1 /*
2  * Copyright (c) 2022 Stefan Sperling <stsp@openbsd.org>
3  *
4  * Permission to use, copy, modify, and distribute this software for any
5  * purpose with or without fee is hereby granted, provided that the above
6  * copyright notice and this permission notice appear in all copies.
7  *
8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15  */
16 
17 #include <sys/types.h>
18 #include <sys/queue.h>
19 #include <sys/uio.h>
20 
21 #include <errno.h>
22 #include <event.h>
23 #include <poll.h>
24 #include <limits.h>
25 #include <sha1.h>
26 #include <sha2.h>
27 #include <stdio.h>
28 #include <stdint.h>
29 #include <stdlib.h>
30 #include <string.h>
31 #include <imsg.h>
32 #include <unistd.h>
33 
34 #include "got_error.h"
35 #include "got_serve.h"
36 #include "got_path.h"
37 #include "got_version.h"
38 #include "got_reference.h"
39 #include "got_object.h"
40 
41 #include "got_lib_pkt.h"
42 #include "got_lib_dial.h"
43 #include "got_lib_gitproto.h"
44 #include "got_lib_hash.h"
45 #include "got_lib_poll.h"
46 
47 #include "gotd.h"
48 
49 #ifndef nitems
50 #define nitems(_a)	(sizeof((_a)) / sizeof((_a)[0]))
51 #endif
52 
53 static const struct got_capability read_capabilities[] = {
54 	{ GOT_CAPA_AGENT, "got/" GOT_VERSION_STR },
55 	{ GOT_CAPA_OFS_DELTA, NULL },
56 	{ GOT_CAPA_SIDE_BAND_64K, NULL },
57 };
58 
59 static const struct got_capability write_capabilities[] = {
60 	{ GOT_CAPA_AGENT, "got/" GOT_VERSION_STR },
61 	{ GOT_CAPA_OFS_DELTA, NULL },
62 	{ GOT_CAPA_REPORT_STATUS, NULL },
63 	{ GOT_CAPA_NO_THIN, NULL },
64 	{ GOT_CAPA_DELETE_REFS, NULL },
65 };
66 
67 static const struct got_error *
68 append_read_capabilities(size_t *capalen, size_t len, const char *symrefstr,
69     uint8_t *buf, size_t bufsize)
70 {
71 	struct got_capability capa[nitems(read_capabilities) + 1];
72 	size_t ncapa;
73 
74 	memcpy(&capa, read_capabilities, sizeof(read_capabilities));
75 	if (symrefstr) {
76 		capa[nitems(read_capabilities)].key = "symref";
77 		capa[nitems(read_capabilities)].value = symrefstr;
78 		ncapa = nitems(capa);
79 	} else
80 		ncapa = nitems(read_capabilities);
81 
82 	return got_gitproto_append_capabilities(capalen, buf, len,
83 	    bufsize, capa, ncapa);
84 }
85 
86 static const struct got_error *
87 send_ref(int outfd, uint8_t *id, const char *refname, int send_capabilities,
88     int client_is_reading, const char *symrefstr, int chattygot)
89 {
90 	const struct got_error *err = NULL;
91 	char hex[SHA1_DIGEST_STRING_LENGTH];
92 	char buf[GOT_PKT_MAX];
93 	size_t len, capalen = 0;
94 
95 	if (got_sha1_digest_to_str(id, hex, sizeof(hex)) == NULL)
96 		return got_error(GOT_ERR_BAD_OBJ_ID);
97 
98 	len = snprintf(buf, sizeof(buf), "%s %s", hex, refname);
99 	if (len >= sizeof(buf))
100 		return got_error(GOT_ERR_NO_SPACE);
101 
102 	if (send_capabilities) {
103 		if (client_is_reading) {
104 			err = append_read_capabilities(&capalen, len,
105 			    symrefstr, buf, sizeof(buf));
106 		} else {
107 			err = got_gitproto_append_capabilities(&capalen,
108 			    buf, len, sizeof(buf), write_capabilities,
109 			    nitems(write_capabilities));
110 		}
111 		if (err)
112 			return err;
113 		len += capalen;
114 	}
115 
116 	if (len + 1 >= sizeof(buf))
117 		return got_error(GOT_ERR_NO_SPACE);
118 	buf[len] = '\n';
119 	len++;
120 	buf[len] = '\0';
121 
122 	return got_pkt_writepkt(outfd, buf, len, chattygot);
123 }
124 
125 static const struct got_error *
126 send_zero_refs(int outfd, int client_is_reading, int chattygot)
127 {
128 	const struct got_error *err = NULL;
129 	const char *line = GOT_SHA1_STRING_ZERO " capabilities^{}";
130 	char buf[GOT_PKT_MAX];
131 	size_t len, capalen = 0;
132 
133 	len = strlcpy(buf, line, sizeof(buf));
134 	if (len >= sizeof(buf))
135 		return got_error(GOT_ERR_NO_SPACE);
136 
137 	if (client_is_reading) {
138 		err = got_gitproto_append_capabilities(&capalen, buf, len,
139 		    sizeof(buf), read_capabilities, nitems(read_capabilities));
140 		if (err)
141 			return err;
142 	} else {
143 		err = got_gitproto_append_capabilities(&capalen, buf, len,
144 		    sizeof(buf), write_capabilities,
145 		    nitems(write_capabilities));
146 		if (err)
147 			return err;
148 	}
149 
150 	return got_pkt_writepkt(outfd, buf, len + capalen, chattygot);
151 }
152 
153 static void
154 echo_error(const struct got_error *err, int outfd, int chattygot)
155 {
156 	char buf[4 + GOT_ERR_MAX_MSG_SIZE];
157 	size_t len;
158 
159 	/*
160 	 * Echo the error to the client on a pkt-line.
161 	 * The client should then terminate its session.
