]> andersk Git - openssh.git/blame - nchan.c
- markus@cvs.openbsd.org 2001/05/16 22:09:21
[openssh.git] / nchan.c
CommitLineData
aa3378df 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.
aa3378df 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
8efc0c15 25#include "includes.h"
7231bd47 26RCSID("$OpenBSD: nchan.c,v 1.25 2001/05/16 22:09:21 markus Exp $");
8efc0c15 27
42f11eb2 28#include "ssh1.h"
29#include "ssh2.h"
8efc0c15 30#include "buffer.h"
31#include "packet.h"
32#include "channels.h"
33#include "nchan.h"
7e7327a1 34#include "compat.h"
42f11eb2 35#include "log.h"
8efc0c15 36
7e7327a1 37/* functions manipulating channel states */
8efc0c15 38/*
5260325f 39 * EVENTS update channel input/output states execute ACTIONS
8efc0c15 40 */
41/* events concerning the INPUT from socket for channel (istate) */
7e7327a1 42chan_event_fn *chan_rcvd_oclose = NULL;
43chan_event_fn *chan_read_failed = NULL;
44chan_event_fn *chan_ibuf_empty = NULL;
45/* events concerning the OUTPUT from channel for socket (ostate) */
46chan_event_fn *chan_rcvd_ieof = NULL;
47chan_event_fn *chan_write_failed = NULL;
48chan_event_fn *chan_obuf_empty = NULL;
49/*
50 * ACTIONS: should never update the channel states
51 */
52static void chan_send_ieof1(Channel *c);
53static void chan_send_oclose1(Channel *c);
54static void chan_send_close2(Channel *c);
55static void chan_send_eof2(Channel *c);
56
7e7327a1 57/* helper */
58static void chan_shutdown_write(Channel *c);
59static void chan_shutdown_read(Channel *c);
60
61/*
62 * SSH1 specific implementation of event functions
63 */
64
65static void
66chan_rcvd_oclose1(Channel *c)
5260325f 67{
7e7327a1 68 debug("channel %d: rcvd oclose", c->self);
5260325f 69 switch (c->istate) {
8efc0c15 70 case CHAN_INPUT_WAIT_OCLOSE:
7e7327a1 71 debug("channel %d: input wait_oclose -> closed", c->self);
5260325f 72 c->istate = CHAN_INPUT_CLOSED;
8efc0c15 73 break;
74 case CHAN_INPUT_OPEN:
7e7327a1 75 debug("channel %d: input open -> closed", c->self);
8efc0c15 76 chan_shutdown_read(c);
7e7327a1 77 chan_send_ieof1(c);
5260325f 78 c->istate = CHAN_INPUT_CLOSED;
48e671d5 79 break;
80 case CHAN_INPUT_WAIT_DRAIN:
81 /* both local read_failed and remote write_failed */
7e7327a1 82 log("channel %d: input drain -> closed", c->self);
83 chan_send_ieof1(c);
48e671d5 84 c->istate = CHAN_INPUT_CLOSED;
8efc0c15 85 break;
86 default:
7e7327a1 87 error("channel %d: protocol error: chan_rcvd_oclose for istate %d",
88 c->self, c->istate);
48e671d5 89 return;
8efc0c15 90 }
91}
7e7327a1 92static void
93chan_read_failed_12(Channel *c)
5260325f 94{
7e7327a1 95 debug("channel %d: read failed", c->self);
5260325f 96 switch (c->istate) {
8efc0c15 97 case CHAN_INPUT_OPEN:
7e7327a1 98 debug("channel %d: input open -> drain", c->self);
8efc0c15 99 chan_shutdown_read(c);
5260325f 100 c->istate = CHAN_INPUT_WAIT_DRAIN;
d0c832f3 101 if (buffer_len(&c->input) == 0) {
102 debug("channel %d: input: no drain shortcut", c->self);
103 chan_ibuf_empty(c);
104 }
8efc0c15 105 break;
106 default:
7e7327a1 107 error("channel %d: internal error: we do not read, but chan_read_failed for istate %d",
108 c->self, c->istate);
