924 lines
26 KiB
C
924 lines
26 KiB
C
/*
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clientloop.c
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Author: Tatu Ylonen <ylo@cs.hut.fi>
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Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
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All rights reserved
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Created: Sat Sep 23 12:23:57 1995 ylo
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The main loop for the interactive session (client side).
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*/
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#include "includes.h"
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RCSID("$Id: clientloop.c,v 1.3 1999/11/12 04:19:27 damien Exp $");
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#include "xmalloc.h"
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#include "ssh.h"
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#include "packet.h"
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#include "buffer.h"
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#include "authfd.h"
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#include "readconf.h"
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/* Flag indicating that stdin should be redirected from /dev/null. */
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extern int stdin_null_flag;
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/* Name of the host we are connecting to. This is the name given on the
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command line, or the HostName specified for the user-supplied name
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in a configuration file. */
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extern char *host;
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/* Flag to indicate that we have received a window change signal which has
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not yet been processed. This will cause a message indicating the new
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window size to be sent to the server a little later. This is volatile
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because this is updated in a signal handler. */
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static volatile int received_window_change_signal = 0;
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/* Terminal modes, as saved by enter_raw_mode. */
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static struct termios saved_tio;
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/* Flag indicating whether we are in raw mode. This is used by enter_raw_mode
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and leave_raw_mode. */
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static int in_raw_mode = 0;
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/* Flag indicating whether the user\'s terminal is in non-blocking mode. */
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static int in_non_blocking_mode = 0;
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/* Common data for the client loop code. */
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static int escape_pending; /* Last character was the escape character */
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static int last_was_cr; /* Last character was a newline. */
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static int exit_status; /* Used to store the exit status of the command. */
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static int stdin_eof; /* EOF has been encountered on standard error. */
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static Buffer stdin_buffer; /* Buffer for stdin data. */
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static Buffer stdout_buffer; /* Buffer for stdout data. */
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static Buffer stderr_buffer; /* Buffer for stderr data. */
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static unsigned int buffer_high; /* Soft max buffer size. */
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static int max_fd; /* Maximum file descriptor number in select(). */
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static int connection_in; /* Connection to server (input). */
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static int connection_out; /* Connection to server (output). */
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static unsigned long stdin_bytes, stdout_bytes, stderr_bytes;
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static int quit_pending; /* Set to non-zero to quit the client loop. */
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static int escape_char; /* Escape character. */
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/* Returns the user\'s terminal to normal mode if it had been put in raw
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mode. */
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void leave_raw_mode()
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{
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if (!in_raw_mode)
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return;
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in_raw_mode = 0;
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if (tcsetattr(fileno(stdin), TCSADRAIN, &saved_tio) < 0)
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perror("tcsetattr");
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fatal_remove_cleanup((void (*)(void *))leave_raw_mode, NULL);
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}
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/* Puts the user\'s terminal in raw mode. */
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void enter_raw_mode()
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{
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struct termios tio;
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if (tcgetattr(fileno(stdin), &tio) < 0)
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perror("tcgetattr");
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saved_tio = tio;
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tio.c_iflag |= IGNPAR;
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tio.c_iflag &= ~(ISTRIP|INLCR|IGNCR|ICRNL|IXON|IXANY|IXOFF);
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tio.c_lflag &= ~(ISIG|ICANON|ECHO|ECHOE|ECHOK|ECHONL);
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#ifdef IEXTEN
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tio.c_lflag &= ~IEXTEN;
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#endif /* IEXTEN */
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tio.c_oflag &= ~OPOST;
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tio.c_cc[VMIN] = 1;
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tio.c_cc[VTIME] = 0;
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if (tcsetattr(fileno(stdin), TCSADRAIN, &tio) < 0)
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perror("tcsetattr");
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in_raw_mode = 1;
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fatal_add_cleanup((void (*)(void *))leave_raw_mode, NULL);
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}
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/* Puts stdin terminal in non-blocking mode. */
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/* Restores stdin to blocking mode. */
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void leave_non_blocking()
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{
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if (in_non_blocking_mode)
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{
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(void)fcntl(fileno(stdin), F_SETFL, 0);
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in_non_blocking_mode = 0;
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fatal_remove_cleanup((void (*)(void *))leave_non_blocking, NULL);
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}
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}
