/*
- *
- * 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.
- *
+ *
+ * As far as I am concerned, the code I have written for this software
+ * can be used freely for any purpose. Any derived versions of this
+ * software must be clearly marked as such, and if the derived work is
+ * incompatible with the protocol description in the RFC file, it must be
+ * called by a name other than "ssh" or "Secure Shell".
+ *
+ * SSH2 support added by Markus Friedl.
+ * Copyright (c) 1999, 2000, 2001 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 1.132 2001/07/17 21:04:56 markus Exp $");
#include "ssh.h"
+#include "ssh1.h"
+#include "ssh2.h"
#include "packet.h"
#include "xmalloc.h"
-#include "buffer.h"
-#include "authfd.h"
#include "uidswap.h"
-#include "readconf.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
+/* -- channel core */
/*
* Pointer to an array containing all allocated channels. The array is
* dynamically extended as needed.
*/
-static Channel *channels = NULL;
+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.
+ * 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.
+ * updated in channel_new.
*/
-static int channel_max_fd_value = 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;
-
-/* Saved X11 authentication protocol name. */
-char *x11_saved_proto = NULL;
+static int channel_max_fd = 0;
-/* Saved X11 authentication data. This is the real data. */
-char *x11_saved_data = NULL;
-unsigned 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.
- */
-char *x11_fake_data = NULL;
-unsigned int x11_fake_data_len;
+/* -- tcp forwarding */
/*
* Data structure for storing which hosts are permitted for forward requests.
* network (which might be behind a firewall).
*/
typedef struct {
- char *host; /* Host name. */
- u_short port; /* Port number. */
+ 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;
/*
*/
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;
-/* Sets specific protocol options. */
+/* -- X11 forwarding */
+
+/* Maximum number of fake X11 displays to try. */
+#define MAX_DISPLAYS 1000
+
+/* Saved X11 authentication protocol name. */
+static char *x11_saved_proto = NULL;
+
+/* Saved X11 authentication data. This is the real data. */
+static char *x11_saved_data = NULL;
+static u_int x11_saved_data_len = 0;
+
+/*
+ * Fake X11 authentication data. This is what the server will be sending us;
+ * we should replace any occurrences of this by the real data.
+ */
+static char *x11_fake_data = NULL;
+static u_int x11_fake_data_len;
+
+
+/* -- agent forwarding */
+
+#define NUM_SOCKS 10
+
+/* Name and directory of socket for authentication agent forwarding. */
+static char *auth_sock_name = NULL;
+static char *auth_sock_dir = NULL;
+
+/* AF_UNSPEC or AF_INET or AF_INET6 */
+extern int IPv4or6;
+
+/* helper */
+static void port_open_helper(Channel *c, char *rtype);
+
+/* -- channel core */
-void
-channel_set_options(int hostname_in_open)
+Channel *
+channel_lookup(int id)
{
- have_hostname_in_open = hostname_in_open;
+ 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;
}
/*
- * 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.
+ * 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_permit_all_opens()
+static void
+channel_register_fds(Channel *c, int rfd, int wfd, int efd,
+ int extusage, int nonblock)
{
- all_opens_permitted = 1;
+ /* 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);
+ }
}
/*
* remote_name to be freed.
*/
-int
-channel_allocate(int type, int sock, char *remote_name)
+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;
- /* Update the maximum file descriptor value. */
- if (sock > channel_max_fd_value)
- channel_max_fd_value = sock;
- /* XXX set close-on-exec -markus */
-
/* Do initial allocation if this is the first call. */
if (channels_alloc == 0) {
+ chan_init();
channels_alloc = 10;
- channels = xmalloc(channels_alloc * sizeof(Channel));
+ 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);
+ channels[i] = NULL;
+ fatal_add_cleanup((void (*) (void *)) channel_free_all, 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) {
+ if (channels[i] == NULL) {
/* Found a free slot. */
found = i;
break;
/* 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));
+ debug2("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;
+ channels[i] = NULL;
}
- /* Initialize and return new channel number. */
- c = &channels[found];
+ /* 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->sock = sock;
+ 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->detach_user = NULL;
+ c->input_filter = NULL;
debug("channel %d: new [%s]", found, remote_name);
- return found;
+ return c;
}
-/* Free the channel and close its socket. */
-
-void
-channel_free(int channel)
+static int
+channel_find_maxfd(void)
{
- if (channel < 0 || channel >= channels_alloc ||
- channels[channel].type == SSH_CHANNEL_FREE)
- packet_disconnect("channel free: bad local channel %d", channel);
+ int i, max = 0;
+ Channel *c;
- 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;
+ for (i = 0; i < channels_alloc; i++) {
+ c = channels[i];
+ if (c != NULL) {
+ max = MAX(max, c->rfd);
+ max = MAX(max, c->wfd);
+ max = MAX(max, c->efd);
+ }
}
+ return max;
}
-/*
- * 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
+channel_close_fd(int *fdp)
{
- 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) < packet_get_maxsize())
- 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) < packet_get_maxsize())
- 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.", ch->self);
- break;
- }
- break;
-
- case SSH_CHANNEL_OUTPUT_DRAINING:
- if (!compat13)
- fatal("cannot happen: OUT_DRAIN");
- if (buffer_len(&ch->output) == 0) {
- 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. */
- proto_len = ucp[6] + 256 * ucp[7];
- data_len = ucp[8] + 256 * ucp[9];
- } 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;
- }
- /* 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);
- ch->type = SSH_CHANNEL_OPEN;
- goto reject;
- }
- /*
- * 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);
-
- /* Start normal processing for the channel. */
- ch->type = SSH_CHANNEL_OPEN;
- 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;
+ int ret = 0, fd = *fdp;
- case SSH_CHANNEL_FREE:
- default:
- continue;
- }
+ if (fd != -1) {
+ ret = close(fd);
+ *fdp = -1;
+ if (fd == channel_max_fd)
+ channel_max_fd = channel_find_maxfd();
}
+ return ret;
}
-/*
- * After select, perform any appropriate operations for channels which have
- * events pending.
- */
+/* Close all channel fd/socket. */
-void
-channel_after_select(fd_set * readset, fd_set * writeset)
+static void
+channel_close_fds(Channel *c)
{
- struct sockaddr addr;
- int newsock, i, newch, len;
- socklen_t addrlen;
- 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;
- }
- 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 port %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;
- }
- remote_hostname = get_remote_hostname(newsock);
- snprintf(buf, sizeof buf, "listen port %d for %.100s port %d, connect from %.200s port %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)) {
- addrlen = sizeof(addr);
- newsock = accept(ch->sock, &addr, &addrlen);
- if (newsock < 0) {
- error("accept from auth socket: %.100s", strerror(errno));
- break;
- }
- newch = channel_allocate(SSH_CHANNEL_OPENING, newsock,
- xstrdup("accepted auth socket"));
- packet_start(SSH_SMSG_AGENT_OPEN);
- packet_put_int(newch);
- 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.
