]> andersk Git - openssh.git/blobdiff - ssh.c
- stevesk@cvs.openbsd.org 2006/02/20 17:02:44
[openssh.git] / ssh.c
diff --git a/ssh.c b/ssh.c
index 0871d06de1609dfe63a1ae7cf5e894843ea44a2a..196da80c5fdf496f2454ee7df21190d5720c99f3 100644 (file)
--- a/ssh.c
+++ b/ssh.c
  */
 
 #include "includes.h"
-RCSID("$OpenBSD: ssh.c,v 1.241 2005/06/06 11:20:36 djm Exp $");
+RCSID("$OpenBSD: ssh.c,v 1.264 2006/02/20 17:19:54 stevesk Exp $");
+
+#include <sys/types.h>
+#ifdef HAVE_SYS_STAT_H
+# include <sys/stat.h>
+#endif
+#include <sys/resource.h>
+#include <sys/ioctl.h>
+#include <sys/un.h>
+
+#include <paths.h>
 
 #include <openssl/evp.h>
 #include <openssl/err.h>
@@ -158,13 +168,13 @@ usage(void)
 {
        fprintf(stderr,
 "usage: ssh [-1246AaCfgkMNnqsTtVvXxY] [-b bind_address] [-c cipher_spec]\n"
-"           [-D port] [-e escape_char] [-F configfile]\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"
-"           [user@]hostname [command]\n"
+"           [-w tunnel:tunnel] [user@]hostname [command]\n"
        );
-       exit(1);
+       exit(255);
 }
 
 static int ssh_session(void);
@@ -185,8 +195,12 @@ main(int ac, char **av)
        int dummy;
        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();
 
@@ -219,7 +233,7 @@ 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);
@@ -240,7 +254,7 @@ main(int ac, char **av)
 
 again:
        while ((opt = getopt(ac, av,
-           "1246ab:c:e:fgi:kl:m:no:p:qstvxACD:F:I:L:MNO:PR:S:TVXY")) != -1) {
+           "1246ab:c:e:fgi:kl:m:no:p:qstvxACD:F:I:L:MNO:PR:S:TVw:XY")) != -1) {
                switch (opt) {
                case '1':
                        options.protocol = SSH_PROTO_1;
@@ -336,6 +350,15 @@ again:
                        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;
@@ -351,7 +374,7 @@ again:
                        else {
                                fprintf(stderr, "Bad escape character '%s'.\n",
                                    optarg);
-                               exit(1);
+                               exit(255);
                        }
                        break;
                case 'c':
@@ -366,7 +389,7 @@ again:
                                        fprintf(stderr,
                                            "Unknown cipher type '%s'\n",
                                            optarg);
-                                       exit(1);
+                                       exit(255);
                                }
                                if (options.cipher == SSH_CIPHER_3DES)
                                        options.ciphers = "3des-cbc";
@@ -382,18 +405,20 @@ again:
                        else {
                                fprintf(stderr, "Unknown mac type '%s'\n",
                                    optarg);
-                               exit(1);
+                               exit(255);
                        }
                        break;
                case 'M':
-                       options.control_master =
-                           (options.control_master >= 1) ? 2 : 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':
@@ -407,7 +432,7 @@ again:
                                fprintf(stderr,
                                    "Bad local forwarding specification '%s'\n",
                                    optarg);
-                               exit(1);
+                               exit(255);
                        }
                        break;
 
@@ -418,7 +443,7 @@ again:
                                fprintf(stderr,
                                    "Bad remote forwarding specification "
                                    "'%s'\n", optarg);
-                               exit(1);
+                               exit(255);
                        }
                        break;
 
@@ -429,20 +454,20 @@ again:
                        if ((fwd.listen_host = hpdelim(&cp)) == NULL) {
                                fprintf(stderr, "Bad dynamic forwarding "
                                    "specification '%.100s'\n", optarg);
-                               exit(1);
+                               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 = "";
+                               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);
                        xfree(p);
@@ -463,7 +488,7 @@ 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':
@@ -604,25 +629,35 @@ again:
                                *p = 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)
                options.proxy_command = NULL;
+       if (options.control_path != NULL &&
+           strcmp(options.control_path, "none") == 0)
+               options.control_path = NULL;
 
        if (options.control_path != NULL) {
+               char me[NI_MAXHOST];
+
+               if (gethostname(me, sizeof(me)) == -1)
+                       fatal("gethostname: %s", strerror(errno));
                snprintf(buf, sizeof(buf), "%d", options.port);
                cp = tilde_expand_filename(options.control_path,
                    original_real_uid);
                options.control_path = percent_expand(cp, "p", buf, "h", host,
-                   "r", options.user, (char *)NULL);
+                   "r", options.user, "l", me, (char *)NULL);
                xfree(cp);
        }
        if (mux_command != 0 && options.control_path == NULL)
                fatal("No ControlPath specified for \"-O\" command");
-       if (options.control_path != NULL && options.control_master == 0) {
-               if (mux_command == 0)
-                       mux_command = SSHMUX_COMMAND_OPEN;
+       if (options.control_path != NULL)
                control_client(options.control_path);
-       }
 
