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1 | /* | |
2 | * Copyright (c) 1999 Markus Friedl. All rights reserved. | |
3 | * | |
4 | * Redistribution and use in source and binary forms, with or without | |
5 | * modification, are permitted provided that the following conditions | |
6 | * are met: | |
7 | * 1. Redistributions of source code must retain the above copyright | |
8 | * notice, this list of conditions and the following disclaimer. | |
9 | * 2. Redistributions in binary form must reproduce the above copyright | |
10 | * notice, this list of conditions and the following disclaimer in the | |
11 | * documentation and/or other materials provided with the distribution. | |
12 | * | |
13 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR | |
14 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES | |
15 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. | |
16 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, | |
17 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT | |
18 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, | |
19 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY | |
20 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT | |
21 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF | |
22 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | |
23 | */ | |
24 | ||
25 | #include "includes.h" | |
26 | RCSID("$OpenBSD: nchan.c,v 1.19 2000/09/07 20:27:52 deraadt Exp $"); | |
27 | ||
28 | #include "ssh.h" | |
29 | ||
30 | #include "buffer.h" | |
31 | #include "packet.h" | |
32 | #include "channels.h" | |
33 | #include "nchan.h" | |
34 | ||
35 | #include "ssh2.h" | |
36 | #include "compat.h" | |
37 | ||
38 | /* functions manipulating channel states */ | |
39 | /* | |
40 | * EVENTS update channel input/output states execute ACTIONS | |
41 | */ | |
42 | /* events concerning the INPUT from socket for channel (istate) */ | |
43 | chan_event_fn *chan_rcvd_oclose = NULL; | |
44 | chan_event_fn *chan_read_failed = NULL; | |
45 | chan_event_fn *chan_ibuf_empty = NULL; | |
46 | /* events concerning the OUTPUT from channel for socket (ostate) */ | |
47 | chan_event_fn *chan_rcvd_ieof = NULL; | |
48 | chan_event_fn *chan_write_failed = NULL; | |
49 | chan_event_fn *chan_obuf_empty = NULL; | |
50 | /* | |
51 | * ACTIONS: should never update the channel states | |
52 | */ | |
53 | static void chan_send_ieof1(Channel *c); | |
54 | static void chan_send_oclose1(Channel *c); | |
55 | static void chan_send_close2(Channel *c); | |
56 | static void chan_send_eof2(Channel *c); | |
57 | ||
58 | /* channel cleanup */ | |
59 | chan_event_fn *chan_delete_if_full_closed = NULL; | |
60 | ||
61 | /* helper */ | |
62 | static void chan_shutdown_write(Channel *c); | |
63 | static void chan_shutdown_read(Channel *c); | |
64 | ||
65 | /* | |
66 | * SSH1 specific implementation of event functions | |
67 | */ | |
68 | ||
69 | static void | |
70 | chan_rcvd_oclose1(Channel *c) | |
71 | { | |
72 | debug("channel %d: rcvd oclose", c->self); | |
73 | switch (c->istate) { | |
74 | case CHAN_INPUT_WAIT_OCLOSE: | |
75 | debug("channel %d: input wait_oclose -> closed", c->self); | |
76 | c->istate = CHAN_INPUT_CLOSED; | |
77 | break; | |
78 | case CHAN_INPUT_OPEN: | |
79 | debug("channel %d: input open -> closed", c->self); | |
80 | chan_shutdown_read(c); | |
81 | chan_send_ieof1(c); | |
82 | c->istate = CHAN_INPUT_CLOSED; | |
83 | break; | |
84 | case CHAN_INPUT_WAIT_DRAIN: | |
85 | /* both local read_failed and remote write_failed */ | |
