Annotation of src/usr.bin/ssh/nchan.c, Revision 1.19.2.2
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"
1.19.2.1 jason 26: RCSID("$OpenBSD: nchan.c,v 1.22 2001/01/21 19:05:52 markus Exp $");
1.1 markus 27:
1.19.2.1 jason 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"
1.19.2.1 jason 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: /* channel cleanup */
58: chan_event_fn *chan_delete_if_full_closed = NULL;
59:
60: /* helper */
61: static void chan_shutdown_write(Channel *c);
62: static void chan_shutdown_read(Channel *c);
63:
64: /*
65: * SSH1 specific implementation of event functions
66: */
1.6 markus 67:
1.13 markus 68: static void
69: chan_rcvd_oclose1(Channel *c)
1.6 markus 70: {
1.13 markus 71: debug("channel %d: rcvd oclose", c->self);
1.6 markus 72: switch (c->istate) {
1.3 markus 73: case CHAN_INPUT_WAIT_OCLOSE:
1.13 markus 74: debug("channel %d: input wait_oclose -> closed", c->self);
1.6 markus 75: c->istate = CHAN_INPUT_CLOSED;
1.3 markus 76: break;
77: case CHAN_INPUT_OPEN:
1.13 markus 78: debug("channel %d: input open -> closed", c->self);
1.3 markus 79: chan_shutdown_read(c);
1.13 markus 80: chan_send_ieof1(c);
1.6 markus 81: c->istate = CHAN_INPUT_CLOSED;
1.10 markus 82: break;
83: case CHAN_INPUT_WAIT_DRAIN:
84: /* both local read_failed and remote write_failed */
1.13 markus 85: log("channel %d: input drain -> closed", c->self);
86: chan_send_ieof1(c);
1.10 markus 87: c->istate = CHAN_INPUT_CLOSED;
1.3 markus 88: break;
89: default:
1.13 markus 90: error("channel %d: protocol error: chan_rcvd_oclose for istate %d",
91: c->self, c->istate);
1.10 markus 92: return;
1.3 markus 93: }
1.1 markus 94: }
1.13 markus 95: static void
96: chan_read_failed_12(Channel *c)
1.6 markus 97: {
1.13 markus 98: debug("channel %d: read failed", c->self);
1.6 markus 99: switch (c->istate) {
1.3 markus 100: case CHAN_INPUT_OPEN:
1.13 markus 101: debug("channel %d: input open -> drain", c->self);
1.3 markus 102: chan_shutdown_read(c);
1.6 markus 103: c->istate = CHAN_INPUT_WAIT_DRAIN;
1.17 markus 104: if (buffer_len(&c->input) == 0) {
105: debug("channel %d: input: no drain shortcut", c->self);
106: chan_ibuf_empty(c);
107: }
1.3 markus 108: break;
109: default:
1.13 markus 110: error("channel %d: internal error: we do not read, but chan_read_failed for istate %d",
111: c->self, c->istate);
1.3 markus 112: break;
1.1 markus 113: }
114: }
1.13 markus 115: static void
116: chan_ibuf_empty1(Channel *c)
1.6 markus 117: {
1.13 markus 118: debug("channel %d: ibuf empty", c->self);
1.6 markus 119: if (buffer_len(&c->input)) {
1.13 markus 120: error("channel %d: internal error: chan_ibuf_empty for non empty buffer",
121: c->self);
1.3 markus 122: return;
123: }
1.6 markus 124: switch (c->istate) {
1.3 markus 125: case CHAN_INPUT_WAIT_DRAIN:
1.13 markus 126: debug("channel %d: input drain -> wait_oclose", c->self);
127: chan_send_ieof1(c);
1.6 markus 128: c->istate = CHAN_INPUT_WAIT_OCLOSE;
1.3 markus 129: break;
130: default:
1.13 markus 131: error("channel %d: internal error: chan_ibuf_empty for istate %d",
132: c->self, c->istate);
1.3 markus 133: break;
1.1 markus 134: }
135: }
1.13 markus 136: static void
137: chan_rcvd_ieof1(Channel *c)
1.6 markus 138: {
1.13 markus 139: debug("channel %d: rcvd ieof", c->self);
1.16 markus 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);
145: chan_send_ieof1(c);
146: c->istate = CHAN_INPUT_WAIT_OCLOSE;
147: } else {
148: error("channel %d: istate %d != open", c->self, c->istate);
149: }
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;
154: } else {
155: error("channel %d: ostate %d != open", c->self, c->ostate);
156: }
157: return;
158: }
1.6 markus 159: switch (c->ostate) {
1.3 markus 160: case CHAN_OUTPUT_OPEN:
1.13 markus 161: debug("channel %d: output open -> drain", c->self);
1.6 markus 162: c->ostate = CHAN_OUTPUT_WAIT_DRAIN;
1.3 markus 163: break;
164: case CHAN_OUTPUT_WAIT_IEOF:
1.13 markus 165: debug("channel %d: output wait_ieof -> closed", c->self);
1.6 markus 166: c->ostate = CHAN_OUTPUT_CLOSED;
1.3 markus 167: break;
168: default:
1.13 markus 169: error("channel %d: protocol error: chan_rcvd_ieof for ostate %d",
170: c->self, c->ostate);
1.3 markus 171: break;
