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openssh-portable/serverloop.c

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/* $OpenBSD: serverloop.c,v 1.199 2017/10/23 05:08:00 djm Exp $ */
/*
* Author: Tatu Ylonen <ylo@cs.hut.fi>
* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
* All rights reserved
* 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"
#include <sys/types.h>
#include <sys/wait.h>
#include <sys/socket.h>
#ifdef HAVE_SYS_TIME_H
# include <sys/time.h>
#endif
#include <netinet/in.h>
#include <errno.h>
#include <fcntl.h>
#include <pwd.h>
#include <signal.h>
#include <string.h>
#include <termios.h>
#include <unistd.h>
#include <stdarg.h>
#include "openbsd-compat/sys-queue.h"
#include "xmalloc.h"
#include "packet.h"
#include "buffer.h"
#include "log.h"
#include "misc.h"
#include "servconf.h"
#include "canohost.h"
#include "sshpty.h"
#include "channels.h"
#include "compat.h"
#include "ssh2.h"
#include "key.h"
#include "cipher.h"
#include "kex.h"
#include "hostfile.h"
#include "auth.h"
#include "session.h"
#include "dispatch.h"
#include "auth-options.h"
#include "serverloop.h"
#include "ssherr.h"
extern ServerOptions options;
/* XXX */
extern Authctxt *the_authctxt;
extern int use_privsep;
static int no_more_sessions = 0; /* Disallow further sessions. */
/*
* 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 volatile sig_atomic_t child_terminated = 0; /* The child has terminated. */
/* Cleanup on signals (!use_privsep case only) */
static volatile sig_atomic_t received_sigterm = 0;
/* prototypes */
static void server_init_dispatch(void);
/* requested tunnel forwarding interface(s), shared with session.c */
char *tun_fwd_ifnames = NULL;
/*
* 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)
{
if (pipe(notify_pipe) < 0) {
error("pipe(notify_pipe) failed %s", strerror(errno));
} else if ((fcntl(notify_pipe[0], F_SETFD, FD_CLOEXEC) == -1) ||
(fcntl(notify_pipe[1], F_SETFD, FD_CLOEXEC) == -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)
(void)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");
}
/*ARGSUSED*/
static void
sigchld_handler(int sig)
{
int save_errno = errno;
child_terminated = 1;
#ifndef _UNICOS
mysignal(SIGCHLD, sigchld_handler);
#endif
notify_parent();
errno = save_errno;
}
/*ARGSUSED*/
static void
sigterm_handler(int sig)
{
received_sigterm = sig;
}
static void
client_alive_check(struct ssh *ssh)
{
int channel_id;
/* timeout, check to see how many we have had */
if (packet_inc_alive_timeouts() > options.client_alive_count_max) {
logit("Timeout, client not responding.");
cleanup_exit(255);
}
/*
* send a bogus global/channel request with "wantreply",
* we should get back a failure
*/
if ((channel_id = channel_find_open(ssh)) == -1) {
packet_start(SSH2_MSG_GLOBAL_REQUEST);
packet_put_cstring("keepalive@openssh.com");
packet_put_char(1); /* boolean: want reply */
} else {
channel_request_start(ssh, channel_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).
*/
static void
wait_until_can_do_something(struct ssh *ssh,
int connection_in, int connection_out,
fd_set **readsetp, fd_set **writesetp, int *maxfdp,
u_int *nallocp, u_int64_t max_time_ms)
{
struct timeval tv, *tvp;
int ret;
time_t minwait_secs = 0;
int client_alive_scheduled = 0;
static time_t last_client_time;
/* Allocate and update select() masks for channel descriptors. */
channel_prepare_select(ssh, readsetp, writesetp, maxfdp,
nallocp, &minwait_secs);
/* XXX need proper deadline system for rekey/client alive */
if (minwait_secs != 0)
max_time_ms = MINIMUM(max_time_ms, (u_int)minwait_secs * 1000);
/*
* 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 (options.client_alive_interval) {
uint64_t keepalive_ms =
(uint64_t)options.client_alive_interval * 1000;
client_alive_scheduled = 1;
if (max_time_ms == 0 || max_time_ms > keepalive_ms)
max_time_ms = keepalive_ms;
}
#if 0
/* wrong: bad condition XXX */
if (channel_not_very_much_buffered_data())
#endif
FD_SET(connection_in, *readsetp);
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, *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_ms == 0 || client_alive_scheduled)
max_time_ms = 100;
if (max_time_ms == 0)
tvp = NULL;
else {
tv.tv_sec = max_time_ms / 1000;
tv.tv_usec = 1000 * (max_time_ms % 1000);
tvp = &tv;
}
/* Wait for something to happen, or the timeout to expire. */
ret = select((*maxfdp)+1, *readsetp, *writesetp, NULL, tvp);
if (ret == -1) {
memset(*readsetp, 0, *nallocp);
memset(*writesetp, 0, *nallocp);
if (errno != EINTR)
error("select: %.100s", strerror(errno));
} else if (client_alive_scheduled) {
time_t now = monotime();
if (ret == 0) { /* timeout */
client_alive_check(ssh);
} else if (FD_ISSET(connection_in, *readsetp)) {
last_client_time = now;
} else if (last_client_time != 0 && last_client_time +
options.client_alive_interval <= now) {
client_alive_check(ssh);
last_client_time = now;
}
}
notify_done(*readsetp);
}
/*
* Processes input from the client and the program. Input data is stored
* in buffers and processed later.