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void enter_non_blocking()
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{
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in_non_blocking_mode = 1;
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(void)fcntl(fileno(stdin), F_SETFL, O_NONBLOCK);
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fatal_add_cleanup((void (*)(void *))leave_non_blocking, NULL);
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}
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/* Signal handler for the window change signal (SIGWINCH). This just
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sets a flag indicating that the window has changed. */
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void window_change_handler(int sig)
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{
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received_window_change_signal = 1;
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signal(SIGWINCH, window_change_handler);
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}
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/* Signal handler for signals that cause the program to terminate. These
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signals must be trapped to restore terminal modes. */
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void signal_handler(int sig)
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{
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if (in_raw_mode)
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leave_raw_mode();
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if (in_non_blocking_mode)
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leave_non_blocking();
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channel_stop_listening();
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packet_close();
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fatal("Killed by signal %d.", sig);
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}
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/* Returns current time in seconds from Jan 1, 1970 with the maximum available
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resolution. */
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double get_current_time()
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{
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struct timeval tv;
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gettimeofday(&tv, NULL);
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return (double)tv.tv_sec + (double)tv.tv_usec / 1000000.0;
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}
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/* This is called when the interactive is entered. This checks if there
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is an EOF coming on stdin. We must check this explicitly, as select()
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does not appear to wake up when redirecting from /dev/null. */
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void client_check_initial_eof_on_stdin()
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{
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int len;
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char buf[1];
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/* If standard input is to be "redirected from /dev/null", we simply
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mark that we have seen an EOF and send an EOF message to the server.
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Otherwise, we try to read a single character; it appears that for some
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files, such /dev/null, select() never wakes up for read for this
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descriptor, which means that we never get EOF. This way we will get
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the EOF if stdin comes from /dev/null or similar. */
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if (stdin_null_flag)
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{
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/* Fake EOF on stdin. */
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debug("Sending eof.");
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stdin_eof = 1;
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packet_start(SSH_CMSG_EOF);
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packet_send();
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}
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else
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{
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/* Enter non-blocking mode for stdin. */
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enter_non_blocking();
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/* Check for immediate EOF on stdin. */
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len = read(fileno(stdin), buf, 1);
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if (len == 0)
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{
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/* EOF. Record that we have seen it and send EOF to server. */
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debug("Sending eof.");
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stdin_eof = 1;
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packet_start(SSH_CMSG_EOF);
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packet_send();
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}
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else
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if (len > 0)
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{
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/* Got data. We must store the data in the buffer, and also
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process it as an escape character if appropriate. */
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if ((unsigned char)buf[0] == escape_char)
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escape_pending = 1;
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else
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{
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buffer_append(&stdin_buffer, buf, 1);
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stdin_bytes += 1;
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}
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}
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/* Leave non-blocking mode. */
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leave_non_blocking();
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}
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}
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/* Get packets from the connection input buffer, and process them as long
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as there are packets available. */
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void client_process_buffered_input_packets()
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{
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int type;
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char *data;
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unsigned int data_len;
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int payload_len;
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/* Process any buffered packets from the server. */
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while (!quit_pending && (type = packet_read_poll(&payload_len)) != SSH_MSG_NONE)
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{
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switch (type)
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{
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case SSH_SMSG_STDOUT_DATA:
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data = packet_get_string(&data_len);
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packet_integrity_check(payload_len, 4 + data_len, type);
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buffer_append(&stdout_buffer, data, data_len);
