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Date:: Wed Mar 18 16:13:46 2020 UTC
Message:: waste less time on sending progress messages over the privsep pipe
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1 /*
2  * Copyright (c) 2019 Ori Bernstein <ori@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 #include <sys/time.h>
21 #include <sys/stat.h>
22 #include <sys/syslimits.h>
23 
24 #include <stdint.h>
25 #include <errno.h>
26 #include <imsg.h>
27 #include <limits.h>
28 #include <signal.h>
29 #include <stdio.h>
30 #include <stdlib.h>
31 #include <string.h>
32 #include <ctype.h>
33 #include <sha1.h>
34 #include <fcntl.h>
35 #include <zlib.h>
36 #include <err.h>
37 
38 #include "got_error.h"
39 #include "got_object.h"
40 #include "got_path.h"
41 #include "got_version.h"
42 
43 #include "got_lib_sha1.h"
44 #include "got_lib_delta.h"
45 #include "got_lib_object.h"
46 #include "got_lib_object_parse.h"
47 #include "got_lib_privsep.h"
48 #include "got_lib_pack.h"
49 
50 #ifndef nitems
51 #define nitems(_a)	(sizeof((_a)) / sizeof((_a)[0]))
52 #endif
53 
54 #define GOT_PKTMAX	65536
55 
56 struct got_object *indexed;
57 static int chattygit;
58 static char *fetchbranch;
59 static struct got_object_id zhash = {.sha1={0}};
60 
61 static const struct got_error *
62 readn(ssize_t *off, int fd, void *buf, size_t n)
63 {
64 	ssize_t r;
65 
66 	*off = 0;
67 	while (*off != n) {
68 		r = read(fd, buf + *off, n - *off);
69 		if (r == -1)
70 			return got_error_from_errno("read");
71 		if (r == 0)
72 			return NULL;
73 		*off += r;
74 	}
75 	return NULL;
76 }
77 
78 static const struct got_error *
79 flushpkt(int fd)
80 {
81 	ssize_t w;
82 
83 	if (chattygit)
84 		fprintf(stderr, "writepkt: 0000\n");
85 
86 	 w = write(fd, "0000", 4);
87 	 if (w == -1)
88 		return got_error_from_errno("write");
89 	if (w != 4)
90 		return got_error(GOT_ERR_IO);
91 	return NULL;
92 }
93 
94 /*
95  * Packet header contains a 4-byte hexstring which specifies the length
96  * of data which follows.
97  */
98 static const struct got_error *
99 read_pkthdr(int *datalen, int fd)
100 {
101 	static const struct got_error *err = NULL;
102 	char lenstr[5];
103 	long len;
104 	char *e;
105 	int n, i;
106 	ssize_t r;
107 
108 	*datalen = 0;
109 
110 	err = readn(&r, fd, lenstr, 4);
111 	if (err)
112 		return err;
113 	if (r == 0) /* implicit "0000" */
114 		return NULL;
115 	if (r != 4)
116 		return got_error_msg(GOT_ERR_BAD_PACKET,
117 		    "wrong packet header length");
118 
119 	lenstr[4] = '\0';
120 	for (i = 0; i < 4; i++) {
121 		if (!isxdigit(lenstr[i]))
122 			return got_error_msg(GOT_ERR_BAD_PACKET,
123 			    "packet length not specified in hex");
124 	}
125 	errno = 0;
126 	len = strtol(lenstr, &e, 16);
127 	if (lenstr[0] == '\0' || *e != '\0')
128 		return got_error(GOT_ERR_BAD_PACKET);
129 	if (errno == ERANGE && (len == LONG_MAX || len == LONG_MIN))
130 		return got_error_msg(GOT_ERR_BAD_PACKET, "bad packet length");
131 	if (len > INT_MAX || len < INT_MIN)
132 		return got_error_msg(GOT_ERR_BAD_PACKET, "bad packet length");
133 	n = len;
134 	if (n == 0)
135 		return NULL;
136 	if (n <= 4)
137 		return got_error_msg(GOT_ERR_BAD_PACKET, "packet too short");
138 	n  -= 4;
139 
140 	*datalen = n;
141 	return NULL;
142 }
143 
144 static const struct got_error *
145 readpkt(int *outlen, int fd, char *buf, int buflen)
146 {
147 	const struct got_error *err = NULL;
148 	int datalen;
149 	ssize_t n;
150 
151 	err = read_pkthdr(&datalen, fd);
