1 files changed, 420 insertions, 58 deletions

diff --git a/clientloop.c b/clientloop.c
index a13d06ddf..1bcf4392f 100644
--- a/clientloop.c
+++ b/clientloop.c
@@ -59,7 +59,7 @@
  */
 
 #include "includes.h"
-RCSID("$OpenBSD: clientloop.c,v 1.117 2003/12/16 15:49:51 markus Exp $");
+RCSID("$OpenBSD: clientloop.c,v 1.130 2004/08/11 21:43:04 avsm Exp $");
 
 #include "ssh.h"
 #include "ssh1.h"
@@ -79,9 +79,11 @@ RCSID("$OpenBSD: clientloop.c,v 1.117 2003/12/16 15:49:51 markus Exp $");
 #include "clientloop.h"
 #include "authfd.h"
 #include "atomicio.h"
-#include "sshtty.h"
+#include "sshpty.h"
 #include "misc.h"
-#include "readpass.h"
+#include "monitor_fdpass.h"
+#include "match.h"
+#include "msg.h"
 
 /* import options */
 extern Options options;
@@ -92,6 +94,9 @@ extern int stdin_null_flag;
 /* Flag indicating that no shell has been requested */
 extern int no_shell_flag;
 
+/* Control socket */
+extern int control_fd;
+
 /*
  * Name of the host we are connecting to.  This is the name given on the
  * command line, or the HostName specified for the user-supplied name in a
@@ -132,16 +137,27 @@ static int server_alive_timeouts = 0;
 static void client_init_dispatch(void);
 int     session_ident = -1;
 
+struct confirm_ctx {
+        int want_tty;
+        int want_subsys;
+        Buffer cmd;
+        char *term;
+        struct termios tio;
+        char **env;
+};
+
 /*XXX*/
 extern Kex *xxx_kex;
 
+void ssh_process_session2_setup(int, int, int, Buffer *);
+
 /* Restores stdin to blocking mode. */
 
 static void
 leave_non_blocking(void)
 {
         if (in_non_blocking_mode) {
-                (void) fcntl(fileno(stdin), F_SETFL, 0);
+                unset_nonblock(fileno(stdin));
                 in_non_blocking_mode = 0;
         }
 }
@@ -152,7 +168,7 @@ static void
 enter_non_blocking(void)
 {
         in_non_blocking_mode = 1;
-        (void) fcntl(fileno(stdin), F_SETFL, O_NONBLOCK);
+        set_nonblock(fileno(stdin));
 }
 
 /*
@@ -292,19 +308,13 @@ client_check_window_change(void)
         /** XXX race */
         received_window_change_signal = 0;
 
-        if (ioctl(fileno(stdin), TIOCGWINSZ, &ws) < 0)
-                return;
-
         debug2("client_check_window_change: changed");
 
         if (compat20) {
-                channel_request_start(session_ident, "window-change", 0);
-                packet_put_int(ws.ws_col);
-                packet_put_int(ws.ws_row);
-                packet_put_int(ws.ws_xpixel);
-                packet_put_int(ws.ws_ypixel);
-                packet_send();
+                channel_send_window_changes();
         } else {
+                if (ioctl(fileno(stdin), TIOCGWINSZ, &ws) < 0)
+                        return;
                 packet_start(SSH_CMSG_WINDOW_SIZE);
                 packet_put_int(ws.ws_row);
                 packet_put_int(ws.ws_col);
@@ -341,10 +351,9 @@ server_alive_check(void)
  * Waits until the client can do something (some data becomes available on
  * one of the file descriptors).
  */
-
 static void
 client_wait_until_can_do_something(fd_set **readsetp, fd_set **writesetp,
-    int *maxfdp, int *nallocp, int rekeying)
+    int *maxfdp, u_int *nallocp, int rekeying)
 {
         struct timeval tv, *tvp;
         int ret;
@@ -387,6 +396,9 @@ client_wait_until_can_do_something(fd_set **readsetp, fd_set **writesetp,
         if (packet_have_data_to_write())
                 FD_SET(connection_out, *writesetp);
 
