/*
-
-channels.c
-
-Author: Tatu Ylonen <ylo@cs.hut.fi>
-
-Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
- All rights reserved
-
-Created: Fri Mar 24 16:35:24 1995 ylo
-
-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.
-
-*/
+ * 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 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"
-RCSID("$Id$");
+RCSID("$OpenBSD: channels.c,v 1.116 2001/05/16 22:09:20 markus Exp $");
+
+#include <openssl/rsa.h>
+#include <openssl/dsa.h>
#include "ssh.h"
+#include "ssh1.h"
+#include "ssh2.h"
#include "packet.h"
#include "xmalloc.h"
#include "buffer.h"
-#include "authfd.h"
+#include "bufaux.h"
#include "uidswap.h"
-#include "servconf.h"
-
+#include "log.h"
+#include "misc.h"
#include "channels.h"
#include "nchan.h"
#include "compat.h"
+#include "canohost.h"
+#include "key.h"
+#include "authfd.h"
/* Maximum number of fake X11 displays to try. */
#define MAX_DISPLAYS 1000
/* Max len of agent socket */
#define MAX_SOCKET_NAME 100
-/* Pointer to an array containing all allocated channels. The array is
- dynamically extended as needed. */
-static Channel *channels = NULL;
+/*
+ * 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 are marked with
- type SSH_CHANNEL_FREE. */
+/*
+ * 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 int channels_alloc = 0;
-/* Maximum file descriptor value used in any of the channels. This is updated
- in channel_allocate. */
-static int channel_max_fd_value = 0;
+/*
+ * Maximum file descriptor value used in any of the channels. This is
+ * updated in channel_new.
+ */
+static int channel_max_fd = 0;
/* Name and directory of socket for authentication agent forwarding. */
static char *channel_forwarded_auth_socket_name = NULL;
-static char *channel_forwarded_auth_socket_dir = NULL;
+static char *channel_forwarded_auth_socket_dir = NULL;
/* Saved X11 authentication protocol name. */
char *x11_saved_proto = NULL;
/* Saved X11 authentication data. This is the real data. */
char *x11_saved_data = NULL;
-unsigned int x11_saved_data_len = 0;
+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. */
+/*
+ * Fake X11 authentication data. This is what the server will be sending us;
+ * we should replace any occurrences of this by the real data.
+ */
char *x11_fake_data = NULL;
-unsigned int x11_fake_data_len;
+u_int x11_fake_data_len;
-/* 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; /* Host name. */
- int port; /* Port number. */
+/*
+ * 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. */
static ForwardPermission permitted_opens[SSH_MAX_FORWARDS_PER_DIRECTION];
/* Number of permitted host/port pairs in the array. */
static int num_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. */
+/*
+ * 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;
/* This is set to true if both sides support SSH_PROTOFLAG_HOST_IN_FWD_OPEN. */
static int have_hostname_in_open = 0;
+/* AF_UNSPEC or AF_INET or AF_INET6 */
+extern int IPv4or6;
+
+void port_open_helper(Channel *c, char *rtype);
+
/* Sets specific protocol options. */
-void channel_set_options(int hostname_in_open)
-{
- have_hostname_in_open = hostname_in_open;
-}
-
-/* Permits opening to any host/port in SSH_MSG_PORT_OPEN. 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()
-{
- all_opens_permitted = 1;
-}
-
-/* Allocate a new channel object and set its type and socket.
- This will cause remote_name to be freed. */
-
-int channel_allocate(int type, int sock, char *remote_name)
-{
- int i, found;
- Channel *c;
-
- /* Update the maximum file descriptor value. */
- if (sock > channel_max_fd_value)
- channel_max_fd_value = sock;
-
- /* Do initial allocation if this is the first call. */
- if (channels_alloc == 0)
- {
- channels_alloc = 10;
- channels = xmalloc(channels_alloc * sizeof(Channel));
- for (i = 0; i < channels_alloc; i++)
- channels[i].type = SSH_CHANNEL_FREE;
-
- /* Kludge: arrange a call to channel_stop_listening if we terminate
- with fatal(). */
- fatal_add_cleanup((void (*)(void *))channel_stop_listening, 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].type == SSH_CHANNEL_FREE)
- {
- /* Found a free slot. */
- found = i;
- break;
- }
-
- if (found == -1)
- {
- /* There are no free slots. Take last+1 slot and expand the array. */
- found = channels_alloc;
- channels_alloc += 10;
- debug("channel: expanding %d", channels_alloc);
- channels = xrealloc(channels, channels_alloc * sizeof(Channel));
- for (i = found; i < channels_alloc; i++)
- channels[i].type = SSH_CHANNEL_FREE;
- }
-
- /* Initialize and return new channel number. */
- c=&channels[found];
- buffer_init(&c->input);
- buffer_init(&c->output);
- chan_init_iostates(c);
- c->self = found;
- c->type = type;
- c->x11 = 0;
- c->sock = sock;
- c->remote_id = -1;
- c->remote_name = remote_name;
- debug("channel %d: new [%s]", found, remote_name);
- return found;
-}
-
-/* Free the channel and close its socket. */
-
-void channel_free(int channel)
-{
- assert(channel >= 0 && channel < channels_alloc &&
- channels[channel].type != SSH_CHANNEL_FREE);
- if(compat13)
- shutdown(channels[channel].sock, SHUT_RDWR);
- close(channels[channel].sock);
- buffer_free(&channels[channel].input);
- buffer_free(&channels[channel].output);
- channels[channel].type = SSH_CHANNEL_FREE;
- if (channels[channel].remote_name)
- {
- xfree(channels[channel].remote_name);
- channels[channel].remote_name = NULL;
- }
-}
-
-/* This is called just before select() to add any bits relevant to
- channels in the select bitmasks. */
-
-void channel_prepare_select(fd_set *readset, fd_set *writeset)
-{
- int i;
- Channel *ch;
- unsigned char *ucp;
- unsigned int proto_len, data_len;
-
- for (i = 0; i < channels_alloc; i++)
- {
- ch = &channels[i];
- redo:
- switch (ch->type)
- {
- case SSH_CHANNEL_X11_LISTENER:
- case SSH_CHANNEL_PORT_LISTENER:
- case SSH_CHANNEL_AUTH_SOCKET:
- FD_SET(ch->sock, readset);
- break;
-
- case SSH_CHANNEL_OPEN:
- if(compat13){
- if (buffer_len(&ch->input) < 32768)
- FD_SET(ch->sock, readset);
- if (buffer_len(&ch->output) > 0)
- FD_SET(ch->sock, writeset);
- break;
- }
- /* test whether sockets are 'alive' for read/write */
