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 static struct sigaction sigact;
44 * Establish a proxy connection on an open socket to a web proxy by
45 * using the CONNECT method. If proxy_user and proxy_pass are not NULL,
46 * they are used to authenticate to the proxy using the "Basic"
47 * proxy-authorization protocol
49 static int establish_proxy_connection(int fd, char *host, int port,
50 char *proxy_user, char *proxy_pass)
52 char *cp, buffer[1024];
53 char *authhdr, authbuf[1024];
56 if (proxy_user && proxy_pass) {
57 stringjoin(buffer, sizeof buffer,
58 proxy_user, ":", proxy_pass, NULL);
61 if ((len*8 + 5) / 6 >= (int)sizeof authbuf - 3) {
63 "authentication information is too long\n");
67 base64_encode(buffer, len, authbuf, 1);
68 authhdr = "\r\nProxy-Authorization: Basic ";
74 snprintf(buffer, sizeof buffer, "CONNECT %s:%d HTTP/1.0%s%s\r\n\r\n",
75 host, port, authhdr, authbuf);
77 if (write(fd, buffer, len) != len) {
78 rsyserr(FERROR, errno, "failed to write to proxy");
82 for (cp = buffer; cp < &buffer[sizeof buffer - 1]; cp++) {
83 if (read(fd, cp, 1) != 1) {
84 rsyserr(FERROR, errno, "failed to read from proxy");
96 if (strncmp(buffer, "HTTP/", 5) != 0) {
97 rprintf(FERROR, "bad response from proxy -- %s\n",
101 for (cp = &buffer[5]; isdigit(*(uchar*)cp) || *cp == '.'; cp++) {}
105 rprintf(FERROR, "bad response from proxy -- %s\n",
109 /* throw away the rest of the HTTP header */
111 for (cp = buffer; cp < &buffer[sizeof buffer - 1]; cp++) {
112 if (read(fd, cp, 1) != 1) {
113 rsyserr(FERROR, errno,
114 "failed to read from proxy");
120 if (cp > buffer && *cp == '\n')
122 if (cp == buffer && (*cp == '\n' || *cp == '\r'))
130 * Try to set the local address for a newly-created socket. Return -1
133 int try_bind_local(int s, int ai_family, int ai_socktype,
134 const char *bind_addr)
137 struct addrinfo bhints, *bres_all, *r;
139 memset(&bhints, 0, sizeof bhints);
140 bhints.ai_family = ai_family;
141 bhints.ai_socktype = ai_socktype;
142 bhints.ai_flags = AI_PASSIVE;
143 if ((error = getaddrinfo(bind_addr, NULL, &bhints, &bres_all))) {
144 rprintf(FERROR, RSYNC_NAME ": getaddrinfo %s: %s\n",
145 bind_addr, gai_strerror(error));
149 for (r = bres_all; r; r = r->ai_next) {
150 if (bind(s, r->ai_addr, r->ai_addrlen) == -1)
152 freeaddrinfo(bres_all);
156 /* no error message; there might be some problem that allows
157 * creation of the socket but not binding, perhaps if the
158 * machine has no ipv6 address of this name. */
159 freeaddrinfo(bres_all);
165 * Open a socket to a tcp remote host with the specified port .
167 * Based on code from Warren. Proxy support by Stephen Rothwell.
168 * getaddrinfo() rewrite contributed by KAME.net.
170 * Now that we support IPv6 we need to look up the remote machine's
171 * address first, using @p af_hint to set a preference for the type
172 * of address. Then depending on whether it has v4 or v6 addresses we
173 * try to open a connection.
175 * The loop allows for machines with some addresses which may not be
176 * reachable, perhaps because we can't e.g. route ipv6 to that network
177 * but we can get ip4 packets through.
179 * @param bind_addr Local address to use. Normally NULL to bind
180 * the wildcard address.
182 * @param af_hint Address family, e.g. AF_INET or AF_INET6.