8efc0c15 109 break;
110 }
111}
7e7327a1 112static void
113chan_ibuf_empty1(Channel *c)
5260325f 114{
7e7327a1 115 debug("channel %d: ibuf empty", c->self);
5260325f 116 if (buffer_len(&c->input)) {
7e7327a1 117 error("channel %d: internal error: chan_ibuf_empty for non empty buffer",
118 c->self);
8efc0c15 119 return;
120 }
5260325f 121 switch (c->istate) {
8efc0c15 122 case CHAN_INPUT_WAIT_DRAIN:
7e7327a1 123 debug("channel %d: input drain -> wait_oclose", c->self);
124 chan_send_ieof1(c);
5260325f 125 c->istate = CHAN_INPUT_WAIT_OCLOSE;
8efc0c15 126 break;
127 default:
7e7327a1 128 error("channel %d: internal error: chan_ibuf_empty for istate %d",
129 c->self, c->istate);
8efc0c15 130 break;
131 }
132}
7e7327a1 133static void
134chan_rcvd_ieof1(Channel *c)
5260325f 135{
7e7327a1 136 debug("channel %d: rcvd ieof", c->self);
1d1ffb87 137 if (c->type != SSH_CHANNEL_OPEN) {
138 debug("channel %d: non-open", c->self);
139 if (c->istate == CHAN_INPUT_OPEN) {
140 debug("channel %d: non-open: input open -> wait_oclose", c->self);
141 chan_shutdown_read(c);
142 chan_send_ieof1(c);
143 c->istate = CHAN_INPUT_WAIT_OCLOSE;
144 } else {
145 error("channel %d: istate %d != open", c->self, c->istate);
146 }
147 if (c->ostate == CHAN_OUTPUT_OPEN) {
148 debug("channel %d: non-open: output open -> closed", c->self);
149 chan_send_oclose1(c);
150 c->ostate = CHAN_OUTPUT_CLOSED;
151 } else {
152 error("channel %d: ostate %d != open", c->self, c->ostate);
153 }
154 return;
155 }
5260325f 156 switch (c->ostate) {
8efc0c15 157 case CHAN_OUTPUT_OPEN:
7e7327a1 158 debug("channel %d: output open -> drain", c->self);
5260325f 159 c->ostate = CHAN_OUTPUT_WAIT_DRAIN;
8efc0c15 160 break;
161 case CHAN_OUTPUT_WAIT_IEOF:
7e7327a1 162 debug("channel %d: output wait_ieof -> closed", c->self);
5260325f 163 c->ostate = CHAN_OUTPUT_CLOSED;
8efc0c15 164 break;
165 default:
7e7327a1 166 error("channel %d: protocol error: chan_rcvd_ieof for ostate %d",
167 c->self, c->ostate);
8efc0c15 168 break;
169 }
170}
7e7327a1 171static void
172chan_write_failed1(Channel *c)
5260325f 173{
7e7327a1 174 debug("channel %d: write failed", c->self);
5260325f 175 switch (c->ostate) {
8efc0c15 176 case CHAN_OUTPUT_OPEN:
7e7327a1 177 debug("channel %d: output open -> wait_ieof", c->self);
178 chan_send_oclose1(c);
5260325f 179 c->ostate = CHAN_OUTPUT_WAIT_IEOF;
8efc0c15 180 break;
181 case CHAN_OUTPUT_WAIT_DRAIN:
7e7327a1 182 debug("channel %d: output wait_drain -> closed", c->self);
183 chan_send_oclose1(c);
5260325f 184 c->ostate = CHAN_OUTPUT_CLOSED;
8efc0c15 185 break;
186 default:
7e7327a1 187 error("channel %d: internal error: chan_write_failed for ostate %d",
188 c->self, c->ostate);
8efc0c15 189 break;
190 }
191}
7e7327a1 192static void
193chan_obuf_empty1(Channel *c)
5260325f 194{
7e7327a1 195 debug("channel %d: obuf empty", c->self);
5260325f 196 if (buffer_len(&c->output)) {
7e7327a1 197 error("channel %d: internal error: chan_obuf_empty for non empty buffer",
198 c->self);
8efc0c15 199 return;
200 }
5260325f 201 switch (c->ostate) {
8efc0c15 202 case CHAN_OUTPUT_WAIT_DRAIN:
7e7327a1 203 debug("channel %d: output drain -> closed", c->self);
