* 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 Markus Friedl. All rights reserved.
+ * 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 1.111 2003/09/23 20:17:11 markus Exp $");
+
#include "xmalloc.h"
-#include "ssh.h"
#include "packet.h"
#include "buffer.h"
+#include "log.h"
#include "servconf.h"
-#include "pty.h"
+#include "canohost.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;
+extern Authctxt *the_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.
- *
- * After SIGCHLD child_has_selected is set to 1 after the first pass
- * through the wait_until_can_do_something() select(). This ensures
- * that the child's output gets a chance to drain before it is yanked.
*/
-static pid_t child_pid; /* Pid of the child. */
-static volatile int child_terminated; /* The child has terminated. */
-static volatile int child_has_selected; /* Child has had chance to drain. */
-static volatile int child_wait_status; /* Status from wait(). */
+static volatile sig_atomic_t child_terminated = 0; /* The child has terminated. */
-void server_init_dispatch(void);
+/* prototypes */
+static void server_init_dispatch(void);
-void
-sigchld_handler(int sig)
+/*
+ * we write to this pipe if a SIGCHLD is caught in order to avoid
+ * the race between select() and child_terminated
+ */
+static int notify_pipe[2];
+static void
+notify_setup(void)
{
- int save_errno = errno;
- pid_t 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;
- child_has_selected = 0;
+ 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;
}
- signal(SIGCHLD, sigchld_handler);
- errno = save_errno;
+ notify_pipe[0] = -1; /* read end */
+ notify_pipe[1] = -1; /* write end */
}
-void
-sigchld_handler2(int sig)
+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;
+
+ if (notify_pipe[0] != -1 && FD_ISSET(notify_pipe[0], readset))
+ while (read(notify_pipe[0], &c, 1) != -1)
+ debug2("notify_done: reading");
+}
+
+static void
+sigchld_handler(int sig)
{
int save_errno = errno;
debug("Received SIGCHLD.");
child_terminated = 1;
+#ifndef _UNICOS
+ mysignal(SIGCHLD, sigchld_handler);
+#endif
+ 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;
+ u_int len;
/* Send buffered stderr data to the client. */
while (buffer_len(&stderr_buffer) > 0 &&
* 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;
+ u_int len;
/* Send buffered stdout data to the client. */
while (buffer_len(&stdout_buffer) > 0 &&
} 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;
+ int client_alive_scheduled = 0;
- /* When select fails we restart from here. */
-retry_select:
+ /*
+ * 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 (compat20 &&
+ max_time_milliseconds == 0 && options.client_alive_interval) {
+ client_alive_scheduled = 1;
+ max_time_milliseconds = options.client_alive_interval * 1000;
+ }
- /* Initialize select() masks. */
- FD_ZERO(readset);
- FD_ZERO(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())
- FD_SET(connection_in, readset);
+#endif
+ FD_SET(connection_in, *readsetp);
} else {
/*
* Read packets from the client unless we have too much
*/
if (buffer_len(&stdin_buffer) < buffer_high &&
channel_not_very_much_buffered_data())
- FD_SET(connection_in, readset);
+ 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, readset);
+ FD_SET(fdout, *readsetp);
if (!fderr_eof)
- FD_SET(fderr, readset);
+ 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, writeset);
+ FD_SET(fdin, *writesetp);
}
- /* Set masks for channel descriptors. */
- channel_prepare_select(readset, writeset);
+ 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);
-
- /* 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)
tv.tv_usec = 1000 * (max_time_milliseconds % 1000);
tvp = &tv;
}
- if (tvp!=NULL)
- debug("tvp!=NULL kid %d mili %d", child_terminated, max_time_milliseconds);
/* 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;
- }
-
- if (child_terminated)
- child_has_selected = 1;
+ } 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;
if (FD_ISSET(connection_in, readset)) {
len = read(connection_in, buf, sizeof(buf));
if (len == 0) {
- verbose("Connection closed by remote host.");
- fatal_cleanup();
+ verbose("Connection closed by %.100s",
+ get_remote_ipaddr());
+ connection_closed = 1;
+ if (compat20)
+ return;
+ cleanup_exit(255);
} else if (len < 0) {
if (errno != EINTR && errno != EAGAIN) {
- verbose("Read error from remote host: %.100s", strerror(errno));
- fatal_cleanup();
+ verbose("Read error from remote host "
+ "%.100s: %.100s",
+ get_remote_ipaddr(), strerror(errno));
+ cleanup_exit(255);
}
} else {
/* Buffer any received data. */
/*
* 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 (!compat20 && fdin != -1 && FD_ISSET(fdin, writeset)) {
- len = write(fdin, buffer_ptr(&stdin_buffer),
- buffer_len(&stdin_buffer));
+ 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) {
-#ifdef USE_PIPES
- close(fdin);
-#else
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();
}
-void
-process_buffered_input_packets()
+static void
+process_buffered_input_packets(void)
{
- dispatch_run(DISPATCH_NONBLOCK, NULL);
+ dispatch_run(DISPATCH_NONBLOCK, NULL, compat20 ? xxx_kex : NULL);
}
/*
void
server_loop(pid_t pid, int fdin_arg, int fdout_arg, int fderr_arg)
{
- fd_set readset, writeset;
+ 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;
- child_has_selected = 0;
- signal(SIGCHLD, sigchld_handler);
+ mysignal(SIGCHLD, sigchld_handler);
/* Initialize our global variables. */
fdin = fdin_arg;
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);
* 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 (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. */
* descriptors, and we have no more data to send to the
* client, and there is no pending buffered data.
