diff options
Diffstat (limited to 'clientloop.c')
| -rw-r--r-- | clientloop.c | 2358 |
1 files changed, 2358 insertions, 0 deletions
diff --git a/clientloop.c b/clientloop.c new file mode 100644 index 0000000..8d312cd --- /dev/null +++ b/clientloop.c @@ -0,0 +1,2358 @@ +/* $OpenBSD: clientloop.c,v 1.318 2018/09/21 12:46:22 djm Exp $ */ +/* + * Author: Tatu Ylonen <ylo@cs.hut.fi> + * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland + * All rights reserved + * The main loop for the interactive session (client side). + * + * As far as I am concerned, the code I have written for this software + * can be used freely for any purpose. Any derived versions of this + * software must be clearly marked as such, and if the derived work is + * incompatible with the protocol description in the RFC file, it must be + * called by a name other than "ssh" or "Secure Shell". + * + * + * Copyright (c) 1999 Theo de Raadt. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR + * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES + * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. + * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT + * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF + * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + * + * + * SSH2 support added by Markus Friedl. + * Copyright (c) 1999, 2000, 2001 Markus Friedl. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR + * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES + * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. + * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT + * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF + * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +#include "includes.h" + +#include <sys/types.h> +#include <sys/ioctl.h> +#ifdef HAVE_SYS_STAT_H +# include <sys/stat.h> +#endif +#ifdef HAVE_SYS_TIME_H +# include <sys/time.h> +#endif +#include <sys/socket.h> + +#include <ctype.h> +#include <errno.h> +#ifdef HAVE_PATHS_H +#include <paths.h> +#endif +#include <signal.h> +#include <stdarg.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <termios.h> +#include <pwd.h> +#include <unistd.h> +#include <limits.h> + +#include "openbsd-compat/sys-queue.h" +#include "xmalloc.h" +#include "ssh.h" +#include "ssh2.h" +#include "packet.h" +#include "sshbuf.h" +#include "compat.h" +#include "channels.h" +#include "dispatch.h" +#include "sshkey.h" +#include "cipher.h" +#include "kex.h" +#include "myproposal.h" +#include "log.h" +#include "misc.h" +#include "readconf.h" +#include "clientloop.h" +#include "sshconnect.h" +#include "authfd.h" +#include "atomicio.h" +#include "sshpty.h" +#include "match.h" +#include "msg.h" +#include "ssherr.h" +#include "hostfile.h" + +/* import options */ +extern Options options; + +/* Flag indicating that stdin should be redirected from /dev/null. */ +extern int stdin_null_flag; + +/* Flag indicating that no shell has been requested */ +extern int no_shell_flag; + +/* Flag indicating that ssh should daemonise after authentication is complete */ +extern int fork_after_authentication_flag; + +/* Control socket */ +extern int muxserver_sock; /* XXX use mux_client_cleanup() instead */ + +/* + * 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 + * configuration file. + */ +extern char *host; + +/* + * Flag to indicate that we have received a window change signal which has + * not yet been processed. This will cause a message indicating the new + * window size to be sent to the server a little later. This is volatile + * because this is updated in a signal handler. + */ +static volatile sig_atomic_t received_window_change_signal = 0; +static volatile sig_atomic_t received_signal = 0; + +/* Flag indicating whether the user's terminal is in non-blocking mode. */ +static int in_non_blocking_mode = 0; + +/* Time when backgrounded control master using ControlPersist should exit */ +static time_t control_persist_exit_time = 0; + +/* Common data for the client loop code. */ +volatile sig_atomic_t quit_pending; /* Set non-zero to quit the loop. */ +static int last_was_cr; /* Last character was a newline. */ +static int exit_status; /* Used to store the command exit status. */ +static struct sshbuf *stderr_buffer; /* Used for final exit message. */ +static int connection_in; /* Connection to server (input). */ +static int connection_out; /* Connection to server (output). */ +static int need_rekeying; /* Set to non-zero if rekeying is requested. */ +static int session_closed; /* In SSH2: login session closed. */ +static u_int x11_refuse_time; /* If >0, refuse x11 opens after this time. */ + +static void client_init_dispatch(void); +int session_ident = -1; + +/* Track escape per proto2 channel */ +struct escape_filter_ctx { + int escape_pending; + int escape_char; +}; + +/* Context for channel confirmation replies */ +struct channel_reply_ctx { + const char *request_type; + int id; + enum confirm_action action; +}; + +/* Global request success/failure callbacks */ +/* XXX move to struct ssh? */ +struct global_confirm { + TAILQ_ENTRY(global_confirm) entry; + global_confirm_cb *cb; + void *ctx; + int ref_count; +}; +TAILQ_HEAD(global_confirms, global_confirm); +static struct global_confirms global_confirms = + TAILQ_HEAD_INITIALIZER(global_confirms); + +void ssh_process_session2_setup(int, int, int, struct sshbuf *); + +/* Restores stdin to blocking mode. */ + +static void +leave_non_blocking(void) +{ + if (in_non_blocking_mode) { + unset_nonblock(fileno(stdin)); + in_non_blocking_mode = 0; + } +} + +/* + * Signal handler for the window change signal (SIGWINCH). This just sets a + * flag indicating that the window has changed. + */ +/*ARGSUSED */ +static void +window_change_handler(int sig) +{ + received_window_change_signal = 1; +} + +/* + * Signal handler for signals that cause the program to terminate. These + * signals must be trapped to restore terminal modes. + */ +/*ARGSUSED */ +static void +signal_handler(int sig) +{ + received_signal = sig; + quit_pending = 1; +} + +/* + * Sets control_persist_exit_time to the absolute time when the + * backgrounded control master should exit due to expiry of the + * ControlPersist timeout. Sets it to 0 if we are not a backgrounded + * control master process, or if there is no ControlPersist timeout. + */ +static void +set_control_persist_exit_time(struct ssh *ssh) +{ + if (muxserver_sock == -1 || !options.control_persist + || options.control_persist_timeout == 0) { + /* not using a ControlPersist timeout */ + control_persist_exit_time = 0; + } else if (channel_still_open(ssh)) { + /* some client connections are still open */ + if (control_persist_exit_time > 0) + debug2("%s: cancel scheduled exit", __func__); + control_persist_exit_time = 0; + } else if (control_persist_exit_time <= 0) { + /* a client connection has recently closed */ + control_persist_exit_time = monotime() + + (time_t)options.control_persist_timeout; + debug2("%s: schedule exit in %d seconds", __func__, + options.control_persist_timeout); + } + /* else we are already counting down to the timeout */ +} + +#define SSH_X11_VALID_DISPLAY_CHARS ":/.