204 chan_send_oclose1(c);
5260325f 205 c->ostate = CHAN_OUTPUT_CLOSED;
8efc0c15 206 break;
207 default:
7e7327a1 208 error("channel %d: internal error: chan_obuf_empty for ostate %d",
209 c->self, c->ostate);
8efc0c15 210 break;
211 }
212}
8efc0c15 213static void
7e7327a1 214chan_send_ieof1(Channel *c)
5260325f 215{
7e7327a1 216 debug("channel %d: send ieof", c->self);
5260325f 217 switch (c->istate) {
8efc0c15 218 case CHAN_INPUT_OPEN:
219 case CHAN_INPUT_WAIT_DRAIN:
220 packet_start(SSH_MSG_CHANNEL_INPUT_EOF);
221 packet_put_int(c->remote_id);
222 packet_send();
223 break;
224 default:
7e7327a1 225 error("channel %d: internal error: cannot send ieof for istate %d",
226 c->self, c->istate);
8efc0c15 227 break;
228 }
229}
230static void
7e7327a1 231chan_send_oclose1(Channel *c)
5260325f 232{
7e7327a1 233 debug("channel %d: send oclose", c->self);
5260325f 234 switch (c->ostate) {
8efc0c15 235 case CHAN_OUTPUT_OPEN:
236 case CHAN_OUTPUT_WAIT_DRAIN:
237 chan_shutdown_write(c);
238 buffer_consume(&c->output, buffer_len(&c->output));
239 packet_start(SSH_MSG_CHANNEL_OUTPUT_CLOSE);
240 packet_put_int(c->remote_id);
241 packet_send();
242 break;
243 default:
7e7327a1 244 error("channel %d: internal error: cannot send oclose for ostate %d",
245 c->self, c->ostate);
8efc0c15 246 break;
247 }
248}
5260325f 249
7e7327a1 250/*
251 * the same for SSH2
252 */
8efc0c15 253static void
7e7327a1 254chan_rcvd_oclose2(Channel *c)
5260325f 255{
7e7327a1 256 debug("channel %d: rcvd close", c->self);
257 if (c->flags & CHAN_CLOSE_RCVD)
258 error("channel %d: protocol error: close rcvd twice", c->self);
259 c->flags |= CHAN_CLOSE_RCVD;
260 if (c->type == SSH_CHANNEL_LARVAL) {
261 /* tear down larval channels immediately */
262 c->ostate = CHAN_OUTPUT_CLOSED;
263 c->istate = CHAN_INPUT_CLOSED;
264 return;
265 }
266 switch (c->ostate) {
267 case CHAN_OUTPUT_OPEN:
268 /* wait until a data from the channel is consumed if a CLOSE is received */
269 debug("channel %d: output open -> drain", c->self);
270 c->ostate = CHAN_OUTPUT_WAIT_DRAIN;
271 break;
272 }
273 switch (c->istate) {
274 case CHAN_INPUT_OPEN:
275 debug("channel %d: input open -> closed", c->self);
276 chan_shutdown_read(c);
277 break;
278 case CHAN_INPUT_WAIT_DRAIN:
279 debug("channel %d: input drain -> closed", c->self);
280 chan_send_eof2(c);
281 break;
282 }
283 c->istate = CHAN_INPUT_CLOSED;
8efc0c15 284}
285static void
7e7327a1 286chan_ibuf_empty2(Channel *c)
287{
288 debug("channel %d: ibuf empty", c->self);
289 if (buffer_len(&c->input)) {
290 error("channel %d: internal error: chan_ibuf_empty for non empty buffer",
291 c->self);
292 return;
293 }
294 switch (c->istate) {
295 case CHAN_INPUT_WAIT_DRAIN:
296 debug("channel %d: input drain -> closed", c->self);
297 if (!(c->flags & CHAN_CLOSE_SENT))
298 chan_send_eof2(c);
299 c->istate = CHAN_INPUT_CLOSED;
300 break;
301 default:
302 error("channel %d: internal error: chan_ibuf_empty for istate %d",
303 c->self, c->istate);
304 break;
305 }
306}
307static void
308chan_rcvd_ieof2(Channel *c)
5260325f 309{
7e7327a1 310 debug("channel %d: rcvd eof", c->self);
