1 /*
2  * Copyright (c) 2018, 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/stat.h>
19 #include <sys/queue.h>
20 #include <sys/uio.h>
21 #include <sys/socket.h>
22 #include <sys/wait.h>
23 #include <sys/resource.h>
24 #include <sys/socket.h>
25 
26 #include <endian.h>
27 #include <errno.h>
28 #include <err.h>
29 #include <fcntl.h>
30 #include <stdio.h>
31 #include <stdlib.h>
32 #include <string.h>
33 #include <stdint.h>
34 #include <sha1.h>
35 #include <unistd.h>
36 #include <zlib.h>
37 #include <ctype.h>
38 #include <limits.h>
39 #include <imsg.h>
40 #include <time.h>
41 #include <uuid.h>
42 #include <netdb.h>
43 #include <netinet/in.h>
44 
45 #include "got_error.h"
46 #include "got_reference.h"
47 #include "got_repository.h"
48 #include "got_path.h"
49 #include "got_cancel.h"
50 #include "got_worktree.h"
51 #include "got_object.h"
52 #include "got_opentemp.h"
53 #include "got_fetch.h"
54 
55 #include "got_lib_delta.h"
56 #include "got_lib_inflate.h"
57 #include "got_lib_object.h"
58 #include "got_lib_object_parse.h"
59 #include "got_lib_object_create.h"
60 #include "got_lib_pack.h"
61 #include "got_lib_sha1.h"
62 #include "got_lib_privsep.h"
63 #include "got_lib_object_cache.h"
64 #include "got_lib_repository.h"
65 
66 #ifndef nitems
67 #define nitems(_a)	(sizeof((_a)) / sizeof((_a)[0]))
68 #endif
69 
70 #ifndef ssizeof
71 #define ssizeof(_x) ((ssize_t)(sizeof(_x)))
72 #endif
73 
74 #ifndef MIN
75 #define	MIN(_a,_b) ((_a) < (_b) ? (_a) : (_b))
76 #endif
77 
78 static int
79 hassuffix(char *base, char *suf)
80 {
81 	int nb, ns;
82 
83 	nb = strlen(base);
84 	ns = strlen(suf);
85 	if (ns <= nb && strcmp(base + (nb - ns), suf) == 0)
86 		return 1;
87 	return 0;
88 }
89 
90 static const struct got_error *
91 dial_ssh(pid_t *fetchpid, int *fetchfd, const char *host, const char *port,
92     const char *path, const char *direction, int verbosity)
93 {
94 	const struct got_error *error = NULL;
95 	int pid, pfd[2];
96 	char cmd[64];
97 	char *argv[11];
98 	int i = 0, j;
99 
100 	*fetchpid = -1;
101 	*fetchfd = -1;
102 
103 	argv[i++] = GOT_FETCH_PATH_SSH;
104 	if (port != NULL) {
105 		argv[i++] = "-p";
106 		argv[i++] = (char *)port;
107 	}
108 	if (verbosity == -1) {
109 		argv[i++] = "-q";
110 	} else {
111 		/* ssh(1) allows up to 3 "-v" options. */
112 		for (j = 0; j < MIN(3, verbosity); j++)
113 			argv[i++] = "-v";
114 	}
115 	argv[i++] = "--";
116 	argv[i++] = (char *)host;
117 	argv[i++] = (char *)cmd;
118 	argv[i++] = (char *)path;
119 	argv[i++] = NULL;
120 
121 	if (pipe(pfd) == -1)
122 		return got_error_from_errno("pipe");
123 
124 	pid = fork();
125 	if (pid == -1) {
126 		error = got_error_from_errno("fork");
127 		close(pfd[0]);
128 		close(pfd[1]);
129 		return error;
130 	} else if (pid == 0) {
131 		int n;
132 		if (close(pfd[1]) == -1)
133 			err(1, "close");
134 		if (dup2(pfd[0], 0) == -1)
135 			err(1, "dup2");
136 		if (dup2(pfd[0], 1) == -1)
137 			err(1, "dup2");
138 		n = snprintf(cmd, sizeof(cmd), "git-%s-pack", direction);
