diff options
Diffstat (limited to 'crypto/openssh/channels.c')
| -rw-r--r-- | crypto/openssh/channels.c | 1754 |
1 files changed, 896 insertions, 858 deletions
diff --git a/crypto/openssh/channels.c b/crypto/openssh/channels.c index 2d27260..9fea660 100644 --- a/crypto/openssh/channels.c +++ b/crypto/openssh/channels.c @@ -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, 2002 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 1.109 2001/04/17 12:55:03 markus Exp $"); +RCSID("$OpenBSD: channels.c,v 1.171 2002/03/04 19:37:58 markus Exp $"); RCSID("$FreeBSD$"); -#include <openssl/rsa.h> -#include <openssl/dsa.h> - #include "ssh.h" #include "ssh1.h" #include "ssh2.h" #include "packet.h" #include "xmalloc.h" -#include "buffer.h" -#include "bufaux.h" #include "uidswap.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" +#include "pathnames.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 = 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; - -/* Saved X11 authentication data. This is the real data. */ -char *x11_saved_data = NULL; -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; -u_int x11_fake_data_len; +/* -- tcp forwarding */ /* * Data structure for storing which hosts are permitted for forward requests. @@ -120,6 +95,7 @@ typedef struct { /* 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; /* @@ -129,34 +105,54 @@ static int num_permitted_opens = 0; */ static int all_opens_permitted = 0; -/* This is set to true if both sides support SSH_PROTOFLAG_HOST_IN_FWD_OPEN. */ -static int have_hostname_in_open = 0; -/* AF_UNSPEC or AF_INET or AF_INET6 */ -int IPv4or6 = AF_UNSPEC; +/* -- X11 forwarding */ -void port_open_helper(Channel *c, char *rtype); +/* Maximum number of fake X11 displays to try. */ +#define MAX_DISPLAYS 1000 -/* Sets specific protocol options. */ +/* Saved X11 authentication protocol name. */ +static char *x11_saved_proto = NULL; -void -channel_set_options(int hostname_in_open) -{ - have_hostname_in_open = hostname_in_open; -} +/* Saved X11 authentication data. This is the real data. */ +static char *x11_saved_data = NULL; +static u_int x11_saved_data_len = 0; -/* lookup channel by id */ +/* + * Fake X11 authentication data. This is what the server will be sending us; + * we should replace any occurrences of this by the real data. + */ +static char *x11_fake_data = NULL; +static u_int x11_fake_data_len; + + +/* -- agent forwarding */ + +#define NUM_SOCKS 10 + +/* Name and directory of socket for authentication agent forwarding. */ +static char *auth_sock_name = NULL; +static char *auth_sock_dir = NULL; + +/* AF_UNSPEC or AF_INET or AF_INET6 */ +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; } @@ -168,7 +164,7 @@ channel_lookup(int id) * 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) { @@ -213,7 +209,7 @@ channel_register_fds(Channel *c, int rfd, int wfd, int efd, * 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) { @@ -222,20 +218,15 @@ channel_new(char *ctype, int type, int rfd, int wfd, int efd, /* Do initial allocation if this is the first call. */ if (channels_alloc == 0) { - chan_init(); channels_alloc = 10; - channels = xmalloc(channels_alloc * sizeof(Channel)); + channels = xmalloc(channels_alloc * sizeof(Channel *)); for (i = 0; i < channels_alloc; i++) - channels[i].type = SSH_CHANNEL_FREE; - /* - * Kludge: arrange a call to channel_stop_listening if we - * terminate with fatal(). - */ - fatal_add_cleanup((void (*) (void *)) channel_stop_listening, NULL); + channels[i] = NULL; + fatal_add_cleanup((void (*) (void *)) channel_free_all, NULL); } /* Try to find a free slot where to put the new channel. */ for (found = -1, i = 0; i < channels_alloc; i++) - if (channels[i].type == SSH_CHANNEL_FREE) { + if (channels[i] == NULL) { /* Found a free slot. */ found = i; break; @@ -245,16 +236,19 @@ channel_new(char *ctype, int type, int rfd, int wfd, int efd, 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); - chan_init_iostates(c); + c->ostate = CHAN_OUTPUT_OPEN; + c->istate = CHAN_INPUT_OPEN; + c->flags = 0; channel_register_fds(c, rfd, wfd, efd, extusage, nonblock); c->self = found; c->type = type; @@ -267,73 +261,402 @@ channel_new(char *ctype, int type, int rfd, int wfd, int efd, 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->force_drain = 0; + c->single_connection = 0; + c->detach_user = NULL; + c->confirm = 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); - char *s = channel_open_message(); + char *s; + int i, n; - if (c == NULL) - packet_disconnect("channel free: bad local channel %d", id); - debug("channel_free: channel %d: status: %s", id, s); + 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->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; } + 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(void) +{ + 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(void) +{ + u_int i; + Channel *c; + + for (i = 0; i < channels_alloc; i++) { + c = channels[i]; + if (c != NULL && c->type == SSH_CHANNEL_OPEN) { +#if 0 + if (!compat20 && + buffer_len(&c->input) > packet_get_maxsize()) { + 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(void) +{ + 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(void) +{ + 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(void) +{ + 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_start(int local_id, char *service, int wantconfirm) +{ + Channel *c = channel_lookup(local_id); + if (c == NULL) { + log("channel_request_start: %d: unknown channel id", local_id); + return; + } + debug("channel request %d: %s", local_id, service) ; + packet_start(SSH2_MSG_CHANNEL_REQUEST); + packet_put_int(c->remote_id); + packet_put_cstring(service); + packet_put_char(wantconfirm); +} +void +channel_register_confirm(int id, channel_callback_fn *fn) +{ + Channel *c = channel_lookup(id); + if (c == NULL) { + log("channel_register_comfirm: %d: bad id", id); + return; + } + c->confirm = fn; +} +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, u_int