diff options
Diffstat (limited to 'crypto/openssh/channels.c')
| -rw-r--r-- | crypto/openssh/channels.c | 3227 |
1 files changed, 0 insertions, 3227 deletions
diff --git a/crypto/openssh/channels.c b/crypto/openssh/channels.c deleted file mode 100644 index 26b63a1..0000000 --- a/crypto/openssh/channels.c +++ /dev/null @@ -1,3227 +0,0 @@ -/* $OpenBSD: channels.c,v 1.266 2006/08/29 10:40:18 djm Exp $ */ -/* - * Author: Tatu Ylonen <ylo@cs.hut.fi> - * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland - * All rights reserved - * This file contains functions for generic socket connection forwarding. - * There is also code for initiating connection forwarding for X11 connections, - * arbitrary tcp/ip connections, and the authentication agent connection. - * - * As far as I am concerned, the code I have written for this software - * can be used freely for any purpose. Any derived versions of this - * software must be clearly marked as such, and if the derived work is - * incompatible with the protocol description in the RFC file, it must be - * called by a name other than "ssh" or "Secure Shell". - * - * SSH2 support added by Markus Friedl. - * Copyright (c) 1999, 2000, 2001, 2002 Markus Friedl. All rights reserved. - * Copyright (c) 1999 Dug Song. All rights reserved. - * Copyright (c) 1999 Theo de Raadt. All rights reserved. - * - * Redistribution and use in source and binary forms, with or without - * modification, are permitted provided that the following conditions - * are met: - * 1. Redistributions of source code must retain the above copyright - * notice, this list of conditions and the following disclaimer. - * 2. Redistributions in binary form must reproduce the above copyright - * notice, this list of conditions and the following disclaimer in the - * documentation and/or other materials provided with the distribution. - * - * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR - * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES - * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. - * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, - * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT - * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, - * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY - * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT - * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF - * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. - */ - -#include "includes.h" - -#include <sys/types.h> -#include <sys/ioctl.h> -#include <sys/un.h> -#include <sys/socket.h> -#ifdef HAVE_SYS_TIME_H -# include <sys/time.h> -#endif - -#include <netinet/in.h> -#include <arpa/inet.h> - -#include <errno.h> -#include <netdb.h> -#include <stdio.h> -#include <stdlib.h> -#include <string.h> -#include <termios.h> -#include <unistd.h> -#include <stdarg.h> - -#include "xmalloc.h" -#include "ssh.h" -#include "ssh1.h" -#include "ssh2.h" -#include "packet.h" -#include "log.h" -#include "misc.h" -#include "buffer.h" -#include "channels.h" -#include "compat.h" -#include "canohost.h" -#include "key.h" -#include "authfd.h" -#include "pathnames.h" - -/* -- channel core */ - -/* - * Pointer to an array containing all allocated channels. The array is - * dynamically extended as needed. - */ -static Channel **channels = NULL; - -/* - * Size of the channel array. All slots of the array must always be - * initialized (at least the type field); unused slots set to NULL - */ -static u_int channels_alloc = 0; - -/* - * Maximum file descriptor value used in any of the channels. This is - * updated in channel_new. - */ -static int channel_max_fd = 0; - - -/* -- tcp forwarding */ - -/* - * Data structure for storing which hosts are permitted for forward requests. - * The local sides of any remote forwards are stored in this array to prevent - * a corrupt remote server from accessing arbitrary TCP/IP ports on our local - * network (which might be behind a firewall). - */ -typedef struct { - char *host_to_connect; /* Connect to 'host'. */ - u_short port_to_connect; /* Connect to 'port'. */ - u_short listen_port; /* Remote side should listen port number. */ -} ForwardPermission; - -/* List of all permitted host/port pairs to connect by the user. */ -static ForwardPermission permitted_opens[SSH_MAX_FORWARDS_PER_DIRECTION]; - -/* List of all permitted host/port pairs to connect by the admin. */ -static ForwardPermission permitted_adm_opens[SSH_MAX_FORWARDS_PER_DIRECTION]; - -/* Number of permitted host/port pairs in the array permitted by the user. */ -static int num_permitted_opens = 0; - -/* Number of permitted host/port pair in the array permitted by the admin. */ -static int num_adm_permitted_opens = 0; - -/* - * If this is true, all opens are permitted. This is the case on the server - * on which we have to trust the client anyway, and the user could do - * anything after logging in anyway. - */ -static int all_opens_permitted = 0; - - -/* -- X11 forwarding */ - -/* Maximum number of fake X11 displays to try. */ -#define MAX_DISPLAYS 1000 - -/* Saved X11 local (client) display. */ -static char *x11_saved_display = NULL; - -/* Saved X11 authentication protocol name. */ -static char *x11_saved_proto = NULL; - -/* Saved X11 authentication data. This is the real data. */ -static char *x11_saved_data = NULL; -static u_int x11_saved_data_len = 0; - -/* - * Fake X11 authentication data. This is what the server will be sending us; - * we should replace any occurrences of this by the real data. - */ -static u_char *x11_fake_data = NULL; -static u_int x11_fake_data_len; - - -/* -- agent forwarding */ - -#define NUM_SOCKS 10 - -/* AF_UNSPEC or AF_INET or AF_INET6 */ -static int IPv4or6 = AF_UNSPEC; - -/* helper */ -static void port_open_helper(Channel *c, char *rtype); - -/* -- channel core */ - -Channel * -channel_by_id(int id) -{ - Channel *c; - - if (id < 0 || (u_int)id >= channels_alloc) { - logit("channel_by_id: %d: bad id", id); - return NULL; - } - c = channels[id]; - if (c == NULL) { - logit("channel_by_id: %d: bad id: channel free", id); - return NULL; - } - return c; -} - -/* - * Returns the channel if it is allowed to receive protocol messages. - * Private channels, like listening sockets, may not receive messages. - */ -Channel * -channel_lookup(int id) -{ - Channel *c; - - if ((c = channel_by_id(id)) == NULL) - return (NULL); - - switch (c->type) { - case SSH_CHANNEL_X11_OPEN: - case SSH_CHANNEL_LARVAL: - case SSH_CHANNEL_CONNECTING: - case SSH_CHANNEL_DYNAMIC: - case SSH_CHANNEL_OPENING: - case SSH_CHANNEL_OPEN: - case SSH_CHANNEL_INPUT_DRAINING: - case SSH_CHANNEL_OUTPUT_DRAINING: - return (c); - } - logit("Non-public channel %d, type %d.", id, c->type); - return (NULL); -} - -/* - * Register filedescriptors for a channel, used when allocating a channel or - * when the channel consumer/producer is ready, e.g. shell exec'd - */ -static void -channel_register_fds(Channel *c, int rfd, int wfd, int efd, - int extusage, int nonblock) -{ - /* Update the maximum file descriptor value. */ - channel_max_fd = MAX(channel_max_fd, rfd); - channel_max_fd = MAX(channel_max_fd, wfd); - channel_max_fd = MAX(channel_max_fd, efd); - - /* XXX set close-on-exec -markus */ - - c->rfd = rfd; - c->wfd = wfd; - c->sock = (rfd == wfd) ? rfd : -1; - c->ctl_fd = -1; /* XXX: set elsewhere */ - c->efd = efd; - c->extended_usage = extusage; - - /* XXX ugly hack: nonblock is only set by the server */ - if (nonblock && isatty(c->rfd)) { - debug2("channel %d: rfd %d isatty", c->self, c->rfd); - c->isatty = 1; - if (!isatty(c->wfd)) { - error("channel %d: wfd %d is not a tty?", - c->self, c->wfd); - } - } else { - c->isatty = 0; - } - c->wfd_isatty = isatty(c->wfd); - - /* enable nonblocking mode */ - if (nonblock) { - if (rfd != -1) - set_nonblock(rfd); - if (wfd != -1) - set_nonblock(wfd); - if (efd != -1) - set_nonblock(efd); - } -} - -/* - * Allocate a new channel object and set its type and socket. This will cause - * remote_name to be freed. - */ -Channel * -channel_new(char *ctype, int type, int rfd, int wfd, int efd, - u_int window, u_int maxpack, int extusage, char *remote_name, int nonblock) -{ - int found; - u_int i; - Channel *c; - - /* Do initial allocation if this is the first call. */ - if (channels_alloc == 0) { - channels_alloc = 10; - channels = xcalloc(channels_alloc, sizeof(Channel *)); - for (i = 0; i < channels_alloc; i++) - channels[i] = NULL; - } - /* Try to find a free slot where to put the new channel. */ - for (found = -1, i = 0; i < channels_alloc; i++) - if (channels[i] == NULL) { - /* Found a free slot. */ - found = (int)i; - break; - } - if (found < 0) { - /* There are no free slots. Take last+1 slot and expand the array. */ - found = channels_alloc; - if (channels_alloc > 10000) - fatal("channel_new: internal error: channels_alloc %d " - "too big.", channels_alloc); - channels = xrealloc(channels, channels_alloc + 10, - sizeof(Channel *)); - channels_alloc += 10; - debug2("channel: expanding %d", channels_alloc); - for (i = found; i < channels_alloc; i++) - channels[i] = NULL; - } - /* Initialize and return new channel. */ - c = channels[found] = xcalloc(1, sizeof(Channel)); - buffer_init(&c->input); - buffer_init(&c->output); - buffer_init(&c->extended); - c->ostate = CHAN_OUTPUT_OPEN; - c->istate = CHAN_INPUT_OPEN; - c->flags = 0; - channel_register_fds(c, rfd, wfd, efd, extusage, nonblock); - c->self = found; - c->type = type; - c->ctype = ctype; - c->local_window = window; - c->local_window_max = window; - c->local_consumed = 0; - c->local_maxpacket = maxpack; - c->remote_id = -1; - c->remote_name = xstrdup(remote_name); - c->remote_window = 