86 | log("channel %d: input drain -> closed", c->self); | |
87 | chan_send_ieof1(c); | |
88 | c->istate = CHAN_INPUT_CLOSED; | |
89 | break; | |
90 | default: | |
91 | error("channel %d: protocol error: chan_rcvd_oclose for istate %d", | |
92 | c->self, c->istate); | |
93 | return; | |
94 | } | |
95 | } | |
96 | static void | |
97 | chan_read_failed_12(Channel *c) | |
98 | { | |
99 | debug("channel %d: read failed", c->self); | |
100 | switch (c->istate) { | |
101 | case CHAN_INPUT_OPEN: | |
102 | debug("channel %d: input open -> drain", c->self); | |
103 | chan_shutdown_read(c); | |
104 | c->istate = CHAN_INPUT_WAIT_DRAIN; | |
105 | if (buffer_len(&c->input) == 0) { | |
106 | debug("channel %d: input: no drain shortcut", c->self); | |
107 | chan_ibuf_empty(c); | |
108 | } | |
109 | break; | |
110 | default: | |
111 | error("channel %d: internal error: we do not read, but chan_read_failed for istate %d", | |
112 | c->self, c->istate); | |
113 | break; | |
114 | } | |
115 | } | |
116 | static void | |
117 | chan_ibuf_empty1(Channel *c) | |
118 | { | |
119 | debug("channel %d: ibuf empty", c->self); | |
120 | if (buffer_len(&c->input)) { | |
121 | error("channel %d: internal error: chan_ibuf_empty for non empty buffer", | |
122 | c->self); | |
123 | return; | |
124 | } | |
125 | switch (c->istate) { | |
126 | case CHAN_INPUT_WAIT_DRAIN: | |
127 | debug("channel %d: input drain -> wait_oclose", c->self); | |
128 | chan_send_ieof1(c); | |
129 | c->istate = CHAN_INPUT_WAIT_OCLOSE; | |
130 | break; | |
131 | default: | |
132 | error("channel %d: internal error: chan_ibuf_empty for istate %d", | |
133 | c->self, c->istate); | |
134 | break; | |
135 | } | |
136 | } | |
137 | static void | |
138 | chan_rcvd_ieof1(Channel *c) | |
139 | { | |
140 | debug("channel %d: rcvd ieof", c->self); | |
141 | if (c->type != SSH_CHANNEL_OPEN) { | |
142 | debug("channel %d: non-open", c->self); | |
143 | if (c->istate == CHAN_INPUT_OPEN) { | |
144 | debug("channel %d: non-open: input open -> wait_oclose", c->self); | |
145 | chan_shutdown_read(c); | |
146 | chan_send_ieof1(c); | |
147 | c->istate = CHAN_INPUT_WAIT_OCLOSE; | |
148 | } else { | |
149 | error("channel %d: istate %d != open", c->self, c->istate); | |
150 | } | |
151 | if (c->ostate == CHAN_OUTPUT_OPEN) { | |
152 | debug("channel %d: non-open: output open -> closed", c->self); | |
153 | chan_send_oclose1(c); | |
154 | c->ostate = CHAN_OUTPUT_CLOSED; | |
155 | } else { | |
156 | error("channel %d: ostate %d != open", c->self, c->ostate); | |
157 | } | |
158 | return; | |
159 | } | |
160 | switch (c->ostate) { | |
161 | case CHAN_OUTPUT_OPEN: | |
162 | debug("channel %d: output open -> drain", c->self); | |
163 | c->ostate = CHAN_OUTPUT_WAIT_DRAIN; | |
164 | break; | |
165 | case CHAN_OUTPUT_WAIT_IEOF: | |
166 | debug("channel %d: output wait_ieof -> closed", c->self); | |
167 | c->ostate = CHAN_OUTPUT_CLOSED; | |
168 | break; | |
169 | default: | |
170 | error("channel %d: protocol error: chan_rcvd_ieof for ostate %d", | |
171 | c->self, c->ostate); | |
172 | break; | |
173 | } | |
174 | } | |
175 | static void | |
176 | chan_write_failed1(Channel *c) | |
177 | { | |
178 | debug("channel %d: write failed", c->self); | |
179 | switch (c->ostate) { | |
180 | case CHAN_OUTPUT_OPEN: | |
181 | debug("channel %d: output open -> wait_ieof", c->self); | |
182 | chan_send_oclose1(c); | |
183 | c->ostate = CHAN_OUTPUT_WAIT_IEOF; | |
184 | break; | |
185 | case CHAN_OUTPUT_WAIT_DRAIN: | |
186 | debug("channel %d: output wait_drain -> closed", c->self); | |