152 	if (err)
153 		return err;
154 
155 	if (datalen > buflen)
156 		return got_error(GOT_ERR_NO_SPACE);
157 
158 	err = readn(&n, fd, buf, datalen);
159 	if (err)
160 		return err;
161 	if (n != datalen)
162 		return got_error_msg(GOT_ERR_BAD_PACKET, "short packet");
163 
164 	*outlen = n;
165 	return NULL;
166 }
167 
168 static const struct got_error *
169 writepkt(int fd, char *buf, int nbuf)
170 {
171 	char len[5];
172 	int i;
173 	ssize_t w;
174 
175 	if (snprintf(len, sizeof(len), "%04x", nbuf + 4) >= sizeof(len))
176 		return got_error(GOT_ERR_NO_SPACE);
177 	w = write(fd, len, 4);
178 	if (w == -1)
179 		return got_error_from_errno("write");
180 	if (w != 4)
181 		return got_error(GOT_ERR_IO);
182 	w = write(fd, buf, nbuf);
183 	if (w == -1)
184 		return got_error_from_errno("write");
185 	if (w != nbuf)
186 		return got_error(GOT_ERR_IO);
187 	if (chattygit) {
188 		fprintf(stderr, "writepkt: %s:\t", len);
189 		fwrite(buf, 1, nbuf, stderr);
190 		for (i = 0; i < nbuf; i++) {
191 			if (isprint(buf[i]))
192 				fputc(buf[i], stderr);
193 		}
194 		fputc('\n', stderr);
195 	}
196 	return NULL;
197 }
198 
199 static const struct got_error *
200 match_remote_ref(struct got_pathlist_head *have_refs, struct got_object_id *id,
201     char *refname, char *id_str)
202 {
203 	struct got_pathlist_entry *pe;
204 
205 	memset(id, 0, sizeof(*id));
206 
207 	TAILQ_FOREACH(pe, have_refs, entry) {
208 		if (strcmp(pe->path, refname) == 0) {
209 			if (!got_parse_sha1_digest(id->sha1, id_str))
210 				return got_error(GOT_ERR_BAD_OBJ_ID_STR);
211 			break;
212 		}
213 	}
214 	return NULL;
215 }
216 
217 static int
218 match_branch(char *br, char *pat)
219 {
220 	char name[128];
221 
222 	if (strstr(pat, "refs/heads") == pat) {
223 		if (snprintf(name, sizeof(name), "%s", pat) >= sizeof(name))
224 			return -1;
225 	} else if (strstr(pat, "heads")) {
226 		if (snprintf(name, sizeof(name), "refs/%s", pat)
227 		    >= sizeof(name))
228 			return -1;
229 	} else {
230 		if (snprintf(name, sizeof(name), "refs/heads/%s", pat)
231 		    >= sizeof(name))
232 			return -1;
233 	}
234 	return strcmp(br, name) == 0;
235 }
236 
237 static const struct got_error *
238 tokenize_refline(char **tokens, char *line, int len, int maxtokens)
239 {
240 	const struct got_error *err = NULL;
241 	char *p;
242 	size_t i, n = 0;
243 
244 	for (i = 0; i < maxtokens; i++)
245 		tokens[i] = NULL;
246 
247 	for (i = 0; n < len && i < maxtokens; i++) {
248 		while (isspace(*line)) {
249 			line++;
250 			n++;
251 		}
252 		p = line;
253 		while (*line != '\0' &&
254 		    (!isspace(*line) || i == maxtokens - 1)) {
255 			line++;
256 			n++;
257 		}
258 		tokens[i] = strndup(p, line - p);
259 		if (tokens[i] == NULL) {
260 			err = got_error_from_errno("strndup");
261 			goto done;
262 		}
263 		/* Skip \0 field-delimiter at end of token. */
264 		while (line[0] == '\0' && n < len) {
265 			line++;
266 			n++;
267 		}
268 	}
269 	if (i <= 2)
270 		err = got_error(GOT_ERR_NOT_REF);
271 done:
272 	if (err) {
273 		int j;
274 		for (j = 0; j < i; j++)
275 			free(tokens[j]);
276 			tokens[j] = NULL;
277 	}
278 	return err;
279 }
280 
281 static const struct got_error *
282 parse_refline(char **id_str, char **refname, char **server_capabilities,
283     char *line, int len)
284 {
285 	const struct got_error *err = NULL;
286 	char *tokens[3];
287 
288 	err = tokenize_refline(tokens, line, len, nitems(tokens));
289 	if (err)
290 		return err;
291 
292 	if (tokens[0])
