rule_iterator_cur = r;
+       DEBUGP_C("%p\n", r);
+
+       return r->entry;
+}
+
+/* Returns NULL when rules run out. */
+const STRUCT_ENTRY *
+TC_NEXT_RULE(const STRUCT_ENTRY *prev, TC_HANDLE_T *handle)
+{
+       struct rule_head *r;
+
+       iptc_fn = TC_NEXT_RULE;
+       DEBUGP("rule_iterator_cur=%p...", (*handle)->rule_iterator_cur);
+
+       if (!(*handle)->rule_iterator_cur) {
+               DEBUGP_C("returning NULL\n");
+               return NULL;
+       }
+       
+       r = list_entry((*handle)->rule_iterator_cur->list.next, 
+                       struct rule_head, list);
+
+       iptc_fn = TC_NEXT_RULE;
+
+       DEBUGP_C("next=%p, head=%p...", &r->list, 
+               &(*handle)->rule_iterator_cur->chain->rules);
+
+       if (&r->list == &(*handle)->rule_iterator_cur->chain->rules) {
+               (*handle)->rule_iterator_cur = NULL;
+               DEBUGP_C("finished, returning NULL\n");
+               return NULL;
+       }
+
+       (*handle)->rule_iterator_cur = r;
+
+       /* NOTE: prev is without any influence ! */
+       DEBUGP_C("returning rule %p\n", r);
+       return r->entry;
+}
+
+/* How many rules in this chain? */
+unsigned int
+TC_NUM_RULES(const char *chain, TC_HANDLE_T *handle)
+{
+       struct chain_head *c;
+       iptc_fn = TC_NUM_RULES;
+       CHECK(*handle);
+
+       c = iptcc_find_label(chain, *handle);
+       if (!c) {
+               errno = ENOENT;
+               return (unsigned int)-1;
+       }
+       
+       return c->num_rules;
+}
+
+const STRUCT_ENTRY *TC_GET_RULE(const char *chain,
+                               unsigned int n,
+                               TC_HANDLE_T *handle)
+{
+       struct chain_head *c;
+       struct rule_head *r;
+       
+       iptc_fn = TC_GET_RULE;
+
+       CHECK(*handle);
+
+       c = iptcc_find_label(chain, *handle);
+       if (!c) {
+               errno = ENOENT;
+               return NULL;
+       }
+
+       r = iptcc_get_rule_num(c, n);
+       if (!r)
+               return NULL;
+       return r->entry;
+}
+
+/* Returns a pointer to the target name of this position. */
+const char *standard_target_map(int verdict)
+{
+       switch (verdict) {
+               case RETURN:
+                       return LABEL_RETURN;
+                       break;
+               case -NF_ACCEPT-1:
+                       return LABEL_ACCEPT;
+                       break;
+               case -NF_DROP-1:
+                       return LABEL_DROP;
+                       break;
+               case -NF_QUEUE-1:
+                       return LABEL_QUEUE;
+                       break;
+               default:
+                       fprintf(stderr, "ERROR: %d not a valid target)\n",
+                               verdict);
+                       abort();
+                       break;
+       }
+       /* not reached */
+       return NULL;
+}
+
+/* Returns a pointer to the target name of this position. */
+const char *TC_GET_TARGET(const STRUCT_ENTRY *ce,
+                         TC_HANDLE_T *handle)
+{
+       STRUCT_ENTRY *e = (STRUCT_ENTRY *)ce;
+       struct rule_head *r = container_of(e, struct rule_head, entry[0]);
+
+       iptc_fn = TC_GET_TARGET;
+
+       switch(r->type) {
+               int spos;
+               case IPTCC_R_FALLTHROUGH:
+                       return "";
+                       break;
+               case IPTCC_R_JUMP:
+                       DEBUGP("r=%p, jump=%p, name=`%s'\n", r, r->jump, r->jump->name);
+                       return r->jump->name;
+                       break;
+               case IPTCC_R_STANDARD:
+                       spos = *(int *)GET_TARGET(e)->data;
+                       DEBUGP("r=%p, spos=%d'\n", r, spos);
+                       return standard_target_map(spos);
+                       break;
+               case IPTCC_R_MODULE:
+                       return GET_TARGET(e)->u.user.name;
+                       break;
+       }
+       return NULL;
+}
+/* Is this a built-in chain?  Actually returns hook + 1. */
+int
+TC_BUILTIN(const char *chain, const TC_HANDLE_T handle)
+{
+       struct chain_head *c;
+       
+       iptc_fn = TC_BUILTIN;
+
+       c = iptcc_find_label(chain, handle);
+       if (!c) {
+               errno = ENOENT;
+               return 0;
+       }
+
+       return iptcc_is_builtin(c);
+}
+
+/* Get the policy of a given built-in chain */
+const char *
+TC_GET_POLICY(const char *chain,
+             STRUCT_COUNTERS *counters,
+             TC_HANDLE_T *handle)
+{
+       struct chain_head *c;
+
+       iptc_fn = TC_GET_POLICY;
+
+       DEBUGP("called for chain %s\n", chain);
+
+       c = iptcc_find_label(chain, *handle);
+       if (!c) {
+               errno = ENOENT;
+               return NULL;
+       }
+
+       if (!iptcc_is_builtin(c))
+               return NULL;
+
+       *counters = c->counters;
+
+       return standard_target_map(c->verdict);
+}
+
+static int
+iptcc_standard_map(struct rule_head *r, int verdict)
+{
+       STRUCT_ENTRY *e = r->entry;
+       STRUCT_STANDARD_TARGET *t;
+
+       t = (STRUCT_STANDARD_TARGET *)GET_TARGET(e);
+
+       if (t->target.u.target_size
+           != ALIGN(sizeof(STRUCT_STANDARD_TARGET))) {
+               errno = EINVAL;
+               return 0;
+       }
+       /* memset for memcmp convenience on delete/replace */
+       memset(t->target.u.user.name, 0, FUNCTION_MAXNAMELEN);
+       strcpy(t->target.u.user.name, STANDARD_TARGET);
+       t->verdict = verdict;
+
+       r->type = IPTCC_R_STANDARD;
+
+       return 1;
+}
+
+static int
+iptcc_map_target(const TC_HANDLE_T handle,
+          struct rule_head *r)
+{
+       STRUCT_ENTRY *e = r->entry;
+       STRUCT_ENTRY_TARGET *t = GET_TARGET(e);
+
+       /* Maybe it's empty (=> fall through) */
+       if (strcmp(t->u.user.name, "") == 0) {
+               r->type = IPTCC_R_FALLTHROUGH;
+               return 1;
+       }
+       /* Maybe it's a standard target name... */
+       else if (strcmp(t->u.user.name, LABEL_ACCEPT) == 0)
+               return iptcc_standard_map(r, -NF_ACCEPT - 1);
+       else if (strcmp(t->u.user.name, LABEL_DROP) == 0)
+               return iptcc_standard_map(r, -NF_DROP - 1);
+       else if (strcmp(t->u.user.name, LABEL_QUEUE) == 0)
+               return iptcc_standard_map(r, -NF_QUEUE - 1);
+       else if (strcmp(t->u.user.name, LABEL_RETURN) == 0)
+               return iptcc_standard_map(r, RETURN);
+       else if (TC_BUILTIN(t->u.user.name, handle)) {
+               /* Can't jump to builtins. */
+               errno = EINVAL;
+               return 0;
+       } else {
+               /* Maybe it's an existing chain name. */
+               struct chain_head *c;
+               DEBUGP("trying to find chain `%s': ", t->u.user.name);
+
+               c = iptcc_find_label(t->u.user.name, handle);
+               if (c) {
+                       DEBUGP_C("found!\n");
+                       r->type = IPTCC_R_JUMP;
+                       r->jump = c;
+                       c->references++;
+                       return 1;
+               }
+               DEBUGP_C("not found :(\n");
+       }
+
+       /* Must be a module?  If not, kernel will reject... */
+       /* memset to all 0 for your memcmp convenience: don't clear version */
+       memset(t->u.user.name + strlen(t->u.user.name),
+              0,
+              FUNCTION_MAXNAMELEN - 1 - strlen(t->u.user.name));
