/*
* Empire - A multi-player, client/server Internet based war game.
- * Copyright (C) 1986-2006, 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,
* 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/>.
*
* ---
*
* ---
*
* 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>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
-#ifdef _WIN32
-#define WIN32
-#include "winsock2.h"
-#undef NS_ALL
-#else
#include <sys/socket.h>
-#include <netdb.h>
-#include <arpa/inet.h>
#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <netdb.h>
#include <unistd.h>
-#endif
#include "prototypes.h"
-static int 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)
* 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 */
-#ifndef _WIN32
- /*
- * SO_REUSEADDR requests to permit another bind even when the
- * port is still in state TIME_WAIT. Windows' SO_REUSEADDR is
- * broken: it makes bind() succeed no matter what, even if
- * there's another server running on the same port. Luckily,
- * bind() seems to be broken as well: it seems to suceed while
- * the port in state TIME_WAIT by default; thus we get the
- * behavior we want by not setting SO_REUSEADDR.
- */
- if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) < 0)
- cant_listen(host, serv, strerror(errno));
+#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
- if (bind(fd, res->ai_addr, res->ai_addrlen) == 0)
+
+ 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;
}
if ((fd = socket(AF_INET, SOCK_STREAM, 0)) < 0)
cant_listen(host, serv, strerror(errno));
-#ifndef _WIN32
- /* see comment on setsockopt() above */
- if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) < 0)
- cant_listen(host, serv, strerror(errno));
-#endif
+ 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)
return fd;
}
-
-static int
+static void
cant_listen(char *host, char *serv, const char *err)
{
fprintf(stderr, "Can't listen on %s%s%s: %s\n",