+        if (control_fd != -1)
+                FD_SET(control_fd, *readsetp);
+
         /*
          * Wait for something to happen.  This will suspend the process until
          * some selected descriptor can be read, written, or has some other
@@ -395,7 +407,7 @@ client_wait_until_can_do_something(fd_set **readsetp, fd_set **writesetp,
 
         if (options.server_alive_interval == 0)
                 tvp = NULL;
-        else {  
+        else {
                 tv.tv_sec = options.server_alive_interval;
                 tv.tv_usec = 0;
                 tvp = &tv;
@@ -506,12 +518,229 @@ client_process_net_input(fd_set * readset)
 }
 
 static void
+client_subsystem_reply(int type, u_int32_t seq, void *ctxt)
+{
+        int id;
+        Channel *c;
+
+        id = packet_get_int();
+        packet_check_eom();
+
+        if ((c = channel_lookup(id)) == NULL) {
+                error("%s: no channel for id %d", __func__, id);
+                return;
+        }
+
+        if (type == SSH2_MSG_CHANNEL_SUCCESS)
+                debug2("Request suceeded on channel %d", id);
+        else if (type == SSH2_MSG_CHANNEL_FAILURE) {
+                error("Request failed on channel %d", id);
+                channel_free(c);
+        }
+}
+
+static void
+client_extra_session2_setup(int id, void *arg)
+{
+        struct confirm_ctx *cctx = arg;
+        Channel *c;
+        int i;
+
+        if (cctx == NULL)
+                fatal("%s: cctx == NULL", __func__);
+        if ((c = channel_lookup(id)) == NULL)
+                fatal("%s: no channel for id %d", __func__, id);
+
+        client_session2_setup(id, cctx->want_tty, cctx->want_subsys,
+            cctx->term, &cctx->tio, c->rfd, &cctx->cmd, cctx->env,
+            client_subsystem_reply);
+
+        c->confirm_ctx = NULL;
+        buffer_free(&cctx->cmd);
+        xfree(cctx->term);
+        if (cctx->env != NULL) {
+                for (i = 0; cctx->env[i] != NULL; i++)
+                        xfree(cctx->env[i]);
+                xfree(cctx->env);
+        }
+        xfree(cctx);
+}
+
+static void
+client_process_control(fd_set * readset)
+{
+        Buffer m;
+        Channel *c;
+        int client_fd, new_fd[3], ver, i, allowed;
+        socklen_t addrlen;
+        struct sockaddr_storage addr;
+        struct confirm_ctx *cctx;
+        char *cmd;
+        u_int len, env_len;
+        uid_t euid;
+        gid_t egid;
+
+        /*
+         * Accept connection on control socket
+         */
+        if (control_fd == -1 || !FD_ISSET(control_fd, readset))
+                return;
+
+        memset(&addr, 0, sizeof(addr));
+        addrlen = sizeof(addr);
+        if ((client_fd = accept(control_fd,
+            (struct sockaddr*)&addr, &addrlen)) == -1) {
+                error("%s accept: %s", __func__, strerror(errno));
+                return;
+        }
+
+        if (getpeereid(client_fd, &euid, &egid) < 0) {
+                error("%s getpeereid failed: %s", __func__, strerror(errno));
+                close(client_fd);
+                return;
+        }
+        if ((euid != 0) && (getuid() != euid)) {
+                error("control mode uid mismatch: peer euid %u != uid %u",
+                    (u_int) euid, (u_int) getuid());
+                close(client_fd);
+                return;
+        }
+
+        allowed = 1;
+        if (options.control_master == 2) {
+                char *p, prompt[1024];
+
+                allowed = 0;
+                snprintf(prompt, sizeof(prompt),
+                    "Allow shared connection to %s? ", host);
+                p = read_passphrase(prompt, RP_USE_ASKPASS|RP_ALLOW_EOF);
+                if (p != NULL) {
+                        /*
+                         * Accept empty responses and responses consisting
+                         * of the word "yes" as affirmative.
+                         */
+                        if (*p == '\0' || *p == '\n' ||
+                            strcasecmp(p, "yes") == 0)