*/
static int
process_input(struct ssh *ssh, fd_set *readset, int connection_in)
{
int len;
char buf[16384];
/* Read and buffer any input data from the client. */
if (FD_ISSET(connection_in, readset)) {
len = read(connection_in, buf, sizeof(buf));
if (len == 0) {
verbose("Connection closed by %.100s port %d",
ssh_remote_ipaddr(ssh), ssh_remote_port(ssh));
return -1;
} else if (len < 0) {
if (errno != EINTR && errno != EAGAIN &&
errno != EWOULDBLOCK) {
verbose("Read error from remote host "
"%.100s port %d: %.100s",
ssh_remote_ipaddr(ssh),
ssh_remote_port(ssh), strerror(errno));
cleanup_exit(255);
}
} else {
/* Buffer any received data. */
packet_process_incoming(buf, len);
}
}
return 0;
}
/*
* Sends data from internal buffers to client program stdin.
*/
static void
process_output(fd_set *writeset, int connection_out)
{
/* Send any buffered packet data to the client. */
if (FD_ISSET(connection_out, writeset))
packet_write_poll();
}
static void
process_buffered_input_packets(struct ssh *ssh)
{
ssh_dispatch_run_fatal(ssh, DISPATCH_NONBLOCK, NULL);
}
static void
collect_children(struct ssh *ssh)
{
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) {
debug("Received SIGCHLD.");
while ((pid = waitpid(-1, &status, WNOHANG)) > 0 ||
(pid < 0 && errno == EINTR))
if (pid > 0)
session_close_by_pid(ssh, pid, status);
child_terminated = 0;
}
sigprocmask(SIG_SETMASK, &oset, NULL);
}
void
server_loop2(struct ssh *ssh, Authctxt *authctxt)
{
fd_set *readset = NULL, *writeset = NULL;
int max_fd;
u_int nalloc = 0, connection_in, connection_out;
u_int64_t rekey_timeout_ms = 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();
if (!use_privsep) {
signal(SIGTERM, sigterm_handler);
signal(SIGINT, sigterm_handler);
signal(SIGQUIT, sigterm_handler);
}
notify_setup();
max_fd = MAXIMUM(connection_in, connection_out);
max_fd = MAXIMUM(max_fd, notify_pipe[0]);
server_init_dispatch();
for (;;) {
process_buffered_input_packets(ssh);
if (!ssh_packet_is_rekeying(ssh) &&
packet_not_very_much_data_to_write())
channel_output_poll(ssh);
if (options.rekey_interval > 0 && !ssh_packet_is_rekeying(ssh))
rekey_timeout_ms = packet_get_rekey_timeout() * 1000;
else
rekey_timeout_ms = 0;
wait_until_can_do_something(ssh, connection_in, connection_out,
&readset, &writeset, &max_fd, &nalloc, rekey_timeout_ms);
if (received_sigterm) {
logit("Exiting on signal %d", (int)received_sigterm);
/* Clean up sessions, utmp, etc. */
cleanup_exit(255);
}
collect_children(ssh);
if (!ssh_packet_is_rekeying(ssh))
channel_after_select(ssh, readset, writeset);
if (process_input(ssh, readset, connection_in) < 0)
break;
process_output(writeset, connection_out);
}
collect_children(ssh);
free(readset);
free(writeset);
/* free all channels, no more reads and writes */
channel_free_all(ssh);
/* free remaining sessions, e.g. remove wtmp entries */
session_destroy_all(ssh, NULL);
}
static int
server_input_keep_alive(int type, u_int32_t seq, struct ssh *ssh)
{
debug("Got %d/%u for keepalive", type, seq);
/*
* 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.
