X-Git-Url: https://mattmccutchen.net/rsync/rsync.git/blobdiff_plain/cb1bcc7ebbb84a056a63fd09e47c456509c52411..e028b9ff53d31dc97a8d491f5551aff02a3850b6:/socket.c diff --git a/socket.c b/socket.c index 0ad8a169..72983517 100644 --- a/socket.c +++ b/socket.c @@ -1,18 +1,20 @@ /* -*- c-file-style: "linux" -*- - + + rsync -- fast file replication program + Copyright (C) 1992-2001 by Andrew Tridgell - Copyright (C) 2001 by Martin Pool - + Copyright (C) 2001, 2002 by Martin Pool + This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. - + This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. - + You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. @@ -20,27 +22,35 @@ /** * @file socket.c - * + * * Socket functions used in rsync. + * + * This file is now converted to use the new-style getaddrinfo() + * interface, which supports IPv6 but is also supported on recent + * IPv4-only machines. On systems that don't have that interface, we + * emulate it using the KAME implementation. **/ #include "rsync.h" -/* Establish a proxy connection on an open socket to a web roxy by - * using the CONNECT method. */ + +/** + * Establish a proxy connection on an open socket to a web proxy by + * using the HTTP CONNECT method. + **/ static int establish_proxy_connection(int fd, char *host, int port) { char buffer[1024]; char *cp; snprintf(buffer, sizeof(buffer), "CONNECT %s:%d HTTP/1.0\r\n\r\n", host, port); - if (write(fd, buffer, strlen(buffer)) != strlen(buffer)) { + if (write(fd, buffer, strlen(buffer)) != (int)strlen(buffer)) { rprintf(FERROR, "failed to write to proxy: %s\n", strerror(errno)); return -1; } - for (cp = buffer; cp < &buffer[sizeof(buffer) - 1]; cp++) { + for (cp = buffer; cp < &buffer[sizeof (buffer) - 1]; cp++) { if (read(fd, cp, 1) != 1) { rprintf(FERROR, "failed to read from proxy: %s\n", strerror(errno)); @@ -60,8 +70,7 @@ static int establish_proxy_connection(int fd, char *host, int port) buffer); return -1; } - for (cp = &buffer[5]; isdigit(*cp) || (*cp == '.'); cp++) - ; + for (cp = &buffer[5]; isdigit(*(uchar*)cp) || *cp == '.'; cp++) {} while (*cp == ' ') cp++; if (*cp != '2') { @@ -71,8 +80,7 @@ static int establish_proxy_connection(int fd, char *host, int port) } /* throw away the rest of the HTTP header */ while (1) { - for (cp = buffer; cp < &buffer[sizeof(buffer) - 1]; - cp++) { + for (cp = buffer; cp < &buffer[sizeof (buffer) - 1]; cp++) { if (read(fd, cp, 1) != 1) { rprintf(FERROR, "failed to read from proxy: %s\n", strerror(errno)); @@ -81,15 +89,49 @@ static int establish_proxy_connection(int fd, char *host, int port) if (*cp == '\n') break; } - if ((cp > buffer) && (*cp == '\n')) + if (cp > buffer && *cp == '\n') cp--; - if ((cp == buffer) && ((*cp == '\n') || (*cp == '\r'))) + if (cp == buffer && (*cp == '\n' || *cp == '\r')) break; } return 0; } +/** + * Try to set the local address for a newly-created socket. Return -1 + * if this fails. + **/ +int try_bind_local(int s, int ai_family, int ai_socktype, + const char *bind_address) +{ + int error; + struct addrinfo bhints, *bres_all, *r; + + memset(&bhints, 0, sizeof(bhints)); + bhints.ai_family = ai_family; + bhints.ai_socktype = ai_socktype; + bhints.ai_flags = AI_PASSIVE; + if ((error = getaddrinfo(bind_address, NULL, &bhints, &bres_all))) { + rprintf(FERROR, RSYNC_NAME ": getaddrinfo %s: %s\n", + bind_address, gai_strerror(error)); + return -1; + } + + for (r = bres_all; r; r = r->ai_next) { + if (bind(s, r->ai_addr, r->ai_addrlen) == -1) + continue; + freeaddrinfo(bres_all); + return s; + } + + /* no error message; there might be some problem that allows + * creation of the socket but not binding, perhaps if the + * machine has no ipv6 address of this name. */ + freeaddrinfo(bres_all); + return -1; +} + /** * Open a socket to a tcp remote host with the specified port . @@ -117,7 +159,6 @@ int open_socket_out(char *host, int port, const char *bind_address, int type = SOCK_STREAM; int error; int s; - int result; struct addrinfo hints, *res0, *res; char portbuf[10]; char *h; @@ -129,7 +170,7 @@ int open_socket_out(char *host, int port, const char *bind_address, * connetcion via a web proxy at the given address. The format * is hostname:port */ h = getenv("RSYNC_PROXY"); - proxied = (h != NULL) && (*h != '\0'); + proxied = h != NULL && *h != '\0'; if (proxied) { strlcpy(buffer, h, sizeof(buffer)); @@ -142,6 +183,10 @@ int open_socket_out(char *host, int port, const char *bind_address, *cp++ = '\0'; strcpy(portbuf, cp); h = buffer; + if (verbose >= 2) { + rprintf(FINFO, "connection via http proxy %s port %s\n", + h, portbuf); + } } else { snprintf(portbuf, sizeof(portbuf), "%d", port); h = host; @@ -167,31 +212,13 @@ int open_socket_out(char *host, int port, const char *bind_address, if (s < 0) continue; - if (bind_address) { - struct addrinfo bhints, *bres; - - memset(&bhints, 0, sizeof(bhints)); - bhints.ai_family = res->ai_family; - bhints.ai_socktype = type; - bhints.ai_flags = AI_PASSIVE; - error = getaddrinfo(bind_address, NULL, &bhints, &bres); - if (error) { - rprintf(FERROR, RSYNC_NAME ": getaddrinfo: " - "bind address %s : %s\n", - bind_address, gai_strerror(error)); - continue; - } - if (bres->ai_next) { - /* I'm not at all sure that this is the right - * response here... -- mbp */ - rprintf(FERROR, RSYNC_NAME ": getaddrinfo: " - "bind address %s resolved to multiple hosts\n", - bind_address); - freeaddrinfo(bres); + if (bind_address) + if (try_bind_local(s, res->ai_family, type, + bind_address) == -1) { + close(s); + s = -1; continue; } - bind(s, bres->ai_addr, bres->ai_addrlen); - } if (connect(s, res->ai_addr, res->ai_addrlen) < 0) { close(s); @@ -228,18 +255,14 @@ int open_socket_out(char *host, int port, const char *bind_address, * * @param bind_address Local address to use. Normally NULL to get the stack default. **/ -int open_socket_out_wrapped (char *host, - int port, - const char *bind_address, - int af_hint) +int open_socket_out_wrapped(char *host, int port, const char *bind_address, + int af_hint) { char *prog; - if ((prog = getenv ("RSYNC_CONNECT_PROG")) != NULL) - return sock_exec (prog); - else - return open_socket_out (host, port, bind_address, - af_hint); + if ((prog = getenv("RSYNC_CONNECT_PROG")) != NULL) + return sock_exec(prog); + return open_socket_out(host, port, bind_address, af_hint); } @@ -249,16 +272,16 @@ int open_socket_out_wrapped (char *host, * * Try to be better about handling the results of getaddrinfo(): when * opening an inbound socket, we might get several address results, - * e.g. for the machine's ipv4 and ipv6 name. - * + * e.g. for the machine's ipv4 and ipv6 name. + * * If binding a wildcard, then any one of them should do. If an address * was specified but it's insufficiently specific then that's not our - * fault. - * + * fault. + * * However, some of the advertized addresses may not work because e.g. we * don't have IPv6 support in the kernel. In that case go on and try all * addresses until one succeeds. - * + * * @param bind_address Local address to bind, or NULL to allow it to * default. **/ @@ -267,7 +290,7 @@ static int open_socket_in(int type, int port, const char *bind_address, { int one=1; int s; - struct addrinfo