1 /* $OpenBSD: channels.h,v 1.104 2010/05/14 23:29:23 djm Exp $ */
5 * Author: Tatu Ylonen <ylo@cs.hut.fi>
6 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
9 * As far as I am concerned, the code I have written for this software
10 * can be used freely for any purpose. Any derived versions of this
11 * software must be clearly marked as such, and if the derived work is
12 * incompatible with the protocol description in the RFC file, it must be
13 * called by a name other than "ssh" or "Secure Shell".
16 * Copyright (c) 1999, 2000, 2001, 2002 Markus Friedl. All rights reserved.
18 * Redistribution and use in source and binary forms, with or without
19 * modification, are permitted provided that the following conditions
21 * 1. Redistributions of source code must retain the above copyright
22 * notice, this list of conditions and the following disclaimer.
23 * 2. Redistributions in binary form must reproduce the above copyright
24 * notice, this list of conditions and the following disclaimer in the
25 * documentation and/or other materials provided with the distribution.
27 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
28 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
29 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
30 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
31 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
32 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
33 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
34 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
35 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
36 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
42 /* Definitions for channel types. */
43 #define SSH_CHANNEL_X11_LISTENER 1 /* Listening for inet X11 conn. */
44 #define SSH_CHANNEL_PORT_LISTENER 2 /* Listening on a port. */
45 #define SSH_CHANNEL_OPENING 3 /* waiting for confirmation */
46 #define SSH_CHANNEL_OPEN 4 /* normal open two-way channel */
47 #define SSH_CHANNEL_CLOSED 5 /* waiting for close confirmation */
48 #define SSH_CHANNEL_AUTH_SOCKET 6 /* authentication socket */
49 #define SSH_CHANNEL_X11_OPEN 7 /* reading first X11 packet */
50 #define SSH_CHANNEL_INPUT_DRAINING 8 /* sending remaining data to conn */
51 #define SSH_CHANNEL_OUTPUT_DRAINING 9 /* sending remaining data to app */
52 #define SSH_CHANNEL_LARVAL 10 /* larval session */
53 #define SSH_CHANNEL_RPORT_LISTENER 11 /* Listening to a R-style port */
54 #define SSH_CHANNEL_CONNECTING 12
55 #define SSH_CHANNEL_DYNAMIC 13
56 #define SSH_CHANNEL_ZOMBIE 14 /* Almost dead. */
57 #define SSH_CHANNEL_MUX_LISTENER 15 /* Listener for mux conn. */
58 #define SSH_CHANNEL_MUX_CLIENT 16 /* Conn. to mux slave */
59 #define SSH_CHANNEL_MAX_TYPE 17
62 typedef struct Channel Channel;
64 typedef void channel_open_fn(int, int, void *);
65 typedef void channel_callback_fn(int, void *);
66 typedef int channel_infilter_fn(struct Channel *, char *, int);
67 typedef void channel_filter_cleanup_fn(int, void *);
68 typedef u_char *channel_outfilter_fn(struct Channel *, u_char **, u_int *);
70 /* Channel success/failure callbacks */
71 typedef void channel_confirm_cb(int, struct Channel *, void *);
72 typedef void channel_confirm_abandon_cb(struct Channel *, void *);
73 struct channel_confirm {
74 TAILQ_ENTRY(channel_confirm) entry;
75 channel_confirm_cb *cb;
76 channel_confirm_abandon_cb *abandon_cb;
79 TAILQ_HEAD(channel_confirms, channel_confirm);
81 /* Context for non-blocking connects */
82 struct channel_connect {
85 struct addrinfo *ai, *aitop;
88 /* Callbacks for mux channels back into client-specific code */
89 typedef int mux_callback_fn(struct Channel *);
92 int type; /* channel type/state */
93 int self; /* my own channel identifier */
94 int remote_id; /* channel identifier for remote peer */
95 u_int istate; /* input from channel (state of receive half) */
96 u_int ostate; /* output to channel (state of transmit half) */
97 int flags; /* close sent/rcvd */
98 int rfd; /* read fd */
99 int wfd; /* write fd */
100 int efd; /* extended fd */
101 int sock; /* sock fd */
102 int ctl_chan; /* control channel (multiplexed connections) */
103 int isatty; /* rfd is a tty */
104 int wfd_isatty; /* wfd is a tty */
105 int client_tty; /* (client) TTY has been requested */
106 int force_drain; /* force close on iEOF */
107 int delayed; /* post-select handlers for newly created
108 * channels are delayed until the first call
109 * to a matching pre-select handler.
