* Author: Tatu Ylonen <ylo@cs.hut.fi>
* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
* All rights reserved
- * Created: Sun Sep 10 00:30:37 1995 ylo
* Server main loop for handling the interactive session.
+ *
+ * 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".
+ *
+ * SSH2 support by Markus Friedl.
+ * Copyright (c) 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: serverloop.c,v 1.101 2002/03/30 18:51:15 markus Exp $");
+
#include "xmalloc.h"
-#include "ssh.h"
#include "packet.h"
#include "buffer.h"
+#include "log.h"
#include "servconf.h"
-#include "pty.h"
+#include "sshpty.h"
+#include "channels.h"
+#include "compat.h"
+#include "ssh1.h"
+#include "ssh2.h"
+#include "auth.h"
+#include "session.h"
+#include "dispatch.h"
+#include "auth-options.h"
+#include "serverloop.h"
+#include "misc.h"
+#include "kex.h"
+
+extern ServerOptions options;
+
+/* XXX */
+extern Kex *xxx_kex;
+static Authctxt *xxx_authctxt;
static Buffer stdin_buffer; /* Buffer for stdin data. */
static Buffer stdout_buffer; /* Buffer for stdout data. */
static int stdin_eof = 0; /* EOF message received from client. */
static int fdout_eof = 0; /* EOF encountered reading from fdout. */
static int fderr_eof = 0; /* EOF encountered readung from fderr. */
+static int fdin_is_tty = 0; /* fdin points to a tty. */
static int connection_in; /* Connection to client (input). */
static int connection_out; /* Connection to client (output). */
-static unsigned int buffer_high;/* "Soft" max buffer size. */
-static int max_fd; /* Max file descriptor number for select(). */
+static int connection_closed = 0; /* Connection to client closed. */
+static u_int buffer_high; /* "Soft" max buffer size. */
+static int client_alive_timeouts = 0;
/*
* This SIGCHLD kludge is used to detect when the child exits. The server
* will exit after that, as soon as forwarded connections have terminated.
*/
-static int child_pid; /* Pid of the child. */
-static volatile int child_terminated; /* The child has terminated. */
-static volatile int child_wait_status; /* Status from wait(). */
+static volatile sig_atomic_t child_terminated = 0; /* The child has terminated. */
-void
-sigchld_handler(int sig)
-{
- int save_errno = errno;
- int wait_pid;
- debug("Received SIGCHLD.");
- wait_pid = wait((int *) &child_wait_status);
- if (wait_pid != -1) {
- if (wait_pid != child_pid)
- error("Strange, got SIGCHLD and wait returned pid %d but child is %d",
- wait_pid, child_pid);
- if (WIFEXITED(child_wait_status) ||
- WIFSIGNALED(child_wait_status))
- child_terminated = 1;
- }
- signal(SIGCHLD, sigchld_handler);
- errno = save_errno;
-}
+/* prototypes */
+static void server_init_dispatch(void);
/*
- * Process any buffered packets that have been received from the client.
+ * we write to this pipe if a SIGCHLD is caught in order to avoid
+ * the race between select() and child_terminated
*/
-void
-process_buffered_input_packets()
+static int notify_pipe[2];
+static void
+notify_setup(void)
{
- int type;
- char *data;
- unsigned int data_len;
- int row, col, xpixel, ypixel;
- int payload_len;
-
- /* Process buffered packets from the client. */
- while ((type = packet_read_poll(&payload_len)) != SSH_MSG_NONE) {
- switch (type) {
- case SSH_CMSG_STDIN_DATA:
- /* Stdin data from the client. Append it to the buffer. */
- /* Ignore any data if the client has closed stdin. */
- if (fdin == -1)
- break;
- data = packet_get_string(&data_len);
- packet_integrity_check(payload_len, (4 + data_len), type);
- buffer_append(&stdin_buffer, data, data_len);
- memset(data, 0, data_len);
- xfree(data);
- break;
-
- case SSH_CMSG_EOF:
- /*
- * Eof from the client. The stdin descriptor to the
- * program will be closed when all buffered data has
- * drained.