+       r->type = IPTCC_R_MODULE;
+       set_changed(handle);
+       return 1;
+}
+
+/* Insert the entry `fw' in chain `chain' into position `rulenum'. */
+int
+TC_INSERT_ENTRY(const IPT_CHAINLABEL chain,
+               const STRUCT_ENTRY *e,
+               unsigned int rulenum,
+               TC_HANDLE_T *handle)
+{
+       struct chain_head *c;
+       struct rule_head *r;
+       struct list_head *prev;
+
+       iptc_fn = TC_INSERT_ENTRY;
+
+       if (!(c = iptcc_find_label(chain, *handle))) {
+               errno = ENOENT;
+               return 0;
+       }
+
+       /* first rulenum index = 0
+          first c->num_rules index = 1 */
+       if (rulenum > c->num_rules) {
+               errno = E2BIG;
+               return 0;
+       }
+
+       /* If we are inserting at the end just take advantage of the
+          double linked list, insert will happen before the entry
+          prev points to. */
+       if (rulenum == c->num_rules) {
+               prev = &c->rules;
+       } else if (rulenum + 1 <= c->num_rules/2) {
+               r = iptcc_get_rule_num(c, rulenum + 1);
+               prev = &r->list;
+       } else {
+               r = iptcc_get_rule_num_reverse(c, c->num_rules - rulenum);
+               prev = &r->list;
+       }
+
+       if (!(r = iptcc_alloc_rule(c, e->next_offset))) {
+               errno = ENOMEM;
+               return 0;
+       }
+
+       memcpy(r->entry, e, e->next_offset);
+       r->counter_map.maptype = COUNTER_MAP_SET;
+
+       if (!iptcc_map_target(*handle, r)) {
+               free(r);
+               return 0;
+       }
+
+       list_add_tail(&r->list, prev);
+       c->num_rules++;
+
+       set_changed(*handle);
+
+       return 1;
+}
+
+/* Atomically replace rule `rulenum' in `chain' with `fw'. */
+int
+TC_REPLACE_ENTRY(const IPT_CHAINLABEL chain,
+                const STRUCT_ENTRY *e,
+                unsigned int rulenum,
+                TC_HANDLE_T *handle)
+{
+       struct chain_head *c;
+       struct rule_head *r, *old;
+
+       iptc_fn = TC_REPLACE_ENTRY;
+
+       if (!(c = iptcc_find_label(chain, *handle))) {
+               errno = ENOENT;
+               return 0;
+       }
+
+       if (rulenum >= c->num_rules) {
+               errno = E2BIG;
+               return 0;
+       }
+
+       /* Take advantage of the double linked list if possible. */
+       if (rulenum + 1 <= c->num_rules/2) {
+               old = iptcc_get_rule_num(c, rulenum + 1);
+       } else {
+               old = iptcc_get_rule_num_reverse(c, c->num_rules - rulenum);
+       }
+
+       if (!(r = iptcc_alloc_rule(c, e->next_offset))) {
+               errno = ENOMEM;
+               return 0;
+       }
+
+       memcpy(r->entry, e, e->next_offset);
+       r->counter_map.maptype = COUNTER_MAP_SET;
+
+       if (!iptcc_map_target(*handle, r)) {
+               free(r);
+               return 0;
+       }
+
+       list_add(&r->list, &old->list);
+       iptcc_delete_rule(old);
+
+       set_changed(*handle);
+
+       return 1;
+}
+
+/* Append entry `fw' to chain `chain'.  Equivalent to insert with
+   rulenum = length of chain. */
+int
+TC_APPEND_ENTRY(const IPT_CHAINLABEL chain,
+               const STRUCT_ENTRY *e,
+               TC_HANDLE_T *handle)
+{
+       struct chain_head *c;
+       struct rule_head *r;
+
+       iptc_fn = TC_APPEND_ENTRY;
+       if (!(c = iptcc_find_label(chain, *handle))) {
+               DEBUGP("unable to find chain `%s'\n", chain);
+               errno = ENOENT;
+               return 0;
+       }
+
+       if (!(r = iptcc_alloc_rule(c, e->next_offset))) {
+               DEBUGP("unable to allocate rule for chain `%s'\n", chain);
+               errno = ENOMEM;
+               return 0;
+       }
+
+       memcpy(r->entry, e, e->next_offset);
+       r->counter_map.maptype = COUNTER_MAP_SET;
+
+       if (!iptcc_map_target(*handle, r)) {
+               DEBUGP("unable to map target of rule for chain `%s'\n", chain);
+               free(r);
+               return 0;
+       }
+
+       list_add_tail(&r->list, &c->rules);
+       c->num_rules++;
+
+       set_changed(*handle);
+
+       return 1;
+}
+
+static inline int
+match_different(const STRUCT_ENTRY_MATCH *a,
+               const unsigned char *a_elems,
+               const unsigned char *b_elems,
+               unsigned char **maskptr)
+{
+       const STRUCT_ENTRY_MATCH *b;
+       unsigned int i;
+
+       /* Offset of b is the same as a. */
+       b = (void *)b_elems + ((unsigned char *)a - a_elems);
+
+       if (a->u.match_size != b->u.match_size)
+               return 1;
+
+       if (strcmp(a->u.user.name, b->u.user.name) != 0)
+               return 1;
+
+       *maskptr += ALIGN(sizeof(*a));
+
+       for (i = 0; i < a->u.match_size - ALIGN(sizeof(*a)); i++)
+               if (((a->data[i] ^ b->data[i]) & (*maskptr)[i]) != 0)
+                       return 1;
+       *maskptr += i;
+       return 0;
+}
+
+static inline int
+target_same(struct rule_head *a, struct rule_head *b,const unsigned char *mask)
+{
+       unsigned int i;
+       STRUCT_ENTRY_TARGET *ta, *tb;
+
+       if (a->type != b->type)
+               return 0;
+
+       ta = GET_TARGET(a->entry);
+       tb = GET_TARGET(b->entry);
+
+       switch (a->type) {
+       case IPTCC_R_FALLTHROUGH:
+               return 1;
+       case IPTCC_R_JUMP:
+               return a->jump == b->jump;
+       case IPTCC_R_STANDARD:
+               return ((STRUCT_STANDARD_TARGET *)ta)->verdict
+                       == ((STRUCT_STANDARD_TARGET *)tb)->verdict;
+       case IPTCC_R_MODULE:
+               if (ta->u.target_size != tb->u.target_size)
+                       return 0;
+               if (strcmp(ta->u.user.name, tb->u.user.name) != 0)
+                       return 0;
+
+               for (i = 0; i < ta->u.target_size - sizeof(*ta); i++)
+                       if (((ta->data[i] ^ tb->data[i]) & mask[i]) != 0)
+                               return 0;
+               return 1;
+       default:
+               fprintf(stderr, "ERROR: bad type %i\n", a->type);
+               abort();
+       }
+}
+
+static unsigned char *
+is_same(const STRUCT_ENTRY *a,
+       const STRUCT_ENTRY *b,
+       unsigned char *matchmask);
+
+/* Delete the first rule in `chain' which matches `fw'. */
+int
+TC_DELETE_ENTRY(const IPT_CHAINLABEL chain,
+               const STRUCT_ENTRY *origfw,
+               unsigned char *matchmask,
+               TC_HANDLE_T *handle)
+{
+       struct chain_head *c;
+       struct rule_head *r, *i;
+
+       iptc_fn = TC_DELETE_ENTRY;
+       if (!(c = iptcc_find_label(chain, *handle))) {
+               errno = ENOENT;
+               return 0;
+       }
+
+       /* Create a rule_head from origfw. */
+       r = iptcc_alloc_rule(c, origfw->next_offset);
+       if (!r) {
+               errno = ENOMEM;
+               return 0;
+       }
+
+       memcpy(r->entry, origfw, origfw->next_offset);
+       r->counter_map.maptype = COUNTER_MAP_NOMAP;
+       if (!iptcc_map_target(*handle, r)) {
+               DEBUGP("unable to map target of rule for chain `%s'\n", chain);
+               free(r);
+               return 0;
+       } else {
+               /* iptcc_map_target increment target chain references
+                * since this is a fake rule only used for matching
+                * the chain references count is decremented again. 
