X-Git-Url: http://andersk.mit.edu/gitweb/openssh.git/blobdiff_plain/0d34d6ceed345dd8d342758ecf0526819181478c..d0420e01bf3d2dcc8541bcaa3a704aaee611ca00:/ssh.c diff --git a/ssh.c b/ssh.c index 6f8114d5..802ba687 100644 --- a/ssh.c +++ b/ssh.c @@ -1,3 +1,4 @@ +/* $OpenBSD: ssh.c,v 1.304 2007/10/29 01:55:04 dtucker Exp $ */ /* * Author: Tatu Ylonen * Copyright (c) 1995 Tatu Ylonen , Espoo, Finland @@ -40,20 +41,46 @@ */ #include "includes.h" -RCSID("$OpenBSD: ssh.c,v 1.216 2004/06/17 15:10:14 djm Exp $"); + +#include +#ifdef HAVE_SYS_STAT_H +# include +#endif +#include +#include +#include +#include + +#include +#include +#include +#include +#ifdef HAVE_PATHS_H +#include +#endif +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include #include #include +#include "xmalloc.h" #include "ssh.h" #include "ssh1.h" #include "ssh2.h" #include "compat.h" #include "cipher.h" -#include "xmalloc.h" #include "packet.h" #include "buffer.h" -#include "bufaux.h" #include "channels.h" #include "key.h" #include "authfd.h" @@ -71,16 +98,14 @@ RCSID("$OpenBSD: ssh.c,v 1.216 2004/06/17 15:10:14 djm Exp $"); #include "match.h" #include "msg.h" #include "monitor_fdpass.h" +#include "uidswap.h" +#include "version.h" #ifdef SMARTCARD #include "scard.h" #endif -#ifdef HAVE___PROGNAME extern char *__progname; -#else -char *__progname; -#endif /* Flag indicating whether debug mode is on. This can be set on the command line. */ int debug_flag = 0; @@ -147,6 +172,9 @@ pid_t proxy_command_pid = 0; /* fd to control socket */ int control_fd = -1; +/* Multiplexing control command */ +static u_int mux_command = 0; + /* Only used in control client mode */ volatile sig_atomic_t control_client_terminate = 0; u_int control_server_pid = 0; @@ -157,12 +185,14 @@ static void usage(void) { fprintf(stderr, -"usage: ssh [-1246AaCfghkNnqsTtVvXxY] [-b bind_address] [-c cipher_spec]\n" -" [-D port] [-e escape_char] [-F configfile] [-i identity_file]\n" -" [-L port:host:hostport] [-l login_name] [-m mac_spec] [-o option]\n" -" [-p port] [-R port:host:hostport] [user@]hostname [command]\n" +"usage: ssh [-1246AaCfgKkMNnqsTtVvXxY] [-b bind_address] [-c cipher_spec]\n" +" [-D [bind_address:]port] [-e escape_char] [-F configfile]\n" +" [-i identity_file] [-L [bind_address:]port:host:hostport]\n" +" [-l login_name] [-m mac_spec] [-O ctl_cmd] [-o option] [-p port]\n" +" [-R [bind_address:]port:host:hostport] [-S ctl_path]\n" +" [-w local_tun[:remote_tun]] [user@]hostname [command]\n" ); - exit(1); + exit(255); } static int ssh_session(void); @@ -177,14 +207,17 @@ int main(int ac, char **av) { int i, opt, exit_status; - u_short fwd_port, fwd_host_port; - char sfwd_port[6], sfwd_host_port[6]; char *p, *cp, *line, buf[256]; struct stat st; struct passwd *pw; - int dummy; + int dummy, timeout_ms; extern int optind, optreset; extern char *optarg; + struct servent *sp; + Forward fwd; + + /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */ + sanitise_stdfd(); __progname = ssh_get_progname(av[0]); init_rng(); @@ -218,7 +251,7 @@ main(int ac, char **av) pw = getpwuid(original_real_uid); if (!pw) { logit("You don't exist, go away!"); - exit(1); + exit(255); } /* Take a copy of the returned structure. */ pw = pwcopy(pw); @@ -237,9 +270,9 @@ main(int ac, char **av) /* Parse command-line arguments. */ host = NULL; -again: + again: while ((opt = getopt(ac, av, - "1246ab:c:e:fgi:kl:m:no:p:qstvxACD:F:I:L:MNPR:S:TVXY")) != -1) { + "1246ab:c:e:fgi:kl:m:no:p:qstvxACD:F:I:KL:MNO:PR:S:TVw:XY")) != -1) { switch (opt) { case '1': options.protocol = SSH_PROTO_1; @@ -273,6 +306,14 @@ again: case 'g': options.gateway_ports = 1; break; + case 'O': + if (strcmp(optarg, "check") == 0) + mux_command = SSHMUX_COMMAND_ALIVE_CHECK; + else if (strcmp(optarg, "exit") == 0) + mux_command = SSHMUX_COMMAND_TERMINATE; + else + fatal("Invalid multiplex command."); + break; case 'P': /* deprecated */ options.use_privileged_port = 0; break; @@ -285,10 +326,15 @@ again: case 'k': options.gss_deleg_creds = 0; break; + case 'K': + options.gss_authentication = 1; + options.gss_deleg_creds = 1; + break; case 'i': if (stat(optarg, &st) < 0) { fprintf(stderr, "Warning: Identity file %s " - "does not exist.