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/syslimits.h>
24 #include <sys/resource.h>
25 #include <sys/socket.h>
26 
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 <zlib.h>
36 #include <ctype.h>
37 #include <limits.h>
38 #include <imsg.h>
39 #include <time.h>
40 #include <uuid.h>
41 #include <netdb.h>
42 #include <netinet/in.h>
43 
44 #include "got_error.h"
45 #include "got_reference.h"
46 #include "got_repository.h"
47 #include "got_path.h"
48 #include "got_cancel.h"
49 #include "got_worktree.h"
50 #include "got_object.h"
51 #include "got_opentemp.h"
52 #include "got_fetch.h"
53 
54 #include "got_lib_delta.h"
55 #include "got_lib_inflate.h"
56 #include "got_lib_object.h"
57 #include "got_lib_object_parse.h"
58 #include "got_lib_object_create.h"
59 #include "got_lib_pack.h"
60 #include "got_lib_sha1.h"
61 #include "got_lib_privsep.h"
62 #include "got_lib_object_cache.h"
63 #include "got_lib_repository.h"
64 
65 #ifndef nitems
66 #define nitems(_a)	(sizeof((_a)) / sizeof((_a)[0]))
67 #endif
68 
69 #ifndef MIN
70 #define	MIN(_a,_b) ((_a) < (_b) ? (_a) : (_b))
71 #endif
72 
73 static int
74 hassuffix(char *base, char *suf)
75 {
76 	int nb, ns;
77 
78 	nb = strlen(base);
79 	ns = strlen(suf);
80 	if (ns <= nb && strcmp(base + (nb - ns), suf) == 0)
81 		return 1;
82 	return 0;
83 }
84 
85 static const struct got_error *
86 dial_ssh(pid_t *fetchpid, int *fetchfd, const char *host, const char *port,
87     const char *path, const char *direction, int verbosity)
88 {
89 	const struct got_error *error = NULL;
90 	int pid, pfd[2];
91 	char cmd[64];
92 	char *argv[11];
93 	int i = 0;
94 
95 	*fetchpid = -1;
96 	*fetchfd = -1;
97 
98 	if (port == NULL)
99 		port = "22";
100 
101 	argv[0] = GOT_FETCH_PATH_SSH;
102 	argv[1] = "-p";
103 	argv[2] = (char *)port;
104 	if (verbosity == -1) {
105 		argv[3 + i++] = "-q";
106 	} else {
107 		/* ssh(1) allows up to 3 "-v" options. */
108 		for (i = 0; i < MIN(3, verbosity); i++)
109 			argv[3 + i] = "-v";
110 	}
111 	argv[3 + i] = "--";
112 	argv[4 + i] = (char *)host;
113 	argv[5 + i] = (char *)cmd;
114 	argv[6 + i] = (char *)path;
115 	argv[7 + i] = NULL;
116 
117 	if (pipe(pfd) == -1)
118 		return got_error_from_errno("pipe");
119 
120 	pid = fork();
121 	if (pid == -1) {
122 		error = got_error_from_errno("fork");
123 		close(pfd[0]);
124 		close(pfd[1]);
125 		return error;
126 	} else if (pid == 0) {
127 		int n;
128 		close(pfd[1]);
129 		dup2(pfd[0], 0);
130 		dup2(pfd[0], 1);
131 		n = snprintf(cmd, sizeof(cmd), "git-%s-pack", direction);
132 		if (n < 0 || n >= sizeof(cmd))
133 			err(1, "snprintf");
134 		if (execv(GOT_FETCH_PATH_SSH, argv) == -1)
135 			err(1, "execl");
136 		abort(); /* not reached */
137 	} else {
138 		close(pfd[0]);
139 		*fetchpid = pid;
140 		*fetchfd = pfd[1];
141 		return NULL;
142 	}
143 }
144 
145 static const struct got_error *
146 dial_git(int *fetchfd, const char *host, const char *port, const char *path,
147     const char *direction)
148 {
149 	const struct got_error *err = NULL;
150 	struct addrinfo hints, *servinfo, *p;
151 	char *cmd = NULL, *pkt = NULL;
152 	int fd = -1, totlen, r, eaicode;
153 
154 	*fetchfd = -1;
155 
156 	if (port == NULL)
157 		port = GOT_DEFAULT_GIT_PORT_STR;
158 
159 	memset(&hints, 0, sizeof hints);
160 	hints.ai_family = AF_UNSPEC;
161 	hints.ai_socktype = SOCK_STREAM;
162 	eaicode = getaddrinfo(host, port, &hints, &servinfo);
163 	if (eaicode) {
164 		char msg[512];
165 		snprintf(msg, sizeof(msg), "%s: %s", host,
166 		    gai_strerror(eaicode));
167 		return got_error_msg(GOT_ERR_ADDRINFO, msg);
