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2b261b9035
[channels.c ssh.c] undo socks5 and https support since they are not really used and only bloat ssh. remove -D from usage(), since '-D' is experimental.
2814 lines
74 KiB
C
2814 lines
74 KiB
C
/*
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* Author: Tatu Ylonen <ylo@cs.hut.fi>
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* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
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* All rights reserved
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* This file contains functions for generic socket connection forwarding.
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* There is also code for initiating connection forwarding for X11 connections,
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* arbitrary tcp/ip connections, and the authentication agent connection.
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*
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* As far as I am concerned, the code I have written for this software
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* can be used freely for any purpose. Any derived versions of this
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* software must be clearly marked as such, and if the derived work is
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* incompatible with the protocol description in the RFC file, it must be
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* called by a name other than "ssh" or "Secure Shell".
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*
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*
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* SSH2 support added by Markus Friedl.
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* Copyright (c) 1999,2000 Markus Friedl. All rights reserved.
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* Copyright (c) 1999 Dug Song. All rights reserved.
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* Copyright (c) 1999 Theo de Raadt. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#include "includes.h"
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RCSID("$OpenBSD: channels.c,v 1.109 2001/04/17 12:55:03 markus Exp $");
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#include <openssl/rsa.h>
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#include <openssl/dsa.h>
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#include "ssh.h"
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#include "ssh1.h"
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#include "ssh2.h"
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#include "packet.h"
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#include "xmalloc.h"
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#include "buffer.h"
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#include "bufaux.h"
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#include "uidswap.h"
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#include "log.h"
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#include "misc.h"
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#include "channels.h"
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#include "nchan.h"
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#include "compat.h"
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#include "canohost.h"
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#include "key.h"
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#include "authfd.h"
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/* Maximum number of fake X11 displays to try. */
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#define MAX_DISPLAYS 1000
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/* Max len of agent socket */
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#define MAX_SOCKET_NAME 100
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/*
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* Pointer to an array containing all allocated channels. The array is
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* dynamically extended as needed.
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*/
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static Channel *channels = NULL;
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/*
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* Size of the channel array. All slots of the array must always be
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* initialized (at least the type field); unused slots are marked with type
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* SSH_CHANNEL_FREE.
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*/
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static int channels_alloc = 0;
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/*
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* Maximum file descriptor value used in any of the channels. This is
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* updated in channel_allocate.
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*/
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static int channel_max_fd = 0;
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/* Name and directory of socket for authentication agent forwarding. */
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static char *channel_forwarded_auth_socket_name = NULL;
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static char *channel_forwarded_auth_socket_dir = NULL;
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/* Saved X11 authentication protocol name. */
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char *x11_saved_proto = NULL;
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/* Saved X11 authentication data. This is the real data. */
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char *x11_saved_data = NULL;
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u_int x11_saved_data_len = 0;
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/*
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* Fake X11 authentication data. This is what the server will be sending us;
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* we should replace any occurrences of this by the real data.
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*/
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char *x11_fake_data = NULL;
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u_int x11_fake_data_len;
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/*
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* Data structure for storing which hosts are permitted for forward requests.
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* The local sides of any remote forwards are stored in this array to prevent
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* a corrupt remote server from accessing arbitrary TCP/IP ports on our local
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* network (which might be behind a firewall).
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*/
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typedef struct {
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char *host_to_connect; /* Connect to 'host'. */
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u_short port_to_connect; /* Connect to 'port'. */
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u_short listen_port; /* Remote side should listen port number. */
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} ForwardPermission;
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/* List of all permitted host/port pairs to connect. */
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static ForwardPermission permitted_opens[SSH_MAX_FORWARDS_PER_DIRECTION];
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/* Number of permitted host/port pairs in the array. */
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static int num_permitted_opens = 0;
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/*
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* If this is true, all opens are permitted. This is the case on the server
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* on which we have to trust the client anyway, and the user could do
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* anything after logging in anyway.
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*/
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static int all_opens_permitted = 0;
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/* This is set to true if both sides support SSH_PROTOFLAG_HOST_IN_FWD_OPEN. */
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static int have_hostname_in_open = 0;
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/* AF_UNSPEC or AF_INET or AF_INET6 */
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extern int IPv4or6;
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void port_open_helper(Channel *c, char *rtype);
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/* Sets specific protocol options. */
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void
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channel_set_options(int hostname_in_open)
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{
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have_hostname_in_open = hostname_in_open;
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}
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/* lookup channel by id */
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Channel *
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channel_lookup(int id)
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{
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Channel *c;
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if (id < 0 || id > channels_alloc) {
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log("channel_lookup: %d: bad id", id);
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return NULL;
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}
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c = &channels[id];
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if (c->type == SSH_CHANNEL_FREE) {
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log("channel_lookup: %d: bad id: channel free", id);
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return NULL;
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}
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return c;
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}
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/*
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* Register filedescriptors for a channel, used when allocating a channel or
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* when the channel consumer/producer is ready, e.g. shell exec'd
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*/
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void
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channel_register_fds(Channel *c, int rfd, int wfd, int efd,
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int extusage, int nonblock)
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{
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/* Update the maximum file descriptor value. */
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channel_max_fd = MAX(channel_max_fd, rfd);
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channel_max_fd = MAX(channel_max_fd, wfd);
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channel_max_fd = MAX(channel_max_fd, efd);
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/* XXX set close-on-exec -markus */
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c->rfd = rfd;
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c->wfd = wfd;
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c->sock = (rfd == wfd) ? rfd : -1;
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c->efd = efd;
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c->extended_usage = extusage;
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/* XXX ugly hack: nonblock is only set by the server */
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if (nonblock && isatty(c->rfd)) {
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debug("channel %d: rfd %d isatty", c->self, c->rfd);
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c->isatty = 1;
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if (!isatty(c->wfd)) {
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error("channel %d: wfd %d is not a tty?",
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c->self, c->wfd);
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}
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} else {
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c->isatty = 0;
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}
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/* enable nonblocking mode */
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if (nonblock) {
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if (rfd != -1)
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set_nonblock(rfd);
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if (wfd != -1)
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set_nonblock(wfd);
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if (efd != -1)
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set_nonblock(efd);
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}
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}
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/*
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* Allocate a new channel object and set its type and socket. This will cause
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* remote_name to be freed.
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*/
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int
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channel_new(char *ctype, int type, int rfd, int wfd, int efd,
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int window, int maxpack, int extusage, char *remote_name, int nonblock)
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{
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int i, found;
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Channel *c;
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/* Do initial allocation if this is the first call. */
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if (channels_alloc == 0) {
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chan_init();
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channels_alloc = 10;
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channels = xmalloc(channels_alloc * sizeof(Channel));
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for (i = 0; i < channels_alloc; i++)
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channels[i].type = SSH_CHANNEL_FREE;
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/*
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* Kludge: arrange a call to channel_stop_listening if we
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* terminate with fatal().
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*/
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fatal_add_cleanup((void (*) (void *)) channel_stop_listening, NULL);
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}
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/* Try to find a free slot where to put the new channel. */
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for (found = -1, i = 0; i < channels_alloc; i++)
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if (channels[i].type == SSH_CHANNEL_FREE) {
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/* Found a free slot. */
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found = i;
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break;
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}
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if (found == -1) {
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/* There are no free slots. Take last+1 slot and expand the array. */
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found = channels_alloc;
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channels_alloc += 10;
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debug2("channel: expanding %d", channels_alloc);
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channels = xrealloc(channels, channels_alloc * sizeof(Channel));
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for (i = found; i < channels_alloc; i++)
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channels[i].type = SSH_CHANNEL_FREE;
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}
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/* Initialize and return new channel number. */
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c = &channels[found];
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buffer_init(&c->input);
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buffer_init(&c->output);
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buffer_init(&c->extended);
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chan_init_iostates(c);
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channel_register_fds(c, rfd, wfd, efd, extusage, nonblock);
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c->self = found;
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c->type = type;
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c->ctype = ctype;
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c->local_window = window;
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c->local_window_max = window;
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c->local_consumed = 0;
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c->local_maxpacket = maxpack;
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c->remote_id = -1;
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c->remote_name = remote_name;
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c->remote_window = 0;
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c->remote_maxpacket = 0;
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c->cb_fn = NULL;
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c->cb_arg = NULL;
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c->cb_event = 0;
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c->dettach_user = NULL;
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c->input_filter = NULL;
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debug("channel %d: new [%s]", found, remote_name);
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return found;
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}
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/* old interface XXX */
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int
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channel_allocate(int type, int sock, char *remote_name)
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{
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return channel_new("", type, sock, sock, -1, 0, 0, 0, remote_name, 1);
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}
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/* Close all channel fd/socket. */
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void
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channel_close_fds(Channel *c)
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{
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if (c->sock != -1) {
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close(c->sock);
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c->sock = -1;
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}
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if (c->rfd != -1) {
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close(c->rfd);
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c->rfd = -1;
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}
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if (c->wfd != -1) {
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close(c->wfd);
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c->wfd = -1;
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}
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if (c->efd != -1) {
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close(c->efd);
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c->efd = -1;
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}
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}
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/* Free the channel and close its fd/socket. */
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void
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channel_free(int id)
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{
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Channel *c = channel_lookup(id);
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char *s = channel_open_message();
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if (c == NULL)
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packet_disconnect("channel free: bad local channel %d", id);
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debug("channel_free: channel %d: status: %s", id, s);
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xfree(s);
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if (c->dettach_user != NULL) {
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debug("channel_free: channel %d: dettaching channel user", id);
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c->dettach_user(c->self, NULL);
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}
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if (c->sock != -1)
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shutdown(c->sock, SHUT_RDWR);
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channel_close_fds(c);
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buffer_free(&c->input);
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buffer_free(&c->output);
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buffer_free(&c->extended);
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c->type = SSH_CHANNEL_FREE;
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if (c->remote_name) {
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xfree(c->remote_name);
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c->remote_name = NULL;
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}
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}
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/*
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* 'channel_pre*' are called just before select() to add any bits relevant to
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* channels in the select bitmasks.
