=================================================================== RCS file: /cvsrepo/anoncvs/cvs/src/usr.bin/ssh/channels.c,v retrieving revision 1.72 retrieving revision 1.72.2.7 diff -u -r1.72 -r1.72.2.7 --- src/usr.bin/ssh/channels.c 2000/10/27 07:48:22 1.72 +++ src/usr.bin/ssh/channels.c 2001/11/15 00:14:59 1.72.2.7 @@ -12,9 +12,8 @@ * 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, 2000, 2001 Markus Friedl. All rights reserved. * Copyright (c) 1999 Dug Song. All rights reserved. * Copyright (c) 1999 Theo de Raadt. All rights reserved. * @@ -40,71 +39,47 @@ */ #include "includes.h" -RCSID("$OpenBSD: channels.c,v 1.72 2000/10/27 07:48:22 markus Exp $"); +RCSID("$OpenBSD: channels.c,v 1.72.2.7 2001/11/15 00:14:59 miod Exp $"); #include "ssh.h" +#include "ssh1.h" +#include "ssh2.h" #include "packet.h" #include "xmalloc.h" -#include "buffer.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 "ssh2.h" - -#include -#include +#include "canohost.h" #include "key.h" #include "authfd.h" -/* Maximum number of fake X11 displays to try. */ -#define MAX_DISPLAYS 1000 -/* Max len of agent socket */ -#define MAX_SOCKET_NAME 100 +/* -- channel core */ /* * Pointer to an array containing all allocated channels. The array is * dynamically extended as needed. */ -static Channel *channels = NULL; +static Channel **channels = NULL; /* * Size of the channel array. All slots of the array must always be - * initialized (at least the type field); unused slots are marked with type - * SSH_CHANNEL_FREE. + * initialized (at least the type field); unused slots set to NULL */ static int channels_alloc = 0; /* * Maximum file descriptor value used in any of the channels. This is - * updated in channel_allocate. + * updated in channel_new. */ -static int channel_max_fd_value = 0; +static int channel_max_fd = 0; -/* Name and directory of socket for authentication agent forwarding. */ -static char *channel_forwarded_auth_socket_name = NULL; -static char *channel_forwarded_auth_socket_dir = NULL; -/* Saved X11 authentication protocol name. */ -char *x11_saved_proto = NULL; +/* -- tcp forwarding */ -/* Saved X11 authentication data. This is the real data. */ -char *x11_saved_data = NULL; -unsigned int x11_saved_data_len = 0; - /* - * Fake X11 authentication data. This is what the server will be sending us; - * we should replace any occurrences of this by the real data. - */ -char *x11_fake_data = NULL; -unsigned int x11_fake_data_len; - -/* * 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 @@ -118,6 +93,7 @@ /* List of all permitted host/port pairs to connect. */ static ForwardPermission permitted_opens[SSH_MAX_FORWARDS_PER_DIRECTION]; + /* Number of permitted host/port pairs in the array. */ static int num_permitted_opens = 0; /* @@ -127,41 +103,54 @@ */ static int all_opens_permitted = 0; -/* This is set to true if both sides support SSH_PROTOFLAG_HOST_IN_FWD_OPEN. */ -static int have_hostname_in_open = 0; -/* Sets specific protocol options. */ +/* -- X11 forwarding */ -void -channel_set_options(int hostname_in_open) -{ - have_hostname_in_open = hostname_in_open; -} +/* Maximum number of fake X11 displays to try. */ +#define MAX_DISPLAYS 1000 +/* Saved X11 authentication protocol name. */ +static char *x11_saved_proto = NULL; + +/* Saved X11 authentication data. This is the real data. */ +static char *x11_saved_data = NULL; +static u_int x11_saved_data_len = 0; + /* - * Permits opening to any host/port in SSH_MSG_PORT_OPEN. This is usually - * called by the server, because the user could connect to any port anyway, - * and the server has no way to know but to trust the client anyway. + * Fake X11 authentication data. This is what the server will be sending us; + * we should replace any occurrences of this by the real data. */ +static char *x11_fake_data = NULL; +static u_int x11_fake_data_len; -void -channel_permit_all_opens() -{ - all_opens_permitted = 1; -} -/* lookup channel by id */ +/* -- agent forwarding */ +#define NUM_SOCKS 10 + +/* Name and directory of socket for authentication agent forwarding. */ +static char *auth_sock_name = NULL; +static char *auth_sock_dir = NULL; + +/* AF_UNSPEC or AF_INET or AF_INET6 */ +static int IPv4or6 = AF_UNSPEC; + +/* helper */ +static void port_open_helper(Channel *c, char *rtype); + +/* -- channel core */ + 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) { + c = channels[id]; + if (c == NULL) { log("channel_lookup: %d: bad id: channel free", id); return NULL; } @@ -173,17 +162,15 @@ * when the channel consumer/producer is ready, e.g. shell exec'd */ -void +static void channel_register_fds(Channel *c, int rfd, int wfd, int efd, int extusage, int nonblock) { /* Update the maximum file descriptor value. */ - if (rfd > channel_max_fd_value) - channel_max_fd_value = rfd; - if (wfd > channel_max_fd_value) - channel_max_fd_value = wfd; - if (efd > channel_max_fd_value) - channel_max_fd_value = efd; + 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; @@ -192,6 +179,18 @@ c->efd = efd; c->extended_usage = extusage; + /* XXX ugly hack: nonblock is only set by the server */ + if (nonblock && isatty(c->rfd)) { + debug("channel %d: rfd %d isatty", c->self, c->rfd); + c->isatty = 1; + if (!isatty(c->wfd)) { + error("channel %d: wfd %d is not a tty?", + c->self, c->wfd); + } + } else { + c->isatty = 0; + } + /* enable nonblocking mode */ if (nonblock) { if (rfd != -1) @@ -208,7 +207,7 @@ * remote_name to be freed. */ -int +Channel * channel_new(char *ctype, int type, int rfd, int wfd, int efd, int window, int maxpack, int extusage, char *remote_name, int nonblock) { @@ -219,18 +218,14 @@ if (channels_alloc == 0) { chan_init(); channels_alloc = 10; - channels = xmalloc(channels_alloc * sizeof(Channel)); + channels = xmalloc(channels_alloc * sizeof(Channel *)); for (i = 0; i < channels_alloc; i++) - channels[i].type = SSH_CHANNEL_FREE; - /* - * Kludge: arrange a call to channel_stop_listening if we - * terminate with fatal(). - */ - fatal_add_cleanup((void (*) (void *)) channel_stop_listening, NULL); + channels[i] = NULL; + fatal_add_cleanup((void (*) (void *)) channel_free_all, NULL); } /* Try to find a free slot where to put the new channel. */ for (found = -1, i = 0; i < channels_alloc; i++) - if (channels[i].type == SSH_CHANNEL_FREE) { + if (channels[i] == NULL) { /* Found a free slot. */ found = i; break; @@ -240,12 +235,13 @@ found = channels_alloc; channels_alloc += 10; debug2("channel: expanding %d", channels_alloc); - channels = xrealloc(channels, channels_alloc * sizeof(Channel)); + channels = xrealloc(channels, channels_alloc * sizeof(Channel *)); for (i = found; i < channels_alloc; i++) - channels[i].type = SSH_CHANNEL_FREE; + channels[i] = NULL; } - /* Initialize and return new channel number. */ - c = &channels[found]; + /* Initialize and return new channel. */ + c = channels[found] = xmalloc(sizeof(Channel)); + memset(c, 0, sizeof(Channel)); buffer_init(&c->input); buffer_init(&c->output); buffer_init(&c->extended); @@ -265,69 +261,412 @@ c->cb_fn = NULL; c->cb_arg = NULL; c->cb_event = 0; - c->dettach_user = NULL; + c->force_drain = 0; + c->detach_user = NULL; c->input_filter = NULL; debug("channel %d: new [%s]", found, remote_name); - return found; + return c; } -/* old interface XXX */ -int -channel_allocate(int type, int sock, char *remote_name) + +static int +channel_find_maxfd(void) { - return channel_new("", type, sock, sock, -1, 0, 0, 0, remote_name, 1); + int i, max = 0; + Channel *c; + + for (i = 0; i < channels_alloc; i++) { + c = channels[i]; + if (c != NULL) { + max = MAX(max, c->rfd); + max = MAX(max, c->wfd); + max = MAX(max, c->efd); + } + } + return max; } +int +channel_close_fd(int *fdp) +{ + int ret = 0, fd = *fdp; + if (fd != -1) { + ret = close(fd); + *fdp = -1; + if (fd == channel_max_fd) + channel_max_fd = channel_find_maxfd(); + } + return ret; +} + /* Close all channel fd/socket. */ -void +static void channel_close_fds(Channel *c) { - if (c->sock != -1) { - close(c->sock); - c->sock = -1; - } - if (c->rfd != -1) { - close(c->rfd); - c->rfd = -1; - } - if (c->wfd != -1) { - close(c->wfd); - c->wfd = -1; - } - if (c->efd != -1) { - close(c->efd); - c->efd = -1; - } + debug3("channel_close_fds: channel %d: r %d w %d e %d", + c->self, c->rfd, c->wfd, c->efd); + + 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(int id) +channel_free(Channel *c) { - Channel *c = channel_lookup(id); - if (c == NULL) - packet_disconnect("channel free: bad local channel %d", id); - debug("channel_free: channel %d: status: %s", id, channel_open_message()); - if (c->dettach_user != NULL) { - debug("channel_free: channel %d: dettaching channel user", id); - c->dettach_user(c->self, NULL); - } + char *s; + int i, n; + + for (n = 0, i = 0; i < channels_alloc; i++) + if (channels[i]) + n++; + debug("channel_free: channel %d: %s, nchannels %d", c->self, + c->remote_name ? c->remote_name : "???", n); + + s = channel_open_message(); + debug3("channel_free: status: %s", s); + xfree(s); + if (c->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; } + channels[c->self] = NULL; + xfree(c); } +void +channel_free_all(void) +{ + 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() +{ + 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) +{ + int i; + Channel *c; + + for (i = 0; i < channels_alloc; i++) { + c = channels[i]; + if (c != NULL) { + switch (c->type) { + case SSH_CHANNEL_AUTH_SOCKET: + case SSH_CHANNEL_PORT_LISTENER: + case SSH_CHANNEL_RPORT_LISTENER: + case SSH_CHANNEL_X11_LISTENER: + channel_close_fd(&c->sock); + channel_free(c); + break; + } + } + } +} + +/* + * Returns true if no channel has too much buffered data, and false if one or + * more channel is overfull. + */ + +int +channel_not_very_much_buffered_data() +{ + 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()) { + debug("channel %d: big input buffer %d", + c->self, buffer_len(&c->input)); + return 0; + } +#endif + if (buffer_len(&c->output) > packet_get_maxsize()) { + debug("channel %d: big output buffer %d > %d", + 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() +{ + int i; + Channel *c; + + for (i = 0; i < channels_alloc; i++) { + c = channels[i]; + if (c == NULL) + continue; + switch (c->type) { + case SSH_CHANNEL_X11_LISTENER: + case SSH_CHANNEL_PORT_LISTENER: + case SSH_CHANNEL_RPORT_LISTENER: + case SSH_CHANNEL_CLOSED: + case SSH_CHANNEL_AUTH_SOCKET: + case SSH_CHANNEL_DYNAMIC: + case SSH_CHANNEL_CONNECTING: + case SSH_CHANNEL_ZOMBIE: + continue; + case SSH_CHANNEL_LARVAL: + if (!compat20) + fatal("cannot happen: SSH_CHANNEL_LARVAL"); + continue; + case SSH_CHANNEL_OPENING: + case SSH_CHANNEL_OPEN: + case SSH_CHANNEL_X11_OPEN: + return 1; + case SSH_CHANNEL_INPUT_DRAINING: + case SSH_CHANNEL_OUTPUT_DRAINING: + if (!compat13) + fatal("cannot happen: OUT_DRAIN"); + return 1; + default: + fatal("channel_still_open: bad channel type %d", c->type); + /* NOTREACHED */ + } + } + return 0; +} + +/* Returns the id of an open channel suitable for keepaliving */ + +int +channel_find_open() +{ + int i; + Channel *c; + + for (i = 0; i < channels_alloc; i++) { + c = channels[i]; + if (c == NULL) + continue; + switch (c->type) { + case SSH_CHANNEL_CLOSED: + case SSH_CHANNEL_DYNAMIC: + case SSH_CHANNEL_X11_LISTENER: + case SSH_CHANNEL_PORT_LISTENER: + case SSH_CHANNEL_RPORT_LISTENER: + case SSH_CHANNEL_OPENING: + case SSH_CHANNEL_CONNECTING: + case SSH_CHANNEL_ZOMBIE: + continue; + case SSH_CHANNEL_LARVAL: + case SSH_CHANNEL_AUTH_SOCKET: + case SSH_CHANNEL_OPEN: + case SSH_CHANNEL_X11_OPEN: + return i; + case SSH_CHANNEL_INPUT_DRAINING: + case SSH_CHANNEL_OUTPUT_DRAINING: + if (!compat13) + fatal("cannot happen: OUT_DRAIN"); + return i; + default: + fatal("channel_find_open: bad channel type %d", c->type); + /* NOTREACHED */ + } + } + return -1; +} + + +/* + * Returns a message describing the currently open forwarded connections, + * suitable for sending to the client. The message contains crlf pairs for + * newlines. + */ + +char * +channel_open_message() +{ + Buffer buffer; + Channel *c; + char buf[1024], *cp; + int i; + + buffer_init(&buffer); + snprintf(buf, sizeof buf, "The following connections are open:\r\n"); + buffer_append(&buffer, buf, strlen(buf)); + for (i = 0; i < channels_alloc; i++) { + c = channels[i]; + if (c == NULL) + continue; + switch (c->type) { + case SSH_CHANNEL_X11_LISTENER: + case SSH_CHANNEL_PORT_LISTENER: + case SSH_CHANNEL_RPORT_LISTENER: + case SSH_CHANNEL_CLOSED: + case SSH_CHANNEL_AUTH_SOCKET: + case SSH_CHANNEL_ZOMBIE: + continue; + case SSH_CHANNEL_LARVAL: + case SSH_CHANNEL_OPENING: + case SSH_CHANNEL_CONNECTING: + case SSH_CHANNEL_DYNAMIC: + case SSH_CHANNEL_OPEN: + case SSH_CHANNEL_X11_OPEN: + case SSH_CHANNEL_INPUT_DRAINING: + case SSH_CHANNEL_OUTPUT_DRAINING: + snprintf(buf, sizeof buf, " #%d %.300s (t%d r%d i%d/%d o%d/%d fd %d/%d)\r\n", + c->self, c->remote_name, + c->type, c->remote_id, + c->istate, buffer_len(&c->input), + c->ostate, buffer_len(&c->output), + c->rfd, c->wfd); + buffer_append(&buffer, buf, strlen(buf)); + continue; + default: + fatal("channel_open_message: bad channel type %d", c->type); + /* NOTREACHED */ + } + } + buffer_append(&buffer, "\0", 1); + cp = xstrdup(buffer_ptr(&buffer)); + buffer_free(&buffer); + return cp; +} + +void +channel_send_open(int id) +{ + Channel *c = channel_lookup(id); + if (c == NULL) { + log("channel_send_open: %d: bad id", id); + return; + } + debug("send channel open %d", id); + packet_start(SSH2_MSG_CHANNEL_OPEN); + packet_put_cstring(c->ctype); + packet_put_int(c->self); + packet_put_int(c->local_window); + packet_put_int(c->local_maxpacket); + packet_send(); +} + +void +channel_request(int id, char *service, int wantconfirm) +{ + channel_request_start(id, service, wantconfirm); + packet_send(); + debug("channel request %d: %s", id, service) ; +} +void +channel_request_start(int id, char *service, int wantconfirm) +{ + Channel *c = channel_lookup(id); + if (c == NULL) { + log("channel_request: %d: bad id", id); + return; + } + packet_start(SSH2_MSG_CHANNEL_REQUEST); + packet_put_int(c->remote_id); + packet_put_cstring(service); + packet_put_char(wantconfirm); +} +void +channel_register_callback(int id, int mtype, channel_callback_fn *fn, void *arg) +{ + Channel *c = channel_lookup(id); + if (c == NULL) { + log("channel_register_callback: %d: bad id", id); + return; + } + c->cb_event = mtype; + c->cb_fn = fn; + c->cb_arg = arg; +} +void +channel_register_cleanup(int id, channel_callback_fn *fn) +{ + Channel *c = channel_lookup(id); + if (c == NULL) { + log("channel_register_cleanup: %d: bad id", id); + return; + } + c->detach_user = fn; +} +void +channel_cancel_cleanup(int id) +{ + Channel *c = channel_lookup(id); + if (c == NULL) { + log("channel_cancel_cleanup: %d: bad id", id); + return; + } + c->detach_user = NULL; +} +void +channel_register_filter(int id, channel_filter_fn *fn) +{ + Channel *c = channel_lookup(id); + if (c == NULL) { + log("channel_register_filter: %d: bad id", id); + return; + } + c->input_filter = fn; +} + +void +channel_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(); +} + +/* * 'channel_pre*' are called just before select() to add any bits relevant to * channels in the select bitmasks. */ @@ -339,13 +678,20 @@ chan_fn *channel_pre[SSH_CHANNEL_MAX_TYPE]; chan_fn *channel_post[SSH_CHANNEL_MAX_TYPE]; -void +static void channel_pre_listener(Channel *c, fd_set * readset, fd_set * writeset) { FD_SET(c->sock, readset); } -void +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()) @@ -354,7 +700,7 @@ FD_SET(c->sock, writeset); } -void +static void channel_pre_open_15(Channel *c, fd_set * readset, fd_set * writeset) { /* test whether sockets are 'alive' for read/write */ @@ -371,7 +717,7 @@ } } -void +static void channel_pre_open_20(Channel *c, fd_set * readset, fd_set * writeset) { if (c->istate == CHAN_INPUT_OPEN && @@ -397,7 +743,7 @@ } } -void +static void