diff options
Diffstat (limited to '')
| -rw-r--r-- | socket.c | 841 |
1 files changed, 841 insertions, 0 deletions
diff --git a/socket.c b/socket.c new file mode 100644 index 0000000..c2075ad --- /dev/null +++ b/socket.c @@ -0,0 +1,841 @@ +/* + * Socket functions used in rsync. + * + * Copyright (C) 1992-2001 Andrew Tridgell <tridge@samba.org> + * Copyright (C) 2001, 2002 Martin Pool <mbp@samba.org> + * Copyright (C) 2003-2020 Wayne Davison + * + * 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 3 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, visit the http://fsf.org website. + */ + +/* 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" +#include "itypes.h" +#include "ifuncs.h" +#ifdef HAVE_NETINET_IN_SYSTM_H +#include <netinet/in_systm.h> +#endif +#ifdef HAVE_NETINET_IP_H +#include <netinet/ip.h> +#endif +#include <netinet/tcp.h> + +extern char *bind_address; +extern char *sockopts; +extern int default_af_hint; +extern int connect_timeout; +extern int pid_file_fd; + +#ifdef HAVE_SIGACTION +static struct sigaction sigact; +#endif + +static int sock_exec(const char *prog); + +/* Establish a proxy connection on an open socket to a web proxy by using the + * CONNECT method. If proxy_user and proxy_pass are not NULL, they are used to + * authenticate to the proxy using the "Basic" proxy-authorization protocol. */ +static int establish_proxy_connection(int fd, char *host, int port, char *proxy_user, char *proxy_pass) +{ + char *cp, buffer[1024]; + char *authhdr, authbuf[1024]; + int len; + + if (proxy_user && proxy_pass) { + stringjoin(buffer, sizeof buffer, + proxy_user, ":", proxy_pass, NULL); + len = strlen(buffer); + + if ((len*8 + 5) / 6 >= (int)sizeof authbuf - 3) { + rprintf(FERROR, + "authentication information is too long\n"); + return -1; + } + + base64_encode(buffer, len, authbuf, 1); + authhdr = "\r\nProxy-Authorization: Basic "; + } else { + *authbuf = '\0'; + authhdr = ""; + } + + len = snprintf(buffer, sizeof buffer, "CONNECT %s:%d HTTP/1.0%s%s\r\n\r\n", host, port, authhdr, authbuf); + assert(len > 0 && len < (int)sizeof buffer); + if (write(fd, buffer, len) != len) { + rsyserr(FERROR, errno, "failed to write to proxy"); + return -1; + } + + for (cp = buffer; cp < &buffer[sizeof buffer - 1]; cp++) { + if (read(fd, cp, 1) != 1) { + rsyserr(FERROR, errno, "failed to read from proxy"); + return -1; + } + if (*cp == '\n') + break; + } + + if (*cp != '\n') + cp++; + *cp-- = '\0'; + if (*cp == '\r') + *cp = '\0'; + if (strncmp(buffer, "HTTP/", 5) != 0) { + rprintf(FERROR, "bad response from proxy -- %s\n", + buffer); + return -1; + } + for (cp = &buffer[5]; isDigit(cp) || *cp == '.'; cp++) {} + while (*cp == ' ') + cp++; + if (*cp != '2') { + rprintf(FERROR, "bad response from proxy -- %s\n", + buffer); + return -1; + } + /* throw away the rest of the HTTP header */ + while (1) { + for (cp = buffer; cp < &buffer[sizeof buffer - 1]; cp++) { + if (read(fd, cp, 1) != 1) { + rsyserr(FERROR, errno, + "failed to read from proxy"); + return -1; + } + if (*cp == '\n') + break; + } + if (cp > buffer && *cp == '\n') + cp--; + 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_addr) +{ + 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_addr, NULL, &bhints, &bres_all))) { + rprintf(FERROR, RSYNC_NAME ": getaddrinfo %s: %s\n", + bind_addr, 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; +} + +/* connect() timeout handler based on alarm() */ +static void contimeout_handler(UNUSED(int val)) +{ + connect_timeout = -1; +} + +/* Open a socket to a tcp remote host with the specified port. + * + * Based on code from Warren. Proxy support by Stephen Rothwell. + * getaddrinfo() rewrite contributed by KAME.net. + * + * Now that we support IPv6 we need to look up the remote machine's address + * first, using af_hint to set