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.
35 #include <netinet/in_systm.h>
36 #include <netinet/ip.h>
38 extern char *bind_address;
39 extern int default_af_hint;
42 static struct sigaction sigact;
46 * Establish a proxy connection on an open socket to a web proxy by
47 * using the CONNECT method. If proxy_user and proxy_pass are not NULL,
48 * they are used to authenticate to the proxy using the "Basic"
49 * proxy-authorization protocol
51 static int establish_proxy_connection(int fd, char *host, int port,
52 char *proxy_user, char *proxy_pass)
54 char *cp, buffer[1024];
55 char *authhdr, authbuf[1024];
58 if (proxy_user && proxy_pass) {
59 stringjoin(buffer, sizeof buffer,
60 proxy_user, ":", proxy_pass, NULL);
63 if ((len*8 + 5) / 6 >= (int)sizeof authbuf - 3) {
65 "authentication information is too long\n");
69 base64_encode(buffer, len, authbuf, 1);
70 authhdr = "\r\nProxy-Authorization: Basic ";
76 snprintf(buffer, sizeof buffer, "CONNECT %s:%d HTTP/1.0%s%s\r\n\r\n",
77 host, port, authhdr, authbuf);
79 if (write(fd, buffer, len) != len) {
80 rsyserr(FERROR, errno, "failed to write to proxy");
84 for (cp = buffer; cp < &buffer[sizeof buffer - 1]; cp++) {
85 if (read(fd, cp, 1) != 1) {
86 rsyserr(FERROR, errno, "failed to read from proxy");
98 if (strncmp(buffer, "HTTP/", 5) != 0) {
99 rprintf(FERROR, "bad response from proxy -- %s\n",
103 for (cp = &buffer[5]; isdigit(*(uchar*)cp) || *cp == '.'; cp++) {}
107 rprintf(FERROR, "bad response from proxy -- %s\n",
111 /* throw away the rest of the HTTP header */
113 for (cp = buffer; cp < &buffer[sizeof buffer - 1]; cp++) {
114 if (read(fd, cp, 1) != 1) {
115 rsyserr(FERROR, errno,
116 "failed to read from proxy");
122 if (cp > buffer && *cp == '\n')
124 if (cp == buffer && (*cp == '\n' || *cp == '\r'))
132 * Try to set the local address for a newly-created socket. Return -1
135 int try_bind_local(int s, int ai_family, int ai_socktype,
136 const char *bind_addr)
139 struct addrinfo bhints, *bres_all, *r;
141 memset(&bhints, 0, sizeof bhints);
142 bhints.ai_family = ai_family;
143 bhints.ai_socktype = ai_socktype;
144 bhints.ai_flags = AI_PASSIVE;
145 if ((error = getaddrinfo(bind_addr, NULL, &bhints, &bres_all))) {
146 rprintf(FERROR, RSYNC_NAME ": getaddrinfo %s: %s\n",
147 bind_addr, gai_strerror(error));
151 for (r = bres_all; r; r = r->ai_next) {
152 if (bind(s, r->ai_addr, r->ai_addrlen) == -1)
154 freeaddrinfo(bres_all);
158 /* no error message; there might be some problem that allows
159 * creation of the socket but not binding, perhaps if the
160 * machine has no ipv6 address of this name. */
161 freeaddrinfo(bres_all);
167 * Open a socket to a tcp remote host with the specified port .
169 * Based on code from Warren. Proxy support by Stephen Rothwell.
170 * getaddrinfo() rewrite contributed by KAME.net.
172 * Now that we support IPv6 we need to look up the remote machine's
173 * address first, using @p af_hint to set a preference for the type
174 * of address. Then depending on whether it has v4 or v6 addresses we
175 * try to open a connection.
177 * The loop allows for machines with some addresses which may not be
178 * reachable, perhaps because we can't e.g. route ipv6 to that network
179 * but we can get ip4 packets through.
181 * @param bind_addr Local address to use. Normally NULL to bind
182 * the wildcard address.
184 * @param af_hint Address family, e.g. AF_INET or AF_INET6.
