X-Git-Url: https://git.octo.it/?p=rrdtool.git;a=blobdiff_plain;f=src%2Frrd_daemon.c;h=2a35ec2abe59cfc2f87a316a0e097c051879a98d;hp=a0e6bdbf9f629d62e8408548cffd39edc9843154;hb=ff4657f155a7acb054aaa702a7c2f610991bd0e9;hpb=fe50f514d5602b06ff585ad3aa168d609f6a1fcc

diff --git a/src/rrd_daemon.c b/src/rrd_daemon.c
index a0e6bdb..2a35ec2 100644
--- a/src/rrd_daemon.c
+++ b/src/rrd_daemon.c
@@ -62,23 +62,37 @@
 /*
  * Now for some includes..
  */
-#include "rrd.h" /* {{{ */
+/* {{{ */
+#if defined(_WIN32) && !defined(__CYGWIN__) && !defined(__CYGWIN32__) && !defined(HAVE_CONFIG_H)
+#include "../win32/config.h"
+#else
+#ifdef HAVE_CONFIG_H
+#include "../rrd_config.h"
+#endif
+#endif
+
+#include "rrd.h"
 #include "rrd_client.h"
 
 #include <stdlib.h>
+
+#ifndef WIN32
 #include <stdint.h>
-#include <stdio.h>
 #include <unistd.h>
-#include <string.h>
 #include <strings.h>
-#include <stdint.h>
 #include <inttypes.h>
+#	include <sys/socket.h>
+
+#else
+
+#endif
+#include <stdio.h>
+#include <string.h>
 
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <fcntl.h>
 #include <signal.h>
-#include <sys/socket.h>
 #include <sys/un.h>
 #include <netdb.h>
 #include <poll.h>
@@ -107,27 +121,68 @@ typedef enum
   PRIV_HIGH
 } socket_privilege;
 
+typedef enum { RESP_ERR = -1, RESP_OK = 0 } response_code;
+
 struct listen_socket_s
 {
   int fd;
   char addr[PATH_MAX + 1];
   int family;
   socket_privilege privilege;
+
+  /* state for BATCH processing */
+  time_t batch_start;
+  int batch_cmd;
+
+  /* buffered IO */
+  char *rbuf;
+  off_t next_cmd;
+  off_t next_read;
+
+  char *wbuf;
+  ssize_t wbuf_len;
 };
 typedef struct listen_socket_s listen_socket_t;
 
+struct command;
+/* note: guard against "unused" warnings in the handlers */
+#define DISPATCH_PROTO	listen_socket_t *sock	__attribute__((unused)),\
+			time_t now		__attribute__((unused)),\
+			char  *buffer		__attribute__((unused)),\
+			size_t buffer_size	__attribute__((unused))
+
+#define HANDLER_PROTO	struct command *cmd	__attribute__((unused)),\
+			DISPATCH_PROTO
+
+struct command {
+  char   *cmd;
+  int (*handler)(HANDLER_PROTO);
+  socket_privilege min_priv;
+
+  char  context;		/* where we expect to see it */
+#define CMD_CONTEXT_CLIENT	(1<<0)
+#define CMD_CONTEXT_BATCH	(1<<1)
+#define CMD_CONTEXT_JOURNAL	(1<<2)
+#define CMD_CONTEXT_ANY		(0x7f)
+
+  char *syntax;
+  char *help;
+};
+
 struct cache_item_s;
 typedef struct cache_item_s cache_item_t;
 struct cache_item_s
 {
   char *file;
   char **values;
-  int values_num;
+  size_t values_num;
   time_t last_flush_time;
+  time_t last_update_stamp;
 #define CI_FLAGS_IN_TREE  (1<<0)
 #define CI_FLAGS_IN_QUEUE (1<<1)
   int flags;
   pthread_cond_t  flushed;
+  cache_item_t *prev;
   cache_item_t *next;
 };
 
@@ -149,21 +204,32 @@ typedef enum queue_side_e queue_side_t;
 
 /* max length of socket command or response */
 #define CMD_MAX 4096
+#define RBUF_SIZE (CMD_MAX*2)
 
 /*
  * Variables
  */
 static int stay_foreground = 0;
+static uid_t daemon_uid;
 
 static listen_socket_t *listen_fds = NULL;
 static size_t listen_fds_num = 0;
 
-static int do_shutdown = 0;
+enum {
+  RUNNING,		/* normal operation */
+  FLUSHING,		/* flushing remaining values */
+  SHUTDOWN		/* shutting down */
+} state = RUNNING;
 
-static pthread_t queue_thread;
+static pthread_t *queue_threads;
+static pthread_cond_t queue_cond = PTHREAD_COND_INITIALIZER;
+static int config_queue_threads = 4;
+
+static pthread_t flush_thread;
+static pthread_cond_t flush_cond = PTHREAD_COND_INITIALIZER;
 
-static pthread_t *connection_threads = NULL;
 static pthread_mutex_t connection_threads_lock = PTHREAD_MUTEX_INITIALIZER;
+static pthread_cond_t  connection_threads_done = PTHREAD_COND_INITIALIZER;
 static int connection_threads_num = 0;
 
 /* Cache stuff */
@@ -171,7 +237,6 @@ static GTree          *cache_tree = NULL;
 static cache_item_t   *cache_queue_head = NULL;
 static cache_item_t   *cache_queue_tail = NULL;
 static pthread_mutex_t cache_lock = PTHREAD_MUTEX_INITIALIZER;
-static pthread_cond_t  cache_cond = PTHREAD_COND_INITIALIZER;
 
 static int config_write_interval = 300;
 static int config_write_jitter   = 0;
@@ -179,9 +244,11 @@ static int config_flush_interval = 3600;
 static int config_flush_at_shutdown = 0;
 static char *config_pid_file = NULL;
 static char *config_base_dir = NULL;
+static size_t _config_base_dir_len = 0;
+static int config_write_base_only = 0;
 
 static listen_socket_t **config_listen_address_list = NULL;
-static int config_listen_address_list_len = 0;
+static size_t config_listen_address_list_len = 0;
 
 static uint64_t stats_queue_length = 0;
 static uint64_t stats_updates_received = 0;
@@ -201,14 +268,18 @@ static int journal_write(char *cmd, char *args);
 static void journal_done(void);
 static void journal_rotate(void);
 
+/* prototypes for forward refernces */
+static int handle_request_help (HANDLER_PROTO);
+
 /* 
  * Functions
  */
 static void sig_common (const char *sig) /* {{{ */
 {
   RRDD_LOG(LOG_NOTICE, "caught SIG%s", sig);
-  do_shutdown++;
-  pthread_cond_broadcast(&cache_cond);
+  state = FLUSHING;
+  pthread_cond_broadcast(&flush_cond);
+  pthread_cond_broadcast(&queue_cond);
 } /* }}} void sig_common */
 
 static void sig_int_handler (int s __attribute__((unused))) /* {{{ */
@@ -266,7 +337,7 @@ static void install_signal_handlers(void) /* {{{ */
 
 } /* }}} void install_signal_handlers */
 
-static int open_pidfile(void) /* {{{ */
+static int open_pidfile(char *action, int oflag) /* {{{ */
 {
   int fd;
   char *file;
@@ -275,14 +346,58 @@ static int open_pidfile(void) /* {{{ */
     ? config_pid_file
     : LOCALSTATEDIR "/run/rrdcached.pid";
 
-  fd = open(file, O_CREAT|O_EXCL|O_WRONLY, S_IRUSR|S_IRGRP|S_IROTH);
+  fd = open(file, oflag, S_IWUSR|S_IRUSR|S_IRGRP|S_IROTH);
   if (fd < 0)
-    fprintf(stderr, "FATAL: cannot create '%s' (%s)\n",
-            file, rrd_strerror(errno));
+    fprintf(stderr, "rrdcached: can't %s pid file '%s' (%s)\n",
+            action, file, rrd_strerror(errno));
 
   return(fd);
 } /* }}} static int open_pidfile */
 
+/* check existing pid file to see whether a daemon is running */
+static int check_pidfile(void)
+{
+  int pid_fd;
+  pid_t pid;
+  char pid_str[16];
+
+  pid_fd = open_pidfile("open", O_RDWR);
+  if (pid_fd < 0)
+    return pid_fd;
+
+  if (read(pid_fd, pid_str, sizeof(pid_str)) <= 0)
+    return -1;
+
+  pid = atoi(pid_str);
+  if (pid <= 0)
+    return -1;
+
+  /* another running process that we can signal COULD be
+   * a competing rrdcached */
+  if (pid != getpid() && kill(pid, 0) == 0)
+  {
+    fprintf(stderr,
+            "FATAL: Another rrdcached daemon is running?? (pid %d)\n", pid);
+    close(pid_fd);
+    return -1;
+  }
+
+  lseek(pid_fd, 0, SEEK_SET);
+  if (ftruncate(pid_fd, 0) == -1)
+  {
+    fprintf(stderr,
+            "FATAL: Faild to truncate stale PID file. (pid %d)\n", pid);
+    close(pid_fd);
+    return -1;
+  }
+
+  fprintf(stderr,
+          "rrdcached: removed stale PID file (no rrdcached on pid %d)\n"
+          "rrdcached: starting normally.\n", pid);
+
+  return pid_fd;
+} /* }}} static int check_pidfile */
+
 static int write_pidfile (int fd) /* {{{ */
 {
   pid_t pid;
@@ -319,99 +434,239 @@ static int remove_pidfile (void) /* {{{ */
   return (errno);
 } /* }}} int remove_pidfile */
 
-static ssize_t sread (int fd, void *buffer_void, size_t buffer_size) /* {{{ */
+static char *next_cmd (listen_socket_t *sock, ssize_t *len) /* {{{ */
 {
-  char    *buffer;
-  size_t   buffer_used;
-  size_t   buffer_free;
-  ssize_t  status;
+  char *eol;
 
-  buffer       = (char *) buffer_void;
-  buffer_used  = 0;
-  buffer_free  = buffer_size;
+  eol = memchr(sock->rbuf + sock->next_cmd, '\n',
+               sock->next_read - sock->next_cmd);
 
-  while (buffer_free > 0)
+  if (eol == NULL)
   {
-    status = read (fd, buffer + buffer_used, buffer_free);
-    if ((status < 0) && ((errno == EAGAIN) || (errno == EINTR)))
-      continue;
-
-    if (status < 0)
-      return (-1);
+    /* no commands left, move remainder back to front of rbuf */
+    memmove(sock->rbuf, sock->rbuf + sock->next_cmd,
+            sock->next_read - sock->next_cmd);
+    sock->next_read -= sock->next_cmd;
+    sock->next_cmd = 0;
+    *len = 0;
+    return NULL;
+  }
+  else
+  {
+    char *cmd = sock->rbuf + sock->next_cmd;
+    *eol = '\0';
 
-    if (status == 0)
-      return (0);
+    sock->next_cmd = eol - sock->rbuf + 1;
 
-    assert ((0 > status) || (buffer_free >= (size_t) status));
+    if (eol > sock->rbuf && *(eol-1) == '\r')
+      *(--eol) = '\0'; /* handle "\r\n" EOL */
 
-    buffer_free = buffer_free - status;
-    buffer_used = buffer_used + status;
+    *len = eol - cmd;
 
-    if (buffer[buffer_used - 1] == '\n')
-      break;
+    return cmd;
   }
 
-  assert (buffer_used > 0);
+  /* NOTREACHED */
+  assert(1==0);
+}
 
-  if (buffer[buffer_used - 1] != '\n')
+/* add the characters directly to the write buffer */
+static int add_to_wbuf(listen_socket_t *sock, char *str, size_t len) /* {{{ */
+{
+  char *new_buf;
+
+  assert(sock != NULL);
+
+  new_buf = rrd_realloc(sock->wbuf, sock->wbuf_len + len + 1);
+  if (new_buf == NULL)
   {
-    errno = ENOBUFS;
-    return (-1);
+    RRDD_LOG(LOG_ERR, "add_to_wbuf: realloc failed");
+    return -1;
   }
 
-  buffer[buffer_used - 1] = 0;
+  strncpy(new_buf + sock->wbuf_len, str, len + 1);
+
+  sock->wbuf = new_buf;
+  sock->wbuf_len += len;
 
