diff options
Diffstat (limited to 'crypto/openssh/clientloop.c')
-rw-r--r-- | crypto/openssh/clientloop.c | 2047 |
1 files changed, 0 insertions, 2047 deletions
diff --git a/crypto/openssh/clientloop.c b/crypto/openssh/clientloop.c deleted file mode 100644 index 4c51081..0000000 --- a/crypto/openssh/clientloop.c +++ /dev/null @@ -1,2047 +0,0 @@ -/* $OpenBSD: clientloop.c,v 1.176 2006/10/11 12:38:03 markus 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> -#include <sys/param.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 "xmalloc.h" -#include "ssh.h" -#include "ssh1.h" -#include "ssh2.h" -#include "packet.h" -#include "buffer.h" -#include "compat.h" -#include "channels.h" -#include "dispatch.h" -#include "key.h" -#include "cipher.h" -#include "kex.h" -#include "log.h" -#include "readconf.h" -#include "clientloop.h" -#include "sshconnect.h" -#include "authfd.h" -#include "atomicio.h" -#include "sshpty.h" -#include "misc.h" -#include "monitor_fdpass.h" -#include "match.h" -#include "msg.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; - -/* 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 - * 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; - -/* Common data for the client loop code. */ -static volatile sig_atomic_t quit_pending; /* Set non-zero to quit the loop. */ -static int escape_char; /* Escape character. */ -static int escape_pending; /* Last character was the escape character */ -static int last_was_cr; /* Last character was a newline. */ -static int exit_status; /* Used to store the exit status of the command. */ -static int stdin_eof; /* EOF has been encountered on standard error. */ -static Buffer stdin_buffer; /* Buffer for stdin data. */ -static Buffer stdout_buffer; /* Buffer for stdout data. */ -static Buffer stderr_buffer; /* Buffer for stderr data. */ -static u_long stdin_bytes, stdout_bytes, stderr_bytes; -static u_int buffer_high;/* Soft max buffer size. */ -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 = 0; /* In SSH2: login session closed. */ -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; - int want_x_fwd; - int want_agent_fwd; - 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) { - unset_nonblock(fileno(stdin)); - in_non_blocking_mode = 0; - } -} - -/* Puts stdin terminal in non-blocking mode. */ - -static void -enter_non_blocking(void) -{ - in_non_blocking_mode = 1; - set_nonblock(fileno(stdin)); -} - -/* - * 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(SIGWINCH, window_change_handler); -} - -/* - * 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; -} - -/* - * Returns current time in seconds from Jan 1, 1970 with the maximum - * available resolution. - */ - -static double -get_current_time(void) -{ - struct timeval tv; - gettimeofday(&tv, NULL); - return (double) tv.tv_sec + (double) tv.tv_usec / 1000000.0; -} - -#define SSH_X11_PROTO "MIT-MAGIC-COOKIE-1" -void -client_x11_get_proto(const char *display, const char *xauth_path, - u_int trusted, 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 *xauthdir, *xauthfile; - struct stat st; - - xauthdir = xauthfile = NULL; - *_proto = proto; - *_data = data; - proto[0] = data[0] = '\0'; - - if (xauth_path == NULL ||(stat(xauth_path, &st) == -1)) { - debug("No xauth program."); - } else { - if (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 (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, - xauth_path, 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, - 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); - } - - 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; - } - } -} - -/* - * This is called when the interactive is entered. This checks if there is - * an EOF coming on stdin. We must check this explicitly, as select() does - * not appear to wake up when redirecting from /dev/null. - */ - -static void -client_check_initial_eof_on_stdin(void) -{ - int len; - char buf[1]; - - /* - * If standard input is to be "redirected from /dev/null", we simply - * mark that we have seen an EOF and send an EOF message to the - * server. Otherwise, we try to read a single character; it appears - * that for some files, such /dev/null, select() never wakes up for - * read for this descriptor, which means that we never get EOF. This - * way we will get the EOF if stdin comes from /dev/null or similar. - */ - if (stdin_null_flag) { - /* Fake EOF on stdin. */ - debug("Sending eof."); - stdin_eof = 