- */
- debug("EOF received for stdin.");
- packet_integrity_check(payload_len, 0, type);
- stdin_eof = 1;
- break;
-
- case SSH_CMSG_WINDOW_SIZE:
- debug("Window change received.");
- packet_integrity_check(payload_len, 4 * 4, type);
- row = packet_get_int();
- col = packet_get_int();
- xpixel = packet_get_int();
- ypixel = packet_get_int();
- if (fdin != -1)
- pty_change_window_size(fdin, row, col, xpixel, ypixel);
- break;
-
- case SSH_MSG_PORT_OPEN:
- debug("Received port open request.");
- channel_input_port_open(payload_len);
- break;
-
- case SSH_MSG_CHANNEL_OPEN_CONFIRMATION:
- debug("Received channel open confirmation.");
- packet_integrity_check(payload_len, 4 + 4, type);
- channel_input_open_confirmation();
- break;
-
- case SSH_MSG_CHANNEL_OPEN_FAILURE:
- debug("Received 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:
- debug("Received channel close.");
- packet_integrity_check(payload_len, 4, type);
- channel_input_close();
- break;
+ if (pipe(notify_pipe) < 0) {
+ error("pipe(notify_pipe) failed %s", strerror(errno));
+ } else if ((fcntl(notify_pipe[0], F_SETFD, 1) == -1) ||
+ (fcntl(notify_pipe[1], F_SETFD, 1) == -1)) {
+ error("fcntl(notify_pipe, F_SETFD) failed %s", strerror(errno));
+ close(notify_pipe[0]);
+ close(notify_pipe[1]);
+ } else {
+ set_nonblock(notify_pipe[0]);
+ set_nonblock(notify_pipe[1]);
+ return;
+ }
+ notify_pipe[0] = -1; /* read end */
+ notify_pipe[1] = -1; /* write end */
+}
+static void
+notify_parent(void)
+{
+ if (notify_pipe[1] != -1)
+ write(notify_pipe[1], "", 1);
+}
+static void
+notify_prepare(fd_set *readset)
+{
+ if (notify_pipe[0] != -1)
+ FD_SET(notify_pipe[0], readset);
+}
+static void
+notify_done(fd_set *readset)
+{
+ char c;
- case SSH_MSG_CHANNEL_CLOSE_CONFIRMATION:
- debug("Received channel close confirmation.");
- packet_integrity_check(payload_len, 4, type);
- channel_input_close_confirmation();
- break;
+ if (notify_pipe[0] != -1 && FD_ISSET(notify_pipe[0], readset))
+ while (read(notify_pipe[0], &c, 1) != -1)
+ debug2("notify_done: reading");
+}
- default:
- /*
- * In this phase, any unexpected messages cause a
- * protocol error. This is to ease debugging; also,
- * since no confirmations are sent messages,
- * unprocessed unknown messages could cause strange
- * problems. Any compatible protocol extensions must
- * be negotiated before entering the interactive
- * session.
- */
- packet_disconnect("Protocol error during session: type %d",
- type);
- }
- }
+static void
+sigchld_handler(int sig)
+{
+ int save_errno = errno;
+ debug("Received SIGCHLD.");
+ child_terminated = 1;
+ mysignal(SIGCHLD, sigchld_handler);
+ notify_parent();
+ errno = save_errno;
}
/*
* Make packets from buffered stderr data, and buffer it for sending
* to the client.
*/
-void
-make_packets_from_stderr_data()
+static void
+make_packets_from_stderr_data(void)
{
int len;
/* Send buffered stderr data to the client. */
while (buffer_len(&stderr_buffer) > 0 &&
- packet_not_very_much_data_to_write()) {
+ packet_not_very_much_data_to_write()) {
len = buffer_len(&stderr_buffer);
if (packet_is_interactive()) {
if (len > 512)
* Make packets from buffered stdout data, and buffer it for sending to the
* client.
*/
-void
-make_packets_from_stdout_data()
+static void
+make_packets_from_stdout_data(void)
{
int len;
/* Send buffered stdout data to the client. */
while (buffer_len(&stdout_buffer) > 0 &&
- packet_not_very_much_data_to_write()) {
+ packet_not_very_much_data_to_write()) {
len = buffer_len(&stdout_buffer);
if (packet_is_interactive()) {
if (len > 512)
} else {
/* Keep the packets at reasonable size. */
if (len > packet_get_maxsize())
- len = packet_get_maxsize();
+ len = packet_get_maxsize();
}
packet_start(SSH_SMSG_STDOUT_DATA);
packet_put_string(buffer_ptr(&stdout_buffer), len);
}
}
+static void
+client_alive_check(void)
+{
+ static int had_channel = 0;
+ int id;
+
+ id = channel_find_open();
+ if (id == -1) {
+ if (!had_channel)
+ return;
+ packet_disconnect("No open channels after timeout!");
+ }
+ had_channel = 1;
+
+ /* timeout, check to see how many we have had */
+ if (++client_alive_timeouts > options.client_alive_count_max)
+ packet_disconnect("Timeout, your session not responding.");
+
+ /*
+ * send a bogus channel request with "wantreply",
+ * we should get back a failure
+ */
+ channel_request_start(id, "keepalive@openssh.com", 1);
+ packet_send();
+}
+
/*
* Sleep in select() until we can do something. This will initialize the
* select masks. Upon return, the masks will indicate which descriptors
* have data or can accept data. Optionally, a maximum time can be specified
* for the duration of the wait (0 = infinite).
