Merge branch 'collectd-4.0' into collectd-4.1
[collectd.git] / src / ntpd.c
index eb871e1..63b037a 100644 (file)
@@ -1,6 +1,6 @@
 /**
  * collectd - src/ntpd.c
- * Copyright (C) 2006  Florian octo Forster
+ * Copyright (C) 2006-2007  Florian octo Forster
  *
  * 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
 #include "plugin.h"
 #include "configfile.h"
 
-#include "ntp_request.h"
-
-#define MODULE_NAME "ntpd"
-
-#if HAVE_SYS_SOCKET_H
-# define NTPD_HAVE_READ 1
-#else
-# define NTPD_HAVE_READ 0
+#if HAVE_STDINT_H
+# include <stdint.h>
 #endif
-
 #if HAVE_NETDB_H
 # include <netdb.h>
 #endif
 #if HAVE_NETINET_IN_H
 # include <netinet/in.h>
 #endif
+#if HAVE_ARPA_INET_H
+# include <arpa/inet.h> /* inet_ntoa */
+#endif
 #if HAVE_NETINET_TCP_H
 # include <netinet/tcp.h>
 #endif
+#if HAVE_POLL_H
+# include <poll.h>
+#endif
 
-/* drift */
-static char *time_offset_file = "ntpd/time_offset-%s.rrd";
-static char *time_offset_ds_def[] =
-{
-       "DS:ms:GAUGE:"COLLECTD_HEARTBEAT":0:100",
-       NULL
-};
-static int time_offset_ds_num = 1;
-
-static char *frequency_offset_file = "ntpd/frequency_offset-%s.rrd";
-static char *frequency_offset_ds_def[] =
+static const char *config_keys[] =
 {
-       "DS:ppm:GAUGE:"COLLECTD_HEARTBEAT":0:100",
+       "Host",
+       "Port",
        NULL
 };
-static int frequency_offset_ds_num = 1;
+static int config_keys_num = 2;
 
