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- markus@cvs.openbsd.org 2001/05/04 14:34:34
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bcbf86ec 1/*
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 */
3ffc6336 35/* RCSID("$OpenBSD: channels.h,v 1.31 2001/04/13 22:46:53 beck Exp $"); */
8efc0c15 36
37#ifndef CHANNELS_H
38#define CHANNELS_H
39
01794848 40#include "buffer.h"
41
8efc0c15 42/* Definitions for channel types. */
aa3378df 43#define SSH_CHANNEL_FREE 0 /* This channel is free (unused). */
44#define SSH_CHANNEL_X11_LISTENER 1 /* Listening for inet X11 conn. */
5260325f 45#define SSH_CHANNEL_PORT_LISTENER 2 /* Listening on a port. */
46#define SSH_CHANNEL_OPENING 3 /* waiting for confirmation */
47#define SSH_CHANNEL_OPEN 4 /* normal open two-way channel */
aa3378df 48#define SSH_CHANNEL_CLOSED 5 /* waiting for close confirmation */
7368a6c8 49#define SSH_CHANNEL_AUTH_SOCKET 6 /* authentication socket */
50#define SSH_CHANNEL_X11_OPEN 7 /* reading first X11 packet */
51#define SSH_CHANNEL_INPUT_DRAINING 8 /* sending remaining data to conn */
52#define SSH_CHANNEL_OUTPUT_DRAINING 9 /* sending remaining data to app */
53#define SSH_CHANNEL_LARVAL 10 /* larval session */
fa08c86b 54#define SSH_CHANNEL_RPORT_LISTENER 11 /* Listening to a R-style port */
97fb6912 55#define SSH_CHANNEL_CONNECTING 12
0490e609 56#define SSH_CHANNEL_DYNAMIC 13
57#define SSH_CHANNEL_MAX_TYPE 14
8efc0c15 58
aa3378df 59/*
60 * Data structure for channel data. This is iniailized in channel_allocate
61 * and cleared in channel_free.
62 */
2e73a022 63struct Channel;
64typedef struct Channel Channel;
65
7368a6c8 66typedef void channel_callback_fn(int id, void *arg);
2e73a022 67typedef int channel_filter_fn(struct Channel *c, char *buf, int len);
8efc0c15 68
2e73a022 69struct Channel {
5260325f 70 int type; /* channel type/state */
71 int self; /* my own channel identifier */
72 int remote_id; /* channel identifier for remote peer */
73 /* peer can be reached over encrypted connection, via packet-sent */
74 int istate; /* input from channel (state of receive half) */
75 int ostate; /* output to channel (state of transmit half) */
7e7327a1 76 int flags; /* close sent/rcvd */
7368a6c8 77 int rfd; /* read fd */
78 int wfd; /* write fd */
79 int efd; /* extended fd */
80 int sock; /* sock fd */
0ae4fe1d 81 int isatty; /* rfd is a tty */
5260325f 82 Buffer input; /* data read from socket, to be sent over
83 * encrypted connection */
84 Buffer output; /* data received over encrypted connection for
85 * send on socket */
7368a6c8 86 Buffer extended;
5260325f 87 char path[200]; /* path for unix domain sockets, or host name
88 * for forwards */
89 int listening_port; /* port being listened for forwards */
90 int host_port; /* remote port to connect for forwards */
91 char *remote_name; /* remote hostname */
7368a6c8 92
93 int remote_window;
94 int remote_maxpacket;
95 int local_window;
96 int local_window_max;
97 int local_consumed;
98 int local_maxpacket;
99 int extended_usage;
100
101 char *ctype; /* type */
102
1d1ffb87 103 /* callback */
7368a6c8 104 channel_callback_fn *cb_fn;
105 void *cb_arg;
106 int cb_event;
107 channel_callback_fn *dettach_user;
2e73a022 108
109 /* filter */
110 channel_filter_fn *input_filter;
111};
7368a6c8 112
113#define CHAN_EXTENDED_IGNORE 0
114#define CHAN_EXTENDED_READ 1
115#define CHAN_EXTENDED_WRITE 2
116
bcbf86ec 117/* default window/packet sizes for tcp/x11-fwd-channel */
118#define CHAN_SES_WINDOW_DEFAULT (32*1024)
119#define CHAN_SES_PACKET_DEFAULT (CHAN_SES_WINDOW_DEFAULT/2)