-  /* Fix network line endings. */
-  if ((buffer_used > 1) && (buffer[buffer_used - 2] == '\r'))
+  return 0;
+} /* }}} static int add_to_wbuf */
+
+/* add the text to the "extra" info that's sent after the status line */
+static int add_response_info(listen_socket_t *sock, char *fmt, ...) /* {{{ */
+{
+  va_list argp;
+  char buffer[CMD_MAX];
+  int len;
+
+  if (sock == NULL) return 0; /* journal replay mode */
+  if (sock->batch_start) return 0; /* no extra info returned when in BATCH */
+
+  va_start(argp, fmt);
+#ifdef HAVE_VSNPRINTF
+  len = vsnprintf(buffer, sizeof(buffer), fmt, argp);
+#else
+  len = vsprintf(buffer, fmt, argp);
+#endif
+  va_end(argp);
+  if (len < 0)
   {
-    buffer_used--;
-    buffer[buffer_used - 1] = 0;
+    RRDD_LOG(LOG_ERR, "add_response_info: vnsprintf failed");
+    return -1;
   }
 
-  return (buffer_used);
-} /* }}} ssize_t sread */
+  return add_to_wbuf(sock, buffer, len);
+} /* }}} static int add_response_info */
 
-static ssize_t swrite (int fd, const void *buf, size_t count) /* {{{ */
+static int count_lines(char *str) /* {{{ */
 {
-  const char *ptr;
-  size_t      nleft;
-  ssize_t     status;
+  int lines = 0;
+
+  if (str != NULL)
+  {
+    while ((str = strchr(str, '\n')) != NULL)
+    {
+      ++lines;
+      ++str;
+    }
+  }
 
-  /* special case for journal replay */
-  if (fd < 0) return 0;
+  return lines;
+} /* }}} static int count_lines */
 
-  ptr   = (const char *) buf;
-  nleft = count;
+/* send the response back to the user.
+ * returns 0 on success, -1 on error
+ * write buffer is always zeroed after this call */
+static int send_response (listen_socket_t *sock, response_code rc,
+                          char *fmt, ...) /* {{{ */
+{
+  va_list argp;
+  char buffer[CMD_MAX];
+  int lines;
+  ssize_t wrote;
+  int rclen, len;
+
+  if (sock == NULL) return rc;  /* journal replay mode */
 
-  while (nleft > 0)
+  if (sock->batch_start)
   {
-    status = write (fd, (const void *) ptr, nleft);
+    if (rc == RESP_OK)
+      return rc; /* no response on success during BATCH */
+    lines = sock->batch_cmd;
+  }
+  else if (rc == RESP_OK)
+    lines = count_lines(sock->wbuf);
+  else
+    lines = -1;
+
+  rclen = sprintf(buffer, "%d ", lines);
+  va_start(argp, fmt);
+#ifdef HAVE_VSNPRINTF
+  len = vsnprintf(buffer+rclen, sizeof(buffer)-rclen, fmt, argp);
+#else
+  len = vsprintf(buffer+rclen, fmt, argp);
+#endif
+  va_end(argp);
+  if (len < 0)
+    return -1;
 
-    if ((status < 0) && ((errno == EAGAIN) || (errno == EINTR)))
-      continue;
+  len += rclen;
 
-    if (status < 0)
-      return (status);
+  /* append the result to the wbuf, don't write to the user */
+  if (sock->batch_start)
+    return add_to_wbuf(sock, buffer, len);
+
+  /* first write must be complete */
+  if (len != write(sock->fd, buffer, len))
+  {
+    RRDD_LOG(LOG_INFO, "send_response: could not write status message");
+    return -1;
+  }
 
-    nleft -= status;
-    ptr   += status;
+  if (sock->wbuf != NULL && rc == RESP_OK)
+  {
+    wrote = 0;
+    while (wrote < sock->wbuf_len)
+    {
+      ssize_t wb = write(sock->fd, sock->wbuf + wrote, sock->wbuf_len - wrote);
+      if (wb <= 0)
+      {
+        RRDD_LOG(LOG_INFO, "send_response: could not write results");
+        return -1;
+      }
+      wrote += wb;
+    }
   }
 
-  return (0);
-} /* }}} ssize_t swrite */
+  free(sock->wbuf); sock->wbuf = NULL;
+  sock->wbuf_len = 0;
+
+  return 0;
+} /* }}} */
 
-static void _wipe_ci_values(cache_item_t *ci, time_t when)
+static void wipe_ci_values(cache_item_t *ci, time_t when)
 {
   ci->values = NULL;
   ci->values_num = 0;
 
   ci->last_flush_time = when;
   if (config_write_jitter > 0)
-    ci->last_flush_time += (random() % config_write_jitter);
-
-  ci->flags &= ~(CI_FLAGS_IN_QUEUE);
+    ci->last_flush_time += (rrd_random() % config_write_jitter);
 }
 
+/* remove_from_queue
+ * remove a "cache_item_t" item from the queue.
+ * must hold 'cache_lock' when calling this
+ */
+static void remove_from_queue(cache_item_t *ci) /* {{{ */
+{
+  if (ci == NULL) return;
+  if ((ci->flags & CI_FLAGS_IN_QUEUE) == 0) return; /* not queued */
+
+  if (ci->prev == NULL)
+    cache_queue_head = ci->next; /* reset head */
+  else
+    ci->prev->next = ci->next;
+
+  if (ci->next == NULL)
+    cache_queue_tail = ci->prev; /* reset the tail */
+  else
+    ci->next->prev = ci->prev;
+
+  ci->next = ci->prev = NULL;
+  ci->flags &= ~CI_FLAGS_IN_QUEUE;
+
+  pthread_mutex_lock (&stats_lock);
+  assert (stats_queue_length > 0);
+  stats_queue_length--;
+  pthread_mutex_unlock (&stats_lock);
+
+} /* }}} static void remove_from_queue */
+
+/* free the resources associated with the cache_item_t
+ * must hold cache_lock when calling this function
+ */
+static void *free_cache_item(cache_item_t *ci) /* {{{ */
+{
+  if (ci == NULL) return NULL;
+
+  remove_from_queue(ci);
+
+  for (size_t i=0; i < ci->values_num; i++)
+    free(ci->values[i]);
+
+  free (ci->values);
+  free (ci->file);
+
+  /* in case anyone is waiting */
+  pthread_cond_broadcast(&ci->flushed);
+  pthread_cond_destroy(&ci->flushed);
+
+  free (ci);
+
+  return NULL;
+} /* }}} static void *free_cache_item */
+
 /*
  * enqueue_cache_item:
  * `cache_lock' must be acquired before calling this function!
@@ -419,8 +674,6 @@ static void _wipe_ci_values(cache_item_t *ci, time_t when)
 static int enqueue_cache_item (cache_item_t *ci, /* {{{ */
     queue_side_t side)
 {
-  int did_insert = 0;
-
   if (ci == NULL)
     return (-1);
 
@@ -429,74 +682,53 @@ static int enqueue_cache_item (cache_item_t *ci, /* {{{ */
 
   if (side == HEAD)
   {
-    if ((ci->flags & CI_FLAGS_IN_QUEUE) == 0)
-    {
-      assert (ci->next == NULL);
-      ci->next = cache_queue_head;
-      cache_queue_head = ci;
-
-      if (cache_queue_tail == NULL)
-        cache_queue_tail = cache_queue_head;
+    if (cache_queue_head == ci)
+      return 0;
 
-      did_insert = 1;
-    }
-    else if (cache_queue_head == ci)
-    {
-      /* do nothing */
-    }
-    else /* enqueued, but not first entry */
-    {
-      cache_item_t *prev;
+    /* remove if further down in queue */
+    remove_from_queue(ci);
 
-      /* find previous entry */
-      for (prev = cache_queue_head; prev != NULL; prev = prev->next)
-        if (prev->next == ci)
-          break;
-      assert (prev != NULL);
+    ci->prev = NULL;
+    ci->next = cache_queue_head;
+    if (ci->next != NULL)
+      ci->next->prev = ci;
+    cache_queue_head = ci;
 
-      /* move to the front */
-      prev->next = ci->next;
-      ci->next = cache_queue_head;
-      cache_queue_head = ci;
-
-      /* check if we need to adapt the tail */
-      if (cache_queue_tail == ci)
-        cache_queue_tail = prev;
-    }
+    if (cache_queue_tail == NULL)
+      cache_queue_tail = cache_queue_head;
   }
   else /* (side == TAIL) */
   {
     /* We don't move values back in the list.. */
-    if ((ci->flags & CI_FLAGS_IN_QUEUE) != 0)
+    if (ci->flags & CI_FLAGS_IN_QUEUE)
       return (0);
 
     assert (ci->next == NULL);
+    assert (ci->prev == NULL);
+
+    ci->prev = cache_queue_tail;
 
     if (cache_queue_tail == NULL)
       cache_queue_head = ci;
     else
       cache_queue_tail->next = ci;
-    cache_queue_tail = ci;
 
-    did_insert = 1;
+    cache_queue_tail = ci;
   }
 
   ci->flags |= CI_FLAGS_IN_QUEUE;
 
-  if (did_insert)
-  {
-    pthread_cond_broadcast(&cache_cond);
-    pthread_mutex_lock (&stats_lock);
-    stats_queue_length++;
-    pthread_mutex_unlock (&stats_lock);
-  }
+  pthread_cond_signal(&queue_cond);
+  pthread_mutex_lock (&stats_lock);
+  stats_queue_length++;
+  pthread_mutex_unlock (&stats_lock);
 
   return (0);
 } /* }}} int enqueue_cache_item */
 
 /*
  * tree_callback_flush:
- * Called via `g_tree_foreach' in `queue_thread_main'. `cache_lock' is held
+ * Called via `g_tree_foreach' in `flush_thread_main'. `cache_lock' is held
  * while this is in progress.
  */
 static gboolean tree_callback_flush (gpointer key, gpointer value, /* {{{ */
@@ -508,36 +740,23 @@ static gboolean tree_callback_flush (gpointer key, gpointer value, /* {{{ */
   ci = (cache_item_t *) value;
   cfd = (callback_flush_data_t *) data;
 
-  if ((ci->last_flush_time <= cfd->abs_timeout)
-      && ((ci->flags & CI_FLAGS_IN_QUEUE) == 0)
-      && (ci->values_num > 0))
-  {
-    enqueue_cache_item (ci, TAIL);
-  }
-  else if ((do_shutdown != 0)
-      && ((ci->flags & CI_FLAGS_IN_QUEUE) == 0)
-      && (ci->values_num > 0))
+  if (ci->flags & CI_FLAGS_IN_QUEUE)
+    return FALSE;
+
+  if (ci->values_num > 0
+      && (ci->last_flush_time <= cfd->abs_timeout || state != RUNNING))
   {
     enqueue_cache_item (ci, TAIL);
   }
   else if (((cfd->now - ci->last_flush_time) >= config_flush_interval)
-      && ((ci->flags & CI_FLAGS_IN_QUEUE) == 0)
       && (ci->values_num <= 0))
   {
-    char **temp;
-
-    temp = (char **) realloc (cfd->keys,
-        sizeof (char *) * (cfd->keys_num + 1));
-    if (temp == NULL)
+    assert ((char *) key == ci->file);
+    if (!rrd_add_ptr((void ***)&cfd->keys, &cfd->keys_num, (void *)key))
     {
-      RRDD_LOG (LOG_ERR, "tree_callback_flush: realloc failed.");
+      RRDD_LOG (LOG_ERR, "tree_callback_flush: rrd_add_ptrs failed.");
       return (FALSE);
     }
-    cfd->keys = temp;
-    /* Make really sure this points to the _same_ place */
-    assert ((char *) key == ci->file);
-    cfd->keys[cfd->keys_num] = (char *) key;
-    cfd->keys_num++;
   }
 
   return (FALSE);
@@ -568,26 +787,10 @@ static int flush_old_values (int max_age)
 
   for (k = 0; k < cfd.keys_num; k++)
   {
-    cache_item_t *ci;
-
-    /* This must not fail. */
-    ci = (cache_item_t *) g_tree_lookup (cache_tree, cfd.keys[k]);
-    assert (ci != NULL);
-
-    /* If we end up here with values available, something's seriously
-     * messed up. */
-    assert (ci->values_num == 0);
-
-    /* Remove the node from the tree */
-    g_tree_remove (cache_tree, cfd.keys[k]);
-    cfd.keys[k] = NULL;
-
-    /* Now free and clean up `ci'. */
-    free (ci->file);
-    ci->file = NULL;
-    free (ci);
-    ci = NULL;
-  } /* for (k = 0; k < cfd.keys_num; k++) */
+    /* should never fail, since we have held the cache_lock
+     * the entire time */
+    assert( g_tree_remove(cache_tree, cfd.keys[k]) == TRUE );
+  }
 
   if (cfd.keys != NULL)
   {
@@ -598,40 +801,34 @@ static int flush_old_values (int max_age)
   return (0);
 } /* int flush_old_values */
 
