Update copyright notice

[empserver] / src / lib / gen / tcp_listen.c

diff --git a/src/lib/gen/tcp_listen.c b/src/lib/gen/tcp_listen.c
index 212c4819dd12478995af38d70cd3e9de6940351f..a3ef26cc590628b75d59a75576e1601df0d1c669 100644 (file)
--- a/src/lib/gen/tcp_listen.c
+++ b/src/lib/gen/tcp_listen.c
@@ -1,11 +1,11 @@
 /*
  *  Empire - A multi-player, client/server Internet based war game.
- *  Copyright (C) 1986-2007, Dave Pare, Jeff Bailey, Thomas Ruschak,
- *                           Ken Stevens, Steve McClure
+ *  Copyright (C) 1986-2015, Dave Pare, Jeff Bailey, Thomas Ruschak,
+ *                Ken Stevens, Steve McClure, Markus Armbruster
  *
- *  This program is free software; you can redistribute it and/or modify
+ *  Empire is free software: you can redistribute it and/or modify
  *  it under the terms of the GNU General Public License as published by
- *  the Free Software Foundation; either version 2 of the License, or
+ *  the Free Software Foundation, either version 3 of the License, or
  *  (at your option) any later version.
  *
  *  This program is distributed in the hope that it will be useful,
@@ -14,8 +14,7 @@
  *  GNU General Public License for more details.
  *
  *  You should have received a copy of the GNU General Public License
- *  along with this program; if not, write to the Free Software
- *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
  *
  *  ---
  *
@@ -26,13 +25,14 @@
  *  ---
  *
  *  tcp_listen.c: Create a socket and listen on it
- * 
+ *
  *  Known contributors to this file:
- *     Markus Armbruster, 2005
+ *     Markus Armbruster, 2005-2013
  */
 
 #include <config.h>
 
+#include <assert.h>
 #include <ctype.h>
 #include <errno.h>
 #include <stdio.h>
@@ -46,7 +46,13 @@
 #include <unistd.h>
 #include "prototypes.h"
 
-static void cant_listen(char *, char *, const char *);
+/* Portability cruft, should become unnecessary eventually */
+#ifndef AI_ADDRCONFIG
+#define AI_ADDRCONFIG 0
+#endif
+
+static void cant_listen(char *, char *, const char *)
+    ATTRIBUTE((noreturn));
 
 int
 tcp_listen(char *host, char *serv, size_t *addrlenp)
@@ -58,41 +64,76 @@ tcp_listen(char *host, char *serv, size_t *addrlenp)
      * Inspired by example code from W. Richard Stevens: UNIX Network
      * Programming, Vol. 1
      */
-    int n;
-    struct addrinfo hints, *res, *ressave;
+    int err;
+    struct addrinfo hints, *first_ai, *ai;
+    /* Crap necessary for OpenBSD, see below */
+    int try_v6only_off = 1, v6only_stuck = 0;
 
     memset(&hints, 0, sizeof(struct addrinfo));
-    hints.ai_flags = AI_PASSIVE;
+    hints.ai_flags = AI_PASSIVE | AI_ADDRCONFIG;
     hints.ai_family = AF_UNSPEC;
     hints.ai_socktype = SOCK_STREAM;
 
-    if ((n = getaddrinfo(host, serv, &hints, &res)) != 0)
-       cant_listen(host, serv, gai_strerror(n));
-    ressave = res;
+    if ((err = getaddrinfo(host, serv, &hints, &first_ai)) != 0)
+       cant_listen(host, serv, gai_strerror(err));
+    assert(first_ai);
 
-    do {
-       fd = socket(res->ai_family, res->ai_socktype, res->ai_protocol);
+again:
+    for (ai = first_ai; ai; ai = ai->ai_next) {
+       fd = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
        if (fd < 0)
            continue;           /* error, try next one */
 
-       if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) < 0)
-           cant_listen(host, serv, strerror(errno));
-       if (bind(fd, res->ai_addr, res->ai_addrlen) == 0)
+#ifdef IPV6_V6ONLY
+       if (ai->ai_family == AF_INET6 && try_v6only_off) {
+           int off = 0;
+
+           if (setsockopt(fd, IPPROTO_IPV6, IPV6_V6ONLY,
+                          &off, sizeof(off)) < 0) {
+               /*
+                * IPV6_V6ONLY is stuck on, violating RFC 3493 (gee,
+                * thanks, OpenBSD!).  Address is good only for IPv6,
+                * not for IPv4.  Means we can't have both on this
+                * system.  Continue looking for one that's good for
+                * IPv4.
+                */
+               v6only_stuck = 1;
+               close(fd);
+               continue;
+           }
+       }
+#else
+       (void)try_v6only_off;
+#endif
+
+       setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on));
+       if (bind(fd, ai->ai_addr, ai->ai_addrlen) == 0)
            break;              /* success */
 
        close(fd);              /* error, close and try next one */
-    } while ((res = res->ai_next) != NULL);
+    }
 
-    if (res == NULL)        /* errno from final socket() or bind() */
+    /* More crap for OpenBSD */
+    if (ai == NULL && v6only_stuck) {
+       /*
+        * No go.  But we skipped IPv6 addresses that don't work for
+        * IPv4, but could for IPv6.  Try again without skipping
+        * these.
+        */
+       try_v6only_off = 0;
+       goto again;
+    }
+
+    if (ai == NULL)         /* errno from final socket() or bind() */
        cant_listen(host, serv, strerror(errno));
 
     if (listen(fd, SOMAXCONN) < 0)
        cant_listen(host, serv, strerror(errno));
 
     if (addrlenp)
-       *addrlenp = res->ai_addrlen;
+       *addrlenp = ai->ai_addrlen;
 
-    freeaddrinfo(ressave);
+    freeaddrinfo(first_ai);
 
 #else  /* !HAVE_GETADDRINFO */
     struct sockaddr_in sin;
@@ -121,8 +162,7 @@ tcp_listen(char *host, char *serv, size_t *addrlenp)
     }
     if ((fd = socket(AF_INET, SOCK_STREAM, 0)) < 0)
        cant_listen(host, serv, strerror(errno));
-    if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) < 0)
-       cant_listen(host, serv, strerror(errno));
+    setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on));
     if (bind(fd, (struct sockaddr *)&sin, sizeof(sin)) < 0)
        cant_listen(host, serv, strerror(errno));
     if (listen(fd, SOMAXCONN) < 0)