X-Git-Url: http://andersk.mit.edu/gitweb/openssh.git/blobdiff_plain/7231bd479a8c576b545fce9036ad5b60606f4a6a..67656ffcb8e1bdacdf86ef1f4b2df44fd4ce238e:/channels.c diff --git a/channels.c b/channels.c index 55cef42c..cc2613a8 100644 --- a/channels.c +++ b/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 Markus Friedl. All rights reserved. * Copyright (c) 1999 Dug Song. All rights reserved. * Copyright (c) 1999 Theo de Raadt. All rights reserved. * @@ -40,33 +39,25 @@ */ #include "includes.h" -RCSID("$OpenBSD: channels.c,v 1.116 2001/05/16 22:09:20 markus Exp $"); - -#include -#include +RCSID("$OpenBSD: channels.c,v 1.150 2001/12/20 22:50:24 djm Exp $"); #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 @@ -86,23 +77,8 @@ static int channels_alloc = 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; - -/* 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. @@ -118,6 +94,7 @@ 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; /* @@ -127,23 +104,42 @@ 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 */ -extern int IPv4or6; +/* -- 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 */ +static int IPv4or6 = AF_UNSPEC; + +/* helper */ +static void port_open_helper(Channel *c, char *rtype); + +/* -- channel core */ Channel * channel_lookup(int id) @@ -167,7 +163,7 @@ 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) { @@ -226,11 +222,7 @@ channel_new(char *ctype, int type, int rfd, int wfd, int efd, channels = xmalloc(channels_alloc * sizeof(Channel *)); for (i = 0; i < channels_alloc; i++) channels[i] = NULL; - /* - * Kludge: arrange a call to channel_stop_listening if we - * terminate with fatal(). - */ - fatal_add_cleanup((void (*) (void *)) channel_stop_listening, 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++) @@ -250,6 +242,7 @@ channel_new(char *ctype, int type, int rfd, int wfd, int efd, } /* 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); @@ -269,33 +262,57 @@ channel_new(char *ctype, int type, int rfd, int wfd, int efd, 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->input_filter = NULL; debug("channel %d: new [%s]", found, remote_name); return c; } +static int +channel_find_maxfd(void) +{ + 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. */ @@ -304,15 +321,18 @@ void channel_free(Channel *c) { char *s; + int i, n; + + for (n = 0, i = 0; i < channels_alloc; i++) + if (channels[i]) + n++; + debug("channel_free: channel %d: %s, nchannels %d", c->self, + c->remote_name ? c->remote_name : "???", n); s = channel_open_message(); - debug("channel_free: channel %d: status: %s", c->self, s); + debug3("channel_free: status: %s", s); xfree(s); - if (c->dettach_user != NULL) { - debug("channel_free: channel %d: dettaching channel user", c->self); - c->dettach_user(c->self, NULL); - } if (c->sock != -1) shutdown(c->sock, SHUT_RDWR); channel_close_fds(c); @@ -323,8 +343,329 @@ channel_free(Channel *c) xfree(c->remote_name); c->remote_name = NULL; } - channels[c->self] = NULL; - xfree(c); + 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(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(); } /* @@ -339,20 +680,20 @@ 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()) @@ -361,7 +702,7 @@ channel_pre_open_13(Channel *c, fd_set * readset, fd_set * writeset) 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 */ @@ -378,7 +719,7 @@ channel_pre_open_15(Channel *c, fd_set * readset, fd_set * writeset) } } -void +static void channel_pre_open_20(Channel *c, fd_set * readset, fd_set * writeset) { if (c->istate == CHAN_INPUT_OPEN && @@ -404,7 +745,7 @@ 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) { @@ -416,7 +757,7 @@ 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) @@ -432,19 +773,20 @@ 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 = (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]; @@ -453,12 +795,12 @@ 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; @@ -491,10 +833,10 @@ 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; @@ -507,7 +849,7 @@ 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); @@ -516,10 +858,13 @@ 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) @@ -535,12 +880,12 @@ channel_pre_x11_open(Channel *c, fd_set * readset, fd_set * writeset) } /* 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; @@ -587,7 +932,7 @@ 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); @@ -605,14 +950,14 @@ 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. */ @@ -645,12 +990,12 @@ 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; + int newsock, on = 1; socklen_t addrlen; char buf[16384], *remote_ipaddr; int remote_port; @@ -659,10 +1004,19 @@ 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; } + if (setsockopt(newsock, IPPROTO_TCP, TCP_NODELAY, &on, + sizeof on) == -1) + error("setsockopt TCP_NODELAY: %.100s", + strerror(errno)); remote_ipaddr = get_peer_ipaddr(newsock); remote_port = get_peer_port(newsock); snprintf(buf, sizeof buf, "X11 connection from %.200s port %d", @@ -681,8 +1035,8 @@ channel_post_x11_listener(Channel *c, fd_set * readset, fd_set * writeset) packet_start(SSH2_MSG_CHANNEL_OPEN); packet_put_cstring("x11"); packet_put_int(nc->self); - packet_put_int(c->local_window_max); - packet_put_int(c->local_maxpacket); + 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) { @@ -694,15 +1048,16 @@ channel_post_x11_listener(Channel *c, fd_set * readset, fd_set * writeset) } else { packet_start(SSH_SMSG_X11_OPEN); packet_put_int(nc->self); - if (have_hostname_in_open) - packet_put_string(buf, strlen(buf)); + 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; @@ -745,7 +1100,8 @@ 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(); } @@ -755,7 +1111,7 @@ 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; @@ -769,11 +1125,18 @@ 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 && - c->type != SSH_CHANNEL_RPORT_LISTENER) ? - 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); @@ -794,8 +1157,16 @@ channel_post_port_listener(Channel *c, fd_set * readset, fd_set * writeset) 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); + } } } @@ -803,10 +1174,11 @@ 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; socklen_t addrlen; @@ -818,12 +1190,14 @@ channel_post_auth_listener(Channel *c, fd_set * readset, fd_set * writeset) error("accept from auth socket: %.100s", strerror(errno)); return; } + name = xstrdup("accepted auth socket"); nc = channel_new("accepted auth socket", SSH_CHANNEL_OPENING, newsock, newsock, -1, c->local_window_max, c->local_maxpacket, - 0, xstrdup("accepted auth socket"), 1); + 0, name, 1); if (nc == NULL) { error("channel_post_auth_listener: channel_new failed"); + xfree(name); close(newsock); } if (compat20) { @@ -840,11 +1214,11 @@ channel_post_auth_listener(Channel *c, fd_set * readset, fd_set * writeset) } } -void +static void channel_post_connecting(Channel *c, fd_set * readset, fd_set * writeset) { int err = 0; - int sz = sizeof(err); + socklen_t sz = sizeof(err); if (FD_ISSET(c->sock, writeset)) { if (getsockopt(c->sock, SOL_SOCKET, SO_ERROR, (char *)&err, @@ -887,13 +1261,13 @@ channel_post_connecting(Channel *c, fd_set * readset, fd_set * writeset) } } -int +static int channel_handle_rfd(Channel *c, fd_set * readset, fd_set * writeset) { char buf[16*1024]; int len; - if (c->istate == CHAN_INPUT_OPEN && + if (c->rfd != -1 && FD_ISSET(c->rfd, readset)) { len = read(c->rfd, buf, sizeof(buf)); if (len < 0 && (errno == EINTR || errno == EAGAIN)) @@ -908,13 +1282,13 @@ channel_handle_rfd(Channel *c, fd_set * readset, fd_set * writeset) } 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); } 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); @@ -925,19 +1299,21 @@ 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->ostate == CHAN_OUTPUT_OPEN || - c->ostate == CHAN_OUTPUT_WAIT_DRAIN) && + 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) { @@ -947,14 +1323,14 @@ channel_handle_wfd(Channel *c, fd_set * readset, fd_set * writeset) 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) { + if (compat20 && c->isatty && dlen >= 1 && data[0] != '\r') { if (tcgetattr(c->wfd, &tio) == 0 && !