Improvements to local interface IP addr detection. Fixes: #802

[exim.git] / src / src / os.c

diff --git a/src/src/os.c b/src/src/os.c
index 810baf6b63a6daa0c9db34c96ddfe943ac22b80b..f9ddbe1a2722940ad39dabc7353e4008b212cbc7 100644 (file)
--- a/src/src/os.c
+++ b/src/src/os.c
@@ -1,10 +1,10 @@
-/* $Cambridge: exim/src/src/os.c,v 1.1 2004/10/07 10:39:01 ph10 Exp $ */
+/* $Cambridge: exim/src/src/os.c,v 1.7 2009/10/20 12:39:47 nm4 Exp $ */

 
 /*************************************************
 *     Exim - an Internet mail transport agent    *
 *************************************************/
 
 
 /*************************************************
 *     Exim - an Internet mail transport agent    *
 *************************************************/
 

-/* Copyright (c) University of Cambridge 1995 - 2004 */
+/* Copyright (c) University of Cambridge 1995 - 2007 */

 /* See the file NOTICE for conditions of use and distribution. */
 
 #ifdef STAND_ALONE
 /* See the file NOTICE for conditions of use and distribution. */
 
 #ifdef STAND_ALONE


@@ -463,6 +463,75 @@ calls the common function; on Linux it calls the Linux function.
 This function finds the addresses of all the running interfaces on the machine.
 A chain of blocks containing the textual form of the addresses is returned.
 
 This function finds the addresses of all the running interfaces on the machine.
 A chain of blocks containing the textual form of the addresses is returned.
 

+getifaddrs() provides a sane consistent way to query this on modern OSs,
+otherwise fall back to a maze of twisty ioctl() calls
+
+Arguments:    none
+Returns:      a chain of ip_address_items, each pointing to a textual
+              version of an IP address, with the port field set to zero
+*/
+
+
+#ifndef NO_FIND_INTERFACES
+
+#ifdef HAVE_GETIFADDRS
+
+#include <ifaddrs.h>
+
+ip_address_item *
+os_common_find_running_interfaces(void)
+{
+struct ifaddrs *ifalist = NULL;
+ip_address_item *yield = NULL;
+ip_address_item *last = NULL;
+ip_address_item  *next;
+
+if (getifaddrs(&ifalist) != 0)
+  log_write(0, LOG_PANIC_DIE, "Unable to call getifaddrs: %d %s",
+    errno, strerror(errno));
+
+struct ifaddrs *ifa;
+for (ifa = ifalist; ifa != NULL; ifa = ifa->ifa_next)
+  {
+  if (ifa->ifa_addr->sa_family != AF_INET
+#if HAVE_IPV6
+    && ifa->ifa_addr->sa_family != AF_INET6
+#endif /* HAVE_IPV6 */
+    )
+    continue;
+
+  if ( !(ifa->ifa_flags & IFF_UP) ) /* Only want 'UP' interfaces */
+    continue;
+
+  /* Create a data block for the address, fill in the data, and put it on the
+  chain. */
+
+  next = store_get(sizeof(ip_address_item));
+  next->next = NULL;
+  next->port = 0;
+  (void)host_ntoa(-1, ifa->ifa_addr, next->address, NULL);
+
+  if (yield == NULL)
+    yield = last = next;
+  else
+    {
+    last->next = next;
+    last = next;
+    }
+
+  DEBUG(D_interface) debug_printf("Actual local interface address is %s (%s)\n",
+    last->address, ifa->ifa_name);
+  }
+
+/* free the list of addresses, and return the chain of data blocks. */
+
+freeifaddrs (ifalist);
+return yield;
+}
+
+#else /* HAVE_GETIFADDRS */
+
+/*

 Problems:
 
   (1) Solaris 2 has the SIOGIFNUM call to get the number of interfaces, but
 Problems:
 
   (1) Solaris 2 has the SIOGIFNUM call to get the number of interfaces, but


@@ -486,15 +555,8 @@ Problems:
   the former, calling the latter does no harm, but it causes grief on Linux and
   BSD systems in the case of IP aliasing, so a means of cutting it out is
   provided.
   the former, calling the latter does no harm, but it causes grief on Linux and
   BSD systems in the case of IP aliasing, so a means of cutting it out is
   provided.