\n", optarg); + "not accessible: %s.\n", optarg, + strerror(errno)); break; } if (options.num_identity_files >= @@ -319,13 +365,22 @@ again: options.log_level++; break; } - /* fallthrough */ + /* FALLTHROUGH */ case 'V': fprintf(stderr, "%s, %s\n", - SSH_VERSION, SSLeay_version(SSLEAY_VERSION)); + SSH_RELEASE, SSLeay_version(SSLEAY_VERSION)); if (opt == 'V') exit(0); break; + case 'w': + if (options.tun_open == -1) + options.tun_open = SSH_TUNMODE_DEFAULT; + options.tun_local = a2tun(optarg, &options.tun_remote); + if (options.tun_local == SSH_TUNID_ERR) { + fprintf(stderr, "Bad tun device '%s'\n", optarg); + exit(255); + } + break; case 'q': options.log_level = SYSLOG_LEVEL_QUIET; break; @@ -341,14 +396,14 @@ again: else { fprintf(stderr, "Bad escape character '%s'.\n", optarg); - exit(1); + exit(255); } break; case 'c': if (ciphers_valid(optarg)) { /* SSH2 only */ options.ciphers = xstrdup(optarg); - options.cipher = SSH_CIPHER_ILLEGAL; + options.cipher = SSH_CIPHER_INVALID; } else { /* SSH1 only */ options.cipher = cipher_number(optarg); @@ -356,7 +411,7 @@ again: fprintf(stderr, "Unknown cipher type '%s'\n", optarg); - exit(1); + exit(255); } if (options.cipher == SSH_CIPHER_3DES) options.ciphers = "3des-cbc"; @@ -372,17 +427,20 @@ again: else { fprintf(stderr, "Unknown mac type '%s'\n", optarg); - exit(1); + exit(255); } break; case 'M': - options.control_master = 1; + if (options.control_master == SSHCTL_MASTER_YES) + options.control_master = SSHCTL_MASTER_ASK; + else + options.control_master = SSHCTL_MASTER_YES; break; case 'p': options.port = a2port(optarg); if (options.port == 0) { fprintf(stderr, "Bad port '%s'\n", optarg); - exit(1); + exit(255); } break; case 'l': @@ -390,39 +448,51 @@ again: break; case 'L': - case 'R': - if (sscanf(optarg, "%5[0123456789]:%255[^:]:%5[0123456789]", - sfwd_port, buf, sfwd_host_port) != 3 && - sscanf(optarg, "%5[0123456789]/%255[^/]/%5[0123456789]", - sfwd_port, buf, sfwd_host_port) != 3) { + if (parse_forward(&fwd, optarg)) + add_local_forward(&options, &fwd); + else { fprintf(stderr, - "Bad forwarding specification '%s'\n", + "Bad local forwarding specification '%s'\n", optarg); - usage(); - /* NOTREACHED */ + exit(255); } - if ((fwd_port = a2port(sfwd_port)) == 0 || - (fwd_host_port = a2port(sfwd_host_port)) == 0) { + break; + + case 'R': + if (parse_forward(&fwd, optarg)) { + add_remote_forward(&options, &fwd); + } else { fprintf(stderr, - "Bad forwarding port(s) '%s'\n", optarg); - exit(1); + "Bad remote forwarding specification " + "'%s'\n", optarg); + exit(255); } - if (opt == 'L') - add_local_forward(&options, fwd_port, buf, - fwd_host_port); - else if (opt == 'R') - add_remote_forward(&options, fwd_port, buf, - fwd_host_port); break; case 'D': - fwd_port = a2port(optarg); - if (fwd_port == 0) { + cp = p = xstrdup(optarg); + memset(&fwd, '\0', sizeof(fwd)); + fwd.connect_host = "socks"; + if ((fwd.listen_host = hpdelim(&cp)) == NULL) { + fprintf(stderr, "Bad dynamic forwarding " + "specification '%.100s'\n", optarg); + exit(255); + } + if (cp != NULL) { + fwd.listen_port = a2port(cp); + fwd.listen_host = cleanhostname(fwd.listen_host); + } else { + fwd.listen_port = a2port(fwd.listen_host); + fwd.listen_host = NULL; + } + + if (fwd.listen_port == 0) { fprintf(stderr, "Bad dynamic port '%s'\n", optarg); - exit(1); + exit(255); } - add_local_forward(&options, fwd_port, "socks", 0); + add_local_forward(&options, &fwd); + xfree(p); break; case 'C': @@ -440,7 +510,7 @@ again: line = xstrdup(optarg); if (process_config_line(&options, host ? host : "", line, "command-line", 0, &dummy) != 0) - exit(1); + exit(255); xfree(line); break; case 's': @@ -450,8 +520,6 @@ again: if (options.control_path != NULL) free(options.control_path); options.control_path = xstrdup(optarg); - if (options.control_master == -1) - options.control_master = 0; break; case 'b': options.bind_address = optarg; @@ -529,7 +597,7 @@ again: if (no_tty_flag) tty_flag = 0; /* Do not allocate a tty if stdin is not a tty. */ - if (!isatty(fileno(stdin)) && !force_tty_flag) { + if ((!isatty(fileno(stdin)) || stdin_null_flag) && !force_tty_flag) { if (tty_flag) logit("Pseudo-terminal will not be allocated because stdin is not a terminal."); tty_flag = 0; @@ -550,13 +618,13 @@ again: if (!read_config_file(config, host, &options, 0)) fatal("Can't open user config file %.100s: " "%.100s", config, strerror(errno)); - } else { + } else { snprintf(buf, sizeof buf, "%.100s/%.100s", pw->pw_dir, _PATH_SSH_USER_CONFFILE); (void)read_config_file(buf, host, &options, 1); /* Read systemwide configuration file after use config. */ - (void)read_config_file(_PATH_HOST_CONFIG_FILE, host, + (void)read_config_file(_PATH_HOST_CONFIG_FILE, host, &options, 0); } @@ -580,30 +648,60 @@ again: if (options.host_key_alias != NULL) { for (p = options.host_key_alias; *p; p++) if (isupper(*p)) - *p = tolower(*p); + *p = (char)tolower(*p); + } + + /* Get default port if port has not been set. */ + if (options.port == 0) { + sp = getservbyname(SSH_SERVICE_NAME, "tcp"); + options.port = sp ? ntohs(sp->s_port) : SSH_DEFAULT_PORT; } if (options.proxy_command != NULL && - strcmp(options.proxy_command, "none") == 0) + strcmp(options.proxy_command, "none") == 0) { + xfree(options.proxy_command); options.proxy_command = NULL; + } + if (options.control_path != NULL && + strcmp(options.control_path, "none") == 0) { + xfree(options.control_path); + options.control_path = NULL; + } if (options.control_path != NULL) { - options.control_path = tilde_expand_filename( - options.control_path, original_real_uid); + char thishost[NI_MAXHOST]; + + if (gethostname(thishost, sizeof(thishost)) == -1) + fatal("gethostname: %s", strerror(errno)); + snprintf(buf, sizeof(buf), "%d", options.port); + cp = tilde_expand_filename(options.control_path, + original_real_uid); + xfree(options.control_path); + options.control_path = percent_expand(cp, "p", buf, "h", host, + "r", options.user, "l", thishost, (char *)NULL); + xfree(cp); } - if (options.control_path != NULL && options.control_master == 0) - control_client(options.control_path); /* This doesn't return */ + if (mux_command != 0 && options.control_path == NULL) + fatal("No ControlPath specified for \"-O\" command"); + if (options.control_path != NULL) + control_client(options.control_path); + + timeout_ms = options.connection_timeout * 1000; /* Open a connection to the remote host. */ if (ssh_connect(host, &hostaddr, options.port, - options.address_family, options.connection_attempts, + options.address_family, options.connection_attempts, &timeout_ms, + options.tcp_keep_alive, #ifdef HAVE_CYGWIN options.use_privileged_port, #else original_effective_uid == 0 && options.use_privileged_port, #endif options.proxy_command) != 0) - exit(1); + exit(255); + + if (timeout_ms > 0) + debug3("timeout: %d ms remain after connect", timeout_ms); /* * If we successfully made the connection, load the host private key @@ -619,16 +717,16 @@ again: if (options.rhosts_rsa_authentication || options.hostbased_authentication) { sensitive_data.nkeys = 3; - sensitive_data.keys = xmalloc(sensitive_data.nkeys * + sensitive_data.keys = xcalloc(sensitive_data.nkeys, sizeof(Key)); PRIV_START; sensitive_data.keys[0] = key_load_private_type(KEY_RSA1, - _PATH_HOST_KEY_FILE, "", NULL); + _PATH_HOST_KEY_FILE, "", NULL, NULL); sensitive_data.keys[1] = key_load_private_type(KEY_DSA, - _PATH_HOST_DSA_KEY_FILE, "", NULL); + _PATH_HOST_DSA_KEY_FILE, "", NULL, NULL); sensitive_data.keys[2] = key_load_private_type(KEY_RSA, - _PATH_HOST_RSA_KEY_FILE, "", NULL); + _PATH_HOST_RSA_KEY_FILE, "", NULL, NULL); PRIV_END; if (options.hostbased_authentication == 1 && @@ -649,12 +747,14 @@ again: * user's home directory if it happens to be on a NFS volume where * root is mapped