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 CONNECT method. If proxy_user and proxy_pass are not NULL,
40 * they are used to authenticate to the proxy using the "Basic"
41 * proxy-authorization protocol
43 static int establish_proxy_connection(int fd, char *host, int port,
44 char *proxy_user, char *proxy_pass)
46 char *cp, buffer[1024];
47 char *authhdr, authbuf[1024];
50 if (proxy_user && proxy_pass) {
51 stringjoin(buffer, sizeof buffer,
52 proxy_user, ":", proxy_pass, NULL);
55 if ((len*8 + 5) / 6 >= (int)sizeof authbuf) {
57 "authentication information is too long\n");
61 base64_encode(buffer, len, authbuf);
62 authhdr = "\r\nProxy-Authorization: Basic ";
68 snprintf(buffer, sizeof buffer, "CONNECT %s:%d HTTP/1.0%s%s\r\n\r\n",
69 host, port, authhdr, authbuf);
71 if (write(fd, buffer, len) != len) {
72 rprintf(FERROR, "failed to write to proxy: %s\n",
77 for (cp = buffer; cp < &buffer[sizeof buffer - 1]; cp++) {
78 if (read(fd, cp, 1) != 1) {
79 rprintf(FERROR, "failed to read from proxy: %s\n",
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 rprintf(FERROR, "failed to read from proxy: %s\n",
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_address)
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_address, NULL, &bhints, &bres_all))) {
140 rprintf(FERROR, RSYNC_NAME ": getaddrinfo %s: %s\n",
141 bind_address, 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_address 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_address,
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 = strchr(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,
258 bind_address) == -1) {
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 rprintf(FERROR, RSYNC_NAME ": failed to connect to %s: %s\n",
288 * Open an outgoing socket, but allow for it to be intercepted by
289 * $RSYNC_CONNECT_PROG, which will execute a program across a TCP
290 * socketpair rather than really opening a socket.
292 * We use this primarily in testing to detect TCP flow bugs, but not
293 * cause security problems by really opening remote connections.
295 * This is based on the Samba LIBSMB_PROG feature.
297 * @param bind_address Local address to use. Normally NULL to get the stack default.
299 int open_socket_out_wrapped(char *host, int port, const char *bind_address,
302 char *prog = getenv("RSYNC_CONNECT_PROG");
305 rprintf(FINFO, "%sopening tcp connection to %s port %d\n",
306 prog ? "Using RSYNC_CONNECT_PROG instead of " : "",
310 return sock_exec(prog);
311 return open_socket_out(host, port, bind_address, af_hint);
317 * Open a socket of the specified type, port and address for incoming data
319 * Try to be better about handling the results of getaddrinfo(): when
320 * opening an inbound socket, we might get several address results,
321 * e.g. for the machine's IPv4 and IPv6 name.
323 * We return an array of socket file-descriptors, with the length of
324 * the array stored as the first element of the list. This allows
325 * the caller to listen on all of them.
327 * @param bind_address Local address to bind, or NULL to allow it to
330 static int *open_socket_in(int type, int port, const char *bind_address,
334 int s, *sp, *socks, maxs;
335 struct addrinfo hints, *all_ai, *resp;
339 memset(&hints, 0, sizeof hints);
340 hints.ai_family = af_hint;
341 hints.ai_socktype = type;
342 hints.ai_flags = AI_PASSIVE;
343 snprintf(portbuf, sizeof portbuf, "%d", port);
344 error = getaddrinfo(bind_address, portbuf, &hints, &all_ai);
346 rprintf(FERROR, RSYNC_NAME ": getaddrinfo: bind address %s: %s\n",
347 bind_address, gai_strerror(error));
351 /* Count max number of sockets we might open. */
352 for (maxs = 0, resp = all_ai; resp; resp = resp->ai_next, maxs++) {}
353 socks = new_array(int, maxs + 1);
356 RSYNC_NAME "couldn't allocate memory for sockets");
360 /* We may not be able to create the socket, if for example the
361 * machine knows about IPv6 in the C library, but not in the
363 sp = socks + 1; /* Leave room for count at start of array. */
364 for (resp = all_ai; resp; resp = resp->ai_next) {
365 s = socket(resp->ai_family, resp->ai_socktype,
369 /* See if there's another address that will work... */
373 setsockopt(s, SOL_SOCKET, SO_REUSEADDR,
374 (char *)&one, sizeof one);
377 if (resp->ai_family == AF_INET6) {
378 if (setsockopt(s, IPPROTO_IPV6, IPV6_V6ONLY,
379 (char *)&one, sizeof one) < 0) {
386 /* Now we've got a socket - we need to bind it. */
387 if (bind(s, resp->ai_addr, resp->ai_addrlen) < 0) {
388 /* Nope, try another */
395 *socks = sp - socks - 1; /* Save count. */
398 freeaddrinfo(all_ai);
402 RSYNC_NAME ": open inbound socket on port %d failed: "
403 "%s\n", port, strerror(errno));
412 * Determine if a file descriptor is in fact a socket
414 int is_a_socket(int fd)
417 socklen_t l = sizeof (int);
419 /* Parameters to getsockopt, setsockopt etc are very
420 * unstandardized across platforms, so don't be surprised if
421 * there are compiler warnings on e.g. SCO OpenSwerver or AIX.
