ntpd plugin: Refactor the peer name generation.
authorFlorian Forster <octo@collectd.org>
Fri, 5 Oct 2012 08:21:17 +0000 (10:21 +0200)
committerFlorian Forster <octo@collectd.org>
Fri, 5 Oct 2012 08:21:17 +0000 (10:21 +0200)
Break it out of the main read-loop and put it into two functions: One for the
reference clocks and one for network hosts. The reference clock code will call
the network host code when the clock name is not available in the internal list
of reference clock names. This eliminates the (thread-unsafe) usage of
inet_ntoa(3).

src/ntpd.c

index 9841e31..d1ce621 100644 (file)
@@ -1,6 +1,6 @@
 /**
  * collectd - src/ntpd.c
- * Copyright (C) 2006-2007  Florian octo Forster
+ * Copyright (C) 2006-2012  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
@@ -16,7 +16,7 @@
  * 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
  *
  * Authors:
- *   Florian octo Forster <octo at verplant.org>
+ *   Florian octo Forster <octo at collectd.org>
  **/
 
 #define _BSD_SOURCE /* For NI_MAXHOST */
@@ -57,12 +57,12 @@ static const char *config_keys[] =
 };
 static int config_keys_num = STATIC_ARRAY_SIZE (config_keys);
 
-static int do_reverse_lookups = 1;
+static _Bool do_reverse_lookups = 1;
 
 /* This option only exists for backward compatibility. If it is false and two
  * ntpd peers use the same refclock driver, the plugin will try to write
  * simultaneous measurements from both to the same type instance. */
-static int include_unit_id = 0;
+static _Bool include_unit_id = 0;
 
 # define NTPD_DEFAULT_HOST "localhost"
 # define NTPD_DEFAULT_PORT "123"
@@ -776,6 +776,108 @@ static double ntpd_read_fp (int32_t val_int)
        return (val_double);
 }
 
+static uint32_t ntpd_get_refclock_id (struct info_peer_summary const *peer_info)
+{
+       uint32_t addr = ntohl (peer_info->srcadr);
+       uint32_t refclock_id = (addr >> 8) & 0x00FF;
+
+       return (refclock_id);
+}
+
+static int ntpd_get_name_from_address (char *buffer, size_t buffer_size,
+               struct info_peer_summary *peer_info, _Bool do_reverse_lookup)
+{
+       struct sockaddr_storage sa;
+       socklen_t sa_len;
+       int flags = 0;
+       int status;
+
+       memset (&sa, 0, sizeof (sa));
+
+       if (peer_info->v6_flag)
+       {
+               struct sockaddr_in6 sa6;
+
+               assert (sizeof (sa) >= sizeof (sa6));
+
+               memset (&sa6, 0, sizeof (sa6));
+               sa6.sin6_family = AF_INET6;
+               sa6.sin6_port = htons (123);
+               memcpy (&sa6.sin6_addr, &peer_info->srcadr6,
+                               sizeof (struct in6_addr));
+               sa_len = sizeof (sa6);
+
+               memcpy (&sa, &sa6, sizeof (sa6));
+       }
+       else
+       {
+               struct sockaddr_in sa4;
+
+               assert (sizeof (sa) >= sizeof (sa4));
+
+               memset (&sa4, 0, sizeof (sa4));
+               sa4.sin_family = AF_INET;
+               sa4.sin_port = htons (123);
+               memcpy (&sa4.sin_addr, &peer_info->srcadr,
+                               sizeof (struct in_addr));
+               sa_len = sizeof (sa4);
+
+               memcpy (&sa, &sa4, sizeof (sa4));
+       }
+
+       if (!do_reverse_lookup)
+               flags |= NI_NUMERICHOST;
+
+       status = getnameinfo ((struct sockaddr const *) &sa, sa_len,
+                       buffer, buffer_size,
+                       NULL, 0, /* No port name */
+                       flags);
+       if (status != 0)
+       {
+               char errbuf[1024];
+               ERROR ("ntpd plugin: getnameinfo failed: %s",
+                               (status == EAI_SYSTEM)
+                               ? sstrerror (errno, errbuf, sizeof (errbuf))
+                               : gai_strerror (status));
+               return (-1);
+       }
+
+       return (0);
+} /* ntpd_get_name_from_address */
+
+static int ntpd_get_name_refclock (char *buffer, size_t buffer_size,
+               struct info_peer_summary *peer_info)
+{
+       uint32_t refclock_id = ntpd_get_refclock_id (peer_info);
+       uint32_t unit_id = ntohl (peer_info->srcadr) & 0x00FF;
+
+       if (refclock_id >= refclock_names_num)
+               return (ntpd_get_name_from_address (buffer, buffer_size,
+                                       peer_info,
+                                       /* do_reverse_lookup = */ 0));
+
+       if (include_unit_id)
+               ssnprintf (buffer, buffer_size, "%s-%"PRIu32,
+                               refclock_names[refclock_id], unit_id);
+       else
+               sstrncpy (buffer, refclock_names[refclock_id], buffer_size);
+
+       return (0);
+} /* int ntpd_get_name_refclock */
+
+static int ntpd_get_name (char *buffer, size_t buffer_size,
+               struct info_peer_summary *peer_info)
+{
+       uint32_t addr = ntohl (peer_info->srcadr);
+
+       if (!peer_info->v6_flag && ((addr & REFCLOCK_MASK) == REFCLOCK_ADDR))
+               return (ntpd_get_name_refclock (buffer, buffer_size,
+                                       peer_info));
+       else
+               return (ntpd_get_name_from_address (buffer, buffer_size,
+                                       peer_info, do_reverse_lookups));
+} /* int ntpd_addr_to_name */
+
 static int ntpd_read (void)
 {
        struct info_kernel *ik;
@@ -850,106 +952,21 @@ static int ntpd_read (void)
                double offset;
 