to nobody. */ - seteuid(original_real_uid); - setuid(original_real_uid); + if (original_effective_uid == 0) { + PRIV_START; + permanently_set_uid(pw); + } /* * Now that we are back to our own permissions, create ~/.ssh - * directory if it doesn\'t already exist. + * directory if it doesn't already exist. */ snprintf(buf, sizeof buf, "%.100s%s%.100s", pw->pw_dir, strcmp(pw->pw_dir, "/") ? "/" : "", _PATH_SSH_USER_DIR); if (stat(buf, &st) < 0) @@ -678,7 +778,8 @@ again: signal(SIGPIPE, SIG_IGN); /* ignore SIGPIPE early */ /* Log into the remote system. This never returns if the login fails. */ - ssh_login(&sensitive_data, host, (struct sockaddr *)&hostaddr, pw); + ssh_login(&sensitive_data, host, (struct sockaddr *)&hostaddr, + pw, timeout_ms); /* We no longer need the private host keys. Clear them now. */ if (sensitive_data.nkeys != 0) { @@ -719,110 +820,6 @@ again: return exit_status; } -#define SSH_X11_PROTO "MIT-MAGIC-COOKIE-1" - -static void -x11_get_proto(char **_proto, char **_data) -{ - char cmd[1024]; - char line[512]; - char xdisplay[512]; - static char proto[512], data[512]; - FILE *f; - int got_data = 0, generated = 0, do_unlink = 0, i; - char *display, *xauthdir, *xauthfile; - struct stat st; - - xauthdir = xauthfile = NULL; - *_proto = proto; - *_data = data; - proto[0] = data[0] = '\0'; - - if (!options.xauth_location || - (stat(options.xauth_location, &st) == -1)) { - debug("No xauth program."); - } else { - if ((display = getenv("DISPLAY")) == NULL) { - debug("x11_get_proto: DISPLAY not set"); - return; - } - /* - * Handle FamilyLocal case where $DISPLAY does - * not match an authorization entry. For this we - * just try "xauth list unix:displaynum.screennum". - * XXX: "localhost" match to determine FamilyLocal - * is not perfect. - */ - if (strncmp(display, "localhost:", 10) == 0) { - snprintf(xdisplay, sizeof(xdisplay), "unix:%s", - display + 10); - display = xdisplay; - } - if (options.forward_x11_trusted == 0) { - xauthdir = xmalloc(MAXPATHLEN); - xauthfile = xmalloc(MAXPATHLEN); - strlcpy(xauthdir, "/tmp/ssh-XXXXXXXXXX", MAXPATHLEN); - if (mkdtemp(xauthdir) != NULL) { - do_unlink = 1; - snprintf(xauthfile, MAXPATHLEN, "%s/xauthfile", - xauthdir); - snprintf(cmd, sizeof(cmd), - "%s -f %s generate %s " SSH_X11_PROTO - " untrusted timeout 1200 2>" _PATH_DEVNULL, - options.xauth_location, xauthfile, display); - debug2("x11_get_proto: %s", cmd); - if (system(cmd) == 0) - generated = 1; - } - } - snprintf(cmd, sizeof(cmd), - "%s %s%s list %s . 2>" _PATH_DEVNULL, - options.xauth_location, - generated ? "-f " : "" , - generated ? xauthfile : "", - display); - debug2("x11_get_proto: %s", cmd); - f = popen(cmd, "r"); - if (f && fgets(line, sizeof(line), f) && - sscanf(line, "%*s %511s %511s", proto, data) == 2) - got_data = 1; - if (f) - pclose(f); - } - - if (do_unlink) { - unlink(xauthfile); - rmdir(xauthdir); - } - if (xauthdir) - xfree(xauthdir); - if (xauthfile) - xfree(xauthfile); - - /* - * If we didn't get authentication data, just make up some - * data. The forwarding code will check the validity of the - * response anyway, and substitute this data. The X11 - * server, however, will ignore this fake data and use - * whatever authentication mechanisms it was using otherwise - * for the local connection. - */ - if (!got_data) { - u_int32_t rand = 0; - - logit("Warning: No xauth data; " - "using fake authentication data for X11 forwarding."); - strlcpy(proto, SSH_X11_PROTO, sizeof proto); - for (i = 0; i < 16; i++) { - if (i % 4 == 0) - rand = arc4random(); - snprintf(data + 2 * i, sizeof data - 2 * i, "%02x", - rand & 0xff); - rand >>= 8; - } - } -} - static void ssh_init_forwarding(void) { @@ -831,37 +828,65 @@ ssh_init_forwarding(void) /* Initiate local TCP/IP port forwardings. */ for (i = 0; i < options.num_local_forwards; i++) { - debug("Connections to local port %d forwarded to remote address %.200s:%d", - options.local_forwards[i].port, - options.local_forwards[i].host, - options.local_forwards[i].host_port); + debug("Local