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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 1.22 2001/01/21 19:05:52 markus Exp $"); | |
27 | ||
28 | #include "ssh1.h" | |
29 | #include "ssh2.h" | |
30 | #include "buffer.h" | |
31 | #include "packet.h" | |
32 | #include "channels.h" | |
33 | #include "nchan.h" | |
34 | #include "compat.h" | |
35 | #include "log.h" | |
36 | ||
37 | /* functions manipulating channel states */ | |
38 | /* | |
39 | * EVENTS update channel input/output states execute ACTIONS | |
40 | */ | |
41 | /* events concerning the INPUT from socket for channel (istate) */ | |
42 | chan_event_fn *chan_rcvd_oclose = NULL; | |
43 | chan_event_fn *chan_read_failed = NULL; | |
44 | chan_event_fn *chan_ibuf_empty = NULL; | |
45 | /* events concerning the OUTPUT from channel for socket (ostate) */ | |
46 | chan_event_fn *chan_rcvd_ieof = NULL; | |
47 | chan_event_fn *chan_write_failed = NULL; | |
48 | chan_event_fn *chan_obuf_empty = NULL; | |
49 | /* | |
50 | * ACTIONS: should never update the channel states | |
51 | */ | |
52 | static void chan_send_ieof1(Channel *c); | |
53 | static void chan_send_oclose1(Channel *c); | |
54 | static void chan_send_close2(Channel *c); | |
55 | static void chan_send_eof2(Channel *c); | |
56 | ||
57 | /* channel cleanup */ | |
58 | chan_event_fn *chan_delete_if_full_closed = NULL; | |
59 | ||
60 | /* helper */ | |
61 | static void chan_shutdown_write(Channel *c); | |
62 | static void chan_shutdown_read(Channel *c); | |
63 | ||
64 | /* | |
65 | * SSH1 specific implementation of event functions | |
66 | */ | |
67 | ||
68 | static void | |
69 | chan_rcvd_oclose1(Channel *c) | |
70 | { | |
71 | debug("channel %d: rcvd oclose", c->self); | |
72 | switch (c->istate) { | |
73 | case CHAN_INPUT_WAIT_OCLOSE: | |
74 | debug("channel %d: input wait_oclose -> closed", c->self); | |
75 | c->istate = CHAN_INPUT_CLOSED; | |
76 | break; | |
77 | case CHAN_INPUT_OPEN: | |
78 | debug("channel %d: input open -> closed", c->self); | |
79 | chan_shutdown_read(c); | |
80 | chan_send_ieof1(c); | |
81 | c->istate = CHAN_INPUT_CLOSED; | |
82 | break; | |
83 | case CHAN_INPUT_WAIT_DRAIN: | |
84 | /* both local read_failed and remote write_failed */ | |
85 | log("channel %d: input drain -> closed", c->self); | |
86 | chan_send_ieof1(c); | |
87 | c->istate = CHAN_INPUT_CLOSED; | |
88 | break; | |
89 | default: | |
90 | error("channel %d: protocol error: chan_rcvd_oclose for istate %d", | |
91 | c->self, c->istate); | |
92 | return; | |
93 | } | |
94 | } | |
95 | static void | |
96 | chan_read_failed_12(Channel *c) | |
97 | { | |
98 | debug("channel %d: read failed", c->self); | |
99 | switch (c->istate) { | |
100 | case CHAN_INPUT_OPEN: | |
101 | debug("channel %d: input open -> drain", c->self); | |
102 | chan_shutdown_read(c); | |
103 | c->istate = CHAN_INPUT_WAIT_DRAIN; | |
104 | if (buffer_len(&c->input) == 0) { | |
105 | debug("channel %d: input: no drain shortcut", c->self); | |
106 | chan_ibuf_empty(c); | |
107 | } | |
108 | break; | |
109 | default: | |
110 | error("channel %d: internal error: we do not read, but chan_read_failed for istate %d", | |
111 | c->self, c->istate); | |
112 | break; | |
113 | } | |
114 | } | |
115 | static void | |
116 | chan_ibuf_empty1(Channel *c) | |
117 | { | |