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*/
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/*
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* 'channel_post*': perform any appropriate operations for channels which
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* have events pending.
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*/
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typedef void chan_fn(Channel *c, fd_set * readset, fd_set * writeset);
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chan_fn *channel_pre[SSH_CHANNEL_MAX_TYPE];
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chan_fn *channel_post[SSH_CHANNEL_MAX_TYPE];
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void
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channel_pre_listener(Channel *c, fd_set * readset, fd_set * writeset)
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{
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FD_SET(c->sock, readset);
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}
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void
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channel_pre_connecting(Channel *c, fd_set * readset, fd_set * writeset)
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{
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debug3("channel %d: waiting for connection", c->self);
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FD_SET(c->sock, writeset);
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}
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void
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channel_pre_open_13(Channel *c, fd_set * readset, fd_set * writeset)
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{
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if (buffer_len(&c->input) < packet_get_maxsize())
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FD_SET(c->sock, readset);
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if (buffer_len(&c->output) > 0)
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FD_SET(c->sock, writeset);
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}
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void
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channel_pre_open_15(Channel *c, fd_set * readset, fd_set * writeset)
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{
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/* test whether sockets are 'alive' for read/write */
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if (c->istate == CHAN_INPUT_OPEN)
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if (buffer_len(&c->input) < packet_get_maxsize())
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FD_SET(c->sock, readset);
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if (c->ostate == CHAN_OUTPUT_OPEN ||
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c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
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if (buffer_len(&c->output) > 0) {
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FD_SET(c->sock, writeset);
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} else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
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chan_obuf_empty(c);
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}
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}
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}
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void
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channel_pre_open_20(Channel *c, fd_set * readset, fd_set * writeset)
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{
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if (c->istate == CHAN_INPUT_OPEN &&
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c->remote_window > 0 &&
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buffer_len(&c->input) < c->remote_window)
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FD_SET(c->rfd, readset);
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if (c->ostate == CHAN_OUTPUT_OPEN ||
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c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
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if (buffer_len(&c->output) > 0) {
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FD_SET(c->wfd, writeset);
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} else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
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chan_obuf_empty(c);
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}
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}
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/** XXX check close conditions, too */
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if (c->efd != -1) {
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if (c->extended_usage == CHAN_EXTENDED_WRITE &&
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buffer_len(&c->extended) > 0)
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FD_SET(c->efd, writeset);
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else if (c->extended_usage == CHAN_EXTENDED_READ &&
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buffer_len(&c->extended) < c->remote_window)
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FD_SET(c->efd, readset);
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}
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}
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void
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channel_pre_input_draining(Channel *c, fd_set * readset, fd_set * writeset)
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{
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if (buffer_len(&c->input) == 0) {
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packet_start(SSH_MSG_CHANNEL_CLOSE);
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packet_put_int(c->remote_id);
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packet_send();
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c->type = SSH_CHANNEL_CLOSED;
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debug("channel %d: closing after input drain.", c->self);
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}
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}
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void
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channel_pre_output_draining(Channel *c, fd_set * readset, fd_set * writeset)
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{
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if (buffer_len(&c->output) == 0)
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channel_free(c->self);
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else
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FD_SET(c->sock, writeset);
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}
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/*
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* This is a special state for X11 authentication spoofing. An opened X11
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* connection (when authentication spoofing is being done) remains in this
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* state until the first packet has been completely read. The authentication
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* data in that packet is then substituted by the real data if it matches the
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* fake data, and the channel is put into normal mode.
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* XXX All this happens at the client side.
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*/
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int
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x11_open_helper(Channel *c)
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{
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u_char *ucp;
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u_int proto_len, data_len;
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/* Check if the fixed size part of the packet is in buffer. */
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if (buffer_len(&c->output) < 12)
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return 0;
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/* Parse the lengths of variable-length fields. */
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ucp = (u_char *) buffer_ptr(&c->output);
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if (ucp[0] == 0x42) { /* Byte order MSB first. */
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proto_len = 256 * ucp[6] + ucp[7];
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data_len = 256 * ucp[8] + ucp[9];
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} else if (ucp[0] == 0x6c) { /* Byte order LSB first. */
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proto_len = ucp[6] + 256 * ucp[7];
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data_len = ucp[8] + 256 * ucp[9];
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} else {
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debug("Initial X11 packet contains bad byte order byte: 0x%x",
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ucp[0]);
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return -1;
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}
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/* Check if the whole packet is in buffer. */
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if (buffer_len(&c->output) <
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12 + ((proto_len + 3) & ~3) + ((data_len + 3) & ~3))
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return 0;
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/* Check if authentication protocol matches. */
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if (proto_len != strlen(x11_saved_proto) ||
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memcmp(ucp + 12, x11_saved_proto, proto_len) != 0) {
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debug("X11 connection uses different authentication protocol.");
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return -1;
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}
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/* Check if authentication data matches our fake data. */
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if (data_len != x11_fake_data_len ||
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memcmp(ucp + 12 + ((proto_len + 3) & ~3),
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x11_fake_data, x11_fake_data_len) != 0) {
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debug("X11 auth data does not match fake data.");
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return -1;
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}
|
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/* Check fake data length */
|
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if (x11_fake_data_len != x11_saved_data_len) {
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error("X11 fake_data_len %d != saved_data_len %d",
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x11_fake_data_len, x11_saved_data_len);
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return -1;
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}
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/*
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* 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;
|
|
}
|
|
|
|
void
|
|
channel_pre_x11_open_13(Channel *c, fd_set * readset, fd_set * writeset)
|
|
{
|
|
int ret = x11_open_helper(c);
|
|
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.
|
|
*/
|
|
log("X11 connection rejected because of wrong authentication.");
|
|
buffer_clear(&c->input);
|
|
buffer_clear(&c->output);
|
|
close(c->sock);
|
|
c->sock = -1;
|
|
c->type = SSH_CHANNEL_CLOSED;
|
|
packet_start(SSH_MSG_CHANNEL_CLOSE);
|
|
packet_put_int(c->remote_id);
|
|
packet_send();
|
|
}
|
|
}
|
|
|
|
void
|
|
channel_pre_x11_open(Channel *c, fd_set * readset, fd_set * writeset)
|
|
{
|
|
int ret = x11_open_helper(c);
|
|
if (ret == 1) {
|
|
c->type = SSH_CHANNEL_OPEN;
|
|
if (compat20)
|
|
channel_pre_open_20(c, readset, writeset);
|
|
else
|
|
channel_pre_open_15(c, readset, writeset);
|
|
} else if (ret == -1) {
|
|
debug("X11 rejected %d i%d/o%d", c->self, c->istate, c->ostate);
|
|
chan_read_failed(c); /** force close? */
|
|
chan_write_failed(c);
|
|
debug("X11 closed %d i%d/o%d", c->self, c->istate, c->ostate);
|
|
}
|
|
}
|
|
|
|
/* try to decode a socks4 header */
|
|
int
|
|
channel_decode_socks4(Channel *c, fd_set * readset, fd_set * writeset)
|
|
{
|
|
u_char *p, *host;
|
|
int len, have, i, found;
|
|
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 = buffer_ptr(&c->input);
|
|
for (found = 0, i = len; i < have; i++) {
|
|
if (p[i] == '\0') {
|
|
found = 1;
|
|
break;
|
|
}
|
|
if (i > 1024) {
|
|
/* the peer is probably sending garbage */
|
|
debug("channel %d: decode socks4: too long",
|
|
c->self);
|
|
return -1;
|
|
}
|
|
}
|
|
if (!found)
|
|
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 = buffer_ptr(&c->input);
|
|
len = strlen(p);
|
|
debug2("channel %d: decode socks4: user %s/%d", c->self, p, len);
|
|
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);
|
|
buffer_consume(&c->input, 1); /* trailing '\0' */
|
|
|
|
host = inet_ntoa(s4_req.dest_addr);
|
|
strlcpy(c->path, host, sizeof(c->path));
|
|
c->host_port = ntohs(s4_req.dest_port);
|
|
|
|
debug("channel %d: dynamic request: socks4 host %s port %u command %u",
|
|
c->self, host, c->host_port, s4_req.command);
|
|
|
|
if (s4_req.command != 1) {
|
|
debug("channel %d: cannot handle: socks4 cn %d",
|
|
c->self, 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, (char *)&s4_rsp, sizeof(s4_rsp));
|
|
return 1;
|
|
}
|
|
|
|
/* dynamic port forwarding */
|
|
void
|
|
channel_pre_dynamic(Channel *c, fd_set * readset, fd_set * writeset)
|
|
{
|
|
u_char *p;
|
|
int have, 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 < 4) {
|
|
/* 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;
|
|
default:
|
|
ret = -1;
|
|
break;
|
|
}
|
|
if (ret < 0) {
|
|
channel_free(c->self);
|
|
} 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. */
|
|
void
|
|
channel_post_x11_listener(Channel *c, fd_set * readset, fd_set * writeset)
|
|
{
|
|
struct sockaddr addr;
|
|
int newsock, newch;
|
|
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, &addr, &addrlen);
|
|
if (newsock < 0) {
|
|
error("accept: %.100s", strerror(errno));
|
|
return;
|
|
}
|
|
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);
|
|
|
|
newch = channel_new("x11",
|
|
SSH_CHANNEL_OPENING, newsock, newsock, -1,
|
|
c->local_window_max, c->local_maxpacket,
|
|
0, xstrdup(buf), 1);
|
|
if (compat20) {
|
|
packet_start(SSH2_MSG_CHANNEL_OPEN);
|
|
packet_put_cstring("x11");
|
|
packet_put_int(newch);
|
|
packet_put_int(c->local_window_max);
|
|
packet_put_int(c->local_maxpacket);
|
|
/* originator ipaddr and port */
|
|
packet_put_cstring(remote_ipaddr);
|
|
if (datafellows & SSH_BUG_X11FWD) {
|
|
debug("ssh2 x11 bug compat mode");
|
|
} else {
|
|
packet_put_int(remote_port);
|
|
}
|
|
packet_send();
|
|
} else {
|
|
packet_start(SSH_SMSG_X11_OPEN);
|
|
packet_put_int(newch);
|
|
if (have_hostname_in_open)
|
|
packet_put_string(buf, strlen(buf));
|
|
packet_send();
|
|
}
|
|
xfree(remote_ipaddr);
|
|
}
|
|
}
|
|
|
|
void
|
|
port_open_helper(Channel *c, char *rtype)
|
|
{
|
|
int direct;
|
|
char buf[1024];
|
|
char *remote_ipaddr = get_peer_ipaddr(c->sock);
|
|
u_short remote_port = get_peer_port(c->sock);
|
|
|
|
direct = (strcmp(rtype, "direct-tcpip") == 0);
|
|
|
|
snprintf(buf, sizeof buf,
|
|
"%s: listening port %d for %.100s port %d, "
|
|
"connect from %.200s port %d",
|
|
rtype, c->listening_port, c->path, c->host_port,
|
|
remote_ipaddr, remote_port);
|
|
|
|
xfree(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 (direct) {
|
|
/* target host, port */
|
|
packet_put_cstring(c->path);
|
|
packet_put_int(c->host_port);
|
|
} else {
|
|
/* listen address, port */
|
|
packet_put_cstring(c->path);
|
|
packet_put_int(c->listening_port);
|
|
}
|
|
/* originator host and port */
|
|
packet_put_cstring(remote_ipaddr);
|
|
packet_put_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 (have_hostname_in_open)
|
|
packet_put_cstring(c->remote_name);
|
|
packet_send();
|
|
}
|
|
xfree(remote_ipaddr);
|
|
}
|
|
|
|
/*
|
|
* This socket is listening for connections to a forwarded TCP/IP port.
