1 /* $OpenBSD: channels.h,v 1.121 2017/02/01 02:59:09 dtucker Exp $ */
4 * Author: Tatu Ylonen <ylo@cs.hut.fi>
5 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
8 * As far as I am concerned, the code I have written for this software
9 * can be used freely for any purpose. Any derived versions of this
10 * software must be clearly marked as such, and if the derived work is
11 * incompatible with the protocol description in the RFC file, it must be
12 * called by a name other than "ssh" or "Secure Shell".
15 * Copyright (c) 1999, 2000, 2001, 2002 Markus Friedl. All rights reserved.
17 * Redistribution and use in source and binary forms, with or without
18 * modification, are permitted provided that the following conditions
20 * 1. Redistributions of source code must retain the above copyright
21 * notice, this list of conditions and the following disclaimer.
22 * 2. Redistributions in binary form must reproduce the above copyright
23 * notice, this list of conditions and the following disclaimer in the
24 * documentation and/or other materials provided with the distribution.
26 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
27 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
28 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
29 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
30 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
31 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
32 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
33 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
34 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
35 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
41 /* Definitions for channel types. */
42 #define SSH_CHANNEL_X11_LISTENER 1 /* Listening for inet X11 conn. */
43 #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 */
46 #define SSH_CHANNEL_CLOSED 5 /* waiting for close confirmation */
47 #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_RPORT_LISTENER 11 /* Listening to a R-style port */
53 #define SSH_CHANNEL_CONNECTING 12
54 #define SSH_CHANNEL_DYNAMIC 13
55 #define SSH_CHANNEL_ZOMBIE 14 /* Almost dead. */
56 #define SSH_CHANNEL_MUX_LISTENER 15 /* Listener for mux conn. */
57 #define SSH_CHANNEL_MUX_CLIENT 16 /* Conn. to mux slave */
58 #define SSH_CHANNEL_ABANDONED 17 /* Abandoned session, eg mux */
59 #define SSH_CHANNEL_UNIX_LISTENER 18 /* Listening on a domain socket. */
60 #define SSH_CHANNEL_RUNIX_LISTENER 19 /* Listening to a R-style domain socket. */
61 #define SSH_CHANNEL_MUX_PROXY 20 /* proxy channel for mux-slave */
62 #define SSH_CHANNEL_MAX_TYPE 21
64 #define CHANNEL_CANCEL_PORT_STATIC -1
67 typedef struct Channel Channel;
69 typedef void channel_open_fn(int, int, void *);
70 typedef void channel_callback_fn(int, void *);
71 typedef int channel_infilter_fn(struct Channel *, char *, int);
72 typedef void channel_filter_cleanup_fn(int, void *);
73 typedef u_char *channel_outfilter_fn(struct Channel *, u_char **, u_int *);
75 /* Channel success/failure callbacks */
76 typedef void channel_confirm_cb(int, struct Channel *, void *);
77 typedef void channel_confirm_abandon_cb(struct Channel *, void *);
78 struct channel_confirm {
79 TAILQ_ENTRY(channel_confirm) entry;
80 channel_confirm_cb *cb;
81 channel_confirm_abandon_cb *abandon_cb;
84 TAILQ_HEAD(channel_confirms, channel_confirm);
86 /* Context for non-blocking connects */
87 struct channel_connect {
90 struct addrinfo *ai, *aitop;
93 /* Callbacks for mux channels back into client-specific code */
94 typedef int mux_callback_fn(struct Channel *);
97 int type; /* channel type/state */
98 int self; /* my own channel identifier */
99 int remote_id; /* channel identifier for remote peer */
100 u_int istate; /* input from channel (state of receive half) */
101 u_int ostate; /* output to channel (state of transmit half) */
102 int flags; /* close sent/rcvd */
103 int rfd; /* read fd */
104 int wfd; /* write fd */
105 int efd; /* extended fd */
106 int sock; /* sock fd */
107 int ctl_chan; /* control channel (multiplexed connections) */
108 int isatty; /* rfd is a tty */
110 int wfd_isatty; /* wfd is a tty */
112 int client_tty; /* (client) TTY has been requested */
113 int force_drain; /* force close on iEOF */
114 time_t notbefore; /* Pause IO until deadline (time_t) */
115 int delayed; /* post-select handlers for newly created
116 * channels are delayed until the first call
117 * to a matching pre-select handler.