118 | debug("channel %d: ibuf empty", c->self); | |
119 | if (buffer_len(&c->input)) { | |
120 | error("channel %d: internal error: chan_ibuf_empty for non empty buffer", | |
121 | c->self); | |
122 | return; | |
123 | } | |
124 | switch (c->istate) { | |
125 | case CHAN_INPUT_WAIT_DRAIN: | |
126 | debug("channel %d: input drain -> wait_oclose", c->self); | |
127 | chan_send_ieof1(c); | |
128 | c->istate = CHAN_INPUT_WAIT_OCLOSE; | |
129 | break; | |
130 | default: | |
131 | error("channel %d: internal error: chan_ibuf_empty for istate %d", | |
132 | c->self, c->istate); | |
133 | break; | |
134 | } | |
135 | } | |
136 | static void | |
137 | chan_rcvd_ieof1(Channel *c) | |
138 | { | |
139 | debug("channel %d: rcvd ieof", c->self); | |
140 | if (c->type != SSH_CHANNEL_OPEN) { | |
141 | debug("channel %d: non-open", c->self); | |
142 | if (c->istate == CHAN_INPUT_OPEN) { | |
143 | debug("channel %d: non-open: input open -> wait_oclose", c->self); | |
144 | chan_shutdown_read(c); | |
145 | chan_send_ieof1(c); | |
146 | c->istate = CHAN_INPUT_WAIT_OCLOSE; | |
147 | } else { | |
148 | error("channel %d: istate %d != open", c->self, c->istate); | |
149 | } | |
150 | if (c->ostate == CHAN_OUTPUT_OPEN) { | |
151 | debug("channel %d: non-open: output open -> closed", c->self); | |
152 | chan_send_oclose1(c); | |
153 | c->ostate = CHAN_OUTPUT_CLOSED; | |
154 | } else { | |
155 | error("channel %d: ostate %d != open", c->self, c->ostate); | |
156 | } | |
157 | return; | |
158 | } | |
159 | switch (c->ostate) { | |
160 | case CHAN_OUTPUT_OPEN: | |
161 | debug("channel %d: output open -> drain", c->self); | |
162 | c->ostate = CHAN_OUTPUT_WAIT_DRAIN; | |
163 | break; | |
164 | case CHAN_OUTPUT_WAIT_IEOF: | |
165 | debug("channel %d: output wait_ieof -> closed", c->self); | |
166 | c->ostate = CHAN_OUTPUT_CLOSED; | |
167 | break; | |
168 | default: | |
169 | error("channel %d: protocol error: chan_rcvd_ieof for ostate %d", | |
170 | c->self, c->ostate); | |
171 | break; | |
172 | } | |
173 | } | |
174 | static void | |
175 | chan_write_failed1(Channel *c) | |
176 | { | |
177 | debug("channel %d: write failed", c->self); | |
178 | switch (c->ostate) { | |
179 | case CHAN_OUTPUT_OPEN: | |
180 | debug("channel %d: output open -> wait_ieof", c->self); | |
181 | chan_send_oclose1(c); | |
182 | c->ostate = CHAN_OUTPUT_WAIT_IEOF; | |
183 | break; | |
184 | case CHAN_OUTPUT_WAIT_DRAIN: | |
185 | debug("channel %d: output wait_drain -> closed", c->self); | |
186 | chan_send_oclose1(c); | |
187 | c->ostate = CHAN_OUTPUT_CLOSED; | |
188 | break; | |
189 | default: | |
190 | error("channel %d: internal error: chan_write_failed for ostate %d", | |
191 | c->self, c->ostate); | |
192 | break; | |
193 | } | |
194 | } | |
195 | static void | |
196 | chan_obuf_empty1(Channel *c) | |
197 | { | |
198 | debug("channel %d: obuf empty", c->self); | |
199 | if (buffer_len(&c->output)) { | |
200 | error("channel %d: internal error: chan_obuf_empty for non empty buffer", | |
201 | c->self); | |
202 | return; | |
203 | } | |
204 | switch (c->ostate) { | |
205 | case CHAN_OUTPUT_WAIT_DRAIN: | |
206 | debug("channel %d: output drain -> closed", c->self); | |
207 | chan_send_oclose1(c); | |
208 | c->ostate = CHAN_OUTPUT_CLOSED; | |
209 | break; | |
210 | default: | |
211 | error("channel %d: internal error: chan_obuf_empty for ostate %d", | |