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stdout_bytes += data_len;
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memset(data, 0, data_len);
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xfree(data);
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break;
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case SSH_SMSG_STDERR_DATA:
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data = packet_get_string(&data_len);
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packet_integrity_check(payload_len, 4 + data_len, type);
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buffer_append(&stderr_buffer, data, data_len);
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stdout_bytes += data_len;
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memset(data, 0, data_len);
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xfree(data);
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break;
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case SSH_SMSG_EXITSTATUS:
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packet_integrity_check(payload_len, 4, type);
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exit_status = packet_get_int();
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/* Acknowledge the exit. */
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packet_start(SSH_CMSG_EXIT_CONFIRMATION);
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packet_send();
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/* Must wait for packet to be sent since we are exiting the
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loop. */
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packet_write_wait();
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/* Flag that we want to exit. */
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quit_pending = 1;
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break;
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case SSH_SMSG_X11_OPEN:
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x11_input_open(payload_len);
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break;
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case SSH_MSG_PORT_OPEN:
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channel_input_port_open(payload_len);
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break;
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case SSH_SMSG_AGENT_OPEN:
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packet_integrity_check(payload_len, 4, type);
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auth_input_open_request();
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break;
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case SSH_MSG_CHANNEL_OPEN_CONFIRMATION:
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packet_integrity_check(payload_len, 4 + 4, type);
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channel_input_open_confirmation();
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break;
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case SSH_MSG_CHANNEL_OPEN_FAILURE:
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packet_integrity_check(payload_len, 4, type);
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channel_input_open_failure();
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break;
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case SSH_MSG_CHANNEL_DATA:
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channel_input_data(payload_len);
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break;
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case SSH_MSG_CHANNEL_CLOSE:
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packet_integrity_check(payload_len, 4, type);
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channel_input_close();
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break;
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case SSH_MSG_CHANNEL_CLOSE_CONFIRMATION:
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packet_integrity_check(payload_len, 4, type);
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channel_input_close_confirmation();
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break;
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default:
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/* Any unknown packets received during the actual session
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cause the session to terminate. This is intended to make
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debugging easier since no confirmations are sent. Any
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compatible protocol extensions must be negotiated during
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the preparatory phase. */
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packet_disconnect("Protocol error during session: type %d",
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type);
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}
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}
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}
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/* Make packets from buffered stdin data, and buffer them for sending to
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the connection. */
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void client_make_packets_from_stdin_data()
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{
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unsigned int len;
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/* Send buffered stdin data to the server. */
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while (buffer_len(&stdin_buffer) > 0 &&
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packet_not_very_much_data_to_write())
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{
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len = buffer_len(&stdin_buffer);
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if (len > 32768)
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len = 32768; /* Keep the packets at reasonable size. */
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packet_start(SSH_CMSG_STDIN_DATA);
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packet_put_string(buffer_ptr(&stdin_buffer), len);
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packet_send();
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buffer_consume(&stdin_buffer, len);
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/* If we have a pending EOF, send it now. */
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if (stdin_eof && buffer_len(&stdin_buffer) == 0)
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{
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packet_start(SSH_CMSG_EOF);
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packet_send();
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}
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}
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}
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/* Checks if the client window has changed, and sends a packet about it to
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the server if so. The actual change is detected elsewhere (by a software
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interrupt on Unix); this just checks the flag and sends a message if
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appropriate. */
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void client_check_window_change()
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{
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/* Send possible window change message to the server. */
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if (received_window_change_signal)
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{
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struct winsize ws;
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/* Clear the window change indicator. */
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received_window_change_signal = 0;
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/* Read new window size. */