0; - c->remote_maxpacket = 0; - c->force_drain = 0; - c->single_connection = 0; - c->detach_user = NULL; - c->detach_close = 0; - c->confirm = NULL; - c->confirm_ctx = NULL; - c->input_filter = NULL; - c->output_filter = NULL; - debug("channel %d: new [%s]", found, remote_name); - return c; -} - -static int -channel_find_maxfd(void) -{ - u_int i; - int max = 0; - Channel *c; - - for (i = 0; i < channels_alloc; i++) { - c = channels[i]; - if (c != NULL) { - max = MAX(max, c->rfd); - max = MAX(max, c->wfd); - max = MAX(max, c->efd); - } - } - return max; -} - -int -channel_close_fd(int *fdp) -{ - int ret = 0, fd = *fdp; - - if (fd != -1) { - ret = close(fd); - *fdp = -1; - if (fd == channel_max_fd) - channel_max_fd = channel_find_maxfd(); - } - return ret; -} - -/* Close all channel fd/socket. */ -static void -channel_close_fds(Channel *c) -{ - debug3("channel %d: close_fds r %d w %d e %d c %d", - c->self, c->rfd, c->wfd, c->efd, c->ctl_fd); - - channel_close_fd(&c->sock); - channel_close_fd(&c->ctl_fd); - channel_close_fd(&c->rfd); - channel_close_fd(&c->wfd); - channel_close_fd(&c->efd); -} - -/* Free the channel and close its fd/socket. */ -void -channel_free(Channel *c) -{ - char *s; - u_int i, n; - - for (n = 0, i = 0; i < channels_alloc; i++) - if (channels[i]) - n++; - debug("channel %d: free: %s, nchannels %u", c->self, - c->remote_name ? c->remote_name : "???", n); - - s = channel_open_message(); - debug3("channel %d: status: %s", c->self, s); - xfree(s); - - if (c->sock != -1) - shutdown(c->sock, SHUT_RDWR); - if (c->ctl_fd != -1) - shutdown(c->ctl_fd, SHUT_RDWR); - channel_close_fds(c); - buffer_free(&c->input); - buffer_free(&c->output); - buffer_free(&c->extended); - if (c->remote_name) { - xfree(c->remote_name); - c->remote_name = NULL; - } - channels[c->self] = NULL; - xfree(c); -} - -void -channel_free_all(void) -{ - u_int i; - - for (i = 0; i < channels_alloc; i++) - if (channels[i] != NULL) - channel_free(channels[i]); -} - -/* - * Closes the sockets/fds of all channels. This is used to close extra file - * descriptors after a fork. - */ -void -channel_close_all(void) -{ - u_int i; - - for (i = 0; i < channels_alloc; i++) - if (channels[i] != NULL) - channel_close_fds(channels[i]); -} - -/* - * Stop listening to channels. - */ -void -channel_stop_listening(void) -{ - u_int i; - Channel *c; - - for (i = 0; i < channels_alloc; i++) { - c = channels[i]; - if (c != NULL) { - switch (c->type) { - case SSH_CHANNEL_AUTH_SOCKET: - case SSH_CHANNEL_PORT_LISTENER: - case SSH_CHANNEL_RPORT_LISTENER: - case SSH_CHANNEL_X11_LISTENER: - channel_close_fd(&c->sock); - channel_free(c); - break; - } - } - } -} - -/* - * Returns true if no channel has too much buffered data, and false if one or - * more channel is overfull. - */ -int -channel_not_very_much_buffered_data(void) -{ - u_int i; - Channel *c; - - for (i = 0; i < channels_alloc; i++) { - c = channels[i]; - if (c != NULL && c->type == SSH_CHANNEL_OPEN) { -#if 0 - if (!compat20 && - buffer_len(&c->input) > packet_get_maxsize()) { - debug2("channel %d: big input buffer %d", - c->self, buffer_len(&c->input)); - return 0; - } -#endif - if (buffer_len(&c->output) > packet_get_maxsize()) { - debug2("channel %d: big output buffer %u > %u", - c->self, buffer_len(&c->output), - packet_get_maxsize()); - return 0; - } - } - } - return 1; -} - -/* Returns true if any channel is still open. */ -int -channel_still_open(void) -{ - u_int i; - Channel *c; - - for (i = 0; i < channels_alloc; i++) { - c = channels[i]; - if (c == NULL) - continue; - switch (c->type) { - case SSH_CHANNEL_X11_LISTENER: - case SSH_CHANNEL_PORT_LISTENER: - case SSH_CHANNEL_RPORT_LISTENER: - case SSH_CHANNEL_CLOSED: - case SSH_CHANNEL_AUTH_SOCKET: - case SSH_CHANNEL_DYNAMIC: - case SSH_CHANNEL_CONNECTING: - case SSH_CHANNEL_ZOMBIE: - 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", c->type); - /* NOTREACHED */ - } - } - return 0; -} - -/* Returns the id of an open channel suitable for keepaliving */ -int -channel_find_open(void) -{ - u_int i; - Channel *c; - - for (i = 0; i < channels_alloc; i++) { - c = channels[i]; - if (c == NULL || c->remote_id < 0) - continue; - switch (c->type) { - case SSH_CHANNEL_CLOSED: - case SSH_CHANNEL_DYNAMIC: - case SSH_CHANNEL_X11_LISTENER: - case SSH_CHANNEL_PORT_LISTENER: - case SSH_CHANNEL_RPORT_LISTENER: - case SSH_CHANNEL_OPENING: - case SSH_CHANNEL_CONNECTING: - case SSH_CHANNEL_ZOMBIE: - continue; - case SSH_CHANNEL_LARVAL: - case SSH_CHANNEL_AUTH_SOCKET: - case SSH_CHANNEL_OPEN: - case SSH_CHANNEL_X11_OPEN: - return i; - case SSH_CHANNEL_INPUT_DRAINING: - case SSH_CHANNEL_OUTPUT_DRAINING: - if (!compat13) - fatal("cannot happen: OUT_DRAIN"); - return i; - default: - fatal("channel_find_open: bad channel type %d", c->type); - /* NOTREACHED */ - } - } - return -1; -} - - -/* - * Returns a message describing the currently open forwarded connections, - * suitable for sending to the client. The message contains crlf pairs for - * newlines. - */ -char * -channel_open_message(void) -{ - Buffer buffer; - Channel *c; - char buf[1024], *cp; - u_int i; - - buffer_init(&buffer); - snprintf(buf, sizeof buf, "The following connections are open:\r\n"); - buffer_append(&buffer, buf, strlen(buf)); - for (i = 0; i < channels_alloc; i++) { - c = channels[i]; - if (c == NULL) - continue; - switch (c->type) { - case SSH_CHANNEL_X11_LISTENER: - case SSH_CHANNEL_PORT_LISTENER: - case SSH_CHANNEL_RPORT_LISTENER: - case SSH_CHANNEL_CLOSED: - case SSH_CHANNEL_AUTH_SOCKET: - case SSH_CHANNEL_ZOMBIE: - 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 cfd %d)\r\n", - c->self, c->remote_name, - c->type, c->remote_id, - c->istate, buffer_len(&c->input), - c->ostate, buffer_len(&c->output), - c->rfd, c->wfd, c->ctl_fd); - 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; -} - -void -channel_send_open(int id) -{ - Channel *c = channel_lookup(id); - - if (c == NULL) { - logit("channel_send_open: %d: bad id", id); - return; - } - debug2("channel %d: send open", id); - packet_start(SSH2_MSG_CHANNEL_OPEN); - packet_put_cstring(c->ctype); - packet_put_int(c->self); - packet_put_int(c->local_window); - packet_put_int(c->local_maxpacket); - packet_send(); -} - -void -channel_request_start(int id, char *service, int wantconfirm) -{ - Channel *c = channel_lookup(id); - - if (c == NULL) { - logit("channel_request_start: %d: unknown channel id", id); - return; - } - debug2("channel %d: request %s confirm %d", id, service, wantconfirm); - packet_start(SSH2_MSG_CHANNEL_REQUEST); - packet_put_int(c->remote_id); - packet_put_cstring(service); - packet_put_char(wantconfirm); -} - -void -channel_register_confirm(int id, channel_callback_fn *fn, void *ctx) -{ - Channel *c = channel_lookup(id); - - if (c == NULL) { - logit("channel_register_comfirm: %d: bad id", id); - return; - } - c->confirm = fn; - c->confirm_ctx = ctx; -} - -void -channel_register_cleanup(int id, channel_callback_fn *fn, int do_close) -{ - Channel *c = channel_by_id(id); - - if (c == NULL) { - logit("channel_register_cleanup: %d: bad id", id); - return; - } - c->detach_user = fn; - c->detach_close = do_close; -} - -void -channel_cancel_cleanup(int id) -{ - Channel *c = channel_by_id(id); - - if (c == NULL) { - logit("channel_cancel_cleanup: %d: bad id", id); - return; - } - c->detach_user = NULL; - c->detach_close = 0; -} - -void -channel_register_filter(int id, channel_infilter_fn *ifn, - channel_outfilter_fn *ofn) -{ - Channel *c = channel_lookup(id); - - if (c == NULL) { - logit("channel_register_filter: %d: bad id", id); - return; - } - c->input_filter = ifn; - c->output_filter = ofn; -} - -void -channel_set_fds(int id, int rfd, int wfd, int efd, - int extusage, int nonblock, u_int window_max) -{ - Channel *c = channel_lookup(id); - - if (c == NULL || c->type != SSH_CHANNEL_LARVAL) - fatal("channel_activate for non-larval channel %d.", id); - channel_register_fds(c, rfd, wfd, efd, extusage, nonblock); - c->type = SSH_CHANNEL_OPEN; - c->local_window = c->local_window_max = window_max; - packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST); - packet_put_int(c->remote_id); - packet_put_int(c->local_window); - packet_send(); -} - -/* - * 'channel_pre*' are called just before select() to add any bits relevant to - * channels in the select bitmasks. - */ -/* - * 'channel_post*': perform any appropriate operations for channels which - * have events pending. - */ -typedef void chan_fn(Channel *c, fd_set *readset, fd_set *writeset); -chan_fn *channel_pre[SSH_CHANNEL_MAX_TYPE]; -chan_fn *channel_post[SSH_CHANNEL_MAX_TYPE]; - -/* ARGSUSED */ -static void -channel_pre_listener(Channel *c, fd_set *readset, fd_set *writeset) -{ - FD_SET(c->sock, readset); -} - -/* ARGSUSED */ -static void -channel_pre_connecting(Channel *c, fd_set *readset, fd_set *writeset) -{ - debug3("channel %d: waiting for connection", c->self); - FD_SET(c->sock, writeset); -} - -static void -channel_pre_open_13(Channel *c, fd_set *readset, fd_set *writeset) -{ - if (buffer_len(&c->input) < packet_get_maxsize()) - FD_SET(c->sock, readset); - if (buffer_len(&c->output) > 0) - FD_SET(c->sock, writeset); -} - -static void -channel_pre_open(Channel *c, fd_set *readset, fd_set *writeset) -{ - u_int limit = compat20 ? c->remote_window : packet_get_maxsize(); - - if (c->istate == CHAN_INPUT_OPEN && - limit > 0 && - buffer_len(&c->input) < limit && - buffer_check_alloc(&c->input, CHAN_RBUF)) - FD_SET(c->rfd, readset); - if (c->ostate == CHAN_OUTPUT_OPEN || - c->ostate == CHAN_OUTPUT_WAIT_DRAIN) { - if (buffer_len(&c->output) > 0) { - FD_SET(c->wfd, writeset); - } else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN) { - if (CHANNEL_EFD_OUTPUT_ACTIVE(c)) - debug2("channel %d: obuf_empty delayed efd %d/(%d)", - c->self, c->efd, buffer_len(&c->extended)); - else - chan_obuf_empty(c); - } - } - /** XXX check close conditions, too */ - if (compat20 && c->efd != -1) { - if (c->extended_usage == CHAN_EXTENDED_WRITE && - buffer_len(&c->extended) > 0) - FD_SET(c->efd, writeset); - else if (!