1 /* $OpenBSD: channels.h,v 1.113 2013/06/07 15:37:52 dtucker 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_ABANDONED 17 /* Abandoned session, eg mux */
60 #define SSH_CHANNEL_MAX_TYPE 18
62 #define CHANNEL_CANCEL_PORT_STATIC -1
65 typedef struct Channel Channel;
67 typedef void channel_open_fn(int, int, void *);
68 typedef void channel_callback_fn(int, void *);
69 typedef int channel_infilter_fn(struct Channel *, char *, int);
70 typedef void channel_filter_cleanup_fn(int, void *);
71 typedef u_char *channel_outfilter_fn(struct Channel *, u_char **, u_int *);
73 /* Channel success/failure callbacks */
74 typedef void channel_confirm_cb(int, struct Channel *, void *);
75 typedef void channel_confirm_abandon_cb(struct Channel *, void *);
76 struct channel_confirm {
77 TAILQ_ENTRY(channel_confirm) entry;
78 channel_confirm_cb *cb;
79 channel_confirm_abandon_cb *abandon_cb;
82 TAILQ_HEAD(channel_confirms, channel_confirm);
84 /* Context for non-blocking connects */
85 struct channel_connect {
88 struct addrinfo *ai, *aitop;
91 /* Callbacks for mux channels back into client-specific code */
92 typedef int mux_callback_fn(struct Channel *);
95 int type; /* channel type/state */
96 int self; /* my own channel identifier */
97 int remote_id; /* channel identifier for remote peer */
98 u_int istate; /* input from channel (state of receive half) */
99 u_int ostate; /* output to channel (state of transmit half) */
100 int flags; /* close sent/rcvd */
101 int rfd; /* read fd */
102 int wfd; /* write fd */
103 int efd; /* extended fd */
104 int sock; /* sock fd */
105 int ctl_chan; /* control channel (multiplexed connections) */
106 int isatty; /* rfd is a tty */
108 int wfd_isatty; /* wfd is a tty */
110 int client_tty; /* (client) TTY has been requested */
111 int force_drain; /* force close on iEOF */
112 time_t notbefore; /* Pause IO until deadline (time_t) */
113 int delayed; /* post-select handlers for newly created
114 * channels are delayed until the first call
115 * to a matching pre-select handler.
116 * this way post-select handlers are not
117 * accidentally called if a FD gets reused */
118 Buffer input; /* data read from socket, to be sent over
119 * encrypted connection */
120 Buffer output; /* data received over encrypted connection for
124 /* path for unix domain sockets, or host name for forwards */
125 int listening_port; /* port being listened for forwards */
126 char *listening_addr; /* addr being listened for forwards */
127 int host_port; /* remote port to connect for forwards */
128 char *remote_name; /* remote hostname */
131 u_int remote_maxpacket;
133 u_int local_window_max;
134 u_int local_consumed;
135 u_int local_maxpacket;
139 int single_connection;
141 char *ctype; /* type */
144 channel_open_fn *open_confirm;
145 void *open_confirm_ctx;
146 channel_callback_fn *detach_user;
148 struct channel_confirms status_confirms;
151 channel_infilter_fn *input_filter;
152 channel_outfilter_fn *output_filter;
154 channel_filter_cleanup_fn *filter_cleanup;
156 /* keep boundaries */
159 /* non-blocking connect */
160 struct channel_connect connect_ctx;
162 /* multiplexing protocol hook, called for each packet received */
163 mux_callback_fn *mux_rcb;
168 #define CHAN_EXTENDED_IGNORE 0
169 #define CHAN_EXTENDED_READ 1
170 #define CHAN_EXTENDED_WRITE 2
172 /* default window/packet sizes for tcp/x11-fwd-channel */
173 #define CHAN_SES_PACKET_DEFAULT (32*1024)
174 #define CHAN_SES_WINDOW_DEFAULT (64*CHAN_SES_PACKET_DEFAULT)
175 #define CHAN_TCP_PACKET_DEFAULT (32*1024)
176 #define CHAN_TCP_WINDOW_DEFAULT (64*CHAN_TCP_PACKET_DEFAULT)
177 #define CHAN_X11_PACKET_DEFAULT (16*1024)
178 #define CHAN_X11_WINDOW_DEFAULT (4*CHAN_X11_PACKET_DEFAULT)
179 #define CHAN_HPN_MIN_WINDOW_DEFAULT (2*1024*1024)
181 /* possible input states */
182 #define CHAN_INPUT_OPEN 0
183 #define CHAN_INPUT_WAIT_DRAIN 1
184 #define CHAN_INPUT_WAIT_OCLOSE 2
185 #define CHAN_INPUT_CLOSED 3
187 /* possible output states */
188 #define CHAN_OUTPUT_OPEN 0
189 #define CHAN_OUTPUT_WAIT_DRAIN 1
190 #define CHAN_OUTPUT_WAIT_IEOF 2
191 #define CHAN_OUTPUT_CLOSED 3
193 #define CHAN_CLOSE_SENT 0x01
194 #define CHAN_CLOSE_RCVD 0x02
195 #define CHAN_EOF_SENT 0x04
196 #define CHAN_EOF_RCVD 0x08
197 #define CHAN_LOCAL 0x10
199 #define CHAN_RBUF 16*1024
201 /* check whether 'efd' is still in use */