162 	 */
163 	buf[0] = 'E'; buf[1] = 'R'; buf[2] = 'R'; buf[3] = ' '; buf[4] = '\0';
164 	len = strlcat(buf, err->msg, sizeof(buf));
165 	got_pkt_writepkt(outfd, buf, len, chattygot);
166 }
167 
168 static const struct got_error *
169 announce_refs(int outfd, struct imsgbuf *ibuf, int client_is_reading,
170     const char *repo_path, int chattygot)
171 {
172 	const struct got_error *err = NULL;
173 	struct imsg imsg;
174 	size_t datalen;
175 	struct gotd_imsg_list_refs lsref;
176 	struct gotd_imsg_reflist ireflist;
177 	struct gotd_imsg_ref iref;
178 	struct gotd_imsg_symref isymref;
179 	size_t nrefs = 0;
180 	int have_nrefs = 0, sent_capabilities = 0;
181 	char *symrefname = NULL, *symreftarget = NULL, *symrefstr = NULL;
182 	char *refname = NULL;
183 
184 	memset(&imsg, 0, sizeof(imsg));
185 	memset(&lsref, 0, sizeof(lsref));
186 
187 	if (strlcpy(lsref.repo_name, repo_path, sizeof(lsref.repo_name)) >=
188 	    sizeof(lsref.repo_name))
189 		return got_error(GOT_ERR_NO_SPACE);
190 	lsref.client_is_reading = client_is_reading;
191 
192 	if (imsg_compose(ibuf, GOTD_IMSG_LIST_REFS, 0, 0, -1,
193 	    &lsref, sizeof(lsref)) == -1)
194 		return got_error_from_errno("imsg_compose LIST_REFS");
195 
196 	err = gotd_imsg_flush(ibuf);
197 	if (err)
198 		return err;
199 
200 	while (!have_nrefs || nrefs > 0) {
201 		err = gotd_imsg_poll_recv(&imsg, ibuf, 0);
202 		if (err)
203 			goto done;
204 		datalen = imsg.hdr.len - IMSG_HEADER_SIZE;
205 		switch (imsg.hdr.type) {
206 		case GOTD_IMSG_ERROR:
207 			err = gotd_imsg_recv_error(NULL, &imsg);
208 			goto done;
209 		case GOTD_IMSG_REFLIST:
210 			if (have_nrefs || nrefs > 0) {
211 				err = got_error(GOT_ERR_PRIVSEP_MSG);
212 				goto done;
213 			}
214 			if (datalen != sizeof(ireflist)) {
215 				err = got_error(GOT_ERR_PRIVSEP_MSG);
216 				goto done;
217 			}
218 			memcpy(&ireflist, imsg.data, sizeof(ireflist));
219 			nrefs = ireflist.nrefs;
220 			have_nrefs = 1;
221 			if (nrefs == 0)
222 				err = send_zero_refs(outfd, client_is_reading,
223 				    chattygot);
224 			break;
225 		case GOTD_IMSG_REF:
226 			if (!have_nrefs || nrefs == 0) {
227 				err = got_error(GOT_ERR_PRIVSEP_MSG);
228 				goto done;
229 			}
230 			if (datalen < sizeof(iref)) {
231 				err = got_error(GOT_ERR_PRIVSEP_MSG);
232 				goto done;
233 			}
234 			memcpy(&iref, imsg.data, sizeof(iref));
235 			if (datalen != sizeof(iref) + iref.name_len) {
236 				err = got_error(GOT_ERR_PRIVSEP_LEN);
237 				goto done;
238 			}
239 			refname = strndup(imsg.data + sizeof(iref),
240 			    iref.name_len);
241 			if (refname == NULL) {
242 				err = got_error_from_errno("strndup");
243 				goto done;
244 			}
245 			err = send_ref(outfd, iref.id, refname,
246 			    !sent_capabilities, client_is_reading,
247 			    NULL, chattygot);
248 			free(refname);
249 			refname = NULL;
250 			if (err)
251 				goto done;
252 			sent_capabilities = 1;
253 			if (nrefs > 0)
254 				nrefs--;
255 			break;
256 		case GOTD_IMSG_SYMREF:
257 			if (!have_nrefs || nrefs == 0) {
258 				err = got_error(GOT_ERR_PRIVSEP_MSG);
259 				goto done;
260 			}
261 			if (datalen < sizeof(isymref)) {
262 				err = got_error(GOT_ERR_PRIVSEP_LEN);
263 				goto done;
264 			}
265 			memcpy(&isymref, imsg.data, sizeof(isymref));
266 			if (datalen != sizeof(isymref) + isymref.name_len +
267 			    isymref.target_len) {
268 				err = got_error(GOT_ERR_PRIVSEP_LEN);
269 				goto done;
270 			}
271 
272 			/*
273 			 * For now, we only announce one symbolic ref,
274 			 * as part of our capability advertisement.
275 			 */
276 			if (sent_capabilities || symrefstr != NULL ||
277 			    symrefname != NULL || symreftarget != NULL)
278 				break;
279 
280 			symrefname = strndup(imsg.data + sizeof(isymref),
281 			    isymref.name_len);
282 			if (symrefname == NULL) {
283 				err = got_error_from_errno("malloc");
284 				goto done;
285 			}
286 
287 			symreftarget = strndup(
288 			    imsg.data + sizeof(isymref) + isymref.name_len,
289 			    isymref.target_len);
290 			if (symreftarget == NULL) {
291 				err = got_error_from_errno("strndup");
292 				goto done;
293 			}
294 
295 			if (asprintf(&symrefstr, "%s:%s", symrefname,
296 			    symreftarget) == -1) {
297 				err = got_error_from_errno("asprintf");
298 				goto done;
299 			}
300 			err = send_ref(outfd, isymref.target_id, symrefname,
301 			    !sent_capabilities, client_is_reading, symrefstr,
302 			    chattygot);
303 			free(refname);
304 			refname = NULL;
305 			if (err)
306 				goto done;
307 			sent_capabilities = 1;
308 			if (nrefs > 0)
309 				nrefs--;
310 			break;
311 		default:
312 			err = got_error(GOT_ERR_PRIVSEP_MSG);
313 			break;
314 		}
315 
316 		imsg_free(&imsg);
317 	}
318 
319 	err = got_pkt_flushpkt(outfd, chattygot);
320 	if (err)
321 		goto done;
322 done:
323 	free(symrefstr);
324 	free(symrefname);
325 	free(symreftarget);
326 	return err;
327 }
328 
329 static const struct got_error *
330 parse_want_line(char **common_capabilities, uint8_t *id, char *buf, size_t len)
331 {
332 	const struct got_error *err;
333 	char *id_str = NULL, *client_capabilities = NULL;
334 
335 	err = got_gitproto_parse_want_line(&id_str,
336 	    &client_capabilities, buf, len);
337 	if (err)
338 		return err;
339 
340 	if (!got_parse_hash_digest(id, id_str, GOT_HASH_SHA1)) {
341 		err = got_error_msg(GOT_ERR_BAD_PACKET,
342 		    "want-line with bad object ID");
343 		goto done;
344 	}
345 