*/
packet_set_alive_timeouts(0);
return 0;
}
static Channel *
server_request_direct_tcpip(struct ssh *ssh, int *reason, const char **errmsg)
{
Channel *c = NULL;
char *target, *originator;
u_short 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 fine grained permissions */
if ((options.allow_tcp_forwarding & FORWARD_LOCAL) != 0 &&
!no_port_forwarding_flag && !options.disable_forwarding) {
c = channel_connect_to_port(ssh, target, target_port,
"direct-tcpip", "direct-tcpip", reason, errmsg);
} else {
logit("refused local port forward: "
"originator %s port %d, target %s port %d",
originator, originator_port, target, target_port);
if (reason != NULL)
*reason = SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED;
}
free(originator);
free(target);
return c;
}
static Channel *
server_request_direct_streamlocal(struct ssh *ssh)
{
Channel *c = NULL;
char *target, *originator;
u_short originator_port;
struct passwd *pw = the_authctxt->pw;
if (pw == NULL || !the_authctxt->valid)
fatal("server_input_global_request: no/invalid user");
target = packet_get_string(NULL);
originator = packet_get_string(NULL);
originator_port = packet_get_int();
packet_check_eom();
debug("server_request_direct_streamlocal: originator %s port %d, target %s",
originator, originator_port, target);
/* XXX fine grained permissions */
if ((options.allow_streamlocal_forwarding & FORWARD_LOCAL) != 0 &&
!no_port_forwarding_flag && !options.disable_forwarding &&
(pw->pw_uid == 0 || use_privsep)) {
c = channel_connect_to_path(ssh, target,
"direct-streamlocal@openssh.com", "direct-streamlocal");
} else {
logit("refused streamlocal port forward: "
"originator %s port %d, target %s",
originator, originator_port, target);
}
free(originator);
free(target);
return c;
}
static Channel *
server_request_tun(struct ssh *ssh)
{
Channel *c = NULL;
int mode, tun;
int sock;
char *tmp, *ifname = NULL;
mode = packet_get_int();
switch (mode) {
case SSH_TUNMODE_POINTOPOINT:
case SSH_TUNMODE_ETHERNET:
break;
default:
packet_send_debug("Unsupported tunnel device mode.");
return NULL;
}
if ((options.permit_tun & mode) == 0) {
packet_send_debug("Server has rejected tunnel device "
"forwarding");
return NULL;
}
tun = packet_get_int();
if (forced_tun_device != -1) {
if (tun != SSH_TUNID_ANY && forced_tun_device != tun)
goto done;
tun = forced_tun_device;
}
sock = tun_open(tun, mode, &ifname);
if (sock < 0)
goto done;
debug("Tunnel forwarding using interface %s", ifname);
c = channel_new(ssh, "tun", SSH_CHANNEL_OPEN, sock, sock, -1,
CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0, "tun", 1);
c->datagram = 1;
#if defined(SSH_TUN_FILTER)
if (mode == SSH_TUNMODE_POINTOPOINT)
channel_register_filter(ssh, c->self, sys_tun_infilter,
sys_tun_outfilter, NULL, NULL);
#endif
/*
* Update the list of names exposed to the session
* XXX remove these if the tunnels are closed (won't matter
* much if they are already in the environment though)
*/
tmp = tun_fwd_ifnames;
xasprintf(&tun_fwd_ifnames, "%s%s%s",
tun_fwd_ifnames == NULL ? "" : tun_fwd_ifnames,
tun_fwd_ifnames == NULL ? "" : ",",
ifname);
free(tmp);
free(ifname);
done:
if (c == NULL)
packet_send_debug("Failed to open the tunnel device.");
return c;
}
static Channel *
server_request_session(struct ssh *ssh)
{
Channel *c;
debug("input_session_request");
packet_check_eom();
if (no_more_sessions) {
packet_disconnect("Possible attack: attempt to open a session "
"after additional sessions disabled");
}
/*
* 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(ssh, "session", 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(ssh, c);
return NULL;
}