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if (ioctl(fileno(stdin), TIOCGWINSZ, &ws) >= 0)
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{
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/* Successful, send the packet now. */
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packet_start(SSH_CMSG_WINDOW_SIZE);
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packet_put_int(ws.ws_row);
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packet_put_int(ws.ws_col);
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packet_put_int(ws.ws_xpixel);
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packet_put_int(ws.ws_ypixel);
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packet_send();
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}
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}
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}
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/* Waits until the client can do something (some data becomes available on
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one of the file descriptors). */
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void client_wait_until_can_do_something(fd_set *readset, fd_set *writeset)
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{
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/* Initialize select masks. */
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FD_ZERO(readset);
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/* Read from the connection, unless our buffers are full. */
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if (buffer_len(&stdout_buffer) < buffer_high &&
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buffer_len(&stderr_buffer) < buffer_high &&
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channel_not_very_much_buffered_data())
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FD_SET(connection_in, readset);
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/* Read from stdin, unless we have seen EOF or have very much buffered
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data to send to the server. */
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if (!stdin_eof && packet_not_very_much_data_to_write())
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FD_SET(fileno(stdin), readset);
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FD_ZERO(writeset);
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/* Add any selections by the channel mechanism. */
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channel_prepare_select(readset, writeset);
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/* Select server connection if have data to write to the server. */
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if (packet_have_data_to_write())
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FD_SET(connection_out, writeset);
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/* Select stdout if have data in buffer. */
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if (buffer_len(&stdout_buffer) > 0)
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FD_SET(fileno(stdout), writeset);
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/* Select stderr if have data in buffer. */
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if (buffer_len(&stderr_buffer) > 0)
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FD_SET(fileno(stderr), writeset);
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/* Update maximum file descriptor number, if appropriate. */
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if (channel_max_fd() > max_fd)
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max_fd = channel_max_fd();
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/* Wait for something to happen. This will suspend the process until
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some selected descriptor can be read, written, or has some other
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event pending. Note: if you want to implement SSH_MSG_IGNORE
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messages to fool traffic analysis, this might be the place to do
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it: just have a random timeout for the select, and send a random
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SSH_MSG_IGNORE packet when the timeout expires. */
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if (select(max_fd + 1, readset, writeset, NULL, NULL) < 0)
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{
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char buf[100];
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/* Some systems fail to clear these automatically. */
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FD_ZERO(readset);
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FD_ZERO(writeset);
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if (errno == EINTR)
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return;
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/* Note: we might still have data in the buffers. */
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snprintf(buf, sizeof buf, "select: %s\r\n", strerror(errno));
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buffer_append(&stderr_buffer, buf, strlen(buf));
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stderr_bytes += strlen(buf);
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quit_pending = 1;
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}
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}
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void client_suspend_self()
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{
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struct winsize oldws, newws;
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/* Flush stdout and stderr buffers. */
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if (buffer_len(&stdout_buffer) > 0)
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write(fileno(stdout),
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buffer_ptr(&stdout_buffer),
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buffer_len(&stdout_buffer));
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if (buffer_len(&stderr_buffer) > 0)
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write(fileno(stderr),
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buffer_ptr(&stderr_buffer),
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buffer_len(&stderr_buffer));
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/* Leave raw mode. */
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leave_raw_mode();
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/* Free (and clear) the buffer to reduce the
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amount of data that gets written to swap. */
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buffer_free(&stdin_buffer);
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buffer_free(&stdout_buffer);
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buffer_free(&stderr_buffer);
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/* Save old window size. */
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ioctl(fileno(stdin), TIOCGWINSZ, &oldws);
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/* Send the suspend signal to the program
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itself. */
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kill(getpid(), SIGTSTP);
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/* Check if the window size has changed. */
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if (ioctl(fileno(stdin), TIOCGWINSZ, &newws) >= 0 &&
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(oldws.ws_row != newws.ws_row || oldws.ws_col != newws.ws_col ||
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oldws.ws_xpixel != newws.ws_xpixel ||
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oldws.ws_ypixel != newws.ws_ypixel))
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received_window_change_signal = 1;
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/* OK, we have been continued by the user.