-_" +static int +client_x11_display_valid(const char *display) +{ + size_t i, dlen; + + if (display == NULL) + return 0; + + dlen = strlen(display); + for (i = 0; i < dlen; i++) { + if (!isalnum((u_char)display[i]) && + strchr(SSH_X11_VALID_DISPLAY_CHARS, display[i]) == NULL) { + debug("Invalid character '%c' in DISPLAY", display[i]); + return 0; + } + } + return 1; +} + +#define SSH_X11_PROTO "MIT-MAGIC-COOKIE-1" +#define X11_TIMEOUT_SLACK 60 +int +client_x11_get_proto(struct ssh *ssh, const char *display, + const char *xauth_path, u_int trusted, u_int timeout, + char **_proto, char **_data) +{ + char *cmd, line[512], xdisplay[512]; + char xauthfile[PATH_MAX], xauthdir[PATH_MAX]; + static char proto[512], data[512]; + FILE *f; + int got_data = 0, generated = 0, do_unlink = 0, r; + struct stat st; + u_int now, x11_timeout_real; + + *_proto = proto; + *_data = data; + proto[0] = data[0] = xauthfile[0] = xauthdir[0] = '\0'; + + if (!client_x11_display_valid(display)) { + if (display != NULL) + logit("DISPLAY \"%s\" invalid; disabling X11 forwarding", + display); + return -1; + } + if (xauth_path != NULL && stat(xauth_path, &st) == -1) { + debug("No xauth program."); + xauth_path = NULL; + } + + if (xauth_path != NULL) { + /* + * 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) { + if ((r = snprintf(xdisplay, sizeof(xdisplay), "unix:%s", + display + 10)) < 0 || + (size_t)r >= sizeof(xdisplay)) { + error("%s: display name too long", __func__); + return -1; + } + display = xdisplay; + } + if (trusted == 0) { + /* + * Generate an untrusted X11 auth cookie. + * + * The authentication cookie should briefly outlive + * ssh's willingness to forward X11 connections to + * avoid nasty fail-open behaviour in the X server. + */ + mktemp_proto(xauthdir, sizeof(xauthdir)); + if (mkdtemp(xauthdir) == NULL) { + error("%s: mkdtemp: %s", + __func__, strerror(errno)); + return -1; + } + do_unlink = 1; + if ((r = snprintf(xauthfile, sizeof(xauthfile), + "%s/xauthfile", xauthdir)) < 0 || + (size_t)r >= sizeof(xauthfile)) { + error("%s: xauthfile path too long", __func__); + unlink(xauthfile); + rmdir(xauthdir); + return -1; + } + + if (timeout == 0) { + /* auth doesn't time out */ + xasprintf(&cmd, "%s -f %s generate %s %s " + "untrusted 2>%s", + xauth_path, xauthfile, display, + SSH_X11_PROTO, _PATH_DEVNULL); + } else { + /* Add some slack to requested expiry */ + if (timeout < UINT_MAX - X11_TIMEOUT_SLACK) + x11_timeout_real = timeout + + X11_TIMEOUT_SLACK; + else { + /* Don't overflow on long timeouts */ + x11_timeout_real = UINT_MAX; + } + xasprintf(&cmd, "%s -f %s generate %s %s " + "untrusted timeout %u 2>%s", + xauth_path, xauthfile, display, + SSH_X11_PROTO, x11_timeout_real, + _PATH_DEVNULL); + } + debug2("%s: %s", __func__, cmd); + + if (timeout != 0 && x11_refuse_time == 0) { + now = monotime() + 1; + if (UINT_MAX - timeout < now) + x11_refuse_time = UINT_MAX; + else + x11_refuse_time = now + timeout; + channel_set_x11_refuse_time(ssh, + x11_refuse_time); + } + if (system(cmd) == 0) + generated = 1; + free(cmd); + } + + /* + * When in untrusted mode, we read the cookie only if it was + * successfully generated as an untrusted one in the step + * above. + */ + if (trusted || generated) { + xasprintf(&cmd, + "%s %s%s list %s 2>" _PATH_DEVNULL, + xauth_path, + 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); + free(cmd); + } + } + + if (do_unlink) { + unlink(xauthfile); + rmdir(xauthdir); + } + + /* Don't fall back to fake X11 data for untrusted forwarding */ + if (!trusted && !got_data) { + error("Warning: untrusted X11 forwarding setup failed: " + "xauth key data not generated"); + return -1; + } + + /* + * 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_int8_t rnd[16]; + u_int i; + + logit("Warning: No xauth data; " + "using fake authentication data for X11 forwarding."); + strlcpy(proto, SSH_X11_PROTO, sizeof proto); + arc4random_buf(rnd, sizeof(rnd)); + for (i = 0; i < sizeof(rnd); i++) { + snprintf(data + 2 * i, sizeof data - 2 * i, "%02x", + rnd[i]); + } + } + + return 0; +} + +/* + * Checks if the client window has changed, and sends a packet about it to + * the server if so. The actual change is detected elsewhere (by a software + * interrupt on Unix); this just checks the flag and sends a message if + * appropriate. + */ + +static void +client_check_window_change(struct ssh *ssh) +{ + if (!received_window_change_signal) + return; + /** XXX race */ + received_window_change_signal = 0; + + debug2("%s: changed", __func__); + + channel_send_window_changes(ssh); +} + +static int +client_global_request_reply(int type, u_int32_t seq, struct ssh *ssh) +{ + struct global_confirm *gc; + + if ((gc = TAILQ_FIRST(&global_confirms)) == NULL) + return 0; + if (gc->cb != NULL) + gc->cb(ssh, type, seq, gc->ctx); + if (--gc->ref_count <= 0) { + TAILQ_REMOVE(&global_confirms, gc, entry); + explicit_bzero(gc, sizeof(*gc)); + free(gc); + } + + packet_set_alive_timeouts(0); + return 0; +} + +static void +server_alive_check(void) +{ + if (packet_inc_alive_timeouts() > options.server_alive_count_max) { + logit("Timeout, server %s not responding.", host); + cleanup_exit(255); + } + packet_start(SSH2_MSG_GLOBAL_REQUEST); + packet_put_cstring("keepalive@openssh.com"); + packet_put_char(1); /* boolean: want reply */ + packet_send(); + /* Insert an empty placeholder to maintain ordering */ + client_register_global_confirm(NULL, NULL); +} + +/* + * 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(struct ssh *ssh, + fd_set **readsetp, fd_set **writesetp, + int *maxfdp, u_int *nallocp, int rekeying) +{ + struct timeval tv, *tvp; + int timeout_secs; + time_t minwait_secs = 0, server_alive_time = 0, now = monotime(); + int r, ret; + + /* Add any selections by the channel mechanism. */ + channel_prepare_select(active_state, readsetp, writesetp, maxfdp, + nallocp, &minwait_secs); + + /* channel_prepare_select could have closed the last channel */ + if (session_closed && !channel_still_open(ssh) && + !packet_have_data_to_write()) { + /* clear mask since we did not call select() */ + memset(*readsetp, 0, *nallocp); + memset(*writesetp, 0, *nallocp); + return; + } + + FD_SET(connection_in, *readsetp); + + /* Select server connection if have data to write to the server. */ + if (packet_have_data_to_write()) + FD_SET(connection_out, *writesetp); + + /* + * Wait for something to happen. This will suspend the process until + * some selected descriptor can be read, written, or has some other + * event pending, or a timeout expires. + */ + + timeout_secs = INT_MAX; /* we use INT_MAX to mean no timeout */ + if (options.server_alive_interval > 0) { + timeout_secs = options.server_alive_interval; + server_alive_time = now + options.server_alive_interval; + } + if (options.rekey_interval > 0 && !rekeying) + timeout_secs = MINIMUM(timeout_secs, packet_get_rekey_timeout()); + set_control_persist_exit_time(ssh); + if (control_persist_exit_time > 0) { + timeout_secs = MINIMUM(timeout_secs, + control_persist_exit_time - now); + if (timeout_secs < 0) + timeout_secs = 0; + } + if (minwait_secs != 0) + timeout_secs = MINIMUM(timeout_secs, (int)minwait_secs); + if (timeout_secs == INT_MAX) + tvp = NULL; + else { + tv.tv_sec = timeout_secs; + tv.tv_usec = 0; + tvp = &tv; + } + + ret = select((*maxfdp)+1, *readsetp, *writesetp, NULL, tvp); + if (ret < 0) { + /* + * We have to clear the select masks, because we return. + * We have to return, because the mainloop checks for the flags + * set by the signal handlers. + */ + memset(*readsetp, 0, *nallocp); + memset(*writesetp, 0, *nallocp); + + if (errno == EINTR) + return; + /* Note: we might still have data in the buffers. */ + if ((r = sshbuf_putf(stderr_buffer, + "select: %s\r\n", strerror(errno))) != 0) + fatal("%s: buffer error: %s", __func__, ssh_err(r)); + quit_pending = 1; + } else if (ret == 0) { + /* + * Timeout. Could have been either keepalive or rekeying. + * Keepalive we check here, rekeying is checked in clientloop. + */ + if (server_alive_time != 0 && server_alive_time <= monotime()) + server_alive_check(); + } + +} + +static void +client_suspend_self(struct sshbuf *bin, struct sshbuf *bout, struct sshbuf *berr) +{ + /* Flush stdout and stderr buffers. */ + if (sshbuf_len(bout) > 0) + atomicio(vwrite, fileno(stdout), sshbuf_mutable_ptr(bout), + sshbuf_len(bout)); + if (sshbuf_len(berr) > 0) + atomicio(vwrite, fileno(stderr), sshbuf_mutable_ptr(berr), + sshbuf_len(berr)); + + leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE); + + sshbuf_reset(bin); + sshbuf_reset(bout); + sshbuf_reset(berr); + + /* Send the suspend signal to the program itself. */ + kill(getpid(), SIGTSTP); + + /* Reset window sizes in case they have changed */ + received_window_change_signal = 1; + + enter_raw_mode(options.request_tty == REQUEST_TTY_FORCE); +} + +static void +client_process_net_input(fd_set *readset) +{ + char buf[SSH_IOBUFSZ]; + int r, len; + + /* + * Read input from the server, and add any such data to the buffer of + * the packet subsystem. + */ + if (FD_ISSET(connection_in, readset)) { + /* Read as much as possible. */ + len = read(connection_in, buf, sizeof(buf)); + if (len == 0) { + /* + * Received EOF. The remote host has closed the + * connection. + */ + if ((r = sshbuf_putf(stderr_buffer, + "Connection to %.300s closed by remote host.