1; - packet_start(SSH_CMSG_EOF); - packet_send(); - } else { - enter_non_blocking(); - - /* Check for immediate EOF on stdin. */ - len = read(fileno(stdin), buf, 1); - if (len == 0) { - /* EOF. Record that we have seen it and send EOF to server. */ - debug("Sending eof."); - stdin_eof = 1; - packet_start(SSH_CMSG_EOF); - packet_send(); - } else if (len > 0) { - /* - * Got data. We must store the data in the buffer, - * and also process it as an escape character if - * appropriate. - */ - if ((u_char) buf[0] == escape_char) - escape_pending = 1; - else - buffer_append(&stdin_buffer, buf, 1); - } - leave_non_blocking(); - } -} - - -/* - * Make packets from buffered stdin data, and buffer them for sending to the - * connection. - */ - -static void -client_make_packets_from_stdin_data(void) -{ - u_int len; - - /* Send buffered stdin data to the server. */ - while (buffer_len(&stdin_buffer) > 0 && - packet_not_very_much_data_to_write()) { - len = buffer_len(&stdin_buffer); - /* Keep the packets at reasonable size. */ - if (len > packet_get_maxsize()) - len = packet_get_maxsize(); - packet_start(SSH_CMSG_STDIN_DATA); - packet_put_string(buffer_ptr(&stdin_buffer), len); - packet_send(); - buffer_consume(&stdin_buffer, len); - stdin_bytes += len; - /* If we have a pending EOF, send it now. */ - if (stdin_eof && buffer_len(&stdin_buffer) == 0) { - packet_start(SSH_CMSG_EOF); - packet_send(); - } - } -} - -/* - * 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(void) -{ - struct winsize ws; - - if (! received_window_change_signal) - return; - /** XXX race */ - received_window_change_signal = 0; - - debug2("client_check_window_change: changed"); - - if (compat20) { - channel_send_window_changes(); - } else { - if (ioctl(fileno(stdin), TIOCGWINSZ, &ws) < 0) - return; - packet_start(SSH_CMSG_WINDOW_SIZE); - packet_put_int((u_int)ws.ws_row); - packet_put_int((u_int)ws.ws_col); - packet_put_int((u_int)ws.ws_xpixel); - packet_put_int((u_int)ws.ws_ypixel); - packet_send(); - } -} - -static void -client_global_request_reply(int type, u_int32_t seq, void *ctxt) -{ - server_alive_timeouts = 0; - client_global_request_reply_fwd(type, seq, ctxt); -} - -static void -server_alive_check(void) -{ - if (++server_alive_timeouts > options.server_alive_count_max) { - logit("Timeout, server not responding."); - cleanup_exit(255); - } - packet_start(SSH2_MSG_GLOBAL_REQUEST); - packet_put_cstring("keepalive@openssh.com"); - packet_put_char(1); /* boolean: want reply */ - packet_send(); -} - -/* - * 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, u_int *nallocp, int rekeying) -{ - struct timeval tv, *tvp; - int ret; - - /* Add any selections by the channel mechanism. */ - channel_prepare_select(readsetp, writesetp, maxfdp, nallocp, rekeying); - - if (!compat20) { - /* Read from the connection, unless our buffers are full. */ - if (buffer_len(&stdout_buffer) < buffer_high && - buffer_len(&stderr_buffer) < buffer_high && - channel_not_very_much_buffered_data()) - FD_SET(connection_in, *readsetp); - /* - * Read from stdin, unless we have seen EOF or have very much - * buffered data to send to the server. - */ - if (!stdin_eof && packet_not_very_much_data_to_write()) - FD_SET(fileno(stdin), *readsetp); - - /* Select stdout/stderr if have data in buffer. */ - if (buffer_len(&stdout_buffer) > 0) - FD_SET(fileno(stdout), *writesetp); - if (buffer_len(&stderr_buffer) > 0) - FD_SET(fileno(stderr), *writesetp); - } else { - /* channel_prepare_select could have closed the last channel */ - if (session_closed && !channel_still_open() && - !packet_have_data_to_write()) { - /* clear mask since we did not call select() */ - memset(*readsetp, 0, *nallocp); - memset(*writesetp, 0, *nallocp); - return; - } else { - 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); - - 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 - * event pending. - */ - - if (options.server_alive_interval == 0 || !compat20) - tvp = NULL; - else { - tv.tv_sec = options.server_alive_interval; - tv.tv_usec = 0; - tvp = &tv; - } - ret = select((*maxfdp)+1, *readsetp, *writesetp, NULL, tvp); - if (ret < 0) { - char buf[100]; - - /* - * 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. */ - snprintf(buf, sizeof buf, "select: %s\r\n", strerror(errno)); - buffer_append(&stderr_buffer, buf, strlen(buf)); - quit_pending = 1; - } else if (ret == 0) - server_alive_check(); -} - -static void -client_suspend_self(Buffer *bin, Buffer *bout, Buffer *berr) -{ - /* Flush stdout and stderr buffers. */ - if (buffer_len(bout) > 0) - atomicio(vwrite, fileno(stdout), buffer_ptr(bout), buffer_len(bout)); - if (buffer_len(berr) > 0) - atomicio(vwrite, fileno(stderr), buffer_ptr(berr), buffer_len(berr)); - - leave_raw_mode(); - - /* - * Free (and clear) the buffer to reduce the amount of data that gets - * written to swap. - */ - buffer_free(bin); - buffer_free(bout); - buffer_free(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; - - /* OK, we have been continued by the user. Reinitialize buffers. */ - buffer_init(bin); - buffer_init(bout); - buffer_init(berr); - - enter_raw_mode(); -} - -static void -client_process_net_input(fd_set *readset) -{ - int len; - char buf[8192]; - - /* - * 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. */ - snprintf(buf, sizeof buf, "Connection to %.300s closed by remote host.\r\n", - host); - buffer_append(&stderr_buffer, buf, strlen(buf)); - 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)) - len = 0; - - if (len < 0) { - /* An error has encountered. Perhaps there is a network problem. */ - snprintf(buf, sizeof buf, "Read from remote host %.300s: %.100s\r\n", - host, strerror(errno)); - buffer_append(&stderr_buffer, buf, strlen(buf)); - quit_pending = 1; - return; - } - packet_process_incoming(buf, len); - } -} - -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; - const char *display; - 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); - - display = getenv("DISPLAY"); - if (cctx->want_x_fwd && options.forward_x11 && display != NULL) { - char *proto, *data; - /* Get reasonable local authentication information. */ - 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, display, proto, data); - /* XXX wait for reply */ - } - - if (cctx->want_agent_fwd && options.forward_agent) { - debug("Requesting authentication agent forwarding."); - channel_request_start(id, "auth-agent-req@openssh.com", 0); - packet_send(); - } - - 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, allowed; - socklen_t addrlen; - struct sockaddr_storage addr; - struct confirm_ctx *cctx; - char *cmd; - u_int i, len, env_len, command, flags; - 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; - } - - unset_nonblock(client_fd); - - /* Read command */ - buffer_init(&m); - 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)) != SSHMUX_VER) { - error("%s: wrong client version %d", __func__, ver); - buffer_free(&m); - close(client_fd); - return; - } - - allowed = 1; - command = buffer_get_int(&m); - flags = buffer_get_int(&m); - - buffer_clear(&m); - - switch (command) { - case SSHMUX_COMMAND_OPEN: - if (options.control_master == SSHCTL_MASTER_ASK || - options.control_master == SSHCTL_MASTER_AUTO_ASK) - allowed = ask_permission("Allow shared connection " - "to %s? ", host); - /* continue below */ - break; - case SSHMUX_COMMAND_TERMINATE: - if (options.control_master == SSHCTL_MASTER_ASK || - options.control_master == SSHCTL_MASTER_AUTO_ASK) - allowed = ask_permission("Terminate shared connection " - "to %s? ", host); - if (allowed) - quit_pending = 1; - /* FALLTHROUGH */ - case SSHMUX_COMMAND_ALIVE_CHECK: - /* Reply for SSHMUX_COMMAND_TERMINATE and ALIVE_CHECK */ - buffer_clear(&m); - buffer_put_int(&m, allowed); - buffer_put_int(&m, getpid()); - if (ssh_msg_send(client_fd, SSHMUX_VER, &m) == -1) { - error("%s: client msg_send failed", __func__); - close(client_fd); - buffer_free(&m); - return; - } - buffer_free(&m); - close(client_fd); - return; - default: - error("Unsupported command %d", command); - buffer_free(&m); - close(client_fd); - return; - } - - /* Reply for SSHMUX_COMMAND_OPEN */ - buffer_clear(&m); - buffer_put_int(&m, allowed); - buffer_put_int(&m, getpid()); - if (ssh_msg_send(client_fd, SSHMUX_VER, &m) == -1) { - error("%s: client msg_send failed", __func__); - close(client_fd); - buffer_free(&m); - return; - } - - if (!allowed) { - error("Refused control connection"); - close(client_fd); - buffer_free(&m); - return; - } - - buffer_clear(&m); - 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)) != SSHMUX_VER) { - error("%s: wrong client version %d", __func__, ver); - buffer_free(&m); - close(client_fd); - return; - } - - cctx = xcalloc(1, sizeof(*cctx)); - cctx->want_tty = (flags & SSHMUX_FLAG_TTY) != 0; - cctx->want_subsys = (flags & SSHMUX_FLAG_SUBSYS) != 0; - cctx->want_x_fwd = (flags & SSHMUX_FLAG_X11_FWD) != 