187 | chan_send_oclose1(c); | |
188 | c->ostate = CHAN_OUTPUT_CLOSED; | |
189 | break; | |
190 | default: | |
191 | error("channel %d: internal error: chan_write_failed for ostate %d", | |
192 | c->self, c->ostate); | |
193 | break; | |
194 | } | |
195 | } | |
196 | static void | |
197 | chan_obuf_empty1(Channel *c) | |
198 | { | |
199 | debug("channel %d: obuf empty", c->self); | |
200 | if (buffer_len(&c->output)) { | |
201 | error("channel %d: internal error: chan_obuf_empty for non empty buffer", | |
202 | c->self); | |
203 | return; | |
204 | } | |
205 | switch (c->ostate) { | |
206 | case CHAN_OUTPUT_WAIT_DRAIN: | |
207 | debug("channel %d: output drain -> closed", c->self); | |
208 | chan_send_oclose1(c); | |
209 | c->ostate = CHAN_OUTPUT_CLOSED; | |
210 | break; | |
211 | default: | |
212 | error("channel %d: internal error: chan_obuf_empty for ostate %d", | |
213 | c->self, c->ostate); | |
214 | break; | |
215 | } | |
216 | } | |
217 | static void | |
218 | chan_send_ieof1(Channel *c) | |
219 | { | |
220 | debug("channel %d: send ieof", c->self); | |
221 | switch (c->istate) { | |
222 | case CHAN_INPUT_OPEN: | |
223 | case CHAN_INPUT_WAIT_DRAIN: | |
224 | packet_start(SSH_MSG_CHANNEL_INPUT_EOF); | |
225 | packet_put_int(c->remote_id); | |
226 | packet_send(); | |
227 | break; | |
228 | default: | |
229 | error("channel %d: internal error: cannot send ieof for istate %d", | |
230 | c->self, c->istate); | |
231 | break; | |
232 | } | |
233 | } | |
234 | static void | |
235 | chan_send_oclose1(Channel *c) | |
236 | { | |
237 | debug("channel %d: send oclose", c->self); | |
238 | switch (c->ostate) { | |
239 | case CHAN_OUTPUT_OPEN: | |
240 | case CHAN_OUTPUT_WAIT_DRAIN: | |
241 | chan_shutdown_write(c); | |
242 | buffer_consume(&c->output, buffer_len(&c->output)); | |
243 | packet_start(SSH_MSG_CHANNEL_OUTPUT_CLOSE); | |
244 | packet_put_int(c->remote_id); | |
245 | packet_send(); | |
246 | break; | |
247 | default: | |
248 | error("channel %d: internal error: cannot send oclose for ostate %d", | |
249 | c->self, c->ostate); | |
250 | break; | |
251 | } | |
252 | } | |
253 | static void | |
254 | chan_delete_if_full_closed1(Channel *c) | |
255 | { | |
256 | if (c->istate == CHAN_INPUT_CLOSED && c->ostate == CHAN_OUTPUT_CLOSED) { | |
257 | debug("channel %d: full closed", c->self); | |
258 | channel_free(c->self); | |
259 | } | |
260 | } | |
261 | ||
262 | /* | |
263 | * the same for SSH2 | |
264 | */ | |
265 | static void | |
266 | chan_rcvd_oclose2(Channel *c) | |
267 | { | |
268 | debug("channel %d: rcvd close", c->self); | |
269 | if (c->flags & CHAN_CLOSE_RCVD) | |
270 | error("channel %d: protocol error: close rcvd twice", c->self); | |
271 | c->flags |= CHAN_CLOSE_RCVD; | |
272 | if (c->type == SSH_CHANNEL_LARVAL) { | |
273 | /* tear down larval channels immediately */ | |
274 | c->ostate = CHAN_OUTPUT_CLOSED; | |
275 | c->istate = CHAN_INPUT_CLOSED; | |
276 | return; | |
277 | } | |
278 | switch (c->ostate) { | |
279 | case CHAN_OUTPUT_OPEN: | |
280 | /* wait until a data from the channel is consumed if a CLOSE is received */ | |
281 | debug("channel %d: output open -> drain", c->self); | |
282 | c->ostate = CHAN_OUTPUT_WAIT_DRAIN; | |
283 | break; | |
284 | } | |
285 | switch (c->istate) { | |
286 | case CHAN_INPUT_OPEN: | |
287 | debug("channel %d: input open -> closed", c->self); | |
288 | chan_shutdown_read(c); | |
289 | break; | |
290 | case CHAN_INPUT_WAIT_DRAIN: | |
291 | debug("channel %d: input drain -> closed", c->self); | |