-#if NTPD_HAVE_READ
 # define NTPD_DEFAULT_HOST "localhost"
 # define NTPD_DEFAULT_PORT "123"
 static int   sock_descr = -1;
 static char *ntpd_host = NULL;
-static char *ntpd_port = NULL;
-#endif
+static char  ntpd_port[16];
+
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
+ * The following definitions were copied from the NTPd distribution  *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+#define MAXFILENAME 128
+#define MAXSEQ  127
+#define MODE_PRIVATE 7
+#define NTP_OLDVERSION ((u_char) 1) /* oldest credible version */
+#define IMPL_XNTPD 3
+#define FP_FRAC 65536.0
+
+#define REFCLOCK_ADDR 0x7f7f0000 /* 127.127.0.0 */
+#define REFCLOCK_MASK 0xffff0000 /* 255.255.0.0 */
+
+/* This structure is missing the message authentication code, since collectd
+ * doesn't use it. */
+struct req_pkt
+{
+       uint8_t  rm_vn_mode;
+       uint8_t  auth_seq;
+       uint8_t  implementation;                /* implementation number */
+       uint8_t  request;                       /* request number */
+       uint16_t err_nitems;            /* error code/number of data items */
+       uint16_t mbz_itemsize;          /* item size */
+       char     data[MAXFILENAME + 48];        /* data area [32 prev](176 byte max) */
+                                       /* struct conf_peer must fit */
+};
+#define REQ_LEN_NOMAC (sizeof(struct req_pkt))
+
+/*
+ * A response packet.  The length here is variable, this is a
+ * maximally sized one.  Note that this implementation doesn't
+ * authenticate responses.
+ */
+#define        RESP_HEADER_SIZE        (8)
+#define        RESP_DATA_SIZE          (500)
+
+struct resp_pkt
+{
+       uint8_t  rm_vn_mode;           /* response, more, version, mode */
+       uint8_t  auth_seq;             /* key, sequence number */
+       uint8_t  implementation;       /* implementation number */
+       uint8_t  request;              /* request number */
+       uint16_t err_nitems;           /* error code/number of data items */
+       uint16_t mbz_itemsize;         /* item size */
+       char     data[RESP_DATA_SIZE]; /* data area */
+};
+
+/*
+ * Bit setting macros for multifield items.
+ */
+#define        RESP_BIT        0x80
+#define        MORE_BIT        0x40
+
+#define        ISRESPONSE(rm_vn_mode)  (((rm_vn_mode)&RESP_BIT)!=0)
+#define        ISMORE(rm_vn_mode)      (((rm_vn_mode)&MORE_BIT)!=0)
+#define INFO_VERSION(rm_vn_mode) ((u_char)(((rm_vn_mode)>>3)&0x7))
+#define        INFO_MODE(rm_vn_mode)   ((rm_vn_mode)&0x7)
+
+#define        RM_VN_MODE(resp, more, version)         \
+                               ((u_char)(((resp)?RESP_BIT:0)\
+                               |((more)?MORE_BIT:0)\
+                               |((version?version:(NTP_OLDVERSION+1))<<3)\
+                               |(MODE_PRIVATE)))
+
+#define        INFO_IS_AUTH(auth_seq)  (((auth_seq) & 0x80) != 0)
+#define        INFO_SEQ(auth_seq)      ((auth_seq)&0x7f)
+#define        AUTH_SEQ(auth, seq)     ((u_char)((((auth)!=0)?0x80:0)|((seq)&0x7f)))
+
+#define        INFO_ERR(err_nitems)    ((u_short)((ntohs(err_nitems)>>12)&0xf))
+#define        INFO_NITEMS(err_nitems) ((u_short)(ntohs(err_nitems)&0xfff))
+#define        ERR_NITEMS(err, nitems) (htons((u_short)((((u_short)(err)<<12)&0xf000)\
+                               |((u_short)(nitems)&0xfff))))
+
+#define        INFO_MBZ(mbz_itemsize)  ((ntohs(mbz_itemsize)>>12)&0xf)
+#define        INFO_ITEMSIZE(mbz_itemsize)     ((u_short)(ntohs(mbz_itemsize)&0xfff))
+#define        MBZ_ITEMSIZE(itemsize)  (htons((u_short)(itemsize)))
+
+/* negate a long float type */
+#define M_NEG(v_i, v_f) \
+       do { \
+               if ((v_f) == 0) \
+               (v_i) = -((uint32_t)(v_i)); \
+               else { \
+                       (v_f) = -((uint32_t)(v_f)); \
+                       (v_i) = ~(v_i); \
+               } \
+       } while(0)
+/* l_fp to double */
+#define M_LFPTOD(r_i, r_uf, d) \
+       do { \
+               register int32_t  i; \
+               register uint32_t f; \
+               \
+               i = (r_i); \
+               f = (r_uf); \
+               if (i < 0) { \
+                       M_NEG(i, f); \
+                       (d) = -((double) i + ((double) f) / 4294967296.0); \
+               } else { \
+                       (d) = (double) i + ((double) f) / 4294967296.0; \
+               } \
+       } while (0)
+
+#define REQ_PEER_LIST_SUM 1
+struct info_peer_summary
+{
+       uint32_t dstadr;         /* local address (zero for undetermined) */
+       uint32_t srcadr;         /* source address */
+       uint16_t srcport;        /* source port */
+       uint8_t stratum;         /* stratum of peer */
+       int8_t hpoll;            /* host polling interval */
+       int8_t ppoll;            /* peer polling interval */
+       uint8_t reach;           /* reachability register */
+       uint8_t flags;           /* flags, from above */
+       uint8_t hmode;           /* peer mode */
+       int32_t  delay;          /* peer.estdelay; s_fp */
+       int32_t  offset_int;     /* peer.estoffset; integral part */
+       int32_t  offset_frc;     /* peer.estoffset; fractional part */
+       uint32_t dispersion;     /* peer.estdisp; u_fp */
+       uint32_t v6_flag;        /* is this v6 or not */
+       uint32_t unused1;        /* (unused) padding for dstadr6 */
+       struct in6_addr dstadr6; /* local address (v6) */
+       struct in6_addr srcadr6; /* source address (v6) */
+};
+
+#define REQ_SYS_INFO 4
+struct info_sys
+{
+       uint32_t peer;           /* system peer address (v4) */
+       uint8_t  peer_mode;      /* mode we are syncing to peer in */
+       uint8_t  leap;           /* system leap bits */
+       uint8_t  stratum;        /* our stratum */
+       int8_t   precision;      /* local clock precision */
+       int32_t  rootdelay;      /* distance from sync source */
+       uint32_t rootdispersion; /* dispersion from sync source */
+       uint32_t refid;          /* reference ID of sync source */
+       uint64_t reftime;        /* system reference time */
+       uint32_t poll;           /* system poll interval */
+       uint8_t  flags;          /* system flags */
+       uint8_t  unused1;        /* unused */
+       uint8_t  unused2;        /* unused */
+       uint8_t  unused3;        /* unused */
+       int32_t  bdelay;         /* default broadcast offset */
+       int32_t  frequency;      /* frequency residual (scaled ppm)  */
+       uint64_t authdelay;      /* default authentication delay */
+       uint32_t stability;      /* clock stability (scaled ppm) */
+       int32_t  v6_flag;        /* is this v6 or not */
+       int32_t  unused4;        /* unused, padding for peer6 */
+       struct in6_addr peer6;   /* system peer address (v6) */
+};
+
+#define REQ_GET_KERNEL 38
+struct info_kernel
+{
+       int32_t  offset;
+       int32_t  freq;
+       int32_t  maxerror;
+       int32_t  esterror;
+       uint16_t status;
+       uint16_t shift;
+       int32_t  constant;
+       int32_t  precision;
+       int32_t  tolerance;
+       /* pps stuff */
+       int32_t  ppsfreq;
+       int32_t  jitter;
+       int32_t  stabil;
+       int32_t  jitcnt;
+       int32_t  calcnt;
+       int32_t  errcnt;
+       int32_t  stbcnt;
+};
 