293 		*id_str = tokens[0];
294 	if (tokens[1])
295 		*refname = tokens[1];
296 	if (tokens[2])
297 		*server_capabilities = tokens[2];
298 	
299 	return NULL;
300 }
301 
302 #define GOT_CAPA_AGENT			"agent"
303 #define GOT_CAPA_OFS_DELTA		"ofs-delta"
304 #define GOT_CAPA_SIDE_BAND_64K		"side-band-64k"
305 
306 #define GOT_SIDEBAND_PACKFILE_DATA	1
307 #define GOT_SIDEBAND_PROGRESS_INFO	2
308 #define GOT_SIDEBAND_ERROR_INFO		3
309 
310 
311 struct got_capability {
312 	const char *key;
313 	const char *value;
314 };
315 static const struct got_capability got_capabilities[] = {
316 	{ GOT_CAPA_AGENT, "got/" GOT_VERSION_STR },
317 	{ GOT_CAPA_OFS_DELTA, NULL },
318 	{ GOT_CAPA_SIDE_BAND_64K, NULL },
319 };
320 
321 static const struct got_error *
322 match_capability(char **my_capabilities, const char *capa,
323     const struct got_capability *mycapa)
324 {
325 	char *equalsign;
326 	char *s;
327 
328 	equalsign = strchr(capa, '=');
329 	if (equalsign) {
330 		if (strncmp(capa, mycapa->key, equalsign - capa) != 0)
331 			return NULL;
332 	} else {
333 		if (strcmp(capa, mycapa->key) != 0)
334 			return NULL;
335 	}
336 
337 	if (asprintf(&s, "%s%s%s%s%s",
338 	    *my_capabilities != NULL ? *my_capabilities : "",
339 	    *my_capabilities != NULL ? " " : "",
340 	    mycapa->key,
341 	    mycapa->value != NULL ? "=" : "",
342 	    mycapa->value != NULL? mycapa->value : "") == -1)
343 		return got_error_from_errno("asprintf");
344 
345 	free(*my_capabilities);
346 	*my_capabilities = s;
347 	return NULL;
348 }
349 
350 static const struct got_error *
351 add_symref(struct got_pathlist_head *symrefs, char *capa)
352 {
353 	const struct got_error *err = NULL;
354 	char *colon, *name = NULL, *target = NULL;
355 
356 	/* Need at least "A:B" */
357 	if (strlen(capa) < 3)
358 		return NULL;
359 
360 	colon = strchr(capa, ':');
361 	if (colon == NULL)
362 		return NULL;
363 
364 	*colon = '\0';
365 	name = strdup(capa);
366 	if (name == NULL)
367 		return got_error_from_errno("strdup");
368 
369 	target = strdup(colon + 1);
370 	if (target == NULL) {
371 		err = got_error_from_errno("strdup");
372 		goto done;
373 	}
374 
375 	/* We can't validate the ref itself here. The main process will. */
376 	err = got_pathlist_append(symrefs, name, target);
377 done:
378 	if (err) {
379 		free(name);
380 		free(target);
381 	}
382 	return err;
383 }
384 
385 static const struct got_error *
386 match_capabilities(char **my_capabilities, struct got_pathlist_head *symrefs,
387     char *server_capabilities)
388 {
389 	const struct got_error *err = NULL;
390 	char *capa, *equalsign;
391 	int i;
392 
393 	*my_capabilities = NULL;
394 	do {
395 		capa = strsep(&server_capabilities, " ");
396 		if (capa == NULL)
397 			return NULL;
398 
399 		equalsign = strchr(capa, '=');
400 		if (equalsign != NULL &&
401 		    strncmp(capa, "symref", equalsign - capa) == 0) {
402 			err = add_symref(symrefs, equalsign + 1);
403 			if (err)
404 				break;
405 			continue;
406 		}
407 
408 		for (i = 0; i < nitems(got_capabilities); i++) {
409 			err = match_capability(my_capabilities,
410 			    capa, &got_capabilities[i]);
411 			if (err)
412 				break;
413 		}
414 	} while (capa);
415 
416 	return err;
417 }
418 
419 static const struct got_error *
420 fetch_progress(struct imsgbuf *ibuf, const char *buf, size_t len)
421 {
422 	int i;
423 
424 	if (len == 0)
425 		return NULL;
426 
427 	/*
428 	 * Truncate messages which exceed the maximum imsg payload size.
