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.
36 extern char *bind_address;
37 extern int default_af_hint;
40 * Establish a proxy connection on an open socket to a web proxy by
41 * using the CONNECT method. If proxy_user and proxy_pass are not NULL,
42 * they are used to authenticate to the proxy using the "Basic"
43 * proxy-authorization protocol
45 static int establish_proxy_connection(int fd, char *host, int port,
46 char *proxy_user, char *proxy_pass)
48 char *cp, buffer[1024];
49 char *authhdr, authbuf[1024];
52 if (proxy_user && proxy_pass) {
53 stringjoin(buffer, sizeof buffer,
54 proxy_user, ":", proxy_pass, NULL);
57 if ((len*8 + 5) / 6 >= (int)sizeof authbuf) {
59 "authentication information is too long\n");
63 base64_encode(buffer, len, authbuf);
64 authhdr = "\r\nProxy-Authorization: Basic ";
70 snprintf(buffer, sizeof buffer, "CONNECT %s:%d HTTP/1.0%s%s\r\n\r\n",
71 host, port, authhdr, authbuf);
73 if (write(fd, buffer, len) != len) {
74 rsyserr(FERROR, errno, "failed to write to proxy");
78 for (cp = buffer; cp < &buffer[sizeof buffer - 1]; cp++) {
79 if (read(fd, cp, 1) != 1) {
80 rsyserr(FERROR, errno, "failed to read from proxy");
92 if (strncmp(buffer, "HTTP/", 5) != 0) {
93 rprintf(FERROR, "bad response from proxy -- %s\n",
97 for (cp = &buffer[5]; isdigit(*(uchar*)cp) || *cp == '.'; cp++) {}
101 rprintf(FERROR, "bad response from proxy -- %s\n",
105 /* throw away the rest of the HTTP header */
107 for (cp = buffer; cp < &buffer[sizeof buffer - 1]; cp++) {
108 if (read(fd, cp, 1) != 1) {
109 rsyserr(FERROR, errno,
110 "failed to read from proxy");
116 if (cp > buffer && *cp == '\n')
118 if (cp == buffer && (*cp == '\n' || *cp == '\r'))
126 * Try to set the local address for a newly-created socket. Return -1
129 int try_bind_local(int s, int ai_family, int ai_socktype,
130 const char *bind_addr)
133 struct addrinfo bhints, *bres_all, *r;
135 memset(&bhints, 0, sizeof bhints);
136 bhints.ai_family = ai_family;
137 bhints.ai_socktype = ai_socktype;
138 bhints.ai_flags = AI_PASSIVE;
139 if ((error = getaddrinfo(bind_addr, NULL, &bhints, &bres_all))) {
140 rprintf(FERROR, RSYNC_NAME ": getaddrinfo %s: %s\n",
141 bind_addr, gai_strerror(error));
145 for (r = bres_all; r; r = r->ai_next) {
146 if (bind(s, r->ai_addr, r->ai_addrlen) == -1)
148 freeaddrinfo(bres_all);
152 /* no error message; there might be some problem that allows
153 * creation of the socket but not binding, perhaps if the
154 * machine has no ipv6 address of this name. */
155 freeaddrinfo(bres_all);
161 * Open a socket to a tcp remote host with the specified port .
163 * Based on code from Warren. Proxy support by Stephen Rothwell.
164 * getaddrinfo() rewrite contributed by KAME.net.
166 * Now that we support IPv6 we need to look up the remote machine's
167 * address first, using @p af_hint to set a preference for the type
168 * of address. Then depending on whether it has v4 or v6 addresses we
169 * try to open a connection.
171 * The loop allows for machines with some addresses which may not be
172 * reachable, perhaps because we can't e.g. route ipv6 to that network
173 * but we can get ip4 packets through.
175 * @param bind_addr Local address to use. Normally NULL to bind
176 * the wildcard address.
178 * @param af_hint Address family, e.g. AF_INET or AF_INET6.