-static void ntpd_init (void)
+/* List of reference clock names */
+static char *refclock_names[] =
 {
-       return;
+       "UNKNOWN",    "LOCAL",        "GPS_TRAK",   "WWV_PST",     /*  0- 3 */
+       "SPECTRACOM", "TRUETIME",     "IRIG_AUDIO", "CHU_AUDIO",   /*  4- 7 */
+       "GENERIC",    "GPS_MX4200",   "GPS_AS2201", "GPS_ARBITER", /*  8-11 */
+       "IRIG_TPRO",  "ATOM_LEITCH",  "MSF_EES",    "GPSTM_TRUE",  /* 12-15 */
+       "GPS_BANC",   "GPS_DATUM",    "ACTS_NIST",  "WWV_HEATH",   /* 16-19 */
+       "GPS_NMEA",   "GPS_VME",      "PPS",        "ACTS_PTB",    /* 20-23 */
+       "ACTS_USNO",  "TRUETIME",     "GPS_HP",     "MSF_ARCRON",  /* 24-27 */
+       "SHM",        "GPS_PALISADE", "GPS_ONCORE", "GPS_JUPITER", /* 28-31 */
+       "CHRONOLOG",  "DUMBCLOCK",    "ULINK_M320", "PCF",         /* 32-35 */
+       "WWV_AUDIO",  "GPS_FG",       "HOPF_S",     "HOPF_P",      /* 36-39 */
+       "JJY",        "TT_IRIG",      "GPS_ZYFER",  "GPS_RIPENCC", /* 40-43 */
+       "NEOCLK4X",   NULL                                         /* 44    */
+};
+static int refclock_names_num = 45;
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
+ * End of the copied stuff..                                         *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+static int ntpd_config (const char *key, const char *value)
+{
+       if (strcasecmp (key, "Host") == 0)
+       {
+               if (ntpd_host != NULL)
+                       free (ntpd_host);
+               if ((ntpd_host = strdup (value)) == NULL)
+                       return (1);
+       }
+       else if (strcasecmp (key, "Port") == 0)
+       {
+               int port = (int) (atof (value));
+               if ((port > 0) && (port <= 65535))
+                       snprintf (ntpd_port, sizeof (ntpd_port),
+                                       "%i", port);
+               else
+                       strncpy (ntpd_port, value, sizeof (ntpd_port));
+               ntpd_port[sizeof (ntpd_port) - 1] = '\0';
+       }
+       else
+       {
+               return (-1);
+       }
+
+       return (0);
 }
 
-static void ntpd_write (char *host, char *inst, char *val)
+static void ntpd_submit (char *type, char *type_inst, double value)
 {
-       rrd_update_file (host, ntpd_file, val, ds_def, ds_num);
+       value_t values[1];
+       value_list_t vl = VALUE_LIST_INIT;
+
+       values[0].gauge = value;
+
+       vl.values = values;
+       vl.values_len = 1;
+       vl.time = time (NULL);
+       strcpy (vl.host, hostname_g);
+       strcpy (vl.plugin, "ntpd");
+       strcpy (vl.plugin_instance, "");
+       strncpy (vl.type_instance, type_inst, sizeof (vl.type_instance));
+
+       plugin_dispatch_values (type, &vl);
 }
 
-#if NTPD_HAVE_READ
-static void ntpd_submit (double snum, double mnum, double lnum)
+/* returns `tv0 - tv1' in milliseconds or 0 if `tv1 > tv0' */
+static int timeval_sub (const struct timeval *tv0, const struct timeval *tv1)
 {
-       char buf[256];
+       int sec;
+       int usec;
+
+       if ((tv0->tv_sec < tv1->tv_sec)
+                       || ((tv0->tv_sec == tv1->tv_sec) && (tv0->tv_usec < tv1->tv_usec)))
+               return (0);
+
+       sec  = tv0->tv_sec  - tv1->tv_sec;
+       usec = tv0->tv_usec - tv1->tv_usec;
+
+       while (usec < 0)
+       {
+               usec += 1000000;
+               sec  -= 1;
+       }
 