311 if (c->ostate == CHAN_OUTPUT_OPEN) {
312 debug("channel %d: output open -> drain", c->self);
313 c->ostate = CHAN_OUTPUT_WAIT_DRAIN;
314 }
8efc0c15 315}
7e7327a1 316static void
317chan_write_failed2(Channel *c)
318{
319 debug("channel %d: write failed", c->self);
320 switch (c->ostate) {
321 case CHAN_OUTPUT_OPEN:
322 debug("channel %d: output open -> closed", c->self);
1d1ffb87 323 chan_shutdown_write(c); /* ?? */
7e7327a1 324 c->ostate = CHAN_OUTPUT_CLOSED;
325 break;
326 case CHAN_OUTPUT_WAIT_DRAIN:
327 debug("channel %d: output drain -> closed", c->self);
328 chan_shutdown_write(c);
329 c->ostate = CHAN_OUTPUT_CLOSED;
330 break;
331 default:
332 error("channel %d: internal error: chan_write_failed for ostate %d",
333 c->self, c->ostate);
334 break;
335 }
336}
337static void
338chan_obuf_empty2(Channel *c)
339{
340 debug("channel %d: obuf empty", c->self);
341 if (buffer_len(&c->output)) {
342 error("internal error: chan_obuf_empty %d for non empty buffer",
343 c->self);
344 return;
345 }
346 switch (c->ostate) {
347 case CHAN_OUTPUT_WAIT_DRAIN:
348 debug("channel %d: output drain -> closed", c->self);
349 chan_shutdown_write(c);
350 c->ostate = CHAN_OUTPUT_CLOSED;
351 break;
352 default:
353 error("channel %d: internal error: chan_obuf_empty for ostate %d",
354 c->self, c->ostate);
355 break;
356 }
357}
358static void
359chan_send_eof2(Channel *c)
360{
361 debug("channel %d: send eof", c->self);
362 switch (c->istate) {
363 case CHAN_INPUT_WAIT_DRAIN:
364 packet_start(SSH2_MSG_CHANNEL_EOF);
365 packet_put_int(c->remote_id);
366 packet_send();
367 break;
368 default:
369 error("channel %d: internal error: cannot send eof for istate %d",
370 c->self, c->istate);
371 break;
372 }
373}
374static void
375chan_send_close2(Channel *c)
376{
377 debug("channel %d: send close", c->self);
378 if (c->ostate != CHAN_OUTPUT_CLOSED ||
379 c->istate != CHAN_INPUT_CLOSED) {
380 error("channel %d: internal error: cannot send close for istate/ostate %d/%d",
381 c->self, c->istate, c->ostate);
382 } else if (c->flags & CHAN_CLOSE_SENT) {
383 error("channel %d: internal error: already sent close", c->self);
384 } else {
385 packet_start(SSH2_MSG_CHANNEL_CLOSE);
386 packet_put_int(c->remote_id);
387 packet_send();
388 c->flags |= CHAN_CLOSE_SENT;
389 }
390}
ee55dacf 391
392/* shared */
393
719fc62f 394void
395chan_mark_dead(Channel *c)
396{
397 c->flags |= CHAN_DEAD;
398}
399
ee55dacf 400int
401chan_is_dead(Channel *c)
5260325f 402{
719fc62f 403 if (c->flags & CHAN_DEAD)
404 return 1;
ee55dacf 405 if (c->istate != CHAN_INPUT_CLOSED || c->ostate != CHAN_OUTPUT_CLOSED)
406 return 0;
407 if (!compat20) {
408 debug("channel %d: is dead", c->self);
409 return 1;
410 }
411 /*
412 * we have to delay the close message if the efd (for stderr) is
413 * still active
414 */
415 if (((c->extended_usage != CHAN_EXTENDED_IGNORE) &&
416 buffer_len(&c->extended) > 0)
417#if 0
418 || ((c->extended_usage == CHAN_EXTENDED_READ) &&
419 c->efd != -1)
420#endif
421 ) {
422 debug2("channel %d: active efd: %d len %d type %s",
423 c->self, c->efd, buffer_len(&c->extended),
424 c->extended_usage==CHAN_EXTENDED_READ ?