hints, *res, *resp; + struct addrinfo hints, *all_ai, *resp; char portbuf[10]; int error; @@ -276,55 +299,45 @@ static int open_socket_in(int type, int port, const char *bind_address, hints.ai_socktype = type; hints.ai_flags = AI_PASSIVE; snprintf(portbuf, sizeof(portbuf), "%d", port); - error = getaddrinfo(bind_address, portbuf, &hints, &res); + error = getaddrinfo(bind_address, portbuf, &hints, &all_ai); if (error) { rprintf(FERROR, RSYNC_NAME ": getaddrinfo: bind address %s: %s\n", bind_address, gai_strerror(error)); return -1; } - /* XXX: Do we need to care about getting multiple results - * back? I think probably not; if the user passed - * bind_address == NULL and we set AI_PASSIVE then we ought to - * get a wildcard result. */ - resp = res; - while (1) { - s = socket(resp->ai_family, resp->ai_socktype, resp->ai_protocol); - - if (s >= 0) { - break; /* got a socket */ - } else if ((resp = resp->ai_next)) { - switch (errno) { - case EPROTONOSUPPORT: - case EAFNOSUPPORT: - case EPFNOSUPPORT: - case EINVAL: - /* See if there's another address that will work... */ - continue; - } - } - - rprintf(FERROR, RSYNC_NAME ": open inbound socket" - "(dom=%d, type=%d, proto=%d) failed: %s\n", - resp->ai_family, resp->ai_socktype, resp->ai_protocol, - strerror(errno)); - goto fail; - } + /* We may not be able to create the socket, if for example the + * machine knows about IPv6 in the C library, but not in the + * kernel. */ + for (resp = all_ai; resp; resp = resp->ai_next) { + s = socket(resp->ai_family, resp->ai_socktype, + resp->ai_protocol); - setsockopt(s,SOL_SOCKET,SO_REUSEADDR,(char *)&one,sizeof(one)); + if (s == -1) + /* See if there's another address that will work... */ + continue; - /* now we've got a socket - we need to bind it */ - if (bind(s, res->ai_addr, res->ai_addrlen) < 0) { - rprintf(FERROR, RSYNC_NAME ": bind failed on port %d\n", port); - close(s); - goto fail; + setsockopt(s, SOL_SOCKET, SO_REUSEADDR, + (char *)&one, sizeof one); + + /* Now we've got a socket - we need to bind it. */ + if (bind(s, resp->ai_addr, resp->ai_addrlen) < 0) { + /* Nope, try another */ + close(s); + continue; + } + + freeaddrinfo(all_ai); + return s; } - return s; + rprintf(FERROR, RSYNC_NAME ": open inbound socket on port %d failed: " + "%s\n", + port, + strerror(errno)); -fail: - freeaddrinfo(res); - return -1; + freeaddrinfo(all_ai); + return -1; } @@ -350,18 +363,27 @@ int is_a_socket(int fd) * also has socklen_t [*]. See also accept(2).'' * * We now return to your regularly scheduled programming. */ - return(getsockopt(fd, SOL_SOCKET, SO_TYPE, (char *)&v, &l) == 0); + return getsockopt(fd, SOL_SOCKET, SO_TYPE, (char *)&v, &l) == 0; +} + + +static RETSIGTYPE sigchld_handler(UNUSED(int val)) +{ + signal(SIGCHLD, sigchld_handler); +#ifdef WNOHANG + while (waitpid(-1, NULL, WNOHANG) > 0) {} +#endif } -void start_accept_loop(int port, int (*fn)(int )) +void start_accept_loop(int port, int (*fn)(int, int)) { int s; extern char *bind_address; + extern int default_af_hint; /* open an incoming socket */ - s = open_socket_in(SOCK_STREAM, port, bind_address, - global_opts.af_hint); + s = open_socket_in(SOCK_STREAM, port, bind_address, default_af_hint); if (s == -1) exit_cleanup(RERR_SOCKETIO); @@ -376,9 +398,10 @@ void start_accept_loop(int port, int (*fn)(int )) for each incoming connection */ while (1) { fd_set fds; + pid_t pid; int fd; struct sockaddr_storage addr; - int addrlen = sizeof(addr); + socklen_t addrlen = sizeof addr; /* close log file before the potentially very long select so file can be trimmed by another process instead of growing @@ -388,34 +411,42 @@ void start_accept_loop(int port, int (*fn)(int )) FD_ZERO(&fds); FD_SET(s, &fds); - if (select(s+1, &fds, NULL, NULL, NULL) != 1) { + if (select(s+1, &fds, NULL, NULL, NULL) != 1) continue; - } - if(!FD_ISSET(s, &fds)) continue; + if (!FD_ISSET(s, &fds)) + continue; fd = accept(s,(struct sockaddr *)&addr,&addrlen); - if (fd == -1) continue; + if (fd == -1) + continue; - signal(SIGCHLD, SIG_IGN); + signal(SIGCHLD, sigchld_handler); - /* we shouldn't have any children left hanging around - but I have had reports that on Digital Unix zombies - are produced, so this ensures that they are reaped */ -#ifdef WNOHANG - while (waitpid(-1, NULL, WNOHANG) > 0); -#endif - - if (fork()==0) { + if ((pid = fork()) == 0) { + int ret; close(s); /* open log file in child before possibly giving up privileges */ log_open(); - _exit(fn(fd)); + ret = fn(fd, fd); + close_all(); + _exit(ret); + } else if (pid < 0) { + rprintf(FERROR, + RSYNC_NAME + ": could not create child server process: %s\n", + strerror(errno)); + close(fd); + /* This might have happened because we're + * overloaded. Sleep briefly before trying to + * accept again. */ + sleep(2); + } else { + /* Parent doesn't need this fd anymore. */ + close(fd); } - - close(fd); } } @@ -462,21 +493,24 @@ struct #endif {NULL,0,0,0,0}}; - -/**************************************************************************** -set user socket options -****************************************************************************/ + +/** + * Set user socket options + **/ void set_socket_options(int fd, char *options) { char *tok; - if (!options || !*options) return; + + if (!options || !*options) + return; options = strdup(options); - - if (!options) out_of_memory("set_socket_options"); - for (tok=strtok(options, " \t,"); tok; tok=strtok(NULL," \t,")) { + if (!options) + out_of_memory("set_socket_options"); + + for (tok = strtok(options, " \t,"); tok; tok = strtok(NULL," \t,")) { int ret=0,i; int value = 1; char *p; @@ -488,9 +522,10 @@ void set_socket_options(int fd, char *options) got_value = 1; } - for (i=0;socket_options[i].name;i++) + for (i = 0; socket_options[i].name; i++) { if (strcmp(socket_options[i].name,tok)==0) break; + } if (!socket_options[i].name) { rprintf(FERROR,"Unknown socket option %s\n",tok); @@ -503,7 +538,7 @@ void set_socket_options(int fd, char *options) ret = setsockopt(fd,socket_options[i].level, socket_options[i].option,(char *)&value,sizeof(int)); break; - + case OPT_ON: if (got_value) rprintf(FERROR,"syntax error - %s does not take a value\n",tok); @@ -513,9 +548,9 @@ void set_socket_options(int fd, char *options) ret = setsockopt(fd,socket_options[i].level, socket_options[i].option,(char *)&on,sizeof(int)); } - break; + break; } - + if (ret != 0) rprintf(FERROR, "failed to set socket option %s: %s\n", tok, strerror(errno)); @@ -524,9 +559,9 @@ void set_socket_options(int fd, char *options) free(options); } -/**************************************************************************** -become a daemon, discarding the controlling terminal -****************************************************************************/ +/** + * Become a daemon, discarding the controlling terminal + **/ void become_daemon(void) { int i; @@ -542,151 +577,29 @@ void become_daemon(void) #ifdef TIOCNOTTY i = open("/dev/tty", O_RDWR); if (i >= 0) { - ioctl(i, (int) TIOCNOTTY, (char *)0); + ioctl(i, (int)TIOCNOTTY, (char *)0); close(i); } #endif /* TIOCNOTTY */ #endif /* make sure that stdin, stdout an stderr don't stuff things up (library functions, for example) */ - for (i=0;i<3;i++) { - close(i); + for (i = 0; i < 3; i++) { + close(i); open("/dev/null", O_RDWR); } } -/** - * Return the IP addr of the client as a string - **/ -char *client_addr(int fd) -{ - struct sockaddr_storage ss; - int length = sizeof(ss); - static char addr_buf[100]; - static int initialised; - - if (initialised) return addr_buf; - - initialised = 1; - - if (getpeername(fd, (struct sockaddr *)&ss, &length)) { - exit_cleanup(RERR_SOCKETIO); - } - - getnameinfo((struct sockaddr *)&ss, length, - addr_buf, sizeof(addr_buf), NULL, 0, NI_NUMERICHOST); - return addr_buf; -} - - -static int get_sockaddr_family(const struct sockaddr_storage *ss) -{ - return ((struct sockaddr *) ss)->sa_family; -} - /** - * Return the DNS name of the client + * This is like socketpair but uses tcp. It is used by the Samba + * regression test code. + * + * The function guarantees that nobody else can attach to the socket, + * or if they do that this function fails and the socket gets closed + * returns 0 on success, -1 on failure the resulting file descriptors + * are symmetrical. **/ -char *client_name(int fd) -{ - struct sockaddr_storage ss; - int length = sizeof(ss); - static char name_buf[100]; - static char port_buf[100]; - char *def = "UNKNOWN"; - static int initialised; - struct addrinfo hints, *res, *res0; - int error; - - if (initialised) return name_buf; - - initialised = 1; - - strcpy(name_buf,def); - - if (getpeername(fd, (struct sockaddr *)&ss, &length)) { - /* FIXME: Can we really not continue? */ - rprintf(FERROR, RSYNC_NAME ": getpeername on fd%d failed: %s\n", - fd, strerror(errno)); - exit_cleanup(RERR_SOCKETIO); - } - -#ifdef INET6 - if (get_sockaddr_family(&ss) == AF_INET6 && - IN6_IS_ADDR_V4MAPPED(&((struct sockaddr_in6 *)&ss)->sin6_addr)) { - struct sockaddr_in6 sin6; - struct sockaddr_in *sin; - - memcpy(&sin6, &ss, sizeof(sin6)); - sin = (struct sockaddr_in *)&ss; - memset(sin, 0, sizeof(*sin)); - sin->sin_family = AF_INET; - length = sizeof(struct sockaddr_in); -#ifdef HAVE_SOCKADDR_LEN - sin->sin_len = length; -#endif - sin->sin_port = sin6.sin6_port; - memcpy(&sin->sin_addr, &sin6.sin6_addr.s6_addr[12], - sizeof(sin->sin_addr)); - } -#endif - - /* reverse lookup */ - if (getnameinfo((struct sockaddr *)&ss, length, - name_buf, sizeof(name_buf), port_buf, sizeof(port_buf), - NI_NAMEREQD | NI_NUMERICSERV) != 0) { - strcpy(name_buf, def); - rprintf(FERROR, "reverse name lookup failed\n"); - } - - /* forward lookup */ - memset(&hints, 0, sizeof(hints)); - hints.ai_family = PF_UNSPEC; - hints.ai_flags = AI_CANONNAME; - hints.ai_socktype = SOCK_STREAM; - error = getaddrinfo(name_buf, port_buf, &hints, &res0); - if (error) { - strcpy(name_buf, def); - rprintf(FERROR, - RSYNC_NAME ": forward name lookup for %s failed: %s\n", - port_buf, - gai_strerror(error)); - return name_buf; - } - - /* XXX sin6_flowinfo and other fields */ - for (res = res0; res; res = res->ai_next) { - if (res->ai_family != get_sockaddr_family(&ss)) - continue; - if (res->ai_addrlen != length) - continue; - if (memcmp(res->ai_addr, &ss, res->ai_addrlen) == 0) - break; - } - - /* TODO: Do a forward lookup as well to prevent spoofing */ - - if (res == NULL) { - strcpy(name_buf, def); - rprintf(FERROR, RSYNC_NAME ": " - "reverse name lookup mismatch on fd%d - spoofed address?