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Damien Millere4340be2000-09-16 13:29:08 +11001/*
2 * Author: Tatu Ylonen <ylo@cs.hut.fi>
3 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
4 * All rights reserved
5 *
6 * As far as I am concerned, the code I have written for this software
7 * can be used freely for any purpose. Any derived versions of this
8 * software must be clearly marked as such, and if the derived work is
9 * incompatible with the protocol description in the RFC file, it must be
10 * called by a name other than "ssh" or "Secure Shell".
11 */
12/*
13 * Copyright (c) 2000 Markus Friedl. All rights reserved.
14 *
15 * Redistribution and use in source and binary forms, with or without
16 * modification, are permitted provided that the following conditions
17 * are met:
18 * 1. Redistributions of source code must retain the above copyright
19 * notice, this list of conditions and the following disclaimer.
20 * 2. Redistributions in binary form must reproduce the above copyright
21 * notice, this list of conditions and the following disclaimer in the
22 * documentation and/or other materials provided with the distribution.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
25 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
26 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
27 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
28 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
29 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
30 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
31 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
32 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
33 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
34 */
Damien Miller69b69aa2000-10-28 14:19:58 +110035/* RCSID("$OpenBSD: channels.h,v 1.22 2000/10/27 07:48:22 markus Exp $"); */
Damien Millerd4a8b7e1999-10-27 13:42:43 +100036
37#ifndef CHANNELS_H
38#define CHANNELS_H
39
40/* Definitions for channel types. */
Damien Miller5428f641999-11-25 11:54:57 +110041#define SSH_CHANNEL_FREE 0 /* This channel is free (unused). */
42#define SSH_CHANNEL_X11_LISTENER 1 /* Listening for inet X11 conn. */
Damien Miller95def091999-11-25 00:26:21 +110043#define SSH_CHANNEL_PORT_LISTENER 2 /* Listening on a port. */
44#define SSH_CHANNEL_OPENING 3 /* waiting for confirmation */
45#define SSH_CHANNEL_OPEN 4 /* normal open two-way channel */
Damien Miller5428f641999-11-25 11:54:57 +110046#define SSH_CHANNEL_CLOSED 5 /* waiting for close confirmation */
Damien Millerb38eff82000-04-01 11:09:21 +100047#define SSH_CHANNEL_AUTH_SOCKET 6 /* authentication socket */
48#define SSH_CHANNEL_X11_OPEN 7 /* reading first X11 packet */
49#define SSH_CHANNEL_INPUT_DRAINING 8 /* sending remaining data to conn */
50#define SSH_CHANNEL_OUTPUT_DRAINING 9 /* sending remaining data to app */
51#define SSH_CHANNEL_LARVAL 10 /* larval session */
52#define SSH_CHANNEL_MAX_TYPE 11
Damien Millerd4a8b7e1999-10-27 13:42:43 +100053
Damien Miller5428f641999-11-25 11:54:57 +110054/*
55 * Data structure for channel data. This is iniailized in channel_allocate
56 * and cleared in channel_free.
57 */
Damien Millerad833b32000-08-23 10:46:23 +100058struct Channel;
59typedef struct Channel Channel;
Damien Millerd4a8b7e1999-10-27 13:42:43 +100060
Damien Millerad833b32000-08-23 10:46:23 +100061typedef void channel_callback_fn(int id, void *arg);
62typedef int channel_filter_fn(struct Channel *c, char *buf, int len);
63
64struct Channel {
Damien Miller95def091999-11-25 00:26:21 +110065 int type; /* channel type/state */
66 int self; /* my own channel identifier */
67 int remote_id; /* channel identifier for remote peer */
68 /* peer can be reached over encrypted connection, via packet-sent */
69 int istate; /* input from channel (state of receive half) */
70 int ostate; /* output to channel (state of transmit half) */
Damien Miller33b13562000-04-04 14:38:59 +100071 int flags; /* close sent/rcvd */
Damien Millerb38eff82000-04-01 11:09:21 +100072 int rfd; /* read fd */
73 int wfd; /* write fd */
74 int efd; /* extended fd */
75 int sock; /* sock fd */
Damien Miller95def091999-11-25 00:26:21 +110076 Buffer input; /* data read from socket, to be sent over
77 * encrypted connection */
78 Buffer output; /* data received over encrypted connection for
79 * send on socket */
Damien Millerb38eff82000-04-01 11:09:21 +100080 Buffer extended;
Damien Miller95def091999-11-25 00:26:21 +110081 char path[200]; /* path for unix domain sockets, or host name
82 * for forwards */