*/
- if (((fdout_eof && fderr_eof) ||
- (child_terminated && child_has_selected)) &&
- !packet_have_data_to_write() &&
- (buffer_len(&stdout_buffer) == 0) &&
- (buffer_len(&stderr_buffer) == 0)) {
+ if (fdout_eof && fderr_eof && !packet_have_data_to_write() &&
+ buffer_len(&stdout_buffer) == 0 && buffer_len(&stderr_buffer) == 0) {
if (!channel_still_open())
break;
if (!waiting_termination) {
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);
/* Cleanup and termination code. */
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 %ld, expected %ld",
+ (long)wait_pid, (long)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);
/* NOTREACHED */
}
-void
-server_loop2(void)
+static void
+collect_children(void)
{
- fd_set readset, writeset;
- int had_channel = 0;
- int status;
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.");
- signal(SIGCHLD, sigchld_handler2);
+ mysignal(SIGCHLD, sigchld_handler);
child_terminated = 0;
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;
+
+ notify_setup();
+
+ max_fd = MAX(connection_in, connection_out);
+ max_fd = MAX(max_fd, notify_pipe[0]);
+
server_init_dispatch();
for (;;) {
process_buffered_input_packets();
- if (!had_channel && channel_still_open())
- had_channel = 1;
- if (had_channel && !channel_still_open()) {
- debug("!channel_still_open.");
- break;
- }
- if (packet_not_very_much_data_to_write())
+
+ 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, 0);
- if (child_terminated) {
- while ((pid = waitpid(-1, &status, WNOHANG)) > 0)
- session_close_by_pid(pid, status);
- child_terminated = 0;
- signal(SIGCHLD, sigchld_handler2);
+ wait_until_can_do_something(&readset, &writeset, &max_fd,
+ &nalloc, 0);
+
+ collect_children();
+ if (!rekeying) {
+ channel_after_select(readset, writeset);
+ if (packet_need_rekeying()) {
+ debug("need rekeying");
+ xxx_kex->done = 0;
+ kex_send_kexinit(xxx_kex);
+ }
}
- channel_after_select(&readset, &writeset);
- process_input(&readset);
- process_output(&writeset);
+ process_input(readset);
+ if (connection_closed)
+ break;
+ process_output(writeset);
}
- signal(SIGCHLD, SIG_DFL);
- while ((pid = waitpid(-1, &status, WNOHANG)) > 0)
- session_close_by_pid(pid, status);
- channel_stop_listening();
+ 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);
}
-void
-server_input_stdin_data(int type, int plen)
+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;
- unsigned int data_len;
+ 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_integrity_check(plen, (4 + data_len), type);
+ packet_check_eom();
buffer_append(&stdin_buffer, data, data_len);
memset(data, 0, data_len);
xfree(data);
}
-void
-server_input_eof(int type, int plen)
+static void
+server_input_eof(int type, u_int32_t seq, void *ctxt)
{
/*
* Eof from the client. The stdin descriptor to the
* drained.
