1 /* -*- c-file-style: "linux" -*-
3 rsync -- fast file replication program
5 Copyright (C) 1992-2001 by Andrew Tridgell <tridge@samba.org>
6 Copyright (C) 2001, 2002 by Martin Pool <mbp@samba.org>
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 2 of the License, or
11 (at your option) any later version.
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with this program; if not, write to the Free Software
20 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
26 * Socket functions used in rsync.
28 * This file is now converted to use the new-style getaddrinfo()
29 * interface, which supports IPv6 but is also supported on recent
30 * IPv4-only machines. On systems that don't have that interface, we
31 * emulate it using the KAME implementation.
38 * Establish a proxy connection on an open socket to a web proxy by
39 * using the HTTP CONNECT method.
41 static int establish_proxy_connection(int fd, char *host, int port)
46 snprintf(buffer, sizeof(buffer), "CONNECT %s:%d HTTP/1.0\r\n\r\n", host, port);
47 if (write(fd, buffer, strlen(buffer)) != (int) strlen(buffer)) {
48 rprintf(FERROR, "failed to write to proxy: %s\n",
53 for (cp = buffer; cp < &buffer[sizeof(buffer) - 1]; cp++) {
54 if (read(fd, cp, 1) != 1) {
55 rprintf(FERROR, "failed to read from proxy: %s\n",
68 if (strncmp(buffer, "HTTP/", 5) != 0) {
69 rprintf(FERROR, "bad response from proxy - %s\n",
73 for (cp = &buffer[5]; isdigit(* (unsigned char *) cp) || (*cp == '.'); cp++)
78 rprintf(FERROR, "bad response from proxy - %s\n",
82 /* throw away the rest of the HTTP header */
84 for (cp = buffer; cp < &buffer[sizeof(buffer) - 1];
86 if (read(fd, cp, 1) != 1) {
87 rprintf(FERROR, "failed to read from proxy: %s\n",
94 if ((cp > buffer) && (*cp == '\n'))
96 if ((cp == buffer) && ((*cp == '\n') || (*cp == '\r')))
104 * Try to set the local address for a newly-created socket. Return -1
107 int try_bind_local(int s,
108 int ai_family, int ai_socktype,
109 const char *bind_address)
112 struct addrinfo bhints, *bres_all, *r;
114 memset(&bhints, 0, sizeof(bhints));
115 bhints.ai_family = ai_family;
116 bhints.ai_socktype = ai_socktype;
117 bhints.ai_flags = AI_PASSIVE;
118 if ((error = getaddrinfo(bind_address, NULL, &bhints, &bres_all))) {
119 rprintf(FERROR, RSYNC_NAME ": getaddrinfo %s: %s\n",
120 bind_address, gai_strerror(error));
124 for (r = bres_all; r; r = r->ai_next) {
125 if (bind(s, r->ai_addr, r->ai_addrlen) == -1)
127 freeaddrinfo(bres_all);
131 /* no error message; there might be some problem that allows
132 * creation of the socket but not binding, perhaps if the
133 * machine has no ipv6 address of this name. */
134 freeaddrinfo(bres_all);
140 * Open a socket to a tcp remote host with the specified port .
142 * Based on code from Warren. Proxy support by Stephen Rothwell.
143 * getaddrinfo() rewrite contributed by KAME.net.
145 * Now that we support IPv6 we need to look up the remote machine's
146 * address first, using @p af_hint to set a preference for the type
147 * of address. Then depending on whether it has v4 or v6 addresses we
148 * try to open a connection.
150 * The loop allows for machines with some addresses which may not be
151 * reachable, perhaps because we can't e.g. route ipv6 to that network
152 * but we can get ip4 packets through.
154 * @param bind_address Local address to use. Normally NULL to bind
155 * the wildcard address.
157 * @param af_hint Address family, e.g. AF_INET or AF_INET6.