346 	if (client_capabilities) {
347 		err = got_gitproto_match_capabilities(common_capabilities,
348 		    NULL, client_capabilities, read_capabilities,
349 		    nitems(read_capabilities));
350 		if (err)
351 			goto done;
352 	}
353 done:
354 	free(id_str);
355 	free(client_capabilities);
356 	return err;
357 }
358 
359 static const struct got_error *
360 parse_have_line(uint8_t *id, char *buf, size_t len)
361 {
362 	const struct got_error *err;
363 	char *id_str = NULL;
364 
365 	err = got_gitproto_parse_have_line(&id_str, buf, len);
366 	if (err)
367 		return err;
368 
369 	if (!got_parse_hash_digest(id, id_str, GOT_HASH_SHA1)) {
370 		err = got_error_msg(GOT_ERR_BAD_PACKET,
371 		    "have-line with bad object ID");
372 		goto done;
373 	}
374 done:
375 	free(id_str);
376 	return err;
377 }
378 
379 static const struct got_error *
380 send_capability(struct got_capability *capa, struct imsgbuf *ibuf)
381 {
382 	const struct got_error *err = NULL;
383 	struct gotd_imsg_capability icapa;
384 	size_t len;
385 	struct ibuf *wbuf;
386 
387 	memset(&icapa, 0, sizeof(icapa));
388 
389 	icapa.key_len = strlen(capa->key);
390 	len = sizeof(icapa) + icapa.key_len;
391 	if (capa->value) {
392 		icapa.value_len = strlen(capa->value);
393 		len += icapa.value_len;
394 	}
395 
396 	wbuf = imsg_create(ibuf, GOTD_IMSG_CAPABILITY, 0, 0, len);
397 	if (wbuf == NULL) {
398 		err = got_error_from_errno("imsg_create CAPABILITY");
399 		return err;
400 	}
401 
402 	if (imsg_add(wbuf, &icapa, sizeof(icapa)) == -1)
403 		return got_error_from_errno("imsg_add CAPABILITY");
404 	if (imsg_add(wbuf, capa->key, icapa.key_len) == -1)
405 		return got_error_from_errno("imsg_add CAPABILITY");
406 	if (capa->value) {
407 		if (imsg_add(wbuf, capa->value, icapa.value_len) == -1)
408 			return got_error_from_errno("imsg_add CAPABILITY");
409 	}
410 
411 	wbuf->fd = -1;
412 	imsg_close(ibuf, wbuf);
413 
414 	return NULL;
415 }
416 
417 static const struct got_error *
418 send_capabilities(int *use_sidebands, int *report_status,
419     char *capabilities_str, struct imsgbuf *ibuf)
420 {
421 	const struct got_error *err = NULL;
422 	struct gotd_imsg_capabilities icapas;
423 	struct got_capability *capa = NULL;
424 	size_t ncapa, i;
425 
426 	err = got_gitproto_split_capabilities_str(&capa, &ncapa,
427 	    capabilities_str);
428 	if (err)
429 		return err;
430 
431 	icapas.ncapabilities = ncapa;
432 	if (imsg_compose(ibuf, GOTD_IMSG_CAPABILITIES, 0, 0, -1,
433 	    &icapas, sizeof(icapas)) == -1) {
434 		err = got_error_from_errno("imsg_compose IMSG_CAPABILITIES");
435 		goto done;
436 	}
437 
438 	for (i = 0; i < ncapa; i++) {
439 		err = send_capability(&capa[i], ibuf);
440 		if (err)
441 			goto done;
442 		if (use_sidebands &&
443 		    strcmp(capa[i].key, GOT_CAPA_SIDE_BAND_64K) == 0)
444 			*use_sidebands = 1;
445 		if (report_status &&
446 		    strcmp(capa[i].key, GOT_CAPA_REPORT_STATUS) == 0)
447 			*report_status = 1;
448 	}
449 done:
450 	free(capa);
451 	return err;
452 }
453 
454 static const struct got_error *
455 forward_flushpkt(struct imsgbuf *ibuf)
456 {
457 	if (imsg_compose(ibuf, GOTD_IMSG_FLUSH, 0, 0, -1, NULL, 0) == -1)
458 		return got_error_from_errno("imsg_compose FLUSH");
459 
460 	return gotd_imsg_flush(ibuf);
461 }
462 
463 static const struct got_error *
464 recv_ack(struct imsg *imsg, uint8_t *expected_id)
465 {
466 	struct gotd_imsg_ack iack;
467 	size_t datalen;
468 
469 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
470 	if (datalen != sizeof(iack))
471 		return got_error(GOT_ERR_PRIVSEP_LEN);
472 
473 	memcpy(&iack, imsg->data, sizeof(iack));
474 	if (memcmp(iack.object_id, expected_id, SHA1_DIGEST_LENGTH) != 0)
475 		return got_error(GOT_ERR_BAD_OBJ_ID);
476 
477 	return NULL;
478 }
479 
480 static const struct got_error *
481 recv_nak(struct imsg *imsg, uint8_t *expected_id)
482 {
483 	struct gotd_imsg_ack inak;
484 	size_t datalen;
485 
486 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
487 	if (datalen != sizeof(inak))
488 		return got_error(GOT_ERR_PRIVSEP_LEN);
489 
490 	memcpy(&inak, imsg->data, sizeof(inak));
491 	if (memcmp(inak.object_id, expected_id, SHA1_DIGEST_LENGTH) != 0)
492 		return got_error(GOT_ERR_BAD_OBJ_ID);
493 
494 	return NULL;
495 }
496 
497 
498 static const struct got_error *
499 recv_want(int *use_sidebands, int outfd, struct imsgbuf *ibuf,
500     char *buf, size_t len, int expect_capabilities, int chattygot)
501 {
502 	const struct got_error *err;
503 	struct gotd_imsg_want iwant;
504 	char *capabilities_str;
505 	int done = 0;
506 	struct imsg imsg;
507 
508 	memset(&iwant, 0, sizeof(iwant));
509 	memset(&imsg, 0, sizeof(imsg));
510 
511 	err = parse_want_line(&capabilities_str, iwant.object_id, buf, len);
512 	if (err)
513 		return err;
514 
515 	if (capabilities_str) {
516 		if (!expect_capabilities) {
517 			err = got_error_msg(GOT_ERR_BAD_PACKET,
518 			    "unexpected capability announcement received");
519 			goto done;
520 		}
521 		err = send_capabilities(use_sidebands, NULL, capabilities_str,
522 		    ibuf);
523 		if (err)
524 			goto done;
525 
526 	}
527 
528 	if (imsg_compose(ibuf, GOTD_IMSG_WANT, 0, 0, -1,
529 	    &iwant, sizeof(iwant)) == -1) {
530 		err = got_error_from_errno("imsg_compose WANT");
531 		goto done;
532 	}
533 
534 	err = gotd_imsg_flush(ibuf);
535 	if (err)
536 		goto done;
537 
538 	/*
539 	 * Wait for an ACK, or an error in case the desired object
540 	 * does not exist.