(tio.c_lflag & ECHO) && (tio.c_lflag & ICANON)) { /* @@ -974,7 +1350,7 @@ 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]; @@ -994,8 +1370,7 @@ 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; @@ -1004,14 +1379,13 @@ 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); } @@ -1019,7 +1393,7 @@ 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 && @@ -1039,16 +1413,20 @@ channel_check_window(Channel *c) 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); @@ -1056,7 +1434,7 @@ channel_post_open_2(Channel *c, fd_set * readset, fd_set * writeset) channel_check_window(c); } -void +static void channel_post_output_drain_13(Channel *c, fd_set * readset, fd_set * writeset) { int len; @@ -1071,7 +1449,7 @@ channel_post_output_drain_13(Channel *c, fd_set * readset, fd_set * writeset) } } -void +static void channel_handler_init_20(void) { channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_20; @@ -1092,7 +1470,7 @@ channel_handler_init_20(void) 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; @@ -1114,7 +1492,7 @@ channel_handler_init_13(void) 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; @@ -1133,11 +1511,11 @@ channel_handler_init_15(void) channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open_1; } -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; } @@ -1149,7 +1527,29 @@ 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; @@ -1164,33 +1564,19 @@ channel_handler(chan_fn *ftab[], fd_set * readset, fd_set * writeset) 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); - } + 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; @@ -1198,15 +1584,13 @@ 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); @@ -1214,27 +1598,34 @@ 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]; 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) @@ -1246,7 +1637,7 @@ 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; } @@ -1254,7 +1645,10 @@ 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; @@ -1312,14 +1706,11 @@ 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, int plen, u_int32_t seq, void *ctxt) { int id; char *data; @@ -1345,7 +1736,7 @@ channel_input_data(int type, int plen, void *ctxt) 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); @@ -1363,8 +1754,9 @@ channel_input_data(int type, int plen, void *ctxt) 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, int plen, u_int32_t seq, void *ctxt) { int id; int tcode; @@ -1403,38 +1795,8 @@ 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 != NULL && c->type == SSH_CHANNEL_OPEN) { - if (!compat20 && buffer_len(&c->input) > packet_get_maxsize()) { - debug("channel %d: big input buffer %d", - c->self, buffer_len(&c->input)); - return 0; - } - if (buffer_len(&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, int plen, u_int32_t seq, void *ctxt) { int id; Channel *c; @@ -1446,10 +1808,17 @@ channel_input_ieof(int type, int plen, void *ctxt) 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 -channel_input_close(int type, int plen, void *ctxt) +channel_input_close(int type, int plen, u_int32_t seq, void *ctxt) { int id; Channel *c; @@ -1488,7 +1857,7 @@ channel_input_close(int type, int plen, void *ctxt) /* proto version 1.5 overloads CLOSE_CONFIRMATION with OCLOSE */ void -channel_input_oclose(int type, int plen, void *ctxt) +channel_input_oclose(int type, int plen, u_int32_t seq, void *ctxt) { int id = packet_get_int(); Channel *c = channel_lookup(id); @@ -1499,7 +1868,7 @@ channel_input_oclose(int type, int plen, void *ctxt) } void -channel_input_close_confirmation(int type, int plen, void *ctxt) +channel_input_close_confirmation(int type, int plen, u_int32_t seq, void *ctxt) { int id = packet_get_int(); Channel *c = channel_lookup(id); @@ -1515,7 +1884,7 @@ channel_input_close_confirmation(int type, int plen, void *ctxt) } void -channel_input_open_confirmation(int