+                                allowed = 1;
+                        xfree(p);
+                }
+        }
+
+        unset_nonblock(client_fd);
+
+        buffer_init(&m);
+
+        buffer_put_int(&m, allowed);
+        buffer_put_int(&m, getpid());
+        if (ssh_msg_send(client_fd, /* version */0, &m) == -1) {
+                error("%s: client msg_send failed", __func__);
+                close(client_fd);
+                buffer_free(&m);
+                return;
+        }
+        buffer_clear(&m);
+
+        if (!allowed) {
+                error("Refused control connection");
+                close(client_fd);
+                buffer_free(&m);
+                return;
+        }
+
+        if (ssh_msg_recv(client_fd, &m) == -1) {
+                error("%s: client msg_recv failed", __func__);
+                close(client_fd);
+                buffer_free(&m);
+                return;
+        }
+
+        if ((ver = buffer_get_char(&m)) != 0) {
+                error("%s: wrong client version %d", __func__, ver);
+                buffer_free(&m);
+                close(client_fd);
+                return;
+        }
+
+        cctx = xmalloc(sizeof(*cctx));
+        memset(cctx, 0, sizeof(*cctx));
+
+        cctx->want_tty = buffer_get_int(&m);
+        cctx->want_subsys = buffer_get_int(&m);
+        cctx->term = buffer_get_string(&m, &len);
+
+        cmd = buffer_get_string(&m, &len);
+        buffer_init(&cctx->cmd);
+        buffer_append(&cctx->cmd, cmd, strlen(cmd));
+
+        env_len = buffer_get_int(&m);
+        env_len = MIN(env_len, 4096);
+        debug3("%s: receiving %d env vars", __func__, env_len);
+        if (env_len != 0) {
+                cctx->env = xmalloc(sizeof(*cctx->env) * (env_len + 1));
+                for (i = 0; i < env_len; i++)
+                        cctx->env[i] = buffer_get_string(&m, &len);
+                cctx->env[i] = NULL;
+        }
+
+        debug2("%s: accepted tty %d, subsys %d, cmd %s", __func__,
+            cctx->want_tty, cctx->want_subsys, cmd);
+
+        /* Gather fds from client */
+        new_fd[0] = mm_receive_fd(client_fd);
+        new_fd[1] = mm_receive_fd(client_fd);
+        new_fd[2] = mm_receive_fd(client_fd);
+
+        debug2("%s: got fds stdin %d, stdout %d, stderr %d", __func__,
+            new_fd[0], new_fd[1], new_fd[2]);
+
+        /* Try to pick up ttymodes from client before it goes raw */
+        if (cctx->want_tty && tcgetattr(new_fd[0], &cctx->tio) == -1)
+                error("%s: tcgetattr: %s", __func__, strerror(errno));
+
+        buffer_clear(&m);
+        if (ssh_msg_send(client_fd, /* version */0, &m) == -1) {
+                error("%s: client msg_send failed", __func__);
+                close(client_fd);
+                close(new_fd[0]);
+                close(new_fd[1]);
+                close(new_fd[2]);
+                buffer_free(&m);
+                return;
+        }
+        buffer_free(&m);
+
+        /* enable nonblocking unless tty */
+        if (!isatty(new_fd[0]))
+                set_nonblock(new_fd[0]);
+        if (!isatty(new_fd[1]))
+                set_nonblock(new_fd[1]);
+        if (!isatty(new_fd[2]))
+                set_nonblock(new_fd[2]);
+
+        set_nonblock(client_fd);
+
+        c = channel_new("session", SSH_CHANNEL_OPENING,
+            new_fd[0], new_fd[1], new_fd[2],
+            CHAN_SES_WINDOW_DEFAULT, CHAN_SES_PACKET_DEFAULT,
+            CHAN_EXTENDED_WRITE, "client-session", /*nonblock*/0);
+
+        /* XXX */
+        c->ctl_fd = client_fd;
+
+        debug3("%s: channel_new: %d", __func__, c->self);
+
+        channel_send_open(c->self);
+        channel_register_confirm(c->self, client_extra_session2_setup, cctx);
+}
+
+static void
 process_cmdline(void)
 {
         void (*handler)(int);
         char *s, *cmd;
         u_short fwd_port, fwd_host_port;
         char buf[1024], sfwd_port[6], sfwd_host_port[6];
+        int delete = 0;
         int local = 0;
 