212 | c->self, c->ostate); | |
213 | break; | |
214 | } | |
215 | } | |
216 | static void | |
217 | chan_send_ieof1(Channel *c) | |
218 | { | |
219 | debug("channel %d: send ieof", c->self); | |
220 | switch (c->istate) { | |
221 | case CHAN_INPUT_OPEN: | |
222 | case CHAN_INPUT_WAIT_DRAIN: | |
223 | packet_start(SSH_MSG_CHANNEL_INPUT_EOF); | |
224 | packet_put_int(c->remote_id); | |
225 | packet_send(); | |
226 | break; | |
227 | default: | |
228 | error("channel %d: internal error: cannot send ieof for istate %d", | |
229 | c->self, c->istate); | |
230 | break; | |
231 | } | |
232 | } | |
233 | static void | |
234 | chan_send_oclose1(Channel *c) | |
235 | { | |
236 | debug("channel %d: send oclose", c->self); | |
237 | switch (c->ostate) { | |
238 | case CHAN_OUTPUT_OPEN: | |
239 | case CHAN_OUTPUT_WAIT_DRAIN: | |
240 | chan_shutdown_write(c); | |
241 | buffer_consume(&c->output, buffer_len(&c->output)); | |
242 | packet_start(SSH_MSG_CHANNEL_OUTPUT_CLOSE); | |
243 | packet_put_int(c->remote_id); | |
244 | packet_send(); | |
245 | break; | |
246 | default: | |
247 | error("channel %d: internal error: cannot send oclose for ostate %d", | |
248 | c->self, c->ostate); | |
249 | break; | |
250 | } | |
251 | } | |
252 | static void | |
253 | chan_delete_if_full_closed1(Channel *c) | |
254 | { | |
255 | debug3("channel %d: chan_delete_if_full_closed1: istate %d ostate %d", | |
256 | c->self, c->istate, c->ostate); | |
257 | if (c->istate == CHAN_INPUT_CLOSED && c->ostate == CHAN_OUTPUT_CLOSED) { | |
258 | debug("channel %d: full closed", c->self); | |
259 | channel_free(c->self); | |
260 | } | |
261 | } | |
262 | ||
263 | /* | |
264 | * the same for SSH2 | |
265 | */ | |
266 | static void | |
267 | chan_rcvd_oclose2(Channel *c) | |
268 | { | |
269 | debug("channel %d: rcvd close", c->self); | |
270 | if (c->flags & CHAN_CLOSE_RCVD) | |
271 | error("channel %d: protocol error: close rcvd twice", c->self); | |
272 | c->flags |= CHAN_CLOSE_RCVD; | |
273 | if (c->type == SSH_CHANNEL_LARVAL) { | |
274 | /* tear down larval channels immediately */ | |
275 | c->ostate = CHAN_OUTPUT_CLOSED; | |
276 | c->istate = CHAN_INPUT_CLOSED; | |
277 | return; | |
278 | } | |
279 | switch (c->ostate) { | |
280 | case CHAN_OUTPUT_OPEN: | |
281 | /* wait until a data from the channel is consumed if a CLOSE is received */ | |
282 | debug("channel %d: output open -> drain", c->self); | |
283 | c->ostate = CHAN_OUTPUT_WAIT_DRAIN; | |
284 | break; | |
285 | } | |
286 | switch (c->istate) { | |
287 | case CHAN_INPUT_OPEN: | |
288 | debug("channel %d: input open -> closed", c->self); | |
289 | chan_shutdown_read(c); | |
290 | break; | |
291 | case CHAN_INPUT_WAIT_DRAIN: | |
292 | debug("channel %d: input drain -> closed", c->self); | |
293 | chan_send_eof2(c); | |
294 | break; | |
295 | } | |
296 | c->istate = CHAN_INPUT_CLOSED; | |
297 | } | |
298 | static void | |
299 | chan_ibuf_empty2(Channel *c) | |
300 | { | |
301 | debug("channel %d: ibuf empty", c->self); | |
302 | if (buffer_len(&c->input)) { | |
303 | error("channel %d: internal error: chan_ibuf_empty for non empty buffer", | |
304 | c->self); | |
305 | return; | |
306 | } | |
307 | switch (c->istate) { | |
308 | case CHAN_INPUT_WAIT_DRAIN: | |
309 | debug("channel %d: input drain -> closed", c->self); | |