0; - cctx->want_agent_fwd = (flags & SSHMUX_FLAG_AGENT_FWD) != 0; - 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 = xcalloc(env_len + 1, sizeof(*cctx->env)); - 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); - xfree(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)); - - /* This roundtrip is just for synchronisation of ttymodes */ - buffer_clear(&m); - if (ssh_msg_send(client_fd, SSHMUX_VER, &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); - xfree(cctx->term); - if (env_len != 0) { - for (i = 0; i < env_len; i++) - xfree(cctx->env[i]); - xfree(cctx->env); - } - 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, *cancel_host; - int delete = 0; - int local = 0; - u_short cancel_port; - Forward fwd; - - leave_raw_mode(); - handler = signal(SIGINT, SIG_IGN); - cmd = s = read_passphrase("\r\nssh> ", RP_ECHO); - if (s == NULL) - goto out; - while (*s && isspace(*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(" -KR[bind_address:]port " - "Cancel remote 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' && *s != 'R') { - logit("Invalid command."); - goto out; - } - if (*s == 'L') - local = 1; - if (local && delete) { - logit("Not supported."); - goto out; - } - if ((!local || delete) && !compat20) { - logit("Not supported for SSH protocol version 1."); - goto out; - } - - s++; - while (*s && isspace(*s)) - s++; - - if (delete) { - cancel_port = 0; - cancel_host = hpdelim(&s); /* may be NULL */ - if (s != NULL) { - cancel_port = a2port(s); - cancel_host = cleanhostname(cancel_host); - } else { - cancel_port = a2port(cancel_host); - cancel_host = NULL; - } - if (cancel_port == 0) { - logit("Bad forwarding close port"); - goto out; - } - channel_request_rforward_cancel(cancel_host, cancel_port); - } else { - if (!parse_forward(&fwd, s)) { - logit("Bad forwarding specification."); - goto out; - } - if (local) { - if (channel_setup_local_fwd_listener(fwd.listen_host, - fwd.listen_port, fwd.connect_host, - fwd.connect_port, options.gateway_ports) < 0) { - logit("Port forwarding failed."); - goto out; - } - } else { - if (channel_request_remote_forwarding(fwd.listen_host, - fwd.listen_port, fwd.connect_host, - fwd.connect_port) < 0) { - logit("Port forwarding failed."); - goto out; - } - } - - logit("Forwarding port."); - } - -out: - signal(SIGINT, handler); - enter_raw_mode(); - if (cmd) - xfree(cmd); -} - -/* process the characters one by one */ -static int -process_escapes(Buffer *bin, Buffer *bout, Buffer *berr, char *buf, int len) -{ - char string[1024]; - pid_t pid; - int bytes = 0; - u_int i; - u_char ch; - char *s; - - if (len <= 0) - return (0); - - for (i = 0; i < (u_int)len; i++) { - /* Get one character at a time. */ - ch = buf[i]; - - if (escape_pending) { - /* We have previously seen an escape character. */ - /* Clear the flag now. */ - escape_pending = 0; - - /* Process the escaped character. */ - switch (ch) { - case '.': - /* Terminate the connection. */ - snprintf(string, sizeof string, "%c.\r\n", escape_char); - buffer_append(berr, string, strlen(string)); - - quit_pending = 1; - return -1; - - case 'Z' - 64: - /* Suspend the program. */ - /* Print a message to that effect to the user. */ - snprintf(string, sizeof string, "%c^Z [suspend ssh]\r\n", escape_char); - buffer_append(berr, string, strlen(string)); - - /* Restore terminal modes and suspend. */ - client_suspend_self(bin, bout, berr); - - /* We have been continued. */ - continue; - - case 'B': - if (compat20) { - snprintf(string, sizeof string, - "%cB\r\n", escape_char); - buffer_append(berr, string, - strlen(string)); - channel_request_start(session_ident, - "break", 0); - packet_put_int(1000); - packet_send(); - } - continue; - - case 'R': - if (compat20) { - if (datafellows & SSH_BUG_NOREKEY) - logit("Server does not support re-keying"); - else - need_rekeying = 1; - } - continue; - - case '&': - /* - * Detach the program (continue to serve connections, - * but put in background and no more new connections). - */ - /* Restore tty modes. */ - leave_raw_mode(); - - /* Stop listening for new connections. */ - channel_stop_listening(); - - snprintf(string, sizeof string, - "%c& [backgrounded]\n", escape_char); - buffer_append(berr, string, strlen(string)); - - /* 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. */ - if (compat20) { - buffer_append(bin, "\004", 1); - /* fake EOF on stdin */ - return -1; - } else if (!stdin_eof) { - /* - * Sending SSH_CMSG_EOF alone does not always appear - * to be enough. So we try to send an EOF character - * first. - */ - packet_start(SSH_CMSG_STDIN_DATA); - packet_put_string("\004", 1); - packet_send(); - /* Close stdin. */ - stdin_eof = 1; - if (buffer_len(bin) == 0) { - packet_start(SSH_CMSG_EOF); - packet_send(); - } - } - continue; - - case '?': - snprintf(string, sizeof string, -"%c?