-static void *queue_thread_main (void *args __attribute__((unused))) /* {{{ */
+static void *flush_thread_main (void *args __attribute__((unused))) /* {{{ */
 {
   struct timeval now;
   struct timespec next_flush;
-  int final_flush = 0; /* make sure we only flush once on shutdown */
+  int status;
 
   gettimeofday (&now, NULL);
   next_flush.tv_sec = now.tv_sec + config_flush_interval;
   next_flush.tv_nsec = 1000 * now.tv_usec;
 
-  pthread_mutex_lock (&cache_lock);
-  while ((do_shutdown == 0) || (cache_queue_head != NULL))
-  {
-    cache_item_t *ci;
-    char *file;
-    char **values;
-    int values_num;
-    int status;
-    int i;
+  pthread_mutex_lock(&cache_lock);
 
-    /* First, check if it's time to do the cache flush. */
+  while (state == RUNNING)
+  {
     gettimeofday (&now, NULL);
     if ((now.tv_sec > next_flush.tv_sec)
         || ((now.tv_sec == next_flush.tv_sec)
           && ((1000 * now.tv_usec) > next_flush.tv_nsec)))
     {
+      RRDD_LOG(LOG_DEBUG, "flushing old values");
+
+      /* Determine the time of the next cache flush. */
+      next_flush.tv_sec = now.tv_sec + config_flush_interval;
+
       /* Flush all values that haven't been written in the last
        * `config_write_interval' seconds. */
       flush_old_values (config_write_interval);
 
-      /* Determine the time of the next cache flush. */
-      while (next_flush.tv_sec <= now.tv_sec)
-        next_flush.tv_sec += config_flush_interval;
-
       /* unlock the cache while we rotate so we don't block incoming
        * updates if the fsync() blocks on disk I/O */
       pthread_mutex_unlock(&cache_lock);
@@ -639,28 +836,49 @@ static void *queue_thread_main (void *args __attribute__((unused))) /* {{{ */
       pthread_mutex_lock(&cache_lock);
     }
 
+    status = pthread_cond_timedwait(&flush_cond, &cache_lock, &next_flush);
+    if (status != 0 && status != ETIMEDOUT)
+    {
+      RRDD_LOG (LOG_ERR, "flush_thread_main: "
+                "pthread_cond_timedwait returned %i.", status);
+    }
+  }
+
+  if (config_flush_at_shutdown)
+    flush_old_values (-1); /* flush everything */
+
+  state = SHUTDOWN;
+
+  pthread_mutex_unlock(&cache_lock);
+
+  return NULL;
+} /* void *flush_thread_main */
+
+static void *queue_thread_main (void *args __attribute__((unused))) /* {{{ */
+{
+  pthread_mutex_lock (&cache_lock);
+
+  while (state != SHUTDOWN
+         || (cache_queue_head != NULL && config_flush_at_shutdown))
+  {
+    cache_item_t *ci;
+    char *file;
+    char **values;
+    size_t values_num;
+    int status;
+
     /* Now, check if there's something to store away. If not, wait until
-     * something comes in or it's time to do the cache flush.  if we are
-     * shutting down, do not wait around.  */
-    if (cache_queue_head == NULL && !do_shutdown)
+     * something comes in. */
+    if (cache_queue_head == NULL)
     {
-      status = pthread_cond_timedwait (&cache_cond, &cache_lock, &next_flush);
+      status = pthread_cond_wait (&queue_cond, &cache_lock);
       if ((status != 0) && (status != ETIMEDOUT))
       {
         RRDD_LOG (LOG_ERR, "queue_thread_main: "
-            "pthread_cond_timedwait returned %i.", status);
+            "pthread_cond_wait returned %i.", status);
       }
     }
 
-    /* We're about to shut down */
-    if (do_shutdown != 0 && !final_flush++)
-    {
-      if (config_flush_at_shutdown)
-        flush_old_values (-1); /* flush everything */
-      else
-        break;
-    }
-
     /* Check if a value has arrived. This may be NULL if we timed out or there
      * was an interrupt such as a signal. */
     if (cache_queue_head == NULL)
@@ -682,22 +900,13 @@ static void *queue_thread_main (void *args __attribute__((unused))) /* {{{ */
     values = ci->values;
     values_num = ci->values_num;
 
-    _wipe_ci_values(ci, time(NULL));
-
-    cache_queue_head = ci->next;
-    if (cache_queue_head == NULL)
-      cache_queue_tail = NULL;
-    ci->next = NULL;
-
-    pthread_mutex_lock (&stats_lock);
-    assert (stats_queue_length > 0);
-    stats_queue_length--;
-    pthread_mutex_unlock (&stats_lock);
+    wipe_ci_values(ci, time(NULL));
+    remove_from_queue(ci);
 
     pthread_mutex_unlock (&cache_lock);
 
     rrd_clear_error ();
-    status = rrd_update_r (file, NULL, values_num, (void *) values);
+    status = rrd_update_r (file, NULL, (int) values_num, (void *) values);
     if (status != 0)
     {
       RRDD_LOG (LOG_NOTICE, "queue_thread_main: "
@@ -706,12 +915,16 @@ static void *queue_thread_main (void *args __attribute__((unused))) /* {{{ */
     }
 
     journal_write("wrote", file);
-    pthread_cond_broadcast(&ci->flushed);
 
-    for (i = 0; i < values_num; i++)
-      free (values[i]);
+    /* Search again in the tree.  It's possible someone issued a "FORGET"
+     * while we were writing the update values. */
+    pthread_mutex_lock(&cache_lock);
+    ci = (cache_item_t *) g_tree_lookup(cache_tree, file);
+    if (ci)
+      pthread_cond_broadcast(&ci->flushed);
+    pthread_mutex_unlock(&cache_lock);
 
-    free(values);
+    rrd_free_ptrs((void ***) &values, &values_num);
     free(file);
 
     if (status == 0)
@@ -723,25 +936,8 @@ static void *queue_thread_main (void *args __attribute__((unused))) /* {{{ */
     }
 
     pthread_mutex_lock (&cache_lock);
-
-    /* We're about to shut down */
-    if (do_shutdown != 0 && !final_flush++)
-    {
-      if (config_flush_at_shutdown)
-          flush_old_values (-1); /* flush everything */
-      else
-        break;
-    }
-  } /* while ((do_shutdown == 0) || (cache_queue_head != NULL)) */
-  pthread_mutex_unlock (&cache_lock);
-
-  if (config_flush_at_shutdown)
-  {
-    assert(cache_queue_head == NULL);
-    RRDD_LOG(LOG_INFO, "clean shutdown; all RRDs flushed");
   }
-
-  journal_done();
+  pthread_mutex_unlock (&cache_lock);
 
   return (NULL);
 } /* }}} void *queue_thread_main */
@@ -809,6 +1005,72 @@ static int buffer_get_field (char **buffer_ret, /* {{{ */
   return (0);
 } /* }}} int buffer_get_field */
 
+/* if we're restricting writes to the base directory,
+ * check whether the file falls within the dir
+ * returns 1 if OK, otherwise 0
+ */
+static int check_file_access (const char *file, listen_socket_t *sock) /* {{{ */
+{
+  assert(file != NULL);
+
+  if (!config_write_base_only
+      || sock == NULL /* journal replay */
+      || config_base_dir == NULL)
+    return 1;
+
+  if (strstr(file, "../") != NULL) goto err;
+
+  /* relative paths without "../" are ok */
+  if (*file != '/') return 1;
+
+  /* file must be of the format base + "/" + <1+ char filename> */
+  if (strlen(file) < _config_base_dir_len + 2) goto err;
+  if (strncmp(file, config_base_dir, _config_base_dir_len) != 0) goto err;
+  if (*(file + _config_base_dir_len) != '/') goto err;
+
+  return 1;
+
+err:
+  if (sock != NULL && sock->fd >= 0)
+    send_response(sock, RESP_ERR, "%s\n", rrd_strerror(EACCES));
+
+  return 0;
+} /* }}} static int check_file_access */
+
+/* when using a base dir, convert relative paths to absolute paths.
+ * if necessary, modifies the "filename" pointer to point
+ * to the new path created in "tmp".  "tmp" is provided
+ * by the caller and sizeof(tmp) must be >= PATH_MAX.
+ *
+ * this allows us to optimize for the expected case (absolute path)
+ * with a no-op.
+ */
+static void get_abs_path(char **filename, char *tmp)
+{
+  assert(tmp != NULL);
+  assert(filename != NULL && *filename != NULL);
+
+  if (config_base_dir == NULL || **filename == '/')
+    return;
+
+  snprintf(tmp, PATH_MAX, "%s/%s", config_base_dir, *filename);
+  *filename = tmp;
+} /* }}} static int get_abs_path */
+
+/* returns 1 if we have the required privilege level,
+ * otherwise issue an error to the user on sock */
+static int has_privilege (listen_socket_t *sock, /* {{{ */
+                          socket_privilege priv)
+{
+  if (sock == NULL) /* journal replay */
+    return 1;
+
+  if (sock->privilege >= priv)
+    return 1;
+
+  return send_response(sock, RESP_ERR, "%s\n", rrd_strerror(EACCES));
+} /* }}} static int has_privilege */
+
 static int flush_file (const char *filename) /* {{{ */
 {
   cache_item_t *ci;
@@ -829,131 +1091,26 @@ static int flush_file (const char *filename) /* {{{ */
     pthread_cond_wait(&ci->flushed, &cache_lock);
   }
 
+  /* DO NOT DO ANYTHING WITH ci HERE!!  The entry
+   * may have been purged during our cond_wait() */
+
   pthread_mutex_unlock(&cache_lock);
 
   return (0);
 } /* }}} int flush_file */
 
-static int handle_request_help (int fd, /* {{{ */
-    char *buffer, size_t buffer_size)
+static int syntax_error(listen_socket_t *sock, struct command *cmd) /* {{{ */
 {
-  int status;
-  char **help_text;
-  size_t help_text_len;
-  char *command;
-  size_t i;
-
-  char *help_help[] =
-  {
-    "5 Command overview\n",
-    "FLUSH <filename>\n",
-    "FLUSHALL\n",
-    "HELP [<command>]\n",
-    "UPDATE <filename> <values> [<values> ...]\n",
-    "STATS\n"
-  };
-  size_t help_help_len = sizeof (help_help) / sizeof (help_help[0]);
-
-  char *help_flush[] =
-  {
-    "4 Help for FLUSH\n",
-    "Usage: FLUSH <filename>\n",
-    "\n",
-    "Adds the given filename to the head of the update queue and returns\n",
-    "after is has been dequeued.\n"
-  };
-  size_t help_flush_len = sizeof (help_flush) / sizeof (help_flush[0]);
-
-  char *help_flushall[] =
-  {
-    "3 Help for FLUSHALL\n",
-    "Usage: FLUSHALL\n",
-    "\n",
-    "Triggers writing of all pending updates.  Returns immediately.\n"
-  };
-  size_t help_flushall_len = sizeof(help_flushall) / sizeof(help_flushall[0]);
-
-  char *help_update[] =
-  {
-    "9 Help for UPDATE\n",
-    "Usage: UPDATE <filename> <values> [<values> ...]\n"
-    "\n",
-    "Adds the given file to the internal cache if it is not yet known and\n",
-    "appends the given value(s) to the entry. See the rrdcached(1) manpage\n",
-    "for details.\n",
-    "\n",
-    "Each <values> has the following form:\n",
-    "  <values> = <time>:<value>[:<value>[...]]\n",
-    "See the rrdupdate(1) manpage for details.\n"
-  };
-  size_t help_update_len = sizeof (help_update) / sizeof (help_update[0]);
-
-  char *help_stats[] =
-  {
-    "4 Help for STATS\n",
-    "Usage: STATS\n",
-    "\n",
-    "Returns some performance counters, see the rrdcached(1) manpage for\n",
-    "a description of the values.\n"
-  };
-  size_t help_stats_len = sizeof (help_stats) / sizeof (help_stats[0]);
-
-  status = buffer_get_field (&buffer, &buffer_size, &command);
-  if (status != 0)
-  {
-    help_text = help_help;
-    help_text_len = help_help_len;
-  }
-  else
-  {
-    if (strcasecmp (command, "update") == 0)
-    {
-      help_text = help_update;
-      help_text_len = help_update_len;
-    }
-    else if (strcasecmp (command, "flush") == 0)
-    {
-      help_text = help_flush;
-      help_text_len = help_flush_len;
-    }
-    else if (strcasecmp (command, "flushall") == 0)
-    {
-      help_text = help_flushall;
-      help_text_len = help_flushall_len;
-    }
-    else if (strcasecmp (command, "stats") == 0)
-    {
-      help_text = help_stats;
-      help_text_len = help_stats_len;
-    }
-    else
-    {
-      help_text = help_help;
-      help_text_len = help_help_len;
-    }
-  }
+  char *err = "Syntax error.\n";
 
