* 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 Markus Friedl. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
*/
#include "includes.h"
-RCSID("$OpenBSD: serverloop.c,v 1.42 2001/01/21 19:05:55 markus Exp $");
+RCSID("$OpenBSD: serverloop.c,v 1.61 2001/04/13 22:46:54 beck Exp $");
#include "xmalloc.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 "auth-options.h"
#include "serverloop.h"
#include "misc.h"
+#include "kex.h"
extern ServerOptions options;
+/* XXX */
+extern Kex *xxx_kex;
+
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 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 u_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. */
/*
* This SIGCHLD kludge is used to detect when the child exits. The server
void server_init_dispatch(void);
+int client_alive_timeouts = 0;
+
void
sigchld_handler(int sig)
{
int save_errno = errno;
debug("Received SIGCHLD.");
child_terminated = 1;
- signal(SIGCHLD, sigchld_handler2);
+ mysignal(SIGCHLD, sigchld_handler2);
errno = save_errno;
}
* to the client.
*/
void
-make_packets_from_stderr_data()
+make_packets_from_stderr_data(void)
{
int len;
* client.
*/
void
-make_packets_from_stdout_data()
+make_packets_from_stdout_data(void)
{
int len;
} 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);
* for the duration of the wait (0 = infinite).
*/
void
-wait_until_can_do_something(fd_set * readset, fd_set * writeset,
- u_int max_time_milliseconds)
+wait_until_can_do_something(fd_set **readsetp, fd_set **writesetp, int *maxfdp,
+ u_int max_time_milliseconds)
{
struct timeval tv, *tvp;
int ret;
+ int client_alive_scheduled = 0;
+
+ /*
+ * 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 (max_time_milliseconds == 0 && options.client_alive_interval) {
+ client_alive_scheduled = 1;
+ max_time_milliseconds = options.client_alive_interval * 1000;
+ } else
+ client_alive_scheduled = 0;
/* When select fails we restart from here. */
retry_select:
- /* Initialize select() masks. */
- FD_ZERO(readset);
- FD_ZERO(writeset);
+ /* Allocate and update select() masks for channel descriptors. */
+ channel_prepare_select(readsetp, writesetp, maxfdp, 0);
if (compat20) {
/* wrong: bad condition XXX */
if (channel_not_very_much_buffered_data())
- FD_SET(connection_in, readset);
+ 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);
/*
* 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)
tvp = &tv;
}
if (tvp!=NULL)
- debug2("tvp!=NULL kid %d mili %d", child_terminated, max_time_milliseconds);
+ debug3("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) {
if (errno != EINTR)
error("select: %.100s", strerror(errno));
else
goto retry_select;
}
+ if (ret == 0 && client_alive_scheduled) {
+ /* timeout, check to see how many we have had */
+ client_alive_timeouts++;
+
+ if (client_alive_timeouts > options.client_alive_count_max ) {
+ packet_disconnect(
+ "Timeout, your session not responding.");
+ } else {
+ /*
+ * send a bogus channel request with "wantreply"
+ * we should get back a failure
+ */
+ int id;
+
+ id = channel_find_open();
+ if (id != -1) {
+ channel_request_start(id,
+ "keepalive@openssh.com", 1);
+ packet_send();
+ } else
+ packet_disconnect(
+ "No open channels after timeout!");
+ }
+ }
}
/*
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) {
void
process_output(fd_set * writeset)
{
+ struct termios tio;
int len;
/* Write buffered data to program stdin. */
#endif
fdin = -1;
} else {
- /* Successful write. Consume the data from the buffer. */
+ /* Successful write. */
+ if (fdin_is_tty && 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;
* This is used when the program terminates.