541 	 */
542 	while (!done && err == NULL) {
543 		err = gotd_imsg_poll_recv(&imsg, ibuf, 0);
544 		if (err)
545 			break;
546 		switch (imsg.hdr.type) {
547 		case GOTD_IMSG_ERROR:
548 			err = gotd_imsg_recv_error(NULL, &imsg);
549 			break;
550 		case GOTD_IMSG_ACK:
551 			err = recv_ack(&imsg, iwant.object_id);
552 			if (err)
553 				break;
554 			done = 1;
555 			break;
556 		default:
557 			err = got_error(GOT_ERR_PRIVSEP_MSG);
558 			break;
559 		}
560 
561 		imsg_free(&imsg);
562 	}
563 done:
564 	free(capabilities_str);
565 	return err;
566 }
567 
568 static const struct got_error *
569 send_ack(int outfd, uint8_t *id, int chattygot)
570 {
571 	char hex[SHA1_DIGEST_STRING_LENGTH];
572 	char buf[GOT_PKT_MAX];
573 	int len;
574 
575 	if (got_sha1_digest_to_str(id, hex, sizeof(hex)) == NULL)
576 		return got_error(GOT_ERR_BAD_OBJ_ID);
577 
578 	len = snprintf(buf, sizeof(buf), "ACK %s\n", hex);
579 	if (len >= sizeof(buf))
580 		return got_error(GOT_ERR_NO_SPACE);
581 
582 	return got_pkt_writepkt(outfd, buf, len, chattygot);
583 }
584 
585 static const struct got_error *
586 send_nak(int outfd, int chattygot)
587 {
588 	char buf[5];
589 	int len;
590 
591 	len = snprintf(buf, sizeof(buf), "NAK\n");
592 	if (len >= sizeof(buf))
593 		return got_error(GOT_ERR_NO_SPACE);
594 
595 	return got_pkt_writepkt(outfd, buf, len, chattygot);
596 }
597 
598 static const struct got_error *
599 recv_have(int *have_ack, int outfd, struct imsgbuf *ibuf, char *buf,
600     size_t len, int chattygot)
601 {
602 	const struct got_error *err;
603 	struct gotd_imsg_have ihave;
604 	int done = 0;
605 	struct imsg imsg;
606 
607 	memset(&ihave, 0, sizeof(ihave));
608 	memset(&imsg, 0, sizeof(imsg));
609 
610 	err = parse_have_line(ihave.object_id, buf, len);
611 	if (err)
612 		return err;
613 
614 	if (imsg_compose(ibuf, GOTD_IMSG_HAVE, 0, 0, -1,
615 	    &ihave, sizeof(ihave)) == -1)
616 		return got_error_from_errno("imsg_compose HAVE");
617 
618 	err = gotd_imsg_flush(ibuf);
619 	if (err)
620 		return err;
621 
622 	/*
623 	 * Wait for an ACK or a NAK, indicating whether a common
624 	 * commit object has been found.
625 	 */
626 	while (!done && err == NULL) {
627 		err = gotd_imsg_poll_recv(&imsg, ibuf, 0);
628 		if (err)
629 			return err;
630 		switch (imsg.hdr.type) {
631 		case GOTD_IMSG_ERROR:
632 			err = gotd_imsg_recv_error(NULL, &imsg);
633 			break;
634 		case GOTD_IMSG_ACK:
635 			err = recv_ack(&imsg, ihave.object_id);
636 			if (err)
637 				break;
638 			if (!*have_ack) {
639 				err = send_ack(outfd, ihave.object_id,
640 				    chattygot);
641 				if (err)
642 					return err;
643 				*have_ack = 1;
644 			}
645 			done = 1;
646 			break;
647 		case GOTD_IMSG_NAK:
648 			err = recv_nak(&imsg, ihave.object_id);
649 			if (err)
650 				break;
651 			done = 1;
652 			break;
653 		default:
654 			err = got_error(GOT_ERR_PRIVSEP_MSG);
655 			break;
656 		}
657 
658 		imsg_free(&imsg);
659 	}
660 
661 	return err;
662 }
663 
664 static const struct got_error *
665 recv_done(int *packfd, int outfd, struct imsgbuf *ibuf, int chattygot)
666 {
667 	const struct got_error *err;
668 	struct imsg imsg;
669 
670 	*packfd = -1;
671 
672 	if (imsg_compose(ibuf, GOTD_IMSG_DONE, 0, 0, -1, NULL, 0) == -1)
673 		return got_error_from_errno("imsg_compose DONE");
674 
675 	err = gotd_imsg_flush(ibuf);
676 	if (err)
677 		return err;
678 
679 	while (*packfd == -1 && err == NULL) {
680 		err = gotd_imsg_poll_recv(&imsg, ibuf, 0);
681 		if (err)
682 			break;
683 
684 		switch (imsg.hdr.type) {
685 		case GOTD_IMSG_ERROR:
686 			err = gotd_imsg_recv_error(NULL, &imsg);
687 			break;
688 		case GOTD_IMSG_PACKFILE_PIPE:
689 			if (imsg.fd != -1)
690 				*packfd = imsg.fd;
691 			else
692 				err = got_error(GOT_ERR_PRIVSEP_NO_FD);
693 			break;
694 		default:
695 			err = got_error(GOT_ERR_PRIVSEP_MSG);
696 			break;
697 		}
698 
699 		imsg_free(&imsg);
700 	}
701 
702 	return err;
703 }
704 
705 static const struct got_error *
706 relay_progress_reports(struct imsgbuf *ibuf, int outfd, int chattygot)
707 {
708 	const struct got_error *err = NULL;
709 	int pack_starting = 0;
710 	struct gotd_imsg_packfile_progress iprog;
711 	char buf[GOT_PKT_MAX];
712 	struct imsg imsg;
713 	size_t datalen;
714 	int p_deltify = 0, n;
715 	const char *eol = "\r";
716 
717 	memset(&imsg, 0, sizeof(imsg));
718 
719 	while (!pack_starting && err == NULL) {
720 		err = gotd_imsg_poll_recv(&imsg, ibuf, 0);
721 		if (err)
722 			break;
723 
724 		datalen = imsg.hdr.len - IMSG_HEADER_SIZE;
725 		switch (imsg.hdr.type) {
726 		case GOTD_IMSG_ERROR:
727 			err = gotd_imsg_recv_error(NULL, &imsg);
728 			break;
729 		case GOTD_IMSG_PACKFILE_READY:
730 			eol = "\n";
731 			pack_starting = 1;
732 			/* fallthrough */
733 		case GOTD_IMSG_PACKFILE_PROGRESS:
734 			if (datalen != sizeof(iprog)) {
735 				err = got_error(GOT_ERR_PRIVSEP_LEN);
736 				break;
737 			}
738 			memcpy(&iprog, imsg.data, sizeof(iprog));
739 			if (iprog.nobj_total > 0) {
740 				p_deltify = (iprog.nobj_deltify * 100) /
