Initial revision
diff --git a/clientloop.c b/clientloop.c
new file mode 100644
index 0000000..43373b7
--- /dev/null
+++ b/clientloop.c
@@ -0,0 +1,924 @@
+/*
+
+clientloop.c
+
+Author: Tatu Ylonen <ylo@cs.hut.fi>
+
+Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
+ All rights reserved
+
+
+Created: Sat Sep 23 12:23:57 1995 ylo
+
+The main loop for the interactive session (client side).
+
+*/
+
+#include "includes.h"
+RCSID("$Id: clientloop.c,v 1.1 1999/10/27 03:42:44 damien Exp $");
+
+#include "xmalloc.h"
+#include "ssh.h"
+#include "packet.h"
+#include "buffer.h"
+#include "authfd.h"
+
+/* Flag indicating whether quiet mode is on. */
+extern int quiet_flag;
+
+/* 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 int received_window_change_signal = 0;
+
+/* Terminal modes, as saved by enter_raw_mode. */
+static struct termios saved_tio;
+
+/* Flag indicating whether we are in raw mode. This is used by enter_raw_mode
+ and leave_raw_mode. */
+static int in_raw_mode = 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 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 unsigned int buffer_high; /* Soft max buffer size. */
+static int max_fd; /* Maximum file descriptor number in select(). */
+static int connection_in; /* Connection to server (input). */
+static int connection_out; /* Connection to server (output). */
+static unsigned long stdin_bytes, stdout_bytes, stderr_bytes;
+static int quit_pending; /* Set to non-zero to quit the client loop. */
+static int escape_char; /* Escape character. */
+
+/* Returns the user\'s terminal to normal mode if it had been put in raw
+ mode. */
+
+void leave_raw_mode()
+{
+ if (!in_raw_mode)
+ return;
+ in_raw_mode = 0;
+ if (tcsetattr(fileno(stdin), TCSADRAIN, &saved_tio) < 0)
+ perror("tcsetattr");
+
+ fatal_remove_cleanup((void (*)(void *))leave_raw_mode, NULL);
+}
+
+/* Puts the user\'s terminal in raw mode. */
+
+void enter_raw_mode()
+{
+ struct termios tio;
+
+ if (tcgetattr(fileno(stdin), &tio) < 0)
+ perror("tcgetattr");
+ saved_tio = tio;
+ tio.c_iflag |= IGNPAR;
+ tio.c_iflag &= ~(ISTRIP|INLCR|IGNCR|ICRNL|IXON|IXANY|IXOFF);
+ tio.c_lflag &= ~(ISIG|ICANON|ECHO|ECHOE|ECHOK|ECHONL);
+#ifdef IEXTEN
+ tio.c_lflag &= ~IEXTEN;
+#endif /* IEXTEN */
+ tio.c_oflag &= ~OPOST;
+ tio.c_cc[VMIN] = 1;
+ tio.c_cc[VTIME] = 0;
+ if (tcsetattr(fileno(stdin), TCSADRAIN, &tio) < 0)
+ perror("tcsetattr");
+ in_raw_mode = 1;
+
+ fatal_add_cleanup((void (*)(void *))leave_raw_mode, NULL);
+}
+
+/* Puts stdin terminal in non-blocking mode. */
+
+/* Restores stdin to blocking mode. */
+
+void leave_non_blocking()
+{
+ 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);
+ }
+}
+
+void enter_non_blocking()
+{
+ 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. */
+
+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. */
+
+void signal_handler(int sig)
+{
+ if (in_raw_mode)
+ leave_raw_mode();
+ if (in_non_blocking_mode)
+ leave_non_blocking();
+ channel_stop_listening();
+ packet_close();
+ fatal("Killed by signal %d.", sig);
+}
+
+/* Returns current time in seconds from Jan 1, 1970 with the maximum available
+ resolution. */
+
+double get_current_time()
+{
+ 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. */
+
+void client_check_initial_eof_on_stdin()
+{
+ 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 mode for stdin. */
+ 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 ((unsigned char)buf[0] == escape_char)
+ escape_pending = 1;
+ else
+ {
+ buffer_append(&stdin_buffer, buf, 1);
+ stdin_bytes += 1;
+ }
+ }
+
+ /* Leave non-blocking mode. */
+ leave_non_blocking();
+ }
+}
+
+/* Get packets from the connection input buffer, and process them as long
+ as there are packets available. */
+
+void client_process_buffered_input_packets()
+{
+ int type;
+ char *data;
+ unsigned int data_len;
+ int payload_len;
+
+ /* Process any buffered packets from the server. */
+ while (!quit_pending && (type = packet_read_poll(&payload_len)) != SSH_MSG_NONE)
+ {
+ switch (type)
+ {
+
+ case SSH_SMSG_STDOUT_DATA:
+ data = packet_get_string(&data_len);
+ packet_integrity_check(payload_len, 4 + data_len, type);
+ buffer_append(&stdout_buffer, data, data_len);
+ stdout_bytes += data_len;
+ memset(data, 0, data_len);
+ xfree(data);
+ break;
+
+ case SSH_SMSG_STDERR_DATA:
+ data = packet_get_string(&data_len);
+ packet_integrity_check(payload_len, 4 + data_len, type);
+ buffer_append(&stderr_buffer, data, data_len);
+ stdout_bytes += data_len;
+ memset(data, 0, data_len);
+ xfree(data);
+ break;
+
+ case SSH_SMSG_EXITSTATUS:
+ packet_integrity_check(payload_len, 4, type);
+ exit_status = packet_get_int();
+ /* 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;