                char peername[NI_MAXHOST];
-               int refclock_id;
-               
-               ptr = ps + i;
-               refclock_id = 0;
+               uint32_t refclock_id;
 
-               /* Convert the `long floating point' offset value to double */
-               M_LFPTOD (ntohl (ptr->offset_int), ntohl (ptr->offset_frc), offset);
+               ptr = ps + i;
 
-               /* Special IP addresses for hardware clocks and stuff.. */
-               if (!ptr->v6_flag
-                               && ((ntohl (ptr->srcadr) & REFCLOCK_MASK)
-                                       == REFCLOCK_ADDR))
+               status = ntpd_get_name (peername, sizeof (peername), ptr);
+               if (status != 0)
                {
-                       struct in_addr  addr_obj;
-                       char *addr_str;
-                       int name_refclock;
-
-                       refclock_id = (ntohl (ptr->srcadr) >> 8) & 0x000000FF;
-
-                       name_refclock = refclock_id < refclock_names_num;
-
-                       if (name_refclock && include_unit_id)
-                       {
-                               /* The unit number is in the lowest byte. */
-                               ssnprintf (peername, sizeof (peername),
-                                               "%s-%u",
-                                               refclock_names[refclock_id],
-                                               ntohl (ptr->srcadr) & 0xFF);
-                       }
-                       else if (name_refclock && !include_unit_id)
-                       {
-                               sstrncpy (peername, refclock_names[refclock_id],
-                                               sizeof (peername));
-                       }
-                       else /* !name_refclock */
-                       {
-                               memset ((void *) &addr_obj, '\0', sizeof (addr_obj));
-                               addr_obj.s_addr = ptr->srcadr;
-                               addr_str = inet_ntoa (addr_obj);
-
-                               sstrncpy (peername, addr_str, sizeof (peername));
-                       }
+                       ERROR ("ntpd plugin: Determining name of peer failed.");
+                       continue;
                }
-               else /* Normal network host. */
-               {
-                       struct sockaddr_storage sa;
-                       socklen_t sa_len;
-                       int flags = 0;
-
-                       memset (&sa, '\0', sizeof (sa));
-
-                       if (ptr->v6_flag)
-                       {
-                               struct sockaddr_in6 sa6;
-
-                               assert (sizeof (sa) >= sizeof (sa6));
-
-                               memset (&sa6, 0, sizeof (sa6));
-                               sa6.sin6_family = AF_INET6;
-                               sa6.sin6_port = htons (123);
-                               memcpy (&sa6.sin6_addr, &ptr->srcadr6,
-                                               sizeof (struct in6_addr));
-                               sa_len = sizeof (sa6);
-
-                               memcpy (&sa, &sa6, sizeof (sa6));
-                       }
-                       else
-                       {
-                               struct sockaddr_in sa4;
-
-                               assert (sizeof (sa) >= sizeof (sa4));
 
-                               memset (&sa4, 0, sizeof (sa4));
-                               sa4.sin_family = AF_INET;
-                               sa4.sin_port = htons (123);
-                               memcpy (&sa4.sin_addr, &ptr->srcadr,
-                                               sizeof (struct in_addr));
-                               sa_len = sizeof (sa4);
+               refclock_id = ntpd_get_refclock_id (ptr);
 
-                               memcpy (&sa, &sa4, sizeof (sa4));
-                       }
-
-                       if (do_reverse_lookups == 0)
-                               flags |= NI_NUMERICHOST;
-
-                       status = getnameinfo ((const struct sockaddr *) &sa,
-                                       sa_len,
-                                       peername, sizeof (peername),
-                                       NULL, 0, /* No port name */
-                                       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;
-                       }
-               }
+               /* Convert the `long floating point' offset value to double */
+               M_LFPTOD (ntohl (ptr->offset_int), ntohl (ptr->offset_frc), offset);
 
                DEBUG ("peer %i:\n"
                                "  peername   = %s\n"