+++ /dev/null
-/* $OpenBSD: channels.c,v 1.355 2016/09/30 20:24:46 djm Exp $ */
-/*
- * Author: Tatu Ylonen <ylo@cs.hut.fi>
- * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
- * All rights reserved
- * This file contains functions for generic socket connection forwarding.
- * There is also code for initiating connection forwarding for X11 connections,
- * arbitrary tcp/ip connections, and the authentication agent connection.
- *
- * 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 added by Markus Friedl.
- * Copyright (c) 1999, 2000, 2001, 2002 Markus Friedl. All rights reserved.
- * Copyright (c) 1999 Dug Song. All rights reserved.
- * Copyright (c) 1999 Theo de Raadt. 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/stat.h>
-#include <sys/ioctl.h>
-#include <sys/un.h>
-#include <sys/socket.h>
-#ifdef HAVE_SYS_TIME_H
-# include <sys/time.h>
-#endif
-
-#include <netinet/in.h>
-#include <arpa/inet.h>
-
-#include <errno.h>
-#include <fcntl.h>
-#include <netdb.h>
-#ifdef HAVE_STDINT_H
-#include <stdint.h>
-#endif
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <termios.h>
-#include <unistd.h>
-#include <stdarg.h>
-
-#include "openbsd-compat/sys-queue.h"
-#include "xmalloc.h"
-#include "ssh.h"
-#include "ssh1.h"
-#include "ssh2.h"
-#include "ssherr.h"
-#include "packet.h"
-#include "log.h"
-#include "misc.h"
-#include "buffer.h"
-#include "channels.h"
-#include "compat.h"
-#include "canohost.h"
-#include "key.h"
-#include "authfd.h"
-#include "pathnames.h"
-
-/* -- channel core */
-
-/*
- * Pointer to an array containing all allocated channels. The array is
- * dynamically extended as needed.
- */
-static Channel **channels = NULL;
-
-/*
- * Size of the channel array. All slots of the array must always be
- * initialized (at least the type field); unused slots set to NULL
- */
-static u_int channels_alloc = 0;
-
-/*
- * Maximum file descriptor value used in any of the channels. This is
- * updated in channel_new.
- */
-static int channel_max_fd = 0;
-
-
-/* -- tcp forwarding */
-
-/*
- * Data structure for storing which hosts are permitted for forward requests.
- * The local sides of any remote forwards are stored in this array to prevent
- * a corrupt remote server from accessing arbitrary TCP/IP ports on our local
- * network (which might be behind a firewall).
- */
-/* XXX: streamlocal wants a path instead of host:port */
-/* Overload host_to_connect; we could just make this match Forward */
-/* XXX - can we use listen_host instead of listen_path? */
-typedef struct {
- char *host_to_connect; /* Connect to 'host'. */
- int port_to_connect; /* Connect to 'port'. */
- char *listen_host; /* Remote side should listen address. */
- char *listen_path; /* Remote side should listen path. */
- int listen_port; /* Remote side should listen port. */
- Channel *downstream; /* Downstream mux*/
-} ForwardPermission;
-
-/* List of all permitted host/port pairs to connect by the user. */
-static ForwardPermission *permitted_opens = NULL;
-
-/* List of all permitted host/port pairs to connect by the admin. */
-static ForwardPermission *permitted_adm_opens = NULL;
-
-/* Number of permitted host/port pairs in the array permitted by the user. */
-static int num_permitted_opens = 0;
-
-/* Number of permitted host/port pair in the array permitted by the admin. */
-static int num_adm_permitted_opens = 0;
-
-/* special-case port number meaning allow any port */
-#define FWD_PERMIT_ANY_PORT 0
-
-/* special-case wildcard meaning allow any host */
-#define FWD_PERMIT_ANY_HOST "*"
-
-/*
- * If this is true, all opens are permitted. This is the case on the server
- * on which we have to trust the client anyway, and the user could do
- * anything after logging in anyway.
- */
-static int all_opens_permitted = 0;
-
-
-/* -- X11 forwarding */
-
-/* Maximum number of fake X11 displays to try. */
-#define MAX_DISPLAYS 1000
-
-/* Saved X11 local (client) display. */
-static char *x11_saved_display = NULL;
-
-/* Saved X11 authentication protocol name. */
-static char *x11_saved_proto = NULL;
-
-/* Saved X11 authentication data. This is the real data. */
-static char *x11_saved_data = NULL;
-static u_int x11_saved_data_len = 0;
-
-/* Deadline after which all X11 connections are refused */
-static u_int x11_refuse_time;
-
-/*
- * Fake X11 authentication data. This is what the server will be sending us;
- * we should replace any occurrences of this by the real data.
- */
-static u_char *x11_fake_data = NULL;
-static u_int x11_fake_data_len;
-
-
-/* -- agent forwarding */
-
-#define NUM_SOCKS 10
-
-/* AF_UNSPEC or AF_INET or AF_INET6 */
-static int IPv4or6 = AF_UNSPEC;
-
-/* helper */
-static void port_open_helper(Channel *c, char *rtype);
-static const char *channel_rfwd_bind_host(const char *listen_host);
-
-/* non-blocking connect helpers */
-static int connect_next(struct channel_connect *);
-static void channel_connect_ctx_free(struct channel_connect *);
-
-/* -- channel core */
-
-Channel *
-channel_by_id(int id)
-{
- Channel *c;
-
- if (id < 0 || (u_int)id >= channels_alloc) {
- logit("channel_by_id: %d: bad id", id);
- return NULL;
- }
- c = channels[id];
- if (c == NULL) {
- logit("channel_by_id: %d: bad id: channel free", id);
- return NULL;
- }
- return c;
-}
-
-Channel *
-channel_by_remote_id(int remote_id)
-{
- Channel *c;
- u_int i;
-
- for (i = 0; i < channels_alloc; i++) {
- c = channels[i];
- if (c != NULL && c->remote_id == remote_id)
- return c;
- }
- return NULL;
-}
-
-/*
- * Returns the channel if it is allowed to receive protocol messages.
- * Private channels, like listening sockets, may not receive messages.
- */
-Channel *
-channel_lookup(int id)
-{
- Channel *c;
-
- if ((c = channel_by_id(id)) == NULL)
- return (NULL);
-
- switch (c->type) {
- case SSH_CHANNEL_X11_OPEN:
- case SSH_CHANNEL_LARVAL:
- case SSH_CHANNEL_CONNECTING:
- case SSH_CHANNEL_DYNAMIC:
- case SSH_CHANNEL_OPENING:
- case SSH_CHANNEL_OPEN:
- case SSH_CHANNEL_INPUT_DRAINING:
- case SSH_CHANNEL_OUTPUT_DRAINING:
- case SSH_CHANNEL_ABANDONED:
- case SSH_CHANNEL_MUX_PROXY:
- return (c);
- }
- logit("Non-public channel %d, type %d.", id, c->type);
- return (NULL);
-}
-
-/*
- * Register filedescriptors for a channel, used when allocating a channel or
- * when the channel consumer/producer is ready, e.g. shell exec'd
- */
-static void
-channel_register_fds(Channel *c, int rfd, int wfd, int efd,
- int extusage, int nonblock, int is_tty)
-{
- /* Update the maximum file descriptor value. */
- channel_max_fd = MAXIMUM(channel_max_fd, rfd);
- channel_max_fd = MAXIMUM(channel_max_fd, wfd);
- channel_max_fd = MAXIMUM(channel_max_fd, efd);
-
- if (rfd != -1)
- fcntl(rfd, F_SETFD, FD_CLOEXEC);
- if (wfd != -1 && wfd != rfd)
- fcntl(wfd, F_SETFD, FD_CLOEXEC);
- if (efd != -1 && efd != rfd && efd != wfd)
- fcntl(efd, F_SETFD, FD_CLOEXEC);
-
- c->rfd = rfd;
- c->wfd = wfd;
- c->sock = (rfd == wfd) ? rfd : -1;
- c->efd = efd;
- c->extended_usage = extusage;
-
- if ((c->isatty = is_tty) != 0)
- debug2("channel %d: rfd %d isatty", c->self, c->rfd);
-#ifdef _AIX
- /* XXX: Later AIX versions can't push as much data to tty */
- c->wfd_isatty = is_tty || isatty(c->wfd);
-#endif
-
- /* enable nonblocking mode */
- if (nonblock) {
- if (rfd != -1)
- set_nonblock(rfd);
- if (wfd != -1)
- set_nonblock(wfd);
- if (efd != -1)
- set_nonblock(efd);
- }
-}
-
-/*
- * Allocate a new channel object and set its type and socket. This will cause
- * remote_name to be freed.
- */
-Channel *
-channel_new(char *ctype, int type, int rfd, int wfd, int efd,
- u_int window, u_int maxpack, int extusage, char *remote_name, int nonblock)
-{
- int found;
- u_int i;
- Channel *c;
-
- /* Do initial allocation if this is the first call. */
- if (channels_alloc == 0) {
- channels_alloc = 10;
- channels = xcalloc(channels_alloc, sizeof(Channel *));
- for (i = 0; i < channels_alloc; i++)
- channels[i] = NULL;
- }
- /* Try to find a free slot where to put the new channel. */
- for (found = -1, i = 0; i < channels_alloc; i++)
- if (channels[i] == NULL) {
- /* Found a free slot. */
- found = (int)i;
- break;
- }
- if (found < 0) {
- /* There are no free slots. Take last+1 slot and expand the array. */
- found = channels_alloc;
- if (channels_alloc > 10000)
- fatal("channel_new: internal error: channels_alloc %d "
- "too big.", channels_alloc);
- channels = xreallocarray(channels, channels_alloc + 10,
- sizeof(Channel *));
- channels_alloc += 10;
- debug2("channel: expanding %d", channels_alloc);
- for (i = found; i < channels_alloc; i++)
- channels[i] = NULL;
- }
- /* Initialize and return new channel. */
- c = channels[found] = xcalloc(1, sizeof(Channel));
- buffer_init(&c->input);
- buffer_init(&c->output);
- buffer_init(&c->extended);
- c->path = NULL;
- c->listening_addr = NULL;
- c->listening_port = 0;
- c->ostate = CHAN_OUTPUT_OPEN;
- c->istate = CHAN_INPUT_OPEN;
- c->flags = 0;
- channel_register_fds(c, rfd, wfd, efd, extusage, nonblock, 0);
- c->notbefore = 0;
- c->self = found;
- c->type = type;
- c->ctype = ctype;
- c->local_window = window;
- c->local_window_max = window;
- c->local_consumed = 0;
- c->local_maxpacket = maxpack;
- c->remote_id = -1;
- c->remote_name = xstrdup(remote_name);
- c->remote_window = 0;
- c->remote_maxpacket = 0;
- c->force_drain = 0;
- c->single_connection = 0;
- c->detach_user = NULL;
- c->detach_close = 0;
- c->open_confirm = NULL;
- c->open_confirm_ctx = NULL;
- c->input_filter = NULL;
- c->output_filter = NULL;
- c->filter_ctx = NULL;
- c->filter_cleanup = NULL;
- c->ctl_chan = -1;
- c->mux_rcb = NULL;
- c->mux_ctx = NULL;
- c->mux_pause = 0;
- c->delayed = 1; /* prevent call to channel_post handler */
- TAILQ_INIT(&c->status_confirms);
- debug("channel %d: new [%s]", found, remote_name);
- return c;
-}
-
-static int
-channel_find_maxfd(void)
-{
- u_int i;
- int max = 0;
- Channel *c;
-
- for (i = 0; i < channels_alloc; i++) {
- c = channels[i];
- if (c != NULL) {
- max = MAXIMUM(max, c->rfd);
- max = MAXIMUM(max, c->wfd);
- max = MAXIMUM(max, c->efd);
- }
- }
- return max;
-}
-
-int
-channel_close_fd(int *fdp)
-{
- int ret = 0, fd = *fdp;
-
- if (fd != -1) {
- ret = close(fd);
- *fdp = -1;
- if (fd == channel_max_fd)
- channel_max_fd = channel_find_maxfd();
- }
- return ret;
-}
-
-/* Close all channel fd/socket. */
-static void
-channel_close_fds(Channel *c)
-{
- channel_close_fd(&c->sock);
- channel_close_fd(&c->rfd);
- channel_close_fd(&c->wfd);
- channel_close_fd(&c->efd);
-}
-
-/* Free the channel and close its fd/socket. */
-void
-channel_free(Channel *c)
-{
- char *s;
- u_int i, n;
- Channel *other;
- struct channel_confirm *cc;
-
- for (n = 0, i = 0; i < channels_alloc; i++) {
- if ((other = channels[i]) != NULL) {
- n++;
-
- /* detach from mux client and prepare for closing */
- if (c->type == SSH_CHANNEL_MUX_CLIENT &&
- other->type == SSH_CHANNEL_MUX_PROXY &&
- other->mux_ctx == c) {
- other->mux_ctx = NULL;
- other->type = SSH_CHANNEL_OPEN;
- other->istate = CHAN_INPUT_CLOSED;
- other->ostate = CHAN_OUTPUT_CLOSED;
- }
- }
- }
- debug("channel %d: free: %s, nchannels %u", c->self,
- c->remote_name ? c->remote_name : "???", n);
-
- /* XXX more MUX cleanup: remove remote forwardings */
- if (c->type == SSH_CHANNEL_MUX_CLIENT) {
- for (i = 0; i < (u_int)num_permitted_opens; i++) {
- if (permitted_opens[i].downstream != c)
- continue;
- /* cancel on the server, since mux client is gone */
- debug("channel %d: cleanup remote forward for %s:%u",
- c->self,
- permitted_opens[i].listen_host,
- permitted_opens[i].listen_port);
- packet_start(SSH2_MSG_GLOBAL_REQUEST);
- packet_put_cstring("cancel-tcpip-forward");
- packet_put_char(0);
- packet_put_cstring(channel_rfwd_bind_host(
- permitted_opens[i].listen_host));
- packet_put_int(permitted_opens[i].listen_port);
- packet_send();
- /* unregister */
- permitted_opens[i].listen_port = 0;
- permitted_opens[i].port_to_connect = 0;
- free(permitted_opens[i].host_to_connect);
- permitted_opens[i].host_to_connect = NULL;
- free(permitted_opens[i].listen_host);
- permitted_opens[i].listen_host = NULL;
- permitted_opens[i].listen_path = NULL;
- permitted_opens[i].downstream = NULL;
- }
- }
-
- s = channel_open_message();
- debug3("channel %d: status: %s", c->self, s);
- free(s);
-
- if (c->sock != -1)
- shutdown(c->sock, SHUT_RDWR);
- channel_close_fds(c);
- buffer_free(&c->input);
- buffer_free(&c->output);
- buffer_free(&c->extended);
- free(c->remote_name);
- c->remote_name = NULL;
- free(c->path);
- c->path = NULL;
- free(c->listening_addr);
- c->listening_addr = NULL;
- while ((cc = TAILQ_FIRST(&c->status_confirms)) != NULL) {
- if (cc->abandon_cb != NULL)
- cc->abandon_cb(c, cc->ctx);
- TAILQ_REMOVE(&c->status_confirms, cc, entry);
- explicit_bzero(cc, sizeof(*cc));
- free(cc);
- }
- if (c->filter_cleanup != NULL && c->filter_ctx != NULL)
- c->filter_cleanup(c->self, c->filter_ctx);
- channels[c->self] = NULL;
- free(c);
-}
-
-void
-channel_free_all(void)
-{
- u_int i;
-
- for (i = 0; i < channels_alloc; i++)
- if (channels[i] != NULL)
- channel_free(channels[i]);
-}
-
-/*
- * Closes the sockets/fds of all channels. This is used to close extra file
- * descriptors after a fork.
- */
-void
-channel_close_all(void)
-{
- u_int i;
-
- for (i = 0; i < channels_alloc; i++)
- if (channels[i] != NULL)
- channel_close_fds(channels[i]);
-}
-
-/*
- * Stop listening to channels.
- */
-void
-channel_stop_listening(void)
-{
- u_int i;
- Channel *c;
-
- for (i = 0; i < channels_alloc; i++) {
- c = channels[i];
- if (c != NULL) {
- switch (c->type) {
- case SSH_CHANNEL_AUTH_SOCKET:
- case SSH_CHANNEL_PORT_LISTENER:
- case SSH_CHANNEL_RPORT_LISTENER:
- case SSH_CHANNEL_X11_LISTENER:
- case SSH_CHANNEL_UNIX_LISTENER:
- case SSH_CHANNEL_RUNIX_LISTENER:
- channel_close_fd(&c->sock);
- channel_free(c);
- break;
- }
- }
- }
-}
-
-/*
- * Returns true if no channel has too much buffered data, and false if one or
- * more channel is overfull.
- */
-int
-channel_not_very_much_buffered_data(void)
-{
- u_int i;
- Channel *c;
-
- for (i = 0; i < channels_alloc; i++) {
- c = channels[i];
- if (c != NULL && c->type == SSH_CHANNEL_OPEN) {
-#if 0
- if (!compat20 &&
- buffer_len(&c->input) > packet_get_maxsize()) {
- debug2("channel %d: big input buffer %d",
- c->self, buffer_len(&c->input));
- return 0;
- }
-#endif
- if (buffer_len(&c->output) > packet_get_maxsize()) {
- debug2("channel %d: big output buffer %u > %u",
- c->self, buffer_len(&c->output),
- packet_get_maxsize());
- return 0;
- }
- }
- }
- return 1;
-}
-
-/* Returns true if any channel is still open. */
-int
-channel_still_open(void)
-{
- u_int i;
- Channel *c;
-
- for (i = 0; i < channels_alloc; i++) {
- c = channels[i];
- if (c == NULL)
- continue;
- switch (c->type) {
- case SSH_CHANNEL_X11_LISTENER:
- case SSH_CHANNEL_PORT_LISTENER:
- case SSH_CHANNEL_RPORT_LISTENER:
- case SSH_CHANNEL_MUX_LISTENER:
- case SSH_CHANNEL_CLOSED:
- case SSH_CHANNEL_AUTH_SOCKET:
- case SSH_CHANNEL_DYNAMIC:
- case SSH_CHANNEL_CONNECTING:
- case SSH_CHANNEL_ZOMBIE:
- case SSH_CHANNEL_ABANDONED:
- case SSH_CHANNEL_UNIX_LISTENER:
- case SSH_CHANNEL_RUNIX_LISTENER:
- continue;
- case SSH_CHANNEL_LARVAL:
- if (!compat20)
- fatal("cannot happen: SSH_CHANNEL_LARVAL");
- continue;
- case SSH_CHANNEL_OPENING:
- case SSH_CHANNEL_OPEN:
- case SSH_CHANNEL_X11_OPEN:
- case SSH_CHANNEL_MUX_CLIENT:
- case SSH_CHANNEL_MUX_PROXY:
- return 1;
- case SSH_CHANNEL_INPUT_DRAINING:
- case SSH_CHANNEL_OUTPUT_DRAINING:
- if (!compat13)
- fatal("cannot happen: OUT_DRAIN");
- return 1;
- default:
- fatal("channel_still_open: bad channel type %d", c->type);
- /* NOTREACHED */
- }
- }
- return 0;
-}
-
-/* Returns the id of an open channel suitable for keepaliving */
-int
-channel_find_open(void)
-{
- u_int i;
- Channel *c;
-
- for (i = 0; i < channels_alloc; i++) {
- c = channels[i];
- if (c == NULL || c->remote_id < 0)
- continue;
- switch (c->type) {
- case SSH_CHANNEL_CLOSED:
- case SSH_CHANNEL_DYNAMIC:
- case SSH_CHANNEL_X11_LISTENER:
- case SSH_CHANNEL_PORT_LISTENER:
- case SSH_CHANNEL_RPORT_LISTENER:
- case SSH_CHANNEL_MUX_LISTENER:
- case SSH_CHANNEL_MUX_CLIENT:
- case SSH_CHANNEL_MUX_PROXY:
- case SSH_CHANNEL_OPENING:
- case SSH_CHANNEL_CONNECTING:
- case SSH_CHANNEL_ZOMBIE:
- case SSH_CHANNEL_ABANDONED:
- case SSH_CHANNEL_UNIX_LISTENER:
- case SSH_CHANNEL_RUNIX_LISTENER:
- continue;
- case SSH_CHANNEL_LARVAL:
- case SSH_CHANNEL_AUTH_SOCKET:
- case SSH_CHANNEL_OPEN:
- case SSH_CHANNEL_X11_OPEN:
- return i;
- case SSH_CHANNEL_INPUT_DRAINING:
- case SSH_CHANNEL_OUTPUT_DRAINING:
- if (!compat13)
- fatal("cannot happen: OUT_DRAIN");
- return i;
- default:
- fatal("channel_find_open: bad channel type %d", c->type);
- /* NOTREACHED */
- }
- }
- return -1;
-}
-
-/*
- * Returns a message describing the currently open forwarded connections,
- * suitable for sending to the client. The message contains crlf pairs for
- * newlines.
