Grid Community Toolkit  6.2.1550507116
channels.h
1 /* $OpenBSD: channels.h,v 1.121 2017/02/01 02:59:09 dtucker Exp $ */
2 
3 /*
4  * Author: Tatu Ylonen <[email protected]>
5  * Copyright (c) 1995 Tatu Ylonen <[email protected]>, Espoo, Finland
6  * All rights reserved
7  *
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".
13  */
14 /*
15  * Copyright (c) 1999, 2000, 2001, 2002 Markus Friedl. All rights reserved.
16  *
17  * Redistribution and use in source and binary forms, with or without
18  * modification, are permitted provided that the following conditions
19  * are met:
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.
25  *
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.
36  */
37 
38 #ifndef CHANNEL_H
39 #define CHANNEL_H
40 
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
63 
64 #define CHANNEL_CANCEL_PORT_STATIC -1
65 
66 struct Channel;
67 typedef struct Channel Channel;
68 
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 *);
74 
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;
82  void *ctx;
83 };
84 TAILQ_HEAD(channel_confirms, channel_confirm);
85 
86 /* Context for non-blocking connects */
87 struct channel_connect {
88  char *host;
89  int port;
90  struct addrinfo *ai, *aitop;
91 };
92 
93 /* Callbacks for mux channels back into client-specific code */
94 typedef int mux_callback_fn(struct Channel *);
95 
96 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 */
109 #ifdef _AIX
110  int wfd_isatty; /* wfd is a tty */
111 #endif
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
123  * send on socket */
124  Buffer extended;
125  char *path;
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 */
131 
132  u_int remote_window;
133  u_int remote_maxpacket;
134  u_int local_window;
135  u_int local_window_max;
136  u_int local_consumed;
137  u_int local_maxpacket;
138  int dynamic_window;
139  int extended_usage;
140  int single_connection;
141  u_int tcpwinsz;
142 
143  char *ctype; /* type */
144 
145  /* callback */
146  channel_open_fn *open_confirm;
147  void *open_confirm_ctx;
148  channel_callback_fn *detach_user;
149  int detach_close;
150  struct channel_confirms status_confirms;
151 
152  /* filter */
153  channel_infilter_fn *input_filter;
154  channel_outfilter_fn *output_filter;
155  void *filter_ctx;
156  channel_filter_cleanup_fn *filter_cleanup;
157 
158  /* keep boundaries */
159  int datagram;
160 
161  /* non-blocking connect */
162  struct channel_connect connect_ctx;
163 
164  /* multiplexing protocol hook, called for each packet received */
165  mux_callback_fn *mux_rcb;
166  void *mux_ctx;
167  int mux_pause;
168  int mux_downstream_id;
169 
170 #ifdef NERSC_MOD
171  Buffer rx_line_buf;
172  Buffer tx_line_buf;
173  int audit_enable;
174 
175  int max_tx_lines;
176  int max_rx_lines;
177  int max_tx_char;
178  int max_rx_char;
179 
180  int tx_lines_sent;
181  int rx_lines_sent;
182  int tx_bytes_sent;
183  int rx_bytes_sent;
184  int tx_bytes_skipped;
185  int rx_bytes_skipped;
186  int rx_passwd_flag;
187  int tx_aux_size;
188 #endif
189 };
190 
191 #define CHAN_EXTENDED_IGNORE 0
192 #define CHAN_EXTENDED_READ 1
193 #define CHAN_EXTENDED_WRITE 2
194 
195 /* default window/packet sizes for tcp/x11-fwd-channel */
196 #define CHAN_SES_PACKET_DEFAULT (32*1024)
197 #define CHAN_SES_WINDOW_DEFAULT (64*CHAN_SES_PACKET_DEFAULT)
198 #define CHAN_TCP_PACKET_DEFAULT (32*1024)
199 #define CHAN_TCP_WINDOW_DEFAULT (64*CHAN_TCP_PACKET_DEFAULT)
200 #define CHAN_X11_PACKET_DEFAULT (16*1024)
201 #define CHAN_X11_WINDOW_DEFAULT (4*CHAN_X11_PACKET_DEFAULT)
202 
203 /* possible input states */
204 #define CHAN_INPUT_OPEN 0
205 #define CHAN_INPUT_WAIT_DRAIN 1
206 #define CHAN_INPUT_WAIT_OCLOSE 2
207 #define CHAN_INPUT_CLOSED 3
208 
209 /* possible output states */
210 #define CHAN_OUTPUT_OPEN 0
211 #define CHAN_OUTPUT_WAIT_DRAIN 1
212 #define CHAN_OUTPUT_WAIT_IEOF 2
213 #define CHAN_OUTPUT_CLOSED 3
214 
215 #define CHAN_CLOSE_SENT 0x01
216 #define CHAN_CLOSE_RCVD 0x02
217 #define CHAN_EOF_SENT 0x04
218 #define CHAN_EOF_RCVD 0x08
219 #define CHAN_LOCAL 0x10
220 
221 #define CHAN_RBUF 16*1024
222 
223 /* check whether 'efd' is still in use */
224 #define CHANNEL_EFD_INPUT_ACTIVE(c) \
225  (compat20 && c->extended_usage == CHAN_EXTENDED_READ && \
226  (c->efd != -1 || \
227  buffer_len(&c->extended) > 0))
228 #define CHANNEL_EFD_OUTPUT_ACTIVE(c) \
229  (compat20 && c->extended_usage == CHAN_EXTENDED_WRITE && \
230  c->efd != -1 && (!(c->flags & (CHAN_EOF_RCVD|CHAN_CLOSE_RCVD)) || \
231  buffer_len(&c->extended) > 0))
232 
233 /* channel management */
234 
