X-Git-Url: https://git.octo.it/?a=blobdiff_plain;f=src%2Frrd_daemon.c;h=40785b00778cc19ffc40b3e97bc687f553f5b4a9;hb=59525f3de81d5f6a9c5e5fc3a6662fa7e074163f;hp=28912c5358f8d17214b34d7c681fe8bcf714b69b;hpb=3c3effad5f54f8c73260068e3ec32c56684243bb;p=rrdtool.git

diff --git a/src/rrd_daemon.c b/src/rrd_daemon.c
index 28912c5..40785b0 100644
--- a/src/rrd_daemon.c
+++ b/src/rrd_daemon.c
@@ -286,7 +286,7 @@ 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;
@@ -295,14 +295,52 @@ 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);
+  ftruncate(pid_fd, 0);
+
+  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;
@@ -748,8 +786,8 @@ static void *queue_thread_main (void *args __attribute__((unused))) /* {{{ */
       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;
+      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 */
@@ -956,6 +994,26 @@ err:
   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, /* {{{ */
@@ -1183,7 +1241,7 @@ static int handle_request_stats (listen_socket_t *sock) /* {{{ */
 static int handle_request_flush (listen_socket_t *sock, /* {{{ */
     char *buffer, size_t buffer_size)
 {
-  char *file;
+  char *file, file_tmp[PATH_MAX];
   int status;
 
   status = buffer_get_field (&buffer, &buffer_size, &file);
@@ -1197,6 +1255,7 @@ static int handle_request_flush (listen_socket_t *sock, /* {{{ */
     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);
@@ -1244,7 +1303,7 @@ static int handle_request_pending(listen_socket_t *sock, /* {{{ */
                                   char *buffer, size_t buffer_size)
 {
   int status;
-  char *file;
+  char *file, file_tmp[PATH_MAX];
   cache_item_t *ci;
 
   status = buffer_get_field(&buffer, &buffer_size, &file);
@@ -1256,6 +1315,8 @@ static int handle_request_pending(listen_socket_t *sock, /* {{{ */
   if (status <= 0)
     return status;
 
+  get_abs_path(&file, file_tmp);
+
   pthread_mutex_lock(&cache_lock);
   ci = g_tree_lookup(cache_tree, file);
   if (ci == NULL)
@@ -1275,7 +1336,7 @@ static int handle_request_forget(listen_socket_t *sock, /* {{{ */
                                  char *buffer, size_t buffer_size)
 {
   int status;
-  char *file;
+  char *file, file_tmp[PATH_MAX];
 
   status = buffer_get_field(&buffer, &buffer_size, &file);
   if (status != 0)
@@ -1286,6 +1347,7 @@ static int handle_request_forget(listen_socket_t *sock, /* {{{ */
   if (status <= 0)
     return status;
 
+  get_abs_path(&file, file_tmp);
   if (!check_file_access(file, sock)) return 0;
 
   pthread_mutex_lock(&cache_lock);
@@ -1311,7 +1373,7 @@ static int handle_request_update (listen_socket_t *sock, /* {{{ */
                                   time_t now,
                                   char *buffer, size_t buffer_size)
 {
-  char *file;
+  char *file, file_tmp[PATH_MAX];
   int values_num = 0;
   int bad_timestamps = 0;
   int status;
@@ -1335,6 +1397,7 @@ static int handle_request_update (listen_socket_t *sock, /* {{{ */
   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);
@@ -1462,6 +1525,9 @@ static int handle_request_update (listen_socket_t *sock, /* {{{ */
 
   if (values_num < 1)
   {
+    /* journal replay mode */
+    if (sock == NULL) return RESP_ERR;
+
     /* if we had only one update attempt, then return the full
        error message... try to get the most information out
        of the limited error space allowed by the protocol
@@ -2293,13 +2359,16 @@ static void *listen_thread_main (void *args __attribute__((unused))) /* {{{ */
 static int daemonize (void) /* {{{ */
 {
   int status;
-  int fd;
+  int pid_fd;
   char *base_dir;
 
   daemon_uid = geteuid();
 
-  fd = open_pidfile();
-  if (fd < 0) return fd;
+  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;
 
   if (!stay_foreground)
   {
@@ -2352,7 +2421,7 @@ static int daemonize (void) /* {{{ */
     return (-1);
   }
 
-  status = write_pidfile (fd);
+  status = write_pidfile (pid_fd);
   return status;
 } /* }}} int daemonize */
 
@@ -2468,6 +2537,7 @@ static int read_options (int argc, char **argv) /* {{{ */
       case 'b':
       {
         size_t len;
+        char base_realpath[PATH_MAX];
 
         if (config_base_dir != NULL)
           free (config_base_dir);
@@ -2478,6 +2548,27 @@ 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] == '/'))
         {