- */
+ debug3("channel_close_fds: channel %d: r %d w %d e %d",
+ c->self, c->rfd, c->wfd, c->efd);
- /*
- * 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;
- }
- 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;
- }
- buffer_consume(&ch->output, len);
- }
- break;
+ channel_close_fd(&c->sock);
+ channel_close_fd(&c->rfd);
+ channel_close_fd(&c->wfd);
+ channel_close_fd(&c->efd);
+}
- 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;
+/* Free the channel and close its fd/socket. */
- case SSH_CHANNEL_X11_OPEN:
- case SSH_CHANNEL_FREE:
- default:
- continue;
- }
+void
+channel_free(Channel *c)
+{
+ char *s;
+ int i, n;
+
+ for (n = 0, i = 0; i < channels_alloc; i++)
+ if (channels[i])
+ n++;
+ debug("channel_free: channel %d: %s, nchannels %d", c->self,
+ c->remote_name ? c->remote_name : "???", n);
+
+ s = channel_open_message();
+ debug3("channel_free: status: %s", s);
+ xfree(s);
+
+ if (c->detach_user != NULL) {
+ debug("channel_free: channel %d: detaching channel user", c->self);
+ c->detach_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);
}
-/* If there is data to send to the connection, send some of it now. */
-
-void
-channel_output_poll()
+void
+channel_free_all(void)
{
- int len, i;
- Channel *ch;
+ int i;
- for (i = 0; i < channels_alloc; i++) {
- ch = &channels[i];
+ for (i = 0; i < channels_alloc; i++)
+ if (channels[i] != NULL)
+ channel_free(channels[i]);
+}
- /* We are only interested in channels that can have buffered incoming data. */
- if (compat13) {
- if (ch->type != SSH_CHANNEL_OPEN &&
- ch->type != SSH_CHANNEL_INPUT_DRAINING)
- continue;
- } else {
- if (ch->type != SSH_CHANNEL_OPEN)
- continue;
- if (ch->istate != CHAN_INPUT_OPEN &&
- ch->istate != CHAN_INPUT_WAIT_DRAIN)
- continue;
- }
+void
+channel_detach_all(void)
+{
+ int i;
+ Channel *c;
- /* 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 {
- /* Keep the packets at reasonable size. */
- if (len > packet_get_maxsize()/2)
- len = packet_get_maxsize()/2;
- }
- 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);
+ for (i = 0; i < channels_alloc; i++) {
+ c = channels[i];
+ if (c != NULL && c->detach_user != NULL) {
+ debug("channel_detach_all: channel %d", c->self);
+ c->detach_user(c->self, NULL);
+ c->detach_user = NULL;
}
}
}
/*
- * 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.
+ * Closes the sockets/fds of all channels. This is used to close extra file
+ * descriptors after a fork.
*/
-void
-channel_input_data(int payload_len)
+void
+channel_close_all()
{
- int id;
- char *data;
- unsigned int data_len;
- Channel *ch;
-
- /* Get the channel number and verify it. */
- id = packet_get_int();
- if (id < 0 || id >= channels_alloc)
- packet_disconnect("Received data for nonexistent channel %d.", id);
- ch = &channels[id];
+ int i;
- if (ch->type == SSH_CHANNEL_FREE)
- packet_disconnect("Received data for free channel %d.", ch->self);
+ for (i = 0; i < channels_alloc; i++)
+ if (channels[i] != NULL)
+ channel_close_fds(channels[i]);
+}
- /* Ignore any data for non-open channels (might happen on close) */
- if (ch->type != SSH_CHANNEL_OPEN &&
- ch->type != SSH_CHANNEL_X11_OPEN)
- return;
+/*
+ * Stop listening to channels.
+ */
- /* same for protocol 1.5 if output end is no longer open */
- if (!compat13 && ch->ostate != CHAN_OUTPUT_OPEN)
- return;
+void
+channel_stop_listening(void)
+{
+ int i;
+ Channel *c;
- /* Get the data. */
- data = packet_get_string(&data_len);
- packet_integrity_check(payload_len, 4 + 4 + data_len, SSH_MSG_CHANNEL_DATA);
- buffer_append(&ch->output, data, data_len);
- xfree(data);
+ for (i = 0; i < channels_alloc; i++) {
+ c = channels[i];
+ if (c != NULL) {
+ switch (c->type) {
+ case SSH_CHANNEL_AUTH_SOCKET:
+ case SSH_CHANNEL_PORT_LISTENER:
+ case SSH_CHANNEL_RPORT_LISTENER:
+ case SSH_CHANNEL_X11_LISTENER:
+ channel_close_fd(&c->sock);
+ channel_free(c);
+ break;
+ }
+ }
+ }
}
/*
* more channel is overfull.
*/
-int
+int
channel_not_very_much_buffered_data()
{
- unsigned int i;
- Channel *ch;
+ u_int i;
+ Channel *c;
for (i = 0; i < channels_alloc; i++) {
- ch = &channels[i];
- if (ch->type == SSH_CHANNEL_OPEN) {
- if (buffer_len(&ch->input) > packet_get_maxsize())
+ 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(&ch->output) > packet_get_maxsize())
+ }
+ 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;
}
-/* This is called after receiving CHANNEL_CLOSE/IEOF. */
+/* Returns true if any channel is still open. */
-void
-channel_input_close()
+int
+channel_still_open()
{
- int channel;
-
- /* 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);
-
- if (!compat13) {
- /* proto version 1.5 overloads CLOSE with IEOF */
- chan_rcvd_ieof(&channels[channel]);
- return;
- }
-
- /*
- * 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();
+ 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;
+ for (i = 0; i < channels_alloc; i++) {
+ c = channels[i];
+ if (c == NULL)
+ continue;
+ switch (c->type) {
+ case SSH_CHANNEL_X11_LISTENER:
+ case SSH_CHANNEL_PORT_LISTENER:
+ case SSH_CHANNEL_RPORT_LISTENER:
+ case SSH_CHANNEL_CLOSED:
+ case SSH_CHANNEL_AUTH_SOCKET:
+ case SSH_CHANNEL_DYNAMIC:
+ case SSH_CHANNEL_CONNECTING:
+ case SSH_CHANNEL_ZOMBIE:
+ continue;
+ case SSH_CHANNEL_LARVAL:
+ if (!compat20)
+ fatal("cannot happen: SSH_CHANNEL_LARVAL");
+ continue;
+ case SSH_CHANNEL_OPENING:
+ case SSH_CHANNEL_OPEN:
+ case SSH_CHANNEL_X11_OPEN:
+ return 1;
+ case SSH_CHANNEL_INPUT_DRAINING:
+ case SSH_CHANNEL_OUTPUT_DRAINING:
+ if (!compat13)
+ fatal("cannot happen: OUT_DRAIN");
+ return 1;
+ default:
+ fatal("channel_still_open: bad channel type %d", c->type);
+ /* NOTREACHED */
+ }
}
+ return 0;
}
-/* This is called after receiving CHANNEL_CLOSE_CONFIRMATION/OCLOSE. */
+/* Returns the id of an open channel suitable for keepaliving */
-void
-channel_input_close_confirmation()
+int
+channel_find_open()
{
- int channel;
+ int i;
+ Channel *c;
- /* 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 (!compat13) {
- /* proto version 1.5 overloads CLOSE_CONFIRMATION with OCLOSE */
- chan_rcvd_oclose(&channels[channel]);
- return;
+ 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:
+ case SSH_CHANNEL_ZOMBIE:
+ continue;
+ case SSH_CHANNEL_LARVAL:
+ case SSH_CHANNEL_AUTH_SOCKET:
+ case SSH_CHANNEL_OPEN:
+ case SSH_CHANNEL_X11_OPEN:
+ return i;
+ case SSH_CHANNEL_INPUT_DRAINING:
+ case SSH_CHANNEL_OUTPUT_DRAINING:
+ if (!compat13)
+ fatal("cannot happen: OUT_DRAIN");
+ return i;
+ default:
+ fatal("channel_find_open: bad channel type %d", c->type);
+ /* NOTREACHED */
+ }
+ }
+ return -1;
+}
+
+
+/*
+ * Returns a message describing the currently open forwarded connections,
+ * suitable for sending to the client. The message contains crlf pairs for
+ * newlines.