429 	 * Server may send up to 64k.
430 	 */
431 	if (len > MAX_IMSGSIZE - IMSG_HEADER_SIZE)
432 		len = MAX_IMSGSIZE - IMSG_HEADER_SIZE;
433 
434 	/* Only allow printable ASCII. */
435 	for (i = 0; i < len; i++) {
436 		if (isprint((unsigned char)buf[i]) ||
437 		    isspace((unsigned char)buf[i]))
438 			continue;
439 		return got_error_msg(GOT_ERR_BAD_PACKET,
440 		    "non-printable progress message received from server");
441 	}
442 
443 	return got_privsep_send_fetch_server_progress(ibuf, buf, len);
444 }
445 
446 static const struct got_error *
447 fetch_error(const char *buf, size_t len)
448 {
449 	static char msg[1024];
450 	int i;
451 
452 	for (i = 0; i < len && i < sizeof(msg) - 1; i++) {
453 		if (!isprint(buf[i]))
454 			return got_error_msg(GOT_ERR_BAD_PACKET,
455 			    "non-printable error message received from server");
456 		msg[i] = buf[i];
457 	}
458 	msg[i] = '\0';
459 	return got_error_msg(GOT_ERR_FETCH_FAILED, msg);
460 }
461 
462 static const struct got_error *
463 fetch_pack(int fd, int packfd, struct got_object_id *packid,
464     struct got_pathlist_head *have_refs, struct imsgbuf *ibuf)
465 {
466 	const struct got_error *err = NULL;
467 	char buf[GOT_PKTMAX];
468 	char hashstr[SHA1_DIGEST_STRING_LENGTH];
469 	struct got_object_id *have, *want;
470 	int is_firstpkt = 1, nref = 0, refsz = 16;
471 	int i, n, req;
472 	off_t packsz = 0, last_reported_packsz = 0;
473 	char *id_str = NULL, *refname = NULL;
474 	char *server_capabilities = NULL, *my_capabilities = NULL;
475 	struct got_pathlist_head symrefs;
476 	struct got_pathlist_entry *pe;
477 	int have_sidebands = 0;
478 
479 	TAILQ_INIT(&symrefs);
480 
481 	have = malloc(refsz * sizeof(have[0]));
482 	if (have == NULL)
483 		return got_error_from_errno("malloc");
484 	want = malloc(refsz * sizeof(want[0]));
485 	if (want == NULL) {
486 		err = got_error_from_errno("malloc");
487 		goto done;
488 	}
489 	if (chattygit)
490 		fprintf(stderr, "starting fetch\n");
491 	while (1) {
492 		err = readpkt(&n, fd, buf, sizeof(buf));
493 		if (err)
494 			goto done;
495 		if (n == 0)
496 			break;
497 		if (n >= 4 && strncmp(buf, "ERR ", 4) == 0) {
498 			err = fetch_error(&buf[4], n - 4);
499 			goto done;
500 		}
501 		err = parse_refline(&id_str, &refname, &server_capabilities,
502 		    buf, n);
503 		if (err)
504 			goto done;
505 		if (chattygit && server_capabilities[0] != '\0')
506 			fprintf(stderr, "server capabilities: %s\n",
507 			    server_capabilities);
508 		if (is_firstpkt) {
509 			err = match_capabilities(&my_capabilities, &symrefs,
510 			    server_capabilities);
511 			if (err)
512 				goto done;
513 			if (chattygit && my_capabilities)