168 	}
169 
170 	for (p = servinfo; p != NULL; p = p->ai_next) {
171 		if ((fd = socket(p->ai_family, p->ai_socktype,
172 		    p->ai_protocol)) == -1)
173 			continue;
174 		if (connect(fd, p->ai_addr, p->ai_addrlen) == 0)
175 			break;
176 		err = got_error_from_errno("connect");
177 		close(fd);
178 	}
179 	if (p == NULL)
180 		goto done;
181 
182 	if (asprintf(&cmd, "git-%s-pack %s", direction, path) == -1) {
183 		err = got_error_from_errno("asprintf");
184 		goto done;
185 	}
186 	totlen = 4 + strlen(cmd) + 1 + strlen("host=") + strlen(host) + 1;
187 	if (asprintf(&pkt, "%04x%s", totlen, cmd) == -1) {
188 		err = got_error_from_errno("asprintf");
189 		goto done;
190 	}
191 	r = write(fd, pkt, strlen(pkt) + 1);
192 	if (r == -1) {
193 		err = got_error_from_errno("write");
194 		goto done;
195 	}
196 	if (asprintf(&pkt, "host=%s", host) == -1) {
197 		err = got_error_from_errno("asprintf");
198 		goto done;
199 	}
200 	r = write(fd, pkt, strlen(pkt) + 1);
201 	if (r == -1) {
202 		err = got_error_from_errno("write");
203 		goto done;
204 	}
205 done:
206 	free(cmd);
207 	free(pkt);
208 	if (err) {
209 		if (fd != -1)
210 			close(fd);
211 	} else
212 		*fetchfd = fd;
213 	return err;
214 }
215 
216 const struct got_error *
217 got_fetch_connect(pid_t *fetchpid, int *fetchfd, const char *proto,
218     const char *host, const char *port, const char *server_path, int verbosity)
219 {
220 	const struct got_error *err = NULL;
221 
222 	*fetchpid = -1;
223 	*fetchfd = -1;
224 
225 	if (strcmp(proto, "ssh") == 0 || strcmp(proto, "git+ssh") == 0)
226 		err = dial_ssh(fetchpid, fetchfd, host, port, server_path,
227 		    "upload", verbosity);
228 	else if (strcmp(proto, "git") == 0)
229 		err = dial_git(fetchfd, host, port, server_path, "upload");
230 	else if (strcmp(proto, "http") == 0 || strcmp(proto, "git+http") == 0)
231 		err = got_error_path(proto, GOT_ERR_NOT_IMPL);
232 	else
233 		err = got_error_path(proto, GOT_ERR_BAD_PROTO);
234 	return err;
235 }
236 
237 const struct got_error *
238 got_fetch_parse_uri(char **proto, char **host, char **port,
239     char **server_path, char **repo_name, const char *uri)
240 {
241 	const struct got_error *err = NULL;
242 	char *s, *p, *q;
243 	int n;
244 
245 	*proto = *host = *port = *server_path = *repo_name = NULL;
246 
247 	p = strstr(uri, "://");
248 	if (!p) {
249 		/* Try parsing Git's "scp" style URL syntax. */
250 		*proto = strdup("ssh");
251 		if (proto == NULL) {
252 			err = got_error_from_errno("strdup");
253 			goto done;
254 		}
255 		s = (char *)uri;
256 		q = strchr(s, ':');
257 		if (q == NULL) {
258 			err = got_error(GOT_ERR_PARSE_URI);
259 			goto done;
260 		}
261 		/* No slashes allowed before first colon. */
262 		p = strchr(s, '/');
263 		if (p && q > p) {
264 			err = got_error(GOT_ERR_PARSE_URI);
265 			goto done;
266 		}
267 		*host = strndup(s, q - s);
268 		if (*host == NULL) {
269 			err = got_error_from_errno("strndup");
270 			goto done;
271 		}
272 		p = q + 1;
273 	} else {
274 		*proto = strndup(uri, p - uri);
275 		if (proto == NULL) {
276 			err = got_error_from_errno("strndup");
277 			goto done;
278 		}
279 		s = p + 3;
280 
281 		p = strstr(s, "/");
282 		if (p == NULL || strlen(p) == 1) {
283 			err = got_error(GOT_ERR_PARSE_URI);
284 			goto done;
285 		}
286 
287 		q = memchr(s, ':', p - s);
288 		if (q) {
289 			*host = strndup(s, q - s);
290 			if (*host == NULL) {
291 				err = got_error_from_errno("strndup");
292 				goto done;
293 			}
294 			*port = strndup(q + 1, p - (q + 1));