-  for (i = 0; i < help_text_len; i++)
-  {
-    status = swrite (fd, help_text[i], strlen (help_text[i]));
-    if (status < 0)
-    {
-      status = errno;
-      RRDD_LOG (LOG_ERR, "handle_request_help: swrite returned an error.");
-      return (status);
-    }
-  }
+  if (cmd && cmd->syntax)
+    err = cmd->syntax;
 
-  return (0);
-} /* }}} int handle_request_help */
+  return send_response(sock, RESP_ERR, "Usage: %s", err);
+} /* }}} static int syntax_error() */
 
-static int handle_request_stats (int fd, /* {{{ */
-    char *buffer __attribute__((unused)),
-    size_t buffer_size __attribute__((unused)))
+static int handle_request_stats (HANDLER_PROTO) /* {{{ */
 {
-  int status;
-  char outbuf[CMD_MAX];
-
   uint64_t copy_queue_length;
   uint64_t copy_updates_received;
   uint64_t copy_flush_received;
@@ -980,70 +1137,35 @@ static int handle_request_stats (int fd, /* {{{ */
   tree_depth        = (uint64_t) g_tree_height (cache_tree);
   pthread_mutex_unlock (&cache_lock);
 
-#define RRDD_STATS_SEND \
-  outbuf[sizeof (outbuf) - 1] = 0; \
-  status = swrite (fd, outbuf, strlen (outbuf)); \
-  if (status < 0) \
-  { \
-    status = errno; \
-    RRDD_LOG (LOG_INFO, "handle_request_stats: swrite returned an error."); \
-    return (status); \
-  }
-
-  strncpy (outbuf, "9 Statistics follow\n", sizeof (outbuf));
-  RRDD_STATS_SEND;
-
-  snprintf (outbuf, sizeof (outbuf),
-      "QueueLength: %"PRIu64"\n", copy_queue_length);
-  RRDD_STATS_SEND;
-
-  snprintf (outbuf, sizeof (outbuf),
-      "UpdatesReceived: %"PRIu64"\n", copy_updates_received);
-  RRDD_STATS_SEND;
-
-  snprintf (outbuf, sizeof (outbuf),
-      "FlushesReceived: %"PRIu64"\n", copy_flush_received);
-  RRDD_STATS_SEND;
-
-  snprintf (outbuf, sizeof (outbuf),
-      "UpdatesWritten: %"PRIu64"\n", copy_updates_written);
-  RRDD_STATS_SEND;
-
-  snprintf (outbuf, sizeof (outbuf),
-      "DataSetsWritten: %"PRIu64"\n", copy_data_sets_written);
-  RRDD_STATS_SEND;
-
-  snprintf (outbuf, sizeof (outbuf),
-      "TreeNodesNumber: %"PRIu64"\n", tree_nodes_number);
-  RRDD_STATS_SEND;
-
-  snprintf (outbuf, sizeof (outbuf),
-      "TreeDepth: %"PRIu64"\n", tree_depth);
-  RRDD_STATS_SEND;
-
-  snprintf (outbuf, sizeof(outbuf),
-      "JournalBytes: %"PRIu64"\n", copy_journal_bytes);
-  RRDD_STATS_SEND;
-
-  snprintf (outbuf, sizeof(outbuf),
-      "JournalRotate: %"PRIu64"\n", copy_journal_rotate);
-  RRDD_STATS_SEND;
+  add_response_info(sock,
+                    "QueueLength: %"PRIu64"\n", copy_queue_length);
+  add_response_info(sock,
+                    "UpdatesReceived: %"PRIu64"\n", copy_updates_received);
+  add_response_info(sock,
+                    "FlushesReceived: %"PRIu64"\n", copy_flush_received);
+  add_response_info(sock,
+                    "UpdatesWritten: %"PRIu64"\n", copy_updates_written);
+  add_response_info(sock,
+                    "DataSetsWritten: %"PRIu64"\n", copy_data_sets_written);
+  add_response_info(sock, "TreeNodesNumber: %"PRIu64"\n", tree_nodes_number);
+  add_response_info(sock, "TreeDepth: %"PRIu64"\n", tree_depth);
+  add_response_info(sock, "JournalBytes: %"PRIu64"\n", copy_journal_bytes);
+  add_response_info(sock, "JournalRotate: %"PRIu64"\n", copy_journal_rotate);
+
+  send_response(sock, RESP_OK, "Statistics follow\n");
 
   return (0);
-#undef RRDD_STATS_SEND
 } /* }}} int handle_request_stats */
 
-static int handle_request_flush (int fd, /* {{{ */
-    char *buffer, size_t buffer_size)
+static int handle_request_flush (HANDLER_PROTO) /* {{{ */
 {
-  char *file;
+  char *file, file_tmp[PATH_MAX];
   int status;
-  char result[CMD_MAX];
 
   status = buffer_get_field (&buffer, &buffer_size, &file);
   if (status != 0)
   {
-    strncpy (result, "-1 Usage: flush <filename>\n", sizeof (result));
+    return syntax_error(sock,cmd);
   }
   else
   {
@@ -1051,9 +1173,12 @@ static int handle_request_flush (int fd, /* {{{ */
     stats_flush_received++;
     pthread_mutex_unlock(&stats_lock);
 
+    get_abs_path(&file, file_tmp);
+    if (!check_file_access(file, sock)) return 0;
+
     status = flush_file (file);
     if (status == 0)
-      snprintf (result, sizeof (result), "0 Successfully flushed %s.\n", file);
+      return send_response(sock, RESP_OK, "Successfully flushed %s.\n", file);
     else if (status == ENOENT)
     {
       /* no file in our tree; see whether it exists at all */
@@ -1061,92 +1186,137 @@ static int handle_request_flush (int fd, /* {{{ */
 
       memset(&statbuf, 0, sizeof(statbuf));
       if (stat(file, &statbuf) == 0 && S_ISREG(statbuf.st_mode))
-        snprintf (result, sizeof (result), "0 Nothing to flush: %s.\n", file);
+        return send_response(sock, RESP_OK, "Nothing to flush: %s.\n", file);
       else
-        snprintf (result, sizeof (result), "-1 No such file: %s.\n", file);
+        return send_response(sock, RESP_ERR, "No such file: %s.\n", file);
     }
     else if (status < 0)
-      strncpy (result, "-1 Internal error.\n", sizeof (result));
+      return send_response(sock, RESP_ERR, "Internal error.\n");
     else
-      snprintf (result, sizeof (result), "-1 Failed with status %i.\n", status);
-  }
-  result[sizeof (result) - 1] = 0;
-
-  status = swrite (fd, result, strlen (result));
-  if (status < 0)
-  {
-    status = errno;
-    RRDD_LOG (LOG_INFO, "handle_request_flush: swrite returned an error.");
-    return (status);
+      return send_response(sock, RESP_ERR, "Failed with status %i.\n", status);
   }
 
-  return (0);
+  /* NOTREACHED */
+  assert(1==0);
 } /* }}} int handle_request_flush */
 
-static int handle_request_flushall(int fd) /* {{{ */
+static int handle_request_flushall(HANDLER_PROTO) /* {{{ */
 {
-  int status;
-  char answer[] ="0 Started flush.\n";
-
   RRDD_LOG(LOG_DEBUG, "Received FLUSHALL");
 
   pthread_mutex_lock(&cache_lock);
   flush_old_values(-1);
   pthread_mutex_unlock(&cache_lock);
 
-  status = swrite(fd, answer, strlen(answer));
-  if (status < 0)
+  return send_response(sock, RESP_OK, "Started flush.\n");
+} /* }}} static int handle_request_flushall */
+
+static int handle_request_pending(HANDLER_PROTO) /* {{{ */
+{
+  int status;
+  char *file, file_tmp[PATH_MAX];
+  cache_item_t *ci;
+
+  status = buffer_get_field(&buffer, &buffer_size, &file);
+  if (status != 0)
+    return syntax_error(sock,cmd);
+
+  get_abs_path(&file, file_tmp);
+
+  pthread_mutex_lock(&cache_lock);
+  ci = g_tree_lookup(cache_tree, file);
+  if (ci == NULL)
   {
-    status = errno;
-    RRDD_LOG(LOG_INFO, "handle_request_flushall: swrite returned an error.");
+    pthread_mutex_unlock(&cache_lock);
+    return send_response(sock, RESP_ERR, "%s\n", rrd_strerror(ENOENT));
   }
 
-  return (status);
-} /* }}} static int handle_request_flushall */
+  for (size_t i=0; i < ci->values_num; i++)
+    add_response_info(sock, "%s\n", ci->values[i]);
+
+  pthread_mutex_unlock(&cache_lock);
+  return send_response(sock, RESP_OK, "updates pending\n");
+} /* }}} static int handle_request_pending */
 
-static int handle_request_update (int fd, /* {{{ */
-    char *buffer, size_t buffer_size)
+static int handle_request_forget(HANDLER_PROTO) /* {{{ */
 {
-  char *file;
-  int values_num = 0;
   int status;
+  gboolean found;
+  char *file, file_tmp[PATH_MAX];
 
-  time_t now;
+  status = buffer_get_field(&buffer, &buffer_size, &file);
+  if (status != 0)
+    return syntax_error(sock,cmd);
+
+  get_abs_path(&file, file_tmp);
+  if (!check_file_access(file, sock)) return 0;
+
+  pthread_mutex_lock(&cache_lock);
+  found = g_tree_remove(cache_tree, file);
+  pthread_mutex_unlock(&cache_lock);
 
+  if (found == TRUE)
+  {
+    if (sock != NULL)
+      journal_write("forget", file);
+
+    return send_response(sock, RESP_OK, "Gone!\n");
+  }
+  else
+    return send_response(sock, RESP_ERR, "%s\n", rrd_strerror(ENOENT));
+
+  /* NOTREACHED */
+  assert(1==0);
+} /* }}} static int handle_request_forget */
+
+static int handle_request_queue (HANDLER_PROTO) /* {{{ */
+{
   cache_item_t *ci;
-  char answer[CMD_MAX];
 
-#define RRDD_UPDATE_SEND \
-  answer[sizeof (answer) - 1] = 0; \
-  status = swrite (fd, answer, strlen (answer)); \
-  if (status < 0) \
-  { \
-    status = errno; \
-    RRDD_LOG (LOG_INFO, "handle_request_update: swrite returned an error."); \
-    return (status); \
+  pthread_mutex_lock(&cache_lock);
+
+  ci = cache_queue_head;
+  while (ci != NULL)
+  {
+    add_response_info(sock, "%d %s\n", ci->values_num, ci->file);
+    ci = ci->next;
   }
 
-  now = time (NULL);
+  pthread_mutex_unlock(&cache_lock);
+
+  return send_response(sock, RESP_OK, "in queue.\n");
+} /* }}} int handle_request_queue */
+
+static int handle_request_update (HANDLER_PROTO) /* {{{ */
+{
+  char *file, file_tmp[PATH_MAX];
+  int values_num = 0;
+  int status;
+  char orig_buf[CMD_MAX];
+
+  cache_item_t *ci;
+
+  /* save it for the journal later */
+  strncpy(orig_buf, buffer, sizeof(orig_buf)-1);
 
   status = buffer_get_field (&buffer, &buffer_size, &file);
   if (status != 0)
-  {
-    strncpy (answer, "-1 Usage: UPDATE <filename> <values> [<values> ...]\n",
-        sizeof (answer));
-    RRDD_UPDATE_SEND;
-    return (0);
-  }
+    return syntax_error(sock,cmd);
 
   pthread_mutex_lock(&stats_lock);
   stats_updates_received++;
   pthread_mutex_unlock(&stats_lock);
 