         leave_raw_mode();
@@ -521,44 +750,77 @@ process_cmdline(void)
                 goto out;
         while (*s && isspace(*s))
                 s++;
-        if (*s == 0)
+        if (*s == '-')
+                s++;    /* Skip cmdline '-', if any */
+        if (*s == '\0')
+                goto out;
+
+        if (*s == 'h' || *s == 'H' || *s == '?') {
+                logit("Commands:");
+                logit("      -Lport:host:hostport    Request local forward");
+                logit("      -Rport:host:hostport    Request remote forward");
+                logit("      -KRhostport             Cancel remote forward");
                 goto out;
-        if (strlen(s) < 2 || s[0] != '-' || !(s[1] == 'L' || s[1] == 'R')) {
+        }
+
+        if (*s == 'K') {
+                delete = 1;
+                s++;
+        }
+        if (*s != 'L' && *s != 'R') {
                 logit("Invalid command.");
                 goto out;
         }
-        if (s[1] == 'L')
+        if (*s == 'L')
                 local = 1;
-        if (!local && !compat20) {
+        if (local && delete) {
+                logit("Not supported.");
+                goto out;
+        }
+        if ((!local || delete) && !compat20) {
                 logit("Not supported for SSH protocol version 1.");
                 goto out;
         }
-        s += 2;
+
+        s++;
         while (*s && isspace(*s))
                 s++;
 
-        if (sscanf(s, "%5[0-9]:%255[^:]:%5[0-9]",
-            sfwd_port, buf, sfwd_host_port) != 3 &&
-            sscanf(s, "%5[0-9]/%255[^/]/%5[0-9]",
-            sfwd_port, buf, sfwd_host_port) != 3) {
-                logit("Bad forwarding specification.");
-                goto out;
-        }
-        if ((fwd_port = a2port(sfwd_port)) == 0 ||
-            (fwd_host_port = a2port(sfwd_host_port)) == 0) {
-                logit("Bad forwarding port(s).");
-                goto out;
-        }
-        if (local) {
-                if (channel_setup_local_fwd_listener(fwd_port, buf,
-                    fwd_host_port, options.gateway_ports) < 0) {
-                        logit("Port forwarding failed.");
+        if (delete) {
+                if (sscanf(s, "%5[0-9]", sfwd_host_port) != 1) {
+                        logit("Bad forwarding specification.");
+                        goto out;
+                }
+                if ((fwd_host_port = a2port(sfwd_host_port)) == 0) {
+                        logit("Bad forwarding port(s).");
+                        goto out;
+                }
+                channel_request_rforward_cancel(fwd_host_port);
+        } else {
+                if (sscanf(s, "%5[0-9]:%255[^:]:%5[0-9]",
+                    sfwd_port, buf, sfwd_host_port) != 3 &&
+                    sscanf(s, "%5[0-9]/%255[^/]/%5[0-9]",
+                    sfwd_port, buf, sfwd_host_port) != 3) {
+                        logit("Bad forwarding specification.");
+                        goto out;
+                }
+                if ((fwd_port = a2port(sfwd_port)) == 0 ||
+                    (fwd_host_port = a2port(sfwd_host_port)) == 0) {
+                        logit("Bad forwarding port(s).");
                         goto out;
                 }
-        } else
-                channel_request_remote_forwarding(fwd_port, buf,
-                    fwd_host_port);
-        logit("Forwarding port.");
+                if (local) {
+                        if (channel_setup_local_fwd_listener(fwd_port, buf,
+                            fwd_host_port, options.gateway_ports) < 0) {
+                                logit("Port forwarding failed.");
+                                goto out;
+                        }
+                } else
+                        channel_request_remote_forwarding(fwd_port, buf,
+                            fwd_host_port);
+                logit("Forwarding port.");
+        }
+
 out:
         signal(SIGINT, handler);
         enter_raw_mode();
@@ -873,9 +1135,6 @@ simple_escape_filter(Channel *c, char *buf, int len)
 static void
 client_channel_closed(int id, void *arg)
 {
-        if (id != session_ident)
-                error("client_channel_closed: id %d != session_ident %d",
-                    id, session_ident);
         channel_cancel_cleanup(id);
         session_closed = 1;
         leave_raw_mode();
@@ -893,7 +1152,8 @@ client_loop(int have_pty, int escape_char_arg, int ssh2_chan_id)
 {
         fd_set *readset = NULL, *writeset = NULL;
         double start_time, total_time;
-        int max_fd = 0, max_fd2 = 0, len, rekeying = 0, nalloc = 0;
+        int max_fd = 0, max_fd2 = 0, len, rekeying = 0;
+        u_int nalloc = 0;
         char buf[100];
 