\r\n", + host)) != 0) + fatal("%s: buffer error: %s", + __func__, ssh_err(r)); + quit_pending = 1; + return; + } + /* + * There is a kernel bug on Solaris that causes select to + * sometimes wake up even though there is no data available. + */ + if (len < 0 && + (errno == EAGAIN || errno == EINTR || errno == EWOULDBLOCK)) + len = 0; + + if (len < 0) { + /* + * An error has encountered. Perhaps there is a + * network problem. + */ + if ((r = sshbuf_putf(stderr_buffer, + "Read from remote host %.300s: %.100s\r\n", + host, strerror(errno))) != 0) + fatal("%s: buffer error: %s", + __func__, ssh_err(r)); + quit_pending = 1; + return; + } + packet_process_incoming(buf, len); + } +} + +static void +client_status_confirm(struct ssh *ssh, int type, Channel *c, void *ctx) +{ + struct channel_reply_ctx *cr = (struct channel_reply_ctx *)ctx; + char errmsg[256]; + int r, tochan; + + /* + * If a TTY was explicitly requested, then a failure to allocate + * one is fatal. + */ + if (cr->action == CONFIRM_TTY && + (options.request_tty == REQUEST_TTY_FORCE || + options.request_tty == REQUEST_TTY_YES)) + cr->action = CONFIRM_CLOSE; + + /* XXX suppress on mux _client_ quietmode */ + tochan = options.log_level >= SYSLOG_LEVEL_ERROR && + c->ctl_chan != -1 && c->extended_usage == CHAN_EXTENDED_WRITE; + + if (type == SSH2_MSG_CHANNEL_SUCCESS) { + debug2("%s request accepted on channel %d", + cr->request_type, c->self); + } else if (type == SSH2_MSG_CHANNEL_FAILURE) { + if (tochan) { + snprintf(errmsg, sizeof(errmsg), + "%s request failed\r\n", cr->request_type); + } else { + snprintf(errmsg, sizeof(errmsg), + "%s request failed on channel %d", + cr->request_type, c->self); + } + /* If error occurred on primary session channel, then exit */ + if (cr->action == CONFIRM_CLOSE && c->self == session_ident) + fatal("%s", errmsg); + /* + * If error occurred on mux client, append to + * their stderr. + */ + if (tochan) { + if ((r = sshbuf_put(c->extended, errmsg, + strlen(errmsg))) != 0) + fatal("%s: buffer error %s", __func__, + ssh_err(r)); + } else + error("%s", errmsg); + if (cr->action == CONFIRM_TTY) { + /* + * If a TTY allocation error occurred, then arrange + * for the correct TTY to leave raw mode. + */ + if (c->self == session_ident) + leave_raw_mode(0); + else + mux_tty_alloc_failed(ssh, c); + } else if (cr->action == CONFIRM_CLOSE) { + chan_read_failed(ssh, c); + chan_write_failed(ssh, c); + } + } + free(cr); +} + +static void +client_abandon_status_confirm(struct ssh *ssh, Channel *c, void *ctx) +{ + free(ctx); +} + +void +client_expect_confirm(struct ssh *ssh, int id, const char *request, + enum confirm_action action) +{ + struct channel_reply_ctx *cr = xcalloc(1, sizeof(*cr)); + + cr->request_type = request; + cr->action = action; + + channel_register_status_confirm(ssh, id, client_status_confirm, + client_abandon_status_confirm, cr); +} + +void +client_register_global_confirm(global_confirm_cb *cb, void *ctx) +{ + struct global_confirm *gc, *last_gc; + + /* Coalesce identical callbacks */ + last_gc = TAILQ_LAST(&global_confirms, global_confirms); + if (last_gc && last_gc->cb == cb && last_gc->ctx == ctx) { + if (++last_gc->ref_count >= INT_MAX) + fatal("%s: last_gc->ref_count = %d", + __func__, last_gc->ref_count); + return; + } + + gc = xcalloc(1, sizeof(*gc)); + gc->cb = cb; + gc->ctx = ctx; + gc->ref_count = 1; + TAILQ_INSERT_TAIL(&global_confirms, gc, entry); +} + +static void +process_cmdline(struct ssh *ssh) +{ + void (*handler)(int); + char *s, *cmd; + int ok, delete = 0, local = 0, remote = 0, dynamic = 0; + struct Forward fwd; + + memset(&fwd, 0, sizeof(fwd)); + + leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE); + handler = signal(SIGINT, SIG_IGN); + cmd = s = read_passphrase("\r\nssh> ", RP_ECHO); + if (s == NULL) + goto out; + while (isspace((u_char)*s)) + s++; + if (*s == '-') + s++; /* Skip cmdline '-', if any */ + if (*s == '\0') + goto out; + + if (*s == 'h' || *s == 'H' || *s == '?') { + logit("Commands:"); + logit(" -L[bind_address:]port:host:hostport " + "Request local forward"); + logit(" -R[bind_address:]port:host:hostport " + "Request remote forward"); + logit(" -D[bind_address:]port " + "Request dynamic forward"); + logit(" -KL[bind_address:]port " + "Cancel local forward"); + logit(" -KR[bind_address:]port " + "Cancel remote forward"); + logit(" -KD[bind_address:]port " + "Cancel dynamic forward"); + if (!options.permit_local_command) + goto out; + logit(" !args " + "Execute local command"); + goto out; + } + + if (*s == '!' && options.permit_local_command) { + s++; + ssh_local_cmd(s); + goto out; + } + + if (*s == 'K') { + delete = 1; + s++; + } + if (*s == 'L') + local = 1; + else if (*s == 'R') + remote = 1; + else if (*s == 'D') + dynamic = 1; + else { + logit("Invalid command."); + goto out; + } + + while (isspace((u_char)*++s)) + ; + + /* XXX update list of forwards in options */ + if (delete) { + /* We pass 1 for dynamicfwd to restrict to 1 or 2 fields. */ + if (!parse_forward(&fwd, s, 1, 0)) { + logit("Bad forwarding close specification."); + goto out; + } + if (remote) + ok = channel_request_rforward_cancel(ssh, &fwd) == 0; + else if (dynamic) + ok = channel_cancel_lport_listener(ssh, &fwd, + 0, &options.fwd_opts) > 0; + else + ok = channel_cancel_lport_listener(ssh, &fwd, + CHANNEL_CANCEL_PORT_STATIC, + &options.fwd_opts) > 0; + if (!ok) { + logit("Unknown port forwarding."); + goto out; + } + logit("Canceled forwarding."); + } else { + if (!parse_forward(&fwd, s, dynamic, remote)) { + logit("Bad forwarding specification."); + goto out; + } + if (local || dynamic) { + if (!channel_setup_local_fwd_listener(ssh, &fwd, + &options.fwd_opts)) { + logit("Port forwarding failed."); + goto out; + } + } else { + if (channel_request_remote_forwarding(ssh, &fwd) < 0) { + logit("Port forwarding failed."); + goto out; + } + } + logit("Forwarding port."); + } + +out: + signal(SIGINT, handler); + enter_raw_mode(options.request_tty == REQUEST_TTY_FORCE); + free(cmd); + free(fwd.listen_host); + free(fwd.listen_path); + free(fwd.connect_host); + free(fwd.connect_path); +} + +/* reasons to suppress output of an escape command in help output */ +#define SUPPRESS_NEVER 0 /* never suppress, always show */ +#define SUPPRESS_MUXCLIENT 1 /* don't show in mux client sessions */ +#define SUPPRESS_MUXMASTER 2 /* don't show in mux master sessions */ +#define SUPPRESS_SYSLOG 4 /* don't show when logging to syslog */ +struct escape_help_text { + const char *cmd; + const char *text; + unsigned int flags; +}; +static struct escape_help_text esc_txt[] = { + {".", "terminate session", SUPPRESS_MUXMASTER}, + {".", "terminate connection (and any multiplexed sessions)", + SUPPRESS_MUXCLIENT}, + {"B", "send a BREAK to the remote system", SUPPRESS_NEVER}, + {"C", "open a command line", SUPPRESS_MUXCLIENT}, + {"R", "request rekey", SUPPRESS_NEVER}, + {"V/v", "decrease/increase verbosity (LogLevel)", SUPPRESS_MUXCLIENT}, + {"^Z", "suspend ssh", SUPPRESS_MUXCLIENT}, + {"#", "list forwarded connections", SUPPRESS_NEVER}, + {"&", "background ssh (when waiting for connections to terminate)", + SUPPRESS_MUXCLIENT}, + {"?", "this message", SUPPRESS_NEVER}, +}; + +static void +print_escape_help(struct sshbuf *b, int escape_char, int mux_client, + int using_stderr) +{ + unsigned int i, suppress_flags; + int r; + + if ((r = sshbuf_putf(b, + "%c?