741 				    iprog.nobj_total;
742 			}
743 			buf[0] = GOT_SIDEBAND_PROGRESS_INFO;
744 			n = snprintf(&buf[1], sizeof(buf) - 1,
745 			    "%d commits colored, "
746 			    "%d objects found, "
747 			    "deltify %d%%%s",
748 			    iprog.ncolored,
749 			    iprog.nfound,
750 			    p_deltify, eol);
751 			if (n >= sizeof(buf) - 1)
752 				break;
753 			err = got_pkt_writepkt(outfd, buf, 1 + n, chattygot);
754 			break;
755 		default:
756 			err = got_error(GOT_ERR_PRIVSEP_MSG);
757 			break;
758 		}
759 
760 		imsg_free(&imsg);
761 	}
762 
763 	return err;
764 }
765 
766 static const struct got_error *
767 serve_read(int infd, int outfd, int gotd_sock, const char *repo_path,
768     int chattygot)
769 {
770 	const struct got_error *err = NULL;
771 	char buf[GOT_PKT_MAX];
772 	struct imsgbuf ibuf;
773 	enum protostate {
774 		STATE_EXPECT_WANT,
775 		STATE_EXPECT_MORE_WANT,
776 		STATE_EXPECT_HAVE,
777 		STATE_EXPECT_DONE,
778 		STATE_DONE,
779 	};
780 	enum protostate curstate = STATE_EXPECT_WANT;
781 	int have_ack = 0, use_sidebands = 0, seen_have = 0;
782 	int packfd = -1;
783 	size_t pack_chunksize;
784 
785 	imsg_init(&ibuf, gotd_sock);
786 
787 	err = announce_refs(outfd, &ibuf, 1, repo_path, chattygot);
788 	if (err)
789 		goto done;
790 
791 	while (curstate != STATE_DONE) {
792 		int n;
793 		buf[0] = '\0';
794 		err = got_pkt_readpkt(&n, infd, buf, sizeof(buf), chattygot);
795 		if (err)
796 			goto done;
797 		if (n == 0) {
798 			if (curstate != STATE_EXPECT_WANT &&
799 			    curstate != STATE_EXPECT_MORE_WANT &&
800 			    curstate != STATE_EXPECT_HAVE &&
801 			    curstate != STATE_EXPECT_DONE) {
802 				err = got_error_msg(GOT_ERR_BAD_PACKET,
803 				    "unexpected flush packet received");
804 				goto done;
805 			}
806 
807 			if (curstate == STATE_EXPECT_WANT) {
808 				ssize_t r;
809 				/*
810 				 * If the client does not want to fetch
811 				 * anything we should receive a flush
812 				 * packet followed by EOF.
813 				 */
814 				r = read(infd, buf, sizeof(buf));
815 				if (r == -1) {
816 					err = got_error_from_errno("read");
817 					goto done;
818 				}
819 				if (r == 0) /* EOF */
820 					goto done;
821 
822 				/* Zero-length field followed by payload. */
823 				err = got_error_msg(GOT_ERR_BAD_PACKET,
824 				    "unexpected flush packet received");
825 				goto done;
826 			}
827 
828 			if (curstate == STATE_EXPECT_WANT ||
829 			    curstate == STATE_EXPECT_MORE_WANT ||
830 			    curstate == STATE_EXPECT_HAVE) {
831 				err = forward_flushpkt(&ibuf);
832 				if (err)
833 					goto done;
834 			}
835 			if (curstate == STATE_EXPECT_HAVE && !have_ack) {
836 				err = send_nak(outfd, chattygot);
837 				if (err)
838 					goto done;
839 			}
840 			if (curstate == STATE_EXPECT_MORE_WANT)
841 				curstate = STATE_EXPECT_HAVE;
842 			else
843 				curstate = STATE_EXPECT_DONE;
844 		} else if (n >= 5 && strncmp(buf, "want ", 5) == 0) {
845 			if (curstate != STATE_EXPECT_WANT &&
846 			    curstate != STATE_EXPECT_MORE_WANT) {
847 				err = got_error_msg(GOT_ERR_BAD_PACKET,
848 				    "unexpected 'want' packet");
849 				goto done;
850 			}
851 			err = recv_want(&use_sidebands, outfd, &ibuf, buf, n,
852 			    curstate == STATE_EXPECT_WANT ? 1 : 0, chattygot);
853 			if (err)
854 				goto done;
855 			if (curstate == STATE_EXPECT_WANT)
856 				curstate = STATE_EXPECT_MORE_WANT;
857 		} else if (n >= 5 && strncmp(buf, "have ", 5) == 0) {
858 			if (curstate != STATE_EXPECT_HAVE &&
859 			    curstate != STATE_EXPECT_DONE) {
860 				err = got_error_msg(GOT_ERR_BAD_PACKET,
861 				    "unexpected 'have' packet");
862 				goto done;
863 			}
864 			if (curstate == STATE_EXPECT_HAVE) {
865 				err = recv_have(&have_ack, outfd, &ibuf,
866 				    buf, n, chattygot);
867 				if (err)
868 					goto done;
869 				seen_have = 1;
870 			}
871 		} else if (n == 5 && strncmp(buf, "done\n", 5) == 0) {
872 			if (curstate != STATE_EXPECT_HAVE &&
873 			    curstate != STATE_EXPECT_DONE) {
874 				err = got_error_msg(GOT_ERR_BAD_PACKET,
875 				    "unexpected 'done' packet");
876 				goto done;
877 			}
878 			err = recv_done(&packfd, outfd, &ibuf, chattygot);
879 			if (err)
880 				goto done;
881 			curstate = STATE_DONE;
882 			break;
883 		} else {
884 			err = got_error(GOT_ERR_BAD_PACKET);
885 			goto done;
886 		}
887 	}
888 
889 	if (!seen_have) {
890 		err = send_nak(outfd, chattygot);
891 		if (err)
892 			goto done;
893 	}
894 
895 	if (use_sidebands) {
896 		err = relay_progress_reports(&ibuf, outfd, chattygot);
897 		if (err)
898 			goto done;
899 		pack_chunksize = GOT_SIDEBAND_64K_PACKFILE_DATA_MAX;
900 	} else
901 		pack_chunksize = sizeof(buf);
902 
903 	for (;;) {
904 		ssize_t r;
905 
906 		r = read(packfd, use_sidebands ? &buf[1] : buf,
907 		    pack_chunksize);
908 		if (r == -1) {
909 			err = got_error_from_errno("read");
910 			break;
911 		} else if (r == 0) {
912 			err = got_pkt_flushpkt(outfd, chattygot);
913 			break;
914 		}
915 
916 		if (use_sidebands) {
