1 /* -*- c-file-style: "linux" -*-
3 Copyright (C) 1992-2001 by Andrew Tridgell <tridge@samba.org>
4 Copyright (C) 2001 by Martin Pool <mbp@samba.org>
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2 of the License, or
9 (at your option) any later version.
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with this program; if not, write to the Free Software
18 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
24 * Socket functions used in rsync.
29 /* Establish a proxy connection on an open socket to a web roxy by
30 * using the CONNECT method. */
31 static int establish_proxy_connection(int fd, char *host, int port)
36 snprintf(buffer, sizeof(buffer), "CONNECT %s:%d HTTP/1.0\r\n\r\n", host, port);
37 if (write(fd, buffer, strlen(buffer)) != strlen(buffer)) {
38 rprintf(FERROR, "failed to write to proxy: %s\n",
43 for (cp = buffer; cp < &buffer[sizeof(buffer) - 1]; cp++) {
44 if (read(fd, cp, 1) != 1) {
45 rprintf(FERROR, "failed to read from proxy: %s\n",
58 if (strncmp(buffer, "HTTP/", 5) != 0) {
59 rprintf(FERROR, "bad response from proxy - %s\n",
63 for (cp = &buffer[5]; isdigit(*cp) || (*cp == '.'); cp++)
68 rprintf(FERROR, "bad response from proxy - %s\n",
72 /* throw away the rest of the HTTP header */
74 for (cp = buffer; cp < &buffer[sizeof(buffer) - 1];
76 if (read(fd, cp, 1) != 1) {
77 rprintf(FERROR, "failed to read from proxy: %s\n",
84 if ((cp > buffer) && (*cp == '\n'))
86 if ((cp == buffer) && ((*cp == '\n') || (*cp == '\r')))
95 * Open a socket to a tcp remote host with the specified port .
97 * Based on code from Warren. Proxy support by Stephen Rothwell.
98 * getaddrinfo() rewrite contributed by KAME.net.
100 * Now that we support IPv6 we need to look up the remote machine's
101 * address first, using @p af_hint to set a preference for the type
102 * of address. Then depending on whether it has v4 or v6 addresses we
103 * try to open a connection.
105 * The loop allows for machines with some addresses which may not be
106 * reachable, perhaps because we can't e.g. route ipv6 to that network
107 * but we can get ip4 packets through.
109 * @param bind_address Local address to use. Normally NULL to bind
110 * the wildcard address.
112 * @param af_hint Address family, e.g. AF_INET or AF_INET6.
114 int open_socket_out(char *host, int port, const char *bind_address,
117 int type = SOCK_STREAM;
121 struct addrinfo hints, *res0, *res;
128 /* if we have a RSYNC_PROXY env variable then redirect our
129 * connetcion via a web proxy at the given address. The format
130 * is hostname:port */
131 h = getenv("RSYNC_PROXY");
132 proxied = (h != NULL) && (*h != '\0');
135 strlcpy(buffer, h, sizeof(buffer));
136 cp = strchr(buffer, ':');
139 "invalid proxy specification: should be HOST:PORT\n");
146 snprintf(portbuf, sizeof(portbuf), "%d", port);
150 memset(&hints, 0, sizeof(hints));
151 hints.ai_family = af_hint;
152 hints.ai_socktype = type;
153 error = getaddrinfo(h, portbuf, &hints, &res0);
155 rprintf(FERROR, RSYNC_NAME ": getaddrinfo: %s %s: %s\n",
156 h, portbuf, gai_strerror(error));
161 /* Try to connect to all addresses for this machine until we get
162 * through. It might e.g. be multi-homed, or have both IPv4 and IPv6
163 * addresses. We need to create a socket for each record, since the
164 * address record tells us what protocol to use to try to connect. */
165 for (res = res0; res; res = res->ai_next) {
166 s = socket(res->ai_family, res->ai_socktype, res->ai_protocol);
171 struct addrinfo bhints, *bres;
173 memset(&bhints, 0, sizeof(bhints));
174 bhints.ai_family = res->ai_family;
175 bhints.ai_socktype = type;
176 bhints.ai_flags = AI_PASSIVE;
177 error = getaddrinfo(bind_address, NULL, &bhints, &bres);
179 rprintf(FERROR, RSYNC_NAME ": getaddrinfo: "
180 "bind address %s <noport>: %s\n",
181 bind_address, gai_strerror(error));
185 /* I'm not at all sure that this is the right
186 * response here... -- mbp */
187 rprintf(FERROR, RSYNC_NAME ": getaddrinfo: "
188 "bind address %s resolved to multiple hosts\n",
193 bind(s, bres->ai_addr, bres->ai_addrlen);
196 if (connect(s, res->ai_addr, res->ai_addrlen) < 0) {
202 establish_proxy_connection(s, host, port) != 0) {
211 rprintf(FERROR, RSYNC_NAME ": failed to connect to %s: %s\n",
220 * Open an outgoing socket, but allow for it to be intercepted by
221 * $RSYNC_CONNECT_PROG, which will execute a program across a TCP
222 * socketpair rather than really opening a socket.
