Annotation of src/usr.bin/ssh/nchan.c, Revision 1.17
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: * 3. All advertising materials mentioning features or use of this software
13: * must display the following acknowledgement:
14: * This product includes software developed by Markus Friedl.
15: * 4. The name of the author may not be used to endorse or promote products
16: * derived from this software without specific prior written permission.
17: *
18: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
19: * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21: * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
22: * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
23: * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24: * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25: * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
27: * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28: */
29:
1.1 markus 30: #include "includes.h"
1.17 ! markus 31: RCSID("$Id: nchan.c,v 1.17 2000/05/08 17:20:40 markus Exp $");
1.2 markus 32:
1.1 markus 33: #include "ssh.h"
34:
35: #include "buffer.h"
1.3 markus 36: #include "packet.h"
1.1 markus 37: #include "channels.h"
38: #include "nchan.h"
39:
1.13 markus 40: #include "ssh2.h"
41: #include "compat.h"
1.3 markus 42:
1.13 markus 43: /* functions manipulating channel states */
1.3 markus 44: /*
1.6 markus 45: * EVENTS update channel input/output states execute ACTIONS
1.3 markus 46: */
1.13 markus 47: /* events concerning the INPUT from socket for channel (istate) */
48: chan_event_fn *chan_rcvd_oclose = NULL;
49: chan_event_fn *chan_read_failed = NULL;
50: chan_event_fn *chan_ibuf_empty = NULL;
51: /* events concerning the OUTPUT from channel for socket (ostate) */
52: chan_event_fn *chan_rcvd_ieof = NULL;
53: chan_event_fn *chan_write_failed = NULL;
54: chan_event_fn *chan_obuf_empty = NULL;
55: /*
56: * ACTIONS: should never update the channel states
57: */
58: static void chan_send_ieof1(Channel *c);
59: static void chan_send_oclose1(Channel *c);
60: static void chan_send_close2(Channel *c);
61: static void chan_send_eof2(Channel *c);
62:
63: /* channel cleanup */
64: chan_event_fn *chan_delete_if_full_closed = NULL;
65:
66: /* helper */
67: static void chan_shutdown_write(Channel *c);
68: static void chan_shutdown_read(Channel *c);
69:
70: /*
71: * SSH1 specific implementation of event functions
72: */
1.6 markus 73:
1.13 markus 74: static void
75: chan_rcvd_oclose1(Channel *c)
1.6 markus 76: {
1.13 markus 77: debug("channel %d: rcvd oclose", c->self);
1.6 markus 78: switch (c->istate) {
1.3 markus 79: case CHAN_INPUT_WAIT_OCLOSE:
1.13 markus 80: debug("channel %d: input wait_oclose -> closed", c->self);
1.6 markus 81: c->istate = CHAN_INPUT_CLOSED;
1.3 markus 82: break;
83: case CHAN_INPUT_OPEN:
1.13 markus 84: debug("channel %d: input open -> closed", c->self);
1.3 markus 85: chan_shutdown_read(c);
1.13 markus 86: chan_send_ieof1(c);
1.6 markus 87: c->istate = CHAN_INPUT_CLOSED;
1.10 markus 88: break;
89: case CHAN_INPUT_WAIT_DRAIN:
90: /* both local read_failed and remote write_failed */
1.13 markus 91: log("channel %d: input drain -> closed", c->self);
92: chan_send_ieof1(c);
1.10 markus 93: c->istate = CHAN_INPUT_CLOSED;
1.3 markus 94: break;