180 int open_socket_out(char *host, int port, const char *bind_addr,
183 int type = SOCK_STREAM;
185 struct addrinfo hints, *res0, *res;
190 char *proxy_user = NULL, *proxy_pass = NULL;
192 /* if we have a RSYNC_PROXY env variable then redirect our
193 * connetcion via a web proxy at the given address. */
194 h = getenv("RSYNC_PROXY");
195 proxied = h != NULL && *h != '\0';
198 strlcpy(buffer, h, sizeof buffer);
200 /* Is the USER:PASS@ prefix present? */
201 if ((cp = strrchr(buffer, '@')) != NULL) {
203 /* The remainder is the HOST:PORT part. */
206 if ((cp = strchr(buffer, ':')) == NULL) {
208 "invalid proxy specification: should be USER:PASS@HOST:PORT\n");
216 /* The whole buffer is the HOST:PORT part. */
220 if ((cp = strchr(h, ':')) == NULL) {
222 "invalid proxy specification: should be HOST:PORT\n");
226 strlcpy(portbuf, cp, sizeof portbuf);
228 rprintf(FINFO, "connection via http proxy %s port %s\n",
232 snprintf(portbuf, sizeof portbuf, "%d", port);
236 memset(&hints, 0, sizeof hints);
237 hints.ai_family = af_hint;
238 hints.ai_socktype = type;
239 error = getaddrinfo(h, portbuf, &hints, &res0);
241 rprintf(FERROR, RSYNC_NAME ": getaddrinfo: %s %s: %s\n",
242 h, portbuf, gai_strerror(error));
247 /* Try to connect to all addresses for this machine until we get
248 * through. It might e.g. be multi-homed, or have both IPv4 and IPv6
249 * addresses. We need to create a socket for each record, since the
250 * address record tells us what protocol to use to try to connect. */
251 for (res = res0; res; res = res->ai_next) {
252 s = socket(res->ai_family, res->ai_socktype, res->ai_protocol);
257 && try_bind_local(s, res->ai_family, type,
263 if (connect(s, res->ai_addr, res->ai_addrlen) < 0) {
269 && establish_proxy_connection(s, host, port,
270 proxy_user, proxy_pass) != 0) {
279 rsyserr(FERROR, errno, "failed to connect to %s", h);
287 * Open an outgoing socket, but allow for it to be intercepted by
288 * $RSYNC_CONNECT_PROG, which will execute a program across a TCP
289 * socketpair rather than really opening a socket.
291 * We use this primarily in testing to detect TCP flow bugs, but not
292 * cause security problems by really opening remote connections.
294 * This is based on the Samba LIBSMB_PROG feature.
296 * @param bind_addr Local address to use. Normally NULL to get the stack default.
298 int open_socket_out_wrapped(char *host, int port, const char *bind_addr,
301 char *prog = getenv("RSYNC_CONNECT_PROG");
304 rprintf(FINFO, "%sopening tcp connection to %s port %d\n",
305 prog ? "Using RSYNC_CONNECT_PROG instead of " : "",
309 return sock_exec(prog);
310 return open_socket_out(host, port, bind_addr, af_hint);
316 * Open one or more sockets for incoming data using the specified type,
319 * The getaddrinfo() call may return several address results, e.g. for
320 * the machine's IPv4 and IPv6 name.
322 * We return an array of file-descriptors to the sockets, with a trailing
323 * -1 value to indicate the end of the list.
325 * @param bind_addr Local address to bind, or NULL to allow it to
328 static int *open_socket_in(int type, int port, const char *bind_addr,
332 int s, *socks, maxs, i;
333 struct addrinfo hints, *all_ai, *resp;
337 memset(&hints, 0, sizeof hints);
338 hints.ai_family = af_hint;
339 hints.ai_socktype = type;
340 hints.ai_flags = AI_PASSIVE;
341 snprintf(portbuf, sizeof portbuf, "%d", port);
342 error = getaddrinfo(bind_addr, portbuf, &hints, &all_ai);
344 rprintf(FERROR, RSYNC_NAME ": getaddrinfo: bind address %s: %s\n",
345 bind_addr, gai_strerror(error));
349 /* Count max number of sockets we might open. */
350 for (maxs = 0, resp = all_ai; resp; resp = resp->ai_next, maxs++) {}
352 if (!(socks = new_array(int, maxs + 1)))
353 out_of_memory("open_socket_in");
355 /* We may not be able to create the socket, if for example the
356 * machine knows about IPv6 in the C library, but not in the
358 for (resp = all_ai, i = 0; resp; resp = resp->ai_next) {
359 s = socket(resp->ai_family, resp->ai_socktype,
363 /* See if there's another address that will work... */
367 setsockopt(s, SOL_SOCKET, SO_REUSEADDR,
368 (char *)&one, sizeof one);
371 if (resp->ai_family == AF_INET6) {
372 if (setsockopt(s, IPPROTO_IPV6, IPV6_V6ONLY,
373 (char *)&one, sizeof one) < 0
374 && default_af_hint != AF_INET6) {
381 /* Now we've got a socket - we need to bind it. */
382 if (bind(s, resp->ai_addr, resp->ai_addrlen) < 0) {
383 /* Nope, try another */
393 freeaddrinfo(all_ai);
397 "unable to bind any inbound sockets on port %d\n",
407 * Determine if a file descriptor is in fact a socket
409 int is_a_socket(int fd)
412 socklen_t l = sizeof (int);
414 /* Parameters to getsockopt, setsockopt etc are very
415 * unstandardized across platforms, so don't be surprised if
416 * there are compiler warnings on e.g. SCO OpenSwerver or AIX.