a preference for the type of address. Then + * depending on whether it has v4 or v6 addresses we try to open a connection. + * + * The loop allows for machines with some addresses which may not be reachable, + * perhaps because we can't e.g. route ipv6 to that network but we can get ip4 + * packets through. + * + * bind_addr: local address to use. Normally NULL to bind the wildcard address. + * + * af_hint: address family, e.g. AF_INET or AF_INET6. */ +int open_socket_out(char *host, int port, const char *bind_addr, int af_hint) +{ + int type = SOCK_STREAM; + int error, s, j, addr_cnt, *errnos; + struct addrinfo hints, *res0, *res; + char portbuf[10]; + char *h, *cp; + int proxied = 0; + char buffer[1024]; + char *proxy_user = NULL, *proxy_pass = NULL; + + /* if we have a RSYNC_PROXY env variable then redirect our + * connection via a web proxy at the given address. */ + h = getenv("RSYNC_PROXY"); + proxied = h != NULL && *h != '\0'; + + if (proxied) { + strlcpy(buffer, h, sizeof buffer); + + /* Is the USER:PASS@ prefix present? */ + if ((cp = strrchr(buffer, '@')) != NULL) { + *cp++ = '\0'; + /* The remainder is the HOST:PORT part. */ + h = cp; + + if ((cp = strchr(buffer, ':')) == NULL) { + rprintf(FERROR, + "invalid proxy specification: should be USER:PASS@HOST:PORT\n"); + return -1; + } + *cp++ = '\0'; + + proxy_user = buffer; + proxy_pass = cp; + } else { + /* The whole buffer is the HOST:PORT part. */ + h = buffer; + } + + if ((cp = strchr(h, ':')) == NULL) { + rprintf(FERROR, + "invalid proxy specification: should be HOST:PORT\n"); + return -1; + } + *cp++ = '\0'; + strlcpy(portbuf, cp, sizeof portbuf); + if (DEBUG_GTE(CONNECT, 1)) { + rprintf(FINFO, "connection via http proxy %s port %s\n", + h, portbuf); + } + } else { + snprintf(portbuf, sizeof portbuf, "%d", port); + h = host; + } + + memset(&hints, 0, sizeof hints); + hints.ai_family = af_hint; + hints.ai_socktype = type; + error = getaddrinfo(h, portbuf, &hints, &res0); + if (error) { + rprintf(FERROR, RSYNC_NAME ": getaddrinfo: %s %s: %s\n", + h, portbuf, gai_strerror(error)); + return -1; + } + + for (res = res0, addr_cnt = 0; res; res = res->ai_next, addr_cnt++) {} + errnos = new_array0(int, addr_cnt); + + s = -1; + /* Try to connect to all addresses for this machine until we get + * through. It might e.g. be multi-homed, or have both IPv4 and IPv6 + * addresses. We need to create a socket for each record, since the + * address record tells us what protocol to use to try to connect. */ + for (res = res0, j = 0; res; res = res->ai_next, j++) { + s = socket(res->ai_family, res->ai_socktype, res->ai_protocol); + if (s < 0) + continue; + + if (bind_addr + && try_bind_local(s, res->ai_family, type, + bind_addr) == -1) { + close(s); + s = -1; + continue; + } + if (connect_timeout > 0) { + SIGACTION(SIGALRM, contimeout_handler); + alarm(connect_timeout); + } + + set_socket_options(s, sockopts); + while (connect(s, res->ai_addr, res->ai_addrlen) < 0) { + if (connect_timeout < 0) + exit_cleanup(RERR_CONTIMEOUT); + if (errno == EINTR) + continue; + close(s); + s = -1; + break; + } + + if (connect_timeout > 0) + alarm(0); + + if (s < 0) { + errnos[j] = errno; + continue; + } + + if (proxied && establish_proxy_connection(s, host, port, proxy_user, proxy_pass) != 0) { + close(s); + s = -1; + continue; + } + if (DEBUG_GTE(CONNECT, 2)) { + char buf[2048]; + if ((error = getnameinfo(res->ai_addr, res->ai_addrlen, buf, sizeof buf, NULL, 0, NI_NUMERICHOST)) != 0) + snprintf(buf, sizeof buf, "*getnameinfo failure: %s*", gai_strerror(error)); + rprintf(FINFO, "Connected to %s (%s)\n", h, buf); + } + break; + } + + if (s < 0 || DEBUG_GTE(CONNECT, 2)) { + char buf[2048]; + for (res = res0, j = 0; res; res = res->ai_next, j++) { + if (errnos[j] == 0) + continue; + if ((error = getnameinfo(res->ai_addr, res->ai_addrlen, buf, sizeof buf, NULL, 0, NI_NUMERICHOST)) != 0) + snprintf(buf, sizeof buf, "*getnameinfo failure: %s*", gai_strerror(error)); + rsyserr(FERROR, errnos[j], "failed to connect to %s (%s)", h, buf); + } + if (s < 0) + s = -1; + } + + freeaddrinfo(res0); + free(errnos); + + return s; +} + + +/* Open an outgoing socket, but allow for it to be intercepted by + * $RSYNC_CONNECT_PROG, which will execute a program across a TCP + * socketpair rather than really opening a socket. + * + * We use this primarily in testing to detect TCP flow bugs, but not + * cause security problems by really opening remote connections. + * + * This is based on the Samba LIBSMB_PROG feature. + * + * bind_addr: local address to use. Normally NULL to get the stack default. */ +int open_socket_out_wrapped(char *host, int port, const char *bind_addr, int af_hint) +{ + char *prog = getenv("RSYNC_CONNECT_PROG"); + + if (prog && strchr(prog, '%')) { + int hlen = strlen(host); + int len = strlen(prog) + 1; + char *f, *t; + for (f = prog; *f; f++) { + if (*f != '%') + continue; + /* Compute more than enough room. */ + if (f[1] == '%') + f++; + else + len += hlen; + } + f = prog; + prog = new_array(char, len); + for (t = prog; *f; f++) { + if (*f == '%') { + switch (*++f) { + case '%': + /* Just skips the extra '%'. */ + break; + case 'H': + memcpy(t, host, hlen); + t += hlen; + continue; + default: + f--; /* pass % through */ + break; + } + } + *t++ = *f; + } + *t = '\0'; + } + + if (DEBUG_GTE(CONNECT, 1)) { + rprintf(FINFO, "%sopening tcp connection to %s port %d\n", + prog ? "Using RSYNC_CONNECT_PROG instead of " : "", + host, port); + } + if (prog) + return sock_exec(prog); + return open_socket_out(host, port, bind_addr, af_hint); +} + + +/* Open one or more sockets for incoming data using the specified type, + * port, and address. + * + * The getaddrinfo() call may return several address results, e.g. for + * the machine's IPv4 and IPv6 name. + * + * We return an array of file-descriptors to the sockets, with a trailing + * -1 value to indicate the end of the list. + * + * bind_addr: local address to bind, or NULL to allow it to default. */ +static int *open_socket_in(int type, int port, const char *bind_addr, + int af_hint) +{ + int one = 1; + int s, *socks, maxs, i, ecnt; + struct addrinfo hints, *all_ai, *resp; + char portbuf[10], **errmsgs; + int error; + + memset(&hints, 0, sizeof hints); + hints.ai_family = af_hint; + hints.ai_socktype = type; + hints.ai_flags = AI_PASSIVE; + snprintf(portbuf, sizeof portbuf, "%d", port); + error = getaddrinfo(bind_addr, portbuf, &hints, &all_ai); + if (error) { + rprintf(FERROR, RSYNC_NAME ": getaddrinfo: bind address %s: %s\n", + bind_addr, gai_strerror(error)); + return NULL; + } + + /* Count max number of sockets we might open. */ + for (maxs = 0, resp = all_ai; resp; resp = resp->ai_next, maxs++) {} + + socks = new_array(int, maxs + 1); + errmsgs = new_array(char *, maxs); + + /* 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, i = ecnt = 0; resp; resp = resp->ai_next) { + s = socket(resp->ai_family, resp->ai_socktype, + resp->ai_protocol); + + if (s == -1) { + int r = asprintf(&errmsgs[ecnt++], + "socket(%d,%d,%d) failed: %s\n", + (int)resp->ai_family, (int)resp->ai_socktype, + (int)resp->ai_protocol, strerror(errno)); + if (r < 0) + out_of_memory("open_socket_in"); + /* See if there's another address that will work... */ + continue; + } + + setsockopt(s, SOL_SOCKET, SO_REUSEADDR, + (char *)&one, sizeof one); + if (sockopts) + set_socket_options(s, sockopts); + else + set_socket_options(s, lp_socket_options()); + +#ifdef IPV6_V6ONLY + if (resp->ai_family == AF_INET6) { + if (setsockopt(s, IPPROTO_IPV6, IPV6_V6ONLY, (char *)&one, sizeof one) < 0 + && default_af_hint != AF_INET6) { + close(s); + continue; + } + } +#endif + + /* Now we've got a socket - we need to bind it. */ + if (bind(s, resp->ai_addr, resp->ai_addrlen) < 0) { + /* Nope, try another */ + int r = asprintf(&errmsgs[ecnt++], + "bind() failed: %s (address-family %d)\n", + strerror(errno), (int)resp->ai_family); + if (r < 0) + out_of_memory("open_socket_in"); + close(s); + continue; + } + + socks[i++] = s; + } + socks[i] = -1; + + if (all_ai) + freeaddrinfo(all_ai); + + /* Only output the socket()/bind() messages if we were totally + * unsuccessful, or if the daemon is being run with -vv. */ + for (s = 0; s < ecnt; s++) { + if (!i || DEBUG_GTE(BIND, 1)) + rwrite(FLOG, errmsgs[s], strlen(errmsgs[s]), 0); + free(errmsgs[s]); + } + free(errmsgs); + + if (!i) { + rprintf(FERROR, + "unable to bind any inbound sockets on port %d\n", + port); + free(socks); + return NULL; + } + return socks; +} + + +/* Determine if a file descriptor is in fact a socket. */ +int is_a_socket(int fd) +{ + int v; + socklen_t l = sizeof (int); + + /* Parameters to getsockopt, setsockopt etc are very + * unstandardized across platforms, so don't be surprised if + * there are compiler warnings on e.g. SCO OpenSwerver or AIX. + * It seems they all eventually get the right idea. + * + * Debian says: ``The fifth argument of getsockopt and + * setsockopt is in reality an int [*] (and this is what BSD + * 4.* and libc4 and libc5 have). Some POSIX confusion + * resulted in the present socklen_t. The draft standard has + * not been adopted yet, but glibc2 already follows it and + * 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; +} + + +static void sigchld_handler(UNUSED(int val)) +{ +#ifdef WNOHANG + while (waitpid(-1, NULL, WNOHANG) > 0) {} +#endif +#ifndef HAVE_SIGACTION + signal(SIGCHLD, sigchld_handler); +#endif +} + + +void start_accept_loop(int port, int (*fn)(int, int)) +{ + fd_set deffds; + int *sp, maxfd, i; + +#ifdef HAVE_SIGACTION + sigact.sa_flags = SA_NOCLDSTOP; +#endif + + /* open an incoming socket */ + sp = open_socket_in(SOCK_STREAM, port, bind_address, default_af_hint); + if (sp == NULL) + exit_cleanup(RERR_SOCKETIO); + + /* ready to listen */ + FD_ZERO(&deffds); + for (i = 0, maxfd = -1; sp[i] >= 0; i++) { + if (listen(sp[i], lp_listen_backlog()) < 0) { + rsyserr(FERROR, errno, "listen() on socket failed"); +#ifdef INET6 + if (errno == EADDRINUSE && i > 0) { + rprintf(FINFO, "Try using --ipv4 or --ipv6 to avoid this listen() error.\n"); + } +#endif + exit_cleanup(RERR_SOCKETIO); + } + FD_SET(sp[i], &deffds); + if (maxfd < sp[i]) + maxfd = sp[i]; + } + + /* now accept incoming connections - forking a new process + * for each incoming connection */ + while (1) { + fd_set fds; + pid_t pid; + int fd; + struct sockaddr_storage 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 + * forever */ + logfile_close(); + +#ifdef FD_COPY + FD_COPY(&deffds, &fds); +#else + fds = deffds; +#endif + + if (select(maxfd + 1, &fds, NULL, NULL, NULL) < 1) + continue; + + for (i = 0, fd = -1; sp[i] >= 0; i++) { + if (FD_ISSET(sp[i], &fds)) { + fd = accept(sp[i], (struct sockaddr *)&addr, &addrlen); + break; + } + } + + if (fd < 0) + continue; + + SIGACTION(SIGCHLD, sigchld_handler); + + if ((pid = fork()) == 0) { + int ret; + if (pid_file_fd >= 0) + close(pid_file_fd); + for (i = 0; sp[i] >= 0; i++) + close(sp[i]); + /* Re-open log file in child before possibly giving + * up privileges (see logfile_close() above). */ + logfile_reopen(); + ret = fn(fd, fd); + close_all(); + _exit(ret); + } else if (pid < 0) { + rsyserr(FERROR, errno, + "could not create child server process"); + 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); + } + } +} + + +enum SOCK_OPT_TYPES {OPT_BOOL,OPT_INT,OPT_ON}; + +struct +{ + char *name; + int level; + int option; + int value; + int