[distcc] ipv6 & EAFNOSUPPORT

[Martin Pool]

On  1 Mar 2004, Lisa Seelye <lisa at gentoo.org> wrote:
> On Mon, 2004-03-01 at 19:37, Martin Pool wrote:
> > So basically this should be done at runtime: if we wanted to create an
> > IPv6 socket but couldn't, then we should fall back to IPv4.  
> > 
> > Was my guess right that you did --enable-rfc2553 but the kernel didn't
> > have ipv6?
> 
> Yeah, the user filed a bug and didn't have ipv6 compiled into their
> kernel. ("I was just planning ahead...")
> 
> Testing at runtime seems like a good idea as you suggest (try ipv6, else
> ipv4 and throw a warning).

Could you ask them to try this, please?


--- srvnet.c.~1.46.~	2004-02-19 14:09:38.000000000 +1100
+++ srvnet.c	2004-03-02 15:17:43.000000000 +1100
@@ -72,24 +72,17 @@
 #include "netutil.h"
 #include "dopt.h"
 
-/**
+/*
  * Listen on a predetermined address (often the passive address).  The way in
  * which we get the address depends on the resolver API in use.
  **/
-static int dcc_listen_by_addr(int *listen_fd,
+static int dcc_listen_by_addr(int fd,
                               struct sockaddr *sa,
                               size_t salen)
 {
     int one = 1;
-    int fd;
     char *sa_buf = NULL;
 
-    fd = socket(sa->sa_family, SOCK_STREAM, 0);
-    if (fd == -1) {
-	rs_log_error("socket creation failed: %s", strerror(errno));
-	return EXIT_BIND_FAILED;
-    }
-
     setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, (char *) &one, sizeof(one));
 
     dcc_sockaddr_to_string(sa, salen, &sa_buf);
@@ -111,10 +104,8 @@ static int dcc_listen_by_addr(int *liste
         close(fd);
         return EXIT_BIND_FAILED;
     }
-    
-    *listen_fd = fd;
-    return 0;
 
+    return 0;
 }
 
 
@@ -122,12 +113,13 @@ static int dcc_listen_by_addr(int *liste
 #if defined(ENABLE_RFC2553)
 /* This version uses getaddrinfo.  It will probably use IPv6 if that's
  * supported by your configuration, kernel, and library. */
-int dcc_socket_listen(int port, int *listen_fd, const char *listen_addr)
+int dcc_socket_listen(int port, int *fd_out, const char *listen_addr)
 {
     char portname[20];
     struct addrinfo hints;
-    struct addrinfo *res, *best;
+    struct addrinfo *res, *ai;
     int error;
+    int ret;
 
     /* getaddrinfo() ought to check for this, but some versions do not.
      * (Debian Bug#192876.) */
@@ -155,11 +147,27 @@ int dcc_socket_listen(int port, int *lis
         return EXIT_BIND_FAILED;
     }
 
-    /* For now we always just use the first entry.  Is that OK? */
-
-    return dcc_listen_by_addr(listen_fd, res->ai_addr, res->ai_addrlen);
+    /* The first sockaddr returned will typically be an IPv6 socket.  Some
+     * kernels might not support that. */
+    for (ai = res; ai; ai=ai->ai_next) {
+        int af = ai->ai_addr->sa_family;
+        if ((*fd_out = socket(af, SOCK_STREAM, 0)) == -1) {
+            if (errno == EAFNOSUPPORT) {
+                rs_log_notice("socket address family %d not supported", af);
+                continue;
+            } else {
+                rs_log_error("socket creation failed: %s", strerror(errno));
+                return EXIT_BIND_FAILED;
+            }
+        } else {
+            ret = dcc_listen_by_addr(*fd_out, res->ai_addr, res->ai_addrlen);
+            freeaddrinfo(res);
+            return ret;
+        }
+    }
 
-    /* FIXME: This leaks the res list. */
+    rs_log_error("failed to find any supported socket family");
+    return EXIT_BIND_FAILED;
 }
 
 #else /* ndef ENABLE_RFC2553 */
@@ -189,7 +197,12 @@ int dcc_socket_listen(int port, int *lis
         sock.sin_addr.s_addr = INADDR_ANY;
     }
 
-    return dcc_listen_by_addr(listen_fd, (struct sockaddr *) &sock,
+    if ((*listen_fd = socket(PF_INET, SOCK_STREAM, 0)) == -1) {
+	rs_log_error("socket creation failed: %s", strerror(errno));
+	return EXIT_BIND_FAILED;
+    }
+
+    return dcc_listen_by_addr(*listen_fd, (struct sockaddr *) &sock,
                               sizeof sock);
 }
 #endif  /* ndef ENABLE_RFC2553 */

-- 
Martin 
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 189 bytes
Desc: Digital signature
Url : http://lists.samba.org/archive/distcc/attachments/20040302/fd5e5892/attachment.bin