connections to %.200s:%d forwarded to remote " + "address %.200s:%d", + (options.local_forwards[i].listen_host == NULL) ? + (options.gateway_ports ? "*" : "LOCALHOST") : + options.local_forwards[i].listen_host, + options.local_forwards[i].listen_port, + options.local_forwards[i].connect_host, + options.local_forwards[i].connect_port); success += channel_setup_local_fwd_listener( - options.local_forwards[i].port, - options.local_forwards[i].host, - options.local_forwards[i].host_port, + options.local_forwards[i].listen_host, + options.local_forwards[i].listen_port, + options.local_forwards[i].connect_host, + options.local_forwards[i].connect_port, options.gateway_ports); } + if (i > 0 && success != i && options.exit_on_forward_failure) + fatal("Could not request local forwarding."); if (i > 0 && success == 0) error("Could not request local forwarding."); /* Initiate remote TCP/IP port forwardings. */ for (i = 0; i < options.num_remote_forwards; i++) { - debug("Connections to remote port %d forwarded to local address %.200s:%d", - options.remote_forwards[i].port, - options.remote_forwards[i].host, - options.remote_forwards[i].host_port); - channel_request_remote_forwarding( - options.remote_forwards[i].port, - options.remote_forwards[i].host, - options.remote_forwards[i].host_port); + debug("Remote connections from %.200s:%d forwarded to " + "local address %.200s:%d", + (options.remote_forwards[i].listen_host == NULL) ? + "LOCALHOST" : options.remote_forwards[i].listen_host, + options.remote_forwards[i].listen_port, + options.remote_forwards[i].connect_host, + options.remote_forwards[i].connect_port); + if (channel_request_remote_forwarding( + options.remote_forwards[i].listen_host, + options.remote_forwards[i].listen_port, + options.remote_forwards[i].connect_host, + options.remote_forwards[i].connect_port) < 0) { + if (options.exit_on_forward_failure) + fatal("Could not request remote forwarding."); + else + logit("Warning: Could not request remote " + "forwarding."); + } } + + /* Initiate tunnel forwarding. */ + if (options.tun_open != SSH_TUNMODE_NO) { + if (client_request_tun_fwd(options.tun_open, + options.tun_local, options.tun_remote) == -1) { + if (options.exit_on_forward_failure) + fatal("Could not request tunnel forwarding."); + else + error("Could not request tunnel forwarding."); + } + } } static void check_agent_present(void) { if (options.forward_agent) { - /* Clear agent forwarding if we don\'t have an agent. */ + /* Clear agent forwarding if we don't have an agent. */ if (!ssh_agent_present()) options.forward_agent = 0; } @@ -875,6 +900,7 @@ ssh_session(void) int have_tty = 0; struct winsize ws; char *cp; + const char *display; /* Enable compression if requested. */ if (options.compression) { @@ -913,10 +939,10 @@ ssh_session(void) /* Store window size in the packet. */ if (ioctl(fileno(stdin), TIOCGWINSZ, &ws) < 0) memset(&ws, 0, sizeof(ws)); - packet_put_int(ws.ws_row); - packet_put_int(ws.ws_col); - packet_put_int(ws.ws_xpixel); - packet_put_int(ws.ws_ypixel); + packet_put_int((u_int)ws.ws_row); + packet_put_int((u_int)ws.ws_col); + packet_put_int((u_int)ws.ws_xpixel); + packet_put_int((u_int)ws.ws_ypixel); /* Store tty modes in the packet. */ tty_make_modes(fileno(stdin), NULL); @@ -936,13 +962,15 @@ ssh_session(void) packet_disconnect("Protocol error waiting for pty request response."); } /* Request X11 forwarding if enabled and DISPLAY is set. */ - if (options.forward_x11 && getenv("DISPLAY") != NULL) { + display = getenv("DISPLAY"); + if (options.forward_x11 && display != NULL) { char *proto, *data; /* Get reasonable local authentication information. */ - x11_get_proto(&proto, &data); + client_x11_get_proto(display, options.xauth_location, + options.forward_x11_trusted, &proto, &data); /* Request forwarding with authentication spoofing. */ debug("Requesting X11 forwarding with authentication