--- /dev/null
+/* $OpenBSD: channels.c,v 1.355 2016/09/30 20:24:46 djm Exp $ */
+/*
+ * Author: Tatu Ylonen <ylo@cs.hut.fi>
+ * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
+ * All rights reserved
+ * This file contains functions for generic socket connection forwarding.
+ * There is also code for initiating connection forwarding for X11 connections,
+ * arbitrary tcp/ip connections, and the authentication agent connection.
+ *
+ * As far as I am concerned, the code I have written for this software
+ * can be used freely for any purpose. Any derived versions of this
+ * software must be clearly marked as such, and if the derived work is
+ * incompatible with the protocol description in the RFC file, it must be
+ * called by a name other than "ssh" or "Secure Shell".
+ *
+ * SSH2 support added by Markus Friedl.
+ * Copyright (c) 1999, 2000, 2001, 2002 Markus Friedl. All rights reserved.
+ * Copyright (c) 1999 Dug Song. All rights reserved.
+ * Copyright (c) 1999 Theo de Raadt. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "includes.h"
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/ioctl.h>
+#include <sys/un.h>
+#include <sys/socket.h>
+#ifdef HAVE_SYS_TIME_H
+# include <sys/time.h>
+#endif
+
+#include <netinet/in.h>
+#include <arpa/inet.h>
+
+#include <errno.h>
+#include <fcntl.h>
+#include <netdb.h>
+#ifdef HAVE_STDINT_H
+#include <stdint.h>
+#endif
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <termios.h>
+#include <unistd.h>
+#include <stdarg.h>
+
+#include "openbsd-compat/sys-queue.h"
+#include "xmalloc.h"
+#include "ssh.h"
+#include "ssh1.h"
+#include "ssh2.h"
+#include "ssherr.h"
+#include "packet.h"
+#include "log.h"
+#include "misc.h"
+#include "buffer.h"
+#include "channels.h"
+#include "compat.h"
+#include "canohost.h"
+#include "key.h"
+#include "authfd.h"
+#include "pathnames.h"
+
+/* -- channel core */
+
+/*
+ * Pointer to an array containing all allocated channels. The array is
+ * dynamically extended as needed.
+ */
+static Channel **channels = NULL;
+
+/*
+ * Size of the channel array. All slots of the array must always be
+ * initialized (at least the type field); unused slots set to NULL
+ */
+static u_int channels_alloc = 0;
+
+/*
+ * Maximum file descriptor value used in any of the channels. This is
+ * updated in channel_new.
+ */
+static int channel_max_fd = 0;
+
+
+/* -- tcp forwarding */
+
+/*
+ * Data structure for storing which hosts are permitted for forward requests.
+ * The local sides of any remote forwards are stored in this array to prevent
+ * a corrupt remote server from accessing arbitrary TCP/IP ports on our local
+ * network (which might be behind a firewall).
+ */
+/* XXX: streamlocal wants a path instead of host:port */
+/* Overload host_to_connect; we could just make this match Forward */
+/* XXX - can we use listen_host instead of listen_path? */
+typedef struct {
+ char *host_to_connect; /* Connect to 'host'. */
+ int port_to_connect; /* Connect to 'port'. */
+ char *listen_host; /* Remote side should listen address. */
+ char *listen_path; /* Remote side should listen path. */
+ int listen_port; /* Remote side should listen port. */
+ Channel *downstream; /* Downstream mux*/
+} ForwardPermission;
+
+/* List of all permitted host/port pairs to connect by the user. */
+static ForwardPermission *permitted_opens = NULL;
+
+/* List of all permitted host/port pairs to connect by the admin. */
+static ForwardPermission *permitted_adm_opens = NULL;
+
+/* Number of permitted host/port pairs in the array permitted by the user. */
+static int num_permitted_opens = 0;
+
+/* Number of permitted host/port pair in the array permitted by the admin. */
+static int num_adm_permitted_opens = 0;
+
+/* special-case port number meaning allow any port */
+#define FWD_PERMIT_ANY_PORT 0
+
+/* special-case wildcard meaning allow any host */
+#define FWD_PERMIT_ANY_HOST "*"
+
+/*
+ * If this is true, all opens are permitted. This is the case on the server
+ * on which we have to trust the client anyway, and the user could do
+ * anything after logging in anyway.
+ */
+static int all_opens_permitted = 0;
+
+
+/* -- X11 forwarding */
+
+/* Maximum number of fake X11 displays to try. */
+#define MAX_DISPLAYS 1000
+
+/* Saved X11 local (client) display. */
+static char *x11_saved_display = NULL;
+
+/* Saved X11 authentication protocol name. */
+static char *x11_saved_proto = NULL;
+
+/* Saved X11 authentication data. This is the real data. */
+static char *x11_saved_data = NULL;
+static u_int x11_saved_data_len = 0;
+
+/* Deadline after which all X11 connections are refused */
+static u_int x11_refuse_time;
+
+/*
+ * Fake X11 authentication data. This is what the server will be sending us;
+ * we should replace any occurrences of this by the real data.
+ */
+static u_char *x11_fake_data = NULL;
+static u_int x11_fake_data_len;
+
+
+/* -- agent forwarding */
+
+#define NUM_SOCKS 10
+
+/* AF_UNSPEC or AF_INET or AF_INET6 */
+static int IPv4or6 = AF_UNSPEC;
+
+/* helper */
+static void port_open_helper(Channel *c, char *rtype);
+static const char *channel_rfwd_bind_host(const char *listen_host);
+
+/* non-blocking connect helpers */
+static int connect_next(struct channel_connect *);
+static void channel_connect_ctx_free(struct channel_connect *);
+
+/* -- channel core */
+
+Channel *
+channel_by_id(int id)
+{
+ Channel *c;
+
+ if (id < 0 || (u_int)id >= channels_alloc) {
+ logit("channel_by_id: %d: bad id", id);
+ return NULL;
+ }
+ c = channels[id];
+ if (c == NULL) {
+ logit("channel_by_id: %d: bad id: channel free", id);
+ return NULL;
+ }
+ return c;
+}
+
+Channel *
+channel_by_remote_id(int remote_id)
+{
+ Channel *c;
+ u_int i;
+
+ for (i = 0; i < channels_alloc; i++) {
+ c = channels[i];
+ if (c != NULL && c->remote_id == remote_id)
+ return c;
+ }
+ return NULL;
+}
+
+/*
+ * Returns the channel if it is allowed to receive protocol messages.
+ * Private channels, like listening sockets, may not receive messages.
+ */
+Channel *
+channel_lookup(int id)
+{
+ Channel *c;
+
+ if ((c = channel_by_id(id)) == NULL)
+ return (NULL);
+
+ switch (c->type) {
+ case SSH_CHANNEL_X11_OPEN:
+ case SSH_CHANNEL_LARVAL:
+ case SSH_CHANNEL_CONNECTING:
+ case SSH_CHANNEL_DYNAMIC:
+ case SSH_CHANNEL_OPENING:
+ case SSH_CHANNEL_OPEN:
+ case SSH_CHANNEL_INPUT_DRAINING:
+ case SSH_CHANNEL_OUTPUT_DRAINING:
+ case SSH_CHANNEL_ABANDONED:
+ case SSH_CHANNEL_MUX_PROXY:
+ return (c);
+ }
+ logit("Non-public channel %d, type %d.", id, c->type);
+ return (NULL);
+}
+
+/*
+ * Register filedescriptors for a channel, used when allocating a channel or
+ * when the channel consumer/producer is ready, e.g. shell exec'd
+ */
+static void
+channel_register_fds(Channel *c, int rfd, int wfd, int efd,
+ int extusage, int nonblock, int is_tty)
+{
+ /* Update the maximum file descriptor value. */
+ channel_max_fd = MAXIMUM(channel_max_fd, rfd);
+ channel_max_fd = MAXIMUM(channel_max_fd, wfd);
+ channel_max_fd = MAXIMUM(channel_max_fd, efd);
+
+ if (rfd != -1)
+ fcntl(rfd, F_SETFD, FD_CLOEXEC);
+ if (wfd != -1 && wfd != rfd)
+ fcntl(wfd, F_SETFD, FD_CLOEXEC);
+ if (efd != -1 && efd != rfd && efd != wfd)
+ fcntl(efd, F_SETFD, FD_CLOEXEC);
+
+ c->rfd = rfd;
+ c->wfd = wfd;
+ c->sock = (rfd == wfd) ? rfd : -1;
+ c->efd = efd;
+ c->extended_usage = extusage;
+
+ if ((c->isatty = is_tty) != 0)
+ debug2("channel %d: rfd %d isatty", c->self, c->rfd);
+#ifdef _AIX
+ /* XXX: Later AIX versions can't push as much data to tty */
+ c->wfd_isatty = is_tty || isatty(c->wfd);
+#endif
+
+ /* enable nonblocking mode */
+ if (nonblock) {
+ if (rfd != -1)
+ set_nonblock(rfd);
+ if (wfd != -1)
+ set_nonblock(wfd);
+ if (efd != -1)
+ set_nonblock(efd);
+ }
+}
+
+/*
+ * Allocate a new channel object and set its type and socket. This will cause
+ * remote_name to be freed.
+ */
+Channel *
+channel_new(char *ctype, int type, int rfd, int wfd, int efd,
+ u_int window, u_int maxpack, int extusage, char *remote_name, int nonblock)
+{
+ int found;
+ u_int i;
+ Channel *c;
+
+ /* Do initial allocation if this is the first call. */
+ if (channels_alloc == 0) {
+ channels_alloc = 10;
+ channels = xcalloc(channels_alloc, sizeof(Channel *));
+ for (i = 0; i < channels_alloc; i++)
+ channels[i] = NULL;
+ }
+ /* Try to find a free slot where to put the new channel. */
+ for (found = -1, i = 0; i < channels_alloc; i++)
+ if (channels[i] == NULL) {
+ /* Found a free slot. */
+ found = (int)i;
+ break;
+ }
+ if (found < 0) {
+ /* There are no free slots. Take last+1 slot and expand the array. */
+ found = channels_alloc;
+ if (channels_alloc > 10000)
+ fatal("channel_new: internal error: channels_alloc %d "
+ "too big.", channels_alloc);
+ channels = xreallocarray(channels, channels_alloc + 10,
+ sizeof(Channel *));
+ channels_alloc += 10;
+ debug2("channel: expanding %d", channels_alloc);
+ for (i = found; i < channels_alloc; i++)
+ channels[i] = NULL;
+ }
+ /* Initialize and return new channel. */
+ c = channels[found] = xcalloc(1, sizeof(Channel));
+ buffer_init(&c->input);
+ buffer_init(&c->output);
+ buffer_init(&c->extended);
+ c->path = NULL;
+ c->listening_addr = NULL;
+ c->listening_port = 0;
+ c->ostate = CHAN_OUTPUT_OPEN;
+ c->istate = CHAN_INPUT_OPEN;
+ c->flags = 0;
+ channel_register_fds(c, rfd, wfd, efd, extusage, nonblock, 0);
+ c->notbefore = 0;
+ c->self = found;
+ c->type = type;
+ c->ctype = ctype;
+ c->local_window = window;
+ c->local_window_max = window;
+ c->local_consumed = 0;
+ c->local_maxpacket = maxpack;
+ c->remote_id = -1;
+ c->remote_name = xstrdup(remote_name);
+ c->remote_window = 0;
+ c->remote_maxpacket = 0;
+ c->force_drain = 0;
+ c->single_connection = 0;
+ c->detach_user = NULL;
+ c->detach_close = 0;
+ c->open_confirm = NULL;
+ c->open_confirm_ctx = NULL;
+ c->input_filter = NULL;
+ c->output_filter = NULL;
+ c->filter_ctx = NULL;
+ c->filter_cleanup = NULL;
+ c->ctl_chan = -1;
+ c->mux_rcb = NULL;
+ c->mux_ctx = NULL;
+ c->mux_pause = 0;
+ c->delayed = 1; /* prevent call to channel_post handler */
+ TAILQ_INIT(&c->status_confirms);
+ debug("channel %d: new [%s]", found, remote_name);
+ return c;
+}
+
+static int
+channel_find_maxfd(void)
+{
+ u_int i;
+ int max = 0;
+ Channel *c;
+
+ for (i = 0; i < channels_alloc; i++) {
+ c = channels[i];
+ if (c != NULL) {
+ max = MAXIMUM(max, c->rfd);
+ max = MAXIMUM(max, c->wfd);
+ max = MAXIMUM(max, c->efd);
+ }
+ }
+ return max;
+}
+
+int
+channel_close_fd(int *fdp)
+{
+ int ret = 0, fd = *fdp;
+
+ if (fd != -1) {
+ ret = close(fd);
+ *fdp = -1;
+ if (fd == channel_max_fd)
+ channel_max_fd = channel_find_maxfd();
+ }
+ return ret;
+}
+
+/* Close all channel fd/socket. */
+static void
+channel_close_fds(Channel *c)
+{
+ channel_close_fd(&c->sock);
+ channel_close_fd(&c->rfd);
+ channel_close_fd(&c->wfd);
+ channel_close_fd(&c->efd);
+}
+
+/* Free the channel and close its fd/socket. */
+void
+channel_free(Channel *c)
+{
+ char *s;
+ u_int i, n;
+ Channel *other;
+ struct channel_confirm *cc;
+
+ for (n = 0, i = 0; i < channels_alloc; i++) {
+ if ((other = channels[i]) != NULL) {
+ n++;
+
+ /* detach from mux client and prepare for closing */
+ if (c->type == SSH_CHANNEL_MUX_CLIENT &&
+ other->type == SSH_CHANNEL_MUX_PROXY &&
+ other->mux_ctx == c) {
+ other->mux_ctx = NULL;
+ other->type = SSH_CHANNEL_OPEN;
+ other->istate = CHAN_INPUT_CLOSED;
+ other->ostate = CHAN_OUTPUT_CLOSED;
+ }
+ }
+ }
+ debug("channel %d: free: %s, nchannels %u", c->self,
+ c->remote_name ? c->remote_name : "???", n);
+
+ /* XXX more MUX cleanup: remove remote forwardings */
+ if (c->type == SSH_CHANNEL_MUX_CLIENT) {
+ for (i = 0; i < (u_int)num_permitted_opens; i++) {
+ if (permitted_opens[i].downstream != c)
+ continue;
+ /* cancel on the server, since mux client is gone */
+ debug("channel %d: cleanup remote forward for %s:%u",
+ c->self,
+ permitted_opens[i].listen_host,
+ permitted_opens[i].listen_port);
+ packet_start(SSH2_MSG_GLOBAL_REQUEST);
+ packet_put_cstring("cancel-tcpip-forward");
+ packet_put_char(0);
+ packet_put_cstring(channel_rfwd_bind_host(
+ permitted_opens[i].listen_host));
+ packet_put_int(permitted_opens[i].listen_port);
+ packet_send();
+ /* unregister */
+ permitted_opens[i].listen_port = 0;
+ permitted_opens[i].port_to_connect = 0;
+ free(permitted_opens[i].host_to_connect);
+ permitted_opens[i].host_to_connect = NULL;
+ free(permitted_opens[i].listen_host);
+ permitted_opens[i].listen_host = NULL;
+ permitted_opens[i].listen_path = NULL;
+ permitted_opens[i].downstream = NULL;
+ }
+ }
+
+ s = channel_open_message();
+ debug3("channel %d: status: %s", c->self, s);
+ free(s);
+
+ if (c->sock != -1)
+ shutdown(c->sock, SHUT_RDWR);
+ channel_close_fds(c);
+ buffer_free(&c->input);
+ buffer_free(&c->output);
+ buffer_free(&c->extended);
+ free(c->remote_name);
+ c->remote_name = NULL;
+ free(c->path);
+ c->path = NULL;
+ free(c->listening_addr);
+ c->listening_addr = NULL;
+ while ((cc = TAILQ_FIRST(&c->status_confirms)) != NULL) {
+ if (cc->abandon_cb != NULL)
+ cc->abandon_cb(c, cc->ctx);
+ TAILQ_REMOVE(&c->status_confirms, cc, entry);
+ explicit_bzero(cc, sizeof(*cc));
+ free(cc);
+ }
+ if (c->filter_cleanup != NULL && c->filter_ctx != NULL)
+ c->filter_cleanup(c->self, c->filter_ctx);
+ channels[c->self] = NULL;
+ free(c);
+}
+
+void
+channel_free_all(void)
+{
+ u_int i;
+
+ for (i = 0; i < channels_alloc; i++)
+ if (channels[i] != NULL)
+ channel_free(channels[i]);
+}
+
+/*
+ * Closes the sockets/fds of all channels. This is used to close extra file
+ * descriptors after a fork.
+ */
+void
+channel_close_all(void)
+{
+ u_int i;
+
+ for (i = 0; i < channels_alloc; i++)
+ if (channels[i] != NULL)
+ channel_close_fds(channels[i]);
+}
+
+/*
+ * Stop listening to channels.
+ */
+void
+channel_stop_listening(void)
+{
+ u_int i;
+ Channel *c;
+
+ for (i = 0; i < channels_alloc; i++) {
+ c = channels[i];
+ if (c != NULL) {
+ switch (c->type) {
+ case SSH_CHANNEL_AUTH_SOCKET:
+ case SSH_CHANNEL_PORT_LISTENER:
+ case SSH_CHANNEL_RPORT_LISTENER:
+ case SSH_CHANNEL_X11_LISTENER:
+ case SSH_CHANNEL_UNIX_LISTENER:
+ case SSH_CHANNEL_RUNIX_LISTENER:
+ channel_close_fd(&c->sock);
+ channel_free(c);
+ break;
+ }
+ }
+ }
+}
+
+/*
+ * Returns true if no channel has too much buffered data, and false if one or
+ * more channel is overfull.
+ */
+int
+channel_not_very_much_buffered_data(void)
+{
+ u_int i;
+ Channel *c;
+
+ for (i = 0; i < channels_alloc; i++) {
+ c = channels[i];
+ if (c != NULL && c->type == SSH_CHANNEL_OPEN) {
+#if 0
+ if (!compat20 &&
+ buffer_len(&c->input) > packet_get_maxsize()) {
+ debug2("channel %d: big input buffer %d",
+ c->self, buffer_len(&c->input));
+ return 0;
+ }
+#endif
+ if (buffer_len(&c->output) > packet_get_maxsize()) {
+ debug2("channel %d: big output buffer %u > %u",
+ c->self, buffer_len(&c->output),
+ packet_get_maxsize());
+ return 0;
+ }
+ }
+ }
+ return 1;
+}
+
+/* Returns true if any channel is still open. */
+int
+channel_still_open(void)
+{
+ u_int i;
+ Channel *c;
+
+ for (i = 0; i < channels_alloc; i++) {
+ c = channels[i];
+ if (c == NULL)
+ continue;
+ switch (c->type) {
+ case SSH_CHANNEL_X11_LISTENER:
+ case SSH_CHANNEL_PORT_LISTENER:
+ case SSH_CHANNEL_RPORT_LISTENER:
+ case SSH_CHANNEL_MUX_LISTENER:
+ case SSH_CHANNEL_CLOSED:
+ case SSH_CHANNEL_AUTH_SOCKET:
+ case SSH_CHANNEL_DYNAMIC:
+ case SSH_CHANNEL_CONNECTING:
+ case SSH_CHANNEL_ZOMBIE:
+ case SSH_CHANNEL_ABANDONED:
+ case SSH_CHANNEL_UNIX_LISTENER:
+ case SSH_CHANNEL_RUNIX_LISTENER:
+ continue;
+ case SSH_CHANNEL_LARVAL:
+ if (!compat20)
+ fatal("cannot happen: SSH_CHANNEL_LARVAL");
+ continue;
+ case SSH_CHANNEL_OPENING:
+ case SSH_CHANNEL_OPEN:
+ case SSH_CHANNEL_X11_OPEN:
+ case SSH_CHANNEL_MUX_CLIENT:
+ case SSH_CHANNEL_MUX_PROXY:
+ return 1;
+ case SSH_CHANNEL_INPUT_DRAINING:
+ case SSH_CHANNEL_OUTPUT_DRAINING:
+ if (!compat13)
+ fatal("cannot happen: OUT_DRAIN");
+ return 1;
+ default:
+ fatal("channel_still_open: bad channel type %d", c->type);
+ /* NOTREACHED */
+ }
+ }
+ return 0;
+}
+
+/* Returns the id of an open channel suitable for keepaliving */
+int
+channel_find_open(void)
+{
+ u_int i;
+ Channel *c;
+
+ for (i = 0; i < channels_alloc; i++) {
+ c = channels[i];
+ if (c == NULL || c->remote_id < 0)
+ continue;
+ switch (c->type) {
+ case SSH_CHANNEL_CLOSED:
+ case SSH_CHANNEL_DYNAMIC:
+ case SSH_CHANNEL_X11_LISTENER:
+ case SSH_CHANNEL_PORT_LISTENER:
+ case SSH_CHANNEL_RPORT_LISTENER:
+ case SSH_CHANNEL_MUX_LISTENER:
+ case SSH_CHANNEL_MUX_CLIENT:
+ case SSH_CHANNEL_MUX_PROXY:
+ case SSH_CHANNEL_OPENING:
+ case SSH_CHANNEL_CONNECTING:
+ case SSH_CHANNEL_ZOMBIE:
+ case SSH_CHANNEL_ABANDONED:
+ case SSH_CHANNEL_UNIX_LISTENER:
+ case SSH_CHANNEL_RUNIX_LISTENER:
+ continue;
+ case SSH_CHANNEL_LARVAL:
+ case SSH_CHANNEL_AUTH_SOCKET:
+ case SSH_CHANNEL_OPEN:
+ case SSH_CHANNEL_X11_OPEN:
+ return i;
+ case SSH_CHANNEL_INPUT_DRAINING:
+ case SSH_CHANNEL_OUTPUT_DRAINING:
+ if (!compat13)
+ fatal("cannot happen: OUT_DRAIN");
+ return i;
+ default:
+ fatal("channel_find_open: bad channel type %d", c->type);
+ /* NOTREACHED */
+ }
+ }
+ return -1;
+}
+
+/*
+ * Returns a message describing the currently open forwarded connections,
+ * suitable for sending to the client. The message contains crlf pairs for
+ * newlines.