type, int plen, void *ctxt) +channel_input_open_confirmation(int type, int plen, u_int32_t seq, void *ctxt) { int id, remote_id; Channel *c; @@ -1548,10 +1917,10 @@ channel_input_open_confirmation(int type, int plen, void *ctxt) } } -char * +static char * reason2txt(int reason) { - switch(reason) { + switch (reason) { case SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED: return "administratively prohibited"; case SSH2_OPEN_CONNECT_FAILED: @@ -1561,11 +1930,11 @@ reason2txt(int reason) case SSH2_OPEN_RESOURCE_SHORTAGE: return "resource shortage"; } - return "unkown reason"; + return "unknown reason"; } void -channel_input_open_failure(int type, int plen, void *ctxt) +channel_input_open_failure(int type, int plen, u_int32_t seq, void *ctxt) { int id, reason; char *msg = NULL, *lang = NULL; @@ -1599,7 +1968,7 @@ channel_input_open_failure(int type, int plen, void *ctxt) } void -channel_input_channel_request(int type, int plen, void *ctxt) +channel_input_channel_request(int type, int plen, u_int32_t seq, void *ctxt) { int id; Channel *c; @@ -1624,7 +1993,7 @@ channel_input_channel_request(int type, int plen, void *ctxt) } void -channel_input_window_adjust(int type, int plen, void *ctxt) +channel_input_window_adjust(int type, int plen, u_int32_t seq, void *ctxt) { Channel *c; int id, adjust; @@ -1647,189 +2016,51 @@ channel_input_window_adjust(int type, int plen, void *ctxt) c->remote_window += adjust; } -/* - * Stops listening for channels, and removes any unix domain sockets that we - * might have. - */ - -void -channel_stop_listening() -{ - 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: - close(c->sock); - unlink(c->path); - channel_free(c); - break; - case SSH_CHANNEL_PORT_LISTENER: - case SSH_CHANNEL_RPORT_LISTENER: - case SSH_CHANNEL_X11_LISTENER: - close(c->sock); - channel_free(c); - 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] != NULL) - channel_close_fds(channels[i]); -} - -/* 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: - 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() +channel_input_port_open(int type, int plen, u_int32_t seq, void *ctxt) { - 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: - 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 */ + 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; } } - return -1; + 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. - */ +/* -- tcp forwarding */ -char * -channel_open_message() +void +channel_set_af(int af) { - 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: - 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; + IPv4or6 = af; } /* @@ -1857,7 +2088,7 @@ channel_request_forwarding( int gateway_ports, int remote_fwd) { Channel *c; - int success, sock, on = 1, ctype; + int success, sock, on = 1, type; struct addrinfo hints, *ai, *aitop; char ntop[NI_MAXHOST], strport[NI_MAXSERV]; const char *host; @@ -1867,10 +2098,10 @@ channel_request_forwarding( if (remote_fwd) { host = listen_address; - ctype = SSH_CHANNEL_RPORT_LISTENER; + type = SSH_CHANNEL_RPORT_LISTENER; } else { host = host_to_connect; - ctype =SSH_CHANNEL_PORT_LISTENER; + type = SSH_CHANNEL_PORT_LISTENER; } if (strlen(host) > SSH_CHANNEL_PATH_LEN - 1) { @@ -1934,7 +2165,7 @@ channel_request_forwarding( continue; } /* Allocate a channel number for the socket. */ - c = 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); if (c == NULL) { @@ -2051,7 +2282,7 @@ 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; @@ -2084,7 +2315,7 @@ 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; @@ -2136,7 +2367,7 @@ connect_to(const char *host, u_short port) } int -channel_connect_by_listen_adress(u_short listen_port) +channel_connect_by_listen_address(u_short listen_port) { int i; @@ -2172,81 +2403,36 @@ 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) -{ - 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 (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) { - 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); -} +/* -- 