*/
void
-drain_output()
+drain_output(void)
{
/* Send any buffered stdout data to the client. */
if (buffer_len(&stdout_buffer) > 0) {
}
void
-process_buffered_input_packets()
+process_buffered_input_packets(void)
{
- dispatch_run(DISPATCH_NONBLOCK, NULL, 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;
int wait_status; /* Status returned by wait(). */
pid_t wait_pid; /* pid returned by wait(). */
int waiting_termination = 0; /* Have displayed waiting close message. */
child_pid = pid;
child_terminated = 0;
signal(SIGCHLD, sigchld_handler);
- signal(SIGPIPE, SIG_IGN);
/* 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();
buffer_high = 64 * 1024;
/* 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(fdin, fdout);
+ if (fderr != -1)
+ max_fd = MAX(max_fd, fderr);
+ max_fd = MAX(max_fd, connection_in);
+ max_fd = MAX(max_fd, connection_out);
/* Initialize Initialize buffers. */
buffer_init(&stdin_buffer);
}
}
/* 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,
+ 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. */
void
server_loop2(void)
{
- fd_set readset, writeset;
- int had_channel = 0;
- int status;
+ fd_set *readset = NULL, *writeset = NULL;
+ int rekeying = 0, max_fd, status;
pid_t pid;
debug("Entering interactive session for SSH2.");
- signal(SIGCHLD, sigchld_handler2);
- signal(SIGPIPE, SIG_IGN);
+ mysignal(SIGCHLD, sigchld_handler2);
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;
+
+ max_fd = MAX(connection_in, connection_out);
+
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);
+ wait_until_can_do_something(&readset, &writeset, &max_fd,
+ rekeying);
if (child_terminated) {
while ((pid = waitpid(-1, &status, WNOHANG)) > 0)
session_close_by_pid(pid, status);
child_terminated = 0;
}
- channel_after_select(&readset, &writeset);
- process_input(&readset);
- process_output(&writeset);
+ if (!rekeying)
+ channel_after_select(readset, writeset);
+ process_input(readset);
+ if (connection_closed)
+ break;
+ process_output(writeset);
}
+ if (readset)
+ xfree(readset);
+ if (writeset)
+ xfree(writeset);
+
signal(SIGCHLD, SIG_DFL);
while ((pid = waitpid(-1, &status, WNOHANG)) > 0)
session_close_by_pid(pid, status);
channel_stop_listening();
}
+void
+server_input_channel_failure(int type, int plen, 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;
+}
+
+
void
server_input_stdin_data(int type, int plen, void *ctxt)
{
originator, originator_port, target, target_port);
/* XXX check permission */
- if (no_port_forwarding_flag || !options.allow_tcp_forwarding) {
- xfree(target);
- xfree(originator);
- return NULL;
- }
sock = channel_connect_to(target, target_port);
xfree(target);
xfree(originator);
xfree(ctype);
}
-void
+void
server_input_global_request(int type, int plen, void *ctxt)
{
char *rtype;
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;
packet_send_debug("Server has disabled port forwarding.");
} else {
/* Start listening on the port */
- channel_request_forwarding(
+ success = channel_request_forwarding(
listen_address, listen_port,
/*unspec host_to_connect*/ "<unspec host>",
/*unspec port_to_connect*/ 0,
options.gateway_ports, /*remote*/ 1);
- success = 1;
}
xfree(listen_address);
}
}
void
-server_init_dispatch_20()
+server_init_dispatch_20(void)
{
debug("server_init_dispatch_20");
dispatch_init(&dispatch_protocol_error);
dispatch_set(SSH2_MSG_CHANNEL_REQUEST, &channel_input_channel_request);
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()
+server_init_dispatch_13(void)
{
debug("server_init_dispatch_13");
dispatch_init(NULL);
dispatch_set(SSH_MSG_PORT_OPEN, &channel_input_port_open);
}
void
-server_init_dispatch_15()
+server_init_dispatch_15(void)
{
server_init_dispatch_13();
debug("server_init_dispatch_15");
dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_oclose);
}
void
-server_init_dispatch()
+server_init_dispatch(void)
{
if (compat20)
server_init_dispatch_20();
else
server_init_dispatch_15();
}
+
andersk / openssh.git / blobdiff