+  get_abs_path(&file, file_tmp);
+  if (!check_file_access(file, sock)) return 0;
+
   pthread_mutex_lock (&cache_lock);
   ci = g_tree_lookup (cache_tree, file);
 
   if (ci == NULL) /* {{{ */
   {
     struct stat statbuf;
+    cache_item_t *tmp;
 
     /* don't hold the lock while we setup; stat(2) might block */
     pthread_mutex_unlock(&cache_lock);
@@ -1159,35 +1329,24 @@ static int handle_request_update (int fd, /* {{{ */
 
       status = errno;
       if (status == ENOENT)
-        snprintf (answer, sizeof (answer), "-1 No such file: %s\n", file);
+        return send_response(sock, RESP_ERR, "No such file: %s\n", file);
       else
-        snprintf (answer, sizeof (answer), "-1 stat failed with error %i.\n",
-            status);
-      RRDD_UPDATE_SEND;
-      return (0);
+        return send_response(sock, RESP_ERR,
+                             "stat failed with error %i.\n", status);
     }
     if (!S_ISREG (statbuf.st_mode))
-    {
-      snprintf (answer, sizeof (answer), "-1 Not a regular file: %s\n", file);
-      RRDD_UPDATE_SEND;
-      return (0);
-    }
+      return send_response(sock, RESP_ERR, "Not a regular file: %s\n", file);
+
     if (access(file, R_OK|W_OK) != 0)
-    {
-      snprintf (answer, sizeof (answer), "-1 Cannot read/write %s: %s\n",
-                file, rrd_strerror(errno));
-      RRDD_UPDATE_SEND;
-      return (0);
-    }
+      return send_response(sock, RESP_ERR, "Cannot read/write %s: %s\n",
+                           file, rrd_strerror(errno));
 
     ci = (cache_item_t *) malloc (sizeof (cache_item_t));
     if (ci == NULL)
     {
       RRDD_LOG (LOG_ERR, "handle_request_update: malloc failed.");
 
-      strncpy (answer, "-1 malloc failed.\n", sizeof (answer));
-      RRDD_UPDATE_SEND;
-      return (0);
+      return send_response(sock, RESP_ERR, "malloc failed.\n");
     }
     memset (ci, 0, sizeof (cache_item_t));
 
@@ -1197,23 +1356,40 @@ static int handle_request_update (int fd, /* {{{ */
       free (ci);
       RRDD_LOG (LOG_ERR, "handle_request_update: strdup failed.");
 
-      strncpy (answer, "-1 strdup failed.\n", sizeof (answer));
-      RRDD_UPDATE_SEND;
-      return (0);
+      return send_response(sock, RESP_ERR, "strdup failed.\n");
     }
 
-    _wipe_ci_values(ci, now);
+    wipe_ci_values(ci, now);
     ci->flags = CI_FLAGS_IN_TREE;
+    pthread_cond_init(&ci->flushed, NULL);
 
     pthread_mutex_lock(&cache_lock);
-    g_tree_insert (cache_tree, (void *) ci->file, (void *) ci);
+
+    /* another UPDATE might have added this entry in the meantime */
+    tmp = g_tree_lookup (cache_tree, file);
+    if (tmp == NULL)
+      g_tree_replace (cache_tree, (void *) ci->file, (void *) ci);
+    else
+    {
+      free_cache_item (ci);
+      ci = tmp;
+    }
+
+    /* state may have changed while we were unlocked */
+    if (state == SHUTDOWN)
+      return -1;
   } /* }}} */
   assert (ci != NULL);
 
+  /* don't re-write updates in replay mode */
+  if (sock != NULL)
+    journal_write("update", orig_buf);
+
   while (buffer_size > 0)
   {
-    char **temp;
     char *value;
+    time_t stamp;
+    char *eostamp;
 
     status = buffer_get_field (&buffer, &buffer_size, &value);
     if (status != 0)
@@ -1222,22 +1398,30 @@ static int handle_request_update (int fd, /* {{{ */
       break;
     }
 
-    temp = (char **) realloc (ci->values,
-        sizeof (char *) * (ci->values_num + 1));
-    if (temp == NULL)
+    /* make sure update time is always moving forward */
+    stamp = strtol(value, &eostamp, 10);
+    if (eostamp == value || eostamp == NULL || *eostamp != ':')
     {
-      RRDD_LOG (LOG_ERR, "handle_request_update: realloc failed.");
-      continue;
+      pthread_mutex_unlock(&cache_lock);
+      return send_response(sock, RESP_ERR,
+                           "Cannot find timestamp in '%s'!\n", value);
+    }
+    else if (stamp <= ci->last_update_stamp)
+    {
+      pthread_mutex_unlock(&cache_lock);
+      return send_response(sock, RESP_ERR,
+                           "illegal attempt to update using time %ld when last"
+                           " update time is %ld (minimum one second step)\n",
+                           stamp, ci->last_update_stamp);
     }
-    ci->values = temp;
+    else
+      ci->last_update_stamp = stamp;
 
-    ci->values[ci->values_num] = strdup (value);
-    if (ci->values[ci->values_num] == NULL)
+    if (!rrd_add_strdup(&ci->values, &ci->values_num, value))
     {
-      RRDD_LOG (LOG_ERR, "handle_request_update: strdup failed.");
+      RRDD_LOG (LOG_ERR, "handle_request_update: rrd_add_strdup failed.");
       continue;
     }
-    ci->values_num++;
 
     values_num++;
   }
@@ -1252,27 +1436,21 @@ static int handle_request_update (int fd, /* {{{ */
   pthread_mutex_unlock (&cache_lock);
 
   if (values_num < 1)
-  {
-    strncpy (answer, "-1 No values updated.\n", sizeof (answer));
-  }
+    return send_response(sock, RESP_ERR, "No values updated.\n");
   else
-  {
-    snprintf (answer, sizeof (answer), "0 Enqueued %i value%s\n", values_num,
-        (values_num == 1) ? "" : "s");
-  }
-  RRDD_UPDATE_SEND;
-  return (0);
-#undef RRDD_UPDATE_SEND
+    return send_response(sock, RESP_OK,
+                         "errors, enqueued %i value(s).\n", values_num);
+
+  /* NOTREACHED */
+  assert(1==0);
+
 } /* }}} int handle_request_update */
 
 /* we came across a "WROTE" entry during journal replay.
  * throw away any values that we have accumulated for this file
  */
-static int handle_request_wrote (int fd __attribute__((unused)), /* {{{ */
-                                 const char *buffer,
-                                 size_t buffer_size __attribute__((unused)))
+static int handle_request_wrote (HANDLER_PROTO) /* {{{ */
 {
-  int i;
   cache_item_t *ci;
   const char *file = buffer;
 
@@ -1286,116 +1464,292 @@ static int handle_request_wrote (int fd __attribute__((unused)), /* {{{ */
   }
 
   if (ci->values)
-  {
-    for (i=0; i < ci->values_num; i++)
-      free(ci->values[i]);
+    rrd_free_ptrs((void ***) &ci->values, &ci->values_num);
 
-    free(ci->values);
-  }
-
-  _wipe_ci_values(ci, time(NULL));
+  wipe_ci_values(ci, now);
+  remove_from_queue(ci);
 
   pthread_mutex_unlock(&cache_lock);
   return (0);
 } /* }}} int handle_request_wrote */
 
-/* returns 1 if we have the required privilege level */
-static int has_privilege (socket_privilege priv, /* {{{ */
-                          socket_privilege required, int fd)
+/* start "BATCH" processing */
+static int batch_start (HANDLER_PROTO) /* {{{ */
 {
   int status;
-  char error[CMD_MAX];
+  if (sock->batch_start)
+    return send_response(sock, RESP_ERR, "Already in BATCH\n");
 
-  if (priv >= required)
-    return 1;
+  status = send_response(sock, RESP_OK,
+                         "Go ahead.  End with dot '.' on its own line.\n");
+  sock->batch_start = time(NULL);
+  sock->batch_cmd = 0;
 
-  sprintf(error, "-1 %s\n", rrd_strerror(EACCES));
-  status = swrite(fd, error, strlen(error));
+  return status;
+} /* }}} static int batch_start */
 
-  if (status < 0)
-    return status;
-  else
-    return 0;
-} /* }}} static int has_privilege */
+/* finish "BATCH" processing and return results to the client */
+static int batch_done (HANDLER_PROTO) /* {{{ */
+{
+  assert(sock->batch_start);
+  sock->batch_start = 0;
+  sock->batch_cmd  = 0;
+  return send_response(sock, RESP_OK, "errors\n");
+} /* }}} static int batch_done */
 
-/* if fd < 0, we are in journal replay mode */
-static int handle_request (int fd, socket_privilege privilege, /* {{{ */
-                           char *buffer, size_t buffer_size)
+static int handle_request_quit (HANDLER_PROTO) /* {{{ */
 {
-  char *buffer_ptr;
-  char *command;
-  int status;
+  return -1;
+} /* }}} static int handle_request_quit */
+
+struct command COMMANDS[] = {
+  {
+    "UPDATE",
+    handle_request_update,
+    PRIV_HIGH,
+    CMD_CONTEXT_ANY,
+    "UPDATE <filename> <values> [<values> ...]\n"
+    ,
+    "Adds the given file to the internal cache if it is not yet known and\n"
+    "appends the given value(s) to the entry. See the rrdcached(1) manpage\n"
+    "for details.\n"
+    "\n"
+    "Each <values> has the following form:\n"
+    "  <values> = <time>:<value>[:<value>[...]]\n"
+    "See the rrdupdate(1) manpage for details.\n"
+  },
+  {
+    "WROTE",
+    handle_request_wrote,
+    PRIV_HIGH,
+    CMD_CONTEXT_JOURNAL,
+    NULL,
+    NULL
+  },
+  {
+    "FLUSH",
+    handle_request_flush,
+    PRIV_LOW,
+    CMD_CONTEXT_CLIENT | CMD_CONTEXT_BATCH,
+    "FLUSH <filename>\n"
+    ,
+    "Adds the given filename to the head of the update queue and returns\n"
+    "after it has been dequeued.\n"
+  },
+  {
+    "FLUSHALL",
+    handle_request_flushall,
+    PRIV_HIGH,
+    CMD_CONTEXT_CLIENT,
+    "FLUSHALL\n"
+    ,
+    "Triggers writing of all pending updates.  Returns immediately.\n"
+  },
+  {
+    "PENDING",
+    handle_request_pending,
+    PRIV_HIGH,
+    CMD_CONTEXT_CLIENT,
+    "PENDING <filename>\n"
+    ,
+    "Shows any 'pending' updates for a file, in order.\n"
+    "The updates shown have not yet been written to the underlying RRD file.\n"
+  },
+  {
+    "FORGET",
+    handle_request_forget,
+    PRIV_HIGH,
+    CMD_CONTEXT_ANY,
+    "FORGET <filename>\n"
+    ,
+    "Removes the file completely from the cache.\n"
+    "Any pending updates for the file will be lost.\n"
+  },
+  {
+    "QUEUE",
+    handle_request_queue,
+    PRIV_LOW,
+    CMD_CONTEXT_CLIENT,
+    "QUEUE\n"
+    ,
+        "Shows all files in the output queue.\n"
+    "The output is zero or more lines in the following format:\n"
+    "(where <num_vals> is the number of values to be written)\n"
+    "\n"
+    "<num_vals> <filename>\n"
+  },
+  {
+    "STATS",
+    handle_request_stats,
+    PRIV_LOW,
+    CMD_CONTEXT_CLIENT,
+    "STATS\n"
+    ,
+    "Returns some performance counters, see the rrdcached(1) manpage for\n"
+    "a description of the values.\n"
+  },
+  {
+    "HELP",
+    handle_request_help,
+    PRIV_LOW,
+    CMD_CONTEXT_CLIENT,
+    "HELP [<command>]\n",
+    NULL, /* special! */
+  },
+  {
+    "BATCH",
+    batch_start,
+    PRIV_LOW,
+    CMD_CONTEXT_CLIENT,
+    "BATCH\n"
+    ,
+    "The 'BATCH' command permits the client to initiate a bulk load\n"
+    "   of commands to rrdcached.\n"
+    "\n"
+    "Usage:\n"
+    "\n"
+    "    client: BATCH\n"
+    "    server: 0 Go ahead.  End with dot '.' on its own line.\n"
+    "    client: command #1\n"
+    "    client: command #2\n"
+    "    client: ... and so on\n"
+    "    client: .\n"
+    "    server: 2 errors\n"
+    "    server: 7 message for command #7\n"
+    "    server: 9 message for command #9\n"
+    "\n"
+    "For more information, consult the rrdcached(1) documentation.\n"
+  },
+  {
+    ".",   /* BATCH terminator */
+    batch_done,
+    PRIV_LOW,
+    CMD_CONTEXT_BATCH,
+    NULL,
+    NULL
+  },
+  {
+    "QUIT",
+    handle_request_quit,
+    PRIV_LOW,
+    CMD_CONTEXT_CLIENT | CMD_CONTEXT_BATCH,
+    "QUIT\n"
+    ,
+    "Disconnect from rrdcached.\n"
+  },
+  {NULL,NULL,0,0,NULL,NULL}  /* LAST ENTRY */
+};
 