514 				fprintf(stderr, "my matched capabilities: %s\n",
515 				    my_capabilities);
516 			err = got_privsep_send_fetch_symrefs(ibuf, &symrefs);
517 			if (err)
518 				goto done;
519 		}
520 		is_firstpkt = 0;
521 		if (strstr(refname, "^{}"))
522 			continue;
523 		if (fetchbranch && !match_branch(refname, fetchbranch))
524 			continue;
525 		if (refsz == nref + 1) {
526 			refsz *= 2;
527 			have = reallocarray(have, refsz, sizeof(have[0]));
528 			if (have == NULL) {
529 				err = got_error_from_errno("reallocarray");
530 				goto done;
531 			}
532 			want = reallocarray(want, refsz, sizeof(want[0]));
533 			if (want == NULL) {
534 				err = got_error_from_errno("reallocarray");
535 				goto done;
536 			}
537 		}
538 		if (!got_parse_sha1_digest(want[nref].sha1, id_str)) {
539 			err = got_error(GOT_ERR_BAD_OBJ_ID_STR);
540 			goto done;
541 		}
542 
543 		err = match_remote_ref(have_refs, &have[nref], id_str, refname);
544 		if (err)
545 			goto done;
546 
547 		err = got_privsep_send_fetch_ref(ibuf, &want[nref],
548 		    refname);
549 		if (err)
550 			goto done;
551 		if (chattygit)
552 			fprintf(stderr, "remote %s\n", refname);
553 		nref++;
554 	}
555 
556 	req = 0;
557 	for (i = 0; i < nref; i++) {
558 		if (got_object_id_cmp(&have[i], &want[i]) == 0)
559 			continue;
560 		got_sha1_digest_to_str(want[i].sha1, hashstr, sizeof(hashstr));
561 		n = snprintf(buf, sizeof(buf), "want %s%s%s\n", hashstr,
562 		   i == 0 && my_capabilities ? " " : "",
563 		   i == 0 && my_capabilities ? my_capabilities : "");
564 		if (n >= sizeof(buf)) {
565 			err = got_error(GOT_ERR_NO_SPACE);
566 			goto done;
567 		}
568 		err = writepkt(fd, buf, n);
569 		if (err)
570 			goto done;
571 		req = 1;
572 	}
573 	err = flushpkt(fd);
574 	if (err)
575 		goto done;
576 	for (i = 0; i < nref; i++) {
577 		if (got_object_id_cmp(&have[i], &zhash) == 0)
578 			continue;
579 		got_sha1_digest_to_str(want[i].sha1, hashstr, sizeof(hashstr));
580 		n = snprintf(buf, sizeof(buf), "have %s\n", hashstr);
581 		if (n >= sizeof(buf)) {
582 			err = got_error(GOT_ERR_NO_SPACE);
583 			goto done;
584 		}
585 		err = writepkt(fd, buf, n + 1);
586 		if (err)
587 			goto done;
588 	}
589 	if (!req) {
590 		if (chattygit)
591 			fprintf(stderr, "up to date\n");
592 		err = flushpkt(fd);
593 		if (err)
594 			goto done;
595 	}
596 	n = snprintf(buf, sizeof(buf), "done\n");
597 	err = writepkt(fd, buf, n);
598 	if (err)
599 		goto done;
600 	if (!req)
601 		return 0;
602 
603 	err = readpkt(&n, fd, buf, sizeof(buf));
604 	if (err)
605 		goto done;
606 	/*
607 	 * For now, we only support a full clone, in which case the server
608 	 * will now send a "NAK" (meaning no common objects were found).