channel_pre_input_draining(Channel *c, fd_set * readset, fd_set * writeset) { if (buffer_len(&c->input) == 0) { @@ -405,15 +751,15 @@ packet_put_int(c->remote_id); packet_send(); c->type = SSH_CHANNEL_CLOSED; - debug("Closing channel %d after input drain.", c->self); + debug("channel %d: closing after input drain.", c->self); } } -void +static void channel_pre_output_draining(Channel *c, fd_set * readset, fd_set * writeset) { if (buffer_len(&c->output) == 0) - channel_free(c->self); + chan_mark_dead(c); else FD_SET(c->sock, writeset); } @@ -425,19 +771,20 @@ * 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 */ -int -x11_open_helper(Channel *c) +static int +x11_open_helper(Buffer *b) { - unsigned char *ucp; - unsigned int proto_len, data_len; + 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) + if (buffer_len(b) < 12) return 0; /* Parse the lengths of variable-length fields. */ - ucp = (unsigned char *) buffer_ptr(&c->output); + ucp = (u_char *) buffer_ptr(b); if (ucp[0] == 0x42) { /* Byte order MSB first. */ proto_len = 256 * ucp[6] + ucp[7]; data_len = 256 * ucp[8] + ucp[9]; @@ -451,7 +798,7 @@ } /* Check if the whole packet is in buffer. */ - if (buffer_len(&c->output) < + if (buffer_len(b) < 12 + ((proto_len + 3) & ~3) + ((data_len + 3) & ~3)) return 0; @@ -484,10 +831,10 @@ return 1; } -void +static void channel_pre_x11_open_13(Channel *c, fd_set * readset, fd_set * writeset) { - int ret = x11_open_helper(c); + int ret = x11_open_helper(&c->output); if (ret == 1) { /* Start normal processing for the channel. */ c->type = SSH_CHANNEL_OPEN; @@ -497,10 +844,10 @@ * We have received an X11 connection that has bad * authentication information. */ - log("X11 connection rejected because of wrong authentication.\r\n"); + log("X11 connection rejected because of wrong authentication."); buffer_clear(&c->input); buffer_clear(&c->output); - close(c->sock); + channel_close_fd(&c->sock); c->sock = -1; c->type = SSH_CHANNEL_CLOSED; packet_start(SSH_MSG_CHANNEL_CLOSE); @@ -509,10 +856,13 @@ } } -void +static void channel_pre_x11_open(Channel *c, fd_set * readset, fd_set * writeset) { - int ret = x11_open_helper(c); + int ret = x11_open_helper(&c->output); + + /* c->force_drain = 1; */ + if (ret == 1) { c->type = SSH_CHANNEL_OPEN; if (compat20) @@ -527,14 +877,125 @@ } } +/* try to decode a socks4 header */ +static int +channel_decode_socks4(Channel *c, fd_set * readset, fd_set * writeset) +{ + u_char *p, *host; + int len, have, i, found; + char username[256]; + struct { + u_int8_t version; + u_int8_t command; + u_int16_t dest_port; + struct in_addr dest_addr; + } s4_req, s4_rsp; + + debug2("channel %d: decode socks4", c->self); + + have = buffer_len(&c->input); + len = sizeof(s4_req); + if (have < len) + return 0; + p = buffer_ptr(&c->input); + for (found = 0, i = len; i < have; i++) { + if (p[i] == '\0') { + found = 1; + break; + } + if (i > 1024) { + /* the peer is probably sending garbage */ + debug("channel %d: decode socks4: too long", + c->self); + return -1; + } + } + if (!found) + return 0; + buffer_get(&c->input, (char *)&s4_req.version, 1); + buffer_get(&c->input, (char *)&s4_req.command, 1); + buffer_get(&c->input, (char *)&s4_req.dest_port, 2); + buffer_get(&c->input, (char *)&s4_req.dest_addr, 4); + have = buffer_len(&c->input); + p = buffer_ptr(&c->input); + len = strlen(p); + debug2("channel %d: decode socks4: user %s/%d", c->self, p, len); + if (len > have) + fatal("channel %d: decode socks4: len %d > have %d", + c->self, len, have); + strlcpy(username, p, sizeof(username)); + buffer_consume(&c->input, len); + buffer_consume(&c->input, 1); /* trailing '\0' */ + + host = inet_ntoa(s4_req.dest_addr); + strlcpy(c->path, host, sizeof(c->path)); + c->host_port = ntohs(s4_req.dest_port); + + debug("channel %d: dynamic request: socks4 host %s port %u command %u", + c->self, host, c->host_port, s4_req.command); + + if (s4_req.command != 1) { + debug("channel %d: cannot handle: socks4 cn %d", + c->self, s4_req.command); + return -1; + } + s4_rsp.version = 0; /* vn: 0 for reply */ + s4_rsp.command = 90; /* cd: req granted */ + s4_rsp.dest_port = 0; /* ignored */ + s4_rsp.dest_addr.s_addr = INADDR_ANY; /* ignored */ + buffer_append(&c->output, (char *)&s4_rsp, sizeof(s4_rsp)); + return 1; +} + +/* dynamic port forwarding */ +static void +channel_pre_dynamic(Channel *c, fd_set * readset, fd_set * writeset) +{ + u_char *p; + int have, ret; + + have = buffer_len(&c->input); + c->delayed = 0; + debug2("channel %d: pre_dynamic: have %d", c->self, have); + /* buffer_dump(&c->input); */ + /* check if the fixed size part of the packet is in buffer. */ + if (have < 4) { + /* need more */ + FD_SET(c->sock, readset); + return; + } + /* try to guess the protocol */ + p = buffer_ptr(&c->input); + switch (p[0]) { + case 0x04: + ret = channel_decode_socks4(c, readset, writeset); + break; + default: + ret = -1; + break; + } + if (ret < 0) { + chan_mark_dead(c); + } else if (ret == 0) { + debug2("channel %d: pre_dynamic: need more", c->self); + /* need more */ + FD_SET(c->sock, readset); + } else { + /* switch to the next state */ + c->type = SSH_CHANNEL_OPENING; + port_open_helper(c, "direct-tcpip"); + } +} + /* This is our fake X11 server socket. */ -void +static void channel_post_x11_listener(Channel *c, fd_set * readset, fd_set * writeset) { + Channel *nc; struct sockaddr addr; - int newsock, newch; + int newsock; socklen_t addrlen; - char buf[16384], *remote_hostname; + char buf[16384], *remote_ipaddr; int remote_port; if (FD_ISSET(c->sock, readset)) { @@ -545,23 +1006,28 @@ error("accept: %.100s", strerror(errno)); return; } - remote_hostname = get_remote_hostname(newsock); + remote_ipaddr = get_peer_ipaddr(newsock); remote_port = get_peer_port(newsock); snprintf(buf, sizeof buf, "X11 connection from %.200s port %d", - remote_hostname, remote_port); + remote_ipaddr, remote_port); - newch = channel_new("x11", + nc = channel_new("accepted x11 socket", SSH_CHANNEL_OPENING, newsock, newsock, -1, c->local_window_max, c->local_maxpacket, 0, xstrdup(buf), 1); + if (nc == NULL) { + close(newsock); + xfree(remote_ipaddr); + return; + } if (compat20) { packet_start(SSH2_MSG_CHANNEL_OPEN); packet_put_cstring("x11"); - packet_put_int(newch); + packet_put_int(nc->self); packet_put_int(c->local_window_max); packet_put_int(c->local_maxpacket); - /* originator host and port */ - packet_put_cstring(remote_hostname); + /* originator ipaddr and port */ + packet_put_cstring(remote_ipaddr); if (datafellows & SSH_BUG_X11FWD) { debug("ssh2 x11 bug compat mode"); } else { @@ -570,72 +1036,126 @@ 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_put_int(nc->self); + if (packet_get_protocol_flags() & + SSH_PROTOFLAG_HOST_IN_FWD_OPEN) + packet_put_cstring(buf); packet_send(); } - xfree(remote_hostname); + xfree(remote_ipaddr); } } +static void +port_open_helper(Channel *c, char *rtype) +{ + int direct; + char buf[1024]; + char *remote_ipaddr = get_peer_ipaddr(c->sock); + u_short remote_port = get_peer_port(c->sock); + + direct = (strcmp(rtype, "direct-tcpip") == 0); + + snprintf(buf, sizeof buf, + "%s: listening port %d for %.100s port %d, " + "connect from %.200s port %d", + rtype, c->listening_port, c->path, c->host_port, + remote_ipaddr, remote_port); + + xfree(c->remote_name); + c->remote_name = xstrdup(buf); + + if (compat20) { + packet_start(SSH2_MSG_CHANNEL_OPEN); + packet_put_cstring(rtype); + packet_put_int(c->self); + packet_put_int(c->local_window_max); + packet_put_int(c->local_maxpacket); + if (direct) { + /* target host, port */ + packet_put_cstring(c->path); + packet_put_int(c->host_port); + } else { + /* listen address, port */ + packet_put_cstring(c->path); + packet_put_int(c->listening_port); + } + /* originator host and port */ + packet_put_cstring(remote_ipaddr); + packet_put_int(remote_port); + packet_send(); + } else { + packet_start(SSH_MSG_PORT_OPEN); + packet_put_int(c->self); + packet_put_cstring(c->path); + packet_put_int(c->host_port); + if (packet_get_protocol_flags() & + SSH_PROTOFLAG_HOST_IN_FWD_OPEN) + packet_put_cstring(c->remote_name); + packet_send(); + } + xfree(remote_ipaddr); +} + /* * This socket is listening for connections to a forwarded TCP/IP port. */ -void +static void channel_post_port_listener(Channel *c, fd_set * readset, fd_set * writeset) { + Channel *nc; struct sockaddr addr; - int newsock, newch; + int newsock, nextstate; socklen_t addrlen; - char buf[1024], *remote_hostname; - int remote_port; + char *rtype; if (FD_ISSET(c->sock, readset)) { debug("Connection to port %d forwarding " "to %.100s port %d requested.", c->listening_port, c->path, c->host_port); + + if (c->type == SSH_CHANNEL_RPORT_LISTENER) { + nextstate = SSH_CHANNEL_OPENING; + rtype = "forwarded-tcpip"; + } else { + if (c->host_port == 0) { + nextstate = SSH_CHANNEL_DYNAMIC; + rtype = "dynamic-tcpip"; + } else { + nextstate = SSH_CHANNEL_OPENING; + rtype = "direct-tcpip"; + } + } + addrlen = sizeof(addr); newsock = accept(c->sock, &addr, &addrlen); if (newsock < 0) { error("accept: %.100s", strerror(errno)); return; } - remote_hostname = get_remote_hostname(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_hostname, remote_port); - newch = channel_new("direct-tcpip", - SSH_CHANNEL_OPENING, newsock, newsock, -1, + nc = channel_new(rtype, + nextstate, 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("direct-tcpip"); - packet_put_int(newch); - packet_put_int(c->local_window_max); - packet_put_int(c->local_maxpacket); - /* target host and port */ - packet_put_string(c->path, strlen(c->path)); - packet_put_int(c->host_port); - /* originator host and port */ - packet_put_cstring(remote_hostname); - packet_put_int(remote_port); - packet_send(); + 0, xstrdup(rtype), 1); + if (nc == NULL) { + error("channel_post_port_listener: no new channel:"); + close(newsock); + return; + } + nc->listening_port = c->listening_port; + nc->host_port = c->host_port; + strlcpy(nc->path, c->path, sizeof(nc->path)); + + if (nextstate == SSH_CHANNEL_DYNAMIC) { + /* + * do not call the channel_post handler until + * this flag has been reset by a pre-handler. + * otherwise the FD_ISSET calls might overflow + */ + nc->delayed = 1; } else { - 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)); - } - packet_send(); + port_open_helper(nc, rtype); } - xfree(remote_hostname); } } @@ -643,11 +1163,13 @@ * This is the authentication agent socket listening for connections from * clients. */ -void +static void channel_post_auth_listener(Channel *c, fd_set * readset, fd_set * writeset) { + Channel *nc; + char *name; + int newsock; struct sockaddr addr; - int newsock, newch; socklen_t addrlen; if (FD_ISSET(c->sock, readset)) { @@ -657,15 +1179,78 @@ error("accept from auth socket: %.100s", strerror(errno)); return; } - newch = channel_allocate(SSH_CHANNEL_OPENING, newsock, - xstrdup("accepted auth socket")); - packet_start(SSH_SMSG_AGENT_OPEN); - packet_put_int(newch); + name = xstrdup("accepted auth socket"); + nc = channel_new("accepted auth socket", + SSH_CHANNEL_OPENING, newsock, newsock, -1, + c->local_window_max, c->local_maxpacket, + 0, name, 1); + if (nc == NULL) { + error("channel_post_auth_listener: channel_new failed"); + xfree(name); + close(newsock); + } + if (compat20) { + packet_start(SSH2_MSG_CHANNEL_OPEN); + packet_put_cstring("auth-agent@openssh.com"); + packet_put_int(nc->self); + packet_put_int(c->local_window_max); + packet_put_int(c->local_maxpacket); + } else { + packet_start(SSH_SMSG_AGENT_OPEN); + packet_put_int(nc->self); + } packet_send(); } } -int +static void +channel_post_connecting(Channel *c, fd_set * readset, fd_set * writeset) +{ + int err = 0; + socklen_t sz = sizeof(err); + + if (FD_ISSET(c->sock, writeset)) { + if (getsockopt(c->sock, SOL_SOCKET, SO_ERROR, (char *)&err, + &sz) < 0) { + err = errno; + error("getsockopt SO_ERROR failed"); + } + if (err == 0) { + debug("channel %d: connected", c->self); + c->type = SSH_CHANNEL_OPEN; + if (compat20) { + packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION); + packet_put_int(c->remote_id); + packet_put_int(c->self); + packet_put_int(c->local_window); + packet_put_int(c->local_maxpacket); + } else { + packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION); + packet_put_int(c->remote_id); + packet_put_int(c->self); + } + } else { + debug("channel %d: not connected: %s", + c->self, strerror(err)); + if (compat20) { + packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE); + packet_put_int(c->remote_id); + packet_put_int(SSH2_OPEN_CONNECT_FAILED); + if (!(datafellows & SSH_BUG_OPENFAILURE)) { + packet_put_cstring(strerror(err)); + packet_put_cstring(""); + } + } else { + packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE); + packet_put_int(c->remote_id); + } + chan_mark_dead(c); + } + packet_send(); + } +} + +static int channel_handle_rfd(Channel *c, fd_set * readset, fd_set * writeset) { char buf[16*1024]; @@ -679,10 +1264,14 @@ if (len <= 0) { debug("channel %d: read<=0 rfd %d len %d", c->self, c->rfd, len); - if (compat13) { + if (c->type != SSH_CHANNEL_OPEN) { + debug("channel %d: not open", c->self); + chan_mark_dead(c); + return -1; + } else if (compat13) { buffer_consume(&c->output, buffer_len(&c->output)); c->type = SSH_CHANNEL_INPUT_DRAINING; - debug("Channel %d status set to input draining.", c->self); + debug("channel %d: input draining.", c->self); } else { chan_read_failed(c); } @@ -690,7 +1279,7 @@ } if(c->input_filter != NULL) { if (c->input_filter(c, buf, len) == -1) { - debug("filter stops channel %d", c->self); + debug("channel %d: filter stops", c->self); chan_read_failed(c); } } else { @@ -699,29 +1288,50 @@ } return 1; } -int +static int channel_handle_wfd(Channel *c, fd_set * readset, fd_set * writeset) { + struct termios tio; + u_char *data; + u_int dlen; int len; /* Send buffered output data to the socket. */ if (c->wfd != -1 && FD_ISSET(c->wfd, writeset) && buffer_len(&c->output) > 0) { - len = write(c->wfd, buffer_ptr(&c->output), - buffer_len(&c->output)); + data = buffer_ptr(&c->output); + dlen = buffer_len(&c->output); + len = write(c->wfd, data, dlen); if (len < 0 && (errno == EINTR || errno == EAGAIN)) return 1; if (len <= 0) { - if (compat13) { + if (c->type != SSH_CHANNEL_OPEN) { + debug("channel %d: not open", c->self); + chan_mark_dead(c); + return -1; + } else if (compat13) { buffer_consume(&c->output, buffer_len(&c->output)); - debug("Channel %d status set to input draining.", c->self); + debug("channel %d: input draining.", c->self); c->type = SSH_CHANNEL_INPUT_DRAINING; } else { chan_write_failed(c); } return -1; } + if (compat20 && c->isatty && dlen >= 1 && data[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 + data) + */ + packet_send_ignore(4 + len); + packet_send(); + } + } buffer_consume(&c->output, len); if (compat20 && len > 0) { c->local_consumed += len; @@ -729,7 +1339,7 @@ } return 1; } -int +static int channel_handle_efd(Channel *c, fd_set * readset, fd_set * writeset) { char buf[16*1024]; @@ -744,7 +1354,13 @@ buffer_len(&c->extended)); debug2("channel %d: written %d to efd %d", c->self, len, c->efd); - if (len > 0) { + if (len < 0 && (errno == EINTR || errno == EAGAIN)) + return 1; + if (len <= 0) { + debug2("channel %d: closing write-efd %d", + c->self, c->efd); + channel_close_fd(&c->efd); + } else { buffer_consume(&c->extended, len); c->local_consumed += len; } @@ -753,21 +1369,24 @@ 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", + if (len < 0 && (errno == EINTR || errno == EAGAIN)) + return 1; + if (len <= 0) { + debug2("channel %d: closing read-efd %d", c->self, c->efd); - close(c->efd); - c->efd = -1; - } else if (len > 0) + channel_close_fd(&c->efd); + } else { buffer_append(&c->extended, buf, len); + } } } return 1; } -int -channel_check_window(Channel *c, fd_set * readset, fd_set * writeset) +static int +channel_check_window(Channel *c) { - if (!