*/
-void
-wait_until_can_do_something(fd_set * readset, fd_set * writeset,
- unsigned int max_time_milliseconds)
+static void
+wait_until_can_do_something(fd_set **readsetp, fd_set **writesetp, int *maxfdp,
+ int *nallocp, u_int max_time_milliseconds)
{
struct timeval tv, *tvp;
int ret;
-
- /* When select fails we restart from here. */
-retry_select:
-
- /* Initialize select() masks. */
- FD_ZERO(readset);
-
- /*
- * Read packets from the client unless we have too much buffered
- * stdin or channel data.
- */
- if (buffer_len(&stdin_buffer) < 4096 &&
- channel_not_very_much_buffered_data())
- FD_SET(connection_in, readset);
+ int client_alive_scheduled = 0;
/*
- * If there is not too much data already buffered going to the
- * client, try to get some more data from the program.
+ * if using client_alive, set the max timeout accordingly,
+ * and indicate that this particular timeout was for client
+ * alive by setting the client_alive_scheduled flag.
+ *
+ * this could be randomized somewhat to make traffic
+ * analysis more difficult, but we're not doing it yet.
*/
- if (packet_not_very_much_data_to_write()) {
- if (!fdout_eof)
- FD_SET(fdout, readset);
- if (!fderr_eof)
- FD_SET(fderr, readset);
+ if (compat20 &&
+ max_time_milliseconds == 0 && options.client_alive_interval) {
+ client_alive_scheduled = 1;
+ max_time_milliseconds = options.client_alive_interval * 1000;
}
- FD_ZERO(writeset);
- /* Set masks for channel descriptors. */
- channel_prepare_select(readset, writeset);
+ /* Allocate and update select() masks for channel descriptors. */
+ channel_prepare_select(readsetp, writesetp, maxfdp, nallocp, 0);
+
+ if (compat20) {
+#if 0
+ /* wrong: bad condition XXX */
+ if (channel_not_very_much_buffered_data())
+#endif
+ FD_SET(connection_in, *readsetp);
+ } else {
+ /*
+ * Read packets from the client unless we have too much
+ * buffered stdin or channel data.
+ */
+ if (buffer_len(&stdin_buffer) < buffer_high &&
+ channel_not_very_much_buffered_data())
+ FD_SET(connection_in, *readsetp);
+ /*
+ * If there is not too much data already buffered going to
+ * the client, try to get some more data from the program.
+ */
+ if (packet_not_very_much_data_to_write()) {
+ if (!fdout_eof)
+ FD_SET(fdout, *readsetp);
+ if (!fderr_eof)
+ FD_SET(fderr, *readsetp);
+ }
+ /*
+ * If we have buffered data, try to write some of that data
+ * to the program.
+ */
+ if (fdin != -1 && buffer_len(&stdin_buffer) > 0)
+ FD_SET(fdin, *writesetp);
+ }
+ notify_prepare(*readsetp);
/*
* If we have buffered packet data going to the client, mark that
* descriptor.
*/
if (packet_have_data_to_write())
- FD_SET(connection_out, writeset);
-
- /* If we have buffered data, try to write some of that data to the
- program. */
- if (fdin != -1 && buffer_len(&stdin_buffer) > 0)
- FD_SET(fdin, writeset);
-
- /* Update the maximum descriptor number if appropriate. */
- if (channel_max_fd() > max_fd)
- max_fd = channel_max_fd();
+ FD_SET(connection_out, *writesetp);
/*
* If child has terminated and there is enough buffer space to read
* from it, then read as much as is available and exit.