184 int open_socket_out(char *host, int port, const char *bind_addr,
187 int type = SOCK_STREAM;
189 struct addrinfo hints, *res0, *res;
194 char *proxy_user = NULL, *proxy_pass = NULL;
196 /* if we have a RSYNC_PROXY env variable then redirect our
197 * connetcion via a web proxy at the given address. */
198 h = getenv("RSYNC_PROXY");
199 proxied = h != NULL && *h != '\0';
202 strlcpy(buffer, h, sizeof buffer);
204 /* Is the USER:PASS@ prefix present? */
205 if ((cp = strrchr(buffer, '@')) != NULL) {
207 /* The remainder is the HOST:PORT part. */
210 if ((cp = strchr(buffer, ':')) == NULL) {
212 "invalid proxy specification: should be USER:PASS@HOST:PORT\n");
220 /* The whole buffer is the HOST:PORT part. */
224 if ((cp = strchr(h, ':')) == NULL) {
226 "invalid proxy specification: should be HOST:PORT\n");
230 strlcpy(portbuf, cp, sizeof portbuf);
232 rprintf(FINFO, "connection via http proxy %s port %s\n",
236 snprintf(portbuf, sizeof portbuf, "%d", port);
240 memset(&hints, 0, sizeof hints);
241 hints.ai_family = af_hint;
242 hints.ai_socktype = type;
243 error = getaddrinfo(h, portbuf, &hints, &res0);
245 rprintf(FERROR, RSYNC_NAME ": getaddrinfo: %s %s: %s\n",
246 h, portbuf, gai_strerror(error));
251 /* Try to connect to all addresses for this machine until we get
252 * through. It might e.g. be multi-homed, or have both IPv4 and IPv6
253 * addresses. We need to create a socket for each record, since the
254 * address record tells us what protocol to use to try to connect. */
255 for (res = res0; res; res = res->ai_next) {
256 s = socket(res->ai_family, res->ai_socktype, res->ai_protocol);
261 && try_bind_local(s, res->ai_family, type,
267 if (connect(s, res->ai_addr, res->ai_addrlen) < 0) {
273 && establish_proxy_connection(s, host, port,
274 proxy_user, proxy_pass) != 0) {
283 rsyserr(FERROR, errno, "failed to connect to %s", h);
291 * Open an outgoing socket, but allow for it to be intercepted by
292 * $RSYNC_CONNECT_PROG, which will execute a program across a TCP
293 * socketpair rather than really opening a socket.
295 * We use this primarily in testing to detect TCP flow bugs, but not
296 * cause security problems by really opening remote connections.
298 * This is based on the Samba LIBSMB_PROG feature.
300 * @param bind_addr Local address to use. Normally NULL to get the stack default.
302 int open_socket_out_wrapped(char *host, int port, const char *bind_addr,
305 char *prog = getenv("RSYNC_CONNECT_PROG");
308 rprintf(FINFO, "%sopening tcp connection to %s port %d\n",
309 prog ? "Using RSYNC_CONNECT_PROG instead of " : "",
313 return sock_exec(prog);
314 return open_socket_out(host, port, bind_addr, af_hint);
320 * Open one or more sockets for incoming data using the specified type,
323 * The getaddrinfo() call may return several address results, e.g. for
324 * the machine's IPv4 and IPv6 name.
326 * We return an array of file-descriptors to the sockets, with a trailing
327 * -1 value to indicate the end of the list.
329 * @param bind_addr Local address to bind, or NULL to allow it to
332 static int *open_socket_in(int type, int port, const char *bind_addr,
336 int s, *socks, maxs, i, ecnt;
337 struct addrinfo hints, *all_ai, *resp;
338 char portbuf[10], **errmsgs;
341 memset(&hints, 0, sizeof hints);
342 hints.ai_family = af_hint;
343 hints.ai_socktype = type;
344 hints.ai_flags = AI_PASSIVE;
345 snprintf(portbuf, sizeof portbuf, "%d", port);
346 error = getaddrinfo(bind_addr, portbuf, &hints, &all_ai);
348 rprintf(FERROR, RSYNC_NAME ": getaddrinfo: bind address %s: %s\n",
349 bind_addr, gai_strerror(error));
353 /* Count max number of sockets we might open. */
354 for (maxs = 0, resp = all_ai; resp; resp = resp->ai_next, maxs++) {}
356 socks = new_array(int, maxs + 1);
357 errmsgs = new_array(char *, maxs);
358 if (!socks || !errmsgs)
359 out_of_memory("open_socket_in");
361 /* We may not be able to create the socket, if for example the
362 * machine knows about IPv6 in the C library, but not in the
364 for (resp = all_ai, i = ecnt = 0; resp; resp = resp->ai_next) {
365 s = socket(resp->ai_family, resp->ai_socktype,
369 int r = asprintf(&errmsgs[ecnt++],
370 "socket(%d,%d,%d) failed: %s\n",
371 (int)resp->ai_family, (int)resp->ai_socktype,
372 (int)resp->ai_protocol, strerror(errno));
374 out_of_memory("open_socket_in");
375 /* See if there's another address that will work... */
379 setsockopt(s, SOL_SOCKET, SO_REUSEADDR,
380 (char *)&one, sizeof one);
383 if (resp->ai_family == AF_INET6) {
384 if (setsockopt(s, IPPROTO_IPV6, IPV6_V6ONLY,
385 (char *)&one, sizeof one) < 0
386 && default_af_hint != AF_INET6) {
393 /* Now we've got a socket - we need to bind it. */
394 if (bind(s, resp->ai_addr, resp->ai_addrlen) < 0) {
395 /* Nope, try another */
396 int r = asprintf(&errmsgs[ecnt++],
397 "bind() failed: %s (address-family %d)\n",
398 strerror(errno), (int)resp->ai_family);
400 out_of_memory("open_socket_in");
410 freeaddrinfo(all_ai);
412 /* Only output the socket()/bind() messages if we were totally
413 * unsuccessful, or if the daemon is being run with -vv. */
414 for (s = 0; s < ecnt; s++) {
415 if (!i || verbose > 1)
416 rwrite(FLOG, errmsgs[s], strlen(errmsgs[s]));
423 "unable to bind any inbound sockets on port %d\n",
433 * Determine if a file descriptor is in fact a socket
435 int is_a_socket(int fd)
438 socklen_t l = sizeof (int);
440 /* Parameters to getsockopt, setsockopt etc are very
441 * unstandardized across platforms, so don't be surprised if
442 * there are compiler warnings on e.g. SCO OpenSwerver or AIX.
