X-Git-Url: http://andersk.mit.edu/gitweb/openssh.git/blobdiff_plain/a7effaacb5466dda6b608606b96a129ab852db82..02a024ddde7f5c272fdea020b633b86f65b29ff8:/channels.c diff --git a/channels.c b/channels.c index c1ddf8c5..354160e8 100644 --- a/channels.c +++ b/channels.c @@ -1,35 +1,65 @@ /* - * - * channels.c - * * Author: Tatu Ylonen - * * Copyright (c) 1995 Tatu Ylonen , Espoo, Finland * All rights reserved - * - * Created: Fri Mar 24 16:35:24 1995 ylo - * * This file contains functions for generic socket connection forwarding. * There is also code for initiating connection forwarding for X11 connections, * arbitrary tcp/ip connections, and the authentication agent connection. - * + * + * As far as I am concerned, the code I have written for this software + * can be used freely for any purpose. Any derived versions of this + * software must be clearly marked as such, and if the derived work is + * incompatible with the protocol description in the RFC file, it must be + * called by a name other than "ssh" or "Secure Shell". + * + * + * SSH2 support added by Markus Friedl. + * Copyright (c) 1999,2000 Markus Friedl. All rights reserved. + * Copyright (c) 1999 Dug Song. All rights reserved. + * Copyright (c) 1999 Theo de Raadt. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR + * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES + * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. + * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT + * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF + * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ #include "includes.h" -RCSID("$Id$"); +RCSID("$OpenBSD: channels.c,v 1.89 2001/02/04 15:32:23 stevesk Exp $"); + +#include +#include #include "ssh.h" +#include "ssh1.h" +#include "ssh2.h" #include "packet.h" #include "xmalloc.h" #include "buffer.h" -#include "authfd.h" #include "uidswap.h" -#include "readconf.h" -#include "servconf.h" - +#include "log.h" +#include "misc.h" #include "channels.h" #include "nchan.h" #include "compat.h" +#include "canohost.h" +#include "key.h" +#include "authfd.h" /* Maximum number of fake X11 displays to try. */ #define MAX_DISPLAYS 1000 @@ -54,7 +84,7 @@ static int channels_alloc = 0; * Maximum file descriptor value used in any of the channels. This is * updated in channel_allocate. */ -static int channel_max_fd_value = 0; +static int channel_max_fd = 0; /* Name and directory of socket for authentication agent forwarding. */ static char *channel_forwarded_auth_socket_name = NULL; @@ -65,14 +95,14 @@ char *x11_saved_proto = NULL; /* Saved X11 authentication data. This is the real data. */ char *x11_saved_data = NULL; -unsigned int x11_saved_data_len = 0; +u_int x11_saved_data_len = 0; /* * Fake X11 authentication data. This is what the server will be sending us; * we should replace any occurrences of this by the real data. */ char *x11_fake_data = NULL; -unsigned int x11_fake_data_len; +u_int x11_fake_data_len; /* * Data structure for storing which hosts are permitted for forward requests. @@ -81,8 +111,9 @@ unsigned int x11_fake_data_len; * network (which might be behind a firewall). */ typedef struct { - char *host; /* Host name. */ - u_short port; /* Port number. */ + char *host_to_connect; /* Connect to 'host'. */ + u_short port_to_connect; /* Connect to 'port'. */ + u_short listen_port; /* Remote side should listen port number. */ } ForwardPermission; /* List of all permitted host/port pairs to connect. */ @@ -99,9 +130,12 @@ static int all_opens_permitted = 0; /* This is set to true if both sides support SSH_PROTOFLAG_HOST_IN_FWD_OPEN. */ static int have_hostname_in_open = 0; +/* AF_UNSPEC or AF_INET or AF_INET6 */ +extern int IPv4or6; + /* Sets specific protocol options. */ -void +void channel_set_options(int hostname_in_open) { have_hostname_in_open = hostname_in_open; @@ -113,30 +147,78 @@ channel_set_options(int hostname_in_open) * and the server has no way to know but to trust the client anyway. */ -void +void channel_permit_all_opens() { all_opens_permitted = 1; } +/* lookup channel by id */ + +Channel * +channel_lookup(int id) +{ + Channel *c; + if (id < 0 || id > channels_alloc) { + log("channel_lookup: %d: bad id", id); + return NULL; + } + c = &channels[id]; + if (c->type == SSH_CHANNEL_FREE) { + log("channel_lookup: %d: bad id: channel free", id); + return NULL; + } + return c; +} + +/* + * Register filedescriptors for a channel, used when allocating a channel or + * when the channel consumer/producer is ready, e.g. shell exec'd + */ + +void +channel_register_fds(Channel *c, int rfd, int wfd, int efd, + int extusage, int nonblock) +{ + /* Update the maximum file descriptor value. */ + channel_max_fd = MAX(channel_max_fd, rfd); + channel_max_fd = MAX(channel_max_fd, wfd); + channel_max_fd = MAX(channel_max_fd, efd); + + /* XXX set close-on-exec -markus */ + + c->rfd = rfd; + c->wfd = wfd; + c->sock = (rfd == wfd) ? rfd : -1; + c->efd = efd; + c->extended_usage = extusage; + + /* 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. */ -int -channel_allocate(int type, int sock, char *remote_name) +int +channel_new(char *ctype, int type, int rfd, int wfd, int efd, + int window, int maxpack, int extusage, char *remote_name, int nonblock) { int i, found; Channel *c; - /* Update the maximum file descriptor value. */ - if (sock > channel_max_fd_value) - channel_max_fd_value = sock; - /* XXX set close-on-exec -markus */ - /* Do initial allocation if this is the first call. */ if (channels_alloc == 0) { + chan_init(); channels_alloc = 10; channels = xmalloc(channels_alloc * sizeof(Channel)); for (i = 0; i < channels_alloc; i++) @@ -158,7 +240,7 @@ channel_allocate(int type, int sock, char *remote_name) /* There are no free slots. Take last+1 slot and expand the array. */ found = channels_alloc; channels_alloc += 10; - debug("channel: expanding %d", channels_alloc); + debug2("channel: expanding %d", channels_alloc); channels = xrealloc(channels, channels_alloc * sizeof(Channel)); for (i = found; i < channels_alloc; i++) channels[i].type = SSH_CHANNEL_FREE; @@ -167,402 +249,831 @@ channel_allocate(int type, int sock, char *remote_name) c = &channels[found]; buffer_init(&c->input); buffer_init(&c->output); + buffer_init(&c->extended); chan_init_iostates(c); + channel_register_fds(c, rfd, wfd, efd, extusage, nonblock); c->self = found; c->type = type; - c->sock = sock; + c->ctype = ctype; + c->local_window = window; + c->local_window_max = window; + c->local_consumed = 0; + c->local_maxpacket = maxpack; c->remote_id = -1; c->remote_name = remote_name; + c->remote_window = 0; + c->remote_maxpacket = 0; + c->cb_fn = NULL; + c->cb_arg = NULL; + c->cb_event = 0; + c->dettach_user = NULL; + c->input_filter = NULL; debug("channel %d: new [%s]", found, remote_name); return found; } +/* old interface XXX */ +int +channel_allocate(int type, int sock, char *remote_name) +{ + return channel_new("", type, sock, sock, -1, 0, 0, 0, remote_name, 1); +} + -/* Free the channel and close its socket. */ +/* Close all channel fd/socket. */ -void -channel_free(int channel) +void +channel_close_fds(Channel *c) { - if (channel < 0 || channel >= channels_alloc || - channels[channel].type == SSH_CHANNEL_FREE) - packet_disconnect("channel free: bad local channel %d", channel); + if (c->sock != -1) { + close(c->sock); + c->sock = -1; + } + if (c->rfd != -1) { + close(c->rfd); + c->rfd = -1; + } + if (c->wfd != -1) { + close(c->wfd); + c->wfd = -1; + } + if (c->efd != -1) { + close(c->efd); + c->efd = -1; + } +} + +/* Free the channel and close its fd/socket. */ - if (compat13) - shutdown(channels[channel].sock, SHUT_RDWR); - close(channels[channel].sock); - buffer_free(&channels[channel].input); - buffer_free(&channels[channel].output); - channels[channel].type = SSH_CHANNEL_FREE; - if (channels[channel].remote_name) { - xfree(channels[channel].remote_name); - channels[channel].remote_name = NULL; +void +channel_free(int id) +{ + Channel *c = channel_lookup(id); + char *s = channel_open_message(); + + if (c == NULL) + packet_disconnect("channel free: bad local channel %d", id); + debug("channel_free: channel %d: status: %s", id, s); + xfree(s); + + if (c->dettach_user != NULL) { + debug("channel_free: channel %d: dettaching channel user", id); + c->dettach_user(c->self, NULL); + } + if (c->sock != -1) + shutdown(c->sock, SHUT_RDWR); + channel_close_fds(c); + buffer_free(&c->input); + buffer_free(&c->output); + buffer_free(&c->extended); + c->type = SSH_CHANNEL_FREE; + if (c->remote_name) { + xfree(c->remote_name); + c->remote_name = NULL; } } /* - * This is called just before select() to add any bits relevant to channels - * in the select bitmasks. + * 'channel_pre*' are called just before select() to add any bits relevant to + * channels in the select bitmasks. + */ +/* + * 'channel_post*': perform any appropriate operations for channels which + * have events pending. */ +typedef void chan_fn(Channel *c, fd_set * readset, fd_set * writeset); +chan_fn *channel_pre[SSH_CHANNEL_MAX_TYPE]; +chan_fn *channel_post[SSH_CHANNEL_MAX_TYPE]; -void -channel_prepare_select(fd_set * readset, fd_set * writeset) +void +channel_pre_listener(Channel *c, fd_set * readset, fd_set * writeset) { - int i; - Channel *ch; - unsigned char *ucp; - unsigned int proto_len, data_len; + FD_SET(c->sock, readset); +} - for (i = 0; i < channels_alloc; i++) { - ch = &channels[i]; -redo: - switch (ch->type) { - case SSH_CHANNEL_X11_LISTENER: - case SSH_CHANNEL_PORT_LISTENER: - case SSH_CHANNEL_AUTH_SOCKET: - FD_SET(ch->sock, readset); - break; +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); +} - case SSH_CHANNEL_OPEN: - if (compat13) { - if (buffer_len(&ch->input) < packet_get_maxsize()) - FD_SET(ch->sock, readset); - if (buffer_len(&ch->output) > 0) - FD_SET(ch->sock, writeset); - break; - } - /* test whether sockets are 'alive' for read/write */ - if (ch->istate == CHAN_INPUT_OPEN) - if (buffer_len(&ch->input) < packet_get_maxsize()) - FD_SET(ch->sock, readset); - if (ch->ostate == CHAN_OUTPUT_OPEN || - ch->ostate == CHAN_OUTPUT_WAIT_DRAIN) { - if (buffer_len(&ch->output) > 0) { - FD_SET(ch->sock, writeset); - } else if (ch->ostate == CHAN_OUTPUT_WAIT_DRAIN) { - chan_obuf_empty(ch); - } - } - break; +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); +} - case SSH_CHANNEL_INPUT_DRAINING: - if (!compat13) - fatal("cannot happen: IN_DRAIN"); - if (buffer_len(&ch->input) == 