|
|
*/
|
|
void
|
|
channel_post_port_listener(Channel *c, fd_set * readset, fd_set * writeset)
|
|
{
|
|
Channel *nc;
|
|
struct sockaddr addr;
|
|
int newsock, newch, 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);
|
|
|
|
rtype = (c->type == SSH_CHANNEL_RPORT_LISTENER) ?
|
|
"forwarded-tcpip" : "direct-tcpip";
|
|
nextstate = (c->host_port == 0) ? SSH_CHANNEL_DYNAMIC :
|
|
SSH_CHANNEL_OPENING;
|
|
|
|
addrlen = sizeof(addr);
|
|
newsock = accept(c->sock, &addr, &addrlen);
|
|
if (newsock < 0) {
|
|
error("accept: %.100s", strerror(errno));
|
|
return;
|
|
}
|
|
newch = channel_new(rtype,
|
|
nextstate, newsock, newsock, -1,
|
|
c->local_window_max, c->local_maxpacket,
|
|
0, xstrdup(rtype), 1);
|
|
|
|
nc = channel_lookup(newch);
|
|
if (nc == NULL) {
|
|
error("xxx: no new channel:");
|
|
return;
|
|
}
|
|
nc->listening_port = c->listening_port;
|
|
nc->host_port = c->host_port;
|
|
strlcpy(nc->path, c->path, sizeof(nc->path));
|
|
|
|
if (nextstate != SSH_CHANNEL_DYNAMIC)
|
|
port_open_helper(nc, rtype);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* This is the authentication agent socket listening for connections from
|
|
* clients.
|
|
*/
|
|
void
|
|
channel_post_auth_listener(Channel *c, fd_set * readset, fd_set * writeset)
|
|
{
|
|
struct sockaddr addr;
|
|
int newsock, newch;
|
|
socklen_t addrlen;
|
|
|
|
if (FD_ISSET(c->sock, readset)) {
|
|
addrlen = sizeof(addr);
|
|
newsock = accept(c->sock, &addr, &addrlen);
|
|
if (newsock < 0) {
|
|
error("accept from auth socket: %.100s", strerror(errno));
|
|
return;
|
|
}
|
|
newch = channel_new("accepted auth socket",
|
|
SSH_CHANNEL_OPENING, newsock, newsock, -1,
|
|
c->local_window_max, c->local_maxpacket,
|
|
0, xstrdup("accepted auth socket"), 1);
|
|
if (compat20) {
|
|
packet_start(SSH2_MSG_CHANNEL_OPEN);
|
|
packet_put_cstring("auth-agent@openssh.com");
|
|
packet_put_int(newch);
|
|
packet_put_int(c->local_window_max);
|
|
packet_put_int(c->local_maxpacket);
|
|
} else {
|
|
packet_start(SSH_SMSG_AGENT_OPEN);
|
|
packet_put_int(newch);
|
|
}
|
|
packet_send();
|
|
}
|
|
}
|
|
|
|
void
|
|
channel_post_connecting(Channel *c, fd_set * readset, fd_set * writeset)
|
|
{
|
|
if (FD_ISSET(c->sock, writeset)) {
|
|
int err = 0;
|
|
int sz = sizeof(err);
|
|
c->type = SSH_CHANNEL_OPEN;
|
|
if (getsockopt(c->sock, SOL_SOCKET, SO_ERROR, (char *)&err, &sz) < 0) {
|
|
debug("getsockopt SO_ERROR failed");
|
|
} else {
|
|
if (err == 0) {
|
|
debug("channel %d: connected)", c->self);
|
|
} else {
|
|
debug("channel %d: not connected: %s",
|
|
c->self, strerror(err));
|
|
chan_read_failed(c);
|
|
chan_write_failed(c);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
int
|
|
channel_handle_rfd(Channel *c, fd_set * readset, fd_set * writeset)
|
|
{
|
|
char buf[16*1024];
|
|
int len;
|
|
|
|
if (c->rfd != -1 &&
|
|
FD_ISSET(c->rfd, readset)) {
|
|
len = read(c->rfd, buf, sizeof(buf));
|
|
if (len < 0 && (errno == EINTR || errno == EAGAIN))
|
|
return 1;
|
|
if (len <= 0) {
|
|
debug("channel %d: read<=0 rfd %d len %d",
|
|
c->self, c->rfd, len);
|
|
if (c->type != SSH_CHANNEL_OPEN) {
|
|
debug("channel %d: not open", c->self);
|
|
channel_free(c->self);
|
|
return -1;
|
|
} else if (compat13) {
|
|
buffer_consume(&c->output, buffer_len(&c->output));
|
|
c->type = SSH_CHANNEL_INPUT_DRAINING;
|
|
debug("channel %d: status set to input draining.", c->self);
|
|
} else {
|
|
chan_read_failed(c);
|
|
}
|
|
return -1;
|
|
}
|
|
if(c->input_filter != NULL) {
|
|
if (c->input_filter(c, buf, len) == -1) {
|
|
debug("channel %d: filter stops", c->self);
|
|
chan_read_failed(c);
|
|
}
|
|
} else {
|
|
buffer_append(&c->input, buf, len);
|
|
}
|
|
}
|
|
return 1;
|
|
}
|
|
int
|
|
channel_handle_wfd(Channel *c, fd_set * readset, fd_set * writeset)
|
|
{
|
|
struct termios tio;
|
|
int len;
|
|
|
|
/* Send buffered output data to the socket. */
|
|
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 1;
|
|
if (len <= 0) {
|
|
if (c->type != SSH_CHANNEL_OPEN) {
|
|
debug("channel %d: not open", c->self);
|
|
channel_free(c->self);
|
|
return -1;
|
|
} else if (compat13) {
|
|
buffer_consume(&c->output, buffer_len(&c->output));
|
|
debug("channel %d: status set to input draining.", c->self);
|
|
c->type = SSH_CHANNEL_INPUT_DRAINING;
|
|
} else {
|
|
chan_write_failed(c);
|
|
}
|
|
return -1;
|
|
}
|
|
if (compat20 && c->isatty) {
|
|
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 + data)
|
|
*/
|
|
packet_send_ignore(4 + len);
|
|
packet_send();
|
|
}
|
|
}
|
|
buffer_consume(&c->output, len);
|
|
if (compat20 && len > 0) {
|
|
c->local_consumed += len;
|
|
}
|
|
}
|
|
return 1;
|
|
}
|
|
int
|
|
channel_handle_efd(Channel *c, fd_set * readset, fd_set * writeset)
|
|
{
|
|
char buf[16*1024];
|
|
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))
|
|
return 1;
|
|
if (len <= 0) {
|
|
debug2("channel %d: closing write-efd %d",
|
|
c->self, c->efd);
|
|
close(c->efd);
|
|
c->efd = -1;
|
|
} else {
|
|
buffer_consume(&c->extended, len);
|
|
c->local_consumed += len;
|
|
}
|
|
} else if (c->extended_usage == CHAN_EXTENDED_READ &&
|
|
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))
|
|
return 1;
|
|
if (len <= 0) {
|
|
debug2("channel %d: closing read-efd %d",
|
|
c->self, c->efd);
|
|
close(c->efd);
|
|
c->efd = -1;
|
|
} else {
|
|
buffer_append(&c->extended, buf, len);
|
|
}
|
|
}
|
|
}
|
|
return 1;
|
|
}
|
|
int
|
|
channel_check_window(Channel *c)
|
|
{
|
|
if (c->type == SSH_CHANNEL_OPEN &&
|
|
!(c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD)) &&
|
|
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;
|
|
}
|
|
|
|
void
|
|
channel_post_open_1(Channel *c, fd_set * readset, fd_set * writeset)
|
|
{
|
|
channel_handle_rfd(c, readset, writeset);
|
|
channel_handle_wfd(c, readset, writeset);
|
|
}
|
|
|
|
void
|
|
channel_post_open_2(Channel *c, fd_set * readset, fd_set * writeset)
|
|
{
|
|
channel_handle_rfd(c, readset, writeset);
|
|
channel_handle_wfd(c, readset, writeset);
|
|
channel_handle_efd(c, readset, writeset);
|
|
|
|
channel_check_window(c);
|
|
}
|
|
|
|
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_consume(&c->output, buffer_len(&c->output));
|
|
else
|
|
buffer_consume(&c->output, len);
|
|
}
|
|
}
|
|
|
|
void
|
|
channel_handler_init_20(void)
|
|
{
|
|
channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_20;
|
|
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_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_post[SSH_CHANNEL_OPEN] = &channel_post_open_2;
|
|
channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
|
|
channel_post[SSH_CHANNEL_RPORT_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_2;
|
|
}
|
|
|
|
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_1;
|
|
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_1;
|
|
}
|
|
|
|
void
|
|
channel_handler_init_15(void)
|
|
{
|
|
channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_15;
|
|
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_1;
|
|
channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
|
|
channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open_1;
|
|
}
|
|
|
|
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();
|
|
}
|
|
|
|
void
|
|
channel_handler(chan_fn *ftab[], fd_set * readset, fd_set * writeset)
|
|
{
|
|
static int did_init = 0;
|
|