         debug("Entering interactive session.");
@@ -909,6 +1169,8 @@ client_loop(int have_pty, int escape_char_arg, int ssh2_chan_id)
         connection_in = packet_get_connection_in();
         connection_out = packet_get_connection_out();
         max_fd = MAX(connection_in, connection_out);
+        if (control_fd != -1)
+                max_fd = MAX(max_fd, control_fd);
 
         if (!compat20) {
                 /* enable nonblocking unless tty */
@@ -1026,6 +1288,9 @@ client_loop(int have_pty, int escape_char_arg, int ssh2_chan_id)
                 /* Buffer input from the connection.  */
                 client_process_net_input(readset);
 
+                /* Accept control connections.  */
+                client_process_control(readset);
+
                 if (quit_pending)
                         break;
 
@@ -1357,7 +1622,7 @@ static void
 client_input_channel_req(int type, u_int32_t seq, void *ctxt)
 {
         Channel *c = NULL;
-        int id, reply, success = 0;
+        int exitval, id, reply, success = 0;
         char *rtype;
 
         id = packet_get_int();
@@ -1367,24 +1632,28 @@ client_input_channel_req(int type, u_int32_t seq, void *ctxt)
         debug("client_input_channel_req: channel %d rtype %s reply %d",
             id, rtype, reply);
 
-        if (session_ident == -1) {
-                error("client_input_channel_req: no channel %d", session_ident);
-        } else if (id != session_ident) {
-                error("client_input_channel_req: channel %d: wrong channel: %d",
-                    session_ident, id);
-        }
-        c = channel_lookup(id);
-        if (c == NULL) {
+        if (id == -1) {
+                error("client_input_channel_req: request for channel -1");
+        } else if ((c = channel_lookup(id)) == NULL) {
                 error("client_input_channel_req: channel %d: unknown channel", id);
         } else if (strcmp(rtype, "exit-status") == 0) {
-                success = 1;
-                exit_status = packet_get_int();
+                exitval = packet_get_int();
+                if (id == session_ident) {
+                        success = 1;
+                        exit_status = exitval;
+                } else if (c->ctl_fd == -1) {
+                        error("client_input_channel_req: unexpected channel %d",
+                            session_ident);
+                } else {
+                        atomicio(vwrite, c->ctl_fd, &exitval, sizeof(exitval));
+                        success = 1;
+                }
                 packet_check_eom();
         }
         if (reply) {
                 packet_start(success ?
                     SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE);
-                packet_put_int(c->remote_id);
+                packet_put_int(id);
                 packet_send();
         }
         xfree(rtype);
@@ -1409,6 +1678,97 @@ client_input_global_request(int type, u_int32_t seq, void *ctxt)
         xfree(rtype);
 }
 