\r\nSupported escape sequences:\r\n", escape_char)) != 0) + fatal("%s: buffer error: %s", __func__, ssh_err(r)); + + suppress_flags = + (mux_client ? SUPPRESS_MUXCLIENT : 0) | + (mux_client ? 0 : SUPPRESS_MUXMASTER) | + (using_stderr ? 0 : SUPPRESS_SYSLOG); + + for (i = 0; i < sizeof(esc_txt)/sizeof(esc_txt[0]); i++) { + if (esc_txt[i].flags & suppress_flags) + continue; + if ((r = sshbuf_putf(b, " %c%-3s - %s\r\n", + escape_char, esc_txt[i].cmd, esc_txt[i].text)) != 0) + fatal("%s: buffer error: %s", __func__, ssh_err(r)); + } + + if ((r = sshbuf_putf(b, + " %c%c - send the escape character by typing it twice\r\n" + "(Note that escapes are only recognized immediately after " + "newline.)\r\n", escape_char, escape_char)) != 0) + fatal("%s: buffer error: %s", __func__, ssh_err(r)); +} + +/* + * Process the characters one by one. + */ +static int +process_escapes(struct ssh *ssh, Channel *c, + struct sshbuf *bin, struct sshbuf *bout, struct sshbuf *berr, + char *buf, int len) +{ + pid_t pid; + int r, bytes = 0; + u_int i; + u_char ch; + char *s; + struct escape_filter_ctx *efc = c->filter_ctx == NULL ? + NULL : (struct escape_filter_ctx *)c->filter_ctx; + + if (c->filter_ctx == NULL) + return 0; + + if (len <= 0) + return (0); + + for (i = 0; i < (u_int)len; i++) { + /* Get one character at a time. */ + ch = buf[i]; + + if (efc->escape_pending) { + /* We have previously seen an escape character. */ + /* Clear the flag now. */ + efc->escape_pending = 0; + + /* Process the escaped character. */ + switch (ch) { + case '.': + /* Terminate the connection. */ + if ((r = sshbuf_putf(berr, "%c.\r\n", + efc->escape_char)) != 0) + fatal("%s: buffer error: %s", + __func__, ssh_err(r)); + if (c && c->ctl_chan != -1) { + chan_read_failed(ssh, c); + chan_write_failed(ssh, c); + if (c->detach_user) { + c->detach_user(ssh, + c->self, NULL); + } + c->type = SSH_CHANNEL_ABANDONED; + sshbuf_reset(c->input); + chan_ibuf_empty(ssh, c); + return 0; + } else + quit_pending = 1; + return -1; + + case 'Z' - 64: + /* XXX support this for mux clients */ + if (c && c->ctl_chan != -1) { + char b[16]; + noescape: + if (ch == 'Z' - 64) + snprintf(b, sizeof b, "^Z"); + else + snprintf(b, sizeof b, "%c", ch); + if ((r = sshbuf_putf(berr, + "%c%s escape not available to " + "multiplexed sessions\r\n", + efc->escape_char, b)) != 0) + fatal("%s: buffer error: %s", + __func__, ssh_err(r)); + continue; + } + /* Suspend the program. Inform the user */ + if ((r = sshbuf_putf(berr, + "%c^Z [suspend ssh]\r\n", + efc->escape_char)) != 0) + fatal("%s: buffer error: %s", + __func__, ssh_err(r)); + + /* Restore terminal modes and suspend. */ + client_suspend_self(bin, bout, berr); + + /* We have been continued. */ + continue; + + case 'B': + if ((r = sshbuf_putf(berr, + "%cB\r\n", efc->escape_char)) != 0) + fatal("%s: buffer error: %s", + __func__, ssh_err(r)); + channel_request_start(ssh, c->self, "break", 0); + if ((r = sshpkt_put_u32(ssh, 1000)) != 0 || + (r = sshpkt_send(ssh)) != 0) + fatal("%s: %s", __func__, + ssh_err(r)); + continue; + + case 'R': + if (datafellows & SSH_BUG_NOREKEY) + logit("Server does not " + "support re-keying"); + else + need_rekeying = 1; + continue; + + case 'V': + /* FALLTHROUGH */ + case 'v': + if (c && c->ctl_chan != -1) + goto noescape; + if (!log_is_on_stderr()) { + if ((r = sshbuf_putf(berr, + "%c%c [Logging to syslog]\r\n", + efc->escape_char, ch)) != 0) + fatal("%s: buffer error: %s", + __func__, ssh_err(r)); + continue; + } + if (ch == 'V' && options.log_level > + SYSLOG_LEVEL_QUIET) + log_change_level(--options.log_level); + if (ch == 'v' && options.log_level < + SYSLOG_LEVEL_DEBUG3) + log_change_level(++options.log_level); + if ((r = sshbuf_putf(berr, + "%c%c [LogLevel %s]\r\n", + efc->escape_char, ch, + log_level_name(options.log_level))) != 0) + fatal("%s: buffer error: %s", + __func__, ssh_err(r)); + continue; + + case '&': + if (c && c->ctl_chan != -1) + goto noescape; + /* + * Detach the program (continue to serve + * connections, but put in background and no + * more new connections). + */ + /* Restore tty modes. */ + leave_raw_mode( + options.request_tty == REQUEST_TTY_FORCE); + + /* Stop listening for new connections. */ + channel_stop_listening(ssh); + + if ((r = sshbuf_putf(berr, + "%c& [backgrounded]\n", efc->escape_char)) + != 0) + fatal("%s: buffer error: %s", + __func__, ssh_err(r)); + + /* Fork into background. */ + pid = fork(); + if (pid < 0) { + error("fork: %.100s", strerror(errno)); + continue; + } + if (pid != 0) { /* This is the parent. */ + /* The parent just exits. */ + exit(0); + } + /* The child continues serving connections. */ + /* fake EOF on stdin */ + if ((r = sshbuf_put_u8(bin, 4)) != 0) + fatal("%s: buffer error: %s", + __func__, ssh_err(r)); + return -1; + case '?': + print_escape_help(berr, efc->escape_char, + (c && c->ctl_chan != -1), + log_is_on_stderr()); + continue; + + case '#': + if ((r = sshbuf_putf(berr, "%c#\r\n", + efc->escape_char)) != 0) + fatal("%s: buffer error: %s", + __func__, ssh_err(r)); + s = channel_open_message(ssh); + if ((r = sshbuf_put(berr, s, strlen(s))) != 0) + fatal("%s: buffer error: %s", + __func__, ssh_err(r)); + free(s); + continue; + + case 'C': + if (c && c->ctl_chan != -1) + goto noescape; + process_cmdline(ssh); + continue; + + default: + if (ch != efc->escape_char) { + if ((r = sshbuf_put_u8(bin, + efc->escape_char)) != 0) + fatal("%s: buffer error: %s", + __func__, ssh_err(r)); + bytes++; + } + /* Escaped characters fall through here */ + break; + } + } else { + /* + * The previous character was not an escape char. + * Check if this is an escape. + */ + if (last_was_cr && ch == efc->escape_char) { + /* + * It is. Set the flag and continue to + * next character. + */ + efc->escape_pending = 1; + continue; + } + } + + /* + * Normal character. Record whether it was a newline, + * and append it to the buffer. + */ + last_was_cr = (ch == '\r' || ch == '\n'); + if ((r = sshbuf_put_u8(bin, ch)) != 0) + fatal("%s: buffer error: %s", __func__, ssh_err(r)); + bytes++; + } + return bytes; +} + +/* + * Get packets from the connection input buffer, and process them as long as + * there are packets available. + * + * Any unknown packets received during the actual + * session cause the session to terminate. This is + * intended to make debugging easier since no + * confirmations are sent. Any compatible protocol + * extensions must be negotiated during the + * preparatory phase. + */ + +static void +client_process_buffered_input_packets(void) +{ + ssh_dispatch_run_fatal(active_state, DISPATCH_NONBLOCK, &quit_pending); +} + +/* scan buf[] for '~' before sending data to the peer */ + +/* Helper: allocate a new escape_filter_ctx and fill in its escape char */ +void * +client_new_escape_filter_ctx(int escape_char) +{ + struct escape_filter_ctx *ret; + + ret = xcalloc(1, sizeof(*ret)); + ret->escape_pending = 0; + ret->escape_char = escape_char; + return (void *)ret; +} + +/* Free the escape filter context on channel free */ +void +client_filter_cleanup(struct ssh *ssh, int cid, void *ctx) +{ + free(ctx); +} + +int +client_simple_escape_filter(struct ssh *ssh, Channel *c, char *buf, int len) +{ + if (c->extended_usage != CHAN_EXTENDED_WRITE) + return 0; + + return process_escapes(ssh, c, c->input, c->output, c->extended, + buf, len); +} + +static void +client_channel_closed(struct ssh *ssh, int id, void *arg) +{ + channel_cancel_cleanup(ssh, id); + session_closed = 1; + leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE); +} + +/* + * Implements the interactive session with the server. This is called after + * the user has been authenticated, and a command has been started on the + * remote host. If escape_char != SSH_ESCAPECHAR_NONE, it is the character + * used as an escape character for terminating or suspending the session. + */ +int +client_loop(struct ssh *ssh, int have_pty, int escape_char_arg, + int ssh2_chan_id) +{ + fd_set *readset = NULL, *writeset = NULL; + double