118 * this way post-select handlers are not
119 * accidentally called if a FD gets reused */
120 Buffer input; /* data read from socket, to be sent over
121 * encrypted connection */
122 Buffer output; /* data received over encrypted connection for
126 /* path for unix domain sockets, or host name for forwards */
127 int listening_port; /* port being listened for forwards */
128 char *listening_addr; /* addr being listened for forwards */
129 int host_port; /* remote port to connect for forwards */
130 char *remote_name; /* remote hostname */
133 u_int remote_maxpacket;
135 u_int local_window_max;
136 u_int local_consumed;
137 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;
166 int mux_downstream_id;
169 #define CHAN_EXTENDED_IGNORE 0
170 #define CHAN_EXTENDED_READ 1
171 #define CHAN_EXTENDED_WRITE 2
173 /* default window/packet sizes for tcp/x11-fwd-channel */
174 #define CHAN_SES_PACKET_DEFAULT (32*1024)
175 #define CHAN_SES_WINDOW_DEFAULT (64*CHAN_SES_PACKET_DEFAULT)
176 #define CHAN_TCP_PACKET_DEFAULT (32*1024)
177 #define CHAN_TCP_WINDOW_DEFAULT (64*CHAN_TCP_PACKET_DEFAULT)
178 #define CHAN_X11_PACKET_DEFAULT (16*1024)
179 #define CHAN_X11_WINDOW_DEFAULT (4*CHAN_X11_PACKET_DEFAULT)
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_by_remote_id(int);
215 Channel *channel_lookup(int);
216 Channel *channel_new(char *, int, int, int, int, u_int, u_int, int, char *, int);
217 void channel_set_fds(int, int, int, int, int, int, int, u_int);
218 void channel_free(Channel *);
219 void channel_free_all(void);
220 void channel_stop_listening(void);
222 void channel_send_open(int);
223 void channel_request_start(int, char *, int);
224 void channel_register_cleanup(int, channel_callback_fn *, int);
225 void channel_register_open_confirm(int, channel_open_fn *, void *);
226 void channel_register_filter(int, channel_infilter_fn *,
227 channel_outfilter_fn *, channel_filter_cleanup_fn *, void *);
228 void channel_register_status_confirm(int, channel_confirm_cb *,
229 channel_confirm_abandon_cb *, void *);
230 void channel_cancel_cleanup(int);
231 int channel_close_fd(int *);
232 void channel_send_window_changes(void);
234 /* mux proxy support */
236 int channel_proxy_downstream(Channel *mc);
237 int channel_proxy_upstream(Channel *, int, u_int32_t, void *);
239 /* protocol handler */
241 int channel_input_close(int, u_int32_t, void *);
242 int channel_input_close_confirmation(int, u_int32_t, void *);
243 int channel_input_data(int, u_int32_t, void *);
244 int channel_input_extended_data(int, u_int32_t, void *);
245 int channel_input_ieof(int, u_int32_t, void *);
246 int channel_input_oclose(int, u_int32_t, void *);
247 int channel_input_open_confirmation(int, u_int32_t, void *);
248 int channel_input_open_failure(int, u_int32_t, void *);
249 int channel_input_port_open(int, u_int32_t, void *);
250 int channel_input_window_adjust(int, u_int32_t, void *);
251 int channel_input_status_confirm(int, u_int32_t, void *);
253 /* file descriptor handling (read/write) */
255 void channel_prepare_select(fd_set **, fd_set **, int *, u_int*,
257 void channel_after_select(fd_set *, fd_set *);
258 void channel_output_poll(void);
260 int channel_not_very_much_buffered_data(void);
261 void channel_close_all(void);
262 int channel_still_open(void);
263 char *channel_open_message(void);
264 int channel_find_open(void);
268 struct ForwardOptions;
269 void channel_set_af(int af);
270 void channel_permit_all_opens(void);
271 void channel_add_permitted_opens(char *, int);
272 int channel_add_adm_permitted_opens(char *, int);
273 void channel_disable_adm_local_opens(void);
274 void channel_update_permitted_opens(int, int);
275 void channel_clear_permitted_opens(void);
276 void channel_clear_adm_permitted_opens(void);
277 void channel_print_adm_permitted_opens(void);
278 Channel *channel_connect_to_port(const char *, u_short, char *, char *, int *,
280 Channel *channel_connect_to_path(const char *, char *, char *);
281 Channel *channel_connect_stdio_fwd(const char*, u_short, int, int);
282 Channel *channel_connect_by_listen_address(const char *, u_short,
284 Channel *channel_connect_by_listen_path(const char *, char *, char *);
285 int channel_request_remote_forwarding(struct Forward *);
286 int channel_setup_local_fwd_listener(struct Forward *, struct ForwardOptions *);
287 int channel_request_rforward_cancel(struct Forward *);
288 int channel_setup_remote_fwd_listener(struct Forward *, int *, struct ForwardOptions *);
289 int channel_cancel_rport_listener(struct Forward *);
290 int channel_cancel_lport_listener(struct Forward *, int, struct ForwardOptions *);
291 int permitopen_port(const char *);
295 void channel_set_x11_refuse_time(u_int);
296 int x11_connect_display(void);
297 int x11_create_display_inet(int, int, int, u_int *, int **);
298 int x11_input_open(int, u_int32_t, void *);
299 void x11_request_forwarding_with_spoofing(int, const char *, const char *,
301 int deny_input_open(int, u_int32_t, void *);
303 /* agent forwarding */
305 void auth_request_forwarding(void);
309 int chan_is_dead(Channel *, int);
310 void chan_mark_dead(Channel *);
314 void chan_rcvd_oclose(Channel *);
315 void chan_rcvd_eow(Channel *); /* SSH2-only */
316 void chan_read_failed(Channel *);
317 void chan_ibuf_empty(Channel *);
319 void chan_rcvd_ieof(Channel *);
320 void chan_write_failed(Channel *);
321 void chan_obuf_empty(Channel *);