443 * It seems they all eventually get the right idea.
445 * Debian says: ``The fifth argument of getsockopt and
446 * setsockopt is in reality an int [*] (and this is what BSD
447 * 4.* and libc4 and libc5 have). Some POSIX confusion
448 * resulted in the present socklen_t. The draft standard has
449 * not been adopted yet, but glibc2 already follows it and
450 * also has socklen_t [*]. See also accept(2).''
452 * We now return to your regularly scheduled programming. */
453 return getsockopt(fd, SOL_SOCKET, SO_TYPE, (char *)&v, &l) == 0;
457 static RETSIGTYPE sigchld_handler(UNUSED(int val))
460 while (waitpid(-1, NULL, WNOHANG) > 0) {}
462 #ifndef HAVE_SIGACTION
463 signal(SIGCHLD, sigchld_handler);
468 void start_accept_loop(int port, int (*fn)(int, int))
473 #ifdef HAVE_SIGACTION
474 sigact.sa_flags = SA_NOCLDSTOP;
477 /* open an incoming socket */
478 sp = open_socket_in(SOCK_STREAM, port, bind_address, default_af_hint);
480 exit_cleanup(RERR_SOCKETIO);
482 /* ready to listen */
484 for (i = 0, maxfd = -1; sp[i] >= 0; i++) {
485 if (listen(sp[i], 5) < 0) {
486 rsyserr(FERROR, errno, "listen() on socket failed");
488 if (errno == EADDRINUSE && i > 0) {
490 "Try using --ipv4 or --ipv6 to avoid this listen() error.\n");
493 exit_cleanup(RERR_SOCKETIO);
495 FD_SET(sp[i], &deffds);
500 /* now accept incoming connections - forking a new process
501 * for each incoming connection */
506 struct sockaddr_storage addr;
507 socklen_t addrlen = sizeof addr;
509 /* close log file before the potentially very long select so
510 * file can be trimmed by another process instead of growing
515 FD_COPY(&deffds, &fds);
520 if (select(maxfd + 1, &fds, NULL, NULL, NULL) != 1)
523 for (i = 0, fd = -1; sp[i] >= 0; i++) {
524 if (FD_ISSET(sp[i], &fds)) {
525 fd = accept(sp[i], (struct sockaddr *)&addr,
534 SIGACTION(SIGCHLD, sigchld_handler);
536 if ((pid = fork()) == 0) {
538 for (i = 0; sp[i] >= 0; i++)
540 /* Re-open log file in child before possibly giving
541 * up privileges (see logfile_close() above). */
546 } else if (pid < 0) {
547 rsyserr(FERROR, errno,
548 "could not create child server process");
550 /* This might have happened because we're
551 * overloaded. Sleep briefly before trying to
555 /* Parent doesn't need this fd anymore. */
562 enum SOCK_OPT_TYPES {OPT_BOOL,OPT_INT,OPT_ON};
571 } socket_options[] = {
572 {"SO_KEEPALIVE", SOL_SOCKET, SO_KEEPALIVE, 0, OPT_BOOL},
573 {"SO_REUSEADDR", SOL_SOCKET, SO_REUSEADDR, 0, OPT_BOOL},
574 {"SO_BROADCAST", SOL_SOCKET, SO_BROADCAST, 0, OPT_BOOL},
576 {"TCP_NODELAY", IPPROTO_TCP, TCP_NODELAY, 0, OPT_BOOL},
578 #ifdef IPTOS_LOWDELAY
579 {"IPTOS_LOWDELAY", IPPROTO_IP, IP_TOS, IPTOS_LOWDELAY, OPT_ON},
581 #ifdef IPTOS_THROUGHPUT
582 {"IPTOS_THROUGHPUT", IPPROTO_IP, IP_TOS, IPTOS_THROUGHPUT, OPT_ON},
585 {"SO_SNDBUF", SOL_SOCKET, SO_SNDBUF, 0, OPT_INT},
588 {"SO_RCVBUF", SOL_SOCKET, SO_RCVBUF, 0, OPT_INT},
591 {"SO_SNDLOWAT", SOL_SOCKET, SO_SNDLOWAT, 0, OPT_INT},
594 {"SO_RCVLOWAT", SOL_SOCKET, SO_RCVLOWAT, 0, OPT_INT},
597 {"SO_SNDTIMEO", SOL_SOCKET, SO_SNDTIMEO, 0, OPT_INT},
600 {"SO_RCVTIMEO", SOL_SOCKET, SO_RCVTIMEO, 0, OPT_INT},
607 * Set user socket options