120#define CHAN_TCP_WINDOW_DEFAULT (32*1024)
121#define CHAN_TCP_PACKET_DEFAULT (CHAN_TCP_WINDOW_DEFAULT/2)
122#define CHAN_X11_WINDOW_DEFAULT (4*1024)
123#define CHAN_X11_PACKET_DEFAULT (CHAN_X11_WINDOW_DEFAULT/2)
124
125
7368a6c8 126void channel_open(int id);
7e7327a1 127void channel_request(int id, char *service, int wantconfirm);
128void channel_request_start(int id, char *service, int wantconfirm);
129void channel_register_callback(int id, int mtype, channel_callback_fn *fn, void *arg);
130void channel_register_cleanup(int id, channel_callback_fn *fn);
2e73a022 131void channel_register_filter(int id, channel_filter_fn *fn);
7e7327a1 132void channel_cancel_cleanup(int id);
7368a6c8 133Channel *channel_lookup(int id);
134
135int
136channel_new(char *ctype, int type, int rfd, int wfd, int efd,
a22aff1f 137 int window, int maxpack, int extended_usage, char *remote_name,
138 int nonblock);
139void
140channel_set_fds(int id, int rfd, int wfd, int efd,
141 int extusage, int nonblock);
142
143void deny_input_open(int type, int plen, void *ctxt);
7368a6c8 144
188adeb2 145void channel_input_channel_request(int type, int plen, void *ctxt);
146void channel_input_close(int type, int plen, void *ctxt);
147void channel_input_close_confirmation(int type, int plen, void *ctxt);
148void channel_input_data(int type, int plen, void *ctxt);
149void channel_input_extended_data(int type, int plen, void *ctxt);
150void channel_input_ieof(int type, int plen, void *ctxt);
151void channel_input_oclose(int type, int plen, void *ctxt);
152void channel_input_open_confirmation(int type, int plen, void *ctxt);
153void channel_input_open_failure(int type, int plen, void *ctxt);
154void channel_input_port_open(int type, int plen, void *ctxt);
155void channel_input_window_adjust(int type, int plen, void *ctxt);
7368a6c8 156
157/* Sets specific protocol options. */
158void channel_set_options(int hostname_in_open);
159
160/*
161 * Allocate a new channel object and set its type and socket. Remote_name
162 * must have been allocated with xmalloc; this will free it when the channel
163 * is freed.
164 */
165int channel_allocate(int type, int sock, char *remote_name);
166
167/* Free the channel and close its socket. */
168void channel_free(int channel);
169
39929cdb 170/*
171 * Allocate/update select bitmasks and add any bits relevant to channels in
172 * select bitmasks.
173 */
174void
c422989b 175channel_prepare_select(fd_set **readsetp, fd_set **writesetp, int *maxfdp,
176 int rekeying);
7368a6c8 177
178/*
179 * After select, perform any appropriate operations for channels which have
180 * events pending.
181 */
182void channel_after_select(fd_set * readset, fd_set * writeset);
183
184/* If there is data to send to the connection, send some of it now. */
185void channel_output_poll(void);
186
187/* Returns true if no channel has too much buffered data. */
188int channel_not_very_much_buffered_data(void);
189
190/* This closes any sockets that are listening for connections; this removes
191 any unix domain sockets. */
192void channel_stop_listening(void);
193
194/*
195 * Closes the sockets of all channels. This is used to close extra file
196 * descriptors after a fork.
197 */
198void channel_close_all(void);
199
7368a6c8 200/* Returns true if there is still an open channel over the connection. */
201int channel_still_open(void);
202
203/*
204 * Returns a string containing a list of all open channels. The list is
205 * suitable for displaying to the user. It uses crlf instead of newlines.
206 * The caller should free the string with xfree.