- if (ch->istate == CHAN_INPUT_OPEN)
- if (buffer_len(&ch->input) < 32768)
- FD_SET(ch->sock, readset);
- if (ch->ostate == CHAN_OUTPUT_OPEN || ch->ostate == CHAN_OUTPUT_WAIT_DRAIN){
- if (buffer_len(&ch->output) > 0){
- FD_SET(ch->sock, writeset);
- }else if(ch->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
- chan_obuf_empty(ch);
- }
- }
- break;
-
- case SSH_CHANNEL_INPUT_DRAINING:
- if (!compat13)
- fatal("cannot happen: IN_DRAIN");
- if (buffer_len(&ch->input) == 0)
- {
- packet_start(SSH_MSG_CHANNEL_CLOSE);
- packet_put_int(ch->remote_id);
- packet_send();
- ch->type = SSH_CHANNEL_CLOSED;
- debug("Closing channel %d after input drain.", i);
- break;
- }
- break;
-
- case SSH_CHANNEL_OUTPUT_DRAINING:
- if (!compat13)
- fatal("cannot happen: OUT_DRAIN");
- if (buffer_len(&ch->output) == 0)
- {
- /* debug("Freeing channel %d after output drain.", i); */
- channel_free(i);
- break;
- }
- FD_SET(ch->sock, writeset);
- break;
-
- case SSH_CHANNEL_X11_OPEN:
- /* 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. */
-
- /* Check if the fixed size part of the packet is in buffer. */
- if (buffer_len(&ch->output) < 12)
- break;
-
- /* Parse the lengths of variable-length fields. */
- ucp = (unsigned char *)buffer_ptr(&ch->output);
- 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. */
+void
+channel_set_options(int hostname_in_open)
+{
+ have_hostname_in_open = hostname_in_open;
+}
+
+/* lookup channel by id */
+
+Channel *
+channel_lookup(int id)
+{
+ Channel *c;
+
+ if (id < 0 || id > channels_alloc) {
+ log("channel_lookup: %d: bad id", id);
+ return NULL;
+ }
+ c = channels[id];
+ if (c == NULL) {
+ log("channel_lookup: %d: bad id: channel free", id);
+ return NULL;
+ }
+ return c;
+}
+
+/*
+ * Register filedescriptors for a channel, used when allocating a channel or
+ * when the channel consumer/producer is ready, e.g. shell exec'd
+ */
+
+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->efd = efd;
+ c->extended_usage = extusage;
+
+ /* XXX ugly hack: nonblock is only set by the server */
+ if (nonblock && isatty(c->rfd)) {
+ debug("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;
+ }
+
+ /* 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,
+ int window, int maxpack, int extusage, char *remote_name, int nonblock)
+{
+ int i, found;
+ Channel *c;
+
+ /* Do initial allocation if this is the first call. */
+ if (channels_alloc == 0) {
+ chan_init();
+ channels_alloc = 10;
+ channels = xmalloc(channels_alloc * sizeof(Channel *));
+ for (i = 0; i < channels_alloc; i++)
+ channels[i] = NULL;
+ /*
+ * Kludge: arrange a call to channel_stop_listening if we
+ * terminate with fatal().
+ */
+ fatal_add_cleanup((void (*) (void *)) channel_stop_listening, 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 = i;
+ break;
+ }
+ if (found == -1) {
+ /* There are no free slots. Take last+1 slot and expand the array. */
+ found = channels_alloc;
+ channels_alloc += 10;
+ debug2("channel: expanding %d", channels_alloc);
+ channels = xrealloc(channels, channels_alloc * sizeof(Channel *));
+ for (i = found; i < channels_alloc; i++)
+ channels[i] = NULL;
+ }
+ /* Initialize and return new channel. */
+ c = channels[found] = xmalloc(sizeof(Channel));
+ buffer_init(&c->input);
+ buffer_init(&c->output);
+ buffer_init(&c->extended);
+ chan_init_iostates(c);
+ 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 = remote_name;
+ c->remote_window = 0;
+ c->remote_maxpacket = 0;
+ c->cb_fn = NULL;
+ c->cb_arg = NULL;
+ c->cb_event = 0;
+ c->dettach_user = NULL;
+ c->input_filter = NULL;
+ debug("channel %d: new [%s]", found, remote_name);
+ return c;
+}
+
+/* Close all channel fd/socket. */
+
+void
+channel_close_fds(Channel *c)
+{
+ if (c->sock != -1) {
+ close(c->sock);
+ c->sock = -1;
+ }
+ if (c->rfd != -1) {
+ close(c->rfd);
+ c->rfd = -1;
+ }
+ if (c->wfd != -1) {
+ close(c->wfd);
+ c->wfd = -1;
+ }
+ if (c->efd != -1) {
+ close(c->efd);
+ c->efd = -1;
+ }
+}
+
+/* Free the channel and close its fd/socket. */
+
+void
+channel_free(Channel *c)
+{
+ char *s;
+
+ s = channel_open_message();
+ debug("channel_free: channel %d: status: %s", c->self, s);
+ xfree(s);
+
+ if (c->dettach_user != NULL) {
+ debug("channel_free: channel %d: dettaching channel user", c->self);
+ c->dettach_user(c->self, NULL);
+ }
+ if (c->sock != -1)
+ shutdown(c->sock, SHUT_RDWR);
+ channel_close_fds(c);
+ buffer_free(&c->input);
+ buffer_free(&c->output);
+ buffer_free(&c->extended);
+ if (c->remote_name) {
+ xfree(c->remote_name);
+ c->remote_name = NULL;
+ }
+ channels[c->self] = NULL;
+ xfree(c);
+}
+
+/*
+ * '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];
+
+void
+channel_pre_listener(Channel *c, fd_set * readset, fd_set * writeset)
+{
+ FD_SET(c->sock, readset);
+}
+
+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);
+}
+
+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);
+}
+
+void
+channel_pre_open_15(Channel *c, fd_set * readset, fd_set * writeset)
+{
+ /* test whether sockets are 'alive' for read/write */
+ if (c->istate == CHAN_INPUT_OPEN)
+ if (buffer_len(&c->input) < packet_get_maxsize())
+ FD_SET(c->sock, readset);
+ if (c->ostate == CHAN_OUTPUT_OPEN ||
+ c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
+ if (buffer_len(&c->output) > 0) {
+ FD_SET(c->sock, writeset);
+ } else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
+ chan_obuf_empty(c);
+ }
+ }
+}
+
+void
+channel_pre_open_20(Channel *c, fd_set * readset, fd_set * writeset)
+{
+ if (c->istate == CHAN_INPUT_OPEN &&
+ c->remote_window > 0 &&
+ buffer_len(&c->input) < c->remote_window)
+ 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) {
+ chan_obuf_empty(c);
+ }
+ }
+ /** XXX check close conditions, too */
+ if (c->efd != -1) {
+ if (c->extended_usage == CHAN_EXTENDED_WRITE &&
+ buffer_len(&c->extended) > 0)
+ FD_SET(c->efd, writeset);
+ else if (c->extended_usage == CHAN_EXTENDED_READ &&
+ buffer_len(&c->extended) < c->remote_window)
+ FD_SET(c->efd, readset);
+ }
+}
+
+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;
+ debug("channel %d: closing after input drain.", c->self);
+ }
+}
+
+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.
