diff options
Diffstat (limited to 'crypto/openssh/clientloop.c')
| -rw-r--r-- | crypto/openssh/clientloop.c | 1369 |
1 files changed, 0 insertions, 1369 deletions
diff --git a/crypto/openssh/clientloop.c b/crypto/openssh/clientloop.c deleted file mode 100644 index cd2eab77a9c0..000000000000 --- a/crypto/openssh/clientloop.c +++ /dev/null @@ -1,1369 +0,0 @@ -/* - * 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" -RCSID("$OpenBSD: clientloop.c,v 1.102 2002/06/24 14:33:27 markus Exp $"); - -#include "ssh.h" -#include "ssh1.h" -#include "ssh2.h" -#include "xmalloc.h" -#include "packet.h" -#include "buffer.h" -#include "compat.h" -#include "channels.h" -#include "dispatch.h" -#include "buffer.h" -#include "bufaux.h" -#include "key.h" -#include "kex.h" -#include "log.h" -#include "readconf.h" -#include "clientloop.h" -#include "authfd.h" -#include "atomicio.h" -#include "sshtty.h" -#include "misc.h" -#include "readpass.h" - -/* import options */ -extern Options options; - -/* Flag indicating that stdin should be redirected from /dev/null. */ -extern int stdin_null_flag; - -/* - * 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 int quit_pending; /* Set to non-zero to quit the client 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 void client_init_dispatch(void); -int session_ident = -1; - -/*XXX*/ -extern Kex *xxx_kex; - -/* Restores stdin to blocking mode. */ - -static void -leave_non_blocking(void) -{ - if (in_non_blocking_mode) { - (void) fcntl(fileno(stdin), F_SETFL, 0); - in_non_blocking_mode = 0; - fatal_remove_cleanup((void (*) (void *)) leave_non_blocking, NULL); - } -} - -/* Puts stdin terminal in non-blocking mode. */ - -static void -enter_non_blocking(void) -{ - in_non_blocking_mode = 1; - (void) fcntl(fileno(stdin), F_SETFL, O_NONBLOCK); - fatal_add_cleanup((void (*) (void *)) leave_non_blocking, NULL); -} - -/* - * Signal handler for the window change signal (SIGWINCH). This just sets a - * flag indicating that the window has changed. - */ - -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. - */ - -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; -} - -/* - * 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; - - if (ioctl(fileno(stdin), TIOCGWINSZ, &ws) < 0) - return; - - debug2("client_check_window_change: changed"); - - if (compat20) { - channel_request_start(session_ident, "window-change", 0); - packet_put_int(ws.ws_col); - packet_put_int(ws.ws_row); - packet_put_int(ws.ws_xpixel); - packet_put_int(ws.ws_ypixel); - packet_send(); - } else { - packet_start(SSH_CMSG_WINDOW_SIZE); - packet_put_int(ws.ws_row); - packet_put_int(ws.ws_col); - packet_put_int(ws.ws_xpixel); - packet_put_int(ws.ws_ypixel); - packet_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, int *nallocp, int rekeying) -{ - /* 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); - - /* - * Wait for something to happen. This will suspend the process until - * some selected descriptor can be read, written, or has some other - * event pending. Note: if you want to implement SSH_MSG_IGNORE - * messages to fool traffic analysis, this might be the place to do - * it: just have a random timeout for the select, and send a random - * SSH_MSG_IGNORE packet when the timeout expires. - */ - - if (select((*maxfdp)+1, *readsetp, *writesetp, NULL, NULL) < 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; - } -} - -static void -client_suspend_self(Buffer *bin, Buffer *bout, Buffer *berr) -{ - struct winsize oldws, newws; - - /* Flush stdout and stderr buffers. */ - if (buffer_len(bout) > 0) - atomicio(write, fileno(stdout), buffer_ptr(bout), buffer_len(bout)); - if (buffer_len(berr) > 0) - atomicio(write, 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); - - /* Save old window size. */ - ioctl(fileno(stdin), TIOCGWINSZ, &oldws); - - /* Send the suspend signal to the program itself. */ - kill(getpid(), SIGTSTP); - - /* Check if the window size has changed. */ - if (ioctl(fileno(stdin), TIOCGWINSZ, &newws) >= 0 && - (oldws.ws_row != newws.ws_row || - oldws.ws_col != newws.ws_col || - oldws.ws_xpixel != newws.ws_xpixel || - oldws.ws_ypixel != newws.ws_ypixel)) - 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 -process_cmdline(void) -{ - void (*handler)(int); - char *s, *cmd; - u_short fwd_port, fwd_host_port; - char buf[1024], sfwd_port[6], sfwd_host_port[6]; - int local = 0; - - 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 == 0) - goto out; - if (strlen(s) < 2 || s[0] != '-' || !