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Date:: Wed Mar 18 16:13:42 2020 UTC
Message:: remove header check from got-fetch-pack; not needed
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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 
425 	if (len == 0)
426 		return NULL;
427 
428 	/*
429 	 * Truncate messages which exceed the maximum imsg payload size.
430 	 * Server may send up to 64k.
431 	 */
432 	if (len > MAX_IMSGSIZE - IMSG_HEADER_SIZE)
433 		len = MAX_IMSGSIZE - IMSG_HEADER_SIZE;
434 
435 	/* Only allow printable ASCII. */
436 	for (i = 0; i < len; i++) {
437 		if (isprint((unsigned char)buf[i]) ||
438 		    isspace((unsigned char)buf[i]))
439 			continue;
440 		return got_error_msg(GOT_ERR_BAD_PACKET,
441 		    "non-printable progress message received from server");
442 	}
443 
444 	return got_privsep_send_fetch_server_progress(ibuf, buf, len);
445 }
446 
447 static const struct got_error *
448 fetch_error(const char *buf, size_t len)
449 {
450 	static char msg[1024];
451 	int i;
452 
453 	for (i = 0; i < len && i < sizeof(msg) - 1; i++) {
454 		if (!isprint(buf[i]))
455 			return got_error_msg(GOT_ERR_BAD_PACKET,
456 			    "non-printable error message received from server");
457 		msg[i] = buf[i];
458 	}
459 	msg[i] = '\0';
460 	return got_error_msg(GOT_ERR_FETCH_FAILED, msg);
461 }
462 
463 static const struct got_error *
464 fetch_pack(int fd, int packfd, struct got_object_id *packid,
465     struct got_pathlist_head *have_refs, struct imsgbuf *ibuf)
466 {
467 	const struct got_error *err = NULL;
468 	char buf[GOT_PKTMAX];
469 	char hashstr[SHA1_DIGEST_STRING_LENGTH];
470 	struct got_object_id *have, *want;
471 	int is_firstpkt = 1, nref = 0, refsz = 16;
472 	int i, n, req;
473 	off_t packsz;
474 	char *id_str = NULL, *refname = NULL;
475 	char *server_capabilities = NULL, *my_capabilities = NULL;
476 	struct got_pathlist_head symrefs;
477 	struct got_pathlist_entry *pe;
478 	int have_sidebands = 0;
479 
480 	TAILQ_INIT(&symrefs);
481 
482 	have = malloc(refsz * sizeof(have[0]));
483 	if (have == NULL)
484 		return got_error_from_errno("malloc");
485 	want = malloc(refsz * sizeof(want[0]));
486 	if (want == NULL) {
487 		err = got_error_from_errno("malloc");
488 		goto done;
489 	}
490 	if (chattygit)
491 		fprintf(stderr, "starting fetch\n");
492 	while (1) {
493 		err = readpkt(&n, fd, buf, sizeof(buf));
494 		if (err)
495 			goto done;
496 		if (n == 0)
497 			break;
498 		if (n >= 4 && strncmp(buf, "ERR ", 4) == 0) {
499 			err = fetch_error(&buf[4], n - 4);
500 			goto done;
501 		}
502 		err = parse_refline(&id_str, &refname, &server_capabilities,
503 		    buf, n);
504 		if (err)
505 			goto done;
506 		if (chattygit && server_capabilities[0] != '\0')
507 			fprintf(stderr, "server capabilities: %s\n",
508 			    server_capabilities);
509 		if (is_firstpkt) {
510 			err = match_capabilities(&my_capabilities, &symrefs,
511 			    server_capabilities);
512 			if (err)
513 				goto done;
514 			if (chattygit && my_capabilities)
515 				fprintf(stderr, "my matched capabilities: %s\n",
516 				    my_capabilities);
517 			err = got_privsep_send_fetch_symrefs(ibuf, &symrefs);
518 			if (err)
519 				goto done;
520 		}
521 		is_firstpkt = 0;
522 		if (strstr(refname, "^{}"))
523 			continue;
524 		if (fetchbranch && !match_branch(refname, fetchbranch))
525 			continue;
526 		if (refsz == nref + 1) {
527 			refsz *= 2;
528 			have = reallocarray(have, refsz, sizeof(have[0]));
529 			if (have == NULL) {
530 				err = got_error_from_errno("reallocarray");
531 				goto done;
532 			}
533 			want = reallocarray(want, refsz, sizeof(want[0]));
534 			if (want == NULL) {
535 				err = got_error_from_errno("reallocarray");
536 				goto done;
537 			}
538 		}
539 		if (!got_parse_sha1_digest(want[nref].sha1, id_str)) {
540 			err = got_error(GOT_ERR_BAD_OBJ_ID_STR);