channel_register_cleanup(ssh, c->self, session_close_by_channel, 0);
return c;
}
static int
server_input_channel_open(int type, u_int32_t seq, struct ssh *ssh)
{
Channel *c = NULL;
char *ctype;
const char *errmsg = NULL;
int rchan, reason = SSH2_OPEN_CONNECT_FAILED;
u_int rmaxpack, rwindow, len;
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(ssh);
} else if (strcmp(ctype, "direct-tcpip") == 0) {
c = server_request_direct_tcpip(ssh, &reason, &errmsg);
} else if (strcmp(ctype, "direct-streamlocal@openssh.com") == 0) {
c = server_request_direct_streamlocal(ssh);
} else if (strcmp(ctype, "tun@openssh.com") == 0) {
c = server_request_tun(ssh);
}
if (c != NULL) {
debug("server_input_channel_open: confirm %s", ctype);
c->remote_id = rchan;
c->have_remote_id = 1;
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(reason);
if (!(datafellows & SSH_BUG_OPENFAILURE)) {
packet_put_cstring(errmsg ? errmsg : "open failed");
packet_put_cstring("");
}
packet_send();
}
free(ctype);
return 0;
}
static int
server_input_hostkeys_prove(struct ssh *ssh, struct sshbuf **respp)
{
struct sshbuf *resp = NULL;
struct sshbuf *sigbuf = NULL;
struct sshkey *key = NULL, *key_pub = NULL, *key_prv = NULL;
int r, ndx, success = 0;
const u_char *blob;
u_char *sig = 0;
size_t blen, slen;
if ((resp = sshbuf_new()) == NULL || (sigbuf = sshbuf_new()) == NULL)
fatal("%s: sshbuf_new", __func__);
while (ssh_packet_remaining(ssh) > 0) {
sshkey_free(key);
key = NULL;
if ((r = sshpkt_get_string_direct(ssh, &blob, &blen)) != 0 ||
(r = sshkey_from_blob(blob, blen, &key)) != 0) {
error("%s: couldn't parse key: %s",
__func__, ssh_err(r));
goto out;
}
/*
* Better check that this is actually one of our hostkeys
* before attempting to sign anything with it.
*/
if ((ndx = ssh->kex->host_key_index(key, 1, ssh)) == -1) {
error("%s: unknown host %s key",
__func__, sshkey_type(key));
goto out;
}
/*
* XXX refactor: make kex->sign just use an index rather
* than passing in public and private keys
*/
if ((key_prv = get_hostkey_by_index(ndx)) == NULL &&
(key_pub = get_hostkey_public_by_index(ndx, ssh)) == NULL) {
error("%s: can't retrieve hostkey %d", __func__, ndx);
goto out;
}
sshbuf_reset(sigbuf);
free(sig);
sig = NULL;
if ((r = sshbuf_put_cstring(sigbuf,
"hostkeys-prove-00@openssh.com")) != 0 ||
(r = sshbuf_put_string(sigbuf,
ssh->kex->session_id, ssh->kex->session_id_len)) != 0 ||
(r = sshkey_puts(key, sigbuf)) != 0 ||
(r = ssh->kex->sign(key_prv, key_pub, &sig, &slen,
sshbuf_ptr(sigbuf), sshbuf_len(sigbuf), NULL, 0)) != 0 ||
(r = sshbuf_put_string(resp, sig, slen)) != 0) {
error("%s: couldn't prepare signature: %s",
__func__, ssh_err(r));
goto out;
}
}
/* Success */
*respp = resp;
resp = NULL; /* don't free it */
success = 1;
out:
free(sig);
sshbuf_free(resp);
sshbuf_free(sigbuf);
sshkey_free(key);
return success;
}
static int
server_input_global_request(int type, u_int32_t seq, struct ssh *ssh)
{
char *rtype;
int want_reply;
int r, success = 0, allocated_listen_port = 0;
struct sshbuf *resp = NULL;
struct passwd *pw = the_authctxt->pw;
if (pw == NULL || !the_authctxt->valid)
fatal("server_input_global_request: no/invalid user");
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 Forward fwd;
memset(&fwd, 0, sizeof(fwd));
fwd.listen_host = packet_get_string(NULL);
fwd.listen_port = (u_short)packet_get_int();
debug("server_input_global_request: tcpip-forward listen %s port %d",
fwd.listen_host, fwd.listen_port);
/* check permissions */
if ((options.allow_tcp_forwarding & FORWARD_REMOTE) == 0 ||
no_port_forwarding_flag || options.disable_forwarding ||
(!want_reply && fwd.listen_port == 0) ||