139 		if (n < 0 || n >= ssizeof(cmd))
140 			err(1, "snprintf");
141 		if (execv(GOT_FETCH_PATH_SSH, argv) == -1)
142 			err(1, "execv");
143 		abort(); /* not reached */
144 	} else {
145 		if (close(pfd[0]) == -1)
146 			return got_error_from_errno("close");
147 		*fetchpid = pid;
148 		*fetchfd = pfd[1];
149 		return NULL;
150 	}
151 }
152 
153 static const struct got_error *
154 dial_git(int *fetchfd, const char *host, const char *port, const char *path,
155     const char *direction)
156 {
157 	const struct got_error *err = NULL;
158 	struct addrinfo hints, *servinfo, *p;
159 	char *cmd = NULL, *pkt = NULL;
160 	int fd = -1, totlen, r, eaicode;
161 
162 	*fetchfd = -1;
163 
164 	if (port == NULL)
165 		port = GOT_DEFAULT_GIT_PORT_STR;
166 
167 	memset(&hints, 0, sizeof hints);
168 	hints.ai_family = AF_UNSPEC;
169 	hints.ai_socktype = SOCK_STREAM;
170 	eaicode = getaddrinfo(host, port, &hints, &servinfo);
171 	if (eaicode) {
172 		char msg[512];
173 		snprintf(msg, sizeof(msg), "%s: %s", host,
174 		    gai_strerror(eaicode));
175 		return got_error_msg(GOT_ERR_ADDRINFO, msg);
176 	}
177 
178 	for (p = servinfo; p != NULL; p = p->ai_next) {
179 		if ((fd = socket(p->ai_family, p->ai_socktype,
180 		    p->ai_protocol)) == -1)
181 			continue;
182 		if (connect(fd, p->ai_addr, p->ai_addrlen) == 0) {
183 			err = NULL;
184 			break;
185 		}
186 		err = got_error_from_errno("connect");
187 		close(fd);
188 	}
189 	if (p == NULL)
190 		goto done;
191 
192 	if (asprintf(&cmd, "git-%s-pack %s", direction, path) == -1) {
193 		err = got_error_from_errno("asprintf");
194 		goto done;
195 	}
196 	totlen = 4 + strlen(cmd) + 1 + strlen("host=") + strlen(host) + 1;
197 	if (asprintf(&pkt, "%04x%s", totlen, cmd) == -1) {
198 		err = got_error_from_errno("asprintf");
199 		goto done;
200 	}
201 	r = write(fd, pkt, strlen(pkt) + 1);
202 	if (r == -1) {
203 		err = got_error_from_errno("write");
204 		goto done;
205 	}
206 	if (asprintf(&pkt, "host=%s", host) == -1) {
207 		err = got_error_from_errno("asprintf");
208 		goto done;
209 	}
210 	r = write(fd, pkt, strlen(pkt) + 1);
211 	if (r == -1) {
212 		err = got_error_from_errno("write");
213 		goto done;
214 	}
215 done:
216 	free(cmd);
217 	free(pkt);
218 	if (err) {
219 		if (fd != -1)
220 			close(fd);
221 	} else
222 		*fetchfd = fd;
223 	return err;
224 }
225 
226 const struct got_error *
227 got_fetch_connect(pid_t *fetchpid, int *fetchfd, const char *proto,
228     const char *host, const char *port, const char *server_path, int verbosity)
229 {
230 	const struct got_error *err = NULL;
231 
232 	*fetchpid = -1;
233 	*fetchfd = -1;
234 
235 	if (strcmp(proto, "ssh") == 0 || strcmp(proto, "git+ssh") == 0)
236 		err = dial_ssh(fetchpid, fetchfd, host, port, server_path,
237 		    "upload", verbosity);
238 	else if (strcmp(proto, "git") == 0)
239 		err = dial_git(fetchfd, host, port, server_path, "upload");
240 	else if (strcmp(proto, "http") == 0 || strcmp(proto, "git+http") == 0)