0) { - packet_start(SSH_MSG_CHANNEL_CLOSE); - packet_put_int(ch->remote_id); - packet_send(); - ch->type = SSH_CHANNEL_CLOSED; - debug("Closing channel %d after input drain.", i); - break; - } - break; +void +channel_pre_open_15(Channel *c, fd_set * readset, fd_set * writeset) +{ + /* test whether sockets are 'alive' for read/write */ + if (c->istate == CHAN_INPUT_OPEN) + if (buffer_len(&c->input) < packet_get_maxsize()) + FD_SET(c->sock, readset); + if (c->ostate == CHAN_OUTPUT_OPEN || + c->ostate == CHAN_OUTPUT_WAIT_DRAIN) { + if (buffer_len(&c->output) > 0) { + FD_SET(c->sock, writeset); + } else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN) { + chan_obuf_empty(c); + } + } +} - case SSH_CHANNEL_OUTPUT_DRAINING: - if (!compat13) - fatal("cannot happen: OUT_DRAIN"); - if (buffer_len(&ch->output) == 0) { - channel_free(i); - break; - } - FD_SET(ch->sock, writeset); - break; +void +channel_pre_open_20(Channel *c, fd_set * readset, fd_set * writeset) +{ + if (c->istate == CHAN_INPUT_OPEN && + c->remote_window > 0 && + buffer_len(&c->input) < c->remote_window) + FD_SET(c->rfd, readset); + if (c->ostate == CHAN_OUTPUT_OPEN || + c->ostate == CHAN_OUTPUT_WAIT_DRAIN) { + if (buffer_len(&c->output) > 0) { + FD_SET(c->wfd, writeset); + } else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN) { + chan_obuf_empty(c); + } + } + /** XXX check close conditions, too */ + if (c->efd != -1) { + if (c->extended_usage == CHAN_EXTENDED_WRITE && + buffer_len(&c->extended) > 0) + FD_SET(c->efd, writeset); + else if (c->extended_usage == CHAN_EXTENDED_READ && + buffer_len(&c->extended) < c->remote_window) + FD_SET(c->efd, readset); + } +} - case SSH_CHANNEL_X11_OPEN: - /* - * This is a special state for X11 authentication - * spoofing. An opened X11 connection (when - * authentication spoofing is being done) remains in - * this state until the first packet has been - * completely read. The authentication data in that - * packet is then substituted by the real data if it - * matches the fake data, and the channel is put into - * normal mode. - */ - /* Check if the fixed size part of the packet is in buffer. */ - if (buffer_len(&ch->output) < 12) - break; +void +channel_pre_input_draining(Channel *c, fd_set * readset, fd_set * writeset) +{ + if (buffer_len(&c->input) == 0) { + packet_start(SSH_MSG_CHANNEL_CLOSE); + packet_put_int(c->remote_id); + packet_send(); + c->type = SSH_CHANNEL_CLOSED; + debug("Closing channel %d after input drain.", c->self); + } +} - /* Parse the lengths of variable-length fields. */ - ucp = (unsigned char *) buffer_ptr(&ch->output); - if (ucp[0] == 0x42) { /* Byte order MSB first. */ - proto_len = 256 * ucp[6] + ucp[7]; - data_len = 256 * ucp[8] + ucp[9]; - } else if (ucp[0] == 0x6c) { /* Byte order LSB first. */ - proto_len = ucp[6] + 256 * ucp[7]; - data_len = ucp[8] + 256 * ucp[9]; - } else { - debug("Initial X11 packet contains bad byte order byte: 0x%x", - ucp[0]); - ch->type = SSH_CHANNEL_OPEN; - goto reject; - } +void +channel_pre_output_draining(Channel *c, fd_set * readset, fd_set * writeset) +{ + if (buffer_len(&c->output) == 0) + channel_free(c->self); + else + FD_SET(c->sock, writeset); +} - /* Check if the whole packet is in buffer. */ - if (buffer_len(&ch->output) < - 12 + ((proto_len + 3) & ~3) + ((data_len + 3) & ~3)) - break; +/* + * This is a special state for X11 authentication spoofing. An opened X11 + * connection (when authentication spoofing is being done) remains in this + * state until the first packet has been completely read. The authentication + * data in that packet is then substituted by the real data if it matches the + * fake data, and the channel is put into normal mode. + * XXX All this happens at the client side. + */ +int +x11_open_helper(Channel *c) +{ + u_char *ucp; + u_int proto_len, data_len; + + /* Check if the fixed size part of the packet is in buffer. */ + if (buffer_len(&c->output) < 12) + return 0; + + /* Parse the lengths of variable-length fields. */ + ucp = (u_char *) buffer_ptr(&c->output); + if (ucp[0] == 0x42) { /* Byte order MSB first. */ + proto_len = 256 * ucp[6] + ucp[7]; + data_len = 256 * ucp[8] + ucp[9]; + } else if (ucp[0] == 0x6c) { /* Byte order LSB first. */ + proto_len = ucp[6] + 256 * ucp[7]; + data_len = ucp[8] + 256 * ucp[9]; + } else { + debug("Initial X11 packet contains bad byte order byte: 0x%x", + ucp[0]); + return -1; + } - /* Check if authentication protocol matches. */ - if (proto_len != strlen(x11_saved_proto) || - memcmp(ucp + 12, x11_saved_proto, proto_len) != 0) { - debug("X11 connection uses different authentication protocol."); - ch->type = SSH_CHANNEL_OPEN; - goto reject; - } - /* Check if authentication data matches our fake data. */ - if (data_len != x11_fake_data_len || - memcmp(ucp + 12 + ((proto_len + 3) & ~3), - x11_fake_data, x11_fake_data_len) != 0) { - debug("X11 auth data does not match fake data."); - ch->type = SSH_CHANNEL_OPEN; - goto reject; - } - /* Check fake data length */ - if (x11_fake_data_len != x11_saved_data_len) { - error("X11 fake_data_len %d != saved_data_len %d", - x11_fake_data_len, x11_saved_data_len); - ch->type = SSH_CHANNEL_OPEN; - goto reject; - } - /* - * Received authentication protocol and data match - * our fake data. Substitute the fake data with real - * data. - */ - memcpy(ucp + 12 + ((proto_len + 3) & ~3), - x11_saved_data, x11_saved_data_len); + /* Check if the whole packet is in buffer. */ + if (buffer_len(&c->output) < + 12 + ((proto_len + 3) & ~3) + ((data_len + 3) & ~3)) + return 0; + + /* Check if authentication protocol matches. */ + if (proto_len != strlen(x11_saved_proto) || + memcmp(ucp + 12, x11_saved_proto, proto_len) != 0) { + debug("X11 connection uses different authentication protocol."); + return -1; + } + /* Check if authentication data matches our fake data. */ + if (data_len != x11_fake_data_len || + memcmp(ucp + 12 + ((proto_len + 3) & ~3), + x11_fake_data, x11_fake_data_len) != 0) { + debug("X11 auth data does not match fake data."); + return -1; + } + /* Check fake data length */ + if (x11_fake_data_len != x11_saved_data_len) { + error("X11 fake_data_len %d != saved_data_len %d", + x11_fake_data_len, x11_saved_data_len); + return -1; + } + /* + * Received authentication protocol and data match + * our fake data. Substitute the fake data with real + * data. + */ + memcpy(ucp + 12 + ((proto_len + 3) & ~3), + x11_saved_data, x11_saved_data_len); + return 1; +} - /* Start normal processing for the channel. */ - ch->type = SSH_CHANNEL_OPEN; - goto redo; +void +channel_pre_x11_open_13(Channel *c, fd_set * readset, fd_set * writeset) +{ + int ret = x11_open_helper(c); + if (ret == 1) { + /* Start normal processing for the channel. */ + c->type = SSH_CHANNEL_OPEN; + channel_pre_open_13(c, readset, writeset); + } else if (ret == -1) { + /* + * We have received an X11 connection that has bad + * authentication information. + */ + log("X11 connection rejected because of wrong authentication.\r\n"); + buffer_clear(&c->input); + buffer_clear(&c->output); + close(c->sock); + c->sock = -1; + c->type = SSH_CHANNEL_CLOSED; + packet_start(SSH_MSG_CHANNEL_CLOSE); + packet_put_int(c->remote_id); + packet_send(); + } +} - reject: - /* - * We have received an X11 connection that has bad - * authentication information. - */ - log("X11 connection rejected because of wrong authentication.\r\n"); - buffer_clear(&ch->input); - buffer_clear(&ch->output); - if (compat13) { - close(ch->sock); - ch->sock = -1; - ch->type = SSH_CHANNEL_CLOSED; - packet_start(SSH_MSG_CHANNEL_CLOSE); - packet_put_int(ch->remote_id); - packet_send(); +void +channel_pre_x11_open(Channel *c, fd_set * readset, fd_set * writeset) +{ + int ret = x11_open_helper(c); + if (ret == 1) { + c->type = SSH_CHANNEL_OPEN; + if (compat20) + channel_pre_open_20(c, readset, writeset); + else + channel_pre_open_15(c, readset, writeset); + } else if (ret == -1) { + debug("X11 rejected %d i%d/o%d", c->self, c->istate, c->ostate); + chan_read_failed(c); /** force close? */ + chan_write_failed(c); + debug("X11 closed %d i%d/o%d", c->self, c->istate, c->ostate); + } +} + +/* This is our fake X11 server socket. */ +void +channel_post_x11_listener(Channel *c, fd_set * readset, fd_set * writeset) +{ + struct sockaddr addr; + int newsock, newch; + socklen_t addrlen; + char buf[16384], *remote_ipaddr; + int remote_port; + + if (FD_ISSET(c->sock, readset)) { + debug("X11 connection requested."); + addrlen = sizeof(addr); + newsock = accept(c->sock, &addr, &addrlen); + if (newsock < 0) { + error("accept: %.100s", strerror(errno)); + return; + } + remote_ipaddr = get_peer_ipaddr(newsock); + remote_port = get_peer_port(newsock); + snprintf(buf, sizeof buf, "X11 connection from %.200s port %d", + remote_ipaddr, remote_port); + + newch = channel_new("x11", + SSH_CHANNEL_OPENING, newsock, newsock, -1, + c->local_window_max, c->local_maxpacket, + 0, xstrdup(buf), 1); + if (compat20) { + packet_start(SSH2_MSG_CHANNEL_OPEN); + packet_put_cstring("x11"); + packet_put_int(newch); + packet_put_int(c->local_window_max); + packet_put_int(c->local_maxpacket); + /* originator ipaddr and port */ + packet_put_cstring(remote_ipaddr); + if (datafellows & SSH_BUG_X11FWD) { + debug("ssh2 x11 bug compat mode"); } else { - debug("X11 rejected %d i%d/o%d", ch->self, ch->istate, ch->ostate); - chan_read_failed(ch); - chan_write_failed(ch); - debug("X11 rejected %d i%d/o%d", ch->self, ch->istate, ch->ostate); + packet_put_int(remote_port); } - break; - - case SSH_CHANNEL_FREE: - default: - continue; + packet_send(); + } else { + packet_start(SSH_SMSG_X11_OPEN); + packet_put_int(newch); + if (have_hostname_in_open) + packet_put_string(buf, strlen(buf)); + packet_send(); } + xfree(remote_ipaddr); } } /* - * After select, perform any appropriate operations for channels which have - * events pending. + * This socket is listening for connections to a forwarded TCP/IP port. */ - -void -channel_after_select(fd_set * readset, fd_set * writeset) +void +channel_post_port_listener(Channel *c, fd_set * readset, fd_set * writeset) { struct sockaddr addr; - int addrlen, newsock, i, newch, len; - Channel *ch; - char buf[16384], *remote_hostname; - - /* Loop over all channels... */ - for (i = 0; i < channels_alloc; i++) { - ch = &channels[i]; - switch (ch->type) { - case SSH_CHANNEL_X11_LISTENER: - /* This is our fake X11 server socket. */ - if (FD_ISSET(ch->sock, readset)) { - debug("X11 connection requested."); - addrlen = sizeof(addr); - newsock = accept(ch->sock, &addr, &addrlen); - if (newsock < 0) { - error("accept: %.100s", strerror(errno)); - break; - } - remote_hostname = get_remote_hostname(newsock); - snprintf(buf, sizeof buf, "X11 connection from %.200s port %d", - remote_hostname, get_peer_port(newsock)); - xfree(remote_hostname); - newch = channel_allocate(SSH_CHANNEL_OPENING, newsock, - xstrdup(buf)); - packet_start(SSH_SMSG_X11_OPEN); - packet_put_int(newch); - if (have_hostname_in_open) - packet_put_string(buf, strlen(buf)); - packet_send(); + int newsock, newch; + socklen_t addrlen; + char buf[1024], *remote_ipaddr, *rtype; + int remote_port; + + rtype = (c->type == SSH_CHANNEL_RPORT_LISTENER) ? + "forwarded-tcpip" : "direct-tcpip"; + + 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); + addrlen = sizeof(addr); + newsock = accept(c->sock, &addr, &addrlen); + if (newsock < 0) { + error("accept: %.100s", strerror(errno)); + return; + } + remote_ipaddr = get_peer_ipaddr(newsock); + remote_port = get_peer_port(newsock); + snprintf(buf, sizeof buf, + "listen port %d for %.100s port %d, " + "connect from %.200s port %d", + c->listening_port, c->path, c->host_port, + remote_ipaddr, remote_port); + + newch = channel_new(rtype, + SSH_CHANNEL_OPENING, newsock, newsock, -1, + c->local_window_max, c->local_maxpacket, + 0, xstrdup(buf), 1); + if (compat20) { + packet_start(SSH2_MSG_CHANNEL_OPEN); + packet_put_cstring(rtype); + packet_put_int(newch); + packet_put_int(c->local_window_max); + packet_put_int(c->local_maxpacket); + if (c->type == SSH_CHANNEL_RPORT_LISTENER) { + /* listen address, port */ + packet_put_string(c->path, strlen(c->path)); + packet_put_int(c->listening_port); + } else { + /* target host, port */ + packet_put_string(c->path, strlen(c->path)); + packet_put_int(c->host_port); } - break; - - case SSH_CHANNEL_PORT_LISTENER: - /* - * This socket is listening for connections to a - * forwarded TCP/IP port. - */ - if (FD_ISSET(ch->sock, readset)) { - debug("Connection to port %d forwarding to %.100s:%d requested.", - ch->listening_port, ch->path, ch->host_port); - addrlen = sizeof(addr); - newsock = accept(ch->sock, &addr, &addrlen); - if (newsock < 0) { - error("accept: %.100s", strerror(errno)); - break; - } - remote_hostname = get_remote_hostname(newsock); - snprintf(buf, sizeof buf, "listen port %d:%.100s:%d, connect from %.200s:%d", - ch->listening_port, ch->path, ch->host_port, - remote_hostname, get_peer_port(newsock)); - xfree(remote_hostname); - newch = channel_allocate(SSH_CHANNEL_OPENING, newsock, - xstrdup(buf)); - packet_start(SSH_MSG_PORT_OPEN); - packet_put_int(newch); - packet_put_string(ch->path, strlen(ch->path)); - packet_put_int(ch->host_port); - if (have_hostname_in_open) - packet_put_string(buf, strlen(buf)); - packet_send(); + /* originator host and port */ + packet_put_cstring(remote_ipaddr); + packet_put_int(remote_port); + packet_send(); + } else { + packet_start(SSH_MSG_PORT_OPEN); + packet_put_int(newch); + packet_put_string(c->path, strlen(c->path)); + packet_put_int(c->host_port); + if (have_hostname_in_open) { + packet_put_string(buf, strlen(buf)); } - break; + packet_send(); + } + xfree(remote_ipaddr); + } +} - case SSH_CHANNEL_AUTH_SOCKET: - /* - * This is the authentication agent socket listening - * for connections from clients. - */ - if (FD_ISSET(ch->sock, readset)) { - int nchan; - len = sizeof(addr); - newsock = accept(ch->sock, &addr, &len); - if (newsock < 0) { - error("accept from auth socket: %.100s", strerror(errno)); - break; - } - nchan = channel_allocate(SSH_CHANNEL_OPENING, newsock, - xstrdup("accepted auth socket")); - packet_start(SSH_SMSG_AGENT_OPEN); - packet_put_int(nchan); - packet_send(); +/* + * This is the authentication agent socket listening for connections from + * clients. + */ +void +channel_post_auth_listener(Channel *c, fd_set * readset, fd_set * writeset) +{ + struct sockaddr addr; + int newsock, newch; + socklen_t addrlen; + + if (FD_ISSET(c->sock, readset)) { + addrlen = sizeof(addr); + newsock = accept(c->sock, &addr, &addrlen); + if (newsock < 0) { + error("accept from auth socket: %.100s", strerror(errno)); + return; + } + newch = channel_new("accepted auth socket", + SSH_CHANNEL_OPENING, newsock, newsock, -1, + c->local_window_max, c->local_maxpacket, + 0, xstrdup("accepted auth socket"), 1); + if (compat20) { + packet_start(SSH2_MSG_CHANNEL_OPEN); + packet_put_cstring("auth-agent@openssh.com"); + packet_put_int(newch); + packet_put_int(c->local_window_max); + packet_put_int(c->local_maxpacket); + } else { + packet_start(SSH_SMSG_AGENT_OPEN); + packet_put_int(newch); + } + packet_send(); + } +} + +void +channel_post_connecting(Channel *c, fd_set * readset, fd_set * writeset) +{ + if (FD_ISSET(c->sock, writeset)) { + int err = 0; + int sz = sizeof(err); + c->type = SSH_CHANNEL_OPEN; + if (getsockopt(c->sock, SOL_SOCKET, SO_ERROR, (char *)&err, &sz) < 0) { + debug("getsockopt SO_ERROR failed"); + } else { + if (err == 0) { + debug("channel %d: connected)", c->self); + } else { + debug("channel %d: not connected: %s", + c->self, strerror(err)); + chan_read_failed(c); + chan_write_failed(c); } - break; + } + } +} - case SSH_CHANNEL_OPEN: - /* - * This is an open two-way communication channel. It - * is not of interest to us at this point what kind - * of data is being transmitted. - */ +int +channel_handle_rfd(Channel *c, fd_set * readset, fd_set * writeset) +{ + char buf[16*1024]; + int len; - /* - * Read available incoming data and append it to - * buffer; shutdown socket, if read or write failes - */ - if (FD_ISSET(ch->sock, readset)) { - len = read(ch->sock, buf, sizeof(buf)); - if (len <= 0) { - if (compat13) { - buffer_consume(&ch->output, buffer_len(&ch->output)); - ch->type = SSH_CHANNEL_INPUT_DRAINING; - debug("Channel %d status set to input draining.", i); - } else { - chan_read_failed(ch); - } - break; - } - buffer_append(&ch->input, buf, len); + if (c->rfd != -1 && + FD_ISSET(c->rfd, readset)) { + len = read(c->rfd, buf, sizeof(buf)); + if (len < 0 && (errno == EINTR || errno == EAGAIN)) + return 1; + if (len <= 0) { + debug("channel %d: read<=0 rfd %d len %d", + c->self, c->rfd, len); + if (compat13) { + buffer_consume(&c->output, buffer_len(&c->output)); + c->type = SSH_CHANNEL_INPUT_DRAINING; + debug("Channel %d status set to input draining.", c->self); + } else { + chan_read_failed(c); } - /* Send buffered output data to the socket. */ - if (FD_ISSET(ch->sock, writeset) && buffer_len(&ch->output) > 0) { - len = write(ch->sock, buffer_ptr(&ch->output), - buffer_len(&ch->output)); - if (len <= 0) { - if (compat13) { - buffer_consume(&ch->output, buffer_len(&ch->output)); - debug("Channel %d status set to input draining.", i); - ch->type = SSH_CHANNEL_INPUT_DRAINING; - } else { - chan_write_failed(ch); - } - break; - } - buffer_consume(&ch->output, len); + return -1; + } + if(c->input_filter != NULL) { + if (c->input_filter(c, buf, len) == -1) { + debug("filter stops channel %d", c->self); + chan_read_failed(c); } - break; - - case SSH_CHANNEL_OUTPUT_DRAINING: - if (!compat13) - fatal("cannot happen: OUT_DRAIN"); - /* Send buffered output data to the socket. */ - if (FD_ISSET(ch->sock, writeset) && buffer_len(&ch->output) > 0) { - len = write(ch->sock, buffer_ptr(&ch->output), - buffer_len(&ch->output)); - if (len <= 0) - buffer_consume(&ch->output, buffer_len(&ch->output)); - else - buffer_consume(&ch->output, len); + } else { + buffer_append(&c->input, buf, len); + } + } + return 1; +} +int +channel_handle_wfd(Channel *c, fd_set * readset, fd_set * writeset) +{ + int len; + + /* Send buffered output data to the socket. */ + if (c->wfd != -1 && + FD_ISSET(c->wfd, writeset) && + buffer_len(&c->output) > 0) { + len = write(c->wfd, buffer_ptr(&c->output), + buffer_len(&c->output)); + if (len < 0 && (errno == EINTR || errno == EAGAIN)) + return 1; + if (len <= 0) { + if (compat13) { + buffer_consume(&c->output, buffer_len(&c->output)); + debug("Channel %d status set to input draining.", c->self); + c->type = SSH_CHANNEL_INPUT_DRAINING; + } else { + chan_write_failed(c); } - break; + return -1; + } + buffer_consume(&c->output, len); + if (compat20 && len > 0) { + c->local_consumed += len; + } + } + return 1; +} +int +channel_handle_efd(Channel *c, fd_set * readset, fd_set * writeset) +{ + char buf[16*1024]; + int len; + +/** XXX handle drain efd, too */ + if (c->efd != -1) { + if (c->extended_usage == CHAN_EXTENDED_WRITE && + FD_ISSET(c->efd, writeset) && + buffer_len(&c->extended) > 0) { + len = write(c->efd, buffer_ptr(&c->extended), + buffer_len(&c->extended)); + debug2("channel %d: written %d to efd %d", + c->self, len, c->efd); + if (len > 0) { + buffer_consume(&c->extended, len); + c->local_consumed += len; + } + } else if (c->extended_usage == CHAN_EXTENDED_READ && + FD_ISSET(c->efd, readset)) { + len = read(c->efd, buf, sizeof(buf)); + debug2("channel %d: read %d from efd %d", + c->self, len, c->efd); + if (len == 0) { + debug("channel %d: closing efd %d", + c->self, c->efd); + close(c->efd); + c->efd = -1; + } else if (len > 0) + buffer_append(&c->extended, buf, len); + } + } + return 1; +} +int +channel_check_window(Channel *c, fd_set * readset, fd_set * writeset) +{ + if (!