+ */
+char *
+channel_open_message(void)
+{
+ Buffer buffer;
+ Channel *c;
+ char buf[1024], *cp;
+ u_int i;
+
+ buffer_init(&buffer);
+ snprintf(buf, sizeof buf, "The following connections are open:\r\n");
+ buffer_append(&buffer, buf, strlen(buf));
+ for (i = 0; i < channels_alloc; i++) {
+ c = channels[i];
+ if (c == NULL)
+ continue;
+ switch (c->type) {
+ case SSH_CHANNEL_X11_LISTENER:
+ case SSH_CHANNEL_PORT_LISTENER:
+ case SSH_CHANNEL_RPORT_LISTENER:
+ case SSH_CHANNEL_CLOSED:
+ case SSH_CHANNEL_AUTH_SOCKET:
+ case SSH_CHANNEL_ZOMBIE:
+ case SSH_CHANNEL_ABANDONED:
+ case SSH_CHANNEL_MUX_LISTENER:
+ case SSH_CHANNEL_UNIX_LISTENER:
+ case SSH_CHANNEL_RUNIX_LISTENER:
+ continue;
+ case SSH_CHANNEL_LARVAL:
+ case SSH_CHANNEL_OPENING:
+ case SSH_CHANNEL_CONNECTING:
+ case SSH_CHANNEL_DYNAMIC:
+ case SSH_CHANNEL_OPEN:
+ case SSH_CHANNEL_X11_OPEN:
+ case SSH_CHANNEL_INPUT_DRAINING:
+ case SSH_CHANNEL_OUTPUT_DRAINING:
+ case SSH_CHANNEL_MUX_PROXY:
+ case SSH_CHANNEL_MUX_CLIENT:
+ snprintf(buf, sizeof buf,
+ " #%d %.300s (t%d r%d i%u/%d o%u/%d fd %d/%d cc %d)\r\n",
+ c->self, c->remote_name,
+ c->type, c->remote_id,
+ c->istate, buffer_len(&c->input),
+ c->ostate, buffer_len(&c->output),
+ c->rfd, c->wfd, c->ctl_chan);
+ buffer_append(&buffer, buf, strlen(buf));
+ continue;
+ default:
+ fatal("channel_open_message: bad channel type %d", c->type);
+ /* NOTREACHED */
+ }
+ }
+ buffer_append(&buffer, "\0", 1);
+ cp = xstrdup((char *)buffer_ptr(&buffer));
+ buffer_free(&buffer);
+ return cp;
+}
+
+void
+channel_send_open(int id)
+{
+ Channel *c = channel_lookup(id);
+
+ if (c == NULL) {
+ logit("channel_send_open: %d: bad id", id);
+ return;
+ }
+ debug2("channel %d: send open", id);
+ packet_start(SSH2_MSG_CHANNEL_OPEN);
+ packet_put_cstring(c->ctype);
+ packet_put_int(c->self);
+ packet_put_int(c->local_window);
+ packet_put_int(c->local_maxpacket);
+ packet_send();
+}
+
+void
+channel_request_start(int id, char *service, int wantconfirm)
+{
+ Channel *c = channel_lookup(id);
+
+ if (c == NULL) {
+ logit("channel_request_start: %d: unknown channel id", id);
+ return;
+ }
+ debug2("channel %d: request %s confirm %d", id, service, wantconfirm);
+ packet_start(SSH2_MSG_CHANNEL_REQUEST);
+ packet_put_int(c->remote_id);
+ packet_put_cstring(service);
+ packet_put_char(wantconfirm);
+}
+
+void
+channel_register_status_confirm(int id, channel_confirm_cb *cb,
+ channel_confirm_abandon_cb *abandon_cb, void *ctx)
+{
+ struct channel_confirm *cc;
+ Channel *c;
+
+ if ((c = channel_lookup(id)) == NULL)
+ fatal("channel_register_expect: %d: bad id", id);
+
+ cc = xcalloc(1, sizeof(*cc));
+ cc->cb = cb;
+ cc->abandon_cb = abandon_cb;
+ cc->ctx = ctx;
+ TAILQ_INSERT_TAIL(&c->status_confirms, cc, entry);
+}
+
+void
+channel_register_open_confirm(int id, channel_open_fn *fn, void *ctx)
+{
+ Channel *c = channel_lookup(id);
+
+ if (c == NULL) {
+ logit("channel_register_open_confirm: %d: bad id", id);
+ return;
+ }
+ c->open_confirm = fn;
+ c->open_confirm_ctx = ctx;
+}
+
+void
+channel_register_cleanup(int id, channel_callback_fn *fn, int do_close)
+{
+ Channel *c = channel_by_id(id);
+
+ if (c == NULL) {
+ logit("channel_register_cleanup: %d: bad id", id);
+ return;
+ }
+ c->detach_user = fn;
+ c->detach_close = do_close;
+}
+
+void
+channel_cancel_cleanup(int id)
+{
+ Channel *c = channel_by_id(id);
+
+ if (c == NULL) {
+ logit("channel_cancel_cleanup: %d: bad id", id);
+ return;
+ }
+ c->detach_user = NULL;
+ c->detach_close = 0;
+}
+
+void
+channel_register_filter(int id, channel_infilter_fn *ifn,
+ channel_outfilter_fn *ofn, channel_filter_cleanup_fn *cfn, void *ctx)
+{
+ Channel *c = channel_lookup(id);
+
+ if (c == NULL) {
+ logit("channel_register_filter: %d: bad id", id);
+ return;
+ }
+ c->input_filter = ifn;
+ c->output_filter = ofn;
+ c->filter_ctx = ctx;
+ c->filter_cleanup = cfn;
+}
+
+void
+channel_set_fds(int id, int rfd, int wfd, int efd,
+ int extusage, int nonblock, int is_tty, u_int window_max)
+{
+ Channel *c = channel_lookup(id);
+
+ if (c == NULL || c->type != SSH_CHANNEL_LARVAL)
+ fatal("channel_activate for non-larval channel %d.", id);
+ channel_register_fds(c, rfd, wfd, efd, extusage, nonblock, is_tty);
+ c->type = SSH_CHANNEL_OPEN;
+ c->local_window = c->local_window_max = window_max;
+ packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
+ packet_put_int(c->remote_id);
+ packet_put_int(c->local_window);
+ packet_send();
+}
+
+/*
+ * 'channel_pre*' are called just before select() to add any bits relevant to
+ * channels in the select bitmasks.
+ */
+/*
+ * 'channel_post*': perform any appropriate operations for channels which
+ * have events pending.
+ */
+typedef void chan_fn(Channel *c, fd_set *readset, fd_set *writeset);
+chan_fn *channel_pre[SSH_CHANNEL_MAX_TYPE];
+chan_fn *channel_post[SSH_CHANNEL_MAX_TYPE];
+
+/* ARGSUSED */
+static void
+channel_pre_listener(Channel *c, fd_set *readset, fd_set *writeset)
+{
+ FD_SET(c->sock, readset);
+}
+
+/* ARGSUSED */
+static void
+channel_pre_connecting(Channel *c, fd_set *readset, fd_set *writeset)
+{
+ debug3("channel %d: waiting for connection", c->self);
+ FD_SET(c->sock, writeset);
+}
+
+static void
+channel_pre_open_13(Channel *c, fd_set *readset, fd_set *writeset)
+{
+ if (buffer_len(&c->input) < packet_get_maxsize())
+ FD_SET(c->sock, readset);
+ if (buffer_len(&c->output) > 0)
+ FD_SET(c->sock, writeset);
+}
+
+static void
+channel_pre_open(Channel *c, fd_set *readset, fd_set *writeset)
+{
+ u_int limit = compat20 ? c->remote_window : packet_get_maxsize();
+
+ if (c->istate == CHAN_INPUT_OPEN &&
+ limit > 0 &&
+ buffer_len(&c->input) < limit &&
+ buffer_check_alloc(&c->input, CHAN_RBUF))
+ FD_SET(c->rfd, readset);
+ if (c->ostate == CHAN_OUTPUT_OPEN ||
+ c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
+ if (buffer_len(&c->output) > 0) {
+ FD_SET(c->wfd, writeset);
+ } else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
+ if (CHANNEL_EFD_OUTPUT_ACTIVE(c))
+ debug2("channel %d: obuf_empty delayed efd %d/(%d)",
+ c->self, c->efd, buffer_len(&c->extended));
+ else
+ chan_obuf_empty(c);
+ }
+ }
+ /** XXX check close conditions, too */
+ if (compat20 && c->efd != -1 &&
+ !(c->istate == CHAN_INPUT_CLOSED && c->ostate == CHAN_OUTPUT_CLOSED)) {
+ if (c->extended_usage == CHAN_EXTENDED_WRITE &&
+ buffer_len(&c->extended) > 0)
+ FD_SET(c->efd, writeset);
+ else if (c->efd != -1 && !(c->flags & CHAN_EOF_SENT) &&
+ (c->extended_usage == CHAN_EXTENDED_READ ||
+ c->extended_usage == CHAN_EXTENDED_IGNORE) &&
+ buffer_len(&c->extended) < c->remote_window)
+ FD_SET(c->efd, readset);
+ }
+ /* XXX: What about efd? races? */
+}
+
+/* ARGSUSED */
+static void
+channel_pre_input_draining(Channel *c, fd_set *readset, fd_set *writeset)
+{
+ if (buffer_len(&c->input) == 0) {
+ packet_start(SSH_MSG_CHANNEL_CLOSE);
+ packet_put_int(c->remote_id);
+ packet_send();
+ c->type = SSH_CHANNEL_CLOSED;
+ debug2("channel %d: closing after input drain.", c->self);
+ }
+}
+
+/* ARGSUSED */
+static void
+channel_pre_output_draining(Channel *c, fd_set *readset, fd_set *writeset)
+{
+ if (buffer_len(&c->output) == 0)
+ chan_mark_dead(c);
+ else
+ FD_SET(c->sock, writeset);
+}
+
+/*
+ * This is a special state for X11 authentication spoofing. An opened X11
+ * connection (when authentication spoofing is being done) remains in this
+ * state until the first packet has been completely read. The authentication
+ * data in that packet is then substituted by the real data if it matches the
+ * fake data, and the channel is put into normal mode.
+ * XXX All this happens at the client side.
+ * Returns: 0 = need more data, -1 = wrong cookie, 1 = ok
+ */
+static int
+x11_open_helper(Buffer *b)
+{
+ u_char *ucp;
+ u_int proto_len, data_len;
+
+ /* Is this being called after the refusal deadline? */
+ if (x11_refuse_time != 0 && (u_int)monotime() >= x11_refuse_time) {
+ verbose("Rejected X11 connection after ForwardX11Timeout "
+ "expired");
+ return -1;
+ }
+
+ /* Check if the fixed size part of the packet is in buffer. */
+ if (buffer_len(b) < 12)
+ return 0;
+
+ /* Parse the lengths of variable-length fields. */
+ ucp = buffer_ptr(b);
+ if (ucp[0] == 0x42) { /* Byte order MSB first. */
+ proto_len = 256 * ucp[6] + ucp[7];
+ data_len = 256 * ucp[8] + ucp[9];
+ } else if (ucp[0] == 0x6c) { /* Byte order LSB first. */
+ proto_len = ucp[6] + 256 * ucp[7];
+ data_len = ucp[8] + 256 * ucp[9];
+ } else {
+ debug2("Initial X11 packet contains bad byte order byte: 0x%x",
+ ucp[0]);
+ return -1;
+ }
+
+ /* Check if the whole packet is in buffer. */
+ if (buffer_len(b) <
+ 12 + ((proto_len + 3) & ~3) + ((data_len + 3) & ~3))
+ return 0;
+
+ /* Check if authentication protocol matches. */
+ if (proto_len != strlen(x11_saved_proto) ||
+ memcmp(ucp + 12, x11_saved_proto, proto_len) != 0) {
+ debug2("X11 connection uses different authentication protocol.");
+ return -1;
+ }
+ /* Check if authentication data matches our fake data. */
+ if (data_len != x11_fake_data_len ||
+ timingsafe_bcmp(ucp + 12 + ((proto_len + 3) & ~3),
+ x11_fake_data, x11_fake_data_len) != 0) {
+ debug2("X11 auth data does not match fake data.");
+ return -1;
+ }
+ /* Check fake data length */
+ if (x11_fake_data_len != x11_saved_data_len) {
+ error("X11 fake_data_len %d != saved_data_len %d",
+ x11_fake_data_len, x11_saved_data_len);
+ return -1;
+ }
+ /*
+ * Received authentication protocol and data match
+ * our fake data. Substitute the fake data with real
+ * data.
+ */
+ memcpy(ucp + 12 + ((proto_len + 3) & ~3),
+ x11_saved_data, x11_saved_data_len);
+ return 1;
+}
+
+static void
+channel_pre_x11_open_13(Channel *c, fd_set *readset, fd_set *writeset)
+{
+ int ret = x11_open_helper(&c->output);
+
+ if (ret == 1) {
+ /* Start normal processing for the channel. */
+ c->type = SSH_CHANNEL_OPEN;
+ channel_pre_open_13(c, readset, writeset);
+ } else if (ret == -1) {
+ /*
+ * We have received an X11 connection that has bad
+ * authentication information.