- */
-char *
-channel_open_message(void)
-{
- Buffer buffer;
- Channel *c;
- char buf[1024], *cp;
- u_int i;
-
- buffer_init(&buffer);
- snprintf(buf, sizeof buf, "The following connections are open:\r\n");
- buffer_append(&buffer, buf, strlen(buf));
- for (i = 0; i < channels_alloc; i++) {
- c = channels[i];
- if (c == NULL)
- continue;
- switch (c->type) {
- case SSH_CHANNEL_X11_LISTENER:
- case SSH_CHANNEL_PORT_LISTENER:
- case SSH_CHANNEL_RPORT_LISTENER:
- case SSH_CHANNEL_CLOSED:
- case SSH_CHANNEL_AUTH_SOCKET:
- case SSH_CHANNEL_ZOMBIE:
- case SSH_CHANNEL_ABANDONED:
- case SSH_CHANNEL_MUX_LISTENER:
- case SSH_CHANNEL_UNIX_LISTENER:
- case SSH_CHANNEL_RUNIX_LISTENER:
- continue;
- case SSH_CHANNEL_LARVAL:
- case SSH_CHANNEL_OPENING:
- case SSH_CHANNEL_CONNECTING:
- case SSH_CHANNEL_DYNAMIC:
- case SSH_CHANNEL_OPEN:
- case SSH_CHANNEL_X11_OPEN:
- case SSH_CHANNEL_INPUT_DRAINING:
- case SSH_CHANNEL_OUTPUT_DRAINING:
- case SSH_CHANNEL_MUX_PROXY:
- case SSH_CHANNEL_MUX_CLIENT:
- snprintf(buf, sizeof buf,
- " #%d %.300s (t%d r%d i%u/%d o%u/%d fd %d/%d cc %d)\r\n",
- c->self, c->remote_name,
- c->type, c->remote_id,
- c->istate, buffer_len(&c->input),
- c->ostate, buffer_len(&c->output),
- c->rfd, c->wfd, c->ctl_chan);
- buffer_append(&buffer, buf, strlen(buf));
- continue;
- default:
- fatal("channel_open_message: bad channel type %d", c->type);
- /* NOTREACHED */
- }
- }
- buffer_append(&buffer, "\0", 1);
- cp = xstrdup((char *)buffer_ptr(&buffer));
- buffer_free(&buffer);
- return cp;
-}
-
-void
-channel_send_open(int id)
-{
- Channel *c = channel_lookup(id);
-
- if (c == NULL) {
- logit("channel_send_open: %d: bad id", id);
- return;
- }
- debug2("channel %d: send open", id);
- packet_start(SSH2_MSG_CHANNEL_OPEN);
- packet_put_cstring(c->ctype);
- packet_put_int(c->self);
- packet_put_int(c->local_window);
- packet_put_int(c->local_maxpacket);
- packet_send();
-}
-
-void
-channel_request_start(int id, char *service, int wantconfirm)
-{
- Channel *c = channel_lookup(id);
-
- if (c == NULL) {
- logit("channel_request_start: %d: unknown channel id", id);
- return;
- }
- debug2("channel %d: request %s confirm %d", id, service, wantconfirm);
- packet_start(SSH2_MSG_CHANNEL_REQUEST);
- packet_put_int(c->remote_id);
- packet_put_cstring(service);
- packet_put_char(wantconfirm);
-}
-
-void
-channel_register_status_confirm(int id, channel_confirm_cb *cb,
- channel_confirm_abandon_cb *abandon_cb, void *ctx)
-{
- struct channel_confirm *cc;
- Channel *c;
-
- if ((c = channel_lookup(id)) == NULL)
- fatal("channel_register_expect: %d: bad id", id);
-
- cc = xcalloc(1, sizeof(*cc));
- cc->cb = cb;
- cc->abandon_cb = abandon_cb;
- cc->ctx = ctx;
- TAILQ_INSERT_TAIL(&c->status_confirms, cc, entry);
-}
-
-void
-channel_register_open_confirm(int id, channel_open_fn *fn, void *ctx)
-{
- Channel *c = channel_lookup(id);
-
- if (c == NULL) {
- logit("channel_register_open_confirm: %d: bad id", id);
- return;
- }
- c->open_confirm = fn;
- c->open_confirm_ctx = ctx;
-}
-
-void
-channel_register_cleanup(int id, channel_callback_fn *fn, int do_close)
-{
- Channel *c = channel_by_id(id);
-
- if (c == NULL) {
- logit("channel_register_cleanup: %d: bad id", id);
- return;
- }
- c->detach_user = fn;
- c->detach_close = do_close;
-}
-
-void
-channel_cancel_cleanup(int id)
-{
- Channel *c = channel_by_id(id);
-
- if (c == NULL) {
- logit("channel_cancel_cleanup: %d: bad id", id);
- return;
- }
- c->detach_user = NULL;
- c->detach_close = 0;
-}
-
-void
-channel_register_filter(int id, channel_infilter_fn *ifn,
- channel_outfilter_fn *ofn, channel_filter_cleanup_fn *cfn, void *ctx)
-{
- Channel *c = channel_lookup(id);
-
- if (c == NULL) {
- logit("channel_register_filter: %d: bad id", id);
- return;
- }
- c->input_filter = ifn;
- c->output_filter = ofn;
- c->filter_ctx = ctx;
- c->filter_cleanup = cfn;
-}
-
-void
-channel_set_fds(int id, int rfd, int wfd, int efd,
- int extusage, int nonblock, int is_tty, u_int window_max)
-{
- Channel *c = channel_lookup(id);
-
- if (c == NULL || c->type != SSH_CHANNEL_LARVAL)
- fatal("channel_activate for non-larval channel %d.", id);
- channel_register_fds(c, rfd, wfd, efd, extusage, nonblock, is_tty);
- c->type = SSH_CHANNEL_OPEN;
- c->local_window = c->local_window_max = window_max;
- packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
- packet_put_int(c->remote_id);
- packet_put_int(c->local_window);
- packet_send();
-}
-
-/*
- * 'channel_pre*' are called just before select() to add any bits relevant to
- * channels in the select bitmasks.
- */
-/*
- * 'channel_post*': perform any appropriate operations for channels which
- * have events pending.
- */
-typedef void chan_fn(Channel *c, fd_set *readset, fd_set *writeset);
-chan_fn *channel_pre[SSH_CHANNEL_MAX_TYPE];
-chan_fn *channel_post[SSH_CHANNEL_MAX_TYPE];
-
-/* ARGSUSED */
-static void
-channel_pre_listener(Channel *c, fd_set *readset, fd_set *writeset)
-{
- FD_SET(c->sock, readset);
-}
-
-/* ARGSUSED */
-static void
-channel_pre_connecting(Channel *c, fd_set *readset, fd_set *writeset)
-{
- debug3("channel %d: waiting for connection", c->self);
- FD_SET(c->sock, writeset);
-}
-
-static void
-channel_pre_open_13(Channel *c, fd_set *readset, fd_set *writeset)
-{
- if (buffer_len(&c->input) < packet_get_maxsize())
- FD_SET(c->sock, readset);
- if (buffer_len(&c->output) > 0)
- FD_SET(c->sock, writeset);
-}
-
-static void
-channel_pre_open(Channel *c, fd_set *readset, fd_set *writeset)
-{
- u_int limit = compat20 ? c->remote_window : packet_get_maxsize();
-
- if (c->istate == CHAN_INPUT_OPEN &&
- limit > 0 &&
- buffer_len(&c->input) < limit &&
- buffer_check_alloc(&c->input, CHAN_RBUF))
- FD_SET(c->rfd, readset);
- if (c->ostate == CHAN_OUTPUT_OPEN ||
- c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
- if (buffer_len(&c->output) > 0) {
- FD_SET(c->wfd, writeset);
- } else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
- if (CHANNEL_EFD_OUTPUT_ACTIVE(c))
- debug2("channel %d: obuf_empty delayed efd %d/(%d)",
- c->self, c->efd, buffer_len(&c->extended));
- else
- chan_obuf_empty(c);
- }
- }
- /** XXX check close conditions, too */
- if (compat20 && c->efd != -1 &&
- !(c->istate == CHAN_INPUT_CLOSED && c->ostate == CHAN_OUTPUT_CLOSED)) {
- if (c->extended_usage == CHAN_EXTENDED_WRITE &&
- buffer_len(&c->extended) > 0)
- FD_SET(c->efd, writeset);
- else if (c->efd != -1 && !(c->flags & CHAN_EOF_SENT) &&
- (c->extended_usage == CHAN_EXTENDED_READ ||
- c->extended_usage == CHAN_EXTENDED_IGNORE) &&
- buffer_len(&c->extended) < c->remote_window)
- FD_SET(c->efd, readset);
- }
- /* XXX: What about efd? races? */
-}
-
-/* ARGSUSED */
-static void
-channel_pre_input_draining(Channel *c, fd_set *readset, fd_set *writeset)
-{
- if (buffer_len(&c->input) == 0) {
- packet_start(SSH_MSG_CHANNEL_CLOSE);
- packet_put_int(c->remote_id);
- packet_send();
- c->type = SSH_CHANNEL_CLOSED;
- debug2("channel %d: closing after input drain.", c->self);
- }
-}
-
-/* ARGSUSED */
-static void
-channel_pre_output_draining(Channel *c, fd_set *readset, fd_set *writeset)
-{
- if (buffer_len(&c->output) == 0)
- chan_mark_dead(c);
- else
- FD_SET(c->sock, writeset);
-}
-
-/*
- * This is a special state for X11 authentication spoofing. An opened X11
- * connection (when authentication spoofing is being done) remains in this
- * state until the first packet has been completely read. The authentication
- * data in that packet is then substituted by the real data if it matches the
- * fake data, and the channel is put into normal mode.
- * XXX All this happens at the client side.
- * Returns: 0 = need more data, -1 = wrong cookie, 1 = ok
- */
-static int
-x11_open_helper(Buffer *b)
-{
- u_char *ucp;
- u_int proto_len, data_len;
-
- /* Is this being called after the refusal deadline? */
- if (x11_refuse_time != 0 && (u_int)monotime() >= x11_refuse_time) {
- verbose("Rejected X11 connection after ForwardX11Timeout "
- "expired");
- return -1;
- }
-
- /* Check if the fixed size part of the packet is in buffer. */
- if (buffer_len(b) < 12)
- return 0;
-
- /* Parse the lengths of variable-length fields. */
- ucp = buffer_ptr(b);
- if (ucp[0] == 0x42) { /* Byte order MSB first. */
- proto_len = 256 * ucp[6] + ucp[7];
- data_len = 256 * ucp[8] + ucp[9];
- } else if (ucp[0] == 0x6c) { /* Byte order LSB first. */
- proto_len = ucp[6] + 256 * ucp[7];
- data_len = ucp[8] + 256 * ucp[9];
- } else {
- debug2("Initial X11 packet contains bad byte order byte: 0x%x",
- ucp[0]);
- return -1;
- }
-
- /* Check if the whole packet is in buffer. */
- if (buffer_len(b) <
- 12 + ((proto_len + 3) & ~3) + ((data_len + 3) & ~3))
- return 0;
-
- /* Check if authentication protocol matches. */
- if (proto_len != strlen(x11_saved_proto) ||
- memcmp(ucp + 12, x11_saved_proto, proto_len) != 0) {
- debug2("X11 connection uses different authentication protocol.");
- return -1;
- }
- /* Check if authentication data matches our fake data. */
- if (data_len != x11_fake_data_len ||
- timingsafe_bcmp(ucp + 12 + ((proto_len + 3) & ~3),
- x11_fake_data, x11_fake_data_len) != 0) {
- debug2("X11 auth data does not match fake data.");
- return -1;
- }
- /* Check fake data length */
- if (x11_fake_data_len != x11_saved_data_len) {
- error("X11 fake_data_len %d != saved_data_len %d",
- x11_fake_data_len, x11_saved_data_len);
- return -1;
- }
- /*
- * Received authentication protocol and data match
- * our fake data. Substitute the fake data with real
- * data.
- */
- memcpy(ucp + 12 + ((proto_len + 3) & ~3),
- x11_saved_data, x11_saved_data_len);
- return 1;
-}
-
-static void
-channel_pre_x11_open_13(Channel *c, fd_set *readset, fd_set *writeset)
-{
- int ret = x11_open_helper(&c->output);
-
- if (ret == 1) {
- /* Start normal processing for the channel. */
- c->type = SSH_CHANNEL_OPEN;
- channel_pre_open_13(c, readset, writeset);
- } else if (ret == -1) {
- /*
- * We have received an X11 connection that has bad
- * authentication information.