224 * We use this primarily in testing to detect TCP flow bugs, but not
225 * cause security problems by really opening remote connections.
227 * This is based on the Samba LIBSMB_PROG feature.
229 * @param bind_address Local address to use. Normally NULL to get the stack default.
231 int open_socket_out_wrapped (char *host,
233 const char *bind_address,
238 if ((prog = getenv ("RSYNC_CONNECT_PROG")) != NULL)
239 return sock_exec (prog);
241 return open_socket_out (host, port, bind_address,
248 * Open a socket of the specified type, port and address for incoming data
250 * Try to be better about handling the results of getaddrinfo(): when
251 * opening an inbound socket, we might get several address results,
252 * e.g. for the machine's ipv4 and ipv6 name.
254 * If binding a wildcard, then any one of them should do. If an address
255 * was specified but it's insufficiently specific then that's not our
258 * However, some of the advertized addresses may not work because e.g. we
259 * don't have IPv6 support in the kernel. In that case go on and try all
260 * addresses until one succeeds.
262 * @param bind_address Local address to bind, or NULL to allow it to
265 static int open_socket_in(int type, int port, const char *bind_address,
270 struct addrinfo hints, *all_ai, *resp;
274 memset(&hints, 0, sizeof(hints));
275 hints.ai_family = af_hint;
276 hints.ai_socktype = type;
277 hints.ai_flags = AI_PASSIVE;
278 snprintf(portbuf, sizeof(portbuf), "%d", port);
279 error = getaddrinfo(bind_address, portbuf, &hints, &all_ai);
281 rprintf(FERROR, RSYNC_NAME ": getaddrinfo: bind address %s: %s\n",
282 bind_address, gai_strerror(error));
286 /* We may not be able to create the socket, if for example the
287 * machine knows about IPv6 in the C library, but not in the
289 for (resp = all_ai; resp; resp = resp->ai_next) {
290 s = socket(resp->ai_family, resp->ai_socktype,
294 /* See if there's another address that will work... */
297 setsockopt(s, SOL_SOCKET, SO_REUSEADDR,
298 (char *)&one, sizeof one);
300 /* now we've got a socket - we need to bind it */
301 if (bind(s, all_ai->ai_addr, all_ai->ai_addrlen) < 0) {
302 /* Nope, try another */
310 rprintf(FERROR, RSYNC_NAME ": open inbound socket on port %d failed: "
315 freeaddrinfo(all_ai);
321 * Determine if a file descriptor is in fact a socket
323 int is_a_socket(int fd)
329 /* Parameters to getsockopt, setsockopt etc are very
330 * unstandardized across platforms, so don't be surprised if
331 * there are compiler warnings on e.g. SCO OpenSwerver or AIX.
332 * It seems they all eventually get the right idea.
334 * Debian says: ``The fifth argument of getsockopt and
335 * setsockopt is in reality an int [*] (and this is what BSD
336 * 4.* and libc4 and libc5 have). Some POSIX confusion
337 * resulted in the present socklen_t. The draft standard has
338 * not been adopted yet, but glibc2 already follows it and
339 * also has socklen_t [*]. See also accept(2).''