+ */
+ logit("X11 connection rejected because of wrong authentication.");
+ buffer_clear(&c->input);
+ buffer_clear(&c->output);
+ channel_close_fd(&c->sock);
+ c->sock = -1;
+ c->type = SSH_CHANNEL_CLOSED;
+ packet_start(SSH_MSG_CHANNEL_CLOSE);
+ packet_put_int(c->remote_id);
+ packet_send();
+ }
+}
+
+static void
+channel_pre_x11_open(Channel *c, fd_set *readset, fd_set *writeset)
+{
+ int ret = x11_open_helper(&c->output);
+
+ /* c->force_drain = 1; */
+
+ if (ret == 1) {
+ c->type = SSH_CHANNEL_OPEN;
+ channel_pre_open(c, readset, writeset);
+ } else if (ret == -1) {
+ logit("X11 connection rejected because of wrong authentication.");
+ debug2("X11 rejected %d i%d/o%d", c->self, c->istate, c->ostate);
+ chan_read_failed(c);
+ buffer_clear(&c->input);
+ chan_ibuf_empty(c);
+ buffer_clear(&c->output);
+ /* for proto v1, the peer will send an IEOF */
+ if (compat20)
+ chan_write_failed(c);
+ else
+ c->type = SSH_CHANNEL_OPEN;
+ debug2("X11 closed %d i%d/o%d", c->self, c->istate, c->ostate);
+ }
+}
+
+static void
+channel_pre_mux_client(Channel *c, fd_set *readset, fd_set *writeset)
+{
+ if (c->istate == CHAN_INPUT_OPEN && !c->mux_pause &&
+ buffer_check_alloc(&c->input, CHAN_RBUF))
+ FD_SET(c->rfd, readset);
+ if (c->istate == CHAN_INPUT_WAIT_DRAIN) {
+ /* clear buffer immediately (discard any partial packet) */
+ buffer_clear(&c->input);
+ chan_ibuf_empty(c);
+ /* Start output drain. XXX just kill chan? */
+ chan_rcvd_oclose(c);
+ }
+ if (c->ostate == CHAN_OUTPUT_OPEN ||
+ c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
+ if (buffer_len(&c->output) > 0)
+ FD_SET(c->wfd, writeset);
+ else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN)
+ chan_obuf_empty(c);
+ }
+}
+
+/* try to decode a socks4 header */
+/* ARGSUSED */
+static int
+channel_decode_socks4(Channel *c, fd_set *readset, fd_set *writeset)
+{
+ char *p, *host;
+ u_int len, have, i, found, need;
+ char username[256];
+ struct {
+ u_int8_t version;
+ u_int8_t command;
+ u_int16_t dest_port;
+ struct in_addr dest_addr;
+ } s4_req, s4_rsp;
+
+ debug2("channel %d: decode socks4", c->self);
+
+ have = buffer_len(&c->input);
+ len = sizeof(s4_req);
+ if (have < len)
+ return 0;
+ p = (char *)buffer_ptr(&c->input);
+
+ need = 1;
+ /* SOCKS4A uses an invalid IP address 0.0.0.x */
+ if (p[4] == 0 && p[5] == 0 && p[6] == 0 && p[7] != 0) {
+ debug2("channel %d: socks4a request", c->self);
+ /* ... and needs an extra string (the hostname) */
+ need = 2;
+ }
+ /* Check for terminating NUL on the string(s) */
+ for (found = 0, i = len; i < have; i++) {
+ if (p[i] == '\0') {
+ found++;
+ if (found == need)
+ break;
+ }
+ if (i > 1024) {
+ /* the peer is probably sending garbage */
+ debug("channel %d: decode socks4: too long",
+ c->self);
+ return -1;
+ }
+ }
+ if (found < need)
+ return 0;
+ buffer_get(&c->input, (char *)&s4_req.version, 1);
+ buffer_get(&c->input, (char *)&s4_req.command, 1);
+ buffer_get(&c->input, (char *)&s4_req.dest_port, 2);
+ buffer_get(&c->input, (char *)&s4_req.dest_addr, 4);
+ have = buffer_len(&c->input);
+ p = (char *)buffer_ptr(&c->input);
+ if (memchr(p, '\0', have) == NULL)
+ fatal("channel %d: decode socks4: user not nul terminated",
+ c->self);
+ len = strlen(p);
+ debug2("channel %d: decode socks4: user %s/%d", c->self, p, len);
+ len++; /* trailing '\0' */
+ if (len > have)
+ fatal("channel %d: decode socks4: len %d > have %d",
+ c->self, len, have);
+ strlcpy(username, p, sizeof(username));
+ buffer_consume(&c->input, len);
+
+ free(c->path);
+ c->path = NULL;
+ if (need == 1) { /* SOCKS4: one string */
+ host = inet_ntoa(s4_req.dest_addr);
+ c->path = xstrdup(host);
+ } else { /* SOCKS4A: two strings */
+ have = buffer_len(&c->input);
+ p = (char *)buffer_ptr(&c->input);
+ len = strlen(p);
+ debug2("channel %d: decode socks4a: host %s/%d",
+ c->self, p, len);
+ len++; /* trailing '\0' */
+ if (len > have)
+ fatal("channel %d: decode socks4a: len %d > have %d",
+ c->self, len, have);
+ if (len > NI_MAXHOST) {
+ error("channel %d: hostname \"%.100s\" too long",
+ c->self, p);
+ return -1;
+ }
+ c->path = xstrdup(p);
+ buffer_consume(&c->input, len);
+ }
+ c->host_port = ntohs(s4_req.dest_port);
+
+ debug2("channel %d: dynamic request: socks4 host %s port %u command %u",
+ c->self, c->path, c->host_port, s4_req.command);
+
+ if (s4_req.command != 1) {
+ debug("channel %d: cannot handle: %s cn %d",
+ c->self, need == 1 ? "SOCKS4" : "SOCKS4A", s4_req.command);
+ return -1;
+ }
+ s4_rsp.version = 0; /* vn: 0 for reply */
+ s4_rsp.command = 90; /* cd: req granted */
+ s4_rsp.dest_port = 0; /* ignored */
+ s4_rsp.dest_addr.s_addr = INADDR_ANY; /* ignored */
+ buffer_append(&c->output, &s4_rsp, sizeof(s4_rsp));
+ return 1;
+}
+
+/* try to decode a socks5 header */
+#define SSH_SOCKS5_AUTHDONE 0x1000
+#define SSH_SOCKS5_NOAUTH 0x00
+#define SSH_SOCKS5_IPV4 0x01
+#define SSH_SOCKS5_DOMAIN 0x03
+#define SSH_SOCKS5_IPV6 0x04
+#define SSH_SOCKS5_CONNECT 0x01
+#define SSH_SOCKS5_SUCCESS 0x00
+
+/* ARGSUSED */
+static int
+channel_decode_socks5(Channel *c, fd_set *readset, fd_set *writeset)
+{
+ struct {
+ u_int8_t version;
+ u_int8_t command;
+ u_int8_t reserved;
+ u_int8_t atyp;
+ } s5_req, s5_rsp;
+ u_int16_t dest_port;
+ char dest_addr[255+1], ntop[INET6_ADDRSTRLEN];
+ u_char *p;
+ u_int have, need, i, found, nmethods, addrlen, af;
+
+ debug2("channel %d: decode socks5", c->self);
+ p = buffer_ptr(&c->input);
+ if (p[0] != 0x05)
+ return -1;
+ have = buffer_len(&c->input);
+ if (!(c->flags & SSH_SOCKS5_AUTHDONE)) {
+ /* format: ver | nmethods | methods */
+ if (have < 2)
+ return 0;
+ nmethods = p[1];
+ if (have < nmethods + 2)
+ return 0;
+ /* look for method: "NO AUTHENTICATION REQUIRED" */
+ for (found = 0, i = 2; i < nmethods + 2; i++) {
+ if (p[i] == SSH_SOCKS5_NOAUTH) {
+ found = 1;
+ break;
+ }
+ }
+ if (!found) {
+ debug("channel %d: method SSH_SOCKS5_NOAUTH not found",
+ c->self);
+ return -1;
+ }
+ buffer_consume(&c->input, nmethods + 2);
+ buffer_put_char(&c->output, 0x05); /* version */
+ buffer_put_char(&c->output, SSH_SOCKS5_NOAUTH); /* method */
+ FD_SET(c->sock, writeset);
+ c->flags |= SSH_SOCKS5_AUTHDONE;
+ debug2("channel %d: socks5 auth done", c->self);
+ return 0; /* need more */
+ }
+ debug2("channel %d: socks5 post auth", c->self);
+ if (have < sizeof(s5_req)+1)
+ return 0; /* need more */
+ memcpy(&s5_req, p, sizeof(s5_req));
+ if (s5_req.version != 0x05 ||
+ s5_req.command != SSH_SOCKS5_CONNECT ||
+ s5_req.reserved != 0x00) {
+ debug2("channel %d: only socks5 connect supported", c->self);
+ return -1;
+ }
+ switch (s5_req.atyp){
+ case SSH_SOCKS5_IPV4:
+ addrlen = 4;
+ af = AF_INET;
+ break;
+ case SSH_SOCKS5_DOMAIN:
+ addrlen = p[sizeof(s5_req)];
+ af = -1;
+ break;
+ case SSH_SOCKS5_IPV6:
+ addrlen = 16;
+ af = AF_INET6;
+ break;
+ default:
+ debug2("channel %d: bad socks5 atyp %d", c->self, s5_req.atyp);
+ return -1;
+ }
+ need = sizeof(s5_req) + addrlen + 2;
+ if (s5_req.atyp == SSH_SOCKS5_DOMAIN)
+ need++;
+ if (have < need)
+ return 0;
+ buffer_consume(&c->input, sizeof(s5_req));
+ if (s5_req.atyp == SSH_SOCKS5_DOMAIN)
+ buffer_consume(&c->input, 1); /* host string length */
+ buffer_get(&c->input, &dest_addr, addrlen);
+ buffer_get(&c->input, (char *)&dest_port, 2);
+ dest_addr[addrlen] = '\0';
+ free(c->path);
+ c->path = NULL;
+ if (s5_req.atyp == SSH_SOCKS5_DOMAIN) {
+ if (addrlen >= NI_MAXHOST) {
+ error("channel %d: dynamic request: socks5 hostname "
+ "\"%.100s\" too long", c->self, dest_addr);
+ return -1;
+ }
+ c->path = xstrdup(dest_addr);
+ } else {
+ if (inet_ntop(af, dest_addr, ntop, sizeof(ntop)) == NULL)
+ return -1;
+ c->path = xstrdup(ntop);
+ }
+ c->host_port = ntohs(dest_port);
+
+ debug2("channel %d: dynamic request: socks5 host %s port %u command %u",
+ c->self, c->path, c->host_port, s5_req.command);
+
+ s5_rsp.version = 0x05;
+ s5_rsp.command = SSH_SOCKS5_SUCCESS;
+ s5_rsp.reserved = 0; /* ignored */
+ s5_rsp.atyp = SSH_SOCKS5_IPV4;
+ dest_port = 0; /* ignored */
+
+ buffer_append(&c->output, &s5_rsp, sizeof(s5_rsp));
+ buffer_put_int(&c->output, ntohl(INADDR_ANY)); /* bind address */
+ buffer_append(&c->output, &dest_port, sizeof(dest_port));
+ return 1;
+}
+
+Channel *
+channel_connect_stdio_fwd(const char *host_to_connect, u_short port_to_connect,
+ int in, int out)
+{
+ Channel *c;
+
+ debug("channel_connect_stdio_fwd %s:%d", host_to_connect,
+ port_to_connect);
+
+ c = channel_new("stdio-forward", SSH_CHANNEL_OPENING, in, out,
+ -1, CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
+ 0, "stdio-forward", /*nonblock*/0);
+
+ c->path = xstrdup(host_to_connect);
+ c->host_port = port_to_connect;
+ c->listening_port = 0;
+ c->force_drain = 1;
+
+ channel_register_fds(c, in, out, -1, 0, 1, 0);
+ port_open_helper(c, "direct-tcpip");
+
+ return c;
+}
+
+/* dynamic port forwarding */
+static void
+channel_pre_dynamic(Channel *c, fd_set *readset, fd_set *writeset)
+{
+ u_char *p;
+ u_int have;
+ int ret;
+
+ have = buffer_len(&c->input);
+ debug2("channel %d: pre_dynamic: have %d", c->self, have);
+ /* buffer_dump(&c->input); */
+ /* check if the fixed size part of the packet is in buffer. */
+ if (have < 3) {
+ /* need more */
+ FD_SET(c->sock, readset);
+ return;
+ }
+ /* try to guess the protocol */
+ p = buffer_ptr(&c->input);
+ switch (p[0]) {
+ case 0x04:
+ ret = channel_decode_socks4(c, readset, writeset);
+ break;
+ case 0x05:
+ ret = channel_decode_socks5(c, readset, writeset);
+ break;
+ default:
+ ret = -1;
+ break;
+ }
+ if (ret < 0) {
+ chan_mark_dead(c);
+ } else if (ret == 0) {
+ debug2("channel %d: pre_dynamic: need more", c->self);
+ /* need more */
+ FD_SET(c->sock, readset);
+ } else {
+ /* switch to the next state */
+ c->type = SSH_CHANNEL_OPENING;
+ port_open_helper(c, "direct-tcpip");
+ }
+}
+
+/* This is our fake X11 server socket. */
+/* ARGSUSED */
+static void
+channel_post_x11_listener(Channel *c, fd_set *readset, fd_set *writeset)
+{
+ Channel *nc;
+ struct sockaddr_storage addr;
+ int newsock, oerrno;
+ socklen_t addrlen;
+ char buf[16384], *remote_ipaddr;
+ int remote_port;
+
+ if (FD_ISSET(c->sock, readset)) {
+ debug("X11 connection requested.");
+ addrlen = sizeof(addr);
+ newsock = accept(c->sock, (struct sockaddr *)&addr, &addrlen);
+ if (c->single_connection) {
+ oerrno = errno;
+ debug2("single_connection: closing X11 listener.");
+ channel_close_fd(&c->sock);
+ chan_mark_dead(c);
+ errno = oerrno;
+ }
+ if (newsock < 0) {
+ if (errno != EINTR && errno != EWOULDBLOCK &&
+ errno != ECONNABORTED)
+ error("accept: %.100s", strerror(errno));
+ if (errno == EMFILE || errno == ENFILE)
+ c->notbefore = monotime() + 1;
+ return;
+ }
+ set_nodelay(newsock);
+ remote_ipaddr = get_peer_ipaddr(newsock);
+ remote_port = get_peer_port(newsock);
+ snprintf(buf, sizeof buf, "X11 connection from %.200s port %d",
+ remote_ipaddr, remote_port);
+
+ nc = channel_new("accepted x11 socket",
+ SSH_CHANNEL_OPENING, newsock, newsock, -1,
+ c->local_window_max, c->local_maxpacket, 0, buf, 1);
+ if (compat20) {
+ packet_start(SSH2_MSG_CHANNEL_OPEN);
+ packet_put_cstring("x11");
+ packet_put_int(nc->self);
+ packet_put_int(nc->local_window_max);
+ packet_put_int(nc->local_maxpacket);
+ /* originator ipaddr and port */
+ packet_put_cstring(remote_ipaddr);
+ if (datafellows & SSH_BUG_X11FWD) {
+ debug2("ssh2 x11 bug compat mode");
+ } else {
+ packet_put_int(remote_port);
+ }
+ packet_send();
+ } else {
+ packet_start(SSH_SMSG_X11_OPEN);
+ packet_put_int(nc->self);
+ if (packet_get_protocol_flags() &
+ SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
+ packet_put_cstring(buf);
+ packet_send();
+ }
+ free(remote_ipaddr);
+ }
+}
+
+static void
+port_open_helper(Channel *c, char *rtype)
+{
+ char buf[1024];
+ char *local_ipaddr = get_local_ipaddr(c->sock);
+ int local_port = c->sock == -1 ? 65536 : get_local_port(c->sock);
+ char *remote_ipaddr = get_peer_ipaddr(c->sock);
+ int remote_port = get_peer_port(c->sock);
+
+ if (remote_port == -1) {
+ /* Fake addr/port to appease peers that validate it (Tectia) */
+ free(remote_ipaddr);
+ remote_ipaddr = xstrdup("127.0.0.1");
+ remote_port = 65535;
+ }
+
+ snprintf(buf, sizeof buf,
+ "%s: listening port %d for %.100s port %d, "
+ "connect from %.200s port %d to %.100s port %d",
+ rtype, c->listening_port, c->path, c->host_port,
+ remote_ipaddr, remote_port, local_ipaddr, local_port);
+
+ free(c->remote_name);
+ c->remote_name = xstrdup(buf);
+
+ if (compat20) {
+ packet_start(SSH2_MSG_CHANNEL_OPEN);
+ packet_put_cstring(rtype);
+ packet_put_int(c->self);
+ packet_put_int(c->local_window_max);
+ packet_put_int(c->local_maxpacket);
+ if (strcmp(rtype, "direct-tcpip") == 0) {
+ /* target host, port */
+ packet_put_cstring(c->path);
+ packet_put_int(c->host_port);
+ } else if (strcmp(rtype, "direct-streamlocal@openssh.com") == 0) {
+ /* target path */
+ packet_put_cstring(c->path);
+ } else if (strcmp(rtype, "forwarded-streamlocal@openssh.com") == 0) {
+ /* listen path */
+ packet_put_cstring(c->path);
+ } else {
+ /* listen address, port */
+ packet_put_cstring(c->path);
+ packet_put_int(local_port);
+ }
+ if (strcmp(rtype, "forwarded-streamlocal@openssh.com") == 0) {
+ /* reserved for future owner/mode info */
+ packet_put_cstring("");
+ } else {
+ /* originator host and port */
+ packet_put_cstring(remote_ipaddr);
+ packet_put_int((u_int)remote_port);
+ }
+ packet_send();
+ } else {
+ packet_start(SSH_MSG_PORT_OPEN);
+ packet_put_int(c->self);
+ packet_put_cstring(c->path);
+ packet_put_int(c->host_port);
+ if (packet_get_protocol_flags() &
+ SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
+ packet_put_cstring(c->remote_name);
+ packet_send();
+ }
+ free(remote_ipaddr);
+ free(local_ipaddr);
+}
+
+static void
+channel_set_reuseaddr(int fd)
+{
+ int on = 1;
+
+ /*
+ * Set socket options.
+ * Allow local port reuse in TIME_WAIT.
+ */
+ if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) == -1)
+ error("setsockopt SO_REUSEADDR fd %d: %s", fd, strerror(errno));
+}
+
+void
+channel_set_x11_refuse_time(u_int refuse_time)
+{
+ x11_refuse_time = refuse_time;
+}
+
+/*
+ * This socket is listening for connections to a forwarded TCP/IP port.
+ */
+/* ARGSUSED */
+static void
+channel_post_port_listener(Channel *c, fd_set *readset, fd_set *writeset)
+{
+ Channel *nc;
+ struct sockaddr_storage addr;
+ int newsock, nextstate;
+ socklen_t addrlen;
+ char *rtype;
+
+ if (FD_ISSET(c->sock, readset)) {
+ debug("Connection to port %d forwarding "
+ "to %.100s port %d requested.",
+ c->listening_port, c->path, c->host_port);
+
+ if (c->type == SSH_CHANNEL_RPORT_LISTENER) {
+ nextstate = SSH_CHANNEL_OPENING;
+ rtype = "forwarded-tcpip";
+ } else if (c->type == SSH_CHANNEL_RUNIX_LISTENER) {
+ nextstate = SSH_CHANNEL_OPENING;
+ rtype = "forwarded-streamlocal@openssh.com";
+ } else if (c->host_port == PORT_STREAMLOCAL) {
+ nextstate = SSH_CHANNEL_OPENING;
+ rtype = "direct-streamlocal@openssh.com";
+ } else if (c->host_port == 0) {
+ nextstate = SSH_CHANNEL_DYNAMIC;
+ rtype = "dynamic-tcpip";
+ } else {
+ nextstate = SSH_CHANNEL_OPENING;
+ rtype = "direct-tcpip";
+ }
+
+ addrlen = sizeof(addr);
+ newsock = accept(c->sock, (struct sockaddr *)&addr, &addrlen);
+ if (newsock < 0) {
+ if (errno != EINTR && errno != EWOULDBLOCK &&
+ errno != ECONNABORTED)
+ error("accept: %.100s", strerror(errno));
+ if (errno == EMFILE || errno == ENFILE)
+ c->notbefore = monotime() + 1;
+ return;
+ }
+ if (c->host_port != PORT_STREAMLOCAL)
+ set_nodelay(newsock);
+ nc = channel_new(rtype, nextstate, newsock, newsock, -1,
+ c->local_window_max, c->local_maxpacket, 0, rtype, 1);
+ nc->listening_port = c->listening_port;
+ nc->host_port = c->host_port;
+ if (c->path != NULL)
+ nc->path = xstrdup(c->path);
+
+ if (nextstate != SSH_CHANNEL_DYNAMIC)
+ port_open_helper(nc, rtype);
+ }
+}
+
+/*
+ * This is the authentication agent socket listening for connections from
+ * clients.