*/
if (child_terminated && packet_not_very_much_data_to_write())
- if (max_time_milliseconds == 0)
+ if (max_time_milliseconds == 0 || client_alive_scheduled)
max_time_milliseconds = 100;
if (max_time_milliseconds == 0)
}
/* Wait for something to happen, or the timeout to expire. */
- ret = select(max_fd + 1, readset, writeset, NULL, tvp);
+ ret = select((*maxfdp)+1, *readsetp, *writesetp, NULL, tvp);
- if (ret < 0) {
+ if (ret == -1) {
+ memset(*readsetp, 0, *nallocp);
+ memset(*writesetp, 0, *nallocp);
if (errno != EINTR)
error("select: %.100s", strerror(errno));
- else
- goto retry_select;
- }
+ } else if (ret == 0 && client_alive_scheduled)
+ client_alive_check();
+
+ notify_done(*readsetp);
}
/*
* Processes input from the client and the program. Input data is stored
* in buffers and processed later.
*/
-void
+static void
process_input(fd_set * readset)
{
int len;
len = read(connection_in, buf, sizeof(buf));
if (len == 0) {
verbose("Connection closed by remote host.");
+ connection_closed = 1;
+ if (compat20)
+ return;
fatal_cleanup();
+ } else if (len < 0) {
+ if (errno != EINTR && errno != EAGAIN) {
+ verbose("Read error from remote host: %.100s", strerror(errno));
+ fatal_cleanup();
+ }
+ } else {
+ /* Buffer any received data. */
+ packet_process_incoming(buf, len);
}
- /*
- * 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) {
- verbose("Read error from remote host: %.100s", strerror(errno));
- fatal_cleanup();
- }
- /* Buffer any received data. */
- packet_process_incoming(buf, len);
}
+ if (compat20)
+ return;
+
/* Read and buffer any available stdout data from the program. */
if (!fdout_eof && FD_ISSET(fdout, readset)) {
len = read(fdout, buf, sizeof(buf));
- if (len <= 0)
+ if (len < 0 && (errno == EINTR || errno == EAGAIN)) {
+ /* do nothing */
+ } else if (len <= 0) {
fdout_eof = 1;
- else {
+ } else {
buffer_append(&stdout_buffer, buf, len);
fdout_bytes += len;
}
/* Read and buffer any available stderr data from the program. */
if (!fderr_eof && FD_ISSET(fderr, readset)) {
len = read(fderr, buf, sizeof(buf));
- if (len <= 0)
+ if (len < 0 && (errno == EINTR || errno == EAGAIN)) {
+ /* do nothing */
+ } else if (len <= 0) {
fderr_eof = 1;
- else
+ } else {
buffer_append(&stderr_buffer, buf, len);
+ }
}
}
/*
* Sends data from internal buffers to client program stdin.
*/
-void
+static void
process_output(fd_set * writeset)
{
+ struct termios tio;
+ u_char *data;
+ u_int dlen;
int len;
/* Write buffered data to program stdin. */
- if (fdin != -1 && FD_ISSET(fdin, writeset)) {
- len = write(fdin, buffer_ptr(&stdin_buffer),
- buffer_len(&stdin_buffer));
- if (len <= 0) {
-#ifdef USE_PIPES
- close(fdin);
-#else
- if (fdout == -1)
+ if (!compat20 && fdin != -1 && FD_ISSET(fdin, writeset)) {
+ data = buffer_ptr(&stdin_buffer);
+ dlen = buffer_len(&stdin_buffer);
+ len = write(fdin, data, dlen);
+ if (len < 0 && (errno == EINTR || errno == EAGAIN)) {
+ /* do nothing */
+ } else if (len <= 0) {
+ if (fdin != fdout)
close(fdin);
else
shutdown(fdin, SHUT_WR); /* We will no longer send. */
-#endif
fdin = -1;
} else {
- /* Successful write. Consume the data from the buffer. */
+ /* Successful write. */
+ if (fdin_is_tty && dlen >= 1 && data[0] != '\r' &&
+ tcgetattr(fdin, &tio) == 0 &&
+ !(tio.c_lflag & ECHO) && (tio.c_lflag & ICANON)) {
+ /*
+ * Simulate echo to reduce the impact of
+ * traffic analysis
+ */
+ packet_send_ignore(len);
+ packet_send();
+ }
+ /* Consume the data from the buffer. */
buffer_consume(&stdin_buffer, len);
/* Update the count of bytes written to the program. */
stdin_bytes += len;
* Wait until all buffered output has been sent to the client.