609 	 */
610 	if (n != 4 || strncmp(buf, "NAK\n", n) != 0) {
611 		err = got_error_msg(GOT_ERR_BAD_PACKET,
612 		    "unexpected message from server");
613 		goto done;
614 	}
615 
616 	if (chattygit)
617 		fprintf(stderr, "fetching...\n");
618 
619 	if (my_capabilities != NULL &&
620 	    strstr(my_capabilities, GOT_CAPA_SIDE_BAND_64K) != NULL)
621 		have_sidebands = 1;
622 
623 	while (1) {
624 		ssize_t r = 0, w;
625 		int datalen = -1;
626 
627 		if (have_sidebands) {
628 			err = read_pkthdr(&datalen, fd);
629 			if (err)
630 				goto done;
631 			if (datalen <= 0)
632 				break;
633 
634 			/* Read sideband channel ID (one byte). */
635 			r = read(fd, buf, 1);
636 			if (r == -1) {
637 				err = got_error_from_errno("read");
638 				goto done;
639 			}
640 			if (r != 1) {
641 				err = got_error_msg(GOT_ERR_BAD_PACKET,
642 				    "short packet");
643 				goto done;
644 			}
645 			if (datalen > sizeof(buf) - 5) {
646 				err = got_error_msg(GOT_ERR_BAD_PACKET,
647 				    "bad packet length");
648 				goto done;
649 			}
650 			datalen--; /* sideband ID has been read */
651 			if (buf[0] == GOT_SIDEBAND_PACKFILE_DATA) {
652 				/* Read packfile data. */
653 				err = readn(&r, fd, buf, datalen);
654 				if (err)
655 					goto done;
656 				if (r != datalen) {
657 					err = got_error_msg(GOT_ERR_BAD_PACKET,
658 					    "packet too short");
659 					goto done;
660 				}
661 			} else if (buf[0] == GOT_SIDEBAND_PROGRESS_INFO) {
662 				err = readn(&r, fd, buf, datalen);
663 				if (err)
664 					goto done;
665 				if (r != datalen) {
666 					err = got_error_msg(GOT_ERR_BAD_PACKET,
667 					    "packet too short");
668 					goto done;
669 				}
670 				err = fetch_progress(ibuf, buf, r);
671 				if (err)
672 					goto done;
673 				continue;
674 			} else if (buf[0] == GOT_SIDEBAND_ERROR_INFO) {
675 				err = readn(&r, fd, buf, datalen);
676 				if (err)
677 					goto done;
678 				if (r != datalen) {
679 					err = got_error_msg(GOT_ERR_BAD_PACKET,
680 					    "packet too short");
681 					goto done;
682 				}
683 				err = fetch_error(buf, r);
684 				goto done;
685 			} else {
686 				err = got_error_msg(GOT_ERR_BAD_PACKET,
687 				    "unknown side-band received from server");
688 				goto done;
689 			}
690 		} else {
691 			/* No sideband channel. Every byte is packfile data. */
692 			err = readn(&r, fd, buf, sizeof buf);
693 			if (err)
694 				goto done;
695 			if (r <= 0)
696 				break;
697 		}
698 
699 		/* Write packfile data to temporary pack file. */
700 		w = write(packfd, buf, r);
701 		if (w == -1) {
702 			err = got_error_from_errno("write");
703 			goto done;
704 		}
705 		if (w != r) {
706 			err = got_error(GOT_ERR_IO);
707 			goto done;
708 		}
709 		packsz += w;
710 
711 		/* Don't send too many progress privsep messages. */
712 		if (packsz > last_reported_packsz + 1024) {
713 			err = got_privsep_send_fetch_download_progress(ibuf,
714 			    packsz);
715 			if (err)
716 				goto done;
717 			last_reported_packsz = packsz;
718 		}
719 	}