159 int open_socket_out(char *host, int port, const char *bind_address,
162 int type = SOCK_STREAM;
165 struct addrinfo hints, *res0, *res;
172 /* if we have a RSYNC_PROXY env variable then redirect our
173 * connetcion via a web proxy at the given address. The format
174 * is hostname:port */
175 h = getenv("RSYNC_PROXY");
176 proxied = (h != NULL) && (*h != '\0');
179 strlcpy(buffer, h, sizeof(buffer));
180 cp = strchr(buffer, ':');
183 "invalid proxy specification: should be HOST:PORT\n");
190 rprintf(FINFO, "connection via http proxy %s port %s\n",
194 snprintf(portbuf, sizeof(portbuf), "%d", port);
198 memset(&hints, 0, sizeof(hints));
199 hints.ai_family = af_hint;
200 hints.ai_socktype = type;
201 error = getaddrinfo(h, portbuf, &hints, &res0);
203 rprintf(FERROR, RSYNC_NAME ": getaddrinfo: %s %s: %s\n",
204 h, portbuf, gai_strerror(error));
209 /* Try to connect to all addresses for this machine until we get
210 * through. It might e.g. be multi-homed, or have both IPv4 and IPv6
211 * addresses. We need to create a socket for each record, since the
212 * address record tells us what protocol to use to try to connect. */
213 for (res = res0; res; res = res->ai_next) {
214 s = socket(res->ai_family, res->ai_socktype, res->ai_protocol);
219 if (try_bind_local(s, res->ai_family, type,
220 bind_address) == -1) {
226 if (connect(s, res->ai_addr, res->ai_addrlen) < 0) {
232 establish_proxy_connection(s, host, port) != 0) {
241 rprintf(FERROR, RSYNC_NAME ": failed to connect to %s: %s\n",
250 * Open an outgoing socket, but allow for it to be intercepted by
251 * $RSYNC_CONNECT_PROG, which will execute a program across a TCP
252 * socketpair rather than really opening a socket.
254 * We use this primarily in testing to detect TCP flow bugs, but not
255 * cause security problems by really opening remote connections.
257 * This is based on the Samba LIBSMB_PROG feature.
259 * @param bind_address Local address to use. Normally NULL to get the stack default.
261 int open_socket_out_wrapped (char *host,
263 const char *bind_address,
268 if ((prog = getenv ("RSYNC_CONNECT_PROG")) != NULL)
269 return sock_exec (prog);
271 return open_socket_out (host, port, bind_address,
278 * Open a socket of the specified type, port and address for incoming data
280 * Try to be better about handling the results of getaddrinfo(): when
281 * opening an inbound socket, we might get several address results,
282 * e.g. for the machine's ipv4 and ipv6 name.
284 * If binding a wildcard, then any one of them should do. If an address
285 * was specified but it's insufficiently specific then that's not our
288 * However, some of the advertized addresses may not work because e.g. we
289 * don't have IPv6 support in the kernel. In that case go on and try all
290 * addresses until one succeeds.
292 * @param bind_address Local address to bind, or NULL to allow it to
295 static int open_socket_in(int type, int port, const char *bind_address,
300 struct addrinfo hints, *all_ai, *resp;
304 memset(&hints, 0, sizeof(hints));
305 hints.ai_family = af_hint;
306 hints.ai_socktype = type;
307 hints.ai_flags = AI_PASSIVE;
308 snprintf(portbuf, sizeof(portbuf), "%d", port);
309 error = getaddrinfo(bind_address, portbuf, &hints, &all_ai);
311 rprintf(FERROR, RSYNC_NAME ": getaddrinfo: bind address %s: %s\n",
312 bind_address, gai_strerror(error));
316 /* We may not be able to create the socket, if for example the
317 * machine knows about IPv6 in the C library, but not in the
319 for (resp = all_ai; resp; resp = resp->ai_next) {
320 s = socket(resp->ai_family, resp->ai_socktype,
324 /* See if there's another address that will work... */
327 setsockopt(s, SOL_SOCKET, SO_REUSEADDR,
328 (char *)&one, sizeof one);
330 /* now we've got a socket - we need to bind it */
331 if (bind(s, all_ai->ai_addr, all_ai->ai_addrlen) < 0) {
332 /* Nope, try another */
337 freeaddrinfo(all_ai);
341 rprintf(FERROR, RSYNC_NAME ": open inbound socket on port %d failed: "
346 freeaddrinfo(all_ai);
352 * Determine if a file descriptor is in fact a socket
354 int is_a_socket(int fd)
360 /* Parameters to getsockopt, setsockopt etc are very
361 * unstandardized across platforms, so don't be surprised if
362 * there are compiler warnings on e.g. SCO OpenSwerver or AIX.