* This is used when the program terminates.
*/
-void
-drain_output()
+static void
+drain_output(void)
{
/* Send any buffered stdout data to the client. */
if (buffer_len(&stdout_buffer) > 0) {
packet_write_wait();
}
+static void
+process_buffered_input_packets(void)
+{
+ dispatch_run(DISPATCH_NONBLOCK, NULL, compat20 ? xxx_kex : NULL);
+}
+
/*
* Performs the interactive session. This handles data transmission between
* the client and the program. Note that the notion of stdin, stdout, and
* stdin (of the child program), and reads from stdout and stderr (of the
* child program).
*/
-void
-server_loop(int pid, int fdin_arg, int fdout_arg, int fderr_arg)
+void
+server_loop(pid_t pid, int fdin_arg, int fdout_arg, int fderr_arg)
{
- int wait_status, wait_pid; /* Status and pid returned by wait(). */
+ fd_set *readset = NULL, *writeset = NULL;
+ int max_fd = 0, nalloc = 0;
+ int wait_status; /* Status returned by wait(). */
+ pid_t wait_pid; /* pid returned by wait(). */
int waiting_termination = 0; /* Have displayed waiting close message. */
- unsigned int max_time_milliseconds;
- unsigned int previous_stdout_buffer_bytes;
- unsigned int stdout_buffer_bytes;
+ u_int max_time_milliseconds;
+ u_int previous_stdout_buffer_bytes;
+ u_int stdout_buffer_bytes;
int type;
debug("Entering interactive session.");
/* Initialize the SIGCHLD kludge. */
- child_pid = pid;
child_terminated = 0;
- signal(SIGCHLD, sigchld_handler);
+ mysignal(SIGCHLD, sigchld_handler);
/* Initialize our global variables. */
fdin = fdin_arg;
fdout = fdout_arg;
fderr = fderr_arg;
+
+ /* nonblocking IO */
+ set_nonblock(fdin);
+ set_nonblock(fdout);
+ /* we don't have stderr for interactive terminal sessions, see below */
+ if (fderr != -1)
+ set_nonblock(fderr);
+
+ if (!(datafellows & SSH_BUG_IGNOREMSG) && isatty(fdin))
+ fdin_is_tty = 1;
+
connection_in = packet_get_connection_in();
connection_out = packet_get_connection_out();
+ notify_setup();
+
previous_stdout_buffer_bytes = 0;
/* Set approximate I/O buffer size. */
else
buffer_high = 64 * 1024;
+#if 0
/* Initialize max_fd to the maximum of the known file descriptors. */
- max_fd = fdin;
- if (fdout > max_fd)
- max_fd = fdout;
- if (fderr != -1 && fderr > max_fd)
- max_fd = fderr;
- if (connection_in > max_fd)
- max_fd = connection_in;
- if (connection_out > max_fd)
- max_fd = connection_out;
+ max_fd = MAX(connection_in, connection_out);
+ max_fd = MAX(max_fd, fdin);
+ max_fd = MAX(max_fd, fdout);
+ if (fderr != -1)
+ max_fd = MAX(max_fd, fderr);
+#endif
/* Initialize Initialize buffers. */
buffer_init(&stdin_buffer);
if (fderr == -1)
fderr_eof = 1;
+ server_init_dispatch();
+
/* Main loop of the server for the interactive session mode. */
for (;;) {
- fd_set readset, writeset;
/* Process buffered packets from the client. */
process_buffered_input_packets();
* input data, cause a real eof by closing fdin.