186 int open_socket_out(char *host, int port, const char *bind_addr,
189 int type = SOCK_STREAM;
191 struct addrinfo hints, *res0, *res;
196 char *proxy_user = NULL, *proxy_pass = NULL;
198 /* if we have a RSYNC_PROXY env variable then redirect our
199 * connetcion via a web proxy at the given address. */
200 h = getenv("RSYNC_PROXY");
201 proxied = h != NULL && *h != '\0';
204 strlcpy(buffer, h, sizeof buffer);
206 /* Is the USER:PASS@ prefix present? */
207 if ((cp = strrchr(buffer, '@')) != NULL) {
209 /* The remainder is the HOST:PORT part. */
212 if ((cp = strchr(buffer, ':')) == NULL) {
214 "invalid proxy specification: should be USER:PASS@HOST:PORT\n");
222 /* The whole buffer is the HOST:PORT part. */
226 if ((cp = strchr(h, ':')) == NULL) {
228 "invalid proxy specification: should be HOST:PORT\n");
232 strlcpy(portbuf, cp, sizeof portbuf);
234 rprintf(FINFO, "connection via http proxy %s port %s\n",
238 snprintf(portbuf, sizeof portbuf, "%d", port);
242 memset(&hints, 0, sizeof hints);
243 hints.ai_family = af_hint;
244 hints.ai_socktype = type;
245 error = getaddrinfo(h, portbuf, &hints, &res0);
247 rprintf(FERROR, RSYNC_NAME ": getaddrinfo: %s %s: %s\n",
248 h, portbuf, gai_strerror(error));
253 /* Try to connect to all addresses for this machine until we get
254 * through. It might e.g. be multi-homed, or have both IPv4 and IPv6
255 * addresses. We need to create a socket for each record, since the
256 * address record tells us what protocol to use to try to connect. */
257 for (res = res0; res; res = res->ai_next) {
258 s = socket(res->ai_family, res->ai_socktype, res->ai_protocol);
263 && try_bind_local(s, res->ai_family, type,
269 if (connect(s, res->ai_addr, res->ai_addrlen) < 0) {
275 && establish_proxy_connection(s, host, port,
276 proxy_user, proxy_pass) != 0) {
285 rsyserr(FERROR, errno, "failed to connect to %s", h);
293 * Open an outgoing socket, but allow for it to be intercepted by
294 * $RSYNC_CONNECT_PROG, which will execute a program across a TCP
295 * socketpair rather than really opening a socket.
297 * We use this primarily in testing to detect TCP flow bugs, but not
298 * cause security problems by really opening remote connections.
300 * This is based on the Samba LIBSMB_PROG feature.
302 * @param bind_addr Local address to use. Normally NULL to get the stack default.
304 int open_socket_out_wrapped(char *host, int port, const char *bind_addr,
307 char *prog = getenv("RSYNC_CONNECT_PROG");
310 rprintf(FINFO, "%sopening tcp connection to %s port %d\n",
311 prog ? "Using RSYNC_CONNECT_PROG instead of " : "",
315 return sock_exec(prog);
316 return open_socket_out(host, port, bind_addr, af_hint);
322 * Open one or more sockets for incoming data using the specified type,
325 * The getaddrinfo() call may return several address results, e.g. for
326 * the machine's IPv4 and IPv6 name.
328 * We return an array of file-descriptors to the sockets, with a trailing
329 * -1 value to indicate the end of the list.
331 * @param bind_addr Local address to bind, or NULL to allow it to
334 static int *open_socket_in(int type, int port, const char *bind_addr,
338 int s, *socks, maxs, i, ecnt;
339 struct addrinfo hints, *all_ai, *resp;
340 char portbuf[10], **errmsgs;
343 memset(&hints, 0, sizeof hints);
344 hints.ai_family = af_hint;
345 hints.ai_socktype = type;
346 hints.ai_flags = AI_PASSIVE;
347 snprintf(portbuf, sizeof portbuf, "%d", port);
348 error = getaddrinfo(bind_addr, portbuf, &hints, &all_ai);
350 rprintf(FERROR, RSYNC_NAME ": getaddrinfo: bind address %s: %s\n",
351 bind_addr, gai_strerror(error));
355 /* Count max number of sockets we might open. */
356 for (maxs = 0, resp = all_ai; resp; resp = resp->ai_next, maxs++) {}
358 socks = new_array(int, maxs + 1);
359 errmsgs = new_array(char *, maxs);
360 if (!socks || !errmsgs)
361 out_of_memory("open_socket_in");
363 /* We may not be able to create the socket, if for example the
364 * machine knows about IPv6 in the C library, but not in the
366 for (resp = all_ai, i = ecnt = 0; resp; resp = resp->ai_next) {
367 s = socket(resp->ai_family, resp->ai_socktype,
371 int r = asprintf(&errmsgs[ecnt++],
372 "socket(%d,%d,%d) failed: %s\n",
373 (int)resp->ai_family, (int)resp->ai_socktype,
374 (int)resp->ai_protocol, strerror(errno));
376 out_of_memory("open_socket_in");
377 /* See if there's another address that will work... */
381 setsockopt(s, SOL_SOCKET, SO_REUSEADDR,
382 (char *)&one, sizeof one);
385 if (resp->ai_family == AF_INET6) {
386 if (setsockopt(s, IPPROTO_IPV6, IPV6_V6ONLY,
387 (char *)&one, sizeof one) < 0
388 && default_af_hint != AF_INET6) {
395 /* Now we've got a socket - we need to bind it. */
396 if (bind(s, resp->ai_addr, resp->ai_addrlen) < 0) {
397 /* Nope, try another */
398 int r = asprintf(&errmsgs[ecnt++],
399 "bind() failed: %s (address-family %d)\n",
400 strerror(errno), (int)resp->ai_family);
402 out_of_memory("open_socket_in");
412 freeaddrinfo(all_ai);
414 /* Only output the socket()/bind() messages if we were totally
415 * unsuccessful, or if the daemon is being run with -vv. */
416 for (s = 0; s < ecnt; s++) {
417 if (!i || verbose > 1)
418 rwrite(FLOG, errmsgs[s], strlen(errmsgs[s]));
425 "unable to bind any inbound sockets on port %d\n",
435 * Determine if a file descriptor is in fact a socket
437 int is_a_socket(int fd)
440 socklen_t l = sizeof (int);
442 /* Parameters to getsockopt, setsockopt etc are very
443 * unstandardized across platforms, so don't be surprised if
444 * there are compiler warnings on e.g. SCO OpenSwerver or AIX.