- */
- logit("X11 connection rejected because of wrong authentication.");
- buffer_clear(&c->input);
- buffer_clear(&c->output);
- channel_close_fd(&c->sock);
- c->sock = -1;
- c->type = SSH_CHANNEL_CLOSED;
- packet_start(SSH_MSG_CHANNEL_CLOSE);
- packet_put_int(c->remote_id);
- packet_send();
- }
-}
-
-static void
-channel_pre_x11_open(Channel *c, fd_set *readset, fd_set *writeset)
-{
- int ret = x11_open_helper(&c->output);
-
- /* c->force_drain = 1; */
-
- if (ret == 1) {
- c->type = SSH_CHANNEL_OPEN;
- channel_pre_open(c, readset, writeset);
- } else if (ret == -1) {
- logit("X11 connection rejected because of wrong authentication.");
- debug2("X11 rejected %d i%d/o%d", c->self, c->istate, c->ostate);
- chan_read_failed(c);
- buffer_clear(&c->input);
- chan_ibuf_empty(c);
- buffer_clear(&c->output);
- /* for proto v1, the peer will send an IEOF */
- if (compat20)
- chan_write_failed(c);
- else
- c->type = SSH_CHANNEL_OPEN;
- debug2("X11 closed %d i%d/o%d", c->self, c->istate, c->ostate);
- }
-}
-
-static void
-channel_pre_mux_client(Channel *c, fd_set *readset, fd_set *writeset)
-{
- if (c->istate == CHAN_INPUT_OPEN && !c->mux_pause &&
- buffer_check_alloc(&c->input, CHAN_RBUF))
- FD_SET(c->rfd, readset);
- if (c->istate == CHAN_INPUT_WAIT_DRAIN) {
- /* clear buffer immediately (discard any partial packet) */
- buffer_clear(&c->input);
- chan_ibuf_empty(c);
- /* Start output drain. XXX just kill chan? */
- chan_rcvd_oclose(c);
- }
- if (c->ostate == CHAN_OUTPUT_OPEN ||
- c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
- if (buffer_len(&c->output) > 0)
- FD_SET(c->wfd, writeset);
- else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN)
- chan_obuf_empty(c);
- }
-}
-
-/* try to decode a socks4 header */
-/* ARGSUSED */
-static int
-channel_decode_socks4(Channel *c, fd_set *readset, fd_set *writeset)
-{
- char *p, *host;
- u_int len, have, i, found, need;
- char username[256];
- struct {
- u_int8_t version;
- u_int8_t command;
- u_int16_t dest_port;
- struct in_addr dest_addr;
- } s4_req, s4_rsp;
-
- debug2("channel %d: decode socks4", c->self);
-
- have = buffer_len(&c->input);
- len = sizeof(s4_req);
- if (have < len)
- return 0;
- p = (char *)buffer_ptr(&c->input);
-
- need = 1;
- /* SOCKS4A uses an invalid IP address 0.0.0.x */
- if (p[4] == 0 && p[5] == 0 && p[6] == 0 && p[7] != 0) {
- debug2("channel %d: socks4a request", c->self);
- /* ... and needs an extra string (the hostname) */
- need = 2;
- }
- /* Check for terminating NUL on the string(s) */
- for (found = 0, i = len; i < have; i++) {
- if (p[i] == '\0') {
- found++;
- if (found == need)
- break;
- }
- if (i > 1024) {
- /* the peer is probably sending garbage */
- debug("channel %d: decode socks4: too long",
- c->self);
- return -1;
- }
- }
- if (found < need)
- return 0;
- buffer_get(&c->input, (char *)&s4_req.version, 1);
- buffer_get(&c->input, (char *)&s4_req.command, 1);
- buffer_get(&c->input, (char *)&s4_req.dest_port, 2);
- buffer_get(&c->input, (char *)&s4_req.dest_addr, 4);
- have = buffer_len(&c->input);
- p = (char *)buffer_ptr(&c->input);
- if (memchr(p, '\0', have) == NULL)
- fatal("channel %d: decode socks4: user not nul terminated",
- c->self);
- len = strlen(p);
- debug2("channel %d: decode socks4: user %s/%d", c->self, p, len);
- len++; /* trailing '\0' */
- if (len > have)
- fatal("channel %d: decode socks4: len %d > have %d",
- c->self, len, have);
- strlcpy(username, p, sizeof(username));
- buffer_consume(&c->input, len);
-
- free(c->path);
- c->path = NULL;
- if (need == 1) { /* SOCKS4: one string */
- host = inet_ntoa(s4_req.dest_addr);
- c->path = xstrdup(host);
- } else { /* SOCKS4A: two strings */
- have = buffer_len(&c->input);
- p = (char *)buffer_ptr(&c->input);
- len = strlen(p);
- debug2("channel %d: decode socks4a: host %s/%d",
- c->self, p, len);
- len++; /* trailing '\0' */
- if (len > have)
- fatal("channel %d: decode socks4a: len %d > have %d",
- c->self, len, have);
- if (len > NI_MAXHOST) {
- error("channel %d: hostname \"%.100s\" too long",
- c->self, p);
- return -1;
- }
- c->path = xstrdup(p);
- buffer_consume(&c->input, len);
- }
- c->host_port = ntohs(s4_req.dest_port);
-
- debug2("channel %d: dynamic request: socks4 host %s port %u command %u",
- c->self, c->path, c->host_port, s4_req.command);
-
- if (s4_req.command != 1) {
- debug("channel %d: cannot handle: %s cn %d",
- c->self, need == 1 ? "SOCKS4" : "SOCKS4A", s4_req.command);
- return -1;
- }
- s4_rsp.version = 0; /* vn: 0 for reply */
- s4_rsp.command = 90; /* cd: req granted */
- s4_rsp.dest_port = 0; /* ignored */
- s4_rsp.dest_addr.s_addr = INADDR_ANY; /* ignored */
- buffer_append(&c->output, &s4_rsp, sizeof(s4_rsp));
- return 1;
-}
-
-/* try to decode a socks5 header */
-#define SSH_SOCKS5_AUTHDONE 0x1000
-#define SSH_SOCKS5_NOAUTH 0x00
-#define SSH_SOCKS5_IPV4 0x01
-#define SSH_SOCKS5_DOMAIN 0x03
-#define SSH_SOCKS5_IPV6 0x04
-#define SSH_SOCKS5_CONNECT 0x01
-#define SSH_SOCKS5_SUCCESS 0x00
-
-/* ARGSUSED */
-static int
-channel_decode_socks5(Channel *c, fd_set *readset, fd_set *writeset)
-{
- struct {
- u_int8_t version;
- u_int8_t command;
- u_int8_t reserved;
- u_int8_t atyp;
- } s5_req, s5_rsp;
- u_int16_t dest_port;
- char dest_addr[255+1], ntop[INET6_ADDRSTRLEN];
- u_char *p;
- u_int have, need, i, found, nmethods, addrlen, af;
-
- debug2("channel %d: decode socks5", c->self);
- p = buffer_ptr(&c->input);
- if (p[0] != 0x05)
- return -1;
- have = buffer_len(&c->input);
- if (!(c->flags & SSH_SOCKS5_AUTHDONE)) {
- /* format: ver | nmethods | methods */
- if (have < 2)
- return 0;
- nmethods = p[1];
- if (have < nmethods + 2)
- return 0;
- /* look for method: "NO AUTHENTICATION REQUIRED" */
- for (found = 0, i = 2; i < nmethods + 2; i++) {
- if (p[i] == SSH_SOCKS5_NOAUTH) {
- found = 1;
- break;
- }
- }
- if (!found) {
- debug("channel %d: method SSH_SOCKS5_NOAUTH not found",
- c->self);
- return -1;
- }
- buffer_consume(&c->input, nmethods + 2);
- buffer_put_char(&c->output, 0x05); /* version */
- buffer_put_char(&c->output, SSH_SOCKS5_NOAUTH); /* method */
- FD_SET(c->sock, writeset);
- c->flags |= SSH_SOCKS5_AUTHDONE;
- debug2("channel %d: socks5 auth done", c->self);
- return 0; /* need more */
- }
- debug2("channel %d: socks5 post auth", c->self);
- if (have < sizeof(s5_req)+1)
- return 0; /* need more */
- memcpy(&s5_req, p, sizeof(s5_req));
- if (s5_req.version != 0x05 ||
- s5_req.command != SSH_SOCKS5_CONNECT ||
- s5_req.reserved != 0x00) {
- debug2("channel %d: only socks5 connect supported", c->self);
- return -1;
- }
- switch (s5_req.atyp){
- case SSH_SOCKS5_IPV4:
- addrlen = 4;
- af = AF_INET;
- break;
- case SSH_SOCKS5_DOMAIN:
- addrlen = p[sizeof(s5_req)];
- af = -1;
- break;
- case SSH_SOCKS5_IPV6:
- addrlen = 16;
- af = AF_INET6;
- break;
- default:
- debug2("channel %d: bad socks5 atyp %d", c->self, s5_req.atyp);
- return -1;
- }
- need = sizeof(s5_req) + addrlen + 2;
- if (s5_req.atyp == SSH_SOCKS5_DOMAIN)
- need++;
- if (have < need)
- return 0;
- buffer_consume(&c->input, sizeof(s5_req));
- if (s5_req.atyp == SSH_SOCKS5_DOMAIN)
- buffer_consume(&c->input, 1); /* host string length */
- buffer_get(&c->input, &dest_addr, addrlen);
- buffer_get(&c->input, (char *)&dest_port, 2);
- dest_addr[addrlen] = '\0';
- free(c->path);
- c->path = NULL;
- if (s5_req.atyp == SSH_SOCKS5_DOMAIN) {
- if (addrlen >= NI_MAXHOST) {
- error("channel %d: dynamic request: socks5 hostname "
- "\"%.100s\" too long", c->self, dest_addr);
- return -1;
- }
- c->path = xstrdup(dest_addr);
- } else {
- if (inet_ntop(af, dest_addr, ntop, sizeof(ntop)) == NULL)
- return -1;
- c->path = xstrdup(ntop);
- }
- c->host_port = ntohs(dest_port);
-
- debug2("channel %d: dynamic request: socks5 host %s port %u command %u",
- c->self, c->path, c->host_port, s5_req.command);
-
- s5_rsp.version = 0x05;
- s5_rsp.command = SSH_SOCKS5_SUCCESS;
- s5_rsp.reserved = 0; /* ignored */
- s5_rsp.atyp = SSH_SOCKS5_IPV4;
- dest_port = 0; /* ignored */
-
- buffer_append(&c->output, &s5_rsp, sizeof(s5_rsp));
- buffer_put_int(&c->output, ntohl(INADDR_ANY)); /* bind address */
- buffer_append(&c->output, &dest_port, sizeof(dest_port));
- return 1;
-}
-
-Channel *
-channel_connect_stdio_fwd(const char *host_to_connect, u_short port_to_connect,
- int in, int out)
-{
- Channel *c;
-
- debug("channel_connect_stdio_fwd %s:%d", host_to_connect,
- port_to_connect);
-
- c = channel_new("stdio-forward", SSH_CHANNEL_OPENING, in, out,
- -1, CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
- 0, "stdio-forward", /*nonblock*/0);
-
- c->path = xstrdup(host_to_connect);
- c->host_port = port_to_connect;
- c->listening_port = 0;
- c->force_drain = 1;
-
- channel_register_fds(c, in, out, -1, 0, 1, 0);
- port_open_helper(c, "direct-tcpip");
-
- return c;
-}
-
-/* dynamic port forwarding */
-static void
-channel_pre_dynamic(Channel *c, fd_set *readset, fd_set *writeset)
-{
- u_char *p;
- u_int have;
- int ret;
-
- have = buffer_len(&c->input);
- debug2("channel %d: pre_dynamic: have %d", c->self, have);
- /* buffer_dump(&c->input); */
- /* check if the fixed size part of the packet is in buffer. */
- if (have < 3) {
- /* need more */
- FD_SET(c->sock, readset);
- return;
- }
- /* try to guess the protocol */
- p = buffer_ptr(&c->input);
- switch (p[0]) {
- case 0x04:
- ret = channel_decode_socks4(c, readset, writeset);
- break;
- case 0x05:
- ret = channel_decode_socks5(c, readset, writeset);
- break;
- default:
- ret = -1;
- break;
- }
- if (ret < 0) {
- chan_mark_dead(c);
- } else if (ret == 0) {
- debug2("channel %d: pre_dynamic: need more", c->self);
- /* need more */
- FD_SET(c->sock, readset);
- } else {
- /* switch to the next state */
- c->type = SSH_CHANNEL_OPENING;
- port_open_helper(c, "direct-tcpip");
- }
-}
-
-/* This is our fake X11 server socket. */
-/* ARGSUSED */
-static void
-channel_post_x11_listener(Channel *c, fd_set *readset, fd_set *writeset)
-{
- Channel *nc;
- struct sockaddr_storage addr;
- int newsock, oerrno;
- socklen_t addrlen;
- char buf[16384], *remote_ipaddr;
- int remote_port;
-
- if (FD_ISSET(c->sock, readset)) {
- debug("X11 connection requested.");
- addrlen = sizeof(addr);
- newsock = accept(c->sock, (struct sockaddr *)&addr, &addrlen);
- if (c->single_connection) {
- oerrno = errno;
- debug2("single_connection: closing X11 listener.");
- channel_close_fd(&c->sock);
- chan_mark_dead(c);
- errno = oerrno;
- }
- if (newsock < 0) {
- if (errno != EINTR && errno != EWOULDBLOCK &&
- errno != ECONNABORTED)
- error("accept: %.100s", strerror(errno));
- if (errno == EMFILE || errno == ENFILE)
- c->notbefore = monotime() + 1;
- return;
- }
- set_nodelay(newsock);
- remote_ipaddr = get_peer_ipaddr(newsock);
- remote_port = get_peer_port(newsock);
- snprintf(buf, sizeof buf, "X11 connection from %.200s port %d",
- remote_ipaddr, remote_port);
-
- nc = channel_new("accepted x11 socket",
- SSH_CHANNEL_OPENING, newsock, newsock, -1,
- c->local_window_max, c->local_maxpacket, 0, buf, 1);
- if (compat20) {
- packet_start(SSH2_MSG_CHANNEL_OPEN);
- packet_put_cstring("x11");
- packet_put_int(nc->self);
- packet_put_int(nc->local_window_max);
- packet_put_int(nc->local_maxpacket);
- /* originator ipaddr and port */
- packet_put_cstring(remote_ipaddr);
- if (datafellows & SSH_BUG_X11FWD) {
- debug2("ssh2 x11 bug compat mode");
- } else {
- packet_put_int(remote_port);
- }
- packet_send();
- } else {
- packet_start(SSH_SMSG_X11_OPEN);
- packet_put_int(nc->self);
- if (packet_get_protocol_flags() &
- SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
- packet_put_cstring(buf);
- packet_send();
- }
- free(remote_ipaddr);
- }
-}
-
-static void
-port_open_helper(Channel *c, char *rtype)
-{
- char buf[1024];
- char *local_ipaddr = get_local_ipaddr(c->sock);
- int local_port = c->sock == -1 ? 65536 : get_local_port(c->sock);
- char *remote_ipaddr = get_peer_ipaddr(c->sock);
- int remote_port = get_peer_port(c->sock);
-
- if (remote_port == -1) {
- /* Fake addr/port to appease peers that validate it (Tectia) */
- free(remote_ipaddr);
- remote_ipaddr = xstrdup("127.0.0.1");
- remote_port = 65535;
- }
-
- snprintf(buf, sizeof buf,
- "%s: listening port %d for %.100s port %d, "
- "connect from %.200s port %d to %.100s port %d",
- rtype, c->listening_port, c->path, c->host_port,
- remote_ipaddr, remote_port, local_ipaddr, local_port);
-
- free(c->remote_name);
- c->remote_name = xstrdup(buf);
-
- if (compat20) {
- packet_start(SSH2_MSG_CHANNEL_OPEN);
- packet_put_cstring(rtype);
- packet_put_int(c->self);
- packet_put_int(c->local_window_max);
- packet_put_int(c->local_maxpacket);
- if (strcmp(rtype, "direct-tcpip") == 0) {
- /* target host, port */
- packet_put_cstring(c->path);
- packet_put_int(c->host_port);
- } else if (strcmp(rtype, "direct-streamlocal@openssh.com") == 0) {
- /* target path */
- packet_put_cstring(c->path);
- } else if (strcmp(rtype, "forwarded-streamlocal@openssh.com") == 0) {
- /* listen path */
- packet_put_cstring(c->path);
- } else {
- /* listen address, port */
- packet_put_cstring(c->path);
- packet_put_int(local_port);
- }
- if (strcmp(rtype, "forwarded-streamlocal@openssh.com") == 0) {
- /* reserved for future owner/mode info */
- packet_put_cstring("");
- } else {
- /* originator host and port */
- packet_put_cstring(remote_ipaddr);
- packet_put_int((u_int)remote_port);
- }
- packet_send();
- } else {
- packet_start(SSH_MSG_PORT_OPEN);
- packet_put_int(c->self);
- packet_put_cstring(c->path);
- packet_put_int(c->host_port);
- if (packet_get_protocol_flags() &
- SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
- packet_put_cstring(c->remote_name);
- packet_send();
- }
- free(remote_ipaddr);
- free(local_ipaddr);
-}
-
-static void
-channel_set_reuseaddr(int fd)
-{
- int on = 1;
-
- /*
- * Set socket options.
- * Allow local port reuse in TIME_WAIT.
- */
- if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) == -1)
- error("setsockopt SO_REUSEADDR fd %d: %s", fd, strerror(errno));
-}
-
-void
-channel_set_x11_refuse_time(u_int refuse_time)
-{
- x11_refuse_time = refuse_time;
-}
-
-/*
- * This socket is listening for connections to a forwarded TCP/IP port.
- */
-/* ARGSUSED */
-static void
-channel_post_port_listener(Channel *c, fd_set *readset, fd_set *writeset)
-{
- Channel *nc;
- struct sockaddr_storage addr;
- int newsock, nextstate;
- socklen_t addrlen;
- char *rtype;
-
- if (FD_ISSET(c->sock, readset)) {
- debug("Connection to port %d forwarding "
- "to %.100s port %d requested.",
- c->listening_port, c->path, c->host_port);
-
- if (c->type == SSH_CHANNEL_RPORT_LISTENER) {
- nextstate = SSH_CHANNEL_OPENING;
- rtype = "forwarded-tcpip";
- } else if (c->type == SSH_CHANNEL_RUNIX_LISTENER) {
- nextstate = SSH_CHANNEL_OPENING;
- rtype = "forwarded-streamlocal@openssh.com";
- } else if (c->host_port == PORT_STREAMLOCAL) {
- nextstate = SSH_CHANNEL_OPENING;
- rtype = "direct-streamlocal@openssh.com";
- } else if (c->host_port == 0) {
- nextstate = SSH_CHANNEL_DYNAMIC;
- rtype = "dynamic-tcpip";
- } else {
- nextstate = SSH_CHANNEL_OPENING;
- rtype = "direct-tcpip";
- }
-
- addrlen = sizeof(addr);
- newsock = accept(c->sock, (struct sockaddr *)&addr, &addrlen);
- if (newsock < 0) {
- if (errno != EINTR && errno != EWOULDBLOCK &&
- errno != ECONNABORTED)
- error("accept: %.100s", strerror(errno));
- if (errno == EMFILE || errno == ENFILE)
- c->notbefore = monotime() + 1;
- return;
- }
- if (c->host_port != PORT_STREAMLOCAL)
- set_nodelay(newsock);
- nc = channel_new(rtype, nextstate, newsock, newsock, -1,
- c->local_window_max, c->local_maxpacket, 0, rtype, 1);
- nc->listening_port = c->listening_port;
- nc->host_port = c->host_port;
- if (c->path != NULL)
- nc->path = xstrdup(c->path);
-
- if (nextstate != SSH_CHANNEL_DYNAMIC)
- port_open_helper(nc, rtype);
- }
-}
-
-/*
- * This is the authentication agent socket listening for connections from
- * clients.