+                */
+               if (r->type == IPTCC_R_JUMP
+                   && r->jump)
+                       r->jump->references--;
+       }
+
+       list_for_each_entry(i, &c->rules, list) {
+               unsigned char *mask;
+
+               mask = is_same(r->entry, i->entry, matchmask);
+               if (!mask)
+                       continue;
+
+               if (!target_same(r, i, mask))
+                       continue;
+
+               /* If we are about to delete the rule that is the
+                * current iterator, move rule iterator back.  next
+                * pointer will then point to real next node */
+               if (i == (*handle)->rule_iterator_cur) {
+                       (*handle)->rule_iterator_cur = 
+                               list_entry((*handle)->rule_iterator_cur->list.prev,
+                                          struct rule_head, list);
+               }
+
+               c->num_rules--;
+               iptcc_delete_rule(i);
+
+               set_changed(*handle);
+               free(r);
+               return 1;
+       }
+
+       free(r);
+       errno = ENOENT;
+       return 0;
+}
+
+
+/* Delete the rule in position `rulenum' in `chain'. */
+int
+TC_DELETE_NUM_ENTRY(const IPT_CHAINLABEL chain,
+                   unsigned int rulenum,
+                   TC_HANDLE_T *handle)
+{
+       struct chain_head *c;
+       struct rule_head *r;
+
+       iptc_fn = TC_DELETE_NUM_ENTRY;
+
+       if (!(c = iptcc_find_label(chain, *handle))) {
+               errno = ENOENT;
+               return 0;
+       }
+
+       if (rulenum >= c->num_rules) {
+               errno = E2BIG;
+               return 0;
+       }
+
+       /* Take advantage of the double linked list if possible. */
+       if (rulenum + 1 <= c->num_rules/2) {
+               r = iptcc_get_rule_num(c, rulenum + 1);
+       } else {
+               r = iptcc_get_rule_num_reverse(c, c->num_rules - rulenum);
+       }
+
+       /* If we are about to delete the rule that is the current
+        * iterator, move rule iterator back.  next pointer will then
+        * point to real next node */
+       if (r == (*handle)->rule_iterator_cur) {
+               (*handle)->rule_iterator_cur = 
+                       list_entry((*handle)->rule_iterator_cur->list.prev,
+                                  struct rule_head, list);
+       }
+
+       c->num_rules--;
+       iptcc_delete_rule(r);
+
+       set_changed(*handle);
+
+       return 1;
+}
+
+/* Check the packet `fw' on chain `chain'.  Returns the verdict, or
+   NULL and sets errno. */
+const char *
+TC_CHECK_PACKET(const IPT_CHAINLABEL chain,
+               STRUCT_ENTRY *entry,
+               TC_HANDLE_T *handle)
+{
+       iptc_fn = TC_CHECK_PACKET;
+       errno = ENOSYS;
+       return NULL;
+}
+
+/* Flushes the entries in the given chain (ie. empties chain). */
+int
+TC_FLUSH_ENTRIES(const IPT_CHAINLABEL chain, TC_HANDLE_T *handle)
+{
+       struct chain_head *c;
+       struct rule_head *r, *tmp;
+
+       iptc_fn = TC_FLUSH_ENTRIES;
+       if (!(c = iptcc_find_label(chain, *handle))) {
+               errno = ENOENT;
+               return 0;
+       }
+
+       list_for_each_entry_safe(r, tmp, &c->rules, list) {
+               iptcc_delete_rule(r);
+       }
+
+       c->num_rules = 0;
+
+       set_changed(*handle);
+
+       return 1;
+}
+
+/* Zeroes the counters in a chain. */
+int
+TC_ZERO_ENTRIES(const IPT_CHAINLABEL chain, TC_HANDLE_T *handle)
+{
+       struct chain_head *c;
+       struct rule_head *r;
+
+       iptc_fn = TC_ZERO_ENTRIES;
+       if (!(c = iptcc_find_label(chain, *handle))) {
+               errno = ENOENT;
+               return 0;
+       }
+
+       if (c->counter_map.maptype == COUNTER_MAP_NORMAL_MAP)
+               c->counter_map.maptype = COUNTER_MAP_ZEROED;
+
+       list_for_each_entry(r, &c->rules, list) {
+               if (r->counter_map.maptype == COUNTER_MAP_NORMAL_MAP)
+                       r->counter_map.maptype = COUNTER_MAP_ZEROED;
+       }
+
+       set_changed(*handle);
+
+       return 1;
+}
+
+STRUCT_COUNTERS *
+TC_READ_COUNTER(const IPT_CHAINLABEL chain,
+               unsigned int rulenum,
+               TC_HANDLE_T *handle)
+{
+       struct chain_head *c;
+       struct rule_head *r;
+
+       iptc_fn = TC_READ_COUNTER;
+       CHECK(*handle);
+
+       if (!(c = iptcc_find_label(chain, *handle))) {
+               errno = ENOENT;
+               return NULL;
+       }
+
+       if (!(r = iptcc_get_rule_num(c, rulenum))) {
+               errno = E2BIG;
+               return NULL;
+       }
+
+       return &r->entry[0].counters;
+}
+
+int
+TC_ZERO_COUNTER(const IPT_CHAINLABEL chain,
+               unsigned int rulenum,
+               TC_HANDLE_T *handle)
+{
+       struct chain_head *c;
+       struct rule_head *r;
+       
+       iptc_fn = TC_ZERO_COUNTER;
+       CHECK(*handle);
+
+       if (!(c = iptcc_find_label(chain, *handle))) {
+               errno = ENOENT;
+               return 0;
+       }
+
+       if (!(r = iptcc_get_rule_num(c, rulenum))) {
+               errno = E2BIG;
+               return 0;
+       }
+
+       if (r->counter_map.maptype == COUNTER_MAP_NORMAL_MAP)
+               r->counter_map.maptype = COUNTER_MAP_ZEROED;
+
+       set_changed(*handle);
+
+       return 1;
+}
+
+int 
+TC_SET_COUNTER(const IPT_CHAINLABEL chain,
+              unsigned int rulenum,
+              STRUCT_COUNTERS *counters,
+              TC_HANDLE_T *handle)
+{
+       struct chain_head *c;
+       struct rule_head *r;
+       STRUCT_ENTRY *e;
+
+       iptc_fn = TC_SET_COUNTER;
+       CHECK(*handle);
+
+       if (!(c = iptcc_find_label(chain, *handle))) {
+               errno = ENOENT;
+               return 0;
+       }
+
+       if (!(r = iptcc_get_rule_num(c, rulenum))) {
+               errno = E2BIG;
+               return 0;
+       }
+
+       e = r->entry;
+       r->counter_map.maptype = COUNTER_MAP_SET;
+
+       memcpy(&e->counters, counters, sizeof(STRUCT_COUNTERS));
+
+       set_changed(*handle);
+
+       return 1;
+}
+
+/* Creates a new chain. */
+/* To create a chain, create two rules: error node and unconditional
+ * return. */
+int
+TC_CREATE_CHAIN(const IPT_CHAINLABEL chain, TC_HANDLE_T *handle)
+{
+       static struct chain_head *c;
+
+       iptc_fn = TC_CREATE_CHAIN;
+
+       /* find_label doesn't cover built-in targets: DROP, ACCEPT,
+           QUEUE, RETURN. */
+       if (iptcc_find_label(chain, *handle)
+           || strcmp(chain, LABEL_DROP) == 0
+           || strcmp(chain, LABEL_ACCEPT) == 0
+           || strcmp(chain, LABEL_QUEUE) == 0
+           || strcmp(chain, LABEL_RETURN) == 0) {
+               DEBUGP("Chain `%s' already exists\n", chain);
+               errno = EEXIST;
+               return 0;
+       }
+
+       if (strlen(chain)+1 > sizeof(IPT_CHAINLABEL)) {
+               DEBUGP("Chain name `%s' too long\n", chain);
+               errno = EINVAL;
+               return 0;
+       }
+
+       c = iptcc_alloc_chain_head(chain, 0);
+       if (!c) {
+               DEBUGP("Cannot allocate memory for chain `%s'\n", chain);
+               errno = ENOMEM;
+               return 0;
+
+       }
+
+       DEBUGP("Creating chain `%s'\n", chain);
+       list_add_tail(&c->list, &(*handle)->chains);
+
+       set_changed(*handle);
+
+       return 1;
+}
+
+/* Get the number of references to this chain. */
+int
+TC_GET_REFERENCES(unsigned int *ref, const IPT_CHAINLABEL chain,
+                 TC_HANDLE_T *handle)
+{
+       struct chain_head *c;
+
+       iptc_fn = TC_GET_REFERENCES;
+       if (!(c = iptcc_find_label(chain, *handle))) {
+               errno = ENOENT;
+               return 0;
+       }
+
+       *ref = c->references;
+
+       return 1;
+}
+
+/* Deletes a chain. */
+int
+TC_DELETE_CHAIN(const IPT_CHAINLABEL chain, TC_HANDLE_T *handle)
+{
+       unsigned int references;
+       struct chain_head *c;
+
+       iptc_fn = TC_DELETE_CHAIN;
+
+       if (!(c = iptcc_find_label(chain, *handle))) {
+               DEBUGP("cannot find chain `%s'\n", chain);
+               errno = ENOENT;
+               return 0;
+       }
+
+       if (TC_BUILTIN(chain, *handle)) {
+               DEBUGP("cannot remove builtin chain `%s'\n", chain);
+               errno = EINVAL;
+               return 0;
+       }
+
+       if (!TC_GET_REFERENCES(&references, chain, handle)) {
+               DEBUGP("cannot get references on chain `%s'\n", chain);
+               return 0;
+       }
+
+       if (references > 0) {
+               DEBUGP("chain `%s' still has references\n", chain);
+               errno = EMLINK;
+               return 0;
+       }
+
+       if (c->num_rules) {
+               DEBUGP("chain `%s' is not empty\n", chain);
+               errno = ENOTEMPTY;
+               return 0;
+       }
+
+       /* If we are about to delete the chain that is the current
+        * iterator, move chain iterator firward. */
+       if (c == (*handle)->chain_iterator_cur)
+               iptcc_chain_iterator_advance(*handle);
+
+       list_del(&c->list);
+       free(c);
+
+       DEBUGP("chain `%s' deleted\n", chain);
+
+       set_changed(*handle);
+
+       return 1;
+}
+
+/* Renames a chain. */
+int TC_RENAME_CHAIN(const IPT_CHAINLABEL oldname,
+                   const IPT_CHAINLABEL newname,
+                   TC_HANDLE_T *handle)
+{
+       struct chain_head *c;
+       iptc_fn = TC_RENAME_CHAIN;
+
+       /* find_label doesn't cover built-in targets: DROP, ACCEPT,
+           QUEUE, RETURN. */
+       if (iptcc_find_label(newname, *handle)
+           || strcmp(newname, LABEL_DROP) == 0
+           || strcmp(newname, LABEL_ACCEPT) == 0
+           || strcmp(newname, LABEL_QUEUE) == 0
+           || strcmp(newname, LABEL_RETURN) == 0) {
+               errno = EEXIST;
+               return 0;
+       }
+
+       if (!(c = iptcc_find_label(oldname, *handle))
+           || TC_BUILTIN(oldname, *handle)) {
+               errno = ENOENT;
+               return 0;
+       }
+
+       if (strlen(newname)+1 > sizeof(IPT_CHAINLABEL)) {
+               errno = EINVAL;
+               return 0;
+       }
+
+       strncpy(c->name, newname, sizeof(IPT_CHAINLABEL));
+       
+       set_changed(*handle);
+
+       return 1;
+}
+
+/* Sets the policy on a built-in chain. */
+int
+TC_SET_POLICY(const IPT_CHAINLABEL chain,
+             const IPT_CHAINLABEL policy,
+             STRUCT_COUNTERS *counters,
+             TC_HANDLE_T *handle)
+{
+       struct chain_head *c;
+
+       iptc_fn = TC_SET_POLICY;
+
+       if (!(c = iptcc_find_label(chain, *handle))) {
+               DEBUGP("cannot find chain `%s'\n", chain);
+               errno = ENOENT;
+               return 0;
+       }
+
+       if (!iptcc_is_builtin(c)) {
+               DEBUGP("cannot set policy of userdefinedchain `%s'\n", chain);
+               errno = ENOENT;
+               return 0;
+       }
+
+       if (strcmp(policy, LABEL_ACCEPT) == 0)
+               c->verdict = -NF_ACCEPT - 1;
+       else if (strcmp(policy, LABEL_DROP) == 0)
+               c->verdict = -NF_DROP - 1;
+       else {
+               errno = EINVAL;
+               return 0;
+       }
+
+       if (counters) {
+               /* set byte and packet counters */
+               memcpy(&c->counters, counters, sizeof(STRUCT_COUNTERS));
+               c->counter_map.maptype = COUNTER_MAP_SET;
+       } else {
+               c->counter_map.maptype = COUNTER_MAP_NOMAP;
+       }
+
+       set_changed(*handle);
+
+       return 1;
+}
+
+/* Without this, on gcc 2.7.2.3, we get:
+   libiptc.c: In function `TC_COMMIT':
+   libiptc.c:833: fixed or forbidden register was spilled.