+ */
+int
+x11_open_helper(Channel *c)
+{
+ u_char *ucp;
+ u_int proto_len, data_len;
+
+ /* Check if the fixed size part of the packet is in buffer. */
+ if (buffer_len(&c->output) < 12)
+ return 0;
+
+ /* Parse the lengths of variable-length fields. */
+ ucp = (u_char *) buffer_ptr(&c->output);
+ 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
- {
+ } else {
debug("Initial X11 packet contains bad byte order byte: 0x%x",
ucp[0]);
- ch->type = SSH_CHANNEL_OPEN;
- goto reject;
- }
-
- /* Check if the whole packet is in buffer. */
- if (buffer_len(&ch->output) <
- 12 + ((proto_len + 3) & ~3) + ((data_len + 3) & ~3))
- break;
-
- /* Check if authentication protocol matches. */
- if (proto_len != strlen(x11_saved_proto) ||
- memcmp(ucp + 12, x11_saved_proto, proto_len) != 0)
- {
- debug("X11 connection uses different authentication protocol.");
- ch->type = SSH_CHANNEL_OPEN;
- goto reject;
- }
-
- /* 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)
- {
- debug("X11 auth data does not match fake data.");
- ch->type = SSH_CHANNEL_OPEN;
- goto reject;
- }
-
- /* Received authentication protocol and data match our fake data.
- Substitute the fake data with real data. */
- assert(x11_fake_data_len == x11_saved_data_len);
- memcpy(ucp + 12 + ((proto_len + 3) & ~3),
- x11_saved_data, x11_saved_data_len);
-
- /* Start normal processing for the channel. */
- ch->type = SSH_CHANNEL_OPEN;
- /* Enable X11 Problem FIX */
- ch->x11 = 1;
- goto redo;
-
- reject:
- /* We have received an X11 connection that has bad authentication
- information. */
- log("X11 connection rejected because of wrong authentication.\r\n");
- buffer_clear(&ch->input);
- buffer_clear(&ch->output);
- if (compat13) {
- close(ch->sock);
- ch->sock = -1;
- ch->type = SSH_CHANNEL_CLOSED;
- packet_start(SSH_MSG_CHANNEL_CLOSE);
- packet_put_int(ch->remote_id);
- packet_send();
- }else{
- debug("X11 rejected %d i%d/o%d", ch->self, ch->istate, ch->ostate);
- chan_read_failed(ch);
- chan_write_failed(ch);
- debug("X11 rejected %d i%d/o%d", ch->self, ch->istate, ch->ostate);
- }
- break;
-
- case SSH_CHANNEL_FREE:
+ return -1;
+ }
+
+ /* Check if the whole packet is in buffer. */
+ if (buffer_len(&c->output) <
+ 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) {
+ debug("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) {
+ debug("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;
+}
+
+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:
- continue;
+ 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");
}
- }
}
-/* After select, perform any appropriate operations for channels which
- have events pending. */
+/* This is our fake X11 server socket. */
+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 (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);
+
+ nc = channel_new("accepted x11 socket",
+ SSH_CHANNEL_OPENING, newsock, newsock, -1,
+ c->local_window_max, c->local_maxpacket,
+ 0, xstrdup(buf), 1);
+ if (nc == NULL) {
+ close(newsock);
+ xfree(remote_ipaddr);
+ return;
+ }
+ if (compat20) {
+ packet_start(SSH2_MSG_CHANNEL_OPEN);
+ packet_put_cstring("x11");
+ packet_put_int(nc->self);
+ 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(nc->self);
+ if (have_hostname_in_open)
+ packet_put_string(buf, strlen(buf));
+ packet_send();
+ }
+ xfree(remote_ipaddr);
+ }
+}
-void channel_after_select(fd_set *readset, fd_set *writeset)
+void
+port_open_helper(Channel *c, char *rtype)
{
- struct sockaddr addr;
- int addrlen, newsock, i, newch, len;
- Channel *ch;
- char buf[16384], *remote_hostname;
-
- /* Loop over all channels... */
- for (i = 0; i < channels_alloc; i++)
- {
- ch = &channels[i];
- switch (ch->type)
- {
- case SSH_CHANNEL_X11_LISTENER:
- /* This is our fake X11 server socket. */
- if (FD_ISSET(ch->sock, readset))
- {
- debug("X11 connection requested.");
- addrlen = sizeof(addr);
- newsock = accept(ch->sock, &addr, &addrlen);
- if (newsock < 0)
- {
- error("accept: %.100s", strerror(errno));
- break;
+ 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);
}
- remote_hostname = get_remote_hostname(newsock);
- snprintf(buf, sizeof buf, "X11 connection from %.200s port %d",
- remote_hostname, get_peer_port(newsock));
- xfree(remote_hostname);
- newch = channel_allocate(SSH_CHANNEL_OPENING, newsock,
- xstrdup(buf));
- packet_start(SSH_SMSG_X11_OPEN);
- packet_put_int(newch);
- if (have_hostname_in_open)
- packet_put_string(buf, strlen(buf));
- packet_send();
- }
- break;
-
- case SSH_CHANNEL_PORT_LISTENER:
- /* This socket is listening for connections to a forwarded TCP/IP
- port. */
- if (FD_ISSET(ch->sock, readset))
- {
- debug("Connection to port %d forwarding to %.100s:%d requested.",
- ch->listening_port, ch->path, ch->host_port);
- addrlen = sizeof(addr);
- newsock = accept(ch->sock, &addr, &addrlen);
- if (newsock < 0)
- {
- error("accept: %.100s", strerror(errno));
- break;
+ /* 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, 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 &&
+ c->type != SSH_CHANNEL_RPORT_LISTENER) ?