(c->flags & CHAN_EOF_SENT) && - c->extended_usage == CHAN_EXTENDED_READ && - buffer_len(&c->extended) < c->remote_window) - FD_SET(c->efd, readset); - } - /* XXX: What about efd? races? */ - if (compat20 && c->ctl_fd != -1 && - c->istate == CHAN_INPUT_OPEN && c->ostate == CHAN_OUTPUT_OPEN) - FD_SET(c->ctl_fd, readset); -} - -/* ARGSUSED */ -static void -channel_pre_input_draining(Channel *c, fd_set *readset, fd_set *writeset) -{ - if (buffer_len(&c->input) == 0) { - packet_start(SSH_MSG_CHANNEL_CLOSE); - packet_put_int(c->remote_id); - packet_send(); - c->type = SSH_CHANNEL_CLOSED; - debug2("channel %d: closing after input drain.", c->self); - } -} - -/* ARGSUSED */ -static void -channel_pre_output_draining(Channel *c, fd_set *readset, fd_set *writeset) -{ - if (buffer_len(&c->output) == 0) - chan_mark_dead(c); - else - FD_SET(c->sock, writeset); -} - -/* - * This is a special state for X11 authentication spoofing. An opened X11 - * connection (when authentication spoofing is being done) remains in this - * state until the first packet has been completely read. The authentication - * data in that packet is then substituted by the real data if it matches the - * fake data, and the channel is put into normal mode. - * XXX All this happens at the client side. - * Returns: 0 = need more data, -1 = wrong cookie, 1 = ok - */ -static int -x11_open_helper(Buffer *b) -{ - u_char *ucp; - u_int proto_len, data_len; - - /* Check if the fixed size part of the packet is in buffer. */ - if (buffer_len(b) < 12) - return 0; - - /* Parse the lengths of variable-length fields. */ - ucp = buffer_ptr(b); - if (ucp[0] == 0x42) { /* Byte order MSB first. */ - proto_len = 256 * ucp[6] + ucp[7]; - data_len = 256 * ucp[8] + ucp[9]; - } else if (ucp[0] == 0x6c) { /* Byte order LSB first. */ - proto_len = ucp[6] + 256 * ucp[7]; - data_len = ucp[8] + 256 * ucp[9]; - } else { - debug2("Initial X11 packet contains bad byte order byte: 0x%x", - ucp[0]); - return -1; - } - - /* Check if the whole packet is in buffer. */ - if (buffer_len(b) < - 12 + ((proto_len + 3) & ~3) + ((data_len + 3) & ~3)) - return 0; - - /* Check if authentication protocol matches. */ - if (proto_len != strlen(x11_saved_proto) || - memcmp(ucp + 12, x11_saved_proto, proto_len) != 0) { - debug2("X11 connection uses different authentication protocol."); - return -1; - } - /* Check if authentication data matches our fake data. */ - if (data_len != x11_fake_data_len || - memcmp(ucp + 12 + ((proto_len + 3) & ~3), - x11_fake_data, x11_fake_data_len) != 0) { - debug2("X11 auth data does not match fake data."); - return -1; - } - /* Check fake data length */ - if (x11_fake_data_len != x11_saved_data_len) { - error("X11 fake_data_len %d != saved_data_len %d", - x11_fake_data_len, x11_saved_data_len); - return -1; - } - /* - * Received authentication protocol and data match - * our fake data. Substitute the fake data with real - * data. - */ - memcpy(ucp + 12 + ((proto_len + 3) & ~3), - x11_saved_data, x11_saved_data_len); - return 1; -} - -static void -channel_pre_x11_open_13(Channel *c, fd_set *readset, fd_set *writeset) -{ - int ret = x11_open_helper(&c->output); - - if (ret == 1) { - /* Start normal processing for the channel. */ - c->type = SSH_CHANNEL_OPEN; - channel_pre_open_13(c, readset, writeset); - } else if (ret == -1) { - /* - * We have received an X11 connection that has bad - * authentication information. - */ - logit("X11 connection rejected because of wrong authentication."); - buffer_clear(&c->input); - buffer_clear(&c->output); - channel_close_fd(&c->sock); - c->sock = -1; - c->type = SSH_CHANNEL_CLOSED; - packet_start(SSH_MSG_CHANNEL_CLOSE); - packet_put_int(c->remote_id); - packet_send(); - } -} - -static void -channel_pre_x11_open(Channel *c, fd_set *readset, fd_set *writeset) -{ - int ret = x11_open_helper(&c->output); - - /* c->force_drain = 1; */ - - if (ret == 1) { - c->type = SSH_CHANNEL_OPEN; - channel_pre_open(c, readset, writeset); - } else if (ret == -1) { - logit("X11 connection rejected because of wrong authentication."); - debug2("X11 rejected %d i%d/o%d", c->self, c->istate, c->ostate); - chan_read_failed(c); - buffer_clear(&c->input); - chan_ibuf_empty(c); - buffer_clear(&c->output); - /* for proto v1, the peer will send an IEOF */ - if (compat20) - chan_write_failed(c); - else - c->type = SSH_CHANNEL_OPEN; - debug2("X11 closed %d i%d/o%d", c->self, c->istate, c->ostate); - } -} - -/* try to decode a socks4 header */ -/* ARGSUSED */ -static int -channel_decode_socks4(Channel *c, fd_set *readset, fd_set *writeset) -{ - char *p, *host; - u_int len, have, i, found; - 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); - - debug2("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, &s4_rsp, sizeof(s4_rsp)); - return 1; -} - -/* try to decode a socks5 header */ -#define SSH_SOCKS5_AUTHDONE 0x1000 -#define SSH_SOCKS5_NOAUTH 0x00 -#define SSH_SOCKS5_IPV4 0x01 -#define SSH_SOCKS5_DOMAIN 0x03 -#define SSH_SOCKS5_IPV6 0x04 -#define SSH_SOCKS5_CONNECT 0x01 -#define SSH_SOCKS5_SUCCESS 0x00 - -/* ARGSUSED */ -static int -channel_decode_socks5(Channel *c, fd_set *readset, fd_set *writeset) -{ - struct { - u_int8_t version; - u_int8_t command; - u_int8_t reserved; - u_int8_t atyp; - } s5_req, s5_rsp; - u_int16_t dest_port; - u_char *p, dest_addr[255+1]; - u_int have, need, i, found, nmethods, addrlen, af; - - debug2("channel %d: decode socks5", c->self); - p = buffer_ptr(&c->input); - if (p[0] != 0x05) - return -1; - have = buffer_len(&c->input); - if (!(c->flags & SSH_SOCKS5_AUTHDONE)) { - /* format: ver | nmethods | methods */ - if (have < 2) - return 0; - nmethods = p[1]; - if (have < nmethods + 2) - return 0; - /* look for method: "NO AUTHENTICATION REQUIRED" */ - for (found = 0, i = 2 ; i < nmethods + 2; i++) { - if (p[i] == SSH_SOCKS5_NOAUTH) { - found = 1; - break; - } - } - if (!found) { - debug("channel %d: method SSH_SOCKS5_NOAUTH not found", - c->self); - return -1; - } - buffer_consume(&c->input, nmethods + 2); - buffer_put_char(&c->output, 0x05); /* version */ - buffer_put_char(&c->output, SSH_SOCKS5_NOAUTH); /* method */ - FD_SET(c->sock, writeset); - c->flags |= SSH_SOCKS5_AUTHDONE; - debug2("channel %d: socks5 auth done", c->self); - return 0; /* need more */ - } - debug2("channel %d: socks5 post auth", c->self); - if (have < sizeof(s5_req)+1) - return 0; /* need more */ - memcpy(&s5_req, p, sizeof(s5_req)); - if (s5_req.version != 0x05 || - s5_req.command != SSH_SOCKS5_CONNECT || - s5_req.reserved != 0x00) { - debug2("channel %d: only socks5 connect supported", c->self); - return -1; - } - switch (s5_req.atyp){ - case SSH_SOCKS5_IPV4: - addrlen = 4; - af = AF_INET; - break; - case SSH_SOCKS5_DOMAIN: - addrlen = p[sizeof(s5_req)]; - af = -1; - break; - case SSH_SOCKS5_IPV6: - addrlen = 16; - af = AF_INET6; - break; - default: - debug2("channel %d: bad socks5 atyp %d", c->self, s5_req.atyp); - return -1; - } - need = sizeof(s5_req) + addrlen + 2; - if (s5_req.atyp == SSH_SOCKS5_DOMAIN) - need++; - if (have < need) - return 0; - buffer_consume(&c->input, sizeof(s5_req)); - if (s5_req.atyp == SSH_SOCKS5_DOMAIN) - buffer_consume(&c->input, 1); /* host string length */ - buffer_get(&c->input, (char *)&dest_addr, addrlen); - buffer_get(&c->input, (char *)&dest_port, 2); - dest_addr[addrlen] = '\0'; - if (s5_req.atyp == SSH_SOCKS5_DOMAIN) - strlcpy(c->path, (char *)dest_addr, sizeof(c->path)); - else if (inet_ntop(af, dest_addr, c->path, sizeof(c->path)) == NULL) - return -1; - c->host_port = ntohs(dest_port); - - debug2("channel %d: dynamic request: socks5 host %s port %u command %u", - c->self, c->path, c->host_port, s5_req.command); - - s5_rsp.version = 0x05; - s5_rsp.command = SSH_SOCKS5_SUCCESS; - s5_rsp.reserved = 0; /* ignored */ - s5_rsp.atyp = SSH_SOCKS5_IPV4; - ((struct in_addr *)&dest_addr)->s_addr = INADDR_ANY; - dest_port = 0; /* ignored */ - - buffer_append(&c->output, &s5_rsp, sizeof(s5_rsp)); - buffer_append(&c->output, &dest_addr, sizeof(struct in_addr)); - buffer_append(&c->output, &dest_port, sizeof(dest_port)); - return 1; -} - -/* dynamic port forwarding */ -static void -channel_pre_dynamic(Channel *c, fd_set *readset, fd_set *writeset) -{ - u_char *p; - u_int have; - int ret; - - have = buffer_len(&c->input); - c->delayed = 0; - debug2("channel %d: pre_dynamic: have %d", c->self, have); - /* buffer_dump(&c->input); */ - /* check if the fixed size part of the packet is in buffer. */ - if (have < 3) { - /* need more */ - FD_SET(c->sock, readset); - return; - } - /* try to guess the protocol */ - p = buffer_ptr(&c->input); - switch (p[0]) { - case 0x04: - ret = channel_decode_socks4(c, readset, writeset); - break; - case 0x05: - ret = channel_decode_socks5(c, readset, writeset); - break; - default: - ret = -1; - break; - } - if (ret < 0) { - chan_mark_dead(c); - } else if (ret == 0) { - debug2("channel %d: pre_dynamic: need more", c->self); - /* need more */ - FD_SET(c->sock, readset); - } else { - /* switch to the next state */ - c->type = SSH_CHANNEL_OPENING; - port_open_helper(c, "direct-tcpip"); - } -} - -/* This is our fake X11 server socket. */ -/* ARGSUSED */ -static void -channel_post_x11_listener(Channel *c, fd_set *readset, fd_set *writeset) -{ - Channel *nc; - struct sockaddr addr; - int newsock; - 