+   This may be due to a compiler bug or to impossible asm
+   statements or clauses.
+*/
+static void
+subtract_counters(STRUCT_COUNTERS *answer,
+                 const STRUCT_COUNTERS *a,
+                 const STRUCT_COUNTERS *b)
+{
+       answer->pcnt = a->pcnt - b->pcnt;
+       answer->bcnt = a->bcnt - b->bcnt;
+}
+
+
+static void counters_nomap(STRUCT_COUNTERS_INFO *newcounters,
+                          unsigned int index)
+{
+       newcounters->counters[index] = ((STRUCT_COUNTERS) { 0, 0});
+       DEBUGP_C("NOMAP => zero\n");
+}
+
+static void counters_normal_map(STRUCT_COUNTERS_INFO *newcounters,
+                               STRUCT_REPLACE *repl,
+                               unsigned int index,
+                               unsigned int mappos)
+{
+       /* Original read: X.
+        * Atomic read on replacement: X + Y.
+        * Currently in kernel: Z.
+        * Want in kernel: X + Y + Z.
+        * => Add in X + Y
+        * => Add in replacement read.
+        */
+       newcounters->counters[index] = repl->counters[mappos];
+       DEBUGP_C("NORMAL_MAP => mappos %u \n", mappos);
+}
+
+static void counters_map_zeroed(STRUCT_COUNTERS_INFO *newcounters,
+                               STRUCT_REPLACE *repl,
+                               unsigned int index,
+                               unsigned int mappos,
+                               STRUCT_COUNTERS *counters)
+{
+       /* Original read: X.
+        * Atomic read on replacement: X + Y.
+        * Currently in kernel: Z.
+        * Want in kernel: Y + Z.
+        * => Add in Y.
+        * => Add in (replacement read - original read).
+        */
+       subtract_counters(&newcounters->counters[index],
+                         &repl->counters[mappos],
+                         counters);
+       DEBUGP_C("ZEROED => mappos %u\n", mappos);
+}
+
+static void counters_map_set(STRUCT_COUNTERS_INFO *newcounters,
+                            unsigned int index,
+                            STRUCT_COUNTERS *counters)
+{
+       /* Want to set counter (iptables-restore) */
+
+       memcpy(&newcounters->counters[index], counters,
+               sizeof(STRUCT_COUNTERS));
+
+       DEBUGP_C("SET\n");
+}
+
+
+int
+TC_COMMIT(TC_HANDLE_T *handle)
+{
+       /* Replace, then map back the counters. */
+       STRUCT_REPLACE *repl;
+       STRUCT_COUNTERS_INFO *newcounters;
+       struct chain_head *c;
+       int ret;
+       size_t counterlen;
+       int new_number;
+       unsigned int new_size;
+
+       iptc_fn = TC_COMMIT;
+       CHECK(*handle);
+
+       /* Don't commit if nothing changed. */
+       if (!(*handle)->changed)
+               goto finished;
+
+       new_number = iptcc_compile_table_prep(*handle, &new_size);
+       if (new_number < 0) {
+               errno = ENOMEM;
+               goto out_zero;
+       }
+
+       repl = malloc(sizeof(*repl) + new_size);
+       if (!repl) {
+               errno = ENOMEM;
+               goto out_zero;
+       }
+       memset(repl, 0, sizeof(*repl) + new_size);
+
+#if 0
+       TC_DUMP_ENTRIES(*handle);
+#endif
+
+       counterlen = sizeof(STRUCT_COUNTERS_INFO)
+                       + sizeof(STRUCT_COUNTERS) * new_number;
+
+       /* These are the old counters we will get from kernel */
+       repl->counters = malloc(sizeof(STRUCT_COUNTERS)
+                               * (*handle)->info.num_entries);
+       if (!repl->counters) {
+               errno = ENOMEM;
+               goto out_free_repl;
+       }
+       /* These are the counters we're going to put back, later. */
+       newcounters = malloc(counterlen);
+       if (!newcounters) {
+               errno = ENOMEM;
+               goto out_free_repl_counters;
+       }
+       memset(newcounters, 0, counterlen);
+
+       strcpy(repl->name, (*handle)->info.name);
+       repl->num_entries = new_number;
+       repl->size = new_size;
+
+       repl->num_counters = (*handle)->info.num_entries;
+       repl->valid_hooks = (*handle)->info.valid_hooks;
+
+       DEBUGP("num_entries=%u, size=%u, num_counters=%u\n",
+               repl->num_entries, repl->size, repl->num_counters);
+
+       ret = iptcc_compile_table(*handle, repl);
+       if (ret < 0) {
+               errno = ret;
+               goto out_free_newcounters;
+       }
+
+
+#ifdef IPTC_DEBUG2
+       {
+               int fd = open("/tmp/libiptc-so_set_replace.blob", 
+                               O_CREAT|O_WRONLY);
+               if (fd >= 0) {
+                       write(fd, repl, sizeof(*repl) + repl->size);
+                       close(fd);
+               }
+       }
+#endif
+
+       ret = setsockopt(sockfd, TC_IPPROTO, SO_SET_REPLACE, repl,
+                        sizeof(*repl) + repl->size);
+       if (ret < 0)
+               goto out_free_newcounters;
+
+       /* Put counters back. */
+       strcpy(newcounters->name, (*handle)->info.name);
+       newcounters->num_counters = new_number;
+
+       list_for_each_entry(c, &(*handle)->chains, list) {
+               struct rule_head *r;
+
+               /* Builtin chains have their own counters */
+               if (iptcc_is_builtin(c)) {
+                       DEBUGP("counter for chain-index %u: ", c->foot_index);
+                       switch(c->counter_map.maptype) {
+                       case COUNTER_MAP_NOMAP:
+                               counters_nomap(newcounters, c->foot_index);
+                               break;
+                       case COUNTER_MAP_NORMAL_MAP:
+                               counters_normal_map(newcounters, repl,
+                                                   c->foot_index, 
+                                                   c->counter_map.mappos);
+                               break;
+                       case COUNTER_MAP_ZEROED:
+                               counters_map_zeroed(newcounters, repl,
+                                                   c->foot_index, 
+                                                   c->counter_map.mappos,
+                                                   &c->counters);
+                               break;
+                       case COUNTER_MAP_SET:
+                               counters_map_set(newcounters, c->foot_index,
+                                                &c->counters);
+                               break;
+                       }
+               }
+
+               list_for_each_entry(r, &c->rules, list) {
+                       DEBUGP("counter for index %u: ", r->index);
+                       switch (r->counter_map.maptype) {
+                       case COUNTER_MAP_NOMAP:
+                               counters_nomap(newcounters, r->index);
+                               break;
+
+                       case COUNTER_MAP_NORMAL_MAP:
+                               counters_normal_map(newcounters, repl,
+                                                   r->index, 
+                                                   r->counter_map.mappos);
+                               break;
+
+                       case COUNTER_MAP_ZEROED:
+                               counters_map_zeroed(newcounters, repl,
+                                                   r->index,
+                                                   r->counter_map.mappos,
+                                                   &r->entry->counters);
+                               break;
+
+                       case COUNTER_MAP_SET:
+                               counters_map_set(newcounters, r->index,
+                                                &r->entry->counters);
+                               break;
+                       }
+               }
+       }
+
+
+#ifdef KERNEL_64_USERSPACE_32
+       {
+               /* Kernel will think that pointer should be 64-bits, and get
+                  padding.  So we accomodate here (assumption: alignment of
+                  `counters' is on 64-bit boundary). */
+               u_int64_t *kernptr = (u_int64_t *)&newcounters->counters;
+               if ((unsigned long)&newcounters->counters % 8 != 0) {
+                       fprintf(stderr,
+                               "counters alignment incorrect! Mail rusty!\n");
+                       abort();
+               }
+               *kernptr = newcounters->counters;
+       }
+#endif /* KERNEL_64_USERSPACE_32 */
+
+#ifdef IPTC_DEBUG2
+       {
+               int fd = open("/tmp/libiptc-so_set_add_counters.blob", 
+                               O_CREAT|O_WRONLY);
+               if (fd >= 0) {
+                       write(fd, newcounters, counterlen);
+                       close(fd);
+               }
+       }
+#endif
+
+       ret = setsockopt(sockfd, TC_IPPROTO, SO_SET_ADD_COUNTERS,
+                        newcounters, counterlen);
+       if (ret < 0)
+               goto out_free_newcounters;
+
+       free(repl->counters);
+       free(repl);
+       free(newcounters);
+
+finished:
+       TC_FREE(handle);
+       return 1;
+
+out_free_newcounters:
+       free(newcounters);
+out_free_repl_counters:
+       free(repl->counters);
+out_free_repl:
+       free(repl);
+out_zero:
+       return 0;
+}
+