720 	err = got_privsep_send_fetch_download_progress(ibuf, packsz);
721 	if (err)
722 		goto done;
723 done:
724 	TAILQ_FOREACH(pe, &symrefs, entry) {
725 		free((void *)pe->path);
726 		free(pe->data);
727 	}
728 	got_pathlist_free(&symrefs);
729 	free(have);
730 	free(want);
731 	free(id_str);
732 	free(refname);
733 	free(server_capabilities);
734 	return err;
735 }
736 
737 
738 int
739 main(int argc, char **argv)
740 {
741 	const struct got_error *err = NULL;
742 	int fetchfd, packfd = -1;
743 	struct got_object_id packid;
744 	struct imsgbuf ibuf;
745 	struct imsg imsg;
746 	struct got_pathlist_head have_refs;
747 	struct got_imsg_fetch_have_refs *fetch_have_refs = NULL;
748 	size_t datalen;
749 
750 	TAILQ_INIT(&have_refs);
751 
752 	if (getenv("GOT_DEBUG") != NULL) {
753 		fprintf(stderr, "fetch-pack being chatty!\n");
754 		chattygit = 1;
755 	}
756 
757 	imsg_init(&ibuf, GOT_IMSG_FD_CHILD);
758 #ifndef PROFILE
759 	/* revoke access to most system calls */
760 	if (pledge("stdio recvfd", NULL) == -1) {
761 		err = got_error_from_errno("pledge");
762 		got_privsep_send_error(&ibuf, err);
763 		return 1;
764 	}
765 #endif
766 	if ((err = got_privsep_recv_imsg(&imsg, &ibuf, 0)) != 0) {
767 		if (err->code == GOT_ERR_PRIVSEP_PIPE)
768 			err = NULL;
769 		goto done;
770 	}
771 	if (imsg.hdr.type == GOT_IMSG_STOP)
772 		goto done;
773 	if (imsg.hdr.type != GOT_IMSG_FETCH_REQUEST) {
774 		err = got_error(GOT_ERR_PRIVSEP_MSG);
775 		goto done;
776 	}
777 	datalen = imsg.hdr.len - IMSG_HEADER_SIZE;
778 	if (datalen < sizeof(struct got_imsg_fetch_have_refs)) {
779 		err = got_error(GOT_ERR_PRIVSEP_LEN);
780 		goto done;
781 	}
782 	fetch_have_refs = (struct got_imsg_fetch_have_refs *)imsg.data;
783 	if (datalen != sizeof(struct got_imsg_fetch_have_refs) +
784 	    sizeof(struct got_imsg_fetch_have_ref) *
785 	    fetch_have_refs->n_have_refs) {
786 		err = got_error(GOT_ERR_PRIVSEP_LEN);
787 		goto done;
788 	}
789 	if (fetch_have_refs->n_have_refs != 0) {
790 		/* TODO: Incremental fetch support */
791 		err = got_error(GOT_ERR_NOT_IMPL);
792 		goto done;
793 	}
794 	fetchfd = imsg.fd;
795 
796 	if ((err = got_privsep_recv_imsg(&imsg, &ibuf, 0)) != 0) {
797 		if (err->code == GOT_ERR_PRIVSEP_PIPE)
798 			err = NULL;
799 		goto done;
800 	}
801 	if (imsg.hdr.type == GOT_IMSG_STOP)
802 		goto done;
803 	if (imsg.hdr.type != GOT_IMSG_FETCH_OUTFD) {
804 		err = got_error(GOT_ERR_PRIVSEP_MSG);
805 		goto done;
806 	}
807 	if (imsg.hdr.len - IMSG_HEADER_SIZE != 0) {
808 		err = got_error(GOT_ERR_PRIVSEP_LEN);
809 		goto done;
810 	}
811 	packfd = imsg.fd;
812 
813 	err = fetch_pack(fetchfd, packfd, &packid, &have_refs, &ibuf);
814 done:
815 	if (packfd != -1 && close(packfd) == -1 && err == NULL)
816 		err = got_error_from_errno("close");
817 	if (err != NULL)
818 		got_privsep_send_error(&ibuf, err);
819 	else
820 		err = got_privsep_send_fetch_done(&ibuf, packid);
821 	if (err != NULL) {
822 		fprintf(stderr, "%s: %s\n", getprogname(), err->msg);
823 		got_privsep_send_error(&ibuf, err);
824 	}
825 
826 	exit(0);
827 }