917 			buf[0] = GOT_SIDEBAND_PACKFILE_DATA;
918 			err = got_pkt_writepkt(outfd, buf, 1 + r, chattygot);
919 			if (err)
920 				break;
921 		} else {
922 			err = got_poll_write_full(outfd, buf, r);
923 			if (err) {
924 				if (err->code == GOT_ERR_EOF)
925 					err = NULL;
926 				break;
927 			}
928 		}
929 	}
930 done:
931 	imsg_clear(&ibuf);
932 	if (packfd != -1 && close(packfd) == -1 && err == NULL)
933 		err = got_error_from_errno("close");
934 	if (err)
935 		echo_error(err, outfd, chattygot);
936 	return err;
937 }
938 
939 static const struct got_error *
940 parse_ref_update_line(char **common_capabilities, char **refname,
941     uint8_t *old_id, uint8_t *new_id, char *buf, size_t len)
942 {
943 	const struct got_error *err;
944 	char *old_id_str = NULL, *new_id_str = NULL;
945 	char *client_capabilities = NULL;
946 
947 	*refname = NULL;
948 
949 	err = got_gitproto_parse_ref_update_line(&old_id_str, &new_id_str,
950 	    refname, &client_capabilities, buf, len);
951 	if (err)
952 		return err;
953 
954 	if (!got_parse_hash_digest(old_id, old_id_str, GOT_HASH_SHA1) ||
955 	    !got_parse_hash_digest(new_id, new_id_str, GOT_HASH_SHA1)) {
956 		err = got_error_msg(GOT_ERR_BAD_PACKET,
957 		    "ref-update with bad object ID");
958 		goto done;
959 	}
960 	if (!got_ref_name_is_valid(*refname)) {
961 		err = got_error_msg(GOT_ERR_BAD_PACKET,
962 		    "ref-update with bad reference name");
963 		goto done;
964 	}
965 
966 	if (client_capabilities) {
967 		err = got_gitproto_match_capabilities(common_capabilities,
968 		    NULL, client_capabilities, write_capabilities,
969 		    nitems(write_capabilities));
970 		if (err)
971 			goto done;
972 	}
973 done:
974 	free(old_id_str);
975 	free(new_id_str);
976 	free(client_capabilities);
977 	if (err) {
978 		free(*refname);
979 		*refname = NULL;
980 	}
981 	return err;
982 }
983 
984 static const struct got_error *
985 recv_ref_update(int *report_status, int outfd, struct imsgbuf *ibuf,
986     char *buf, size_t len, int expect_capabilities, int chattygot)
987 {
988 	const struct got_error *err;
989 	struct gotd_imsg_ref_update iref;
990 	struct ibuf *wbuf;
991 	char *capabilities_str = NULL, *refname = NULL;
992 	int done = 0;
993 	struct imsg imsg;
994 
995 	memset(&iref, 0, sizeof(iref));
996 	memset(&imsg, 0, sizeof(imsg));
997 
998 	err = parse_ref_update_line(&capabilities_str, &refname,
999 	    iref.old_id, iref.new_id, buf, len);
1000 	if (err)
1001 		return err;
1002 
1003 	if (capabilities_str) {
1004 		if (!expect_capabilities) {
1005 			err = got_error_msg(GOT_ERR_BAD_PACKET,
1006 			    "unexpected capability announcement received");
1007 			goto done;
1008 		}
1009 		err = send_capabilities(NULL, report_status, capabilities_str,
1010 		    ibuf);
1011 		if (err)
1012 			goto done;
1013 	}
1014 
1015 	iref.name_len = strlen(refname);
1016 	len = sizeof(iref) + iref.name_len;
1017 	wbuf = imsg_create(ibuf, GOTD_IMSG_REF_UPDATE, 0, 0, len);
1018 	if (wbuf == NULL) {
1019 		err = got_error_from_errno("imsg_create REF_UPDATE");
1020 		goto done;
1021 	}
1022 
1023 	if (imsg_add(wbuf, &iref, sizeof(iref)) == -1)
1024 		return got_error_from_errno("imsg_add REF_UPDATE");
1025 	if (imsg_add(wbuf, refname, iref.name_len) == -1)
1026 		return got_error_from_errno("imsg_add REF_UPDATE");
1027 	wbuf->fd = -1;
1028 	imsg_close(ibuf, wbuf);
1029 
1030 	err = gotd_imsg_flush(ibuf);
1031 	if (err)
1032 		goto done;
1033 
1034 	/* Wait for ACK or an error. */
1035 	while (!done && err == NULL) {
1036 		err = gotd_imsg_poll_recv(&imsg, ibuf, 0);
1037 		if (err)
1038 			break;
1039 		switch (imsg.hdr.type) {
1040 		case GOTD_IMSG_ERROR:
1041 			err = gotd_imsg_recv_error(NULL, &imsg);
1042 			break;
1043 		case GOTD_IMSG_ACK:
1044 			err = recv_ack(&imsg, iref.new_id);
1045 			if (err)
1046 				break;
1047 			done = 1;
1048 			break;
1049 		default:
1050 			err = got_error(GOT_ERR_PRIVSEP_MSG);
1051 			break;
1052 		}
1053 
1054 		imsg_free(&imsg);
1055 	}
1056 done:
1057 	free(capabilities_str);
1058 	free(refname);
1059 	return err;
1060 }
1061 
1062 static const struct got_error *
1063 recv_packfile(struct imsg *imsg, int infd)
1064 {
1065 	const struct got_error *err = NULL;
1066 	size_t datalen;
1067 	int packfd;
1068 	char buf[GOT_PKT_MAX];
1069 	int pack_done = 0;
1070 
1071 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
1072 	if (datalen != 0)
1073 		return got_error(GOT_ERR_PRIVSEP_MSG);
1074 
1075 	if (imsg->fd == -1)
1076 		return got_error(GOT_ERR_PRIVSEP_NO_FD);
1077 
1078 	packfd = imsg->fd;
1079 	while (!pack_done) {
1080 		ssize_t r = 0;
1081 
1082 		err = got_poll_fd(infd, POLLIN, 1);
1083 		if (err) {
1084 			if (err->code != GOT_ERR_TIMEOUT)
1085 				break;
1086 			err = NULL;
1087 		} else {
1088 			r = read(infd, buf, sizeof(buf));
1089 			if (r == -1) {
1090 				err = got_error_from_errno("read");
1091 				break;
1092 			}
1093 			if (r == 0) {
1094 				/*
1095 				 * Git clients hang up their side of the
1096 				 * connection after sending the pack file.