        /* Open a connection to the remote host. */
        if (ssh_connect(host, &hostaddr, options.port,
@@ -633,7 +668,7 @@ again:
            original_effective_uid == 0 && options.use_privileged_port,
 #endif
            options.proxy_command) != 0)
-               exit(1);
+               exit(255);
 
        /*
         * If we successfully made the connection, load the host private key
@@ -686,7 +721,7 @@ again:
 
        /*
         * 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)
@@ -751,110 +786,6 @@ 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 rnd = 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)
-                               rnd = arc4random();
-                       snprintf(data + 2 * i, sizeof data - 2 * i, "%02x",
-                           rnd & 0xff);
-                       rnd >>= 8;
-               }
-       }
-}
-
 static void
 ssh_init_forwarding(void)
 {
@@ -885,9 +816,8 @@ ssh_init_forwarding(void)
        for (i = 0; i < options.num_remote_forwards; i++) {
                debug("Remote connections from %.200s:%d forwarded to "
                    "local address %.200s:%d",
-                   (options.remote_forwards[i].listen_host == NULL) ? 
-                   (options.gateway_ports ? "*" : "LOCALHOST") : 
-                   options.remote_forwards[i].listen_host,
+                   (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);
@@ -903,7 +833,7 @@ 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;
        }
@@ -917,6 +847,7 @@ ssh_session(void)
        int have_tty = 0;
        struct winsize ws;
        char *cp;
+       const char *display;
 
        /* Enable compression if requested. */
        if (options.compression) {
@@ -978,13 +909,15 @@ 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();
@@ -1086,9 +1019,12 @@ 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) +
@@ -1099,7 +1035,7 @@ 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) {
@@ -1108,12 +1044,12 @@ ssh_control_listener(void)
                        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);
 }
@@ -1123,15 +1059,18 @@ 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 */
        }
@@ -1143,6 +1082,33 @@ ssh_session2_setup(int id, void *arg)
                packet_send();
        }
 
+       if (options.tun_open != SSH_TUNMODE_NO) {
+               Channel *c;
+               int fd;
+
+               debug("Requesting tun.");
+               if ((fd = tun_open(options.tun_local,
+                   options.tun_open)) >= 0) {
+                       c = channel_new("tun", SSH_CHANNEL_OPENING, fd, fd, -1,
+                           CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
+                           0, "tun", 1);
+                       c->datagram = 1;
+#if defined(SSH_TUN_FILTER)
+                       if (options.tun_open == SSH_TUNMODE_POINTOPOINT)
+                               channel_register_filter(c->self, sys_tun_infilter,
+                                   sys_tun_outfilter);
+#endif
+                       packet_start(SSH2_MSG_CHANNEL_OPEN);
+                       packet_put_cstring("tun@openssh.com");
+                       packet_put_int(c->self);
+                       packet_put_int(c->local_window_max);
+                       packet_put_int(c->local_maxpacket);
+                       packet_put_int(options.tun_open);
+                       packet_put_int(options.tun_remote);
+                       packet_send();
+               }
+       }
+
        client_session2_setup(id, tty_flag, subsystem_flag, getenv("TERM"),
            NULL, fileno(stdin), &command, environ, &ssh_subsystem_reply);
 
@@ -1207,6 +1173,11 @@ ssh_session2(void)
        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);
+
        /* If requested, let ssh continue in the background. */
        if (fork_after_authentication_flag)
                if (daemon(1, 1) < 0)
@@ -1299,6 +1270,20 @@ control_client(const char *path)
        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) +
@@ -1322,41 +1307,44 @@ control_client(const char *path)
                        error("Control socket connect(%.100s): %s", path,
                            strerror(errno));
                }
-               close(sock);
-               return;
-       }
+               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 (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 ((term = getenv("TERM")) == NULL)
-               term = "";
+       term = getenv("TERM");
 
        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);
 
        /* Send our command to server */
        buffer_put_int(&m, mux_command);
        buffer_put_int(&m, flags);
-       if (ssh_msg_send(sock, /* version */1, &m) == -1)
+       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) != 1)
+       if (buffer_get_char(&m) != SSHMUX_VER)
                fatal("%s: wrong version", __func__);
        if (buffer_get_int(&m) != 1)
                fatal("Connection to master denied");
@@ -1380,7 +1368,7 @@ control_client(const char *path)
        }
 
        /* SSHMUX_COMMAND_OPEN */
-       buffer_put_cstring(&m, term);
+       buffer_put_cstring(&m, term ? term : "");
        buffer_append(&command, "\0", 1);
        buffer_put_cstring(&m, buffer_ptr(&command));
 
@@ -1402,7 +1390,7 @@ control_client(const char *path)
                        }
        }
 
-       if (ssh_msg_send(sock, /* version */1, &m) == -1)
+       if (ssh_msg_send(sock, SSHMUX_VER, &m) == -1)
                fatal("%s: msg_send", __func__);
 
        mm_send_fd(sock, STDIN_FILENO);
@@ -1413,7 +1401,7 @@ control_client(const char *path)
        buffer_clear(&m);
        if (ssh_msg_recv(sock, &m) == -1)
                fatal("%s: msg_recv", __func__);
-       if (buffer_get_char(&m) != 1)
+       if (buffer_get_char(&m) != SSHMUX_VER)
                fatal("%s: wrong version", __func__);
        buffer_free(&m);
 
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