+/* Get raw socket. */
+int
+TC_GET_RAW_SOCKET()
+{
+       return sockfd;
+}
+
+/* Translates errno numbers into more human-readable form than strerror. */
+const char *
+TC_STRERROR(int err)
+{
+       unsigned int i;
+       struct table_struct {
+               void *fn;
+               int err;
+               const char *message;
+       } table [] =
+         { { TC_INIT, EPERM, "Permission denied (you must be root)" },
+           { TC_INIT, EINVAL, "Module is wrong version" },
+           { TC_INIT, ENOENT, 
+                   "Table does not exist (do you need to insmod?)" },
+           { TC_DELETE_CHAIN, ENOTEMPTY, "Chain is not empty" },
+           { TC_DELETE_CHAIN, EINVAL, "Can't delete built-in chain" },
+           { TC_DELETE_CHAIN, EMLINK,
+             "Can't delete chain with references left" },
+           { TC_CREATE_CHAIN, EEXIST, "Chain already exists" },
+           { TC_INSERT_ENTRY, E2BIG, "Index of insertion too big" },
+           { TC_REPLACE_ENTRY, E2BIG, "Index of replacement too big" },
+           { TC_DELETE_NUM_ENTRY, E2BIG, "Index of deletion too big" },
+           { TC_READ_COUNTER, E2BIG, "Index of counter too big" },
+           { TC_ZERO_COUNTER, E2BIG, "Index of counter too big" },
+           { TC_INSERT_ENTRY, ELOOP, "Loop found in table" },
+           { TC_INSERT_ENTRY, EINVAL, "Target problem" },
+           /* EINVAL for CHECK probably means bad interface. */
+           { TC_CHECK_PACKET, EINVAL,
+             "Bad arguments (does that interface exist?)" },
+           { TC_CHECK_PACKET, ENOSYS,
+             "Checking will most likely never get implemented" },
+           /* ENOENT for DELETE probably means no matching rule */
+           { TC_DELETE_ENTRY, ENOENT,
+             "Bad rule (does a matching rule exist in that chain?)" },
+           { TC_SET_POLICY, ENOENT,
+             "Bad built-in chain name" },
+           { TC_SET_POLICY, EINVAL,
+             "Bad policy name" },
+
+           { NULL, 0, "Incompatible with this kernel" },
+           { NULL, ENOPROTOOPT, "iptables who? (do you need to insmod?)" },
+           { NULL, ENOSYS, "Will be implemented real soon.  I promise ;)" },
+           { NULL, ENOMEM, "Memory allocation problem" },
+           { NULL, ENOENT, "No chain/target/match by that name" },
+         };
+
+       for (i = 0; i < sizeof(table)/sizeof(struct table_struct); i++) {
+               if ((!table[i].fn || table[i].fn == iptc_fn)
+                   && table[i].err == err)
+                       return table[i].message;
+       }
+
+       return strerror(err);
+}
diff --git a/src/libiptc/libiptc.h b/src/libiptc/libiptc.h
new file mode 100644 (file)
index 0000000..50765d9
--- /dev/null
@@ -0,0 +1,166 @@
+#ifndef _LIBIPTC_H
+#define _LIBIPTC_H
+/* Library which manipulates filtering rules. */
+
+#include <libiptc/ipt_kernel_headers.h>
+#include <linux/netfilter_ipv4/ip_tables.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#ifndef IPT_MIN_ALIGN
+/* ipt_entry has pointers and u_int64_t's in it, so if you align to
+   it, you'll also align to any crazy matches and targets someone
+   might write */
+#define IPT_MIN_ALIGN (__alignof__(struct ipt_entry))
+#endif
+
+#define IPT_ALIGN(s) (((s) + ((IPT_MIN_ALIGN)-1)) & ~((IPT_MIN_ALIGN)-1))
+
+typedef char ipt_chainlabel[32];
+
+#define IPTC_LABEL_ACCEPT  "ACCEPT"
+#define IPTC_LABEL_DROP    "DROP"
+#define IPTC_LABEL_QUEUE   "QUEUE"
+#define IPTC_LABEL_RETURN  "RETURN"
+
+/* Transparent handle type. */
+typedef struct iptc_handle *iptc_handle_t;
+
+/* Does this chain exist? */
+int iptc_is_chain(const char *chain, const iptc_handle_t handle);
+
+/* Take a snapshot of the rules.  Returns NULL on error. */
+iptc_handle_t iptc_init(const char *tablename);
+
+/* Cleanup after iptc_init(). */
+void iptc_free(iptc_handle_t *h);
+
+/* Iterator functions to run through the chains.  Returns NULL at end. */
+const char *iptc_first_chain(iptc_handle_t *handle);
+const char *iptc_next_chain(iptc_handle_t *handle);
+
+/* Get first rule in the given chain: NULL for empty chain. */
+const struct ipt_entry *iptc_first_rule(const char *chain,
+                                       iptc_handle_t *handle);
+
+/* Returns NULL when rules run out. */
+const struct ipt_entry *iptc_next_rule(const struct ipt_entry *prev,
+                                      iptc_handle_t *handle);
+
+/* Returns a pointer to the target name of this entry. */
+const char *iptc_get_target(const struct ipt_entry *e,
+                           iptc_handle_t *handle);
+
+/* Is this a built-in chain? */
+int iptc_builtin(const char *chain, const iptc_handle_t handle);
+
+/* Get the policy of a given built-in chain */
+const char *iptc_get_policy(const char *chain,
+                           struct ipt_counters *counter,
+                           iptc_handle_t *handle);
+
+/* These functions return TRUE for OK or 0 and set errno.  If errno ==
+   0, it means there was a version error (ie. upgrade libiptc). */
+/* Rule numbers start at 1 for the first rule. */
+
+/* Insert the entry `e' in chain `chain' into position `rulenum'. */
+int iptc_insert_entry(const ipt_chainlabel chain,
+                     const struct ipt_entry *e,
+                     unsigned int rulenum,
+                     iptc_handle_t *handle);
+
+/* Atomically replace rule `rulenum' in `chain' with `e'. */
+int iptc_replace_entry(const ipt_chainlabel chain,
+                      const struct ipt_entry *e,
+                      unsigned int rulenum,
+                      iptc_handle_t *handle);
+
+/* Append entry `e' to chain `chain'.  Equivalent to insert with
+   rulenum = length of chain. */
+int iptc_append_entry(const ipt_chainlabel chain,
+                     const struct ipt_entry *e,
+                     iptc_handle_t *handle);
+
+/* Delete the first rule in `chain' which matches `e', subject to
+   matchmask (array of length == origfw) */
+int iptc_delete_entry(const ipt_chainlabel chain,
+                     const struct ipt_entry *origfw,
+                     unsigned char *matchmask,
+                     iptc_handle_t *handle);
+
+/* Delete the rule in position `rulenum' in `chain'. */
+int iptc_delete_num_entry(const ipt_chainlabel chain,
+                         unsigned int rulenum,
+                         iptc_handle_t *handle);
+
+/* Check the packet `e' on chain `chain'.  Returns the verdict, or
+   NULL and sets errno. */
+const char *iptc_check_packet(const ipt_chainlabel chain,
+                             struct ipt_entry *entry,
+                             iptc_handle_t *handle);
+
+/* Flushes the entries in the given chain (ie. empties chain). */
+int iptc_flush_entries(const ipt_chainlabel chain,
+                      iptc_handle_t *handle);
+
+/* Zeroes the counters in a chain. */
+int iptc_zero_entries(const ipt_chainlabel chain,
+                     iptc_handle_t *handle);
+
+/* Creates a new chain. */
+int iptc_create_chain(const ipt_chainlabel chain,
+                     iptc_handle_t *handle);
+
+/* Deletes a chain. */
+int iptc_delete_chain(const ipt_chainlabel chain,
+                     iptc_handle_t *handle);
+
+/* Renames a chain. */
+int iptc_rename_chain(const ipt_chainlabel oldname,
+                     const ipt_chainlabel newname,
+                     iptc_handle_t *handle);
+
+/* Sets the policy on a built-in chain. */
+int iptc_set_policy(const ipt_chainlabel chain,
+                   const ipt_chainlabel policy,
+                   struct ipt_counters *counters,
+                   iptc_handle_t *handle);
+
+/* Get the number of references to this chain */
+int iptc_get_references(unsigned int *ref,
+                       const ipt_chainlabel chain,
+                       iptc_handle_t *handle);
+
+/* read packet and byte counters for a specific rule */
+struct ipt_counters *iptc_read_counter(const ipt_chainlabel chain,
+                                      unsigned int rulenum,
+                                      iptc_handle_t *handle);
+
+/* zero packet and byte counters for a specific rule */
+int iptc_zero_counter(const ipt_chainlabel chain,
+                     unsigned int rulenum,
+                     iptc_handle_t *handle);
+
+/* set packet and byte counters for a specific rule */
+int iptc_set_counter(const ipt_chainlabel chain,
+                    unsigned int rulenum,
+                    struct ipt_counters *counters,
+                    iptc_handle_t *handle);
+
+/* Makes the actual changes. */
+int iptc_commit(iptc_handle_t *handle);
+
+/* Get raw socket. */
+int iptc_get_raw_socket();
+
+/* Translates errno numbers into more human-readable form than strerror. */
+const char *iptc_strerror(int err);
+
+#ifdef __cplusplus
+}
+#endif
+
+
+#endif /* _LIBIPTC_H */
diff --git a/src/libiptc/linux_list.h b/src/libiptc/linux_list.h
new file mode 100644 (file)
index 0000000..abdcf88
--- /dev/null
@@ -0,0 +1,723 @@
+#ifndef _LINUX_LIST_H
+#define _LINUX_LIST_H
+
+#undef offsetof
+#define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER)
+
+/**
+ * container_of - cast a member of a structure out to the containing structure
+ *
+ * @ptr:       the pointer to the member.