+ SSH_CHANNEL_DYNAMIC : SSH_CHANNEL_OPENING;
+
+ addrlen = sizeof(addr);
+ newsock = accept(c->sock, &addr, &addrlen);
+ if (newsock < 0) {
+ error("accept: %.100s", strerror(errno));
+ return;
}
- remote_hostname = get_remote_hostname(newsock);
- snprintf(buf, sizeof buf, "listen port %d:%.100s:%d, connect from %.200s:%d",
- ch->listening_port, ch->path, ch->host_port,
- remote_hostname, get_peer_port(newsock));
- xfree(remote_hostname);
- newch = channel_allocate(SSH_CHANNEL_OPENING, newsock,
- xstrdup(buf));
- packet_start(SSH_MSG_PORT_OPEN);
- packet_put_int(newch);
- packet_put_string(ch->path, strlen(ch->path));
- packet_put_int(ch->host_port);
- if (have_hostname_in_open)
- packet_put_string(buf, strlen(buf));
- packet_send();
- }
- break;
-
- case SSH_CHANNEL_AUTH_SOCKET:
- /* This is the authentication agent socket listening for connections
- from clients. */
- if (FD_ISSET(ch->sock, readset))
- {
- int nchan;
- len = sizeof(addr);
- newsock = accept(ch->sock, &addr, &len);
- if (newsock < 0)
- {
- error("accept from auth socket: %.100s", strerror(errno));
- break;
+ nc = channel_new(rtype,
+ nextstate, newsock, newsock, -1,
+ c->local_window_max, c->local_maxpacket,
+ 0, xstrdup(rtype), 1);
+ if (nc == NULL) {
+ error("channel_post_port_listener: no new channel:");
+ close(newsock);
+ 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);
+ }
+}
- nchan = channel_allocate(SSH_CHANNEL_OPENING, newsock,
- xstrdup("accepted auth socket"));
- packet_start(SSH_SMSG_AGENT_OPEN);
- packet_put_int(nchan);
- packet_send();
- }
- break;
-
- case SSH_CHANNEL_OPEN:
- /* This is an open two-way communication channel. It is not of
- interest to us at this point what kind of data is being
- transmitted. */
-
- /* Read available incoming data and append it to buffer;
- shutdown socket, if read or write failes */
- if (FD_ISSET(ch->sock, readset))
- {
- len = read(ch->sock, buf, sizeof(buf));
- if (len <= 0)
- {
- if (compat13) {
- buffer_consume(&ch->output, buffer_len(&ch->output));
- ch->type = SSH_CHANNEL_INPUT_DRAINING;
- debug("Channel %d status set to input draining.", i);
- }else{
- chan_read_failed(ch);
- }
- break;
+/*
+ * This is the authentication agent socket listening for connections from
+ * clients.
+ */
+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;
}
- buffer_append(&ch->input, buf, len);
- }
- /* Send buffered output data to the socket. */
- if (FD_ISSET(ch->sock, writeset) && buffer_len(&ch->output) > 0)
- {
- len = write(ch->sock, buffer_ptr(&ch->output),
- buffer_len(&ch->output));
- if (len <= 0)
- {
- if (compat13) {
- buffer_consume(&ch->output, buffer_len(&ch->output));
- debug("Channel %d status set to input draining.", i);
- ch->type = SSH_CHANNEL_INPUT_DRAINING;
- }else{
- chan_write_failed(ch);
- }
- break;
+ nc = 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 (nc == NULL) {
+ error("channel_post_auth_listener: channel_new failed");
+ close(newsock);
}
- buffer_consume(&ch->output, len);
- }
- break;
-
- case SSH_CHANNEL_OUTPUT_DRAINING:
- if (!compat13)
- fatal("cannot happen: OUT_DRAIN");
- /* Send buffered output data to the socket. */
- if (FD_ISSET(ch->sock, writeset) && buffer_len(&ch->output) > 0)
- {
- len = write(ch->sock, buffer_ptr(&ch->output),
- buffer_len(&ch->output));
- if (len <= 0)
- buffer_consume(&ch->output, buffer_len(&ch->output));
- else
- buffer_consume(&ch->output, len);
- }
- break;
-
- case SSH_CHANNEL_X11_OPEN:
- case SSH_CHANNEL_FREE:
- default:
- continue;
+ 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();
}
- }
}
-/* If there is data to send to the connection, send some of it now. */
+void
+channel_post_connecting(Channel *c, fd_set * readset, fd_set * writeset)
+{
+ int err = 0;
+ int sz = sizeof(err);
+
+ if (FD_ISSET(c->sock, writeset)) {
+ if (getsockopt(c->sock, SOL_SOCKET, SO_ERROR, (char *)&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();
+ }
+}
-void channel_output_poll()
+int
+channel_handle_rfd(Channel *c, fd_set * readset, fd_set * writeset)
{
- int len, i;
- Channel *ch;
+ char buf[16*1024];
+ int len;
+
+ if (c->istate == CHAN_INPUT_OPEN &&
+ 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);
+ chan_mark_dead(c);
+ 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->ostate == CHAN_OUTPUT_OPEN ||
+ c->ostate == CHAN_OUTPUT_WAIT_DRAIN) &&
+ 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);
+ chan_mark_dead(c);
+ 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;
+}
- for (i = 0; i < channels_alloc; i++)
- {
- ch = &channels[i];
- /* We are only interested in channels that can have buffered incoming
- data. */
- if (ch->type != SSH_CHANNEL_OPEN &&
- ch->type != SSH_CHANNEL_INPUT_DRAINING)
- continue;
+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);
+}
- /* Get the amount of buffered data for this channel. */
- len = buffer_len(&ch->input);
- if (len > 0)
- {
- /* Send some data for the other side over the secure connection. */
- if (packet_is_interactive())
- {
- if (len > 1024)
- len = 512;
- }
- else
- {
- if (len > 16384)
- len = 16384; /* Keep the packets at reasonable size. */
- }
- packet_start(SSH_MSG_CHANNEL_DATA);
- packet_put_int(ch->remote_id);
- packet_put_string(buffer_ptr(&ch->input), len);
- packet_send();
- buffer_consume(&ch->input, len);
- }
- else if(ch->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(ch);
- }
- }
-}
-
-/* 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 payload_len)
-{
- int channel;
- char *data;
- unsigned int data_len;
-
- /* Get the channel number and verify it. */
- channel = packet_get_int();
- if (channel < 0 || channel >= channels_alloc ||
- channels[channel].type == SSH_CHANNEL_FREE)
- packet_disconnect("Received data for nonexistent channel %d.", channel);
-
- /* Ignore any data for non-open channels (might happen on close) */
- if (channels[channel].type != SSH_CHANNEL_OPEN &&
- channels[channel].type != SSH_CHANNEL_X11_OPEN)
- return;
-
- /* Get the data. */
- data = packet_get_string(&data_len);
- packet_integrity_check(payload_len, 4 + 4+data_len, SSH_MSG_CHANNEL_DATA);
- buffer_append(&channels[channel].output, 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()
-{
- unsigned int i;
- Channel *ch;
-
- for (i = 0; i < channels_alloc; i++)
- {
- ch = &channels[i];
- switch (ch->type)
- {
- case SSH_CHANNEL_X11_LISTENER:
- case SSH_CHANNEL_PORT_LISTENER:
- case SSH_CHANNEL_AUTH_SOCKET:
- continue;
- case SSH_CHANNEL_OPEN:
- if (buffer_len(&ch->input) > 32768)
- return 0;
- if (buffer_len(&ch->output) > 32768)
- return 0;
- continue;
- case SSH_CHANNEL_INPUT_DRAINING:
- case SSH_CHANNEL_OUTPUT_DRAINING:
- case SSH_CHANNEL_X11_OPEN:
- case SSH_CHANNEL_FREE:
- default:
- continue;