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 gateway_ports, + 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 = gateway_ports ? AI_PASSIVE : 0; 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) @@ -2255,7 +2441,7 @@ x11_create_display_inet(int screen_number, int x11_display_offset) if (sock < 0) { if ((errno != EINVAL) && (errno != EAFNOSUPPORT)) { error("socket: %.100s", strerror(errno)); - return NULL; + return -1; } else { debug("x11_create_display_inet: Socket family %d not supported", ai->ai_family); @@ -2264,14 +2450,12 @@ x11_create_display_inet(int screen_number, int x11_display_offset) } if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) { debug("bind port %d: %.100s", port, strerror(errno)); - shutdown(sock, SHUT_RDWR); close(sock); if (ai->ai_next) continue; for (n = 0; n < num_socks; n++) { - shutdown(socks[n], SHUT_RDWR); close(socks[n]); } num_socks = 0; @@ -2291,104 +2475,48 @@ 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; - } - } - - /* Set up a suitable value for the DISPLAY variable. */ - if (gethostname(hostname, sizeof(hostname)) < 0) - fatal("gethostname: %.100s", strerror(errno)); - -#ifdef IPADDR_IN_DISPLAY - /* - * HPUX detects the local hostname in the DISPLAY variable and tries - * to set up a shared memory connection to the server, which it - * incorrectly supposes to be local. - * - * The workaround - as used in later $$H and other programs - is - * is to set display to the host's IP address. - */ - { - struct hostent *he; - struct in_addr my_addr; - - he = gethostbyname(hostname); - if (he == NULL) { - error("[X11-broken-fwd-hostname-workaround] Could not get " - "IP address for hostname %s.", hostname); - - packet_send_debug("[X11-broken-fwd-hostname-workaround]" - "Could not get IP address for hostname %s.", hostname); - - shutdown(sock, SHUT_RDWR); close(sock); - - return NULL; + return -1; } - - memcpy(&my_addr, he->h_addr_list[0], sizeof(struct in_addr)); - - /* Set DISPLAY to :screen.display */ - snprintf(display, sizeof(display), "%.50s:%d.%d", inet_ntoa(my_addr), - display_number, screen_number); } -#else /* IPADDR_IN_DISPLAY */ - /* Just set DISPLAY to hostname:screen.display */ - snprintf(display, sizeof display, "%.400s:%d.%d", hostname, - display_number, screen_number); -#endif /* IPADDR_IN_DISPLAY */ /* 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); + if (nc != NULL) + 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; } @@ -2396,7 +2524,7 @@ connect_local_xsocket(u_int dnr) int x11_connect_display(void) { - int display_number, sock = 0; + int display_number, sock = 0, on = 1; const char *display; char buf[1024], *cp; struct addrinfo hints, *ai, *aitop; @@ -2423,7 +2551,7 @@ 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. */ @@ -2438,8 +2566,7 @@ 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); @@ -2449,7 +2576,7 @@ 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; } @@ -2485,6 +2612,8 @@ x11_connect_display(void) strerror(errno)); return -1; } + if (setsockopt(sock, IPPROTO_TCP, TCP_NODELAY, &on, sizeof on) == -1) + error("setsockopt TCP_NODELAY: %.100s", strerror(errno)); return sock; } @@ -2495,7 +2624,7 @@ x11_connect_display(void) */ void -x11_input_open(int type, int plen, void *ctxt) +x11_input_open(int type, int plen, u_int32_t seq, void *ctxt) { Channel *c = NULL; int remote_id, sock = 0; @@ -2504,7 +2633,8 @@ x11_input_open(int type, int plen, void *ctxt) debug("Received X11 open request."); remote_id = packet_get_int(); - if (have_hostname_in_open) { + + 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)"); @@ -2523,6 +2653,7 @@ x11_input_open(int type, int plen, void *ctxt) close(sock); } else { c->remote_id = remote_id; + c->force_drain = 1; } } if (c == NULL) { @@ -2540,10 +2671,10 @@ x11_input_open(int type, int plen, void *ctxt) /* 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, int plen, 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; @@ -2563,8 +2694,8 @@ 