+ */
+
+char *
+channel_open_message()
+{
+ 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));
+ for (i = 0; i < channels_alloc; i++) {
+ c = channels[i];
+ if (c == NULL)
+ continue;
+ switch (c->type) {
+ case SSH_CHANNEL_X11_LISTENER:
+ case SSH_CHANNEL_PORT_LISTENER:
+ case SSH_CHANNEL_RPORT_LISTENER:
+ case SSH_CHANNEL_CLOSED:
+ case SSH_CHANNEL_AUTH_SOCKET:
+ case SSH_CHANNEL_ZOMBIE:
+ continue;
+ case SSH_CHANNEL_LARVAL:
+ case SSH_CHANNEL_OPENING:
+ case SSH_CHANNEL_CONNECTING:
+ case SSH_CHANNEL_DYNAMIC:
+ case SSH_CHANNEL_OPEN:
+ case SSH_CHANNEL_X11_OPEN:
+ case SSH_CHANNEL_INPUT_DRAINING:
+ case SSH_CHANNEL_OUTPUT_DRAINING:
+ snprintf(buf, sizeof buf, " #%d %.300s (t%d r%d i%d/%d o%d/%d fd %d/%d)\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 (channels[channel].type != SSH_CHANNEL_CLOSED)
- packet_disconnect("Received close confirmation for non-closed channel %d (type %d).",
- channel, channels[channel].type);
+ buffer_append(&buffer, "\0", 1);
+ cp = xstrdup(buffer_ptr(&buffer));
+ buffer_free(&buffer);
+ return cp;
+}
- /* Free the channel. */
- channel_free(channel);
+void
+channel_send_open(int id)
+{
+ Channel *c = channel_lookup(id);
+ if (c == NULL) {
+ log("channel_send_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);
+ packet_send();
}
-/* This is called after receiving CHANNEL_OPEN_CONFIRMATION. */
+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->detach_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->detach_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_input_open_confirmation()
+void
+channel_set_fds(int id, int rfd, int wfd, int efd,
+ int extusage, int nonblock)
{
- int channel, remote_channel;
+ 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();
+}
- /* 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);
+/*
+ * '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];
- /* Get remote side's id for this channel. */
- remote_channel = packet_get_int();
+static void
+channel_pre_listener(Channel *c, fd_set * readset, fd_set * writeset)
+{
+ FD_SET(c->sock, readset);
+}
- /* 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;
+static void
+channel_pre_connecting(Channel *c, fd_set * readset, fd_set * writeset)
+{
+ debug3("channel %d: waiting for connection", c->self);
+ FD_SET(c->sock, writeset);
}
-/* This is called after receiving CHANNEL_OPEN_FAILURE from the other side. */
+static void
+channel_pre_open_13(Channel *c, fd_set * readset, fd_set * writeset)
+{
+ if (buffer_len(&c->input) < packet_get_maxsize())
+ FD_SET(c->sock, readset);
+ if (buffer_len(&c->output) > 0)
+ FD_SET(c->sock, writeset);
+}
-void
-channel_input_open_failure()
+static void
+channel_pre_open_15(Channel *c, fd_set * readset, fd_set * writeset)
{
- int channel;
+ /* 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);
+ }
+ }
+}
- /* 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);
+static 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);
+ }
+}
- /* Free the channel. This will also close the socket. */
- channel_free(channel);
+static void
+channel_pre_input_draining(Channel *c, fd_set * readset, fd_set * writeset)
+{
+ if (buffer_len(&c->input) == 0) {
+ packet_start(SSH_MSG_CHANNEL_CLOSE);
+ packet_put_int(c->remote_id);
+ packet_send();
+ c->type = SSH_CHANNEL_CLOSED;
+ debug("channel %d: closing after input drain.", c->self);
+ }
+}
+
+static void
+channel_pre_output_draining(Channel *c, fd_set * readset, fd_set * writeset)
+{
+ if (buffer_len(&c->output) == 0)
+ chan_mark_dead(c);
+ else
+ FD_SET(c->sock, writeset);
}
/*
- * Stops listening for channels, and removes any unix domain sockets that we
- * might have.
+ * This is a special state for X11 authentication spoofing. An opened X11
+ * connection (when authentication spoofing is being done) remains in this
+ * state until the first packet has been completely read. The authentication
+ * data in that packet is then substituted by the real data if it matches the
+ * fake data, and the channel is put into normal mode.
+ * XXX All this happens at the client side.
+ * Returns: 0 = need more data, -1 = wrong cookie, 1 = ok
*/
+static int
+x11_open_helper(Buffer *b)
+{
+ u_char *ucp;
+ u_int proto_len, data_len;
+
+ /* Check if the fixed size part of the packet is in buffer. */
+ if (buffer_len(b) < 12)
+ return 0;
+
+ /* Parse the lengths of variable-length fields. */
+ ucp = (u_char *) buffer_ptr(b);
+ if (ucp[0] == 0x42) { /* Byte order MSB first. */
+ proto_len = 256 * ucp[6] + ucp[7];
+ data_len = 256 * ucp[8] + ucp[9];
+ } else if (ucp[0] == 0x6c) { /* Byte order LSB first. */
+ proto_len = ucp[6] + 256 * ucp[7];
+ data_len = ucp[8] + 256 * ucp[9];
+ } else {
+ debug("Initial X11 packet contains bad byte order byte: 0x%x",
+ ucp[0]);
+ return -1;
+ }
+
+ /* Check if the whole packet is in buffer. */
+ if (buffer_len(b) <
+ 12 + ((proto_len + 3) & ~3) + ((data_len + 3) & ~3))
+ return 0;
+
+ /* Check if authentication protocol matches. */
+ if (proto_len != strlen(x11_saved_proto) ||
+ memcmp(ucp + 12, x11_saved_proto, proto_len) != 0) {
+ 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_stop_listening()
+static void
+channel_pre_x11_open_13(Channel *c, fd_set * readset, fd_set * writeset)
{
- 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:
+ int ret = x11_open_helper(&c->output);
+ if (ret == 1) {
+ /* Start normal processing for the channel. */
+ c->type = SSH_CHANNEL_OPEN;
+ channel_pre_open_13(c, readset, writeset);
+ } else if (ret == -1) {
+ /*
+ * We have received an X11 connection that has bad
+ * authentication information.