+ */
+/* ARGSUSED */
+static void
+channel_post_auth_listener(Channel *c, fd_set *readset, fd_set *writeset)
+{
+ Channel *nc;
+ int newsock;
+ struct sockaddr_storage addr;
+ socklen_t addrlen;
+
+ if (FD_ISSET(c->sock, readset)) {
+ addrlen = sizeof(addr);
+ newsock = accept(c->sock, (struct sockaddr *)&addr, &addrlen);
+ if (newsock < 0) {
+ error("accept from auth socket: %.100s",
+ strerror(errno));
+ if (errno == EMFILE || errno == ENFILE)
+ c->notbefore = monotime() + 1;
+ return;
+ }
+ nc = channel_new("accepted auth socket",
+ SSH_CHANNEL_OPENING, newsock, newsock, -1,
+ c->local_window_max, c->local_maxpacket,
+ 0, "accepted auth socket", 1);
+ if (compat20) {
+ packet_start(SSH2_MSG_CHANNEL_OPEN);
+ packet_put_cstring("auth-agent@openssh.com");
+ packet_put_int(nc->self);
+ packet_put_int(c->local_window_max);
+ packet_put_int(c->local_maxpacket);
+ } else {
+ packet_start(SSH_SMSG_AGENT_OPEN);
+ packet_put_int(nc->self);
+ }
+ packet_send();
+ }
+}
+
+/* ARGSUSED */
+static void
+channel_post_connecting(Channel *c, fd_set *readset, fd_set *writeset)
+{
+ int err = 0, sock;
+ socklen_t sz = sizeof(err);
+
+ if (FD_ISSET(c->sock, writeset)) {
+ if (getsockopt(c->sock, SOL_SOCKET, SO_ERROR, &err, &sz) < 0) {
+ err = errno;
+ error("getsockopt SO_ERROR failed");
+ }
+ if (err == 0) {
+ debug("channel %d: connected to %s port %d",
+ c->self, c->connect_ctx.host, c->connect_ctx.port);
+ channel_connect_ctx_free(&c->connect_ctx);
+ c->type = SSH_CHANNEL_OPEN;
+ if (compat20) {
+ packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
+ packet_put_int(c->remote_id);
+ packet_put_int(c->self);
+ packet_put_int(c->local_window);
+ packet_put_int(c->local_maxpacket);
+ } else {
+ packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
+ packet_put_int(c->remote_id);
+ packet_put_int(c->self);
+ }
+ } else {
+ debug("channel %d: connection failed: %s",
+ c->self, strerror(err));
+ /* Try next address, if any */
+ if ((sock = connect_next(&c->connect_ctx)) > 0) {
+ close(c->sock);
+ c->sock = c->rfd = c->wfd = sock;
+ channel_max_fd = channel_find_maxfd();
+ return;
+ }
+ /* Exhausted all addresses */
+ error("connect_to %.100s port %d: failed.",
+ c->connect_ctx.host, c->connect_ctx.port);
+ channel_connect_ctx_free(&c->connect_ctx);
+ if (compat20) {
+ packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
+ packet_put_int(c->remote_id);
+ packet_put_int(SSH2_OPEN_CONNECT_FAILED);
+ if (!(datafellows & SSH_BUG_OPENFAILURE)) {
+ packet_put_cstring(strerror(err));
+ packet_put_cstring("");
+ }
+ } else {
+ packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
+ packet_put_int(c->remote_id);
+ }
+ chan_mark_dead(c);
+ }
+ packet_send();
+ }
+}
+
+/* ARGSUSED */
+static int
+channel_handle_rfd(Channel *c, fd_set *readset, fd_set *writeset)
+{
+ char buf[CHAN_RBUF];
+ int len, force;
+
+ force = c->isatty && c->detach_close && c->istate != CHAN_INPUT_CLOSED;
+ if (c->rfd != -1 && (force || FD_ISSET(c->rfd, readset))) {
+ errno = 0;
+ len = read(c->rfd, buf, sizeof(buf));
+ if (len < 0 && (errno == EINTR ||
+ ((errno == EAGAIN || errno == EWOULDBLOCK) && !force)))
+ return 1;
+#ifndef PTY_ZEROREAD
+ if (len <= 0) {
+#else
+ if ((!c->isatty && len <= 0) ||
+ (c->isatty && (len < 0 || (len == 0 && errno != 0)))) {
+#endif
+ debug2("channel %d: read<=0 rfd %d len %d",
+ c->self, c->rfd, len);
+ if (c->type != SSH_CHANNEL_OPEN) {
+ debug2("channel %d: not open", c->self);
+ chan_mark_dead(c);
+ return -1;
+ } else if (compat13) {
+ buffer_clear(&c->output);
+ c->type = SSH_CHANNEL_INPUT_DRAINING;
+ debug2("channel %d: input draining.", c->self);
+ } else {
+ chan_read_failed(c);
+ }
+ return -1;
+ }
+ if (c->input_filter != NULL) {
+ if (c->input_filter(c, buf, len) == -1) {
+ debug2("channel %d: filter stops", c->self);
+ chan_read_failed(c);
+ }
+ } else if (c->datagram) {
+ buffer_put_string(&c->input, buf, len);
+ } else {
+ buffer_append(&c->input, buf, len);
+ }
+ }
+ return 1;
+}
+
+/* ARGSUSED */
+static int
+channel_handle_wfd(Channel *c, fd_set *readset, fd_set *writeset)
+{
+ struct termios tio;
+ u_char *data = NULL, *buf;
+ u_int dlen, olen = 0;
+ int len;
+
+ /* Send buffered output data to the socket. */
+ if (c->wfd != -1 &&
+ FD_ISSET(c->wfd, writeset) &&
+ buffer_len(&c->output) > 0) {
+ olen = buffer_len(&c->output);
+ if (c->output_filter != NULL) {
+ if ((buf = c->output_filter(c, &data, &dlen)) == NULL) {
+ debug2("channel %d: filter stops", c->self);
+ if (c->type != SSH_CHANNEL_OPEN)
+ chan_mark_dead(c);
+ else
+ chan_write_failed(c);
+ return -1;
+ }
+ } else if (c->datagram) {
+ buf = data = buffer_get_string(&c->output, &dlen);
+ } else {
+ buf = data = buffer_ptr(&c->output);
+ dlen = buffer_len(&c->output);
+ }
+
+ if (c->datagram) {
+ /* ignore truncated writes, datagrams might get lost */
+ len = write(c->wfd, buf, dlen);
+ free(data);
+ if (len < 0 && (errno == EINTR || errno == EAGAIN ||
+ errno == EWOULDBLOCK))
+ return 1;
+ if (len <= 0) {
+ if (c->type != SSH_CHANNEL_OPEN)
+ chan_mark_dead(c);
+ else
+ chan_write_failed(c);
+ return -1;
+ }
+ goto out;
+ }
+#ifdef _AIX
+ /* XXX: Later AIX versions can't push as much data to tty */
+ if (compat20 && c->wfd_isatty)
+ dlen = MIN(dlen, 8*1024);
+#endif
+
+ len = write(c->wfd, buf, dlen);
+ if (len < 0 &&
+ (errno == EINTR || errno == EAGAIN || errno == EWOULDBLOCK))
+ return 1;
+ if (len <= 0) {
+ if (c->type != SSH_CHANNEL_OPEN) {
+ debug2("channel %d: not open", c->self);
+ chan_mark_dead(c);
+ return -1;
+ } else if (compat13) {
+ buffer_clear(&c->output);
+ debug2("channel %d: input draining.", c->self);
+ c->type = SSH_CHANNEL_INPUT_DRAINING;
+ } else {
+ chan_write_failed(c);
+ }
+ return -1;
+ }
+#ifndef BROKEN_TCGETATTR_ICANON
+ if (compat20 && c->isatty && dlen >= 1 && buf[0] != '\r') {
+ if (tcgetattr(c->wfd, &tio) == 0 &&
+ !(tio.c_lflag & ECHO) && (tio.c_lflag & ICANON)) {
+ /*
+ * Simulate echo to reduce the impact of
+ * traffic analysis. We need to match the
+ * size of a SSH2_MSG_CHANNEL_DATA message
+ * (4 byte channel id + buf)
+ */
+ packet_send_ignore(4 + len);
+ packet_send();
+ }
+ }
+#endif
+ buffer_consume(&c->output, len);
+ }
+ out:
+ if (compat20 && olen > 0)
+ c->local_consumed += olen - buffer_len(&c->output);
+ return 1;
+}
+
+static int
+channel_handle_efd(Channel *c, fd_set *readset, fd_set *writeset)
+{
+ char buf[CHAN_RBUF];
+ int len;
+
+/** XXX handle drain efd, too */
+ if (c->efd != -1) {
+ if (c->extended_usage == CHAN_EXTENDED_WRITE &&
+ FD_ISSET(c->efd, writeset) &&
+ buffer_len(&c->extended) > 0) {
+ len = write(c->efd, buffer_ptr(&c->extended),
+ buffer_len(&c->extended));
+ debug2("channel %d: written %d to efd %d",
+ c->self, len, c->efd);
+ if (len < 0 && (errno == EINTR || errno == EAGAIN ||
+ errno == EWOULDBLOCK))
+ return 1;
+ if (len <= 0) {
+ debug2("channel %d: closing write-efd %d",
+ c->self, c->efd);
+ channel_close_fd(&c->efd);
+ } else {
+ buffer_consume(&c->extended, len);
+ c->local_consumed += len;
+ }
+ } else if (c->efd != -1 &&
+ (c->extended_usage == CHAN_EXTENDED_READ ||
+ c->extended_usage == CHAN_EXTENDED_IGNORE) &&
+ (c->detach_close || FD_ISSET(c->efd, readset))) {
+ len = read(c->efd, buf, sizeof(buf));
+ debug2("channel %d: read %d from efd %d",
+ c->self, len, c->efd);
+ if (len < 0 && (errno == EINTR || ((errno == EAGAIN ||
+ errno == EWOULDBLOCK) && !c->detach_close)))
+ return 1;
+ if (len <= 0) {
+ debug2("channel %d: closing read-efd %d",
+ c->self, c->efd);
+ channel_close_fd(&c->efd);
+ } else {
+ if (c->extended_usage == CHAN_EXTENDED_IGNORE) {
+ debug3("channel %d: discard efd",
+ c->self);
+ } else
+ buffer_append(&c->extended, buf, len);
+ }
+ }
+ }
+ return 1;
+}
+
+static int
+channel_check_window(Channel *c)
+{
+ if (c->type == SSH_CHANNEL_OPEN &&
+ !(c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD)) &&
+ ((c->local_window_max - c->local_window >
+ c->local_maxpacket*3) ||
+ c->local_window < c->local_window_max/2) &&
+ c->local_consumed > 0) {
+ packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
+ packet_put_int(c->remote_id);
+ packet_put_int(c->local_consumed);
+ packet_send();
+ debug2("channel %d: window %d sent adjust %d",
+ c->self, c->local_window,
+ c->local_consumed);
+ c->local_window += c->local_consumed;
+ c->local_consumed = 0;
+ }
+ return 1;
+}
+
+static void
+channel_post_open(Channel *c, fd_set *readset, fd_set *writeset)
+{
+ channel_handle_rfd(c, readset, writeset);
+ channel_handle_wfd(c, readset, writeset);
+ if (!compat20)
+ return;
+ channel_handle_efd(c, readset, writeset);
+ channel_check_window(c);
+}
+
+static u_int
+read_mux(Channel *c, u_int need)
+{
+ char buf[CHAN_RBUF];
+ int len;
+ u_int rlen;
+
+ if (buffer_len(&c->input) < need) {
+ rlen = need - buffer_len(&c->input);
+ len = read(c->rfd, buf, MINIMUM(rlen, CHAN_RBUF));
+ if (len < 0 && (errno == EINTR || errno == EAGAIN))
+ return buffer_len(&c->input);
+ if (len <= 0) {
+ debug2("channel %d: ctl read<=0 rfd %d len %d",
+ c->self, c->rfd, len);
+ chan_read_failed(c);
+ return 0;
+ } else
+ buffer_append(&c->input, buf, len);
+ }
+ return buffer_len(&c->input);
+}
+
+static void
+channel_post_mux_client(Channel *c, fd_set *readset, fd_set *writeset)
+{
+ u_int need;
+ ssize_t len;
+
+ if (!compat20)
+ fatal("%s: entered with !compat20", __func__);
+
+ if (c->rfd != -1 && !c->mux_pause && FD_ISSET(c->rfd, readset) &&
+ (c->istate == CHAN_INPUT_OPEN ||
+ c->istate == CHAN_INPUT_WAIT_DRAIN)) {
+ /*
+ * Don't not read past the precise end of packets to
+ * avoid disrupting fd passing.
+ */
+ if (read_mux(c, 4) < 4) /* read header */
+ return;
+ need = get_u32(buffer_ptr(&c->input));
+#define CHANNEL_MUX_MAX_PACKET (256 * 1024)
+ if (need > CHANNEL_MUX_MAX_PACKET) {
+ debug2("channel %d: packet too big %u > %u",
+ c->self, CHANNEL_MUX_MAX_PACKET, need);
+ chan_rcvd_oclose(c);
+ return;
+ }
+ if (read_mux(c, need + 4) < need + 4) /* read body */
+ return;
+ if (c->mux_rcb(c) != 0) {
+ debug("channel %d: mux_rcb failed", c->self);
+ chan_mark_dead(c);
+ return;
+ }
+ }
+
+ if (c->wfd != -1 && FD_ISSET(c->wfd, writeset) &&
+ buffer_len(&c->output) > 0) {
+ len = write(c->wfd, buffer_ptr(&c->output),
+ buffer_len(&c->output));
+ if (len < 0 && (errno == EINTR || errno == EAGAIN))
+ return;
+ if (len <= 0) {
+ chan_mark_dead(c);
+ return;
+ }
+ buffer_consume(&c->output, len);
+ }
+}
+
+static void
+channel_post_mux_listener(Channel *c, fd_set *readset, fd_set *writeset)
+{
+ Channel *nc;
+ struct sockaddr_storage addr;
+ socklen_t addrlen;
+ int newsock;
+ uid_t euid;
+ gid_t egid;
+
+ if (!FD_ISSET(c->sock, readset))
+ return;
+
+ debug("multiplexing control connection");
+
+ /*
+ * Accept connection on control socket
+ */
+ memset(&addr, 0, sizeof(addr));
+ addrlen = sizeof(addr);
+ if ((newsock = accept(c->sock, (struct sockaddr*)&addr,
+ &addrlen)) == -1) {
+ error("%s accept: %s", __func__, strerror(errno));
+ if (errno == EMFILE || errno == ENFILE)
+ c->notbefore = monotime() + 1;
+ return;
+ }
+
+ if (getpeereid(newsock, &euid, &egid) < 0) {
+ error("%s getpeereid failed: %s", __func__,
+ strerror(errno));
+ close(newsock);
+ return;
+ }
+ if ((euid != 0) && (getuid() != euid)) {
+ error("multiplex uid mismatch: peer euid %u != uid %u",
+ (u_int)euid, (u_int)getuid());
+ close(newsock);
+ return;
+ }
+ nc = channel_new("multiplex client", SSH_CHANNEL_MUX_CLIENT,
+ newsock, newsock, -1, c->local_window_max,
+ c->local_maxpacket, 0, "mux-control", 1);
+ nc->mux_rcb = c->mux_rcb;
+ debug3("%s: new mux channel %d fd %d", __func__,
+ nc->self, nc->sock);
+ /* establish state */
+ nc->mux_rcb(nc);
+ /* mux state transitions must not elicit protocol messages */
+ nc->flags |= CHAN_LOCAL;
+}
+
+/* ARGSUSED */
+static void
+channel_post_output_drain_13(Channel *c, fd_set *readset, fd_set *writeset)
+{
+ int len;
+
+ /* Send buffered output data to the socket. */
+ if (FD_ISSET(c->sock, writeset) && buffer_len(&c->output) > 0) {
+ len = write(c->sock, buffer_ptr(&c->output),
+ buffer_len(&c->output));
+ if (len <= 0)
+ buffer_clear(&c->output);
+ else
+ buffer_consume(&c->output, len);
+ }
+}
+
+static void
+channel_handler_init_20(void)
+{
+ channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open;
+ channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
+ channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
+ channel_pre[SSH_CHANNEL_RPORT_LISTENER] = &channel_pre_listener;
+ channel_pre[SSH_CHANNEL_UNIX_LISTENER] = &channel_pre_listener;
+ channel_pre[SSH_CHANNEL_RUNIX_LISTENER] = &channel_pre_listener;
+ channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
+ channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
+ channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
+ channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
+ channel_pre[SSH_CHANNEL_MUX_LISTENER] = &channel_pre_listener;
+ channel_pre[SSH_CHANNEL_MUX_CLIENT] = &channel_pre_mux_client;
+
+ channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
+ channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
+ channel_post[SSH_CHANNEL_RPORT_LISTENER] = &channel_post_port_listener;
+ channel_post[SSH_CHANNEL_UNIX_LISTENER] = &channel_post_port_listener;
+ channel_post[SSH_CHANNEL_RUNIX_LISTENER] = &channel_post_port_listener;
+ channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
+ channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
+ channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
+ channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
+ channel_post[SSH_CHANNEL_MUX_LISTENER] = &channel_post_mux_listener;
+ channel_post[SSH_CHANNEL_MUX_CLIENT] = &channel_post_mux_client;
+}
+
+static void
+channel_handler_init_13(void)
+{
+ channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_13;
+ channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open_13;
+ channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
+ channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
+ channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
+ channel_pre[SSH_CHANNEL_INPUT_DRAINING] = &channel_pre_input_draining;
+ channel_pre[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_pre_output_draining;
+ channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
+ channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
+
+ channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
+ channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
+ channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
+ channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
+ channel_post[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_post_output_drain_13;
+ channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
+ channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
+}
+
+static void
+channel_handler_init_15(void)
+{
+ channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open;
+ channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
+ channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
+ channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
+ channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
+ channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
+ channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
+
+ channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
+ channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
+ channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
+ channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
+ channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
+ channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
+}
+
+static void
+channel_handler_init(void)
+{
+ int i;
+
+ for (i = 0; i < SSH_CHANNEL_MAX_TYPE; i++) {
+ channel_pre[i] = NULL;
+ channel_post[i] = NULL;
+ }
+ if (compat20)
+ channel_handler_init_20();
+ else if (compat13)
+ channel_handler_init_13();
+ else
+ channel_handler_init_15();
+}
+
+/* gc dead channels */
+static void
+channel_garbage_collect(Channel *c)
+{
+ if (c == NULL)
+ return;
+ if (c->detach_user != NULL) {
+ if (!chan_is_dead(c, c->detach_close))
+ return;
+ debug2("channel %d: gc: notify user", c->self);
+ c->detach_user(c->self, NULL);
+ /* if we still have a callback */
+ if (c->detach_user != NULL)
+ return;
+ debug2("channel %d: gc: user detached", c->self);
+ }
+ if (!chan_is_dead(c, 1))
+ return;
+ debug2("channel %d: garbage collecting", c->self);
+ channel_free(c);
+}
+
+static void
+channel_handler(chan_fn *ftab[], fd_set *readset, fd_set *writeset,
+ time_t *unpause_secs)
+{
+ static int did_init = 0;
+ u_int i, oalloc;
+ Channel *c;
+ time_t now;
+
+ if (!did_init) {
+ channel_handler_init();
+ did_init = 1;
+ }
+ now = monotime();
+ if (unpause_secs != NULL)
+ *unpause_secs = 0;
+ for (i = 0, oalloc = channels_alloc; i < oalloc; i++) {
+ c = channels[i];
+ if (c == NULL)
+ continue;
+ if (c->delayed) {
+ if (ftab == channel_pre)
+ c->delayed = 0;
+ else
+ continue;
+ }
+ if (ftab[c->type] != NULL) {
+ /*
+ * Run handlers that are not paused.
+ */
+ if (c->notbefore <= now)
+ (*ftab[c->type])(c, readset, writeset);
+ else if (unpause_secs != NULL) {
+ /*
+ * Collect the time that the earliest
+ * channel comes off pause.
+ */
+ debug3("%s: chan %d: skip for %d more seconds",
+ __func__, c->self,
+ (int)(c->notbefore - now));
+ if (*unpause_secs == 0 ||
+ (c->notbefore - now) < *unpause_secs)
+ *unpause_secs = c->notbefore - now;
+ }
+ }
+ channel_garbage_collect(c);
+ }
+ if (unpause_secs != NULL && *unpause_secs != 0)
+ debug3("%s: first channel unpauses in %d seconds",
+ __func__, (int)*unpause_secs);
+}
+
+/*
+ * Allocate/update select bitmasks and add any bits relevant to channels in
+ * select bitmasks.
+ */
+void
+channel_prepare_select(fd_set **readsetp, fd_set **writesetp, int *maxfdp,
+ u_int *nallocp, time_t *minwait_secs, int rekeying)
+{
+ u_int n, sz, nfdset;
+
+ n = MAXIMUM(*maxfdp, channel_max_fd);
+
+ nfdset = howmany(n+1, NFDBITS);
+ /* Explicitly test here, because xrealloc isn't always called */
+ if (nfdset && SIZE_MAX / nfdset < sizeof(fd_mask))
+ fatal("channel_prepare_select: max_fd (%d) is too large", n);
+ sz = nfdset * sizeof(fd_mask);
+
+ /* perhaps check sz < nalloc/2 and shrink? */
+ if (*readsetp == NULL || sz > *nallocp) {
+ *readsetp = xreallocarray(*readsetp, nfdset, sizeof(fd_mask));
+ *writesetp = xreallocarray(*writesetp, nfdset, sizeof(fd_mask));
+ *nallocp = sz;
+ }
+ *maxfdp = n;
+ memset(*readsetp, 0, sz);
+ memset(*writesetp, 0, sz);
+
+ if (!rekeying)
+ channel_handler(channel_pre, *readsetp, *writesetp,
+ minwait_secs);
+}
+
+/*
+ * After select, perform any appropriate operations for channels which have
+ * events pending.
+ */
+void
+channel_after_select(fd_set *readset, fd_set *writeset)
+{
+ channel_handler(channel_post, readset, writeset, NULL);
+}
+
+
+/* If there is data to send to the connection, enqueue some of it now. */
+void
+channel_output_poll(void)
+{
+ Channel *c;
+ u_int i, len;
+
+ for (i = 0; i < channels_alloc; i++) {
+ c = channels[i];
+ if (c == NULL)
+ continue;
+
+ /*
+ * We are only interested in channels that can have buffered
+ * incoming data.
+ */
+ if (compat13) {
+ if (c->type != SSH_CHANNEL_OPEN &&
+ c->type != SSH_CHANNEL_INPUT_DRAINING)
+ continue;
+ } else {
+ if (c->type != SSH_CHANNEL_OPEN)
+ continue;
+ }
+ if (compat20 &&
+ (c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD))) {
+ /* XXX is this true? */
+ debug3("channel %d: will not send data after close", c->self);
+ continue;
+ }
+
+ /* Get the amount of buffered data for this channel. */
+ if ((c->istate == CHAN_INPUT_OPEN ||
+ c->istate == CHAN_INPUT_WAIT_DRAIN) &&
+ (len = buffer_len(&c->input)) > 0) {
+ if (c->datagram) {
+ if (len > 0) {
+ u_char *data;
+ u_int dlen;
+
+ data = buffer_get_string(&c->input,
+ &dlen);
+ if (dlen > c->remote_window ||
+ dlen > c->remote_maxpacket) {
+ debug("channel %d: datagram "
+ "too big for channel",
+ c->self);
+ free(data);
+ continue;
+ }
+ packet_start(SSH2_MSG_CHANNEL_DATA);
+ packet_put_int(c->remote_id);
+ packet_put_string(data, dlen);
+ packet_send();
+ c->remote_window -= dlen;
+ free(data);
+ }
+ continue;
+ }
+ /*
+ * Send some data for the other side over the secure
+ * connection.