241 		err = got_error_path(proto, GOT_ERR_NOT_IMPL);
242 	else
243 		err = got_error_path(proto, GOT_ERR_BAD_PROTO);
244 	return err;
245 }
246 
247 const struct got_error *
248 got_fetch_parse_uri(char **proto, char **host, char **port,
249     char **server_path, char **repo_name, const char *uri)
250 {
251 	const struct got_error *err = NULL;
252 	char *s, *p, *q;
253 	int n;
254 
255 	*proto = *host = *port = *server_path = *repo_name = NULL;
256 
257 	p = strstr(uri, "://");
258 	if (!p) {
259 		/* Try parsing Git's "scp" style URL syntax. */
260 		*proto = strdup("ssh");
261 		if (proto == NULL) {
262 			err = got_error_from_errno("strdup");
263 			goto done;
264 		}
265 		s = (char *)uri;
266 		q = strchr(s, ':');
267 		if (q == NULL) {
268 			err = got_error(GOT_ERR_PARSE_URI);
269 			goto done;
270 		}
271 		/* No slashes allowed before first colon. */
272 		p = strchr(s, '/');
273 		if (p && q > p) {
274 			err = got_error(GOT_ERR_PARSE_URI);
275 			goto done;
276 		}
277 		*host = strndup(s, q - s);
278 		if (*host == NULL) {
279 			err = got_error_from_errno("strndup");
280 			goto done;
281 		}
282 		p = q + 1;
283 	} else {
284 		*proto = strndup(uri, p - uri);
285 		if (proto == NULL) {
286 			err = got_error_from_errno("strndup");
287 			goto done;
288 		}
289 		s = p + 3;
290 
291 		p = strstr(s, "/");
292 		if (p == NULL || strlen(p) == 1) {
293 			err = got_error(GOT_ERR_PARSE_URI);
294 			goto done;
295 		}
296 
297 		q = memchr(s, ':', p - s);
298 		if (q) {
299 			*host = strndup(s, q - s);
300 			if (*host == NULL) {
301 				err = got_error_from_errno("strndup");
302 				goto done;
303 			}
304 			*port = strndup(q + 1, p - (q + 1));
305 			if (*port == NULL) {
306 				err = got_error_from_errno("strndup");
307 				goto done;
308 			}
309 		} else {
310 			*host = strndup(s, p - s);
311 			if (*host == NULL) {
312 				err = got_error_from_errno("strndup");
313 				goto done;
314 			}
315 		}
316 	}
317 
318 	while (p[0] == '/' && p[1] == '/')
319 		p++;
320 	*server_path = strdup(p);
321 	if (*server_path == NULL) {
322 		err = got_error_from_errno("strdup");
323 		goto done;
324 	}
325 	got_path_strip_trailing_slashes(*server_path);
326 
327 	p = strrchr(p, '/');
328 	if (!p || strlen(p) <= 1) {
329 		err = got_error(GOT_ERR_PARSE_URI);
330 		goto done;
331 	}
332 	p++;
333 	n = strlen(p);
334 	if (n == 0) {
335 		err = got_error(GOT_ERR_PARSE_URI);
336 		goto done;
337 	}
338 	if (hassuffix(p, ".git"))
339 		n -= 4;
340 	*repo_name = strndup(p, (p + n) - p);
341 	if (*repo_name == NULL) {
342 		err = got_error_from_errno("strndup");
343 		goto done;
344 	}
345 done:
346 	if (err) {
347 		free(*proto);
348 		*proto = NULL;
349 		free(*host);
350 		*host = NULL;
351 		free(*port);
352 		*port = NULL;
353 		free(*server_path);
354 		*server_path = NULL;
355 		free(*repo_name);
356 		*repo_name = NULL;
357 	}
358 	return err;
359 }
360 
361 const struct got_error*
362 got_fetch_pack(struct got_object_id **pack_hash, struct got_pathlist_head *refs,