+ */
+ log("X11 connection rejected because of wrong authentication.");
+ buffer_clear(&c->input);
+ buffer_clear(&c->output);
+ channel_close_fd(&c->sock);
+ c->sock = -1;
+ c->type = SSH_CHANNEL_CLOSED;
+ packet_start(SSH_MSG_CHANNEL_CLOSE);
+ packet_put_int(c->remote_id);
+ packet_send();
+ }
+}
+
+static void
+channel_pre_x11_open(Channel *c, fd_set * readset, fd_set * writeset)
+{
+ int ret = x11_open_helper(&c->output);
+ 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 */
+static 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 */
+static void
+channel_pre_dynamic(Channel *c, fd_set * readset, fd_set * writeset)
+{
+ u_char *p;
+ int have, ret;
+
+ have = buffer_len(&c->input);
+
+ debug2("channel %d: pre_dynamic: have %d", c->self, have);
+ /* buffer_dump(&c->input); */
+ /* check if the fixed size part of the packet is in buffer. */
+ if (have < 4) {
+ /* need more */
+ FD_SET(c->sock, readset);
+ return;
+ }
+ /* try to guess the protocol */
+ p = buffer_ptr(&c->input);
+ switch (p[0]) {
+ case 0x04:
+ ret = channel_decode_socks4(c, readset, writeset);
+ break;
+ default:
+ ret = -1;
+ break;
+ }
+ if (ret < 0) {
+ chan_mark_dead(c);
+ } else if (ret == 0) {
+ debug2("channel %d: pre_dynamic: need more", c->self);
+ /* need more */
+ FD_SET(c->sock, readset);
+ } else {
+ /* switch to the next state */
+ c->type = SSH_CHANNEL_OPENING;
+ port_open_helper(c, "direct-tcpip");
+ }
+}
+
+/* This is our fake X11 server socket. */
+static void
+channel_post_x11_listener(Channel *c, fd_set * readset, fd_set * writeset)
+{
+ Channel *nc;
+ struct sockaddr addr;
+ int newsock;
+ socklen_t addrlen;
+ char buf[16384], *remote_ipaddr;
+ int remote_port;
+
+ if (FD_ISSET(c->sock, readset)) {
+ debug("X11 connection requested.");
+ addrlen = sizeof(addr);
+ newsock = accept(c->sock, &addr, &addrlen);
+ if (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 (packet_get_protocol_flags() &
+ SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
+ packet_put_cstring(buf);
+ packet_send();
+ }
+ xfree(remote_ipaddr);
+ }
+}
+
+static void
+port_open_helper(Channel *c, char *rtype)
+{
+ int direct;
+ char buf[1024];
+ char *remote_ipaddr = get_peer_ipaddr(c->sock);
+ u_short remote_port = get_peer_port(c->sock);
+
+ direct = (strcmp(rtype, "direct-tcpip") == 0);
+
+ snprintf(buf, sizeof buf,
+ "%s: listening port %d for %.100s port %d, "
+ "connect from %.200s port %d",
+ rtype, c->listening_port, c->path, c->host_port,
+ remote_ipaddr, remote_port);
+
+ xfree(c->remote_name);
+ c->remote_name = xstrdup(buf);
+
+ if (compat20) {
+ packet_start(SSH2_MSG_CHANNEL_OPEN);
+ packet_put_cstring(rtype);
+ packet_put_int(c->self);
+ packet_put_int(c->local_window_max);
+ packet_put_int(c->local_maxpacket);
+ if (direct) {
+ /* target host, port */
+ packet_put_cstring(c->path);
+ packet_put_int(c->host_port);
+ } else {
+ /* listen address, port */
+ packet_put_cstring(c->path);
+ packet_put_int(c->listening_port);
+ }
+ /* originator host and port */
+ packet_put_cstring(remote_ipaddr);
+ packet_put_int(remote_port);
+ packet_send();
+ } else {
+ packet_start(SSH_MSG_PORT_OPEN);
+ packet_put_int(c->self);
+ packet_put_cstring(c->path);
+ packet_put_int(c->host_port);
+ if (packet_get_protocol_flags() &
+ SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
+ packet_put_cstring(c->remote_name);
+ packet_send();
}
+ xfree(remote_ipaddr);
}
/*
- * Closes the sockets of all channels. This is used to close extra file
- * descriptors after a fork.
+ * This socket is listening for connections to a forwarded TCP/IP port.
+ */
+static void
+channel_post_port_listener(Channel *c, fd_set * readset, fd_set * writeset)
+{
+ Channel *nc;
+ struct sockaddr addr;
+ int newsock, nextstate;
+ socklen_t addrlen;
+ char *rtype;
+
+ if (FD_ISSET(c->sock, readset)) {
+ debug("Connection to port %d forwarding "
+ "to %.100s port %d requested.",
+ c->listening_port, c->path, c->host_port);
+
+ 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;
+ }
+ 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);
+ }
+}
+
+/*
+ * This is the authentication agent socket listening for connections from
+ * clients.