172: }
173: }
1.13 markus 174: static void
175: chan_write_failed1(Channel *c)
1.6 markus 176: {
1.13 markus 177: debug("channel %d: write failed", c->self);
1.6 markus 178: switch (c->ostate) {
1.3 markus 179: case CHAN_OUTPUT_OPEN:
1.13 markus 180: debug("channel %d: output open -> wait_ieof", c->self);
181: chan_send_oclose1(c);
1.6 markus 182: c->ostate = CHAN_OUTPUT_WAIT_IEOF;
1.3 markus 183: break;
184: case CHAN_OUTPUT_WAIT_DRAIN:
1.13 markus 185: debug("channel %d: output wait_drain -> closed", c->self);
186: chan_send_oclose1(c);
1.6 markus 187: c->ostate = CHAN_OUTPUT_CLOSED;
1.3 markus 188: break;
189: default:
1.13 markus 190: error("channel %d: internal error: chan_write_failed for ostate %d",
191: c->self, c->ostate);
1.3 markus 192: break;
193: }
194: }
1.13 markus 195: static void
196: chan_obuf_empty1(Channel *c)
1.6 markus 197: {
1.13 markus 198: debug("channel %d: obuf empty", c->self);
1.6 markus 199: if (buffer_len(&c->output)) {
1.13 markus 200: error("channel %d: internal error: chan_obuf_empty for non empty buffer",
201: c->self);
1.3 markus 202: return;
203: }
1.6 markus 204: switch (c->ostate) {
1.3 markus 205: case CHAN_OUTPUT_WAIT_DRAIN:
1.13 markus 206: debug("channel %d: output drain -> closed", c->self);
207: chan_send_oclose1(c);
1.6 markus 208: c->ostate = CHAN_OUTPUT_CLOSED;
1.3 markus 209: break;
210: default:
1.13 markus 211: error("channel %d: internal error: chan_obuf_empty for ostate %d",
212: c->self, c->ostate);
1.3 markus 213: break;
214: }
215: }
216: static void
1.13 markus 217: chan_send_ieof1(Channel *c)
1.6 markus 218: {
1.13 markus 219: debug("channel %d: send ieof", c->self);
1.6 markus 220: switch (c->istate) {
1.3 markus 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);
225: packet_send();
226: break;
227: default:
1.13 markus 228: error("channel %d: internal error: cannot send ieof for istate %d",
229: c->self, c->istate);
1.3 markus 230: break;
1.1 markus 231: }
232: }
1.3 markus 233: static void
1.13 markus 234: chan_send_oclose1(Channel *c)
1.6 markus 235: {
1.13 markus 236: debug("channel %d: send oclose", c->self);
1.6 markus 237: switch (c->ostate) {
1.3 markus 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);
244: packet_send();
245: break;
246: default:
1.13 markus 247: error("channel %d: internal error: cannot send oclose for ostate %d",
248: c->self, c->ostate);
1.3 markus 249: break;
1.1 markus 250: }
251: }
1.13 markus 252: static void
253: chan_delete_if_full_closed1(Channel *c)
254: {
1.19.2.1 jason 255: debug3("channel %d: chan_delete_if_full_closed1: istate %d ostate %d",
256: c->self, c->istate, c->ostate);
1.13 markus 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);
260: }
261: }
1.6 markus 262:
1.13 markus 263: /*
264: * the same for SSH2
265: */
266: static void
267: chan_rcvd_oclose2(Channel *c)
268: {
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;
277: return;
278: }
279: switch (c->ostate) {
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;
284: break;
285: }
286: switch (c->istate) {
287: case CHAN_INPUT_OPEN:
288: debug("channel %d: input open -> closed", c->self);
289: chan_shutdown_read(c);
290: break;
291: case CHAN_INPUT_WAIT_DRAIN:
292: debug("channel %d: input drain -> closed", c->self);
293: chan_send_eof2(c);
294: break;
295: }
296: c->istate = CHAN_INPUT_CLOSED;
297: }
298: static void
299: chan_ibuf_empty2(Channel *c)
300: {
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",
304: c->self);
305: return;
306: }
307: switch (c->istate) {
308: case CHAN_INPUT_WAIT_DRAIN:
309: debug("channel %d: input drain -> closed", c->self);
310: if (!(c->flags & CHAN_CLOSE_SENT))
311: chan_send_eof2(c);
312: c->istate = CHAN_INPUT_CLOSED;
313: break;
314: default:
315: error("channel %d: internal error: chan_ibuf_empty for istate %d",
316: c->self, c->istate);
317: break;
318: }
319: }
320: static void
321: chan_rcvd_ieof2(Channel *c)
322: {
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;
327: }
328: }
329: static void
330: chan_write_failed2(Channel *c)
331: {
332: debug("channel %d: write failed", c->self);
333: switch (c->ostate) {
334: case CHAN_OUTPUT_OPEN:
335: debug("channel %d: output open -> closed", c->self);