(c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD)) && + if (c->type == SSH_CHANNEL_OPEN && + !(c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD)) && c->local_window < c->local_window_max/2 && c->local_consumed > 0) { packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST); @@ -783,23 +1402,28 @@ return 1; } -void +static void channel_post_open_1(Channel *c, fd_set * readset, fd_set * writeset) { + if (c->delayed) + return; channel_handle_rfd(c, readset, writeset); channel_handle_wfd(c, readset, writeset); } -void +static void channel_post_open_2(Channel *c, fd_set * readset, fd_set * writeset) { + if (c->delayed) + return; channel_handle_rfd(c, readset, writeset); channel_handle_wfd(c, readset, writeset); channel_handle_efd(c, readset, writeset); - channel_check_window(c, readset, writeset); + + channel_check_window(c); } -void +static void channel_post_output_drain_13(Channel *c, fd_set * readset, fd_set * writeset) { int len; @@ -814,20 +1438,28 @@ } } -void +static void channel_handler_init_20(void) { channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_20; channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open; channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener; + channel_pre[SSH_CHANNEL_RPORT_LISTENER] = &channel_pre_listener; channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener; + channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener; + channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting; + channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic; channel_post[SSH_CHANNEL_OPEN] = &channel_post_open_2; channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener; + channel_post[SSH_CHANNEL_RPORT_LISTENER] = &channel_post_port_listener; channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener; + channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener; + channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting; + channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open_2; } -void +static void channel_handler_init_13(void) { channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_13; @@ -837,15 +1469,19 @@ channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener; channel_pre[SSH_CHANNEL_INPUT_DRAINING] = &channel_pre_input_draining; channel_pre[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_pre_output_draining; + channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting; + channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic; channel_post[SSH_CHANNEL_OPEN] = &channel_post_open_1; channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener; channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener; channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener; channel_post[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_post_output_drain_13; + channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting; + channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open_1; } -void +static void channel_handler_init_15(void) { channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_15; @@ -853,14 +1489,18 @@ channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener; channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener; channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener; + channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting; + channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic; channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener; channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener; channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener; channel_post[SSH_CHANNEL_OPEN] = &channel_post_open_1; + channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting; + channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open_1; } -void +static void channel_handler_init(void) { int i; @@ -876,7 +1516,29 @@ channel_handler_init_15(); } -void +/* gc dead channels */ +static void +channel_garbage_collect(Channel *c) +{ + if (c == NULL) + return; + if (c->detach_user != NULL) { + if (!chan_is_dead(c, 0)) + return; + debug("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; + debug("channel %d: gc: user detached", c->self); + } + if (!chan_is_dead(c, 1)) + return; + debug("channel %d: garbage collecting", c->self); + channel_free(c); +} + +static void channel_handler(chan_fn *ftab[], fd_set * readset, fd_set * writeset) { static int did_init = 0; @@ -888,30 +1550,56 @@ did_init = 1; } for (i = 0; i < channels_alloc; i++) { - c = &channels[i]; - if (c->type == SSH_CHANNEL_FREE) + c = channels[i]; + if (c == NULL) continue; - if (ftab[c->type] == NULL) - continue; - (*ftab[c->type])(c, readset, writeset); - chan_delete_if_full_closed(c); + if (ftab[c->type] != NULL) + (*ftab[c->type])(c, readset, writeset); + channel_garbage_collect(c); } } +/* + * Allocate/update select bitmasks and add any bits relevant to channels in + * select bitmasks. + */ void -channel_prepare_select(fd_set * readset, fd_set * writeset) +channel_prepare_select(fd_set **readsetp, fd_set **writesetp, int *maxfdp, + int *nallocp, int rekeying) { - channel_handler(channel_pre, readset, writeset); + int n; + u_int sz; + + n = MAX(*maxfdp, channel_max_fd); + + sz = howmany(n+1, NFDBITS) * sizeof(fd_mask); + /* perhaps check sz < nalloc/2 and shrink? */ + if (*readsetp == NULL || sz > *nallocp) { + *readsetp = xrealloc(*readsetp, sz); + *writesetp = xrealloc(*writesetp, sz); + *nallocp = sz; + } + *maxfdp = n; + memset(*readsetp, 0, sz); + memset(*writesetp, 0, sz); + + if (!rekeying) + channel_handler(channel_pre, *readsetp, *writesetp); } +/* + * After select, perform any appropriate operations for channels which have + * events pending. + */ void channel_after_select(fd_set * readset, fd_set * writeset) { channel_handler(channel_post, readset, writeset); } -/* If there is data to send to the connection, send some of it now. */ +/* If there is data to send to the connection, enqueue some of it now. */ + void channel_output_poll() { @@ -919,9 +1607,14 @@ Channel *c; for (i = 0; i < channels_alloc; i++) { - c = &channels[i]; + c = channels[i]; + if (c == NULL) + continue; - /* We are only interested in channels that can have buffered incoming data. */ + /* + * 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) @@ -929,20 +1622,22 @@ } 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); + /* 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. */ - len = buffer_len(&c->input); - if (len > 0) { - /* Send some data for the other side over the secure connection. */ + if ((c->istate == CHAN_INPUT_OPEN || + c->istate == CHAN_INPUT_WAIT_DRAIN) && + (len = buffer_len(&c->input)) > 0) { + /* + * Send some data for the other side over the secure + * connection. + */ if (compat20) { if (len > c->remote_window) len = c->remote_window; @@ -981,6 +1676,9 @@ c->remote_window > 0 && (len = buffer_len(&c->extended)) > 0 && c->extended_usage == CHAN_EXTENDED_READ) { + debug2("channel %d: rwin %d elen %d euse %d", + c->self, c->remote_window, buffer_len(&c->extended), + c->extended_usage); if (len > c->remote_window) len = c->remote_window; if (len > c->remote_maxpacket) @@ -992,22 +1690,20 @@ packet_send(); buffer_consume(&c->extended, len); c->remote_window -= len; + debug2("channel %d: sent ext data %d", c->self, len); } } } -/* - * This is called when a packet of type CHANNEL_DATA has just been received. - * The message type has already been consumed, but channel number and data is - * still there. - */ +/* -- protocol input */ + void channel_input_data(int type, int plen, void *ctxt) { int id; char *data; - unsigned int data_len; + u_int data_len; Channel *c; /* Get the channel number and verify it. */ @@ -1047,13 +1743,14 @@ 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; - unsigned int data_len; + u_int data_len; Channel *c; /* Get the channel number and verify it. */ @@ -1087,36 +1784,6 @@ xfree(data); } - -/* - * Returns true if