Re: [Exim] Re: Exim and IPv6 Help - Solved

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Autor: Kevin Sindhu
Data:  
A: exim-users, Peter Galbavy, tech, ipv6
CC: Philip Hazel, Sheldon Hearn
Assumptes vells: [Exim] Re: Exim and IPv6 Help
Assumpte: Re: [Exim] Re: Exim and IPv6 Help - Solved
Hello,

First off, I would like to thank Philip and Sheldon for helping me out
solve this problem. I believe this would be included in the next Exim-3.22 release as well. However for those of you out there who wish to have IPv6 in their
current 3.31, please apply the below patch.

Again, kudos to Philip and Sheldon..

Rgds

-Kevin

--
Teach children to be polite and courteous in the home, and, when they
grows up, they will never be able to edge a car onto a freeway.
Only in .: Local
Only in .: NOTICE.orig
diff -ur ../exim-3.31-src/OS/os.h-OpenBSD ./OS/os.h-OpenBSD
--- ../exim-3.31-src/OS/os.h-OpenBSD    Mon Jul  2 02:46:40 2001
+++ ./OS/os.h-OpenBSD    Fri Jul 13 10:02:43 2001
@@ -3,6 +3,7 @@
 #define HAVE_BSD_GETLOADAVG
 #define HAVE_MMAP
 #define HAVE_SYS_MOUNT_H
+#define SIOCGIFCONF_GIVES_ADDR


typedef struct flock flock_t;

Only in ./OS: os.h-OpenBSD.orig
Only in .: build-OpenBSD-i386
Only in ./doc: ChangeLog.orig
Only in .: exim-texinfo-3.30
Only in .: exim-texinfo-3.30.tar.gz
Only in .: exim_newaliases
Only in .: patch
Only in .: patch2
Only in ./src: configure.default.orig
diff -ur ../exim-3.31-src/src/daemon.c ./src/daemon.c
--- ../exim-3.31-src/src/daemon.c    Mon Jul  2 02:46:42 2001
+++ ./src/daemon.c    Fri Jul 13 10:02:37 2001
@@ -661,7 +661,7 @@
   union sockaddr_46 sin;


#if HAVE_IPV6
- struct in6_addr anyaddr6 = IN6ADDR_ANY_INIT;
+ struct in6_addr anyaddr6 = in6addr_any;
#endif

   /* Find the standard SMTP port if no port number given; otherwise
@@ -690,7 +690,11 @@
     }


/* Otherwise set up one address item with a null address, implying listening
- on all interfaces. */
+ on all interfaces. In an IPv6 world, we set up a second address for listening
+ on all IPv6 interfaces. Some IPv6 stacks will pick up incoming IPv4 calls on
+ an IPv6 wildcard socket, but some won't (there are security issues). Using
+ two sockets should work in all cases. We identify an IPv6 wildcard address by
+ the string ":". */

   else
     {
@@ -698,6 +702,14 @@
     addresses->next = NULL;
     addresses->address[0] = 0;
     listen_socket_count = 1;
+
+    #if HAVE_IPV6
+    addresses->next = store_get(sizeof(ip_address_item));
+    addresses->next->next = NULL;
+    addresses->next->address[0] = ':';
+    addresses->next->address[1] = 0;
+    listen_socket_count++;
+    #endif  /* HAVE_IPV6 */
     }


/* Get a vector to remember all the sockets in */
@@ -714,41 +726,20 @@
#endif

/* For each IP address, create a socket and bind it to the appropriate
- port. Note that if local_interfaces is not set, we bind a single socket to
- all interfaces. */
+ port. Some IPv6 stacks can handle IPv4 addresses on IPv6 sockets using
+ the mapping facilities. However, some don't do this because of security
+ concerns. Therefore, we use IPv4 sockets for IPv4 addresses even in an
+ IPv6 world. */

   for (ipa = addresses, sk = 0; sk < listen_socket_count; ipa = ipa->next, sk++)
     {
     int i;
+    int af = (strchr(ipa->address, ':') != NULL)? AF_INET6 : AF_INET;


-    #if HAVE_IPV6
-    BOOL ipv6_socket = TRUE;
-    BOOL ipv6_address = strchr(ipa->address, ':') != NULL;
-
-    /* A system which has all the IPv6 libraries etc. may nevertheless not
-    support IPv6 in the kernel, so if the socket creation fails, fall back
-    on creating an IPv4 socket, except when we have an explicit IPv6 address,
-    for which we really do need an IPv6 socket. */
-
-    listen_sockets[sk] = socket(AF_INET6, SOCK_STREAM, 0);
+    listen_sockets[sk] = socket(af, SOCK_STREAM, 0);
     if (listen_sockets[sk] < 0)
-      {
-      if (!ipv6_address)
-        {
-        listen_sockets[sk] = socket(AF_INET, SOCK_STREAM, 0);
-        ipv6_socket = FALSE;
-        }
-      }
-
-    /* The IPv4 case */
-
-    #else    /* HAVE_IPV6 */
-    listen_sockets[sk] = socket(AF_INET, SOCK_STREAM, 0);
-    #endif   /* HAVE_IPV6 */
-
-    if (listen_sockets[sk] < 0)
-      log_write(0, LOG_PANIC_DIE, "socket creation failed: %s",
-        strerror(errno));
+      log_write(0, LOG_PANIC_DIE, "IPv%c socket creation failed: %s",
+        (af == AF_INET6)? '6' : '4', strerror(errno));


