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(*(uchar*)cp) || *cp == '.'; cp++) {}
77 rprintf(FERROR, "bad response from proxy - %s\n",
81 /* throw away the rest of the HTTP header */
83 for (cp = buffer; cp < &buffer[sizeof (buffer) - 1];
85 if (read(fd, cp, 1) != 1) {
86 rprintf(FERROR, "failed to read from proxy: %s\n",
93 if (cp > buffer && *cp == '\n')
95 if (cp == buffer && (*cp == '\n' || *cp == '\r'))
103 * Try to set the local address for a newly-created socket. Return -1
106 int try_bind_local(int s,
107 int ai_family, int ai_socktype,
108 const char *bind_address)
111 struct addrinfo bhints, *bres_all, *r;
113 memset(&bhints, 0, sizeof(bhints));
114 bhints.ai_family = ai_family;
115 bhints.ai_socktype = ai_socktype;
116 bhints.ai_flags = AI_PASSIVE;
117 if ((error = getaddrinfo(bind_address, NULL, &bhints, &bres_all))) {
118 rprintf(FERROR, RSYNC_NAME ": getaddrinfo %s: %s\n",
119 bind_address, gai_strerror(error));
123 for (r = bres_all; r; r = r->ai_next) {
124 if (bind(s, r->ai_addr, r->ai_addrlen) == -1)
126 freeaddrinfo(bres_all);
130 /* no error message; there might be some problem that allows
131 * creation of the socket but not binding, perhaps if the
132 * machine has no ipv6 address of this name. */
133 freeaddrinfo(bres_all);
139 * Open a socket to a tcp remote host with the specified port .
141 * Based on code from Warren. Proxy support by Stephen Rothwell.
142 * getaddrinfo() rewrite contributed by KAME.net.
144 * Now that we support IPv6 we need to look up the remote machine's
145 * address first, using @p af_hint to set a preference for the type
146 * of address. Then depending on whether it has v4 or v6 addresses we
147 * try to open a connection.
149 * The loop allows for machines with some addresses which may not be
150 * reachable, perhaps because we can't e.g. route ipv6 to that network
151 * but we can get ip4 packets through.
153 * @param bind_address Local address to use. Normally NULL to bind
154 * the wildcard address.
156 * @param af_hint Address family, e.g. AF_INET or AF_INET6.
158 int open_socket_out(char *host, int port, const char *bind_address,
161 int type = SOCK_STREAM;
164 struct addrinfo hints, *res0, *res;
171 /* if we have a RSYNC_PROXY env variable then redirect our
172 * connetcion via a web proxy at the given address. The format
173 * is hostname:port */
174 h = getenv("RSYNC_PROXY");
175 proxied = h != NULL && *h != '\0';
178 strlcpy(buffer, h, sizeof(buffer));
179 cp = strchr(buffer, ':');
182 "invalid proxy specification: should be HOST:PORT\n");
189 rprintf(FINFO, "connection via http proxy %s port %s\n",
193 snprintf(portbuf, sizeof(portbuf), "%d", port);
197 memset(&hints, 0, sizeof(hints));
198 hints.ai_family = af_hint;
199 hints.ai_socktype = type;
200 error = getaddrinfo(h, portbuf, &hints, &res0);
202 rprintf(FERROR, RSYNC_NAME ": getaddrinfo: %s %s: %s\n",
203 h, portbuf, gai_strerror(error));
208 /* Try to connect to all addresses for this machine until we get
209 * through. It might e.g. be multi-homed, or have both IPv4 and IPv6
210 * addresses. We need to create a socket for each record, since the
211 * address record tells us what protocol to use to try to connect. */
212 for (res = res0; res; res = res->ai_next) {
213 s = socket(res->ai_family, res->ai_socktype, res->ai_protocol);
218 if (try_bind_local(s, res->ai_family, type,
219 bind_address) == -1) {
225 if (connect(s, res->ai_addr, res->ai_addrlen) < 0) {
231 establish_proxy_connection(s, host, port) != 0) {
240 rprintf(FERROR, RSYNC_NAME ": failed to connect to %s: %s\n",
249 * Open an outgoing socket, but allow for it to be intercepted by
250 * $RSYNC_CONNECT_PROG, which will execute a program across a TCP
251 * socketpair rather than really opening a socket.
253 * We use this primarily in testing to detect TCP flow bugs, but not
254 * cause security problems by really opening remote connections.
256 * This is based on the Samba LIBSMB_PROG feature.
258 * @param bind_address Local address to use. Normally NULL to get the stack default.
260 int open_socket_out_wrapped(char *host, int port, const char *bind_address,
265 if ((prog = getenv("RSYNC_CONNECT_PROG")) != NULL)
266 return sock_exec(prog);
267 return open_socket_out(host, port, bind_address, af_hint);
273 * Open a socket of the specified type, port and address for incoming data
275 * Try to be better about handling the results of getaddrinfo(): when
276 * opening an inbound socket, we might get several address results,
277 * e.g. for the machine's ipv4 and ipv6 name.