+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);
}
- }
- return 1;
}
-/* This is called after receiving CHANNEL_CLOSE/IEOF. */
+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_input_close()
+void
+channel_handler_init_13(void)
{
- int channel;
+ 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;
+}
- /* Get the channel number and verify it. */
- channel = packet_get_int();
- if (channel < 0 || channel >= channels_alloc ||
- channels[channel].type == SSH_CHANNEL_FREE)
- packet_disconnect("Received data for nonexistent channel %d.", channel);
+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;
+}
- if(!compat13){
- /* proto version 1.5 overloads CLOSE with IEOF */
- chan_rcvd_ieof(&channels[channel]);
- return;
- }
+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();
+}
- /* 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(channels[channel].remote_id);
- packet_send();
+void
+channel_handler(chan_fn *ftab[], fd_set * readset, fd_set * writeset)
+{
+ static int did_init = 0;
+ int i;
+ Channel *c;
- /* 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 (channels[channel].type != SSH_CHANNEL_CLOSED)
- {
- /* Not a closed channel - mark it as draining, which will cause it to
- be freed later. */
- buffer_consume(&channels[channel].input,
- buffer_len(&channels[channel].input));
- channels[channel].type = SSH_CHANNEL_OUTPUT_DRAINING;
- /* debug("Setting status to output draining; output len = %d",
- buffer_len(&channels[channel].output)); */
- }
+ 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)
+ 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);
+ }
+ }
}
-/* This is called after receiving CHANNEL_CLOSE_CONFIRMATION/OCLOSE. */
+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_input_close_confirmation()
+void
+channel_after_select(fd_set * readset, fd_set * writeset)
{
- int channel;
+ channel_handler(channel_post, readset, writeset);
+}
- /* Get the channel number and verify it. */
- channel = packet_get_int();
- if (channel < 0 || channel >= channels_alloc)
- packet_disconnect("Received close confirmation for out-of-range channel %d.",
- channel);
+/* If there is data to send to the connection, enqueue some of it now. */
- if(!compat13){
- /* proto version 1.5 overloads CLOSE_CONFIRMATION with OCLOSE */
- chan_rcvd_oclose(&channels[channel]);
- return;
- }
+void
+channel_output_poll()
+{
+ int len, i;
+ Channel *c;
+
+ 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? */
+ debug2("channel %d: no data after CLOSE", c->self);
+ continue;
+ }
- if (channels[channel].type != SSH_CHANNEL_CLOSED)
- packet_disconnect("Received close confirmation for non-closed channel %d (type %d).",
- channel, channels[channel].type);
+ /* 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);
+ }
+ }
+}
- /* Free the channel. */
- channel_free(channel);
+/*
+ * 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);
}
-/* This is called after receiving CHANNEL_OPEN_CONFIRMATION. */
-void channel_input_open_confirmation()
+/*
+ * 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()
{
- int channel, remote_channel;
+ u_int i;
+ Channel *c;
+
+ for (i = 0; i < channels_alloc; i++) {
+ c = channels[i];
+ if (c != NULL && 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;
+}
- /* Get the channel number and verify it. */
- channel = packet_get_int();
- if (channel < 0 || channel >= channels_alloc ||
- channels[channel].type != SSH_CHANNEL_OPENING)
- packet_disconnect("Received open confirmation for non-opening channel %d.",
- channel);
+void
+channel_input_ieof(int type, int plen, void *ctxt)
+{
+ int id;
+ Channel *c;
- /* Get remote side's id for this channel. */
- remote_channel = packet_get_int();
+ packet_integrity_check(plen, 4, type);
- /* Record the remote channel number and mark that the channel is now open. */
- channels[channel].remote_id = remote_channel;
- channels[channel].type = SSH_CHANNEL_OPEN;
+ id = packet_get_int();
+ c = channel_lookup(id);
+ if (c == NULL)
+ packet_disconnect("Received ieof for nonexistent channel %d.", id);
+ chan_rcvd_ieof(c);
}
-/* This is called after receiving CHANNEL_OPEN_FAILURE from the other side. */
+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;
+ }
+}
-void channel_input_open_failure()
+/* proto version 1.5 overloads CLOSE_CONFIRMATION with OCLOSE */
+void
+channel_input_oclose(int type, int plen, void *ctxt)
{
- int channel;
+ 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);
+}
- /* Get the channel number and verify it. */
- channel = packet_get_int();
- if (channel < 0 || channel >= channels_alloc ||
- channels[channel].type != SSH_CHANNEL_OPENING)
- packet_disconnect("Received open failure for non-opening channel %d.",
- channel);
-
- /* Free the channel. This will also close the socket. */
- channel_free(channel);
+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);
}
-/* Stops listening for channels, and removes any unix domain sockets that
- we might have. */
+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_stop_listening()
+char *
+reason2txt(int reason)
{
- int i;
- for (i = 0; i < channels_alloc; i++)
- {
- switch (channels[i].type)
- {
- case SSH_CHANNEL_AUTH_SOCKET:
- close(channels[i].sock);
- remove(channels[i].path);
- channel_free(i);
- break;
- case SSH_CHANNEL_PORT_LISTENER:
- case SSH_CHANNEL_X11_LISTENER:
- close(channels[i].sock);
- channel_free(i);
- break;
- default:
- break;
+ 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 "unkown reason";
}
-/* Closes the sockets of all channels. This is used to close extra file
- descriptors after a fork. */
+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 (!(datafellows & SSH_BUG_OPENFAILURE)) {
+ msg = packet_get_string(NULL);
+ lang = packet_get_string(NULL);
+ }
+ packet_done();
+ log("channel %d: open failed: %s%s%s", id,
+ reason2txt(reason), msg ? ": ": "", msg ? msg : "");
+ if (msg != NULL)
+ xfree(msg);
+ if (lang != NULL)
+ xfree(lang);
+ }
+ /* Free the channel. This will also close the socket. */
+ channel_free(c);
+}
+
+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;
+}
-void channel_close_all()
+/*
+ * 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++)
- {
- if (channels[i].type != SSH_CHANNEL_FREE)
- close(channels[i].sock);
- }
+ 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:
+ close(c->sock);
+ unlink(c->path);
+ channel_free(c);
+ break;
+ case SSH_CHANNEL_PORT_LISTENER:
+ case SSH_CHANNEL_RPORT_LISTENER:
+ case SSH_CHANNEL_X11_LISTENER:
+ close(c->sock);
+ channel_free(c);
+ break;
+ default:
+ break;
+ }
+ }
+ }
}
-/* Returns the maximum file descriptor number used by the channels. */
+/*
+ * Closes the sockets/fds of all channels. This is used to close extra file
+ * descriptors after a fork.