110 * this way post-select handlers are not
111 * accidenly called if a FD gets reused */
112 Buffer input; /* data read from socket, to be sent over
113 * encrypted connection */
114 Buffer output; /* data received over encrypted connection for
118 /* path for unix domain sockets, or host name for forwards */
119 int listening_port; /* port being listened for forwards */
120 int host_port; /* remote port to connect for forwards */
121 char *remote_name; /* remote hostname */
124 u_int remote_maxpacket;
126 u_int local_window_max;
127 u_int local_consumed;
128 u_int local_maxpacket;
132 int single_connection;
134 char *ctype; /* type */
137 channel_open_fn *open_confirm;
138 void *open_confirm_ctx;
139 channel_callback_fn *detach_user;
141 struct channel_confirms status_confirms;
144 channel_infilter_fn *input_filter;
145 channel_outfilter_fn *output_filter;
147 channel_filter_cleanup_fn *filter_cleanup;
149 /* keep boundaries */
152 /* non-blocking connect */
153 struct channel_connect connect_ctx;
155 /* multiplexing protocol hook, called for each packet received */
156 mux_callback_fn *mux_rcb;
161 #define CHAN_EXTENDED_IGNORE 0
162 #define CHAN_EXTENDED_READ 1
163 #define CHAN_EXTENDED_WRITE 2
165 /* default window/packet sizes for tcp/x11-fwd-channel */
166 #define CHAN_SES_PACKET_DEFAULT (32*1024)
167 #define CHAN_SES_WINDOW_DEFAULT (64*CHAN_SES_PACKET_DEFAULT)
169 #define CHAN_TCP_PACKET_DEFAULT (32*1024)
170 #define CHAN_TCP_WINDOW_DEFAULT (64*CHAN_TCP_PACKET_DEFAULT)
172 #define CHAN_X11_PACKET_DEFAULT (16*1024)
173 #define CHAN_X11_WINDOW_DEFAULT (4*CHAN_X11_PACKET_DEFAULT)
175 #define CHAN_HPN_MIN_WINDOW_DEFAULT (2*1024*1024)
177 /* possible input states */
178 #define CHAN_INPUT_OPEN 0
179 #define CHAN_INPUT_WAIT_DRAIN 1
180 #define CHAN_INPUT_WAIT_OCLOSE 2
181 #define CHAN_INPUT_CLOSED 3
183 /* possible output states */
184 #define CHAN_OUTPUT_OPEN 0
185 #define CHAN_OUTPUT_WAIT_DRAIN 1
186 #define CHAN_OUTPUT_WAIT_IEOF 2
187 #define CHAN_OUTPUT_CLOSED 3
189 #define CHAN_CLOSE_SENT 0x01
190 #define CHAN_CLOSE_RCVD 0x02
191 #define CHAN_EOF_SENT 0x04
192 #define CHAN_EOF_RCVD 0x08
193 #define CHAN_LOCAL 0x10
195 #define CHAN_RBUF 16*1024
197 /* check whether 'efd' is still in use */
198 #define CHANNEL_EFD_INPUT_ACTIVE(c) \
199 (compat20 && c->extended_usage == CHAN_EXTENDED_READ && \
201 buffer_len(&c->extended) > 0))
202 #define CHANNEL_EFD_OUTPUT_ACTIVE(c) \
203 (compat20 && c->extended_usage == CHAN_EXTENDED_WRITE && \
204 c->efd != -1 && (!(c->flags & (CHAN_EOF_RCVD|CHAN_CLOSE_RCVD)) || \
205 buffer_len(&c->extended) > 0))
207 /* channel management */
209 Channel *channel_by_id(int);
210 Channel *channel_lookup(int);
211 Channel *channel_new(char *, int, int, int, int, u_int, u_int, int, char *, int);
212 void channel_set_fds(int, int, int, int, int, int, int, u_int);
213 void channel_free(Channel *);
214 void channel_free_all(void);
215 void channel_stop_listening(void);
217 void channel_send_open(int);
218 void channel_request_start(int, char *, int);
219 void channel_register_cleanup(int, channel_callback_fn *, int);
220 void channel_register_open_confirm(int, channel_open_fn *, void *);