445 * It seems they all eventually get the right idea.
447 * Debian says: ``The fifth argument of getsockopt and
448 * setsockopt is in reality an int [*] (and this is what BSD
449 * 4.* and libc4 and libc5 have). Some POSIX confusion
450 * resulted in the present socklen_t. The draft standard has
451 * not been adopted yet, but glibc2 already follows it and
452 * also has socklen_t [*]. See also accept(2).''
454 * We now return to your regularly scheduled programming. */
455 return getsockopt(fd, SOL_SOCKET, SO_TYPE, (char *)&v, &l) == 0;
459 static RETSIGTYPE sigchld_handler(UNUSED(int val))
462 while (waitpid(-1, NULL, WNOHANG) > 0) {}
464 #ifndef HAVE_SIGACTION
465 signal(SIGCHLD, sigchld_handler);
470 void start_accept_loop(int port, int (*fn)(int, int))
475 #ifdef HAVE_SIGACTION
476 sigact.sa_flags = SA_NOCLDSTOP;
479 /* open an incoming socket */
480 sp = open_socket_in(SOCK_STREAM, port, bind_address, default_af_hint);
482 exit_cleanup(RERR_SOCKETIO);
484 /* ready to listen */
486 for (i = 0, maxfd = -1; sp[i] >= 0; i++) {
487 if (listen(sp[i], 5) < 0) {
488 rsyserr(FERROR, errno, "listen() on socket failed");
490 if (errno == EADDRINUSE && i > 0) {
492 "Try using --ipv4 or --ipv6 to avoid this listen() error.\n");
495 exit_cleanup(RERR_SOCKETIO);
497 FD_SET(sp[i], &deffds);
502 /* now accept incoming connections - forking a new process
503 * for each incoming connection */
508 struct sockaddr_storage addr;
509 socklen_t addrlen = sizeof addr;
511 /* close log file before the potentially very long select so
512 * file can be trimmed by another process instead of growing
517 FD_COPY(&deffds, &fds);
522 if (select(maxfd + 1, &fds, NULL, NULL, NULL) != 1)
525 for (i = 0, fd = -1; sp[i] >= 0; i++) {
526 if (FD_ISSET(sp[i], &fds)) {
527 fd = accept(sp[i], (struct sockaddr *)&addr,
536 SIGACTION(SIGCHLD, sigchld_handler);
538 if ((pid = fork()) == 0) {
540 for (i = 0; sp[i] >= 0; i++)
542 /* Re-open log file in child before possibly giving
543 * up privileges (see logfile_close() above). */
548 } else if (pid < 0) {
549 rsyserr(FERROR, errno,
550 "could not create child server process");
552 /* This might have happened because we're
553 * overloaded. Sleep briefly before trying to
557 /* Parent doesn't need this fd anymore. */
564 enum SOCK_OPT_TYPES {OPT_BOOL,OPT_INT,OPT_ON};
573 } socket_options[] = {
574 {"SO_KEEPALIVE", SOL_SOCKET, SO_KEEPALIVE, 0, OPT_BOOL},
575 {"SO_REUSEADDR", SOL_SOCKET, SO_REUSEADDR, 0, OPT_BOOL},
576 {"SO_BROADCAST", SOL_SOCKET, SO_BROADCAST, 0, OPT_BOOL},
578 {"TCP_NODELAY", IPPROTO_TCP, TCP_NODELAY, 0, OPT_BOOL},
580 #ifdef IPTOS_LOWDELAY
581 {"IPTOS_LOWDELAY", IPPROTO_IP, IP_TOS, IPTOS_LOWDELAY, OPT_ON},
583 #ifdef IPTOS_THROUGHPUT
584 {"IPTOS_THROUGHPUT", IPPROTO_IP, IP_TOS, IPTOS_THROUGHPUT, OPT_ON},
587 {"SO_SNDBUF", SOL_SOCKET, SO_SNDBUF, 0, OPT_INT},
590 {"SO_RCVBUF", SOL_SOCKET, SO_RCVBUF, 0, OPT_INT},
593 {"SO_SNDLOWAT", SOL_SOCKET, SO_SNDLOWAT, 0, OPT_INT},
596 {"SO_RCVLOWAT", SOL_SOCKET, SO_RCVLOWAT, 0, OPT_INT},
599 {"SO_SNDTIMEO", SOL_SOCKET, SO_SNDTIMEO, 0, OPT_INT},
602 {"SO_RCVTIMEO", SOL_SOCKET, SO_RCVTIMEO, 0, OPT_INT},
609 * Set user socket options