541 			goto done;
542 		}
543 
544 		err = match_remote_ref(have_refs, &have[nref], id_str, refname);
545 		if (err)
546 			goto done;
547 
548 		err = got_privsep_send_fetch_ref(ibuf, &want[nref],
549 		    refname);
550 		if (err)
551 			goto done;
552 		if (chattygit)
553 			fprintf(stderr, "remote %s\n", refname);
554 		nref++;
555 	}
556 
557 	req = 0;
558 	for (i = 0; i < nref; i++) {
559 		if (got_object_id_cmp(&have[i], &want[i]) == 0)
560 			continue;
561 		got_sha1_digest_to_str(want[i].sha1, hashstr, sizeof(hashstr));
562 		n = snprintf(buf, sizeof(buf), "want %s%s%s\n", hashstr,
563 		   i == 0 && my_capabilities ? " " : "",
564 		   i == 0 && my_capabilities ? my_capabilities : "");
565 		if (n >= sizeof(buf)) {
566 			err = got_error(GOT_ERR_NO_SPACE);
567 			goto done;
568 		}
569 		err = writepkt(fd, buf, n);
570 		if (err)
571 			goto done;
572 		req = 1;
573 	}
574 	err = flushpkt(fd);
575 	if (err)
576 		goto done;
577 	for (i = 0; i < nref; i++) {
578 		if (got_object_id_cmp(&have[i], &zhash) == 0)
579 			continue;
580 		got_sha1_digest_to_str(want[i].sha1, hashstr, sizeof(hashstr));
581 		n = snprintf(buf, sizeof(buf), "have %s\n", hashstr);
582 		if (n >= sizeof(buf)) {
583 			err = got_error(GOT_ERR_NO_SPACE);
584 			goto done;
585 		}
586 		err = writepkt(fd, buf, n + 1);
587 		if (err)
588 			goto done;
589 	}
590 	if (!req) {
591 		if (chattygit)
592 			fprintf(stderr, "up to date\n");
593 		err = flushpkt(fd);
594 		if (err)
595 			goto done;
596 	}
597 	n = snprintf(buf, sizeof(buf), "done\n");
598 	err = writepkt(fd, buf, n);
599 	if (err)
600 		goto done;
601 	if (!req)
602 		return 0;
603 
604 	err = readpkt(&n, fd, buf, sizeof(buf));
605 	if (err)
606 		goto done;
607 	/*
608 	 * For now, we only support a full clone, in which case the server
609 	 * will now send a "NAK" (meaning no common objects were found).
610 	 */
611 	if (n != 4 || strncmp(buf, "NAK\n", n) != 0) {
612 		err = got_error_msg(GOT_ERR_BAD_PACKET,
613 		    "unexpected message from server");
614 		goto done;
615 	}
616 
617 	if (chattygit)
618 		fprintf(stderr, "fetching...\n");
619 
620 	if (my_capabilities != NULL &&
621 	    strstr(my_capabilities, GOT_CAPA_SIDE_BAND_64K) != NULL)
622 		have_sidebands = 1;
623 
624 	packsz = 0;
625 	while (1) {
626 		ssize_t r = 0, w;
627 		int datalen = -1;
628 
629 		if (have_sidebands) {
630 			err = read_pkthdr(&datalen, fd);
631 			if (err)
632 				goto done;
633 			if (datalen <= 0)
634 				break;
635 
636 			/* Read sideband channel ID (one byte). */
637 			r = read(fd, buf, 1);
638 			if (r == -1) {
639 				err = got_error_from_errno("read");
640 				goto done;
641 			}
642 			if (r != 1) {
643 				err = got_error_msg(GOT_ERR_BAD_PACKET,
644 				    "short packet");
645 				goto done;
646 			}
647 			if (datalen > sizeof(buf) - 5) {
648 				err = got_error_msg(GOT_ERR_BAD_PACKET,
649 				    "bad packet length");
650 				goto done;
651 			}
652 			datalen--; /* sideband ID has been read */
653 			if (buf[0] == GOT_SIDEBAND_PACKFILE_DATA) {
654 				/* Read packfile data. */
655 				err = readn(&r, fd, buf, datalen);
656 				if (err)
657 					goto done;
658 				if (r != datalen) {
659 					err = got_error_msg(GOT_ERR_BAD_PACKET,
660 					    "packet too short");
661 					goto done;
662 				}
663 			} else if (buf[0] == GOT_SIDEBAND_PROGRESS_INFO) {
664 				err = readn(&r, fd, buf, datalen);
665 				if (err)
666 					goto done;
667 				if (r != datalen) {
668 					err = got_error_msg(GOT_ERR_BAD_PACKET,
669 					    "packet too short");
670 					goto done;
671 				}
672 				err = fetch_progress(ibuf, buf, r);
673 				if (err)
674 					goto done;
675 				continue;
676 			} else if (buf[0] == GOT_SIDEBAND_ERROR_INFO) {
677 				err = readn(&r, fd, buf, datalen);
678 				if (err)
679 					goto done;
680 				if (r != datalen) {