422 * It seems they all eventually get the right idea.
424 * Debian says: ``The fifth argument of getsockopt and
425 * setsockopt is in reality an int [*] (and this is what BSD
426 * 4.* and libc4 and libc5 have). Some POSIX confusion
427 * resulted in the present socklen_t. The draft standard has
428 * not been adopted yet, but glibc2 already follows it and
429 * also has socklen_t [*]. See also accept(2).''
431 * We now return to your regularly scheduled programming. */
432 return getsockopt(fd, SOL_SOCKET, SO_TYPE, (char *)&v, &l) == 0;
436 static RETSIGTYPE sigchld_handler(UNUSED(int val))
439 while (waitpid(-1, NULL, WNOHANG) > 0) {}
441 signal(SIGCHLD, sigchld_handler);
445 void start_accept_loop(int port, int (*fn)(int, int))
449 extern char *bind_address;
450 extern int default_af_hint;
452 /* open an incoming socket */
453 sp = open_socket_in(SOCK_STREAM, port, bind_address, default_af_hint);
455 exit_cleanup(RERR_SOCKETIO);
457 /* ready to listen */
460 for (i = 1; i <= *sp; i++) {
461 if (listen(sp[i], 5) == -1) {
462 exit_cleanup(RERR_SOCKETIO);
464 FD_SET(sp[i], &deffds);
470 /* now accept incoming connections - forking a new process
471 * for each incoming connection */
476 struct sockaddr_storage addr;
477 socklen_t addrlen = sizeof addr;
479 /* close log file before the potentially very long select so
480 * file can be trimmed by another process instead of growing
485 FD_COPY(&deffds, &fds);
490 if (select(maxfd + 1, &fds, NULL, NULL, NULL) != 1)
494 for (i = 1; i <= *sp; i++) {
495 if (FD_ISSET(sp[i], &fds)) {
496 fd = accept(sp[i], (struct sockaddr *)&addr,
505 signal(SIGCHLD, sigchld_handler);
507 if ((pid = fork()) == 0) {
510 /* open log file in child before possibly giving
516 } else if (pid < 0) {
519 ": could not create child server process: %s\n",
522 /* This might have happened because we're
523 * overloaded. Sleep briefly before trying to
527 /* Parent doesn't need this fd anymore. */
535 enum SOCK_OPT_TYPES {OPT_BOOL,OPT_INT,OPT_ON};
544 } socket_options[] = {
545 {"SO_KEEPALIVE", SOL_SOCKET, SO_KEEPALIVE, 0, OPT_BOOL},
546 {"SO_REUSEADDR", SOL_SOCKET, SO_REUSEADDR, 0, OPT_BOOL},
547 {"SO_BROADCAST", SOL_SOCKET, SO_BROADCAST, 0, OPT_BOOL},
549 {"TCP_NODELAY", IPPROTO_TCP, TCP_NODELAY, 0, OPT_BOOL},
551 #ifdef IPTOS_LOWDELAY
552 {"IPTOS_LOWDELAY", IPPROTO_IP, IP_TOS, IPTOS_LOWDELAY, OPT_ON},
554 #ifdef IPTOS_THROUGHPUT
555 {"IPTOS_THROUGHPUT", IPPROTO_IP, IP_TOS, IPTOS_THROUGHPUT, OPT_ON},
558 {"SO_SNDBUF", SOL_SOCKET, SO_SNDBUF, 0, OPT_INT},
561 {"SO_RCVBUF", SOL_SOCKET, SO_RCVBUF, 0, OPT_INT},
564 {"SO_SNDLOWAT", SOL_SOCKET, SO_SNDLOWAT, 0, OPT_INT},
567 {"SO_RCVLOWAT", SOL_SOCKET, SO_RCVLOWAT, 0, OPT_INT},
570 {"SO_SNDTIMEO", SOL_SOCKET, SO_SNDTIMEO, 0, OPT_INT},
573 {"SO_RCVTIMEO", SOL_SOCKET, SO_RCVTIMEO, 0, OPT_INT},
580 * Set user socket options
582 void set_socket_options(int fd, char *options)
586 if (!options || !*options)
589 options = strdup(options);
592 out_of_memory("set_socket_options");