-  assert (buffer[buffer_size - 1] == '\0');
+static struct command *find_command(char *cmd)
+{
+  struct command *c = COMMANDS;
 
-  buffer_ptr = buffer;
-  command = NULL;
-  status = buffer_get_field (&buffer_ptr, &buffer_size, &command);
-  if (status != 0)
+  while (c->cmd != NULL)
   {
-    RRDD_LOG (LOG_INFO, "handle_request: Unable parse command.");
-    return (-1);
+    if (strcasecmp(cmd, c->cmd) == 0)
+      break;
+    c++;
   }
 
-  if (strcasecmp (command, "update") == 0)
-  {
-    /* don't re-write updates in replay mode */
-    if (fd >= 0)
-      journal_write(command, buffer_ptr);
+  if (c->cmd == NULL)
+    return NULL;
+  else
+    return c;
+}
 
-    status = has_privilege(privilege, PRIV_HIGH, fd);
-    if (status <= 0)
-      return status;
+/* check whether commands are received in the expected context */
+static int command_check_context(listen_socket_t *sock, struct command *cmd)
+{
+  if (sock == NULL)
+    return (cmd->context & CMD_CONTEXT_JOURNAL);
+  else if (sock->batch_start)
+    return (cmd->context & CMD_CONTEXT_BATCH);
+  else
+    return (cmd->context & CMD_CONTEXT_CLIENT);
 
-    return (handle_request_update (fd, buffer_ptr, buffer_size));
-  }
-  else if (strcasecmp (command, "wrote") == 0 && fd < 0)
-  {
-    /* this is only valid in replay mode */
-    return (handle_request_wrote (fd, buffer_ptr, buffer_size));
-  }
-  else if (strcasecmp (command, "flush") == 0)
-  {
-    return (handle_request_flush (fd, buffer_ptr, buffer_size));
-  }
-  else if (strcasecmp (command, "flushall") == 0)
-  {
-    status = has_privilege(privilege, PRIV_HIGH, fd);
-    if (status <= 0)
-      return status;
+  /* NOTREACHED */
+  assert(1==0);
+}
 
-    return (handle_request_flushall(fd));
-  }
-  else if (strcasecmp (command, "stats") == 0)
-  {
-    return (handle_request_stats (fd, buffer_ptr, buffer_size));
-  }
-  else if (strcasecmp (command, "help") == 0)
+static int handle_request_help (HANDLER_PROTO) /* {{{ */
+{
+  int status;
+  char *cmd_str;
+  char *resp_txt;
+  struct command *help = NULL;
+
+  status = buffer_get_field (&buffer, &buffer_size, &cmd_str);
+  if (status == 0)
+    help = find_command(cmd_str);
+
+  if (help && (help->syntax || help->help))
   {
-    return (handle_request_help (fd, buffer_ptr, buffer_size));
+    char tmp[CMD_MAX];
+
+    snprintf(tmp, sizeof(tmp)-1, "Help for %s\n", help->cmd);
+    resp_txt = tmp;
+
+    if (help->syntax)
+      add_response_info(sock, "Usage: %s\n", help->syntax);
+
+    if (help->help)
+      add_response_info(sock, "%s\n", help->help);
   }
   else
   {
-    char result[CMD_MAX];
+    help = COMMANDS;
+    resp_txt = "Command overview\n";
 
-    snprintf (result, sizeof (result), "-1 Unknown command: %s\n", command);
-    result[sizeof (result) - 1] = 0;
-
-    status = swrite (fd, result, strlen (result));
-    if (status < 0)
+    while (help->cmd)
     {
-      RRDD_LOG (LOG_ERR, "handle_request: swrite failed.");
-      return (-1);
+      if (help->syntax)
+        add_response_info(sock, "%s", help->syntax);
+      help++;
     }
   }
 
-  return (0);
+  return send_response(sock, RESP_OK, resp_txt);
+} /* }}} int handle_request_help */
+
+/* if sock==NULL, we are in journal replay mode */
+static int handle_request (DISPATCH_PROTO) /* {{{ */
+{
+  char *buffer_ptr = buffer;
+  char *cmd_str = NULL;
+  struct command *cmd = NULL;
+  int status;
+
+  assert (buffer[buffer_size - 1] == '\0');
+
+  status = buffer_get_field (&buffer_ptr, &buffer_size, &cmd_str);
+  if (status != 0)
+  {
+    RRDD_LOG (LOG_INFO, "handle_request: Unable parse command.");
+    return (-1);
+  }
+
+  if (sock != NULL && sock->batch_start)
+    sock->batch_cmd++;
+
+  cmd = find_command(cmd_str);
+  if (!cmd)
+    return send_response(sock, RESP_ERR, "Unknown command: %s\n", cmd_str);
+
+  status = has_privilege(sock, cmd->min_priv);
+  if (status <= 0)
+    return status;
+
+  if (!command_check_context(sock, cmd))
+    return send_response(sock, RESP_ERR, "Can't use '%s' here.\n", cmd_str);
+
+  return cmd->handler(cmd, sock, now, buffer_ptr, buffer_size);
 } /* }}} int handle_request */
 
 /* MUST NOT hold journal_lock before calling this */
 static void journal_rotate(void) /* {{{ */
 {
   FILE *old_fh = NULL;
+  int new_fd;
 
   if (journal_cur == NULL || journal_old == NULL)
     return;
@@ -1410,11 +1764,20 @@ static void journal_rotate(void) /* {{{ */
   if (journal_fh != NULL)
   {
     old_fh = journal_fh;
+    journal_fh = NULL;
     rename(journal_cur, journal_old);
     ++stats_journal_rotate;
   }
 
-  journal_fh = fopen(journal_cur, "a");
+  new_fd = open(journal_cur, O_WRONLY|O_CREAT|O_APPEND,
+                S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH);
+  if (new_fd >= 0)
+  {
+    journal_fh = fdopen(new_fd, "a");
+    if (journal_fh == NULL)
+      close(new_fd);
+  }
+
   pthread_mutex_unlock(&journal_lock);
 
   if (old_fh != NULL)
@@ -1489,9 +1852,48 @@ static int journal_replay (const char *file) /* {{{ */
   int fail_cnt = 0;
   uint64_t line = 0;
   char entry[CMD_MAX];
+  time_t now;
 
   if (file == NULL) return 0;
 
+  {
+    char *reason = "unknown error";
+    int status = 0;
+    struct stat statbuf;
+
+    memset(&statbuf, 0, sizeof(statbuf));
+    if (stat(file, &statbuf) != 0)
+    {
+      if (errno == ENOENT)
+        return 0;
+
+      reason = "stat error";
+      status = errno;
+    }
+    else if (!S_ISREG(statbuf.st_mode))
+    {
+      reason = "not a regular file";
+      status = EPERM;
+    }
+    if (statbuf.st_uid != daemon_uid)
+    {
+      reason = "not owned by daemon user";
+      status = EACCES;
+    }
+    if (statbuf.st_mode & (S_IWGRP|S_IWOTH))
+    {
+      reason = "must not be user/group writable";
+      status = EACCES;
+    }
+
+    if (status != 0)
+    {
+      RRDD_LOG(LOG_ERR, "journal_replay: %s : %s (%s)",
+               file, rrd_strerror(status), reason);
+      return 0;
+    }
+  }
+
   fh = fopen(file, "r");
   if (fh == NULL)
   {
@@ -1503,6 +1905,8 @@ static int journal_replay (const char *file) /* {{{ */
   else
     RRDD_LOG(LOG_NOTICE, "replaying from journal: %s", file);
 
+  now = time(NULL);
+
   while(!feof(fh))
   {
     size_t entry_len;
@@ -1524,7 +1928,7 @@ static int journal_replay (const char *file) /* {{{ */
 
     entry[entry_len - 1] = '\0';
 
-    if (handle_request(-1, PRIV_HIGH, entry, entry_len) == 0)
+    if (handle_request(NULL, now, entry, entry_len) == 0)
       ++entry_cnt;
     else
       ++fail_cnt;
@@ -1532,49 +1936,85 @@ static int journal_replay (const char *file) /* {{{ */
 
   fclose(fh);
 
-  if (entry_cnt > 0)
+  RRDD_LOG(LOG_INFO, "Replayed %d entries (%d failures)",
+           entry_cnt, fail_cnt);
+
+  return entry_cnt > 0 ? 1 : 0;
+} /* }}} static int journal_replay */
+
+static void journal_init(void) /* {{{ */
+{
+  int had_journal = 0;
+
+  if (journal_cur == NULL) return;
+
+  pthread_mutex_lock(&journal_lock);
+
+  RRDD_LOG(LOG_INFO, "checking for journal files");
+
+  had_journal += journal_replay(journal_old);
+  had_journal += journal_replay(journal_cur);
+
+  /* it must have been a crash.  start a flush */
+  if (had_journal && config_flush_at_shutdown)
+    flush_old_values(-1);
+
+  pthread_mutex_unlock(&journal_lock);
+  journal_rotate();
+
+  RRDD_LOG(LOG_INFO, "journal processing complete");
+
+} /* }}} static void journal_init */
+
+static void free_listen_socket(listen_socket_t *sock) /* {{{ */
+{
+  assert(sock != NULL);
+
+  free(sock->rbuf);  sock->rbuf = NULL;
+  free(sock->wbuf);  sock->wbuf = NULL;
+  free(sock);
+} /* }}} void free_listen_socket */
+
+static void close_connection(listen_socket_t *sock) /* {{{ */
+{
+  if (sock->fd >= 0)
   {
-    RRDD_LOG(LOG_INFO, "Replayed %d entries (%d failures)",
-             entry_cnt, fail_cnt);
-    return 1;
+    close(sock->fd);
+    sock->fd = -1;
   }
-  else
-    return 0;
 
-} /* }}} static int journal_replay */
+  free_listen_socket(sock);
+
+} /* }}} void close_connection */
 
 static void *connection_thread_main (void *args) /* {{{ */
 {
-  pthread_t self;
   listen_socket_t *sock;
-  int i;
   int fd;
 
   sock = (listen_socket_t *) args;
   fd = sock->fd;
 
-  pthread_mutex_lock (&connection_threads_lock);
+  /* init read buffers */
+  sock->next_read = sock->next_cmd = 0;
+  sock->rbuf = malloc(RBUF_SIZE);
+  if (sock->rbuf == NULL)
   {
-    pthread_t *temp;
-
-    temp = (pthread_t *) realloc (connection_threads,
-        sizeof (pthread_t) * (connection_threads_num + 1));
-    if (temp == NULL)
-    {
-      RRDD_LOG (LOG_ERR, "connection_thread_main: realloc failed.");
-    }
-    else
-    {
-      connection_threads = temp;
-      connection_threads[connection_threads_num] = pthread_self ();
-      connection_threads_num++;
-    }
+    RRDD_LOG(LOG_ERR, "connection_thread_main: cannot malloc read buffer");
+    close_connection(sock);
+    return NULL;
   }
+
+  pthread_mutex_lock (&connection_threads_lock);
+  connection_threads_num++;
   pthread_mutex_unlock (&connection_threads_lock);
 