- */
-/* ARGSUSED */
-static void
-channel_post_auth_listener(Channel *c, fd_set *readset, fd_set *writeset)
-{
- Channel *nc;
- int newsock;
- struct sockaddr_storage addr;
- socklen_t addrlen;
-
- if (FD_ISSET(c->sock, readset)) {
- addrlen = sizeof(addr);
- newsock = accept(c->sock, (struct sockaddr *)&addr, &addrlen);
- if (newsock < 0) {
- error("accept from auth socket: %.100s",
- strerror(errno));
- if (errno == EMFILE || errno == ENFILE)
- c->notbefore = monotime() + 1;
- return;
- }
- nc = channel_new("accepted auth socket",
- SSH_CHANNEL_OPENING, newsock, newsock, -1,
- c->local_window_max, c->local_maxpacket,
- 0, "accepted auth socket", 1);
- if (compat20) {
- packet_start(SSH2_MSG_CHANNEL_OPEN);
- packet_put_cstring("auth-agent@openssh.com");
- packet_put_int(nc->self);
- packet_put_int(c->local_window_max);
- packet_put_int(c->local_maxpacket);
- } else {
- packet_start(SSH_SMSG_AGENT_OPEN);
- packet_put_int(nc->self);
- }
- packet_send();
- }
-}
-
-/* ARGSUSED */
-static void
-channel_post_connecting(Channel *c, fd_set *readset, fd_set *writeset)
-{
- int err = 0, sock;
- socklen_t sz = sizeof(err);
-
- if (FD_ISSET(c->sock, writeset)) {
- if (getsockopt(c->sock, SOL_SOCKET, SO_ERROR, &err, &sz) < 0) {
- err = errno;
- error("getsockopt SO_ERROR failed");
- }
- if (err == 0) {
- debug("channel %d: connected to %s port %d",
- c->self, c->connect_ctx.host, c->connect_ctx.port);
- channel_connect_ctx_free(&c->connect_ctx);
- c->type = SSH_CHANNEL_OPEN;
- if (compat20) {
- 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);
- } else {
- packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
- packet_put_int(c->remote_id);
- packet_put_int(c->self);
- }
- } else {
- debug("channel %d: connection failed: %s",
- c->self, strerror(err));
- /* Try next address, if any */
- if ((sock = connect_next(&c->connect_ctx)) > 0) {
- close(c->sock);
- c->sock = c->rfd = c->wfd = sock;
- channel_max_fd = channel_find_maxfd();
- return;
- }
- /* Exhausted all addresses */
- error("connect_to %.100s port %d: failed.",
- c->connect_ctx.host, c->connect_ctx.port);
- channel_connect_ctx_free(&c->connect_ctx);
- if (compat20) {
- packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
- packet_put_int(c->remote_id);
- packet_put_int(SSH2_OPEN_CONNECT_FAILED);
- if (!(datafellows & SSH_BUG_OPENFAILURE)) {
- packet_put_cstring(strerror(err));
- packet_put_cstring("");
- }
- } else {
- packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
- packet_put_int(c->remote_id);
- }
- chan_mark_dead(c);
- }
- packet_send();
- }
-}
-
-/* ARGSUSED */
-static int
-channel_handle_rfd(Channel *c, fd_set *readset, fd_set *writeset)
-{
- char buf[CHAN_RBUF];
- int len, force;
-
- force = c->isatty && c->detach_close && c->istate != CHAN_INPUT_CLOSED;
- if (c->rfd != -1 && (force || FD_ISSET(c->rfd, readset))) {
- errno = 0;
- len = read(c->rfd, buf, sizeof(buf));
- if (len < 0 && (errno == EINTR ||
- ((errno == EAGAIN || errno == EWOULDBLOCK) && !force)))
- return 1;
-#ifndef PTY_ZEROREAD
- if (len <= 0) {
-#else
- if ((!c->isatty && len <= 0) ||
- (c->isatty && (len < 0 || (len == 0 && errno != 0)))) {
-#endif
- debug2("channel %d: read<=0 rfd %d len %d",
- c->self, c->rfd, len);
- if (c->type != SSH_CHANNEL_OPEN) {
- debug2("channel %d: not open", c->self);
- chan_mark_dead(c);
- return -1;
- } else if (compat13) {
- buffer_clear(&c->output);
- c->type = SSH_CHANNEL_INPUT_DRAINING;
- debug2("channel %d: input draining.", c->self);
- } else {
- chan_read_failed(c);
- }
- return -1;
- }
- if (c->input_filter != NULL) {
- if (c->input_filter(c, buf, len) == -1) {
- debug2("channel %d: filter stops", c->self);
- chan_read_failed(c);
- }
- } else if (c->datagram) {
- buffer_put_string(&c->input, buf, len);
- } else {
- buffer_append(&c->input, buf, len);
- }
- }
- return 1;
-}
-
-/* ARGSUSED */
-static int
-channel_handle_wfd(Channel *c, fd_set *readset, fd_set *writeset)
-{
- struct termios tio;
- u_char *data = NULL, *buf;
- u_int dlen, olen = 0;
- int len;
-
- /* Send buffered output data to the socket. */
- if (c->wfd != -1 &&
- FD_ISSET(c->wfd, writeset) &&
- buffer_len(&c->output) > 0) {
- olen = buffer_len(&c->output);
- if (c->output_filter != NULL) {
- if ((buf = c->output_filter(c, &data, &dlen)) == NULL) {
- debug2("channel %d: filter stops", c->self);
- if (c->type != SSH_CHANNEL_OPEN)
- chan_mark_dead(c);
- else
- chan_write_failed(c);
- return -1;
- }
- } else if (c->datagram) {
- buf = data = buffer_get_string(&c->output, &dlen);
- } else {
- buf = data = buffer_ptr(&c->output);
- dlen = buffer_len(&c->output);
- }
-
- if (c->datagram) {
- /* ignore truncated writes, datagrams might get lost */
- len = write(c->wfd, buf, dlen);
- free(data);
- if (len < 0 && (errno == EINTR || errno == EAGAIN ||
- errno == EWOULDBLOCK))
- return 1;
- if (len <= 0) {
- if (c->type != SSH_CHANNEL_OPEN)
- chan_mark_dead(c);
- else
- chan_write_failed(c);
- return -1;
- }
- goto out;
- }
-#ifdef _AIX
- /* XXX: Later AIX versions can't push as much data to tty */
- if (compat20 && c->wfd_isatty)
- dlen = MIN(dlen, 8*1024);
-#endif
-
- len = write(c->wfd, buf, dlen);
- if (len < 0 &&
- (errno == EINTR || errno == EAGAIN || errno == EWOULDBLOCK))
- return 1;
- if (len <= 0) {
- if (c->type != SSH_CHANNEL_OPEN) {
- debug2("channel %d: not open", c->self);
- chan_mark_dead(c);
- return -1;
- } else if (compat13) {
- buffer_clear(&c->output);
- debug2("channel %d: input draining.", c->self);
- c->type = SSH_CHANNEL_INPUT_DRAINING;
- } else {
- chan_write_failed(c);
- }
- return -1;
- }
-#ifndef BROKEN_TCGETATTR_ICANON
- if (compat20 && c->isatty && dlen >= 1 && buf[0] != '\r') {
- if (tcgetattr(c->wfd, &tio) == 0 &&
- !(tio.c_lflag & ECHO) && (tio.c_lflag & ICANON)) {
- /*
- * Simulate echo to reduce the impact of
- * traffic analysis. We need to match the
- * size of a SSH2_MSG_CHANNEL_DATA message
- * (4 byte channel id + buf)
- */
- packet_send_ignore(4 + len);
- packet_send();
- }
- }
-#endif
- buffer_consume(&c->output, len);
- }
- out:
- if (compat20 && olen > 0)
- c->local_consumed += olen - buffer_len(&c->output);
- return 1;
-}
-
-static int
-channel_handle_efd(Channel *c, fd_set *readset, fd_set *writeset)
-{
- char buf[CHAN_RBUF];
- int len;
-
-/** XXX handle drain efd, too */
- if (c->efd != -1) {
- if (c->extended_usage == CHAN_EXTENDED_WRITE &&
- FD_ISSET(c->efd, writeset) &&
- buffer_len(&c->extended) > 0) {
- len = write(c->efd, buffer_ptr(&c->extended),
- buffer_len(&c->extended));
- debug2("channel %d: written %d to efd %d",
- c->self, len, c->efd);
- if (len < 0 && (errno == EINTR || errno == EAGAIN ||
- errno == EWOULDBLOCK))
- return 1;
- if (len <= 0) {
- debug2("channel %d: closing write-efd %d",
- c->self, c->efd);
- channel_close_fd(&c->efd);
- } else {
- buffer_consume(&c->extended, len);
- c->local_consumed += len;
- }
- } else if (c->efd != -1 &&
- (c->extended_usage == CHAN_EXTENDED_READ ||
- c->extended_usage == CHAN_EXTENDED_IGNORE) &&
- (c->detach_close || FD_ISSET(c->efd, readset))) {
- len = read(c->efd, buf, sizeof(buf));
- debug2("channel %d: read %d from efd %d",
- c->self, len, c->efd);
- if (len < 0 && (errno == EINTR || ((errno == EAGAIN ||
- errno == EWOULDBLOCK) && !c->detach_close)))
- return 1;
- if (len <= 0) {
- debug2("channel %d: closing read-efd %d",
- c->self, c->efd);
- channel_close_fd(&c->efd);
- } else {
- if (c->extended_usage == CHAN_EXTENDED_IGNORE) {
- debug3("channel %d: discard efd",
- c->self);
- } else
- buffer_append(&c->extended, buf, len);
- }
- }
- }
- return 1;
-}
-
-static int
-channel_check_window(Channel *c)
-{
- if (c->type == SSH_CHANNEL_OPEN &&
- !(c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD)) &&
- ((c->local_window_max - c->local_window >
- c->local_maxpacket*3) ||
- c->local_window < c->local_window_max/2) &&
- c->local_consumed > 0) {
- packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
- packet_put_int(c->remote_id);
- packet_put_int(c->local_consumed);
- packet_send();
- debug2("channel %d: window %d sent adjust %d",
- c->self, c->local_window,
- c->local_consumed);
- c->local_window += c->local_consumed;
- c->local_consumed = 0;
- }
- return 1;
-}
-
-static void
-channel_post_open(Channel *c, fd_set *readset, fd_set *writeset)
-{
- channel_handle_rfd(c, readset, writeset);
- channel_handle_wfd(c, readset, writeset);
- if (!compat20)
- return;
- channel_handle_efd(c, readset, writeset);
- channel_check_window(c);
-}
-
-static u_int
-read_mux(Channel *c, u_int need)
-{
- char buf[CHAN_RBUF];
- int len;
- u_int rlen;
-
- if (buffer_len(&c->input) < need) {
- rlen = need - buffer_len(&c->input);
- len = read(c->rfd, buf, MINIMUM(rlen, CHAN_RBUF));
- if (len < 0 && (errno == EINTR || errno == EAGAIN))
- return buffer_len(&c->input);
- if (len <= 0) {
- debug2("channel %d: ctl read<=0 rfd %d len %d",
- c->self, c->rfd, len);
- chan_read_failed(c);
- return 0;
- } else
- buffer_append(&c->input, buf, len);
- }
- return buffer_len(&c->input);
-}
-
-static void
-channel_post_mux_client(Channel *c, fd_set *readset, fd_set *writeset)
-{
- u_int need;
- ssize_t len;
-
- if (!compat20)
- fatal("%s: entered with !compat20", __func__);
-
- if (c->rfd != -1 && !c->mux_pause && FD_ISSET(c->rfd, readset) &&
- (c->istate == CHAN_INPUT_OPEN ||
- c->istate == CHAN_INPUT_WAIT_DRAIN)) {
- /*
- * Don't not read past the precise end of packets to
- * avoid disrupting fd passing.
- */
- if (read_mux(c, 4) < 4) /* read header */
- return;
- need = get_u32(buffer_ptr(&c->input));
-#define CHANNEL_MUX_MAX_PACKET (256 * 1024)
- if (need > CHANNEL_MUX_MAX_PACKET) {
- debug2("channel %d: packet too big %u > %u",
- c->self, CHANNEL_MUX_MAX_PACKET, need);
- chan_rcvd_oclose(c);
- return;
- }
- if (read_mux(c, need + 4) < need + 4) /* read body */
- return;
- if (c->mux_rcb(c) != 0) {
- debug("channel %d: mux_rcb failed", c->self);
- chan_mark_dead(c);
- return;
- }
- }
-
- if (c->wfd != -1 && FD_ISSET(c->wfd, writeset) &&
- buffer_len(&c->output) > 0) {
- len = write(c->wfd, buffer_ptr(&c->output),
- buffer_len(&c->output));
- if (len < 0 && (errno == EINTR || errno == EAGAIN))
- return;
- if (len <= 0) {
- chan_mark_dead(c);
- return;
- }
- buffer_consume(&c->output, len);
- }
-}
-
-static void
-channel_post_mux_listener(Channel *c, fd_set *readset, fd_set *writeset)
-{
- Channel *nc;
- struct sockaddr_storage addr;
- socklen_t addrlen;
- int newsock;
- uid_t euid;
- gid_t egid;
-
- if (!FD_ISSET(c->sock, readset))
- return;
-
- debug("multiplexing control connection");
-
- /*
- * Accept connection on control socket
- */
- memset(&addr, 0, sizeof(addr));
- addrlen = sizeof(addr);
- if ((newsock = accept(c->sock, (struct sockaddr*)&addr,
- &addrlen)) == -1) {
- error("%s accept: %s", __func__, strerror(errno));
- if (errno == EMFILE || errno == ENFILE)
- c->notbefore = monotime() + 1;
- return;
- }
-
- if (getpeereid(newsock, &euid, &egid) < 0) {
- error("%s getpeereid failed: %s", __func__,
- strerror(errno));
- close(newsock);
- return;
- }
- if ((euid != 0) && (getuid() != euid)) {
- error("multiplex uid mismatch: peer euid %u != uid %u",
- (u_int)euid, (u_int)getuid());
- close(newsock);
- return;
- }
- nc = channel_new("multiplex client", SSH_CHANNEL_MUX_CLIENT,
- newsock, newsock, -1, c->local_window_max,
- c->local_maxpacket, 0, "mux-control", 1);
- nc->mux_rcb = c->mux_rcb;
- debug3("%s: new mux channel %d fd %d", __func__,
- nc->self, nc->sock);
- /* establish state */
- nc->mux_rcb(nc);
- /* mux state transitions must not elicit protocol messages */
- nc->flags |= CHAN_LOCAL;
-}
-
-/* ARGSUSED */
-static void
-channel_post_output_drain_13(Channel *c, fd_set *readset, fd_set *writeset)
-{
- int len;
-
- /* Send buffered output data to the socket. */
- if (FD_ISSET(c->sock, writeset) && buffer_len(&c->output) > 0) {
- len = write(c->sock, buffer_ptr(&c->output),
- buffer_len(&c->output));
- if (len <= 0)
- buffer_clear(&c->output);
- else
- buffer_consume(&c->output, len);
- }
-}
-
-static void
-channel_handler_init_20(void)
-{
- channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open;
- channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
- channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
- channel_pre[SSH_CHANNEL_RPORT_LISTENER] = &channel_pre_listener;
- channel_pre[SSH_CHANNEL_UNIX_LISTENER] = &channel_pre_listener;
- channel_pre[SSH_CHANNEL_RUNIX_LISTENER] = &channel_pre_listener;
- channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
- channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
- channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
- channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
- channel_pre[SSH_CHANNEL_MUX_LISTENER] = &channel_pre_listener;
- channel_pre[SSH_CHANNEL_MUX_CLIENT] = &channel_pre_mux_client;
-
- channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
- channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
- channel_post[SSH_CHANNEL_RPORT_LISTENER] = &channel_post_port_listener;
- channel_post[SSH_CHANNEL_UNIX_LISTENER] = &channel_post_port_listener;
- channel_post[SSH_CHANNEL_RUNIX_LISTENER] = &channel_post_port_listener;
- channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
- channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
- channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
- channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
- channel_post[SSH_CHANNEL_MUX_LISTENER] = &channel_post_mux_listener;
- channel_post[SSH_CHANNEL_MUX_CLIENT] = &channel_post_mux_client;
-}
-
-static void
-channel_handler_init_13(void)
-{
- channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_13;
- channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open_13;
- channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
- channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
- channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
- channel_pre[SSH_CHANNEL_INPUT_DRAINING] = &channel_pre_input_draining;
- channel_pre[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_pre_output_draining;
- channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
- channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
-
- channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
- channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
- channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
- channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
- channel_post[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_post_output_drain_13;
- channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
- channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
-}
-
-static void
-channel_handler_init_15(void)
-{
- channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open;
- channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
- channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
- channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
- channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
- channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
- channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
-
- channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
- channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
- channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
- channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
- channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
- channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
-}
-
-static void
-channel_handler_init(void)
-{
- int i;
-
- for (i = 0; i < SSH_CHANNEL_MAX_TYPE; i++) {
- channel_pre[i] = NULL;
- channel_post[i] = NULL;
- }
- if (compat20)
- channel_handler_init_20();
- else if (compat13)
- channel_handler_init_13();
- else
- channel_handler_init_15();
-}
-
-/* gc dead channels */
-static void
-channel_garbage_collect(Channel *c)
-{
- if (c == NULL)
- return;
- if (c->detach_user != NULL) {
- if (!chan_is_dead(c, c->detach_close))
- return;
- debug2("channel %d: gc: notify user", c->self);
- c->detach_user(c->self, NULL);
- /* if we still have a callback */
- if (c->detach_user != NULL)
- return;
- debug2("channel %d: gc: user detached", c->self);
- }
- if (!chan_is_dead(c, 1))
- return;
- debug2("channel %d: garbage collecting", c->self);
- channel_free(c);
-}
-
-static void
-channel_handler(chan_fn *ftab[], fd_set *readset, fd_set *writeset,
- time_t *unpause_secs)
-{
- static int did_init = 0;
- u_int i, oalloc;
- Channel *c;
- time_t now;
-
- if (!did_init) {
- channel_handler_init();
- did_init = 1;
- }
- now = monotime();
- if (unpause_secs != NULL)
- *unpause_secs = 0;
- for (i = 0, oalloc = channels_alloc; i < oalloc; i++) {
- c = channels[i];
- if (c == NULL)
- continue;
- if (c->delayed) {
- if (ftab == channel_pre)
- c->delayed = 0;
- else
- continue;
- }
- if (ftab[c->type] != NULL) {
- /*
- * Run handlers that are not paused.
- */
- if (c->notbefore <= now)
- (*ftab[c->type])(c, readset, writeset);
- else if (unpause_secs != NULL) {
- /*
- * Collect the time that the earliest
- * channel comes off pause.
- */
- debug3("%s: chan %d: skip for %d more seconds",
- __func__, c->self,
- (int)(c->notbefore - now));
- if (*unpause_secs == 0 ||
- (c->notbefore - now) < *unpause_secs)
- *unpause_secs = c->notbefore - now;
- }
- }
- channel_garbage_collect(c);
- }
- if (unpause_secs != NULL && *unpause_secs != 0)
- debug3("%s: first channel unpauses in %d seconds",
- __func__, (int)*unpause_secs);
-}
-
-/*
- * Allocate/update select bitmasks and add any bits relevant to channels in
- * select bitmasks.
- */
-void
-channel_prepare_select(fd_set **readsetp, fd_set **writesetp, int *maxfdp,
- u_int *nallocp, time_t *minwait_secs, int rekeying)
-{
- u_int n, sz, nfdset;
-
- n = MAXIMUM(*maxfdp, channel_max_fd);
-
- nfdset = howmany(n+1, NFDBITS);
- /* Explicitly test here, because xrealloc isn't always called */
- if (nfdset && SIZE_MAX / nfdset < sizeof(fd_mask))
- fatal("channel_prepare_select: max_fd (%d) is too large", n);
- sz = nfdset * sizeof(fd_mask);
-
- /* perhaps check sz < nalloc/2 and shrink? */
- if (*readsetp == NULL || sz > *nallocp) {
- *readsetp = xreallocarray(*readsetp, nfdset, sizeof(fd_mask));
- *writesetp = xreallocarray(*writesetp, nfdset, sizeof(fd_mask));
- *nallocp = sz;
- }
- *maxfdp = n;
- memset(*readsetp, 0, sz);
- memset(*writesetp, 0, sz);
-
- if (!rekeying)
- channel_handler(channel_pre, *readsetp, *writesetp,
- minwait_secs);
-}
-
-/*
- * After select, perform any appropriate operations for channels which have
- * events pending.
- */
-void
-channel_after_select(fd_set *readset, fd_set *writeset)
-{
- channel_handler(channel_post, readset, writeset, NULL);
-}
-
-
-/* If there is data to send to the connection, enqueue some of it now. */
-void
-channel_output_poll(void)
-{
- Channel *c;
- u_int i, len;
-
- for (i = 0; i < channels_alloc; i++) {
- c = channels[i];
- if (c == NULL)
- continue;
-
- /*
- * We are only interested in channels that can have buffered
- * incoming data.
- */
- if (compat13) {
- if (c->type != SSH_CHANNEL_OPEN &&
- c->type != SSH_CHANNEL_INPUT_DRAINING)
- continue;
- } else {
- if (c->type != SSH_CHANNEL_OPEN)
- continue;
- }
- if (compat20 &&
- (c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD))) {
- /* XXX is this true? */
- debug3("channel %d: will not send data after close", c->self);
- continue;
- }
-
- /* Get the amount of buffered data for this channel. */
- if ((c->istate == CHAN_INPUT_OPEN ||
- c->istate == CHAN_INPUT_WAIT_DRAIN) &&
- (len = buffer_len(&c->input)) > 0) {
- if (c->datagram) {
- if (len > 0) {
- u_char *data;
- u_int dlen;
-
- data = buffer_get_string(&c->input,
- &dlen);
- if (dlen > c->remote_window ||
- dlen > c->remote_maxpacket) {
- debug("channel %d: datagram "
- "too big for channel",
- c->self);
- free(data);
- continue;
- }
- packet_start(SSH2_MSG_CHANNEL_DATA);
- packet_put_int(c->remote_id);
- packet_put_string(data, dlen);
- packet_send();
- c->remote_window -= dlen;
- free(data);
- }
- continue;
- }
- /*
- * Send some data for the other side over the secure
- * connection.