*/
if (stdin_eof && fdin != -1 && buffer_len(&stdin_buffer) == 0) {
-#ifdef USE_PIPES
- close(fdin);
-#else
- if (fdout == -1)
+ if (fdin != fdout)
close(fdin);
else
shutdown(fdin, SHUT_WR); /* We will no longer send. */
-#endif
fdin = -1;
}
/* Make packets from buffered stderr data to send to the client. */
if (fdout_eof && fderr_eof && !packet_have_data_to_write() &&
buffer_len(&stdout_buffer) == 0 && buffer_len(&stderr_buffer) == 0) {
if (!channel_still_open())
- goto quit;
+ break;
if (!waiting_termination) {
const char *s = "Waiting for forwarded connections to terminate...\r\n";
char *cp;
xfree(cp);
}
}
+ max_fd = MAX(connection_in, connection_out);
+ max_fd = MAX(max_fd, fdin);
+ max_fd = MAX(max_fd, fdout);
+ max_fd = MAX(max_fd, fderr);
+ max_fd = MAX(max_fd, notify_pipe[0]);
+
/* Sleep in select() until we can do something. */
- wait_until_can_do_something(&readset, &writeset,
- max_time_milliseconds);
+ wait_until_can_do_something(&readset, &writeset, &max_fd,
+ &nalloc, max_time_milliseconds);
/* Process any channel events. */
- channel_after_select(&readset, &writeset);
+ channel_after_select(readset, writeset);
/* Process input from the client and from program stdout/stderr. */
- process_input(&readset);
+ process_input(readset);
/* Process output to the client and to program stdin. */
- process_output(&writeset);
+ process_output(writeset);
}
+ if (readset)
+ xfree(readset);
+ if (writeset)
+ xfree(writeset);
-quit:
/* Cleanup and termination code. */
/* Wait until all output has been sent to the client. */
drain_output();
debug("End of interactive session; stdin %ld, stdout (read %ld, sent %ld), stderr %ld bytes.",
- stdin_bytes, fdout_bytes, stdout_bytes, stderr_bytes);
+ stdin_bytes, fdout_bytes, stdout_bytes, stderr_bytes);
/* Free and clear the buffers. */
buffer_free(&stdin_buffer);
close(fdin);
fdin = -1;
- /* Stop listening for channels; this removes unix domain sockets. */
- channel_stop_listening();
-
- /* Wait for the child to exit. Get its exit status. */
- wait_pid = wait(&wait_status);
- if (wait_pid < 0) {
- /*
- * It is possible that the wait was handled by SIGCHLD
- * handler. This may result in either: this call
- * returning with EINTR, or: this call returning ECHILD.
- */
- if (child_terminated)
- wait_status = child_wait_status;
- else
- packet_disconnect("wait: %.100s", strerror(errno));
- } else {
- /* Check if it matches the process we forked. */
- if (wait_pid != pid)
- error("Strange, wait returned pid %d, expected %d",
- wait_pid, pid);
- }
+ channel_free_all();
/* We no longer want our SIGCHLD handler to be called. */
- signal(SIGCHLD, SIG_DFL);
+ mysignal(SIGCHLD, SIG_DFL);
+
+ while ((wait_pid = waitpid(-1, &wait_status, 0)) < 0)
+ if (errno != EINTR)
+ packet_disconnect("wait: %.100s", strerror(errno));
+ if (wait_pid != pid)
+ error("Strange, wait returned pid %d, expected %d",
+ wait_pid, pid);
/* Check if it exited normally. */
if (WIFEXITED(wait_status)) {
* the exit status.
*/
do {
- int plen;
- type = packet_read(&plen);
+ type = packet_read();
}
while (type != SSH_CMSG_EXIT_CONFIRMATION);
packet_disconnect("wait returned status %04x.", wait_status);
/* NOTREACHED */
}
+
+static void
+collect_children(void)
+{
+ pid_t pid;
+ sigset_t oset, nset;
+ int status;
+
+ /* block SIGCHLD while we check for dead children */
+ sigemptyset(&nset);
+ sigaddset(&nset, SIGCHLD);
+ sigprocmask(SIG_BLOCK, &nset, &oset);
+ if (child_terminated) {
+ while ((pid = waitpid(-1, &status, WNOHANG)) > 0 ||
+ (pid < 0 && errno == EINTR))
+ if (pid > 0)
+ session_close_by_pid(pid, status);
+ child_terminated = 0;
+ }
+ sigprocmask(SIG_SETMASK, &oset, NULL);
+}
+
+void
+server_loop2(Authctxt *authctxt)
+{
+ fd_set *readset = NULL, *writeset = NULL;
+ int rekeying = 0, max_fd, nalloc = 0;
+
+ debug("Entering interactive session for SSH2.");
+
+ mysignal(SIGCHLD, sigchld_handler);
+ child_terminated = 0;
+ connection_in = packet_get_connection_in();
+ connection_out = packet_get_connection_out();
+
+ notify_setup();
+
+ max_fd = MAX(connection_in, connection_out);
+ max_fd = MAX(max_fd, notify_pipe[0]);
+
+ xxx_authctxt = authctxt;
+
+ server_init_dispatch();
+
+ for (;;) {
+ process_buffered_input_packets();
+
+ rekeying = (xxx_kex != NULL && !xxx_kex->done);
+
+ if (!rekeying && packet_not_very_much_data_to_write())
+ channel_output_poll();
+ wait_until_can_do_something(&readset, &writeset, &max_fd,
+ &nalloc, 0);
+
+ collect_children();
+ if (!rekeying)
+ channel_after_select(readset, writeset);
+ process_input(readset);
+ if (connection_closed)
+ break;
+ process_output(writeset);
+ }
+ collect_children();
+
+ if (readset)
+ xfree(readset);
+ if (writeset)
+ xfree(writeset);
+
+ /* free all channels, no more reads and writes */
+ channel_free_all();
+
+ /* free remaining sessions, e.g. remove wtmp entries */
+ session_destroy_all(NULL);
+}
+
+static void
+server_input_channel_failure(int type, u_int32_t seq, void *ctxt)
+{
+ debug("Got CHANNEL_FAILURE for keepalive");
+ /*
+ * reset timeout, since we got a sane answer from the client.