417 * It seems they all eventually get the right idea.
419 * Debian says: ``The fifth argument of getsockopt and
420 * setsockopt is in reality an int [*] (and this is what BSD
421 * 4.* and libc4 and libc5 have). Some POSIX confusion
422 * resulted in the present socklen_t. The draft standard has
423 * not been adopted yet, but glibc2 already follows it and
424 * also has socklen_t [*]. See also accept(2).''
426 * We now return to your regularly scheduled programming. */
427 return getsockopt(fd, SOL_SOCKET, SO_TYPE, (char *)&v, &l) == 0;
431 static RETSIGTYPE sigchld_handler(UNUSED(int val))
434 while (waitpid(-1, NULL, WNOHANG) > 0) {}
436 signal(SIGCHLD, sigchld_handler);
440 void start_accept_loop(int port, int (*fn)(int, int))
445 /* open an incoming socket */
446 sp = open_socket_in(SOCK_STREAM, port, bind_address, default_af_hint);
448 exit_cleanup(RERR_SOCKETIO);
450 /* ready to listen */
452 for (i = 0, maxfd = -1; sp[i] >= 0; i++) {
453 if (listen(sp[i], 5) < 0) {
454 rsyserr(FERROR, errno, "listen() on socket failed");
456 if (errno == EADDRINUSE && i > 0) {
458 "Try using --ipv4 or --ipv6 to avoid this listen() error.\n");
461 exit_cleanup(RERR_SOCKETIO);
463 FD_SET(sp[i], &deffds);
469 /* now accept incoming connections - forking a new process
470 * for each incoming connection */
475 struct sockaddr_storage addr;
476 socklen_t addrlen = sizeof addr;
478 /* close log file before the potentially very long select so
479 * file can be trimmed by another process instead of growing
484 FD_COPY(&deffds, &fds);
489 if (select(maxfd + 1, &fds, NULL, NULL, NULL) != 1)
492 for (i = 0, fd = -1; sp[i] >= 0; i++) {
493 if (FD_ISSET(sp[i], &fds)) {
494 fd = accept(sp[i], (struct sockaddr *)&addr,
503 signal(SIGCHLD, sigchld_handler);
505 if ((pid = fork()) == 0) {
507 for (i = 0; sp[i] >= 0; i++)
509 /* Re-open log file in child before possibly giving
510 * up privileges (see logfile_close() above). */
515 } else if (pid < 0) {
516 rsyserr(FERROR, errno,
517 "could not create child server process");
519 /* This might have happened because we're
520 * overloaded. Sleep briefly before trying to
524 /* Parent doesn't need this fd anymore. */
531 enum SOCK_OPT_TYPES {OPT_BOOL,OPT_INT,OPT_ON};
540 } socket_options[] = {
541 {"SO_KEEPALIVE", SOL_SOCKET, SO_KEEPALIVE, 0, OPT_BOOL},
542 {"SO_REUSEADDR", SOL_SOCKET, SO_REUSEADDR, 0, OPT_BOOL},
543 {"SO_BROADCAST", SOL_SOCKET, SO_BROADCAST, 0, OPT_BOOL},
545 {"TCP_NODELAY", IPPROTO_TCP, TCP_NODELAY, 0, OPT_BOOL},
547 #ifdef IPTOS_LOWDELAY
548 {"IPTOS_LOWDELAY", IPPROTO_IP, IP_TOS, IPTOS_LOWDELAY, OPT_ON},
550 #ifdef IPTOS_THROUGHPUT
551 {"IPTOS_THROUGHPUT", IPPROTO_IP, IP_TOS, IPTOS_THROUGHPUT, OPT_ON},
554 {"SO_SNDBUF", SOL_SOCKET, SO_SNDBUF, 0, OPT_INT},
557 {"SO_RCVBUF", SOL_SOCKET, SO_RCVBUF, 0, OPT_INT},
560 {"SO_SNDLOWAT", SOL_SOCKET, SO_SNDLOWAT, 0, OPT_INT},
563 {"SO_RCVLOWAT", SOL_SOCKET, SO_RCVLOWAT, 0, OPT_INT},
566 {"SO_SNDTIMEO", SOL_SOCKET, SO_SNDTIMEO, 0, OPT_INT},
569 {"SO_RCVTIMEO", SOL_SOCKET, SO_RCVTIMEO, 0, OPT_INT},
576 * Set user socket options
578 void set_socket_options(int fd, char *options)