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 (c->single_connection) { - debug2("single_connection: closing X11 listener."); - channel_close_fd(&c->sock); - chan_mark_dead(c); - } - if (newsock < 0) { - error("accept: %.100s", strerror(errno)); - return; - } - set_nodelay(newsock); - remote_ipaddr = get_peer_ipaddr(newsock); - remote_port = get_peer_port(newsock); - snprintf(buf, sizeof buf, "X11 connection from %.200s port %d", - remote_ipaddr, remote_port); - - nc = channel_new("accepted x11 socket", - SSH_CHANNEL_OPENING, newsock, newsock, -1, - c->local_window_max, c->local_maxpacket, 0, buf, 1); - if (compat20) { - packet_start(SSH2_MSG_CHANNEL_OPEN); - packet_put_cstring("x11"); - packet_put_int(nc->self); - packet_put_int(nc->local_window_max); - packet_put_int(nc->local_maxpacket); - /* originator ipaddr and port */ - packet_put_cstring(remote_ipaddr); - if (datafellows & SSH_BUG_X11FWD) { - debug2("ssh2 x11 bug compat mode"); - } else { - packet_put_int(remote_port); - } - packet_send(); - } else { - packet_start(SSH_SMSG_X11_OPEN); - packet_put_int(nc->self); - if (packet_get_protocol_flags() & - SSH_PROTOFLAG_HOST_IN_FWD_OPEN) - packet_put_cstring(buf); - packet_send(); - } - xfree(remote_ipaddr); - } -} - -static void -port_open_helper(Channel *c, char *rtype) -{ - int direct; - char buf[1024]; - char *remote_ipaddr = get_peer_ipaddr(c->sock); - int 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((u_int)remote_port); - packet_send(); - } else { - packet_start(SSH_MSG_PORT_OPEN); - packet_put_int(c->self); - packet_put_cstring(c->path); - packet_put_int(c->host_port); - if (packet_get_protocol_flags() & - SSH_PROTOFLAG_HOST_IN_FWD_OPEN) - packet_put_cstring(c->remote_name); - packet_send(); - } - xfree(remote_ipaddr); -} - -static void -channel_set_reuseaddr(int fd) -{ - int on = 1; - - /* - * Set socket options. - * Allow local port reuse in TIME_WAIT. - */ - if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) == -1) - error("setsockopt SO_REUSEADDR fd %d: %s", fd, strerror(errno)); -} - -/* - * This socket is listening for connections to a forwarded TCP/IP port. - */ -/* ARGSUSED */ -static void -channel_post_port_listener(Channel *c, fd_set *readset, fd_set *writeset) -{ - Channel *nc; - struct sockaddr addr; - int newsock, nextstate; - socklen_t addrlen; - char *rtype; - - if (FD_ISSET(c->sock, readset)) { - debug("Connection to port %d forwarding " - "to %.100s port %d requested.", - c->listening_port, c->path, c->host_port); - - if (c->type == SSH_CHANNEL_RPORT_LISTENER) { - nextstate = SSH_CHANNEL_OPENING; - rtype = "forwarded-tcpip"; - } else { - if (c->host_port == 0) { - nextstate = SSH_CHANNEL_DYNAMIC; - rtype = "dynamic-tcpip"; - } else { - nextstate = SSH_CHANNEL_OPENING; - rtype = "direct-tcpip"; - } - } - - addrlen = sizeof(addr); - newsock = accept(c->sock, &addr, &addrlen); - if (newsock < 0) { - error("accept: %.100s", strerror(errno)); - return; - } - set_nodelay(newsock); - nc = channel_new(rtype, nextstate, newsock, newsock, -1, - c->local_window_max, c->local_maxpacket, 0, rtype, 1); - nc->listening_port = c->listening_port; - nc->host_port = c->host_port; - strlcpy(nc->path, c->path, sizeof(nc->path)); - - if (nextstate == SSH_CHANNEL_DYNAMIC) { - /* - * do not call the channel_post handler until - * this flag has been reset by a pre-handler. - * otherwise the FD_ISSET calls might overflow - */ - nc->delayed = 1; - } else { - port_open_helper(nc, rtype); - } - } -} - -/* - * This is the authentication agent socket listening for connections from - * clients. - */ -/* ARGSUSED */ -static void -channel_post_auth_listener(Channel *c, fd_set *readset, fd_set *writeset) -{ - Channel *nc; - int newsock; - struct sockaddr addr; - 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; - } - nc = channel_new("accepted auth socket", - SSH_CHANNEL_OPENING, newsock, newsock, -1, - c->local_window_max, c->local_maxpacket, - 0, "accepted auth socket", 1); - if (compat20) { - packet_start(SSH2_MSG_CHANNEL_OPEN); - packet_put_cstring("auth-agent@openssh.com"); - packet_put_int(nc->self); - packet_put_int(c->local_window_max); - packet_put_int(c->local_maxpacket); - } else { - packet_start(SSH_SMSG_AGENT_OPEN); - packet_put_int(nc->self); - } - packet_send(); - } -} - -/* ARGSUSED */ -static void -channel_post_connecting(Channel *c, fd_set *readset, fd_set *writeset) -{ - int err = 0; - socklen_t sz = sizeof(err); - - if (FD_ISSET(c->sock, writeset)) { - if (getsockopt(c->sock, SOL_SOCKET, SO_ERROR, &err, &sz) < 0) { - err = errno; - error("getsockopt SO_ERROR failed"); - } - if (err == 0) { - debug("channel %d: connected", c->self); - c->type = SSH_CHANNEL_OPEN; - if (compat20) { - packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION); - packet_put_int(c->remote_id); - packet_put_int(c->self); - packet_put_int(c->local_window); - packet_put_int(c->local_maxpacket); - } else { - packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION); - packet_put_int(c->remote_id); - packet_put_int(c->self); - } - } else { - debug("channel %d: not connected: %s", - c->self, strerror(err)); - if (compat20) { - packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE); - packet_put_int(c->remote_id); - packet_put_int(SSH2_OPEN_CONNECT_FAILED); - if (!(datafellows & SSH_BUG_OPENFAILURE)) { - packet_put_cstring(strerror(err)); - packet_put_cstring(""); - } - } else { - packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE); - packet_put_int(c->remote_id); - } - chan_mark_dead(c); - } - packet_send(); - } -} - -/* ARGSUSED */ -static int -channel_handle_rfd(Channel *c, fd_set *readset, fd_set *writeset) -{ - char buf[CHAN_RBUF]; - int len; - - if (c->rfd != -1 && - FD_ISSET(c->rfd, readset)) { - errno = 0; - len = read(c->rfd, buf, sizeof(buf)); - if (len < 0 && (errno == EINTR || errno == EAGAIN)) - return 1; -#ifndef PTY_ZEROREAD - if (len <= 0) { -#else - if ((!c->isatty && len <= 0) || - (c->isatty && (len < 0 || (len == 0 && errno != 0)))) { -#endif - debug2("channel %d: read<=0 rfd %d len %d", - c->self, c->rfd, len); - if (c->type != SSH_CHANNEL_OPEN) { - debug2("channel %d: not open", c->self); - chan_mark_dead(c); - return -1; - } else if (compat13) { - buffer_clear(&c->output); - c->type = SSH_CHANNEL_INPUT_DRAINING; - debug2("channel %d: input draining.", c->self); - } else { - chan_read_failed(c); - } - return -1; - } - if (c->input_filter != NULL) { - if (c->input_filter(c, buf, len) == -1) { - debug2("channel %d: filter stops", c->self); - chan_read_failed(c); - } - } else if (c->datagram) { - buffer_put_string(&c->input, buf, len); - } else { - buffer_append(&c->input, buf, len); - } - } - return 1; -} - -/* ARGSUSED */ -static int -channel_handle_wfd(Channel *c, fd_set *readset, fd_set *writeset) -{ - struct termios tio; - u_char *data = NULL, *buf; - u_int dlen; - int len; - - /* Send buffered output data to the socket. */ - if (c->wfd != -1 && - FD_ISSET(c->wfd, writeset) && - buffer_len(&c->output) > 0) { - if (c->output_filter != NULL) { - if ((buf = c->output_filter(c, &data, &dlen)) == NULL) { - debug2("channel %d: filter stops", c->self); - if (c->type != SSH_CHANNEL_OPEN) - chan_mark_dead(c); - else - chan_write_failed(c); - return -1; - } - } else if (c->datagram) { - buf = data = buffer_get_string(&c->output, &dlen); - } else { - buf = data = buffer_ptr(&c->output); - dlen = buffer_len(&c->output); - } - - if (c->datagram) { - /* ignore truncated writes, datagrams might get lost */ - c->local_consumed += dlen + 4; - len = write(c->wfd, buf, dlen); - xfree(data); - if (len < 0 && (errno == EINTR || errno == EAGAIN)) - return 1; - if (len <= 0) { - if (c->type != SSH_CHANNEL_OPEN) - chan_mark_dead(c); - else - chan_write_failed(c); - return -1; - } - return 1; - } -#ifdef _AIX - /* XXX: Later AIX versions can't push as much data to tty */ - if (compat20 && c->wfd_isatty) - dlen = MIN(dlen, 8*1024); -#endif - - len = write(c->wfd, buf, dlen); - if (len < 0 && (errno == EINTR || errno == EAGAIN)) - return 1; - if (len <= 0) { - if (c->type != SSH_CHANNEL_OPEN) { - debug2("channel %d: not open", c->self); - chan_mark_dead(c); - return -1; - } else if (compat13) { - buffer_clear(&c->output); - debug2("channel %d: input draining.", c->self); - c->type = SSH_CHANNEL_INPUT_DRAINING; - } else { - chan_write_failed(c); - } - return -1; - } - if (compat20 && c->isatty && dlen >= 1 && buf[0] != '\r') { - if (tcgetattr(c->wfd, &tio) == 0 && - !(tio.c_lflag & ECHO) && (tio.c_lflag & ICANON)) { - /* - * Simulate echo to reduce the impact of - * traffic analysis. We need to match the - * size of a SSH2_MSG_CHANNEL_DATA message - * (4 byte channel id + buf) - */ - packet_send_ignore(4 + len); - packet_send(); - } - } - buffer_consume(&c->output, len); - if (compat20 && len > 0) { - c->local_consumed += len; - } - } - return 1; -} - -static int -channel_handle_efd(Channel *c, fd_set *readset, fd_set *writeset) -{ - char buf[CHAN_RBUF]; - int len; - -/** XXX handle drain efd, too */ - if (c->efd != -1) { - if (c->extended_usage == CHAN_EXTENDED_WRITE && - FD_ISSET(c->efd, writeset) && - buffer_len(&c->extended) > 0) { - len = write(c->efd, buffer_ptr(&c->extended), - buffer_len(&c->extended)); - debug2("channel %d: written %d to efd %d", - c->self, len, c->efd); - if (len < 0 && (errno == EINTR || errno == EAGAIN)) - return 1; - if (len <= 0) { - debug2("channel %d: closing write-efd %d", - c->self, c->efd); - channel_close_fd(&c->efd); - } else { - buffer_consume(&c->extended, len); - c->local_consumed += len; - } - } else if (c->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); - channel_close_fd(&c->efd); - } else { - buffer_append(&c->extended, buf, len); - } - } - } - return 1; -} - -/* ARGSUSED */ -static int -channel_handle_ctl(Channel *c, fd_set *readset, fd_set *writeset) -{ - char buf[16]; - int len; - - /* Monitor control fd to detect if the slave client exits */ - if (c->ctl_fd != -1 && FD_ISSET(c->ctl_fd, readset)) { - len = read(c->ctl_fd, buf, sizeof(buf)); - if (len < 0 && (errno == EINTR || errno == EAGAIN)) - return 1; - if (len <= 0) { - debug2("channel %d: ctl read<=0", c->self); - if (c->type != SSH_CHANNEL_OPEN) { - debug2("channel %d: not open", c->self); - chan_mark_dead(c); - return -1; - } else { - chan_read_failed(c); - chan_write_failed(c); - } - return -1; - } else - fatal("%s: unexpected data on ctl fd", __func__); - } - return 1; -} - -static int -channel_check_window(Channel *c) -{ - if (c->type == SSH_CHANNEL_OPEN && - !