+ */
+ if (compat20) {
+ if (len > c->remote_window)
+ len = c->remote_window;
+ if (len > c->remote_maxpacket)
+ len = c->remote_maxpacket;
+ } else {
+ if (packet_is_interactive()) {
+ if (len > 1024)
+ len = 512;
+ } else {
+ /* Keep the packets at reasonable size. */
+ if (len > packet_get_maxsize()/2)
+ len = packet_get_maxsize()/2;
+ }
+ }
+ if (len > 0) {
+ packet_start(compat20 ?
+ SSH2_MSG_CHANNEL_DATA : SSH_MSG_CHANNEL_DATA);
+ packet_put_int(c->remote_id);
+ packet_put_string(buffer_ptr(&c->input), len);
+ packet_send();
+ buffer_consume(&c->input, len);
+ c->remote_window -= len;
+ }
+ } else if (c->istate == CHAN_INPUT_WAIT_DRAIN) {
+ if (compat13)
+ fatal("cannot happen: istate == INPUT_WAIT_DRAIN for proto 1.3");
+ /*
+ * input-buffer is empty and read-socket shutdown:
+ * tell peer, that we will not send more data: send IEOF.
+ * hack for extended data: delay EOF if EFD still in use.
+ */
+ if (CHANNEL_EFD_INPUT_ACTIVE(c))
+ debug2("channel %d: ibuf_empty delayed efd %d/(%d)",
+ c->self, c->efd, buffer_len(&c->extended));
+ else
+ chan_ibuf_empty(c);
+ }
+ /* Send extended data, i.e. stderr */
+ if (compat20 &&
+ !(c->flags & CHAN_EOF_SENT) &&
+ c->remote_window > 0 &&
+ (len = buffer_len(&c->extended)) > 0 &&
+ c->extended_usage == CHAN_EXTENDED_READ) {
+ debug2("channel %d: rwin %u elen %u euse %d",
+ c->self, c->remote_window, buffer_len(&c->extended),
+ c->extended_usage);
+ if (len > c->remote_window)
+ len = c->remote_window;
+ if (len > c->remote_maxpacket)
+ len = c->remote_maxpacket;
+ packet_start(SSH2_MSG_CHANNEL_EXTENDED_DATA);
+ packet_put_int(c->remote_id);
+ packet_put_int(SSH2_EXTENDED_DATA_STDERR);
+ packet_put_string(buffer_ptr(&c->extended), len);
+ packet_send();
+ buffer_consume(&c->extended, len);
+ c->remote_window -= len;
+ debug2("channel %d: sent ext data %d", c->self, len);
+ }
+ }
+}
+
+/* -- mux proxy support */
+
+/*
+ * When multiplexing channel messages for mux clients we have to deal
+ * with downstream messages from the mux client and upstream messages
+ * from the ssh server:
+ * 1) Handling downstream messages is straightforward and happens
+ * in channel_proxy_downstream():
+ * - We forward all messages (mostly) unmodified to the server.
+ * - However, in order to route messages from upstream to the correct
+ * downstream client, we have to replace the channel IDs used by the
+ * mux clients with a unique channel ID because the mux clients might
+ * use conflicting channel IDs.
+ * - so we inspect and change both SSH2_MSG_CHANNEL_OPEN and
+ * SSH2_MSG_CHANNEL_OPEN_CONFIRMATION messages, create a local
+ * SSH_CHANNEL_MUX_PROXY channel and replace the mux clients ID
+ * with the newly allocated channel ID.
+ * 2) Upstream messages are received by matching SSH_CHANNEL_MUX_PROXY
+ * channels and procesed by channel_proxy_upstream(). The local channel ID
+ * is then translated back to the original mux client ID.
+ * 3) In both cases we need to keep track of matching SSH2_MSG_CHANNEL_CLOSE
+ * messages so we can clean up SSH_CHANNEL_MUX_PROXY channels.
+ * 4) The SSH_CHANNEL_MUX_PROXY channels also need to closed when the
+ * downstream mux client are removed.
+ * 5) Handling SSH2_MSG_CHANNEL_OPEN messages from the upstream server
+ * requires more work, because they are not addressed to a specific
+ * channel. E.g. client_request_forwarded_tcpip() needs to figure
+ * out whether the request is addressed to the local client or a
+ * specific downstream client based on the listen-address/port.
+ * 6) Agent and X11-Forwarding have a similar problem and are currenly
+ * not supported as the matching session/channel cannot be identified
+ * easily.
+ */
+
+/*
+ * receive packets from downstream mux clients:
+ * channel callback fired on read from mux client, creates
+ * SSH_CHANNEL_MUX_PROXY channels and translates channel IDs
+ * on channel creation.
+ */
+int
+channel_proxy_downstream(Channel *downstream)
+{
+ Channel *c = NULL;
+ struct ssh *ssh = active_state;
+ struct sshbuf *original = NULL, *modified = NULL;
+ const u_char *cp;
+ char *ctype = NULL, *listen_host = NULL;
+ u_char type;
+ size_t have;
+ int ret = -1, r, idx;
+ u_int id, remote_id, listen_port;
+
+ /* sshbuf_dump(&downstream->input, stderr); */
+ if ((r = sshbuf_get_string_direct(&downstream->input, &cp, &have))
+ != 0) {
+ error("%s: malformed message: %s", __func__, ssh_err(r));
+ return -1;
+ }
+ if (have < 2) {
+ error("%s: short message", __func__);
+ return -1;
+ }
+ type = cp[1];
+ /* skip padlen + type */
+ cp += 2;
+ have -= 2;
+ if (ssh_packet_log_type(type))
+ debug3("%s: channel %u: down->up: type %u", __func__,
+ downstream->self, type);
+
+ switch (type) {
+ case SSH2_MSG_CHANNEL_OPEN:
+ if ((original = sshbuf_from(cp, have)) == NULL ||
+ (modified = sshbuf_new()) == NULL) {
+ error("%s: alloc", __func__);
+ goto out;
+ }
+ if ((r = sshbuf_get_cstring(original, &ctype, NULL)) != 0 ||
+ (r = sshbuf_get_u32(original, &id)) != 0) {
+ error("%s: parse error %s", __func__, ssh_err(r));
+ goto out;
+ }
+ c = channel_new("mux proxy", SSH_CHANNEL_MUX_PROXY,
+ -1, -1, -1, 0, 0, 0, ctype, 1);
+ c->mux_ctx = downstream; /* point to mux client */
+ c->mux_downstream_id = id; /* original downstream id */
+ if ((r = sshbuf_put_cstring(modified, ctype)) != 0 ||
+ (r = sshbuf_put_u32(modified, c->self)) != 0 ||
+ (r = sshbuf_putb(modified, original)) != 0) {
+ error("%s: compose error %s", __func__, ssh_err(r));
+ channel_free(c);
+ goto out;
+ }
+ break;
+ case SSH2_MSG_CHANNEL_OPEN_CONFIRMATION:
+ /*
+ * Almost the same as SSH2_MSG_CHANNEL_OPEN, except then we
+ * need to parse 'remote_id' instead of 'ctype'.
+ */
+ if ((original = sshbuf_from(cp, have)) == NULL ||
+ (modified = sshbuf_new()) == NULL) {
+ error("%s: alloc", __func__);
+ goto out;
+ }
+ if ((r = sshbuf_get_u32(original, &remote_id)) != 0 ||
+ (r = sshbuf_get_u32(original, &id)) != 0) {
+ error("%s: parse error %s", __func__, ssh_err(r));
+ goto out;
+ }
+ c = channel_new("mux proxy", SSH_CHANNEL_MUX_PROXY,
+ -1, -1, -1, 0, 0, 0, "mux-down-connect", 1);
+ c->mux_ctx = downstream; /* point to mux client */
+ c->mux_downstream_id = id;
+ c->remote_id = remote_id;
+ if ((r = sshbuf_put_u32(modified, remote_id)) != 0 ||
+ (r = sshbuf_put_u32(modified, c->self)) != 0 ||
+ (r = sshbuf_putb(modified, original)) != 0) {
+ error("%s: compose error %s", __func__, ssh_err(r));
+ channel_free(c);
+ goto out;
+ }
+ break;
+ case SSH2_MSG_GLOBAL_REQUEST:
+ if ((original = sshbuf_from(cp, have)) == NULL) {
+ error("%s: alloc", __func__);
+ goto out;
+ }
+ if ((r = sshbuf_get_cstring(original, &ctype, NULL)) != 0) {
+ error("%s: parse error %s", __func__, ssh_err(r));
+ goto out;
+ }
+ if (strcmp(ctype, "tcpip-forward") != 0) {
+ error("%s: unsupported request %s", __func__, ctype);
+ goto out;
+ }
+ if ((r = sshbuf_get_u8(original, NULL)) != 0 ||
+ (r = sshbuf_get_cstring(original, &listen_host, NULL)) != 0 ||
+ (r = sshbuf_get_u32(original, &listen_port)) != 0) {
+ error("%s: parse error %s", __func__, ssh_err(r));
+ goto out;
+ }
+ if (listen_port > 65535) {
+ error("%s: tcpip-forward for %s: bad port %u",
+ __func__, listen_host, listen_port);
+ goto out;
+ }
+ /* Record that connection to this host/port is permitted. */
+ permitted_opens = xreallocarray(permitted_opens,
+ num_permitted_opens + 1, sizeof(*permitted_opens));
+ idx = num_permitted_opens++;
+ permitted_opens[idx].host_to_connect = xstrdup("<mux>");
+ permitted_opens[idx].port_to_connect = -1;
+ permitted_opens[idx].listen_host = listen_host;
+ permitted_opens[idx].listen_port = (int)listen_port;
+ permitted_opens[idx].downstream = downstream;
+ listen_host = NULL;
+ break;
+ case SSH2_MSG_CHANNEL_CLOSE:
+ if (have < 4)
+ break;
+ remote_id = PEEK_U32(cp);
+ if ((c = channel_by_remote_id(remote_id)) != NULL) {
+ if (c->flags & CHAN_CLOSE_RCVD)
+ channel_free(c);
+ else
+ c->flags |= CHAN_CLOSE_SENT;
+ }
+ break;
+ }
+ if (modified) {
+ if ((r = sshpkt_start(ssh, type)) != 0 ||
+ (r = sshpkt_putb(ssh, modified)) != 0 ||
+ (r = sshpkt_send(ssh)) != 0) {
+ error("%s: send %s", __func__, ssh_err(r));
+ goto out;
+ }
+ } else {
+ if ((r = sshpkt_start(ssh, type)) != 0 ||
+ (r = sshpkt_put(ssh, cp, have)) != 0 ||
+ (r = sshpkt_send(ssh)) != 0) {
+ error("%s: send %s", __func__, ssh_err(r));
+ goto out;
+ }
+ }
+ ret = 0;
+ out:
+ free(ctype);
+ free(listen_host);
+ sshbuf_free(original);
+ sshbuf_free(modified);
+ return ret;
+}
+
+/*
+ * receive packets from upstream server and de-multiplex packets
+ * to correct downstream:
+ * implemented as a helper for channel input handlers,
+ * replaces local (proxy) channel ID with downstream channel ID.
+ */
+int
+channel_proxy_upstream(Channel *c, int type, u_int32_t seq, void *ctxt)
+{
+ struct ssh *ssh = active_state;
+ struct sshbuf *b = NULL;
+ Channel *downstream;
+ const u_char *cp = NULL;
+ size_t len;
+ int r;
+
+ /*
+ * When receiving packets from the peer we need to check whether we
+ * need to forward the packets to the mux client. In this case we
+ * restore the orignal channel id and keep track of CLOSE messages,
+ * so we can cleanup the channel.
+ */
+ if (c == NULL || c->type != SSH_CHANNEL_MUX_PROXY)
+ return 0;
+ if ((downstream = c->mux_ctx) == NULL)
+ return 0;
+ switch (type) {
+ case SSH2_MSG_CHANNEL_CLOSE:
+ case SSH2_MSG_CHANNEL_DATA:
+ case SSH2_MSG_CHANNEL_EOF:
+ case SSH2_MSG_CHANNEL_EXTENDED_DATA:
+ case SSH2_MSG_CHANNEL_OPEN_CONFIRMATION:
+ case SSH2_MSG_CHANNEL_OPEN_FAILURE:
+ case SSH2_MSG_CHANNEL_WINDOW_ADJUST:
+ case SSH2_MSG_CHANNEL_SUCCESS:
+ case SSH2_MSG_CHANNEL_FAILURE:
+ case SSH2_MSG_CHANNEL_REQUEST:
+ break;
+ default:
+ debug2("%s: channel %u: unsupported type %u", __func__,
+ c->self, type);
+ return 0;
+ }
+ if ((b = sshbuf_new()) == NULL) {
+ error("%s: alloc reply", __func__);
+ goto out;
+ }
+ /* get remaining payload (after id) */
+ cp = sshpkt_ptr(ssh, &len);
+ if (cp == NULL) {
+ error("%s: no packet", __func__);
+ goto out;
+ }
+ /* translate id and send to muxclient */
+ if ((r = sshbuf_put_u8(b, 0)) != 0 || /* padlen */
+ (r = sshbuf_put_u8(b, type)) != 0 ||
+ (r = sshbuf_put_u32(b, c->mux_downstream_id)) != 0 ||
+ (r = sshbuf_put(b, cp, len)) != 0 ||
+ (r = sshbuf_put_stringb(&downstream->output, b)) != 0) {
+ error("%s: compose for muxclient %s", __func__, ssh_err(r));
+ goto out;
+ }
+ /* sshbuf_dump(b, stderr); */
+ if (ssh_packet_log_type(type))
+ debug3("%s: channel %u: up->down: type %u", __func__, c->self,
+ type);
+ out:
+ /* update state */
+ switch (type) {
+ case SSH2_MSG_CHANNEL_OPEN_CONFIRMATION:
+ /* record remote_id for SSH2_MSG_CHANNEL_CLOSE */
+ if (cp && len > 4)
+ c->remote_id = PEEK_U32(cp);
+ break;
+ case SSH2_MSG_CHANNEL_CLOSE:
+ if (c->flags & CHAN_CLOSE_SENT)
+ channel_free(c);
+ else
+ c->flags |= CHAN_CLOSE_RCVD;
+ break;
+ }
+ sshbuf_free(b);
+ return 1;
+}
+
+/* -- protocol input */
+
+/* ARGSUSED */
+int
+channel_input_data(int type, u_int32_t seq, void *ctxt)
+{
+ int id;
+ const u_char *data;
+ u_int data_len, win_len;
+ Channel *c;
+
+ /* Get the channel number and verify it. */
+ id = packet_get_int();
+ c = channel_lookup(id);
+ if (c == NULL)
+ packet_disconnect("Received data for nonexistent channel %d.", id);
+ if (channel_proxy_upstream(c, type, seq, ctxt))
+ return 0;
+
+ /* Ignore any data for non-open channels (might happen on close) */
+ if (c->type != SSH_CHANNEL_OPEN &&
+ c->type != SSH_CHANNEL_X11_OPEN)
+ return 0;
+
+ /* Get the data. */
+ data = packet_get_string_ptr(&data_len);
+ win_len = data_len;
+ if (c->datagram)
+ win_len += 4; /* string length header */
+
+ /*
+ * Ignore data for protocol > 1.3 if output end is no longer open.
+ * For protocol 2 the sending side is reducing its window as it sends
+ * data, so we must 'fake' consumption of the data in order to ensure
+ * that window updates are sent back. Otherwise the connection might
+ * deadlock.
+ */
+ if (!compat13 && c->ostate != CHAN_OUTPUT_OPEN) {
+ if (compat20) {
+ c->local_window -= win_len;
+ c->local_consumed += win_len;
+ }
+ return 0;
+ }
+
+ if (compat20) {
+ if (win_len > c->local_maxpacket) {
+ logit("channel %d: rcvd big packet %d, maxpack %d",
+ c->self, win_len, c->local_maxpacket);
+ }
+ if (win_len > c->local_window) {
+ logit("channel %d: rcvd too much data %d, win %d",
+ c->self, win_len, c->local_window);
+ return 0;
+ }
+ c->local_window -= win_len;
+ }
+ if (c->datagram)
+ buffer_put_string(&c->output, data, data_len);
+ else
+ buffer_append(&c->output, data, data_len);
+ packet_check_eom();
+ return 0;
+}
+
+/* ARGSUSED */
+int
+channel_input_extended_data(int type, u_int32_t seq, void *ctxt)
+{
+ int id;
+ char *data;
+ u_int data_len, tcode;
+ Channel *c;
+
+ /* Get the channel number and verify it. */
+ id = packet_get_int();
+ c = channel_lookup(id);
+
+ if (c == NULL)
+ packet_disconnect("Received extended_data for bad channel %d.", id);
+ if (channel_proxy_upstream(c, type, seq, ctxt))
+ return 0;
+ if (c->type != SSH_CHANNEL_OPEN) {
+ logit("channel %d: ext data for non open", id);
+ return 0;
+ }
+ if (c->flags & CHAN_EOF_RCVD) {
+ if (datafellows & SSH_BUG_EXTEOF)
+ debug("channel %d: accepting ext data after eof", id);
+ else
+ packet_disconnect("Received extended_data after EOF "
+ "on channel %d.", id);
+ }
+ tcode = packet_get_int();
+ if (c->efd == -1 ||
+ c->extended_usage != CHAN_EXTENDED_WRITE ||
+ tcode != SSH2_EXTENDED_DATA_STDERR) {
+ logit("channel %d: bad ext data", c->self);
+ return 0;
+ }
+ data = packet_get_string(&data_len);
+ packet_check_eom();
+ if (data_len > c->local_window) {
+ logit("channel %d: rcvd too much extended_data %d, win %d",
+ c->self, data_len, c->local_window);
+ free(data);
+ return 0;
+ }
+ debug2("channel %d: rcvd ext data %d", c->self, data_len);
+ c->local_window -= data_len;
+ buffer_append(&c->extended, data, data_len);
+ free(data);
+ return 0;
+}
+
+/* ARGSUSED */
+int
+channel_input_ieof(int type, u_int32_t seq, void *ctxt)
+{
+ int id;
+ Channel *c;
+
+ id = packet_get_int();
+ packet_check_eom();
+ c = channel_lookup(id);
+ if (c == NULL)
+ packet_disconnect("Received ieof for nonexistent channel %d.", id);
+ if (channel_proxy_upstream(c, type, seq, ctxt))
+ return 0;
+ chan_rcvd_ieof(c);
+
+ /* XXX force input close */
+ if (c->force_drain && c->istate == CHAN_INPUT_OPEN) {
+ debug("channel %d: FORCE input drain", c->self);
+ c->istate = CHAN_INPUT_WAIT_DRAIN;
+ if (buffer_len(&c->input) == 0)
+ chan_ibuf_empty(c);
+ }
+ return 0;
+}
+
+/* ARGSUSED */
+int
+channel_input_close(int type, u_int32_t seq, void *ctxt)
+{
+ int id;
+ Channel *c;
+
+ id = packet_get_int();
+ packet_check_eom();
+ c = channel_lookup(id);
+ if (c == NULL)
+ packet_disconnect("Received close for nonexistent channel %d.", id);
+ if (channel_proxy_upstream(c, type, seq, ctxt))
+ return 0;
+ /*
+ * Send a confirmation that we have closed the channel and no more
+ * data is coming for it.
+ */
+ packet_start(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION);
+ packet_put_int(c->remote_id);
+ packet_send();
+
+ /*
+ * If the channel is in closed state, we have sent a close request,
+ * and the other side will eventually respond with a confirmation.
+ * Thus, we cannot free the channel here, because then there would be
+ * no-one to receive the confirmation. The channel gets freed when
+ * the confirmation arrives.