+ * even if this was generated by something other than
+ * the bogus CHANNEL_REQUEST we send for keepalives.
+ */
+ client_alive_timeouts = 0;
+}
+
+
+static void
+server_input_stdin_data(int type, u_int32_t seq, void *ctxt)
+{
+ char *data;
+ u_int data_len;
+
+ /* Stdin data from the client. Append it to the buffer. */
+ /* Ignore any data if the client has closed stdin. */
+ if (fdin == -1)
+ return;
+ data = packet_get_string(&data_len);
+ packet_check_eom();
+ buffer_append(&stdin_buffer, data, data_len);
+ memset(data, 0, data_len);
+ xfree(data);
+}
+
+static void
+server_input_eof(int type, u_int32_t seq, void *ctxt)
+{
+ /*
+ * Eof from the client. The stdin descriptor to the
+ * program will be closed when all buffered data has
+ * drained.
+ */
+ debug("EOF received for stdin.");
+ packet_check_eom();
+ stdin_eof = 1;
+}
+
+static void
+server_input_window_size(int type, u_int32_t seq, void *ctxt)
+{
+ int row = packet_get_int();
+ int col = packet_get_int();
+ int xpixel = packet_get_int();
+ int ypixel = packet_get_int();
+
+ debug("Window change received.");
+ packet_check_eom();
+ if (fdin != -1)
+ pty_change_window_size(fdin, row, col, xpixel, ypixel);
+}
+
+static Channel *
+server_request_direct_tcpip(char *ctype)
+{
+ Channel *c;
+ int sock;
+ char *target, *originator;
+ int target_port, originator_port;
+
+ target = packet_get_string(NULL);
+ target_port = packet_get_int();
+ originator = packet_get_string(NULL);
+ originator_port = packet_get_int();
+ packet_check_eom();
+
+ debug("server_request_direct_tcpip: originator %s port %d, target %s port %d",
+ originator, originator_port, target, target_port);
+
+ /* XXX check permission */
+ sock = channel_connect_to(target, target_port);
+ xfree(target);
+ xfree(originator);
+ if (sock < 0)
+ return NULL;
+ c = channel_new(ctype, SSH_CHANNEL_CONNECTING,
+ sock, sock, -1, CHAN_TCP_WINDOW_DEFAULT,
+ CHAN_TCP_PACKET_DEFAULT, 0, xstrdup("direct-tcpip"), 1);
+ return c;
+}
+
+static Channel *
+server_request_session(char *ctype)
+{
+ Channel *c;
+
+ debug("input_session_request");
+ packet_check_eom();
+ /*
+ * A server session has no fd to read or write until a
+ * CHANNEL_REQUEST for a shell is made, so we set the type to
+ * SSH_CHANNEL_LARVAL. Additionally, a callback for handling all
+ * CHANNEL_REQUEST messages is registered.