-       if (snprintf (buf, 256, "%u:%.2f:%.2f:%.2f", (unsigned int) curtime,
-                               snum, mnum, lnum) >= 256)
-               return;
+       if (sec < 0)
+               return (0);
 
-       plugin_submit (MODULE_NAME, "-", buf);
+       return ((sec * 1000) + ((usec + 500) / 1000));
 }
 
-static void ntpd_connect (void)
+static int ntpd_connect (void)
 {
        char *host;
        char *port;
@@ -107,25 +337,33 @@ static void ntpd_connect (void)
        if (sock_descr >= 0)
                return (sock_descr);
 
+       DEBUG ("Opening a new socket");
+
        host = ntpd_host;
        if (host == NULL)
                host = NTPD_DEFAULT_HOST;
 
        port = ntpd_port;
-       if (port == NULL)
+       if (strlen (port) == 0)
                port = NTPD_DEFAULT_PORT;
 
        memset (&ai_hints, '\0', sizeof (ai_hints));
-       ai_hints.ai_flags    = AI_ADDRCONFIG;
+       ai_hints.ai_flags    = 0;
+#ifdef AI_ADDRCONFIG
+       ai_hints.ai_flags   |= AI_ADDRCONFIG;
+#endif
        ai_hints.ai_family   = PF_UNSPEC;
        ai_hints.ai_socktype = SOCK_DGRAM;
        ai_hints.ai_protocol = IPPROTO_UDP;
 
        if ((status = getaddrinfo (host, port, &ai_hints, &ai_list)) != 0)
        {
-               syslog (LOG_ERR, "ntpd plugin: getaddrinfo (%s, %s): %s",
+               char errbuf[1024];
+               ERROR ("ntpd plugin: getaddrinfo (%s, %s): %s",
                                host, port,
-                               status == EAI_SYSTEM ? strerror (errno) : gai_strerror (status));
+                               (status == EAI_SYSTEM)
+                               ? sstrerror (errno, errbuf, sizeof (errbuf))
+                               : gai_strerror (status));
                return (-1);
        }
 
@@ -151,7 +389,9 @@ static void ntpd_connect (void)
        freeaddrinfo (ai_list);
 
        if (sock_descr < 0)
-               syslog (LOG_ERR, "ntpd plugin: Unable to connect to server.");
+       {
+               ERROR ("ntpd plugin: Unable to connect to server.");
+       }
 
        return (sock_descr);
 }
@@ -161,13 +401,19 @@ static int ntpd_receive_response (int req_code, int *res_items, int *res_size,
                char **res_data, int res_item_size)
 {
        int              sd;
+       struct pollfd    poll_s;
        struct resp_pkt  res;
-       ssize_t          status;
+       int              status;
        int              done;
+       int              i;
 
        char            *items;
        size_t           items_num;
 
+       struct timeval   time_end;
+       struct timeval   time_now;
+       int              timeout;
+
        int              pkt_item_num;        /* items in this packet */
        int              pkt_item_len;        /* size of the items in this packet */
        int              pkt_sequence;
@@ -190,11 +436,53 @@ static int ntpd_receive_response (int req_code, int *res_items, int *res_size,
        *res_size  = 0;
        *res_data  = NULL;
 
+       if (gettimeofday (&time_end, NULL) < 0)
+       {
+               char errbuf[1024];
+               ERROR ("ntpd plugin: gettimeofday failed: %s",
+                               sstrerror (errno, errbuf, sizeof (errbuf)));
+               return (-1);
+       }
+       time_end.tv_sec++; /* wait for a most one second */
+
        done = 0;
        while (done == 0)
        {
-               /* TODO calculate time */
-               /* TODO poll(2) */
+               if (gettimeofday (&time_now, NULL) < 0)
+               {
+                       char errbuf[1024];
+                       ERROR ("ntpd plugin: gettimeofday failed: %s",
+                                       sstrerror (errno, errbuf, sizeof (errbuf)));
+                       return (-1);
+               }
+
+               /* timeout reached */
+               if ((timeout = timeval_sub (&time_end, &time_now)) == 0)
+                       break;
+
+               poll_s.fd      = sd;
+               poll_s.events  = POLLIN | POLLPRI;
+               poll_s.revents = 0;
+               
+               DEBUG ("Polling for %ims", timeout);
+               status = poll (&poll_s, 1, timeout);
+
+               if ((status < 0) && ((errno == EAGAIN) || (errno == EINTR)))
+                       continue;
+
+               if (status < 0)
+               {
+                       char errbuf[1024];
+                       ERROR ("ntpd plugin: poll failed: %s",
+                                       sstrerror (errno, errbuf, sizeof (errbuf)));
+                       return (-1);
+               }
+
+               if (status == 0) /* timeout */
+               {
+                       DEBUG ("timeout reached.");
+                       break;
+               }
 