(c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD)) && - c->local_window < c->local_window_max/2 && - c->local_consumed > 0) { - packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST); - packet_put_int(c->remote_id); - packet_put_int(c->local_consumed); - packet_send(); - debug2("channel %d: window %d sent adjust %d", - c->self, c->local_window, - c->local_consumed); - c->local_window += c->local_consumed; - c->local_consumed = 0; - } - return 1; -} - -static void -channel_post_open(Channel *c, fd_set *readset, fd_set *writeset) -{ - if (c->delayed) - return; - channel_handle_rfd(c, readset, writeset); - channel_handle_wfd(c, readset, writeset); - if (!compat20) - return; - channel_handle_efd(c, readset, writeset); - channel_handle_ctl(c, readset, writeset); - channel_check_window(c); -} - -/* ARGSUSED */ -static void -channel_post_output_drain_13(Channel *c, fd_set *readset, fd_set *writeset) -{ - int len; - - /* Send buffered output data to the socket. */ - if (FD_ISSET(c->sock, writeset) && buffer_len(&c->output) > 0) { - len = write(c->sock, buffer_ptr(&c->output), - buffer_len(&c->output)); - if (len <= 0) - buffer_clear(&c->output); - else - buffer_consume(&c->output, len); - } -} - -static void -channel_handler_init_20(void) -{ - channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open; - channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open; - channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener; - channel_pre[SSH_CHANNEL_RPORT_LISTENER] = &channel_pre_listener; - channel_pre[SSH_CHANNEL_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; - 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; -} - -static void -channel_handler_init_13(void) -{ - channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_13; - channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open_13; - channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener; - channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener; - channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener; - channel_pre[SSH_CHANNEL_INPUT_DRAINING] = &channel_pre_input_draining; - channel_pre[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_pre_output_draining; - channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting; - channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic; - - channel_post[SSH_CHANNEL_OPEN] = &channel_post_open; - channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener; - channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener; - channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener; - channel_post[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_post_output_drain_13; - channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting; - channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open; -} - -static void -channel_handler_init_15(void) -{ - channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open; - channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open; - channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener; - channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener; - channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener; - channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting; - channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic; - - channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener; - channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener; - channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener; - channel_post[SSH_CHANNEL_OPEN] = &channel_post_open; - channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting; - channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open; -} - -static void -channel_handler_init(void) -{ - int i; - - for (i = 0; i < SSH_CHANNEL_MAX_TYPE; i++) { - channel_pre[i] = NULL; - channel_post[i] = NULL; - } - if (compat20) - channel_handler_init_20(); - else if (compat13) - channel_handler_init_13(); - else - channel_handler_init_15(); -} - -/* gc dead channels */ -static void -channel_garbage_collect(Channel *c) -{ - if (c == NULL) - return; - if (c->detach_user != NULL) { - if (!chan_is_dead(c, c->detach_close)) - return; - debug2("channel %d: gc: notify user", c->self); - c->detach_user(c->self, NULL); - /* if we still have a callback */ - if (c->detach_user != NULL) - return; - debug2("channel %d: gc: user detached", c->self); - } - if (!chan_is_dead(c, 1)) - return; - debug2("channel %d: garbage collecting", c->self); - channel_free(c); -} - -static void -channel_handler(chan_fn *ftab[], fd_set *readset, fd_set *writeset) -{ - static int did_init = 0; - u_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 == NULL) - continue; - if (ftab[c->type] != NULL) - (*ftab[c->type])(c, readset, writeset); - channel_garbage_collect(c); - } -} - -/* - * Allocate/update select bitmasks and add any bits relevant to channels in - * select bitmasks. - */ -void -channel_prepare_select(fd_set **readsetp, fd_set **writesetp, int *maxfdp, - u_int *nallocp, int rekeying) -{ - u_int n, sz, nfdset; - - n = MAX(*maxfdp, channel_max_fd); - - nfdset = howmany(n+1, NFDBITS); - /* Explicitly test here, because xrealloc isn't always called */ - if (nfdset && SIZE_T_MAX / nfdset < sizeof(fd_mask)) - fatal("channel_prepare_select: max_fd (%d) is too large", n); - sz = nfdset * sizeof(fd_mask); - - /* perhaps check sz < nalloc/2 and shrink? */ - if (*readsetp == NULL || sz > *nallocp) { - *readsetp = xrealloc(*readsetp, nfdset, sizeof(fd_mask)); - *writesetp = xrealloc(*writesetp, nfdset, sizeof(fd_mask)); - *nallocp = sz; - } - *maxfdp = n; - memset(*readsetp, 0, sz); - memset(*writesetp, 0, sz); - - if (!rekeying) - channel_handler(channel_pre, *readsetp, *writesetp); -} - -/* - * After select, perform any appropriate operations for channels which have - * events pending. - */ -void -channel_after_select(fd_set *readset, fd_set *writeset) -{ - channel_handler(channel_post, readset, writeset); -} - - -/* If there is data to send to the connection, enqueue some of it now. */ -void -channel_output_poll(void) -{ - Channel *c; - u_int i, len; - - for (i = 0; i < channels_alloc; i++) { - c = channels[i]; - if (c == NULL) - continue; - - /* - * We are only interested in channels that can have buffered - * incoming data. - */ - if (compat13) { - if (c->type != SSH_CHANNEL_OPEN && - c->type != SSH_CHANNEL_INPUT_DRAINING) - continue; - } else { - if (c->type != SSH_CHANNEL_OPEN) - continue; - } - if (compat20 && - (c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD))) { - /* XXX is this true? */ - debug3("channel %d: will not send data after close", c->self); - continue; - } - - /* Get the amount of buffered data for this channel. */ - if ((c->istate == CHAN_INPUT_OPEN || - c->istate == CHAN_INPUT_WAIT_DRAIN) && - (len = buffer_len(&c->input)) > 0) { - if (c->datagram) { - if (len > 0) { - u_char *data; - u_int dlen; - - data = buffer_get_string(&c->input, - &dlen); - packet_start(SSH2_MSG_CHANNEL_DATA); - packet_put_int(c->remote_id); - packet_put_string(data, dlen); - packet_send(); - c->remote_window -= dlen + 4; - xfree(data); - } - continue; - } - /* - * Send some data for the other side over the secure - * connection. - */ - if (compat20) { - if (len > c->remote_window) - len = c->remote_window; - if (len > c->remote_maxpacket) - len = c->remote_maxpacket; - } else { - if (packet_is_interactive()) { - if (len > 1024) - len = 512; - } else { - /* Keep the packets at reasonable size. */ - if (len > packet_get_maxsize()/2) - len = packet_get_maxsize()/2; - } - } - if (len > 0) { - packet_start(compat20 ? - SSH2_MSG_CHANNEL_DATA : SSH_MSG_CHANNEL_DATA); - packet_put_int(c->remote_id); - packet_put_string(buffer_ptr(&c->input), len); - packet_send(); - buffer_consume(&c->input, len); - c->remote_window -= len; - } - } else if (c->istate == CHAN_INPUT_WAIT_DRAIN) { - if (compat13) - fatal("cannot happen: istate == INPUT_WAIT_DRAIN for proto 1.3"); - /* - * input-buffer is empty and read-socket shutdown: - * tell peer, that we will not send more data: send IEOF. - * hack for extended data: delay EOF if EFD still in use. - */ - if (CHANNEL_EFD_INPUT_ACTIVE(c)) - debug2("channel %d: ibuf_empty delayed efd %d/(%d)", - c->self, c->efd, buffer_len(&c->extended)); - else - chan_ibuf_empty(c); - } - /* Send extended data, i.e. stderr */ - if (compat20 && - !