425 "read": "write");
426 } else {
7e7327a1 427 if (!(c->flags & CHAN_CLOSE_SENT)) {
428 chan_send_close2(c);
429 }
6ae2364d 430 if ((c->flags & CHAN_CLOSE_SENT) &&
7e7327a1 431 (c->flags & CHAN_CLOSE_RCVD)) {
ee55dacf 432 debug("channel %d: is dead", c->self);
433 return 1;
6ae2364d 434 }
8efc0c15 435 }
ee55dacf 436 return 0;
8efc0c15 437}
7e7327a1 438
8efc0c15 439void
5260325f 440chan_init_iostates(Channel *c)
441{
442 c->ostate = CHAN_OUTPUT_OPEN;
443 c->istate = CHAN_INPUT_OPEN;
7e7327a1 444 c->flags = 0;
445}
446
447/* init */
448void
449chan_init(void)
450{
451 if (compat20) {
452 chan_rcvd_oclose = chan_rcvd_oclose2;
453 chan_read_failed = chan_read_failed_12;
454 chan_ibuf_empty = chan_ibuf_empty2;
455
456 chan_rcvd_ieof = chan_rcvd_ieof2;
457 chan_write_failed = chan_write_failed2;
458 chan_obuf_empty = chan_obuf_empty2;
7e7327a1 459 } else {
460 chan_rcvd_oclose = chan_rcvd_oclose1;
461 chan_read_failed = chan_read_failed_12;
462 chan_ibuf_empty = chan_ibuf_empty1;
463
464 chan_rcvd_ieof = chan_rcvd_ieof1;
465 chan_write_failed = chan_write_failed1;
466 chan_obuf_empty = chan_obuf_empty1;
7e7327a1 467 }
468}
469
470/* helper */
471static void
472chan_shutdown_write(Channel *c)
473{
474 buffer_consume(&c->output, buffer_len(&c->output));
475 if (compat20 && c->type == SSH_CHANNEL_LARVAL)
476 return;
477 /* shutdown failure is allowed if write failed already */
478 debug("channel %d: close_write", c->self);
479 if (c->sock != -1) {
480 if (shutdown(c->sock, SHUT_WR) < 0)
481 debug("channel %d: chan_shutdown_write: shutdown() failed for fd%d: %.100s",
482 c->self, c->sock, strerror(errno));
483 } else {
484 if (close(c->wfd) < 0)
485 log("channel %d: chan_shutdown_write: close() failed for fd%d: %.100s",
486 c->self, c->wfd, strerror(errno));
7e7327a1 487 }
488}
489static void
490chan_shutdown_read(Channel *c)
491{
492 if (compat20 && c->type == SSH_CHANNEL_LARVAL)
493 return;
494 debug("channel %d: close_read", c->self);
495 if (c->sock != -1) {
2b87da3b 496 /*
47670e77 497 * shutdown(sock, SHUT_READ) may return ENOTCONN if the
498 * write side has been closed already. (bug on Linux)
fe39c3df 499 * HP-UX will return EINVAL.
47670e77 500 */
501 if (shutdown(c->sock, SHUT_RD) < 0
fe39c3df 502 && (errno != ENOTCONN && errno != EINVAL))
7e7327a1 503 error("channel %d: chan_shutdown_read: shutdown() failed for fd%d [i%d o%d]: %.100s",
504 c->self, c->sock, c->istate, c->ostate, strerror(errno));
505 } else {
506 if (close(c->rfd) < 0)
507 log("channel %d: chan_shutdown_read: close() failed for fd%d: %.100s",
508 c->self, c->rfd, strerror(errno));
7e7327a1 509 }
8efc0c15 510}
This page took 0.182607 seconds and 5 git commands to generate.