no channel has too much buffered data, and false if one or - * more channel is overfull. - */ - -int -channel_not_very_much_buffered_data() -{ - unsigned int i; - Channel *c; - - for (i = 0; i < channels_alloc; i++) { - 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(&c->output) > packet_get_maxsize()) { - debug("channel %d: big output buffer %d", - c->self, buffer_len(&c->output)); - return 0; - } - } - } - return 1; -} - void channel_input_ieof(int type, int plen, void *ctxt) { @@ -1130,6 +1797,13 @@ if (c == NULL) packet_disconnect("Received ieof for nonexistent channel %d.", id); chan_rcvd_ieof(c); + + /* XXX force input close */ + if (c->force_drain) { + debug("channel %d: FORCE input drain", c->self); + c->istate = CHAN_INPUT_WAIT_DRAIN; + } + } void @@ -1195,7 +1869,7 @@ 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); + channel_free(c); } void @@ -1232,10 +1906,27 @@ } } +static char * +reason2txt(int reason) +{ + switch(reason) { + case SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED: + return "administratively prohibited"; + case SSH2_OPEN_CONNECT_FAILED: + return "connect failed"; + case SSH2_OPEN_UNKNOWN_CHANNEL_TYPE: + return "unknown channel type"; + case SSH2_OPEN_RESOURCE_SHORTAGE: + return "resource shortage"; + } + return "unknown reason"; +} + void channel_input_open_failure(int type, int plen, void *ctxt) { - int id; + int id, reason; + char *msg = NULL, *lang = NULL; Channel *c; if (!compat20) @@ -1248,16 +1939,21 @@ packet_disconnect("Received open failure for " "non-opening channel %d.", id); if (compat20) { - int reason = packet_get_int(); - char *msg = packet_get_string(NULL); - char *lang = packet_get_string(NULL); - log("channel_open_failure: %d: reason %d: %s", id, reason, msg); + reason = packet_get_int(); + if (!(datafellows & SSH_BUG_OPENFAILURE)) { + msg = packet_get_string(NULL); + lang = packet_get_string(NULL); + } packet_done(); - xfree(msg); - xfree(lang); + log("channel %d: open failed: %s%s%s", id, + reason2txt(reason), msg ? ": ": "", msg ? msg : ""); + if (msg != NULL) + xfree(msg); + if (lang != NULL) + xfree(lang); } /* Free the channel. This will also close the socket. */ - channel_free(id); + channel_free(c); } void @@ -1279,7 +1975,7 @@ debug2("callback done"); } else { char *service = packet_get_string(NULL); - debug("channel: %d rcvd request for %s", c->self, service); + 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); } @@ -1309,156 +2005,100 @@ c->remote_window += adjust; } -/* - * Stops listening for channels, and removes any unix domain sockets that we - * might have. - */ - void -channel_stop_listening() +channel_input_port_open(int type, int plen, void *ctxt) { - int i; - for (i = 0; i < channels_alloc; i++) { - switch (channels[i].type) { - case SSH_CHANNEL_AUTH_SOCKET: - close(channels[i].sock); - remove(channels[i].path); - channel_free(i); - break; - case SSH_CHANNEL_PORT_LISTENER: - case SSH_CHANNEL_X11_LISTENER: - close(channels[i].sock); - channel_free(i); - break; - default: - break; + Channel *c = NULL; + u_short host_port; + char *host, *originator_string; + int remote_id, sock = -1; + + remote_id = packet_get_int(); + host = packet_get_string(NULL); + host_port = packet_get_int(); + + if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) { + originator_string = packet_get_string(NULL); + } else { + originator_string = xstrdup("unknown (remote did not supply name)"); + } + packet_done(); + sock = channel_connect_to(host, host_port); + if (sock != -1) { + c = channel_new("connected socket", + SSH_CHANNEL_CONNECTING, sock, sock, -1, 0, 0, 0, + originator_string, 1); + if (c == NULL) { + error("channel_input_port_open: channel_new failed"); + close(sock); + } else { + c->remote_id = remote_id; } } + if (c == NULL) { + packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE); + packet_put_int(remote_id); + packet_send(); + } + xfree(host); } -/* - * Closes the sockets/fds of all channels. This is used to close extra file - * descriptors after a fork. - */ +/* -- tcp forwarding */ + void -channel_close_all() +channel_set_af(int af) { - int i; - for (i = 0; i < channels_alloc; i++) - if (channels[i].type != SSH_CHANNEL_FREE) - channel_close_fds(&channels[i]); + IPv4or6 = af; } -/* Returns the maximum file descriptor number used by the channels. */ - -int -channel_max_fd() -{ - return channel_max_fd_value; -} - -/* Returns true if any channel is still open. */ - -int -channel_still_open() -{ - unsigned int i; - for (i = 0; i < channels_alloc; i++) - switch (channels[i].type) { - case SSH_CHANNEL_FREE: - case SSH_CHANNEL_X11_LISTENER: - case SSH_CHANNEL_PORT_LISTENER: - case SSH_CHANNEL_CLOSED: - case SSH_CHANNEL_AUTH_SOCKET: - continue; - case SSH_CHANNEL_LARVAL: - if (!compat20) - fatal("cannot happen: SSH_CHANNEL_LARVAL"); - continue; - case SSH_CHANNEL_OPENING: - case SSH_CHANNEL_OPEN: - case SSH_CHANNEL_X11_OPEN: - return 1; - case SSH_CHANNEL_INPUT_DRAINING: - case SSH_CHANNEL_OUTPUT_DRAINING: - if (!compat13) - fatal("cannot happen: OUT_DRAIN"); - return 1; - default: - fatal("channel_still_open: bad channel type %d", channels[i].type); - /* NOTREACHED */ - } - return 0; -} - /* - * Returns a message describing the currently open forwarded connections, - * suitable for sending to the client. The message contains crlf pairs for - * newlines. + * Initiate forwarding of connections to local port "port" through the secure + * channel to host:port from remote side. */ - -char * -channel_open_message() +int +channel_request_local_forwarding(u_short listen_port, const char *host_to_connect, + u_short port_to_connect, int gateway_ports) { - Buffer buffer; - int i; - char buf[512], *cp; - - buffer_init(&buffer); - snprintf(buf, sizeof buf, "The following connections are open:\r\n"); - buffer_append(&buffer, buf, strlen(buf)); - for (i = 0; i < channels_alloc; i++) { - Channel *c = &channels[i]; - switch (c->type) { - case SSH_CHANNEL_FREE: - case SSH_CHANNEL_X11_LISTENER: - case SSH_CHANNEL_PORT_LISTENER: - case SSH_CHANNEL_CLOSED: - case SSH_CHANNEL_AUTH_SOCKET: - continue; - case SSH_CHANNEL_LARVAL: - case SSH_CHANNEL_OPENING: - case SSH_CHANNEL_OPEN: - case SSH_CHANNEL_X11_OPEN: - case SSH_CHANNEL_INPUT_DRAINING: - case SSH_CHANNEL_OUTPUT_DRAINING: - snprintf(buf, sizeof buf, " #%d %.300s (t%d r%d i%d/%d o%d/%d fd %d/%d)\r\n", - c->self, c->remote_name, - c->type, c->remote_id, - c->istate, buffer_len(&c->input), - c->ostate, buffer_len(&c->output), - c->rfd, c->wfd); - buffer_append(&buffer, buf, strlen(buf)); - continue; - default: - fatal("channel_open_message: bad channel type %d", c->type); - /* NOTREACHED */ - } - } - buffer_append(&buffer, "\0", 1); - cp = xstrdup(buffer_ptr(&buffer)); - buffer_free(&buffer); - return cp; + return channel_request_forwarding( + NULL, listen_port, + host_to_connect, port_to_connect, + gateway_ports, /*remote_fwd*/ 0); } /* - * Initiate forwarding of connections to local port "port" through the secure - * channel to host:port from remote side. + * If 'remote_fwd' is true we have a '-R style' listener for protocol 2 + * (SSH_CHANNEL_RPORT_LISTENER). */ - -void -channel_request_local_forwarding(u_short port, const char *host, - u_short host_port, int gateway_ports) +int +channel_request_forwarding( + const char *listen_address, u_short listen_port, + const char *host_to_connect, u_short port_to_connect, + int gateway_ports, int remote_fwd) { - int success, ch, sock, on = 1; + Channel *c; + int success, sock, on = 1, type; struct addrinfo hints, *ai, *aitop; char ntop[NI_MAXHOST], strport[NI_MAXSERV]; + const char *host; struct linger linger; - if (strlen(host) > sizeof(channels[0].path) - 1) - packet_disconnect("Forward host name too long."); + success = 0; + if (remote_fwd) { + host = listen_address; + type = SSH_CHANNEL_RPORT_LISTENER; + } else { + host = host_to_connect; + type = SSH_CHANNEL_PORT_LISTENER; + } + + if (strlen(host) > SSH_CHANNEL_PATH_LEN - 1) { + error("Forward