-
-Arguments:    none
-Returns:      a chain of ip_address_items, each pointing to a textual
-              version of an IP address, with the port field set to zero

 */
 
 */
 

-
-#ifndef NO_FIND_INTERFACES
-

 /* If there is IPv6 support, and SIOCGLIFCONF is defined, define macros to
 use these new, longer versions of the old IPv4 interfaces. Otherwise, define
 the macros to use the historical versions. */
 /* If there is IPv6 support, and SIOCGLIFCONF is defined, define macros to
 use these new, longer versions of the old IPv4 interfaces. Otherwise, define
 the macros to use the historical versions. */


@@ -556,7 +618,7 @@ char *cp;
 char buf[MAX_INTERFACES*sizeof(struct V_ifreq)];
 struct sockaddr *addrp;
 size_t len = 0;
 char buf[MAX_INTERFACES*sizeof(struct V_ifreq)];
 struct sockaddr *addrp;
 size_t len = 0;

-char addrbuf[256];
+char addrbuf[512];

 
 /* We have to create a socket in order to do ioctls on it to find out
 what we want to know. */
 
 /* We have to create a socket in order to do ioctls on it to find out
 what we want to know. */


@@ -661,8 +723,9 @@ for (cp = buf; cp < buf + ifc.V_ifc_len; cp += len)
   if ((ifreq.V_ifr_flags & IFF_UP) == 0) continue;
 
   /* On some operating systems we have to get the IP address of the interface
   if ((ifreq.V_ifr_flags & IFF_UP) == 0) continue;
 
   /* On some operating systems we have to get the IP address of the interface

-  by another call. On others, it's already there, but we must reinstate the
-  data in ifreq, because SIOCGIFFLAGS may wreck it. */
+  by another call. On others, it's already there, but we must copy the full
+  length because we only copied the basic length above, and anyway,
+  GIFFLAGS may have wrecked the data. */

 
   #ifndef SIOCGIFCONF_GIVES_ADDR
   if (ioctl(vs, V_GIFADDR, (char *)&ifreq) < 0)
 
   #ifndef SIOCGIFCONF_GIVES_ADDR
   if (ioctl(vs, V_GIFADDR, (char *)&ifreq) < 0)


@@ -671,8 +734,8 @@ for (cp = buf; cp < buf + ifc.V_ifc_len; cp += len)
   addrp = &ifreq.V_ifr_addr;
 
   #else
   addrp = &ifreq.V_ifr_addr;
 
   #else

-  memcpy((char *)&ifreq, cp, sizeof(ifreq));
-  memcpy(addrbuf, (char *)&(ifreq.V_ifr_addr), len - sizeof(ifreq.V_ifr_name));
+  memcpy(addrbuf, cp + offsetof(struct V_ifreq, V_ifr_addr),
+    len - sizeof(ifreq.V_ifr_name));

   addrp = (struct sockaddr *)addrbuf;
   #endif
 
   addrp = (struct sockaddr *)addrbuf;
   #endif
 


@@ -696,10 +759,12 @@ for (cp = buf; cp < buf + ifc.V_ifc_len; cp += len)
 
 /* Close the socket, and return the chain of data blocks. */
 
 
 /* Close the socket, and return the chain of data blocks. */
 

-close(vs);
+(void)close(vs);

 return yield;
 }
 
 return yield;
 }
 

+#endif /* HAVE_GETIFADDRS */
+

 #else  /* NO_FIND_INTERFACES */
 
 /* Some experimental or developing OS (e.g. GNU/Hurd) do not have the ioctls,
 #else  /* NO_FIND_INTERFACES */
 
 /* Some experimental or developing OS (e.g. GNU/Hurd) do not have the ioctls,