279 * If binding a wildcard, then any one of them should do. If an address
280 * was specified but it's insufficiently specific then that's not our
283 * However, some of the advertized addresses may not work because e.g. we
284 * don't have IPv6 support in the kernel. In that case go on and try all
285 * addresses until one succeeds.
287 * @param bind_address Local address to bind, or NULL to allow it to
290 static int open_socket_in(int type, int port, const char *bind_address,
295 struct addrinfo hints, *all_ai, *resp;
299 memset(&hints, 0, sizeof(hints));
300 hints.ai_family = af_hint;
301 hints.ai_socktype = type;
302 hints.ai_flags = AI_PASSIVE;
303 snprintf(portbuf, sizeof(portbuf), "%d", port);
304 error = getaddrinfo(bind_address, portbuf, &hints, &all_ai);
306 rprintf(FERROR, RSYNC_NAME ": getaddrinfo: bind address %s: %s\n",
307 bind_address, gai_strerror(error));
311 /* We may not be able to create the socket, if for example the
312 * machine knows about IPv6 in the C library, but not in the
314 for (resp = all_ai; resp; resp = resp->ai_next) {
315 s = socket(resp->ai_family, resp->ai_socktype,
319 /* See if there's another address that will work... */
322 setsockopt(s, SOL_SOCKET, SO_REUSEADDR,
323 (char *)&one, sizeof one);
325 /* now we've got a socket - we need to bind it */
326 if (bind(s, all_ai->ai_addr, all_ai->ai_addrlen) < 0) {
327 /* Nope, try another */
332 freeaddrinfo(all_ai);
336 rprintf(FERROR, RSYNC_NAME ": open inbound socket on port %d failed: "
341 freeaddrinfo(all_ai);
347 * Determine if a file descriptor is in fact a socket
349 int is_a_socket(int fd)
355 /* Parameters to getsockopt, setsockopt etc are very
356 * unstandardized across platforms, so don't be surprised if
357 * there are compiler warnings on e.g. SCO OpenSwerver or AIX.
358 * It seems they all eventually get the right idea.
360 * Debian says: ``The fifth argument of getsockopt and
361 * setsockopt is in reality an int [*] (and this is what BSD
362 * 4.* and libc4 and libc5 have). Some POSIX confusion
363 * resulted in the present socklen_t. The draft standard has
364 * not been adopted yet, but glibc2 already follows it and
365 * also has socklen_t [*]. See also accept(2).''
367 * We now return to your regularly scheduled programming. */
368 return getsockopt(fd, SOL_SOCKET, SO_TYPE, (char *)&v, &l) == 0;
372 static RETSIGTYPE sigchld_handler(UNUSED(int val))
374 signal(SIGCHLD, sigchld_handler);
376 while (waitpid(-1, NULL, WNOHANG) > 0) {}
381 void start_accept_loop(int port, int (*fn)(int, int))
384 extern char *bind_address;
385 extern int default_af_hint;
387 /* open an incoming socket */
388 s = open_socket_in(SOCK_STREAM, port, bind_address, default_af_hint);
390 exit_cleanup(RERR_SOCKETIO);
392 /* ready to listen */
393 if (listen(s, 5) == -1) {
395 exit_cleanup(RERR_SOCKETIO);
399 /* now accept incoming connections - forking a new process
400 for each incoming connection */
405 struct sockaddr_storage addr;
406 socklen_t addrlen = sizeof addr;
408 /* close log file before the potentially very long select so
409 file can be trimmed by another process instead of growing
416 if (select(s+1, &fds, NULL, NULL, NULL) != 1)
419 if (!FD_ISSET(s, &fds))
422 fd = accept(s,(struct sockaddr *)&addr,&addrlen);
427 signal(SIGCHLD, sigchld_handler);
429 if ((pid = fork()) == 0) {
432 /* open log file in child before possibly giving
438 } else if (pid < 0) {
441 ": could not create child server process: %s\n",
444 /* This might have happened because we're
445 * overloaded. Sleep briefly before trying to
449 /* Parent doesn't need this fd anymore. */
456 enum SOCK_OPT_TYPES {OPT_BOOL,OPT_INT,OPT_ON};
465 } socket_options[] = {
466 {"SO_KEEPALIVE", SOL_SOCKET, SO_KEEPALIVE, 0, OPT_BOOL},
467 {"SO_REUSEADDR", SOL_SOCKET, SO_REUSEADDR, 0, OPT_BOOL},
468 {"SO_BROADCAST", SOL_SOCKET, SO_BROADCAST, 0, OPT_BOOL},