                memset ((void *) &res, '\0', sizeof (res));
                status = recv (sd, (void *) &res, sizeof (res), 0 /* no flags */);
@@ -203,51 +491,61 @@ static int ntpd_receive_response (int req_code, int *res_items, int *res_size,
                        continue;
 
                if (status < 0)
+               {
+                       char errbuf[1024];
+                       DEBUG ("recv(2) failed: %s",
+                                       sstrerror (errno, errbuf, sizeof (errbuf)));
+                       DEBUG ("Closing socket #%i", sd);
+                       close (sd);
+                       sock_descr = sd = -1;
                        return (-1);
+               }
+
+               DEBUG ("recv'd %i bytes", status);
 
                /* 
                 * Do some sanity checks first
                 */
                if (status < RESP_HEADER_SIZE)
                {
-                       syslog (LOG_WARNING, "ntpd plugin: Short (%i bytes) packet received",
+                       WARNING ("ntpd plugin: Short (%i bytes) packet received",
                                        (int) status);
                        continue;
                }
                if (INFO_MODE (res.rm_vn_mode) != MODE_PRIVATE)
                {
-                       syslog (LOG_NOTICE, "ntpd plugin: Packet received with mode %i",
+                       NOTICE ("ntpd plugin: Packet received with mode %i",
                                        INFO_MODE (res.rm_vn_mode));
                        continue;
                }
                if (INFO_IS_AUTH (res.auth_seq))
                {
-                       syslog (LOG_NOTICE, "ntpd plugin: Encrypted packet received");
+                       NOTICE ("ntpd plugin: Encrypted packet received");
                        continue;
                }
                if (!ISRESPONSE (res.rm_vn_mode))
                {
-                       syslog (LOG_NOTICE, "ntpd plugin: Received request packet, "
+                       NOTICE ("ntpd plugin: Received request packet, "
                                        "wanted response");
                        continue;
                }
                if (INFO_MBZ (res.mbz_itemsize))
                {
-                       syslog (LOG_WARNING, "ntpd plugin: Received packet with nonzero "
+                       WARNING ("ntpd plugin: Received packet with nonzero "
                                        "MBZ field!");
                        continue;
                }
-               if (res.implementation != req_code)
+               if (res.implementation != IMPL_XNTPD)
                {
-                       syslog (LOG_WARNING, "ntpd plugin: Asked for request of type %i, "
-                                       "got %i", (int) req_code, (int) res.implementation);
+                       WARNING ("ntpd plugin: Asked for request of type %i, "
+                                       "got %i", (int) IMPL_XNTPD, (int) res.implementation);
                        continue;
                }
 
                /* Check for error code */
-               if (INFO_ERR (res.err_nitems) != INFO_OKAY)
+               if (INFO_ERR (res.err_nitems) != 0)
                {
-                       syslog (LOG_ERR, "ntpd plugin: Received error code %i",
+                       ERROR ("ntpd plugin: Received error code %i",
                                        (int) INFO_ERR(res.err_nitems));
                        return ((int) INFO_ERR (res.err_nitems));
                }
@@ -255,40 +553,62 @@ static int ntpd_receive_response (int req_code, int *res_items, int *res_size,
                /* extract number of items in this packet and the size of these items */
                pkt_item_num = INFO_NITEMS (res.err_nitems);
                pkt_item_len = INFO_ITEMSIZE (res.mbz_itemsize);
+               DEBUG ("pkt_item_num = %i; pkt_item_len = %i;",
+                               pkt_item_num, pkt_item_len);
 
                /* Check if the reported items fit in the packet */
                if ((pkt_item_num * pkt_item_len) > (status - RESP_HEADER_SIZE))
                {
-                       syslog (LOG_ERR, "ntpd plugin: %i items * %i bytes > "
+                       ERROR ("ntpd plugin: %i items * %i bytes > "
                                        "%i bytes - %i bytes header",
                                        (int) pkt_item_num, (int) pkt_item_len,
                                        (int) status, (int) RESP_HEADER_SIZE);
                        continue;
                }
 