- */
- if (compat20) {
- if (len > c->remote_window)
- len = c->remote_window;
- if (len > c->remote_maxpacket)
- len = c->remote_maxpacket;
- } else {
- if (packet_is_interactive()) {
- if (len > 1024)
- len = 512;
- } else {
- /* Keep the packets at reasonable size. */
- if (len > packet_get_maxsize()/2)
- len = packet_get_maxsize()/2;
- }
- }
- if (len > 0) {
- packet_start(compat20 ?
- SSH2_MSG_CHANNEL_DATA : SSH_MSG_CHANNEL_DATA);
- packet_put_int(c->remote_id);
- packet_put_string(buffer_ptr(&c->input), len);
- packet_send();
- buffer_consume(&c->input, len);
- c->remote_window -= len;
- }
- } else if (c->istate == CHAN_INPUT_WAIT_DRAIN) {
- if (compat13)
- fatal("cannot happen: istate == INPUT_WAIT_DRAIN for proto 1.3");
- /*
- * input-buffer is empty and read-socket shutdown:
- * tell peer, that we will not send more data: send IEOF.
- * hack for extended data: delay EOF if EFD still in use.
- */
- if (CHANNEL_EFD_INPUT_ACTIVE(c))
- debug2("channel %d: ibuf_empty delayed efd %d/(%d)",
- c->self, c->efd, buffer_len(&c->extended));
- else
- chan_ibuf_empty(c);
- }
- /* Send extended data, i.e. stderr */
- if (compat20 &&
- !(c->flags & CHAN_EOF_SENT) &&
- c->remote_window > 0 &&
- (len = buffer_len(&c->extended)) > 0 &&
- c->extended_usage == CHAN_EXTENDED_READ) {
- debug2("channel %d: rwin %u elen %u euse %d",
- c->self, c->remote_window, buffer_len(&c->extended),
- c->extended_usage);
- if (len > c->remote_window)
- len = c->remote_window;
- if (len > c->remote_maxpacket)
- len = c->remote_maxpacket;
- packet_start(SSH2_MSG_CHANNEL_EXTENDED_DATA);
- packet_put_int(c->remote_id);
- packet_put_int(SSH2_EXTENDED_DATA_STDERR);
- packet_put_string(buffer_ptr(&c->extended), len);
- packet_send();
- buffer_consume(&c->extended, len);
- c->remote_window -= len;
- debug2("channel %d: sent ext data %d", c->self, len);
- }
- }
-}
-
-/* -- mux proxy support */
-
-/*
- * When multiplexing channel messages for mux clients we have to deal
- * with downstream messages from the mux client and upstream messages
- * from the ssh server:
- * 1) Handling downstream messages is straightforward and happens
- * in channel_proxy_downstream():
- * - We forward all messages (mostly) unmodified to the server.
- * - However, in order to route messages from upstream to the correct
- * downstream client, we have to replace the channel IDs used by the
- * mux clients with a unique channel ID because the mux clients might
- * use conflicting channel IDs.
- * - so we inspect and change both SSH2_MSG_CHANNEL_OPEN and
- * SSH2_MSG_CHANNEL_OPEN_CONFIRMATION messages, create a local
- * SSH_CHANNEL_MUX_PROXY channel and replace the mux clients ID
- * with the newly allocated channel ID.
- * 2) Upstream messages are received by matching SSH_CHANNEL_MUX_PROXY
- * channels and procesed by channel_proxy_upstream(). The local channel ID
- * is then translated back to the original mux client ID.
- * 3) In both cases we need to keep track of matching SSH2_MSG_CHANNEL_CLOSE
- * messages so we can clean up SSH_CHANNEL_MUX_PROXY channels.
- * 4) The SSH_CHANNEL_MUX_PROXY channels also need to closed when the
- * downstream mux client are removed.
- * 5) Handling SSH2_MSG_CHANNEL_OPEN messages from the upstream server
- * requires more work, because they are not addressed to a specific
- * channel. E.g. client_request_forwarded_tcpip() needs to figure
- * out whether the request is addressed to the local client or a
- * specific downstream client based on the listen-address/port.
- * 6) Agent and X11-Forwarding have a similar problem and are currenly
- * not supported as the matching session/channel cannot be identified
- * easily.
- */
-
-/*
- * receive packets from downstream mux clients:
- * channel callback fired on read from mux client, creates
- * SSH_CHANNEL_MUX_PROXY channels and translates channel IDs
- * on channel creation.
- */
-int
-channel_proxy_downstream(Channel *downstream)
-{
- Channel *c = NULL;
- struct ssh *ssh = active_state;
- struct sshbuf *original = NULL, *modified = NULL;
- const u_char *cp;
- char *ctype = NULL, *listen_host = NULL;
- u_char type;
- size_t have;
- int ret = -1, r, idx;
- u_int id, remote_id, listen_port;
-
- /* sshbuf_dump(&downstream->input, stderr); */
- if ((r = sshbuf_get_string_direct(&downstream->input, &cp, &have))
- != 0) {
- error("%s: malformed message: %s", __func__, ssh_err(r));
- return -1;
- }
- if (have < 2) {
- error("%s: short message", __func__);
- return -1;
- }
- type = cp[1];
- /* skip padlen + type */
- cp += 2;
- have -= 2;
- if (ssh_packet_log_type(type))
- debug3("%s: channel %u: down->up: type %u", __func__,
- downstream->self, type);
-
- switch (type) {
- case SSH2_MSG_CHANNEL_OPEN:
- if ((original = sshbuf_from(cp, have)) == NULL ||
- (modified = sshbuf_new()) == NULL) {
- error("%s: alloc", __func__);
- goto out;
- }
- if ((r = sshbuf_get_cstring(original, &ctype, NULL)) != 0 ||
- (r = sshbuf_get_u32(original, &id)) != 0) {
- error("%s: parse error %s", __func__, ssh_err(r));
- goto out;
- }
- c = channel_new("mux proxy", SSH_CHANNEL_MUX_PROXY,
- -1, -1, -1, 0, 0, 0, ctype, 1);
- c->mux_ctx = downstream; /* point to mux client */
- c->mux_downstream_id = id; /* original downstream id */
- if ((r = sshbuf_put_cstring(modified, ctype)) != 0 ||
- (r = sshbuf_put_u32(modified, c->self)) != 0 ||
- (r = sshbuf_putb(modified, original)) != 0) {
- error("%s: compose error %s", __func__, ssh_err(r));
- channel_free(c);
- goto out;
- }
- break;
- case SSH2_MSG_CHANNEL_OPEN_CONFIRMATION:
- /*
- * Almost the same as SSH2_MSG_CHANNEL_OPEN, except then we
- * need to parse 'remote_id' instead of 'ctype'.
- */
- if ((original = sshbuf_from(cp, have)) == NULL ||
- (modified = sshbuf_new()) == NULL) {
- error("%s: alloc", __func__);
- goto out;
- }
- if ((r = sshbuf_get_u32(original, &remote_id)) != 0 ||
- (r = sshbuf_get_u32(original, &id)) != 0) {
- error("%s: parse error %s", __func__, ssh_err(r));
- goto out;
- }
- c = channel_new("mux proxy", SSH_CHANNEL_MUX_PROXY,
- -1, -1, -1, 0, 0, 0, "mux-down-connect", 1);
- c->mux_ctx = downstream; /* point to mux client */
- c->mux_downstream_id = id;
- c->remote_id = remote_id;
- if ((r = sshbuf_put_u32(modified, remote_id)) != 0 ||
- (r = sshbuf_put_u32(modified, c->self)) != 0 ||
- (r = sshbuf_putb(modified, original)) != 0) {
- error("%s: compose error %s", __func__, ssh_err(r));
- channel_free(c);
- goto out;
- }
- break;
- case SSH2_MSG_GLOBAL_REQUEST:
- if ((original = sshbuf_from(cp, have)) == NULL) {
- error("%s: alloc", __func__);
- goto out;
- }
- if ((r = sshbuf_get_cstring(original, &ctype, NULL)) != 0) {
- error("%s: parse error %s", __func__, ssh_err(r));
- goto out;
- }
- if (strcmp(ctype, "tcpip-forward") != 0) {
- error("%s: unsupported request %s", __func__, ctype);
- goto out;
- }
- if ((r = sshbuf_get_u8(original, NULL)) != 0 ||
- (r = sshbuf_get_cstring(original, &listen_host, NULL)) != 0 ||
- (r = sshbuf_get_u32(original, &listen_port)) != 0) {
- error("%s: parse error %s", __func__, ssh_err(r));
- goto out;
- }
- if (listen_port > 65535) {
- error("%s: tcpip-forward for %s: bad port %u",
- __func__, listen_host, listen_port);
- goto out;
- }
- /* Record that connection to this host/port is permitted. */
- permitted_opens = xreallocarray(permitted_opens,
- num_permitted_opens + 1, sizeof(*permitted_opens));
- idx = num_permitted_opens++;
- permitted_opens[idx].host_to_connect = xstrdup("<mux>");
- permitted_opens[idx].port_to_connect = -1;
- permitted_opens[idx].listen_host = listen_host;
- permitted_opens[idx].listen_port = (int)listen_port;
- permitted_opens[idx].downstream = downstream;
- listen_host = NULL;
- break;
- case SSH2_MSG_CHANNEL_CLOSE:
- if (have < 4)
- break;
- remote_id = PEEK_U32(cp);
- if ((c = channel_by_remote_id(remote_id)) != NULL) {
- if (c->flags & CHAN_CLOSE_RCVD)
- channel_free(c);
- else
- c->flags |= CHAN_CLOSE_SENT;
- }
- break;
- }
- if (modified) {
- if ((r = sshpkt_start(ssh, type)) != 0 ||
- (r = sshpkt_putb(ssh, modified)) != 0 ||
- (r = sshpkt_send(ssh)) != 0) {
- error("%s: send %s", __func__, ssh_err(r));
- goto out;
- }
- } else {
- if ((r = sshpkt_start(ssh, type)) != 0 ||
- (r = sshpkt_put(ssh, cp, have)) != 0 ||
- (r = sshpkt_send(ssh)) != 0) {
- error("%s: send %s", __func__, ssh_err(r));
- goto out;
- }
- }
- ret = 0;
- out:
- free(ctype);
- free(listen_host);
- sshbuf_free(original);
- sshbuf_free(modified);
- return ret;
-}
-
-/*
- * receive packets from upstream server and de-multiplex packets
- * to correct downstream:
- * implemented as a helper for channel input handlers,
- * replaces local (proxy) channel ID with downstream channel ID.
- */
-int
-channel_proxy_upstream(Channel *c, int type, u_int32_t seq, void *ctxt)
-{
- struct ssh *ssh = active_state;
- struct sshbuf *b = NULL;
- Channel *downstream;
- const u_char *cp = NULL;
- size_t len;
- int r;
-
- /*
- * When receiving packets from the peer we need to check whether we
- * need to forward the packets to the mux client. In this case we
- * restore the orignal channel id and keep track of CLOSE messages,
- * so we can cleanup the channel.
- */
- if (c == NULL || c->type != SSH_CHANNEL_MUX_PROXY)
- return 0;
- if ((downstream = c->mux_ctx) == NULL)
- return 0;
- switch (type) {
- case SSH2_MSG_CHANNEL_CLOSE:
- case SSH2_MSG_CHANNEL_DATA:
- case SSH2_MSG_CHANNEL_EOF:
- case SSH2_MSG_CHANNEL_EXTENDED_DATA:
- case SSH2_MSG_CHANNEL_OPEN_CONFIRMATION:
- case SSH2_MSG_CHANNEL_OPEN_FAILURE:
- case SSH2_MSG_CHANNEL_WINDOW_ADJUST:
- case SSH2_MSG_CHANNEL_SUCCESS:
- case SSH2_MSG_CHANNEL_FAILURE:
- case SSH2_MSG_CHANNEL_REQUEST:
- break;
- default:
- debug2("%s: channel %u: unsupported type %u", __func__,
- c->self, type);
- return 0;
- }
- if ((b = sshbuf_new()) == NULL) {
- error("%s: alloc reply", __func__);
- goto out;
- }
- /* get remaining payload (after id) */
- cp = sshpkt_ptr(ssh, &len);
- if (cp == NULL) {
- error("%s: no packet", __func__);
- goto out;
- }
- /* translate id and send to muxclient */
- if ((r = sshbuf_put_u8(b, 0)) != 0 || /* padlen */
- (r = sshbuf_put_u8(b, type)) != 0 ||
- (r = sshbuf_put_u32(b, c->mux_downstream_id)) != 0 ||
- (r = sshbuf_put(b, cp, len)) != 0 ||
- (r = sshbuf_put_stringb(&downstream->output, b)) != 0) {
- error("%s: compose for muxclient %s", __func__, ssh_err(r));
- goto out;
- }
- /* sshbuf_dump(b, stderr); */
- if (ssh_packet_log_type(type))
- debug3("%s: channel %u: up->down: type %u", __func__, c->self,
- type);
- out:
- /* update state */
- switch (type) {
- case SSH2_MSG_CHANNEL_OPEN_CONFIRMATION:
- /* record remote_id for SSH2_MSG_CHANNEL_CLOSE */
- if (cp && len > 4)
- c->remote_id = PEEK_U32(cp);
- break;
- case SSH2_MSG_CHANNEL_CLOSE:
- if (c->flags & CHAN_CLOSE_SENT)
- channel_free(c);
- else
- c->flags |= CHAN_CLOSE_RCVD;
- break;
- }
- sshbuf_free(b);
- return 1;
-}
-
-/* -- protocol input */
-
-/* ARGSUSED */
-int
-channel_input_data(int type, u_int32_t seq, void *ctxt)
-{
- int id;
- const u_char *data;
- u_int data_len, win_len;
- Channel *c;
-
- /* Get the channel number and verify it. */
- id = packet_get_int();
- c = channel_lookup(id);
- if (c == NULL)
- packet_disconnect("Received data for nonexistent channel %d.", id);
- if (channel_proxy_upstream(c, type, seq, ctxt))
- return 0;
-
- /* Ignore any data for non-open channels (might happen on close) */
- if (c->type != SSH_CHANNEL_OPEN &&
- c->type != SSH_CHANNEL_X11_OPEN)
- return 0;
-
- /* Get the data. */
- data = packet_get_string_ptr(&data_len);
- win_len = data_len;
- if (c->datagram)
- win_len += 4; /* string length header */
-
- /*
- * Ignore data for protocol > 1.3 if output end is no longer open.
- * For protocol 2 the sending side is reducing its window as it sends
- * data, so we must 'fake' consumption of the data in order to ensure
- * that window updates are sent back. Otherwise the connection might
- * deadlock.
- */
- if (!compat13 && c->ostate != CHAN_OUTPUT_OPEN) {
- if (compat20) {
- c->local_window -= win_len;
- c->local_consumed += win_len;
- }
- return 0;
- }
-
- if (compat20) {
- if (win_len > c->local_maxpacket) {
- logit("channel %d: rcvd big packet %d, maxpack %d",
- c->self, win_len, c->local_maxpacket);
- }
- if (win_len > c->local_window) {
- logit("channel %d: rcvd too much data %d, win %d",
- c->self, win_len, c->local_window);
- return 0;
- }
- c->local_window -= win_len;
- }
- if (c->datagram)
- buffer_put_string(&c->output, data, data_len);
- else
- buffer_append(&c->output, data, data_len);
- packet_check_eom();
- return 0;
-}
-
-/* ARGSUSED */
-int
-channel_input_extended_data(int type, u_int32_t seq, void *ctxt)
-{
- int id;
- char *data;
- u_int data_len, tcode;
- Channel *c;
-
- /* Get the channel number and verify it. */
- id = packet_get_int();
- c = channel_lookup(id);
-
- if (c == NULL)
- packet_disconnect("Received extended_data for bad channel %d.", id);
- if (channel_proxy_upstream(c, type, seq, ctxt))
- return 0;
- if (c->type != SSH_CHANNEL_OPEN) {
- logit("channel %d: ext data for non open", id);
- return 0;
- }
- if (c->flags & CHAN_EOF_RCVD) {
- if (datafellows & SSH_BUG_EXTEOF)
- debug("channel %d: accepting ext data after eof", id);
- else
- packet_disconnect("Received extended_data after EOF "
- "on channel %d.", id);
- }
- tcode = packet_get_int();
- if (c->efd == -1 ||
- c->extended_usage != CHAN_EXTENDED_WRITE ||
- tcode != SSH2_EXTENDED_DATA_STDERR) {
- logit("channel %d: bad ext data", c->self);
- return 0;
- }
- data = packet_get_string(&data_len);
- packet_check_eom();
- if (data_len > c->local_window) {
- logit("channel %d: rcvd too much extended_data %d, win %d",
- c->self, data_len, c->local_window);
- free(data);
- return 0;
- }
- debug2("channel %d: rcvd ext data %d", c->self, data_len);
- c->local_window -= data_len;
- buffer_append(&c->extended, data, data_len);
- free(data);
- return 0;
-}
-
-/* ARGSUSED */
-int
-channel_input_ieof(int type, u_int32_t seq, void *ctxt)
-{
- int id;
- Channel *c;
-
- id = packet_get_int();
- packet_check_eom();
- c = channel_lookup(id);
- if (c == NULL)
- packet_disconnect("Received ieof for nonexistent channel %d.", id);
- if (channel_proxy_upstream(c, type, seq, ctxt))
- return 0;
- chan_rcvd_ieof(c);
-
- /* XXX force input close */
- if (c->force_drain && c->istate == CHAN_INPUT_OPEN) {
- debug("channel %d: FORCE input drain", c->self);
- c->istate = CHAN_INPUT_WAIT_DRAIN;
- if (buffer_len(&c->input) == 0)
- chan_ibuf_empty(c);
- }
- return 0;
-}
-
-/* ARGSUSED */
-int
-channel_input_close(int type, u_int32_t seq, void *ctxt)
-{
- int id;
- Channel *c;
-
- id = packet_get_int();
- packet_check_eom();
- c = channel_lookup(id);
- if (c == NULL)
- packet_disconnect("Received close for nonexistent channel %d.", id);
- if (channel_proxy_upstream(c, type, seq, ctxt))
- return 0;
- /*
- * Send a confirmation that we have closed the channel and no more
- * data is coming for it.
- */
- packet_start(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION);
- packet_put_int(c->remote_id);
- packet_send();
-
- /*
- * If the channel is in closed state, we have sent a close request,
- * and the other side will eventually respond with a confirmation.
- * Thus, we cannot free the channel here, because then there would be
- * no-one to receive the confirmation. The channel gets freed when
- * the confirmation arrives.
