Globus Toolkit  6.0.1493297102
channels.h
1 /* $OpenBSD: channels.h,v 1.118 2015/07/01 02:26:31 djm Exp $ */
2 
3 /*
4  * Author: Tatu Ylonen <ylo@cs.hut.fi>
5  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, 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_MAX_TYPE 20
62 
63 #define CHANNEL_CANCEL_PORT_STATIC -1
64 
65 struct Channel;
66 typedef struct Channel Channel;
67 
68 typedef void channel_open_fn(int, int, void *);
69 typedef void channel_callback_fn(int, void *);
70 typedef int channel_infilter_fn(struct Channel *, char *, int);
71 typedef void channel_filter_cleanup_fn(int, void *);
72 typedef u_char *channel_outfilter_fn(struct Channel *, u_char **, u_int *);
73 
74 /* Channel success/failure callbacks */
75 typedef void channel_confirm_cb(int, struct Channel *, void *);
76 typedef void channel_confirm_abandon_cb(struct Channel *, void *);
77 struct channel_confirm {
78  TAILQ_ENTRY(channel_confirm) entry;
79  channel_confirm_cb *cb;
80  channel_confirm_abandon_cb *abandon_cb;
81  void *ctx;
82 };
83 TAILQ_HEAD(channel_confirms, channel_confirm);
84 
85 /* Context for non-blocking connects */
86 struct channel_connect {
87  char *host;
88  int port;
89  struct addrinfo *ai, *aitop;
90 };
91 
92 /* Callbacks for mux channels back into client-specific code */
93 typedef int mux_callback_fn(struct Channel *);
94 
95 struct Channel {
96  int type; /* channel type/state */
97  int self; /* my own channel identifier */
98  int remote_id; /* channel identifier for remote peer */
99  u_int istate; /* input from channel (state of receive half) */
100  u_int ostate; /* output to channel (state of transmit half) */
101  int flags; /* close sent/rcvd */
102  int rfd; /* read fd */
103  int wfd; /* write fd */
104  int efd; /* extended fd */
105  int sock; /* sock fd */
106  int ctl_chan; /* control channel (multiplexed connections) */
107  int isatty; /* rfd is a tty */
108 #ifdef _AIX
109  int wfd_isatty; /* wfd is a tty */
110 #endif
111  int client_tty; /* (client) TTY has been requested */
112  int force_drain; /* force close on iEOF */
113  time_t notbefore; /* Pause IO until deadline (time_t) */
114  int delayed; /* post-select handlers for newly created
115  * channels are delayed until the first call
116  * to a matching pre-select handler.
117  * this way post-select handlers are not
118  * accidentally called if a FD gets reused */
119  Buffer input; /* data read from socket, to be sent over
120  * encrypted connection */
121  Buffer output; /* data received over encrypted connection for
122  * send on socket */
123  Buffer extended;
124  char *path;
125  /* path for unix domain sockets, or host name for forwards */
126  int listening_port; /* port being listened for forwards */
127  char *listening_addr; /* addr being listened for forwards */
128  int host_port; /* remote port to connect for forwards */
129  char *remote_name; /* remote hostname */
130 
131  u_int remote_window;
132  u_int remote_maxpacket;
133  u_int local_window;
134  u_int local_window_max;
135  u_int local_consumed;
136  u_int local_maxpacket;
137  int dynamic_window;
138  int extended_usage;
139  int single_connection;
140  u_int tcpwinsz;
141 
142  char *ctype; /* type */
143 
144  /* callback */
145  channel_open_fn *open_confirm;
146  void *open_confirm_ctx;
147  channel_callback_fn *detach_user;
148  int detach_close;
149  struct channel_confirms status_confirms;