609 void set_socket_options(int fd, char *options)
613 if (!options || !*options)
616 options = strdup(options);
619 out_of_memory("set_socket_options");
621 for (tok = strtok(options, " \t,"); tok; tok = strtok(NULL," \t,")) {
627 if ((p = strchr(tok,'='))) {
633 for (i = 0; socket_options[i].name; i++) {
634 if (strcmp(socket_options[i].name,tok)==0)
638 if (!socket_options[i].name) {
639 rprintf(FERROR,"Unknown socket option %s\n",tok);
643 switch (socket_options[i].opttype) {
646 ret = setsockopt(fd,socket_options[i].level,
647 socket_options[i].option,
648 (char *)&value, sizeof (int));
653 rprintf(FERROR,"syntax error -- %s does not take a value\n",tok);
656 int on = socket_options[i].value;
657 ret = setsockopt(fd,socket_options[i].level,
658 socket_options[i].option,
659 (char *)&on, sizeof (int));
665 rsyserr(FERROR, errno,
666 "failed to set socket option %s", tok);
674 * Become a daemon, discarding the controlling terminal
676 void become_daemon(void)
684 /* detach from the terminal */
687 #elif defined TIOCNOTTY
688 i = open("/dev/tty", O_RDWR);
690 ioctl(i, (int)TIOCNOTTY, (char *)0);
694 /* make sure that stdin, stdout an stderr don't stuff things
695 * up (library functions, for example) */
696 for (i = 0; i < 3; i++) {
698 open("/dev/null", O_RDWR);
704 * This is like socketpair but uses tcp. It is used by the Samba
705 * regression test code.
707 * The function guarantees that nobody else can attach to the socket,
708 * or if they do that this function fails and the socket gets closed
709 * returns 0 on success, -1 on failure the resulting file descriptors
712 static int socketpair_tcp(int fd[2])
715 struct sockaddr_in sock;
716 struct sockaddr_in sock2;
717 socklen_t socklen = sizeof sock;
718 int connect_done = 0;
720 fd[0] = fd[1] = listener = -1;
722 memset(&sock, 0, sizeof sock);
724 if ((listener = socket(PF_INET, SOCK_STREAM, 0)) == -1)
727 memset(&sock2, 0, sizeof sock2);
728 #ifdef HAVE_SOCKADDR_IN_LEN
729 sock2.sin_len = sizeof sock2;
731 sock2.sin_family = PF_INET;
733 bind(listener, (struct sockaddr *)&sock2, sizeof sock2);
735 if (listen(listener, 1) != 0)
738 if (getsockname(listener, (struct sockaddr *)&sock, &socklen) != 0)
741 if ((fd[1] = socket(PF_INET, SOCK_STREAM, 0)) == -1)
744 set_nonblocking(fd[1]);
746 sock.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
748 if (connect(fd[1], (struct sockaddr *)&sock, sizeof sock) == -1) {
749 if (errno != EINPROGRESS)
754 if ((fd[0] = accept(listener, (struct sockaddr *)&sock, &socklen)) == -1)
762 if (connect_done == 0) {
763 if (connect(fd[1], (struct sockaddr *)&sock, sizeof sock) != 0
784 * Run a program on a local tcp socket, so that we can talk to it's
785 * stdin and stdout. This is used to fake a connection to a daemon
786 * for testing -- not for the normal case of running SSH.
788 * @return a socket which is attached to a subprocess running
789 * "prog". stdin and stdout are attached. stderr is left attached to
790 * the original stderr
792 int sock_exec(const char *prog)
796 if (socketpair_tcp(fd) != 0) {
797 rsyserr(FERROR, errno, "socketpair_tcp failed");
801 rprintf(FINFO, "Running socket program: \"%s\"\n", prog);