opttype; +} socket_options[] = { + {"SO_KEEPALIVE", SOL_SOCKET, SO_KEEPALIVE, 0, OPT_BOOL}, + {"SO_REUSEADDR", SOL_SOCKET, SO_REUSEADDR, 0, OPT_BOOL}, +#ifdef SO_BROADCAST + {"SO_BROADCAST", SOL_SOCKET, SO_BROADCAST, 0, OPT_BOOL}, +#endif +#ifdef TCP_NODELAY + {"TCP_NODELAY", IPPROTO_TCP, TCP_NODELAY, 0, OPT_BOOL}, +#endif +#ifdef IPTOS_LOWDELAY + {"IPTOS_LOWDELAY", IPPROTO_IP, IP_TOS, IPTOS_LOWDELAY, OPT_ON}, +#endif +#ifdef IPTOS_THROUGHPUT + {"IPTOS_THROUGHPUT", IPPROTO_IP, IP_TOS, IPTOS_THROUGHPUT, OPT_ON}, +#endif +#ifdef SO_SNDBUF + {"SO_SNDBUF", SOL_SOCKET, SO_SNDBUF, 0, OPT_INT}, +#endif +#ifdef SO_RCVBUF + {"SO_RCVBUF", SOL_SOCKET, SO_RCVBUF, 0, OPT_INT}, +#endif +#ifdef SO_SNDLOWAT + {"SO_SNDLOWAT", SOL_SOCKET, SO_SNDLOWAT, 0, OPT_INT}, +#endif +#ifdef SO_RCVLOWAT + {"SO_RCVLOWAT", SOL_SOCKET, SO_RCVLOWAT, 0, OPT_INT}, +#endif +#ifdef SO_SNDTIMEO + {"SO_SNDTIMEO", SOL_SOCKET, SO_SNDTIMEO, 0, OPT_INT}, +#endif +#ifdef SO_RCVTIMEO + {"SO_RCVTIMEO", SOL_SOCKET, SO_RCVTIMEO, 0, OPT_INT}, +#endif + {NULL,0,0,0,0} +}; + + +/* Set user socket options. */ +void set_socket_options(int fd, char *options) +{ + char *tok; + + if (!options || !*options) + return; + + options = strdup(options); + + for (tok = strtok(options, " \t,"); tok; tok = strtok(NULL," \t,")) { + int ret=0,i; + int value = 1; + char *p; + int got_value = 0; + + if ((p = strchr(tok,'='))) { + *p = 0; + value = atoi(p+1); + got_value = 1; + } + + 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); + continue; + } + + switch (socket_options[i].opttype) { + case OPT_BOOL: + case OPT_INT: + 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); + + { + int on = socket_options[i].value; + ret = setsockopt(fd,socket_options[i].level, + socket_options[i].option, + (char *)&on, sizeof (int)); + } + break; + } + + if (ret != 0) { + rsyserr(FERROR, errno, + "failed to set socket option %s", tok); + } + } + + free(options); +} + + +/* This is like socketpair but uses tcp. 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. Currently only for RSYNC_CONNECT_PROG. */ +static int socketpair_tcp(int fd[2]) +{ + int listener; + struct sockaddr_in sock; + 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; + + memset(&sock2, 0, sizeof sock2); +#ifdef HAVE_SOCKADDR_IN_LEN + sock2.sin_len = sizeof sock2; +#endif + sock2.sin_family = PF_INET; + sock2.sin_addr.s_addr = htonl(INADDR_LOOPBACK); + + if (bind(listener, (struct sockaddr *)&sock2, sizeof sock2) != 0 + || listen(listener, 1) != 0 + || getsockname(listener, (struct sockaddr *)&sock, &socklen) != 0 + || (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 + connect_done = 1; + + if ((fd[0] = accept(listener, (struct sockaddr *)&sock2, &socklen)) == -1) + goto failed; + + close(listener); + listener = -1; + + set_blocking(fd[1]); + + if (connect_done == 0) { + if (connect(fd[1], (struct sockaddr *)&sock, sizeof sock) != 0 && errno != EISCONN) + goto failed; + } + + /* all OK! */ + return 0; + + failed: + 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, 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. + * + * Returns a socket which is attached to a subprocess running "prog". stdin and + * stdout are attached. stderr is left attached to the original stderr. */ +static int sock_exec(const char *prog) +{ + pid_t pid; + int fd[2]; + + if (socketpair_tcp(fd) != 0) { + rsyserr(FERROR, errno, "socketpair_tcp failed"); + return -1; + } + if (DEBUG_GTE(CMD, 1)) + rprintf(FINFO, "Running socket program: \"%s\"\n", prog); + + pid = fork(); + if (pid < 0) { + rsyserr(FERROR, errno, "fork"); + exit_cleanup(RERR_IPC); + } + + if (pid == 0) { + close(fd[0]); + if (dup2(fd[1], STDIN_FILENO) < 0 + || dup2(fd[1], STDOUT_FILENO) < 0) { + fprintf(stderr, "Failed to run \"%s\"\n", prog); + exit(1); + } + exit(shell_exec(prog)); + } + + close(fd[1]); + return fd[0]; +} |