     /* Set SO_REUSEADDR so that the daemon can be restarted while a connection
     is being handled.  Without this, a connection will prevent reuse of the
@@ -765,44 +756,31 @@


     memset(&sin, 0, sizeof(sin));


-    /* This code has to be entirely different for IPv6 and IPv4 because
-    of the different struct layouts. Sigh. Under IPv6, however, we may have
-    ended up with an IPv4 socket because the kernel may not support IPv6 even
-    if the libraries etc. are available. In this case, revert to IPv4 style
-    code (this will happen only when the the address is not an IPv6 one).
-    Although the code is identical, I've chosen to replicate it for ease of
-    reading the two cases. */
+    /* Setup code when using an IPv6 socket. The wildcard address is ":", to
+    ensure an IPv6 socket is used. */


     #if HAVE_IPV6
-    if (ipv6_socket)
+    if (af == AF_INET6)
       {
       sin.v6.sin6_family = AF_INET6;
       sin.v6.sin6_port = net_port;
-
-      if (ipa->address[0] == 0)
+      if (ipa->address[0] == ':' && ipa->address[1] == 0)
         {
         sin.v6.sin6_addr = anyaddr6;
         DEBUG(9) debug_printf("listening on all interfaces (IPv6)\n");
         }
       else
         {
-        int rc;
-        if (ipv6_address)
-          rc = inet_pton(AF_INET6, ipa->address, &sin.v6.sin6_addr);
-        else
-        /* We have an IPv6 socket, and an IPv4 address. We have to turn the
-        address into an IPv6 mapped form. */
-          {
-          memmove(ipa->address+7, ipa->address, (int)strlen(ipa->address) + 1);
-          memcpy(ipa->address, "::ffff:", 7);
-          rc = inet_pton(AF_INET6, ipa->address, &sin.v6.sin6_addr);
-          }
-        if (rc != 1)
+        if (inet_pton(AF_INET6, ipa->address, &sin.v6.sin6_addr) != 1)
           log_write(0, LOG_PANIC_DIE, "unable to parse \"%s\"", ipa->address);
         DEBUG(9) debug_printf("listening on %s\n", ipa->address);
         }
       }
-    else   /* Revert to IPv4 code */
+    else
+    #endif  /* HAVE_IPV6 */
+
+    /* Setup code when using IPv4 socket. The wildcard address is "". */
+
       {
       sin.v4.sin_family = AF_INET;
       sin.v4.sin_port = net_port;
@@ -817,34 +795,25 @@
         DEBUG(9) debug_printf("listening on %s\n", ipa->address);
         }
       }
-    #else   /* HAVE_IPV6 */
-
-
-    /* The IPv4 case is simple. */
-
-    sin.v4.sin_family = AF_INET;
-    sin.v4.sin_port = net_port;
-    if (ipa->address[0] == 0)
-      {
-      sin.v4.sin_addr.s_addr = (S_ADDR_TYPE)INADDR_ANY;
-      DEBUG(9) debug_printf("listening on all interfaces\n");
-      }
-    else
-      {
-      sin.v4.sin_addr.s_addr = (S_ADDR_TYPE)inet_addr(ipa->address);
-      DEBUG(9) debug_printf("listening on %s\n", ipa->address);
-      }
-    #endif  /* HAVE_IPV6 */
-


-    /* Retry loop */
+    /* Retry loop. Need to get the length of sin right for IPv4/IPv6
+    for some operating systems that check it. Although AF_INET6 is always
+    available (even on old IPv4 systems), the sin.v6 field isn't. */


     for (i = 9; i >= 0; i--)
       {
-      if (bind(listen_sockets[sk], (struct sockaddr *)&sin, sizeof(sin)) < 0)
+      if (bind(listen_sockets[sk], (struct sockaddr *)&sin,
+               #if HAVE_IPV6
+               (af == AF_INET6)? sizeof(sin.v6) : sizeof(sin.v4)
+               #else
+               sizeof(sin)
+               #endif /* HAVE_IPV6 */
+           ) < 0)
         {
         char *msg = strerror(errno);
-        char *addr = (ipa->address[0] == 0)? "(any)" : ipa->address;
+        char *addr = (ipa->address[0] == 0)? "(any IPv4)" :
+          (ipa->address[0] == ':' && ipa->address[1] == 0)? "(any IPv6)" :
+          ipa->address;
         if (i == 0)
           log_write(0, LOG_MAIN|LOG_PANIC_DIE,
             "socket bind() to port %d for address %s failed: %s: "
Only in ./src: daemon.c.3.31
Only in ./src: daemon.c.orig
Only in ./src: daemon.c.rej
diff -ur ../exim-3.31-src/src/os.c ./src/os.c
--- ../exim-3.31-src/src/os.c    Mon Jul  2 02:46:44 2001
+++ ./src/os.c    Fri Jul 13 10:02:36 2001
@@ -620,6 +620,7 @@
   by another call. On others, it's already there, but we must reinstate the
   data in ifreq, because SIOCGIFFLAGS may wreck it. */


+
   #ifndef SIOCGIFCONF_GIVES_ADDR
   if (ioctl(vs, V_GIFADDR, (char *)&ifreq) < 0)
     log_write(0, LOG_PANIC_DIE, "Unable to get IP address for %s interface: "
Only in ./src/transports: appendfile.c.orig
Only in ./src/transports: pipe.c.orig
Only in ./src: tree.c.orig
Only in ./src: version.c.orig
Only in .: typescript
Only in ./util: convert4r3
Only in ./util: exigrep
Only in ./util: eximstats
Only in ./util: exiqsumm
Only in ./util: pcretest
Only in ./util: transport-filter.pl