network plugin: Interface option moved to Server/Listen block

Hello list!

On Tue, Mar 09, 2010 at 06:17:35PM +0100, Florian Forster wrote:
[...]
> On Fri, Feb 26, 2010 at 12:49:02PM +0100, Max Henkel wrote:
[...]
> > @@ -2842,6 +2929,8 @@ static int network_config (oconfig_item_t *ci) /* {{{ */
> >        network_config_add_server (child);
> >      else if (strcasecmp ("TimeToLive", child->key) == 0)
> >        network_config_set_ttl (child);
> > +    else if (strcasecmp ("Interface", child->key) == 0)
> > +      network_config_set_interface (child);
> >      else if (strcasecmp ("MaxPacketSize", child->key) == 0)
> >        network_config_set_buffer_size (child);
> >      else if (strcasecmp ("Forward", child->key) == 0)
>
> Starting with the signing and encryption option, we have <Server> and
> <Listen> blocks that take socket specific options. It'd be kind of
> inconsistent with the "TimeToLive" and other options, but maybe adding
> this to those blocks would be even better. It would enable to forward
> data from one multicast group on interface-0 to the *same* multicast
> group on interface-1, which I guess could be useful. But maybe it's an
> academic case, I dunno.. Thoughts, anyone?
[...]

This patch provides the configuration possibility inside the
Server/Listen-block, but I'm unsure if the "int interface" is
located properly inside the sockent_t.

Best regards,

Max

Signed-off-by: Florian Forster <octo@huhu.verplant.org>

diff --git a/src/collectd.conf.pod b/src/collectd.conf.pod
index e2306d2..3c8b26c 100644 (file)
--- a/src/collectd.conf.pod
+++ b/src/collectd.conf.pod
@@ -2512,6 +2512,15 @@ B<None> require this setting.
 This feature is only available if the I<network> plugin was linked with
 I<libgcrypt>.
 
+=item B<Interface> I<Interface name>
+
+Set the outgoing interface for IP packets. This applies at least
+to IPv6 packets and if possible to IPv4. If this option is not applicable,
+undefined or a non-existent interface name is specified, the default
+behaviour is to let the kernel choose the appropriate interface. Be warned
+that the manual selection of an interface for unicast traffic is only
+necessary in rare cases.
+
 =back
 
 =item B<E<lt>Listen> I<Host> [I<Port>]B<E<gt>>
@@ -2560,6 +2569,14 @@ Each time a packet is received, the modification time of the file is checked
 using L<stat(2)>. If the file has been changed, the contents is re-read. While
 the file is being read, it is locked using L<fcntl(2)>.
 
+=item B<Interface> I<Interface name>
+
+Set the incoming interface for IP packets explicitly. This applies at least
+to IPv6 packets and if possible to IPv4. If this option is not applicable,
+undefined or a non-existent interface name is specified, the default
+behaviour is, to let the kernel choose the appropriate interface. Thus incoming
+traffic gets only accepted, if it arrives on the given interface.
+
 =back
 
 =item B<TimeToLive> I<1-255>
@@ -2569,15 +2586,6 @@ multicast, and IPv4 and IPv6 packets. The default is to not change this value.
 That means that multicast packets will be sent with a TTL of C<1> (one) on most
 operating systems.
 
-=item B<Interface> I<Interface name>
-
-Set the outgoing or incoming interface for IP packets. This applies at least
-to IPv6 packets and if possible to IPv4. If this option is not applicable,
-undefined or a non-existent interface name is specified, the default
-behaviour is to let the kernel choose the appropriate interface. Be warned
-that the manual selection of an interface for unicast traffic is only
-necessary in rare cases.
-
 =item B<MaxPacketSize> I<1024-65535>
 