(c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD)) && + c->local_window < c->local_window_max/2 && + c->local_consumed > 0) { + packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST); + packet_put_int(c->remote_id); + packet_put_int(c->local_consumed); + packet_send(); + debug2("channel %d: window %d sent adjust %d", + c->self, c->local_window, + c->local_consumed); + c->local_window += c->local_consumed; + c->local_consumed = 0; + } + return 1; +} - case SSH_CHANNEL_X11_OPEN: - case SSH_CHANNEL_FREE: - default: +void +channel_post_open_1(Channel *c, fd_set * readset, fd_set * writeset) +{ + channel_handle_rfd(c, readset, writeset); + channel_handle_wfd(c, readset, writeset); +} + +void +channel_post_open_2(Channel *c, fd_set * readset, fd_set * writeset) +{ + channel_handle_rfd(c, readset, writeset); + channel_handle_wfd(c, readset, writeset); + channel_handle_efd(c, readset, writeset); + channel_check_window(c, readset, writeset); +} + +void +channel_post_output_drain_13(Channel *c, fd_set * readset, fd_set * writeset) +{ + int len; + /* Send buffered output data to the socket. */ + if (FD_ISSET(c->sock, writeset) && buffer_len(&c->output) > 0) { + len = write(c->sock, buffer_ptr(&c->output), + buffer_len(&c->output)); + if (len <= 0) + buffer_consume(&c->output, buffer_len(&c->output)); + else + buffer_consume(&c->output, len); + } +} + +void +channel_handler_init_20(void) +{ + channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_20; + channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open; + channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener; + channel_pre[SSH_CHANNEL_RPORT_LISTENER] = &channel_pre_listener; + channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener; + channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener; + channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting; + + channel_post[SSH_CHANNEL_OPEN] = &channel_post_open_2; + channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener; + channel_post[SSH_CHANNEL_RPORT_LISTENER] = &channel_post_port_listener; + channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener; + channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener; + channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting; +} + +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_post[SSH_CHANNEL_OPEN] = &channel_post_open_1; + channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener; + channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener; + channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener; + channel_post[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_post_output_drain_13; + channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting; +} + +void +channel_handler_init_15(void) +{ + channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_15; + channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open; + channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener; + channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener; + channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener; + channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting; + + channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener; + channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener; + channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener; + channel_post[SSH_CHANNEL_OPEN] = &channel_post_open_1; + channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting; +} + +void +channel_handler_init(void) +{ + int i; + for(i = 0; i < SSH_CHANNEL_MAX_TYPE; i++) { + channel_pre[i] = NULL; + channel_post[i] = NULL; + } + if (compat20) + channel_handler_init_20(); + else if (compat13) + channel_handler_init_13(); + else + channel_handler_init_15(); +} + +void +channel_handler(chan_fn *ftab[], fd_set * readset, fd_set * writeset) +{ + static int did_init = 0; + int i; + Channel *c; + + if (!did_init) { + channel_handler_init(); + did_init = 1; + } + for (i = 0; i < channels_alloc; i++) { + c = &channels[i]; + if (c->type == SSH_CHANNEL_FREE) continue; - } + if (ftab[c->type] == NULL) + continue; + (*ftab[c->type])(c, readset, writeset); + chan_delete_if_full_closed(c); } } -/* If there is data to send to the connection, send some of it now. */ +void +channel_prepare_select(fd_set **readsetp, fd_set **writesetp, int *maxfdp) +{ + int n; + u_int sz; + + n = MAX(*maxfdp, channel_max_fd); + + sz = howmany(n+1, NFDBITS) * sizeof(fd_mask); + if (*readsetp == NULL || n > *maxfdp) { + if (*readsetp) + xfree(*readsetp); + if (*writesetp) + xfree(*writesetp); + *readsetp = xmalloc(sz); + *writesetp = xmalloc(sz); + *maxfdp = n; + } + memset(*readsetp, 0, sz); + memset(*writesetp, 0, sz); + + channel_handler(channel_pre, *readsetp, *writesetp); +} + +void +channel_after_select(fd_set * readset, fd_set * writeset) +{ + channel_handler(channel_post, readset, writeset); +} -void +/* If there is data to send to the connection, enqueue some of it now. */ + +void channel_output_poll() { int len, i; - Channel *ch; + Channel *c; for (i = 0; i < channels_alloc; i++) { - ch = &channels[i]; + c = &channels[i]; + /* We are only interested in channels that can have buffered incoming data. */ - if (ch->type != SSH_CHANNEL_OPEN && - ch->type != SSH_CHANNEL_INPUT_DRAINING) + if (compat13) { + if (c->type != SSH_CHANNEL_OPEN && + c->type != SSH_CHANNEL_INPUT_DRAINING) + continue; + } else { + if (c->type != SSH_CHANNEL_OPEN) + continue; + if (c->istate != CHAN_INPUT_OPEN && + c->istate != CHAN_INPUT_WAIT_DRAIN) + continue; + } + if (compat20 && + (c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD))) { + debug("channel: %d: no data after CLOSE", c->self); continue; + } /* Get the amount of buffered data for this channel. */ - len = buffer_len(&ch->input); + len = buffer_len(&c->input); if (len > 0) { /* Send some data for the other side over the secure connection. */ - if (packet_is_interactive()) { - if (len > 1024) - len = 512; + if (compat20) { + if (len > c->remote_window) + len = c->remote_window; + if (len > c->remote_maxpacket) + len = c->remote_maxpacket; } else { - /* Keep the packets at reasonable size. */ - if (len > 16384) - len = 16384; + if (packet_is_interactive()) { + if (len > 1024) + len = 512; + } else { + /* Keep the packets at reasonable size. */ + if (len > packet_get_maxsize()/2) + len = packet_get_maxsize()/2; + } } - packet_start(SSH_MSG_CHANNEL_DATA); - packet_put_int(ch->remote_id); - packet_put_string(buffer_ptr(&ch->input), len); - packet_send(); - buffer_consume(&ch->input, len); - } else if (ch->istate == CHAN_INPUT_WAIT_DRAIN) { + if (len > 0) { + packet_start(compat20 ? + SSH2_MSG_CHANNEL_DATA : SSH_MSG_CHANNEL_DATA); + packet_put_int(c->remote_id); + packet_put_string(buffer_ptr(&c->input), len); + packet_send(); + buffer_consume(&c->input, len); + c->remote_window -= len; + } + } else if (c->istate == CHAN_INPUT_WAIT_DRAIN) { if (compat13) fatal("cannot happen: istate == INPUT_WAIT_DRAIN for proto 1.3"); /* * input-buffer is empty and read-socket shutdown: * tell peer, that we will not send more data: send IEOF */ - chan_ibuf_empty(ch); + chan_ibuf_empty(c); + } + /* Send extended data, i.e. stderr */ + if (compat20 && + c->remote_window > 0 && + (len = buffer_len(&c->extended)) > 0 && + c->extended_usage == CHAN_EXTENDED_READ) { + 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; } } } @@ -573,91 +1084,155 @@ channel_output_poll() * still there. */ -void -channel_input_data(int payload_len) +void +channel_input_data(int type, int plen, void *ctxt) { - int channel; + int id; char *data; - unsigned int data_len; + u_int data_len; + Channel *c; /* Get the channel number and verify it. */ - channel = packet_get_int(); - if (channel < 0 || channel >= channels_alloc || - channels[channel].type == SSH_CHANNEL_FREE) - packet_disconnect("Received data for nonexistent channel %d.", channel); + id = packet_get_int(); + c = channel_lookup(id); + if (c == NULL) + packet_disconnect("Received data for nonexistent channel %d.", id); /* Ignore any data for non-open channels (might happen on close) */ - if (channels[channel].type != SSH_CHANNEL_OPEN && - channels[channel].type != SSH_CHANNEL_X11_OPEN) + if (c->type != SSH_CHANNEL_OPEN && + c->type != SSH_CHANNEL_X11_OPEN) + return; + + /* same for protocol 1.5 if output end is no longer open */ + if (!compat13 && c->ostate != CHAN_OUTPUT_OPEN) return; /* Get the data. */ data = packet_get_string(&data_len); - packet_integrity_check(payload_len, 4 + 4 + data_len, SSH_MSG_CHANNEL_DATA); - buffer_append(&channels[channel].output, data, data_len); + packet_done(); + + if (compat20){ + if (data_len > c->local_maxpacket) { + log("channel %d: rcvd big packet %d, maxpack %d", + c->self, data_len, c->local_maxpacket); + } + if (data_len > c->local_window) { + log("channel %d: rcvd too much data %d, win %d", + c->self, data_len, c->local_window); + xfree(data); + return; + } + c->local_window -= data_len; + }else{ + packet_integrity_check(plen, 4 + 4 + data_len, type); + } + buffer_append(&c->output, data, data_len); + xfree(data); +} +void +channel_input_extended_data(int type, int plen, void *ctxt) +{ + int id; + int tcode; + char *data; + u_int data_len; + Channel *c; + + /* Get the channel number and verify it. */ + id = packet_get_int(); + c = channel_lookup(id); + + if (c == NULL) + packet_disconnect("Received extended_data for bad channel %d.", id); + if (c->type != SSH_CHANNEL_OPEN) { + log("channel %d: ext data for non open", id); + return; + } + tcode = packet_get_int(); + if (c->efd == -1 || + c->extended_usage != CHAN_EXTENDED_WRITE || + tcode != SSH2_EXTENDED_DATA_STDERR) { + log("channel %d: bad ext data", c->self); + return; + } + data = packet_get_string(&data_len); + packet_done(); + if (data_len > c->local_window) { + log("channel %d: rcvd too much extended_data %d, win %d", + c->self, data_len, c->local_window); + xfree(data); + return; + } + debug2("channel %d: rcvd ext data %d", c->self, data_len); + c->local_window -= data_len; + buffer_append(&c->extended, data, data_len); xfree(data); } + /* * Returns true if no channel has too much buffered data, and false if one or * more channel is overfull. */ -int +int channel_not_very_much_buffered_data() { - unsigned int i; - Channel *ch; + u_int i; + Channel *c; for (i = 0; i < channels_alloc; i++) { - ch = &channels[i]; - switch (ch->type) { - case SSH_CHANNEL_X11_LISTENER: - case SSH_CHANNEL_PORT_LISTENER: - case SSH_CHANNEL_AUTH_SOCKET: - continue; - case SSH_CHANNEL_OPEN: - if (buffer_len(&ch->input) > packet_get_maxsize()) + c = &channels[i]; + if (c->type == SSH_CHANNEL_OPEN) { + if (!compat20 && buffer_len(&c->input) > packet_get_maxsize()) { + debug("channel %d: big input buffer %d", + c->self, buffer_len(&c->input)); return 0; - if (buffer_len(&ch->output) > packet_get_maxsize()) + } + if (buffer_len(&c->output) > packet_get_maxsize()) { + debug("channel %d: big output buffer %d", + c->self, buffer_len(&c->output)); return 0; - continue; - case SSH_CHANNEL_INPUT_DRAINING: - case SSH_CHANNEL_OUTPUT_DRAINING: - case SSH_CHANNEL_X11_OPEN: - case SSH_CHANNEL_FREE: - default: - continue; + } } } return 1; } -/* This is called after receiving CHANNEL_CLOSE/IEOF. */ +void +channel_input_ieof(int type, int plen, void *ctxt) +{ + int id; + Channel *c; + + packet_integrity_check(plen, 4, type); + + id = packet_get_int(); + c = channel_lookup(id); + if (c == NULL) + packet_disconnect("Received ieof for nonexistent channel %d.", id); + chan_rcvd_ieof(c); +} -void -channel_input_close() +void +channel_input_close(int type, int plen, void *ctxt) { - int channel; + int id; + Channel *c; - /* Get the channel number and verify it. */ - channel = packet_get_int(); - if (channel < 0 || channel >= channels_alloc || - channels[channel].type == SSH_CHANNEL_FREE) - packet_disconnect("Received data for nonexistent channel %d.", channel); - - if (!compat13) { - /* proto version 1.5 overloads CLOSE with IEOF */ - chan_rcvd_ieof(&channels[channel]); - return; - } + packet_integrity_check(plen, 4, type); + + id = packet_get_int(); + c = channel_lookup(id); + if (c == NULL) + packet_disconnect("Received close for nonexistent channel %d.", id); /* * Send a confirmation that we have closed the channel and no more * data is coming for it. */ packet_start(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION); - packet_put_int(channels[channel].remote_id); + packet_put_int(c->remote_id); packet_send(); /* @@ -667,81 +1242,159 @@ channel_input_close() * no-one to receive the confirmation. The channel gets freed when * the confirmation arrives. */ - if (channels[channel].type != SSH_CHANNEL_CLOSED) { + if (c->type != SSH_CHANNEL_CLOSED) { /* * Not a closed channel - mark it as draining, which will * cause it to be freed later. */ - buffer_consume(&channels[channel].input, - buffer_len(&channels[channel].input)); - channels[channel].type = SSH_CHANNEL_OUTPUT_DRAINING; + buffer_consume(&c->input, buffer_len(&c->input)); + c->type = SSH_CHANNEL_OUTPUT_DRAINING; } } -/* This is called after receiving CHANNEL_CLOSE_CONFIRMATION/OCLOSE. */ +/* proto version 1.5 overloads CLOSE_CONFIRMATION with OCLOSE */ +void +channel_input_oclose(int type, int plen, void *ctxt) +{ + int id = packet_get_int(); + Channel *c = channel_lookup(id); + packet_integrity_check(plen, 4, type); + if (c == NULL) + packet_disconnect("Received oclose for nonexistent channel %d.", id); + chan_rcvd_oclose(c); +} -void -channel_input_close_confirmation() +void +channel_input_close_confirmation(int type, int plen, void *ctxt) { - int channel; + int id = packet_get_int(); + Channel *c = channel_lookup(id); + + packet_done(); + if (c == NULL) + packet_disconnect("Received close confirmation for " + "out-of-range channel %d.", id); + if (c->type != SSH_CHANNEL_CLOSED) + packet_disconnect("Received close confirmation for " + "non-closed channel %d (type %d).", id, c->type); + channel_free(c->self); +} - /* Get the channel number and verify it. */ - channel = packet_get_int(); - if (channel < 0 || channel >= channels_alloc) - packet_disconnect("Received close confirmation for out-of-range channel %d.", - channel); - - if (!compat13) { - /* proto version 1.5 overloads CLOSE_CONFIRMATION with OCLOSE */ - chan_rcvd_oclose(&channels[channel]); - return; - } - if (channels[channel].type != SSH_CHANNEL_CLOSED) - packet_disconnect("Received close confirmation for non-closed channel %d (type %d).", - channel, channels[channel].type); +void +channel_input_open_confirmation(int type, int plen, void *ctxt) +{ + int id, remote_id; + Channel *c; - /* Free the channel. */ - channel_free(channel); -} + if (!compat20) + packet_integrity_check(plen, 4 + 4, type); -/* This is called after receiving CHANNEL_OPEN_CONFIRMATION. */ + id = packet_get_int(); + c = channel_lookup(id); -void -channel_input_open_confirmation() + if (c==NULL || c->type != SSH_CHANNEL_OPENING) + packet_disconnect("Received open confirmation for " + "non-opening channel %d.", id); + remote_id = packet_get_int(); + /* Record the remote channel number and mark that the channel is now open. */ + c->remote_id = remote_id; + c->type = SSH_CHANNEL_OPEN; + + if (compat20) { + c->remote_window = packet_get_int(); + c->remote_maxpacket = packet_get_int(); + packet_done(); + if (c->cb_fn != NULL && c->cb_event == type) { + debug2("callback start"); + c->cb_fn(c->self, c->cb_arg); + debug2("callback done"); + } + debug("channel %d: open confirm rwindow %d rmax %d", c->self, + c->remote_window, c->remote_maxpacket); + } +} + +void +channel_input_open_failure(int type, int plen, void *ctxt) { - int channel, remote_channel; + int id, reason; + char *msg = NULL, *lang = NULL; + Channel *c; - /* Get the channel number and verify it. */ - channel = packet_get_int(); - if (channel < 0 || channel >= channels_alloc || - channels[channel].type != SSH_CHANNEL_OPENING) - packet_disconnect("Received open confirmation for non-opening channel %d.", - channel); + if (!compat20) + packet_integrity_check(plen, 4, type); - /* Get remote side's id for this channel. */ - remote_channel = packet_get_int(); + id = packet_get_int(); + c = channel_lookup(id); - /* Record the remote channel number and mark that the channel is now open. */ - channels[channel].remote_id = remote_channel; - channels[channel].type = SSH_CHANNEL_OPEN; + if (c==NULL || c->type != SSH_CHANNEL_OPENING) + packet_disconnect("Received open failure for " + "non-opening channel %d.", id); + if (compat20) { + reason = packet_get_int(); + if (packet_remaining() > 0) { + msg = packet_get_string(NULL); + lang = packet_get_string(NULL); + } + packet_done(); + log("channel_open_failure: %d: reason %d %s", id, + reason, msg ? msg : ""); + if (msg != NULL) + xfree(msg); + if (lang != NULL) + xfree(lang); + } + /* Free the channel. This will also close the socket. */ + channel_free(id); } -/* This is called after receiving CHANNEL_OPEN_FAILURE from the other side. */ +void +channel_input_channel_request(int type, int plen, void *ctxt) +{ + int id; + Channel *c; -void -channel_input_open_failure() + id = packet_get_int(); + c = channel_lookup(id); + + if (c == NULL || + (c->type != SSH_CHANNEL_OPEN && c->type != SSH_CHANNEL_LARVAL)) + packet_disconnect("Received request for " + "non-open channel %d.", id); + if (c->cb_fn != NULL && c->cb_event == type) { + debug2("callback start"); + c->cb_fn(c->self, c->cb_arg); + debug2("callback done"); + } else { + char *service = packet_get_string(NULL); + debug("channel: %d rcvd request for %s", c->self, service); + debug("cb_fn %p cb_event %d", c->cb_fn , c->cb_event); + xfree(service); + } +} + +void +channel_input_window_adjust(int type, int plen, void *ctxt) { - int channel; + Channel *c; + int id, adjust; + + if (!compat20) + return; /* Get the channel number and verify it. */ - channel = packet_get_int(); - if (channel < 0 || channel >= channels_alloc || - channels[channel].type != SSH_CHANNEL_OPENING) - packet_disconnect("Received open failure for non-opening channel %d.", - channel); + id = packet_get_int(); + c = channel_lookup(id); - /* Free the channel. This will also close the socket. */ - channel_free(channel); + if (c == NULL || c->type != SSH_CHANNEL_OPEN) { + log("Received window adjust for " + "non-open channel %d.", id); + return; + } + adjust = packet_get_int(); + packet_done(); + debug2("channel %d: rcvd adjust %d", id, adjust); + c->remote_window += adjust; } /* @@ -749,7 +1402,7 @@ channel_input_open_failure() * might have. */ -void +void channel_stop_listening() { int i; @@ -757,10 +1410,11 @@ channel_stop_listening() switch (channels[i].type) { case SSH_CHANNEL_AUTH_SOCKET: close(channels[i].sock); - remove(channels[i].path); + unlink(channels[i].path); channel_free(i); break; case SSH_CHANNEL_PORT_LISTENER: + case SSH_CHANNEL_RPORT_LISTENER: case SSH_CHANNEL_X11_LISTENER: close(channels[i].sock); channel_free(i); @@ -772,41 +1426,38 @@ channel_stop_listening() } /* - * Closes the sockets of all channels. This is used to close extra file + * Closes the sockets/fds of all channels. This is used to close extra file * descriptors after a fork. */ -void +void channel_close_all() { int i; - for (i = 0; i < channels_alloc; i++) { + for (i = 0; i < channels_alloc; i++) if (channels[i].type != SSH_CHANNEL_FREE) - close(channels[i].sock); - } -} - -/* Returns the maximum file descriptor number used by the channels. */ - -int -channel_max_fd() -{ - return channel_max_fd_value; + channel_close_fds(&channels[i]); } /* Returns true if any channel is still open. */ -int +int channel_still_open() { - unsigned int i; + u_int i; for (i = 0; i < channels_alloc; i++) switch (channels[i].type) { case SSH_CHANNEL_FREE: case SSH_CHANNEL_X11_LISTENER: case SSH_CHANNEL_PORT_LISTENER: + case SSH_CHANNEL_RPORT_LISTENER: case SSH_CHANNEL_CLOSED: case SSH_CHANNEL_AUTH_SOCKET: + case SSH_CHANNEL_CONNECTING: /* XXX ??? */ + continue; + case SSH_CHANNEL_LARVAL: + if (!compat20) + fatal("cannot happen: SSH_CHANNEL_LARVAL"); continue; case SSH_CHANNEL_OPENING: case SSH_CHANNEL_OPEN: @@ -846,21 +1497,27 @@ channel_open_message() case SSH_CHANNEL_FREE: case SSH_CHANNEL_X11_LISTENER: case SSH_CHANNEL_PORT_LISTENER: + case SSH_CHANNEL_RPORT_LISTENER: case SSH_CHANNEL_CLOSED: case SSH_CHANNEL_AUTH_SOCKET: continue; + case SSH_CHANNEL_LARVAL: case SSH_CHANNEL_OPENING: + case SSH_CHANNEL_CONNECTING: case SSH_CHANNEL_OPEN: case SSH_CHANNEL_X11_OPEN: case SSH_CHANNEL_INPUT_DRAINING: case SSH_CHANNEL_OUTPUT_DRAINING: - snprintf(buf, sizeof buf, " #%d %.300s (t%d r%d i%d o%d)\r\n", - c->self, c->remote_name, - c->type, c->remote_id, c->istate, c->ostate); + snprintf(buf, sizeof buf, " #%d %.300s (t%d r%d i%d/%d o%d/%d fd %d/%d)\r\n", + c->self, c->remote_name, + c->type, c->remote_id, + c->istate, buffer_len(&c->input), + c->ostate, buffer_len(&c->output), + c->rfd, c->wfd); buffer_append(&buffer, buf, strlen(buf)); continue; default: - fatal("channel_still_open: bad channel type %d", c->type); + fatal("channel_open_message: bad channel type %d", c->type); /* NOTREACHED */ } } @@ -874,55 +1531,116 @@ channel_open_message() * Initiate forwarding of connections to local port "port" through the secure * channel to host:port from remote side. */ +int +channel_request_local_forwarding(u_short listen_port, const char *host_to_connect, + u_short port_to_connect, int gateway_ports) +{ + return channel_request_forwarding( + NULL, listen_port, + host_to_connect, port_to_connect, + gateway_ports, /*remote_fwd*/ 0); +} -void -channel_request_local_forwarding(u_short port, const char *host, - u_short host_port, int gateway_ports) +/* + * If 'remote_fwd' is true we have a '-R style' listener for protocol 2 + * (SSH_CHANNEL_RPORT_LISTENER). + */ +int +channel_request_forwarding( + const char *listen_address, u_short listen_port, + const char *host_to_connect, u_short port_to_connect, + int gateway_ports, int remote_fwd) { - int ch, sock, on = 1; - struct sockaddr_in sin; + int success, ch, sock, on = 1, ctype; + struct addrinfo hints, *ai, *aitop; + char