235 Channel *channel_by_id(int);
236 Channel *channel_by_remote_id(int);
237 Channel *channel_lookup(int);
238 Channel *channel_new(char *, int, int, int, int, u_int, u_int, int, char *, int);
239 void channel_set_fds(int, int, int, int, int, int, int, u_int);
240 void channel_free(Channel *);
241 void channel_free_all(void);
242 void channel_stop_listening(void);
243 
244 void channel_send_open(int);
245 void channel_request_start(int, char *, int);
246 void channel_register_cleanup(int, channel_callback_fn *, int);
247 void channel_register_open_confirm(int, channel_open_fn *, void *);
248 void channel_register_filter(int, channel_infilter_fn *,
249  channel_outfilter_fn *, channel_filter_cleanup_fn *, void *);
250 void channel_register_status_confirm(int, channel_confirm_cb *,
251  channel_confirm_abandon_cb *, void *);
252 void channel_cancel_cleanup(int);
253 int channel_close_fd(int *);
254 void channel_send_window_changes(void);
255 
256 /* mux proxy support */
257 
258 int channel_proxy_downstream(Channel *mc);
259 int channel_proxy_upstream(Channel *, int, u_int32_t, void *);
260 
261 /* protocol handler */
262 
263 int channel_input_close(int, u_int32_t, void *);
264 int channel_input_close_confirmation(int, u_int32_t, void *);
265 int channel_input_data(int, u_int32_t, void *);
266 int channel_input_extended_data(int, u_int32_t, void *);
267 int channel_input_ieof(int, u_int32_t, void *);
268 int channel_input_oclose(int, u_int32_t, void *);
269 int channel_input_open_confirmation(int, u_int32_t, void *);
270 int channel_input_open_failure(int, u_int32_t, void *);
271 int channel_input_port_open(int, u_int32_t, void *);
272 int channel_input_window_adjust(int, u_int32_t, void *);
273 int channel_input_status_confirm(int, u_int32_t, void *);
274 
275 /* file descriptor handling (read/write) */
276 
277 void channel_prepare_select(fd_set **, fd_set **, int *, u_int*,
278  time_t*, int);
279 void channel_after_select(fd_set *, fd_set *);
280 void channel_output_poll(void);
281 
282 int channel_not_very_much_buffered_data(void);
283 void channel_close_all(void);
284 int channel_still_open(void);
285 char *channel_open_message(void);
286 int channel_find_open(void);
287 
288 /* tcp forwarding */
289 struct Forward;
290 struct ForwardOptions;
291 void channel_set_af(int af);
292 void channel_permit_all_opens(void);
293 void channel_add_permitted_opens(char *, int);
294 int channel_add_adm_permitted_opens(char *, int);
295 void channel_disable_adm_local_opens(void);
296 void channel_update_permitted_opens(int, int);
297 void channel_clear_permitted_opens(void);
298 void channel_clear_adm_permitted_opens(void);
299 void channel_print_adm_permitted_opens(void);
300 Channel *channel_connect_to_port(const char *, u_short, char *, char *, int *,
301  const char **);
302 Channel *channel_connect_to_path(const char *, char *, char *);
303 Channel *channel_connect_stdio_fwd(const char*, u_short, int, int);
304 Channel *channel_connect_by_listen_address(const char *, u_short,
305  char *, char *);
306 Channel *channel_connect_by_listen_path(const char *, char *, char *);
307 int channel_request_remote_forwarding(struct Forward *);
308 int channel_setup_local_fwd_listener(struct Forward *, struct ForwardOptions *);
309 int channel_request_rforward_cancel(struct Forward *);
310 int channel_setup_remote_fwd_listener(struct Forward *, int *, struct ForwardOptions *);
311 int channel_cancel_rport_listener(struct Forward *);
312 int channel_cancel_lport_listener(struct Forward *, int, struct ForwardOptions *);
313 int permitopen_port(const char *);
314 
315 /* x11 forwarding */
316 
317 void channel_set_x11_refuse_time(u_int);
318 int x11_connect_display(void);
319 int x11_create_display_inet(int, int, int, u_int *, int **);
320 int x11_input_open(int, u_int32_t, void *);
321 void x11_request_forwarding_with_spoofing(int, const char *, const char *,
322  const char *, int);
323 int deny_input_open(int, u_int32_t, void *);
324 
325 /* agent forwarding */
326 
327 void auth_request_forwarding(void);
328 
329 /* channel close */
330 
331 int chan_is_dead(Channel *, int);
332 void chan_mark_dead(Channel *);
333 
334 /* channel events */
335 
336 void chan_rcvd_oclose(Channel *);
337 void chan_rcvd_eow(Channel *); /* SSH2-only */
338 void chan_read_failed(Channel *);
339 void chan_ibuf_empty(Channel *);
340 
341 void chan_rcvd_ieof(Channel *);
342 void chan_write_failed(Channel *);
343 void chan_obuf_empty(Channel *);
344 
345 /* hpn handler */
346 void channel_set_hpn(int, int);
347 
348 #endif
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