-  while (do_shutdown == 0)
+  while (state == RUNNING)
   {
-    char buffer[CMD_MAX];
+    char *cmd;
+    ssize_t cmd_len;
+    ssize_t rbytes;
+    time_t now;
 
     struct pollfd pollfd;
     int status;
@@ -1584,70 +2024,61 @@ static void *connection_thread_main (void *args) /* {{{ */
     pollfd.revents = 0;
 
     status = poll (&pollfd, 1, /* timeout = */ 500);
-    if (do_shutdown)
+    if (state != RUNNING)
       break;
     else if (status == 0) /* timeout */
       continue;
     else if (status < 0) /* error */
     {
       status = errno;
-      if (status == EINTR)
-        continue;
-      RRDD_LOG (LOG_ERR, "connection_thread_main: poll(2) failed.");
+      if (status != EINTR)
+        RRDD_LOG (LOG_ERR, "connection_thread_main: poll(2) failed.");
       continue;
     }
 
     if ((pollfd.revents & POLLHUP) != 0) /* normal shutdown */
-    {
-      close (fd);
       break;
-    }
     else if ((pollfd.revents & (POLLIN | POLLPRI)) == 0)
     {
       RRDD_LOG (LOG_WARNING, "connection_thread_main: "
           "poll(2) returned something unexpected: %#04hx",
           pollfd.revents);
-      close (fd);
       break;
     }
 
-    status = (int) sread (fd, buffer, sizeof (buffer));
-    if (status <= 0)
+    rbytes = read(fd, sock->rbuf + sock->next_read,
+                  RBUF_SIZE - sock->next_read);
+    if (rbytes < 0)
     {
-      close (fd);
-
-      if (status < 0)
-        RRDD_LOG(LOG_ERR, "connection_thread_main: sread failed.");
-
+      RRDD_LOG(LOG_ERR, "connection_thread_main: read() failed.");
       break;
     }
+    else if (rbytes == 0)
+      break; /* eof */
 
-    status = handle_request (fd, sock->privilege, buffer, status);
-    if (status != 0)
-      break;
+    sock->next_read += rbytes;
+
+    if (sock->batch_start)
+      now = sock->batch_start;
+    else
+      now = time(NULL);
+
+    while ((cmd = next_cmd(sock, &cmd_len)) != NULL)
+    {
+      status = handle_request (sock, now, cmd, cmd_len+1);
+      if (status != 0)
+        goto out_close;
+    }
   }
 
-  close(fd);
-  free(args);
+out_close:
+  close_connection(sock);
 
-  self = pthread_self ();
   /* Remove this thread from the connection threads list */
   pthread_mutex_lock (&connection_threads_lock);
-  /* Find out own index in the array */
-  for (i = 0; i < connection_threads_num; i++)
-    if (pthread_equal (connection_threads[i], self) != 0)
-      break;
-  assert (i < connection_threads_num);
-
-  /* Move the trailing threads forward. */
-  if (i < (connection_threads_num - 1))
-  {
-    memmove (connection_threads + i,
-        connection_threads + i + 1,
-        sizeof (pthread_t) * (connection_threads_num - i - 1));
-  }
-
   connection_threads_num--;
+  if (connection_threads_num <= 0)
+    pthread_cond_broadcast(&connection_threads_done);
   pthread_mutex_unlock (&connection_threads_lock);
 
   return (NULL);
@@ -1665,11 +2096,11 @@ static int open_listen_socket_unix (const listen_socket_t *sock) /* {{{ */
   if (strncmp(path, "unix:", strlen("unix:")) == 0)
     path += strlen("unix:");
 
-  temp = (listen_socket_t *) realloc (listen_fds,
+  temp = (listen_socket_t *) rrd_realloc (listen_fds,
       sizeof (listen_fds[0]) * (listen_fds_num + 1));
   if (temp == NULL)
   {
-    RRDD_LOG (LOG_ERR, "open_listen_socket_unix: realloc failed.");
+    fprintf (stderr, "rrdcached: open_listen_socket_unix: realloc failed.\n");
     return (-1);
   }
   listen_fds = temp;
@@ -1678,7 +2109,8 @@ static int open_listen_socket_unix (const listen_socket_t *sock) /* {{{ */
   fd = socket (PF_UNIX, SOCK_STREAM, /* protocol = */ 0);
   if (fd < 0)
   {
-    RRDD_LOG (LOG_ERR, "open_listen_socket_unix: socket(2) failed.");
+    fprintf (stderr, "rrdcached: unix socket(2) failed: %s\n",
+             rrd_strerror(errno));
     return (-1);
   }
 
@@ -1686,19 +2118,26 @@ static int open_listen_socket_unix (const listen_socket_t *sock) /* {{{ */
   sa.sun_family = AF_UNIX;
   strncpy (sa.sun_path, path, sizeof (sa.sun_path) - 1);
 
+  /* if we've gotten this far, we own the pid file.  any daemon started
+   * with the same args must not be alive.  therefore, ensure that we can
+   * create the socket...
+   */
+  unlink(path);
+
   status = bind (fd, (struct sockaddr *) &sa, sizeof (sa));
   if (status != 0)
   {
-    RRDD_LOG (LOG_ERR, "open_listen_socket_unix: bind(2) failed.");
+    fprintf (stderr, "rrdcached: bind(%s) failed: %s.\n",
+             path, rrd_strerror(errno));
     close (fd);
-    unlink (path);
     return (-1);
   }
 
   status = listen (fd, /* backlog = */ 10);
   if (status != 0)
   {
-    RRDD_LOG (LOG_ERR, "open_listen_socket_unix: listen(2) failed.");
+    fprintf (stderr, "rrdcached: listen(%s) failed: %s.\n",
+             path, rrd_strerror(errno));
     close (fd);
     unlink (path);
     return (-1);
@@ -1723,7 +2162,7 @@ static int open_listen_socket_network(const listen_socket_t *sock) /* {{{ */
   char *port;
   int status;
 
-  strncpy (addr_copy, sock->addr, sizeof (addr_copy));
+  strncpy (addr_copy, sock->addr, sizeof(addr_copy)-1);
   addr_copy[sizeof (addr_copy) - 1] = 0;
   addr = addr_copy;
 
@@ -1744,8 +2183,7 @@ static int open_listen_socket_network(const listen_socket_t *sock) /* {{{ */
     port = strchr (addr, ']');
     if (port == NULL)
     {
-      RRDD_LOG (LOG_ERR, "open_listen_socket_network: Malformed address: %s",
-          sock->addr);
+      fprintf (stderr, "rrdcached: Malformed address: %s\n", sock->addr);
       return (-1);
     }
     *port = 0;
@@ -1757,8 +2195,7 @@ static int open_listen_socket_network(const listen_socket_t *sock) /* {{{ */
       port = NULL;
     else
     {
-      RRDD_LOG (LOG_ERR, "open_listen_socket_network: Garbage after address: %s",
-          port);
+      fprintf (stderr, "rrdcached: Garbage after address: %s\n", port);
       return (-1);
     }
   } /* if (*addr = ']') */
@@ -1777,8 +2214,8 @@ static int open_listen_socket_network(const listen_socket_t *sock) /* {{{ */
                         &ai_hints, &ai_res);
   if (status != 0)
   {
-    RRDD_LOG (LOG_ERR, "open_listen_socket_network: getaddrinfo(%s) failed: "
-        "%s", addr, gai_strerror (status));
+    fprintf (stderr, "rrdcached: getaddrinfo(%s) failed: %s\n",
+             addr, gai_strerror (status));
     return (-1);
   }
 
@@ -1788,11 +2225,12 @@ static int open_listen_socket_network(const listen_socket_t *sock) /* {{{ */
     listen_socket_t *temp;
     int one = 1;
 
-    temp = (listen_socket_t *) realloc (listen_fds,
+    temp = (listen_socket_t *) rrd_realloc (listen_fds,
         sizeof (listen_fds[0]) * (listen_fds_num + 1));
     if (temp == NULL)
     {
-      RRDD_LOG (LOG_ERR, "open_listen_socket_network: realloc failed.");
+      fprintf (stderr,
+               "rrdcached: open_listen_socket_network: realloc failed.\n");
       continue;
     }
     listen_fds = temp;
@@ -1801,7 +2239,8 @@ static int open_listen_socket_network(const listen_socket_t *sock) /* {{{ */
     fd = socket (ai_ptr->ai_family, ai_ptr->ai_socktype, ai_ptr->ai_protocol);
     if (fd < 0)
     {
-      RRDD_LOG (LOG_ERR, "open_listen_socket_network: socket(2) failed.");
+      fprintf (stderr, "rrdcached: network socket(2) failed: %s.\n",
+               rrd_strerror(errno));
       continue;
     }
 
@@ -1810,7 +2249,8 @@ static int open_listen_socket_network(const listen_socket_t *sock) /* {{{ */
     status = bind (fd, ai_ptr->ai_addr, ai_ptr->ai_addrlen);
     if (status != 0)
     {
-      RRDD_LOG (LOG_ERR, "open_listen_socket_network: bind(2) failed.");
+      fprintf (stderr, "rrdcached: bind(%s) failed: %s.\n",
+               sock->addr, rrd_strerror(errno));
       close (fd);
       continue;
     }
@@ -1818,8 +2258,10 @@ static int open_listen_socket_network(const listen_socket_t *sock) /* {{{ */
     status = listen (fd, /* backlog = */ 10);
     if (status != 0)
     {
-      RRDD_LOG (LOG_ERR, "open_listen_socket_network: listen(2) failed.");
+      fprintf (stderr, "rrdcached: listen(%s) failed: %s\n.",
+               sock->addr, rrd_strerror(errno));
       close (fd);
+      freeaddrinfo(ai_res);
       return (-1);
     }
 
@@ -1828,6 +2270,7 @@ static int open_listen_socket_network(const listen_socket_t *sock) /* {{{ */
     listen_fds_num++;
   } /* for (ai_ptr) */
 
+  freeaddrinfo(ai_res);
   return (0);
 } /* }}} static int open_listen_socket_network */
 
@@ -1869,21 +2312,9 @@ static void *listen_thread_main (void *args __attribute__((unused))) /* {{{ */
   int status;
   int i;
 
-  for (i = 0; i < config_listen_address_list_len; i++)
-    open_listen_socket (config_listen_address_list[i]);
-
-  if (config_listen_address_list_len < 1)
-  {
-    listen_socket_t sock;
-    memset(&sock, 0, sizeof(sock));
-    strncpy(sock.addr, RRDCACHED_DEFAULT_ADDRESS, sizeof(sock.addr));
-    open_listen_socket (&sock);
-  }
-
   if (listen_fds_num < 1)
   {
-    RRDD_LOG (LOG_ERR, "listen_thread_main: No listen sockets "
-        "could be opened. Sorry.");
+    RRDD_LOG(LOG_ERR, "listen_thread_main: no listen_fds !");
     return (NULL);
   }
 
@@ -1898,9 +2329,8 @@ static void *listen_thread_main (void *args __attribute__((unused))) /* {{{ */
 
   RRDD_LOG(LOG_INFO, "listening for connections");
 
-  while (do_shutdown == 0)
+  while (state == RUNNING)
   {
-    assert (pollfds_num == ((int) listen_fds_num));
     for (i = 0; i < pollfds_num; i++)
     {
       pollfds[i].fd = listen_fds[i].fd;
@@ -1909,7 +2339,7 @@ static void *listen_thread_main (void *args __attribute__((unused))) /* {{{ */
     }
 
     status = poll (pollfds, pollfds_num, /* timeout = */ 1000);
-    if (do_shutdown)
+    if (state != RUNNING)
       break;
     else if (status == 0) /* timeout */
       continue;
@@ -1968,12 +2398,11 @@ static void *listen_thread_main (void *args __attribute__((unused))) /* {{{ */
       if (status != 0)
       {
         RRDD_LOG (LOG_ERR, "listen_thread_main: pthread_create failed.");
-        close (client_sock->fd);
-        free (client_sock);
+        close_connection(client_sock);
         continue;
       }
     } /* for (pollfds_num) */
-  } /* while (do_shutdown == 0) */
+  } /* while (state == RUNNING) */
 
   RRDD_LOG(LOG_INFO, "starting shutdown");
 