+               if (pkt_item_len > res_item_size)
+               {
+                       ERROR ("ntpd plugin: (pkt_item_len = %i) "
+                                       ">= (res_item_size = %i)",
+                                       pkt_item_len, res_item_size);
+                       continue;
+               }
+
                /* If this is the first packet (time wise, not sequence wise),
                 * set `res_size'. If it's not the first packet check if the
                 * items have the same size. Discard invalid packets. */
                if (items_num == 0) /* first packet */
                {
+                       DEBUG ("*res_size = %i", pkt_item_len);
                        *res_size = pkt_item_len;
                }
                else if (*res_size != pkt_item_len)
                {
-                       syslog (LOG_ERR, "Item sizes differ.");
+                       DEBUG ("Error: *res_size = %i; pkt_item_len = %i;",
+                                       *res_size, pkt_item_len);
+                       ERROR ("Item sizes differ.");
                        continue;
                }
 
+               /*
+                * Because the items in the packet may be smaller than the
+                * items requested, the following holds true:
+                */
+               assert ((*res_size == pkt_item_len)
+                               && (pkt_item_len <= res_item_size));
+
                /* Calculate the padding. No idea why there might be any padding.. */
                pkt_padding = 0;
-               if (res_item_size > pkt_item_len)
+               if (pkt_item_len < res_item_size)
                        pkt_padding = res_item_size - pkt_item_len;
+               DEBUG ("res_item_size = %i; pkt_padding = %i;",
+                               res_item_size, pkt_padding);
 
                /* Extract the sequence number */
                pkt_sequence = INFO_SEQ (res.auth_seq);
                if ((pkt_sequence < 0) || (pkt_sequence > MAXSEQ))
                {
-                       syslog (LOG_ERR, "ntpd plugin: Received packet with sequence %i",
+                       ERROR ("ntpd plugin: Received packet with sequence %i",
                                        pkt_sequence);
                        continue;
                }
@@ -296,7 +616,7 @@ static int ntpd_receive_response (int req_code, int *res_items, int *res_size,
                /* Check if this sequence has been received before. If so, discard it. */
                if (pkt_recvd[pkt_sequence] != '\0')
                {
-                       syslog (LOG_NOTICE, "ntpd plugin: Sequence %i received twice",
+                       NOTICE ("ntpd plugin: Sequence %i received twice",
                                        pkt_sequence);
                        continue;
                }
@@ -307,31 +627,43 @@ static int ntpd_receive_response (int req_code, int *res_items, int *res_size,
                {
                        if (pkt_lastseq != -1)
                        {
-                               syslog (LOG_ERR, "ntpd plugin: Two packets which both "
+                               ERROR ("ntpd plugin: Two packets which both "
                                                "claim to be the last one in the "
                                                "sequence have been received.");
                                continue;
                        }
                        pkt_lastseq = pkt_sequence;
+                       DEBUG ("Last sequence = %i;", pkt_lastseq);
                }
 
                /*
                 * Enough with the checks. Copy the data now.
                 * We start by allocating some more memory.
                 */
+               DEBUG ("realloc (%p, %i)", (void *) *res_data,
+                               (items_num + pkt_item_num) * res_item_size);
                items = realloc ((void *) *res_data,
                                (items_num + pkt_item_num) * res_item_size);
                if (items == NULL)
                {
                        items = *res_data;
-                       syslog (LOG_ERR, "ntpd plugin: realloc failed.");
+                       ERROR ("ntpd plugin: realloc failed.");
                        continue;
                }
+               items_num += pkt_item_num;
                *res_data = items;
 
                for (i = 0; i < pkt_item_num; i++)
                {
+                       /* dst: There are already `*res_items' items with
+                        *      res_item_size bytes each in in `*res_data'. Set
+                        *      dst to the first byte after that. */
                        void *dst = (void *) (*res_data + ((*res_items) * res_item_size));
+                       /* src: We use `pkt_item_len' to calculate the offset
+                        *      from the beginning of the packet, because the
+                        *      items in the packet may be smaller than the
+                        *      items that were requested. We skip `i' such
+                        *      items. */
                        void *src = (void *) (((char *) res.data) + (i * pkt_item_len));
 
                        /* Set the padding to zeros */
@@ -339,8 +671,10 @@ static int ntpd_receive_response (int req_code, int *res_items, int *res_size,
                                memset (dst, '\0', res_item_size);
                        memcpy (dst, src, (size_t) pkt_item_len);
 
+                       /* Increment `*res_items' by one, so `dst' will end up
+                        * one further in the next round. */
                        (*res_items)++;
-               }
+               } /* for (pkt_item_num) */
 
                pkt_recvd[pkt_sequence] = (char) 1;
                pkt_recvd_num++;
@@ -350,7 +684,7 @@ static int ntpd_receive_response (int req_code, int *res_items, int *res_size,
        } /* while (done == 0) */
 
        return (0);
-}
+} /* int ntpd_receive_response */
 
 /* For a description of the arguments see `ntpd_do_query' below. */
 static int ntpd_send_request (int req_code, int req_items, int req_size, char *req_data)
@@ -377,15 +711,23 @@ static int ntpd_send_request (int req_code, int req_items, int req_size, char *r
        assert (((req_data != NULL) && (req_data_len > 0))
                        || ((req_data == NULL) && (req_items == 0) && (req_size == 0)));
 