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Reinitialize buffers. */
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buffer_init(&stdin_buffer);
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buffer_init(&stdout_buffer);
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buffer_init(&stderr_buffer);
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/* Re-enter raw mode. */
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enter_raw_mode();
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}
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void client_process_input(fd_set *readset)
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{
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int len, pid;
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char buf[8192], *s;
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/* Read input from the server, and add any such data to the buffer of the
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packet subsystem. */
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if (FD_ISSET(connection_in, readset))
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{
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/* Read as much as possible. */
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len = read(connection_in, buf, sizeof(buf));
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if (len == 0)
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{
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/* Received EOF. The remote host has closed the connection. */
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snprintf(buf, sizeof buf, "Connection to %.300s closed by remote host.\r\n",
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host);
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buffer_append(&stderr_buffer, buf, strlen(buf));
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stderr_bytes += strlen(buf);
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quit_pending = 1;
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return;
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}
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/* There is a kernel bug on Solaris that causes select to sometimes
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wake up even though there is no data available. */
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if (len < 0 && errno == EAGAIN)
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len = 0;
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if (len < 0)
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{
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/* An error has encountered. Perhaps there is a network
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problem. */
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snprintf(buf, sizeof buf, "Read from remote host %.300s: %.100s\r\n",
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host, strerror(errno));
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buffer_append(&stderr_buffer, buf, strlen(buf));
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stderr_bytes += strlen(buf);
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quit_pending = 1;
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return;
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}
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packet_process_incoming(buf, len);
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}
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/* Read input from stdin. */
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if (FD_ISSET(fileno(stdin), readset))
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{
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/* Read as much as possible. */
|
|
len = read(fileno(stdin), buf, sizeof(buf));
|
|
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));
|
|
stderr_bytes += 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 == -1)
|
|
{
|
|
/* Normal successful read, and no escape character. Just
|
|
append the data to buffer. */
|
|
buffer_append(&stdin_buffer, buf, len);
|
|
stdin_bytes += len;
|
|
}
|
|
else
|
|
{
|
|
/* Normal, successful read. But we have an escape character
|
|
and have to process the characters one by one. */
|
|
unsigned int i;
|
|
for (i = 0; i < len; i++)
|
|
{
|
|
unsigned char ch;
|
|
/* Get one character at a time. */
|
|
ch = buf[i];
|
|
|
|
/* Check if we have a pending escape character. */
|
|
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(buf, sizeof buf, "%c.\r\n", escape_char);
|
|
buffer_append(&stderr_buffer, buf, strlen(buf));
|
|
stderr_bytes += strlen(buf);
|
|
quit_pending = 1;