- */
- if (c->type != SSH_CHANNEL_CLOSED) {
- /*
- * Not a closed channel - mark it as draining, which will
- * cause it to be freed later.
- */
- buffer_clear(&c->input);
- c->type = SSH_CHANNEL_OUTPUT_DRAINING;
- }
- return 0;
-}
-
-/* proto version 1.5 overloads CLOSE_CONFIRMATION with OCLOSE */
-/* ARGSUSED */
-int
-channel_input_oclose(int type, u_int32_t seq, void *ctxt)
-{
- int id = packet_get_int();
- Channel *c = channel_lookup(id);
-
- if (c == NULL)
- packet_disconnect("Received oclose for nonexistent channel %d.", id);
- if (channel_proxy_upstream(c, type, seq, ctxt))
- return 0;
- packet_check_eom();
- chan_rcvd_oclose(c);
- return 0;
-}
-
-/* ARGSUSED */
-int
-channel_input_close_confirmation(int type, u_int32_t seq, void *ctxt)
-{
- int id = packet_get_int();
- Channel *c = channel_lookup(id);
-
- if (c == NULL)
- packet_disconnect("Received close confirmation for "
- "out-of-range channel %d.", id);
- if (channel_proxy_upstream(c, type, seq, ctxt))
- return 0;
- packet_check_eom();
- if (c->type != SSH_CHANNEL_CLOSED && c->type != SSH_CHANNEL_ABANDONED)
- packet_disconnect("Received close confirmation for "
- "non-closed channel %d (type %d).", id, c->type);
- channel_free(c);
- return 0;
-}
-
-/* ARGSUSED */
-int
-channel_input_open_confirmation(int type, u_int32_t seq, void *ctxt)
-{
- int id, remote_id;
- Channel *c;
-
- id = packet_get_int();
- c = channel_lookup(id);
-
- if (c==NULL)
- packet_disconnect("Received open confirmation for "
- "unknown channel %d.", id);
- if (channel_proxy_upstream(c, type, seq, ctxt))
- return 0;
- if (c->type != SSH_CHANNEL_OPENING)
- packet_disconnect("Received open confirmation for "
- "non-opening channel %d.", id);
- remote_id = packet_get_int();
- /* Record the remote channel number and mark that the channel is now open. */
- c->remote_id = remote_id;
- c->type = SSH_CHANNEL_OPEN;
-
- if (compat20) {
- c->remote_window = packet_get_int();
- c->remote_maxpacket = packet_get_int();
- if (c->open_confirm) {
- debug2("callback start");
- c->open_confirm(c->self, 1, c->open_confirm_ctx);
- debug2("callback done");
- }
- debug2("channel %d: open confirm rwindow %u rmax %u", c->self,
- c->remote_window, c->remote_maxpacket);
- }
- packet_check_eom();
- return 0;
-}
-
-static char *
-reason2txt(int reason)
-{
- switch (reason) {
- case SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED:
- return "administratively prohibited";
- case SSH2_OPEN_CONNECT_FAILED:
- return "connect failed";
- case SSH2_OPEN_UNKNOWN_CHANNEL_TYPE:
- return "unknown channel type";
- case SSH2_OPEN_RESOURCE_SHORTAGE:
- return "resource shortage";
- }
- return "unknown reason";
-}
-
-/* ARGSUSED */
-int
-channel_input_open_failure(int type, u_int32_t seq, void *ctxt)
-{
- int id, reason;
- char *msg = NULL, *lang = NULL;
- Channel *c;
-
- id = packet_get_int();
- c = channel_lookup(id);
-
- if (c==NULL)
- packet_disconnect("Received open failure for "
- "unknown channel %d.", id);
- if (channel_proxy_upstream(c, type, seq, ctxt))
- return 0;
- if (c->type != SSH_CHANNEL_OPENING)
- packet_disconnect("Received open failure for "
- "non-opening channel %d.", id);
- if (compat20) {
- reason = packet_get_int();
- if (!(datafellows & SSH_BUG_OPENFAILURE)) {
- msg = packet_get_string(NULL);
- lang = packet_get_string(NULL);
- }
- logit("channel %d: open failed: %s%s%s", id,
- reason2txt(reason), msg ? ": ": "", msg ? msg : "");
- free(msg);
- free(lang);
- if (c->open_confirm) {
- debug2("callback start");
- c->open_confirm(c->self, 0, c->open_confirm_ctx);
- debug2("callback done");
- }
- }
- packet_check_eom();
- /* Schedule the channel for cleanup/deletion. */
- chan_mark_dead(c);
- return 0;
-}
-
-/* ARGSUSED */
-int
-channel_input_window_adjust(int type, u_int32_t seq, void *ctxt)
-{
- Channel *c;
- int id;
- u_int adjust, tmp;
-
- if (!compat20)
- return 0;
-
- /* Get the channel number and verify it. */
- id = packet_get_int();
- c = channel_lookup(id);
-
- if (c == NULL) {
- logit("Received window adjust for non-open channel %d.", id);
- return 0;
- }
- if (channel_proxy_upstream(c, type, seq, ctxt))
- return 0;
- adjust = packet_get_int();
- packet_check_eom();
- debug2("channel %d: rcvd adjust %u", id, adjust);
- if ((tmp = c->remote_window + adjust) < c->remote_window)
- fatal("channel %d: adjust %u overflows remote window %u",
- id, adjust, c->remote_window);
- c->remote_window = tmp;
- return 0;
-}
-
-/* ARGSUSED */
-int
-channel_input_port_open(int type, u_int32_t seq, void *ctxt)
-{
- Channel *c = NULL;
- u_short host_port;
- char *host, *originator_string;
- int remote_id;
-
- remote_id = packet_get_int();
- host = packet_get_string(NULL);
- host_port = packet_get_int();
-
- if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {
- originator_string = packet_get_string(NULL);
- } else {
- originator_string = xstrdup("unknown (remote did not supply name)");
- }
- packet_check_eom();
- c = channel_connect_to_port(host, host_port,
- "connected socket", originator_string);
- free(originator_string);
- free(host);
- if (c == NULL) {
- packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
- packet_put_int(remote_id);
- packet_send();
- } else
- c->remote_id = remote_id;
- return 0;
-}
-
-/* ARGSUSED */
-int
-channel_input_status_confirm(int type, u_int32_t seq, void *ctxt)
-{
- Channel *c;
- struct channel_confirm *cc;
- int id;
-
- /* Reset keepalive timeout */
- packet_set_alive_timeouts(0);
-
- id = packet_get_int();
- debug2("channel_input_status_confirm: type %d id %d", type, id);
-
- if ((c = channel_lookup(id)) == NULL) {
- logit("channel_input_status_confirm: %d: unknown", id);
- return 0;
- }
- if (channel_proxy_upstream(c, type, seq, ctxt))
- return 0;
- packet_check_eom();
- if ((cc = TAILQ_FIRST(&c->status_confirms)) == NULL)
- return 0;
- cc->cb(type, c, cc->ctx);
- TAILQ_REMOVE(&c->status_confirms, cc, entry);
- explicit_bzero(cc, sizeof(*cc));
- free(cc);
- return 0;
-}
-
-/* -- tcp forwarding */
-
-void
-channel_set_af(int af)
-{
- IPv4or6 = af;
-}
-
-
-/*
- * Determine whether or not a port forward listens to loopback, the
- * specified address or wildcard. On the client, a specified bind
- * address will always override gateway_ports. On the server, a
- * gateway_ports of 1 (``yes'') will override the client's specification
- * and force a wildcard bind, whereas a value of 2 (``clientspecified'')
- * will bind to whatever address the client asked for.
- *
- * Special-case listen_addrs are:
- *
- * "0.0.0.0" -> wildcard v4/v6 if SSH_OLD_FORWARD_ADDR
- * "" (empty string), "*" -> wildcard v4/v6
- * "localhost" -> loopback v4/v6
- * "127.0.0.1" / "::1" -> accepted even if gateway_ports isn't set
- */
-static const char *
-channel_fwd_bind_addr(const char *listen_addr, int *wildcardp,
- int is_client, struct ForwardOptions *fwd_opts)
-{
- const char *addr = NULL;
- int wildcard = 0;
-
- if (listen_addr == NULL) {
- /* No address specified: default to gateway_ports setting */
- if (fwd_opts->gateway_ports)
- wildcard = 1;
- } else if (fwd_opts->gateway_ports || is_client) {
- if (((datafellows & SSH_OLD_FORWARD_ADDR) &&
- strcmp(listen_addr, "0.0.0.0") == 0 && is_client == 0) ||
- *listen_addr == '\0' || strcmp(listen_addr, "*") == 0 ||
- (!is_client && fwd_opts->gateway_ports == 1)) {
- wildcard = 1;
- /*
- * Notify client if they requested a specific listen
- * address and it was overridden.
- */
- if (*listen_addr != '\0' &&
- strcmp(listen_addr, "0.0.0.0") != 0 &&
- strcmp(listen_addr, "*") != 0) {
- packet_send_debug("Forwarding listen address "
- "\"%s\" overridden by server "
- "GatewayPorts", listen_addr);
- }
- } else if (strcmp(listen_addr, "localhost") != 0 ||
- strcmp(listen_addr, "127.0.0.1") == 0 ||
- strcmp(listen_addr, "::1") == 0) {
- /* Accept localhost address when GatewayPorts=yes */
- addr = listen_addr;
- }
- } else if (strcmp(listen_addr, "127.0.0.1") == 0 ||
- strcmp(listen_addr, "::1") == 0) {
- /*
- * If a specific IPv4/IPv6 localhost address has been
- * requested then accept it even if gateway_ports is in
- * effect. This allows the client to prefer IPv4 or IPv6.
- */
- addr = listen_addr;
- }
- if (wildcardp != NULL)
- *wildcardp = wildcard;
- return addr;
-}
-
-static int
-channel_setup_fwd_listener_tcpip(int type, struct Forward *fwd,
- int *allocated_listen_port, struct ForwardOptions *fwd_opts)
-{
- Channel *c;
- int sock, r, success = 0, wildcard = 0, is_client;
- struct addrinfo hints, *ai, *aitop;
- const char *host, *addr;
- char ntop[NI_MAXHOST], strport[NI_MAXSERV];
- in_port_t *lport_p;
-
- is_client = (type == SSH_CHANNEL_PORT_LISTENER);
-
- if (is_client && fwd->connect_path != NULL) {
- host = fwd->connect_path;
- } else {
- host = (type == SSH_CHANNEL_RPORT_LISTENER) ?
- fwd->listen_host : fwd->connect_host;
- if (host == NULL) {
- error("No forward host name.");
- return 0;
- }
- if (strlen(host) >= NI_MAXHOST) {
- error("Forward host name too long.");
- return 0;
- }
- }
-
- /* Determine the bind address, cf. channel_fwd_bind_addr() comment */
- addr = channel_fwd_bind_addr(fwd->listen_host, &wildcard,
- is_client, fwd_opts);
- debug3("%s: type %d wildcard %d addr %s", __func__,
- type, wildcard, (addr == NULL) ? "NULL" : addr);
-
- /*
- * getaddrinfo returns a loopback address if the hostname is
- * set to NULL and hints.ai_flags is not AI_PASSIVE
- */
- memset(&hints, 0, sizeof(hints));
- hints.ai_family = IPv4or6;
- hints.ai_flags = wildcard ? AI_PASSIVE : 0;
- hints.ai_socktype = SOCK_STREAM;
- snprintf(strport, sizeof strport, "%d", fwd->listen_port);
- if ((r = getaddrinfo(addr, strport, &hints, &aitop)) != 0) {
- if (addr == NULL) {
- /* This really shouldn't happen */
- packet_disconnect("getaddrinfo: fatal error: %s",
- ssh_gai_strerror(r));
- } else {
- error("%s: getaddrinfo(%.64s): %s", __func__, addr,
- ssh_gai_strerror(r));
- }
- return 0;
- }
- if (allocated_listen_port != NULL)
- *allocated_listen_port = 0;
- for (ai = aitop; ai; ai = ai->ai_next) {
- switch (ai->ai_family) {
- case AF_INET:
- lport_p = &((struct sockaddr_in *)ai->ai_addr)->
- sin_port;
- break;
- case AF_INET6:
- lport_p = &((struct sockaddr_in6 *)ai->ai_addr)->
- sin6_port;
- break;
- default:
- continue;
- }
- /*
- * If allocating a port for -R forwards, then use the
- * same port for all address families.
- */
- if (type == SSH_CHANNEL_RPORT_LISTENER && fwd->listen_port == 0 &&
- allocated_listen_port != NULL && *allocated_listen_port > 0)
- *lport_p = htons(*allocated_listen_port);
-
- if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
- strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
- error("%s: getnameinfo failed", __func__);
- continue;
- }
- /* Create a port to listen for the host. */
- sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
- if (sock < 0) {
- /* this is no error since kernel may not support ipv6 */
- verbose("socket: %.100s", strerror(errno));
- continue;
- }
-
- channel_set_reuseaddr(sock);
- if (ai->ai_family == AF_INET6)
- sock_set_v6only(sock);
-
- debug("Local forwarding listening on %s port %s.",
- ntop, strport);
-
- /* Bind the socket to the address. */
- if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
- /* address can be in use ipv6 address is already bound */
- if (!ai->ai_next)
- error("bind: %.100s", strerror(errno));
- else
- verbose("bind: %.100s", strerror(errno));
-
- close(sock);
- continue;
- }
- /* Start listening for connections on the socket. */
- if (listen(sock, SSH_LISTEN_BACKLOG) < 0) {
- error("listen: %.100s", strerror(errno));
- close(sock);
- continue;
- }
-
- /*
- * fwd->listen_port == 0 requests a dynamically allocated port -
- * record what we got.
- */
- if (type == SSH_CHANNEL_RPORT_LISTENER && fwd->listen_port == 0 &&
- allocated_listen_port != NULL &&
- *allocated_listen_port == 0) {
- *allocated_listen_port = get_local_port(sock);
- debug("Allocated listen port %d",
- *allocated_listen_port);
- }
-
- /* Allocate a channel number for the socket. */
- c = channel_new("port listener", type, sock, sock, -1,
- CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
- 0, "port listener", 1);
- c->path = xstrdup(host);
- c->host_port = fwd->connect_port;
- c->listening_addr = addr == NULL ? NULL : xstrdup(addr);
- if (fwd->listen_port == 0 && allocated_listen_port != NULL &&
- !(datafellows & SSH_BUG_DYNAMIC_RPORT))
- c->listening_port = *allocated_listen_port;
- else
- c->listening_port = fwd->listen_port;
- success = 1;
- }
- if (success == 0)
- error("%s: cannot listen to port: %d", __func__,
- fwd->listen_port);
- freeaddrinfo(aitop);
- return success;
-}
-
-static int
-channel_setup_fwd_listener_streamlocal(int type, struct Forward *fwd,
- struct ForwardOptions *fwd_opts)
-{
- struct sockaddr_un sunaddr;
- const char *path;
- Channel *c;
- int port, sock;
- mode_t omask;
-
- switch (type) {
- case SSH_CHANNEL_UNIX_LISTENER:
- if (fwd->connect_path != NULL) {
- if (strlen(fwd->connect_path) > sizeof(sunaddr.sun_path)) {
- error("Local connecting path too long: %s",
- fwd->connect_path);
- return 0;
- }
- path = fwd->connect_path;
- port = PORT_STREAMLOCAL;
- } else {
- if (fwd->connect_host == NULL) {
- error("No forward host name.");
- return 0;
- }
- if (strlen(fwd->connect_host) >= NI_MAXHOST) {
- error("Forward host name too long.");
- return 0;
- }
- path = fwd->connect_host;
- port = fwd->connect_port;
- }
- break;
- case SSH_CHANNEL_RUNIX_LISTENER:
- path = fwd->listen_path;
- port = PORT_STREAMLOCAL;
- break;
- default:
- error("%s: unexpected channel type %d", __func__, type);
- return 0;
- }
-
- if (fwd->listen_path == NULL) {
- error("No forward path name.");
- return 0;
- }
- if (strlen(fwd->listen_path) > sizeof(sunaddr.sun_path)) {
- error("Local listening path too long: %s", fwd->listen_path);
- return 0;
- }
-
- debug3("%s: type %d path %s", __func__, type, fwd->listen_path);
-
- /* Start a Unix domain listener. */
- omask = umask(fwd_opts->streamlocal_bind_mask);
- sock = unix_listener(fwd->listen_path, SSH_LISTEN_BACKLOG,
- fwd_opts->streamlocal_bind_unlink);
- umask(omask);
- if (sock < 0)
- return 0;
-
- debug("Local forwarding listening on path %s.", fwd->listen_path);
-
- /* Allocate a channel number for the socket. */
- c = channel_new("unix listener", type, sock, sock, -1,
- CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
- 0, "unix listener", 1);
- c->path = xstrdup(path);
- c->host_port = port;
- c->listening_port = PORT_STREAMLOCAL;
- c->listening_addr = xstrdup(fwd->listen_path);
- return 1;
-}
-
-static int
-channel_cancel_rport_listener_tcpip(const char *host, u_short port)
-{
- u_int i;
- int found = 0;
-
- for (i = 0; i < channels_alloc; i++) {
- Channel *c = channels[i];
- if (c == NULL || c->type != SSH_CHANNEL_RPORT_LISTENER)
- continue;
- if (strcmp(c->path, host) == 0 && c->listening_port == port) {
- debug2("%s: close channel %d", __func__, i);
- channel_free(c);
- found = 1;
- }
- }
-
- return (found);
-}
-
-static int
-channel_cancel_rport_listener_streamlocal(const char *path)
-{
- u_int i;
- int found = 0;
-
- for (i = 0; i < channels_alloc; i++) {
- Channel *c = channels[i];
- if (c == NULL || c->type != SSH_CHANNEL_RUNIX_LISTENER)
- continue;
- if (c->path == NULL)
- continue;
- if (strcmp(c->path, path) == 0) {
- debug2("%s: close channel %d", __func__, i);
- channel_free(c);
- found = 1;
- }
- }
-
- return (found);
-}
-
-int
-channel_cancel_rport_listener(struct Forward *fwd)
-{
- if (fwd->listen_path != NULL)
- return channel_cancel_rport_listener_streamlocal(fwd->listen_path);
- else
- return channel_cancel_rport_listener_tcpip(fwd->listen_host, fwd->listen_port);
-}
-
-static int
-channel_cancel_lport_listener_tcpip(const char *lhost, u_short lport,
- int cport, struct ForwardOptions *fwd_opts)
-{
- u_int i;
- int found = 0;
- const char *addr = channel_fwd_bind_addr(lhost, NULL, 1, fwd_opts);
-
- for (i = 0; i < channels_alloc; i++) {
- Channel *c = channels[i];
- if (c == NULL || c->type != SSH_CHANNEL_PORT_LISTENER)
- continue;
- if (c->listening_port != lport)
- continue;
- if (cport == CHANNEL_CANCEL_PORT_STATIC) {
- /* skip dynamic forwardings */
- if (c->host_port == 0)
- continue;
- } else {
- if (c->host_port != cport)
- continue;
- }
- if ((c->listening_addr == NULL && addr != NULL) ||
- (c->listening_addr != NULL && addr == NULL))
- continue;
- if (addr == NULL || strcmp(c->listening_addr, addr) == 0) {
- debug2("%s: close channel %d", __func__, i);
- channel_free(c);
- found = 1;
- }
- }
-
- return (found);
-}
-
-static int
-channel_cancel_lport_listener_streamlocal(const char *path)
-{
- u_int i;
- int found = 0;
-
- if (path == NULL) {
- error("%s: no path specified.", __func__);
- return 0;
- }
-
- for (i = 0; i < channels_alloc; i++) {
- Channel *c = channels[i];
- if (c == NULL || c->type != SSH_CHANNEL_UNIX_LISTENER)
- continue;
- if (c->listening_addr == NULL)
- continue;
- if (strcmp(c->listening_addr, path) == 0) {
- debug2("%s: close channel %d", __func__, i);
- channel_free(c);
- found = 1;
- }
- }
-
- return (found);
-}
-
-int
-channel_cancel_lport_listener(struct Forward *fwd, int cport, struct ForwardOptions *fwd_opts)
-{
- if (fwd->listen_path != NULL)
- return channel_cancel_lport_listener_streamlocal(fwd->listen_path);
- else
- return channel_cancel_lport_listener_tcpip(fwd->listen_host, fwd->listen_port, cport, fwd_opts);
-}
-
-/* protocol local port fwd, used by ssh (and sshd in v1) */
-int
-channel_setup_local_fwd_listener(struct Forward *fwd, struct ForwardOptions *fwd_opts)
-{
- if (fwd->listen_path != NULL) {
- return channel_setup_fwd_listener_streamlocal(
- SSH_CHANNEL_UNIX_LISTENER, fwd, fwd_opts);
- } else {
- return channel_setup_fwd_listener_tcpip(SSH_CHANNEL_PORT_LISTENER,
- fwd, NULL, fwd_opts);
- }
-}
-
-/* protocol v2 remote port fwd, used by sshd */
-int
-channel_setup_remote_fwd_listener(struct Forward *fwd,
- int *allocated_listen_port, struct ForwardOptions *fwd_opts)
-{
- if (fwd->listen_path != NULL) {
- return channel_setup_fwd_listener_streamlocal(
- SSH_CHANNEL_RUNIX_LISTENER, fwd, fwd_opts);
- } else {
- return channel_setup_fwd_listener_tcpip(
- SSH_CHANNEL_RPORT_LISTENER, fwd, allocated_listen_port,
- fwd_opts);
- }
-}
-
-/*
- * Translate the requested rfwd listen host to something usable for
- * this server.