150 
151  /* filter */
152  channel_infilter_fn *input_filter;
153  channel_outfilter_fn *output_filter;
154  void *filter_ctx;
155  channel_filter_cleanup_fn *filter_cleanup;
156 
157  /* keep boundaries */
158  int datagram;
159 
160  /* non-blocking connect */
161  struct channel_connect connect_ctx;
162 
163  /* multiplexing protocol hook, called for each packet received */
164  mux_callback_fn *mux_rcb;
165  void *mux_ctx;
166  int mux_pause;
167 #ifdef NERSC_MOD
168  Buffer rx_line_buf;
169  Buffer tx_line_buf;
170  int audit_enable;
171 
172  int max_tx_lines;
173  int max_rx_lines;
174  int max_tx_char;
175  int max_rx_char;
176 
177  int tx_lines_sent;
178  int rx_lines_sent;
179  int tx_bytes_sent;
180  int rx_bytes_sent;
181  int tx_bytes_skipped;
182  int rx_bytes_skipped;
183  int rx_passwd_flag;
184  int tx_aux_size;
185 #endif
186 };
187 
188 #define CHAN_EXTENDED_IGNORE 0
189 #define CHAN_EXTENDED_READ 1
190 #define CHAN_EXTENDED_WRITE 2
191 
192 /* default window/packet sizes for tcp/x11-fwd-channel */
193 #define CHAN_SES_PACKET_DEFAULT (32*1024)
194 #define CHAN_SES_WINDOW_DEFAULT (64*CHAN_SES_PACKET_DEFAULT)
195 #define CHAN_TCP_PACKET_DEFAULT (32*1024)
196 #define CHAN_TCP_WINDOW_DEFAULT (64*CHAN_TCP_PACKET_DEFAULT)
197 #define CHAN_X11_PACKET_DEFAULT (16*1024)
198 #define CHAN_X11_WINDOW_DEFAULT (4*CHAN_X11_PACKET_DEFAULT)
199 
200 /* possible input states */
201 #define CHAN_INPUT_OPEN 0
202 #define CHAN_INPUT_WAIT_DRAIN 1
203 #define CHAN_INPUT_WAIT_OCLOSE 2
204 #define CHAN_INPUT_CLOSED 3
205 
206 /* possible output states */
207 #define CHAN_OUTPUT_OPEN 0
208 #define CHAN_OUTPUT_WAIT_DRAIN 1
209 #define CHAN_OUTPUT_WAIT_IEOF 2
210 #define CHAN_OUTPUT_CLOSED 3
211 
212 #define CHAN_CLOSE_SENT 0x01
213 #define CHAN_CLOSE_RCVD 0x02
214 #define CHAN_EOF_SENT 0x04
215 #define CHAN_EOF_RCVD 0x08
216 #define CHAN_LOCAL 0x10
217 
218 #define CHAN_RBUF 16*1024
219 
220 /* check whether 'efd' is still in use */
221 #define CHANNEL_EFD_INPUT_ACTIVE(c) \
222  (compat20 && c->extended_usage == CHAN_EXTENDED_READ && \
223  (c->efd != -1 || \
224  buffer_len(&c->extended) > 0))
225 #define CHANNEL_EFD_OUTPUT_ACTIVE(c) \
226  (compat20 && c->extended_usage == CHAN_EXTENDED_WRITE && \
227  c->efd != -1 && (!(c->flags & (CHAN_EOF_RCVD|CHAN_CLOSE_RCVD)) || \
228  buffer_len(&c->extended) > 0))
229 
230 /* channel management */
231 
232 Channel *channel_by_id(int);
233 Channel *channel_lookup(int);
234 Channel *channel_new(char *, int, int, int, int, u_int, u_int, int, char *, int);
235 void channel_set_fds(int, int, int, int, int, int, int, u_int);
236 void channel_free(Channel *);
237 void channel_free_all(void);
238 void channel_stop_listening(void);
239 
240 void channel_send_open(int);
241 void channel_request_start(int, char *, int);
242 void channel_register_cleanup(int, channel_callback_fn *, int);
243 void channel_register_open_confirm(int, channel_open_fn *, void *);
244 void channel_register_filter(int, channel_infilter_fn *,
245  channel_outfilter_fn *, channel_filter_cleanup_fn *, void *);
246 void channel_register_status_confirm(int, channel_confirm_cb *,
247  channel_confirm_abandon_cb *, void *);
248 void channel_cancel_cleanup(int);
249 int channel_close_fd(int *);
250 void channel_send_window_changes(void);
251 
252 /* protocol handler */
253 
254 int channel_input_close(int, u_int32_t, void *);