*/
+static void
+channel_post_auth_listener(Channel *c, fd_set * readset, fd_set * writeset)
+{
+ Channel *nc;
+ char *name;
+ int newsock;
+ struct sockaddr addr;
+ socklen_t addrlen;
-void
-channel_close_all()
+ 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;
+ }
+ name = xstrdup("accepted auth socket");
+ nc = channel_new("accepted auth socket",
+ SSH_CHANNEL_OPENING, newsock, newsock, -1,
+ c->local_window_max, c->local_maxpacket,
+ 0, name, 1);
+ if (nc == NULL) {
+ error("channel_post_auth_listener: channel_new failed");
+ xfree(name);
+ close(newsock);
+ }
+ 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();
+ }
+}
+
+static void
+channel_post_connecting(Channel *c, fd_set * readset, fd_set * writeset)
{
- int i;
- for (i = 0; i < channels_alloc; i++) {
- if (channels[i].type != SSH_CHANNEL_FREE)
- close(channels[i].sock);
+ int err = 0;
+ socklen_t 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();
+ }
+}
+
+static int
+channel_handle_rfd(Channel *c, fd_set * readset, fd_set * writeset)
+{
+ char buf[16*1024];
+ int len;
+
+ if (c->rfd != -1 &&
+ FD_ISSET(c->rfd, readset)) {
+ len = read(c->rfd, buf, sizeof(buf));
+ if (len < 0 && (errno == EINTR || errno == EAGAIN))
+ return 1;
+ if (len <= 0) {
+ debug("channel %d: read<=0 rfd %d len %d",
+ c->self, c->rfd, len);
+ if (c->type != SSH_CHANNEL_OPEN) {
+ debug("channel %d: not open", c->self);
+ 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: 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;
+}
+static int
+channel_handle_wfd(Channel *c, fd_set * readset, fd_set * writeset)
+{
+ struct termios tio;
+ int len;
+
+ /* Send buffered output data to the socket. */
+ if (c->wfd != -1 &&
+ FD_ISSET(c->wfd, writeset) &&
+ buffer_len(&c->output) > 0) {
+ len = write(c->wfd, buffer_ptr(&c->output),
+ buffer_len(&c->output));
+ if (len < 0 && (errno == EINTR || errno == EAGAIN))
+ return 1;
+ if (len <= 0) {
+ if (c->type != SSH_CHANNEL_OPEN) {
+ debug("channel %d: not open", c->self);
+ chan_mark_dead(c);
+ return -1;
+ } else if (compat13) {
+ buffer_consume(&c->output, buffer_len(&c->output));
+ debug("channel %d: 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;
+}
+static 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);
+ channel_close_fd(&c->efd);
+ } else {
+ buffer_consume(&c->extended, len);
+ c->local_consumed += len;
+ }
+ } else if (c->extended_usage == CHAN_EXTENDED_READ &&
+ FD_ISSET(c->efd, readset)) {
+ len = read(c->efd, buf, sizeof(buf));
+ debug2("channel %d: read %d from efd %d",
+ c->self, len, c->efd);
+ if (len < 0 && (errno == EINTR || errno == EAGAIN))
+ return 1;
+ if (len <= 0) {
+ debug2("channel %d: closing read-efd %d",
+ c->self, c->efd);
+ channel_close_fd(&c->efd);
+ } else {
+ buffer_append(&c->extended, buf, len);
+ }
+ }
+ }
+ return 1;
+}
+static int
+channel_check_window(Channel *c)
+{
+ if (c->type == SSH_CHANNEL_OPEN &&
+ !(c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD)) &&
+ c->local_window < c->local_window_max/2 &&
+ c->local_consumed > 0) {
+ packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
+ packet_put_int(c->remote_id);
+ packet_put_int(c->local_consumed);
+ packet_send();
+ debug2("channel %d: window %d sent adjust %d",
+ c->self, c->local_window,
+ c->local_consumed);
+ c->local_window += c->local_consumed;
+ c->local_consumed = 0;
+ }
+ return 1;
+}
+
+static void
+channel_post_open_1(Channel *c, fd_set * readset, fd_set * writeset)
+{
+ channel_handle_rfd(c, readset, writeset);
+ channel_handle_wfd(c, readset, writeset);
+}
+
+static 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);
+}
+
+static void
+channel_post_output_drain_13(Channel *c, fd_set * readset, fd_set * writeset)
+{
+ int len;
+ /* Send buffered output data to the socket. */
+ if (FD_ISSET(c->sock, writeset) && buffer_len(&c->output) > 0) {
+ len = write(c->sock, buffer_ptr(&c->output),
+ buffer_len(&c->output));
+ if (len <= 0)
+ buffer_consume(&c->output, buffer_len(&c->output));
+ else
+ buffer_consume(&c->output, len);
+ }
+}
+
+static 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;
+}
+
+static void
+channel_handler_init_13(void)
+{
+ channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_13;
+ channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open_13;
+ channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
+ channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
+ channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
+ channel_pre[SSH_CHANNEL_INPUT_DRAINING] = &channel_pre_input_draining;
+ channel_pre[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_pre_output_draining;
+ channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
+ channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
+
+ channel_post[SSH_CHANNEL_OPEN] = &channel_post_open_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;
+}
+
+static 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;
+}
+
+static void
+channel_handler_init(void)
+{
+ int i;
+ for(i = 0; i < SSH_CHANNEL_MAX_TYPE; i++) {
+ channel_pre[i] = NULL;
+ channel_post[i] = NULL;
+ }
+ if (compat20)
+ channel_handler_init_20();
+ else if (compat13)
+ channel_handler_init_13();
+ else
+ channel_handler_init_15();
+}
+
+static void
+channel_handler(chan_fn *ftab[], fd_set * readset, fd_set * writeset)
+{
+ static int did_init = 0;
+ int i;
+ Channel *c;
+
+ if (!did_init) {
+ channel_handler_init();
+ did_init = 1;
+ }
+ for (i = 0; i < channels_alloc; i++) {
+ c = channels[i];
+ if (c == NULL)
+ continue;
+ if (ftab[c->type] != NULL)
+ (*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);
+ }
+ }
+}
+
+/*
+ * Allocate/update select bitmasks and add any bits relevant to channels in
+ * select bitmasks.
+ */
+void
+channel_prepare_select(fd_set **readsetp, fd_set **writesetp, int *maxfdp,
+ int *nallocp, int rekeying)
+{
+ int n;
+ u_int sz;
+
+ n = MAX(*maxfdp, channel_max_fd);
+
+ sz = howmany(n+1, NFDBITS) * sizeof(fd_mask);
+ /* perhaps check sz < nalloc/2 and shrink? */
+ if (*readsetp == NULL || sz > *nallocp) {
+ *readsetp = xrealloc(*readsetp, sz);
+ *writesetp = xrealloc(*writesetp, sz);
+ *nallocp = sz;
+ }
+ *maxfdp = n;
+ memset(*readsetp, 0, sz);
+ memset(*writesetp, 0, sz);
+
+ if (!rekeying)
+ channel_handler(channel_pre, *readsetp, *writesetp);
+}
+
+/*
+ * After select, perform any appropriate operations for channels which have
+ * events pending.
+ */
+void
+channel_after_select(fd_set * readset, fd_set * writeset)
+{
+ channel_handler(channel_post, readset, writeset);
+}
+
+
+/* If there is data to send to the connection, enqueue some of it now. */
+
+void
+channel_output_poll()
+{
+ 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;
+ }
+
+ /* 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);
+ }
+ }
+}
+
+
+/* -- protocol input */
+
+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);
+}
+
+void
+channel_input_ieof(int type, int plen, void *ctxt)
+{
+ int id;
+ Channel *c;
+
+ packet_integrity_check(plen, 4, type);
+
+ id = packet_get_int();
+ c = channel_lookup(id);
+ if (c == NULL)
+ packet_disconnect("Received ieof for nonexistent channel %d.", id);
+ chan_rcvd_ieof(c);
+}
+
+void
+channel_input_close(int type, int plen, void *ctxt)
+{
+ int id;
+ Channel *c;
+
+ packet_integrity_check(plen, 4, type);
+
+ id = packet_get_int();
+ c = channel_lookup(id);
+ if (c == NULL)
+ packet_disconnect("Received close for nonexistent channel %d.", id);
+
+ /*
+ * Send a confirmation that we have closed the channel and no more
+ * data is coming for it.
+ */
+ packet_start(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION);
+ packet_put_int(c->remote_id);
+ packet_send();
+
+ /*
+ * If the channel is in closed state, we have sent a close request,
+ * and the other side will eventually respond with a confirmation.