- */
-static const char *
-channel_rfwd_bind_host(const char *listen_host)
-{
- if (listen_host == NULL) {
- if (datafellows & SSH_BUG_RFWD_ADDR)
- return "127.0.0.1";
- else
- return "localhost";
- } else if (*listen_host == '\0' || strcmp(listen_host, "*") == 0) {
- if (datafellows & SSH_BUG_RFWD_ADDR)
- return "0.0.0.0";
- else
- return "";
- } else
- return listen_host;
-}
-
-/*
- * Initiate forwarding of connections to port "port" on remote host through
- * the secure channel to host:port from local side.
- * Returns handle (index) for updating the dynamic listen port with
- * channel_update_permitted_opens().
- */
-int
-channel_request_remote_forwarding(struct Forward *fwd)
-{
- int type, success = 0, idx = -1;
-
- /* Send the forward request to the remote side. */
- if (compat20) {
- packet_start(SSH2_MSG_GLOBAL_REQUEST);
- if (fwd->listen_path != NULL) {
- packet_put_cstring("streamlocal-forward@openssh.com");
- packet_put_char(1); /* boolean: want reply */
- packet_put_cstring(fwd->listen_path);
- } else {
- packet_put_cstring("tcpip-forward");
- packet_put_char(1); /* boolean: want reply */
- packet_put_cstring(channel_rfwd_bind_host(fwd->listen_host));
- packet_put_int(fwd->listen_port);
- }
- packet_send();
- packet_write_wait();
- /* Assume that server accepts the request */
- success = 1;
- } else if (fwd->listen_path == NULL) {
- packet_start(SSH_CMSG_PORT_FORWARD_REQUEST);
- packet_put_int(fwd->listen_port);
- packet_put_cstring(fwd->connect_host);
- packet_put_int(fwd->connect_port);
- packet_send();
- packet_write_wait();
-
- /* Wait for response from the remote side. */
- type = packet_read();
- switch (type) {
- case SSH_SMSG_SUCCESS:
- success = 1;
- break;
- case SSH_SMSG_FAILURE:
- break;
- default:
- /* Unknown packet */
- packet_disconnect("Protocol error for port forward request:"
- "received packet type %d.", type);
- }
- } else {
- logit("Warning: Server does not support remote stream local forwarding.");
- }
- if (success) {
- /* Record that connection to this host/port is permitted. */
- permitted_opens = xreallocarray(permitted_opens,
- num_permitted_opens + 1, sizeof(*permitted_opens));
- idx = num_permitted_opens++;
- if (fwd->connect_path != NULL) {
- permitted_opens[idx].host_to_connect =
- xstrdup(fwd->connect_path);
- permitted_opens[idx].port_to_connect =
- PORT_STREAMLOCAL;
- } else {
- permitted_opens[idx].host_to_connect =
- xstrdup(fwd->connect_host);
- permitted_opens[idx].port_to_connect =
- fwd->connect_port;
- }
- if (fwd->listen_path != NULL) {
- permitted_opens[idx].listen_host = NULL;
- permitted_opens[idx].listen_path =
- xstrdup(fwd->listen_path);
- permitted_opens[idx].listen_port = PORT_STREAMLOCAL;
- } else {
- permitted_opens[idx].listen_host =
- fwd->listen_host ? xstrdup(fwd->listen_host) : NULL;
- permitted_opens[idx].listen_path = NULL;
- permitted_opens[idx].listen_port = fwd->listen_port;
- }
- permitted_opens[idx].downstream = NULL;
- }
- return (idx);
-}
-
-static int
-open_match(ForwardPermission *allowed_open, const char *requestedhost,
- int requestedport)
-{
- if (allowed_open->host_to_connect == NULL)
- return 0;
- if (allowed_open->port_to_connect != FWD_PERMIT_ANY_PORT &&
- allowed_open->port_to_connect != requestedport)
- return 0;
- if (strcmp(allowed_open->host_to_connect, FWD_PERMIT_ANY_HOST) != 0 &&
- strcmp(allowed_open->host_to_connect, requestedhost) != 0)
- return 0;
- return 1;
-}
-
-/*
- * Note that in the listen host/port case
- * we don't support FWD_PERMIT_ANY_PORT and
- * need to translate between the configured-host (listen_host)
- * and what we've sent to the remote server (channel_rfwd_bind_host)
- */
-static int
-open_listen_match_tcpip(ForwardPermission *allowed_open,
- const char *requestedhost, u_short requestedport, int translate)
-{
- const char *allowed_host;
-
- if (allowed_open->host_to_connect == NULL)
- return 0;
- if (allowed_open->listen_port != requestedport)
- return 0;
- if (!translate && allowed_open->listen_host == NULL &&
- requestedhost == NULL)
- return 1;
- allowed_host = translate ?
- channel_rfwd_bind_host(allowed_open->listen_host) :
- allowed_open->listen_host;
- if (allowed_host == NULL ||
- strcmp(allowed_host, requestedhost) != 0)
- return 0;
- return 1;
-}
-
-static int
-open_listen_match_streamlocal(ForwardPermission *allowed_open,
- const char *requestedpath)
-{
- if (allowed_open->host_to_connect == NULL)
- return 0;
- if (allowed_open->listen_port != PORT_STREAMLOCAL)
- return 0;
- if (allowed_open->listen_path == NULL ||
- strcmp(allowed_open->listen_path, requestedpath) != 0)
- return 0;
- return 1;
-}
-
-/*
- * Request cancellation of remote forwarding of connection host:port from
- * local side.
- */
-static int
-channel_request_rforward_cancel_tcpip(const char *host, u_short port)
-{
- int i;
-
- if (!compat20)
- return -1;
-
- for (i = 0; i < num_permitted_opens; i++) {
- if (open_listen_match_tcpip(&permitted_opens[i], host, port, 0))
- break;
- }
- if (i >= num_permitted_opens) {
- debug("%s: requested forward not found", __func__);
- return -1;
- }
- packet_start(SSH2_MSG_GLOBAL_REQUEST);
- packet_put_cstring("cancel-tcpip-forward");
- packet_put_char(0);
- packet_put_cstring(channel_rfwd_bind_host(host));
- packet_put_int(port);
- packet_send();
-
- permitted_opens[i].listen_port = 0;
- permitted_opens[i].port_to_connect = 0;
- free(permitted_opens[i].host_to_connect);
- permitted_opens[i].host_to_connect = NULL;
- free(permitted_opens[i].listen_host);
- permitted_opens[i].listen_host = NULL;
- permitted_opens[i].listen_path = NULL;
- permitted_opens[i].downstream = NULL;
-
- return 0;
-}
-
-/*
- * Request cancellation of remote forwarding of Unix domain socket
- * path from local side.
- */
-static int
-channel_request_rforward_cancel_streamlocal(const char *path)
-{
- int i;
-
- if (!compat20)
- return -1;
-
- for (i = 0; i < num_permitted_opens; i++) {
- if (open_listen_match_streamlocal(&permitted_opens[i], path))
- break;
- }
- if (i >= num_permitted_opens) {
- debug("%s: requested forward not found", __func__);
- return -1;
- }
- packet_start(SSH2_MSG_GLOBAL_REQUEST);
- packet_put_cstring("cancel-streamlocal-forward@openssh.com");
- packet_put_char(0);
- packet_put_cstring(path);
- packet_send();
-
- permitted_opens[i].listen_port = 0;
- permitted_opens[i].port_to_connect = 0;
- free(permitted_opens[i].host_to_connect);
- permitted_opens[i].host_to_connect = NULL;
- permitted_opens[i].listen_host = NULL;
- free(permitted_opens[i].listen_path);
- permitted_opens[i].listen_path = NULL;
- permitted_opens[i].downstream = NULL;
-
- return 0;
-}
-
-/*
- * Request cancellation of remote forwarding of a connection from local side.
- */
-int
-channel_request_rforward_cancel(struct Forward *fwd)
-{
- if (fwd->listen_path != NULL) {
- return (channel_request_rforward_cancel_streamlocal(
- fwd->listen_path));
- } else {
- return (channel_request_rforward_cancel_tcpip(fwd->listen_host,
- fwd->listen_port ? fwd->listen_port : fwd->allocated_port));
- }
-}
-
-/*
- * This is called after receiving CHANNEL_FORWARDING_REQUEST. This initates
- * listening for the port, and sends back a success reply (or disconnect
- * message if there was an error).
- */
-int
-channel_input_port_forward_request(int is_root, struct ForwardOptions *fwd_opts)
-{
- int success = 0;
- struct Forward fwd;
-
- /* Get arguments from the packet. */
- memset(&fwd, 0, sizeof(fwd));
- fwd.listen_port = packet_get_int();
- fwd.connect_host = packet_get_string(NULL);
- fwd.connect_port = packet_get_int();
-
- /*
- * Check that an unprivileged user is not trying to forward a
- * privileged port.
- */
- if (fwd.listen_port < IPPORT_RESERVED && !is_root)
- packet_disconnect(
- "Requested forwarding of port %d but user is not root.",
- fwd.listen_port);
- if (fwd.connect_port == 0)
- packet_disconnect("Dynamic forwarding denied.");
-
- /* Initiate forwarding */
- success = channel_setup_local_fwd_listener(&fwd, fwd_opts);
-
- /* Free the argument string. */
- free(fwd.connect_host);
-
- return (success ? 0 : -1);
-}
-
-/*
- * Permits opening to any host/port if permitted_opens[] is empty. This is
- * usually called by the server, because the user could connect to any port
- * anyway, and the server has no way to know but to trust the client anyway.
- */
-void
-channel_permit_all_opens(void)
-{
- if (num_permitted_opens == 0)
- all_opens_permitted = 1;
-}
-
-void
-channel_add_permitted_opens(char *host, int port)
-{
- debug("allow port forwarding to host %s port %d", host, port);
-
- permitted_opens = xreallocarray(permitted_opens,
- num_permitted_opens + 1, sizeof(*permitted_opens));
- permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host);
- permitted_opens[num_permitted_opens].port_to_connect = port;
- permitted_opens[num_permitted_opens].listen_host = NULL;
- permitted_opens[num_permitted_opens].listen_path = NULL;
- permitted_opens[num_permitted_opens].listen_port = 0;
- permitted_opens[num_permitted_opens].downstream = NULL;
- num_permitted_opens++;
-
- all_opens_permitted = 0;
-}
-
-/*
- * Update the listen port for a dynamic remote forward, after
- * the actual 'newport' has been allocated. If 'newport' < 0 is
- * passed then they entry will be invalidated.
- */
-void
-channel_update_permitted_opens(int idx, int newport)
-{
- if (idx < 0 || idx >= num_permitted_opens) {
- debug("channel_update_permitted_opens: index out of range:"
- " %d num_permitted_opens %d", idx, num_permitted_opens);
- return;
- }
- debug("%s allowed port %d for forwarding to host %s port %d",
- newport > 0 ? "Updating" : "Removing",
- newport,
- permitted_opens[idx].host_to_connect,
- permitted_opens[idx].port_to_connect);
- if (newport >= 0) {
- permitted_opens[idx].listen_port =
- (datafellows & SSH_BUG_DYNAMIC_RPORT) ? 0 : newport;
- } else {
- permitted_opens[idx].listen_port = 0;
- permitted_opens[idx].port_to_connect = 0;
- free(permitted_opens[idx].host_to_connect);
- permitted_opens[idx].host_to_connect = NULL;
- free(permitted_opens[idx].listen_host);
- permitted_opens[idx].listen_host = NULL;
- free(permitted_opens[idx].listen_path);
- permitted_opens[idx].listen_path = NULL;
- }
-}
-
-int
-channel_add_adm_permitted_opens(char *host, int port)
-{
- debug("config allows port forwarding to host %s port %d", host, port);
-
- permitted_adm_opens = xreallocarray(permitted_adm_opens,
- num_adm_permitted_opens + 1, sizeof(*permitted_adm_opens));
- permitted_adm_opens[num_adm_permitted_opens].host_to_connect
- = xstrdup(host);
- permitted_adm_opens[num_adm_permitted_opens].port_to_connect = port;
- permitted_adm_opens[num_adm_permitted_opens].listen_host = NULL;
- permitted_adm_opens[num_adm_permitted_opens].listen_path = NULL;
- permitted_adm_opens[num_adm_permitted_opens].listen_port = 0;
- return ++num_adm_permitted_opens;
-}
-
-void
-channel_disable_adm_local_opens(void)
-{
- channel_clear_adm_permitted_opens();
- permitted_adm_opens = xcalloc(sizeof(*permitted_adm_opens), 1);
- permitted_adm_opens[num_adm_permitted_opens].host_to_connect = NULL;
- num_adm_permitted_opens = 1;
-}
-
-void
-channel_clear_permitted_opens(void)
-{
- int i;
-
- for (i = 0; i < num_permitted_opens; i++) {
- free(permitted_opens[i].host_to_connect);
- free(permitted_opens[i].listen_host);
- free(permitted_opens[i].listen_path);
- }
- free(permitted_opens);
- permitted_opens = NULL;
- num_permitted_opens = 0;
-}
-
-void
-channel_clear_adm_permitted_opens(void)
-{
- int i;
-
- for (i = 0; i < num_adm_permitted_opens; i++) {
- free(permitted_adm_opens[i].host_to_connect);
- free(permitted_adm_opens[i].listen_host);
- free(permitted_adm_opens[i].listen_path);
- }
- free(permitted_adm_opens);
- permitted_adm_opens = NULL;
- num_adm_permitted_opens = 0;
-}
-
-void
-channel_print_adm_permitted_opens(void)
-{
- int i;
-
- printf("permitopen");
- if (num_adm_permitted_opens == 0) {
- printf(" any\n");
- return;
- }
- for (i = 0; i < num_adm_permitted_opens; i++)
- if (permitted_adm_opens[i].host_to_connect == NULL)
- printf(" none");
- else
- printf(" %s:%d", permitted_adm_opens[i].host_to_connect,
- permitted_adm_opens[i].port_to_connect);
- printf("\n");
-}
-
-/* returns port number, FWD_PERMIT_ANY_PORT or -1 on error */
-int
-permitopen_port(const char *p)
-{
- int port;
-
- if (strcmp(p, "*") == 0)
- return FWD_PERMIT_ANY_PORT;
- if ((port = a2port(p)) > 0)
- return port;
- return -1;
-}
-
-/* Try to start non-blocking connect to next host in cctx list */
-static int
-connect_next(struct channel_connect *cctx)
-{
- int sock, saved_errno;
- struct sockaddr_un *sunaddr;
- char ntop[NI_MAXHOST], strport[MAXIMUM(NI_MAXSERV,sizeof(sunaddr->sun_path))];
-
- for (; cctx->ai; cctx->ai = cctx->ai->ai_next) {
- switch (cctx->ai->ai_family) {
- case AF_UNIX:
- /* unix:pathname instead of host:port */
- sunaddr = (struct sockaddr_un *)cctx->ai->ai_addr;
- strlcpy(ntop, "unix", sizeof(ntop));
- strlcpy(strport, sunaddr->sun_path, sizeof(strport));
- break;
- case AF_INET:
- case AF_INET6:
- if (getnameinfo(cctx->ai->ai_addr, cctx->ai->ai_addrlen,
- ntop, sizeof(ntop), strport, sizeof(strport),
- NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
- error("connect_next: getnameinfo failed");
- continue;
- }
- break;
- default:
- continue;
- }
- if ((sock = socket(cctx->ai->ai_family, cctx->ai->ai_socktype,
- cctx->ai->ai_protocol)) == -1) {
- if (cctx->ai->ai_next == NULL)
- error("socket: %.100s", strerror(errno));
- else
- verbose("socket: %.100s", strerror(errno));
- continue;
- }
- if (set_nonblock(sock) == -1)
- fatal("%s: set_nonblock(%d)", __func__, sock);
- if (connect(sock, cctx->ai->ai_addr,
- cctx->ai->ai_addrlen) == -1 && errno != EINPROGRESS) {
- debug("connect_next: host %.100s ([%.100s]:%s): "
- "%.100s", cctx->host, ntop, strport,
- strerror(errno));
- saved_errno = errno;
- close(sock);
- errno = saved_errno;
- continue; /* fail -- try next */
- }
- if (cctx->ai->ai_family != AF_UNIX)
- set_nodelay(sock);
- debug("connect_next: host %.100s ([%.100s]:%s) "
- "in progress, fd=%d", cctx->host, ntop, strport, sock);
- cctx->ai = cctx->ai->ai_next;
- return sock;
- }
- return -1;
-}
-
-static void
-channel_connect_ctx_free(struct channel_connect *cctx)
-{
- free(cctx->host);
- if (cctx->aitop) {
- if (cctx->aitop->ai_family == AF_UNIX)
- free(cctx->aitop);
- else
- freeaddrinfo(cctx->aitop);
- }
- memset(cctx, 0, sizeof(*cctx));
-}
-
-/* Return CONNECTING channel to remote host:port or local socket path */
-static Channel *
-connect_to(const char *name, int port, char *ctype, char *rname)
-{
- struct addrinfo hints;
- int gaierr;
- int sock = -1;
- char strport[NI_MAXSERV];
- struct channel_connect cctx;
- Channel *c;
-
- memset(&cctx, 0, sizeof(cctx));
-
- if (port == PORT_STREAMLOCAL) {
- struct sockaddr_un *sunaddr;
- struct addrinfo *ai;
-
- if (strlen(name) > sizeof(sunaddr->sun_path)) {
- error("%.100s: %.100s", name, strerror(ENAMETOOLONG));
- return (NULL);
- }
-
- /*
- * Fake up a struct addrinfo for AF_UNIX connections.