363     struct got_pathlist_head *symrefs, const char *remote_name,
364     int mirror_references, int fetch_all_branches,
365     struct got_pathlist_head *wanted_branches,
366     struct got_pathlist_head *wanted_refs, int list_refs_only, int verbosity,
367     int fetchfd, struct got_repository *repo,
368     got_fetch_progress_cb progress_cb, void *progress_arg)
369 {
370 	size_t i;
371 	int imsg_fetchfds[2], imsg_idxfds[2];
372 	int packfd = -1, npackfd = -1, idxfd = -1, nidxfd = -1, nfetchfd = -1;
373 	int tmpfds[3];
374 	int fetchstatus, idxstatus, done = 0;
375 	const struct got_error *err;
376 	struct imsgbuf fetchibuf, idxibuf;
377 	pid_t fetchpid, idxpid;
378 	char *tmppackpath = NULL, *tmpidxpath = NULL;
379 	char *packpath = NULL, *idxpath = NULL, *id_str = NULL;
380 	const char *repo_path = NULL;
381 	struct got_pathlist_head have_refs;
382 	struct got_pathlist_entry *pe;
383 	struct got_reflist_head my_refs;
384 	struct got_reflist_entry *re;
385 	off_t packfile_size = 0;
386 	struct got_packfile_hdr pack_hdr;
387 	uint32_t nobj = 0;
388 	char *ref_prefix = NULL;
389 	size_t ref_prefixlen = 0;
390 	char *path;
391 	char *progress = NULL;
392 
393 	*pack_hash = NULL;
394 
395 	/*
396 	 * Prevent fetching of references that won't make any
397 	 * sense outside of the remote repository's context.
398 	 */
399 	TAILQ_FOREACH(pe, wanted_refs, entry) {
400 		const char *refname = pe->path;
401 		if (strncmp(refname, "refs/got/", 9) == 0 ||
402 		    strncmp(refname, "got/", 4) == 0 ||
403 		    strncmp(refname, "refs/remotes/", 13) == 0 ||
404 		    strncmp(refname, "remotes/", 8) == 0)
405 			return got_error_path(refname, GOT_ERR_FETCH_BAD_REF);
406 	}
407 
408 	if (!list_refs_only)
409 		repo_path = got_repo_get_path_git_dir(repo);
410 
411 	for (i = 0; i < nitems(tmpfds); i++)
412 		tmpfds[i] = -1;
413 
414 	TAILQ_INIT(&have_refs);
415 	TAILQ_INIT(&my_refs);
416 
417 	if (!mirror_references) {
418 		if (asprintf(&ref_prefix, "refs/remotes/%s/",
419 		    remote_name) == -1)
420 			return got_error_from_errno("asprintf");
421 		ref_prefixlen = strlen(ref_prefix);
422 	}
423 
424 	if (!list_refs_only) {
425 		err = got_ref_list(&my_refs, repo, NULL,
426 		    got_ref_cmp_by_name, NULL);
427 		if (err)
428 			goto done;
429 	}
430 
431 	TAILQ_FOREACH(re, &my_refs, entry) {
432 		struct got_object_id *id;
433 		const char *refname;
434 
435 		if (got_ref_is_symbolic(re->ref))
436 			continue;
437 
438 		refname = got_ref_get_name(re->ref);
439 
440 		if (mirror_references) {
441 			char *name;
442 			err = got_ref_resolve(&id, repo, re->ref);
443 			if (err)
444 				goto done;
445 			name = strdup(refname);
446 			if (name == NULL) {
447 				err = got_error_from_errno("strdup");
448 				goto done;
449 			}
450 			err = got_pathlist_append(&have_refs, name, id);
451 			if (err)
452 				goto done;
453 			continue;
454 		}
455 
456 		if (strncmp("refs/tags/", refname, 10) == 0) {
457 			char *tagname;
458 
459 			err = got_ref_resolve(&id, repo, re->ref);