*/
debug("EOF received for stdin.");
- packet_integrity_check(plen, 0, type);
+ packet_check_eom();
stdin_eof = 1;
}
-void
-server_input_window_size(int type, int plen)
+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 ypixel = packet_get_int();
debug("Window change received.");
- packet_integrity_check(plen, 4 * 4, type);
+ packet_check_eom();
if (fdin != -1)
pty_change_window_size(fdin, row, col, xpixel, ypixel);
}
-int
-input_direct_tcpip(void)
+static Channel *
+server_request_direct_tcpip(char *ctype)
{
+ Channel *c;
int sock;
char *target, *originator;
int target_port, originator_port;
target_port = packet_get_int();
originator = packet_get_string(NULL);
originator_port = packet_get_int();
- packet_done();
+ packet_check_eom();
- debug("open direct-tcpip: from %s port %d to %s port %d",
+ 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 -1;
- return channel_new("direct-tcpip", SSH_CHANNEL_OPEN,
- sock, sock, -1, 4*1024, 32*1024, 0, xstrdup("direct-tcpip"));
+ return NULL;
+ c = channel_new(ctype, SSH_CHANNEL_CONNECTING,
+ sock, sock, -1, CHAN_TCP_WINDOW_DEFAULT,
+ CHAN_TCP_PACKET_DEFAULT, 0, "direct-tcpip", 1);
+ return c;
}
-void
-server_input_channel_open(int type, int plen)
+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, "server-session", 1);
+ if (session_open(the_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;
- int id;
- unsigned int len;
int rchan;
- int rmaxpack;
- int rwindow;
+ u_int rmaxpack, rwindow, len;
ctype = packet_get_string(&len);
rchan = packet_get_int();
rwindow = packet_get_int();
rmaxpack = packet_get_int();
- debug("channel_input_open: ctype %s rchan %d win %d max %d",
+ debug("server_input_channel_open: ctype %s rchan %d win %d max %d",
ctype, rchan, rwindow, rmaxpack);
if (strcmp(ctype, "session") == 0) {
- debug("open session");
- packet_done();
- /*
- * 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.
- */
- id = channel_new(ctype, SSH_CHANNEL_LARVAL,
- -1, -1, -1, 0, 32*1024, 0, xstrdup("server-session"));
- if (session_open(id) == 1) {
- channel_register_callback(id, SSH2_MSG_CHANNEL_REQUEST,
- session_input_channel_req, (void *)0);
- channel_register_cleanup(id, session_close_by_channel);
- c = channel_lookup(id);
- } else {
- debug("session open failed, free channel %d", id);
- channel_free(id);
- }
+ c = server_request_session(ctype);
} else if (strcmp(ctype, "direct-tcpip") == 0) {
- id = input_direct_tcpip();
- if (id >= 0)
- c = channel_lookup(id);
+ c = server_request_direct_tcpip(ctype);
}
if (c != NULL) {
- debug("confirm %s", ctype);
+ debug("server_input_channel_open: confirm %s", ctype);
c->remote_id = rchan;
c->remote_window = rwindow;
c->remote_maxpacket = rmaxpack;
-
- 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();
+ if (c->type != SSH_CHANNEL_CONNECTING) {
+ packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
+ packet_put_int(c->remote_id);
+ packet_put_int(c->self);
+ packet_put_int(c->local_window);
+ packet_put_int(c->local_maxpacket);
+ packet_send();
+ }
} else {
- debug("failure %s", ctype);
+ 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);
- packet_put_cstring("bla bla");
- packet_put_cstring("");
+ if (!(datafellows & SSH_BUG_OPENFAILURE)) {
+ packet_put_cstring("open failed");
+ packet_put_cstring("");
+ }
packet_send();
}
xfree(ctype);
}
-void
-server_init_dispatch_20()
+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 = the_authctxt->pw;
+ if (pw == NULL)
+ fatal("server_input_global_request: no user");
+ listen_address = packet_get_string(NULL);
+ 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
+#ifndef NO_IPPORT_RESERVED_CONCEPT
+ || (listen_port < IPPORT_RESERVED && pw->pw_uid != 0)
+#endif
+ ) {
+ 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_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, &channel_input_channel_request);
+ 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);
}
-void
-server_init_dispatch_13()
+static void
+server_init_dispatch_13(void)
{
debug("server_init_dispatch_13");
dispatch_init(NULL);
dispatch_set(SSH_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
dispatch_set(SSH_MSG_PORT_OPEN, &channel_input_port_open);
}
-void
-server_init_dispatch_15()
+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);
}
-void
-server_init_dispatch()
+static void
+server_init_dispatch(void)
{
if (compat20)
server_init_dispatch_20();
andersk / openssh.git / blobdiff