+ * @type:      the type of the container struct this is embedded in.
+ * @member:    the name of the member within the struct.
+ *
+ */
+#define container_of(ptr, type, member) ({                     \
+        const typeof( ((type *)0)->member ) *__mptr = (ptr);   \
+        (type *)( (char *)__mptr - offsetof(type,member) );})
+
+/*
+ * Check at compile time that something is of a particular type.
+ * Always evaluates to 1 so you may use it easily in comparisons.
+ */
+#define typecheck(type,x) \
+({     type __dummy; \
+       typeof(x) __dummy2; \
+       (void)(&__dummy == &__dummy2); \
+       1; \
+})
+
+#define prefetch(x)            1
+
+/* empty define to make this work in userspace -HW */
+#define smp_wmb()
+
+/*
+ * These are non-NULL pointers that will result in page faults
+ * under normal circumstances, used to verify that nobody uses
+ * non-initialized list entries.
+ */
+#define LIST_POISON1  ((void *) 0x00100100)
+#define LIST_POISON2  ((void *) 0x00200200)
+
+/*
+ * Simple doubly linked list implementation.
+ *
+ * Some of the internal functions ("__xxx") are useful when
+ * manipulating whole lists rather than single entries, as
+ * sometimes we already know the next/prev entries and we can
+ * generate better code by using them directly rather than
+ * using the generic single-entry routines.
+ */
+
+struct list_head {
+       struct list_head *next, *prev;
+};
+
+#define LIST_HEAD_INIT(name) { &(name), &(name) }
+
+#define LIST_HEAD(name) \
+       struct list_head name = LIST_HEAD_INIT(name)
+
+#define INIT_LIST_HEAD(ptr) do { \
+       (ptr)->next = (ptr); (ptr)->prev = (ptr); \
+} while (0)
+
+/*
+ * Insert a new entry between two known consecutive entries.
+ *
+ * This is only for internal list manipulation where we know
+ * the prev/next entries already!
+ */
+static inline void __list_add(struct list_head *new,
+                             struct list_head *prev,
+                             struct list_head *next)
+{
+       next->prev = new;
+       new->next = next;
+       new->prev = prev;
+       prev->next = new;
+}
+
+/**
+ * list_add - add a new entry
+ * @new: new entry to be added
+ * @head: list head to add it after
+ *
+ * Insert a new entry after the specified head.
+ * This is good for implementing stacks.
+ */
+static inline void list_add(struct list_head *new, struct list_head *head)
+{
+       __list_add(new, head, head->next);
+}
+
+/**
+ * list_add_tail - add a new entry
+ * @new: new entry to be added
+ * @head: list head to add it before
+ *
+ * Insert a new entry before the specified head.
+ * This is useful for implementing queues.
+ */
+static inline void list_add_tail(struct list_head *new, struct list_head *head)
+{
+       __list_add(new, head->prev, head);
+}
+
+/*
+ * Insert a new entry between two known consecutive entries.
+ *
+ * This is only for internal list manipulation where we know
+ * the prev/next entries already!
+ */
+static inline void __list_add_rcu(struct list_head * new,
+               struct list_head * prev, struct list_head * next)
+{
+       new->next = next;
+       new->prev = prev;
+       smp_wmb();
+       next->prev = new;
+       prev->next = new;
+}
+
+/**
+ * list_add_rcu - add a new entry to rcu-protected list
+ * @new: new entry to be added
+ * @head: list head to add it after
+ *
+ * Insert a new entry after the specified head.
+ * This is good for implementing stacks.
+ *
+ * The caller must take whatever precautions are necessary
+ * (such as holding appropriate locks) to avoid racing
+ * with another list-mutation primitive, such as list_add_rcu()
+ * or list_del_rcu(), running on this same list.
+ * However, it is perfectly legal to run concurrently with
+ * the _rcu list-traversal primitives, such as
+ * list_for_each_entry_rcu().
+ */
+static inline void list_add_rcu(struct list_head *new, struct list_head *head)
+{
+       __list_add_rcu(new, head, head->next);
+}
+
+/**
+ * list_add_tail_rcu - add a new entry to rcu-protected list
+ * @new: new entry to be added
+ * @head: list head to add it before
+ *
+ * Insert a new entry before the specified head.
+ * This is useful for implementing queues.
+ *
+ * The caller must take whatever precautions are necessary
+ * (such as holding appropriate locks) to avoid racing
+ * with another list-mutation primitive, such as list_add_tail_rcu()
+ * or list_del_rcu(), running on this same list.
+ * However, it is perfectly legal to run concurrently with
+ * the _rcu list-traversal primitives, such as
+ * list_for_each_entry_rcu().
+ */
+static inline void list_add_tail_rcu(struct list_head *new,
+                                       struct list_head *head)
+{
+       __list_add_rcu(new, head->prev, head);
+}
+
+/*
+ * Delete a list entry by making the prev/next entries
+ * point to each other.
+ *
+ * This is only for internal list manipulation where we know
+ * the prev/next entries already!
+ */
+static inline void __list_del(struct list_head * prev, struct list_head * next)
+{
+       next->prev = prev;
+       prev->next = next;
+}
+
+/**
+ * list_del - deletes entry from list.
+ * @entry: the element to delete from the list.
+ * Note: list_empty on entry does not return true after this, the entry is
+ * in an undefined state.
+ */
+static inline void list_del(struct list_head *entry)
+{
+       __list_del(entry->prev, entry->next);
+       entry->next = LIST_POISON1;
+       entry->prev = LIST_POISON2;
+}
+
+/**
+ * list_del_rcu - deletes entry from list without re-initialization
+ * @entry: the element to delete from the list.
+ *
+ * Note: list_empty on entry does not return true after this,
+ * the entry is in an undefined state. It is useful for RCU based
+ * lockfree traversal.
+ *
+ * In particular, it means that we can not poison the forward
+ * pointers that may still be used for walking the list.
+ *
+ * The caller must take whatever precautions are necessary
+ * (such as holding appropriate locks) to avoid racing
+ * with another list-mutation primitive, such as list_del_rcu()
+ * or list_add_rcu(), running on this same list.
+ * However, it is perfectly legal to run concurrently with
+ * the _rcu list-traversal primitives, such as
+ * list_for_each_entry_rcu().
+ *
+ * Note that the caller is not permitted to immediately free
+ * the newly deleted entry.  Instead, either synchronize_kernel()
+ * or call_rcu() must be used to defer freeing until an RCU
+ * grace period has elapsed.
+ */
+static inline void list_del_rcu(struct list_head *entry)
+{
+       __list_del(entry->prev, entry->next);
+       entry->prev = LIST_POISON2;
+}
+
+/**
+ * list_del_init - deletes entry from list and reinitialize it.
+ * @entry: the element to delete from the list.
+ */
+static inline void list_del_init(struct list_head *entry)
+{
+       __list_del(entry->prev, entry->next);
+       INIT_LIST_HEAD(entry);
+}
+
+/**
+ * list_move - delete from one list and add as another's head
+ * @list: the entry to move
+ * @head: the head that will precede our entry
+ */
+static inline void list_move(struct list_head *list, struct list_head *head)
+{
+        __list_del(list->prev, list->next);
+        list_add(list, head);
+}
+
+/**
+ * list_move_tail - delete from one list and add as another's tail
+ * @list: the entry to move
+ * @head: the head that will follow our entry
+ */
+static inline void list_move_tail(struct list_head *list,
+                                 struct list_head *head)
+{
+        __list_del(list->prev, list->next);
+        list_add_tail(list, head);
+}
+
+/**
+ * list_empty - tests whether a list is empty
+ * @head: the list to test.