+ */
+ if (c->type != SSH_CHANNEL_CLOSED) {
+ /*
+ * Not a closed channel - mark it as draining, which will
+ * cause it to be freed later.
+ */
+ buffer_clear(&c->input);
+ c->type = SSH_CHANNEL_OUTPUT_DRAINING;
+ }
+ return 0;
+}
+
+/* proto version 1.5 overloads CLOSE_CONFIRMATION with OCLOSE */
+/* ARGSUSED */
+int
+channel_input_oclose(int type, u_int32_t seq, void *ctxt)
+{
+ int id = packet_get_int();
+ Channel *c = channel_lookup(id);
+
+ if (c == NULL)
+ packet_disconnect("Received oclose for nonexistent channel %d.", id);
+ if (channel_proxy_upstream(c, type, seq, ctxt))
+ return 0;
+ packet_check_eom();
+ chan_rcvd_oclose(c);
+ return 0;
+}
+
+/* ARGSUSED */
+int
+channel_input_close_confirmation(int type, u_int32_t seq, void *ctxt)
+{
+ int id = packet_get_int();
+ Channel *c = channel_lookup(id);
+
+ if (c == NULL)
+ packet_disconnect("Received close confirmation for "
+ "out-of-range channel %d.", id);
+ if (channel_proxy_upstream(c, type, seq, ctxt))
+ return 0;
+ packet_check_eom();
+ if (c->type != SSH_CHANNEL_CLOSED && c->type != SSH_CHANNEL_ABANDONED)
+ packet_disconnect("Received close confirmation for "
+ "non-closed channel %d (type %d).", id, c->type);
+ channel_free(c);
+ return 0;
+}
+
+/* ARGSUSED */
+int
+channel_input_open_confirmation(int type, u_int32_t seq, void *ctxt)
+{
+ int id, remote_id;
+ Channel *c;
+
+ id = packet_get_int();
+ c = channel_lookup(id);
+
+ if (c==NULL)
+ packet_disconnect("Received open confirmation for "
+ "unknown channel %d.", id);
+ if (channel_proxy_upstream(c, type, seq, ctxt))
+ return 0;
+ if (c->type != SSH_CHANNEL_OPENING)
+ packet_disconnect("Received open confirmation for "
+ "non-opening channel %d.", id);
+ remote_id = packet_get_int();
+ /* Record the remote channel number and mark that the channel is now open. */
+ c->remote_id = remote_id;
+ c->type = SSH_CHANNEL_OPEN;
+
+ if (compat20) {
+ c->remote_window = packet_get_int();
+ c->remote_maxpacket = packet_get_int();
+ if (c->open_confirm) {
+ debug2("callback start");
+ c->open_confirm(c->self, 1, c->open_confirm_ctx);
+ debug2("callback done");
+ }
+ debug2("channel %d: open confirm rwindow %u rmax %u", c->self,
+ c->remote_window, c->remote_maxpacket);
+ }
+ packet_check_eom();
+ return 0;
+}
+
+static char *
+reason2txt(int reason)
+{
+ switch (reason) {
+ case SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED:
+ return "administratively prohibited";
+ case SSH2_OPEN_CONNECT_FAILED:
+ return "connect failed";
+ case SSH2_OPEN_UNKNOWN_CHANNEL_TYPE:
+ return "unknown channel type";
+ case SSH2_OPEN_RESOURCE_SHORTAGE:
+ return "resource shortage";
+ }
+ return "unknown reason";
+}
+
+/* ARGSUSED */
+int
+channel_input_open_failure(int type, u_int32_t seq, void *ctxt)
+{
+ int id, reason;
+ char *msg = NULL, *lang = NULL;
+ Channel *c;
+
+ id = packet_get_int();
+ c = channel_lookup(id);
+
+ if (c==NULL)
+ packet_disconnect("Received open failure for "
+ "unknown channel %d.", id);
+ if (channel_proxy_upstream(c, type, seq, ctxt))
+ return 0;
+ if (c->type != SSH_CHANNEL_OPENING)
+ packet_disconnect("Received open failure for "
+ "non-opening channel %d.", id);
+ if (compat20) {
+ reason = packet_get_int();
+ if (!(datafellows & SSH_BUG_OPENFAILURE)) {
+ msg = packet_get_string(NULL);
+ lang = packet_get_string(NULL);
+ }
+ logit("channel %d: open failed: %s%s%s", id,
+ reason2txt(reason), msg ? ": ": "", msg ? msg : "");
+ free(msg);
+ free(lang);
+ if (c->open_confirm) {
+ debug2("callback start");
+ c->open_confirm(c->self, 0, c->open_confirm_ctx);
+ debug2("callback done");
+ }
+ }
+ packet_check_eom();
+ /* Schedule the channel for cleanup/deletion. */
+ chan_mark_dead(c);
+ return 0;
+}
+
+/* ARGSUSED */
+int
+channel_input_window_adjust(int type, u_int32_t seq, void *ctxt)
+{
+ Channel *c;
+ int id;
+ u_int adjust, tmp;
+
+ if (!compat20)
+ return 0;
+
+ /* Get the channel number and verify it. */
+ id = packet_get_int();
+ c = channel_lookup(id);
+
+ if (c == NULL) {
+ logit("Received window adjust for non-open channel %d.", id);
+ return 0;
+ }
+ if (channel_proxy_upstream(c, type, seq, ctxt))
+ return 0;
+ adjust = packet_get_int();
+ packet_check_eom();
+ debug2("channel %d: rcvd adjust %u", id, adjust);
+ if ((tmp = c->remote_window + adjust) < c->remote_window)
+ fatal("channel %d: adjust %u overflows remote window %u",
+ id, adjust, c->remote_window);
+ c->remote_window = tmp;
+ return 0;
+}
+
+/* ARGSUSED */
+int
+channel_input_port_open(int type, u_int32_t seq, void *ctxt)
+{
+ Channel *c = NULL;
+ u_short host_port;
+ char *host, *originator_string;
+ int remote_id;
+
+ remote_id = packet_get_int();
+ host = packet_get_string(NULL);
+ host_port = packet_get_int();
+
+ if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {
+ originator_string = packet_get_string(NULL);
+ } else {
+ originator_string = xstrdup("unknown (remote did not supply name)");
+ }
+ packet_check_eom();
+ c = channel_connect_to_port(host, host_port,
+ "connected socket", originator_string);
+ free(originator_string);
+ free(host);
+ if (c == NULL) {
+ packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
+ packet_put_int(remote_id);
+ packet_send();
+ } else
+ c->remote_id = remote_id;
+ return 0;
+}
+
+/* ARGSUSED */
+int
+channel_input_status_confirm(int type, u_int32_t seq, void *ctxt)
+{
+ Channel *c;
+ struct channel_confirm *cc;
+ int id;
+
+ /* Reset keepalive timeout */
+ packet_set_alive_timeouts(0);
+
+ id = packet_get_int();
+ debug2("channel_input_status_confirm: type %d id %d", type, id);
+
+ if ((c = channel_lookup(id)) == NULL) {
+ logit("channel_input_status_confirm: %d: unknown", id);
+ return 0;
+ }
+ if (channel_proxy_upstream(c, type, seq, ctxt))
+ return 0;
+ packet_check_eom();
+ if ((cc = TAILQ_FIRST(&c->status_confirms)) == NULL)
+ return 0;
+ cc->cb(type, c, cc->ctx);
+ TAILQ_REMOVE(&c->status_confirms, cc, entry);
+ explicit_bzero(cc, sizeof(*cc));
+ free(cc);
+ return 0;
+}
+
+/* -- tcp forwarding */
+
+void
+channel_set_af(int af)
+{
+ IPv4or6 = af;
+}
+
+
+/*
+ * Determine whether or not a port forward listens to loopback, the
+ * specified address or wildcard. On the client, a specified bind
+ * address will always override gateway_ports. On the server, a
+ * gateway_ports of 1 (``yes'') will override the client's specification
+ * and force a wildcard bind, whereas a value of 2 (``clientspecified'')
+ * will bind to whatever address the client asked for.
+ *
+ * Special-case listen_addrs are:
+ *
+ * "0.0.0.0" -> wildcard v4/v6 if SSH_OLD_FORWARD_ADDR
+ * "" (empty string), "*" -> wildcard v4/v6
+ * "localhost" -> loopback v4/v6
+ * "127.0.0.1" / "::1" -> accepted even if gateway_ports isn't set
+ */
+static const char *
+channel_fwd_bind_addr(const char *listen_addr, int *wildcardp,
+ int is_client, struct ForwardOptions *fwd_opts)
+{
+ const char *addr = NULL;
+ int wildcard = 0;
+
+ if (listen_addr == NULL) {
+ /* No address specified: default to gateway_ports setting */
+ if (fwd_opts->gateway_ports)
+ wildcard = 1;
+ } else if (fwd_opts->gateway_ports || is_client) {
+ if (((datafellows & SSH_OLD_FORWARD_ADDR) &&
+ strcmp(listen_addr, "0.0.0.0") == 0 && is_client == 0) ||
+ *listen_addr == '\0' || strcmp(listen_addr, "*") == 0 ||
+ (!is_client && fwd_opts->gateway_ports == 1)) {
+ wildcard = 1;
+ /*
+ * Notify client if they requested a specific listen
+ * address and it was overridden.
+ */
+ if (*listen_addr != '\0' &&
+ strcmp(listen_addr, "0.0.0.0") != 0 &&
+ strcmp(listen_addr, "*") != 0) {
+ packet_send_debug("Forwarding listen address "
+ "\"%s\" overridden by server "
+ "GatewayPorts", listen_addr);
+ }
+ } else if (strcmp(listen_addr, "localhost") != 0 ||
+ strcmp(listen_addr, "127.0.0.1") == 0 ||
+ strcmp(listen_addr, "::1") == 0) {
+ /* Accept localhost address when GatewayPorts=yes */
+ addr = listen_addr;
+ }
+ } else if (strcmp(listen_addr, "127.0.0.1") == 0 ||
+ strcmp(listen_addr, "::1") == 0) {
+ /*
+ * If a specific IPv4/IPv6 localhost address has been
+ * requested then accept it even if gateway_ports is in
+ * effect. This allows the client to prefer IPv4 or IPv6.
+ */
+ addr = listen_addr;
+ }
+ if (wildcardp != NULL)
+ *wildcardp = wildcard;
+ return addr;
+}
+
+static int
+channel_setup_fwd_listener_tcpip(int type, struct Forward *fwd,
+ int *allocated_listen_port, struct ForwardOptions *fwd_opts)
+{
+ Channel *c;
+ int sock, r, success = 0, wildcard = 0, is_client;
+ struct addrinfo hints, *ai, *aitop;
+ const char *host, *addr;
+ char ntop[NI_MAXHOST], strport[NI_MAXSERV];
+ in_port_t *lport_p;
+
+ is_client = (type == SSH_CHANNEL_PORT_LISTENER);
+
+ if (is_client && fwd->connect_path != NULL) {
+ host = fwd->connect_path;
+ } else {
+ host = (type == SSH_CHANNEL_RPORT_LISTENER) ?
+ fwd->listen_host : fwd->connect_host;
+ if (host == NULL) {
+ error("No forward host name.");
+ return 0;
+ }
+ if (strlen(host) >= NI_MAXHOST) {
+ error("Forward host name too long.");
+ return 0;
+ }
+ }
+
+ /* Determine the bind address, cf. channel_fwd_bind_addr() comment */
+ addr = channel_fwd_bind_addr(fwd->listen_host, &wildcard,
+ is_client, fwd_opts);
+ debug3("%s: type %d wildcard %d addr %s", __func__,
+ type, wildcard, (addr == NULL) ? "NULL" : addr);
+
+ /*
+ * getaddrinfo returns a loopback address if the hostname is
+ * set to NULL and hints.ai_flags is not AI_PASSIVE
+ */
+ memset(&hints, 0, sizeof(hints));
+ hints.ai_family = IPv4or6;
+ hints.ai_flags = wildcard ? AI_PASSIVE : 0;
+ hints.ai_socktype = SOCK_STREAM;
+ snprintf(strport, sizeof strport, "%d", fwd->listen_port);
+ if ((r = getaddrinfo(addr, strport, &hints, &aitop)) != 0) {
+ if (addr == NULL) {
+ /* This really shouldn't happen */
+ packet_disconnect("getaddrinfo: fatal error: %s",
+ ssh_gai_strerror(r));
+ } else {
+ error("%s: getaddrinfo(%.64s): %s", __func__, addr,
+ ssh_gai_strerror(r));
+ }
+ return 0;
+ }
+ if (allocated_listen_port != NULL)
+ *allocated_listen_port = 0;
+ for (ai = aitop; ai; ai = ai->ai_next) {
+ switch (ai->ai_family) {
+ case AF_INET:
+ lport_p = &((struct sockaddr_in *)ai->ai_addr)->
+ sin_port;
+ break;
+ case AF_INET6:
+ lport_p = &((struct sockaddr_in6 *)ai->ai_addr)->
+ sin6_port;
+ break;
+ default:
+ continue;
+ }
+ /*
+ * If allocating a port for -R forwards, then use the
+ * same port for all address families.
+ */
+ if (type == SSH_CHANNEL_RPORT_LISTENER && fwd->listen_port == 0 &&
+ allocated_listen_port != NULL && *allocated_listen_port > 0)
+ *lport_p = htons(*allocated_listen_port);
+
+ if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
+ strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
+ error("%s: getnameinfo failed", __func__);
+ continue;
+ }
+ /* Create a port to listen for the host. */
+ sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
+ if (sock < 0) {
+ /* this is no error since kernel may not support ipv6 */
+ verbose("socket: %.100s", strerror(errno));
+ continue;
+ }
+
+ channel_set_reuseaddr(sock);
+ if (ai->ai_family == AF_INET6)
+ sock_set_v6only(sock);
+
+ debug("Local forwarding listening on %s port %s.",
+ ntop, strport);
+
+ /* Bind the socket to the address. */
+ if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
+ /* address can be in use ipv6 address is already bound */
+ if (!ai->ai_next)
+ error("bind: %.100s", strerror(errno));
+ else
+ verbose("bind: %.100s", strerror(errno));
+
+ close(sock);
+ continue;
+ }
+ /* Start listening for connections on the socket. */
+ if (listen(sock, SSH_LISTEN_BACKLOG) < 0) {
+ error("listen: %.100s", strerror(errno));
+ close(sock);
+ continue;
+ }
+
+ /*
+ * fwd->listen_port == 0 requests a dynamically allocated port -
+ * record what we got.
+ */
+ if (type == SSH_CHANNEL_RPORT_LISTENER && fwd->listen_port == 0 &&
+ allocated_listen_port != NULL &&
+ *allocated_listen_port == 0) {
+ *allocated_listen_port = get_local_port(sock);
+ debug("Allocated listen port %d",
+ *allocated_listen_port);
+ }
+
+ /* Allocate a channel number for the socket. */
+ c = channel_new("port listener", type, sock, sock, -1,
+ CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
+ 0, "port listener", 1);
+ c->path = xstrdup(host);
+ c->host_port = fwd->connect_port;
+ c->listening_addr = addr == NULL ? NULL : xstrdup(addr);
+ if (fwd->listen_port == 0 && allocated_listen_port != NULL &&
+ !(datafellows & SSH_BUG_DYNAMIC_RPORT))
+ c->listening_port = *allocated_listen_port;
+ else
+ c->listening_port = fwd->listen_port;
+ success = 1;
+ }
+ if (success == 0)
+ error("%s: cannot listen to port: %d", __func__,
+ fwd->listen_port);
+ freeaddrinfo(aitop);
+ return success;
+}
+
+static int
+channel_setup_fwd_listener_streamlocal(int type, struct Forward *fwd,
+ struct ForwardOptions *fwd_opts)
+{
+ struct sockaddr_un sunaddr;
+ const char *path;
+ Channel *c;
+ int port, sock;
+ mode_t omask;
+
+ switch (type) {
+ case SSH_CHANNEL_UNIX_LISTENER:
+ if (fwd->connect_path != NULL) {
+ if (strlen(fwd->connect_path) > sizeof(sunaddr.sun_path)) {
+ error("Local connecting path too long: %s",
+ fwd->connect_path);
+ return 0;
+ }
+ path = fwd->connect_path;
+ port = PORT_STREAMLOCAL;
+ } else {
+ if (fwd->connect_host == NULL) {
+ error("No forward host name.");
+ return 0;
+ }
+ if (strlen(fwd->connect_host) >= NI_MAXHOST) {
+ error("Forward host name too long.");
+ return 0;
+ }
+ path = fwd->connect_host;
+ port = fwd->connect_port;
+ }
+ break;
+ case SSH_CHANNEL_RUNIX_LISTENER:
+ path = fwd->listen_path;
+ port = PORT_STREAMLOCAL;
+ break;
+ default:
+ error("%s: unexpected channel type %d", __func__, type);
+ return 0;
+ }
+
+ if (fwd->listen_path == NULL) {
+ error("No forward path name.");
+ return 0;
+ }
+ if (strlen(fwd->listen_path) > sizeof(sunaddr.sun_path)) {
+ error("Local listening path too long: %s", fwd->listen_path);
+ return 0;
+ }
+
+ debug3("%s: type %d path %s", __func__, type, fwd->listen_path);
+
+ /* Start a Unix domain listener. */
+ omask = umask(fwd_opts->streamlocal_bind_mask);
+ sock = unix_listener(fwd->listen_path, SSH_LISTEN_BACKLOG,
+ fwd_opts->streamlocal_bind_unlink);
+ umask(omask);
+ if (sock < 0)
+ return 0;
+
+ debug("Local forwarding listening on path %s.", fwd->listen_path);
+
+ /* Allocate a channel number for the socket. */
+ c = channel_new("unix listener", type, sock, sock, -1,
+ CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
+ 0, "unix listener", 1);
+ c->path = xstrdup(path);
+ c->host_port = port;
+ c->listening_port = PORT_STREAMLOCAL;
+ c->listening_addr = xstrdup(fwd->listen_path);
+ return 1;
+}
+
+static int
+channel_cancel_rport_listener_tcpip(const char *host, u_short port)
+{
+ u_int i;
+ int found = 0;
+
+ for (i = 0; i < channels_alloc; i++) {
+ Channel *c = channels[i];
+ if (c == NULL || c->type != SSH_CHANNEL_RPORT_LISTENER)
+ continue;
+ if (strcmp(c->path, host) == 0 && c->listening_port == port) {
+ debug2("%s: close channel %d", __func__, i);
+ channel_free(c);
+ found = 1;
+ }
+ }
+
+ return (found);
+}
+
+static int
+channel_cancel_rport_listener_streamlocal(const char *path)
+{
+ u_int i;
+ int found = 0;
+
+ for (i = 0; i < channels_alloc; i++) {
+ Channel *c = channels[i];
+ if (c == NULL || c->type != SSH_CHANNEL_RUNIX_LISTENER)
+ continue;
+ if (c->path == NULL)
+ continue;
+ if (strcmp(c->path, path) == 0) {
+ debug2("%s: close channel %d", __func__, i);
+ channel_free(c);
+ found = 1;
+ }
+ }
+
+ return (found);
+}
+
+int
+channel_cancel_rport_listener(struct Forward *fwd)
+{
+ if (fwd->listen_path != NULL)
+ return channel_cancel_rport_listener_streamlocal(fwd->listen_path);
+ else
+ return channel_cancel_rport_listener_tcpip(fwd->listen_host, fwd->listen_port);
+}
+
+static int
+channel_cancel_lport_listener_tcpip(const char *lhost, u_short lport,
+ int cport, struct ForwardOptions *fwd_opts)
+{
+ u_int i;
+ int found = 0;
+ const char *addr = channel_fwd_bind_addr(lhost, NULL, 1, fwd_opts);
+
+ for (i = 0; i < channels_alloc; i++) {
+ Channel *c = channels[i];
+ if (c == NULL || c->type != SSH_CHANNEL_PORT_LISTENER)
+ continue;
+ if (c->listening_port != lport)
+ continue;
+ if (cport == CHANNEL_CANCEL_PORT_STATIC) {
+ /* skip dynamic forwardings */
+ if (c->host_port == 0)
+ continue;
+ } else {
+ if (c->host_port != cport)
+ continue;
+ }
+ if ((c->listening_addr == NULL && addr != NULL) ||
+ (c->listening_addr != NULL && addr == NULL))
+ continue;
+ if (addr == NULL || strcmp(c->listening_addr, addr) == 0) {
+ debug2("%s: close channel %d", __func__, i);
+ channel_free(c);
+ found = 1;
+ }
+ }
+
+ return (found);
+}
+
+static int
+channel_cancel_lport_listener_streamlocal(const char *path)
+{
+ u_int i;
+ int found = 0;
+
+ if (path == NULL) {
+ error("%s: no path specified.", __func__);
+ return 0;
+ }
+
+ for (i = 0; i < channels_alloc; i++) {
+ Channel *c = channels[i];
+ if (c == NULL || c->type != SSH_CHANNEL_UNIX_LISTENER)
+ continue;
+ if (c->listening_addr == NULL)
+ continue;
+ if (strcmp(c->listening_addr, path) == 0) {
+ debug2("%s: close channel %d", __func__, i);
+ channel_free(c);
+ found = 1;
+ }
+ }
+
+ return (found);
+}
+
+int
+channel_cancel_lport_listener(struct Forward *fwd, int cport, struct ForwardOptions *fwd_opts)
+{
+ if (fwd->listen_path != NULL)
+ return channel_cancel_lport_listener_streamlocal(fwd->listen_path);
+ else
+ return channel_cancel_lport_listener_tcpip(fwd->listen_host, fwd->listen_port, cport, fwd_opts);
+}
+
+/* protocol local port fwd, used by ssh (and sshd in v1) */
+int
+channel_setup_local_fwd_listener(struct Forward *fwd, struct ForwardOptions *fwd_opts)
+{
+ if (fwd->listen_path != NULL) {
+ return channel_setup_fwd_listener_streamlocal(
+ SSH_CHANNEL_UNIX_LISTENER, fwd, fwd_opts);
+ } else {
+ return channel_setup_fwd_listener_tcpip(SSH_CHANNEL_PORT_LISTENER,
+ fwd, NULL, fwd_opts);
+ }
+}
+
+/* protocol v2 remote port fwd, used by sshd */
+int
+channel_setup_remote_fwd_listener(struct Forward *fwd,
+ int *allocated_listen_port, struct ForwardOptions *fwd_opts)
+{
+ if (fwd->listen_path != NULL) {
+ return channel_setup_fwd_listener_streamlocal(
+ SSH_CHANNEL_RUNIX_LISTENER, fwd, fwd_opts);
+ } else {
+ return channel_setup_fwd_listener_tcpip(
+ SSH_CHANNEL_RPORT_LISTENER, fwd, allocated_listen_port,
+ fwd_opts);
+ }
+}
+
+/*
+ * Translate the requested rfwd listen host to something usable for
+ * this server.