+ * Thus, we cannot free the channel here, because then there would be
+ * no-one to receive the confirmation. The channel gets freed when
+ * the confirmation arrives.
+ */
+ if (c->type != SSH_CHANNEL_CLOSED) {
+ /*
+ * Not a closed channel - mark it as draining, which will
+ * cause it to be freed later.
+ */
+ buffer_consume(&c->input, buffer_len(&c->input));
+ c->type = SSH_CHANNEL_OUTPUT_DRAINING;
+ }
+}
+
+/* proto version 1.5 overloads CLOSE_CONFIRMATION with OCLOSE */
+void
+channel_input_oclose(int type, int plen, void *ctxt)
+{
+ int id = packet_get_int();
+ Channel *c = channel_lookup(id);
+ packet_integrity_check(plen, 4, type);
+ if (c == NULL)
+ packet_disconnect("Received oclose for nonexistent channel %d.", id);
+ chan_rcvd_oclose(c);
+}
+
+void
+channel_input_close_confirmation(int type, int plen, void *ctxt)
+{
+ int id = packet_get_int();
+ Channel *c = channel_lookup(id);
+
+ packet_done();
+ if (c == NULL)
+ packet_disconnect("Received close confirmation for "
+ "out-of-range channel %d.", id);
+ if (c->type != SSH_CHANNEL_CLOSED)
+ packet_disconnect("Received close confirmation for "
+ "non-closed channel %d (type %d).", id, c->type);
+ channel_free(c);
+}
+
+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);
+ }
+}
+
+static char *
+reason2txt(int reason)
+{
+ switch(reason) {
+ case SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED:
+ return "administratively prohibited";
+ case SSH2_OPEN_CONNECT_FAILED:
+ return "connect failed";
+ case SSH2_OPEN_UNKNOWN_CHANNEL_TYPE:
+ return "unknown channel type";
+ case SSH2_OPEN_RESOURCE_SHORTAGE:
+ return "resource shortage";
+ }
+ return "unknown reason";
+}
+
+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;
}
-/* Returns the maximum file descriptor number used by the channels. */
-
-int
-channel_max_fd()
+void
+channel_input_port_open(int type, int plen, void *ctxt)
{
- return channel_max_fd_value;
-}
+ Channel *c = NULL;
+ u_short host_port;
+ char *host, *originator_string;
+ int remote_id, sock = -1;
-/* Returns true if any channel is still open. */
+ remote_id = packet_get_int();
+ host = packet_get_string(NULL);
+ host_port = packet_get_int();
-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 */
+ if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {
+ originator_string = packet_get_string(NULL);
+ } else {
+ originator_string = xstrdup("unknown (remote did not supply name)");
+ }
+ packet_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;
}
- return 0;
+ }
+ if (c == NULL) {
+ packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
+ packet_put_int(remote_id);
+ packet_send();
+ }
+ xfree(host);
}
-/*
- * 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/%d o%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));
- 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;
-}
+/* -- tcp forwarding */
/*
* 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);
+}
-void
-channel_request_local_forwarding(u_short port, const char *host,
- u_short host_port, int gateway_ports)
+/*
+ * If 'remote_fwd' is true we have a '-R style' listener for protocol 2
+ * (SSH_CHANNEL_RPORT_LISTENER).
+ */
+int
+channel_request_forwarding(
+ const char *listen_address, u_short listen_port,
+ const char *host_to_connect, u_short port_to_connect,
+ int gateway_ports, int remote_fwd)
{
- int success, ch, sock, on = 1;
+ Channel *c;
+ int success, sock, on = 1, type;
struct addrinfo hints, *ai, *aitop;
char ntop[NI_MAXHOST], strport[NI_MAXSERV];
+ const char *host;
struct linger linger;
- if (strlen(host) > sizeof(channels[0].path) - 1)
- packet_disconnect("Forward host name too long.");
+ success = 0;
+
+ if (remote_fwd) {
+ host = listen_address;
+ type = SSH_CHANNEL_RPORT_LISTENER;
+ } else {
+ host = host_to_connect;
+ type = SSH_CHANNEL_PORT_LISTENER;
+ }
+
+ 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
hints.ai_family = IPv4or6;
hints.ai_flags = gateway_ports ? AI_PASSIVE : 0;
hints.ai_socktype = SOCK_STREAM;
- snprintf(strport, sizeof strport, "%d", port);
+ snprintf(strport, sizeof strport, "%d", listen_port);
if (getaddrinfo(NULL, strport, &hints, &aitop) != 0)
packet_disconnect("getaddrinfo: fatal error");
- success = 0;
for (ai = aitop; ai; ai = ai->ai_next) {
if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
continue;
if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
- error("channel_request_local_forwarding: getnameinfo failed");
+ error("channel_request_forwarding: getnameinfo failed");
continue;
}
/* Create a port to listen for the host. */
error("bind: %.100s", strerror(errno));
else
verbose("bind: %.100s", strerror(errno));
-
+
close(sock);
continue;
}
continue;
}
/* Allocate a channel number for the socket. */
- ch = channel_allocate(SSH_CHANNEL_PORT_LISTENER, sock,
- xstrdup("port listener"));
- strlcpy(channels[ch].path, host, sizeof(channels[ch].path));
- channels[ch].host_port = host_port;
- channels[ch].listening_port = port;
+ c = channel_new("port listener", type, 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)
- packet_disconnect("cannot listen port: %d", port);
+ error("channel_request_forwarding: cannot listen to port: %d",
+ listen_port);
freeaddrinfo(aitop);
+ return success;
}
/*
* the secure channel to host:port from local side.
*/
-void
-channel_request_remote_forwarding(u_short port, const char *host,
- u_short remote_port)
+void
+channel_request_remote_forwarding(u_short listen_port,
+ const char *host_to_connect, u_short port_to_connect)
{
- int payload_len;
+ 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");
- 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();
+ 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. It will send a disconnect
- * message on failure, and we will never see it here.
- */
- packet_read_expect(&payload_len, SSH_SMSG_SUCCESS);
+ /* 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++;
+ }
}
/*
* message if there was an error). This never returns if there was an error.
*/
-void
-channel_input_port_forward_request(int is_root)
+void
+channel_input_port_forward_request(int is_root, int gateway_ports)
{
u_short port, host_port;
char *hostname;
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);
- /*
- * Initiate forwarding,
- * bind port to localhost only (gateway ports == 0).
- */
- channel_request_local_forwarding(port, hostname, host_port, 0);
+#endif
+ /* Initiate forwarding */
+ channel_request_local_forwarding(port, hostname, host_port, gateway_ports);
/* 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.