470 {"TCP_NODELAY", IPPROTO_TCP, TCP_NODELAY, 0, OPT_BOOL},
472 #ifdef IPTOS_LOWDELAY
473 {"IPTOS_LOWDELAY", IPPROTO_IP, IP_TOS, IPTOS_LOWDELAY, OPT_ON},
475 #ifdef IPTOS_THROUGHPUT
476 {"IPTOS_THROUGHPUT", IPPROTO_IP, IP_TOS, IPTOS_THROUGHPUT, OPT_ON},
479 {"SO_SNDBUF", SOL_SOCKET, SO_SNDBUF, 0, OPT_INT},
482 {"SO_RCVBUF", SOL_SOCKET, SO_RCVBUF, 0, OPT_INT},
485 {"SO_SNDLOWAT", SOL_SOCKET, SO_SNDLOWAT, 0, OPT_INT},
488 {"SO_RCVLOWAT", SOL_SOCKET, SO_RCVLOWAT, 0, OPT_INT},
491 {"SO_SNDTIMEO", SOL_SOCKET, SO_SNDTIMEO, 0, OPT_INT},
494 {"SO_RCVTIMEO", SOL_SOCKET, SO_RCVTIMEO, 0, OPT_INT},
501 * Set user socket options
503 void set_socket_options(int fd, char *options)
507 if (!options || !*options)
510 options = strdup(options);
513 out_of_memory("set_socket_options");
515 for (tok = strtok(options, " \t,"); tok; tok = strtok(NULL," \t,")) {
521 if ((p = strchr(tok,'='))) {
527 for (i = 0; socket_options[i].name; i++) {
528 if (strcmp(socket_options[i].name,tok)==0)
532 if (!socket_options[i].name) {
533 rprintf(FERROR,"Unknown socket option %s\n",tok);
537 switch (socket_options[i].opttype) {
540 ret = setsockopt(fd,socket_options[i].level,
541 socket_options[i].option,(char *)&value,sizeof(int));
546 rprintf(FERROR,"syntax error - %s does not take a value\n",tok);
549 int on = socket_options[i].value;
550 ret = setsockopt(fd,socket_options[i].level,
551 socket_options[i].option,(char *)&on,sizeof(int));
557 rprintf(FERROR, "failed to set socket option %s: %s\n", tok,
565 * Become a daemon, discarding the controlling terminal
567 void become_daemon(void)
575 /* detach from the terminal */
580 i = open("/dev/tty", O_RDWR);
582 ioctl(i, (int)TIOCNOTTY, (char *)0);
585 #endif /* TIOCNOTTY */
587 /* make sure that stdin, stdout an stderr don't stuff things
588 up (library functions, for example) */
589 for (i = 0; i < 3; i++) {
591 open("/dev/null", O_RDWR);
597 * This is like socketpair but uses tcp. It is used by the Samba
598 * regression test code.
600 * The function guarantees that nobody else can attach to the socket,
601 * or if they do that this function fails and the socket gets closed
602 * returns 0 on success, -1 on failure the resulting file descriptors
605 static int socketpair_tcp(int fd[2])
608 struct sockaddr_in sock;
609 struct sockaddr_in sock2;
610 socklen_t socklen = sizeof(sock);
611 int connect_done = 0;
613 fd[0] = fd[1] = listener = -1;
615 memset(&sock, 0, sizeof(sock));
617 if ((listener = socket(PF_INET, SOCK_STREAM, 0)) == -1)
620 memset(&sock2, 0, sizeof(sock2));
621 #ifdef HAVE_SOCKADDR_LEN
622 sock2.sin_len = sizeof(sock2);
624 sock2.sin_family = PF_INET;
626 bind(listener, (struct sockaddr *)&sock2, sizeof(sock2));
628 if (listen(listener, 1) != 0)
631 if (getsockname(listener, (struct sockaddr *)&sock, &socklen) != 0)
634 if ((fd[1] = socket(PF_INET, SOCK_STREAM, 0)) == -1)
637 set_nonblocking(fd[1]);
639 sock.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
641 if (connect(fd[1],(struct sockaddr *)&sock,sizeof(sock)) == -1) {
642 if (errno != EINPROGRESS)
647 if ((fd[0] = accept(listener, (struct sockaddr *)&sock, &socklen)) == -1)
651 if (connect_done == 0) {
652 if (connect(fd[1],(struct sockaddr *)&sock,sizeof(sock)) != 0
675 * Run a program on a local tcp socket, so that we can talk to it's
676 * stdin and stdout. This is used to fake a connection to a daemon
677 * for testing -- not for the normal case of running SSH.
679 * @return a socket which is attached to a subprocess running
680 * "prog". stdin and stdout are attached. stderr is left attached to
681 * the original stderr
683 int sock_exec(const char *prog)
687 if (socketpair_tcp(fd) != 0) {
688 rprintf(FERROR, RSYNC_NAME ": socketpair_tcp failed (%s)\n",
699 /* Can't use rprintf because we've forked. */
701 RSYNC_NAME ": execute socket program \"%s\"\n",