|
|
return;
|
|
|
|
case 'Z' - 64:
|
|
/* Suspend the program. */
|
|
/* Print a message to that effect to the user. */
|
|
snprintf(buf, sizeof buf, "%c^Z\r\n", escape_char);
|
|
buffer_append(&stderr_buffer, buf, strlen(buf));
|
|
stderr_bytes += strlen(buf);
|
|
|
|
/* Restore terminal modes and suspend. */
|
|
client_suspend_self();
|
|
|
|
/* We have been continued. */
|
|
continue;
|
|
|
|
case '&':
|
|
/* Detach the program (continue to serve connections,
|
|
but put in background and no more new
|
|
connections). */
|
|
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(&stdin_buffer) == 0)
|
|
{
|
|
packet_start(SSH_CMSG_EOF);
|
|
packet_send();
|
|
}
|
|
}
|
|
/* Restore tty modes. */
|
|
leave_raw_mode();
|
|
|
|
/* Stop listening for new connections. */
|
|
channel_stop_listening();
|
|
|
|
printf("%c& [backgrounded]\n", escape_char);
|
|
|
|
/* 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. */
|
|
continue;
|
|
|
|
case '?':
|
|
snprintf(buf, sizeof buf, "%c?\r\n\
|
|
Supported escape sequences:\r\n\
|
|
~. - terminate connection\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(&stderr_buffer, buf, strlen(buf));
|
|
continue;
|
|
|
|
case '#':
|
|
snprintf(buf, sizeof buf, "%c#\r\n", escape_char);
|
|
buffer_append(&stderr_buffer, buf, strlen(buf));
|
|
s = channel_open_message();
|
|
buffer_append(&stderr_buffer, s, strlen(s));
|
|
xfree(s);
|
|
continue;
|
|
|
|
default:
|
|
if (ch != escape_char)
|
|
{
|
|
/* Escape character followed by non-special
|
|
character. Append both to the input
|
|
buffer. */
|
|
buf[0] = escape_char;
|
|
buf[1] = ch;
|
|
buffer_append(&stdin_buffer, buf, 2);
|
|
stdin_bytes += 2;
|
|
continue;
|
|
}
|
|
/* Note that escape character typed twice falls through
|
|
here; the latter gets processed as a normal
|
|
character below. */
|
|
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');
|
|
buf[0] = ch;
|
|
buffer_append(&stdin_buffer, buf, 1);
|
|
stdin_bytes += 1;
|
|
continue;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
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 == 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));
|
|
stderr_bytes += strlen(buf);
|
|
quit_pending = 1;
|
|
return;
|
|
}
|
|
}
|
|
/* Consume printed data from the buffer. */
|
|
buffer_consume(&stdout_buffer, 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 == 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);
|
|
}
|
|
}
|
|
|
|
/* 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 != -1, 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)
|
|
{
|
|
extern Options options;
|
|
double start_time, total_time;
|
|
int len;
|
|
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 = connection_in;
|
|
if (connection_out > max_fd)
|
|
max_fd = connection_out;
|
|
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);
|
|
|
|
/* Set signal handlers to restore non-blocking mode. */
|
|
signal(SIGINT, signal_handler);
|
|
signal(SIGQUIT, signal_handler);
|
|
signal(SIGTERM, signal_handler);
|
|
signal(SIGPIPE, SIG_IGN);
|
|
if (have_pty)
|
|
signal(SIGWINCH, window_change_handler);
|
|
|
|
/* Enter raw mode if have a pseudo terminal. */
|
|
if (have_pty)
|
|
enter_raw_mode();
|
|
|
|
/* Check if we should immediately send of on stdin. */
|
|
client_check_initial_eof_on_stdin();
|
|
|
|
/* Main loop of the client for the interactive session mode. */
|
|
while (!quit_pending)
|
|
{
|
|
fd_set readset, writeset;
|
|
|
|
/* Precess buffered packets sent by the server. */
|
|
client_process_buffered_input_packets();
|
|
|
|
/* Make packets of buffered stdin data, and buffer them for sending
|
|
to the server. */
|
|
client_make_packets_from_stdin_data();
|
|
|
|
/* Make packets from buffered channel data, and buffer 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). */
|
|
client_wait_until_can_do_something(&readset, &writeset);
|
|
|
|
if (quit_pending)
|
|
break;
|
|
|
|
/* Do channel operations. */
|
|
channel_after_select(&readset, &writeset);
|
|
|
|
/* Process input from the connection and from stdin. Buffer any data
|
|
that is available. */
|
|
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();
|
|
}
|
|
|
|
/* Terminate the session. */
|
|
|
|
/* Stop watching for window change. */
|
|
if (have_pty)
|
|
signal(SIGWINCH, SIG_DFL);
|
|
|
|
/* Stop listening for connections. */
|
|
channel_stop_listening();
|
|
|
|
/* 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));
|
|
stderr_bytes += 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);
|
|
}
|
|
|
|
/* 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);
|
|
}
|
|
|
|
/* Leave raw mode. */
|
|
if (have_pty)
|
|
leave_raw_mode();
|
|
|
|
/* 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;
|
|
}
|