+ * 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_input_port_open(int payload_len)
+void
+channel_add_permitted_opens(char *host, int port)
{
- int remote_channel, sock = 0, newch, i;
- u_short host_port;
- char *host, *originator_string;
- int host_len, originator_len;
- struct addrinfo hints, *ai, *aitop;
- char ntop[NI_MAXHOST], strport[NI_MAXSERV];
- int gaierr;
+ 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);
- /* Get remote channel number. */
- remote_channel = packet_get_int();
+ permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host);
+ permitted_opens[num_permitted_opens].port_to_connect = port;
+ num_permitted_opens++;
- /* Get host name to connect to. */
- host = packet_get_string(&host_len);
+ all_opens_permitted = 0;
+}
- /* Get port to connect to. */
- host_port = packet_get_int();
+void
+channel_clear_permitted_opens(void)
+{
+ int i;
- /* Get remote originator name. */
- if (have_hostname_in_open) {
- originator_string = packet_get_string(&originator_len);
- originator_len += 4; /* size of packet_int */
- } else {
- originator_string = xstrdup("unknown (remote did not supply name)");
- originator_len = 0; /* no originator supplied */
- }
+ for (i = 0; i < num_permitted_opens; i++)
+ xfree(permitted_opens[i].host_to_connect);
+ num_permitted_opens = 0;
- packet_integrity_check(payload_len,
- 4 + 4 + host_len + 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();
- }
- }
+/* return socket to remote host, port */
+static int
+connect_to(const char *host, u_short port)
+{
+ struct addrinfo hints, *ai, *aitop;
+ char ntop[NI_MAXHOST], strport[NI_MAXSERV];
+ int gaierr;
+ int sock = -1;
memset(&hints, 0, sizeof(hints));
hints.ai_family = IPv4or6;
hints.ai_socktype = SOCK_STREAM;
- snprintf(strport, sizeof strport, "%d", host_port);
+ snprintf(strport, sizeof strport, "%d", port);
if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0) {
- error("%.100s: unknown host (%s)", host, gai_strerror(gaierr));
- goto fail;
+ 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("channel_input_port_open: getnameinfo failed");
+ error("connect_to: getnameinfo failed");
continue;
}
- /* Create the socket. */
sock = socket(ai->ai_family, SOCK_STREAM, 0);
if (sock < 0) {
error("socket: %.100s", strerror(errno));
continue;
}
- /* Connect to the host/port. */
- if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
- error("connect %.100s port %s: %.100s", ntop, strport,
+ 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 */
+ continue; /* fail -- try next */
}
break; /* success */
}
freeaddrinfo(aitop);
-
if (!ai) {
- error("connect %.100s port %d: failed.", host, host_port);
- goto fail;
+ error("connect_to %.100s port %d: failed.", host, port);
+ return -1;
}
+ /* success */
+ return sock;
+}
- /* 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();
+int
+channel_connect_by_listen_address(u_short listen_port)
+{
+ int i;
- /* Free the argument string. */
- xfree(host);
+ 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;
+}
- return;
+/* Check if connecting to that port is permitted and connect. */
+int
+channel_connect_to(const char *host, u_short port)
+{
+ int i, permit;
-fail:
- /* Free the argument string. */
- xfree(host);
+ 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;
- /* Send refusal to the remote host. */
- packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
- packet_put_int(remote_channel);
- packet_send();
+ }
+ 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);
}
+/* -- X11 forwarding */
+
/*
* Creates an internet domain socket for listening for X11 connections.
* Returns a suitable value for the DISPLAY variable, or NULL if an error
* occurs.
*/
-
-#define NUM_SOCKS 10
-
char *
x11_create_display_inet(int screen_number, int x11_display_offset)
{
continue;
sock = socket(ai->ai_family, SOCK_STREAM, 0);
if (sock < 0) {
- if (errno != EINVAL) {
+ if ((errno != EINVAL) && (errno != EAFNOSUPPORT)) {
error("socket: %.100s", strerror(errno));
return NULL;
} else {
- debug("Socket family %d not supported [X11 disp create]", ai->ai_family);
+ debug("x11_create_display_inet: Socket family %d not supported",
+ ai->ai_family);
continue;
}
}
break;
#endif
}
+ freeaddrinfo(aitop);
if (num_socks > 0)
break;
}
}
/* 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.
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);
+ 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);
+ 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_allocate(SSH_CHANNEL_X11_LISTENER, sock,
- xstrdup("X11 inet listener"));
+ (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. */
#define X_UNIX_PATH "/tmp/.X11-unix/X"
#endif
-static
-int
-connect_local_xsocket(unsigned int dnr)
+static int
+connect_local_xsocket(u_int dnr)
{
static const char *const x_sockets[] = {
X_UNIX_PATH "%u",
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
+x11_connect_display(void)
{
- int remote_channel, display_number, sock = 0, newch;
+ int display_number, sock = 0;
const char *display;
- char buf[1024], *cp, *remote_host;
- int remote_len;
+ char buf[1024], *cp;
struct addrinfo hints, *ai, *aitop;
char strport[NI_MAXSERV];
int gaierr;
- /* Get remote channel number. */
- remote_channel = packet_get_int();
-
- /* Get remote originator name. */
- if (have_hostname_in_open) {
- remote_host = packet_get_string(&remote_len);
- remote_len += 4;
- } else {
- remote_host = xstrdup("unknown (remote did not supply name)");
- remote_len = 0;
- }
-
- debug("Received X11 open request.");
- packet_integrity_check(payload_len, 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;
+ return -1;
}
/*
* Now we decode the value of the DISPLAY variable and make a
if (sscanf(strrchr(display, ':') + 1, "%d", &display_number) != 1) {
error("Could not parse display number from DISPLAY: %.100s",
display);
- goto fail;
+ return -1;
}
/* Create a socket. */
sock = connect_local_xsocket(display_number);
if (sock < 0)
- goto fail;
+ return -1;
/* OK, we now have a connection to the display. */
- goto success;
+ return sock;
}
/*
* Connect to an inet socket. The DISPLAY value is supposedly
cp = strchr(buf, ':');
if (!cp) {
error("Could not find ':' in DISPLAY: %.100s", display);
- goto fail;
+ 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);
- goto fail;
+ return -1;
}
/* Look up the host address */
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));
- goto fail;
+ 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;
+ 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;
}
- /* Success */
- break;
-
- } /* (ai = aitop, ai; ai = ai->ai_next) */
freeaddrinfo(aitop);
if (!ai) {
- error("connect %.100s port %d: %.100s", buf, 6000 + display_number,
+ error("connect %.100s port %d: %.100s", buf, 6000 + display_number,
strerror(errno));
- goto fail;
+ return -1;
}
-success:
- /* We have successfully obtained a connection to the real X display. */
+ return sock;
+}
- /* 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;
+/*
+ * 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.
+ */
- /* 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();
+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();
- return;
+ if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {
+ remote_host = packet_get_string(NULL);
+ } else {
+ remote_host = xstrdup("unknown (remote did not supply name)");
+ }
+ packet_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();
+}
-fail:
- /* Send refusal to the remote host. */
+/* dummy protocol handler that denies SSH-1 requests (agent/x11) */
+void
+deny_input_open(int type, int plen, void *ctxt)
+{
+ int rchan = packet_get_int();
+ switch(type){
+ case SSH_SMSG_AGENT_OPEN:
+ error("Warning: ssh server tried agent forwarding.");
+ break;
+ case SSH_SMSG_X11_OPEN:
+ error("Warning: ssh server tried X11 forwarding.");
+ break;
+ default:
+ error("deny_input_open: type %d plen %d", type, plen);
+ break;
+ }
+ error("Warning: this is probably a break in attempt by a malicious server.");
packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
- packet_put_int(remote_channel);
+ packet_put_int(rchan);
packet_send();
}
/*
* Requests forwarding of X11 connections, generates fake authentication
* data, and enables authentication spoofing.