95: default:
1.13 markus 96: error("channel %d: protocol error: chan_rcvd_oclose for istate %d",
97: c->self, c->istate);
1.10 markus 98: return;
1.3 markus 99: }
1.1 markus 100: }
1.13 markus 101: static void
102: chan_read_failed_12(Channel *c)
1.6 markus 103: {
1.13 markus 104: debug("channel %d: read failed", c->self);
1.6 markus 105: switch (c->istate) {
1.3 markus 106: case CHAN_INPUT_OPEN:
1.13 markus 107: debug("channel %d: input open -> drain", c->self);
1.3 markus 108: chan_shutdown_read(c);
1.6 markus 109: c->istate = CHAN_INPUT_WAIT_DRAIN;
1.17 ! markus 110: if (buffer_len(&c->input) == 0) {
! 111: debug("channel %d: input: no drain shortcut", c->self);
! 112: chan_ibuf_empty(c);
! 113: }
1.3 markus 114: break;
115: default:
1.13 markus 116: error("channel %d: internal error: we do not read, but chan_read_failed for istate %d",
117: c->self, c->istate);
1.3 markus 118: break;
1.1 markus 119: }
120: }
1.13 markus 121: static void
122: chan_ibuf_empty1(Channel *c)
1.6 markus 123: {
1.13 markus 124: debug("channel %d: ibuf empty", c->self);
1.6 markus 125: if (buffer_len(&c->input)) {
1.13 markus 126: error("channel %d: internal error: chan_ibuf_empty for non empty buffer",
127: c->self);
1.3 markus 128: return;
129: }
1.6 markus 130: switch (c->istate) {
1.3 markus 131: case CHAN_INPUT_WAIT_DRAIN:
1.13 markus 132: debug("channel %d: input drain -> wait_oclose", c->self);
133: chan_send_ieof1(c);
1.6 markus 134: c->istate = CHAN_INPUT_WAIT_OCLOSE;
1.3 markus 135: break;
136: default:
1.13 markus 137: error("channel %d: internal error: chan_ibuf_empty for istate %d",
138: c->self, c->istate);
1.3 markus 139: break;
1.1 markus 140: }
141: }
1.13 markus 142: static void
143: chan_rcvd_ieof1(Channel *c)
1.6 markus 144: {
1.13 markus 145: debug("channel %d: rcvd ieof", c->self);
1.16 markus 146: if (c->type != SSH_CHANNEL_OPEN) {
147: debug("channel %d: non-open", c->self);
148: if (c->istate == CHAN_INPUT_OPEN) {
149: debug("channel %d: non-open: input open -> wait_oclose", c->self);
150: chan_shutdown_read(c);
151: chan_send_ieof1(c);
152: c->istate = CHAN_INPUT_WAIT_OCLOSE;
153: } else {
154: error("channel %d: istate %d != open", c->self, c->istate);
155: }
156: if (c->ostate == CHAN_OUTPUT_OPEN) {
157: debug("channel %d: non-open: output open -> closed", c->self);
158: chan_send_oclose1(c);
159: c->ostate = CHAN_OUTPUT_CLOSED;
160: } else {
161: error("channel %d: ostate %d != open", c->self, c->ostate);
162: }
163: return;
164: }
1.6 markus 165: switch (c->ostate) {
1.3 markus 166: case CHAN_OUTPUT_OPEN:
1.13 markus 167: debug("channel %d: output open -> drain", c->self);
1.6 markus 168: c->ostate = CHAN_OUTPUT_WAIT_DRAIN;
1.3 markus 169: break;
170: case CHAN_OUTPUT_WAIT_IEOF:
1.13 markus 171: debug("channel %d: output wait_ieof -> closed", c->self);
1.6 markus 172: c->ostate = CHAN_OUTPUT_CLOSED;
1.3 markus 173: break;
174: default:
1.13 markus 175: error("channel %d: protocol error: chan_rcvd_ieof for ostate %d",
176: c->self, c->ostate);
1.3 markus 177: break;
178: }
179: }
1.13 markus 180: static void
181: chan_write_failed1(Channel *c)
1.6 markus 182: {
1.13 markus 183: debug("channel %d: write failed", c->self);
1.6 markus 184: switch (c->ostate) {
1.3 markus 185: case CHAN_OUTPUT_OPEN:
1.13 markus 186: debug("channel %d: output open -> wait_ieof", c->self);
187: chan_send_oclose1(c);
1.6 markus 188: c->ostate = CHAN_OUTPUT_WAIT_IEOF;
1.3 markus 189: break;
190: case CHAN_OUTPUT_WAIT_DRAIN:
1.13 markus 191: debug("channel %d: output wait_drain -> closed", c->self);
192: chan_send_oclose1(c);
1.6 markus 193: c->ostate = CHAN_OUTPUT_CLOSED;
1.3 markus 194: break;
195: default:
1.13 markus 196: error("channel %d: internal error: chan_write_failed for ostate %d",
197: c->self, c->ostate);
1.3 markus 198: break;
199: }
200: }
1.13 markus 201: static void
202: chan_obuf_empty1(Channel *c)
1.6 markus 203: {
1.13 markus 204: debug("channel %d: obuf empty", c->self);
1.6 markus 205: if (buffer_len(&c->output)) {
1.13 markus 206: error("channel %d: internal error: chan_obuf_empty for non empty buffer",
207: c->self);
1.3 markus 208: return;
209: }
1.6 markus 210: switch (c->ostate) {
1.3 markus 211: case CHAN_OUTPUT_WAIT_DRAIN:
1.13 markus 212: debug("channel %d: output drain -> closed", c->self);
213: chan_send_oclose1(c);
1.6 markus 214: c->ostate = CHAN_OUTPUT_CLOSED;
1.3 markus 215: break;
216: default:
1.13 markus 217: error("channel %d: internal error: chan_obuf_empty for ostate %d",
218: c->self, c->ostate);
1.3 markus 219: break;
220: }
221: }
222: static void
1.13 markus 223: chan_send_ieof1(Channel *c)
1.6 markus 224: {
1.13 markus 225: debug("channel %d: send ieof", c->self);
1.6 markus 226: switch (c->istate) {
1.3 markus 227: case CHAN_INPUT_OPEN:
228: case CHAN_INPUT_WAIT_DRAIN:
229: packet_start(SSH_MSG_CHANNEL_INPUT_EOF);
230: packet_put_int(c->remote_id);
231: packet_send();
232: break;
233: default:
1.13 markus 234: error("channel %d: internal error: cannot send ieof for istate %d",
235: c->self, c->istate);
1.3 markus 236: break;
1.1 markus 237: }
238: }
1.3 markus 239: static void
1.13 markus 240: chan_send_oclose1(Channel *c)
1.6 markus 241: {
1.13 markus 242: debug("channel %d: send oclose", c->self);
1.6 markus 243: switch (c->ostate) {
1.3 markus 244: case CHAN_OUTPUT_OPEN:
245: case CHAN_OUTPUT_WAIT_DRAIN:
246: chan_shutdown_write(c);
247: buffer_consume(&c->output, buffer_len(&c->output));
248: packet_start(SSH_MSG_CHANNEL_OUTPUT_CLOSE);
249: packet_put_int(c->remote_id);
250: packet_send();
251: break;
252: default:
1.13 markus 253: error("channel %d: internal error: cannot send oclose for ostate %d",
254: c->self, c->ostate);
1.3 markus 255: break;
1.1 markus 256: }
257: }
1.13 markus 258: static void
259: chan_delete_if_full_closed1(Channel *c)
260: {
261: if (c->istate == CHAN_INPUT_CLOSED && c->ostate == CHAN_OUTPUT_CLOSED) {
262: debug("channel %d: full closed", c->self);
263: channel_free(c->self);
264: }
265: }
1.6 markus 266:
1.13 markus 267: /*
268: * the same for SSH2
269: */
270: static void
271: chan_rcvd_oclose2(Channel *c)
272: {
273: debug("channel %d: rcvd close", c->self);
274: if (c->flags & CHAN_CLOSE_RCVD)
275: error("channel %d: protocol error: close rcvd twice", c->self);
276: c->flags |= CHAN_CLOSE_RCVD;
277: if (c->type == SSH_CHANNEL_LARVAL) {
278: /* tear down larval channels immediately */
279: c->ostate = CHAN_OUTPUT_CLOSED;
280: c->istate = CHAN_INPUT_CLOSED;
281: return;
282: }
283: switch (c->ostate) {
284: case CHAN_OUTPUT_OPEN:
285: /* wait until a data from the channel is consumed if a CLOSE is received */
286: debug("channel %d: output open -> drain", c->self);
287: c->ostate = CHAN_OUTPUT_WAIT_DRAIN;
288: break;
289: }
290: switch (c->istate) {
291: case CHAN_INPUT_OPEN:
292: debug("channel %d: input open -> closed", c->self);
293: chan_shutdown_read(c);
294: break;
295: case CHAN_INPUT_WAIT_DRAIN:
296: debug("channel %d: input drain -> closed", c->self);
297: chan_send_eof2(c);
298: break;
299: }
300: c->istate = CHAN_INPUT_CLOSED;
301: }
302: static void
303: chan_ibuf_empty2(Channel *c)
304: {
305: debug("channel %d: ibuf empty", c->self);
306: if (buffer_len(&c->input)) {
307: error("channel %d: internal error: chan_ibuf_empty for non empty buffer",
308: c->self);
309: return;
310: }
311: switch (c->istate) {
312: case CHAN_INPUT_WAIT_DRAIN:
313: debug("channel %d: input drain -> closed", c->self);
314: if (!(c->flags & CHAN_CLOSE_SENT))
315: chan_send_eof2(c);
316: c->istate = CHAN_INPUT_CLOSED;
317: break;
318: default:
319: error("channel %d: internal error: chan_ibuf_empty for istate %d",
320: c->self, c->istate);
321: break;
322: }
323: }
324: static void
325: chan_rcvd_ieof2(Channel *c)
326: {
327: debug("channel %d: rcvd eof", c->self);
328: if (c->ostate == CHAN_OUTPUT_OPEN) {
329: debug("channel %d: output open -> drain", c->self);
330: c->ostate = CHAN_OUTPUT_WAIT_DRAIN;
331: }
332: }
333: static void
334: chan_write_failed2(Channel *c)
335: {
336: debug("channel %d: write failed", c->self);
337: switch (c->ostate) {
338: case CHAN_OUTPUT_OPEN:
339: debug("channel %d: output open -> closed", c->self);
1.15 markus 340: chan_shutdown_write(c); /* ?? */
1.13 markus 341: c->ostate = CHAN_OUTPUT_CLOSED;
342: break;
343: case CHAN_OUTPUT_WAIT_DRAIN:
344: debug("channel %d: output drain -> closed", c->self);
345: chan_shutdown_write(c);
346: c->ostate = CHAN_OUTPUT_CLOSED;
347: break;
348: default:
349: error("channel %d: internal error: chan_write_failed for ostate %d",
350: c->self, c->ostate);
351: break;
352: }
353: }
354: static void
355: chan_obuf_empty2(Channel *c)
356: {
357: debug("channel %d: obuf empty", c->self);
358: if (buffer_len(&c->output)) {
359: error("internal error: chan_obuf_empty %d for non empty buffer",
360: c->self);
361: return;
362: }
363: switch (c->ostate) {
364: case CHAN_OUTPUT_WAIT_DRAIN:
365: debug("channel %d: output drain -> closed", c->self);
366: chan_shutdown_write(c);
367: c->ostate = CHAN_OUTPUT_CLOSED;
368: break;
369: default:
370: error("channel %d: internal error: chan_obuf_empty for ostate %d",
371: c->self, c->ostate);
372: break;
373: }
374: }
1.3 markus 375: static void
1.13 markus 376: chan_send_eof2(Channel *c)
1.6 markus 377: {
1.13 markus 378: debug("channel %d: send eof", c->self);
379: switch (c->istate) {
380: case CHAN_INPUT_WAIT_DRAIN:
381: packet_start(SSH2_MSG_CHANNEL_EOF);
382: packet_put_int(c->remote_id);
383: packet_send();
384: break;
385: default:
386: error("channel %d: internal error: cannot send eof for istate %d",
387: c->self, c->istate);
388: break;
389: }
1.1 markus 390: }
1.3 markus 391: static void
1.13 markus 392: chan_send_close2(Channel *c)
1.6 markus 393: {
1.13 markus 394: debug("channel %d: send close", c->self);
395: if (c->ostate != CHAN_OUTPUT_CLOSED ||