341 * We now return to your regularly scheduled programming. */
342 return(getsockopt(fd, SOL_SOCKET, SO_TYPE, (char *)&v, &l) == 0);
346 void start_accept_loop(int port, int (*fn)(int ))
349 extern char *bind_address;
350 extern int default_af_hint;
352 /* open an incoming socket */
353 s = open_socket_in(SOCK_STREAM, port, bind_address, default_af_hint);
355 exit_cleanup(RERR_SOCKETIO);
357 /* ready to listen */
358 if (listen(s, 5) == -1) {
360 exit_cleanup(RERR_SOCKETIO);
364 /* now accept incoming connections - forking a new process
365 for each incoming connection */
369 struct sockaddr_storage addr;
370 int addrlen = sizeof(addr);
372 /* close log file before the potentially very long select so
373 file can be trimmed by another process instead of growing
380 if (select(s+1, &fds, NULL, NULL, NULL) != 1) {
384 if(!FD_ISSET(s, &fds)) continue;
386 fd = accept(s,(struct sockaddr *)&addr,&addrlen);
388 if (fd == -1) continue;
390 signal(SIGCHLD, SIG_IGN);
392 /* we shouldn't have any children left hanging around
393 but I have had reports that on Digital Unix zombies
394 are produced, so this ensures that they are reaped */
396 while (waitpid(-1, NULL, WNOHANG) > 0);
401 /* open log file in child before possibly giving
412 enum SOCK_OPT_TYPES {OPT_BOOL,OPT_INT,OPT_ON};
421 } socket_options[] = {
422 {"SO_KEEPALIVE", SOL_SOCKET, SO_KEEPALIVE, 0, OPT_BOOL},
423 {"SO_REUSEADDR", SOL_SOCKET, SO_REUSEADDR, 0, OPT_BOOL},
424 {"SO_BROADCAST", SOL_SOCKET, SO_BROADCAST, 0, OPT_BOOL},
426 {"TCP_NODELAY", IPPROTO_TCP, TCP_NODELAY, 0, OPT_BOOL},
428 #ifdef IPTOS_LOWDELAY
429 {"IPTOS_LOWDELAY", IPPROTO_IP, IP_TOS, IPTOS_LOWDELAY, OPT_ON},
431 #ifdef IPTOS_THROUGHPUT
432 {"IPTOS_THROUGHPUT", IPPROTO_IP, IP_TOS, IPTOS_THROUGHPUT, OPT_ON},
435 {"SO_SNDBUF", SOL_SOCKET, SO_SNDBUF, 0, OPT_INT},
438 {"SO_RCVBUF", SOL_SOCKET, SO_RCVBUF, 0, OPT_INT},
441 {"SO_SNDLOWAT", SOL_SOCKET, SO_SNDLOWAT, 0, OPT_INT},
444 {"SO_RCVLOWAT", SOL_SOCKET, SO_RCVLOWAT, 0, OPT_INT},
447 {"SO_SNDTIMEO", SOL_SOCKET, SO_SNDTIMEO, 0, OPT_INT},
450 {"SO_RCVTIMEO", SOL_SOCKET, SO_RCVTIMEO, 0, OPT_INT},
456 /****************************************************************************
457 set user socket options
458 ****************************************************************************/
459 void set_socket_options(int fd, char *options)
462 if (!options || !*options) return;
464 options = strdup(options);
466 if (!options) out_of_memory("set_socket_options");
468 for (tok=strtok(options, " \t,"); tok; tok=strtok(NULL," \t,")) {
474 if ((p = strchr(tok,'='))) {
480 for (i=0;socket_options[i].name;i++)
481 if (strcmp(socket_options[i].name,tok)==0)
484 if (!socket_options[i].name) {
485 rprintf(FERROR,"Unknown socket option %s\n",tok);
489 switch (socket_options[i].opttype) {
492 ret = setsockopt(fd,socket_options[i].level,
493 socket_options[i].option,(char *)&value,sizeof(int));
498 rprintf(FERROR,"syntax error - %s does not take a value\n",tok);
501 int on = socket_options[i].value;
502 ret = setsockopt(fd,socket_options[i].level,
503 socket_options[i].option,(char *)&on,sizeof(int));
509 rprintf(FERROR, "failed to set socket option %s: %s\n", tok,
516 /****************************************************************************
517 become a daemon, discarding the controlling terminal
518 ****************************************************************************/
519 void become_daemon(void)
527 /* detach from the terminal */
532 i = open("/dev/tty", O_RDWR);
534 ioctl(i, (int) TIOCNOTTY, (char *)0);
537 #endif /* TIOCNOTTY */
539 /* make sure that stdin, stdout an stderr don't stuff things
540 up (library functions, for example) */
543 open("/dev/null", O_RDWR);
548 * Return the IP addr of the client as a string
550 char *client_addr(int fd)
552 struct sockaddr_storage ss;
553 int length = sizeof(ss);
554 static char addr_buf[100];
555 static int initialised;
557 if (initialised) return addr_buf;
561 if (getpeername(fd, (struct sockaddr *)&ss, &length)) {
562 exit_cleanup(RERR_SOCKETIO);
565 getnameinfo((struct sockaddr *)&ss, length,
566 addr_buf, sizeof(addr_buf), NULL, 0, NI_NUMERICHOST);
571 static int get_sockaddr_family(const struct sockaddr_storage *ss)
573 return ((struct sockaddr *) ss)->sa_family;
578 * Return the DNS name of the client
580 char *client_name(int fd)
582 struct sockaddr_storage ss;