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) @@ -2629,10 +2760,13 @@ 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(); @@ -2646,18 +2780,25 @@ 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 */ void -cleanup_socket(void) +auth_sock_cleanup_proc(void *_pw) { - unlink(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(); + } } /* @@ -2672,36 +2813,36 @@ auth_input_request_forwarding(struct passwd * pw) 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); - if (atexit(cleanup_socket) < 0) { - int saved = errno; - cleanup_socket(); - packet_disconnect("socket: %.100s", strerror(saved)); - } /* Create the socket. */ sock = socket(AF_UNIX, SOCK_STREAM, 0); if (sock < 0) @@ -2710,8 +2851,7 @@ 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)); @@ -2730,21 +2870,23 @@ auth_input_request_forwarding(struct passwd * pw) 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, channel_forwarded_auth_socket_name, sizeof(nc->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, int plen, u_int32_t seq, void *ctxt) { Channel *c = NULL; int remote_id, sock; - char *dummyname; + char *name; packet_integrity_check(plen, 4, type); @@ -2764,13 +2906,16 @@ auth_input_open_request(int type, int plen, void *ctxt) * agent. */ if (sock >= 0) { - dummyname = xstrdup("authentication agent connection"); - c = channel_new("", SSH_CHANNEL_OPEN, sock, sock, -1, 0, 0, 0, dummyname, 1); + 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; } } if (c == NULL) { @@ -2785,105 +2930,3 @@ auth_input_open_request(int type, int plen, void *ctxt) } packet_send(); } - -void -channel_start_open(int id) -{ - Channel *c = channel_lookup(id); - if (c == NULL) { - log("channel_open: %d: bad id", id); - return; - } - debug("send channel open %d", id); - packet_start(SSH2_MSG_CHANNEL_OPEN); - packet_put_cstring(c->ctype); - packet_put_int(c->self); - packet_put_int(c->local_window); - packet_put_int(c->local_maxpacket); -} -void -channel_open(int id) -{ - /* XXX REMOVE ME */ - channel_start_open(id); - packet_send(); -} -void -channel_request(int id, char *service, int wantconfirm) -{ - channel_request_start(id, service, wantconfirm); - packet_send(); - debug("channel request %d: %s", id, service) ; -} -void -channel_request_start(int id, char *service, int wantconfirm) -{ - Channel *c = channel_lookup(id); - if (c == NULL) { - log("channel_request: %d: bad id", id); - return; - } - packet_start(SSH2_MSG_CHANNEL_REQUEST); - packet_put_int(c->remote_id); - packet_put_cstring(service); - packet_put_char(wantconfirm); -} -void -channel_register_callback(int id, int mtype, channel_callback_fn *fn, void *arg) -{ - Channel *c = channel_lookup(id); - if (c == NULL) { - log("channel_register_callback: %d: bad id", id); - return; - } - c->cb_event = mtype; - c->cb_fn = fn; - c->cb_arg = arg; -} -void -channel_register_cleanup(int id, channel_callback_fn *fn) -{ - Channel *c = channel_lookup(id); - if (c == NULL) { - log("channel_register_cleanup: %d: bad id", id); - return; - } - c->dettach_user = fn; -} -void -channel_cancel_cleanup(int id) -{ - Channel *c = channel_lookup(id); - if (c == NULL) { - log("channel_cancel_cleanup: %d: bad id", id); - return; - } - c->dettach_user = NULL; -} -void -channel_register_filter(int id, channel_filter_fn *fn) -{ - Channel *c = channel_lookup(id); - if (c == NULL) { - log("channel_register_filter: %d: bad id", id); - return; - } - c->input_filter = fn; -} - -void -channel_set_fds(int id, int rfd, int wfd, int efd, - int extusage, int nonblock) -{ - Channel *c = channel_lookup(id); - if (c == NULL || c->type != SSH_CHANNEL_LARVAL) - fatal("channel_activate for non-larval channel %d.", id); - channel_register_fds(c, rfd, wfd, efd, extusage, nonblock); - c->type = SSH_CHANNEL_OPEN; - /* XXX window size? */ - c->local_window = c->local_window_max = c->local_maxpacket * 2; - packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST); - packet_put_int(c->remote_id); - packet_put_int(c->local_window); - packet_send(); -}