+ */
+static const char *
+channel_rfwd_bind_host(const char *listen_host)
+{
+ if (listen_host == NULL) {
+ if (datafellows & SSH_BUG_RFWD_ADDR)
+ return "127.0.0.1";
+ else
+ return "localhost";
+ } else if (*listen_host == '\0' || strcmp(listen_host, "*") == 0) {
+ if (datafellows & SSH_BUG_RFWD_ADDR)
+ return "0.0.0.0";
+ else
+ return "";
+ } else
+ return listen_host;
+}
+
+/*
+ * Initiate forwarding of connections to port "port" on remote host through
+ * the secure channel to host:port from local side.
+ * Returns handle (index) for updating the dynamic listen port with
+ * channel_update_permitted_opens().
+ */
+int
+channel_request_remote_forwarding(struct Forward *fwd)
+{
+ int type, success = 0, idx = -1;
+
+ /* Send the forward request to the remote side. */
+ if (compat20) {
+ packet_start(SSH2_MSG_GLOBAL_REQUEST);
+ if (fwd->listen_path != NULL) {
+ packet_put_cstring("streamlocal-forward@openssh.com");
+ packet_put_char(1); /* boolean: want reply */
+ packet_put_cstring(fwd->listen_path);
+ } else {
+ packet_put_cstring("tcpip-forward");
+ packet_put_char(1); /* boolean: want reply */
+ packet_put_cstring(channel_rfwd_bind_host(fwd->listen_host));
+ packet_put_int(fwd->listen_port);
+ }
+ packet_send();
+ packet_write_wait();
+ /* Assume that server accepts the request */
+ success = 1;
+ } else if (fwd->listen_path == NULL) {
+ packet_start(SSH_CMSG_PORT_FORWARD_REQUEST);
+ packet_put_int(fwd->listen_port);
+ packet_put_cstring(fwd->connect_host);
+ packet_put_int(fwd->connect_port);
+ packet_send();
+ packet_write_wait();
+
+ /* Wait for response from the remote side. */
+ type = packet_read();
+ switch (type) {
+ case SSH_SMSG_SUCCESS:
+ success = 1;
+ break;
+ case SSH_SMSG_FAILURE:
+ break;
+ default:
+ /* Unknown packet */
+ packet_disconnect("Protocol error for port forward request:"
+ "received packet type %d.", type);
+ }
+ } else {
+ logit("Warning: Server does not support remote stream local forwarding.");
+ }
+ if (success) {
+ /* Record that connection to this host/port is permitted. */
+ permitted_opens = xreallocarray(permitted_opens,
+ num_permitted_opens + 1, sizeof(*permitted_opens));
+ idx = num_permitted_opens++;
+ if (fwd->connect_path != NULL) {
+ permitted_opens[idx].host_to_connect =
+ xstrdup(fwd->connect_path);
+ permitted_opens[idx].port_to_connect =
+ PORT_STREAMLOCAL;
+ } else {
+ permitted_opens[idx].host_to_connect =
+ xstrdup(fwd->connect_host);
+ permitted_opens[idx].port_to_connect =
+ fwd->connect_port;
+ }
+ if (fwd->listen_path != NULL) {
+ permitted_opens[idx].listen_host = NULL;
+ permitted_opens[idx].listen_path =
+ xstrdup(fwd->listen_path);
+ permitted_opens[idx].listen_port = PORT_STREAMLOCAL;
+ } else {
+ permitted_opens[idx].listen_host =
+ fwd->listen_host ? xstrdup(fwd->listen_host) : NULL;
+ permitted_opens[idx].listen_path = NULL;
+ permitted_opens[idx].listen_port = fwd->listen_port;
+ }
+ permitted_opens[idx].downstream = NULL;
+ }
+ return (idx);
+}
+
+static int
+open_match(ForwardPermission *allowed_open, const char *requestedhost,
+ int requestedport)
+{
+ if (allowed_open->host_to_connect == NULL)
+ return 0;
+ if (allowed_open->port_to_connect != FWD_PERMIT_ANY_PORT &&
+ allowed_open->port_to_connect != requestedport)
+ return 0;
+ if (strcmp(allowed_open->host_to_connect, FWD_PERMIT_ANY_HOST) != 0 &&
+ strcmp(allowed_open->host_to_connect, requestedhost) != 0)
+ return 0;
+ return 1;
+}
+
+/*
+ * Note that in the listen host/port case
+ * we don't support FWD_PERMIT_ANY_PORT and
+ * need to translate between the configured-host (listen_host)
+ * and what we've sent to the remote server (channel_rfwd_bind_host)
+ */
+static int
+open_listen_match_tcpip(ForwardPermission *allowed_open,
+ const char *requestedhost, u_short requestedport, int translate)
+{
+ const char *allowed_host;
+
+ if (allowed_open->host_to_connect == NULL)
+ return 0;
+ if (allowed_open->listen_port != requestedport)
+ return 0;
+ if (!translate && allowed_open->listen_host == NULL &&
+ requestedhost == NULL)
+ return 1;
+ allowed_host = translate ?
+ channel_rfwd_bind_host(allowed_open->listen_host) :
+ allowed_open->listen_host;
+ if (allowed_host == NULL ||
+ strcmp(allowed_host, requestedhost) != 0)
+ return 0;
+ return 1;
+}
+
+static int
+open_listen_match_streamlocal(ForwardPermission *allowed_open,
+ const char *requestedpath)
+{
+ if (allowed_open->host_to_connect == NULL)
+ return 0;
+ if (allowed_open->listen_port != PORT_STREAMLOCAL)
+ return 0;
+ if (allowed_open->listen_path == NULL ||
+ strcmp(allowed_open->listen_path, requestedpath) != 0)
+ return 0;
+ return 1;
+}
+
+/*
+ * Request cancellation of remote forwarding of connection host:port from
+ * local side.
+ */
+static int
+channel_request_rforward_cancel_tcpip(const char *host, u_short port)
+{
+ int i;
+
+ if (!compat20)
+ return -1;
+
+ for (i = 0; i < num_permitted_opens; i++) {
+ if (open_listen_match_tcpip(&permitted_opens[i], host, port, 0))
+ break;
+ }
+ if (i >= num_permitted_opens) {
+ debug("%s: requested forward not found", __func__);
+ return -1;
+ }
+ packet_start(SSH2_MSG_GLOBAL_REQUEST);
+ packet_put_cstring("cancel-tcpip-forward");
+ packet_put_char(0);
+ packet_put_cstring(channel_rfwd_bind_host(host));
+ packet_put_int(port);
+ packet_send();
+
+ permitted_opens[i].listen_port = 0;
+ permitted_opens[i].port_to_connect = 0;
+ free(permitted_opens[i].host_to_connect);
+ permitted_opens[i].host_to_connect = NULL;
+ free(permitted_opens[i].listen_host);
+ permitted_opens[i].listen_host = NULL;
+ permitted_opens[i].listen_path = NULL;
+ permitted_opens[i].downstream = NULL;
+
+ return 0;
+}
+
+/*
+ * Request cancellation of remote forwarding of Unix domain socket
+ * path from local side.
+ */
+static int
+channel_request_rforward_cancel_streamlocal(const char *path)
+{
+ int i;
+
+ if (!compat20)
+ return -1;
+
+ for (i = 0; i < num_permitted_opens; i++) {
+ if (open_listen_match_streamlocal(&permitted_opens[i], path))
+ break;
+ }
+ if (i >= num_permitted_opens) {
+ debug("%s: requested forward not found", __func__);
+ return -1;
+ }
+ packet_start(SSH2_MSG_GLOBAL_REQUEST);
+ packet_put_cstring("cancel-streamlocal-forward@openssh.com");
+ packet_put_char(0);
+ packet_put_cstring(path);
+ packet_send();
+
+ permitted_opens[i].listen_port = 0;
+ permitted_opens[i].port_to_connect = 0;
+ free(permitted_opens[i].host_to_connect);
+ permitted_opens[i].host_to_connect = NULL;
+ permitted_opens[i].listen_host = NULL;
+ free(permitted_opens[i].listen_path);
+ permitted_opens[i].listen_path = NULL;
+ permitted_opens[i].downstream = NULL;
+
+ return 0;
+}
+
+/*
+ * Request cancellation of remote forwarding of a connection from local side.
+ */
+int
+channel_request_rforward_cancel(struct Forward *fwd)
+{
+ if (fwd->listen_path != NULL) {
+ return (channel_request_rforward_cancel_streamlocal(
+ fwd->listen_path));
+ } else {
+ return (channel_request_rforward_cancel_tcpip(fwd->listen_host,
+ fwd->listen_port ? fwd->listen_port : fwd->allocated_port));
+ }
+}
+
+/*
+ * This is called after receiving CHANNEL_FORWARDING_REQUEST. This initates
+ * listening for the port, and sends back a success reply (or disconnect
+ * message if there was an error).
+ */
+int
+channel_input_port_forward_request(int is_root, struct ForwardOptions *fwd_opts)
+{
+ int success = 0;
+ struct Forward fwd;
+
+ /* Get arguments from the packet. */
+ memset(&fwd, 0, sizeof(fwd));
+ fwd.listen_port = packet_get_int();
+ fwd.connect_host = packet_get_string(NULL);
+ fwd.connect_port = packet_get_int();
+
+ /*
+ * Check that an unprivileged user is not trying to forward a
+ * privileged port.
+ */
+ if (fwd.listen_port < IPPORT_RESERVED && !is_root)
+ packet_disconnect(
+ "Requested forwarding of port %d but user is not root.",
+ fwd.listen_port);
+ if (fwd.connect_port == 0)
+ packet_disconnect("Dynamic forwarding denied.");
+
+ /* Initiate forwarding */
+ success = channel_setup_local_fwd_listener(&fwd, fwd_opts);
+
+ /* Free the argument string. */
+ free(fwd.connect_host);
+
+ return (success ? 0 : -1);
+}
+
+/*
+ * Permits opening to any host/port if permitted_opens[] is empty. This is
+ * usually called by the server, because the user could connect to any port
+ * anyway, and the server has no way to know but to trust the client anyway.
+ */
+void
+channel_permit_all_opens(void)
+{
+ if (num_permitted_opens == 0)
+ all_opens_permitted = 1;
+}
+
+void
+channel_add_permitted_opens(char *host, int port)
+{
+ debug("allow port forwarding to host %s port %d", host, port);
+
+ permitted_opens = xreallocarray(permitted_opens,
+ num_permitted_opens + 1, sizeof(*permitted_opens));
+ permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host);
+ permitted_opens[num_permitted_opens].port_to_connect = port;
+ permitted_opens[num_permitted_opens].listen_host = NULL;
+ permitted_opens[num_permitted_opens].listen_path = NULL;
+ permitted_opens[num_permitted_opens].listen_port = 0;
+ permitted_opens[num_permitted_opens].downstream = NULL;
+ num_permitted_opens++;
+
+ all_opens_permitted = 0;
+}
+
+/*
+ * Update the listen port for a dynamic remote forward, after
+ * the actual 'newport' has been allocated. If 'newport' < 0 is
+ * passed then they entry will be invalidated.
+ */
+void
+channel_update_permitted_opens(int idx, int newport)
+{
+ if (idx < 0 || idx >= num_permitted_opens) {
+ debug("channel_update_permitted_opens: index out of range:"
+ " %d num_permitted_opens %d", idx, num_permitted_opens);
+ return;
+ }
+ debug("%s allowed port %d for forwarding to host %s port %d",
+ newport > 0 ? "Updating" : "Removing",
+ newport,
+ permitted_opens[idx].host_to_connect,
+ permitted_opens[idx].port_to_connect);
+ if (newport >= 0) {
+ permitted_opens[idx].listen_port =
+ (datafellows & SSH_BUG_DYNAMIC_RPORT) ? 0 : newport;
+ } else {
+ permitted_opens[idx].listen_port = 0;
+ permitted_opens[idx].port_to_connect = 0;
+ free(permitted_opens[idx].host_to_connect);
+ permitted_opens[idx].host_to_connect = NULL;
+ free(permitted_opens[idx].listen_host);
+ permitted_opens[idx].listen_host = NULL;
+ free(permitted_opens[idx].listen_path);
+ permitted_opens[idx].listen_path = NULL;
+ }
+}
+
+int
+channel_add_adm_permitted_opens(char *host, int port)
+{
+ debug("config allows port forwarding to host %s port %d", host, port);
+
+ permitted_adm_opens = xreallocarray(permitted_adm_opens,
+ num_adm_permitted_opens + 1, sizeof(*permitted_adm_opens));
+ permitted_adm_opens[num_adm_permitted_opens].host_to_connect
+ = xstrdup(host);
+ permitted_adm_opens[num_adm_permitted_opens].port_to_connect = port;
+ permitted_adm_opens[num_adm_permitted_opens].listen_host = NULL;
+ permitted_adm_opens[num_adm_permitted_opens].listen_path = NULL;
+ permitted_adm_opens[num_adm_permitted_opens].listen_port = 0;
+ return ++num_adm_permitted_opens;
+}
+
+void
+channel_disable_adm_local_opens(void)
+{
+ channel_clear_adm_permitted_opens();
+ permitted_adm_opens = xcalloc(sizeof(*permitted_adm_opens), 1);
+ permitted_adm_opens[num_adm_permitted_opens].host_to_connect = NULL;
+ num_adm_permitted_opens = 1;
+}
+
+void
+channel_clear_permitted_opens(void)
+{
+ int i;
+
+ for (i = 0; i < num_permitted_opens; i++) {
+ free(permitted_opens[i].host_to_connect);
+ free(permitted_opens[i].listen_host);
+ free(permitted_opens[i].listen_path);
+ }
+ free(permitted_opens);
+ permitted_opens = NULL;
+ num_permitted_opens = 0;
+}
+
+void
+channel_clear_adm_permitted_opens(void)
+{
+ int i;
+
+ for (i = 0; i < num_adm_permitted_opens; i++) {
+ free(permitted_adm_opens[i].host_to_connect);
+ free(permitted_adm_opens[i].listen_host);
+ free(permitted_adm_opens[i].listen_path);
+ }
+ free(permitted_adm_opens);
+ permitted_adm_opens = NULL;
+ num_adm_permitted_opens = 0;
+}
+
+void
+channel_print_adm_permitted_opens(void)
+{
+ int i;
+
+ printf("permitopen");
+ if (num_adm_permitted_opens == 0) {
+ printf(" any\n");
+ return;
+ }
+ for (i = 0; i < num_adm_permitted_opens; i++)
+ if (permitted_adm_opens[i].host_to_connect == NULL)
+ printf(" none");
+ else
+ printf(" %s:%d", permitted_adm_opens[i].host_to_connect,
+ permitted_adm_opens[i].port_to_connect);
+ printf("\n");
+}
+
+/* returns port number, FWD_PERMIT_ANY_PORT or -1 on error */
+int
+permitopen_port(const char *p)
+{
+ int port;
+
+ if (strcmp(p, "*") == 0)
+ return FWD_PERMIT_ANY_PORT;
+ if ((port = a2port(p)) > 0)
+ return port;
+ return -1;
+}
+
+/* Try to start non-blocking connect to next host in cctx list */
+static int
+connect_next(struct channel_connect *cctx)
+{
+ int sock, saved_errno;
+ struct sockaddr_un *sunaddr;
+ char ntop[NI_MAXHOST], strport[MAXIMUM(NI_MAXSERV,sizeof(sunaddr->sun_path))];
+
+ for (; cctx->ai; cctx->ai = cctx->ai->ai_next) {
+ switch (cctx->ai->ai_family) {
+ case AF_UNIX:
+ /* unix:pathname instead of host:port */
+ sunaddr = (struct sockaddr_un *)cctx->ai->ai_addr;
+ strlcpy(ntop, "unix", sizeof(ntop));
+ strlcpy(strport, sunaddr->sun_path, sizeof(strport));
+ break;
+ case AF_INET:
+ case AF_INET6:
+ if (getnameinfo(cctx->ai->ai_addr, cctx->ai->ai_addrlen,
+ ntop, sizeof(ntop), strport, sizeof(strport),
+ NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
+ error("connect_next: getnameinfo failed");
+ continue;
+ }
+ break;
+ default:
+ continue;
+ }
+ if ((sock = socket(cctx->ai->ai_family, cctx->ai->ai_socktype,
+ cctx->ai->ai_protocol)) == -1) {
+ if (cctx->ai->ai_next == NULL)
+ error("socket: %.100s", strerror(errno));
+ else
+ verbose("socket: %.100s", strerror(errno));
+ continue;
+ }
+ if (set_nonblock(sock) == -1)
+ fatal("%s: set_nonblock(%d)", __func__, sock);
+ if (connect(sock, cctx->ai->ai_addr,
+ cctx->ai->ai_addrlen) == -1 && errno != EINPROGRESS) {
+ debug("connect_next: host %.100s ([%.100s]:%s): "
+ "%.100s", cctx->host, ntop, strport,
+ strerror(errno));
+ saved_errno = errno;
+ close(sock);
+ errno = saved_errno;
+ continue; /* fail -- try next */
+ }
+ if (cctx->ai->ai_family != AF_UNIX)
+ set_nodelay(sock);
+ debug("connect_next: host %.100s ([%.100s]:%s) "
+ "in progress, fd=%d", cctx->host, ntop, strport, sock);
+ cctx->ai = cctx->ai->ai_next;
+ return sock;
+ }
+ return -1;
+}
+
+static void
+channel_connect_ctx_free(struct channel_connect *cctx)
+{
+ free(cctx->host);
+ if (cctx->aitop) {
+ if (cctx->aitop->ai_family == AF_UNIX)
+ free(cctx->aitop);
+ else
+ freeaddrinfo(cctx->aitop);
+ }
+ memset(cctx, 0, sizeof(*cctx));
+}
+
+/* Return CONNECTING channel to remote host:port or local socket path */
+static Channel *
+connect_to(const char *name, int port, char *ctype, char *rname)
+{
+ struct addrinfo hints;
+ int gaierr;
+ int sock = -1;
+ char strport[NI_MAXSERV];
+ struct channel_connect cctx;
+ Channel *c;
+
+ memset(&cctx, 0, sizeof(cctx));
+
+ if (port == PORT_STREAMLOCAL) {
+ struct sockaddr_un *sunaddr;
+ struct addrinfo *ai;
+
+ if (strlen(name) > sizeof(sunaddr->sun_path)) {
+ error("%.100s: %.100s", name, strerror(ENAMETOOLONG));
+ return (NULL);
+ }
+
+ /*
+ * Fake up a struct addrinfo for AF_UNIX connections.