594 for (tok = strtok(options, " \t,"); tok; tok = strtok(NULL," \t,")) {
600 if ((p = strchr(tok,'='))) {
606 for (i = 0; socket_options[i].name; i++) {
607 if (strcmp(socket_options[i].name,tok)==0)
611 if (!socket_options[i].name) {
612 rprintf(FERROR,"Unknown socket option %s\n",tok);
616 switch (socket_options[i].opttype) {
619 ret = setsockopt(fd,socket_options[i].level,
620 socket_options[i].option,
621 (char *)&value, sizeof (int));
626 rprintf(FERROR,"syntax error - %s does not take a value\n",tok);
629 int on = socket_options[i].value;
630 ret = setsockopt(fd,socket_options[i].level,
631 socket_options[i].option,
632 (char *)&on, sizeof (int));
638 rprintf(FERROR, "failed to set socket option %s: %s\n", tok,
646 * Become a daemon, discarding the controlling terminal
648 void become_daemon(void)
656 /* detach from the terminal */
661 i = open("/dev/tty", O_RDWR);
663 ioctl(i, (int)TIOCNOTTY, (char *)0);
666 #endif /* TIOCNOTTY */
668 /* make sure that stdin, stdout an stderr don't stuff things
669 * up (library functions, for example) */
670 for (i = 0; i < 3; i++) {
672 open("/dev/null", O_RDWR);
678 * This is like socketpair but uses tcp. It is used by the Samba
679 * regression test code.
681 * The function guarantees that nobody else can attach to the socket,
682 * or if they do that this function fails and the socket gets closed
683 * returns 0 on success, -1 on failure the resulting file descriptors
686 static int socketpair_tcp(int fd[2])
689 struct sockaddr_in sock;
690 struct sockaddr_in sock2;
691 socklen_t socklen = sizeof sock;
692 int connect_done = 0;
694 fd[0] = fd[1] = listener = -1;
696 memset(&sock, 0, sizeof sock);
698 if ((listener = socket(PF_INET, SOCK_STREAM, 0)) == -1)
701 memset(&sock2, 0, sizeof sock2);
702 #if HAVE_SOCKADDR_IN_LEN
703 sock2.sin_len = sizeof sock2;
705 sock2.sin_family = PF_INET;
707 bind(listener, (struct sockaddr *)&sock2, sizeof sock2);
709 if (listen(listener, 1) != 0)
712 if (getsockname(listener, (struct sockaddr *)&sock, &socklen) != 0)
715 if ((fd[1] = socket(PF_INET, SOCK_STREAM, 0)) == -1)
718 set_nonblocking(fd[1]);
720 sock.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
722 if (connect(fd[1], (struct sockaddr *)&sock, sizeof sock) == -1) {
723 if (errno != EINPROGRESS)
728 if ((fd[0] = accept(listener, (struct sockaddr *)&sock, &socklen)) == -1)
732 if (connect_done == 0) {
733 if (connect(fd[1], (struct sockaddr *)&sock, sizeof sock) != 0
756 * Run a program on a local tcp socket, so that we can talk to it's
757 * stdin and stdout. This is used to fake a connection to a daemon
758 * for testing -- not for the normal case of running SSH.
760 * @return a socket which is attached to a subprocess running
761 * "prog". stdin and stdout are attached. stderr is left attached to
762 * the original stderr
764 int sock_exec(const char *prog)
768 if (socketpair_tcp(fd) != 0) {
769 rprintf(FERROR, RSYNC_NAME ": socketpair_tcp failed (%s)\n",
774 rprintf(FINFO, "Running socket program: \"%s\"\n", prog);