+ */
+static inline int list_empty(const struct list_head *head)
+{
+       return head->next == head;
+}
+
+/**
+ * list_empty_careful - tests whether a list is
+ * empty _and_ checks that no other CPU might be
+ * in the process of still modifying either member
+ *
+ * NOTE: using list_empty_careful() without synchronization
+ * can only be safe if the only activity that can happen
+ * to the list entry is list_del_init(). Eg. it cannot be used
+ * if another CPU could re-list_add() it.
+ *
+ * @head: the list to test.
+ */
+static inline int list_empty_careful(const struct list_head *head)
+{
+       struct list_head *next = head->next;
+       return (next == head) && (next == head->prev);
+}
+
+static inline void __list_splice(struct list_head *list,
+                                struct list_head *head)
+{
+       struct list_head *first = list->next;
+       struct list_head *last = list->prev;
+       struct list_head *at = head->next;
+
+       first->prev = head;
+       head->next = first;
+
+       last->next = at;
+       at->prev = last;
+}
+
+/**
+ * list_splice - join two lists
+ * @list: the new list to add.
+ * @head: the place to add it in the first list.
+ */
+static inline void list_splice(struct list_head *list, struct list_head *head)
+{
+       if (!list_empty(list))
+               __list_splice(list, head);
+}
+
+/**
+ * list_splice_init - join two lists and reinitialise the emptied list.
+ * @list: the new list to add.
+ * @head: the place to add it in the first list.
+ *
+ * The list at @list is reinitialised
+ */
+static inline void list_splice_init(struct list_head *list,
+                                   struct list_head *head)
+{
+       if (!list_empty(list)) {
+               __list_splice(list, head);
+               INIT_LIST_HEAD(list);
+       }
+}
+
+/**
+ * list_entry - get the struct for this entry
+ * @ptr:       the &struct list_head pointer.
+ * @type:      the type of the struct this is embedded in.
+ * @member:    the name of the list_struct within the struct.
+ */
+#define list_entry(ptr, type, member) \
+       container_of(ptr, type, member)
+
+/**
+ * list_for_each       -       iterate over a list
+ * @pos:       the &struct list_head to use as a loop counter.
+ * @head:      the head for your list.
+ */
+#define list_for_each(pos, head) \
+       for (pos = (head)->next, prefetch(pos->next); pos != (head); \
+               pos = pos->next, prefetch(pos->next))
+
+/**
+ * __list_for_each     -       iterate over a list
+ * @pos:       the &struct list_head to use as a loop counter.
+ * @head:      the head for your list.
+ *
+ * This variant differs from list_for_each() in that it's the
+ * simplest possible list iteration code, no prefetching is done.
+ * Use this for code that knows the list to be very short (empty
+ * or 1 entry) most of the time.
+ */
+#define __list_for_each(pos, head) \
+       for (pos = (head)->next; pos != (head); pos = pos->next)
+
+/**
+ * list_for_each_prev  -       iterate over a list backwards
+ * @pos:       the &struct list_head to use as a loop counter.
+ * @head:      the head for your list.
+ */
+#define list_for_each_prev(pos, head) \
+       for (pos = (head)->prev, prefetch(pos->prev); pos != (head); \
+               pos = pos->prev, prefetch(pos->prev))
+
+/**
+ * list_for_each_safe  -       iterate over a list safe against removal of list entry
+ * @pos:       the &struct list_head to use as a loop counter.
+ * @n:         another &struct list_head to use as temporary storage
+ * @head:      the head for your list.
+ */
+#define list_for_each_safe(pos, n, head) \
+       for (pos = (head)->next, n = pos->next; pos != (head); \
+               pos = n, n = pos->next)
+
+/**
+ * list_for_each_entry -       iterate over list of given type
+ * @pos:       the type * to use as a loop counter.
+ * @head:      the head for your list.
+ * @member:    the name of the list_struct within the struct.
+ */
+#define list_for_each_entry(pos, head, member)                         \
+       for (pos = list_entry((head)->next, typeof(*pos), member),      \
+                    prefetch(pos->member.next);                        \
+            &pos->member != (head);                                    \
+            pos = list_entry(pos->member.next, typeof(*pos), member),  \
+                    prefetch(pos->member.next))
+
+/**
+ * list_for_each_entry_reverse - iterate backwards over list of given type.
+ * @pos:       the type * to use as a loop counter.
+ * @head:      the head for your list.
+ * @member:    the name of the list_struct within the struct.
+ */
+#define list_for_each_entry_reverse(pos, head, member)                 \
+       for (pos = list_entry((head)->prev, typeof(*pos), member),      \
+                    prefetch(pos->member.prev);                        \
+            &pos->member != (head);                                    \
+            pos = list_entry(pos->member.prev, typeof(*pos), member),  \
+                    prefetch(pos->member.prev))
+
+/**
+ * list_prepare_entry - prepare a pos entry for use as a start point in
+ *                     list_for_each_entry_continue
+ * @pos:       the type * to use as a start point
+ * @head:      the head of the list
+ * @member:    the name of the list_struct within the struct.
+ */
+#define list_prepare_entry(pos, head, member) \
+       ((pos) ? : list_entry(head, typeof(*pos), member))
+
+/**
+ * list_for_each_entry_continue -      iterate over list of given type
+ *                     continuing after existing point
+ * @pos:       the type * to use as a loop counter.
+ * @head:      the head for your list.
+ * @member:    the name of the list_struct within the struct.
+ */
+#define list_for_each_entry_continue(pos, head, member)                \
+       for (pos = list_entry(pos->member.next, typeof(*pos), member),  \
+                    prefetch(pos->member.next);                        \
+            &pos->member != (head);                                    \
+            pos = list_entry(pos->member.next, typeof(*pos), member),  \
+                    prefetch(pos->member.next))
+
+/**
+ * list_for_each_entry_safe - iterate over list of given type safe against removal of list entry
+ * @pos:       the type * to use as a loop counter.
+ * @n:         another type * to use as temporary storage
+ * @head:      the head for your list.
+ * @member:    the name of the list_struct within the struct.
+ */
+#define list_for_each_entry_safe(pos, n, head, member)                 \
+       for (pos = list_entry((head)->next, typeof(*pos), member),      \
+               n = list_entry(pos->member.next, typeof(*pos), member); \
+            &pos->member != (head);                                    \
+            pos = n, n = list_entry(n->member.next, typeof(*n), member))
+
+/**
+ * list_for_each_rcu   -       iterate over an rcu-protected list
+ * @pos:       the &struct list_head to use as a loop counter.
+ * @head:      the head for your list.
+ *
+ * This list-traversal primitive may safely run concurrently with
+ * the _rcu list-mutation primitives such as list_add_rcu()
+ * as long as the traversal is guarded by rcu_read_lock().
+ */
+#define list_for_each_rcu(pos, head) \
+       for (pos = (head)->next, prefetch(pos->next); pos != (head); \
+               pos = pos->next, ({ smp_read_barrier_depends(); 0;}), prefetch(pos->next))
+
+#define __list_for_each_rcu(pos, head) \
+       for (pos = (head)->next; pos != (head); \
+               pos = pos->next, ({ smp_read_barrier_depends(); 0;}))
+
+/**
+ * list_for_each_safe_rcu      -       iterate over an rcu-protected list safe
+ *                                     against removal of list entry
+ * @pos:       the &struct list_head to use as a loop counter.
+ * @n:         another &struct list_head to use as temporary storage
+ * @head:      the head for your list.
+ *
+ * This list-traversal primitive may safely run concurrently with
+ * the _rcu list-mutation primitives such as list_add_rcu()
+ * as long as the traversal is guarded by rcu_read_lock().
+ */
+#define list_for_each_safe_rcu(pos, n, head) \
+       for (pos = (head)->next, n = pos->next; pos != (head); \
+               pos = n, ({ smp_read_barrier_depends(); 0;}), n = pos->next)
+
+/**
+ * list_for_each_entry_rcu     -       iterate over rcu list of given type
+ * @pos:       the type * to use as a loop counter.
+ * @head:      the head for your list.
+ * @member:    the name of the list_struct within the struct.
+ *
+ * This list-traversal primitive may safely run concurrently with
+ * the _rcu list-mutation primitives such as list_add_rcu()
+ * as long as the traversal is guarded by rcu_read_lock().
+ */
+#define list_for_each_entry_rcu(pos, head, member)                     \
+       for (pos = list_entry((head)->next, typeof(*pos), member),      \
+                    prefetch(pos->member.next);                        \
+            &pos->member != (head);                                    \
+            pos = list_entry(pos->member.next, typeof(*pos), member),  \
+                    ({ smp_read_barrier_depends(); 0;}),               \
+                    prefetch(pos->member.next))
+
+
+/**
+ * list_for_each_continue_rcu  -       iterate over an rcu-protected list
+ *                     continuing after existing point.
+ * @pos:       the &struct list_head to use as a loop counter.
+ * @head:      the head for your list.
+ *
+ * This list-traversal primitive may safely run concurrently with
+ * the _rcu list-mutation primitives such as list_add_rcu()
+ * as long as the traversal is guarded by rcu_read_lock().
+ */
+#define list_for_each_continue_rcu(pos, head) \
+       for ((pos) = (pos)->next, prefetch((pos)->next); (pos) != (head); \
+               (pos) = (pos)->next, ({ smp_read_barrier_depends(); 0;}), prefetch((pos)->next))
+
+/*
+ * Double linked lists with a single pointer list head.