583 int length = sizeof(ss);
584 static char name_buf[100];
585 static char port_buf[100];
586 char *def = "UNKNOWN";
587 static int initialised;
588 struct addrinfo hints, *res, *res0;
591 if (initialised) return name_buf;
595 strcpy(name_buf,def);
597 if (getpeername(fd, (struct sockaddr *)&ss, &length)) {
598 /* FIXME: Can we really not continue? */
599 rprintf(FERROR, RSYNC_NAME ": getpeername on fd%d failed: %s\n",
600 fd, strerror(errno));
601 exit_cleanup(RERR_SOCKETIO);
605 if (get_sockaddr_family(&ss) == AF_INET6 &&
606 IN6_IS_ADDR_V4MAPPED(&((struct sockaddr_in6 *)&ss)->sin6_addr)) {
607 struct sockaddr_in6 sin6;
608 struct sockaddr_in *sin;
610 memcpy(&sin6, &ss, sizeof(sin6));
611 sin = (struct sockaddr_in *)&ss;
612 memset(sin, 0, sizeof(*sin));
613 sin->sin_family = AF_INET;
614 length = sizeof(struct sockaddr_in);
615 #ifdef HAVE_SOCKADDR_LEN
616 sin->sin_len = length;
618 sin->sin_port = sin6.sin6_port;
619 memcpy(&sin->sin_addr, &sin6.sin6_addr.s6_addr[12],
620 sizeof(sin->sin_addr));
625 if (getnameinfo((struct sockaddr *)&ss, length,
626 name_buf, sizeof(name_buf), port_buf, sizeof(port_buf),
627 NI_NAMEREQD | NI_NUMERICSERV) != 0) {
628 strcpy(name_buf, def);
629 rprintf(FERROR, "reverse name lookup failed\n");
633 memset(&hints, 0, sizeof(hints));
634 hints.ai_family = PF_UNSPEC;
635 hints.ai_flags = AI_CANONNAME;
636 hints.ai_socktype = SOCK_STREAM;
637 error = getaddrinfo(name_buf, port_buf, &hints, &res0);
639 strcpy(name_buf, def);
641 RSYNC_NAME ": forward name lookup for %s failed: %s\n",
643 gai_strerror(error));
647 /* XXX sin6_flowinfo and other fields */
648 for (res = res0; res; res = res->ai_next) {
649 if (res->ai_family != get_sockaddr_family(&ss))
651 if (res->ai_addrlen != length)
653 if (memcmp(res->ai_addr, &ss, res->ai_addrlen) == 0)
657 /* TODO: Do a forward lookup as well to prevent spoofing */
660 strcpy(name_buf, def);
661 rprintf(FERROR, RSYNC_NAME ": "
662 "reverse name lookup mismatch on fd%d - spoofed address?\n",
671 /*******************************************************************
672 this is like socketpair but uses tcp. It is used by the Samba
674 The function guarantees that nobody else can attach to the socket,
675 or if they do that this function fails and the socket gets closed
676 returns 0 on success, -1 on failure
677 the resulting file descriptors are symmetrical
678 ******************************************************************/
679 static int socketpair_tcp(int fd[2])
682 struct sockaddr_in sock;
683 struct sockaddr_in sock2;
684 socklen_t socklen = sizeof(sock);
685 int connect_done = 0;
687 fd[0] = fd[1] = listener = -1;
689 memset(&sock, 0, sizeof(sock));
691 if ((listener = socket(PF_INET, SOCK_STREAM, 0)) == -1) goto failed;
693 memset(&sock2, 0, sizeof(sock2));
694 #ifdef HAVE_SOCK_SIN_LEN
695 sock2.sin_len = sizeof(sock2);
697 sock2.sin_family = PF_INET;
699 bind(listener, (struct sockaddr *)&sock2, sizeof(sock2));
701 if (listen(listener, 1) != 0) goto failed;
703 if (getsockname(listener, (struct sockaddr *)&sock, &socklen) != 0) goto failed;
705 if ((fd[1] = socket(PF_INET, SOCK_STREAM, 0)) == -1) goto failed;
707 set_nonblocking(fd[1]);
709 sock.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
711 if (connect(fd[1],(struct sockaddr *)&sock,sizeof(sock)) == -1) {
712 if (errno != EINPROGRESS) goto failed;
717 if ((fd[0] = accept(listener, (struct sockaddr *)&sock, &socklen)) == -1) goto failed;
720 if (connect_done == 0) {
721 if (connect(fd[1],(struct sockaddr *)&sock,sizeof(sock)) != 0
722 && errno != EISCONN) goto failed;
725 set_blocking (fd[1]);
731 if (fd[0] != -1) close(fd[0]);
732 if (fd[1] != -1) close(fd[1]);
733 if (listener != -1) close(listener);
738 /*******************************************************************
739 run a program on a local tcp socket, this is used to launch smbd
740 when regression testing
741 the return value is a socket which is attached to a subprocess
742 running "prog". stdin and stdout are attached. stderr is left
743 attached to the original stderr
744 ******************************************************************/
745 int sock_exec(const char *prog)
748 if (socketpair_tcp(fd) != 0) {
749 rprintf (FERROR, RSYNC_NAME
750 ": socketpair_tcp failed (%s)\n",
762 RSYNC_NAME ": execute socket program \"%s\"\n",
764 exit (system (prog));