- * channel_connect_ctx_free() must check ai_family
- * and use free() not freeaddirinfo() for AF_UNIX.
- */
- ai = xmalloc(sizeof(*ai) + sizeof(*sunaddr));
- memset(ai, 0, sizeof(*ai) + sizeof(*sunaddr));
- ai->ai_addr = (struct sockaddr *)(ai + 1);
- ai->ai_addrlen = sizeof(*sunaddr);
- ai->ai_family = AF_UNIX;
- ai->ai_socktype = SOCK_STREAM;
- ai->ai_protocol = PF_UNSPEC;
- sunaddr = (struct sockaddr_un *)ai->ai_addr;
- sunaddr->sun_family = AF_UNIX;
- strlcpy(sunaddr->sun_path, name, sizeof(sunaddr->sun_path));
- cctx.aitop = ai;
- } else {
- memset(&hints, 0, sizeof(hints));
- hints.ai_family = IPv4or6;
- hints.ai_socktype = SOCK_STREAM;
- snprintf(strport, sizeof strport, "%d", port);
- if ((gaierr = getaddrinfo(name, strport, &hints, &cctx.aitop)) != 0) {
- error("connect_to %.100s: unknown host (%s)", name,
- ssh_gai_strerror(gaierr));
- return NULL;
- }
- }
-
- cctx.host = xstrdup(name);
- cctx.port = port;
- cctx.ai = cctx.aitop;
-
- if ((sock = connect_next(&cctx)) == -1) {
- error("connect to %.100s port %d failed: %s",
- name, port, strerror(errno));
- channel_connect_ctx_free(&cctx);
- return NULL;
- }
- c = channel_new(ctype, SSH_CHANNEL_CONNECTING, sock, sock, -1,
- CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0, rname, 1);
- c->connect_ctx = cctx;
- return c;
-}
-
-/*
- * returns either the newly connected channel or the downstream channel
- * that needs to deal with this connection.
- */
-Channel *
-channel_connect_by_listen_address(const char *listen_host,
- u_short listen_port, char *ctype, char *rname)
-{
- int i;
-
- for (i = 0; i < num_permitted_opens; i++) {
- if (open_listen_match_tcpip(&permitted_opens[i], listen_host,
- listen_port, 1)) {
- if (permitted_opens[i].downstream)
- return permitted_opens[i].downstream;
- return connect_to(
- permitted_opens[i].host_to_connect,
- permitted_opens[i].port_to_connect, ctype, rname);
- }
- }
- error("WARNING: Server requests forwarding for unknown listen_port %d",
- listen_port);
- return NULL;
-}
-
-Channel *
-channel_connect_by_listen_path(const char *path, char *ctype, char *rname)
-{
- int i;
-
- for (i = 0; i < num_permitted_opens; i++) {
- if (open_listen_match_streamlocal(&permitted_opens[i], path)) {
- return connect_to(
- permitted_opens[i].host_to_connect,
- permitted_opens[i].port_to_connect, ctype, rname);
- }
- }
- error("WARNING: Server requests forwarding for unknown path %.100s",
- path);
- return NULL;
-}
-
-/* Check if connecting to that port is permitted and connect. */
-Channel *
-channel_connect_to_port(const char *host, u_short port, char *ctype, char *rname)
-{
- int i, permit, permit_adm = 1;
-
- permit = all_opens_permitted;
- if (!permit) {
- for (i = 0; i < num_permitted_opens; i++)
- if (open_match(&permitted_opens[i], host, port)) {
- permit = 1;
- break;
- }
- }
-
- if (num_adm_permitted_opens > 0) {
- permit_adm = 0;
- for (i = 0; i < num_adm_permitted_opens; i++)
- if (open_match(&permitted_adm_opens[i], host, port)) {
- permit_adm = 1;
- break;
- }
- }
-
- if (!permit || !permit_adm) {
- logit("Received request to connect to host %.100s port %d, "
- "but the request was denied.", host, port);
- return NULL;
- }
- return connect_to(host, port, ctype, rname);
-}
-
-/* Check if connecting to that path is permitted and connect. */
-Channel *
-channel_connect_to_path(const char *path, char *ctype, char *rname)
-{
- int i, permit, permit_adm = 1;
-
- permit = all_opens_permitted;
- if (!permit) {
- for (i = 0; i < num_permitted_opens; i++)
- if (open_match(&permitted_opens[i], path, PORT_STREAMLOCAL)) {
- permit = 1;
- break;
- }
- }
-
- if (num_adm_permitted_opens > 0) {
- permit_adm = 0;
- for (i = 0; i < num_adm_permitted_opens; i++)
- if (open_match(&permitted_adm_opens[i], path, PORT_STREAMLOCAL)) {
- permit_adm = 1;
- break;
- }
- }
-
- if (!permit || !permit_adm) {
- logit("Received request to connect to path %.100s, "
- "but the request was denied.", path);
- return NULL;
- }
- return connect_to(path, PORT_STREAMLOCAL, ctype, rname);
-}
-
-void
-channel_send_window_changes(void)
-{
- u_int i;
- struct winsize ws;
-
- for (i = 0; i < channels_alloc; i++) {
- if (channels[i] == NULL || !channels[i]->client_tty ||
- channels[i]->type != SSH_CHANNEL_OPEN)
- continue;
- if (ioctl(channels[i]->rfd, TIOCGWINSZ, &ws) < 0)
- continue;
- channel_request_start(i, "window-change", 0);
- packet_put_int((u_int)ws.ws_col);
- packet_put_int((u_int)ws.ws_row);
- packet_put_int((u_int)ws.ws_xpixel);
- packet_put_int((u_int)ws.ws_ypixel);
- packet_send();
- }
-}
-
-/* -- X11 forwarding */
-
-/*
- * Creates an internet domain socket for listening for X11 connections.
- * Returns 0 and a suitable display number for the DISPLAY variable
- * stored in display_numberp , or -1 if an error occurs.
- */
-int
-x11_create_display_inet(int x11_display_offset, int x11_use_localhost,
- int single_connection, u_int *display_numberp, int **chanids)
-{
- Channel *nc = NULL;
- int display_number, sock;
- u_short port;
- struct addrinfo hints, *ai, *aitop;
- char strport[NI_MAXSERV];
- int gaierr, n, num_socks = 0, socks[NUM_SOCKS];
-
- if (chanids == NULL)
- return -1;
-
- for (display_number = x11_display_offset;
- display_number < MAX_DISPLAYS;
- display_number++) {
- port = 6000 + display_number;
- memset(&hints, 0, sizeof(hints));
- hints.ai_family = IPv4or6;
- hints.ai_flags = x11_use_localhost ? 0: AI_PASSIVE;
- hints.ai_socktype = SOCK_STREAM;
- snprintf(strport, sizeof strport, "%d", port);
- if ((gaierr = getaddrinfo(NULL, strport, &hints, &aitop)) != 0) {
- error("getaddrinfo: %.100s", ssh_gai_strerror(gaierr));
- return -1;
- }
- for (ai = aitop; ai; ai = ai->ai_next) {
- if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
- continue;
- sock = socket(ai->ai_family, ai->ai_socktype,
- ai->ai_protocol);
- if (sock < 0) {
- if ((errno != EINVAL) && (errno != EAFNOSUPPORT)
-#ifdef EPFNOSUPPORT
- && (errno != EPFNOSUPPORT)
-#endif
- ) {
- error("socket: %.100s", strerror(errno));
- freeaddrinfo(aitop);
- return -1;
- } else {
- debug("x11_create_display_inet: Socket family %d not supported",
- ai->ai_family);
- continue;
- }
- }
- if (ai->ai_family == AF_INET6)
- sock_set_v6only(sock);
- if (x11_use_localhost)
- channel_set_reuseaddr(sock);
- if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
- debug2("bind port %d: %.100s", port, strerror(errno));
- close(sock);
-
- for (n = 0; n < num_socks; n++) {
- close(socks[n]);
- }
- num_socks = 0;
- break;
- }
- socks[num_socks++] = sock;
- if (num_socks == NUM_SOCKS)
- break;
- }
- freeaddrinfo(aitop);
- if (num_socks > 0)
- break;
- }
- if (display_number >= MAX_DISPLAYS) {
- error("Failed to allocate internet-domain X11 display socket.");
- return -1;
- }
- /* Start listening for connections on the socket. */
- for (n = 0; n < num_socks; n++) {
- sock = socks[n];
- if (listen(sock, SSH_LISTEN_BACKLOG) < 0) {
- error("listen: %.100s", strerror(errno));
- close(sock);
- return -1;
- }
- }
-
- /* Allocate a channel for each socket. */
- *chanids = xcalloc(num_socks + 1, sizeof(**chanids));
- for (n = 0; n < num_socks; n++) {
- sock = socks[n];
- nc = channel_new("x11 listener",
- SSH_CHANNEL_X11_LISTENER, sock, sock, -1,
- CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
- 0, "X11 inet listener", 1);
- nc->single_connection = single_connection;
- (*chanids)[n] = nc->self;
- }
- (*chanids)[n] = -1;
-
- /* Return the display number for the DISPLAY environment variable. */
- *display_numberp = display_number;
- return (0);
-}
-
-static int
-connect_local_xsocket_path(const char *pathname)
-{
- int sock;
- struct sockaddr_un addr;
-
- sock = socket(AF_UNIX, SOCK_STREAM, 0);
- if (sock < 0)
- error("socket: %.100s", strerror(errno));
- memset(&addr, 0, sizeof(addr));
- addr.sun_family = AF_UNIX;
- strlcpy(addr.sun_path, pathname, sizeof addr.sun_path);
- if (connect(sock, (struct sockaddr *)&addr, sizeof(addr)) == 0)
- return sock;
- close(sock);
- error("connect %.100s: %.100s", addr.sun_path, strerror(errno));
- return -1;
-}
-
-static int
-connect_local_xsocket(u_int dnr)
-{
- char buf[1024];
- snprintf(buf, sizeof buf, _PATH_UNIX_X, dnr);
- return connect_local_xsocket_path(buf);
-}
-
-int
-x11_connect_display(void)
-{
- u_int display_number;
- const char *display;
- char buf[1024], *cp;
- struct addrinfo hints, *ai, *aitop;
- char strport[NI_MAXSERV];
- int gaierr, sock = 0;
-
- /* Try to open a socket for the local X server. */
- display = getenv("DISPLAY");
- if (!display) {
- error("DISPLAY not set.");
- return -1;
- }
- /*
- * Now we decode the value of the DISPLAY variable and make a
- * connection to the real X server.
- */
-
- /* Check if the display is from launchd. */
-#ifdef __APPLE__
- if (strncmp(display, "/tmp/launch", 11) == 0) {
- sock = connect_local_xsocket_path(display);
- if (sock < 0)
- return -1;
-
- /* OK, we now have a connection to the display. */
- return sock;
- }
-#endif
- /*
- * Check if it is a unix domain socket. Unix domain displays are in
- * one of the following formats: unix:d[.s], :d[.s], ::d[.s]
- */
- if (strncmp(display, "unix:", 5) == 0 ||
- display[0] == ':') {
- /* Connect to the unix domain socket. */
- if (sscanf(strrchr(display, ':') + 1, "%u", &display_number) != 1) {
- error("Could not parse display number from DISPLAY: %.100s",
- display);
- return -1;
- }
- /* Create a socket. */
- sock = connect_local_xsocket(display_number);
- if (sock < 0)
- return -1;
-
- /* OK, we now have a connection to the display. */
- return sock;
- }
- /*
- * Connect to an inet socket. The DISPLAY value is supposedly
- * hostname:d[.s], where hostname may also be numeric IP address.
- */
- strlcpy(buf, display, sizeof(buf));
- cp = strchr(buf, ':');
- if (!cp) {
- error("Could not find ':' in DISPLAY: %.100s", display);
- return -1;
- }
- *cp = 0;
- /* buf now contains the host name. But first we parse the display number. */
- if (sscanf(cp + 1, "%u", &display_number) != 1) {
- error("Could not parse display number from DISPLAY: %.100s",
- display);
- return -1;
- }
-
- /* Look up the host address */
- memset(&hints, 0, sizeof(hints));
- hints.ai_family = IPv4or6;
- hints.ai_socktype = SOCK_STREAM;
- snprintf(strport, sizeof strport, "%u", 6000 + display_number);
- if ((gaierr = getaddrinfo(buf, strport, &hints, &aitop)) != 0) {
- error("%.100s: unknown host. (%s)", buf,
- ssh_gai_strerror(gaierr));
- return -1;
- }
- for (ai = aitop; ai; ai = ai->ai_next) {
- /* Create a socket. */
- sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
- if (sock < 0) {
- debug2("socket: %.100s", strerror(errno));
- continue;
- }
- /* Connect it to the display. */
- if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
- debug2("connect %.100s port %u: %.100s", buf,
- 6000 + display_number, strerror(errno));
- close(sock);
- continue;
- }
- /* Success */
- break;
- }
- freeaddrinfo(aitop);
- if (!ai) {
- error("connect %.100s port %u: %.100s", buf, 6000 + display_number,
- strerror(errno));
- return -1;
- }
- set_nodelay(sock);
- return sock;
-}
-
-/*
- * This is called when SSH_SMSG_X11_OPEN is received. The packet contains
- * the remote channel number. We should do whatever we want, and respond
- * with either SSH_MSG_OPEN_CONFIRMATION or SSH_MSG_OPEN_FAILURE.
- */
-
-/* ARGSUSED */
-int
-x11_input_open(int type, u_int32_t seq, void *ctxt)
-{
- Channel *c = NULL;
- int remote_id, sock = 0;
- char *remote_host;
-
- debug("Received X11 open request.");
-
- remote_id = packet_get_int();
-
- if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {
- remote_host = packet_get_string(NULL);
- } else {
- remote_host = xstrdup("unknown (remote did not supply name)");
- }
- packet_check_eom();
-
- /* Obtain a connection to the real X display. */
- sock = x11_connect_display();
- if (sock != -1) {
- /* Allocate a channel for this connection. */
- c = channel_new("connected x11 socket",
- SSH_CHANNEL_X11_OPEN, sock, sock, -1, 0, 0, 0,
- remote_host, 1);
- c->remote_id = remote_id;
- c->force_drain = 1;
- }
- free(remote_host);
- if (c == NULL) {
- /* Send refusal to the remote host. */
- packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
- packet_put_int(remote_id);
- } else {
- /* Send a confirmation to the remote host. */
- packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
- packet_put_int(remote_id);
- packet_put_int(c->self);
- }
- packet_send();
- return 0;
-}
-
-/* dummy protocol handler that denies SSH-1 requests (agent/x11) */
-/* ARGSUSED */
-int
-deny_input_open(int type, u_int32_t seq, void *ctxt)
-{
- int rchan = packet_get_int();
-
- switch (type) {
- case SSH_SMSG_AGENT_OPEN:
- error("Warning: ssh server tried agent forwarding.");
- break;
- case SSH_SMSG_X11_OPEN:
- error("Warning: ssh server tried X11 forwarding.");
- break;
- default:
- error("deny_input_open: type %d", type);
- break;
- }
- error("Warning: this is probably a break-in attempt by a malicious server.");
- packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
- packet_put_int(rchan);
- packet_send();
- return 0;
-}
-
-/*
- * Requests forwarding of X11 connections, generates fake authentication
- * data, and enables authentication spoofing.
- * This should be called in the client only.
- */
-void
-x11_request_forwarding_with_spoofing(int client_session_id, const char *disp,
- const char *proto, const char *data, int want_reply)
-{
- u_int data_len = (u_int) strlen(data) / 2;
- u_int i, value;
- char *new_data;
- int screen_number;
- const char *cp;
-
- if (x11_saved_display == NULL)
- x11_saved_display = xstrdup(disp);
- else if (strcmp(disp, x11_saved_display) != 0) {
- error("x11_request_forwarding_with_spoofing: different "
- "$DISPLAY already forwarded");
- return;
- }
-
- cp = strchr(disp, ':');
- if (cp)
- cp = strchr(cp, '.');
- if (cp)
- screen_number = (u_int)strtonum(cp + 1, 0, 400, NULL);
- else
- screen_number = 0;
-
- if (x11_saved_proto == NULL) {
- /* Save protocol name. */
- x11_saved_proto = xstrdup(proto);
-
- /* Extract real authentication data. */
- x11_saved_data = xmalloc(data_len);
- for (i = 0; i < data_len; i++) {
- if (sscanf(data + 2 * i, "%2x", &value) != 1)
- fatal("x11_request_forwarding: bad "
- "authentication data: %.100s", data);
- x11_saved_data[i] = value;
- }
- x11_saved_data_len = data_len;
-
- /* Generate fake data of the same length. */
- x11_fake_data = xmalloc(data_len);
- arc4random_buf(x11_fake_data, data_len);
- x11_fake_data_len = data_len;
- }
-
- /* Convert the fake data into hex. */
- new_data = tohex(x11_fake_data, data_len);
-
- /* Send the request packet. */
- if (compat20) {
- channel_request_start(client_session_id, "x11-req", want_reply);
- packet_put_char(0); /* XXX bool single connection */
- } else {
- packet_start(SSH_CMSG_X11_REQUEST_FORWARDING);
- }
- packet_put_cstring(proto);
- packet_put_cstring(new_data);
- packet_put_int(screen_number);
- packet_send();
- packet_write_wait();
- free(new_data);
-}
-
-
-/* -- agent forwarding */
-
-/* Sends a message to the server to request authentication fd forwarding. */
-
-void
-auth_request_forwarding(void)
-{
- packet_start(SSH_CMSG_AGENT_REQUEST_FORWARDING);
- packet_send();
- packet_write_wait();
-}
projects / thirdparty / openssh-portable.git / commitdiff