292 | chan_send_eof2(c); | |
293 | break; | |
294 | } | |
295 | c->istate = CHAN_INPUT_CLOSED; | |
296 | } | |
297 | static void | |
298 | chan_ibuf_empty2(Channel *c) | |
299 | { | |
300 | debug("channel %d: ibuf empty", c->self); | |
301 | if (buffer_len(&c->input)) { | |
302 | error("channel %d: internal error: chan_ibuf_empty for non empty buffer", | |
303 | c->self); | |
304 | return; | |
305 | } | |
306 | switch (c->istate) { | |
307 | case CHAN_INPUT_WAIT_DRAIN: | |
308 | debug("channel %d: input drain -> closed", c->self); | |
309 | if (!(c->flags & CHAN_CLOSE_SENT)) | |
310 | chan_send_eof2(c); | |
311 | c->istate = CHAN_INPUT_CLOSED; | |
312 | break; | |
313 | default: | |
314 | error("channel %d: internal error: chan_ibuf_empty for istate %d", | |
315 | c->self, c->istate); | |
316 | break; | |
317 | } | |
318 | } | |
319 | static void | |
320 | chan_rcvd_ieof2(Channel *c) | |
321 | { | |
322 | debug("channel %d: rcvd eof", c->self); | |
323 | if (c->ostate == CHAN_OUTPUT_OPEN) { | |
324 | debug("channel %d: output open -> drain", c->self); | |
325 | c->ostate = CHAN_OUTPUT_WAIT_DRAIN; | |
326 | } | |
327 | } | |
328 | static void | |
329 | chan_write_failed2(Channel *c) | |
330 | { | |
331 | debug("channel %d: write failed", c->self); | |
332 | switch (c->ostate) { | |
333 | case CHAN_OUTPUT_OPEN: | |
334 | debug("channel %d: output open -> closed", c->self); | |
335 | chan_shutdown_write(c); /* ?? */ | |
336 | c->ostate = CHAN_OUTPUT_CLOSED; | |
337 | break; | |
338 | case CHAN_OUTPUT_WAIT_DRAIN: | |
339 | debug("channel %d: output drain -> closed", c->self); | |
340 | chan_shutdown_write(c); | |
341 | c->ostate = CHAN_OUTPUT_CLOSED; | |
342 | break; | |
343 | default: | |
344 | error("channel %d: internal error: chan_write_failed for ostate %d", | |
345 | c->self, c->ostate); | |
346 | break; | |
347 | } | |
348 | } | |
349 | static void | |
350 | chan_obuf_empty2(Channel *c) | |
351 | { | |
352 | debug("channel %d: obuf empty", c->self); | |
353 | if (buffer_len(&c->output)) { | |
354 | error("internal error: chan_obuf_empty %d for non empty buffer", | |
355 | c->self); | |
356 | return; | |
357 | } | |
358 | switch (c->ostate) { | |
359 | case CHAN_OUTPUT_WAIT_DRAIN: | |
360 | debug("channel %d: output drain -> closed", c->self); | |
361 | chan_shutdown_write(c); | |
362 | c->ostate = CHAN_OUTPUT_CLOSED; | |
363 | break; | |
364 | default: | |
365 | error("channel %d: internal error: chan_obuf_empty for ostate %d", | |
366 | c->self, c->ostate); | |
367 | break; | |
368 | } | |
369 | } | |
370 | static void | |
371 | chan_send_eof2(Channel *c) | |
372 | { | |
373 | debug("channel %d: send eof", c->self); | |
374 | switch (c->istate) { | |
375 | case CHAN_INPUT_WAIT_DRAIN: | |
376 | packet_start(SSH2_MSG_CHANNEL_EOF); | |
377 | packet_put_int(c->remote_id); | |
378 | packet_send(); | |
379 | break; | |
380 | default: | |
381 | error("channel %d: internal error: cannot send eof for istate %d", | |
382 | c->self, c->istate); | |
383 | break; | |
384 | } | |
385 | } | |
386 | static void | |
387 | chan_send_close2(Channel *c) | |
388 | { | |
389 | debug("channel %d: send close", c->self); | |
390 | if (c->ostate != CHAN_OUTPUT_CLOSED || | |
391 | c->istate != CHAN_INPUT_CLOSED) { | |
392 | error("channel %d: internal error: cannot send close for istate/ostate %d/%d", | |
393 | c->self, c->istate, c->ostate); | |
394 | } else if (c->flags & CHAN_CLOSE_SENT) { | |
395 | error("channel %d: internal error: already sent close", c->self); | |