host name too long."); + return success; + } + + /* XXX listen_address is currently ignored */ /* * getaddrinfo returns a loopback address if the hostname is * set to NULL and hints.ai_flags is not AI_PASSIVE @@ -1467,17 +2107,16 @@ hints.ai_family = IPv4or6; hints.ai_flags = gateway_ports ? AI_PASSIVE : 0; hints.ai_socktype = SOCK_STREAM; - snprintf(strport, sizeof strport, "%d", port); + snprintf(strport, sizeof strport, "%d", listen_port); if (getaddrinfo(NULL, strport, &hints, &aitop) != 0) packet_disconnect("getaddrinfo: fatal error"); - success = 0; for (ai = aitop; ai; ai = ai->ai_next) { if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6) continue; if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop), strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) { - error("channel_request_local_forwarding: getnameinfo failed"); + error("channel_request_forwarding: getnameinfo failed"); continue; } /* Create a port to listen for the host. */ @@ -1511,19 +2150,24 @@ continue; } /* Allocate a channel number for the socket. */ - ch = channel_new( - "port listener", SSH_CHANNEL_PORT_LISTENER, - sock, sock, -1, + c = channel_new("port listener", type, 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 = host_port; - channels[ch].listening_port = port; + if (c == NULL) { + error("channel_request_forwarding: channel_new failed"); + close(sock); + continue; + } + strlcpy(c->path, host, sizeof(c->path)); + c->host_port = port_to_connect; + c->listening_port = listen_port; success = 1; } if (success == 0) - packet_disconnect("cannot listen port: %d", port); + error("channel_request_forwarding: cannot listen to port: %d", + listen_port); freeaddrinfo(aitop); + return success; } /* @@ -1532,19 +2176,15 @@ */ void -channel_request_remote_forwarding(u_short listen_port, const char *host_to_connect, - u_short port_to_connect) +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_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++; - /* Send the forward request to the remote side. */ if (compat20) { const char *address_to_bind = "0.0.0.0"; @@ -1553,6 +2193,10 @@ 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); @@ -1560,12 +2204,28 @@ 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++; + } } /* @@ -1592,19 +2252,55 @@ if (port < IPPORT_RESERVED && !is_root) packet_disconnect("Requested forwarding of port %d but user is not root.", port); - /* - * Initiate forwarding, - */ + /* 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) +/* + * Permits opening to any host/port if permitted_opens[] is empty. This is + * usually called by the server, because the user could connect to any port + * anyway, and the server has no way to know but to trust the client anyway. + */ +void +channel_permit_all_opens() { + if (num_permitted_opens == 0) + all_opens_permitted = 1; +} + +void +channel_add_permitted_opens(char *host, int port) +{ + if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION) + fatal("channel_request_remote_forwarding: too many forwards"); + debug("allow port forwarding to host %s port %d", host, port); + + permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host); + permitted_opens[num_permitted_opens].port_to_connect = port; + num_permitted_opens++; + + all_opens_permitted = 0; +} + +void +channel_clear_permitted_opens(void) +{ + int i; + + for (i = 0; i < num_permitted_opens; i++) + xfree(permitted_opens[i].host_to_connect); + num_permitted_opens = 0; + +} + + +/* return socket to remote host, port */ +static int +connect_to(const char *host, u_short port) +{ struct addrinfo hints, *ai, *aitop; char ntop[NI_MAXHOST], strport[NI_MAXSERV]; int gaierr; @@ -1613,9 +2309,10 @@ memset(&hints, 0, sizeof(hints)); hints.ai_family = IPv4or6; hints.ai_socktype = SOCK_STREAM; - snprintf(strport, sizeof strport, "%d", host_port); + snprintf(strport, sizeof strport, "%d", port); if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0) { - error("%.100s: unknown host (%s)", host, gai_strerror(gaierr)); + error("connect_to %.100s: unknown host (%s)", host, + gai_strerror(gaierr)); return -1; } for (ai = aitop; ai; ai = ai->ai_next) { @@ -1623,111 +2320,79 @@ 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"); + error("connect_to: getnameinfo failed"); continue; } - /* Create the socket. */ sock = socket(ai->ai_family, SOCK_STREAM, 0); if (sock < 0) { error("socket: %.100s", strerror(errno)); continue; } - /* Connect to the host/port. */ - if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0) { - error("connect %.100s port %s: %.100s", ntop, strport, + if (fcntl(sock, F_SETFL, O_NONBLOCK) < 0) + fatal("connect_to: F_SETFL: %s", strerror(errno)); + if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0 && + errno != EINPROGRESS) { + error("connect_to %.100s port %s: %.100s", ntop, strport, strerror(errno)); close(sock); - continue; /* fail -- try next */ + continue; /* fail -- try next */ } break; /* success */ } freeaddrinfo(aitop); if (!ai) { - error("connect %.100s port %d: failed.", host, host_port); + error("connect_to %.100s port %d: failed.", host, port); return -1; } /* success */ return sock; } -/* - * 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 type, int plen, void *ctxt) +int +channel_connect_by_listen_address(u_short listen_port) { - u_short host_port; - char *host, *originator_string; - int remote_channel, sock = -1, newch, i, denied; - unsigned int host_len, originator_len; + int i; - /* Get remote channel number. */ - remote_channel = packet_get_int(); + for (i = 0; i < num_permitted_opens; i++) + if (permitted_opens[i].listen_port == listen_port) + return connect_to( + permitted_opens[i].host_to_connect, + permitted_opens[i].port_to_connect); + error("WARNING: Server requests forwarding for unknown listen_port %d", + listen_port); + return -1; +} - /* Get host name to connect to. */ - host = packet_get_string(&host_len); +/* Check if connecting to that port is permitted and connect. */ +int +channel_connect_to(const char *host, u_short port) +{ + int i, permit; - /* Get port to connect to. */ - host_port = packet_get_int(); - - /* Get remote originator name. */ - if (have_hostname_in_open) { - originator_string = packet_get_string(&originator_len); - originator_len += 4; /* size of packet_int */ - } else { - originator_string = xstrdup("unknown (remote did not supply name)"); - originator_len = 0; /* no originator supplied */ - } - - 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. */ + permit = all_opens_permitted; + if (!permit) { for (i = 0; i < num_permitted_opens; i++) - if (permitted_opens[i].port_to_connect == host_port && + if (permitted_opens[i].port_to_connect == port && strcmp(permitted_opens[i].host_to_connect, host) == 0) - break; + permit = 1; - /* Check if we found the requested port among those permitted. */ - if (i >= num_permitted_opens) { - /* The port is not permitted. */ - log("Received request to connect to %.100s:%d, but the request was denied.", - host, host_port); - denied = 1; - } } - sock = denied ? -1 : channel_connect_to(host, host_port); - if (sock > 0) { - /* Allocate a channel for this connection. */ - newch = channel_allocate(SSH_CHANNEL_OPEN, sock, originator_string); - 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 { - packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE); - packet_put_int(remote_channel); - packet_send(); + if (!permit) { + log("Received request to connect to host %.100s port %d, " + "but the request was denied.", host, port); + return -1; } - xfree(host); + return connect_to(host, port); } +/* -- X11 forwarding */ + /* * Creates an internet domain socket for listening for X11 connections. * Returns a suitable value for the DISPLAY variable, or NULL if an error * occurs. */ - -#define NUM_SOCKS 10 - char * x11_create_display_inet(int screen_number, int x11_display_offset) { @@ -1775,6 +2440,7 @@ if (num_socks == NUM_SOCKS) break; } + freeaddrinfo(aitop); if (num_socks > 