363 * It seems they all eventually get the right idea.
365 * Debian says: ``The fifth argument of getsockopt and
366 * setsockopt is in reality an int [*] (and this is what BSD
367 * 4.* and libc4 and libc5 have). Some POSIX confusion
368 * resulted in the present socklen_t. The draft standard has
369 * not been adopted yet, but glibc2 already follows it and
370 * also has socklen_t [*]. See also accept(2).''
372 * We now return to your regularly scheduled programming. */
373 return(getsockopt(fd, SOL_SOCKET, SO_TYPE, (char *)&v, &l) == 0);
377 void start_accept_loop(int port, int (*fn)(int, int))
380 extern char *bind_address;
381 extern int default_af_hint;
383 /* open an incoming socket */
384 s = open_socket_in(SOCK_STREAM, port, bind_address, default_af_hint);
386 exit_cleanup(RERR_SOCKETIO);
388 /* ready to listen */
389 if (listen(s, 5) == -1) {
391 exit_cleanup(RERR_SOCKETIO);
395 /* now accept incoming connections - forking a new process
396 for each incoming connection */
401 struct sockaddr_storage addr;
402 socklen_t addrlen = sizeof addr;
404 /* close log file before the potentially very long select so
405 file can be trimmed by another process instead of growing
412 if (select(s+1, &fds, NULL, NULL, NULL) != 1) {
416 if(!FD_ISSET(s, &fds)) continue;
418 fd = accept(s,(struct sockaddr *)&addr,&addrlen);
420 if (fd == -1) continue;
422 signal(SIGCHLD, SIG_IGN);
424 /* we shouldn't have any children left hanging around
425 but I have had reports that on Digital Unix zombies
426 are produced, so this ensures that they are reaped */
428 while (waitpid(-1, NULL, WNOHANG) > 0);
431 if ((pid = fork()) == 0) {
434 /* open log file in child before possibly giving
440 } else if (pid < 0) {
443 ": could not create child server process: %s\n",
446 /* This might have happened because we're
447 * overloaded. Sleep briefly before trying to
451 /* Parent doesn't need this fd anymore. */
458 enum SOCK_OPT_TYPES {OPT_BOOL,OPT_INT,OPT_ON};
467 } socket_options[] = {
468 {"SO_KEEPALIVE", SOL_SOCKET, SO_KEEPALIVE, 0, OPT_BOOL},
469 {"SO_REUSEADDR", SOL_SOCKET, SO_REUSEADDR, 0, OPT_BOOL},
470 {"SO_BROADCAST", SOL_SOCKET, SO_BROADCAST, 0, OPT_BOOL},
472 {"TCP_NODELAY", IPPROTO_TCP, TCP_NODELAY, 0, OPT_BOOL},
474 #ifdef IPTOS_LOWDELAY
475 {"IPTOS_LOWDELAY", IPPROTO_IP, IP_TOS, IPTOS_LOWDELAY, OPT_ON},
477 #ifdef IPTOS_THROUGHPUT
478 {"IPTOS_THROUGHPUT", IPPROTO_IP, IP_TOS, IPTOS_THROUGHPUT, OPT_ON},
481 {"SO_SNDBUF", SOL_SOCKET, SO_SNDBUF, 0, OPT_INT},
484 {"SO_RCVBUF", SOL_SOCKET, SO_RCVBUF, 0, OPT_INT},
487 {"SO_SNDLOWAT", SOL_SOCKET, SO_SNDLOWAT, 0, OPT_INT},
490 {"SO_RCVLOWAT", SOL_SOCKET, SO_RCVLOWAT, 0, OPT_INT},
493 {"SO_SNDTIMEO", SOL_SOCKET, SO_SNDTIMEO, 0, OPT_INT},
496 {"SO_RCVTIMEO", SOL_SOCKET, SO_RCVTIMEO, 0, OPT_INT},
503 * Set user socket options
505 void set_socket_options(int fd, char *options)
508 if (!options || !*options) return;
510 options = strdup(options);
512 if (!options) out_of_memory("set_socket_options");
514 for (tok=strtok(options, " \t,"); tok; tok=strtok(NULL," \t,")) {
520 if ((p = strchr(tok,'='))) {
526 for (i=0;socket_options[i].name;i++)