+ */
-int channel_max_fd()
+void
+channel_close_all()
{
- return channel_max_fd_value;
+ int i;
+
+ for (i = 0; i < channels_alloc; i++)
+ if (channels[i] != NULL)
+ channel_close_fds(channels[i]);
}
/* Returns true if any channel is still open. */
-int channel_still_open()
-{
- unsigned 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_CLOSED:
- case SSH_CHANNEL_AUTH_SOCKET:
- 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 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_CLOSED:
- case SSH_CHANNEL_AUTH_SOCKET:
- continue;
- case SSH_CHANNEL_OPENING:
- 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 o%d)\r\n",
- c->self,c->remote_name,
- c->type,c->remote_id, c->istate,c->ostate);
+int
+channel_still_open()
+{
+ 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:
+ 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()
+{
+ int i;
+ Channel *c;
+
+ for (i = 0; i < channels_alloc; i++) {
+ c = channels[i];
+ if (c == NULL)
+ 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:
+ 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()
+{
+ Buffer buffer;
+ Channel *c;
+ char buf[1024], *cp;
+ int i;
+
+ buffer_init(&buffer);
+ snprintf(buf, sizeof buf, "The following connections are open:\r\n");
buffer_append(&buffer, buf, strlen(buf));
- continue;
- default:
- fatal("channel_still_open: 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. */
-
-void channel_request_local_forwarding(int port, const char *host,
- int host_port)
-{
- int ch, sock;
- struct sockaddr_in sin;
- extern Options options;
-
- if (strlen(host) > sizeof(channels[0].path) - 1)
- packet_disconnect("Forward host name too long.");
-
- /* Create a port to listen for the host. */
- sock = socket(AF_INET, SOCK_STREAM, 0);
- if (sock < 0)
- packet_disconnect("socket: %.100s", strerror(errno));
-
- /* Initialize socket address. */
- memset(&sin, 0, sizeof(sin));
- sin.sin_family = AF_INET;
- if (options.gateway_ports == 1)
- sin.sin_addr.s_addr = htonl(INADDR_ANY);
- else
- sin.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
- sin.sin_port = htons(port);
-
- /* Bind the socket to the address. */
- if (bind(sock, (struct sockaddr *)&sin, sizeof(sin)) < 0)
- packet_disconnect("bind: %.100s", strerror(errno));
-
- /* Start listening for connections on the socket. */
- if (listen(sock, 5) < 0)
- packet_disconnect("listen: %.100s", strerror(errno));
-
- /* Allocate a channel number for the socket. */
- ch = channel_allocate(SSH_CHANNEL_PORT_LISTENER, sock,
- xstrdup("port listener"));
- strcpy(channels[ch].path, host); /* note: host name stored here */
- channels[ch].host_port = host_port; /* port on host to connect to */
- channels[ch].listening_port = port; /* port being listened */
-}
-
-/* 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(int port, const char *host,
- int remote_port)
-{
- int payload_len;
- /* 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");
- permitted_opens[num_permitted_opens].host = xstrdup(host);
- permitted_opens[num_permitted_opens].port = remote_port;
- num_permitted_opens++;
-
- /* Send the forward request to the remote side. */
- packet_start(SSH_CMSG_PORT_FORWARD_REQUEST);
- packet_put_int(port);
- packet_put_string(host, strlen(host));
- packet_put_int(remote_port);
- packet_send();
- packet_write_wait();
-
- /* Wait for response from the remote side. It will send a disconnect
- message on failure, and we will never see it here. */
- packet_read_expect(&payload_len, SSH_SMSG_SUCCESS);
-}
-
-/* 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 port, host_port;
- char *hostname;
-
- /* Get arguments from the packet. */
- port = packet_get_int();
- hostname = packet_get_string(NULL);
- host_port = packet_get_int();
-
- /* Port numbers are 16 bit quantities. */
- if ((port & 0xffff) != port)
- packet_disconnect("Requested forwarding of nonexistent port %d.", port);
-
- /* 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);
-
- /* Initiate forwarding. */
- channel_request_local_forwarding(port, hostname, host_port);
-
- /* Free the argument string. */
- xfree(hostname);
-}
-
-/* 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 payload_len)
-{
- int remote_channel, sock, newch, host_port, i;
- struct sockaddr_in sin;
- char *host, *originator_string;
- struct hostent *hp;
- int host_len, originator_len;
-
- /* Get remote channel number. */
- remote_channel = packet_get_int();
-
- /* Get host name to connect to. */
- host = packet_get_string(&host_len);
-
- /* Get port to connect to. */
- host_port = packet_get_int();
-
- /* Get remote originator name. */
- if (have_hostname_in_open)
- originator_string = packet_get_string(&originator_len);
- else
- originator_string = xstrdup("unknown (remote did not supply name)");
-
- packet_integrity_check(payload_len,
- 4 + 4 + host_len + 4 + 4 + originator_len,
- SSH_MSG_PORT_OPEN);
-
- /* Check if opening that port is permitted. */
- if (!all_opens_permitted)
- {
- /* Go trough all permitted ports. */
- for (i = 0; i < num_permitted_opens; i++)
- if (permitted_opens[i].port == host_port &&
- strcmp(permitted_opens[i].host, host) == 0)
- break;
-
- /* Check if we found the requested port among those permitted. */
- if (i >= num_permitted_opens)
- {
- /* The port is not permitted. */
- log("Received request to connect to %.100s:%d, but the request was denied.",
- host, host_port);
- packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
- packet_put_int(remote_channel);
- packet_send();
- }
- }
-
- memset(&sin, 0, sizeof(sin));
- sin.sin_addr.s_addr = inet_addr(host);
- if ((sin.sin_addr.s_addr & 0xffffffff) != 0xffffffff)
- {
- /* It was a valid numeric host address. */
- sin.sin_family = AF_INET;
- }
- else
- {
- /* Look up the host address from the name servers. */
- hp = gethostbyname(host);
- if (!hp)
- {
- error("%.100s: unknown host.", host);
- goto fail;
+ 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:
+ 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 */
+ }
}
- if (!hp->h_addr_list[0])
- {
- error("%.100s: host has no IP address.", host);
- goto fail;
- }
- sin.sin_family = hp->h_addrtype;
- memcpy(&sin.sin_addr, hp->h_addr_list[0],
- sizeof(sin.sin_addr));
- }
- sin.sin_port = htons(host_port);
-
- /* Create the socket. */
- sock = socket(sin.sin_family, SOCK_STREAM, 0);
- if (sock < 0)
- {
- error("socket: %.100s", strerror(errno));
- goto fail;
- }
-
- /* Connect to the host/port. */
- if (connect(sock, (struct sockaddr *)&sin, sizeof(sin)) < 0)
- {
- error("connect %.100s:%d: %.100s", host, host_port,
- strerror(errno));
- close(sock);
- goto fail;
- }
-
- /* Successful connection. */
-
- /* Allocate a channel for this connection. */
- newch = channel_allocate(SSH_CHANNEL_OPEN, sock, originator_string);
- 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();
-
- /* Free the argument string. */
- xfree(host);
-
- return;
-
- fail:
- /* Free the argument string. */
- xfree(host);
-
- /* Send refusal to the remote host. */
- packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
- packet_put_int(remote_channel);
- packet_send();
-}
-
-/* Creates an internet domain socket for listening for X11 connections.