83 int listening_port; /* port being listened for forwards */
84 int host_port; /* remote port to connect for forwards */
85 char *remote_name; /* remote hostname */
Damien Millerb38eff82000-04-01 11:09:21 +100086
87 int remote_window;
88 int remote_maxpacket;
89 int local_window;
90 int local_window_max;
91 int local_consumed;
92 int local_maxpacket;
93 int extended_usage;
94
95 char *ctype; /* type */
96
Damien Millere247cc42000-05-07 12:03:14 +100097 /* callback */
Damien Millerb38eff82000-04-01 11:09:21 +100098 channel_callback_fn *cb_fn;
99 void *cb_arg;
100 int cb_event;
101 channel_callback_fn *dettach_user;
Damien Millerad833b32000-08-23 10:46:23 +1000102
103 /* filter */
104 channel_filter_fn *input_filter;
105};
Damien Millerb38eff82000-04-01 11:09:21 +1000106
107#define CHAN_EXTENDED_IGNORE 0
108#define CHAN_EXTENDED_READ 1
109#define CHAN_EXTENDED_WRITE 2
110
Damien Millere4340be2000-09-16 13:29:08 +1100111/* default window/packet sizes for tcp/x11-fwd-channel */
112#define CHAN_SES_WINDOW_DEFAULT (32*1024)
113#define CHAN_SES_PACKET_DEFAULT (CHAN_SES_WINDOW_DEFAULT/2)
114#define CHAN_TCP_WINDOW_DEFAULT (32*1024)
115#define CHAN_TCP_PACKET_DEFAULT (CHAN_TCP_WINDOW_DEFAULT/2)
116#define CHAN_X11_WINDOW_DEFAULT (4*1024)
117#define CHAN_X11_PACKET_DEFAULT (CHAN_X11_WINDOW_DEFAULT/2)
118
119
Damien Millerb38eff82000-04-01 11:09:21 +1000120void channel_open(int id);
Damien Miller33b13562000-04-04 14:38:59 +1000121void channel_request(int id, char *service, int wantconfirm);
122void channel_request_start(int id, char *service, int wantconfirm);
123void channel_register_callback(int id, int mtype, channel_callback_fn *fn, void *arg);
124void channel_register_cleanup(int id, channel_callback_fn *fn);
Damien Millerad833b32000-08-23 10:46:23 +1000125void channel_register_filter(int id, channel_filter_fn *fn);
Damien Miller33b13562000-04-04 14:38:59 +1000126void channel_cancel_cleanup(int id);
Damien Millerb38eff82000-04-01 11:09:21 +1000127Channel *channel_lookup(int id);
128
129int
130channel_new(char *ctype, int type, int rfd, int wfd, int efd,
Damien Miller69b69aa2000-10-28 14:19:58 +1100131 int window, int maxpack, int extended_usage, char *remote_name,
132 int nonblock);
133void
134channel_set_fds(int id, int rfd, int wfd, int efd,
135 int extusage, int nonblock);
136
137void deny_input_open(int type, int plen, void *ctxt);
Damien Millerb38eff82000-04-01 11:09:21 +1000138
Damien Miller62cee002000-09-23 17:15:56 +1100139void channel_input_channel_request(int type, int plen, void *ctxt);
140void channel_input_close(int type, int plen, void *ctxt);
141void channel_input_close_confirmation(int type, int plen, void *ctxt);
142void channel_input_data(int type, int plen, void *ctxt);
143void channel_input_extended_data(int type, int plen, void *ctxt);
144void channel_input_ieof(int type, int plen, void *ctxt);
145void channel_input_oclose(int type, int plen, void *ctxt);
146void channel_input_open_confirmation(int type, int plen, void *ctxt);
147void channel_input_open_failure(int type, int plen, void *ctxt);
148void channel_input_port_open(int type, int plen, void *ctxt);
149void channel_input_window_adjust(int type, int plen, void *ctxt);
150void channel_input_open(int type, int plen, void *ctxt);
Damien Millerb38eff82000-04-01 11:09:21 +1000151
152/* Sets specific protocol options. */
153void channel_set_options(int hostname_in_open);
154
155/*
156 * Allocate a new channel object and set its type and socket. Remote_name
157 * must have been allocated with xmalloc; this will free it when the channel
158 * is freed.
159 */
160int channel_allocate(int type, int sock, char *remote_name);
161
162/* Free the channel and close its socket. */
163void channel_free(int channel);
164
165/* Add any bits relevant to channels in select bitmasks. */
166void channel_prepare_select(fd_set * readset, fd_set * writeset);
167
168/*
169 * After select, perform any appropriate operations for channels which have
170 * events pending.
171 */
172void channel_after_select(fd_set * readset, fd_set * writeset);
173
174/* If there is data to send to the connection, send some of it now. */
175void channel_output_poll(void);
176
177/* Returns true if no channel has too much buffered data. */
178int channel_not_very_much_buffered_data(void);
179
180/* This closes any sockets that are listening for connections; this removes
181 any unix domain sockets. */
182void channel_stop_listening(void);
183
184/*
185 * Closes the sockets of all channels. This is used to close extra file
186 * descriptors after a fork.
