Annotation of src/usr.bin/ssh/nchan.c, Revision 1.24
1.7 markus 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:
1.1 markus 25: #include "includes.h"
1.24 ! markus 26: RCSID("$OpenBSD: nchan.c,v 1.23 2001/02/28 08:54:55 markus Exp $");
1.1 markus 27:
1.22 markus 28: #include "ssh1.h"
29: #include "ssh2.h"
1.1 markus 30: #include "buffer.h"
1.3 markus 31: #include "packet.h"
1.1 markus 32: #include "channels.h"
33: #include "nchan.h"
1.13 markus 34: #include "compat.h"
1.22 markus 35: #include "log.h"
1.3 markus 36:
1.13 markus 37: /* functions manipulating channel states */
1.3 markus 38: /*
1.6 markus 39: * EVENTS update channel input/output states execute ACTIONS
1.3 markus 40: */
1.13 markus 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: /* helper */
58: static void chan_shutdown_write(Channel *c);
59: static void chan_shutdown_read(Channel *c);
60:
61: /*
62: * SSH1 specific implementation of event functions
63: */
1.6 markus 64:
1.13 markus 65: static void
66: chan_rcvd_oclose1(Channel *c)
1.6 markus 67: {
1.13 markus 68: debug("channel %d: rcvd oclose", c->self);
1.6 markus 69: switch (c->istate) {
1.3 markus 70: case CHAN_INPUT_WAIT_OCLOSE:
1.13 markus 71: debug("channel %d: input wait_oclose -> closed", c->self);
1.6 markus 72: c->istate = CHAN_INPUT_CLOSED;
1.3 markus 73: break;
74: case CHAN_INPUT_OPEN:
1.13 markus 75: debug("channel %d: input open -> closed", c->self);
1.3 markus 76: chan_shutdown_read(c);
1.13 markus 77: chan_send_ieof1(c);
1.6 markus 78: c->istate = CHAN_INPUT_CLOSED;
1.10 markus 79: break;
80: case CHAN_INPUT_WAIT_DRAIN:
81: /* both local read_failed and remote write_failed */
1.13 markus 82: log("channel %d: input drain -> closed", c->self);
83: chan_send_ieof1(c);
1.10 markus 84: c->istate = CHAN_INPUT_CLOSED;
1.3 markus 85: break;
86: default:
1.13 markus 87: error("channel %d: protocol error: chan_rcvd_oclose for istate %d",
88: c->self, c->istate);
1.10 markus 89: return;
1.3 markus 90: }
1.1 markus 91: }
1.13 markus 92: static void
93: chan_read_failed_12(Channel *c)
1.6 markus 94: {
1.13 markus 95: debug("channel %d: read failed", c->self);
1.6 markus 96: switch (c->istate) {
1.3 markus 97: case CHAN_INPUT_OPEN:
1.13 markus 98: debug("channel %d: input open -> drain", c->self);
1.3 markus 99: chan_shutdown_read(c);
1.6 markus 100: c->istate = CHAN_INPUT_WAIT_DRAIN;
1.17 markus 101: if (buffer_len(&c->input) == 0) {
102: debug("channel %d: input: no drain shortcut", c->self);
103: chan_ibuf_empty(c);
104: }
1.3 markus 105: break;
106: default:
1.13 markus 107: error("channel %d: internal error: we do not read, but chan_read_failed for istate %d",
108: c->self, c->istate);
1.3 markus 109: break;
1.1 markus 110: }
111: }
1.13 markus 112: static void
113: chan_ibuf_empty1(Channel *c)
1.6 markus 114: {
1.13 markus 115: debug("channel %d: ibuf empty", c->self);
1.6 markus 116: if (buffer_len(&c->input)) {
1.13 markus 117: error("channel %d: internal error: chan_ibuf_empty for non empty buffer",
118: c->self);
1.3 markus 119: return;
120: }
1.6 markus 121: switch (c->istate) {
1.3 markus 122: case CHAN_INPUT_WAIT_DRAIN:
1.13 markus 123: debug("channel %d: input drain -> wait_oclose", c->self);
124: chan_send_ieof1(c);
1.6 markus 125: c->istate = CHAN_INPUT_WAIT_OCLOSE;
1.3 markus 126: break;
127: default:
1.13 markus 128: error("channel %d: internal error: chan_ibuf_empty for istate %d",
129: c->self, c->istate);
1.3 markus 130: break;
1.1 markus 131: }
132: }
1.13 markus 133: static void
134: chan_rcvd_ieof1(Channel *c)
1.6 markus 135: {
1.13 markus 136: debug("channel %d: rcvd ieof", c->self);
1.16 markus 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: }
1.6 markus 156: switch (c->ostate) {
1.3 markus 157: case CHAN_OUTPUT_OPEN:
1.13 markus 158: debug("channel %d: output open -> drain", c->self);
1.6 markus 159: c->ostate = CHAN_OUTPUT_WAIT_DRAIN;
1.3 markus 160: break;
161: case CHAN_OUTPUT_WAIT_IEOF:
1.13 markus 162: debug("channel %d: output wait_ieof -> closed", c->self);
1.6 markus 163: c->ostate = CHAN_OUTPUT_CLOSED;
1.3 markus 164: break;
165: default:
1.13 markus 166: error("channel %d: protocol error: chan_rcvd_ieof for ostate %d",
167: c->self, c->ostate);
1.3 markus 168: break;
169: }
170: }
1.13 markus 171: static void
172: chan_write_failed1(Channel *c)
1.6 markus 173: {
1.13 markus 174: debug("channel %d: write failed", c->self);
1.6 markus 175: switch (c->ostate) {
1.3 markus 176: case CHAN_OUTPUT_OPEN:
1.13 markus 177: debug("channel %d: output open -> wait_ieof", c->self);
178: chan_send_oclose1(c);
1.6 markus 179: c->ostate = CHAN_OUTPUT_WAIT_IEOF;
1.3 markus 180: break;
181: case CHAN_OUTPUT_WAIT_DRAIN:
1.13 markus 182: debug("channel %d: output wait_drain -> closed", c->self);