611 void set_socket_options(int fd, char *options)
615 if (!options || !*options)
618 options = strdup(options);
621 out_of_memory("set_socket_options");
623 for (tok = strtok(options, " \t,"); tok; tok = strtok(NULL," \t,")) {
629 if ((p = strchr(tok,'='))) {
635 for (i = 0; socket_options[i].name; i++) {
636 if (strcmp(socket_options[i].name,tok)==0)
640 if (!socket_options[i].name) {
641 rprintf(FERROR,"Unknown socket option %s\n",tok);
645 switch (socket_options[i].opttype) {
648 ret = setsockopt(fd,socket_options[i].level,
649 socket_options[i].option,
650 (char *)&value, sizeof (int));
655 rprintf(FERROR,"syntax error -- %s does not take a value\n",tok);
658 int on = socket_options[i].value;
659 ret = setsockopt(fd,socket_options[i].level,
660 socket_options[i].option,
661 (char *)&on, sizeof (int));
667 rsyserr(FERROR, errno,
668 "failed to set socket option %s", tok);
676 * Become a daemon, discarding the controlling terminal
678 void become_daemon(void)
686 /* detach from the terminal */
689 #elif defined TIOCNOTTY
690 i = open("/dev/tty", O_RDWR);
692 ioctl(i, (int)TIOCNOTTY, (char *)0);
696 /* make sure that stdin, stdout an stderr don't stuff things
697 * up (library functions, for example) */
698 for (i = 0; i < 3; i++) {
700 open("/dev/null", O_RDWR);
706 * This is like socketpair but uses tcp. It is used by the Samba
707 * regression test code.
709 * The function guarantees that nobody else can attach to the socket,
710 * or if they do that this function fails and the socket gets closed
711 * returns 0 on success, -1 on failure the resulting file descriptors
714 static int socketpair_tcp(int fd[2])
717 struct sockaddr_in sock;
718 struct sockaddr_in sock2;
719 socklen_t socklen = sizeof sock;
720 int connect_done = 0;
722 fd[0] = fd[1] = listener = -1;
724 memset(&sock, 0, sizeof sock);
726 if ((listener = socket(PF_INET, SOCK_STREAM, 0)) == -1)
729 memset(&sock2, 0, sizeof sock2);
730 #ifdef HAVE_SOCKADDR_IN_LEN
731 sock2.sin_len = sizeof sock2;
733 sock2.sin_family = PF_INET;
735 bind(listener, (struct sockaddr *)&sock2, sizeof sock2);
737 if (listen(listener, 1) != 0)
740 if (getsockname(listener, (struct sockaddr *)&sock, &socklen) != 0)
743 if ((fd[1] = socket(PF_INET, SOCK_STREAM, 0)) == -1)
746 set_nonblocking(fd[1]);
748 sock.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
750 if (connect(fd[1], (struct sockaddr *)&sock, sizeof sock) == -1) {
751 if (errno != EINPROGRESS)
756 if ((fd[0] = accept(listener, (struct sockaddr *)&sock, &socklen)) == -1)
764 if (connect_done == 0) {
765 if (connect(fd[1], (struct sockaddr *)&sock, sizeof sock) != 0
786 * Run a program on a local tcp socket, so that we can talk to it's
787 * stdin and stdout. This is used to fake a connection to a daemon
788 * for testing -- not for the normal case of running SSH.
790 * @return a socket which is attached to a subprocess running
791 * "prog". stdin and stdout are attached. stderr is left attached to
792 * the original stderr
794 int sock_exec(const char *prog)
798 if (socketpair_tcp(fd) != 0) {
799 rsyserr(FERROR, errno, "socketpair_tcp failed");
803 rprintf(FINFO, "Running socket program: \"%s\"\n", prog);