- Returns a suitable value for the DISPLAY variable, or NULL if an error
- occurs. */
-
-char *x11_create_display_inet(int screen_number)
-{
- extern ServerOptions options;
- int display_number, port, sock;
- struct sockaddr_in sin;
- char buf[512];
- char hostname[MAXHOSTNAMELEN];
-
- for (display_number = options.x11_display_offset; display_number < MAX_DISPLAYS; display_number++)
- {
- port = 6000 + display_number;
- memset(&sin, 0, sizeof(sin));
- sin.sin_family = AF_INET;
- sin.sin_addr.s_addr = htonl(INADDR_ANY);
- sin.sin_port = htons(port);
-
- sock = socket(AF_INET, SOCK_STREAM, 0);
- if (sock < 0)
- {
- error("socket: %.100s", strerror(errno));
- return NULL;
+ 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)
+{
+ Channel *c;
+ int success, 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 (bind(sock, (struct sockaddr *)&sin, sizeof(sin)) < 0)
- {
- debug("bind port %d: %.100s", port, strerror(errno));
- shutdown(sock, SHUT_RDWR);
- close(sock);
- continue;
- }
- break;
- }
- if (display_number >= MAX_DISPLAYS)
- {
- error("Failed to allocate internet-domain X11 display socket.");
- return NULL;
- }
-
- /* Start listening for connections on the socket. */
- 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));
- snprintf(buf, sizeof buf, "%.400s:%d.%d", hostname,
- display_number, screen_number);
-
- /* Allocate a channel for the socket. */
- (void)channel_allocate(SSH_CHANNEL_X11_LISTENER, sock,
- xstrdup("X11 inet listener"));
-
- /* Return a suitable value for the DISPLAY environment variable. */
- return xstrdup(buf);
+
+ if (strlen(host) > SSH_CHANNEL_PATH_LEN - 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. */
+ c = channel_new("port listener", ctype, sock, sock, -1,
+ CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
+ 0, xstrdup("port listener"), 1);
+ if (c == NULL) {
+ error("channel_request_forwarding: channel_new failed");
+ close(sock);
+ continue;
+ }
+ 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_request_forwarding: cannot listen to port: %d",
+ listen_port);
+ freeaddrinfo(aitop);
+ return success;
}
-#ifndef X_UNIX_PATH
-#define X_UNIX_PATH "/tmp/.X11-unix/X"
+/*
+ * 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);
-static
+ /* 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_local_xsocket(unsigned 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)
+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;
- close(sock);
- }
- error("connect %.100s: %.100s", addr.sun_path, strerror(errno));
- return -1;
-}
-
-
-/* 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 payload_len)
-{
- int remote_channel, display_number, sock, newch;
- const char *display;
- struct sockaddr_in sin;
- char buf[1024], *cp, *remote_host;
- struct hostent *hp;
- 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);
- else
- remote_host = xstrdup("unknown (remote did not supply name)");
-
- debug("Received X11 open request.");
- packet_integrity_check(payload_len, 4 + 4+remote_len, SSH_SMSG_X11_OPEN);
-
- /* Try to open a socket for the local X server. */
- display = getenv("DISPLAY");
- if (!display)
- {
- error("DISPLAY not set.");
- goto fail;
- }
-
- /* 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);
- goto fail;
- }
- /* Create a socket. */
- sock = connect_local_xsocket(display_number);
- if (sock < 0)
- goto fail;
-
- /* OK, we now have a connection to the display. */
- goto success;
- }
-
- /* 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);
- goto fail;
- }
- *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);
- goto fail;
- }
-
- /* Try to parse the host name as a numeric IP address. */
- memset(&sin, 0, sizeof(sin));
- sin.sin_addr.s_addr = inet_addr(buf);
- if ((sin.sin_addr.s_addr & 0xffffffff) != 0xffffffff)
- {
- /* It was a valid numeric host address. */
- sin.sin_family = AF_INET;
- }
- else
- {
- /* Not a numeric IP address. */
- /* Look up the host address from the name servers. */
- hp = gethostbyname(buf);
- if (!hp)
- {
- error("%.100s: unknown host.", buf);
- goto fail;
+}
+
+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 (!hp->h_addr_list[0])
- {
- error("%.100s: host has no IP address.", buf);
- goto fail;
- }
- sin.sin_family = hp->h_addrtype;
- memcpy(&sin.sin_addr, hp->h_addr_list[0],
- sizeof(sin.sin_addr));
- }
- /* Set port number. */
- sin.sin_port = htons(6000 + display_number);
-
- /* Create a socket. */
- sock = socket(sin.sin_family, SOCK_STREAM, 0);
- if (sock < 0)
- {
- error("socket: %.100s", strerror(errno));
- goto fail;
- }
- /* Connect it to the display. */
- if (connect(sock, (struct sockaddr *)&sin, sizeof(sin)) < 0)
- {
- error("connect %.100s:%d: %.100s", buf, 6000 + display_number,
- strerror(errno));
- close(sock);
- goto fail;
- }
-
- success:
- /* We have successfully obtained a connection to the real X display. */
-
- /* Allocate a channel for this connection. */
- if (x11_saved_proto == NULL)
- newch = channel_allocate(SSH_CHANNEL_OPEN, sock, remote_host);
- else
- newch = channel_allocate(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();
-
- return;
-
- fail:
- /* Send refusal to the remote host. */
- packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
- packet_put_int(remote_channel);
- packet_send();
-}
-
-/* Requests forwarding of X11 connections, generates fake authentication
- data, and enables authentication spoofing. */
-
-void x11_request_forwarding_with_spoofing(const char *proto, const char *data)
-{
- unsigned int data_len = (unsigned int)strlen(data) / 2;
- unsigned int i, value;
- 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. */
- new_data = xmalloc(2 * data_len + 1);
- for (i = 0; i < data_len; i++)
- sprintf(new_data + 2 * i, "%02x", (unsigned char)x11_fake_data[i]);
-
- /* Send the request packet. */
- packet_start(SSH_CMSG_X11_REQUEST_FORWARDING);
- packet_put_string(proto, strlen(proto));
- packet_put_string(new_data, strlen(new_data));
- packet_put_int(screen_number);
- packet_send();
- packet_write_wait();
- xfree(new_data);
+ 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);
}
-/* Sends a message to the server to request authentication fd forwarding. */
+/*
+ * 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 auth_request_forwarding()
+void
+channel_input_port_open(int type, int plen, void *ctxt)
{
- packet_start(SSH_CMSG_AGENT_REQUEST_FORWARDING);
- packet_send();
- packet_write_wait();
+ 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 (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) {
+ c = channel_new("connected socket",
+ SSH_CHANNEL_CONNECTING, sock, sock, -1, 0, 0, 0,
+ originator_string, 1);
+ if (c == NULL) {
+ error("channel_input_port_open: channel_new failed");
+ close(sock);
+ } else {
+ c->remote_id = remote_id;
+ }
+ }
+ if (c == NULL) {
+ packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
+ packet_put_int(remote_id);
+ packet_send();
+ }
+ xfree(host);
}
-/* 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. */
+/*
+ * Creates an internet domain socket for listening for X11 connections.