1.15 markus 336: chan_shutdown_write(c); /* ?? */
1.13 markus 337: c->ostate = CHAN_OUTPUT_CLOSED;
338: break;
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;
343: break;
344: default:
345: error("channel %d: internal error: chan_write_failed for ostate %d",
346: c->self, c->ostate);
347: break;
348: }
349: }
350: static void
351: chan_obuf_empty2(Channel *c)
352: {
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",
356: c->self);
357: return;
358: }
359: switch (c->ostate) {
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;
364: break;
365: default:
366: error("channel %d: internal error: chan_obuf_empty for ostate %d",
367: c->self, c->ostate);
368: break;
369: }
370: }
1.3 markus 371: static void
1.13 markus 372: chan_send_eof2(Channel *c)
1.6 markus 373: {
1.13 markus 374: debug("channel %d: send eof", c->self);
375: switch (c->istate) {
376: case CHAN_INPUT_WAIT_DRAIN:
377: packet_start(SSH2_MSG_CHANNEL_EOF);
378: packet_put_int(c->remote_id);
379: packet_send();
380: break;
381: default:
382: error("channel %d: internal error: cannot send eof for istate %d",
383: c->self, c->istate);
384: break;
385: }
1.1 markus 386: }
1.3 markus 387: static void
1.13 markus 388: chan_send_close2(Channel *c)
1.6 markus 389: {
1.13 markus 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);
397: } else {
398: packet_start(SSH2_MSG_CHANNEL_CLOSE);
399: packet_put_int(c->remote_id);
400: packet_send();
401: c->flags |= CHAN_CLOSE_SENT;
402: }
1.1 markus 403: }
1.13 markus 404: static void
405: chan_delete_if_full_closed2(Channel *c)
1.6 markus 406: {
1.19.2.1 jason 407: debug3("channel %d: chan_delete_if_full_closed2: istate %d ostate %d",
408: c->self, c->istate, c->ostate);
1.6 markus 409: if (c->istate == CHAN_INPUT_CLOSED && c->ostate == CHAN_OUTPUT_CLOSED) {
1.13 markus 410: if (!(c->flags & CHAN_CLOSE_SENT)) {
411: chan_send_close2(c);
412: }
1.14 markus 413: if ((c->flags & CHAN_CLOSE_SENT) &&
1.13 markus 414: (c->flags & CHAN_CLOSE_RCVD)) {
415: debug("channel %d: full closed2", c->self);
416: channel_free(c->self);
1.14 markus 417: }
1.1 markus 418: }
1.3 markus 419: }
1.13 markus 420:
421: /* shared */
1.3 markus 422: void
1.6 markus 423: chan_init_iostates(Channel *c)
424: {
425: c->ostate = CHAN_OUTPUT_OPEN;
426: c->istate = CHAN_INPUT_OPEN;
1.13 markus 427: c->flags = 0;
428: }
429:
430: /* init */
431: void
432: chan_init(void)
433: {
434: if (compat20) {
435: chan_rcvd_oclose = chan_rcvd_oclose2;
436: chan_read_failed = chan_read_failed_12;
437: chan_ibuf_empty = chan_ibuf_empty2;
438:
439: chan_rcvd_ieof = chan_rcvd_ieof2;
440: chan_write_failed = chan_write_failed2;
441: chan_obuf_empty = chan_obuf_empty2;
442:
443: chan_delete_if_full_closed = chan_delete_if_full_closed2;
444: } else {
445: chan_rcvd_oclose = chan_rcvd_oclose1;
446: chan_read_failed = chan_read_failed_12;
447: chan_ibuf_empty = chan_ibuf_empty1;
448:
449: chan_rcvd_ieof = chan_rcvd_ieof1;
450: chan_write_failed = chan_write_failed1;
451: chan_obuf_empty = chan_obuf_empty1;
452:
453: chan_delete_if_full_closed = chan_delete_if_full_closed1;
454: }
455: }
456:
457: /* helper */
458: static void
459: chan_shutdown_write(Channel *c)
460: {
461: buffer_consume(&c->output, buffer_len(&c->output));
462: if (compat20 && c->type == SSH_CHANNEL_LARVAL)
463: return;
464: /* shutdown failure is allowed if write failed already */
465: debug("channel %d: close_write", c->self);
466: if (c->sock != -1) {
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));
470: } else {
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));
474: c->wfd = -1;
475: }
476: }
477: static void
478: chan_shutdown_read(Channel *c)
479: {
480: if (compat20 && c->type == SSH_CHANNEL_LARVAL)
481: return;
482: debug("channel %d: close_read", c->self);
483: if (c->sock != -1) {
484: if (shutdown(c->sock, SHUT_RD) < 0)
485: error("channel %d: chan_shutdown_read: shutdown() failed for fd%d [i%d o%d]: %.100s",
486: c->self, c->sock, c->istate, c->ostate, strerror(errno));
487: } else {
488: if (close(c->rfd) < 0)
489: log("channel %d: chan_shutdown_read: close() failed for fd%d: %.100s",
490: c->self, c->rfd, strerror(errno));
491: c->rfd = -1;
492: }
1.1 markus 493: }