255 int channel_input_close_confirmation(int, u_int32_t, void *);
256 int channel_input_data(int, u_int32_t, void *);
257 int channel_input_extended_data(int, u_int32_t, void *);
258 int channel_input_ieof(int, u_int32_t, void *);
259 int channel_input_oclose(int, u_int32_t, void *);
260 int channel_input_open_confirmation(int, u_int32_t, void *);
261 int channel_input_open_failure(int, u_int32_t, void *);
262 int channel_input_port_open(int, u_int32_t, void *);
263 int channel_input_window_adjust(int, u_int32_t, void *);
264 int channel_input_status_confirm(int, u_int32_t, void *);
265 
266 /* file descriptor handling (read/write) */
267 
268 void channel_prepare_select(fd_set **, fd_set **, int *, u_int*,
269  time_t*, int);
270 void channel_after_select(fd_set *, fd_set *);
271 void channel_output_poll(void);
272 
273 int channel_not_very_much_buffered_data(void);
274 void channel_close_all(void);
275 int channel_still_open(void);
276 char *channel_open_message(void);
277 int channel_find_open(void);
278 
279 /* tcp forwarding */
280 struct Forward;
281 struct ForwardOptions;
282 void channel_set_af(int af);
283 void channel_permit_all_opens(void);
284 void channel_add_permitted_opens(char *, int);
285 int channel_add_adm_permitted_opens(char *, int);
286 void channel_disable_adm_local_opens(void);
287 void channel_update_permitted_opens(int, int);
288 void channel_clear_permitted_opens(void);
289 void channel_clear_adm_permitted_opens(void);
290 void channel_print_adm_permitted_opens(void);
291 int channel_input_port_forward_request(int, struct ForwardOptions *);
292 Channel *channel_connect_to_port(const char *, u_short, char *, char *);
293 Channel *channel_connect_to_path(const char *, char *, char *);
294 Channel *channel_connect_stdio_fwd(const char*, u_short, int, int);
295 Channel *channel_connect_by_listen_address(const char *, u_short,
296  char *, char *);
297 Channel *channel_connect_by_listen_path(const char *, char *, char *);
298 int channel_request_remote_forwarding(struct Forward *);
299 int channel_setup_local_fwd_listener(struct Forward *, struct ForwardOptions *);
300 int channel_request_rforward_cancel(struct Forward *);
301 int channel_setup_remote_fwd_listener(struct Forward *, int *, struct ForwardOptions *);
302 int channel_cancel_rport_listener(struct Forward *);
303 int channel_cancel_lport_listener(struct Forward *, int, struct ForwardOptions *);
304 int permitopen_port(const char *);
305 
306 /* x11 forwarding */
307 
308 void channel_set_x11_refuse_time(u_int);
309 int x11_connect_display(void);
310 int x11_create_display_inet(int, int, int, u_int *, int **);
311 int x11_input_open(int, u_int32_t, void *);
312 void x11_request_forwarding_with_spoofing(int, const char *, const char *,
313  const char *, int);
314 int deny_input_open(int, u_int32_t, void *);
315 
316 /* agent forwarding */
317 
318 void auth_request_forwarding(void);
319 
320 /* channel close */
321 
322 int chan_is_dead(Channel *, int);
323 void chan_mark_dead(Channel *);
324 
325 /* channel events */
326 
327 void chan_rcvd_oclose(Channel *);
328 void chan_rcvd_eow(Channel *); /* SSH2-only */
329 void chan_read_failed(Channel *);
330 void chan_ibuf_empty(Channel *);
331 
332 void chan_rcvd_ieof(Channel *);
333 void chan_write_failed(Channel *);
334 void chan_obuf_empty(Channel *);
335 
336 /* hpn handler */
337 void channel_set_hpn(int, int);
338 
339 #endif