window_max) +{ + Channel *c = channel_lookup(id); + if (c == NULL || c->type != SSH_CHANNEL_LARVAL) + fatal("channel_activate for non-larval channel %d.", id); + channel_register_fds(c, rfd, wfd, efd, extusage, nonblock); + c->type = SSH_CHANNEL_OPEN; + c->local_window = c->local_window_max = window_max; + packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST); + packet_put_int(c->remote_id); + packet_put_int(c->local_window); + packet_send(); } /* @@ -348,20 +671,20 @@ 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 +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); } -void +static void channel_pre_open_13(Channel *c, fd_set * readset, fd_set * writeset) { if (buffer_len(&c->input) < packet_get_maxsize()) @@ -370,29 +693,14 @@ channel_pre_open_13(Channel *c, fd_set * readset, fd_set * writeset) FD_SET(c->sock, writeset); } -void -channel_pre_open_15(Channel *c, fd_set * readset, fd_set * writeset) +static void +channel_pre_open(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); - } - } -} + u_int limit = compat20 ? c->remote_window : packet_get_maxsize(); -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) + limit > 0 && + buffer_len(&c->input) < limit) FD_SET(c->rfd, readset); if (c->ostate == CHAN_OUTPUT_OPEN || c->ostate == CHAN_OUTPUT_WAIT_DRAIN) { @@ -403,7 +711,7 @@ channel_pre_open_20(Channel *c, fd_set * readset, fd_set * writeset) } } /** XXX check close conditions, too */ - if (c->efd != -1) { + if (compat20 && c->efd != -1) { if (c->extended_usage == CHAN_EXTENDED_WRITE && buffer_len(&c->extended) > 0) FD_SET(c->efd, writeset); @@ -413,7 +721,7 @@ channel_pre_open_20(Channel *c, fd_set * readset, fd_set * writeset) } } -void +static void channel_pre_input_draining(Channel *c, fd_set * readset, fd_set * writeset) { if (buffer_len(&c->input) == 0) { @@ -425,11 +733,11 @@ channel_pre_input_draining(Channel *c, fd_set * readset, fd_set * writeset) } } -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); } @@ -441,19 +749,20 @@ channel_pre_output_draining(Channel *c, fd_set * readset, fd_set * writeset) * 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) { 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 = (u_char *) buffer_ptr(&c->output); + ucp = buffer_ptr(b); if (ucp[0] == 0x42) { /* Byte order MSB first. */ proto_len = 256 * ucp[6] + ucp[7]; data_len = 256 * ucp[8] + ucp[9]; @@ -462,12 +771,12 @@ x11_open_helper(Channel *c) data_len = ucp[8] + 256 * ucp[9]; } else { debug("Initial X11 packet contains bad byte order byte: 0x%x", - ucp[0]); + ucp[0]); return -1; } /* 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; @@ -500,10 +809,10 @@ x11_open_helper(Channel *c) 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; @@ -516,7 +825,7 @@ channel_pre_x11_open_13(Channel *c, fd_set * readset, fd_set * writeset) 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); @@ -525,31 +834,39 @@ channel_pre_x11_open_13(Channel *c, fd_set * readset, fd_set * writeset) } } -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) - channel_pre_open_20(c, readset, writeset); - else - channel_pre_open_15(c, readset, writeset); + channel_pre_open(c, readset, writeset); } else if (ret == -1) { + log("X11 connection rejected because of wrong authentication."); debug("X11 rejected %d i%d/o%d", c->self, c->istate, c->ostate); - chan_read_failed(c); /** force close? */ - chan_write_failed(c); + chan_read_failed(c); + buffer_clear(&c->input); + chan_ibuf_empty(c); + buffer_clear(&c->output); + /* for proto v1, the peer will send an IEOF */ + if (compat20) + chan_write_failed(c); + else + c->type = SSH_CHANNEL_OPEN; debug("X11 closed %d i%d/o%d", c->self, c->istate, c->ostate); } } /* try to decode a socks4 header */ -int +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]; + char username[256]; struct { u_int8_t version; u_int8_t command; @@ -596,7 +913,7 @@ channel_decode_socks4(Channel *c, fd_set * readset, fd_set * writeset) 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); @@ -614,14 +931,14 @@ channel_decode_socks4(Channel *c, fd_set * readset, fd_set * writeset) } /* dynamic port forwarding */ -void +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. */ @@ -641,7 +958,7 @@ channel_pre_dynamic(Channel *c, fd_set * readset, fd_set * writeset) break; } if (ret < 0) { - channel_free(c->self); + chan_mark_dead(c); } else if (ret == 0) { debug2("channel %d: pre_dynamic: need more", c->self); /* need more */ @@ -654,11 +971,12 @@ channel_pre_dynamic(Channel *c, fd_set * readset, fd_set * writeset) } /* 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_ipaddr; int remote_port; @@ -667,25 +985,31 @@ channel_post_x11_listener(Channel *c, fd_set * readset, fd_set * writeset) debug("X11 connection requested."); addrlen = sizeof(addr); newsock = accept(c->sock, &addr, &addrlen); + if (c->single_connection) { + debug("single_connection: closing X11 listener."); + channel_close_fd(&c->sock); + chan_mark_dead(c); + } if (newsock < 0) { error("accept: %.100s", strerror(errno)); return; } + set_nodelay(newsock); remote_ipaddr = get_peer_ipaddr(newsock); remote_port = get_peer_port(newsock); snprintf(buf, sizeof buf, "X11 connection from %.200s port %d", remote_ipaddr, remote_port); - 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 (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); + packet_put_int(nc->self); + packet_put_int(nc->local_window_max); + packet_put_int(nc->local_maxpacket); /* originator ipaddr and port */ packet_put_cstring(remote_ipaddr); if (datafellows & SSH_BUG_X11FWD) { @@ -696,16 +1020,17 @@ channel_post_x11_listener(Channel *c, fd_set * readset, fd_set * writeset) 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_ipaddr); } } -void +static void port_open_helper(Channel *c, char *rtype) { int direct; @@ -748,7 +1073,8 @@ port_open_helper(Channel *c, char *rtype) packet_put_int(c->self); packet_put_cstring(c->path); packet_put_int(c->host_port); - if (have_hostname_in_open) + if (packet_get_protocol_flags() & + SSH_PROTOFLAG_HOST_IN_FWD_OPEN) packet_put_cstring(c->remote_name); packet_send(); } @@ -758,12 +1084,12 @@ port_open_helper(Channel *c, char *rtype) /* * 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, nextstate; + int newsock, nextstate; socklen_t addrlen; char *rtype; @@ -772,10 +1098,18 @@ channel_post_port_listener(Channel *c, fd_set * readset, fd_set * writeset) "to %.100s port %d requested.", c->listening_port, c->path, c->host_port); - rtype = (c->type == SSH_CHANNEL_RPORT_LISTENER) ? - "forwarded-tcpip" : "direct-tcpip"; - nextstate = (c->host_port == 0) ? SSH_CHANNEL_DYNAMIC : - SSH_CHANNEL_OPENING; + 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); @@ -783,22 +1117,25 @@ channel_post_port_listener(Channel *c, fd_set * readset, fd_set * writeset) error("accept: %.100s", strerror(errno)); return; } - newch = channel_new(rtype, + set_nodelay(newsock); + nc = channel_new(rtype, nextstate, newsock, newsock, -1, c->local_window_max, c->local_maxpacket, 0, xstrdup(rtype), 1); - - nc = channel_lookup(newch); - if (nc == NULL) { - error("xxx: no new channel:"); - 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) + 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 { port_open_helper(nc, rtype); + } } } @@ -806,11 +1143,13 @@ channel_post_port_listener(Channel *c, fd_set * readset, fd_set * writeset) * 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)) { @@ -820,47 +1159,72 @@ channel_post_auth_listener(Channel *c, fd_set * readset, fd_set * writeset) error("accept from auth socket: %.100s", strerror(errno)); return; } - newch = channel_new("accepted auth socket", + 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, xstrdup("accepted auth socket"), 1); + 0, name, 1); if (compat20) { packet_start(SSH2_MSG_CHANNEL_OPEN); packet_put_cstring("auth-agent@openssh.com"); - packet_put_int(newch); + 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(newch); + packet_put_int(nc->self); } packet_send(); } } -void +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)) { - 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"); + if (getsockopt(c->sock, SOL_SOCKET, SO_ERROR, &err, &sz) < 0) { + err = errno; + error("getsockopt SO_ERROR failed"); + } + if (err == 0) { + debug("channel %d: connected", 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 { - if (err == 0) { - debug("channel %d: connected)", c->self); + 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 { - debug("channel %d: not connected: %s", - c->self, strerror(err)); - chan_read_failed(c); - chan_write_failed(c); + packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE); + packet_put_int(c->remote_id); } + chan_mark_dead(c); } + packet_send(); } } -int +static int channel_handle_rfd(Channel *c, fd_set * readset, fd_set * writeset) { char buf[16*1024]; @@ -876,18 +1240,18 @@ channel_handle_rfd(Channel *c, fd_set * readset, fd_set * writeset) c->self, c->rfd, len); if (c->type != SSH_CHANNEL_OPEN) { debug("channel %d: not open", c->self); - channel_free(c->self); + chan_mark_dead(c); return -1; } else if (compat13) { - buffer_consume(&c->output, buffer_len(&c->output)); + buffer_clear(&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); } return -1; } - if(c->input_filter != NULL) { + if (c->input_filter != NULL) { if (c->input_filter(c, buf, len) == -1) { debug("channel %d: filter stops", c->self); chan_read_failed(c); @@ -898,35 +1262,38 @@ channel_handle_rfd(Channel *c, fd_set * readset, fd_set * writeset) } 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 (c->type != SSH_CHANNEL_OPEN) { debug("channel %d: not open", c->self); - channel_free(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); + buffer_clear(&c->output); + debug("channel %d: input draining.", c->self); c->type = SSH_CHANNEL_INPUT_DRAINING; } else { chan_write_failed(c); } return -1; } - if (compat20 && c->isatty) { + if (compat20 && c->isatty && dlen >= 1 && data[0] != '\r') { if (tcgetattr(c->wfd, &tio) == 0 && !(tio.c_lflag & ECHO) && (tio.c_lflag & ICANON)) { /* @@ -946,7 +1313,7 @@ channel_handle_wfd(Channel *c, fd_set * readset, fd_set * writeset) } return 1; } -int +static int channel_handle_efd(Channel *c, fd_set * readset, fd_set * writeset) { char buf[16*1024]; @@ -966,8 +1333,7 @@ channel_handle_efd(Channel *c, fd_set * readset, fd_set * writeset) if (len <= 0) { debug2("channel %d: closing write-efd %d", c->self, c->efd); - close(c->efd); - c->efd = -1; + channel_close_fd(&c->efd); } else { buffer_consume(&c->extended, len); c->local_consumed += len; @@ -976,14 +1342,13 @@ channel_handle_efd(Channel *c, fd_set * readset, fd_set * writeset) 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); + c->self, len, c->efd); if (len < 0 && (errno == EINTR || errno == EAGAIN)) return 1; if (len <= 0) { debug2("channel %d: closing read-efd %d", c->self, c->efd); - close(c->efd); - c->efd = -1; + channel_close_fd(&c->efd); } else { buffer_append(&c->extended, buf, len); } @@ -991,7 +1356,7 @@ channel_handle_efd(Channel *c, fd_set * readset, fd_set * writeset) } return 1; } -int +static int channel_check_window(Channel *c) { if (c->type == SSH_CHANNEL_OPEN && @@ -1011,24 +1376,20 @@ channel_check_window(Channel *c) return 1; } -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) +static void +channel_post_open(Channel *c, fd_set * readset, fd_set * writeset) { + if (c->delayed) + return; channel_handle_rfd(c, readset, writeset); channel_handle_wfd(c, readset, writeset); + if (!compat20) + return; channel_handle_efd(c, readset, writeset); - channel_check_window(c); } -void +static void channel_post_output_drain_13(Channel *c, fd_set * readset, fd_set * writeset) { int len; @@ -1037,16 +1398,16 @@ channel_post_output_drain_13(Channel *c, fd_set * readset, fd_set * writeset) len = write(c->sock, buffer_ptr(&c->output), buffer_len(&c->output)); if (len <= 0) - buffer_consume(&c->output, buffer_len(&c->output)); + buffer_clear(&c->output); else buffer_consume(&c->output, len); } } -void +static void channel_handler_init_20(void) { - channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_20; + channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open; channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open; channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener; channel_pre[SSH_CHANNEL_RPORT_LISTENER] = &channel_pre_listener; @@ -1055,16 +1416,16 @@ channel_handler_init_20(void) 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_OPEN] = &channel_post_open; channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener; channel_post[SSH_CHANNEL_RPORT_LISTENER] = &channel_post_port_listener; channel_post[SSH_CHANNEL_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; + channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open; } -void +static void channel_handler_init_13(void) { channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_13; @@ -1077,19 +1438,19 @@ channel_handler_init_13(void) 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_OPEN] = &channel_post_open; channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener; channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener; channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener; channel_post[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_post_output_drain_13; channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting; - channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open_1; + channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open; } -void +static void channel_handler_init_15(void) { - channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_15; + channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open; channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open; channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener; channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener; @@ -1100,16 +1461,16 @@ channel_handler_init_15(void) 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_OPEN] = &channel_post_open; channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting; - channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open_1; + channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open; } -void +static void channel_handler_init(void) { int i; - for(i = 0; i < SSH_CHANNEL_MAX_TYPE; i++) { + for (i = 0; i < SSH_CHANNEL_MAX_TYPE; i++) { channel_pre[i] = NULL; channel_post[i] = NULL; } @@ -1121,7 +1482,29 @@ channel_handler_init(void) 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; @@ -1133,36 +1516,22 @@ channel_handler(chan_fn *ftab[], fd_set * readset, fd_set * writeset) 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); - if (chan_is_dead(c)) { - /* - * we have to remove the fd's from the select mask - * before the channels are free'd and the fd's are - * closed - */ - if (c->wfd != -1) - FD_CLR(c->wfd, writeset); - if (c->rfd != -1) - FD_CLR(c->rfd, readset); - if (c->efd != -1) { - if (c->extended_usage == CHAN_EXTENDED_READ) - FD_CLR(c->efd, readset); - if (c->extended_usage == CHAN_EXTENDED_WRITE) - FD_CLR(c->efd, writeset); - } - channel_free(c->self); - } + 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 **readsetp, fd_set **writesetp, int *maxfdp, - int rekeying) + int *nallocp, int rekeying) { int n; u_int sz; @@ -1170,15 +1539,13 @@ channel_prepare_select(fd_set **readsetp, fd_set **writesetp, int *maxfdp, 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; + /* 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); @@ -1186,24 +1553,34 @@ channel_prepare_select(fd_set **readsetp, fd_set **writesetp, int *maxfdp, channel_handler(channel_pre, *readsetp, *writesetp); } +/* + * After select, perform any appropriate operations for channels which have + * events pending. + */ void channel_after_select(fd_set * readset, fd_set * writeset) { channel_handler(channel_post, readset, writeset); } + /* If there is data to send to the connection, enqueue some of it now. */ void -channel_output_poll() +channel_output_poll(void) { int len, i; 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) @@ -1215,7 +1592,7 @@ channel_output_poll() if (compat20 && (c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD))) { /* XXX is this true? */ - debug2("channel %d: no data after CLOSE", c->self); + debug3("channel %d: will not send data after close", c->self); continue; } @@ -1223,7 +1600,10 @@ channel_output_poll() 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. */ + /* + * Send some data for the other side over the secure + * connection. + */ if (compat20) { if (len > c->remote_window) len = c->remote_window; @@ -1281,14 +1661,11 @@ channel_output_poll() } } -/* - * 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) +channel_input_data(int type, u_int32_t seq, void *ctxt) { int id; char *data; @@ -1312,9 +1689,8 @@ channel_input_data(int type, int plen, void *ctxt) /* Get the data. */ data = packet_get_string(&data_len); - packet_done(); - if (compat20){ + if (compat20) { if (data_len > c->local_maxpacket) { log("channel %d: rcvd big packet %d, maxpack %d", c->self, data_len, c->local_maxpacket); @@ -1326,14 +1702,14 @@ channel_input_data(int type, int plen, void *ctxt) return; } c->local_window -= data_len; - }else{ - packet_integrity_check(plen, 4 + 4 + data_len, type); } + packet_check_eom(); buffer_append(&c->output, data, data_len); xfree(data); } + void -channel_input_extended_data(int type, int plen, void *ctxt) +channel_input_extended_data(int type, u_int32_t seq, void *ctxt) { int id; int tcode; @@ -1359,7 +1735,7 @@ channel_input_extended_data(int type, int plen, void *ctxt) return; } data = packet_get_string(&data_len); - packet_done(); + packet_check_eom(); if (data_len > c->local_window) { log("channel %d: rcvd too much extended_data %d, win %d", c->self, data_len, c->local_window); @@ -1372,60 +1748,37 @@ channel_input_extended_data(int type, int plen, void *ctxt) 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() -{ - u_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) +channel_input_ieof(int type, u_int32_t seq, void *ctxt) { int id; Channel *c; - packet_integrity_check(plen, 4, type); - id = packet_get_int(); + packet_check_eom(); c = channel_lookup(id); if (c == NULL) packet_disconnect("Received ieof for nonexistent channel %d.", id); chan_rcvd_ieof(c); + + /* XXX force input close */ + if (c->force_drain && c->istate == CHAN_INPUT_OPEN) { + debug("channel %d: FORCE input drain", c->self); + c->istate = CHAN_INPUT_WAIT_DRAIN; + if (buffer_len(&c->input) == 0) + chan_ibuf_empty(c); + } + } void -channel_input_close(int type, int plen, void *ctxt) +channel_input_close(int type, u_int32_t seq, void *ctxt) { int id; Channel *c; - packet_integrity_check(plen, 4, type); - id = packet_get_int(); + packet_check_eom(); c = channel_lookup(id); if (c == NULL) packet_disconnect("Received close for nonexistent channel %d.", id); @@ -1450,48 +1803,46 @@ channel_input_close(int type, int plen, void *ctxt) * Not a closed channel - mark it as draining, which will * cause it to be freed later. */ - buffer_consume(&c->input, buffer_len(&c->input)); + buffer_clear(&c->input); c->type = SSH_CHANNEL_OUTPUT_DRAINING; } } /* proto version 1.5 overloads CLOSE_CONFIRMATION with OCLOSE */ void -channel_input_oclose(int type, int plen, void *ctxt) +channel_input_oclose(int type, u_int32_t seq, void *ctxt) { int id = packet_get_int(); Channel *c = channel_lookup(id); - packet_integrity_check(plen, 4, type); + + packet_check_eom(); if (c == NULL) packet_disconnect("Received oclose for nonexistent channel %d.", id); chan_rcvd_oclose(c); } void -channel_input_close_confirmation(int type, int plen, void *ctxt) +channel_input_close_confirmation(int type, u_int32_t seq, void *ctxt) { int id = packet_get_int(); Channel *c = channel_lookup(id); - packet_done(); + packet_check_eom(); 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); + channel_free(c); } void -channel_input_open_confirmation(int type, int plen, void *ctxt) +channel_input_open_confirmation(int type, u_int32_t seq, void *ctxt) { int id, remote_id; Channel *c; - if (!compat20) - packet_integrity_check(plen, 4 + 4, type); - id = packet_get_int(); c = channel_lookup(id); @@ -1506,27 +1857,40 @@ channel_input_open_confirmation(int type, int plen, void *ctxt) 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) { + if (c->confirm) { debug2("callback start"); - c->cb_fn(c->self, c->cb_arg); + c->confirm(c->self, NULL); debug2("callback done"); } debug("channel %d: open confirm rwindow %d rmax %d", c->self, c->remote_window, c->remote_maxpacket); } + packet_check_eom(); +} + +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) +channel_input_open_failure(int type, u_int32_t seq, void *ctxt) { int id, reason; char *msg = NULL, *lang = NULL; Channel *c; - if (!compat20) - packet_integrity_check(plen, 4, type); - id = packet_get_int(); c = channel_lookup(id); @@ -1535,49 +1899,24 @@ channel_input_open_failure(int type, int plen, void *ctxt) "non-opening channel %d.", id); if (compat20) { reason = packet_get_int(); - if (packet_remaining() > 0) { + if (!(datafellows & SSH_BUG_OPENFAILURE)) { msg = packet_get_string(NULL); lang = packet_get_string(NULL); } - packet_done(); - log("channel_open_failure: %d: reason %d %s", id, - reason, msg ? msg : "<no additional info>"); + log("channel %d: open failed: %s%s%s", id, + reason2txt(reason), msg ? ": ": "", msg ? msg : ""); if (msg != NULL) xfree(msg); if (lang != NULL) xfree(lang); } + packet_check_eom(); /* Free the channel. This will also close the socket. */ - channel_free(id); -} - -void -channel_input_channel_request(int type, int plen, void *ctxt) -{ - int id; - Channel *c; - - id = packet_get_int(); - c = channel_lookup(id); - - if (c == NULL || - (c->type != SSH_CHANNEL_OPEN && c->type != SSH_CHANNEL_LARVAL)) - packet_disconnect("Received request for " - "non-open channel %d.", id); - if (c->cb_fn != NULL && c->cb_event == type) { - debug2("callback start"); - c->cb_fn(c->self, c->cb_arg); - debug2("callback done"); - } else { - char *service = packet_get_string(NULL); - debug("channel %d: rcvd request for %s", c->self, service); - debug("cb_fn %p cb_event %d", c->cb_fn , c->cb_event); - xfree(service); - } + channel_free(c); } void -channel_input_window_adjust(int type, int plen, void *ctxt) +channel_input_window_adjust(int type, u_int32_t seq, void *ctxt) { Channel *c; int id, adjust; @@ -1595,224 +1934,77 @@ channel_input_window_adjust(int type, int plen, void *ctxt) return; } adjust = packet_get_int(); - packet_done(); + packet_check_eom(); debug2("channel %d: rcvd adjust %d", id, adjust); c->remote_window += adjust; } -/* - * Stops listening for channels, and removes any unix domain sockets that we - * might have. - */ - -void -channel_stop_listening() -{ - int i; - for (i = 0; i < channels_alloc; i++) { - switch (channels[i].type) { - case SSH_CHANNEL_AUTH_SOCKET: - close(channels[i].sock); - /* auth_sock_cleanup_proc deletes the socket */ - 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); - break; - default: - break; - } - } -} - -/* - * 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].type != SSH_CHANNEL_FREE) - channel_close_fds(&channels[i]); -} - -/* Returns true if any channel is still open. */ - -int -channel_still_open() +channel_input_port_open(int type, u_int32_t seq, void *ctxt) { - 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_DYNAMIC: - 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: - 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; -} + Channel *c = NULL; + u_short host_port; + char *host, *originator_string; + int remote_id, sock = -1; -/* Returns the id of an open channel suitable for keepaliving */ + remote_id = packet_get_int(); + host = packet_get_string(NULL); + host_port = packet_get_int(); -int -channel_find_open() -{ - u_int i; - for (i = 0; i < channels_alloc; i++) - switch (channels[i].type) { - case SSH_CHANNEL_CLOSED: - case SSH_CHANNEL_DYNAMIC: - case SSH_CHANNEL_FREE: - case SSH_CHANNEL_X11_LISTENER: - case SSH_CHANNEL_PORT_LISTENER: - case SSH_CHANNEL_RPORT_LISTENER: - case SSH_CHANNEL_OPENING: - continue; - case SSH_CHANNEL_LARVAL: - case SSH_CHANNEL_AUTH_SOCKET: - case SSH_CHANNEL_CONNECTING: /* XXX ??? */ - 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", channels[i].type); - /* NOTREACHED */ - } - return -1; + if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) { + originator_string = packet_get_string(NULL); + } else { + originator_string = xstrdup("unknown (remote did not supply name)"); + } + packet_check_eom(); + 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); + c->remote_id = remote_id; + } + if (c == NULL) { + packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE); + packet_put_int(remote_id); + packet_send(); + } + xfree(host); } -/* - * Returns a message describing the currently open forwarded connections, - * suitable for sending to the client. The message contains crlf pairs for - * newlines. - */ - -char * -channel_open_message() -{ - Buffer buffer; - int i; - char buf[512], *cp; - - buffer_init(&buffer); - snprintf(buf, sizeof buf, "The following connections are open:\r\n"); - buffer_append(&buffer, buf, strlen(buf)); - for (i = 0; i < channels_alloc; i++) { - Channel *c = &channels[i]; - switch (c->type) { - case SSH_CHANNEL_FREE: - case SSH_CHANNEL_X11_LISTENER: - case SSH_CHANNEL_PORT_LISTENER: - case SSH_CHANNEL_RPORT_LISTENER: - case SSH_CHANNEL_CLOSED: - case SSH_CHANNEL_AUTH_SOCKET: - continue; - case SSH_CHANNEL_LARVAL: - case SSH_CHANNEL_OPENING: - case SSH_CHANNEL_CONNECTING: - case SSH_CHANNEL_DYNAMIC: - case SSH_CHANNEL_OPEN: - case SSH_CHANNEL_X11_OPEN: - case SSH_CHANNEL_INPUT_DRAINING: - case SSH_CHANNEL_OUTPUT_DRAINING: - snprintf(buf, sizeof buf, " #%d %.300s (t%d r%d i%d/%d o%d/%d fd %d/%d)\r\n", - c->self, c->remote_name, - c->type, c->remote_id, - c->istate, buffer_len(&c->input), - c->ostate, buffer_len(&c->output), - c->rfd, c->wfd); - buffer_append(&buffer, buf, strlen(buf)); - continue; - default: - fatal("channel_open_message: bad channel type %d", c->type); - /* NOTREACHED */ - } - } - buffer_append(&buffer, "\0", 1); - cp = xstrdup(buffer_ptr(&buffer)); - buffer_free(&buffer); - return cp; -} +/* -- tcp forwarding */ -/* - * Initiate forwarding of connections to local port "port" through the secure - * channel to host:port from remote side. - */ -int -channel_request_local_forwarding(u_short listen_port, const char *host_to_connect, - u_short port_to_connect, int gateway_ports) +void +channel_set_af(int af) { - return channel_request_forwarding( - NULL, listen_port, - host_to_connect, port_to_connect, - gateway_ports, /*remote_fwd*/ 0); + IPv4or6 = af; } -/* - * 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) +static int +channel_setup_fwd_listener(int type, const char *listen_addr, u_short listen_port, + const char *host_to_connect, u_short port_to_connect, int gateway_ports) { - int success, ch, sock, on = 1, ctype; + Channel *c; + int success, sock, on = 1; struct addrinfo hints, *ai, *aitop; - char ntop[NI_MAXHOST], strport[NI_MAXSERV]; const char *host; + char ntop[NI_MAXHOST], strport[NI_MAXSERV]; struct linger linger; success = 0; + host = (type == SSH_CHANNEL_RPORT_LISTENER) ? + listen_addr : host_to_connect; - if (remote_fwd) { - host = listen_address; - ctype = SSH_CHANNEL_RPORT_LISTENER; - } else { - host = host_to_connect; - ctype =SSH_CHANNEL_PORT_LISTENER; + if (host == NULL) { + error("No forward host name."); + return success; } - - if (strlen(host) > sizeof(channels[0].path) - 1) { + 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 @@ -1830,7 +2022,7 @@ channel_request_forwarding( 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"); + error("channel_setup_fwd_listener: getnameinfo failed"); continue; } /* Create a port to listen for the host. */ @@ -1844,10 +2036,10 @@ channel_request_forwarding( * 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)); + setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)); linger.l_onoff = 1; linger.l_linger = 5; - setsockopt(sock, SOL_SOCKET, SO_LINGER, (void *)&linger, sizeof(linger)); + setsockopt(sock, SOL_SOCKET, SO_LINGER, &linger, sizeof(linger)); debug("Local forwarding listening on %s port %s.", ntop, strport); /* Bind the socket to the address. */ @@ -1864,21 +2056,39 @@ channel_request_forwarding( continue; } /* Allocate a channel number for the socket. */ - ch = channel_new("port listener", ctype, 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 = port_to_connect; - channels[ch].listening_port = listen_port; + strlcpy(c->path, host, sizeof(c->path)); + c->host_port = port_to_connect; + c->listening_port = listen_port; success = 1; } if (success == 0) - error("channel_request_forwarding: cannot listen to port: %d", + error("channel_setup_fwd_listener: cannot listen to port: %d", listen_port); freeaddrinfo(aitop); return success; } +/* protocol local port fwd, used by ssh (and sshd in v1) */ +int +channel_setup_local_fwd_listener(u_short listen_port, + const char *host_to_connect, u_short port_to_connect, int gateway_ports) +{ + return channel_setup_fwd_listener(SSH_CHANNEL_PORT_LISTENER, + NULL, listen_port, host_to_connect, port_to_connect, gateway_ports); +} + +/* protocol v2 remote port fwd, used by sshd */ +int +channel_setup_remote_fwd_listener(const char *listen_address, + u_short listen_port, int gateway_ports) +{ + return channel_setup_fwd_listener(SSH_CHANNEL_RPORT_LISTENER, + listen_address, listen_port, NULL, 0, gateway_ports); +} + /* * Initiate forwarding of connections to port "port" on remote host through * the secure channel to host:port from local side. @@ -1888,7 +2098,7 @@ void channel_request_remote_forwarding(u_short listen_port, const char *host_to_connect, u_short port_to_connect) { - int payload_len, type, success = 0; + int type, success = 0; /* Record locally that connection to this host/port is permitted. */ if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION) @@ -1915,7 +2125,7 @@ channel_request_remote_forwarding(u_short listen_port, packet_write_wait(); /* Wait for response from the remote side. */ - type = packet_read(&payload_len); + type = packet_read(); switch (type) { case SSH_SMSG_SUCCESS: success = 1; @@ -1962,7 +2172,7 @@ channel_input_port_forward_request(int is_root, int gateway_ports) packet_disconnect("Requested forwarding of port %d but user is not root.", port); /* Initiate forwarding */ - channel_request_local_forwarding(port, hostname, host_port, gateway_ports); + channel_setup_local_fwd_listener(port, hostname, host_port, gateway_ports); /* Free the argument string. */ xfree(hostname); @@ -1974,7 +2184,7 @@ channel_input_port_forward_request(int is_root, int gateway_ports) * anyway, and the server has no way to know but to trust the client anyway. */ void -channel_permit_all_opens() +channel_permit_all_opens(void) { if (num_permitted_opens == 0) all_opens_permitted = 1; @@ -2007,7 +2217,7 @@ channel_clear_permitted_opens(void) /* return socket to remote host, port */ -int +static int connect_to(const char *host, u_short port) { struct addrinfo hints, *ai, *aitop; @@ -2055,11 +2265,12 @@ connect_to(const char *host, u_short port) return -1; } /* success */ + set_nodelay(sock); return sock; } int -channel_connect_by_listen_adress(u_short listen_port) +channel_connect_by_listen_address(u_short listen_port) { int i; @@ -2095,79 +2306,36 @@ channel_connect_to(const char *host, u_short port) return connect_to(host, port); } -/* - * 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) -{ - u_short host_port; - char *host, *originator_string; - int remote_channel, sock = -1, newch; - - remote_channel = packet_get_int(); - host = packet_get_string(NULL); - host_port = packet_get_int(); - - if (have_hostname_in_open) { - originator_string = packet_get_string(NULL); - } else { - originator_string = xstrdup("unknown (remote did not supply name)"); - } - packet_done(); - sock = channel_connect_to(host, host_port); - if (sock != -1) { - newch = channel_allocate(SSH_CHANNEL_CONNECTING, - sock, originator_string); - channels[newch].remote_id = remote_channel; - - /*XXX delay answer? */ - 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(); - } - xfree(host); -} +/* -- 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. + * Returns a suitable display number for the DISPLAY variable, or -1 if + * an error occurs. */ - -#define NUM_SOCKS 10 - -char * -x11_create_display_inet(int screen_number, int x11_display_offset) +int +x11_create_display_inet(int x11_display_offset, int x11_use_localhost, + int single_connection) { + Channel *nc = NULL; int display_number, sock; u_short port; struct addrinfo hints, *ai, *aitop; char strport[NI_MAXSERV]; int gaierr, n, num_socks = 0, socks[NUM_SOCKS]; - char display[512]; - char hostname[MAXHOSTNAMELEN]; for (display_number = x11_display_offset; - display_number < MAX_DISPLAYS; - display_number++) { + display_number < MAX_DISPLAYS; + display_number++) { port = 6000 + display_number; memset(&hints, 0, sizeof(hints)); hints.ai_family = IPv4or6; - hints.ai_flags = AI_PASSIVE; /* XXX loopback only ? */ + hints.ai_flags = x11_use_localhost ? 0: AI_PASSIVE; hints.ai_socktype = SOCK_STREAM; snprintf(strport, sizeof strport, "%d", port); if ((gaierr = getaddrinfo(NULL, strport, &hints, &aitop)) != 0) { error("getaddrinfo: %.100s", gai_strerror(gaierr)); - return NULL; + return -1; } for (ai = aitop; ai; ai = ai->ai_next) { if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6) @@ -2175,14 +2343,12 @@ x11_create_display_inet(int screen_number, int x11_display_offset) sock = socket(ai->ai_family, SOCK_STREAM, 0); if (sock < 0) { error("socket: %.100s", strerror(errno)); - return NULL; + return -1; } if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) { debug("bind port %d: %.100s", port, strerror(errno)); - shutdown(sock, SHUT_RDWR); close(sock); for (n = 0; n < num_socks; n++) { - shutdown(socks[n], SHUT_RDWR); close(socks[n]); } num_socks = 0; @@ -2198,67 +2364,47 @@ x11_create_display_inet(int screen_number, int x11_display_offset) } if (display_number >= MAX_DISPLAYS) { error("Failed to allocate internet-domain X11 display socket."); - return NULL; + return -1; } /* Start listening for connections on the socket. */ for (n = 0; n < num_socks; n++) { sock = socks[n]; if (listen(sock, 5) < 0) { error("listen: %.100s", strerror(errno)); - shutdown(sock, SHUT_RDWR); close(sock); - return NULL; + return -1; } } - /* Set up a suitable value for the DISPLAY variable. */ - if (gethostname(hostname, sizeof(hostname)) < 0) - fatal("gethostname: %.100s", strerror(errno)); - snprintf(display, sizeof display, "%.400s:%d.%d", hostname, - display_number, screen_number); - /* Allocate a channel for each socket. */ for (n = 0; n < num_socks; n++) { sock = socks[n]; - (void) channel_new("x11 listener", + nc = 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); + nc->single_connection = single_connection; } - /* Return a suitable value for the DISPLAY environment variable. */ - return xstrdup(display); + /* Return the display number for the DISPLAY environment variable. */ + return display_number; } -#ifndef X_UNIX_PATH -#define X_UNIX_PATH "/tmp/.X11-unix/X" -#endif - -static -int +static int connect_local_xsocket(u_int dnr) { - static const char *const x_sockets[] = { - X_UNIX_PATH "%u", - "/var/X/.X11-unix/X" "%u", - "/usr/spool/sockets/X11/" "%u", - NULL - }; int sock; struct sockaddr_un addr; - const char *const * path; - for (path = x_sockets; *path; ++path) { - sock = socket(AF_UNIX, SOCK_STREAM, 0); - if (sock < 0) - error("socket: %.100s", strerror(errno)); - memset(&addr, 0, sizeof(addr)); - addr.sun_family = AF_UNIX; - snprintf(addr.sun_path, sizeof addr.sun_path, *path, dnr); - if (connect(sock, (struct sockaddr *) & addr, sizeof(addr)) == 0) - return sock; - close(sock); - } + sock = socket(AF_UNIX, SOCK_STREAM, 0); + if (sock < 0) + error("socket: %.100s", strerror(errno)); + memset(&addr, 0, sizeof(addr)); + addr.sun_family = AF_UNIX; + snprintf(addr.sun_path, sizeof addr.sun_path, _PATH_UNIX_X, dnr); + if (connect(sock, (struct sockaddr *) & addr, sizeof(addr)) == 0) + return sock; + close(sock); error("connect %.100s: %.100s", addr.sun_path, strerror(errno)); return -1; } @@ -2293,7 +2439,7 @@ x11_connect_display(void) /* Connect to the unix domain socket. */ if (sscanf(strrchr(display, ':') + 1, "%d", &display_number) != 1) { error("Could not parse display number from DISPLAY: %.100s", - display); + display); return -1; } /* Create a socket. */ @@ -2308,8 +2454,7 @@ x11_connect_display(void) * Connect to an inet socket. The DISPLAY value is supposedly * hostname:d[.s], where hostname may also be numeric IP address. */ - strncpy(buf, display, sizeof(buf)); - buf[sizeof(buf) - 1] = 0; + strlcpy(buf, display, sizeof(buf)); cp = strchr(buf, ':'); if (!cp) { error("Could not find ':' in DISPLAY: %.100s", display); @@ -2319,7 +2464,7 @@ x11_connect_display(void) /* 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); + display); return -1; } @@ -2355,6 +2500,7 @@ x11_connect_display(void) strerror(errno)); return -1; } + set_nodelay(sock); return sock; } @@ -2365,56 +2511,52 @@ x11_connect_display(void) */ void -x11_input_open(int type, int plen, void *ctxt) +x11_input_open(int type, u_int32_t seq, void *ctxt) { - int remote_channel, sock = 0, newch; + Channel *c = NULL; + int remote_id, sock = 0; char *remote_host; - u_int remote_len; - /* Get remote channel number. */ - remote_channel = packet_get_int(); + debug("Received X11 open request."); + + remote_id = packet_get_int(); - /* Get remote originator name. */ - if (have_hostname_in_open) { - remote_host = packet_get_string(&remote_len); - remote_len += 4; + 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; } - - debug("Received X11 open request."); - packet_integrity_check(plen, 4 + remote_len, SSH_SMSG_X11_OPEN); + packet_check_eom(); /* 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); + 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) */ void -deny_input_open(int type, int plen, void *ctxt) +deny_input_open(int type, u_int32_t seq, void *ctxt) { int rchan = packet_get_int(); - switch(type){ + switch (type) { case SSH_SMSG_AGENT_OPEN: error("Warning: ssh server tried agent forwarding."); break; @@ -2422,7 +2564,7 @@ deny_input_open(int type, int plen, void *ctxt) error("Warning: ssh server tried X11 forwarding."); break; default: - error("deny_input_open: type %d plen %d", type, plen); + error("deny_input_open: type %d", type); break; } error("Warning: this is probably a break in attempt by a malicious server."); @@ -2434,8 +2576,8 @@ deny_input_open(int type, int plen, void *ctxt) /* * 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) @@ -2500,10 +2642,13 @@ x11_request_forwarding_with_spoofing(int client_session_id, xfree(new_data); } + +/* -- agent forwarding */ + /* Sends a message to the server to request authentication fd forwarding. */ void -auth_request_forwarding() +auth_request_forwarding(void) { packet_start(SSH_CMSG_AGENT_REQUEST_FORWARDING); packet_send(); @@ -2517,9 +2662,9 @@ auth_request_forwarding() */ char * -auth_get_socket_name() +auth_get_socket_name(void) { - return channel_forwarded_auth_socket_name; + return auth_sock_name; } /* removes the agent forwarding socket */ @@ -2529,11 +2674,11 @@ auth_sock_cleanup_proc(void *_pw) { struct passwd *pw = _pw; - if (channel_forwarded_auth_socket_name) { + if (auth_sock_name) { temporarily_use_uid(pw); - unlink(channel_forwarded_auth_socket_name); - rmdir(channel_forwarded_auth_socket_dir); - channel_forwarded_auth_socket_name = NULL; + unlink(auth_sock_name); + rmdir(auth_sock_dir); + auth_sock_name = NULL; restore_uid(); } } @@ -2546,33 +2691,36 @@ auth_sock_cleanup_proc(void *_pw) 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); /* 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()); /* delete agent socket on fatal() */ fatal_add_cleanup(auth_sock_cleanup_proc, pw); @@ -2585,8 +2733,7 @@ auth_input_request_forwarding(struct passwd * pw) /* Bind it to the name. */ memset(&sunaddr, 0, sizeof(sunaddr)); sunaddr.sun_family = AF_UNIX; - strncpy(sunaddr.sun_path, channel_forwarded_auth_socket_name, - sizeof(sunaddr.sun_path)); + strlcpy(sunaddr.sun_path, auth_sock_name, sizeof(sunaddr.sun_path)); if (bind(sock, (struct sockaddr *) & sunaddr, sizeof(sunaddr)) < 0) packet_disconnect("bind: %.100s", strerror(errno)); @@ -2599,28 +2746,26 @@ auth_input_request_forwarding(struct passwd * pw) packet_disconnect("listen: %.100s", strerror(errno)); /* Allocate a channel for the authentication agent socket. */ - newch = channel_new("auth socket", + nc = channel_new("auth socket", SSH_CHANNEL_AUTH_SOCKET, sock, sock, -1, CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT, 0, xstrdup("auth socket"), 1); - - strlcpy(channels[newch].path, channel_forwarded_auth_socket_name, - sizeof(channels[newch].path)); + strlcpy(nc->path, auth_sock_name, sizeof(nc->path)); return 1; } /* This is called to process an SSH_SMSG_AGENT_OPEN message. */ void -auth_input_open_request(int type, int plen, void *ctxt) +auth_input_open_request(int type, u_int32_t seq, void *ctxt) { - int remch, sock, newch; - char *dummyname; - - packet_integrity_check(plen, 4, type); + Channel *c = NULL; + int remote_id, sock; + char *name; /* Read the remote channel number from the message. */ - remch = packet_get_int(); + remote_id = packet_get_int(); + packet_check_eom(); /* * Get a connection to the local authentication agent (this may again @@ -2634,129 +2779,22 @@ auth_input_open_request(int type, int plen, void *ctxt) * 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); + 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; - } - 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; + 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); } - 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(); } |