ntop[NI_MAXHOST], strport[NI_MAXSERV]; + const char *host; struct linger linger; - if (strlen(host) > sizeof(channels[0].path) - 1) - packet_disconnect("Forward host name too long."); + success = 0; - /* Create a port to listen for the host. */ - sock = socket(AF_INET, SOCK_STREAM, 0); - if (sock < 0) - packet_disconnect("socket: %.100s", strerror(errno)); + if (remote_fwd) { + host = listen_address; + ctype = SSH_CHANNEL_RPORT_LISTENER; + } else { + host = host_to_connect; + ctype =SSH_CHANNEL_PORT_LISTENER; + } - /* Initialize socket address. */ - memset(&sin, 0, sizeof(sin)); - sin.sin_family = AF_INET; - if (gateway_ports == 1) - sin.sin_addr.s_addr = htonl(INADDR_ANY); - else - sin.sin_addr.s_addr = htonl(INADDR_LOOPBACK); - sin.sin_port = htons(port); + if (strlen(host) > sizeof(channels[0].path) - 1) { + error("Forward host name too long."); + return success; + } + /* XXX listen_address is currently ignored */ /* - * Set socket options. We would like the socket to disappear as soon - * as it has been closed for whatever reason. + * getaddrinfo returns a loopback address if the hostname is + * set to NULL and hints.ai_flags is not AI_PASSIVE */ - setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, (void *)&on, sizeof(on)); - linger.l_onoff = 1; - linger.l_linger = 5; - setsockopt(sock, SOL_SOCKET, SO_LINGER, (void *) &linger, sizeof(linger)); - - /* Bind the socket to the address. */ - if (bind(sock, (struct sockaddr *) & sin, sizeof(sin)) < 0) - packet_disconnect("bind: %.100s", strerror(errno)); - - /* Start listening for connections on the socket. */ - if (listen(sock, 5) < 0) - packet_disconnect("listen: %.100s", strerror(errno)); + memset(&hints, 0, sizeof(hints)); + hints.ai_family = IPv4or6; + hints.ai_flags = gateway_ports ? AI_PASSIVE : 0; + hints.ai_socktype = SOCK_STREAM; + snprintf(strport, sizeof strport, "%d", listen_port); + if (getaddrinfo(NULL, strport, &hints, &aitop) != 0) + packet_disconnect("getaddrinfo: fatal error"); + + for (ai = aitop; ai; ai = ai->ai_next) { + if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6) + continue; + if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop), + strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) { + error("channel_request_forwarding: getnameinfo failed"); + continue; + } + /* Create a port to listen for the host. */ + sock = socket(ai->ai_family, SOCK_STREAM, 0); + if (sock < 0) { + /* this is no error since kernel may not support ipv6 */ + verbose("socket: %.100s", strerror(errno)); + continue; + } + /* + * Set socket options. We would like the socket to disappear + * as soon as it has been closed for whatever reason. + */ + setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, (void *)&on, sizeof(on)); + linger.l_onoff = 1; + linger.l_linger = 5; + setsockopt(sock, SOL_SOCKET, SO_LINGER, (void *)&linger, sizeof(linger)); + debug("Local forwarding listening on %s port %s.", ntop, strport); + + /* Bind the socket to the address. */ + if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) { + /* address can be in use ipv6 address is already bound */ + if (!ai->ai_next) + error("bind: %.100s", strerror(errno)); + else + verbose("bind: %.100s", strerror(errno)); - /* Allocate a channel number for the socket. */ - ch = channel_allocate(SSH_CHANNEL_PORT_LISTENER, sock, - xstrdup("port listener")); - strlcpy(channels[ch].path, host, sizeof(channels[ch].path)); - channels[ch].host_port = host_port; - channels[ch].listening_port = port; + close(sock); + continue; + } + /* Start listening for connections on the socket. */ + if (listen(sock, 5) < 0) { + error("listen: %.100s", strerror(errno)); + close(sock); + continue; + } + /* Allocate a channel number for the socket. */ + ch = channel_new("port listener", ctype, sock, sock, -1, + CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, + 0, xstrdup("port listener"), 1); + strlcpy(channels[ch].path, host, sizeof(channels[ch].path)); + channels[ch].host_port = port_to_connect; + channels[ch].listening_port = listen_port; + success = 1; + } + if (success == 0) + error("channel_request_forwarding: cannot listen to port: %d", + listen_port); + freeaddrinfo(aitop); + return success; } /* @@ -930,32 +1648,57 @@ channel_request_local_forwarding(u_short port, const char *host, * the secure channel to host:port from local side. */ -void -channel_request_remote_forwarding(u_short port, const char *host, - u_short remote_port) +void +channel_request_remote_forwarding(u_short listen_port, + const char *host_to_connect, u_short port_to_connect) { - int payload_len; + int payload_len, type, success = 0; + /* Record locally that connection to this host/port is permitted. */ if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION) fatal("channel_request_remote_forwarding: too many forwards"); - permitted_opens[num_permitted_opens].host = xstrdup(host); - permitted_opens[num_permitted_opens].port = remote_port; - num_permitted_opens++; - /* Send the forward request to the remote side. */ - packet_start(SSH_CMSG_PORT_FORWARD_REQUEST); - packet_put_int(port); - packet_put_string(host, strlen(host)); - packet_put_int(remote_port); - packet_send(); - packet_write_wait(); + if (compat20) { + const char *address_to_bind = "0.0.0.0"; + packet_start(SSH2_MSG_GLOBAL_REQUEST); + packet_put_cstring("tcpip-forward"); + packet_put_char(0); /* boolean: want reply */ + packet_put_cstring(address_to_bind); + packet_put_int(listen_port); + packet_send(); + packet_write_wait(); + /* Assume that server accepts the request */ + success = 1; + } else { + packet_start(SSH_CMSG_PORT_FORWARD_REQUEST); + packet_put_int(listen_port); + packet_put_cstring(host_to_connect); + packet_put_int(port_to_connect); + packet_send(); + packet_write_wait(); - /* - * Wait for response from the remote side. It will send a disconnect - * message on failure, and we will never see it here. - */ - packet_read_expect(&payload_len, SSH_SMSG_SUCCESS); + /* Wait for response from the remote side. */ + type = packet_read(&payload_len); + switch (type) { + case SSH_SMSG_SUCCESS: + success = 1; + break; + case SSH_SMSG_FAILURE: + log("Warning: Server denied remote port forwarding."); + break; + default: + /* Unknown packet */ + packet_disconnect("Protocol error for port forward request:" + "received packet type %d.", type); + } + } + if (success) { + permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host_to_connect); + permitted_opens[num_permitted_opens].port_to_connect = port_to_connect; + permitted_opens[num_permitted_opens].listen_port = listen_port; + num_permitted_opens++; + } } /* @@ -964,8 +1707,8 @@ channel_request_remote_forwarding(u_short port, const char *host, * message if there was an error). This never returns if there was an error. */ -void -channel_input_port_forward_request(int is_root) +void +channel_input_port_forward_request(int is_root, int gateway_ports) { u_short port, host_port; char *hostname; @@ -975,6 +1718,7 @@ channel_input_port_forward_request(int is_root) hostname = packet_get_string(NULL); host_port = packet_get_int(); +#ifndef HAVE_CYGWIN /* * Check that an unprivileged user is not trying to forward a * privileged port. @@ -982,31 +1726,93 @@ channel_input_port_forward_request(int is_root) if (port < IPPORT_RESERVED && !is_root) packet_disconnect("Requested forwarding of port %d but user is not root.", port); - /* - * Initiate forwarding, - * bind port to localhost only (gateway ports == 0). - */ - channel_request_local_forwarding(port, hostname, host_port, 0); +#endif + /* Initiate forwarding */ + channel_request_local_forwarding(port, hostname, host_port, gateway_ports); /* Free the argument string. */ xfree(hostname); } +/* XXX move to aux.c */ +int +channel_connect_to(const char *host, u_short host_port) +{ + struct addrinfo hints, *ai, *aitop; + char ntop[NI_MAXHOST], strport[NI_MAXSERV]; + int gaierr; + int sock = -1; + + memset(&hints, 0, sizeof(hints)); + hints.ai_family = IPv4or6; + hints.ai_socktype = SOCK_STREAM; + snprintf(strport, sizeof strport, "%d", host_port); + if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0) { + error("%.100s: unknown host (%s)", host, gai_strerror(gaierr)); + return -1; + } + for (ai = aitop; ai; ai = ai->ai_next) { + if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6) + continue; + if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop), + strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) { + error("channel_connect_to: getnameinfo failed"); + continue; + } + /* Create the socket. */ + sock = socket(ai->ai_family, SOCK_STREAM, 0); + if (sock < 0) { + error("socket: %.100s", strerror(errno)); + continue; + } + if (fcntl(sock, F_SETFL, O_NONBLOCK) < 0) + fatal("connect_to: F_SETFL: %s", strerror(errno)); + /* Connect to the host/port. */ + if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0 && + errno != EINPROGRESS) { + error("connect %.100s port %s: %.100s", ntop, strport, + strerror(errno)); + close(sock); + continue; /* fail -- try next */ + } + break; /* success */ + + } + freeaddrinfo(aitop); + if (!ai) { + error("connect %.100s port %d: failed.", host, host_port); + return -1; + } + /* success */ + return sock; +} +int +channel_connect_by_listen_adress(u_short listen_port) +{ + int i; + for (i = 0; i < num_permitted_opens; i++) + if (permitted_opens[i].listen_port == listen_port) + return channel_connect_to( + permitted_opens[i].host_to_connect, + permitted_opens[i].port_to_connect); + error("WARNING: Server requests forwarding for unknown listen_port %d", + listen_port); + return -1; +} + /* * This is called after receiving PORT_OPEN message. This attempts to * connect to the given host:port, and sends back CHANNEL_OPEN_CONFIRMATION * or CHANNEL_OPEN_FAILURE. */ -void -channel_input_port_open(int payload_len) +void +channel_input_port_open(int type, int plen, void *ctxt) { - int remote_channel, sock, newch, i; u_short host_port; - struct sockaddr_in sin; char *host, *originator_string; - struct hostent *hp; - int host_len, originator_len; + int remote_channel, sock = -1, newch, i, denied; + u_int host_len, originator_len; /* Get remote channel number. */ remote_channel = packet_get_int(); @@ -1026,16 +1832,16 @@ channel_input_port_open(int payload_len) originator_len = 0; /* no originator supplied */ } - packet_integrity_check(payload_len, - 4 + 4 + host_len + 4 + originator_len, - SSH_MSG_PORT_OPEN); + packet_integrity_check(plen, + 4 + 4 + host_len + 4 + originator_len, SSH_MSG_PORT_OPEN); /* Check if opening that port is permitted. */ + denied = 0; if (!all_opens_permitted) { /* Go trough all permitted ports. */ for (i = 0; i < num_permitted_opens; i++) - if (permitted_opens[i].port == host_port && - strcmp(permitted_opens[i].host, host) == 0) + if (permitted_opens[i].port_to_connect == host_port && + strcmp(permitted_opens[i].host_to_connect, host) == 0) break; /* Check if we found the requested port among those permitted. */ @@ -1043,71 +1849,27 @@ channel_input_port_open(int payload_len) /* The port is not permitted. */ log("Received request to connect to %.100s:%d, but the request was denied.", host, host_port); - packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE); - packet_put_int(remote_channel); - packet_send(); + denied = 1; } } - memset(&sin, 0, sizeof(sin)); - sin.sin_addr.s_addr = inet_addr(host); - if ((sin.sin_addr.s_addr & 0xffffffff) != 0xffffffff) { - /* It was a valid numeric host address. */ - sin.sin_family = AF_INET; + sock = denied ? -1 : channel_connect_to(host, host_port); + if (sock > 0) { + /* Allocate a channel for this connection. */ + newch = channel_allocate(SSH_CHANNEL_CONNECTING, + sock, originator_string); +/*XXX delay answer? */ + channels[newch].remote_id = remote_channel; + + packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION); + packet_put_int(remote_channel); + packet_put_int(newch); + packet_send(); } else { - /* Look up the host address from the name servers. */ - hp = gethostbyname(host); - if (!hp) { - error("%.100s: unknown host.", host); - goto fail; - } - if (!hp->h_addr_list[0]) { - error("%.100s: host has no IP address.", host); - goto fail; - } - sin.sin_family = hp->h_addrtype; - memcpy(&sin.sin_addr, hp->h_addr_list[0], - sizeof(sin.sin_addr)); - } - sin.sin_port = htons(host_port); - - /* Create the socket. */ - sock = socket(sin.sin_family, SOCK_STREAM, 0); - if (sock < 0) { - error("socket: %.100s", strerror(errno)); - goto fail; - } - /* Connect to the host/port. */ - if (connect(sock, (struct sockaddr *) & sin, sizeof(sin)) < 0) { - error("connect %.100s:%d: %.100s", host, host_port, - strerror(errno)); - close(sock); - goto fail; + packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE); + packet_put_int(remote_channel); + packet_send(); } - /* Successful connection. */ - - /* Allocate a channel for this connection. */ - newch = channel_allocate(SSH_CHANNEL_OPEN, sock, originator_string); - channels[newch].remote_id = remote_channel; - - /* Send a confirmation to the remote host. */ - packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION); - packet_put_int(remote_channel); - packet_put_int(newch); - packet_send(); - - /* Free the argument string. */ - xfree(host); - - return; - -fail: - /* Free the argument string. */ xfree(host); - - /* Send refusal to the remote host. */ - packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE); - packet_put_int(remote_channel); - packet_send(); } /* @@ -1116,55 +1878,94 @@ fail: * occurs. */ +#define NUM_SOCKS 10 + char * x11_create_display_inet(int screen_number, int x11_display_offset) { int display_number, sock; u_short port; - struct sockaddr_in sin; - char buf[512]; + struct addrinfo hints, *ai, *aitop; + char strport[NI_MAXSERV]; + int gaierr, n, num_socks = 0, socks[NUM_SOCKS]; + char display[512]; char hostname[MAXHOSTNAMELEN]; for (display_number = x11_display_offset; display_number < MAX_DISPLAYS; display_number++) { port = 6000 + display_number; - memset(&sin, 0, sizeof(sin)); - sin.sin_family = AF_INET; - sin.sin_addr.s_addr = htonl(INADDR_ANY); - sin.sin_port = htons(port); - - sock = socket(AF_INET, SOCK_STREAM, 0); - if (sock < 0) { - error("socket: %.100s", strerror(errno)); + memset(&hints, 0, sizeof(hints)); + hints.ai_family = IPv4or6; + hints.ai_flags = AI_PASSIVE; /* XXX loopback only ? */ + hints.ai_socktype = SOCK_STREAM; + snprintf(strport, sizeof strport, "%d", port); + if ((gaierr = getaddrinfo(NULL, strport, &hints, &aitop)) != 0) { + error("getaddrinfo: %.100s", gai_strerror(gaierr)); return NULL; } - if (bind(sock, (struct sockaddr *) & sin, sizeof(sin)) < 0) { - debug("bind port %d: %.100s", port, strerror(errno)); - shutdown(sock, SHUT_RDWR); - close(sock); - continue; + for (ai = aitop; ai; ai = ai->ai_next) { + if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6) + continue; + sock = socket(ai->ai_family, SOCK_STREAM, 0); + if (sock < 0) { + if ((errno != EINVAL) && (errno != EAFNOSUPPORT)) { + error("socket: %.100s", strerror(errno)); + return NULL; + } else { + debug("x11_create_display_inet: Socket family %d not supported", + ai->ai_family); + continue; + } + } + if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) { + debug("bind port %d: %.100s", port, strerror(errno)); + shutdown(sock, SHUT_RDWR); + close(sock); + + if (ai->ai_next) + continue; + + for (n = 0; n < num_socks; n++) { + shutdown(socks[n], SHUT_RDWR); + close(socks[n]); + } + num_socks = 0; + break; + } + socks[num_socks++] = sock; +#ifndef DONT_TRY_OTHER_AF + if (num_socks == NUM_SOCKS) + break; +#else + break; +#endif } - break; + freeaddrinfo(aitop); + if (num_socks > 0) + break; } if (display_number >= MAX_DISPLAYS) { error("Failed to allocate internet-domain X11 display socket."); return NULL; } /* Start listening for connections on the socket. */ - if (listen(sock, 5) < 0) { - error("listen: %.100s", strerror(errno)); - shutdown(sock, SHUT_RDWR); - close(sock); - return NULL; + for (n = 0; n < num_socks; n++) { + sock = socks[n]; + if (listen(sock, 5) < 0) { + error("listen: %.100s", strerror(errno)); + shutdown(sock, SHUT_RDWR); + close(sock); + return NULL; + } } - /* Set up a suitable value for the DISPLAY variable. */ + /* Set up a suitable value for the DISPLAY variable. */ if (gethostname(hostname, sizeof(hostname)) < 0) fatal("gethostname: %.100s", strerror(errno)); #ifdef IPADDR_IN_DISPLAY - /* + /* * HPUX detects the local hostname in the DISPLAY variable and tries * to set up a shared memory connection to the server, which it * incorrectly supposes to be local. @@ -1193,21 +1994,26 @@ x11_create_display_inet(int screen_number, int x11_display_offset) memcpy(&my_addr, he->h_addr_list[0], sizeof(struct in_addr)); /* Set DISPLAY to :screen.display */ - snprintf(buf, sizeof(buf), "%.50s:%d.%d", inet_ntoa(my_addr), - display_number, screen_number); + snprintf(display, sizeof(display), "%.50s:%d.%d", inet_ntoa(my_addr), + display_number, screen_number); } #else /* IPADDR_IN_DISPLAY */ /* Just set DISPLAY to hostname:screen.display */ - snprintf(buf, sizeof buf, "%.400s:%d.%d", hostname, - display_number, screen_number); + snprintf(display, sizeof display, "%.400s:%d.%d", hostname, + display_number, screen_number); #endif /* IPADDR_IN_DISPLAY */ - /* Allocate a channel for the socket. */ - (void) channel_allocate(SSH_CHANNEL_X11_LISTENER, sock, - xstrdup("X11 inet listener")); + /* Allocate a channel for each socket. */ + for (n = 0; n < num_socks; n++) { + sock = socks[n]; + (void) channel_new("x11 listener", + SSH_CHANNEL_X11_LISTENER, sock, sock, -1, + CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT, + 0, xstrdup("X11 inet listener"), 1); + } /* Return a suitable value for the DISPLAY environment variable. */ - return xstrdup(buf); + return xstrdup(display); } #ifndef X_UNIX_PATH @@ -1216,7 +2022,7 @@ x11_create_display_inet(int screen_number, int x11_display_offset) static int -connect_local_xsocket(unsigned int dnr) +connect_local_xsocket(u_int dnr) { static const char *const x_sockets[] = { X_UNIX_PATH "%u", @@ -1243,43 +2049,21 @@ connect_local_xsocket(unsigned int dnr) return -1; } - -/* - * This is called when SSH_SMSG_X11_OPEN is received. The packet contains - * the remote channel number. We should do whatever we want, and respond - * with either SSH_MSG_OPEN_CONFIRMATION or SSH_MSG_OPEN_FAILURE. - */ - -void -x11_input_open(int payload_len) +int +x11_connect_display(void) { - int remote_channel, display_number, sock, newch; + int display_number, sock = 0; const char *display; - struct sockaddr_in sin; - char buf[1024], *cp, *remote_host; - struct hostent *hp; - int remote_len; - - /* Get remote channel number. */ - remote_channel = packet_get_int(); - - /* Get remote originator name. */ - if (have_hostname_in_open) { - remote_host = packet_get_string(&remote_len); - remote_len += 4; - } else { - remote_host = xstrdup("unknown (remote did not supply name)"); - remote_len = 0; - } - - debug("Received X11 open request."); - packet_integrity_check(payload_len, 4 + remote_len, SSH_SMSG_X11_OPEN); + char buf[1024], *cp; + struct addrinfo hints, *ai, *aitop; + char strport[NI_MAXSERV]; + int gaierr; /* Try to open a socket for the local X server. */ display = getenv("DISPLAY"); if (!display) { error("DISPLAY not set."); - goto fail; + return -1; } /* * Now we decode the value of the DISPLAY variable and make a @@ -1296,15 +2080,15 @@ x11_input_open(int payload_len) if (sscanf(strrchr(display, ':') + 1, "%d", &display_number) != 1) { error("Could not parse display number from DISPLAY: %.100s", display); - goto fail; + return -1; } /* Create a socket. */ sock = connect_local_xsocket(display_number); if (sock < 0) - goto fail; + return -1; /* OK, we now have a connection to the display. */ - goto success; + return sock; } /* * Connect to an inet socket. The DISPLAY value is supposedly @@ -1315,75 +2099,121 @@ x11_input_open(int payload_len) cp = strchr(buf, ':'); if (!cp) { error("Could not find ':' in DISPLAY: %.100s", display); - goto fail; + return -1; } *cp = 0; /* buf now contains the host name. But first we parse the display number. */ if (sscanf(cp + 1, "%d", &display_number) != 1) { error("Could not parse display number from DISPLAY: %.100s", display); - goto fail; - } - /* Try to parse the host name as a numeric IP address. */ - memset(&sin, 0, sizeof(sin)); - sin.sin_addr.s_addr = inet_addr(buf); - if ((sin.sin_addr.s_addr & 0xffffffff) != 0xffffffff) { - /* It was a valid numeric host address. */ - sin.sin_family = AF_INET; - } else { - /* Not a numeric IP address. */ - /* Look up the host address from the name servers. */ - hp = gethostbyname(buf); - if (!hp) { - error("%.100s: unknown host.", buf); - goto fail; - } - if (!hp->h_addr_list[0]) { - error("%.100s: host has no IP address.", buf); - goto fail; - } - sin.sin_family = hp->h_addrtype; - memcpy(&sin.sin_addr, hp->h_addr_list[0], - sizeof(sin.sin_addr)); + return -1; } - /* Set port number. */ - sin.sin_port = htons(6000 + display_number); - /* Create a socket. */ - sock = socket(sin.sin_family, SOCK_STREAM, 0); - if (sock < 0) { - error("socket: %.100s", strerror(errno)); - goto fail; + /* Look up the host address */ + memset(&hints, 0, sizeof(hints)); + hints.ai_family = IPv4or6; + hints.ai_socktype = SOCK_STREAM; + snprintf(strport, sizeof strport, "%d", 6000 + display_number); + if ((gaierr = getaddrinfo(buf, strport, &hints, &aitop)) != 0) { + error("%.100s: unknown host. (%s)", buf, gai_strerror(gaierr)); + return -1; } - /* Connect it to the display. */ - if (connect(sock, (struct sockaddr *) & sin, sizeof(sin)) < 0) { - error("connect %.100s:%d: %.100s", buf, 6000 + display_number, - strerror(errno)); - close(sock); - goto fail; + for (ai = aitop; ai; ai = ai->ai_next) { + /* Create a socket. */ + sock = socket(ai->ai_family, SOCK_STREAM, 0); + if (sock < 0) { + debug("socket: %.100s", strerror(errno)); + continue; + } + /* Connect it to the display. */ + if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0) { + debug("connect %.100s port %d: %.100s", buf, + 6000 + display_number, strerror(errno)); + close(sock); + continue; + } + /* Success */ + break; } -success: - /* We have successfully obtained a connection to the real X display. */ + freeaddrinfo(aitop); + if (!ai) { + error("connect %.100s port %d: %.100s", buf, 6000 + display_number, + strerror(errno)); + return -1; + } + return sock; +} - /* Allocate a channel for this connection. */ - if (x11_saved_proto == NULL) - newch = channel_allocate(SSH_CHANNEL_OPEN, sock, remote_host); - else - newch = channel_allocate(SSH_CHANNEL_X11_OPEN, sock, remote_host); - channels[newch].remote_id = remote_channel; +/* + * This is called when SSH_SMSG_X11_OPEN is received. The packet contains + * the remote channel number. We should do whatever we want, and respond + * with either SSH_MSG_OPEN_CONFIRMATION or SSH_MSG_OPEN_FAILURE. + */ - /* Send a confirmation to the remote host. */ - packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION); - packet_put_int(remote_channel); - packet_put_int(newch); - packet_send(); +void +x11_input_open(int type, int plen, void *ctxt) +{ + int remote_channel, sock = 0, newch; + char *remote_host; + u_int remote_len; + + /* Get remote channel number. */ + remote_channel = packet_get_int(); - return; + /* Get remote originator name. */ + if (have_hostname_in_open) { + remote_host = packet_get_string(&remote_len); + remote_len += 4; + } else { + remote_host = xstrdup("unknown (remote did not supply name)"); + remote_len = 0; + } + + debug("Received X11 open request."); + packet_integrity_check(plen, 4 + remote_len, SSH_SMSG_X11_OPEN); + + /* Obtain a connection to the real X display. */ + sock = x11_connect_display(); + if (sock == -1) { + /* Send refusal to the remote host. */ + packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE); + packet_put_int(remote_channel); + packet_send(); + } else { + /* Allocate a channel for this connection. */ + newch = channel_allocate( + (x11_saved_proto == NULL) ? + SSH_CHANNEL_OPEN : SSH_CHANNEL_X11_OPEN, + sock, remote_host); + channels[newch].remote_id = remote_channel; + + /* Send a confirmation to the remote host. */ + packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION); + packet_put_int(remote_channel); + packet_put_int(newch); + packet_send(); + } +} -fail: - /* Send refusal to the remote host. */ +/* dummy protocol handler that denies SSH-1 requests (agent/x11) */ +void +deny_input_open(int type, int plen, void *ctxt) +{ + int rchan = packet_get_int(); + switch(type){ + case SSH_SMSG_AGENT_OPEN: + error("Warning: ssh server tried agent forwarding."); + break; + case SSH_SMSG_X11_OPEN: + error("Warning: ssh server tried X11 forwarding."); + break; + default: + error("deny_input_open: type %d plen %d", type, plen); + break; + } + error("Warning: this is probably a break in attempt by a malicious server."); packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE); - packet_put_int(remote_channel); + packet_put_int(rchan); packet_send(); } @@ -1392,11 +2222,12 @@ fail: * data, and enables authentication spoofing. */ -void -x11_request_forwarding_with_spoofing(const char *proto, const char *data) +void +x11_request_forwarding_with_spoofing(int client_session_id, + const char *proto, const char *data) { - unsigned int data_len = (unsigned int) strlen(data) / 2; - unsigned int i, value; + u_int data_len = (u_int) strlen(data) / 2; + u_int i, value; char *new_data; int screen_number; const char *cp; @@ -1436,12 +2267,17 @@ x11_request_forwarding_with_spoofing(const char *proto, const char *data) /* Convert the fake data into hex. */ new_data = xmalloc(2 * data_len + 1); for (i = 0; i < data_len; i++) - sprintf(new_data + 2 * i, "%02x", (unsigned char) x11_fake_data[i]); + sprintf(new_data + 2 * i, "%02x", (u_char) x11_fake_data[i]); /* Send the request packet. */ - packet_start(SSH_CMSG_X11_REQUEST_FORWARDING); - packet_put_string(proto, strlen(proto)); - packet_put_string(new_data, strlen(new_data)); + if (compat20) { + channel_request_start(client_session_id, "x11-req", 0); + packet_put_char(0); /* XXX bool single connection */ + } else { + packet_start(SSH_CMSG_X11_REQUEST_FORWARDING); + } + packet_put_cstring(proto); + packet_put_cstring(new_data); packet_put_int(screen_number); packet_send(); packet_write_wait(); @@ -1450,7 +2286,7 @@ x11_request_forwarding_with_spoofing(const char *proto, const char *data) /* Sends a message to the server to request authentication fd forwarding. */ -void +void auth_request_forwarding() { packet_start(SSH_CMSG_AGENT_REQUEST_FORWARDING); @@ -1472,19 +2308,19 @@ auth_get_socket_name() /* removes the agent forwarding socket */ -void +void cleanup_socket(void) { - remove(channel_forwarded_auth_socket_name); + unlink(channel_forwarded_auth_socket_name); rmdir(channel_forwarded_auth_socket_dir); } /* - * This if called to process SSH_CMSG_AGENT_REQUEST_FORWARDING on the server. + * This is called to process SSH_CMSG_AGENT_REQUEST_FORWARDING on the server. * This starts forwarding authentication requests. */ -void +int auth_input_request_forwarding(struct passwd * pw) { int sock, newch; @@ -1502,8 +2338,16 @@ auth_input_request_forwarding(struct passwd * pw) strlcpy(channel_forwarded_auth_socket_dir, "/tmp/ssh-XXXXXXXX", MAX_SOCKET_NAME); /* Create private directory for socket */ - if (mkdtemp(channel_forwarded_auth_socket_dir) == NULL) - packet_disconnect("mkdtemp: %.100s", strerror(errno)); + if (mkdtemp(channel_forwarded_auth_socket_dir) == NULL) { + packet_send_debug("Agent forwarding disabled: mkdtemp() failed: %.100s", + strerror(errno)); + restore_uid(); + xfree(channel_forwarded_auth_socket_name); + xfree(channel_forwarded_auth_socket_dir); + channel_forwarded_auth_socket_name = NULL; + channel_forwarded_auth_socket_dir = NULL; + return 0; + } snprintf(channel_forwarded_auth_socket_name, MAX_SOCKET_NAME, "%s/agent.%d", channel_forwarded_auth_socket_dir, (int) getpid()); @@ -1534,20 +2378,26 @@ auth_input_request_forwarding(struct passwd * pw) packet_disconnect("listen: %.100s", strerror(errno)); /* Allocate a channel for the authentication agent socket. */ - newch = channel_allocate(SSH_CHANNEL_AUTH_SOCKET, sock, - xstrdup("auth socket")); + newch = channel_new("auth socket", + SSH_CHANNEL_AUTH_SOCKET, sock, sock, -1, + CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT, + 0, xstrdup("auth socket"), 1); + strlcpy(channels[newch].path, channel_forwarded_auth_socket_name, sizeof(channels[newch].path)); + return 1; } /* This is called to process an SSH_SMSG_AGENT_OPEN message. */ -void -auth_input_open_request() +void +auth_input_open_request(int type, int plen, void *ctxt) { int remch, sock, newch; char *dummyname; + packet_integrity_check(plen, 4, type); + /* Read the remote channel number from the message. */ remch = packet_get_int(); @@ -1587,3 +2437,105 @@ auth_input_open_request() packet_put_int(newch); packet_send(); } + +void +channel_start_open(int id) +{ + Channel *c = channel_lookup(id); + if (c == NULL) { + log("channel_open: %d: bad id", id); + return; + } + debug("send channel open %d", id); + packet_start(SSH2_MSG_CHANNEL_OPEN); + packet_put_cstring(c->ctype); + packet_put_int(c->self); + packet_put_int(c->local_window); + packet_put_int(c->local_maxpacket); +} +void +channel_open(int id) +{ + /* XXX REMOVE ME */ + channel_start_open(id); + packet_send(); +} +void +channel_request(int id, char *service, int wantconfirm) +{ + channel_request_start(id, service, wantconfirm); + packet_send(); + debug("channel request %d: %s", id, service) ; +} +void +channel_request_start(int id, char *service, int wantconfirm) +{ + Channel *c = channel_lookup(id); + if (c == NULL) { + log("channel_request: %d: bad id", id); + return; + } + packet_start(SSH2_MSG_CHANNEL_REQUEST); + packet_put_int(c->remote_id); + packet_put_cstring(service); + packet_put_char(wantconfirm); +} +void +channel_register_callback(int id, int mtype, channel_callback_fn *fn, void *arg) +{ + Channel *c = channel_lookup(id); + if (c == NULL) { + log("channel_register_callback: %d: bad id", id); + return; + } + c->cb_event = mtype; + c->cb_fn = fn; + c->cb_arg = arg; +} +void +channel_register_cleanup(int id, channel_callback_fn *fn) +{ + Channel *c = channel_lookup(id); + if (c == NULL) { + log("channel_register_cleanup: %d: bad id", id); + return; + } + c->dettach_user = fn; +} +void +channel_cancel_cleanup(int id) +{ + Channel *c = channel_lookup(id); + if (c == NULL) { + log("channel_cancel_cleanup: %d: bad id", id); + return; + } + c->dettach_user = NULL; +} +void +channel_register_filter(int id, channel_filter_fn *fn) +{ + Channel *c = channel_lookup(id); + if (c == NULL) { + log("channel_register_filter: %d: bad id", id); + return; + } + c->input_filter = fn; +} + +void +channel_set_fds(int id, int rfd, int wfd, int efd, + int extusage, int nonblock) +{ + Channel *c = channel_lookup(id); + if (c == NULL || c->type != SSH_CHANNEL_LARVAL) + fatal("channel_activate for non-larval channel %d.", id); + channel_register_fds(c, rfd, wfd, efd, extusage, nonblock); + c->type = SSH_CHANNEL_OPEN; + /* XXX window size? */ + c->local_window = c->local_window_max = c->local_maxpacket * 2; + packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST); + packet_put_int(c->remote_id); + packet_put_int(c->local_window); + packet_send(); +}