int i;
|
|
Channel *c;
|
|
|
|
if (!did_init) {
|
|
channel_handler_init();
|
|
did_init = 1;
|
|
}
|
|
for (i = 0; i < channels_alloc; i++) {
|
|
c = &channels[i];
|
|
if (c->type == SSH_CHANNEL_FREE)
|
|
continue;
|
|
if (ftab[c->type] == NULL)
|
|
continue;
|
|
(*ftab[c->type])(c, readset, writeset);
|
|
if (chan_is_dead(c)) {
|
|
/*
|
|
* we have to remove the fd's from the select mask
|
|
* before the channels are free'd and the fd's are
|
|
* closed
|
|
*/
|
|
if (c->wfd != -1)
|
|
FD_CLR(c->wfd, writeset);
|
|
if (c->rfd != -1)
|
|
FD_CLR(c->rfd, readset);
|
|
if (c->efd != -1) {
|
|
if (c->extended_usage == CHAN_EXTENDED_READ)
|
|
FD_CLR(c->efd, readset);
|
|
if (c->extended_usage == CHAN_EXTENDED_WRITE)
|
|
FD_CLR(c->efd, writeset);
|
|
}
|
|
channel_free(c->self);
|
|
}
|
|
}
|
|
}
|
|
|
|
void
|
|
channel_prepare_select(fd_set **readsetp, fd_set **writesetp, int *maxfdp,
|
|
int rekeying)
|
|
{
|
|
int n;
|
|
u_int sz;
|
|
|
|
n = MAX(*maxfdp, channel_max_fd);
|
|
|
|
sz = howmany(n+1, NFDBITS) * sizeof(fd_mask);
|
|
if (*readsetp == NULL || n > *maxfdp) {
|
|
if (*readsetp)
|
|
xfree(*readsetp);
|
|
if (*writesetp)
|
|
xfree(*writesetp);
|
|
*readsetp = xmalloc(sz);
|
|
*writesetp = xmalloc(sz);
|
|
*maxfdp = n;
|
|
}
|
|
memset(*readsetp, 0, sz);
|
|
memset(*writesetp, 0, sz);
|
|
|
|
if (!rekeying)
|
|
channel_handler(channel_pre, *readsetp, *writesetp);
|
|
}
|
|
|
|
void
|
|
channel_after_select(fd_set * readset, fd_set * writeset)
|
|
{
|
|
channel_handler(channel_post, readset, writeset);
|
|
}
|
|
|
|
/* If there is data to send to the connection, enqueue some of it now. */
|
|
|
|
void
|
|
channel_output_poll()
|
|
{
|
|
int len, i;
|
|
Channel *c;
|
|
|
|
for (i = 0; i < channels_alloc; i++) {
|
|
c = &channels[i];
|
|
|
|
/* 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? */
|
|
debug2("channel %d: no 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) {
|
|
/* 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
|
|
*/
|
|
chan_ibuf_empty(c);
|
|
}
|
|
/* Send extended data, i.e. stderr */
|
|
if (compat20 &&
|
|
c->remote_window > 0 &&
|
|
(len = buffer_len(&c->extended)) > 0 &&
|
|
c->extended_usage == CHAN_EXTENDED_READ) {
|
|
debug2("channel %d: rwin %d elen %d 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);
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* This is called when a packet of type CHANNEL_DATA has just been received.
|
|
* The message type has already been consumed, but channel number and data is
|
|
* still there.
|
|
*/
|
|
|
|
void
|
|
channel_input_data(int type, int plen, void *ctxt)
|
|
{
|
|
int id;
|
|
char *data;
|
|
u_int data_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);
|
|
|
|
/* Ignore any data for non-open channels (might happen on close) */
|
|
if (c->type != SSH_CHANNEL_OPEN &&
|
|
c->type != SSH_CHANNEL_X11_OPEN)
|
|
return;
|
|
|
|
/* same for protocol 1.5 if output end is no longer open */
|
|
if (!compat13 && c->ostate != CHAN_OUTPUT_OPEN)
|
|
return;
|
|
|
|
/* Get the data. */
|
|
data = packet_get_string(&data_len);
|
|
packet_done();
|
|
|
|
if (compat20){
|
|
if (data_len > c->local_maxpacket) {
|
|
log("channel %d: rcvd big packet %d, maxpack %d",
|
|
c->self, data_len, c->local_maxpacket);
|
|
}
|
|
if (data_len > c->local_window) {
|
|
log("channel %d: rcvd too much data %d, win %d",
|
|
c->self, data_len, c->local_window);
|
|
xfree(data);
|
|
return;
|
|
}
|
|
c->local_window -= data_len;
|
|
}else{
|
|
packet_integrity_check(plen, 4 + 4 + data_len, type);
|
|
}
|
|
buffer_append(&c->output, data, data_len);
|
|
xfree(data);
|
|
}
|
|
void
|
|
channel_input_extended_data(int type, int plen, void *ctxt)
|
|
{
|
|
int id;
|
|
int tcode;
|
|
char *data;
|
|
u_int data_len;
|
|
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 (c->type != SSH_CHANNEL_OPEN) {
|
|
log("channel %d: ext data for non open", id);
|
|
return;
|
|
}
|
|
tcode = packet_get_int();
|
|
if (c->efd == -1 ||
|
|
c->extended_usage != CHAN_EXTENDED_WRITE ||
|
|
tcode != SSH2_EXTENDED_DATA_STDERR) {
|
|
log("channel %d: bad ext data", c->self);
|
|
return;
|
|
}
|
|
data = packet_get_string(&data_len);
|
|
packet_done();
|
|
if (data_len > c->local_window) {
|
|
log("channel %d: rcvd too much extended_data %d, win %d",
|
|
c->self, data_len, c->local_window);
|
|
xfree(data);
|
|
return;
|
|
}
|
|
debug2("channel %d: rcvd ext data %d", c->self, data_len);
|
|
c->local_window -= data_len;
|
|
buffer_append(&c->extended, data, data_len);
|
|
xfree(data);
|
|
}
|
|
|
|
|
|
/*
|
|
* 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()
|
|
{
|
|
u_int i;
|
|
Channel *c;
|
|
|
|
for (i = 0; i < channels_alloc; i++) {
|
|
c = &channels[i];
|
|
if (c->type == SSH_CHANNEL_OPEN) {
|
|
if (!compat20 && buffer_len(&c->input) > packet_get_maxsize()) {
|
|
debug("channel %d: big input buffer %d",
|
|
c->self, buffer_len(&c->input));
|
|
return 0;
|
|
}
|
|
if (buffer_len(&c->output) > packet_get_maxsize()) {
|
|
debug("channel %d: big output buffer %d",
|
|
c->self, buffer_len(&c->output));
|
|
return 0;
|
|
}
|
|
}
|
|
}
|
|
return 1;
|
|
}
|
|
|
|
void
|
|
channel_input_ieof(int type, int plen, void *ctxt)
|
|
{
|
|
int id;
|
|
Channel *c;
|
|
|
|
packet_integrity_check(plen, 4, type);
|
|
|
|
id = packet_get_int();
|
|
c = channel_lookup(id);
|
|
if (c == NULL)
|
|
packet_disconnect("Received ieof for nonexistent channel %d.", id);
|
|
chan_rcvd_ieof(c);
|
|
}
|
|
|
|
void
|
|
channel_input_close(int type, int plen, void *ctxt)
|
|
{
|
|
int id;
|
|
Channel *c;
|
|
|
|
packet_integrity_check(plen, 4, type);
|
|
|
|
id = packet_get_int();
|
|
c = channel_lookup(id);
|
|
if (c == NULL)
|
|
packet_disconnect("Received close for nonexistent channel %d.", id);
|
|
|
|
/*
|
|
* 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_consume(&c->input, buffer_len(&c->input));
|
|
c->type = SSH_CHANNEL_OUTPUT_DRAINING;
|
|
}
|
|
}
|
|
|
|
/* proto version 1.5 overloads CLOSE_CONFIRMATION with OCLOSE */
|
|
void
|
|
channel_input_oclose(int type, int plen, void *ctxt)
|
|
{
|
|
int id = packet_get_int();
|
|
Channel *c = channel_lookup(id);
|
|
packet_integrity_check(plen, 4, type);
|
|
if (c == NULL)
|
|
packet_disconnect("Received oclose for nonexistent channel %d.", id);
|
|
chan_rcvd_oclose(c);
|
|
}
|
|
|
|
void
|
|
channel_input_close_confirmation(int type, int plen, void *ctxt)
|
|
{
|
|
int id = packet_get_int();
|
|
Channel *c = channel_lookup(id);
|
|
|
|
packet_done();
|
|
if (c == NULL)
|
|
packet_disconnect("Received close confirmation for "
|
|
"out-of-range channel %d.", id);
|
|
if (c->type != SSH_CHANNEL_CLOSED)
|
|
packet_disconnect("Received close confirmation for "
|
|
"non-closed channel %d (type %d).", id, c->type);
|
|
channel_free(c->self);
|
|
}
|
|
|
|
void
|
|
channel_input_open_confirmation(int type, int plen, void *ctxt)
|
|
{
|
|
int id, remote_id;
|
|
Channel *c;
|
|
|
|
if (!compat20)
|
|
packet_integrity_check(plen, 4 + 4, type);
|
|
|
|
id = packet_get_int();
|
|
c = channel_lookup(id);
|
|
|
|
if (c==NULL || 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();
|
|
packet_done();
|
|
if (c->cb_fn != NULL && c->cb_event == type) {
|
|
debug2("callback start");
|
|
c->cb_fn(c->self, c->cb_arg);
|
|
debug2("callback done");
|
|
}
|
|
debug("channel %d: open confirm rwindow %d rmax %d", c->self,