spoofing."); - x11_request_forwarding_with_spoofing(0, proto, data); + x11_request_forwarding_with_spoofing(0, display, proto, data); /* Read response from the server. */ type = packet_read(); @@ -1029,12 +1057,19 @@ client_global_request_reply_fwd(int type, u_int32_t seq, void *ctxt) return; debug("remote forward %s for: listen %d, connect %s:%d", type == SSH2_MSG_REQUEST_SUCCESS ? "success" : "failure", - options.remote_forwards[i].port, - options.remote_forwards[i].host, - options.remote_forwards[i].host_port); - if (type == SSH2_MSG_REQUEST_FAILURE) - logit("Warning: remote port forwarding failed for listen port %d", - options.remote_forwards[i].port); + options.remote_forwards[i].listen_port, + options.remote_forwards[i].connect_host, + options.remote_forwards[i].connect_port); + if (type == SSH2_MSG_REQUEST_FAILURE) { + if (options.exit_on_forward_failure) + fatal("Error: remote port forwarding failed for " + "listen port %d", + options.remote_forwards[i].listen_port); + else + logit("Warning: remote port forwarding failed for " + "listen port %d", + options.remote_forwards[i].listen_port); + } } static void @@ -1044,9 +1079,12 @@ ssh_control_listener(void) mode_t old_umask; int addr_len; - if (options.control_path == NULL || options.control_master <= 0) + if (options.control_path == NULL || + options.control_master == SSHCTL_MASTER_NO) return; + debug("setting up multiplex master socket"); + memset(&addr, '\0', sizeof(addr)); addr.sun_family = AF_UNIX; addr_len = offsetof(struct sockaddr_un, sun_path) + @@ -1057,21 +1095,21 @@ ssh_control_listener(void) fatal("ControlPath too long"); if ((control_fd = socket(PF_UNIX, SOCK_STREAM, 0)) < 0) - fatal("%s socket(): %s\n", __func__, strerror(errno)); + fatal("%s socket(): %s", __func__, strerror(errno)); old_umask = umask(0177); - if (bind(control_fd, (struct sockaddr*)&addr, addr_len) == -1) { + if (bind(control_fd, (struct sockaddr *)&addr, addr_len) == -1) { control_fd = -1; - if (errno == EINVAL) + if (errno == EINVAL || errno == EADDRINUSE) fatal("ControlSocket %s already exists", options.control_path); else - fatal("%s bind(): %s\n", __func__, strerror(errno)); + fatal("%s bind(): %s", __func__, strerror(errno)); } umask(old_umask); if (listen(control_fd, 64) == -1) - fatal("%s listen(): %s\n", __func__, strerror(errno)); + fatal("%s listen(): %s", __func__, strerror(errno)); set_nonblock(control_fd); } @@ -1081,15 +1119,18 @@ static void ssh_session2_setup(int id, void *arg) { extern char **environ; - + const char *display; int interactive = tty_flag; - if (options.forward_x11 && getenv("DISPLAY") != NULL) { + + display = getenv("DISPLAY"); + if (options.forward_x11 && display != NULL) { char *proto, *data; /* Get reasonable local authentication information. */ - x11_get_proto(&proto, &data); + client_x11_get_proto(display, options.xauth_location, + options.forward_x11_trusted, &proto, &data); /* Request forwarding with authentication spoofing. */ debug("Requesting X11 forwarding with authentication spoofing."); - x11_request_forwarding_with_spoofing(id, proto, data); + x11_request_forwarding_with_spoofing(id, display, proto, data); interactive = 1; /* XXX wait for reply */ } @@ -1160,11 +1201,18 @@ ssh_session2(void) /* XXX should be pre-session */ ssh_init_forwarding(); - ssh_control_listener(); if (!no_shell_flag || (datafellows & SSH_BUG_DUMMYCHAN)) id = ssh_session2_open(); + /* Execute a local command */ + if (options.local_command != NULL && + options.permit_local_command) + ssh_local_cmd(options.local_command); + + /* Start listening for multiplex clients */ + ssh_control_listener(); + /* If requested, let ssh continue in the background. */ if (fork_after_authentication_flag) if (daemon(1, 1) < 0) @@ -1177,15 +1225,16 @@ ssh_session2(void) static void load_public_identity_files(void) { - char *filename; + char *filename, *cp, thishost[NI_MAXHOST]; int i = 0; Key *public; + struct passwd *pw; #ifdef SMARTCARD Key **keys; if (options.smartcard_device != NULL && options.num_identity_files < SSH_MAX_IDENTITY_FILES && - (keys = sc_get_keys(options.smartcard_device, NULL)) != NULL ) { + (keys = sc_get_keys(options.smartcard_device, NULL)) != NULL) { int count = 0; for (i = 0; keys[i] != NULL; i++) { count++; @@ -1203,9 +1252,18 @@ load_public_identity_files(void) xfree(keys); } #endif /* SMARTCARD */ + if ((pw = getpwuid(original_real_uid)) == NULL) + fatal("load_public_identity_files: getpwuid failed"); + if (gethostname(thishost, sizeof(thishost)) == -1) + fatal("load_public_identity_files: gethostname: %s", + strerror(errno)); for (; i < options.num_identity_files; i++) { - filename = tilde_expand_filename(options.identity_files[i], + cp = tilde_expand_filename(options.identity_files[i], original_real_uid); + filename = percent_expand(cp, "d", pw->pw_dir, + "u", pw->pw_name, "l", thishost, "h", host, + "r", options.user, (char *)NULL); + xfree(cp); public = key_load_public(filename, NULL); debug("identity file %s type %d", filename, public ? public->type : -1); @@ -1228,15 +1286,49 @@ control_client_sigrelay(int signo) kill(control_server_pid, signo); } +static int +env_permitted(char *env) +{ + int i, ret; + char name[1024], *cp; + + if ((cp = strchr(env, '=')) == NULL || cp == env) + return (0); + ret = snprintf(name, sizeof(name), "%.*s", (int)(cp - env), env); + if (ret <= 0 || (size_t)ret >= sizeof(name)) + fatal("env_permitted: name '%.100s...' too long", env); + + for (i = 0; i < options.num_send_env; i++) + if (match_pattern(name, options.send_env[i])) + return (1); + + return (0); +} + static void control_client(const char *path) { struct sockaddr_un addr; - int i, r, sock, exitval, addr_len; + int i, r, fd, sock, exitval[2], num_env, addr_len; Buffer m; - char *cp; + char *term; extern char **environ; - + u_int flags; + + if (mux_command == 0) + mux_command = SSHMUX_COMMAND_OPEN; + + switch (options.control_master) { + case SSHCTL_MASTER_AUTO: + case SSHCTL_MASTER_AUTO_ASK: + debug("auto-mux: Trying existing master"); + /* FALLTHROUGH */ + case SSHCTL_MASTER_NO: + break; + default: + return; + } + memset(&addr, '\0', sizeof(addr)); addr.sun_family = AF_UNIX; addr_len = offsetof(struct sockaddr_un, sun_path) + @@ -1249,84 +1341,162 @@ control_client(const char *path) if ((sock = socket(PF_UNIX, SOCK_STREAM, 0)) < 0) fatal("%s socket(): %s", __func__, strerror(errno)); - if (connect(sock, (struct sockaddr*)&addr, addr_len) == -1) - fatal("Couldn't connect to %s: %s", path, strerror(errno)); + if (connect(sock, (struct sockaddr *)&addr, addr_len) == -1) { + if (mux_command != SSHMUX_COMMAND_OPEN) { + fatal("Control socket connect(%.100s): %s", path, + strerror(errno)); + } + if (errno == ENOENT) + debug("Control socket \"%.100s\" does not exist", path); + else { + error("Control socket connect(%.100s): %s", path, + strerror(errno)); + } + close(sock); + return; + } + + if (stdin_null_flag) { + if ((fd = open(_PATH_DEVNULL, O_RDONLY)) == -1) + fatal("open(/dev/null): %s", strerror(errno)); + if (dup2(fd, STDIN_FILENO) == -1) + fatal("dup2: %s", strerror(errno)); + if (fd > STDERR_FILENO) + close(fd); + } - if ((cp = getenv("TERM")) == NULL) - cp = ""; + term = getenv("TERM"); - signal(SIGINT, control_client_sighandler); - signal(SIGTERM, control_client_sighandler); - signal(SIGWINCH, control_client_sigrelay); + flags = 0; + if (tty_flag) + flags |= SSHMUX_FLAG_TTY; + if (subsystem_flag) + flags |= SSHMUX_FLAG_SUBSYS; + if (options.forward_x11) + flags |= SSHMUX_FLAG_X11_FWD; + if (options.forward_agent) + flags |= SSHMUX_FLAG_AGENT_FWD; buffer_init(&m); - /* Get PID of controlee */ + /* Send our command to server */ + buffer_put_int(&m, mux_command); + buffer_put_int(&m, flags); + if (ssh_msg_send(sock, SSHMUX_VER, &m) == -1) + fatal("%s: msg_send", __func__); + buffer_clear(&m); + + /* Get authorisation status and PID of controlee */ if (ssh_msg_recv(sock, &m) == -1) fatal("%s: msg_recv", __func__); - if (buffer_get_char(&m) != 0) + if (buffer_get_char(&m) != SSHMUX_VER) fatal("%s: wrong version", __func__); - /* Connection allowed? */ if (buffer_get_int(&m) != 1) fatal("Connection to master denied"); control_server_pid = buffer_get_int(&m); buffer_clear(&m); - buffer_put_int(&m, tty_flag); - buffer_put_int(&m, subsystem_flag); - buffer_put_cstring(&m, cp); + switch (mux_command) { + case SSHMUX_COMMAND_ALIVE_CHECK: + fprintf(stderr, "Master running (pid=%d)\r\n", + control_server_pid); + exit(0); + case SSHMUX_COMMAND_TERMINATE: + fprintf(stderr, "Exit request sent.