310 | if (!(c->flags & CHAN_CLOSE_SENT)) | |
311 | chan_send_eof2(c); | |
312 | c->istate = CHAN_INPUT_CLOSED; | |
313 | break; | |
314 | default: | |
315 | error("channel %d: internal error: chan_ibuf_empty for istate %d", | |
316 | c->self, c->istate); | |
317 | break; | |
318 | } | |
319 | } | |
320 | static void | |
321 | chan_rcvd_ieof2(Channel *c) | |
322 | { | |
323 | debug("channel %d: rcvd eof", c->self); | |
324 | if (c->ostate == CHAN_OUTPUT_OPEN) { | |
325 | debug("channel %d: output open -> drain", c->self); | |
326 | c->ostate = CHAN_OUTPUT_WAIT_DRAIN; | |
327 | } | |
328 | } | |
329 | static void | |
330 | chan_write_failed2(Channel *c) | |
331 | { | |
332 | debug("channel %d: write failed", c->self); | |
333 | switch (c->ostate) { | |
334 | case CHAN_OUTPUT_OPEN: | |
335 | debug("channel %d: output open -> closed", c->self); | |
336 | chan_shutdown_write(c); /* ?? */ | |
337 | c->ostate = CHAN_OUTPUT_CLOSED; | |
338 | break; | |
339 | case CHAN_OUTPUT_WAIT_DRAIN: | |
340 | debug("channel %d: output drain -> closed", c->self); | |
341 | chan_shutdown_write(c); | |
342 | c->ostate = CHAN_OUTPUT_CLOSED; | |
343 | break; | |
344 | default: | |
345 | error("channel %d: internal error: chan_write_failed for ostate %d", | |
346 | c->self, c->ostate); | |
347 | break; | |
348 | } | |
349 | } | |
350 | static void | |
351 | chan_obuf_empty2(Channel *c) | |
352 | { | |
353 | debug("channel %d: obuf empty", c->self); | |
354 | if (buffer_len(&c->output)) { | |
355 | error("internal error: chan_obuf_empty %d for non empty buffer", | |
356 | c->self); | |
357 | return; | |
358 | } | |
359 | switch (c->ostate) { | |
360 | case CHAN_OUTPUT_WAIT_DRAIN: | |
361 | debug("channel %d: output drain -> closed", c->self); | |
362 | chan_shutdown_write(c); | |
363 | c->ostate = CHAN_OUTPUT_CLOSED; | |
364 | break; | |
365 | default: | |
366 | error("channel %d: internal error: chan_obuf_empty for ostate %d", | |
367 | c->self, c->ostate); | |
368 | break; | |
369 | } | |
370 | } | |
371 | static void | |
372 | chan_send_eof2(Channel *c) | |
373 | { | |
374 | debug("channel %d: send eof", c->self); | |
375 | switch (c->istate) { | |
376 | case CHAN_INPUT_WAIT_DRAIN: | |
377 | packet_start(SSH2_MSG_CHANNEL_EOF); | |
378 | packet_put_int(c->remote_id); | |
379 | packet_send(); | |
380 | break; | |
381 | default: | |
382 | error("channel %d: internal error: cannot send eof for istate %d", | |
383 | c->self, c->istate); | |
384 | break; | |
385 | } | |
386 | } | |
387 | static void | |
388 | chan_send_close2(Channel *c) | |
389 | { | |
390 | debug("channel %d: send close", c->self); | |
391 | if (c->ostate != CHAN_OUTPUT_CLOSED || | |
392 | c->istate != CHAN_INPUT_CLOSED) { | |
393 | error("channel %d: internal error: cannot send close for istate/ostate %d/%d", | |
394 | c->self, c->istate, c->ostate); | |
395 | } else if (c->flags & CHAN_CLOSE_SENT) { | |
396 | error("channel %d: internal error: already sent close", c->self); | |
397 | } else { | |
398 | packet_start(SSH2_MSG_CHANNEL_CLOSE); | |
399 | packet_put_int(c->remote_id); | |
400 | packet_send(); | |
401 | c->flags |= CHAN_CLOSE_SENT; | |
402 | } | |
403 | } | |
404 | static void | |
405 | chan_delete_if_full_closed2(Channel *c) | |
406 | { | |
407 | debug3("channel %d: chan_delete_if_full_closed2: istate %d ostate %d", | |