|
|
c->remote_window, c->remote_maxpacket);
|
|
}
|
|
}
|
|
|
|
void
|
|
channel_input_open_failure(int type, int plen, void *ctxt)
|
|
{
|
|
int id, reason;
|
|
char *msg = NULL, *lang = NULL;
|
|
Channel *c;
|
|
|
|
if (!compat20)
|
|
packet_integrity_check(plen, 4, type);
|
|
|
|
id = packet_get_int();
|
|
c = channel_lookup(id);
|
|
|
|
if (c==NULL || c->type != SSH_CHANNEL_OPENING)
|
|
packet_disconnect("Received open failure for "
|
|
"non-opening channel %d.", id);
|
|
if (compat20) {
|
|
reason = packet_get_int();
|
|
if (packet_remaining() > 0) {
|
|
msg = packet_get_string(NULL);
|
|
lang = packet_get_string(NULL);
|
|
}
|
|
packet_done();
|
|
log("channel_open_failure: %d: reason %d %s", id,
|
|
reason, msg ? msg : "<no additional info>");
|
|
if (msg != NULL)
|
|
xfree(msg);
|
|
if (lang != NULL)
|
|
xfree(lang);
|
|
}
|
|
/* Free the channel. This will also close the socket. */
|
|
channel_free(id);
|
|
}
|
|
|
|
void
|
|
channel_input_channel_request(int type, int plen, void *ctxt)
|
|
{
|
|
int id;
|
|
Channel *c;
|
|
|
|
id = packet_get_int();
|
|
c = channel_lookup(id);
|
|
|
|
if (c == NULL ||
|
|
(c->type != SSH_CHANNEL_OPEN && c->type != SSH_CHANNEL_LARVAL))
|
|
packet_disconnect("Received request for "
|
|
"non-open channel %d.", id);
|
|
if (c->cb_fn != NULL && c->cb_event == type) {
|
|
debug2("callback start");
|
|
c->cb_fn(c->self, c->cb_arg);
|
|
debug2("callback done");
|
|
} else {
|
|
char *service = packet_get_string(NULL);
|
|
debug("channel %d: rcvd request for %s", c->self, service);
|
|
debug("cb_fn %p cb_event %d", c->cb_fn , c->cb_event);
|
|
xfree(service);
|
|
}
|
|
}
|
|
|
|
void
|
|
channel_input_window_adjust(int type, int plen, void *ctxt)
|
|
{
|
|
Channel *c;
|
|
int id, adjust;
|
|
|
|
if (!compat20)
|
|
return;
|
|
|
|
/* Get the channel number and verify it. */
|
|
id = packet_get_int();
|
|
c = channel_lookup(id);
|
|
|
|
if (c == NULL || c->type != SSH_CHANNEL_OPEN) {
|
|
log("Received window adjust for "
|
|
"non-open channel %d.", id);
|
|
return;
|
|
}
|
|
adjust = packet_get_int();
|
|
packet_done();
|
|
debug2("channel %d: rcvd adjust %d", id, adjust);
|
|
c->remote_window += adjust;
|
|
}
|
|
|
|
/*
|
|
* Stops listening for channels, and removes any unix domain sockets that we
|
|
* might have.
|
|
*/
|
|
|
|
void
|
|
channel_stop_listening()
|
|
{
|
|
int i;
|
|
for (i = 0; i < channels_alloc; i++) {
|
|
switch (channels[i].type) {
|
|
case SSH_CHANNEL_AUTH_SOCKET:
|
|
close(channels[i].sock);
|
|
unlink(channels[i].path);
|
|
channel_free(i);
|
|
break;
|
|
case SSH_CHANNEL_PORT_LISTENER:
|
|
case SSH_CHANNEL_RPORT_LISTENER:
|
|
case SSH_CHANNEL_X11_LISTENER:
|
|
close(channels[i].sock);
|
|
channel_free(i);
|
|
break;
|
|
default:
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Closes the sockets/fds of all channels. This is used to close extra file
|
|
* descriptors after a fork.
|
|
*/
|
|
|
|
void
|
|
channel_close_all()
|
|
{
|
|
int i;
|
|
for (i = 0; i < channels_alloc; i++)
|
|
if (channels[i].type != SSH_CHANNEL_FREE)
|
|
channel_close_fds(&channels[i]);
|
|
}
|
|
|
|
/* Returns true if any channel is still open. */
|
|
|
|
int
|
|
channel_still_open()
|
|
{
|
|
u_int i;
|
|
for (i = 0; i < channels_alloc; i++)
|
|
switch (channels[i].type) {
|
|
case SSH_CHANNEL_FREE:
|
|
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_DYNAMIC:
|
|
case SSH_CHANNEL_CONNECTING: /* XXX ??? */
|
|
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:
|
|
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", channels[i].type);
|
|
/* NOTREACHED */
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/* Returns the id of an open channel suitable for keepaliving */
|
|
|
|
int
|
|
channel_find_open()
|
|
{
|
|
u_int i;
|
|
for (i = 0; i < channels_alloc; i++)
|
|
switch (channels[i].type) {
|
|
case SSH_CHANNEL_CLOSED:
|
|
case SSH_CHANNEL_DYNAMIC:
|
|
case SSH_CHANNEL_FREE:
|
|
case SSH_CHANNEL_X11_LISTENER:
|
|
case SSH_CHANNEL_PORT_LISTENER:
|
|
case SSH_CHANNEL_RPORT_LISTENER:
|
|
case SSH_CHANNEL_OPENING:
|
|
continue;
|
|
case SSH_CHANNEL_LARVAL:
|
|
case SSH_CHANNEL_AUTH_SOCKET:
|
|
case SSH_CHANNEL_CONNECTING: /* XXX ??? */
|
|
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", channels[i].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()
|
|
{
|
|
Buffer buffer;
|
|
int i;
|
|
char buf[512], *cp;
|
|
|
|
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++) {
|
|
Channel *c = &channels[i];
|
|
switch (c->type) {
|
|
case SSH_CHANNEL_FREE:
|
|
case SSH_CHANNEL_X11_LISTENER:
|
|
case SSH_CHANNEL_PORT_LISTENER:
|
|
case SSH_CHANNEL_RPORT_LISTENER:
|
|
case SSH_CHANNEL_CLOSED:
|
|
case SSH_CHANNEL_AUTH_SOCKET:
|
|
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:
|
|
snprintf(buf, sizeof buf, " #%d %.300s (t%d r%d i%d/%d o%d/%d fd %d/%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);
|
|
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(buffer_ptr(&buffer));
|
|
buffer_free(&buffer);
|
|
return cp;
|
|
}
|
|
|
|
/*
|
|
* Initiate forwarding of connections to local port "port" through the secure
|
|
* channel to host:port from remote side.
|
|
*/
|
|
int
|
|
channel_request_local_forwarding(u_short listen_port, const char *host_to_connect,
|
|
u_short port_to_connect, int gateway_ports)
|
|
{
|
|
return channel_request_forwarding(
|
|
NULL, listen_port,
|
|
host_to_connect, port_to_connect,
|
|
gateway_ports, /*remote_fwd*/ 0);
|
|
}
|
|
|
|
/*
|
|
* If 'remote_fwd' is true we have a '-R style' listener for protocol 2
|
|
* (SSH_CHANNEL_RPORT_LISTENER).
|
|
*/
|
|
int
|
|
channel_request_forwarding(
|
|
const char *listen_address, u_short listen_port,
|
|
const char *host_to_connect, u_short port_to_connect,
|
|
int gateway_ports, int remote_fwd)
|
|
{
|
|
int success, ch, sock, on = 1, ctype;
|
|
struct addrinfo hints, *ai, *aitop;
|
|
char ntop[NI_MAXHOST], strport[NI_MAXSERV];
|
|
const char *host;
|
|
struct linger linger;
|
|
|
|
success = 0;
|
|
|
|
if (remote_fwd) {
|
|
host = listen_address;
|
|
ctype = SSH_CHANNEL_RPORT_LISTENER;
|
|
} else {
|
|
host = host_to_connect;
|
|
ctype =SSH_CHANNEL_PORT_LISTENER;
|
|
}
|
|
|
|
if (strlen(host) > sizeof(channels[0].path) - 1) {
|
|
error("Forward host name too long.");
|
|
return success;
|
|
}
|
|
|
|
/* XXX listen_address is currently ignored */
|
|
/*
|
|
* 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 = gateway_ports ? AI_PASSIVE : 0;
|
|
hints.ai_socktype = SOCK_STREAM;
|
|
snprintf(strport, sizeof strport, "%d", listen_port);
|
|
if (getaddrinfo(NULL, strport, &hints, &aitop) != 0)
|
|
packet_disconnect("getaddrinfo: fatal error");
|
|
|
|
for (ai = aitop; ai; ai = ai->ai_next) {
|
|
if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
|
|
continue;
|
|
if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
|
|
strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
|
|
error("channel_request_forwarding: getnameinfo failed");
|
|
continue;
|
|
}
|
|
/* Create a port to listen for the host. */
|
|
sock = socket(ai->ai_family, SOCK_STREAM, 0);
|
|
if (sock < 0) {
|
|
/* this is no error since kernel may not support ipv6 */
|
|
verbose("socket: %.100s", strerror(errno));
|
|
continue;
|
|
}
|
|
/*
|
|
* Set socket options. We would like the socket to disappear
|
|
* as soon as it has been closed for whatever reason.