\n", - fd); - } - - freeaddrinfo(res0); - return name_buf; -} - - -/******************************************************************* -this is like socketpair but uses tcp. It is used by the Samba -regression test code -The function guarantees that nobody else can attach to the socket, -or if they do that this function fails and the socket gets closed -returns 0 on success, -1 on failure -the resulting file descriptors are symmetrical - ******************************************************************/ static int socketpair_tcp(int fd[2]) { int listener; @@ -694,72 +607,84 @@ static int socketpair_tcp(int fd[2]) struct sockaddr_in sock2; socklen_t socklen = sizeof(sock); int connect_done = 0; - + fd[0] = fd[1] = listener = -1; memset(&sock, 0, sizeof(sock)); - - if ((listener = socket(PF_INET, SOCK_STREAM, 0)) == -1) goto failed; + + if ((listener = socket(PF_INET, SOCK_STREAM, 0)) == -1) + goto failed; memset(&sock2, 0, sizeof(sock2)); -#ifdef HAVE_SOCK_SIN_LEN +#ifdef HAVE_SOCKADDR_LEN sock2.sin_len = sizeof(sock2); #endif sock2.sin_family = PF_INET; bind(listener, (struct sockaddr *)&sock2, sizeof(sock2)); - if (listen(listener, 1) != 0) goto failed; + if (listen(listener, 1) != 0) + goto failed; - if (getsockname(listener, (struct sockaddr *)&sock, &socklen) != 0) goto failed; + if (getsockname(listener, (struct sockaddr *)&sock, &socklen) != 0) + goto failed; - if ((fd[1] = socket(PF_INET, SOCK_STREAM, 0)) == -1) goto failed; + if ((fd[1] = socket(PF_INET, SOCK_STREAM, 0)) == -1) + goto failed; set_nonblocking(fd[1]); sock.sin_addr.s_addr = htonl(INADDR_LOOPBACK); if (connect(fd[1],(struct sockaddr *)&sock,sizeof(sock)) == -1) { - if (errno != EINPROGRESS) goto failed; - } else { + if (errno != EINPROGRESS) + goto failed; + } else connect_done = 1; - } - if ((fd[0] = accept(listener, (struct sockaddr *)&sock, &socklen)) == -1) goto failed; + if ((fd[0] = accept(listener, (struct sockaddr *)&sock, &socklen)) == -1) + goto failed; close(listener); if (connect_done == 0) { if (connect(fd[1],(struct sockaddr *)&sock,sizeof(sock)) != 0 - && errno != EISCONN) goto failed; + && errno != EISCONN) + goto failed; } - set_blocking (fd[1]); + set_blocking(fd[1]); /* all OK! */ return 0; failed: - if (fd[0] != -1) close(fd[0]); - if (fd[1] != -1) close(fd[1]); - if (listener != -1) close(listener); + if (fd[0] != -1) + close(fd[0]); + if (fd[1] != -1) + close(fd[1]); + if (listener != -1) + close(listener); return -1; } -/******************************************************************* -run a program on a local tcp socket, this is used to launch smbd -when regression testing -the return value is a socket which is attached to a subprocess -running "prog". stdin and stdout are attached. stderr is left -attached to the original stderr - ******************************************************************/ + +/** + * Run a program on a local tcp socket, so that we can talk to it's + * stdin and stdout. This is used to fake a connection to a daemon + * for testing -- not for the normal case of running SSH. + * + * @return a socket which is attached to a subprocess running + * "prog". stdin and stdout are attached. stderr is left attached to + * the original stderr + **/ int sock_exec(const char *prog) { int fd[2]; + if (socketpair_tcp(fd) != 0) { - rprintf (FERROR, RSYNC_NAME - ": socketpair_tcp failed (%s)\n", - strerror(errno)); + rprintf(FERROR, RSYNC_NAME ": socketpair_tcp failed (%s)\n", + strerror(errno)); return -1; } if (fork() == 0) { @@ -768,15 +693,14 @@ int sock_exec(const char *prog) close(1); dup(fd[1]); dup(fd[1]); - if (verbose > 3) - fprintf (stderr, - RSYNC_NAME ": execute socket program \"%s\"\n", - prog); - exit (system (prog)); + if (verbose > 3) { + /* Can't use rprintf because we've forked. */ + fprintf(stderr, + RSYNC_NAME ": execute socket program \"%s\"\n", + prog); + } + exit(system(prog)); } - close (fd[1]); + close(fd[1]); return fd[0]; } - - -