207 */
208char *channel_open_message(void);
209
210/*
211 * Initiate forwarding of connections to local port "port" through the secure
fa08c86b 212 * channel to host:port from remote side.
7368a6c8 213 */
02a024dd 214int
fa08c86b 215channel_request_local_forwarding(u_short listen_port,
216 const char *host_to_connect, u_short port_to_connect, int gateway_ports);
02a024dd 217int
fa08c86b 218channel_request_forwarding(const char *listen_address, u_short listen_port,
219 const char *host_to_connect, u_short port_to_connect, int gateway_ports,
220 int remote_fwd);
7368a6c8 221
222/*
223 * Initiate forwarding of connections to port "port" on remote host through
224 * the secure channel to host:port from local side. This never returns if
225 * there was an error. This registers that open requests for that port are
226 * permitted.
227 */
6ae2364d 228void
7368a6c8 229channel_request_remote_forwarding(u_short port, const char *host,
230 u_short remote_port);
231
232/*
01794848 233 * Permits opening to any host/port if permitted_opens[] is empty. This is
234 * usually called by the server, because the user could connect to any port
235 * anyway, and the server has no way to know but to trust the client anyway.
7368a6c8 236 */
237void channel_permit_all_opens(void);
238
01794848 239/* Add host/port to list of allowed targets for port forwarding */
240void channel_add_permitted_opens(char *host, int port);
241
242/* Flush list */
243void channel_clear_permitted_opens(void);
244
7368a6c8 245/*
246 * This is called after receiving CHANNEL_FORWARDING_REQUEST. This initates
247 * listening for the port, and sends back a success reply (or disconnect
248 * message if there was an error). This never returns if there was an error.
249 */
1d1ffb87 250void channel_input_port_forward_request(int is_root, int gateway_ports);
7368a6c8 251
252/*
253 * Creates a port for X11 connections, and starts listening for it. Returns
254 * the display name, or NULL if an error was encountered.
255 */
256char *x11_create_display(int screen);
257
258/*
259 * Creates an internet domain socket for listening for X11 connections.
260 * Returns a suitable value for the DISPLAY variable, or NULL if an error
261 * occurs.
262 */
263char *x11_create_display_inet(int screen, int x11_display_offset);
264
265/*
266 * This is called when SSH_SMSG_X11_OPEN is received. The packet contains
267 * the remote channel number. We should do whatever we want, and respond
268 * with either SSH_MSG_OPEN_CONFIRMATION or SSH_MSG_OPEN_FAILURE.
269 */
188adeb2 270void x11_input_open(int type, int plen, void *ctxt);
7368a6c8 271
272/*
273 * Requests forwarding of X11 connections. This should be called on the
274 * client only.
275 */
276void x11_request_forwarding(void);
277
278/*
279 * Requests forwarding for X11 connections, with authentication spoofing.
280 * This should be called in the client only.
281 */
0b242b12 282void
283x11_request_forwarding_with_spoofing(int client_session_id,
284 const char *proto, const char *data);
7368a6c8 285
286/* Sends a message to the server to request authentication fd forwarding. */
287void auth_request_forwarding(void);
288
289/*
290 * Returns the name of the forwarded authentication socket. Returns NULL if
291 * there is no forwarded authentication socket. The returned value points to
292 * a static buffer.
293 */
294char *auth_get_socket_name(void);
295
296/*
fa649821 297 * This is called to process SSH_CMSG_AGENT_REQUEST_FORWARDING on the server.
7368a6c8 298 * This starts forwarding authentication requests.
299 */
fa649821 300int auth_input_request_forwarding(struct passwd * pw);
7368a6c8 301
302/* This is called to process an SSH_SMSG_AGENT_OPEN message. */
188adeb2 303void auth_input_open_request(int type, int plen, void *ctxt);
7368a6c8 304
7e7327a1 305/* XXX */
306int channel_connect_to(const char *host, u_short host_port);
fa08c86b 307int channel_connect_by_listen_adress(u_short listen_port);
0b242b12 308int x11_connect_display(void);
7e7327a1 309
3ffc6336 310int channel_find_open(void);
311
8efc0c15 312#endif
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