681 					err = got_error_msg(GOT_ERR_BAD_PACKET,
682 					    "packet too short");
683 					goto done;
684 				}
685 				err = fetch_error(buf, r);
686 				goto done;
687 			} else {
688 				err = got_error_msg(GOT_ERR_BAD_PACKET,
689 				    "unknown side-band received from server");
690 				goto done;
691 			}
692 		} else {
693 			/* No sideband channel. Every byte is packfile data. */
694 			err = readn(&r, fd, buf, sizeof buf);
695 			if (err)
696 				goto done;
697 			if (r <= 0)
698 				break;
699 		}
700 
701 		/* Write packfile data to temporary pack file. */
702 		w = write(packfd, buf, r);
703 		if (w == -1) {
704 			err = got_error_from_errno("write");
705 			goto done;
706 		}
707 		if (w != r) {
708 			err = got_error(GOT_ERR_IO);
709 			goto done;
710 		}
711 		packsz += w;
712 		err = got_privsep_send_fetch_download_progress(ibuf, packsz);
713 		if (err)
714 			goto done;
715 	}
716 done:
717 	TAILQ_FOREACH(pe, &symrefs, entry) {
718 		free((void *)pe->path);
719 		free(pe->data);
720 	}
721 	got_pathlist_free(&symrefs);
722 	free(have);
723 	free(want);
724 	free(id_str);
725 	free(refname);
726 	free(server_capabilities);
727 	return err;
728 }
729 
730 
731 int
732 main(int argc, char **argv)
733 {
734 	const struct got_error *err = NULL;
735 	int fetchfd, packfd = -1;
736 	struct got_object_id packid;
737 	struct imsgbuf ibuf;
738 	struct imsg imsg;
739 	struct got_pathlist_head have_refs;
740 	struct got_imsg_fetch_have_refs *fetch_have_refs = NULL;
741 	size_t datalen;
742 
743 	TAILQ_INIT(&have_refs);
744 
745 	if (getenv("GOT_DEBUG") != NULL) {
746 		fprintf(stderr, "fetch-pack being chatty!\n");
747 		chattygit = 1;
748 	}
749 
750 	imsg_init(&ibuf, GOT_IMSG_FD_CHILD);
751 #ifndef PROFILE
752 	/* revoke access to most system calls */
753 	if (pledge("stdio recvfd", NULL) == -1) {
754 		err = got_error_from_errno("pledge");
755 		got_privsep_send_error(&ibuf, err);
756 		return 1;
757 	}
758 #endif
759 	if ((err = got_privsep_recv_imsg(&imsg, &ibuf, 0)) != 0) {
760 		if (err->code == GOT_ERR_PRIVSEP_PIPE)
761 			err = NULL;
762 		goto done;
763 	}
764 	if (imsg.hdr.type == GOT_IMSG_STOP)
765 		goto done;
766 	if (imsg.hdr.type != GOT_IMSG_FETCH_REQUEST) {
767 		err = got_error(GOT_ERR_PRIVSEP_MSG);
768 		goto done;
769 	}
770 	datalen = imsg.hdr.len - IMSG_HEADER_SIZE;
771 	if (datalen < sizeof(struct got_imsg_fetch_have_refs)) {
772 		err = got_error(GOT_ERR_PRIVSEP_LEN);
773 		goto done;
774 	}
775 	fetch_have_refs = (struct got_imsg_fetch_have_refs *)imsg.data;
776 	if (datalen != sizeof(struct got_imsg_fetch_have_refs) +
777 	    sizeof(struct got_imsg_fetch_have_ref) *
778 	    fetch_have_refs->n_have_refs) {
779 		err = got_error(GOT_ERR_PRIVSEP_LEN);
780 		goto done;
781 	}
782 	if (fetch_have_refs->n_have_refs != 0) {
783 		/* TODO: Incremental fetch support */
784 		err = got_error(GOT_ERR_NOT_IMPL);
785 		goto done;
786 	}
787 	fetchfd = imsg.fd;
788 
789 	if ((err = got_privsep_recv_imsg(&imsg, &ibuf, 0)) != 0) {
790 		if (err->code == GOT_ERR_PRIVSEP_PIPE)
791 			err = NULL;
792 		goto done;
793 	}
794 	if (imsg.hdr.type == GOT_IMSG_STOP)
795 		goto done;
796 	if (imsg.hdr.type != GOT_IMSG_TMPFD) {
797 		err = got_error(GOT_ERR_PRIVSEP_MSG);
798 		goto done;
799 	}
800 	if (imsg.hdr.len - IMSG_HEADER_SIZE != 0) {
801 		err = got_error(GOT_ERR_PRIVSEP_LEN);
802 		goto done;
803 	}
804 	packfd = imsg.fd;
805 
806 	err = fetch_pack(fetchfd, packfd, &packid, &have_refs, &ibuf);
807 done:
808 	if (packfd != -1 && close(packfd) == -1 && err == NULL)
809 		err = got_error_from_errno("close");
810 	if (err != NULL)
811 		got_privsep_send_error(&ibuf, err);
812 	else
813 		err = got_privsep_send_fetch_done(&ibuf, packid);
814 	if (err != NULL) {
815 		fprintf(stderr, "%s: %s\n", getprogname(), err->msg);
816 		got_privsep_send_error(&ibuf, err);
817 	}
818 
819 	exit(0);
820 }