1097 				 */
1098 				err = NULL;
1099 				pack_done = 1;
1100 				break;
1101 			}
1102 		}
1103 
1104 		if (r == 0) {
1105 			/* Detect gotd(8) closing the pack pipe when done. */
1106 			err = got_poll_fd(packfd, POLLOUT, 1);
1107 			if (err) {
1108 				if (err->code != GOT_ERR_EOF)
1109 					break;
1110 				err = NULL;
1111 				pack_done = 1;
1112 			}
1113 		} else {
1114 			/* Write pack data and/or detect pipe being closed. */
1115 			err = got_poll_write_full(packfd, buf, r);
1116 			if (err) {
1117 				if (err->code == GOT_ERR_EOF)
1118 					err = NULL;
1119 				break;
1120 			}
1121 		}
1122 	}
1123 
1124 	close(packfd);
1125 	return err;
1126 }
1127 
1128 static const struct got_error *
1129 report_unpack_status(struct imsg *imsg, int outfd, int chattygot)
1130 {
1131 	const struct got_error *err = NULL;
1132 	struct gotd_imsg_packfile_status istatus;
1133 	char buf[GOT_PKT_MAX];
1134 	size_t datalen, len;
1135 	char *reason = NULL;
1136 
1137 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
1138 	if (datalen < sizeof(istatus))
1139 		return got_error(GOT_ERR_PRIVSEP_LEN);
1140 	memcpy(&istatus, imsg->data, sizeof(istatus));
1141 	if (datalen != sizeof(istatus) + istatus.reason_len)
1142 		return got_error(GOT_ERR_PRIVSEP_LEN);
1143 
1144 	reason = strndup(imsg->data + sizeof(istatus), istatus.reason_len);
1145 	if (reason == NULL) {
1146 		err = got_error_from_errno("strndup");
1147 		goto done;
1148 	}
1149 
1150 	if (err == NULL)
1151 		len = snprintf(buf, sizeof(buf), "unpack ok\n");
1152 	else
1153 		len = snprintf(buf, sizeof(buf), "unpack %s\n", reason);
1154 	if (len >= sizeof(buf)) {
1155 		err = got_error(GOT_ERR_NO_SPACE);
1156 		goto done;
1157 	}
1158 
1159 	err = got_pkt_writepkt(outfd, buf, len, chattygot);
1160 done:
1161 	free(reason);
1162 	return err;
1163 }
1164 
1165 static const struct got_error *
1166 recv_ref_update_ok(struct imsg *imsg, int outfd, int chattygot)
1167 {
1168 	const struct got_error *err = NULL;
1169 	struct gotd_imsg_ref_update_ok iok;
1170 	size_t datalen, len;
1171 	char buf[GOT_PKT_MAX];
1172 	char *refname = NULL;
1173 
1174 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
1175 	if (datalen < sizeof(iok))
1176 		return got_error(GOT_ERR_PRIVSEP_LEN);
1177 	memcpy(&iok, imsg->data, sizeof(iok));
1178 	if (datalen != sizeof(iok) + iok.name_len)
1179 		return got_error(GOT_ERR_PRIVSEP_LEN);
1180 
1181 	memcpy(&iok, imsg->data, sizeof(iok));
1182 
1183 	refname = strndup(imsg->data + sizeof(iok), iok.name_len);
1184 	if (refname == NULL)
1185 		return got_error_from_errno("strndup");
1186 
1187 	len = snprintf(buf, sizeof(buf), "ok %s\n", refname);
1188 	if (len >= sizeof(buf)) {
1189 		err = got_error(GOT_ERR_NO_SPACE);
1190 		goto done;
1191 	}
1192 
1193 	err = got_pkt_writepkt(outfd, buf, len, chattygot);
1194 done:
1195 	free(refname);
1196 	return err;
1197 }
1198 
1199 static const struct got_error *
1200 recv_ref_update_ng(struct imsg *imsg, int outfd, int chattygot)
1201 {
1202 	const struct got_error *err = NULL;
1203 	struct gotd_imsg_ref_update_ng ing;
1204 	size_t datalen, len;
1205 	char buf[GOT_PKT_MAX];
1206 	char *refname = NULL, *reason = NULL;
1207 
1208 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
1209 	if (datalen < sizeof(ing))
1210 		return got_error(GOT_ERR_PRIVSEP_LEN);
1211 	memcpy(&ing, imsg->data, sizeof(ing));
1212 	if (datalen != sizeof(ing) + ing.name_len + ing.reason_len)
1213 		return got_error(GOT_ERR_PRIVSEP_LEN);
1214 
1215 	memcpy(&ing, imsg->data, sizeof(ing));
1216 
1217 	refname = strndup(imsg->data + sizeof(ing), ing.name_len);
1218 	if (refname == NULL)
1219 		return got_error_from_errno("strndup");
1220 
1221 	reason = strndup(imsg->data + sizeof(ing) + ing.name_len,
1222 	    ing.reason_len);
1223 	if (reason == NULL) {
1224 		err = got_error_from_errno("strndup");
1225 		goto done;
1226 	}
1227 
1228 	len = snprintf(buf, sizeof(buf), "ng %s %s\n", refname, reason);
1229 	if (len >= sizeof(buf)) {
1230 		err = got_error(GOT_ERR_NO_SPACE);
1231 		goto done;
1232 	}
1233 
1234 	err = got_pkt_writepkt(outfd, buf, len, chattygot);
1235 done:
1236 	free(refname);
1237 	free(reason);
1238 	return err;
1239 }
1240 
1241 static const struct got_error *
1242 serve_write(int infd, int outfd, int gotd_sock, const char *repo_path,
1243     int chattygot)
1244 {
1245 	const struct got_error *err = NULL;