+ */
+ c = channel_new(ctype, SSH_CHANNEL_LARVAL,
+ -1, -1, -1, /*window size*/0, CHAN_SES_PACKET_DEFAULT,
+ 0, xstrdup("server-session"), 1);
+ if (session_open(xxx_authctxt, c->self) != 1) {
+ debug("session open failed, free channel %d", c->self);
+ channel_free(c);
+ return NULL;
+ }
+ channel_register_cleanup(c->self, session_close_by_channel);
+ return c;
+}
+
+static void
+server_input_channel_open(int type, u_int32_t seq, void *ctxt)
+{
+ Channel *c = NULL;
+ char *ctype;
+ u_int len;
+ int rchan;
+ int rmaxpack;
+ int rwindow;
+
+ ctype = packet_get_string(&len);
+ rchan = packet_get_int();
+ rwindow = packet_get_int();
+ rmaxpack = packet_get_int();
+
+ debug("server_input_channel_open: ctype %s rchan %d win %d max %d",
+ ctype, rchan, rwindow, rmaxpack);
+
+ if (strcmp(ctype, "session") == 0) {
+ c = server_request_session(ctype);
+ } else if (strcmp(ctype, "direct-tcpip") == 0) {
+ c = server_request_direct_tcpip(ctype);
+ }
+ if (c != NULL) {
+ debug("server_input_channel_open: 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("server_input_channel_open: 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
+server_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("server_input_global_request: rtype %s want_reply %d", rtype, want_reply);
+
+ /* -R style forwarding */
+ if (strcmp(rtype, "tcpip-forward") == 0) {
+ struct passwd *pw;
+ char *listen_address;
+ u_short listen_port;
+
+ pw = auth_get_user();
+ if (pw == NULL)
+ fatal("server_input_global_request: no user");
+ listen_address = packet_get_string(NULL); /* XXX currently ignored */
+ listen_port = (u_short)packet_get_int();
+ debug("server_input_global_request: tcpip-forward listen %s port %d",
+ listen_address, listen_port);
+
+ /* check permissions */
+ if (!options.allow_tcp_forwarding ||
+ no_port_forwarding_flag ||
+ (listen_port < IPPORT_RESERVED && pw->pw_uid != 0)) {
+ success = 0;
+ packet_send_debug("Server has disabled port forwarding.");
+ } else {
+ /* Start listening on the port */
+ success = channel_setup_remote_fwd_listener(
+ listen_address, listen_port, options.gateway_ports);
+ }
+ xfree(listen_address);
+ }
+ if (want_reply) {
+ packet_start(success ?
+ SSH2_MSG_REQUEST_SUCCESS : SSH2_MSG_REQUEST_FAILURE);
+ packet_send();
+ packet_write_wait();
+ }
+ xfree(rtype);
+}
+static void
+server_input_channel_req(int type, u_int32_t seq, void *ctxt)
+{
+ Channel *c;
+ int id, reply, success = 0;
+ char *rtype;
+
+ id = packet_get_int();
+ rtype = packet_get_string(NULL);
+ reply = packet_get_char();
+
+ debug("server_input_channel_req: channel %d request %s reply %d",
+ id, rtype, reply);
+
+ if ((c = channel_lookup(id)) == NULL)
+ packet_disconnect("server_input_channel_req: "
+ "unknown channel %d", id);
+ if (c->type == SSH_CHANNEL_LARVAL || c->type == SSH_CHANNEL_OPEN)
+ success = session_input_channel_req(c, rtype);
+ 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
+server_init_dispatch_20(void)
+{
+ debug("server_init_dispatch_20");
+ 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, &server_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, &server_input_channel_req);
+ dispatch_set(SSH2_MSG_CHANNEL_WINDOW_ADJUST, &channel_input_window_adjust);
+ dispatch_set(SSH2_MSG_GLOBAL_REQUEST, &server_input_global_request);
+ /* client_alive */
+ dispatch_set(SSH2_MSG_CHANNEL_FAILURE, &server_input_channel_failure);
+ /* rekeying */
+ dispatch_set(SSH2_MSG_KEXINIT, &kex_input_kexinit);
+}
+static void
+server_init_dispatch_13(void)
+{
+ debug("server_init_dispatch_13");
+ dispatch_init(NULL);
+ dispatch_set(SSH_CMSG_EOF, &server_input_eof);
+ dispatch_set(SSH_CMSG_STDIN_DATA, &server_input_stdin_data);
+ dispatch_set(SSH_CMSG_WINDOW_SIZE, &server_input_window_size);
+ 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);
+}
+static void
+server_init_dispatch_15(void)
+{
+ server_init_dispatch_13();
+ debug("server_init_dispatch_15");
+ dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_ieof);
+ dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_oclose);
+}
+static void
+server_init_dispatch(void)
+{
+ if (compat20)
+ server_init_dispatch_20();
+ else if (compat13)
+ server_init_dispatch_13();
+ else
+ server_init_dispatch_15();
+}