-       req.err_nitems   = ERR_NITEMS (0, qitems);
-       req.mbz_itemsize = MBZ_ITEMSIZE (qsize);
+       req.err_nitems   = ERR_NITEMS (0, req_items);
+       req.mbz_itemsize = MBZ_ITEMSIZE (req_size);
        
        if (req_data != NULL)
                memcpy ((void *) req.data, (const void *) req_data, req_data_len);
 
-       status = swrite (fd, (const char *) &req, REQ_LEN_NOMAC);
+       DEBUG ("req_items = %i; req_size = %i; req_data = %p;",
+                       req_items, req_size, (void *) req_data);
+
+       status = swrite (sd, (const char *) &req, REQ_LEN_NOMAC);
        if (status < 0)
+       {
+               DEBUG ("`swrite' failed. Closing socket #%i", sd);
+               close (sd);
+               sock_descr = sd = -1;
                return (status);
+       }
 
        return (0);
 }
@@ -418,26 +760,201 @@ static int ntpd_do_query (int req_code, int req_items, int req_size, char *req_d
        return (status);
 }
 
-static void ntpd_read (void)
+static double ntpd_read_fp (int32_t val_int)
 {
-       static sd = -1;
-       struct req_pkt req;
+       double val_double;
 
-       ntpd_connect (&sd);
-       if (sd < 0)
-               return;
+       val_int = ntohl (val_int);
+       val_double = ((double) val_int) / FP_FRAC;
 
-       memset ((void *) &req, '\0', sizeof (req));
-       req.rm_vn_mode = RM_VN_MODE (0, 0, 0); /* response, more, version, mode */
-       req.implementation = IMPL_XNTPD;
+       return (val_double);
 }
-#else
-# define ntpd_read NULL
-#endif /* NTPD_HAVE_READ */
 
-void module_register (void)
+static int ntpd_read (void)
 {
-       plugin_register (MODULE_NAME, ntpd_init, ntpd_read, ntpd_write);
-}
+       struct info_kernel *ik;
+       int                 ik_num;
+       int                 ik_size;
+
+       struct info_peer_summary *ps;
+       int                       ps_num;
+       int                       ps_size;
+
+       int status;
+       int i;
 