187 */
188void channel_close_all(void);
189
190/* Returns the maximum file descriptor number used by the channels. */
191int channel_max_fd(void);
192
193/* Returns true if there is still an open channel over the connection. */
194int channel_still_open(void);
195
196/*
197 * Returns a string containing a list of all open channels. The list is
198 * suitable for displaying to the user. It uses crlf instead of newlines.
199 * The caller should free the string with xfree.
200 */
201char *channel_open_message(void);
202
203/*
204 * Initiate forwarding of connections to local port "port" through the secure
205 * channel to host:port from remote side. This never returns if there was an
206 * error.
207 */
Damien Miller4af51302000-04-16 11:18:38 +1000208void
Damien Millerb38eff82000-04-01 11:09:21 +1000209channel_request_local_forwarding(u_short port, const char *host,
210 u_short remote_port, int gateway_ports);
211
212/*
213 * Initiate forwarding of connections to port "port" on remote host through
214 * the secure channel to host:port from local side. This never returns if
215 * there was an error. This registers that open requests for that port are
216 * permitted.
217 */
Damien Miller4af51302000-04-16 11:18:38 +1000218void
Damien Millerb38eff82000-04-01 11:09:21 +1000219channel_request_remote_forwarding(u_short port, const char *host,
220 u_short remote_port);
221
222/*
223 * Permits opening to any host/port in SSH_MSG_PORT_OPEN. This is usually
224 * called by the server, because the user could connect to any port anyway,
225 * and the server has no way to know but to trust the client anyway.
226 */
227void channel_permit_all_opens(void);
228
229/*
230 * This is called after receiving CHANNEL_FORWARDING_REQUEST. This initates
231 * listening for the port, and sends back a success reply (or disconnect
232 * message if there was an error). This never returns if there was an error.
233 */
Damien Millere247cc42000-05-07 12:03:14 +1000234void channel_input_port_forward_request(int is_root, int gateway_ports);
Damien Millerb38eff82000-04-01 11:09:21 +1000235
236/*
237 * Creates a port for X11 connections, and starts listening for it. Returns
238 * the display name, or NULL if an error was encountered.
239 */
240char *x11_create_display(int screen);
241
242/*
243 * Creates an internet domain socket for listening for X11 connections.
244 * Returns a suitable value for the DISPLAY variable, or NULL if an error
245 * occurs.
246 */
247char *x11_create_display_inet(int screen, int x11_display_offset);
248
249/*
250 * This is called when SSH_SMSG_X11_OPEN is received. The packet contains
251 * the remote channel number. We should do whatever we want, and respond
252 * with either SSH_MSG_OPEN_CONFIRMATION or SSH_MSG_OPEN_FAILURE.
253 */
Damien Miller62cee002000-09-23 17:15:56 +1100254void x11_input_open(int type, int plen, void *ctxt);
Damien Millerb38eff82000-04-01 11:09:21 +1000255
256/*
257 * Requests forwarding of X11 connections. This should be called on the
258 * client only.
259 */
260void x11_request_forwarding(void);
261
262/*
263 * Requests forwarding for X11 connections, with authentication spoofing.
264 * This should be called in the client only.
265 */
Damien Millerbd483e72000-04-30 10:00:53 +1000266void
267x11_request_forwarding_with_spoofing(int client_session_id,
268 const char *proto, const char *data);
Damien Millerb38eff82000-04-01 11:09:21 +1000269
270/* Sends a message to the server to request authentication fd forwarding. */
271void auth_request_forwarding(void);
272
273/*
274 * Returns the name of the forwarded authentication socket. Returns NULL if
275 * there is no forwarded authentication socket. The returned value points to
276 * a static buffer.
277 */
278char *auth_get_socket_name(void);
279
280/*
Damien Millerd3a18572000-06-07 19:55:44 +1000281 * This is called to process SSH_CMSG_AGENT_REQUEST_FORWARDING on the server.
Damien Millerb38eff82000-04-01 11:09:21 +1000282 * This starts forwarding authentication requests.
283 */
Damien Millerd3a18572000-06-07 19:55:44 +1000284int auth_input_request_forwarding(struct passwd * pw);
Damien Millerb38eff82000-04-01 11:09:21 +1000285
286/* This is called to process an SSH_SMSG_AGENT_OPEN message. */
Damien Miller62cee002000-09-23 17:15:56 +1100287void auth_input_open_request(int type, int plen, void *ctxt);
Damien Millerb38eff82000-04-01 11:09:21 +1000288
Damien Miller33b13562000-04-04 14:38:59 +1000289/* XXX */
290int channel_connect_to(const char *host, u_short host_port);
Damien Millerbd483e72000-04-30 10:00:53 +1000291int x11_connect_display(void);
Damien Miller33b13562000-04-04 14:38:59 +1000292
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000293#endif