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 1.19 2000/09/07 20:27:52 deraadt Exp $");
38 /* functions manipulating channel states */
40 * EVENTS update channel input/output states execute ACTIONS
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;
51 * ACTIONS: should never update the channel states
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);
59 chan_event_fn *chan_delete_if_full_closed = NULL;
62 static void chan_shutdown_write(Channel *c);
63 static void chan_shutdown_read(Channel *c);
66 * SSH1 specific implementation of event functions
70 chan_rcvd_oclose1(Channel *c)
72 debug("channel %d: rcvd oclose", c->self);
74 case CHAN_INPUT_WAIT_OCLOSE:
75 debug("channel %d: input wait_oclose -> closed", c->self);
76 c->istate = CHAN_INPUT_CLOSED;
79 debug("channel %d: input open -> closed", c->self);
80 chan_shutdown_read(c);
82 c->istate = CHAN_INPUT_CLOSED;
84 case CHAN_INPUT_WAIT_DRAIN:
85 /* both local read_failed and remote write_failed */
86 log("channel %d: input drain -> closed", c->self);
88 c->istate = CHAN_INPUT_CLOSED;
91 error("channel %d: protocol error: chan_rcvd_oclose for istate %d",
97 chan_read_failed_12(Channel *c)
99 debug("channel %d: read failed", c->self);
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);
111 error("channel %d: internal error: we do not read, but chan_read_failed for istate %d",
117 chan_ibuf_empty1(Channel *c)
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",
126 case CHAN_INPUT_WAIT_DRAIN:
127 debug("channel %d: input drain -> wait_oclose", c->self);
129 c->istate = CHAN_INPUT_WAIT_OCLOSE;
132 error("channel %d: internal error: chan_ibuf_empty for istate %d",
138 chan_rcvd_ieof1(Channel *c)
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);
147 c->istate = CHAN_INPUT_WAIT_OCLOSE;
149 error("channel %d: istate %d != open", c->self, c->istate);
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;
156 error("channel %d: ostate %d != open", c->self, c->ostate);
161 case CHAN_OUTPUT_OPEN:
162 debug("channel %d: output open -> drain", c->self);
163 c->ostate = CHAN_OUTPUT_WAIT_DRAIN;
165 case CHAN_OUTPUT_WAIT_IEOF:
166 debug("channel %d: output wait_ieof -> closed", c->self);
167 c->ostate = CHAN_OUTPUT_CLOSED;
170 error("channel %d: protocol error: chan_rcvd_ieof for ostate %d",
176 chan_write_failed1(Channel *c)
178 debug("channel %d: write failed", c->self);
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;
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;
191 error("channel %d: internal error: chan_write_failed for ostate %d",
197 chan_obuf_empty1(Channel *c)
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",
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;
212 error("channel %d: internal error: chan_obuf_empty for ostate %d",
218 chan_send_ieof1(Channel *c)
220 debug("channel %d: send ieof", c->self);
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);
229 error("channel %d: internal error: cannot send ieof for istate %d",
235 chan_send_oclose1(Channel *c)
237 debug("channel %d: send oclose", c->self);
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);
248 error("channel %d: internal error: cannot send oclose for ostate %d",
254 chan_delete_if_full_closed1(Channel *c)
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);
266 chan_rcvd_oclose2(Channel *c)
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;
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;
286 case CHAN_INPUT_OPEN:
287 debug("channel %d: input open -> closed", c->self);
288 chan_shutdown_read(c);
290 case CHAN_INPUT_WAIT_DRAIN:
291 debug("channel %d: input drain -> closed", c->self);
295 c->istate = CHAN_INPUT_CLOSED;
298 chan_ibuf_empty2(Channel *c)
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",
307 case CHAN_INPUT_WAIT_DRAIN:
308 debug("channel %d: input drain -> closed", c->self);
309 if (!(c->flags & CHAN_CLOSE_SENT))
311 c->istate = CHAN_INPUT_CLOSED;
314 error("channel %d: internal error: chan_ibuf_empty for istate %d",
320 chan_rcvd_ieof2(Channel *c)
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;
329 chan_write_failed2(Channel *c)
331 debug("channel %d: write failed", c->self);
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;
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;
344 error("channel %d: internal error: chan_write_failed for ostate %d",
350 chan_obuf_empty2(Channel *c)
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",
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;
365 error("channel %d: internal error: chan_obuf_empty for ostate %d",
371 chan_send_eof2(Channel *c)
373 debug("channel %d: send eof", c->self);
375 case CHAN_INPUT_WAIT_DRAIN:
376 packet_start(SSH2_MSG_CHANNEL_EOF);
377 packet_put_int(c->remote_id);
381 error("channel %d: internal error: cannot send eof for istate %d",
387 chan_send_close2(Channel *c)
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);
397 packet_start(SSH2_MSG_CHANNEL_CLOSE);
398 packet_put_int(c->remote_id);
400 c->flags |= CHAN_CLOSE_SENT;
404 chan_delete_if_full_closed2(Channel *c)
406 if (c->istate == CHAN_INPUT_CLOSED && c->ostate == CHAN_OUTPUT_CLOSED) {
407 if (!(c->flags & CHAN_CLOSE_SENT)) {
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);
420 chan_init_iostates(Channel *c)
422 c->ostate = CHAN_OUTPUT_OPEN;
423 c->istate = CHAN_INPUT_OPEN;
432 chan_rcvd_oclose = chan_rcvd_oclose2;
433 chan_read_failed = chan_read_failed_12;
434 chan_ibuf_empty = chan_ibuf_empty2;
436 chan_rcvd_ieof = chan_rcvd_ieof2;
437 chan_write_failed = chan_write_failed2;
438 chan_obuf_empty = chan_obuf_empty2;
440 chan_delete_if_full_closed = chan_delete_if_full_closed2;
442 chan_rcvd_oclose = chan_rcvd_oclose1;
443 chan_read_failed = chan_read_failed_12;
444 chan_ibuf_empty = chan_ibuf_empty1;
446 chan_rcvd_ieof = chan_rcvd_ieof1;
447 chan_write_failed = chan_write_failed1;
448 chan_obuf_empty = chan_obuf_empty1;
450 chan_delete_if_full_closed = chan_delete_if_full_closed1;
456 chan_shutdown_write(Channel *c)
458 buffer_consume(&c->output, buffer_len(&c->output));
459 if (compat20 && c->type == SSH_CHANNEL_LARVAL)
461 /* shutdown failure is allowed if write failed already */
462 debug("channel %d: close_write", c->self);
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));
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));
475 chan_shutdown_read(Channel *c)
477 if (compat20 && c->type == SSH_CHANNEL_LARVAL)
479 debug("channel %d: close_read", c->self);
482 * shutdown(sock, SHUT_READ) may return ENOTCONN if the
483 * write side has been closed already. (bug on Linux)
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));
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));