396 | } else { | |
397 | packet_start(SSH2_MSG_CHANNEL_CLOSE); | |
398 | packet_put_int(c->remote_id); | |
399 | packet_send(); | |
400 | c->flags |= CHAN_CLOSE_SENT; | |
401 | } | |
402 | } | |
403 | static void | |
404 | chan_delete_if_full_closed2(Channel *c) | |
405 | { | |
406 | if (c->istate == CHAN_INPUT_CLOSED && c->ostate == CHAN_OUTPUT_CLOSED) { | |
407 | if (!(c->flags & CHAN_CLOSE_SENT)) { | |
408 | chan_send_close2(c); | |
409 | } | |
410 | if ((c->flags & CHAN_CLOSE_SENT) && | |
411 | (c->flags & CHAN_CLOSE_RCVD)) { | |
412 | debug("channel %d: full closed2", c->self); | |
413 | channel_free(c->self); | |
414 | } | |
415 | } | |
416 | } | |
417 | ||
418 | /* shared */ | |
419 | void | |
420 | chan_init_iostates(Channel *c) | |
421 | { | |
422 | c->ostate = CHAN_OUTPUT_OPEN; | |
423 | c->istate = CHAN_INPUT_OPEN; | |
424 | c->flags = 0; | |
425 | } | |
426 | ||
427 | /* init */ | |
428 | void | |
429 | chan_init(void) | |
430 | { | |
431 | if (compat20) { | |
432 | chan_rcvd_oclose = chan_rcvd_oclose2; | |
433 | chan_read_failed = chan_read_failed_12; | |
434 | chan_ibuf_empty = chan_ibuf_empty2; | |
435 | ||
436 | chan_rcvd_ieof = chan_rcvd_ieof2; | |
437 | chan_write_failed = chan_write_failed2; | |
438 | chan_obuf_empty = chan_obuf_empty2; | |
439 | ||
440 | chan_delete_if_full_closed = chan_delete_if_full_closed2; | |
441 | } else { | |
442 | chan_rcvd_oclose = chan_rcvd_oclose1; | |
443 | chan_read_failed = chan_read_failed_12; | |
444 | chan_ibuf_empty = chan_ibuf_empty1; | |
445 | ||
446 | chan_rcvd_ieof = chan_rcvd_ieof1; | |
447 | chan_write_failed = chan_write_failed1; | |
448 | chan_obuf_empty = chan_obuf_empty1; | |
449 | ||
450 | chan_delete_if_full_closed = chan_delete_if_full_closed1; | |
451 | } | |
452 | } | |
453 | ||
454 | /* helper */ | |
455 | static void | |
456 | chan_shutdown_write(Channel *c) | |
457 | { | |
458 | buffer_consume(&c->output, buffer_len(&c->output)); | |
459 | if (compat20 && c->type == SSH_CHANNEL_LARVAL) | |
460 | return; | |
461 | /* shutdown failure is allowed if write failed already */ | |
462 | debug("channel %d: close_write", c->self); | |
463 | if (c->sock != -1) { | |
464 | if (shutdown(c->sock, SHUT_WR) < 0) | |
465 | debug("channel %d: chan_shutdown_write: shutdown() failed for fd%d: %.100s", | |
466 | c->self, c->sock, strerror(errno)); | |
467 | } else { | |
468 | if (close(c->wfd) < 0) | |
469 | log("channel %d: chan_shutdown_write: close() failed for fd%d: %.100s", | |
470 | c->self, c->wfd, strerror(errno)); | |
471 | c->wfd = -1; | |
472 | } | |
473 | } | |
474 | static void | |
475 | chan_shutdown_read(Channel *c) | |
476 | { | |
477 | if (compat20 && c->type == SSH_CHANNEL_LARVAL) | |
478 | return; | |
479 | debug("channel %d: close_read", c->self); | |
480 | if (c->sock != -1) { | |
481 | /* | |
482 | * shutdown(sock, SHUT_READ) may return ENOTCONN if the | |
483 | * write side has been closed already. (bug on Linux) | |
484 | */ | |
485 | if (shutdown(c->sock, SHUT_RD) < 0 | |
486 | && (errno != ENOTCONN | |
487 | || c->ostate == CHAN_OUTPUT_OPEN | |
488 | || c->ostate == CHAN_OUTPUT_WAIT_DRAIN)) | |
489 | error("channel %d: chan_shutdown_read: shutdown() failed for fd%d [i%d o%d]: %.100s", | |
490 | c->self, c->sock, c->istate, c->ostate, strerror(errno)); | |
491 | } else { | |
492 | if (close(c->rfd) < 0) | |
493 | log("channel %d: chan_shutdown_read: close() failed for fd%d: %.100s", | |
494 | c->self, c->rfd, strerror(errno)); | |
495 | c->rfd = -1; | |
496 | } | |
497 | } |