582 if (!options || !*options)
585 options = strdup(options);
588 out_of_memory("set_socket_options");
590 for (tok = strtok(options, " \t,"); tok; tok = strtok(NULL," \t,")) {
596 if ((p = strchr(tok,'='))) {
602 for (i = 0; socket_options[i].name; i++) {
603 if (strcmp(socket_options[i].name,tok)==0)
607 if (!socket_options[i].name) {
608 rprintf(FERROR,"Unknown socket option %s\n",tok);
612 switch (socket_options[i].opttype) {
615 ret = setsockopt(fd,socket_options[i].level,
616 socket_options[i].option,
617 (char *)&value, sizeof (int));
622 rprintf(FERROR,"syntax error -- %s does not take a value\n",tok);
625 int on = socket_options[i].value;
626 ret = setsockopt(fd,socket_options[i].level,
627 socket_options[i].option,
628 (char *)&on, sizeof (int));
634 rsyserr(FERROR, errno,
635 "failed to set socket option %s", tok);
643 * Become a daemon, discarding the controlling terminal
645 void become_daemon(void)
653 /* detach from the terminal */
656 #elif defined TIOCNOTTY
657 i = open("/dev/tty", O_RDWR);
659 ioctl(i, (int)TIOCNOTTY, (char *)0);
663 /* make sure that stdin, stdout an stderr don't stuff things
664 * up (library functions, for example) */
665 for (i = 0; i < 3; i++) {
667 open("/dev/null", O_RDWR);
673 * This is like socketpair but uses tcp. It is used by the Samba
674 * regression test code.
676 * The function guarantees that nobody else can attach to the socket,
677 * or if they do that this function fails and the socket gets closed
678 * returns 0 on success, -1 on failure the resulting file descriptors
681 static int socketpair_tcp(int fd[2])
684 struct sockaddr_in sock;
685 struct sockaddr_in sock2;
686 socklen_t socklen = sizeof sock;
687 int connect_done = 0;
689 fd[0] = fd[1] = listener = -1;
691 memset(&sock, 0, sizeof sock);
693 if ((listener = socket(PF_INET, SOCK_STREAM, 0)) == -1)
696 memset(&sock2, 0, sizeof sock2);
697 #ifdef HAVE_SOCKADDR_IN_LEN
698 sock2.sin_len = sizeof sock2;
700 sock2.sin_family = PF_INET;
702 bind(listener, (struct sockaddr *)&sock2, sizeof sock2);
704 if (listen(listener, 1) != 0)
707 if (getsockname(listener, (struct sockaddr *)&sock, &socklen) != 0)
710 if ((fd[1] = socket(PF_INET, SOCK_STREAM, 0)) == -1)
713 set_nonblocking(fd[1]);
715 sock.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
717 if (connect(fd[1], (struct sockaddr *)&sock, sizeof sock) == -1) {
718 if (errno != EINPROGRESS)
723 if ((fd[0] = accept(listener, (struct sockaddr *)&sock, &socklen)) == -1)
731 if (connect_done == 0) {
732 if (connect(fd[1], (struct sockaddr *)&sock, sizeof sock) != 0
753 * Run a program on a local tcp socket, so that we can talk to it's
754 * stdin and stdout. This is used to fake a connection to a daemon
755 * for testing -- not for the normal case of running SSH.
757 * @return a socket which is attached to a subprocess running
758 * "prog". stdin and stdout are attached. stderr is left attached to
759 * the original stderr
761 int sock_exec(const char *prog)
765 if (socketpair_tcp(fd) != 0) {
766 rsyserr(FERROR, errno, "socketpair_tcp failed");
770 rprintf(FINFO, "Running socket program: \"%s\"\n", prog);