0) break; } @@ -1816,9 +2482,8 @@ #define X_UNIX_PATH "/tmp/.X11-unix/X" #endif -static -int -connect_local_xsocket(unsigned int dnr) +static int +connect_local_xsocket(u_int dnr) { static const char *const x_sockets[] = { X_UNIX_PATH "%u", @@ -1949,46 +2614,47 @@ void x11_input_open(int type, int plen, void *ctxt) { - int remote_channel, sock = 0, newch; + Channel *c = NULL; + int remote_id, sock = 0; char *remote_host; - unsigned int remote_len; - /* Get remote channel number. */ - remote_channel = packet_get_int(); + debug("Received X11 open request."); - /* Get remote originator name. */ - if (have_hostname_in_open) { - remote_host = packet_get_string(&remote_len); - remote_len += 4; + 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)"); - remote_len = 0; } + packet_done(); - 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) { + if (sock != -1) { + /* Allocate a channel for this connection. */ + c = channel_new("connected x11 socket", + SSH_CHANNEL_X11_OPEN, sock, sock, -1, 0, 0, 0, + remote_host, 1); + if (c == NULL) { + error("x11_input_open: channel_new failed"); + close(sock); + } else { + c->remote_id = remote_id; + c->force_drain = 1; + } + } + if (c == NULL) { /* Send refusal to the remote host. */ packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE); - packet_put_int(remote_channel); - packet_send(); + packet_put_int(remote_id); } 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(); + packet_put_int(remote_id); + packet_put_int(c->self); } + packet_send(); } /* dummy protocol handler that denies SSH-1 requests (agent/x11) */ @@ -2016,14 +2682,14 @@ /* * 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 *proto, const char *data) { - unsigned int data_len = (unsigned int) strlen(data) / 2; - unsigned int i, value; + u_int data_len = (u_int) strlen(data) / 2; + u_int i, value, len; char *new_data; int screen_number; const char *cp; @@ -2061,9 +2727,11 @@ x11_fake_data_len = data_len; /* Convert the fake data into hex. */ - new_data = xmalloc(2 * data_len + 1); + len = 2 * data_len + 1; + new_data = xmalloc(len); for (i = 0; i < data_len; i++) - sprintf(new_data + 2 * i, "%02x", (unsigned char) x11_fake_data[i]); + snprintf(new_data + 2 * i, len - 2 * i, + "%02x", (u_char) x11_fake_data[i]); /* Send the request packet. */ if (compat20) { @@ -2080,6 +2748,9 @@ xfree(new_data); } + +/* -- agent forwarding */ + /* Sends a message to the server to request authentication fd forwarding. */ void @@ -2099,16 +2770,23 @@ char * auth_get_socket_name() { - return channel_forwarded_auth_socket_name; + return auth_sock_name; } /* removes the agent forwarding socket */ void -cleanup_socket(void) +auth_sock_cleanup_proc(void *_pw) { - remove(channel_forwarded_auth_socket_name); - rmdir(channel_forwarded_auth_socket_dir); + struct passwd *pw = _pw; + + if (auth_sock_name) { + temporarily_use_uid(pw); + unlink(auth_sock_name); + rmdir(auth_sock_dir); + auth_sock_name = NULL; + restore_uid(); + } } /* @@ -2119,39 +2797,40 @@ int auth_input_request_forwarding(struct passwd * pw) { - int sock, newch; + Channel *nc; + int sock; struct sockaddr_un sunaddr; - if (auth_get_socket_name() != NULL) - fatal("Protocol error: authentication forwarding requested twice."); + if (auth_get_socket_name() != NULL) { + error("authentication forwarding requested twice."); + return 0; + } /* Temporarily drop privileged uid for mkdir/bind. */ - temporarily_use_uid(pw->pw_uid); + temporarily_use_uid(pw); /* Allocate a buffer for the socket name, and format the name. */ - channel_forwarded_auth_socket_name = xmalloc(MAX_SOCKET_NAME); - channel_forwarded_auth_socket_dir = xmalloc(MAX_SOCKET_NAME); - strlcpy(channel_forwarded_auth_socket_dir, "/tmp/ssh-XXXXXXXX", MAX_SOCKET_NAME); + auth_sock_name = xmalloc(MAXPATHLEN); + auth_sock_dir = xmalloc(MAXPATHLEN); + strlcpy(auth_sock_dir, "/tmp/ssh-XXXXXXXX", MAXPATHLEN); /* Create private directory for socket */ - if (mkdtemp(channel_forwarded_auth_socket_dir) == NULL) { - packet_send_debug("Agent forwarding disabled: mkdtemp() failed: %.100s", - strerror(errno)); + if (mkdtemp(auth_sock_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; + xfree(auth_sock_name); + xfree(auth_sock_dir); + auth_sock_name = NULL; + auth_sock_dir = NULL; return 0; } - snprintf(channel_forwarded_auth_socket_name, MAX_SOCKET_NAME, "%s/agent.%d", - channel_forwarded_auth_socket_dir, (int) getpid()); + snprintf(auth_sock_name, MAXPATHLEN, "%s/agent.%d", + auth_sock_dir, (int) getpid()); - if (atexit(cleanup_socket) < 0) { - int saved = errno; - cleanup_socket(); - packet_disconnect("socket: %.100s", strerror(saved)); - } + /* delete agent socket on fatal() */ + fatal_add_cleanup(auth_sock_cleanup_proc, pw); + /* Create the socket. */ sock = socket(AF_UNIX, SOCK_STREAM, 0); if (sock < 0) @@ -2160,7 +2839,7 @@ /* Bind it to the name. */ memset(&sunaddr, 0, sizeof(sunaddr)); sunaddr.sun_family = AF_UNIX; - strncpy(sunaddr.sun_path, channel_forwarded_auth_socket_name, + strncpy(sunaddr.sun_path, auth_sock_name, sizeof(sunaddr.sun_path)); if (bind(sock, (struct sockaddr *) & sunaddr, sizeof(sunaddr)) < 0) @@ -2174,10 +2853,18 @@ packet_disconnect("listen: %.100s", strerror(errno)); /* Allocate a channel for the authentication agent socket. */ - newch = channel_allocate(SSH_CHANNEL_AUTH_SOCKET, sock, - xstrdup("auth socket")); - strlcpy(channels[newch].path, channel_forwarded_auth_socket_name, - sizeof(channels[newch].path)); + nc = channel_new("auth socket", + SSH_CHANNEL_AUTH_SOCKET, sock, sock, -1, + CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT, + 0, xstrdup("auth socket"), 1); + if (nc == NULL) { + error("auth_input_request_forwarding: channel_new failed"); + auth_sock_cleanup_proc(pw); + fatal_remove_cleanup(auth_sock_cleanup_proc, pw); + close(sock); + return 0; + } + strlcpy(nc->path, auth_sock_name, sizeof(nc->path)); return 1; } @@ -2186,13 +2873,14 @@ void auth_input_open_request(int type, int plen, void *ctxt) { - int remch, sock, newch; - char *dummyname; + Channel *c = NULL; + int remote_id, sock; + char *name; packet_integrity_check(plen, 4, type); /* Read the remote channel number from the message. */ - remch = packet_get_int(); + remote_id = packet_get_int(); /* * Get a connection to the local authentication agent (this may again @@ -2206,129 +2894,28 @@ * because authentication forwarding is only enabled if we have an * agent. */ - if (sock < 0) { - packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE); - packet_put_int(remch); - packet_send(); - return; + if (sock >= 0) { + name = xstrdup("authentication agent connection"); + c = channel_new("", SSH_CHANNEL_OPEN, sock, sock, + -1, 0, 0, 0, name, 1); + if (c == NULL) { + error("auth_input_open_request: channel_new failed"); + xfree(name); + close(sock); + } else { + c->remote_id = remote_id; + c->force_drain = 1; + } } - debug("Forwarding authentication connection."); - - /* - * Dummy host name. This will be freed when the channel is freed; it - * will still be valid in the packet_put_string below since the - * channel cannot yet be freed at that point. - */ - dummyname = xstrdup("authentication agent connection"); - - newch = channel_allocate(SSH_CHANNEL_OPEN, sock, dummyname); - channels[newch].remote_id = remch; - - /* Send a confirmation to the remote host. */ - packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION); - packet_put_int(remch); - packet_put_int(newch); - packet_send(); -} - -void -channel_start_open(int id) -{ - Channel *c = channel_lookup(id); if (c == NULL) { - log("channel_open: %d: bad id", id); - return; + packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE); + packet_put_int(remote_id); + } else { + /* Send a confirmation to the remote host. */ + debug("Forwarding authentication connection."); + packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION); + packet_put_int(remote_id); + packet_put_int(c->self); } - 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(); }