+void
+client_session2_setup(int id, int want_tty, int want_subsystem,
+    const char *term, struct termios *tiop, int in_fd, Buffer *cmd, char **env,
+    dispatch_fn *subsys_repl)
+{
+        int len;
+
+        debug2("%s: id %d", __func__, id);
+
+        if (want_tty) {
+                struct winsize ws;
+                struct termios tio;
+
+                /* Store window size in the packet. */
+                if (ioctl(in_fd, TIOCGWINSZ, &ws) < 0)
+                        memset(&ws, 0, sizeof(ws));
+
+                channel_request_start(id, "pty-req", 0);
+                packet_put_cstring(term != NULL ? term : "");
+                packet_put_int(ws.ws_col);
+                packet_put_int(ws.ws_row);
+                packet_put_int(ws.ws_xpixel);
+                packet_put_int(ws.ws_ypixel);
+                tio = get_saved_tio();
+                tty_make_modes(-1, tiop != NULL ? tiop : &tio);
+                packet_send();
+                /* XXX wait for reply */
+        }
+
+        /* Transfer any environment variables from client to server */
+        if (options.num_send_env != 0 && env != NULL) {
+                int i, j, matched;
+                char *name, *val;
+
+                debug("Sending environment.");
+                for (i = 0; env[i] != NULL; i++) {
+                        /* Split */
+                        name = xstrdup(env[i]);
+                        if ((val = strchr(name, '=')) == NULL) {
+                                free(name);
+                                continue;
+                        }
+                        *val++ = '\0';
+
+                        matched = 0;
+                        for (j = 0; j < options.num_send_env; j++) {
+                                if (match_pattern(name, options.send_env[j])) {
+                                        matched = 1;
+                                        break;
+                                }
+                        }
+                        if (!matched) {
+                                debug3("Ignored env %s", name);
+                                free(name);
+                                continue;
+                        }
+
+                        debug("Sending env %s = %s", name, val);
+                        channel_request_start(id, "env", 0);
+                        packet_put_cstring(name);
+                        packet_put_cstring(val);
+                        packet_send();
+                        free(name);
+                }
+        }
+
+        len = buffer_len(cmd);
+        if (len > 0) {
+                if (len > 900)
+                        len = 900;
+                if (want_subsystem) {
+                        debug("Sending subsystem: %.*s", len, (u_char*)buffer_ptr(cmd));
+                        channel_request_start(id, "subsystem", subsys_repl != NULL);
+                        if (subsys_repl != NULL) {
+                                /* register callback for reply */
+                                /* XXX we assume that client_loop has already been called */
+                                dispatch_set(SSH2_MSG_CHANNEL_FAILURE, subsys_repl);
+                                dispatch_set(SSH2_MSG_CHANNEL_SUCCESS, subsys_repl);
+                        }
+                } else {
+                        debug("Sending command: %.*s", len, (u_char*)buffer_ptr(cmd));
+                        channel_request_start(id, "exec", 0);
+                }
+                packet_put_string(buffer_ptr(cmd), buffer_len(cmd));
+                packet_send();
+        } else {
+                channel_request_start(id, "shell", 0);
+                packet_send();
+        }
+}
+
 static void
 client_init_dispatch_20(void)
 {
@@ -1475,5 +1835,7 @@ cleanup_exit(int i)
 {
         leave_raw_mode();
         leave_non_blocking();
+        if (options.control_path != NULL && control_fd != -1)
+                unlink(options.control_path);
         _exit(i);
 }