460 			if (err)
461 				goto done;
462 			tagname = strdup(refname);
463 			if (tagname == NULL) {
464 				err = got_error_from_errno("strdup");
465 				goto done;
466 			}
467 			err = got_pathlist_append(&have_refs, tagname, id);
468 			if (err) {
469 				free(tagname);
470 				goto done;
471 			}
472 		}
473 
474 		if (strncmp(ref_prefix, refname, ref_prefixlen) == 0) {
475 			char *branchname;
476 
477 			err = got_ref_resolve(&id, repo, re->ref);
478 			if (err)
479 				goto done;
480 
481 			if (asprintf(&branchname, "refs/heads/%s",
482 			    refname + ref_prefixlen) == -1) {
483 				err = got_error_from_errno("asprintf");
484 				goto done;
485 			}
486 			err = got_pathlist_append(&have_refs, branchname, id);
487 			if (err) {
488 				free(branchname);
489 				goto done;
490 			}
491 		}
492 	}
493 
494 	if (list_refs_only) {
495 		packfd = got_opentempfd();
496 		if (packfd == -1) {
497 			err = got_error_from_errno("got_opentempfd");
498 			goto done;
499 		}
500 	} else {
501 		if (asprintf(&path, "%s/%s/fetching.pack",
502 		    repo_path, GOT_OBJECTS_PACK_DIR) == -1) {
503 			err = got_error_from_errno("asprintf");
504 			goto done;
505 		}
506 		err = got_opentemp_named_fd(&tmppackpath, &packfd, path);
507 		free(path);
508 		if (err)
509 			goto done;
510 		if (fchmod(packfd, GOT_DEFAULT_FILE_MODE) != 0) {
511 			err = got_error_from_errno2("fchmod", tmppackpath);
512 			goto done;
513 		}
514 	}
515 	if (list_refs_only) {
516 		idxfd = got_opentempfd();
517 		if (idxfd == -1) {
518 			err = got_error_from_errno("got_opentempfd");
519 			goto done;
520 		}
521 	} else {
522 		if (asprintf(&path, "%s/%s/fetching.idx",
523 		    repo_path, GOT_OBJECTS_PACK_DIR) == -1) {
524 			err = got_error_from_errno("asprintf");
525 			goto done;
526 		}
527 		err = got_opentemp_named_fd(&tmpidxpath, &idxfd, path);
528 		free(path);
529 		if (err)
530 			goto done;
531 		if (fchmod(idxfd, GOT_DEFAULT_FILE_MODE) != 0) {
532 			err = got_error_from_errno2("fchmod", tmpidxpath);
533 			goto done;
534 		}
535 	}
536 	nidxfd = dup(idxfd);
537 	if (nidxfd == -1) {
538 		err = got_error_from_errno("dup");
539 		goto done;
540 	}
541 
542 	for (i = 0; i < nitems(tmpfds); i++) {
543 		tmpfds[i] = got_opentempfd();
544 		if (tmpfds[i] == -1) {
545 			err = got_error_from_errno("got_opentempfd");
546 			goto done;
547 		}
548 	}
549 
550 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, imsg_fetchfds) == -1) {
551 		err = got_error_from_errno("socketpair");
552 		goto done;
553 	}
554 
555 	fetchpid = fork();
556 	if (fetchpid == -1) {
557 		err = got_error_from_errno("fork");
558 		goto done;
559 	} else if (fetchpid == 0){
560 		got_privsep_exec_child(imsg_fetchfds,
561 		    GOT_PATH_PROG_FETCH_PACK, tmppackpath);
562 	}
563 
564 	if (close(imsg_fetchfds[1]) == -1) {
565 		err = got_error_from_errno("close");
566 		goto done;
567 	}
568 	imsg_init(&fetchibuf, imsg_fetchfds[0]);
569 	nfetchfd = dup(fetchfd);
570 	if (nfetchfd == -1) {