|
|
*/
|
|
setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, (void *)&on, sizeof(on));
|
|
linger.l_onoff = 1;
|
|
linger.l_linger = 5;
|
|
setsockopt(sock, SOL_SOCKET, SO_LINGER, (void *)&linger, sizeof(linger));
|
|
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, 5) < 0) {
|
|
error("listen: %.100s", strerror(errno));
|
|
close(sock);
|
|
continue;
|
|
}
|
|
/* Allocate a channel number for the socket. */
|
|
ch = channel_new("port listener", ctype, sock, sock, -1,
|
|
CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
|
|
0, xstrdup("port listener"), 1);
|
|
strlcpy(channels[ch].path, host, sizeof(channels[ch].path));
|
|
channels[ch].host_port = port_to_connect;
|
|
channels[ch].listening_port = listen_port;
|
|
success = 1;
|
|
}
|
|
if (success == 0)
|
|
error("channel_request_forwarding: cannot listen to port: %d",
|
|
listen_port);
|
|
freeaddrinfo(aitop);
|
|
return success;
|
|
}
|
|
|
|
/*
|
|
* Initiate forwarding of connections to port "port" on remote host through
|
|
* the secure channel to host:port from local side.
|
|
*/
|
|
|
|
void
|
|
channel_request_remote_forwarding(u_short listen_port,
|
|
const char *host_to_connect, u_short port_to_connect)
|
|
{
|
|
int payload_len, type, success = 0;
|
|
|
|
/* Record locally that connection to this host/port is permitted. */
|
|
if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)
|
|
fatal("channel_request_remote_forwarding: too many forwards");
|
|
|
|
/* Send the forward request to the remote side. */
|
|
if (compat20) {
|
|
const char *address_to_bind = "0.0.0.0";
|
|
packet_start(SSH2_MSG_GLOBAL_REQUEST);
|
|
packet_put_cstring("tcpip-forward");
|
|
packet_put_char(0); /* boolean: want reply */
|
|
packet_put_cstring(address_to_bind);
|
|
packet_put_int(listen_port);
|
|
packet_send();
|
|
packet_write_wait();
|
|
/* Assume that server accepts the request */
|
|
success = 1;
|
|
} else {
|
|
packet_start(SSH_CMSG_PORT_FORWARD_REQUEST);
|
|
packet_put_int(listen_port);
|
|
packet_put_cstring(host_to_connect);
|
|
packet_put_int(port_to_connect);
|
|
packet_send();
|
|
packet_write_wait();
|
|
|
|
/* Wait for response from the remote side. */
|
|
type = packet_read(&payload_len);
|
|
switch (type) {
|
|
case SSH_SMSG_SUCCESS:
|
|
success = 1;
|
|
break;
|
|
case SSH_SMSG_FAILURE:
|
|
log("Warning: Server denied remote port forwarding.");
|
|
break;
|
|
default:
|
|
/* Unknown packet */
|
|
packet_disconnect("Protocol error for port forward request:"
|
|
"received packet type %d.", type);
|
|
}
|
|
}
|
|
if (success) {
|
|
permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host_to_connect);
|
|
permitted_opens[num_permitted_opens].port_to_connect = port_to_connect;
|
|
permitted_opens[num_permitted_opens].listen_port = listen_port;
|
|
num_permitted_opens++;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* 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). This never returns if there was an error.
|
|
*/
|
|
|
|
void
|
|
channel_input_port_forward_request(int is_root, int gateway_ports)
|
|
{
|
|
u_short port, host_port;
|
|
char *hostname;
|
|
|
|
/* Get arguments from the packet. */
|
|
port = packet_get_int();
|
|
hostname = packet_get_string(NULL);
|
|
host_port = packet_get_int();
|
|
|
|
#ifndef HAVE_CYGWIN
|
|
/*
|
|
* Check that an unprivileged user is not trying to forward a
|
|
* privileged port.
|
|
*/
|
|
if (port < IPPORT_RESERVED && !is_root)
|
|
packet_disconnect("Requested forwarding of port %d but user is not root.",
|
|
port);
|
|
#endif
|
|
/* Initiate forwarding */
|
|
channel_request_local_forwarding(port, hostname, host_port, gateway_ports);
|
|
|
|
/* Free the argument string. */
|
|
xfree(hostname);
|
|
}
|
|
|
|
/*
|
|
* 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()
|
|
{
|
|
if (num_permitted_opens == 0)
|
|
all_opens_permitted = 1;
|
|
}
|
|
|
|
void
|
|
channel_add_permitted_opens(char *host, int port)
|
|
{
|
|
if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)
|
|
fatal("channel_request_remote_forwarding: too many forwards");
|
|
debug("allow port forwarding to host %s port %d", host, port);
|
|
|
|
permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host);
|
|
permitted_opens[num_permitted_opens].port_to_connect = port;
|
|
num_permitted_opens++;
|
|
|
|
all_opens_permitted = 0;
|
|
}
|
|
|
|
void
|
|
channel_clear_permitted_opens(void)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < num_permitted_opens; i++)
|
|
xfree(permitted_opens[i].host_to_connect);
|
|
num_permitted_opens = 0;
|
|
|
|
}
|
|
|
|
|
|
/* return socket to remote host, port */
|
|
int
|
|
connect_to(const char *host, u_short port)
|
|
{
|
|
struct addrinfo hints, *ai, *aitop;
|
|
char ntop[NI_MAXHOST], strport[NI_MAXSERV];
|
|
int gaierr;
|
|
int sock = -1;
|
|
|
|
memset(&hints, 0, sizeof(hints));
|
|
hints.ai_family = IPv4or6;
|
|
hints.ai_socktype = SOCK_STREAM;
|
|
snprintf(strport, sizeof strport, "%d", port);
|
|
if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0) {
|
|
error("connect_to %.100s: unknown host (%s)", host,
|
|
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;
|
|
if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
|
|
strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
|
|
error("connect_to: getnameinfo failed");
|
|
continue;
|
|
}
|
|
sock = socket(ai->ai_family, SOCK_STREAM, 0);
|
|
if (sock < 0) {
|
|
error("socket: %.100s", strerror(errno));
|
|
continue;
|
|
}
|
|
if (fcntl(sock, F_SETFL, O_NONBLOCK) < 0)
|
|
fatal("connect_to: F_SETFL: %s", strerror(errno));
|
|
if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0 &&
|
|
errno != EINPROGRESS) {
|
|
error("connect_to %.100s port %s: %.100s", ntop, strport,
|
|
strerror(errno));
|
|
close(sock);
|
|
continue; /* fail -- try next */
|
|
}
|
|
break; /* success */
|
|
|
|
}
|
|
freeaddrinfo(aitop);
|
|
if (!ai) {
|
|
error("connect_to %.100s port %d: failed.", host, port);
|
|
return -1;
|
|
}
|
|
/* success */
|
|
return sock;
|
|
}
|
|
|
|
int
|
|
channel_connect_by_listen_adress(u_short listen_port)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < num_permitted_opens; i++)
|
|
if (permitted_opens[i].listen_port == listen_port)
|
|
return connect_to(
|
|
permitted_opens[i].host_to_connect,
|
|
permitted_opens[i].port_to_connect);
|
|
error("WARNING: Server requests forwarding for unknown listen_port %d",
|
|
listen_port);
|
|
return -1;
|
|
}
|
|
|
|
/* Check if connecting to that port is permitted and connect. */
|
|
int
|
|
channel_connect_to(const char *host, u_short port)
|
|
{
|
|
int i, permit;
|
|
|
|
permit = all_opens_permitted;
|
|
if (!permit) {
|
|
for (i = 0; i < num_permitted_opens; i++)
|
|
if (permitted_opens[i].port_to_connect == port &&
|
|
strcmp(permitted_opens[i].host_to_connect, host) == 0)
|
|
permit = 1;
|
|
|
|
}
|
|
if (!permit) {
|
|
log("Received request to connect to host %.100s port %d, "
|
|
"but the request was denied.", host, port);
|
|
return -1;
|
|
}
|
|
return connect_to(host, port);
|
|
}
|
|
|
|
/*
|
|
* This is called after receiving PORT_OPEN message. This attempts to
|
|
* connect to the given host:port, and sends back CHANNEL_OPEN_CONFIRMATION
|
|
* or CHANNEL_OPEN_FAILURE.
|
|
*/
|
|
|
|
void
|
|
channel_input_port_open(int type, int plen, void *ctxt)
|
|
{
|
|
u_short host_port;
|
|
char *host, *originator_string;
|
|
int remote_channel, sock = -1, newch;
|
|
|
|
remote_channel = packet_get_int();
|
|
host = packet_get_string(NULL);
|
|
host_port = packet_get_int();
|
|
|
|
if (have_hostname_in_open) {
|
|
originator_string = packet_get_string(NULL);
|
|
} else {
|
|
originator_string = xstrdup("unknown (remote did not supply name)");
|
|
}
|
|
packet_done();
|
|
sock = channel_connect_to(host, host_port);
|
|
if (sock != -1) {
|
|
newch = channel_allocate(SSH_CHANNEL_CONNECTING,
|
|
sock, originator_string);
|
|
channels[newch].remote_id = remote_channel;
|
|
|
|
/*XXX delay answer? */
|
|
packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
|
|
packet_put_int(remote_channel);
|
|
packet_put_int(newch);
|
|
packet_send();
|
|
} else {
|
|
packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
|
|
packet_put_int(remote_channel);
|
|
packet_send();
|
|
}
|
|
xfree(host);
|
|
}
|
|
|
|
/*
|
|
* Creates an internet domain socket for listening for X11 connections.
|
|
* Returns a suitable value for the DISPLAY variable, or NULL if an error
|
|
* occurs.