(c->flags & CHAN_EOF_SENT) && - c->remote_window > 0 && - (len = buffer_len(&c->extended)) > 0 && - c->extended_usage == CHAN_EXTENDED_READ) { - debug2("channel %d: rwin %u elen %u euse %d", - c->self, c->remote_window, buffer_len(&c->extended), - c->extended_usage); - if (len > c->remote_window) - len = c->remote_window; - if (len > c->remote_maxpacket) - len = c->remote_maxpacket; - packet_start(SSH2_MSG_CHANNEL_EXTENDED_DATA); - packet_put_int(c->remote_id); - packet_put_int(SSH2_EXTENDED_DATA_STDERR); - packet_put_string(buffer_ptr(&c->extended), len); - packet_send(); - buffer_consume(&c->extended, len); - c->remote_window -= len; - debug2("channel %d: sent ext data %d", c->self, len); - } - } -} - - -/* -- protocol input */ - -/* ARGSUSED */ -void -channel_input_data(int type, u_int32_t seq, 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; - - /* Get the data. */ - data = packet_get_string(&data_len); - - /* - * Ignore data for protocol > 1.3 if output end is no longer open. - * For protocol 2 the sending side is reducing its window as it sends - * data, so we must 'fake' consumption of the data in order to ensure - * that window updates are sent back. Otherwise the connection might - * deadlock. - */ - if (!compat13 && c->ostate != CHAN_OUTPUT_OPEN) { - if (compat20) { - c->local_window -= data_len; - c->local_consumed += data_len; - } - xfree(data); - return; - } - - if (compat20) { - if (data_len > c->local_maxpacket) { - logit("channel %d: rcvd big packet %d, maxpack %d", - c->self, data_len, c->local_maxpacket); - } - if (data_len > c->local_window) { - logit("channel %d: rcvd too much data %d, win %d", - c->self, data_len, c->local_window); - xfree(data); - return; - } - c->local_window -= data_len; - } - packet_check_eom(); - if (c->datagram) - buffer_put_string(&c->output, data, data_len); - else - buffer_append(&c->output, data, data_len); - xfree(data); -} - -/* ARGSUSED */ -void -channel_input_extended_data(int type, u_int32_t seq, void *ctxt) -{ - int id; - char *data; - u_int data_len, tcode; - Channel *c; - - /* Get the channel number and verify it. */ - id = packet_get_int(); - c = channel_lookup(id); - - if (c == NULL) - packet_disconnect("Received extended_data for bad channel %d.", id); - if (c->type != SSH_CHANNEL_OPEN) { - logit("channel %d: ext data for non open", id); - return; - } - if (c->flags & CHAN_EOF_RCVD) { - if (datafellows & SSH_BUG_EXTEOF) - debug("channel %d: accepting ext data after eof", id); - else - packet_disconnect("Received extended_data after EOF " - "on channel %d.", id); - } - tcode = packet_get_int(); - if (c->efd == -1 || - c->extended_usage != CHAN_EXTENDED_WRITE || - tcode != SSH2_EXTENDED_DATA_STDERR) { - logit("channel %d: bad ext data", c->self); - return; - } - data = packet_get_string(&data_len); - packet_check_eom(); - if (data_len > c->local_window) { - logit("channel %d: rcvd too much extended_data %d, win %d", - c->self, data_len, c->local_window); - 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); -} - -/* ARGSUSED */ -void -channel_input_ieof(int type, u_int32_t seq, void *ctxt) -{ - int id; - Channel *c; - - id = packet_get_int(); - packet_check_eom(); - c = channel_lookup(id); - if (c == NULL) - packet_disconnect("Received ieof for nonexistent channel %d.", id); - chan_rcvd_ieof(c); - - /* XXX force input close */ - if (c->force_drain && c->istate == CHAN_INPUT_OPEN) { - debug("channel %d: FORCE input drain", c->self); - c->istate = CHAN_INPUT_WAIT_DRAIN; - if (buffer_len(&c->input) == 0) - chan_ibuf_empty(c); - } - -} - -/* ARGSUSED */ -void -channel_input_close(int type, u_int32_t seq, void *ctxt) -{ - int id; - Channel *c; - - id = packet_get_int(); - packet_check_eom(); - c = channel_lookup(id); - if (c == NULL) - packet_disconnect("Received close for nonexistent channel %d.", id); - - /* - * Send a confirmation that we have closed the channel and no more - * data is coming for it. - */ - packet_start(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION); - packet_put_int(c->remote_id); - packet_send(); - - /* - * If the channel is in closed state, we have sent a close request, - * and the other side will eventually respond with a confirmation. - * Thus, we cannot free the channel here, because then there would be - * no-one to receive the confirmation. The channel gets freed when - * the confirmation arrives. - */ - if (c->type != SSH_CHANNEL_CLOSED) { - /* - * Not a closed channel - mark it as draining, which will - * cause it to be freed later. - */ - buffer_clear(&c->input); - c->type = SSH_CHANNEL_OUTPUT_DRAINING; - } -} - -/* proto version 1.5 overloads CLOSE_CONFIRMATION with OCLOSE */ -/* ARGSUSED */ -void -channel_input_oclose(int type, u_int32_t seq, void *ctxt) -{ - int id = packet_get_int(); - Channel *c = channel_lookup(id); - - packet_check_eom(); - if (c == NULL) - packet_disconnect("Received oclose for nonexistent channel %d.", id); - chan_rcvd_oclose(c); -} - -/* ARGSUSED */ -void -channel_input_close_confirmation(int type, u_int32_t seq, void *ctxt) -{ - int id = packet_get_int(); - Channel *c = channel_lookup(id); - - packet_check_eom(); - 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); -} - -/* ARGSUSED */ -void -channel_input_open_confirmation(int type, u_int32_t seq, void *ctxt) -{ - int id, remote_id; - Channel *c; - - id = packet_get_int(); - c = channel_lookup(id); - - if (c==NULL || c->type != SSH_CHANNEL_OPENING) - packet_disconnect("Received open confirmation for " - "non-opening channel %d.", id); - remote_id = packet_get_int(); - /* Record the remote channel number and mark that the channel is now open. */ - c->remote_id = remote_id; - c->type = SSH_CHANNEL_OPEN; - - if (compat20) { - c->remote_window = packet_get_int(); - c->remote_maxpacket = packet_get_int(); - if (c->confirm) { - debug2("callback start"); - c->confirm(c->self, c->confirm_ctx); - debug2("callback done"); - } - debug2("channel %d: open confirm rwindow %u rmax %u", c->self, - c->remote_window, c->remote_maxpacket); - } - packet_check_eom(); -} - -static char * -reason2txt(int reason) -{ - switch (reason) { - case SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED: - return "administratively prohibited"; - case SSH2_OPEN_CONNECT_FAILED: - return "connect failed"; - case SSH2_OPEN_UNKNOWN_CHANNEL_TYPE: - return "unknown channel type"; - case SSH2_OPEN_RESOURCE_SHORTAGE: - return "resource shortage"; - } - return "unknown reason"; -} - -/* ARGSUSED */ -void -channel_input_open_failure(int type, u_int32_t seq, void *ctxt) -{ - int id, reason; - char *msg = NULL, *lang = NULL; - Channel *c; - - id = packet_get_int(); - c = channel_lookup(id); - - if (c==NULL || c->type != SSH_CHANNEL_OPENING) - packet_disconnect("Received open failure for " - "non-opening channel %d.", id); - if (compat20) { - reason = packet_get_int(); - if (!(datafellows & SSH_BUG_OPENFAILURE)) { - msg = packet_get_string(NULL); - lang = packet_get_string(NULL); - } - logit("channel %d: open failed: %s%s%s", id, - reason2txt(reason), msg ? ": ": "", msg ? msg : ""); - if (msg != NULL) - xfree(msg); - if (lang != NULL) - xfree(lang); - } - packet_check_eom(); - /* Free the channel. This will also close the socket. */ - channel_free(c); -} - -/* ARGSUSED */ -void -channel_input_window_adjust(int type, u_int32_t seq, void *ctxt) -{ - Channel *c; - int id; - u_int adjust; - - if (!compat20) - return; - - /* Get the channel number and verify it. */ - id = packet_get_int(); - c = channel_lookup(id); - - if (c == NULL) { - logit("Received window adjust for non-open channel %d.", id); - return; - } - adjust = packet_get_int(); - packet_check_eom(); - debug2("channel %d: rcvd adjust %u", id, adjust); - c->remote_window += adjust; -} - -/* ARGSUSED */ -void -channel_input_port_open(int type, u_int32_t seq, void *ctxt) -{ - Channel *c = NULL; - u_short host_port; - char *host, *originator_string; - int remote_id, sock = -1; - - remote_id = packet_get_int(); - host = packet_get_string(NULL); - host_port = packet_get_int(); - - if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) { - originator_string = packet_get_string(NULL); - } else { - originator_string = xstrdup("unknown (remote did not supply name)"); - } - packet_check_eom(); - sock = channel_connect_to(host, host_port); - if (sock != -1) { - c = channel_new("connected socket", - SSH_CHANNEL_CONNECTING, sock, sock, -1, 0, 0, 0, - originator_string, 1); - c->remote_id = remote_id; - } - xfree(originator_string); - if (c == NULL) { - packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE); - packet_put_int(remote_id); - packet_send(); - } - xfree(host); -} - - -/* -- tcp forwarding */ - -void -channel_set_af(int af) -{ - IPv4or6 = af; -} - -static int -channel_setup_fwd_listener(int type, const char *listen_addr, u_short listen_port, - const char *host_to_connect, u_short port_to_connect, int gateway_ports) -{ - Channel *c; - int sock, r, success = 0, wildcard = 0, is_client; - struct addrinfo hints, *ai, *aitop; - const char *host, *addr; - char ntop[NI_MAXHOST], strport[NI_MAXSERV]; - - host = (type == SSH_CHANNEL_RPORT_LISTENER) ? - listen_addr : host_to_connect; - is_client = (type == SSH_CHANNEL_PORT_LISTENER); - - if (host == NULL) { - error("No forward host name."); - return 0; - } - if (strlen(host) > SSH_CHANNEL_PATH_LEN - 1) { - error("Forward host name too long."); - return 0; - } - - /* - * Determine whether or not a port forward listens to loopback, - * specified address or wildcard. On the client, a specified bind - * address will always override gateway_ports. On the server, a - * gateway_ports of 1 (``yes'') will override the client's - * specification and force a wildcard bind, whereas a value of 2 - * (``clientspecified'') will bind to whatever address the client - * asked for. - * - * Special-case listen_addrs are: - * - * "0.0.0.0" -> wildcard v4/v6 if SSH_OLD_FORWARD_ADDR - * "" (empty string), "*" -> wildcard v4/v6 - * "localhost" -> loopback v4/v6 - */ - addr = NULL; - if (listen_addr == NULL) { - /* No address specified: default to gateway_ports setting */ - if (gateway_ports) - wildcard = 1; - } else if (gateway_ports || is_client) { - if (((datafellows & SSH_OLD_FORWARD_ADDR) && - strcmp(listen_addr, "0.0.0.0") == 0) || - *listen_addr == '\0' || strcmp(listen_addr, "*") == 0 || - (!is_client && gateway_ports == 1)) - wildcard = 1; - else if (strcmp(listen_addr, "localhost") != 0) - addr = listen_addr; - } - - debug3("channel_setup_fwd_listener: type %d wildcard %d addr %s", - type, wildcard, (addr == NULL) ? "NULL" : addr); - - /* - * getaddrinfo returns a loopback address if the hostname is - * set to NULL and hints.ai_flags is not AI_PASSIVE - */ - memset(&hints, 0, sizeof(hints)); - hints.ai_family = IPv4or6; - hints.ai_flags = wildcard ? AI_PASSIVE : 0; - hints.ai_socktype = SOCK_STREAM; - snprintf(strport, sizeof strport, "%d", listen_port); - if ((r = getaddrinfo(addr, strport, &hints, &aitop)) != 0) { - if (addr == NULL) { - /* This really shouldn't happen */ - packet_disconnect("getaddrinfo: fatal error: %s", - gai_strerror(r)); - } else { - error("channel_setup_fwd_listener: " - "getaddrinfo(%.64s): %s", addr, gai_strerror(r)); - } - return 0; - } - - 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_setup_fwd_listener: getnameinfo failed"); - continue; - } - /* Create a port to listen for the host. */ - sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol); - if (sock < 0) { - /* this is no error since kernel may not support ipv6 */ - verbose("socket: %.100s", strerror(errno)); - continue; - } - - channel_set_reuseaddr(sock); - - debug("Local forwarding listening on %s port %s.", ntop, strport); - - /* Bind the socket to the address. */ - if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) { - /* address can be in use ipv6 address is already bound */ - if (!ai->ai_next) - error("bind: %.100s", strerror(errno)); - else - verbose("bind: %.100s", strerror(errno)); - - close(sock); - continue; - } - /* Start listening for connections on the socket. */ - if (listen(sock, SSH_LISTEN_BACKLOG) < 0) { - error("listen: %.100s", strerror(errno)); - close(sock); - continue; - } - /* Allocate a channel number for the socket. */ - c = channel_new("port listener", type, sock, sock, -1, - CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, - 0, "port listener", 1); - strlcpy(c->path, host, sizeof(c->path)); - c->host_port = port_to_connect; - c->listening_port = listen_port; - success = 1; - } - if (success == 0) - error("channel_setup_fwd_listener: cannot listen to port: %d", - listen_port); - freeaddrinfo(aitop); - return success; -} - -int -channel_cancel_rport_listener(const char *host, u_short port) -{ - u_int i; - int found = 0; - - for (i = 0; i < channels_alloc; i++) { - Channel *c = channels[i]; - - if (c != NULL && c->type == SSH_CHANNEL_RPORT_LISTENER && - strncmp(c->path, host, sizeof(c->path)) == 0 && - c->listening_port == port) { - debug2("%s: close channel %d", __func__, i); - channel_free(c); - found = 1; - } - } - - return (found); -} - -/* protocol local port fwd, used by ssh (and sshd in v1) */ -int -channel_setup_local_fwd_listener(const char *listen_host, u_short listen_port, - const char *host_to_connect, u_short port_to_connect, int gateway_ports) -{ - return channel_setup_fwd_listener(SSH_CHANNEL_PORT_LISTENER, - listen_host, listen_port, host_to_connect, port_to_connect, - gateway_ports); -} - -/* protocol v2 remote port fwd, used by sshd */ -int -channel_setup_remote_fwd_listener(const char *listen_address, - u_short listen_port, int gateway_ports) -{ - return channel_setup_fwd_listener(SSH_CHANNEL_RPORT_LISTENER, - listen_address, listen_port, NULL, 0, gateway_ports); -} - -/* - * Initiate forwarding of connections to port "port" on remote host through - * the secure channel to host:port from local side. - */ - -int -channel_request_remote_forwarding(const char *listen_host, u_short listen_port, - const char *host_to_connect, u_short port_to_connect) -{ - int 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; - if (listen_host == NULL) - address_to_bind = "localhost"; - else if (*listen_host == '\0' || strcmp(listen_host, "*") == 0) - address_to_bind = ""; - else - address_to_bind = listen_host; - - packet_start(SSH2_MSG_GLOBAL_REQUEST); - packet_put_cstring("tcpip-forward"); - packet_put_char(1); /* 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(); - switch (type) { - case SSH_SMSG_SUCCESS: - success = 1; - break; - case SSH_SMSG_FAILURE: - break; - default: - /* Unknown packet */ - packet_disconnect("Protocol error for port forward request:" - "received packet type %d.", type); - } - } - 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++; - } - return (success ? 0 : -1); -} - -/* - * Request cancellation of remote forwarding of connection host:port from - * local side. - */ -void -channel_request_rforward_cancel(const char *host, u_short port) -{ - int i; - - if (!compat20) - return; - - for (i = 0; i < num_permitted_opens; i++) { - if (permitted_opens[i].host_to_connect != NULL && - permitted_opens[i].listen_port == port) - break; - } - if (i >= num_permitted_opens) { - debug("%s: requested forward not found", __func__); - return; - } - packet_start(SSH2_MSG_GLOBAL_REQUEST); - packet_put_cstring("cancel-tcpip-forward"); - packet_put_char(0); - packet_put_cstring(host == NULL ? "" : host); - packet_put_int(port); - packet_send(); - - permitted_opens[i].listen_port = 0; - permitted_opens[i].port_to_connect = 0; - xfree(permitted_opens[i].host_to_connect); - permitted_opens[i].host_to_connect = NULL; -} - -/* - * This is called after receiving CHANNEL_FORWARDING_REQUEST. This initates - * listening for the port, and sends back a success reply (or disconnect - * message if there was an error). - */ -int -channel_input_port_forward_request(int is_root, int gateway_ports) -{ - u_short port, host_port; - int success = 0; - 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); - if (host_port == 0) - packet_disconnect("Dynamic forwarding denied."); -#endif - - /* Initiate forwarding */ - success = channel_setup_local_fwd_listener(NULL, port, hostname, - host_port, gateway_ports); - - /* Free the argument string. */ - xfree(hostname); - - return (success ? 0 : -1); -} - -/* - * Permits opening to any host/port if permitted_opens[] is empty. This is - * usually called by the server, because the user could connect to any port - * anyway, and the server has no way to know but to trust the client anyway. - */ -void -channel_permit_all_opens(void) -{ - if (num_permitted_opens == 0) - all_opens_permitted = 1; -} - -void -channel_add_permitted_opens(char *host, int port) -{ - if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION) - fatal("channel_add_permitted_opens: 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; -} - -int -channel_add_adm_permitted_opens(char *host, int port) -{ - if (num_adm_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION) - fatal("channel_add_adm_permitted_opens: too many forwards"); - debug("config allows port forwarding to host %s port %d", host, port); - - permitted_adm_opens[num_adm_permitted_opens].host_to_connect - = xstrdup(host); - permitted_adm_opens[num_adm_permitted_opens].port_to_connect = port; - return ++num_adm_permitted_opens; -} - -void -channel_clear_permitted_opens(void) -{ - int i; - - for (i = 0; i < num_permitted_opens; i++) - if (permitted_opens[i].host_to_connect != NULL) - xfree(permitted_opens[i].host_to_connect); - num_permitted_opens = 0; -} - -void -channel_clear_adm_permitted_opens(void) -{ - int i; - - for (i = 0; i < num_adm_permitted_opens; i++) - if (permitted_adm_opens[i].host_to_connect != NULL) - xfree(permitted_adm_opens[i].host_to_connect); - num_adm_permitted_opens = 0; -} - -/* return socket to remote host, port */ -static 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, ai->ai_socktype, ai->ai_protocol); - if (sock < 0) { - if (ai->ai_next == NULL) - error("socket: %.100s", strerror(errno)); - else - verbose("socket: %.100s", strerror(errno)); - continue; - } - if (set_nonblock(sock) == -1) - fatal("%s: set_nonblock(%d)", __func__, sock); - if (connect(sock, 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 */ - set_nodelay(sock); - return sock; -} - -int -channel_connect_by_listen_address(u_short listen_port) -{ - int i; - - for (i = 0; i < num_permitted_opens; i++) - if (permitted_opens[i].host_to_connect != NULL && - 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_adm = 1; - - permit = all_opens_permitted; - if (!permit) { - for (i = 0; i < num_permitted_opens; i++) - if (permitted_opens[i].host_to_connect != NULL && - permitted_opens[i].port_to_connect == port && - strcmp(permitted_opens[i].host_to_connect, host) == 0) - permit = 1; - } - - if (num_adm_permitted_opens > 0) { - permit_adm = 0; - for (i = 0; i < num_adm_permitted_opens; i++) - if (permitted_adm_opens[i].host_to_connect != NULL && - permitted_adm_opens[i].port_to_connect == port && - strcmp(permitted_adm_opens[i].host_to_connect, host) - == 0) - permit_adm = 1; - } - - if (!permit || !permit_adm) { - logit("Received request to connect to host %.100s port %d, " - "but the request was denied.", host, port); - return -1; - } - return connect_to(host, port); -} - -void -channel_send_window_changes(void) -{ - u_int i; - struct winsize ws; - - for (i = 0; i < channels_alloc; i++) { - if (channels[i] == NULL || !channels[i]->client_tty || - channels[i]->type != SSH_CHANNEL_OPEN) - continue; - if (ioctl(channels[i]->rfd, TIOCGWINSZ, &ws) < 0) - continue; - channel_request_start(i, "window-change", 0); - packet_put_int((u_int)ws.ws_col); - packet_put_int((u_int)ws.ws_row); - packet_put_int((u_int)ws.ws_xpixel); - packet_put_int((u_int)ws.ws_ypixel); - packet_send(); - } -} - -/* -- X11 forwarding */ - -/* - * Creates an internet domain socket for listening for X11 connections. - * Returns 0 and a suitable display number for the DISPLAY variable - * stored in display_numberp , or -1 if an error occurs. - */ -int -x11_create_display_inet(int x11_display_offset, int x11_use_localhost, - int single_connection, u_int *display_numberp, int **chanids) -{ - Channel *nc = NULL; - int display_number, sock; - u_short port; - struct addrinfo hints, *ai, *aitop; - char strport[NI_MAXSERV]; - int gaierr, n, num_socks = 0, socks[NUM_SOCKS]; - - if (chanids == NULL) - return -1; - - for (display_number = x11_display_offset; - display_number < MAX_DISPLAYS; - display_number++) { - port = 6000 + display_number; - memset(&hints, 0, sizeof(hints)); - hints.ai_family = IPv4or6; - hints.ai_flags = x11_use_localhost ? 