571 		err = got_error_from_errno("dup");
572 		goto done;
573 	}
574 	err = got_privsep_send_fetch_req(&fetchibuf, nfetchfd, &have_refs,
575 	    fetch_all_branches, wanted_branches, wanted_refs,
576 	    list_refs_only, verbosity);
577 	if (err != NULL)
578 		goto done;
579 	nfetchfd = -1;
580 	npackfd = dup(packfd);
581 	if (npackfd == -1) {
582 		err = got_error_from_errno("dup");
583 		goto done;
584 	}
585 	err = got_privsep_send_fetch_outfd(&fetchibuf, npackfd);
586 	if (err != NULL)
587 		goto done;
588 	npackfd = -1;
589 
590 	packfile_size = 0;
591 	progress = calloc(GOT_FETCH_PKTMAX, 1);
592 	if (progress == NULL) {
593 		err = got_error_from_errno("calloc");
594 		goto done;
595 	}
596 
597 	*pack_hash = calloc(1, sizeof(**pack_hash));
598 	if (*pack_hash == NULL) {
599 		err = got_error_from_errno("calloc");
600 		goto done;
601 	}
602 
603 	while (!done) {
604 		struct got_object_id *id = NULL;
605 		char *refname = NULL;
606 		char *server_progress = NULL;
607 		off_t packfile_size_cur = 0;
608 
609 		err = got_privsep_recv_fetch_progress(&done,
610 		    &id, &refname, symrefs, &server_progress,
611 		    &packfile_size_cur, (*pack_hash)->sha1, &fetchibuf);
612 		if (err != NULL)
613 			goto done;
614 		if (!done && refname && id) {
615 			err = got_pathlist_insert(NULL, refs, refname, id);
616 			if (err)
617 				goto done;
618 		} else if (!done && server_progress) {
619 			char *p;
620 			/*
621 			 * XXX git-daemon tends to send batched output with
622 			 * lines spanning separate packets. Buffer progress
623 			 * output until we see a CR or LF to avoid giving
624 			 * partial lines of progress output to the callback.
625 			 */
626 			if (strlcat(progress, server_progress,
627 			    GOT_FETCH_PKTMAX) >= GOT_FETCH_PKTMAX) {
628 				progress[0] = '\0'; /* discard */
629 				continue;
630 			}
631 			while ((p = strchr(progress, '\r')) != NULL ||
632 			    (p = strchr(progress, '\n')) != NULL) {
633 				char *s;
634 				size_t n;
635 				char c = *p;
636 				*p = '\0';
637 				if (asprintf(&s, "%s%s", progress,
638 				    c == '\n' ? "\n" : "") == -1) {
639 					err = got_error_from_errno("asprintf");
640 					goto done;
641 				}
642 				err = progress_cb(progress_arg, s,
643 				    packfile_size_cur, 0, 0, 0, 0);
644 				free(s);
645 				if (err)
646 					break;
647 				n = strlen(progress);
648 				if (n < GOT_FETCH_PKTMAX - 1) {
649 					memmove(progress, &progress[n + 1],
650 					    GOT_FETCH_PKTMAX - n - 1);
651 				} else
652 					progress[0] = '\0';
653 			}
654 			free(server_progress);
655 			if (err)
656 				goto done;
657 		} else if (!done && packfile_size_cur != packfile_size) {
658 			err = progress_cb(progress_arg, NULL,
659 			    packfile_size_cur, 0, 0, 0, 0);
660 			if (err)
661 				break;
662 			packfile_size = packfile_size_cur;
663 		}
664 	}
665 	if (waitpid(fetchpid, &fetchstatus, 0) == -1) {
666 		err = got_error_from_errno("waitpid");
667 		goto done;
668 	}
669 
670 	if (lseek(packfd, 0, SEEK_SET) == -1) {