183: chan_send_oclose1(c);
1.6 markus 184: c->ostate = CHAN_OUTPUT_CLOSED;
1.3 markus 185: break;
186: default:
1.13 markus 187: error("channel %d: internal error: chan_write_failed for ostate %d",
188: c->self, c->ostate);
1.3 markus 189: break;
190: }
191: }
1.13 markus 192: static void
193: chan_obuf_empty1(Channel *c)
1.6 markus 194: {
1.13 markus 195: debug("channel %d: obuf empty", c->self);
1.6 markus 196: if (buffer_len(&c->output)) {
1.13 markus 197: error("channel %d: internal error: chan_obuf_empty for non empty buffer",
198: c->self);
1.3 markus 199: return;
200: }
1.6 markus 201: switch (c->ostate) {
1.3 markus 202: case CHAN_OUTPUT_WAIT_DRAIN:
1.13 markus 203: debug("channel %d: output drain -> closed", c->self);
204: chan_send_oclose1(c);
1.6 markus 205: c->ostate = CHAN_OUTPUT_CLOSED;
1.3 markus 206: break;
207: default:
1.13 markus 208: error("channel %d: internal error: chan_obuf_empty for ostate %d",
209: c->self, c->ostate);
1.3 markus 210: break;
211: }
212: }
213: static void
1.13 markus 214: chan_send_ieof1(Channel *c)
1.6 markus 215: {
1.13 markus 216: debug("channel %d: send ieof", c->self);
1.6 markus 217: switch (c->istate) {
1.3 markus 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:
1.13 markus 225: error("channel %d: internal error: cannot send ieof for istate %d",
226: c->self, c->istate);
1.3 markus 227: break;
1.1 markus 228: }
229: }
1.3 markus 230: static void
1.13 markus 231: chan_send_oclose1(Channel *c)
1.6 markus 232: {
1.13 markus 233: debug("channel %d: send oclose", c->self);
1.6 markus 234: switch (c->ostate) {
1.3 markus 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:
1.13 markus 244: error("channel %d: internal error: cannot send oclose for ostate %d",
245: c->self, c->ostate);
1.3 markus 246: break;
1.1 markus 247: }
248: }
1.6 markus 249:
1.13 markus 250: /*
251: * the same for SSH2
252: */
253: static void
254: chan_rcvd_oclose2(Channel *c)
255: {
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;
284: }
285: static void
286: chan_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: }
307: static void
308: chan_rcvd_ieof2(Channel *c)
309: {
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: }
315: }
316: static void
317: chan_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);
1.15 markus 323: chan_shutdown_write(c); /* ?? */
1.13 markus 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: }
337: static void
338: chan_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: }
1.3 markus 358: static void
1.13 markus 359: chan_send_eof2(Channel *c)
1.6 markus 360: {
1.13 markus 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: }
1.1 markus 373: }
1.3 markus 374: static void
1.13 markus 375: chan_send_close2(Channel *c)
1.6 markus 376: {
1.13 markus 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: }
1.1 markus 390: }
1.23 markus 391:
392: /* shared */
393:
1.24 ! markus 394: void
! 395: chan_mark_dead(Channel *c)
! 396: {
! 397: c->flags |= CHAN_DEAD;
! 398: }
! 399:
1.23 markus 400: int
401: chan_is_dead(Channel *c)
1.6 markus 402: {
1.24 ! markus 403: if (c->flags & CHAN_DEAD)
! 404: return 1;
1.23 markus 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 {
1.13 markus 427: if (!(c->flags & CHAN_CLOSE_SENT)) {
428: chan_send_close2(c);
429: }
1.14 markus 430: if ((c->flags & CHAN_CLOSE_SENT) &&
1.13 markus 431: (c->flags & CHAN_CLOSE_RCVD)) {
1.23 markus 432: debug("channel %d: is dead", c->self);
433: return 1;
1.14 markus 434: }
1.1 markus 435: }
1.23 markus 436: return 0;
1.3 markus 437: }
1.13 markus 438:
1.3 markus 439: void
1.6 markus 440: chan_init_iostates(Channel *c)
441: {
442: c->ostate = CHAN_OUTPUT_OPEN;
443: c->istate = CHAN_INPUT_OPEN;
1.13 markus 444: c->flags = 0;
445: }
446:
447: /* init */
448: void
449: chan_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;
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;
467: }
468: }
469:
470: /* helper */
471: static void
472: chan_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));
487: c->wfd = -1;
488: }
489: }
490: static void
491: chan_shutdown_read(Channel *c)
492: {
493: if (compat20 && c->type == SSH_CHANNEL_LARVAL)
494: return;
495: debug("channel %d: close_read", c->self);
496: if (c->sock != -1) {
497: if (shutdown(c->sock, SHUT_RD) < 0)
498: error("channel %d: chan_shutdown_read: shutdown() failed for fd%d [i%d o%d]: %.100s",
499: c->self, c->sock, c->istate, c->ostate, strerror(errno));
500: } else {
501: if (close(c->rfd) < 0)
502: log("channel %d: chan_shutdown_read: close() failed for fd%d: %.100s",
503: c->self, c->rfd, strerror(errno));
504: c->rfd = -1;
505: }
1.1 markus 506: }
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