\r\n"); + exit(0); + case SSHMUX_COMMAND_OPEN: + /* continue below */ + break; + default: + fatal("silly mux_command %d", mux_command); + } + + /* SSHMUX_COMMAND_OPEN */ + buffer_put_cstring(&m, term ? term : ""); buffer_append(&command, "\0", 1); buffer_put_cstring(&m, buffer_ptr(&command)); - /* Pass environment */ - for (i = 0; environ != NULL && environ[i] != NULL; i++) - ; - buffer_put_int(&m, i); - for (i = 0; environ != NULL && environ[i] != NULL; i++) - buffer_put_cstring(&m, environ[i]); + if (options.num_send_env == 0 || environ == NULL) { + buffer_put_int(&m, 0); + } else { + /* Pass environment */ + num_env = 0; + for (i = 0; environ[i] != NULL; i++) + if (env_permitted(environ[i])) + num_env++; /* Count */ + + buffer_put_int(&m, num_env); + + for (i = 0; environ[i] != NULL && num_env >= 0; i++) + if (env_permitted(environ[i])) { + num_env--; + buffer_put_cstring(&m, environ[i]); + } + } - if (ssh_msg_send(sock, /* version */0, &m) == -1) + if (ssh_msg_send(sock, SSHMUX_VER, &m) == -1) fatal("%s: msg_send", __func__); - mm_send_fd(sock, STDIN_FILENO); - mm_send_fd(sock, STDOUT_FILENO); - mm_send_fd(sock, STDERR_FILENO); + if (mm_send_fd(sock, STDIN_FILENO) == -1 || + mm_send_fd(sock, STDOUT_FILENO) == -1 || + mm_send_fd(sock, STDERR_FILENO) == -1) + fatal("%s: send fds failed", __func__); /* Wait for reply, so master has a chance to gather ttymodes */ buffer_clear(&m); if (ssh_msg_recv(sock, &m) == -1) fatal("%s: msg_recv", __func__); - if (buffer_get_char(&m) != 0) - fatal("%s: master returned error", __func__); + if (buffer_get_char(&m) != SSHMUX_VER) + fatal("%s: wrong version", __func__); buffer_free(&m); + signal(SIGHUP, control_client_sighandler); + signal(SIGINT, control_client_sighandler); + signal(SIGTERM, control_client_sighandler); + signal(SIGWINCH, control_client_sigrelay); + if (tty_flag) enter_raw_mode(); - /* Stick around until the controlee closes the client_fd */ - exitval = 0; - for (;!control_client_terminate;) { - r = read(sock, &exitval, sizeof(exitval)); + /* + * Stick around until the controlee closes the client_fd. + * Before it does, it is expected to write this process' exit + * value (one int). This process must read the value and wait for + * the closure of the client_fd; if this one closes early, the + * multiplex master will terminate early too (possibly losing data). + */ + exitval[0] = 0; + for (i = 0; !control_client_terminate && i < (int)sizeof(exitval);) { + r = read(sock, (char *)exitval + i, sizeof(exitval) - i); if (r == 0) { debug2("Received EOF from master"); break; } - if (r > 0) - debug2("Received exit status from master %d", exitval); - if (r == -1 && errno != EINTR) + if (r == -1) { + if (errno == EINTR) + continue; fatal("%s: read %s", __func__, strerror(errno)); + } + i += r; } - if (control_client_terminate) - debug2("Exiting on signal %d", control_client_terminate); - close(sock); - leave_raw_mode(); + if (i > (int)sizeof(int)) + fatal("%s: master returned too much data (%d > %lu)", + __func__, i, sizeof(int)); + if (control_client_terminate) { + debug2("Exiting on signal %d", control_client_terminate); + exitval[0] = 255; + } else if (i < (int)sizeof(int)) { + debug2("Control master terminated unexpectedly"); + exitval[0] = 255; + } else + debug2("Received exit status from master %d", exitval[0]); if (tty_flag && options.log_level != SYSLOG_LEVEL_QUIET) - fprintf(stderr, "Connection to master closed.\r\n"); + fprintf(stderr, "Shared connection to %s closed.\r\n", host); - exit(exitval); + exit(exitval[0]); }