 Set the maximum size for datagrams received over the network. Packets larger

diff --git a/src/network.c b/src/network.c
index eb074e9..b1b9e39 100644 (file)
--- a/src/network.c
+++ b/src/network.c
@@ -121,6 +121,7 @@ typedef struct sockent
 
        char *node;
        char *service;
+       int interface;
 
        union
        {
@@ -257,7 +258,6 @@ typedef struct receive_list_entry_s receive_list_entry_t;
  * Private variables
  */
 static int network_config_ttl = 0;
-static int network_config_interface_idx = 0;
 static size_t network_config_packet_size = 1024;
 static int network_config_forward = 0;
 static int network_config_stats = 0;
@@ -1590,7 +1590,7 @@ static int network_set_ttl (const sockent_t *se, const struct addrinfo *ai)
 static int network_set_interface (const sockent_t *se, const struct addrinfo *ai) /* {{{ */
 {
        DEBUG ("network plugin: network_set_interface: interface index = %i;",
-                       network_config_interface_idx);
+                       se->interface);
 
         assert (se->type == SOCKENT_TYPE_CLIENT);
 
@@ -1609,7 +1609,7 @@ static int network_set_interface (const sockent_t *se, const struct addrinfo *ai
                        mreq.imr_multiaddr.s_addr = addr->sin_addr.s_addr;
 #if KERNEL_LINUX
                        mreq.imr_address.s_addr = ntohl (INADDR_ANY);
-                       mreq.imr_ifindex = network_config_interface_idx;
+                       mreq.imr_ifindex = se->interface;
 #else
                        mreq.imr_interface.s_addr = ntohl (INADDR_ANY);
 #endif
@@ -1633,8 +1633,8 @@ static int network_set_interface (const sockent_t *se, const struct addrinfo *ai
                if (IN6_IS_ADDR_MULTICAST (&addr->sin6_addr))
                {
                        if (setsockopt (se->data.client.fd, IPPROTO_IPV6, IPV6_MULTICAST_IF,
-                                               &network_config_interface_idx,
-                                               sizeof (network_config_interface_idx)) == -1)
+                                               &se->interface,
+                                               sizeof (se->interface)) == -1)
                        {
                                char errbuf[1024];
                                ERROR ("setsockopt: %s",
@@ -1648,11 +1648,11 @@ static int network_set_interface (const sockent_t *se, const struct addrinfo *ai
        }
 
 #if KERNEL_LINUX
-       if (network_config_interface_idx != 0)
+       if (se->interface != 0)
        {
                char interface_name[IFNAMSIZ];
 
-               if (if_indextoname (network_config_interface_idx, interface_name) == NULL)
+               if (if_indextoname (se->interface, interface_name) == NULL)
                        return (-1);
 
                DEBUG ("network plugin: Binding socket to interface %s", interface_name);
@@ -1672,7 +1672,7 @@ static int network_set_interface (const sockent_t *se, const struct addrinfo *ai
        return (0);
 } /* }}} network_set_interface */
 
-static int network_bind_socket (int fd, const struct addrinfo *ai)
+static int network_bind_socket (int fd, const struct addrinfo *ai, const int interface_idx)
 {
        int loop = 0;
        int yes  = 1;
@@ -1712,7 +1712,7 @@ static int network_bind_socket (int fd, const struct addrinfo *ai)
                        mreq.imr_multiaddr.s_addr = addr->sin_addr.s_addr;
 #if KERNEL_LINUX
                        mreq.imr_address.s_addr = ntohl (INADDR_ANY);
-                       mreq.imr_ifindex = network_config_interface_idx;
+                       mreq.imr_ifindex = interface_idx;
 #else
                        mreq.imr_interface.s_addr = ntohl (INADDR_ANY);
 #endif
@@ -1763,7 +1763,7 @@ static int network_bind_socket (int fd, const struct addrinfo *ai)
                         * single interface; programs running on
                         * multihomed hosts may need to join the same
                         * group on more than one interface.*/
-                       mreq.ipv6mr_interface = network_config_interface_idx;
+                       mreq.ipv6mr_interface = interface_idx;
 