(fwd.listen_port != 0 &&
!bind_permitted(fwd.listen_port, pw->pw_uid))) {
success = 0;
packet_send_debug("Server has disabled port forwarding.");
} else {
/* Start listening on the port */
success = channel_setup_remote_fwd_listener(ssh, &fwd,
&allocated_listen_port, &options.fwd_opts);
}
free(fwd.listen_host);
if ((resp = sshbuf_new()) == NULL)
fatal("%s: sshbuf_new", __func__);
if (allocated_listen_port != 0 &&
(r = sshbuf_put_u32(resp, allocated_listen_port)) != 0)
fatal("%s: sshbuf_put_u32: %s", __func__, ssh_err(r));
} else if (strcmp(rtype, "cancel-tcpip-forward") == 0) {
struct Forward fwd;
memset(&fwd, 0, sizeof(fwd));
fwd.listen_host = packet_get_string(NULL);
fwd.listen_port = (u_short)packet_get_int();
debug("%s: cancel-tcpip-forward addr %s port %d", __func__,
fwd.listen_host, fwd.listen_port);
success = channel_cancel_rport_listener(ssh, &fwd);
free(fwd.listen_host);
} else if (strcmp(rtype, "streamlocal-forward@openssh.com") == 0) {
struct Forward fwd;
memset(&fwd, 0, sizeof(fwd));
fwd.listen_path = packet_get_string(NULL);
debug("server_input_global_request: streamlocal-forward listen path %s",
fwd.listen_path);
/* check permissions */
if ((options.allow_streamlocal_forwarding & FORWARD_REMOTE) == 0
|| no_port_forwarding_flag || options.disable_forwarding ||
(pw->pw_uid != 0 && !use_privsep)) {
success = 0;
packet_send_debug("Server has disabled "
"streamlocal forwarding.");
} else {
/* Start listening on the socket */
success = channel_setup_remote_fwd_listener(ssh,
&fwd, NULL, &options.fwd_opts);
}
free(fwd.listen_path);
} else if (strcmp(rtype, "cancel-streamlocal-forward@openssh.com") == 0) {
struct Forward fwd;
memset(&fwd, 0, sizeof(fwd));
fwd.listen_path = packet_get_string(NULL);
debug("%s: cancel-streamlocal-forward path %s", __func__,
fwd.listen_path);
success = channel_cancel_rport_listener(ssh, &fwd);
free(fwd.listen_path);
} else if (strcmp(rtype, "no-more-sessions@openssh.com") == 0) {
no_more_sessions = 1;
success = 1;
} else if (strcmp(rtype, "hostkeys-prove-00@openssh.com") == 0) {
success = server_input_hostkeys_prove(ssh, &resp);
}
if (want_reply) {
packet_start(success ?
SSH2_MSG_REQUEST_SUCCESS : SSH2_MSG_REQUEST_FAILURE);
if (success && resp != NULL)
ssh_packet_put_raw(ssh, sshbuf_ptr(resp),
sshbuf_len(resp));
packet_send();
packet_write_wait();
}
free(rtype);
sshbuf_free(resp);
return 0;
}
static int
server_input_channel_req(int type, u_int32_t seq, struct ssh *ssh)
{
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(ssh, id)) == NULL)
packet_disconnect("server_input_channel_req: "
"unknown channel %d", id);
if (!strcmp(rtype, "eow@openssh.com")) {
packet_check_eom();
chan_rcvd_eow(ssh, c);
} else if ((c->type == SSH_CHANNEL_LARVAL ||
c->type == SSH_CHANNEL_OPEN) && strcmp(c->ctype, "session") == 0)
success = session_input_channel_req(ssh, c, rtype);
if (reply && !(c->flags & CHAN_CLOSE_SENT)) {
if (!c->have_remote_id)
fatal("%s: channel %d: no remote_id",
__func__, c->self);
packet_start(success ?
SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE);
packet_put_int(c->remote_id);
packet_send();
}
free(rtype);
return 0;
}
static void
server_init_dispatch(void)
{
debug("server_init_dispatch");
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_SUCCESS, &server_input_keep_alive);
dispatch_set(SSH2_MSG_CHANNEL_FAILURE, &server_input_keep_alive);
dispatch_set(SSH2_MSG_REQUEST_SUCCESS, &server_input_keep_alive);
dispatch_set(SSH2_MSG_REQUEST_FAILURE, &server_input_keep_alive);
/* rekeying */
dispatch_set(SSH2_MSG_KEXINIT, &kex_input_kexinit);
}
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