+ * channel_connect_ctx_free() must check ai_family
+ * and use free() not freeaddirinfo() for AF_UNIX.
+ */
+ ai = xmalloc(sizeof(*ai) + sizeof(*sunaddr));
+ memset(ai, 0, sizeof(*ai) + sizeof(*sunaddr));
+ ai->ai_addr = (struct sockaddr *)(ai + 1);
+ ai->ai_addrlen = sizeof(*sunaddr);
+ ai->ai_family = AF_UNIX;
+ ai->ai_socktype = SOCK_STREAM;
+ ai->ai_protocol = PF_UNSPEC;
+ sunaddr = (struct sockaddr_un *)ai->ai_addr;
+ sunaddr->sun_family = AF_UNIX;
+ strlcpy(sunaddr->sun_path, name, sizeof(sunaddr->sun_path));
+ cctx.aitop = ai;
+ } else {
+ memset(&hints, 0, sizeof(hints));
+ hints.ai_family = IPv4or6;
+ hints.ai_socktype = SOCK_STREAM;
+ snprintf(strport, sizeof strport, "%d", port);
+ if ((gaierr = getaddrinfo(name, strport, &hints, &cctx.aitop)) != 0) {
+ error("connect_to %.100s: unknown host (%s)", name,
+ ssh_gai_strerror(gaierr));
+ return NULL;
+ }
+ }
+
+ cctx.host = xstrdup(name);
+ cctx.port = port;
+ cctx.ai = cctx.aitop;
+
+ if ((sock = connect_next(&cctx)) == -1) {
+ error("connect to %.100s port %d failed: %s",
+ name, port, strerror(errno));
+ channel_connect_ctx_free(&cctx);
+ return NULL;
+ }
+ c = channel_new(ctype, SSH_CHANNEL_CONNECTING, sock, sock, -1,
+ CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0, rname, 1);
+ c->connect_ctx = cctx;
+ return c;
+}
+
+/*
+ * returns either the newly connected channel or the downstream channel
+ * that needs to deal with this connection.
+ */
+Channel *
+channel_connect_by_listen_address(const char *listen_host,
+ u_short listen_port, char *ctype, char *rname)
+{
+ int i;
+
+ for (i = 0; i < num_permitted_opens; i++) {
+ if (open_listen_match_tcpip(&permitted_opens[i], listen_host,
+ listen_port, 1)) {
+ if (permitted_opens[i].downstream)
+ return permitted_opens[i].downstream;
+ return connect_to(
+ permitted_opens[i].host_to_connect,
+ permitted_opens[i].port_to_connect, ctype, rname);
+ }
+ }
+ error("WARNING: Server requests forwarding for unknown listen_port %d",
+ listen_port);
+ return NULL;
+}
+
+Channel *
+channel_connect_by_listen_path(const char *path, char *ctype, char *rname)
+{
+ int i;
+
+ for (i = 0; i < num_permitted_opens; i++) {
+ if (open_listen_match_streamlocal(&permitted_opens[i], path)) {
+ return connect_to(
+ permitted_opens[i].host_to_connect,
+ permitted_opens[i].port_to_connect, ctype, rname);
+ }
+ }
+ error("WARNING: Server requests forwarding for unknown path %.100s",
+ path);
+ return NULL;
+}
+
+/* Check if connecting to that port is permitted and connect. */
+Channel *
+channel_connect_to_port(const char *host, u_short port, char *ctype, char *rname)
+{
+ int i, permit, permit_adm = 1;
+
+ permit = all_opens_permitted;
+ if (!permit) {
+ for (i = 0; i < num_permitted_opens; i++)
+ if (open_match(&permitted_opens[i], host, port)) {
+ permit = 1;
+ break;
+ }
+ }
+
+ if (num_adm_permitted_opens > 0) {
+ permit_adm = 0;
+ for (i = 0; i < num_adm_permitted_opens; i++)
+ if (open_match(&permitted_adm_opens[i], host, port)) {
+ permit_adm = 1;
+ break;
+ }
+ }
+
+ if (!permit || !permit_adm) {
+ logit("Received request to connect to host %.100s port %d, "
+ "but the request was denied.", host, port);
+ return NULL;
+ }
+ return connect_to(host, port, ctype, rname);
+}
+
+/* Check if connecting to that path is permitted and connect. */
+Channel *
+channel_connect_to_path(const char *path, char *ctype, char *rname)
+{
+ int i, permit, permit_adm = 1;
+
+ permit = all_opens_permitted;
+ if (!permit) {
+ for (i = 0; i < num_permitted_opens; i++)
+ if (open_match(&permitted_opens[i], path, PORT_STREAMLOCAL)) {
+ permit = 1;
+ break;
+ }
+ }
+
+ if (num_adm_permitted_opens > 0) {
+ permit_adm = 0;
+ for (i = 0; i < num_adm_permitted_opens; i++)
+ if (open_match(&permitted_adm_opens[i], path, PORT_STREAMLOCAL)) {
+ permit_adm = 1;
+ break;
+ }
+ }
+
+ if (!permit || !permit_adm) {
+ logit("Received request to connect to path %.100s, "
+ "but the request was denied.", path);
+ return NULL;
+ }
+ return connect_to(path, PORT_STREAMLOCAL, ctype, rname);
+}
+
+void
+channel_send_window_changes(void)
+{
+ u_int i;
+ struct winsize ws;
+
+ for (i = 0; i < channels_alloc; i++) {
+ if (channels[i] == NULL || !channels[i]->client_tty ||
+ channels[i]->type != SSH_CHANNEL_OPEN)
+ continue;
+ if (ioctl(channels[i]->rfd, TIOCGWINSZ, &ws) < 0)
+ continue;
+ channel_request_start(i, "window-change", 0);
+ packet_put_int((u_int)ws.ws_col);
+ packet_put_int((u_int)ws.ws_row);
+ packet_put_int((u_int)ws.ws_xpixel);
+ packet_put_int((u_int)ws.ws_ypixel);
+ packet_send();
+ }
+}
+
+/* -- X11 forwarding */
+
+/*
+ * Creates an internet domain socket for listening for X11 connections.
+ * Returns 0 and a suitable display number for the DISPLAY variable
+ * stored in display_numberp , or -1 if an error occurs.
+ */
+int
+x11_create_display_inet(int x11_display_offset, int x11_use_localhost,
+ int single_connection, u_int *display_numberp, int **chanids)
+{
+ Channel *nc = NULL;
+ int display_number, sock;
+ u_short port;
+ struct addrinfo hints, *ai, *aitop;
+ char strport[NI_MAXSERV];
+ int gaierr, n, num_socks = 0, socks[NUM_SOCKS];
+
+ if (chanids == NULL)
+ return -1;
+
+ for (display_number = x11_display_offset;
+ display_number < MAX_DISPLAYS;
+ display_number++) {
+ port = 6000 + display_number;
+ memset(&hints, 0, sizeof(hints));
+ hints.ai_family = IPv4or6;
+ hints.ai_flags = x11_use_localhost ? 0: AI_PASSIVE;
+ hints.ai_socktype = SOCK_STREAM;
+ snprintf(strport, sizeof strport, "%d", port);
+ if ((gaierr = getaddrinfo(NULL, strport, &hints, &aitop)) != 0) {
+ error("getaddrinfo: %.100s", ssh_gai_strerror(gaierr));
+ return -1;
+ }
+ for (ai = aitop; ai; ai = ai->ai_next) {
+ if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
+ continue;
+ sock = socket(ai->ai_family, ai->ai_socktype,
+ ai->ai_protocol);
+ if (sock < 0) {
+ if ((errno != EINVAL) && (errno != EAFNOSUPPORT)
+#ifdef EPFNOSUPPORT
+ && (errno != EPFNOSUPPORT)
+#endif
+ ) {
+ error("socket: %.100s", strerror(errno));
+ freeaddrinfo(aitop);
+ return -1;
+ } else {
+ debug("x11_create_display_inet: Socket family %d not supported",
+ ai->ai_family);
+ continue;
+ }
+ }
+ if (ai->ai_family == AF_INET6)
+ sock_set_v6only(sock);
+ if (x11_use_localhost)
+ channel_set_reuseaddr(sock);
+ if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
+ debug2("bind port %d: %.100s", port, strerror(errno));
+ close(sock);
+
+ for (n = 0; n < num_socks; n++) {
+ close(socks[n]);
+ }
+ num_socks = 0;
+ break;
+ }
+ socks[num_socks++] = sock;
+ if (num_socks == NUM_SOCKS)
+ break;
+ }
+ freeaddrinfo(aitop);
+ if (num_socks > 0)
+ break;
+ }
+ if (display_number >= MAX_DISPLAYS) {
+ error("Failed to allocate internet-domain X11 display socket.");
+ return -1;
+ }
+ /* Start listening for connections on the socket. */
+ for (n = 0; n < num_socks; n++) {
+ sock = socks[n];
+ if (listen(sock, SSH_LISTEN_BACKLOG) < 0) {
+ error("listen: %.100s", strerror(errno));
+ close(sock);
+ return -1;
+ }
+ }
+
+ /* Allocate a channel for each socket. */
+ *chanids = xcalloc(num_socks + 1, sizeof(**chanids));
+ for (n = 0; n < num_socks; n++) {
+ sock = socks[n];
+ nc = channel_new("x11 listener",
+ SSH_CHANNEL_X11_LISTENER, sock, sock, -1,
+ CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
+ 0, "X11 inet listener", 1);
+ nc->single_connection = single_connection;
+ (*chanids)[n] = nc->self;
+ }
+ (*chanids)[n] = -1;
+
+ /* Return the display number for the DISPLAY environment variable. */
+ *display_numberp = display_number;
+ return (0);
+}
+
+static int
+connect_local_xsocket_path(const char *pathname)
+{
+ int sock;
+ struct sockaddr_un addr;
+
+ sock = socket(AF_UNIX, SOCK_STREAM, 0);
+ if (sock < 0)
+ error("socket: %.100s", strerror(errno));
+ memset(&addr, 0, sizeof(addr));
+ addr.sun_family = AF_UNIX;
+ strlcpy(addr.sun_path, pathname, sizeof addr.sun_path);
+ if (connect(sock, (struct sockaddr *)&addr, sizeof(addr)) == 0)
+ return sock;
+ close(sock);
+ error("connect %.100s: %.100s", addr.sun_path, strerror(errno));
+ return -1;
+}
+
+static int
+connect_local_xsocket(u_int dnr)
+{
+ char buf[1024];
+ snprintf(buf, sizeof buf, _PATH_UNIX_X, dnr);
+ return connect_local_xsocket_path(buf);
+}
+
+int
+x11_connect_display(void)
+{
+ u_int display_number;
+ const char *display;
+ char buf[1024], *cp;
+ struct addrinfo hints, *ai, *aitop;
+ char strport[NI_MAXSERV];
+ int gaierr, sock = 0;
+
+ /* Try to open a socket for the local X server. */
+ display = getenv("DISPLAY");
+ if (!display) {
+ error("DISPLAY not set.");
+ return -1;
+ }
+ /*
+ * Now we decode the value of the DISPLAY variable and make a
+ * connection to the real X server.
+ */
+
+ /* Check if the display is from launchd. */
+#ifdef __APPLE__
+ if (strncmp(display, "/tmp/launch", 11) == 0) {
+ sock = connect_local_xsocket_path(display);
+ if (sock < 0)
+ return -1;
+
+ /* OK, we now have a connection to the display. */
+ return sock;
+ }
+#endif
+ /*
+ * Check if it is a unix domain socket. Unix domain displays are in
+ * one of the following formats: unix:d[.s], :d[.s], ::d[.s]
+ */
+ if (strncmp(display, "unix:", 5) == 0 ||
+ display[0] == ':') {
+ /* Connect to the unix domain socket. */
+ if (sscanf(strrchr(display, ':') + 1, "%u", &display_number) != 1) {
+ error("Could not parse display number from DISPLAY: %.100s",
+ display);
+ return -1;
+ }
+ /* Create a socket. */
+ sock = connect_local_xsocket(display_number);
+ if (sock < 0)
+ return -1;
+
+ /* OK, we now have a connection to the display. */
+ return sock;
+ }
+ /*
+ * Connect to an inet socket. The DISPLAY value is supposedly
+ * hostname:d[.s], where hostname may also be numeric IP address.
+ */
+ strlcpy(buf, display, sizeof(buf));
+ cp = strchr(buf, ':');
+ if (!cp) {
+ error("Could not find ':' in DISPLAY: %.100s", display);
+ return -1;
+ }
+ *cp = 0;
+ /* buf now contains the host name. But first we parse the display number. */
+ if (sscanf(cp + 1, "%u", &display_number) != 1) {
+ error("Could not parse display number from DISPLAY: %.100s",
+ display);
+ return -1;
+ }
+
+ /* Look up the host address */
+ memset(&hints, 0, sizeof(hints));
+ hints.ai_family = IPv4or6;
+ hints.ai_socktype = SOCK_STREAM;
+ snprintf(strport, sizeof strport, "%u", 6000 + display_number);
+ if ((gaierr = getaddrinfo(buf, strport, &hints, &aitop)) != 0) {
+ error("%.100s: unknown host. (%s)", buf,
+ ssh_gai_strerror(gaierr));
+ return -1;
+ }
+ for (ai = aitop; ai; ai = ai->ai_next) {
+ /* Create a socket. */
+ sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
+ if (sock < 0) {
+ debug2("socket: %.100s", strerror(errno));
+ continue;
+ }
+ /* Connect it to the display. */
+ if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
+ debug2("connect %.100s port %u: %.100s", buf,
+ 6000 + display_number, strerror(errno));
+ close(sock);
+ continue;
+ }
+ /* Success */
+ break;
+ }
+ freeaddrinfo(aitop);
+ if (!ai) {
+ error("connect %.100s port %u: %.100s", buf, 6000 + display_number,
+ strerror(errno));
+ return -1;
+ }
+ set_nodelay(sock);
+ return sock;
+}
+
+/*
+ * This is called when SSH_SMSG_X11_OPEN is received. The packet contains
+ * the remote channel number. We should do whatever we want, and respond
+ * with either SSH_MSG_OPEN_CONFIRMATION or SSH_MSG_OPEN_FAILURE.
+ */
+
+/* ARGSUSED */
+int
+x11_input_open(int type, u_int32_t seq, void *ctxt)
+{
+ Channel *c = NULL;
+ int remote_id, sock = 0;
+ char *remote_host;
+
+ debug("Received X11 open request.");
+
+ remote_id = packet_get_int();
+
+ if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {
+ remote_host = packet_get_string(NULL);
+ } else {
+ remote_host = xstrdup("unknown (remote did not supply name)");
+ }
+ packet_check_eom();
+
+ /* Obtain a connection to the real X display. */
+ sock = x11_connect_display();
+ if (sock != -1) {
+ /* Allocate a channel for this connection. */
+ c = channel_new("connected x11 socket",
+ SSH_CHANNEL_X11_OPEN, sock, sock, -1, 0, 0, 0,
+ remote_host, 1);
+ c->remote_id = remote_id;
+ c->force_drain = 1;
+ }
+ free(remote_host);
+ if (c == NULL) {
+ /* Send refusal to the remote host. */
+ packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
+ packet_put_int(remote_id);
+ } else {
+ /* Send a confirmation to the remote host. */
+ packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
+ packet_put_int(remote_id);
+ packet_put_int(c->self);
+ }
+ packet_send();
+ return 0;
+}
+
+/* dummy protocol handler that denies SSH-1 requests (agent/x11) */
+/* ARGSUSED */
+int
+deny_input_open(int type, u_int32_t seq, void *ctxt)
+{
+ int rchan = packet_get_int();
+
+ switch (type) {
+ case SSH_SMSG_AGENT_OPEN:
+ error("Warning: ssh server tried agent forwarding.");
+ break;
+ case SSH_SMSG_X11_OPEN:
+ error("Warning: ssh server tried X11 forwarding.");
+ break;
+ default:
+ error("deny_input_open: type %d", type);
+ break;
+ }
+ error("Warning: this is probably a break-in attempt by a malicious server.");
+ packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
+ packet_put_int(rchan);
+ packet_send();
+ return 0;
+}
+
+/*
+ * Requests forwarding of X11 connections, generates fake authentication
+ * data, and enables authentication spoofing.
+ * This should be called in the client only.
+ */
+void
+x11_request_forwarding_with_spoofing(int client_session_id, const char *disp,
+ const char *proto, const char *data, int want_reply)
+{
+ u_int data_len = (u_int) strlen(data) / 2;
+ u_int i, value;
+ char *new_data;
+ int screen_number;
+ const char *cp;
+
+ if (x11_saved_display == NULL)
+ x11_saved_display = xstrdup(disp);
+ else if (strcmp(disp, x11_saved_display) != 0) {
+ error("x11_request_forwarding_with_spoofing: different "
+ "$DISPLAY already forwarded");
+ return;
+ }
+
+ cp = strchr(disp, ':');
+ if (cp)
+ cp = strchr(cp, '.');
+ if (cp)
+ screen_number = (u_int)strtonum(cp + 1, 0, 400, NULL);
+ else
+ screen_number = 0;
+
+ if (x11_saved_proto == NULL) {
+ /* Save protocol name. */
+ x11_saved_proto = xstrdup(proto);
+
+ /* Extract real authentication data. */
+ x11_saved_data = xmalloc(data_len);
+ for (i = 0; i < data_len; i++) {
+ if (sscanf(data + 2 * i, "%2x", &value) != 1)
+ fatal("x11_request_forwarding: bad "
+ "authentication data: %.100s", data);
+ x11_saved_data[i] = value;
+ }
+ x11_saved_data_len = data_len;
+
+ /* Generate fake data of the same length. */
+ x11_fake_data = xmalloc(data_len);
+ arc4random_buf(x11_fake_data, data_len);
+ x11_fake_data_len = data_len;
+ }
+
+ /* Convert the fake data into hex. */
+ new_data = tohex(x11_fake_data, data_len);
+
+ /* Send the request packet. */
+ if (compat20) {
+ channel_request_start(client_session_id, "x11-req", want_reply);
+ packet_put_char(0); /* XXX bool single connection */
+ } else {
+ packet_start(SSH_CMSG_X11_REQUEST_FORWARDING);
+ }
+ packet_put_cstring(proto);
+ packet_put_cstring(new_data);
+ packet_put_int(screen_number);
+ packet_send();
+ packet_write_wait();
+ free(new_data);
+}
+
+
+/* -- agent forwarding */
+
+/* Sends a message to the server to request authentication fd forwarding. */
+
+void
+auth_request_forwarding(void)
+{
+ packet_start(SSH_CMSG_AGENT_REQUEST_FORWARDING);
+ packet_send();
+ packet_write_wait();
+}
projects / thirdparty / openssh-portable.git / commitdiff