\r\n\ -Supported escape sequences:\r\n\ -%c. - terminate connection\r\n\ -%cB - send a BREAK to the remote system\r\n\ -%cC - open a command line\r\n\ -%cR - Request rekey (SSH protocol 2 only)\r\n\ -%c^Z - suspend ssh\r\n\ -%c# - list forwarded connections\r\n\ -%c& - background ssh (when waiting for connections to terminate)\r\n\ -%c? - this message\r\n\ -%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, escape_char, escape_char, - escape_char, escape_char, escape_char, escape_char, - escape_char, escape_char, escape_char); - buffer_append(berr, string, strlen(string)); - continue; - - case '#': - snprintf(string, sizeof string, "%c#\r\n", escape_char); - buffer_append(berr, string, strlen(string)); - s = channel_open_message(); - buffer_append(berr, s, strlen(s)); - xfree(s); - continue; - - case 'C': - process_cmdline(); - continue; - - default: - if (ch != escape_char) { - buffer_put_char(bin, escape_char); - 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 == escape_char) { - /* It is. Set the flag and continue to next character. */ - 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'); - buffer_put_char(bin, ch); - bytes++; - } - return bytes; -} - -static void -client_process_input(fd_set *readset) -{ - int len; - char buf[8192]; - - /* Read input from stdin. */ - if (FD_ISSET(fileno(stdin), readset)) { - /* Read as much as possible. */ - len = read(fileno(stdin), buf, sizeof(buf)); - if (len < 0 && (errno == EAGAIN || errno == EINTR)) - return; /* we'll try again later */ - if (len <= 0) { - /* - * Received EOF or error. They are treated - * similarly, except that an error message is printed - * if it was an error condition. - */ - if (len < 0) { - snprintf(buf, sizeof buf, "read: %.100s\r\n", strerror(errno)); - buffer_append(&stderr_buffer, buf, strlen(buf)); - } - /* Mark that we have seen EOF. */ - stdin_eof = 1; - /* - * Send an EOF message to the server unless there is - * data in the buffer. If there is data in the - * buffer, no message will be sent now. Code - * elsewhere will send the EOF when the buffer - * becomes empty if stdin_eof is set. - */ - if (buffer_len(&stdin_buffer) == 0) { - packet_start(SSH_CMSG_EOF); - packet_send(); - } - } else if (escape_char == SSH_ESCAPECHAR_NONE) { - /* - * Normal successful read, and no escape character. - * Just append the data to buffer. - */ - buffer_append(&stdin_buffer, buf, len); - } else { - /* - * Normal, successful read. But we have an escape character - * and have to process the characters one by one. - */ - if (process_escapes(&stdin_buffer, &stdout_buffer, - &stderr_buffer, buf, len) == -1) - return; - } - } -} - -static void -client_process_output(fd_set *writeset) -{ - int len; - char buf[100]; - - /* Write buffered output to stdout. */ - if (FD_ISSET(fileno(stdout), writeset)) { - /* Write as much data as possible. */ - len = write(fileno(stdout), buffer_ptr(&stdout_buffer), - buffer_len(&stdout_buffer)); - if (len <= 0) { - if (errno == EINTR || errno == EAGAIN) - len = 0; - else { - /* - * An error or EOF was encountered. Put an - * error message to stderr buffer. - */ - snprintf(buf, sizeof buf, "write stdout: %.50s\r\n", strerror(errno)); - buffer_append(&stderr_buffer, buf, strlen(buf)); - quit_pending = 1; - return; - } - } - /* Consume printed data from the buffer. */ - buffer_consume(&stdout_buffer, len); - stdout_bytes += len; - } - /* Write buffered output to stderr. */ - if (FD_ISSET(fileno(stderr), writeset)) { - /* Write as much data as possible. */ - len = write(fileno(stderr), buffer_ptr(&stderr_buffer), - buffer_len(&stderr_buffer)); - if (len <= 0) { - if (errno == EINTR || errno == EAGAIN) - len = 0; - else { - /* EOF or error, but can't even print error message. */ - quit_pending = 1; - return; - } - } - /* Consume printed characters from the buffer. */ - buffer_consume(&stderr_buffer, len); - stderr_bytes += len; - } -} - -/* - * 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) -{ - dispatch_run(DISPATCH_NONBLOCK, &quit_pending, compat20 ? xxx_kex : NULL); -} - -/* scan buf[] for '~' before sending data to the peer */ - -static int -simple_escape_filter(Channel *c, char *buf, int len) -{ - /* XXX we assume c->extended is writeable */ - return process_escapes(&c->input, &c->output, &c->extended, buf, len); -} - -static void -client_channel_closed(int id, void *arg) -{ - channel_cancel_cleanup(id); - session_closed = 1; - leave_raw_mode(); -} - -/* - * 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(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; - u_int nalloc = 0; - char buf[100]; - - debug("Entering interactive session."); - - start_time = get_current_time(); - - /* Initialize variables. */ - escape_pending = 0; - last_was_cr = 1; - exit_status = -1; - stdin_eof = 0; - buffer_high = 64 * 1024; - 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 */ - if (!isatty(fileno(stdin))) - set_nonblock(fileno(stdin)); - if (!isatty(fileno(stdout))) - set_nonblock(fileno(stdout)); - if (!isatty(fileno(stderr))) - set_nonblock(fileno(stderr)); - max_fd = MAX(max_fd, fileno(stdin)); - max_fd = MAX(max_fd, fileno(stdout)); - max_fd = MAX(max_fd, fileno(stderr)); - } - stdin_bytes = 0; - stdout_bytes = 0; - stderr_bytes = 0; - quit_pending = 0; - escape_char = escape_char_arg; - - /* Initialize buffers. */ - buffer_init(&stdin_buffer); - buffer_init(&stdout_buffer); - buffer_init(&stderr_buffer); - - 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(); - - if (compat20) { - session_ident = ssh2_chan_id; - if (escape_char != SSH_ESCAPECHAR_NONE) - channel_register_filter(session_ident, - simple_escape_filter, NULL); - if (session_ident != -1) - channel_register_cleanup(session_ident, - client_channel_closed, 0); - } else { - /* Check if we should immediately send eof on stdin. */ - client_check_initial_eof_on_stdin(); - } - - /* 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 (compat20 && session_closed && !channel_still_open()) - break; - - rekeying = (xxx_kex != NULL && !xxx_kex->done); - - if (rekeying) { - debug("rekeying in progress"); - } else { - /* - * Make packets of buffered stdin data, and buffer - * them for sending to the server. - */ - if (!compat20) - client_make_packets_from_stdin_data(); - - /* - * 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(); - - /* - * Check if the window size has changed, and buffer a - * message about it to the server if so. - */ - client_check_window_change(); - - 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(&readset, &writeset, - &max_fd2, &nalloc, rekeying); - - if (quit_pending) - break; - - /* Do channel operations unless rekeying in progress. */ - if (!rekeying) { - channel_after_select(readset, writeset); - if (need_rekeying || packet_need_rekeying()) { - debug("need rekeying"); - xxx_kex->done = 0; - kex_send_kexinit(xxx_kex); - need_rekeying = 0; - } - } - - /* Buffer input from the connection. */ - client_process_net_input(readset); - - /* Accept control connections. */ - client_process_control(readset); - - if (quit_pending) - break; - - if (!compat20) { - /* Buffer data from stdin */ - client_process_input(readset); - /* - * Process output to stdout and stderr. Output to - * the connection is processed elsewhere (above). - */ - client_process_output(writeset); - } - - /* Send as much buffered packet data as possible to the sender. */ - if (FD_ISSET(connection_out, writeset)) - packet_write_poll(); - } - if (readset) - xfree(readset); - if (writeset) - xfree(writeset); - - /* Terminate the session. */ - - /* Stop watching for window change. */ - signal(SIGWINCH, SIG_DFL); - - channel_free_all(); - - if (have_pty) - leave_raw_mode(); - - /* 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) - fatal("Killed by signal %d.", (int) received_signal); - - /* - * 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) { - snprintf(buf, sizeof buf, "Connection to %.64s closed.