+ * Mostly useful for hash tables where the two pointer list head is
+ * too wasteful.
+ * You lose the ability to access the tail in O(1).
+ */
+
+struct hlist_head {
+       struct hlist_node *first;
+};
+
+struct hlist_node {
+       struct hlist_node *next, **pprev;
+};
+
+#define HLIST_HEAD_INIT { .first = NULL }
+#define HLIST_HEAD(name) struct hlist_head name = {  .first = NULL }
+#define INIT_HLIST_HEAD(ptr) ((ptr)->first = NULL)
+#define INIT_HLIST_NODE(ptr) ((ptr)->next = NULL, (ptr)->pprev = NULL)
+
+static inline int hlist_unhashed(const struct hlist_node *h)
+{
+       return !h->pprev;
+}
+
+static inline int hlist_empty(const struct hlist_head *h)
+{
+       return !h->first;
+}
+
+static inline void __hlist_del(struct hlist_node *n)
+{
+       struct hlist_node *next = n->next;
+       struct hlist_node **pprev = n->pprev;
+       *pprev = next;
+       if (next)
+               next->pprev = pprev;
+}
+
+static inline void hlist_del(struct hlist_node *n)
+{
+       __hlist_del(n);
+       n->next = LIST_POISON1;
+       n->pprev = LIST_POISON2;
+}
+
+/**
+ * hlist_del_rcu - deletes entry from hash list without re-initialization
+ * @n: the element to delete from the hash list.
+ *
+ * Note: list_unhashed() on entry does not return true after this,
+ * the entry is in an undefined state. It is useful for RCU based
+ * lockfree traversal.
+ *
+ * In particular, it means that we can not poison the forward
+ * pointers that may still be used for walking the hash list.
+ *
+ * The caller must take whatever precautions are necessary
+ * (such as holding appropriate locks) to avoid racing
+ * with another list-mutation primitive, such as hlist_add_head_rcu()
+ * or hlist_del_rcu(), running on this same list.
+ * However, it is perfectly legal to run concurrently with
+ * the _rcu list-traversal primitives, such as
+ * hlist_for_each_entry().
+ */
+static inline void hlist_del_rcu(struct hlist_node *n)
+{
+       __hlist_del(n);
+       n->pprev = LIST_POISON2;
+}
+
+static inline void hlist_del_init(struct hlist_node *n)
+{
+       if (n->pprev)  {
+               __hlist_del(n);
+               INIT_HLIST_NODE(n);
+       }
+}
+
+#define hlist_del_rcu_init hlist_del_init
+
+static inline void hlist_add_head(struct hlist_node *n, struct hlist_head *h)
+{
+       struct hlist_node *first = h->first;
+       n->next = first;
+       if (first)
+               first->pprev = &n->next;
+       h->first = n;
+       n->pprev = &h->first;
+}
+
+
+/**
+ * hlist_add_head_rcu - adds the specified element to the specified hlist,
+ * while permitting racing traversals.
+ * @n: the element to add to the hash list.
+ * @h: the list to add to.
+ *
+ * The caller must take whatever precautions are necessary
+ * (such as holding appropriate locks) to avoid racing
+ * with another list-mutation primitive, such as hlist_add_head_rcu()
+ * or hlist_del_rcu(), running on this same list.
+ * However, it is perfectly legal to run concurrently with
+ * the _rcu list-traversal primitives, such as
+ * hlist_for_each_entry(), but only if smp_read_barrier_depends()
+ * is used to prevent memory-consistency problems on Alpha CPUs.
+ * Regardless of the type of CPU, the list-traversal primitive
+ * must be guarded by rcu_read_lock().
+ *
+ * OK, so why don't we have an hlist_for_each_entry_rcu()???
+ */
+static inline void hlist_add_head_rcu(struct hlist_node *n,
+                                       struct hlist_head *h)
+{
+       struct hlist_node *first = h->first;
+       n->next = first;
+       n->pprev = &h->first;
+       smp_wmb();
+       if (first)
+               first->pprev = &n->next;
+       h->first = n;
+}
+
+/* next must be != NULL */
+static inline void hlist_add_before(struct hlist_node *n,
+                                       struct hlist_node *next)
+{
+       n->pprev = next->pprev;
+       n->next = next;
+       next->pprev = &n->next;
+       *(n->pprev) = n;
+}
+
+static inline void hlist_add_after(struct hlist_node *n,
+                                       struct hlist_node *next)
+{
+       next->next = n->next;
+       n->next = next;
+       next->pprev = &n->next;
+
+       if(next->next)
+               next->next->pprev  = &next->next;
+}
+
+#define hlist_entry(ptr, type, member) container_of(ptr,type,member)
+
+#define hlist_for_each(pos, head) \
+       for (pos = (head)->first; pos && ({ prefetch(pos->next); 1; }); \
+            pos = pos->next)
+
+#define hlist_for_each_safe(pos, n, head) \
+       for (pos = (head)->first; pos && ({ n = pos->next; 1; }); \
+            pos = n)
+
+/**
+ * hlist_for_each_entry        - iterate over list of given type
+ * @tpos:      the type * to use as a loop counter.
+ * @pos:       the &struct hlist_node to use as a loop counter.
+ * @head:      the head for your list.
+ * @member:    the name of the hlist_node within the struct.
+ */
+#define hlist_for_each_entry(tpos, pos, head, member)                   \
+       for (pos = (head)->first;                                        \
+            pos && ({ prefetch(pos->next); 1;}) &&                      \
+               ({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); \
+            pos = pos->next)
+
+/**
+ * hlist_for_each_entry_continue - iterate over a hlist continuing after existing point
+ * @tpos:      the type * to use as a loop counter.
+ * @pos:       the &struct hlist_node to use as a loop counter.
+ * @member:    the name of the hlist_node within the struct.
+ */
+#define hlist_for_each_entry_continue(tpos, pos, member)                \
+       for (pos = (pos)->next;                                          \
+            pos && ({ prefetch(pos->next); 1;}) &&                      \
+               ({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); \
+            pos = pos->next)
+
+/**
+ * hlist_for_each_entry_from - iterate over a hlist continuing from existing point
+ * @tpos:      the type * to use as a loop counter.
+ * @pos:       the &struct hlist_node to use as a loop counter.
+ * @member:    the name of the hlist_node within the struct.
+ */
+#define hlist_for_each_entry_from(tpos, pos, member)                    \
+       for (; pos && ({ prefetch(pos->next); 1;}) &&                    \
+               ({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); \
+            pos = pos->next)
+
+/**
+ * hlist_for_each_entry_safe - iterate over list of given type safe against removal of list entry
+ * @tpos:      the type * to use as a loop counter.
+ * @pos:       the &struct hlist_node to use as a loop counter.
+ * @n:         another &struct hlist_node to use as temporary storage
+ * @head:      the head for your list.
+ * @member:    the name of the hlist_node within the struct.
+ */
+#define hlist_for_each_entry_safe(tpos, pos, n, head, member)           \
+       for (pos = (head)->first;                                        \
+            pos && ({ n = pos->next; 1; }) &&                           \
+               ({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); \
+            pos = n)
+
+/**
+ * hlist_for_each_entry_rcu - iterate over rcu list of given type
+ * @pos:       the type * to use as a loop counter.
+ * @pos:       the &struct hlist_node to use as a loop counter.
+ * @head:      the head for your list.
+ * @member:    the name of the hlist_node within the struct.
+ *
+ * This list-traversal primitive may safely run concurrently with
+ * the _rcu list-mutation primitives such as hlist_add_rcu()
+ * as long as the traversal is guarded by rcu_read_lock().
+ */
+#define hlist_for_each_entry_rcu(tpos, pos, head, member)               \
+       for (pos = (head)->first;                                        \
+            pos && ({ prefetch(pos->next); 1;}) &&                      \
+               ({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); \
+            pos = pos->next, ({ smp_read_barrier_depends(); 0; }) )
+
+#endif
diff --git a/src/libiptc/linux_stddef.h b/src/libiptc/linux_stddef.h
new file mode 100644 (file)
index 0000000..56416f1
--- /dev/null
@@ -0,0 +1,39 @@
+#ifndef _LINUX_STDDEF_H
+#define _LINUX_STDDEF_H
+
+#undef NULL
+#if defined(__cplusplus)
+#define NULL 0
+#else
+#define NULL ((void *)0)
+#endif
+
+#undef offsetof
+#define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER)
+
+
+/**
+ * container_of - cast a member of a structure out to the containing structure
+ *
+ * @ptr:       the pointer to the member.
+ * @type:      the type of the container struct this is embedded in.
+ * @member:    the name of the member within the struct.
+ *
+ */
+#define container_of(ptr, type, member) ({                     \
+        const typeof( ((type *)0)->member ) *__mptr = (ptr);   \
+        (type *)( (char *)__mptr - offsetof(type,member) );})
+
+/*
+ * Check at compile time that something is of a particular type.
+ * Always evaluates to 1 so you may use it easily in comparisons.
+ */
+#define typecheck(type,x) \
+({     type __dummy; \
+       typeof(x) __dummy2; \
+       (void)(&__dummy == &__dummy2); \
+       1; \
+})
+
+
+#endif