0: AI_PASSIVE; - hints.ai_socktype = SOCK_STREAM; - snprintf(strport, sizeof strport, "%d", port); - if ((gaierr = getaddrinfo(NULL, strport, &hints, &aitop)) != 0) { - error("getaddrinfo: %.100s", gai_strerror(gaierr)); - return -1; - } - for (ai = aitop; ai; ai = ai->ai_next) { - if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6) - continue; - sock = socket(ai->ai_family, ai->ai_socktype, - ai->ai_protocol); - if (sock < 0) { - if ((errno != EINVAL) && (errno != EAFNOSUPPORT)) { - error("socket: %.100s", strerror(errno)); - freeaddrinfo(aitop); - return -1; - } else { - debug("x11_create_display_inet: Socket family %d not supported", - ai->ai_family); - continue; - } - } -#ifdef IPV6_V6ONLY - if (ai->ai_family == AF_INET6) { - int on = 1; - if (setsockopt(sock, IPPROTO_IPV6, IPV6_V6ONLY, &on, sizeof(on)) < 0) - error("setsockopt IPV6_V6ONLY: %.100s", strerror(errno)); - } -#endif - channel_set_reuseaddr(sock); - if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) { - debug2("bind port %d: %.100s", port, strerror(errno)); - close(sock); - - if (ai->ai_next) - continue; - - for (n = 0; n < num_socks; n++) { - close(socks[n]); - } - num_socks = 0; - break; - } - socks[num_socks++] = sock; -#ifndef DONT_TRY_OTHER_AF - if (num_socks == NUM_SOCKS) - break; -#else - if (x11_use_localhost) { - 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 -1; - } - /* Start listening for connections on the socket. */ - for (n = 0; n < num_socks; n++) { - sock = socks[n]; - if (listen(sock, SSH_LISTEN_BACKLOG) < 0) { - error("listen: %.100s", strerror(errno)); - close(sock); - return -1; - } - } - - /* Allocate a channel for each socket. */ - *chanids = xcalloc(num_socks + 1, sizeof(**chanids)); - for (n = 0; n < num_socks; n++) { - sock = socks[n]; - nc = channel_new("x11 listener", - SSH_CHANNEL_X11_LISTENER, sock, sock, -1, - CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT, - 0, "X11 inet listener", 1); - nc->single_connection = single_connection; - (*chanids)[n] = nc->self; - } - (*chanids)[n] = -1; - - /* Return the display number for the DISPLAY environment variable. */ - *display_numberp = display_number; - return (0); -} - -static int -connect_local_xsocket(u_int dnr) -{ - int sock; - struct sockaddr_un addr; - - sock = socket(AF_UNIX, SOCK_STREAM, 0); - if (sock < 0) - error("socket: %.100s", strerror(errno)); - memset(&addr, 0, sizeof(addr)); - addr.sun_family = AF_UNIX; - snprintf(addr.sun_path, sizeof addr.sun_path, _PATH_UNIX_X, 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) -{ - u_int display_number; - const char *display; - char buf[1024], *cp; - struct addrinfo hints, *ai, *aitop; - char strport[NI_MAXSERV]; - int gaierr, sock = 0; - - /* Try to open a socket for the local X server. */ - display = getenv("DISPLAY"); - if (!display) { - error("DISPLAY not set."); - return -1; - } - /* - * Now we decode the value of the DISPLAY variable and make a - * connection to the real X server. - */ - - /* - * Check if it is a unix domain socket. Unix domain displays are in - * one of the following formats: unix:d[.s], :d[.s], ::d[.s] - */ - if (strncmp(display, "unix:", 5) == 0 || - display[0] == ':') { - /* Connect to the unix domain socket. */ - if (sscanf(strrchr(display, ':') + 1, "%u", &display_number) != 1) { - error("Could not parse display number from DISPLAY: %.100s", - display); - return -1; - } - /* Create a socket. */ - sock = connect_local_xsocket(display_number); - if (sock < 0) - return -1; - - /* OK, we now have a connection to the display. */ - return sock; - } - /* - * Connect to an inet socket. The DISPLAY value is supposedly - * hostname:d[.s], where hostname may also be numeric IP address. - */ - strlcpy(buf, display, sizeof(buf)); - cp = strchr(buf, ':'); - if (!cp) { - error("Could not find ':' in DISPLAY: %.100s", display); - return -1; - } - *cp = 0; - /* buf now contains the host name. But first we parse the display number. */ - if (sscanf(cp + 1, "%u", &display_number) != 1) { - error("Could not parse display number from DISPLAY: %.100s", - display); - return -1; - } - - /* Look up the host address */ - memset(&hints, 0, sizeof(hints)); - hints.ai_family = IPv4or6; - hints.ai_socktype = SOCK_STREAM; - snprintf(strport, sizeof strport, "%u", 6000 + display_number); - if ((gaierr = getaddrinfo(buf, strport, &hints, &aitop)) != 0) { - error("%.100s: unknown host. (%s)", buf, gai_strerror(gaierr)); - return -1; - } - for (ai = aitop; ai; ai = ai->ai_next) { - /* Create a socket. */ - sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol); - if (sock < 0) { - debug2("socket: %.100s", strerror(errno)); - continue; - } - /* Connect it to the display. */ - if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0) { - debug2("connect %.100s port %u: %.100s", buf, - 6000 + display_number, strerror(errno)); - close(sock); - continue; - } - /* Success */ - break; - } - freeaddrinfo(aitop); - if (!ai) { - error("connect %.100s port %u: %.100s", buf, 6000 + display_number, - strerror(errno)); - return -1; - } - set_nodelay(sock); - return sock; -} - -/* - * This is called when SSH_SMSG_X11_OPEN is received. The packet contains - * the remote channel number. We should do whatever we want, and respond - * with either SSH_MSG_OPEN_CONFIRMATION or SSH_MSG_OPEN_FAILURE. - */ - -/* ARGSUSED */ -void -x11_input_open(int type, u_int32_t seq, void *ctxt) -{ - Channel *c = NULL; - int remote_id, sock = 0; - char *remote_host; - - debug("Received X11 open request."); - - remote_id = packet_get_int(); - - if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) { - remote_host = packet_get_string(NULL); - } else { - remote_host = xstrdup("unknown (remote did not supply name)"); - } - packet_check_eom(); - - /* Obtain a connection to the real X display. */ - sock = x11_connect_display(); - if (sock != -1) { - /* Allocate a channel for this connection. */ - c = channel_new("connected x11 socket", - SSH_CHANNEL_X11_OPEN, sock, sock, -1, 0, 0, 0, - remote_host, 1); - c->remote_id = remote_id; - c->force_drain = 1; - } - xfree(remote_host); - if (c == NULL) { - /* Send refusal to the remote host. */ - packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE); - packet_put_int(remote_id); - } else { - /* Send a confirmation to the remote host. */ - packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION); - packet_put_int(remote_id); - packet_put_int(c->self); - } - packet_send(); -} - -/* dummy protocol handler that denies SSH-1 requests (agent/x11) */ -/* ARGSUSED */ -void -deny_input_open(int type, u_int32_t seq, void *ctxt) -{ - int rchan = packet_get_int(); - - switch (type) { - case SSH_SMSG_AGENT_OPEN: - error("Warning: ssh server tried agent forwarding."); - break; - case SSH_SMSG_X11_OPEN: - error("Warning: ssh server tried X11 forwarding."); - break; - default: - error("deny_input_open: type %d", type); - break; - } - error("Warning: this is probably a break-in attempt by a malicious server."); - packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE); - packet_put_int(rchan); - packet_send(); -} - -/* - * Requests forwarding of X11 connections, generates fake authentication - * data, and enables authentication spoofing. - * This should be called in the client only. - */ -void -x11_request_forwarding_with_spoofing(int client_session_id, const char *disp, - const char *proto, const char *data) -{ - u_int data_len = (u_int) strlen(data) / 2; - u_int i, value; - char *new_data; - int screen_number; - const char *cp; - u_int32_t rnd = 0; - - if (x11_saved_display == NULL) - x11_saved_display = xstrdup(disp); - else if (strcmp(disp, x11_saved_display) != 0) { - error("x11_request_forwarding_with_spoofing: different " - "$DISPLAY already forwarded"); - return; - } - - cp = strchr(disp, ':'); - if (cp) - cp = strchr(cp, '.'); - if (cp) - screen_number = (u_int)strtonum(cp + 1, 0, 400, NULL); - else - screen_number = 0; - - if (x11_saved_proto == NULL) { - /* Save protocol name. */ - x11_saved_proto = xstrdup(proto); - /* - * Extract real authentication data 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) - rnd = arc4random(); - x11_saved_data[i] = value; - x11_fake_data[i] = rnd & 0xff; - rnd >>= 8; - } - x11_saved_data_len = data_len; - x11_fake_data_len = data_len; - } - - /* Convert the fake data into hex. */ - new_data = tohex(x11_fake_data, data_len); - - /* Send the request packet. */ - if (compat20) { - channel_request_start(client_session_id, "x11-req", 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); -} - - -/* -- agent forwarding */ - -/* Sends a message to the server to request authentication fd forwarding. */ - -void -auth_request_forwarding(void) -{ - packet_start(SSH_CMSG_AGENT_REQUEST_FORWARDING); - packet_send(); - packet_write_wait(); -} |