                        if (setsockopt (fd, IPPROTO_IPV6, IPV6_MULTICAST_LOOP,
                                                &loop, sizeof (loop)) == -1)
@@ -1793,11 +1793,11 @@ static int network_bind_socket (int fd, const struct addrinfo *ai)
        /* if a specific interface was set, bind the socket to it. But to avoid
         * possible problems with multicast routing, only do that for non-multicast
         * addresses */
-       if (network_config_interface_idx != 0)
+       if (interface_idx != 0)
        {
                char interface_name[IFNAMSIZ];
 
-               if (if_indextoname (network_config_interface_idx, interface_name) == NULL)
+               if (if_indextoname (interface_idx, interface_name) == NULL)
                        return (-1);
 
                DEBUG ("fd = %i; Binding socket to interface %s", fd, interface_name);
@@ -1829,6 +1829,7 @@ static int sockent_init (sockent_t *se, int type) /* {{{ */
        se->type = SOCKENT_TYPE_CLIENT;
        se->node = NULL;
        se->service = NULL;
+       se->interface = 0;
        se->next = NULL;
 
        if (type == SOCKENT_TYPE_SERVER)
@@ -1977,7 +1978,7 @@ static int sockent_open (sockent_t *se) /* {{{ */
                                continue;
                        }
 
-                       status = network_bind_socket (*tmp, ai_ptr);
+                       status = network_bind_socket (*tmp, ai_ptr, se->interface);
                        if (status != 0)
                        {
                                close (*tmp);
@@ -2729,7 +2730,8 @@ static int network_config_set_ttl (const oconfig_item_t *ci) /* {{{ */
   return (0);
 } /* }}} int network_config_set_ttl */
 
-static int network_config_set_interface (const oconfig_item_t *ci) /* {{{ */
+static int network_config_set_interface (const oconfig_item_t *ci, /* {{{ */
+    int *interface)
 {
   if ((ci->values_num != 1)
       || (ci->values[0].type != OCONFIG_TYPE_STRING))
@@ -2739,7 +2741,10 @@ static int network_config_set_interface (const oconfig_item_t *ci) /* {{{ */
     return (-1);
   }
 
-  network_config_interface_idx = if_nametoindex (ci->values[0].value.string);
+  if (interface == NULL)
+    return (-1);
+
+  *interface = if_nametoindex (ci->values[0].value.string);
 
   return (0);
 } /* }}} int network_config_set_interface */
@@ -2855,6 +2860,10 @@ static int network_config_add_listen (const oconfig_item_t *ci) /* {{{ */
           &se->data.server.security_level);
     else
 #endif /* HAVE_LIBGCRYPT */
+    if (strcasecmp ("Interface", child->key) == 0)
+      network_config_set_interface (child,
+          &se->interface);
+    else
     {
       WARNING ("network plugin: Option `%s' is not allowed here.",
           child->key);
@@ -2933,6 +2942,10 @@ static int network_config_add_server (const oconfig_item_t *ci) /* {{{ */
           &se->data.client.security_level);
     else
 #endif /* HAVE_LIBGCRYPT */
+    if (strcasecmp ("Interface", child->key) == 0)
+      network_config_set_interface (child,
+          &se->interface);
+    else
     {
       WARNING ("network plugin: Option `%s' is not allowed here.",
           child->key);
@@ -2985,8 +2998,6 @@ static int network_config (oconfig_item_t *ci) /* {{{ */
       network_config_add_server (child);
     else if (strcasecmp ("TimeToLive", child->key) == 0)
       network_config_set_ttl (child);
-    else if (strcasecmp ("Interface", child->key) == 0)
-      network_config_set_interface (child);
     else if (strcasecmp ("MaxPacketSize", child->key) == 0)
       network_config_set_buffer_size (child);
     else if (strcasecmp ("Forward", child->key) == 0)