671 		err = got_error_from_errno("lseek");
672 		goto done;
673 	}
674 
675 	/* If zero data was fetched without error we are already up-to-date. */
676 	if (packfile_size == 0) {
677 		free(*pack_hash);
678 		*pack_hash = NULL;
679 		goto done;
680 	} else if (packfile_size < ssizeof(pack_hdr) + SHA1_DIGEST_LENGTH) {
681 		err = got_error_msg(GOT_ERR_BAD_PACKFILE, "short pack file");
682 		goto done;
683 	} else {
684 		ssize_t n;
685 
686 		n = read(packfd, &pack_hdr, ssizeof(pack_hdr));
687 		if (n == -1) {
688 			err = got_error_from_errno("read");
689 			goto done;
690 		}
691 		if (n != ssizeof(pack_hdr)) {
692 			err = got_error(GOT_ERR_IO);
693 			goto done;
694 		}
695 		if (pack_hdr.signature != htobe32(GOT_PACKFILE_SIGNATURE)) {
696 			err = got_error_msg(GOT_ERR_BAD_PACKFILE,
697 			    "bad pack file signature");
698 			goto done;
699 		}
700 		if (pack_hdr.version != htobe32(GOT_PACKFILE_VERSION)) {
701 			err = got_error_msg(GOT_ERR_BAD_PACKFILE,
702 			    "bad pack file version");
703 			goto done;
704 		}
705 		nobj = be32toh(pack_hdr.nobjects);
706 		if (nobj == 0 &&
707 		    packfile_size > ssizeof(pack_hdr) + SHA1_DIGEST_LENGTH)
708 			return got_error_msg(GOT_ERR_BAD_PACKFILE,
709 			    "bad pack file with zero objects");
710 		if (nobj != 0 &&
711 		    packfile_size <= ssizeof(pack_hdr) + SHA1_DIGEST_LENGTH)
712 			return got_error_msg(GOT_ERR_BAD_PACKFILE,
713 			    "empty pack file with non-zero object count");
714 	}
715 
716 	/*
717 	 * If the pack file contains no objects, we may only need to update
718 	 * references in our repository. The caller will take care of that.
719 	 */
720 	if (nobj == 0)
721 		goto done;
722 
723 	if (lseek(packfd, 0, SEEK_SET) == -1) {
724 		err = got_error_from_errno("lseek");
725 		goto done;
726 	}
727  
728 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, imsg_idxfds) == -1) {
729 		err = got_error_from_errno("socketpair");
730 		goto done;
731 	}
732 	idxpid = fork();
733 	if (idxpid == -1) {
734 		err= got_error_from_errno("fork");
735 		goto done;
736 	} else if (idxpid == 0)
737 		got_privsep_exec_child(imsg_idxfds,
738 		    GOT_PATH_PROG_INDEX_PACK, tmppackpath);
739 	if (close(imsg_idxfds[1]) == -1) {
740 		err = got_error_from_errno("close");
741 		goto done;
742 	}
743 	imsg_init(&idxibuf, imsg_idxfds[0]);
744 
745 	npackfd = dup(packfd);
746 	if (npackfd == -1) {
747 		err = got_error_from_errno("dup");
748 		goto done;
749 	}
750 	err = got_privsep_send_index_pack_req(&idxibuf, (*pack_hash)->sha1,
751 	    npackfd);
752 	if (err != NULL)
753 		goto done;
754 	npackfd = -1;
755 	err = got_privsep_send_index_pack_outfd(&idxibuf, nidxfd);
756 	if (err != NULL)
757 		goto done;
758 	nidxfd = -1;
759 	for (i = 0; i < nitems(tmpfds); i++) {
760 		err = got_privsep_send_tmpfd(&idxibuf, tmpfds[i]);
761 		if (err != NULL)
762 			goto done;
763 		tmpfds[i] = -1;
764 	}
765 	done = 0;
766 	while (!done) {
767 		int nobj_total, nobj_indexed, nobj_loose, nobj_resolved;