+ * Returns a suitable value for the DISPLAY variable, or NULL if an error
+ * occurs.
+ */
-char *auth_get_socket_name()
+#define NUM_SOCKS 10
+
+char *
+x11_create_display_inet(int screen_number, int x11_display_offset)
{
- return channel_forwarded_auth_socket_name;
+ 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);
}
-/* removes the agent forwarding socket */
+#ifndef X_UNIX_PATH
+#define X_UNIX_PATH "/tmp/.X11-unix/X"
+#endif
-void cleanup_socket(void) {
- remove(channel_forwarded_auth_socket_name);
- rmdir(channel_forwarded_auth_socket_dir);
+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;
}
-/* This if called to process SSH_CMSG_AGENT_REQUEST_FORWARDING on the server.
- This starts forwarding authentication requests. */
+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)
+{
+ Channel *c = NULL;
+ int remote_id, sock = 0;
+ char *remote_host;
+
+ debug("Received X11 open request.");
+
+ remote_id = packet_get_int();
+ if (have_hostname_in_open) {
+ remote_host = packet_get_string(NULL);
+ } else {
+ remote_host = xstrdup("unknown (remote did not supply name)");
+ }
+ packet_done();
+
+ /* 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);
+ if (c == NULL) {
+ error("x11_input_open: channel_new failed");
+ close(sock);
+ } else {
+ c->remote_id = remote_id;
+ }
+ }
+ 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();
+}
-void auth_input_request_forwarding(struct passwd *pw)
+/* dummy protocol handler that denies SSH-1 requests (agent/x11) */
+void
+deny_input_open(int type, int plen, void *ctxt)
{
- int sock, newch;
- struct sockaddr_un sunaddr;
-
- if (auth_get_socket_name() != NULL)
- fatal("Protocol error: authentication forwarding requested twice.");
+ 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();
+}
- /* Temporarily drop privileged uid for mkdir/bind. */
- temporarily_use_uid(pw->pw_uid);
+/*
+ * Requests forwarding of X11 connections, generates fake authentication
+ * data, and enables authentication spoofing.
+ */
- /* 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);
+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);
+}
- /* Create private directory for socket */
- if (mkdtemp(channel_forwarded_auth_socket_dir) == NULL)
- packet_disconnect("mkdtemp: %.100s", strerror(errno));
- snprintf(channel_forwarded_auth_socket_name, MAX_SOCKET_NAME,
- "%s/agent.%d", channel_forwarded_auth_socket_dir, (int)getpid());
+/* 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();
+}
- if (atexit(cleanup_socket) < 0) {
- int saved=errno;
- cleanup_socket();
- packet_disconnect("socket: %.100s", strerror(saved));
- }
+/*
+ * 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.
+ */
- /* Create the socket. */
- sock = socket(AF_UNIX, SOCK_STREAM, 0);
- if (sock < 0)
- packet_disconnect("socket: %.100s", strerror(errno));
+char *
+auth_get_socket_name()
+{
+ return channel_forwarded_auth_socket_name;
+}
- /* 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));
+/* removes the agent forwarding socket */
- if (bind(sock, (struct sockaddr *)&sunaddr, sizeof(sunaddr)) < 0)
- packet_disconnect("bind: %.100s", strerror(errno));
+void
+cleanup_socket(void)
+{
+ unlink(channel_forwarded_auth_socket_name);
+ rmdir(channel_forwarded_auth_socket_dir);
+}
- /* Restore the privileged uid. */
- restore_uid();
+/*
+ * This is called to process SSH_CMSG_AGENT_REQUEST_FORWARDING on the server.
+ * This starts forwarding authentication requests.
+ */
- /* Start listening on the socket. */
- if (listen(sock, 5) < 0)
- packet_disconnect("listen: %.100s", strerror(errno));
+int
+auth_input_request_forwarding(struct passwd * pw)
+{
+ Channel *nc;
+ int sock;
+ 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());
- /* Allocate a channel for the authentication agent socket. */
- newch = channel_allocate(SSH_CHANNEL_AUTH_SOCKET, sock,
- xstrdup("auth socket"));
- strcpy(channels[newch].path, channel_forwarded_auth_socket_name);
+ 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. */
+ nc = channel_new("auth socket",
+ SSH_CHANNEL_AUTH_SOCKET, sock, sock, -1,
+ CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
+ 0, xstrdup("auth socket"), 1);
+ if (nc == NULL) {
+ error("auth_input_request_forwarding: channel_new failed");
+ close(sock);
+ return 0;
+ }
+ strlcpy(nc->path, channel_forwarded_auth_socket_name, sizeof(nc->path));
+ return 1;
}
/* This is called to process an SSH_SMSG_AGENT_OPEN message. */
-void auth_input_open_request()
-{
- int remch, sock, newch;
- char *dummyname;
-
- /* 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
+auth_input_open_request(int type, int plen, void *ctxt)
+{
+ Channel *c = NULL;
+ int remote_id, sock;
+ char *dummyname;
+
+ packet_integrity_check(plen, 4, type);
+
+ /* Read the remote channel number from the message. */
+ remote_id = 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) {
+ dummyname = xstrdup("authentication agent connection");
+ c = channel_new("", SSH_CHANNEL_OPEN, sock, sock, -1, 0, 0, 0, dummyname, 1);
+ if (c == NULL) {
+ error("auth_input_open_request: channel_new failed");
+ close(sock);
+ } else {
+ c->remote_id = remote_id;
+ }
+ }
+ if (c == NULL) {
+ packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
+ packet_put_int(remote_id);
+ } else {
+ /* Send a confirmation to the remote host. */
+ debug("Forwarding authentication connection.");
+ packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
+ packet_put_int(remote_id);
+ packet_put_int(c->self);
+ }
+ 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();
}
andersk / openssh.git / blobdiff