|
|
*/
|
|
|
|
#define NUM_SOCKS 10
|
|
|
|
char *
|
|
x11_create_display_inet(int screen_number, int x11_display_offset)
|
|
{
|
|
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];
|
|
char display[512];
|
|
char hostname[MAXHOSTNAMELEN];
|
|
|
|
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 = AI_PASSIVE; /* XXX loopback only ? */
|
|
hints.ai_socktype = SOCK_STREAM;
|
|
snprintf(strport, sizeof strport, "%d", port);
|
|
if ((gaierr = getaddrinfo(NULL, strport, &hints, &aitop)) != 0) {
|
|
error("getaddrinfo: %.100s", gai_strerror(gaierr));
|
|
return NULL;
|
|
}
|
|
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, SOCK_STREAM, 0);
|
|
if (sock < 0) {
|
|
if ((errno != EINVAL) && (errno != EAFNOSUPPORT)) {
|
|
error("socket: %.100s", strerror(errno));
|
|
return NULL;
|
|
} else {
|
|
debug("x11_create_display_inet: Socket family %d not supported",
|
|
ai->ai_family);
|
|
continue;
|
|
}
|
|
}
|
|
if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
|
|
debug("bind port %d: %.100s", port, strerror(errno));
|
|
shutdown(sock, SHUT_RDWR);
|
|
close(sock);
|
|
|
|
if (ai->ai_next)
|
|
continue;
|
|
|
|
for (n = 0; n < num_socks; n++) {
|
|
shutdown(socks[n], SHUT_RDWR);
|
|
close(socks[n]);
|
|
}
|
|
num_socks = 0;
|
|
break;
|
|
}
|
|
socks[num_socks++] = sock;
|
|
#ifndef DONT_TRY_OTHER_AF
|
|
if (num_socks == NUM_SOCKS)
|
|
break;
|
|
#else
|
|
break;
|
|
#endif
|
|
}
|
|
freeaddrinfo(aitop);
|
|
if (num_socks > 0)
|
|
break;
|
|
}
|
|
if (display_number >= MAX_DISPLAYS) {
|
|
error("Failed to allocate internet-domain X11 display socket.");
|
|
return NULL;
|
|
}
|
|
/* Start listening for connections on the socket. */
|
|
for (n = 0; n < num_socks; n++) {
|
|
sock = socks[n];
|
|
if (listen(sock, 5) < 0) {
|
|
error("listen: %.100s", strerror(errno));
|
|
shutdown(sock, SHUT_RDWR);
|
|
close(sock);
|
|
return NULL;
|
|
}
|
|
}
|
|
|
|
/* Set up a suitable value for the DISPLAY variable. */
|
|
if (gethostname(hostname, sizeof(hostname)) < 0)
|
|
fatal("gethostname: %.100s", strerror(errno));
|
|
|
|
#ifdef IPADDR_IN_DISPLAY
|
|
/*
|
|
* HPUX detects the local hostname in the DISPLAY variable and tries
|
|
* to set up a shared memory connection to the server, which it
|
|
* incorrectly supposes to be local.
|
|
*
|
|
* The workaround - as used in later $$H and other programs - is
|
|
* is to set display to the host's IP address.
|
|
*/
|
|
{
|
|
struct hostent *he;
|
|
struct in_addr my_addr;
|
|
|
|
he = gethostbyname(hostname);
|
|
if (he == NULL) {
|
|
error("[X11-broken-fwd-hostname-workaround] Could not get "
|
|
"IP address for hostname %s.", hostname);
|
|
|
|
packet_send_debug("[X11-broken-fwd-hostname-workaround]"
|
|
"Could not get IP address for hostname %s.", hostname);
|
|
|
|
shutdown(sock, SHUT_RDWR);
|
|
close(sock);
|
|
|
|
return NULL;
|
|
}
|
|
|
|
memcpy(&my_addr, he->h_addr_list[0], sizeof(struct in_addr));
|
|
|
|
/* Set DISPLAY to <ip address>:screen.display */
|
|
snprintf(display, sizeof(display), "%.50s:%d.%d", inet_ntoa(my_addr),
|
|
display_number, screen_number);
|
|
}
|
|
#else /* IPADDR_IN_DISPLAY */
|
|
/* Just set DISPLAY to hostname:screen.display */
|
|
snprintf(display, sizeof display, "%.400s:%d.%d", hostname,
|
|
display_number, screen_number);
|
|
#endif /* IPADDR_IN_DISPLAY */
|
|
|
|
/* Allocate a channel for each socket. */
|
|
for (n = 0; n < num_socks; n++) {
|
|
sock = socks[n];
|
|
(void) channel_new("x11 listener",
|
|
SSH_CHANNEL_X11_LISTENER, sock, sock, -1,
|
|
CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
|
|
0, xstrdup("X11 inet listener"), 1);
|
|
}
|
|
|
|
/* Return a suitable value for the DISPLAY environment variable. */
|
|
return xstrdup(display);
|
|
}
|
|
|
|
#ifndef X_UNIX_PATH
|
|
#define X_UNIX_PATH "/tmp/.X11-unix/X"
|
|
#endif
|
|
|
|
static
|
|
int
|
|
connect_local_xsocket(u_int dnr)
|
|
{
|
|
static const char *const x_sockets[] = {
|
|
X_UNIX_PATH "%u",
|
|
"/var/X/.X11-unix/X" "%u",
|
|
"/usr/spool/sockets/X11/" "%u",
|
|
NULL
|
|
};
|
|
int sock;
|
|
struct sockaddr_un addr;
|
|
const char *const * path;
|
|
|
|
for (path = x_sockets; *path; ++path) {
|
|
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;
|
|
snprintf(addr.sun_path, sizeof addr.sun_path, *path, dnr);
|
|
if (connect(sock, (struct sockaddr *) & addr, sizeof(addr)) == 0)
|
|
return sock;
|
|
close(sock);
|
|
}
|
|
error("connect %.100s: %.100s", addr.sun_path, strerror(errno));
|
|
return -1;
|
|
}
|
|
|
|
int
|
|
x11_connect_display(void)
|
|
{
|
|
int display_number, sock = 0;
|
|
const char *display;
|
|
char buf[1024], *cp;
|
|
struct addrinfo hints, *ai, *aitop;
|
|
char strport[NI_MAXSERV];
|
|
int gaierr;
|
|
|
|
/* 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 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, "%d", &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.
|
|
*/
|
|
strncpy(buf, display, sizeof(buf));
|
|
buf[sizeof(buf) - 1] = 0;
|
|
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, "%d", &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, "%d", 6000 + display_number);
|
|
if ((gaierr = getaddrinfo(buf, strport, &hints, &aitop)) != 0) {
|
|
error("%.100s: unknown host. (%s)", buf, gai_strerror(gaierr));
|
|
return -1;
|
|
}
|
|
for (ai = aitop; ai; ai = ai->ai_next) {
|
|
/* Create a socket. */
|
|
sock = socket(ai->ai_family, SOCK_STREAM, 0);
|
|
if (sock < 0) {
|
|
debug("socket: %.100s", strerror(errno));
|
|
continue;
|
|
}
|
|
/* Connect it to the display. */
|
|
if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
|
|
debug("connect %.100s port %d: %.100s", buf,
|
|
6000 + display_number, strerror(errno));
|
|
close(sock);
|
|
continue;
|
|
}
|
|
/* Success */
|
|
break;
|
|
}
|
|
freeaddrinfo(aitop);
|
|
if (!ai) {
|
|
error("connect %.100s port %d: %.100s", buf, 6000 + display_number,
|
|
strerror(errno));
|
|
return -1;
|
|
}
|
|
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.
|
|
*/
|
|
|
|
void
|
|
x11_input_open(int type, int plen, void *ctxt)
|
|
{
|
|
int remote_channel, sock = 0, newch;
|
|
char *remote_host;
|
|
u_int remote_len;
|
|
|
|
/* Get remote channel number. */
|
|
remote_channel = packet_get_int();
|
|
|
|
/* Get remote originator name. */
|
|
if (have_hostname_in_open) {
|
|
remote_host = packet_get_string(&remote_len);
|
|
remote_len += 4;
|
|
} else {
|
|
remote_host = xstrdup("unknown (remote did not supply name)");
|
|
remote_len = 0;
|
|
}
|
|
|
|
debug("Received X11 open request.");
|
|
packet_integrity_check(plen, 4 + remote_len, SSH_SMSG_X11_OPEN);
|
|
|
|
/* Obtain a connection to the real X display. */
|
|
sock = x11_connect_display();
|
|
if (sock == -1) {
|
|
/* Send refusal to the remote host. */
|
|
packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
|
|
packet_put_int(remote_channel);
|
|
packet_send();
|
|
} else {
|
|
/* Allocate a channel for this connection. */
|
|
newch = channel_allocate(
|
|
(x11_saved_proto == NULL) ?
|
|
SSH_CHANNEL_OPEN : SSH_CHANNEL_X11_OPEN,
|
|
sock, remote_host);
|
|
channels[newch].remote_id = remote_channel;
|
|
|
|
/* Send a confirmation to the remote host. */
|
|
packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
|
|
packet_put_int(remote_channel);
|
|
packet_put_int(newch);
|
|
packet_send();
|
|
}
|
|
}
|
|
|
|
/* dummy protocol handler that denies SSH-1 requests (agent/x11) */
|
|
void
|
|
deny_input_open(int type, int plen, 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 plen %d", type, plen);
|
|
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();
|
|
}
|
|
|
|
/*
|
|
* Requests forwarding of X11 connections, generates fake authentication
|
|
* data, and enables authentication spoofing.
|
|
*/
|
|
|
|
void
|
|
x11_request_forwarding_with_spoofing(int client_session_id,
|
|
const char *proto, const char *data)
|
|
{
|
|
u_int data_len = (u_int) strlen(data) / 2;
|
|
u_int i, value, len;
|
|
char *new_data;
|
|
int screen_number;
|
|
const char *cp;
|
|
u_int32_t rand = 0;
|
|
|
|
cp = getenv("DISPLAY");
|
|
if (cp)
|
|
cp = strchr(cp, ':');
|
|
if (cp)
|
|
cp = strchr(cp, '.');
|
|
if (cp)
|
|
screen_number = atoi(cp + 1);
|
|
else
|
|
screen_number = 0;
|
|
|
|
/* Save protocol name. */
|
|
x11_saved_proto = xstrdup(proto);
|
|
|
|
/*
|
|
* Extract real authentication data and generate fake data of the
|
|
* same length.