\r\n", host); - buffer_append(&stderr_buffer, buf, strlen(buf)); - } - - /* Output any buffered data for stdout. */ - while (buffer_len(&stdout_buffer) > 0) { - len = write(fileno(stdout), buffer_ptr(&stdout_buffer), - buffer_len(&stdout_buffer)); - if (len <= 0) { - error("Write failed flushing stdout buffer."); - break; - } - buffer_consume(&stdout_buffer, len); - stdout_bytes += len; - } - - /* Output any buffered data for stderr. */ - while (buffer_len(&stderr_buffer) > 0) { - len = write(fileno(stderr), buffer_ptr(&stderr_buffer), - buffer_len(&stderr_buffer)); - if (len <= 0) { - error("Write failed flushing stderr buffer."); - break; - } - buffer_consume(&stderr_buffer, len); - stderr_bytes += len; - } - - /* Clear and free any buffers. */ - memset(buf, 0, sizeof(buf)); - buffer_free(&stdin_buffer); - buffer_free(&stdout_buffer); - buffer_free(&stderr_buffer); - - /* Report bytes transferred, and transfer rates. */ - total_time = get_current_time() - start_time; - debug("Transferred: stdin %lu, stdout %lu, stderr %lu bytes in %.1f seconds", - stdin_bytes, stdout_bytes, stderr_bytes, total_time); - if (total_time > 0) - debug("Bytes per second: stdin %.1f, stdout %.1f, stderr %.1f", - stdin_bytes / total_time, stdout_bytes / total_time, - stderr_bytes / total_time); - - /* Return the exit status of the program. */ - debug("Exit status %d", exit_status); - return exit_status; -} - -/*********/ - -static void -client_input_stdout_data(int type, u_int32_t seq, void *ctxt) -{ - u_int data_len; - char *data = packet_get_string(&data_len); - packet_check_eom(); - buffer_append(&stdout_buffer, data, data_len); - memset(data, 0, data_len); - xfree(data); -} -static void -client_input_stderr_data(int type, u_int32_t seq, void *ctxt) -{ - u_int data_len; - char *data = packet_get_string(&data_len); - packet_check_eom(); - buffer_append(&stderr_buffer, data, data_len); - memset(data, 0, data_len); - xfree(data); -} -static void -client_input_exit_status(int type, u_int32_t seq, void *ctxt) -{ - exit_status = packet_get_int(); - packet_check_eom(); - /* Acknowledge the exit. */ - packet_start(SSH_CMSG_EXIT_CONFIRMATION); - packet_send(); - /* - * Must wait for packet to be sent since we are - * exiting the loop. - */ - packet_write_wait(); - /* Flag that we want to exit. */ - quit_pending = 1; -} -static void -client_input_agent_open(int type, u_int32_t seq, void *ctxt) -{ - Channel *c = NULL; - int remote_id, sock; - - /* Read the remote channel number from the message. */ - remote_id = packet_get_int(); - packet_check_eom(); - - /* - * Get a connection to the local authentication agent (this may again - * get forwarded). - */ - sock = ssh_get_authentication_socket(); - - /* - * If we could not connect the agent, send an error message back to - * the server. This should never happen unless the agent dies, - * because authentication forwarding is only enabled if we have an - * agent. - */ - if (sock >= 0) { - c = channel_new("", SSH_CHANNEL_OPEN, sock, sock, - -1, 0, 0, 0, "authentication agent connection", 1); - c->remote_id = remote_id; - c->force_drain = 1; - } - if (c == NULL) { - packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE); - packet_put_int(remote_id); - } else { - /* Send a confirmation to the remote host. */ - debug("Forwarding authentication connection."); - packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION); - packet_put_int(remote_id); - packet_put_int(c->self); - } - packet_send(); -} - -static Channel * -client_request_forwarded_tcpip(const char *request_type, int rchan) -{ - Channel *c = NULL; - char *listen_address, *originator_address; - int listen_port, originator_port; - int sock; - - /* 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("client_request_forwarded_tcpip: listen %s port %d, originator %s port %d", - listen_address, listen_port, originator_address, originator_port); - - sock = channel_connect_by_listen_address(listen_port); - if (sock < 0) { - xfree(originator_address); - xfree(listen_address); - return NULL; - } - c = channel_new("forwarded-tcpip", - SSH_CHANNEL_CONNECTING, sock, sock, -1, - CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_WINDOW_DEFAULT, 0, - originator_address, 1); - xfree(originator_address); - xfree(listen_address); - return c; -} - -static Channel * -client_request_x11(const char *request_type, int rchan) -{ - Channel *c = NULL; - char *originator; - int 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; - } - originator = packet_get_string(NULL); - if (datafellows & SSH_BUG_X11FWD) { - debug2("buggy server: x11 request w/o originator_port"); - originator_port = 0; - } else { - originator_port = packet_get_int(); - } - packet_check_eom(); - /* XXX check permission */ - debug("client_request_x11: request from %s %d", originator, - originator_port); - xfree(originator); - sock = x11_connect_display(); - if (sock < 0) - return NULL; - c = channel_new("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(const char *request_type, int rchan) -{ - Channel *c = NULL; - int 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; - } - sock = ssh_get_authentication_socket(); - if (sock < 0) - return NULL; - c = channel_new("authentication agent connection", - SSH_CHANNEL_OPEN, sock, sock, -1, - CHAN_X11_WINDOW_DEFAULT, CHAN_TCP_WINDOW_DEFAULT, 0, - "authentication agent connection", 1); - c->force_drain = 1; - return c; -} - -/* XXXX move to generic input handler */ -static void -client_input_channel_open(int type, u_int32_t seq, void *ctxt) -{ - 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(ctype, rchan); - } else if (strcmp(ctype, "x11") == 0) { - c = client_request_x11(ctype, rchan); - } else if (strcmp(ctype, "auth-agent@openssh.com") == 0) { - c = client_request_agent(ctype, rchan); - } -/* XXX duplicate : */ - if (c != NULL) { - debug("confirm %s", ctype); - c->remote_id = rchan; - 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); - if (!(datafellows & SSH_BUG_OPENFAILURE)) { - packet_put_cstring("open failed"); - packet_put_cstring(""); - } - packet_send(); - } - xfree(ctype); -} -static void -client_input_channel_req(int type, u_int32_t seq, void *ctxt) -{ - Channel *c = NULL; - int exitval, id, reply, success = 0; - char *rtype; - - id = packet_get_int(); - 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 = channel_lookup(id)) == NULL) { - error("client_input_channel_req: channel %d: unknown channel", id); - } else if (strcmp(rtype, "exit-status") == 0) { - 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(id); - packet_send(); - } - xfree(rtype); -} -static void -client_input_global_request(int type, u_int32_t seq, void *ctxt) -{ - char *rtype; - int want_reply; - int success = 0; - - rtype = packet_get_string(NULL); - want_reply = packet_get_char(); - debug("client_input_global_request: rtype %s want_reply %d", - rtype, want_reply); - if (want_reply) { - packet_start(success ? - SSH2_MSG_REQUEST_SUCCESS : SSH2_MSG_REQUEST_FAILURE); - packet_send(); - packet_write_wait(); - } - 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; - Channel *c = NULL; - - debug2("%s: id %d", __func__, id); - - if ((c = channel_lookup(id)) == NULL) - fatal("client_session2_setup: channel %d: unknown channel", 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((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); - tio = get_saved_tio(); - tty_make_modes(-1, tiop != NULL ? tiop : &tio); - 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) { - 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) { - xfree(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); - xfree(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(); - xfree(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) -{ - 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_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); -} -static void -client_init_dispatch_13(void) -{ - dispatch_init(NULL); - dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_close); - dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_close_confirmation); - dispatch_set(SSH_MSG_CHANNEL_DATA, &channel_input_data); - dispatch_set(SSH_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation); - dispatch_set(SSH_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure); - dispatch_set(SSH_MSG_PORT_OPEN, &channel_input_port_open); - dispatch_set(SSH_SMSG_EXITSTATUS, &client_input_exit_status); - dispatch_set(SSH_SMSG_STDERR_DATA, &client_input_stderr_data); - dispatch_set(SSH_SMSG_STDOUT_DATA, &client_input_stdout_data); - - dispatch_set(SSH_SMSG_AGENT_OPEN, options.forward_agent ? - &client_input_agent_open : &deny_input_open); - dispatch_set(SSH_SMSG_X11_OPEN, options.forward_x11 ? - &x11_input_open : &deny_input_open); -} -static void -client_init_dispatch_15(void) -{ - client_init_dispatch_13(); - dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_ieof); - dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, & channel_input_oclose); -} -static void -client_init_dispatch(void) -{ - if (compat20) - client_init_dispatch_20(); - else if (compat13) - client_init_dispatch_13(); - else - client_init_dispatch_15(); -} - -/* client specific fatal cleanup */ -void -cleanup_exit(int i) -{ - leave_raw_mode(); - leave_non_blocking(); - if (options.control_path != NULL && control_fd != -1) - unlink(options.control_path); - _exit(i); -} |