2 * Copyright (c) 1999 Markus Friedl. All rights reserved.
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
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.
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.
26 RCSID("$OpenBSD: nchan.c,v 1.22 2001/01/21 19:05:52 markus Exp $");
37 /* functions manipulating channel states */
39 * EVENTS update channel input/output states execute ACTIONS
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;
50 * ACTIONS: should never update the channel states
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);
58 chan_event_fn *chan_delete_if_full_closed = NULL;
61 static void chan_shutdown_write(Channel *c);
62 static void chan_shutdown_read(Channel *c);
65 * SSH1 specific implementation of event functions
69 chan_rcvd_oclose1(Channel *c)
71 debug("channel %d: rcvd oclose", c->self);
73 case CHAN_INPUT_WAIT_OCLOSE:
74 debug("channel %d: input wait_oclose -> closed", c->self);
75 c->istate = CHAN_INPUT_CLOSED;
78 debug("channel %d: input open -> closed", c->self);
79 chan_shutdown_read(c);
81 c->istate = CHAN_INPUT_CLOSED;
83 case CHAN_INPUT_WAIT_DRAIN:
84 /* both local read_failed and remote write_failed */
85 log("channel %d: input drain -> closed", c->self);
87 c->istate = CHAN_INPUT_CLOSED;
90 error("channel %d: protocol error: chan_rcvd_oclose for istate %d",
96 chan_read_failed_12(Channel *c)
98 debug("channel %d: read failed", c->self);
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);
110 error("channel %d: internal error: we do not read, but chan_read_failed for istate %d",
116 chan_ibuf_empty1(Channel *c)
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",
125 case CHAN_INPUT_WAIT_DRAIN:
126 debug("channel %d: input drain -> wait_oclose", c->self);
128 c->istate = CHAN_INPUT_WAIT_OCLOSE;
131 error("channel %d: internal error: chan_ibuf_empty for istate %d",
137 chan_rcvd_ieof1(Channel *c)
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);
146 c->istate = CHAN_INPUT_WAIT_OCLOSE;
148 error("channel %d: istate %d != open", c->self, c->istate);
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;
155 error("channel %d: ostate %d != open", c->self, c->ostate);
160 case CHAN_OUTPUT_OPEN:
161 debug("channel %d: output open -> drain", c->self);
162 c->ostate = CHAN_OUTPUT_WAIT_DRAIN;
164 case CHAN_OUTPUT_WAIT_IEOF:
165 debug("channel %d: output wait_ieof -> closed", c->self);
166 c->ostate = CHAN_OUTPUT_CLOSED;
169 error("channel %d: protocol error: chan_rcvd_ieof for ostate %d",
175 chan_write_failed1(Channel *c)
177 debug("channel %d: write failed", c->self);
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;
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;
190 error("channel %d: internal error: chan_write_failed for ostate %d",
196 chan_obuf_empty1(Channel *c)
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",
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;
211 error("channel %d: internal error: chan_obuf_empty for ostate %d",
217 chan_send_ieof1(Channel *c)
219 debug("channel %d: send ieof", c->self);
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);
228 error("channel %d: internal error: cannot send ieof for istate %d",
234 chan_send_oclose1(Channel *c)
236 debug("channel %d: send oclose", c->self);
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);
247 error("channel %d: internal error: cannot send oclose for ostate %d",
253 chan_delete_if_full_closed1(Channel *c)
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);
267 chan_rcvd_oclose2(Channel *c)
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;
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;
287 case CHAN_INPUT_OPEN:
288 debug("channel %d: input open -> closed", c->self);
289 chan_shutdown_read(c);
291 case CHAN_INPUT_WAIT_DRAIN:
292 debug("channel %d: input drain -> closed", c->self);
296 c->istate = CHAN_INPUT_CLOSED;
299 chan_ibuf_empty2(Channel *c)
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",
308 case CHAN_INPUT_WAIT_DRAIN:
309 debug("channel %d: input drain -> closed", c->self);
310 if (!(c->flags & CHAN_CLOSE_SENT))
312 c->istate = CHAN_INPUT_CLOSED;
315 error("channel %d: internal error: chan_ibuf_empty for istate %d",
321 chan_rcvd_ieof2(Channel *c)
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;
330 chan_write_failed2(Channel *c)
332 debug("channel %d: write failed", c->self);
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;
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;
345 error("channel %d: internal error: chan_write_failed for ostate %d",
351 chan_obuf_empty2(Channel *c)
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",
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;
366 error("channel %d: internal error: chan_obuf_empty for ostate %d",
372 chan_send_eof2(Channel *c)
374 debug("channel %d: send eof", c->self);
376 case CHAN_INPUT_WAIT_DRAIN:
377 packet_start(SSH2_MSG_CHANNEL_EOF);
378 packet_put_int(c->remote_id);
382 error("channel %d: internal error: cannot send eof for istate %d",
388 chan_send_close2(Channel *c)
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);
398 packet_start(SSH2_MSG_CHANNEL_CLOSE);
399 packet_put_int(c->remote_id);
401 c->flags |= CHAN_CLOSE_SENT;
405 chan_delete_if_full_closed2(Channel *c)
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)) {
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);
423 chan_init_iostates(Channel *c)
425 c->ostate = CHAN_OUTPUT_OPEN;
426 c->istate = CHAN_INPUT_OPEN;
435 chan_rcvd_oclose = chan_rcvd_oclose2;
436 chan_read_failed = chan_read_failed_12;
437 chan_ibuf_empty = chan_ibuf_empty2;
439 chan_rcvd_ieof = chan_rcvd_ieof2;
440 chan_write_failed = chan_write_failed2;
441 chan_obuf_empty = chan_obuf_empty2;
443 chan_delete_if_full_closed = chan_delete_if_full_closed2;
445 chan_rcvd_oclose = chan_rcvd_oclose1;
446 chan_read_failed = chan_read_failed_12;
447 chan_ibuf_empty = chan_ibuf_empty1;
449 chan_rcvd_ieof = chan_rcvd_ieof1;
450 chan_write_failed = chan_write_failed1;
451 chan_obuf_empty = chan_obuf_empty1;
453 chan_delete_if_full_closed = chan_delete_if_full_closed1;
459 chan_shutdown_write(Channel *c)
461 buffer_consume(&c->output, buffer_len(&c->output));
462 if (compat20 && c->type == SSH_CHANNEL_LARVAL)
464 /* shutdown failure is allowed if write failed already */
465 debug("channel %d: close_write", c->self);
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));
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));
478 chan_shutdown_read(Channel *c)
480 if (compat20 && c->type == SSH_CHANNEL_LARVAL)
482 debug("channel %d: close_read", c->self);
485 * shutdown(sock, SHUT_READ) may return ENOTCONN if the
486 * write side has been closed already. (bug on Linux)
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));
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));