408 | c->self, c->istate, c->ostate); | |
409 | if (c->istate == CHAN_INPUT_CLOSED && c->ostate == CHAN_OUTPUT_CLOSED) { | |
410 | if (!(c->flags & CHAN_CLOSE_SENT)) { | |
411 | chan_send_close2(c); | |
412 | } | |
413 | if ((c->flags & CHAN_CLOSE_SENT) && | |
414 | (c->flags & CHAN_CLOSE_RCVD)) { | |
415 | debug("channel %d: full closed2", c->self); | |
416 | channel_free(c->self); | |
417 | } | |
418 | } | |
419 | } | |
420 | ||
421 | /* shared */ | |
422 | void | |
423 | chan_init_iostates(Channel *c) | |
424 | { | |
425 | c->ostate = CHAN_OUTPUT_OPEN; | |
426 | c->istate = CHAN_INPUT_OPEN; | |
427 | c->flags = 0; | |
428 | } | |
429 | ||
430 | /* init */ | |
431 | void | |
432 | chan_init(void) | |
433 | { | |
434 | if (compat20) { | |
435 | chan_rcvd_oclose = chan_rcvd_oclose2; | |
436 | chan_read_failed = chan_read_failed_12; | |
437 | chan_ibuf_empty = chan_ibuf_empty2; | |
438 | ||
439 | chan_rcvd_ieof = chan_rcvd_ieof2; | |
440 | chan_write_failed = chan_write_failed2; | |
441 | chan_obuf_empty = chan_obuf_empty2; | |
442 | ||
443 | chan_delete_if_full_closed = chan_delete_if_full_closed2; | |
444 | } else { | |
445 | chan_rcvd_oclose = chan_rcvd_oclose1; | |
446 | chan_read_failed = chan_read_failed_12; | |
447 | chan_ibuf_empty = chan_ibuf_empty1; | |
448 | ||
449 | chan_rcvd_ieof = chan_rcvd_ieof1; | |
450 | chan_write_failed = chan_write_failed1; | |
451 | chan_obuf_empty = chan_obuf_empty1; | |
452 | ||
453 | chan_delete_if_full_closed = chan_delete_if_full_closed1; | |
454 | } | |
455 | } | |
456 | ||
457 | /* helper */ | |
458 | static void | |
459 | chan_shutdown_write(Channel *c) | |
460 | { | |
461 | buffer_consume(&c->output, buffer_len(&c->output)); | |
462 | if (compat20 && c->type == SSH_CHANNEL_LARVAL) | |
463 | return; | |
464 | /* shutdown failure is allowed if write failed already */ | |
465 | debug("channel %d: close_write", c->self); | |
466 | if (c->sock != -1) { | |
467 | if (shutdown(c->sock, SHUT_WR) < 0) | |
468 | debug("channel %d: chan_shutdown_write: shutdown() failed for fd%d: %.100s", | |
469 | c->self, c->sock, strerror(errno)); | |
470 | } else { | |
471 | if (close(c->wfd) < 0) | |
472 | log("channel %d: chan_shutdown_write: close() failed for fd%d: %.100s", | |
473 | c->self, c->wfd, strerror(errno)); | |
474 | c->wfd = -1; | |
475 | } | |
476 | } | |
477 | static void | |
478 | chan_shutdown_read(Channel *c) | |
479 | { | |
480 | if (compat20 && c->type == SSH_CHANNEL_LARVAL) | |
481 | return; | |
482 | debug("channel %d: close_read", c->self); | |
483 | if (c->sock != -1) { | |
484 | /* | |
485 | * shutdown(sock, SHUT_READ) may return ENOTCONN if the | |
486 | * write side has been closed already. (bug on Linux) | |
487 | */ | |
488 | if (shutdown(c->sock, SHUT_RD) < 0 | |
489 | && (errno != ENOTCONN | |
490 | || c->ostate == CHAN_OUTPUT_OPEN | |
491 | || c->ostate == CHAN_OUTPUT_WAIT_DRAIN)) | |
492 | error("channel %d: chan_shutdown_read: shutdown() failed for fd%d [i%d o%d]: %.100s", | |
493 | c->self, c->sock, c->istate, c->ostate, strerror(errno)); | |
494 | } else { | |
495 | if (close(c->rfd) < 0) | |
496 | log("channel %d: chan_shutdown_read: close() failed for fd%d: %.100s", | |
497 | c->self, c->rfd, strerror(errno)); | |
498 | c->rfd = -1; | |
499 | } | |
500 | } |