1246 	char buf[GOT_PKT_MAX];
1247 	struct imsgbuf ibuf;
1248 	enum protostate {
1249 		STATE_EXPECT_REF_UPDATE,
1250 		STATE_EXPECT_MORE_REF_UPDATES,
1251 		STATE_EXPECT_PACKFILE,
1252 		STATE_PACKFILE_RECEIVED,
1253 		STATE_REFS_UPDATED,
1254 	};
1255 	enum protostate curstate = STATE_EXPECT_REF_UPDATE;
1256 	struct imsg imsg;
1257 	int report_status = 0;
1258 
1259 	imsg_init(&ibuf, gotd_sock);
1260 	memset(&imsg, 0, sizeof(imsg));
1261 
1262 	err = announce_refs(outfd, &ibuf, 0, repo_path, chattygot);
1263 	if (err)
1264 		goto done;
1265 
1266 	while (curstate != STATE_EXPECT_PACKFILE) {
1267 		int n;
1268 		buf[0] = '\0';
1269 		err = got_pkt_readpkt(&n, infd, buf, sizeof(buf), chattygot);
1270 		if (err)
1271 			goto done;
1272 		if (n == 0) {
1273 			if (curstate != STATE_EXPECT_MORE_REF_UPDATES) {
1274 				err = got_error_msg(GOT_ERR_BAD_PACKET,
1275 				    "unexpected flush packet received");
1276 				goto done;
1277 			}
1278 			err = forward_flushpkt(&ibuf);
1279 			if (err)
1280 				goto done;
1281 			curstate = STATE_EXPECT_PACKFILE;
1282 		} else if (n >= (SHA1_DIGEST_STRING_LENGTH * 2) + 2) {
1283 			if (curstate != STATE_EXPECT_REF_UPDATE &&
1284 			    curstate != STATE_EXPECT_MORE_REF_UPDATES) {
1285 				err = got_error_msg(GOT_ERR_BAD_PACKET,
1286 				    "unexpected ref-update packet");
1287 				goto done;
1288 			}
1289 			if (curstate == STATE_EXPECT_REF_UPDATE) {
1290 				err = recv_ref_update(&report_status,
1291 				    outfd, &ibuf, buf, n, 1, chattygot);
1292 			} else {
1293 				err = recv_ref_update(NULL, outfd, &ibuf,
1294 				    buf, n, 0, chattygot);
1295 			}
1296 			if (err)
1297 				goto done;
1298 			curstate = STATE_EXPECT_MORE_REF_UPDATES;
1299 		} else {
1300 			err = got_error(GOT_ERR_BAD_PACKET);
1301 			goto done;
1302 		}
1303 	}
1304 
1305 	while (curstate != STATE_PACKFILE_RECEIVED) {
1306 		err = gotd_imsg_poll_recv(&imsg, &ibuf, 0);
1307 		if (err)
1308 			goto done;
1309 		switch (imsg.hdr.type) {
1310 		case GOTD_IMSG_ERROR:
1311 			err = gotd_imsg_recv_error(NULL, &imsg);
1312 			goto done;
1313 		case GOTD_IMSG_PACKFILE_PIPE:
1314 			err = recv_packfile(&imsg, infd);
1315 			if (err) {
1316 				if (err->code != GOT_ERR_EOF)
1317 					goto done;
1318 				/*
1319 				 * EOF is reported when the client hangs up,
1320 				 * which can happen with Git clients.
1321 				 * The socket should stay half-open so we
1322 				 * can still send our reports if requested.
1323 				 */
1324 				err = NULL;
1325 			}
1326 			curstate = STATE_PACKFILE_RECEIVED;
1327 			break;
1328 		default:
1329 			err = got_error(GOT_ERR_PRIVSEP_MSG);
1330 			break;
1331 		}
1332 
1333 		imsg_free(&imsg);
1334 		if (err)
1335 			goto done;
1336 	}
1337 
1338 	while (curstate != STATE_REFS_UPDATED && err == NULL) {
1339 		err = gotd_imsg_poll_recv(&imsg, &ibuf, 0);
1340 		if (err)
1341 			break;
1342 		switch (imsg.hdr.type) {
1343 		case GOTD_IMSG_ERROR:
1344 			err = gotd_imsg_recv_error(NULL, &imsg);
1345 			break;
1346 		case GOTD_IMSG_PACKFILE_STATUS:
1347 			if (!report_status)
1348 				break;
1349 			err = report_unpack_status(&imsg, outfd, chattygot);
1350 			break;
1351 		case GOTD_IMSG_REF_UPDATE_OK:
1352 			if (!report_status)
1353 				break;
1354 			err = recv_ref_update_ok(&imsg, outfd, chattygot);
1355 			break;
1356 		case GOTD_IMSG_REF_UPDATE_NG:
1357 			if (!report_status)
1358 				break;
1359 			err = recv_ref_update_ng(&imsg, outfd, chattygot);
1360 			break;
1361 		case GOTD_IMSG_REFS_UPDATED:
1362 			curstate = STATE_REFS_UPDATED;
1363 			err = got_pkt_flushpkt(outfd, chattygot);
1364 			break;
1365 		default:
1366 			err = got_error(GOT_ERR_PRIVSEP_MSG);
1367 			break;
1368 		}
1369 
1370 		imsg_free(&imsg);
1371 	}
1372 done:
1373 	imsg_clear(&ibuf);
1374 	if (err)
1375 		echo_error(err, outfd, chattygot);
1376 	return err;
1377 }
1378 
1379 const struct got_error *
1380 got_serve(int infd, int outfd, const char *command, const char *repo_path,
1381     int gotd_sock, int chattygot)
1382 {
1383 	const struct got_error *err = NULL;
1384 
1385 	if (strcmp(command, GOT_DIAL_CMD_FETCH) == 0)
1386 		err = serve_read(infd, outfd, gotd_sock, repo_path, chattygot);
1387 	else if (strcmp(command, GOT_DIAL_CMD_SEND) == 0)
1388 		err = serve_write(infd, outfd, gotd_sock, repo_path,
1389 		    chattygot);
1390 	else
1391 		err = got_error(GOT_ERR_BAD_PACKET);
1392 
1393 	return err;
1394 }