@@ -1981,28 +2410,49 @@ static void *listen_thread_main (void *args __attribute__((unused))) /* {{{ */
 
   pthread_mutex_lock (&connection_threads_lock);
   while (connection_threads_num > 0)
-  {
-    pthread_t wait_for;
-
-    wait_for = connection_threads[0];
-
-    pthread_mutex_unlock (&connection_threads_lock);
-    pthread_join (wait_for, /* retval = */ NULL);
-    pthread_mutex_lock (&connection_threads_lock);
-  }
+    pthread_cond_wait(&connection_threads_done, &connection_threads_lock);
   pthread_mutex_unlock (&connection_threads_lock);
 
+  free(pollfds);
+
   return (NULL);
 } /* }}} void *listen_thread_main */
 
 static int daemonize (void) /* {{{ */
 {
-  int status;
-  int fd;
+  int pid_fd;
   char *base_dir;
 
-  fd = open_pidfile();
-  if (fd < 0) return fd;
+  daemon_uid = geteuid();
+
+  pid_fd = open_pidfile("create", O_CREAT|O_EXCL|O_WRONLY);
+  if (pid_fd < 0)
+    pid_fd = check_pidfile();
+  if (pid_fd < 0)
+    return pid_fd;
+
+  /* open all the listen sockets */
+  if (config_listen_address_list_len > 0)
+  {
+    for (size_t i = 0; i < config_listen_address_list_len; i++)
+      open_listen_socket (config_listen_address_list[i]);
+
+    rrd_free_ptrs((void ***) &config_listen_address_list,
+                  &config_listen_address_list_len);
+  }
+  else
+  {
+    listen_socket_t sock;
+    memset(&sock, 0, sizeof(sock));
+    strncpy(sock.addr, RRDCACHED_DEFAULT_ADDRESS, sizeof(sock.addr)-1);
+    open_listen_socket (&sock);
+  }
+
+  if (listen_fds_num < 1)
+  {
+    fprintf (stderr, "rrdcached: FATAL: cannot open any listen sockets\n");
+    goto error;
+  }
 
   if (!stay_foreground)
   {
@@ -2012,12 +2462,10 @@ static int daemonize (void) /* {{{ */
     if (child < 0)
     {
       fprintf (stderr, "daemonize: fork(2) failed.\n");
-      return (-1);
+      goto error;
     }
     else if (child > 0)
-    {
-      return (1);
-    }
+      exit(0);
 
     /* Become session leader */
     setsid ();
@@ -2028,19 +2476,20 @@ static int daemonize (void) /* {{{ */
     close (0);
 
     open ("/dev/null", O_RDWR);
-    dup (0);
-    dup (0);
+    if (dup(0) == -1 || dup(0) == -1){
+        RRDD_LOG (LOG_ERR, "faild to run dup.\n");
+    }
   } /* if (!stay_foreground) */
 
   /* Change into the /tmp directory. */
   base_dir = (config_base_dir != NULL)
     ? config_base_dir
     : "/tmp";
-  status = chdir (base_dir);
-  if (status != 0)
+
+  if (chdir (base_dir) != 0)
   {
     fprintf (stderr, "daemonize: chdir (%s) failed.\n", base_dir);
-    return (-1);
+    goto error;
   }
 
   install_signal_handlers();
@@ -2048,26 +2497,48 @@ static int daemonize (void) /* {{{ */
   openlog ("rrdcached", LOG_PID, LOG_DAEMON);
   RRDD_LOG(LOG_INFO, "starting up");
 
-  cache_tree = g_tree_new ((GCompareFunc) strcmp);
+  cache_tree = g_tree_new_full ((GCompareDataFunc) strcmp, NULL, NULL,
+                                (GDestroyNotify) free_cache_item);
   if (cache_tree == NULL)
   {
     RRDD_LOG (LOG_ERR, "daemonize: g_tree_new failed.");
-    return (-1);
+    goto error;
   }
 
-  status = write_pidfile (fd);
-  return status;
+  return write_pidfile (pid_fd);
+
+error:
+  remove_pidfile();
+  return -1;
 } /* }}} int daemonize */
 
 static int cleanup (void) /* {{{ */
 {
-  do_shutdown++;
+  pthread_cond_broadcast (&flush_cond);
+  pthread_join (flush_thread, NULL);
 
-  pthread_cond_signal (&cache_cond);
-  pthread_join (queue_thread, /* return = */ NULL);
+  pthread_cond_broadcast (&queue_cond);
+  for (int i = 0; i < config_queue_threads; i++)
+    pthread_join (queue_threads[i], NULL);
+
+  if (config_flush_at_shutdown)
+  {
+    assert(cache_queue_head == NULL);
+    RRDD_LOG(LOG_INFO, "clean shutdown; all RRDs flushed");
+  }
 
+  journal_done();
   remove_pidfile ();
 
+  free(queue_threads);
+  free(config_base_dir);
+  free(config_pid_file);
+  free(journal_cur);
+  free(journal_old);
+
+  pthread_mutex_lock(&cache_lock);
+  g_tree_destroy(cache_tree);
+
   RRDD_LOG(LOG_INFO, "goodbye");
   closelog ();
 
@@ -2079,7 +2550,7 @@ static int read_options (int argc, char **argv) /* {{{ */
   int option;
   int status = 0;
 
-  while ((option = getopt(argc, argv, "gl:L:f:w:b:z:p:j:h?F")) != -1)
+  while ((option = getopt(argc, argv, "gl:L:f:w:z:t:Bb:p:Fj:h?")) != -1)
   {
     switch (option)
     {
@@ -2090,7 +2561,6 @@ static int read_options (int argc, char **argv) /* {{{ */
       case 'L':
       case 'l':
       {
-        listen_socket_t **temp;
         listen_socket_t *new;
 
         new = malloc(sizeof(listen_socket_t));
@@ -2101,20 +2571,15 @@ static int read_options (int argc, char **argv) /* {{{ */
         }
         memset(new, 0, sizeof(listen_socket_t));
 
-        temp = (listen_socket_t **) realloc (config_listen_address_list,
-            sizeof (listen_socket_t *) * (config_listen_address_list_len + 1));
-        if (temp == NULL)
-        {
-          fprintf (stderr, "read_options: realloc failed.\n");
-          return (2);
-        }
-        config_listen_address_list = temp;
-
         strncpy(new->addr, optarg, sizeof(new->addr)-1);
         new->privilege = (option == 'l') ? PRIV_HIGH : PRIV_LOW;
 
-        temp[config_listen_address_list_len] = new;
-        config_listen_address_list_len++;
+        if (!rrd_add_ptr((void ***)&config_listen_address_list,
+                         &config_listen_address_list_len, new))
+        {
+          fprintf(stderr, "read_options: rrd_add_ptr failed.\n");
+          return (2);
+        }
       }
       break;
 
@@ -2164,9 +2629,28 @@ static int read_options (int argc, char **argv) /* {{{ */
         break;
       }
 
+      case 't':
+      {
+        int threads;
+        threads = atoi(optarg);
+        if (threads >= 1)
+          config_queue_threads = threads;
+        else
+        {
+          fprintf (stderr, "Invalid thread count: -t %s\n", optarg);
+          return 1;
+        }
+      }
+      break;
+
+      case 'B':
+        config_write_base_only = 1;
+        break;
+
       case 'b':
       {
         size_t len;
+        char base_realpath[PATH_MAX];
 
         if (config_base_dir != NULL)
           free (config_base_dir);
@@ -2177,6 +2661,27 @@ static int read_options (int argc, char **argv) /* {{{ */
           return (3);
         }
 
+        /* make sure that the base directory is not resolved via
+         * symbolic links.  this makes some performance-enhancing
+         * assumptions possible (we don't have to resolve paths
+         * that start with a "/")
+         */
+        if (realpath(config_base_dir, base_realpath) == NULL)
+        {
+          fprintf (stderr, "Invalid base directory '%s'.\n", config_base_dir);
+          return 5;
+        }
+        else if (strncmp(config_base_dir,
+                         base_realpath, sizeof(base_realpath)) != 0)
+        {
+          fprintf(stderr,
+                  "Base directory (-b) resolved via file system links!\n"
+                  "Please consult rrdcached '-b' documentation!\n"
+                  "Consider specifying the real directory (%s)\n",
+                  base_realpath);
+          return 5;
+        }
+
         len = strlen (config_base_dir);
         while ((len > 0) && (config_base_dir[len - 1] == '/'))
         {
@@ -2189,6 +2694,8 @@ static int read_options (int argc, char **argv) /* {{{ */
           fprintf (stderr, "Invalid base directory: %s\n", optarg);
           return (4);
         }
+
+        _config_base_dir_len = len;
       }
       break;
 
@@ -2255,9 +2762,11 @@ static int read_options (int argc, char **argv) /* {{{ */
             "  -L <address>  Socket address to listen to ('FLUSH' only).\n"
             "  -w <seconds>  Interval in which to write data.\n"
             "  -z <delay>    Delay writes up to <delay> seconds to spread load\n"
+            "  -t <threads>  Number of write threads.\n"
             "  -f <seconds>  Interval in which to flush dead data.\n"
             "  -p <file>     Location of the PID-file.\n"
             "  -b <dir>      Base directory to change to.\n"
+            "  -B            Restrict file access to paths within -b <dir>\n"
             "  -g            Do not fork and run in the foreground.\n"
             "  -j <dir>      Directory in which to create the journal files.\n"
             "  -F            Always flush all updates at shutdown\n"
@@ -2279,6 +2788,10 @@ static int read_options (int argc, char **argv) /* {{{ */
     fprintf(stderr, "WARNING: write delay (-z) should NOT be larger than"
             " write interval (-w) !\n");
 
+  if (config_write_base_only && config_base_dir == NULL)
+    fprintf(stderr, "WARNING: -B does not make sense without -b!\n"
+            "  Consult the rrdcached documentation\n");
+
   if (journal_cur == NULL)
     config_flush_at_shutdown = 1;
 
@@ -2298,51 +2811,40 @@ int main (int argc, char **argv)
   }
 
   status = daemonize ();
-  if (status == 1)
+  if (status != 0)
   {
-    struct sigaction sigchld;
+    fprintf (stderr, "rrdcached: daemonize failed, exiting.\n");
+    return (1);
+  }
 
-    memset (&sigchld, 0, sizeof (sigchld));
-    sigchld.sa_handler = SIG_IGN;
-    sigaction (SIGCHLD, &sigchld, NULL);
+  journal_init();
 
-    return (0);
-  }
-  else if (status != 0)
+  /* start the queue threads */
+  queue_threads = calloc(config_queue_threads, sizeof(*queue_threads));
+  if (queue_threads == NULL)
   {
-    fprintf (stderr, "daemonize failed, exiting.\n");
+    RRDD_LOG (LOG_ERR, "FATAL: cannot calloc queue threads");
+    cleanup();
     return (1);
   }
-
-  if (journal_cur != NULL)
+  for (int i = 0; i < config_queue_threads; i++)
   {
-    int had_journal = 0;
-
-    pthread_mutex_lock(&journal_lock);
-
-    RRDD_LOG(LOG_INFO, "checking for journal files");
-
-    had_journal += journal_replay(journal_old);
-    had_journal += journal_replay(journal_cur);
-
-    if (had_journal)
-      flush_old_values(-1);
-
-    pthread_mutex_unlock(&journal_lock);
-    journal_rotate();
-
-    RRDD_LOG(LOG_INFO, "journal processing complete");
+    memset (&queue_threads[i], 0, sizeof (*queue_threads));
+    status = pthread_create (&queue_threads[i], NULL, queue_thread_main, NULL);
+    if (status != 0)
+    {
+      RRDD_LOG (LOG_ERR, "FATAL: cannot create queue thread");
+      cleanup();
+      return (1);
+    }
   }
 
-  /* start the queue thread */
-  memset (&queue_thread, 0, sizeof (queue_thread));
-  status = pthread_create (&queue_thread,
-                           NULL, /* attr */
-                           queue_thread_main,
-                           NULL); /* args */
+  /* start the flush thread */
+  memset(&flush_thread, 0, sizeof(flush_thread));
+  status = pthread_create (&flush_thread, NULL, flush_thread_main, NULL);
   if (status != 0)
   {
-    RRDD_LOG (LOG_ERR, "FATAL: cannot create queue thread");
+    RRDD_LOG (LOG_ERR, "FATAL: cannot create flush thread");
     cleanup();
     return (1);
   }