202 #define CHANNEL_EFD_INPUT_ACTIVE(c) \
203 (compat20 && c->extended_usage == CHAN_EXTENDED_READ && \
205 buffer_len(&c->extended) > 0))
206 #define CHANNEL_EFD_OUTPUT_ACTIVE(c) \
207 (compat20 && c->extended_usage == CHAN_EXTENDED_WRITE && \
208 c->efd != -1 && (!(c->flags & (CHAN_EOF_RCVD|CHAN_CLOSE_RCVD)) || \
209 buffer_len(&c->extended) > 0))
211 /* channel management */
213 Channel *channel_by_id(int);
214 Channel *channel_lookup(int);
215 Channel *channel_new(char *, int, int, int, int, u_int, u_int, int, char *, int);
216 void channel_set_fds(int, int, int, int, int, int, int, u_int);
217 void channel_free(Channel *);
218 void channel_free_all(void);
219 void channel_stop_listening(void);
221 void channel_send_open(int);
222 void channel_request_start(int, char *, int);
223 void channel_register_cleanup(int, channel_callback_fn *, int);
224 void channel_register_open_confirm(int, channel_open_fn *, void *);
225 void channel_register_filter(int, channel_infilter_fn *,
226 channel_outfilter_fn *, channel_filter_cleanup_fn *, void *);
227 void channel_register_status_confirm(int, channel_confirm_cb *,
228 channel_confirm_abandon_cb *, void *);
229 void channel_cancel_cleanup(int);
230 int channel_close_fd(int *);
231 void channel_send_window_changes(void);
233 /* protocol handler */
235 void channel_input_close(int, u_int32_t, void *);
236 void channel_input_close_confirmation(int, u_int32_t, void *);
237 void channel_input_data(int, u_int32_t, void *);
238 void channel_input_extended_data(int, u_int32_t, void *);
239 void channel_input_ieof(int, u_int32_t, void *);
240 void channel_input_oclose(int, u_int32_t, void *);
241 void channel_input_open_confirmation(int, u_int32_t, void *);
242 void channel_input_open_failure(int, u_int32_t, void *);
243 void channel_input_port_open(int, u_int32_t, void *);
244 void channel_input_window_adjust(int, u_int32_t, void *);
245 void channel_input_status_confirm(int, u_int32_t, void *);
247 /* file descriptor handling (read/write) */
249 void channel_prepare_select(fd_set **, fd_set **, int *, u_int*,
251 void channel_after_select(fd_set *, fd_set *);
252 void channel_output_poll(void);
254 int channel_not_very_much_buffered_data(void);
255 void channel_close_all(void);
256 int channel_still_open(void);
257 char *channel_open_message(void);
258 int channel_find_open(void);
261 void channel_set_af(int af);
262 void channel_permit_all_opens(void);
263 void channel_add_permitted_opens(char *, int);
264 int channel_add_adm_permitted_opens(char *, int);
265 void channel_disable_adm_local_opens(void);
266 void channel_update_permitted_opens(int, int);
267 void channel_clear_permitted_opens(void);
268 void channel_clear_adm_permitted_opens(void);
269 void channel_print_adm_permitted_opens(void);
270 int channel_input_port_forward_request(int, int);
271 Channel *channel_connect_to(const char *, u_short, char *, char *);
272 Channel *channel_connect_stdio_fwd(const char*, u_short, int, int);
273 Channel *channel_connect_by_listen_address(u_short, char *, char *);
274 int channel_request_remote_forwarding(const char *, u_short,
275 const char *, u_short);
276 int channel_setup_local_fwd_listener(const char *, u_short,
277 const char *, u_short, int);
278 int channel_request_rforward_cancel(const char *host, u_short port);
279 int channel_setup_remote_fwd_listener(const char *, u_short, int *, int);
280 int channel_cancel_rport_listener(const char *, u_short);
281 int channel_cancel_lport_listener(const char *, u_short, int, int);
282 int permitopen_port(const char *);
286 int x11_connect_display(void);
287 int x11_create_display_inet(int, int, int, u_int *, int **);
288 void x11_input_open(int, u_int32_t, void *);
289 void x11_request_forwarding_with_spoofing(int, const char *, const char *,
291 void deny_input_open(int, u_int32_t, void *);
293 /* agent forwarding */
295 void auth_request_forwarding(void);
299 int chan_is_dead(Channel *, int);
300 void chan_mark_dead(Channel *);
304 void chan_rcvd_oclose(Channel *);
305 void chan_rcvd_eow(Channel *); /* SSH2-only */
306 void chan_read_failed(Channel *);
307 void chan_ibuf_empty(Channel *);
309 void chan_rcvd_ieof(Channel *);
310 void chan_write_failed(Channel *);
311 void chan_obuf_empty(Channel *);
315 void channel_set_hpn(int, u_int);