(s[1] == 'L' || s[1] == 'R')) { - log("Invalid command."); - goto out; - } - if (s[1] == 'L') - local = 1; - if (!local && !compat20) { - log("Not supported for SSH protocol version 1."); - goto out; - } - s += 2; - while (*s && isspace(*s)) - s++; - - if (sscanf(s, "%5[0-9]:%255[^:]:%5[0-9]", - sfwd_port, buf, sfwd_host_port) != 3 && - sscanf(s, "%5[0-9]/%255[^/]/%5[0-9]", - sfwd_port, buf, sfwd_host_port) != 3) { - log("Bad forwarding specification."); - goto out; - } - if ((fwd_port = a2port(sfwd_port)) == 0 || - (fwd_host_port = a2port(sfwd_host_port)) == 0) { - log("Bad forwarding port(s)."); - goto out; - } - if (local) { - if (channel_setup_local_fwd_listener(fwd_port, buf, - fwd_host_port, options.gateway_ports) < 0) { - log("Port forwarding failed."); - goto out; - } - } else - channel_request_remote_forwarding(fwd_port, buf, - fwd_host_port); - log("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; - - for (i = 0; i < 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 'R': - if (compat20) { - if (datafellows & SSH_BUG_NOREKEY) - log("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\ -~. - terminate connection\r\n\ -~C - open a command line\r\n\ -~R - Request rekey (SSH protocol 2 only)\r\n\ -~^Z - suspend ssh\r\n\ -~# - list forwarded connections\r\n\ -~& - background ssh (when waiting for connections to terminate)\r\n\ -~? - this message\r\n\ -~~ - send the escape character by typing it twice\r\n\ -(Note that escapes are only recognized immediately after newline.)\r\n", - 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) -{ - if (id != session_ident) - error("client_channel_closed: id %d != session_ident %d", - id, session_ident); - channel_cancel_cleanup(id); - session_closed = 1; - if (in_raw_mode()) - 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, 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 (!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 to restore non-blocking mode. */ - signal(SIGINT, signal_handler); - signal(SIGQUIT, signal_handler); - signal(SIGTERM, signal_handler); - if (have_pty) - 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); - if (session_ident != -1) - channel_register_cleanup(session_ident, - client_channel_closed); - } 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) { - debug("user requests rekeying"); - xxx_kex->done = 0; - kex_send_kexinit(xxx_kex); - need_rekeying = 0; - } - } - - /* Buffer input from the connection. */ - client_process_net_input(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. */ - if (have_pty) - 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 (received_signal) { - if (in_non_blocking_mode) /* XXX */ - leave_non_blocking(); - 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 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, - xstrdup(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, - xstrdup("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, - xstrdup("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 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 (session_ident == -1) { - error("client_input_channel_req: no channel %d", session_ident); - } else if (id != session_ident) { - error("client_input_channel_req: channel %d: wrong channel: %d", - session_ident, id); - } - c = channel_lookup(id); - if (c == NULL) { - error("client_input_channel_req: channel %d: unknown channel", id); - } else if (strcmp(rtype, "exit-status") == 0) { - success = 1; - exit_status = packet_get_int(); - packet_check_eom(); - } - if (reply) { - packet_start(success ? - SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE); - packet_put_int(c->remote_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); -} - -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 ? - &auth_input_open_request : &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(); -} |