-#undef MODULE_NAME
+       ik      = NULL;
+       ik_num  = 0;
+       ik_size = 0;
+
+       status = ntpd_do_query (REQ_GET_KERNEL,
+                       0, 0, NULL, /* request data */
+                       &ik_num, &ik_size, (char **) ((void *) &ik), /* response data */
+                       sizeof (struct info_kernel));
+
+       if (status != 0)
+       {
+               DEBUG ("ntpd_do_query failed with status %i", status);
+               return (-1);
+       }
+       if ((ik == NULL) || (ik_num == 0) || (ik_size == 0))
+       {
+               DEBUG ("ntpd_do_query returned: ik = %p; ik_num = %i; ik_size = %i;",
+                               (void *) ik, ik_num, ik_size);
+               return (-1);
+       }
+
+       /* kerninfo -> estimated error */
+
+       DEBUG ("info_kernel:\n"
+                       "  pll offset    = %.8f\n"
+                       "  pll frequency = %.8f\n" /* drift compensation */
+                       "  est error     = %.8f\n",
+                       ntpd_read_fp (ik->offset),
+                       ntpd_read_fp (ik->freq),
+                       ntpd_read_fp (ik->esterror));
+
+       ntpd_submit ("frequency_offset", "loop",  ntpd_read_fp (ik->freq));
+       ntpd_submit ("time_offset",      "loop",  ntpd_read_fp (ik->offset));
+       ntpd_submit ("time_offset",      "error", ntpd_read_fp (ik->esterror));
+
+       free (ik);
+       ik = NULL;
+
+       status = ntpd_do_query (REQ_PEER_LIST_SUM,
+                       0, 0, NULL, /* request data */
+                       &ps_num, &ps_size, (char **) ((void *) &ps), /* response data */
+                       sizeof (struct info_peer_summary));
+       if (status != 0)
+       {
+               DEBUG ("ntpd_do_query failed with status %i", status);
+               return (-1);
+       }
+       if ((ps == NULL) || (ps_num == 0) || (ps_size == 0))
+       {
+               DEBUG ("ntpd_do_query returned: ps = %p; ps_num = %i; ps_size = %i;",
+                               (void *) ps, ps_num, ps_size);
+               return (-1);
+       }
+
+       for (i = 0; i < ps_num; i++)
+       {
+               struct info_peer_summary *ptr;
+               double offset;
+
+               char peername[NI_MAXHOST];
+               int refclock_id;
+               
+               ptr = ps + i;
+               refclock_id = 0;
+
+               /*
+               if (((ntohl (ptr->dstadr) & 0xFFFFFF00) == 0x7F000000) || (ptr->dstadr == 0))
+                       continue;
+                       */
+
+               /* Convert the `long floating point' offset value to double */
+               M_LFPTOD (ntohl (ptr->offset_int), ntohl (ptr->offset_frc), offset);
+
+               if (ptr->v6_flag)
+               {
+                       struct sockaddr_in6 sa;
+
+                       memset (&sa, 0, sizeof (sa));
+                       sa.sin6_family = AF_INET6;
+                       sa.sin6_port = htons (123);
+                       memcpy (&sa.sin6_addr, &ptr->srcadr6, sizeof (struct in6_addr));
+
+                       status = getnameinfo ((const struct sockaddr *) &sa,
+                                       sizeof (sa),
+                                       peername, sizeof (peername),
+                                       NULL, 0, 0 /* no flags */);
+                       if (status != 0)
+                       {
+                               char errbuf[1024];
+                               ERROR ("ntpd plugin: getnameinfo failed: %s",
+                                               (status == EAI_SYSTEM)
+                                               ? sstrerror (errno, errbuf, sizeof (errbuf))
+                                               : gai_strerror (status));
+                               continue;
+                       }
+               }
+               else if ((ntohl (ptr->srcadr) & REFCLOCK_MASK) == REFCLOCK_ADDR)
+               {
+                       struct in_addr  addr_obj;
+                       char *addr_str;
+
+                       refclock_id = (ntohl (ptr->srcadr) >> 8) & 0x000000FF;
+
+                       if (refclock_id < refclock_names_num)
+                       {
+                               strncpy (peername, refclock_names[refclock_id],
+                                               sizeof (peername));
+                       }
+                       else
+                       {
+                               memset ((void *) &addr_obj, '\0', sizeof (addr_obj));
+                               addr_obj.s_addr = ptr->srcadr;
+                               addr_str = inet_ntoa (addr_obj);
+
+                               strncpy (peername, addr_str, sizeof (peername));
+                       }
+               }
+               else /* IPv4 */
+               {
+                       struct in_addr  addr_obj;
+                       struct hostent *addr_he;
+                       char           *addr_str;
+
+                       memset ((void *) &addr_obj, '\0', sizeof (addr_obj));
+                       addr_obj.s_addr = ptr->srcadr;
+                       addr_str = inet_ntoa (addr_obj);
+
+                       addr_he = gethostbyaddr ((const void *) &addr_obj,
+                                       sizeof (addr_obj), AF_INET);
+                       if (addr_he != NULL)
+                       {
+                               strncpy (peername, addr_he->h_name, sizeof (peername));
+                       }
+                       else
+                       {
+                               strncpy (peername, addr_str, sizeof (peername));
+                       }
+               }
+
+               DEBUG ("peer %i:\n"
+                               "  peername   = %s\n"
+                               "  srcadr     = 0x%08x\n"
+                               "  delay      = %f\n"
+                               "  offset_int = %i\n"
+                               "  offset_frc = %i\n"
+                               "  offset     = %f\n"
+                               "  dispersion = %f\n",
+                               i,
+                               peername,
+                               ntohl (ptr->srcadr),
+                               ntpd_read_fp (ptr->delay),
+                               ntohl (ptr->offset_int),
+                               ntohl (ptr->offset_frc),
+                               offset,
+                               ntpd_read_fp (ptr->dispersion));
+
+               if (refclock_id != 1) /* not the system clock (offset will always be zero.. */
+                       ntpd_submit ("time_offset", peername, offset);
+               ntpd_submit ("time_dispersion", peername, ntpd_read_fp (ptr->dispersion));
+               if (refclock_id == 0) /* not a reference clock */
+                       ntpd_submit ("delay", peername, ntpd_read_fp (ptr->delay));
+       }
+
+       free (ps);
+       ps = NULL;
+
+       return (0);
+} /* int ntpd_read */
+
+void module_register (void)
+{
+       plugin_register_config ("ntpd", ntpd_config,
+                       config_keys, config_keys_num);
+       plugin_register_read ("ntpd", ntpd_read);
+} /* void module_register */