221 void channel_register_filter(int, channel_infilter_fn *,
222 channel_outfilter_fn *, channel_filter_cleanup_fn *, void *);
223 void channel_register_status_confirm(int, channel_confirm_cb *,
224 channel_confirm_abandon_cb *, void *);
225 void channel_cancel_cleanup(int);
226 int channel_close_fd(int *);
227 void channel_send_window_changes(void);
229 /* protocol handler */
231 void channel_input_close(int, u_int32_t, void *);
232 void channel_input_close_confirmation(int, u_int32_t, void *);
233 void channel_input_data(int, u_int32_t, void *);
234 void channel_input_extended_data(int, u_int32_t, void *);
235 void channel_input_ieof(int, u_int32_t, void *);
236 void channel_input_oclose(int, u_int32_t, void *);
237 void channel_input_open_confirmation(int, u_int32_t, void *);
238 void channel_input_open_failure(int, u_int32_t, void *);
239 void channel_input_port_open(int, u_int32_t, void *);
240 void channel_input_window_adjust(int, u_int32_t, void *);
241 void channel_input_status_confirm(int, u_int32_t, void *);
243 /* file descriptor handling (read/write) */
245 void channel_prepare_select(fd_set **, fd_set **, int *, u_int*, int);
246 void channel_after_select(fd_set *, fd_set *);
247 void channel_output_poll(void);
249 int channel_not_very_much_buffered_data(void);
250 void channel_close_all(void);
251 int channel_still_open(void);
252 char *channel_open_message(void);
253 int channel_find_open(void);
256 void channel_set_af(int af);
257 void channel_permit_all_opens(void);
258 void channel_add_permitted_opens(char *, int);
259 int channel_add_adm_permitted_opens(char *, int);
260 void channel_clear_permitted_opens(void);
261 void channel_clear_adm_permitted_opens(void);
262 void channel_print_adm_permitted_opens(void);
263 int channel_input_port_forward_request(int, int);
264 Channel *channel_connect_to(const char *, u_short, char *, char *);
265 Channel *channel_connect_stdio_fwd(const char*, u_short, int, int);
266 Channel *channel_connect_by_listen_address(u_short, char *, char *);
267 int channel_request_remote_forwarding(const char *, u_short,
268 const char *, u_short);
269 int channel_setup_local_fwd_listener(const char *, u_short,
270 const char *, u_short, int);
271 void channel_request_rforward_cancel(const char *host, u_short port);
272 int channel_setup_remote_fwd_listener(const char *, u_short, int *, int);
273 int channel_cancel_rport_listener(const char *, u_short);
277 int x11_connect_display(void);
278 int x11_create_display_inet(int, int, int, u_int *, int **);
279 void x11_input_open(int, u_int32_t, void *);
280 void x11_request_forwarding_with_spoofing(int, const char *, const char *,
282 void deny_input_open(int, u_int32_t, void *);
284 /* agent forwarding */
286 void auth_request_forwarding(void);
290 int chan_is_dead(Channel *, int);
291 void chan_mark_dead(Channel *);
295 void chan_rcvd_oclose(Channel *);
296 void chan_rcvd_eow(Channel *); /* SSH2-only */
297 void chan_read_failed(Channel *);
298 void chan_ibuf_empty(Channel *);
300 void chan_rcvd_ieof(Channel *);
301 void chan_write_failed(Channel *);
302 void chan_obuf_empty(Channel *);
305 void channel_set_hpn(int, u_int);