|
|
*/
|
|
x11_saved_data = xmalloc(data_len);
|
|
x11_fake_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);
|
|
if (i % 4 == 0)
|
|
rand = arc4random();
|
|
x11_saved_data[i] = value;
|
|
x11_fake_data[i] = rand & 0xff;
|
|
rand >>= 8;
|
|
}
|
|
x11_saved_data_len = data_len;
|
|
x11_fake_data_len = data_len;
|
|
|
|
/* Convert the fake data into hex. */
|
|
len = 2 * data_len + 1;
|
|
new_data = xmalloc(len);
|
|
for (i = 0; i < data_len; i++)
|
|
snprintf(new_data + 2 * i, len - 2 * i,
|
|
"%02x", (u_char) x11_fake_data[i]);
|
|
|
|
/* Send the request packet. */
|
|
if (compat20) {
|
|
channel_request_start(client_session_id, "x11-req", 0);
|
|
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();
|
|
xfree(new_data);
|
|
}
|
|
|
|
/* Sends a message to the server to request authentication fd forwarding. */
|
|
|
|
void
|
|
auth_request_forwarding()
|
|
{
|
|
packet_start(SSH_CMSG_AGENT_REQUEST_FORWARDING);
|
|
packet_send();
|
|
packet_write_wait();
|
|
}
|
|
|
|
/*
|
|
* Returns the name of the forwarded authentication socket. Returns NULL if
|
|
* there is no forwarded authentication socket. The returned value points to
|
|
* a static buffer.
|
|
*/
|
|
|
|
char *
|
|
auth_get_socket_name()
|
|
{
|
|
return channel_forwarded_auth_socket_name;
|
|
}
|
|
|
|
/* removes the agent forwarding socket */
|
|
|
|
void
|
|
cleanup_socket(void)
|
|
{
|
|
unlink(channel_forwarded_auth_socket_name);
|
|
rmdir(channel_forwarded_auth_socket_dir);
|
|
}
|
|
|
|
/*
|
|
* This is called to process SSH_CMSG_AGENT_REQUEST_FORWARDING on the server.
|
|
* This starts forwarding authentication requests.
|
|
*/
|
|
|
|
int
|
|
auth_input_request_forwarding(struct passwd * pw)
|
|
{
|
|
int sock, newch;
|
|
struct sockaddr_un sunaddr;
|
|
|
|
if (auth_get_socket_name() != NULL)
|
|
fatal("Protocol error: authentication forwarding requested twice.");
|
|
|
|
/* Temporarily drop privileged uid for mkdir/bind. */
|
|
temporarily_use_uid(pw);
|
|
|
|
/* Allocate a buffer for the socket name, and format the name. */
|
|
channel_forwarded_auth_socket_name = xmalloc(MAX_SOCKET_NAME);
|
|
channel_forwarded_auth_socket_dir = xmalloc(MAX_SOCKET_NAME);
|
|
strlcpy(channel_forwarded_auth_socket_dir, "/tmp/ssh-XXXXXXXX", MAX_SOCKET_NAME);
|
|
|
|
/* Create private directory for socket */
|
|
if (mkdtemp(channel_forwarded_auth_socket_dir) == NULL) {
|
|
packet_send_debug("Agent forwarding disabled: mkdtemp() failed: %.100s",
|
|
strerror(errno));
|
|
restore_uid();
|
|
xfree(channel_forwarded_auth_socket_name);
|
|
xfree(channel_forwarded_auth_socket_dir);
|
|
channel_forwarded_auth_socket_name = NULL;
|
|
channel_forwarded_auth_socket_dir = NULL;
|
|
return 0;
|
|
}
|
|
snprintf(channel_forwarded_auth_socket_name, MAX_SOCKET_NAME, "%s/agent.%d",
|
|
channel_forwarded_auth_socket_dir, (int) getpid());
|
|
|
|
if (atexit(cleanup_socket) < 0) {
|
|
int saved = errno;
|
|
cleanup_socket();
|
|
packet_disconnect("socket: %.100s", strerror(saved));
|
|
}
|
|
/* Create the socket. */
|
|
sock = socket(AF_UNIX, SOCK_STREAM, 0);
|
|
if (sock < 0)
|
|
packet_disconnect("socket: %.100s", strerror(errno));
|
|
|
|
/* Bind it to the name. */
|
|
memset(&sunaddr, 0, sizeof(sunaddr));
|
|
sunaddr.sun_family = AF_UNIX;
|
|
strncpy(sunaddr.sun_path, channel_forwarded_auth_socket_name,
|
|
sizeof(sunaddr.sun_path));
|
|
|
|
if (bind(sock, (struct sockaddr *) & sunaddr, sizeof(sunaddr)) < 0)
|
|
packet_disconnect("bind: %.100s", strerror(errno));
|
|
|
|
/* Restore the privileged uid. */
|
|
restore_uid();
|
|
|
|
/* Start listening on the socket. */
|
|
if (listen(sock, 5) < 0)
|
|
packet_disconnect("listen: %.100s", strerror(errno));
|
|
|
|
/* Allocate a channel for the authentication agent socket. */
|
|
newch = channel_new("auth socket",
|
|
SSH_CHANNEL_AUTH_SOCKET, sock, sock, -1,
|
|
CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
|
|
0, xstrdup("auth socket"), 1);
|
|
|
|
strlcpy(channels[newch].path, channel_forwarded_auth_socket_name,
|
|
sizeof(channels[newch].path));
|
|
return 1;
|
|
}
|
|
|
|
/* This is called to process an SSH_SMSG_AGENT_OPEN message. */
|
|
|
|
void
|
|
auth_input_open_request(int type, int plen, void *ctxt)
|
|
{
|
|
int remch, sock, newch;
|
|
char *dummyname;
|
|
|
|
packet_integrity_check(plen, 4, type);
|
|
|
|
/* Read the remote channel number from the message. */
|
|
remch = packet_get_int();
|
|
|
|
/*
|
|
* Get a connection to the local authentication agent (this may again
|
|
* get forwarded).
|
|
*/
|
|
sock = ssh_get_authentication_socket();
|
|
|
|
/*
|
|
* If we could not connect the agent, send an error message back to
|
|
* the server. This should never happen unless the agent dies,
|
|
* because authentication forwarding is only enabled if we have an
|
|
* agent.
|
|
*/
|
|
if (sock < 0) {
|
|
packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
|
|
packet_put_int(remch);
|
|
packet_send();
|
|
return;
|
|
}
|
|
debug("Forwarding authentication connection.");
|
|
|
|
/*
|
|
* Dummy host name. This will be freed when the channel is freed; it
|
|
* will still be valid in the packet_put_string below since the
|
|
* channel cannot yet be freed at that point.
|
|
*/
|
|
dummyname = xstrdup("authentication agent connection");
|
|
|
|
newch = channel_allocate(SSH_CHANNEL_OPEN, sock, dummyname);
|
|
channels[newch].remote_id = remch;
|
|
|
|
/* Send a confirmation to the remote host. */
|
|
packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
|
|
packet_put_int(remch);
|
|
packet_put_int(newch);
|
|
packet_send();
|
|
}
|
|
|
|
void
|
|
channel_start_open(int id)
|
|
{
|
|
Channel *c = channel_lookup(id);
|
|
if (c == NULL) {
|
|
log("channel_open: %d: bad id", id);
|
|
return;
|
|
}
|
|
debug("send channel open %d", 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);
|
|
}
|
|
void
|
|
channel_open(int id)
|
|
{
|
|
/* XXX REMOVE ME */
|
|
channel_start_open(id);
|
|
packet_send();
|
|
}
|
|
void
|
|
channel_request(int id, char *service, int wantconfirm)
|
|
{
|
|
channel_request_start(id, service, wantconfirm);
|
|
packet_send();
|
|
debug("channel request %d: %s", id, service) ;
|
|
}
|
|
void
|
|
channel_request_start(int id, char *service, int wantconfirm)
|
|
{
|
|
Channel *c = channel_lookup(id);
|
|
if (c == NULL) {
|
|
log("channel_request: %d: bad id", id);
|
|
return;
|
|
}
|
|
packet_start(SSH2_MSG_CHANNEL_REQUEST);
|
|
packet_put_int(c->remote_id);
|
|
packet_put_cstring(service);
|
|
packet_put_char(wantconfirm);
|
|
}
|
|
void
|
|
channel_register_callback(int id, int mtype, channel_callback_fn *fn, void *arg)
|
|
{
|
|
Channel *c = channel_lookup(id);
|
|
if (c == NULL) {
|
|
log("channel_register_callback: %d: bad id", id);
|
|
return;
|
|
}
|
|
c->cb_event = mtype;
|
|
c->cb_fn = fn;
|
|
c->cb_arg = arg;
|
|
}
|
|
void
|
|
channel_register_cleanup(int id, channel_callback_fn *fn)
|
|
{
|
|
Channel *c = channel_lookup(id);
|
|
if (c == NULL) {
|
|
log("channel_register_cleanup: %d: bad id", id);
|
|
return;
|
|
}
|
|
c->dettach_user = fn;
|
|
}
|
|
void
|
|
channel_cancel_cleanup(int id)
|
|
{
|
|
Channel *c = channel_lookup(id);
|
|
if (c == NULL) {
|
|
log("channel_cancel_cleanup: %d: bad id", id);
|
|
return;
|
|
}
|
|
c->dettach_user = NULL;
|
|
}
|
|
void
|
|
channel_register_filter(int id, channel_filter_fn *fn)
|
|
{
|
|
Channel *c = channel_lookup(id);
|
|
if (c == NULL) {
|
|
log("channel_register_filter: %d: bad id", id);
|
|
return;
|
|
}
|
|
c->input_filter = fn;
|
|
}
|
|
|
|
void
|
|
channel_set_fds(int id, int rfd, int wfd, int efd,
|
|
int extusage, int nonblock)
|
|
{
|
|
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);
|
|
c->type = SSH_CHANNEL_OPEN;
|
|
/* XXX window size? */
|
|
c->local_window = c->local_window_max = c->local_maxpacket * 2;
|
|
packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
|
|
packet_put_int(c->remote_id);
|
|
packet_put_int(c->local_window);
|
|
packet_send();
|
|
}
|