768 
769 		err = got_privsep_recv_index_progress(&done, &nobj_total,
770 		    &nobj_indexed, &nobj_loose, &nobj_resolved,
771 		    &idxibuf);
772 		if (err != NULL)
773 			goto done;
774 		if (nobj_indexed != 0) {
775 			err = progress_cb(progress_arg, NULL,
776 			    packfile_size, nobj_total,
777 			    nobj_indexed, nobj_loose, nobj_resolved);
778 			if (err)
779 				break;
780 		}
781 		imsg_clear(&idxibuf);
782 	}
783 	if (close(imsg_idxfds[0]) == -1) {
784 		err = got_error_from_errno("close");
785 		goto done;
786 	}
787 	if (waitpid(idxpid, &idxstatus, 0) == -1) {
788 		err = got_error_from_errno("waitpid");
789 		goto done;
790 	}
791 
792 	err = got_object_id_str(&id_str, *pack_hash);
793 	if (err)
794 		goto done;
795 	if (asprintf(&packpath, "%s/%s/pack-%s.pack",
796 	    repo_path, GOT_OBJECTS_PACK_DIR, id_str) == -1) {
797 		err = got_error_from_errno("asprintf");
798 		goto done;
799 	}
800 
801 	if (asprintf(&idxpath, "%s/%s/pack-%s.idx",
802 	    repo_path, GOT_OBJECTS_PACK_DIR, id_str) == -1) {
803 		err = got_error_from_errno("asprintf");
804 		goto done;
805 	}
806 
807 	if (rename(tmppackpath, packpath) == -1) {
808 		err = got_error_from_errno3("rename", tmppackpath, packpath);
809 		goto done;
810 	}
811 	free(tmppackpath);
812 	tmppackpath = NULL;
813 	if (rename(tmpidxpath, idxpath) == -1) {
814 		err = got_error_from_errno3("rename", tmpidxpath, idxpath);
815 		goto done;
816 	}
817 	free(tmpidxpath);
818 	tmpidxpath = NULL;
819 
820 done:
821 	if (tmppackpath && unlink(tmppackpath) == -1 && err == NULL)
822 		err = got_error_from_errno2("unlink", tmppackpath);
823 	if (tmpidxpath && unlink(tmpidxpath) == -1 && err == NULL)
824 		err = got_error_from_errno2("unlink", tmpidxpath);
825 	if (nfetchfd != -1 && close(nfetchfd) == -1 && err == NULL)
826 		err = got_error_from_errno("close");
827 	if (npackfd != -1 && close(npackfd) == -1 && err == NULL)
828 		err = got_error_from_errno("close");
829 	if (packfd != -1 && close(packfd) == -1 && err == NULL)
830 		err = got_error_from_errno("close");
831 	if (idxfd != -1 && close(idxfd) == -1 && err == NULL)
832 		err = got_error_from_errno("close");
833 	for (i = 0; i < nitems(tmpfds); i++) {
834 		if (tmpfds[i] != -1 && close(tmpfds[i]) == -1 && err == NULL)
835 			err = got_error_from_errno("close");
836 	}
837 	free(tmppackpath);
838 	free(tmpidxpath);
839 	free(idxpath);
840 	free(packpath);
841 	free(ref_prefix);
842 	free(progress);
843 
844 	TAILQ_FOREACH(pe, &have_refs, entry) {
845 		free((char *)pe->path);
846 		free(pe->data);
847 	}
848 	got_pathlist_free(&have_refs);
849 	got_ref_list_free(&my_refs);
850 	if (err) {
851 		free(*pack_hash);
852 		*pack_hash = NULL;
853 		TAILQ_FOREACH(pe, refs, entry) {
854 			free((void *)pe->path);
855 			free(pe->data);
856 		}
857 		got_pathlist_free(refs);
858 		TAILQ_FOREACH(pe, symrefs, entry) {
859 			free((void *)pe->path);
860 			free(pe->data);
861 		}
862 		got_pathlist_free(symrefs);
863 	}
864 	return err;
865 }