start_time, total_time; + int r, max_fd = 0, max_fd2 = 0, len; + u_int64_t ibytes, obytes; + u_int nalloc = 0; + char buf[100]; + + debug("Entering interactive session."); + + if (options.control_master && + !option_clear_or_none(options.control_path)) { + debug("pledge: id"); + if (pledge("stdio rpath wpath cpath unix inet dns recvfd proc exec id tty", + NULL) == -1) + fatal("%s pledge(): %s", __func__, strerror(errno)); + + } else if (options.forward_x11 || options.permit_local_command) { + debug("pledge: exec"); + if (pledge("stdio rpath wpath cpath unix inet dns proc exec tty", + NULL) == -1) + fatal("%s pledge(): %s", __func__, strerror(errno)); + + } else if (options.update_hostkeys) { + debug("pledge: filesystem full"); + if (pledge("stdio rpath wpath cpath unix inet dns proc tty", + NULL) == -1) + fatal("%s pledge(): %s", __func__, strerror(errno)); + + } else if (!option_clear_or_none(options.proxy_command) || + fork_after_authentication_flag) { + debug("pledge: proc"); + if (pledge("stdio cpath unix inet dns proc tty", NULL) == -1) + fatal("%s pledge(): %s", __func__, strerror(errno)); + + } else { + debug("pledge: network"); + if (pledge("stdio unix inet dns proc tty", NULL) == -1) + fatal("%s pledge(): %s", __func__, strerror(errno)); + } + + start_time = monotime_double(); + + /* Initialize variables. */ + last_was_cr = 1; + exit_status = -1; + connection_in = packet_get_connection_in(); + connection_out = packet_get_connection_out(); + max_fd = MAXIMUM(connection_in, connection_out); + + quit_pending = 0; + + /* Initialize buffer. */ + if ((stderr_buffer = sshbuf_new()) == NULL) + fatal("%s: sshbuf_new failed", __func__); + + client_init_dispatch(); + + /* + * Set signal handlers, (e.g. to restore non-blocking mode) + * but don't overwrite SIG_IGN, matches behaviour from rsh(1) + */ + if (signal(SIGHUP, SIG_IGN) != SIG_IGN) + signal(SIGHUP, signal_handler); + if (signal(SIGINT, SIG_IGN) != SIG_IGN) + signal(SIGINT, signal_handler); + if (signal(SIGQUIT, SIG_IGN) != SIG_IGN) + signal(SIGQUIT, signal_handler); + if (signal(SIGTERM, SIG_IGN) != SIG_IGN) + signal(SIGTERM, signal_handler); + signal(SIGWINCH, window_change_handler); + + if (have_pty) + enter_raw_mode(options.request_tty == REQUEST_TTY_FORCE); + + session_ident = ssh2_chan_id; + if (session_ident != -1) { + if (escape_char_arg != SSH_ESCAPECHAR_NONE) { + channel_register_filter(ssh, session_ident, + client_simple_escape_filter, NULL, + client_filter_cleanup, + client_new_escape_filter_ctx( + escape_char_arg)); + } + channel_register_cleanup(ssh, session_ident, + client_channel_closed, 0); + } + + /* Main loop of the client for the interactive session mode. */ + while (!quit_pending) { + + /* Process buffered packets sent by the server. */ + client_process_buffered_input_packets(); + + if (session_closed && !channel_still_open(ssh)) + break; + + if (ssh_packet_is_rekeying(ssh)) { + debug("rekeying in progress"); + } else if (need_rekeying) { + /* manual rekey request */ + debug("need rekeying"); + if ((r = kex_start_rekex(ssh)) != 0) + fatal("%s: kex_start_rekex: %s", __func__, + ssh_err(r)); + need_rekeying = 0; + } else { + /* + * Make packets from buffered channel data, and + * enqueue them for sending to the server. + */ + if (packet_not_very_much_data_to_write()) + channel_output_poll(ssh); + + /* + * Check if the window size has changed, and buffer a + * message about it to the server if so. + */ + client_check_window_change(ssh); + + if (quit_pending) + break; + } + /* + * Wait until we have something to do (something becomes + * available on one of the descriptors). + */ + max_fd2 = max_fd; + client_wait_until_can_do_something(ssh, &readset, &writeset, + &max_fd2, &nalloc, ssh_packet_is_rekeying(ssh)); + + if (quit_pending) + break; + + /* Do channel operations unless rekeying in progress. */ + if (!ssh_packet_is_rekeying(ssh)) + channel_after_select(ssh, readset, writeset); + + /* Buffer input from the connection. */ + client_process_net_input(readset); + + if (quit_pending) + break; + + /* + * Send as much buffered packet data as possible to the + * sender. + */ + if (FD_ISSET(connection_out, writeset)) + packet_write_poll(); + + /* + * If we are a backgrounded control master, and the + * timeout has expired without any active client + * connections, then quit. + */ + if (control_persist_exit_time > 0) { + if (monotime() >= control_persist_exit_time) { + debug("ControlPersist timeout expired"); + break; + } + } + } + free(readset); + free(writeset); + + /* Terminate the session. */ + + /* Stop watching for window change. */ + signal(SIGWINCH, SIG_DFL); + + packet_start(SSH2_MSG_DISCONNECT); + packet_put_int(SSH2_DISCONNECT_BY_APPLICATION); + packet_put_cstring("disconnected by user"); + packet_put_cstring(""); /* language tag */ + packet_send(); + packet_write_wait(); + + channel_free_all(ssh); + + if (have_pty) + leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE); + + /* restore blocking io */ + if (!isatty(fileno(stdin))) + unset_nonblock(fileno(stdin)); + if (!isatty(fileno(stdout))) + unset_nonblock(fileno(stdout)); + if (!isatty(fileno(stderr))) + unset_nonblock(fileno(stderr)); + + /* + * If there was no shell or command requested, there will be no remote + * exit status to be returned. In that case, clear error code if the + * connection was deliberately terminated at this end. + */ + if (no_shell_flag && received_signal == SIGTERM) { + received_signal = 0; + exit_status = 0; + } + + if (received_signal) { + verbose("Killed by signal %d.", (int) received_signal); + cleanup_exit(0); + } + + /* + * In interactive mode (with pseudo tty) display a message indicating + * that the connection has been closed. + */ + if (have_pty && options.log_level != SYSLOG_LEVEL_QUIET) { + if ((r = sshbuf_putf(stderr_buffer, + "Connection to %.64s closed.\r\n", host)) != 0) + fatal("%s: buffer error: %s", __func__, ssh_err(r)); + } + + /* Output any buffered data for stderr. */ + if (sshbuf_len(stderr_buffer) > 0) { + len = atomicio(vwrite, fileno(stderr), + (u_char *)sshbuf_ptr(stderr_buffer), + sshbuf_len(stderr_buffer)); + if (len < 0 || (u_int)len != sshbuf_len(stderr_buffer)) + error("Write failed flushing stderr buffer."); + else if ((r = sshbuf_consume(stderr_buffer, len)) != 0) + fatal("%s: buffer error: %s", __func__, ssh_err(r)); + } + + /* Clear and free any buffers. */ + explicit_bzero(buf, sizeof(buf)); + sshbuf_free(stderr_buffer); + + /* Report bytes transferred, and transfer rates. */ + total_time = monotime_double() - start_time; + packet_get_bytes(&ibytes, &obytes); + verbose("Transferred: sent %llu, received %llu bytes, in %.1f seconds", + (unsigned long long)obytes, (unsigned long long)ibytes, total_time); + if (total_time > 0) + verbose("Bytes per second: sent %.1f, received %.1f", + obytes / total_time, ibytes / total_time); + /* Return the exit status of the program. */ + debug("Exit status %d", exit_status); + return exit_status; +} + +/*********/ + +static Channel * +client_request_forwarded_tcpip(struct ssh *ssh, const char *request_type, + int rchan, u_int rwindow, u_int rmaxpack) +{ + Channel *c = NULL; + struct sshbuf *b = NULL; + char *listen_address, *originator_address; + u_short listen_port, originator_port; + int r; + + /* Get rest of the packet */ + listen_address = packet_get_string(NULL); + listen_port = packet_get_int(); + originator_address = packet_get_string(NULL); + originator_port = packet_get_int(); + packet_check_eom(); + + debug("%s: listen %s port %d, originator %s port %d", __func__, + listen_address, listen_port, originator_address, originator_port); + + c = channel_connect_by_listen_address(ssh, listen_address, listen_port, + "forwarded-tcpip", originator_address); + + if (c != NULL && c->type == SSH_CHANNEL_MUX_CLIENT) { + if ((b = sshbuf_new()) == NULL) { + error("%s: alloc reply", __func__); + goto out; + } + /* reconstruct and send to muxclient */ + if ((r = sshbuf_put_u8(b, 0)) != 0 || /* padlen */ + (r = sshbuf_put_u8(b, SSH2_MSG_CHANNEL_OPEN)) != 0 || + (r = sshbuf_put_cstring(b, request_type)) != 0 || + (r = sshbuf_put_u32(b, rchan)) != 0 || + (r = sshbuf_put_u32(b, rwindow)) != 0 || + (r = sshbuf_put_u32(b, rmaxpack)) != 0 || + (r = sshbuf_put_cstring(b, listen_address)) != 0 || + (r = sshbuf_put_u32(b, listen_port)) != 0 || + (r = sshbuf_put_cstring(b, originator_address)) != 0 || + (r = sshbuf_put_u32(b, originator_port)) != 0 || + (r = sshbuf_put_stringb(c->output, b)) != 0) { + error("%s: compose for muxclient %s", __func__, + ssh_err(r)); + goto out; + } + } + + out: + sshbuf_free(b); + free(originator_address); + free(listen_address); + return c; +} + +static Channel * +client_request_forwarded_streamlocal(struct ssh *ssh, + const char *request_type, int rchan) +{ + Channel *c = NULL; + char *listen_path; + + /* Get the remote path. */ + listen_path = packet_get_string(NULL); + /* XXX: Skip reserved field for now. */ + if (packet_get_string_ptr(NULL) == NULL) + fatal("%s: packet_get_string_ptr failed", __func__); + packet_check_eom(); + + debug("%s: %s", __func__, listen_path); + + c = channel_connect_by_listen_path(ssh, listen_path, + "forwarded-streamlocal@openssh.com", "forwarded-streamlocal"); + free(listen_path); + return c; +} + +static Channel * +client_request_x11(struct ssh *ssh, const char *request_type, int rchan) +{ + Channel *c = NULL; + char *originator; + u_short originator_port; + int sock; + + if (!options.forward_x11) { + error("Warning: ssh server tried X11 forwarding."); + error("Warning: this is probably a break-in attempt by a " + "malicious server."); + return NULL; + } + if (x11_refuse_time != 0 && (u_int)monotime() >= x11_refuse_time) { + verbose("Rejected X11 connection after ForwardX11Timeout " + "expired"); + return NULL; + } + originator = packet_get_string(NULL); + originator_port = packet_get_int(); + packet_check_eom(); + /* XXX check permission */ + debug("client_request_x11: request from %s %d", originator, + originator_port); + free(originator); + sock = x11_connect_display(ssh); + if (sock < 0) + return NULL; + c = channel_new(ssh, "x11", + SSH_CHANNEL_X11_OPEN, sock, sock, -1, + CHAN_TCP_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT, 0, "x11", 1); + c->force_drain = 1; + return c; +} + +static Channel * +client_request_agent(struct ssh *ssh, const char *request_type, int rchan) +{ + Channel *c = NULL; + int r, sock; + + if (!options.forward_agent) { + error("Warning: ssh server tried agent forwarding."); + error("Warning: this is probably a break-in attempt by a " + "malicious server."); + return NULL; + } + if ((r = ssh_get_authentication_socket(&sock)) != 0) { + if (r != SSH_ERR_AGENT_NOT_PRESENT) + debug("%s: ssh_get_authentication_socket: %s", + __func__, ssh_err(r)); + return NULL; + } + c = channel_new(ssh, "authentication agent connection", + SSH_CHANNEL_OPEN, sock, sock, -1, + CHAN_X11_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0, + "authentication agent connection", 1); + c->force_drain = 1; + return c; +} + +char * +client_request_tun_fwd(struct ssh *ssh, int tun_mode, + int local_tun, int remote_tun) +{ + Channel *c; + int fd; + char *ifname = NULL; + + if (tun_mode == SSH_TUNMODE_NO) + return 0; + + debug("Requesting tun unit %d in mode %d", local_tun, tun_mode); + + /* Open local tunnel device */ + if ((fd = tun_open(local_tun, tun_mode, &ifname)) == -1) { + error("Tunnel device open failed."); + return NULL; + } + debug("Tunnel forwarding using interface %s", ifname); + + c = channel_new(ssh, "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(ssh, c->self, sys_tun_infilter, + sys_tun_outfilter, NULL, NULL); +#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(tun_mode); + packet_put_int(remote_tun); + packet_send(); + + return ifname; +} + +/* XXXX move to generic input handler */ +static int +client_input_channel_open(int type, u_int32_t seq, struct ssh *ssh) +{ + Channel *c = NULL; + char *ctype; + int rchan; + u_int rmaxpack, rwindow, len; + + ctype = packet_get_string(&len); + rchan = packet_get_int(); + rwindow = packet_get_int(); + rmaxpack = packet_get_int(); + + debug("client_input_channel_open: ctype %s rchan %d win %d max %d", + ctype, rchan, rwindow, rmaxpack); + + if (strcmp(ctype, "forwarded-tcpip") == 0) { + c = client_request_forwarded_tcpip(ssh, ctype, rchan, rwindow, + rmaxpack); + } else if (strcmp(ctype, "forwarded-streamlocal@openssh.com") == 0) { + c = client_request_forwarded_streamlocal(ssh, ctype, rchan); + } else if (strcmp(ctype, "x11") == 0) { + c = client_request_x11(ssh, ctype, rchan); + } else if (strcmp(ctype, "auth-agent@openssh.com") == 0) { + c = client_request_agent(ssh, ctype, rchan); + } + if (c != NULL && c->type == SSH_CHANNEL_MUX_CLIENT) { + debug3("proxied to downstream: %s", ctype); + } else if (c != NULL) { + debug("confirm %s", ctype); + c->remote_id = rchan; + c->have_remote_id = 1; + c->remote_window = rwindow; + c->remote_maxpacket = rmaxpack; + if (c->type != SSH_CHANNEL_CONNECTING) { + packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION); + packet_put_int(c->remote_id); + packet_put_int(c->self); + packet_put_int(c->local_window); + packet_put_int(c->local_maxpacket); + packet_send(); + } + } else { + debug("failure %s", ctype); + packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE); + packet_put_int(rchan); + packet_put_int(SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED); + packet_put_cstring("open failed"); + packet_put_cstring(""); + packet_send(); + } + free(ctype); + return 0; +} + +static int +client_input_channel_req(int type, u_int32_t seq, struct ssh *ssh) +{ + Channel *c = NULL; + int exitval, id, reply, success = 0; + char *rtype; + + id = packet_get_int(); + c = channel_lookup(ssh, id); + if (channel_proxy_upstream(c, type, seq, ssh)) + return 0; + rtype = packet_get_string(NULL); + reply = packet_get_char(); + + debug("client_input_channel_req: channel %d rtype %s reply %d", + id, rtype, reply); + + if (id == -1) { + error("client_input_channel_req: request for channel -1"); + } else if (c == NULL) { + error("client_input_channel_req: channel %d: " + "unknown channel", id); + } else if (strcmp(rtype, "eow@openssh.com") == 0) { + packet_check_eom(); + chan_rcvd_eow(ssh, c); + } else if (strcmp(rtype, "exit-status") == 0) { + exitval = packet_get_int(); + if (c->ctl_chan != -1) { + mux_exit_message(ssh, c, exitval); + success = 1; + } else if (id == session_ident) { + /* Record exit value of local session */ + success = 1; + exit_status = exitval; + } else { + /* Probably for a mux channel that has already closed */ + debug("%s: no sink for exit-status on channel %d", + __func__, id); + } + packet_check_eom(); + } + if (reply && c != NULL && !