+ * This should be called in the client only.
*/
-
-void
-x11_request_forwarding_with_spoofing(const char *proto, const char *data)
+void
+x11_request_forwarding_with_spoofing(int client_session_id,
+ const char *proto, const char *data)
{
- unsigned int data_len = (unsigned int) strlen(data) / 2;
- unsigned int i, value;
+ u_int data_len = (u_int) strlen(data) / 2;
+ u_int i, value, len;
char *new_data;
int screen_number;
const char *cp;
x11_fake_data_len = data_len;
/* Convert the fake data into hex. */
- new_data = xmalloc(2 * data_len + 1);
+ len = 2 * data_len + 1;
+ new_data = xmalloc(len);
for (i = 0; i < data_len; i++)
- sprintf(new_data + 2 * i, "%02x", (unsigned char) x11_fake_data[i]);
+ snprintf(new_data + 2 * i, len - 2 * i,
+ "%02x", (u_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));
+ if (compat20) {
+ channel_request_start(client_session_id, "x11-req", 0);
+ packet_put_char(0); /* XXX bool single connection */
+ } else {
+ packet_start(SSH_CMSG_X11_REQUEST_FORWARDING);
+ }
+ packet_put_cstring(proto);
+ packet_put_cstring(new_data);
packet_put_int(screen_number);
packet_send();
packet_write_wait();
xfree(new_data);
}
+
+/* -- agent forwarding */
+
/* Sends a message to the server to request authentication fd forwarding. */
-void
+void
auth_request_forwarding()
{
packet_start(SSH_CMSG_AGENT_REQUEST_FORWARDING);
char *
auth_get_socket_name()
{
- return channel_forwarded_auth_socket_name;
+ return auth_sock_name;
}
/* removes the agent forwarding socket */
-void
-cleanup_socket(void)
+void
+auth_sock_cleanup_proc(void *_pw)
{
- remove(channel_forwarded_auth_socket_name);
- rmdir(channel_forwarded_auth_socket_dir);
+ struct passwd *pw = _pw;
+
+ if (auth_sock_name) {
+ temporarily_use_uid(pw);
+ unlink(auth_sock_name);
+ rmdir(auth_sock_dir);
+ auth_sock_name = NULL;
+ restore_uid();
+ }
}
/*
- * This if called to process SSH_CMSG_AGENT_REQUEST_FORWARDING on the server.
+ * This is called to process SSH_CMSG_AGENT_REQUEST_FORWARDING on the server.
* This starts forwarding authentication requests.
*/
-void
+int
auth_input_request_forwarding(struct passwd * pw)
{
- int sock, newch;
+ Channel *nc;
+ int sock;
struct sockaddr_un sunaddr;
- if (auth_get_socket_name() != NULL)
- fatal("Protocol error: authentication forwarding requested twice.");
+ if (auth_get_socket_name() != NULL) {
+ error("authentication forwarding requested twice.");
+ return 0;
+ }
/* Temporarily drop privileged uid for mkdir/bind. */
- temporarily_use_uid(pw->pw_uid);
+ 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);
+ auth_sock_name = xmalloc(MAXPATHLEN);
+ auth_sock_dir = xmalloc(MAXPATHLEN);
+ strlcpy(auth_sock_dir, "/tmp/ssh-XXXXXXXX", MAXPATHLEN);
/* 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());
-
- if (atexit(cleanup_socket) < 0) {
- int saved = errno;
- cleanup_socket();
- packet_disconnect("socket: %.100s", strerror(saved));
+ if (mkdtemp(auth_sock_dir) == NULL) {
+ packet_send_debug("Agent forwarding disabled: "
+ "mkdtemp() failed: %.100s", strerror(errno));
+ restore_uid();
+ xfree(auth_sock_name);
+ xfree(auth_sock_dir);
+ auth_sock_name = NULL;
+ auth_sock_dir = NULL;
+ return 0;
}
+ snprintf(auth_sock_name, MAXPATHLEN, "%s/agent.%d",
+ auth_sock_dir, (int) getpid());
+
+ /* delete agent socket on fatal() */
+ fatal_add_cleanup(auth_sock_cleanup_proc, pw);
+
/* Create the socket. */
sock = socket(AF_UNIX, SOCK_STREAM, 0);
if (sock < 0)
/* Bind it to the name. */
memset(&sunaddr, 0, sizeof(sunaddr));
sunaddr.sun_family = AF_UNIX;
- strncpy(sunaddr.sun_path, channel_forwarded_auth_socket_name,
+ strncpy(sunaddr.sun_path, auth_sock_name,
sizeof(sunaddr.sun_path));
if (bind(sock, (struct sockaddr *) & sunaddr, sizeof(sunaddr)) < 0)
packet_disconnect("listen: %.100s", strerror(errno));
/* Allocate a channel for the authentication agent socket. */
- newch = channel_allocate(SSH_CHANNEL_AUTH_SOCKET, sock,
- xstrdup("auth socket"));
- strlcpy(channels[newch].path, channel_forwarded_auth_socket_name,
- sizeof(channels[newch].path));
+ 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");
+ auth_sock_cleanup_proc(pw);
+ fatal_remove_cleanup(auth_sock_cleanup_proc, pw);
+ close(sock);
+ return 0;
+ }
+ strlcpy(nc->path, auth_sock_name, sizeof(nc->path));
+ return 1;
}
/* This is called to process an SSH_SMSG_AGENT_OPEN message. */
-void
-auth_input_open_request()
+void
+auth_input_open_request(int type, int plen, void *ctxt)
{
- int remch, sock, newch;
- char *dummyname;
+ Channel *c = NULL;
+ int remote_id, sock;
+ char *name;
+
+ packet_integrity_check(plen, 4, type);
/* Read the remote channel number from the message. */
- remch = packet_get_int();
+ remote_id = packet_get_int();
/*
* Get a connection to the local authentication agent (this may again
* because authentication forwarding is only enabled if we have an
* agent.
*/
- if (sock < 0) {
+ if (sock >= 0) {
+ name = xstrdup("authentication agent connection");
+ c = channel_new("", SSH_CHANNEL_OPEN, sock, sock,
+ -1, 0, 0, 0, name, 1);
+ if (c == NULL) {
+ error("auth_input_open_request: channel_new failed");
+ xfree(name);
+ close(sock);
+ } else {
+ c->remote_id = remote_id;
+ }
+ }
+ if (c == NULL) {
packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
- packet_put_int(remch);
- packet_send();
- return;
+ 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);
}
- 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();
}