+ break;
+
+ case SSH_SMSG_X11_OPEN:
+ x11_input_open(payload_len);
+ break;
+
+ case SSH_MSG_PORT_OPEN:
+ channel_input_port_open(payload_len);
+ break;
+
+ case SSH_SMSG_AGENT_OPEN:
+ packet_integrity_check(payload_len, 4, type);
+ auth_input_open_request();
+ break;
+
+ case SSH_MSG_CHANNEL_OPEN_CONFIRMATION:
+ packet_integrity_check(payload_len, 4 + 4, type);
+ channel_input_open_confirmation();
+ break;
+
+ case SSH_MSG_CHANNEL_OPEN_FAILURE:
+ packet_integrity_check(payload_len, 4, type);
+ channel_input_open_failure();
+ break;
+
+ case SSH_MSG_CHANNEL_DATA:
+ channel_input_data(payload_len);
+ break;
+
+ case SSH_MSG_CHANNEL_CLOSE:
+ packet_integrity_check(payload_len, 4, type);
+ channel_input_close();
+ break;
+
+ case SSH_MSG_CHANNEL_CLOSE_CONFIRMATION:
+ packet_integrity_check(payload_len, 4, type);
+ channel_input_close_confirmation();
+ break;
+
+ default:
+ /* 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. */
+ packet_disconnect("Protocol error during session: type %d",
+ type);
+ }
+ }
+}
+
+/* Make packets from buffered stdin data, and buffer them for sending to
+ the connection. */
+
+void client_make_packets_from_stdin_data()
+{
+ unsigned 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);
+ if (len > 32768)
+ len = 32768; /* Keep the packets at reasonable size. */
+ packet_start(SSH_CMSG_STDIN_DATA);
+ packet_put_string(buffer_ptr(&stdin_buffer), len);
+ packet_send();
+ buffer_consume(&stdin_buffer, 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. */
+
+void client_check_window_change()
+{
+ /* Send possible window change message to the server. */
+ if (received_window_change_signal)
+ {
+ struct winsize ws;
+
+ /* Clear the window change indicator. */
+ received_window_change_signal = 0;
+
+ /* Read new window size. */
+ if (ioctl(fileno(stdin), TIOCGWINSZ, &ws) >= 0)
+ {
+ /* Successful, send the packet now. */
+ 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). */
+
+void client_wait_until_can_do_something(fd_set *readset, fd_set *writeset)
+{
+ /* Initialize select masks. */
+ FD_ZERO(readset);
+
+ /* 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, readset);
+
+ /* 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), readset);
+
+ FD_ZERO(writeset);
+
+ /* Add any selections by the channel mechanism. */
+ channel_prepare_select(readset, writeset);
+
+ /* Select server connection if have data to write to the server. */
+ if (packet_have_data_to_write())
+ FD_SET(connection_out, writeset);
+
+ /* Select stdout if have data in buffer. */
+ if (buffer_len(&stdout_buffer) > 0)
+ FD_SET(fileno(stdout), writeset);
+
+ /* Select stderr if have data in buffer. */
+ if (buffer_len(&stderr_buffer) > 0)
+ FD_SET(fileno(stderr), writeset);
+
+ /* Update maximum file descriptor number, if appropriate. */
+ if (channel_max_fd() > max_fd)
+ max_fd = channel_max_fd();
+
+ /* 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(max_fd + 1, readset, writeset, NULL, NULL) < 0)
+ {
+ char buf[100];
+ /* Some systems fail to clear these automatically. */
+ FD_ZERO(readset);
+ FD_ZERO(writeset);
+ 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));
+ stderr_bytes += strlen(buf);
+ quit_pending = 1;
+ }
+}
+
+void client_suspend_self()
+{
+ struct winsize oldws, newws;
+
+ /* Flush stdout and stderr buffers. */
+ if (buffer_len(&stdout_buffer) > 0)
+ write(fileno(stdout),
+ buffer_ptr(&stdout_buffer),
+ buffer_len(&stdout_buffer));
+ if (buffer_len(&stderr_buffer) > 0)
+ write(fileno(stderr),
+ buffer_ptr(&stderr_buffer),
+ buffer_len(&stderr_buffer));
+
+ /* Leave raw mode. */
+ leave_raw_mode();
+
+ /* Free (and clear) the buffer to reduce the
+ amount of data that gets written to swap. */
+ buffer_free(&stdin_buffer);
+ buffer_free(&stdout_buffer);
+ buffer_free(&stderr_buffer);
+
+ /* 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(&stdin_buffer);
+ buffer_init(&stdout_buffer);
+ buffer_init(&stderr_buffer);
+
+ /* Re-enter raw mode. */
+ enter_raw_mode();
+}
+
+void client_process_input(fd_set *readset)
+{
+ int len, pid;
+ char buf[8192], *s;
+
+ /* 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));
+ stderr_bytes += 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)
+ 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));
+ stderr_bytes += strlen(buf);
+ quit_pending = 1;
+ return;
+ }
+ packet_process_incoming(buf, len);
+ }
+
+ /* 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)
+ {
+ /* 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)
+{
+ 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 && !quiet_flag)
+ {
+ 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;
+}