(c->flags & CHAN_CLOSE_SENT)) { + if (!c->have_remote_id) + fatal("%s: channel %d: no remote_id", + __func__, c->self); + packet_start(success ? + SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE); + packet_put_int(c->remote_id); + packet_send(); + } + free(rtype); + return 0; +} + +struct hostkeys_update_ctx { + /* The hostname and (optionally) IP address string for the server */ + char *host_str, *ip_str; + + /* + * Keys received from the server and a flag for each indicating + * whether they already exist in known_hosts. + * keys_seen is filled in by hostkeys_find() and later (for new + * keys) by client_global_hostkeys_private_confirm(). + */ + struct sshkey **keys; + int *keys_seen; + size_t nkeys, nnew; + + /* + * Keys that are in known_hosts, but were not present in the update + * from the server (i.e. scheduled to be deleted). + * Filled in by hostkeys_find(). + */ + struct sshkey **old_keys; + size_t nold; +}; + +static void +hostkeys_update_ctx_free(struct hostkeys_update_ctx *ctx) +{ + size_t i; + + if (ctx == NULL) + return; + for (i = 0; i < ctx->nkeys; i++) + sshkey_free(ctx->keys[i]); + free(ctx->keys); + free(ctx->keys_seen); + for (i = 0; i < ctx->nold; i++) + sshkey_free(ctx->old_keys[i]); + free(ctx->old_keys); + free(ctx->host_str); + free(ctx->ip_str); + free(ctx); +} + +static int +hostkeys_find(struct hostkey_foreach_line *l, void *_ctx) +{ + struct hostkeys_update_ctx *ctx = (struct hostkeys_update_ctx *)_ctx; + size_t i; + struct sshkey **tmp; + + if (l->status != HKF_STATUS_MATCHED || l->key == NULL) + return 0; + + /* Mark off keys we've already seen for this host */ + for (i = 0; i < ctx->nkeys; i++) { + if (sshkey_equal(l->key, ctx->keys[i])) { + debug3("%s: found %s key at %s:%ld", __func__, + sshkey_ssh_name(ctx->keys[i]), l->path, l->linenum); + ctx->keys_seen[i] = 1; + return 0; + } + } + /* This line contained a key that not offered by the server */ + debug3("%s: deprecated %s key at %s:%ld", __func__, + sshkey_ssh_name(l->key), l->path, l->linenum); + if ((tmp = recallocarray(ctx->old_keys, ctx->nold, ctx->nold + 1, + sizeof(*ctx->old_keys))) == NULL) + fatal("%s: recallocarray failed nold = %zu", + __func__, ctx->nold); + ctx->old_keys = tmp; + ctx->old_keys[ctx->nold++] = l->key; + l->key = NULL; + + return 0; +} + +static void +update_known_hosts(struct hostkeys_update_ctx *ctx) +{ + int r, was_raw = 0; + int loglevel = options.update_hostkeys == SSH_UPDATE_HOSTKEYS_ASK ? + SYSLOG_LEVEL_INFO : SYSLOG_LEVEL_VERBOSE; + char *fp, *response; + size_t i; + + for (i = 0; i < ctx->nkeys; i++) { + if (ctx->keys_seen[i] != 2) + continue; + if ((fp = sshkey_fingerprint(ctx->keys[i], + options.fingerprint_hash, SSH_FP_DEFAULT)) == NULL) + fatal("%s: sshkey_fingerprint failed", __func__); + do_log2(loglevel, "Learned new hostkey: %s %s", + sshkey_type(ctx->keys[i]), fp); + free(fp); + } + for (i = 0; i < ctx->nold; i++) { + if ((fp = sshkey_fingerprint(ctx->old_keys[i], + options.fingerprint_hash, SSH_FP_DEFAULT)) == NULL) + fatal("%s: sshkey_fingerprint failed", __func__); + do_log2(loglevel, "Deprecating obsolete hostkey: %s %s", + sshkey_type(ctx->old_keys[i]), fp); + free(fp); + } + if (options.update_hostkeys == SSH_UPDATE_HOSTKEYS_ASK) { + if (get_saved_tio() != NULL) { + leave_raw_mode(1); + was_raw = 1; + } + response = NULL; + for (i = 0; !quit_pending && i < 3; i++) { + free(response); + response = read_passphrase("Accept updated hostkeys? " + "(yes/no): ", RP_ECHO); + if (strcasecmp(response, "yes") == 0) + break; + else if (quit_pending || response == NULL || + strcasecmp(response, "no") == 0) { + options.update_hostkeys = 0; + break; + } else { + do_log2(loglevel, "Please enter " + "\"yes\" or \"no\""); + } + } + if (quit_pending || i >= 3 || response == NULL) + options.update_hostkeys = 0; + free(response); + if (was_raw) + enter_raw_mode(1); + } + + /* + * Now that all the keys are verified, we can go ahead and replace + * them in known_hosts (assuming SSH_UPDATE_HOSTKEYS_ASK didn't + * cancel the operation). + */ + if (options.update_hostkeys != 0 && + (r = hostfile_replace_entries(options.user_hostfiles[0], + ctx->host_str, ctx->ip_str, ctx->keys, ctx->nkeys, + options.hash_known_hosts, 0, + options.fingerprint_hash)) != 0) + error("%s: hostfile_replace_entries failed: %s", + __func__, ssh_err(r)); +} + +static void +client_global_hostkeys_private_confirm(struct ssh *ssh, int type, + u_int32_t seq, void *_ctx) +{ + struct hostkeys_update_ctx *ctx = (struct hostkeys_update_ctx *)_ctx; + size_t i, ndone; + struct sshbuf *signdata; + int r, kexsigtype, use_kexsigtype; + const u_char *sig; + size_t siglen; + + if (ctx->nnew == 0) + fatal("%s: ctx->nnew == 0", __func__); /* sanity */ + if (type != SSH2_MSG_REQUEST_SUCCESS) { + error("Server failed to confirm ownership of " + "private host keys"); + hostkeys_update_ctx_free(ctx); + return; + } + kexsigtype = sshkey_type_plain( + sshkey_type_from_name(ssh->kex->hostkey_alg)); + + if ((signdata = sshbuf_new()) == NULL) + fatal("%s: sshbuf_new failed", __func__); + /* Don't want to accidentally accept an unbound signature */ + if (ssh->kex->session_id_len == 0) + fatal("%s: ssh->kex->session_id_len == 0", __func__); + /* + * Expect a signature for each of the ctx->nnew private keys we + * haven't seen before. They will be in the same order as the + * ctx->keys where the corresponding ctx->keys_seen[i] == 0. + */ + for (ndone = i = 0; i < ctx->nkeys; i++) { + if (ctx->keys_seen[i]) + continue; + /* Prepare data to be signed: session ID, unique string, key */ + sshbuf_reset(signdata); + if ( (r = sshbuf_put_cstring(signdata, + "hostkeys-prove-00@openssh.com")) != 0 || + (r = sshbuf_put_string(signdata, ssh->kex->session_id, + ssh->kex->session_id_len)) != 0 || + (r = sshkey_puts(ctx->keys[i], signdata)) != 0) + fatal("%s: failed to prepare signature: %s", + __func__, ssh_err(r)); + /* Extract and verify signature */ + if ((r = sshpkt_get_string_direct(ssh, &sig, &siglen)) != 0) { + error("%s: couldn't parse message: %s", + __func__, ssh_err(r)); + goto out; + } + /* + * For RSA keys, prefer to use the signature type negotiated + * during KEX to the default (SHA1). + */ + use_kexsigtype = kexsigtype == KEY_RSA && + sshkey_type_plain(ctx->keys[i]->type) == KEY_RSA; + if ((r = sshkey_verify(ctx->keys[i], sig, siglen, + sshbuf_ptr(signdata), sshbuf_len(signdata), + use_kexsigtype ? ssh->kex->hostkey_alg : NULL, 0)) != 0) { + error("%s: server gave bad signature for %s key %zu", + __func__, sshkey_type(ctx->keys[i]), i); + goto out; + } + /* Key is good. Mark it as 'seen' */ + ctx->keys_seen[i] = 2; + ndone++; + } + if (ndone != ctx->nnew) + fatal("%s: ndone != ctx->nnew (%zu / %zu)", __func__, + ndone, ctx->nnew); /* Shouldn't happen */ + ssh_packet_check_eom(ssh); + + /* Make the edits to known_hosts */ + update_known_hosts(ctx); + out: + hostkeys_update_ctx_free(ctx); +} + +/* + * Returns non-zero if the key is accepted by HostkeyAlgorithms. + * Made slightly less trivial by the multiple RSA signature algorithm names. + */ +static int +key_accepted_by_hostkeyalgs(const struct sshkey *key) +{ + const char *ktype = sshkey_ssh_name(key); + const char *hostkeyalgs = options.hostkeyalgorithms != NULL ? + options.hostkeyalgorithms : KEX_DEFAULT_PK_ALG; + + if (key == NULL || key->type == KEY_UNSPEC) + return 0; + if (key->type == KEY_RSA && + (match_pattern_list("rsa-sha2-256", hostkeyalgs, 0) == 1 || + match_pattern_list("rsa-sha2-512", hostkeyalgs, 0) == 1)) + return 1; + return match_pattern_list(ktype, hostkeyalgs, 0) == 1; +} + +/* + * Handle hostkeys-00@openssh.com global request to inform the client of all + * the server's hostkeys. The keys are checked against the user's + * HostkeyAlgorithms preference before they are accepted. + */ +static int +client_input_hostkeys(void) +{ + struct ssh *ssh = active_state; /* XXX */ + const u_char *blob = NULL; + size_t i, len = 0; + struct sshbuf *buf = NULL; + struct sshkey *key = NULL, **tmp; + int r; + char *fp; + static int hostkeys_seen = 0; /* XXX use struct ssh */ + extern struct sockaddr_storage hostaddr; /* XXX from ssh.c */ + struct hostkeys_update_ctx *ctx = NULL; + + if (hostkeys_seen) + fatal("%s: server already sent hostkeys", __func__); + if (options.update_hostkeys == SSH_UPDATE_HOSTKEYS_ASK && + options.batch_mode) + return 1; /* won't ask in batchmode, so don't even try */ + if (!options.update_hostkeys || options.num_user_hostfiles <= 0) + return 1; + + ctx = xcalloc(1, sizeof(*ctx)); + while (ssh_packet_remaining(ssh) > 0) { + sshkey_free(key); + key = NULL; + if ((r = sshpkt_get_string_direct(ssh, &blob, &len)) != 0) { + error("%s: couldn't parse message: %s", + __func__, ssh_err(r)); + goto out; + } + if ((r = sshkey_from_blob(blob, len, &key)) != 0) { + error("%s: parse key: %s", __func__, ssh_err(r)); + goto out; + } + fp = sshkey_fingerprint(key, options.fingerprint_hash, + SSH_FP_DEFAULT); + debug3("%s: received %s key %s", __func__, + sshkey_type(key), fp); + free(fp); + + if (!key_accepted_by_hostkeyalgs(key)) { + debug3("%s: %s key not permitted by HostkeyAlgorithms", + __func__, sshkey_ssh_name(key)); + continue; + } + /* Skip