396: c->istate != CHAN_INPUT_CLOSED) {
397: error("channel %d: internal error: cannot send close for istate/ostate %d/%d",
398: c->self, c->istate, c->ostate);
399: } else if (c->flags & CHAN_CLOSE_SENT) {
400: error("channel %d: internal error: already sent close", c->self);
401: } else {
402: packet_start(SSH2_MSG_CHANNEL_CLOSE);
403: packet_put_int(c->remote_id);
404: packet_send();
405: c->flags |= CHAN_CLOSE_SENT;
406: }
1.1 markus 407: }
1.13 markus 408: static void
409: chan_delete_if_full_closed2(Channel *c)
1.6 markus 410: {
411: if (c->istate == CHAN_INPUT_CLOSED && c->ostate == CHAN_OUTPUT_CLOSED) {
1.13 markus 412: if (!(c->flags & CHAN_CLOSE_SENT)) {
413: chan_send_close2(c);
414: }
1.14 markus 415: if ((c->flags & CHAN_CLOSE_SENT) &&
1.13 markus 416: (c->flags & CHAN_CLOSE_RCVD)) {
417: debug("channel %d: full closed2", c->self);
418: channel_free(c->self);
1.14 markus 419: }
1.1 markus 420: }
1.3 markus 421: }
1.13 markus 422:
423: /* shared */
1.3 markus 424: void
1.6 markus 425: chan_init_iostates(Channel *c)
426: {
427: c->ostate = CHAN_OUTPUT_OPEN;
428: c->istate = CHAN_INPUT_OPEN;
1.13 markus 429: c->flags = 0;
430: }
431:
432: /* init */
433: void
434: chan_init(void)
435: {
436: if (compat20) {
437: chan_rcvd_oclose = chan_rcvd_oclose2;
438: chan_read_failed = chan_read_failed_12;
439: chan_ibuf_empty = chan_ibuf_empty2;
440:
441: chan_rcvd_ieof = chan_rcvd_ieof2;
442: chan_write_failed = chan_write_failed2;
443: chan_obuf_empty = chan_obuf_empty2;
444:
445: chan_delete_if_full_closed = chan_delete_if_full_closed2;
446: } else {
447: chan_rcvd_oclose = chan_rcvd_oclose1;
448: chan_read_failed = chan_read_failed_12;
449: chan_ibuf_empty = chan_ibuf_empty1;
450:
451: chan_rcvd_ieof = chan_rcvd_ieof1;
452: chan_write_failed = chan_write_failed1;
453: chan_obuf_empty = chan_obuf_empty1;
454:
455: chan_delete_if_full_closed = chan_delete_if_full_closed1;
456: }
457: }
458:
459: /* helper */
460: static void
461: chan_shutdown_write(Channel *c)
462: {
463: buffer_consume(&c->output, buffer_len(&c->output));
464: if (compat20 && c->type == SSH_CHANNEL_LARVAL)
465: return;
466: /* shutdown failure is allowed if write failed already */
467: debug("channel %d: close_write", c->self);
468: if (c->sock != -1) {
469: if (shutdown(c->sock, SHUT_WR) < 0)
470: debug("channel %d: chan_shutdown_write: shutdown() failed for fd%d: %.100s",
471: c->self, c->sock, strerror(errno));
472: } else {
473: if (close(c->wfd) < 0)
474: log("channel %d: chan_shutdown_write: close() failed for fd%d: %.100s",
475: c->self, c->wfd, strerror(errno));
476: c->wfd = -1;
477: }
478: }
479: static void
480: chan_shutdown_read(Channel *c)
481: {
482: if (compat20 && c->type == SSH_CHANNEL_LARVAL)
483: return;
484: debug("channel %d: close_read", c->self);
485: if (c->sock != -1) {
486: if (shutdown(c->sock, SHUT_RD) < 0)
487: error("channel %d: chan_shutdown_read: shutdown() failed for fd%d [i%d o%d]: %.100s",
488: c->self, c->sock, c->istate, c->ostate, strerror(errno));
489: } else {
490: if (close(c->rfd) < 0)
491: log("channel %d: chan_shutdown_read: close() failed for fd%d: %.100s",
492: c->self, c->rfd, strerror(errno));
493: c->rfd = -1;
494: }
1.1 markus 495: }
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