527 if (strcmp(socket_options[i].name,tok)==0)
530 if (!socket_options[i].name) {
531 rprintf(FERROR,"Unknown socket option %s\n",tok);
535 switch (socket_options[i].opttype) {
538 ret = setsockopt(fd,socket_options[i].level,
539 socket_options[i].option,(char *)&value,sizeof(int));
544 rprintf(FERROR,"syntax error - %s does not take a value\n",tok);
547 int on = socket_options[i].value;
548 ret = setsockopt(fd,socket_options[i].level,
549 socket_options[i].option,(char *)&on,sizeof(int));
555 rprintf(FERROR, "failed to set socket option %s: %s\n", tok,
563 * Become a daemon, discarding the controlling terminal
565 void become_daemon(void)
573 /* detach from the terminal */
578 i = open("/dev/tty", O_RDWR);
580 ioctl(i, (int) TIOCNOTTY, (char *)0);
583 #endif /* TIOCNOTTY */
585 /* make sure that stdin, stdout an stderr don't stuff things
586 up (library functions, for example) */
589 open("/dev/null", O_RDWR);
595 * This is like socketpair but uses tcp. It is used by the Samba
596 * regression test code.
598 * The function guarantees that nobody else can attach to the socket,
599 * or if they do that this function fails and the socket gets closed
600 * returns 0 on success, -1 on failure the resulting file descriptors
603 static int socketpair_tcp(int fd[2])
606 struct sockaddr_in sock;
607 struct sockaddr_in sock2;
608 socklen_t socklen = sizeof(sock);
609 int connect_done = 0;
611 fd[0] = fd[1] = listener = -1;
613 memset(&sock, 0, sizeof(sock));
615 if ((listener = socket(PF_INET, SOCK_STREAM, 0)) == -1) goto failed;
617 memset(&sock2, 0, sizeof(sock2));
618 #ifdef HAVE_SOCKADDR_LEN
619 sock2.sin_len = sizeof(sock2);
621 sock2.sin_family = PF_INET;
623 bind(listener, (struct sockaddr *)&sock2, sizeof(sock2));
625 if (listen(listener, 1) != 0) goto failed;
627 if (getsockname(listener, (struct sockaddr *)&sock, &socklen) != 0) goto failed;
629 if ((fd[1] = socket(PF_INET, SOCK_STREAM, 0)) == -1) goto failed;
631 set_nonblocking(fd[1]);
633 sock.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
635 if (connect(fd[1],(struct sockaddr *)&sock,sizeof(sock)) == -1) {
636 if (errno != EINPROGRESS) goto failed;
641 if ((fd[0] = accept(listener, (struct sockaddr *)&sock, &socklen)) == -1) goto failed;
644 if (connect_done == 0) {
645 if (connect(fd[1],(struct sockaddr *)&sock,sizeof(sock)) != 0
646 && errno != EISCONN) goto failed;
649 set_blocking (fd[1]);
655 if (fd[0] != -1) close(fd[0]);
656 if (fd[1] != -1) close(fd[1]);
657 if (listener != -1) close(listener);
664 * Run a program on a local tcp socket, so that we can talk to it's
665 * stdin and stdout. This is used to fake a connection to a daemon
666 * for testing -- not for the normal case of running SSH.
668 * @return a socket which is attached to a subprocess running
669 * "prog". stdin and stdout are attached. stderr is left attached to
670 * the original stderr
672 int sock_exec(const char *prog)
676 if (socketpair_tcp(fd) != 0) {
677 rprintf (FERROR, RSYNC_NAME
678 ": socketpair_tcp failed (%s)\n",
689 /* Can't use rprintf because we've forked. */
691 RSYNC_NAME ": execute socket program \"%s\"\n",
694 exit (system (prog));