certs */ + if (sshkey_is_cert(key)) { + debug3("%s: %s key is a certificate; skipping", + __func__, sshkey_ssh_name(key)); + continue; + } + /* Ensure keys are unique */ + for (i = 0; i < ctx->nkeys; i++) { + if (sshkey_equal(key, ctx->keys[i])) { + error("%s: received duplicated %s host key", + __func__, sshkey_ssh_name(key)); + goto out; + } + } + /* Key is good, record it */ + if ((tmp = recallocarray(ctx->keys, ctx->nkeys, ctx->nkeys + 1, + sizeof(*ctx->keys))) == NULL) + fatal("%s: recallocarray failed nkeys = %zu", + __func__, ctx->nkeys); + ctx->keys = tmp; + ctx->keys[ctx->nkeys++] = key; + key = NULL; + } + + if (ctx->nkeys == 0) { + debug("%s: server sent no hostkeys", __func__); + goto out; + } + + if ((ctx->keys_seen = calloc(ctx->nkeys, + sizeof(*ctx->keys_seen))) == NULL) + fatal("%s: calloc failed", __func__); + + get_hostfile_hostname_ipaddr(host, + options.check_host_ip ? (struct sockaddr *)&hostaddr : NULL, + options.port, &ctx->host_str, + options.check_host_ip ? &ctx->ip_str : NULL); + + /* Find which keys we already know about. */ + if ((r = hostkeys_foreach(options.user_hostfiles[0], hostkeys_find, + ctx, ctx->host_str, ctx->ip_str, + HKF_WANT_PARSE_KEY|HKF_WANT_MATCH)) != 0) { + error("%s: hostkeys_foreach failed: %s", __func__, ssh_err(r)); + goto out; + } + + /* Figure out if we have any new keys to add */ + ctx->nnew = 0; + for (i = 0; i < ctx->nkeys; i++) { + if (!ctx->keys_seen[i]) + ctx->nnew++; + } + + debug3("%s: %zu keys from server: %zu new, %zu retained. %zu to remove", + __func__, ctx->nkeys, ctx->nnew, ctx->nkeys - ctx->nnew, ctx->nold); + + if (ctx->nnew == 0 && ctx->nold != 0) { + /* We have some keys to remove. Just do it. */ + update_known_hosts(ctx); + } else if (ctx->nnew != 0) { + /* + * We have received hitherto-unseen keys from the server. + * Ask the server to confirm ownership of the private halves. + */ + debug3("%s: asking server to prove ownership for %zu keys", + __func__, ctx->nnew); + if ((r = sshpkt_start(ssh, SSH2_MSG_GLOBAL_REQUEST)) != 0 || + (r = sshpkt_put_cstring(ssh, + "hostkeys-prove-00@openssh.com")) != 0 || + (r = sshpkt_put_u8(ssh, 1)) != 0) /* bool: want reply */ + fatal("%s: cannot prepare packet: %s", + __func__, ssh_err(r)); + if ((buf = sshbuf_new()) == NULL) + fatal("%s: sshbuf_new", __func__); + for (i = 0; i < ctx->nkeys; i++) { + if (ctx->keys_seen[i]) + continue; + sshbuf_reset(buf); + if ((r = sshkey_putb(ctx->keys[i], buf)) != 0) + fatal("%s: sshkey_putb: %s", + __func__, ssh_err(r)); + if ((r = sshpkt_put_stringb(ssh, buf)) != 0) + fatal("%s: sshpkt_put_string: %s", + __func__, ssh_err(r)); + } + if ((r = sshpkt_send(ssh)) != 0) + fatal("%s: sshpkt_send: %s", __func__, ssh_err(r)); + client_register_global_confirm( + client_global_hostkeys_private_confirm, ctx); + ctx = NULL; /* will be freed in callback */ + } + + /* Success */ + out: + hostkeys_update_ctx_free(ctx); + sshkey_free(key); + sshbuf_free(buf); + /* + * NB. Return success for all cases. The server doesn't need to know + * what the client does with its hosts file. + */ + return 1; +} + +static int +client_input_global_request(int type, u_int32_t seq, struct ssh *ssh) +{ + char *rtype; + int want_reply; + int success = 0; + + rtype = packet_get_cstring(NULL); + want_reply = packet_get_char(); + debug("client_input_global_request: rtype %s want_reply %d", + rtype, want_reply); + if (strcmp(rtype, "hostkeys-00@openssh.com") == 0) + success = client_input_hostkeys(); + if (want_reply) { + packet_start(success ? + SSH2_MSG_REQUEST_SUCCESS : SSH2_MSG_REQUEST_FAILURE); + packet_send(); + packet_write_wait(); + } + free(rtype); + return 0; +} + +void +client_session2_setup(struct ssh *ssh, int id, int want_tty, int want_subsystem, + const char *term, struct termios *tiop, int in_fd, struct sshbuf *cmd, + char **env) +{ + int i, j, matched, len; + char *name, *val; + Channel *c = NULL; + + debug2("%s: id %d", __func__, id); + + if ((c = channel_lookup(ssh, id)) == NULL) + fatal("%s: channel %d: unknown channel", __func__, id); + + packet_set_interactive(want_tty, + options.ip_qos_interactive, options.ip_qos_bulk); + + if (want_tty) { + struct winsize ws; + + /* Store window size in the packet. */ + if (ioctl(in_fd, TIOCGWINSZ, &ws) < 0) + memset(&ws, 0, sizeof(ws)); + + channel_request_start(ssh, id, "pty-req", 1); + client_expect_confirm(ssh, id, "PTY allocation", CONFIRM_TTY); + packet_put_cstring(term != NULL ? term : ""); + packet_put_int((u_int)ws.ws_col); + packet_put_int((u_int)ws.ws_row); + packet_put_int((u_int)ws.ws_xpixel); + packet_put_int((u_int)ws.ws_ypixel); + if (tiop == NULL) + tiop = get_saved_tio(); + ssh_tty_make_modes(ssh, -1, tiop); + packet_send(); + /* XXX wait for reply */ + c->client_tty = 1; + } + + /* Transfer any environment variables from client to server */ + if (options.num_send_env != 0 && env != NULL) { + 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(ssh, id, "env", 0); + packet_put_cstring(name); + packet_put_cstring(val); + packet_send(); + free(name); + } + } + for (i = 0; i < options.num_setenv; i++) { + /* Split */ + name = xstrdup(options.setenv[i]); + if ((val = strchr(name, '=')) == NULL) { + free(name); + continue; + } + *val++ = '\0'; + + debug("Setting env %s = %s", name, val); + channel_request_start(ssh, id, "env", 0); + packet_put_cstring(name); + packet_put_cstring(val); + packet_send(); + free(name); + } + + len = sshbuf_len(cmd); + if (len > 0) { + if (len > 900) + len = 900; + if (want_subsystem) { + debug("Sending subsystem: %.*s", + len, (const u_char*)sshbuf_ptr(cmd)); + channel_request_start(ssh, id, "subsystem", 1); + client_expect_confirm(ssh, id, "subsystem", + CONFIRM_CLOSE); + } else { + debug("Sending command: %.*s", + len, (const u_char*)sshbuf_ptr(cmd)); + channel_request_start(ssh, id, "exec", 1); + client_expect_confirm(ssh, id, "exec", CONFIRM_CLOSE); + } + packet_put_string(sshbuf_ptr(cmd), sshbuf_len(cmd)); + packet_send(); + } else { + channel_request_start(ssh, id, "shell", 1); + client_expect_confirm(ssh, id, "shell", CONFIRM_CLOSE); + packet_send(); + } +} + +static void +client_init_dispatch(void) +{ + dispatch_init(&dispatch_protocol_error); + + dispatch_set(SSH2_MSG_CHANNEL_CLOSE, &channel_input_oclose); + dispatch_set(SSH2_MSG_CHANNEL_DATA, &channel_input_data); + dispatch_set(SSH2_MSG_CHANNEL_EOF, &channel_input_ieof); + dispatch_set(SSH2_MSG_CHANNEL_EXTENDED_DATA, &channel_input_extended_data); + dispatch_set(SSH2_MSG_CHANNEL_OPEN, &client_input_channel_open); + dispatch_set(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation); + dispatch_set(SSH2_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure); + dispatch_set(SSH2_MSG_CHANNEL_REQUEST, &client_input_channel_req); + dispatch_set(SSH2_MSG_CHANNEL_WINDOW_ADJUST, &channel_input_window_adjust); + dispatch_set(SSH2_MSG_CHANNEL_SUCCESS, &channel_input_status_confirm); + dispatch_set(SSH2_MSG_CHANNEL_FAILURE, &channel_input_status_confirm); + dispatch_set(SSH2_MSG_GLOBAL_REQUEST, &client_input_global_request); + + /* rekeying */ + dispatch_set(SSH2_MSG_KEXINIT, &kex_input_kexinit); + + /* global request reply messages */ + dispatch_set(SSH2_MSG_REQUEST_FAILURE, &client_global_request_reply); + dispatch_set(SSH2_MSG_REQUEST_SUCCESS, &client_global_request_reply); +} + +void +client_stop_mux(void) +{ + if (options.control_path != NULL && muxserver_sock != -1) + unlink(options.control_path); + /* + * If we are in persist mode, or don't have a shell, signal that we + * should close when all active channels are closed. + */ + if (options.control_persist || no_shell_flag) { + session_closed = 1; + setproctitle("[stopped mux]"); + } +} + +/* client specific fatal cleanup */ +void +cleanup_exit(int i) +{ + leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE); + leave_non_blocking(); + if (options.control_path != NULL && muxserver_sock != -1) + unlink(options.control_path); + ssh_kill_proxy_command(); + _exit(i); +} |