295 			if (*port == NULL) {
296 				err = got_error_from_errno("strndup");
297 				goto done;
298 			}
299 		} else {
300 			*host = strndup(s, p - s);
301 			if (*host == NULL) {
302 				err = got_error_from_errno("strndup");
303 				goto done;
304 			}
305 		}
306 	}
307 
308 	*server_path = strdup(p);
309 	if (*server_path == NULL) {
310 		err = got_error_from_errno("strdup");
311 		goto done;
312 	}
313 
314 	p = strrchr(p, '/');
315 	if (!p || strlen(p) <= 1) {
316 		err = got_error(GOT_ERR_PARSE_URI);
317 		goto done;
318 	}
319 	p++;
320 	n = strlen(p);
321 	if (n == 0) {
322 		err = got_error(GOT_ERR_PARSE_URI);
323 		goto done;
324 	}
325 	if (hassuffix(p, ".git"))
326 		n -= 4;
327 	*repo_name = strndup(p, (p + n) - p);
328 	if (*repo_name == NULL) {
329 		err = got_error_from_errno("strndup");
330 		goto done;
331 	}
332 done:
333 	if (err) {
334 		free(*proto);
335 		*proto = NULL;
336 		free(*host);
337 		*host = NULL;
338 		free(*port);
339 		*port = NULL;
340 		free(*server_path);
341 		*server_path = NULL;
342 		free(*repo_name);
343 		*repo_name = NULL;
344 	}
345 	return err;
346 }
347 
348 static const struct got_error *
349 check_pack_hash(int fd, size_t sz, uint8_t *hcomp)
350 {
351 	SHA1_CTX ctx;
352 	uint8_t hexpect[SHA1_DIGEST_LENGTH];
353 	uint8_t buf[32 * 1024];
354 	ssize_t n, r, nr;
355 
356 	if (sz < sizeof(struct got_packfile_hdr) + SHA1_DIGEST_LENGTH)
357 		return got_error_msg(GOT_ERR_BAD_PACKFILE, "short packfile");
358 
359 	n = 0;
360 	SHA1Init(&ctx);
361 	while (n < sz - 20) {
362 		nr = sizeof(buf);
363 		if (sz - n - 20 < sizeof(buf))
364 			nr = sz - n - 20;
365 		r = read(fd, buf, nr);
366 		if (r == -1)
367 			return got_error_from_errno("read");
368 		if (r != nr)
369 			return got_error_msg(GOT_ERR_BAD_PACKFILE,
370 			    "short pack file");
371 		SHA1Update(&ctx, buf, nr);
372 		n += r;
373 	}
374 	SHA1Final(hcomp, &ctx);
375 
376 	r = read(fd, hexpect, sizeof(hexpect));
377 	if (r == -1)
378 		return got_error_from_errno("read");
379 	if (r != sizeof(hexpect))
380 		return got_error_msg(GOT_ERR_BAD_PACKFILE,
381 		    "short pack file");
382 
383 	if (memcmp(hcomp, hexpect, SHA1_DIGEST_LENGTH) != 0)
384 		return got_error_msg(GOT_ERR_BAD_PACKFILE,
385 		    "packfile checksum mismatch");
386 
387 	return NULL;
388 }
389 
390 const struct got_error*
391 got_fetch_pack(struct got_object_id **pack_hash, struct got_pathlist_head *refs,
392     struct got_pathlist_head *symrefs, const char *remote_name,
393     int mirror_references, int fetch_all_branches,
394     struct got_pathlist_head *wanted_branches,
395     struct got_pathlist_head *wanted_refs, int list_refs_only, int verbosity,
396     int fetchfd, struct got_repository *repo,
397     got_fetch_progress_cb progress_cb, void *progress_arg)
398 {
399 	int imsg_fetchfds[2], imsg_idxfds[2];
400 	int packfd = -1, npackfd = -1, idxfd = -1, nidxfd = -1, nfetchfd = -1;
401 	int tmpfds[3], i;
402 	int fetchstatus, idxstatus, done = 0;
403 	const struct got_error *err;
404 	struct imsgbuf fetchibuf, idxibuf;
405 	pid_t fetchpid, idxpid;
406 	char *tmppackpath = NULL, *tmpidxpath = NULL;
407 	char *packpath = NULL, *idxpath = NULL, *id_str = NULL;
408 	const char *repo_path = NULL;
409 	struct got_pathlist_head have_refs;
410 	struct got_pathlist_entry *pe;
411 	struct got_reflist_head my_refs;
412 	struct got_reflist_entry *re;
413 	off_t packfile_size = 0;
414 	struct got_packfile_hdr pack_hdr;
415 	uint32_t nobj = 0;
416 	char *ref_prefix = NULL;
417 	size_t ref_prefixlen = 0;
418 	char *path;
419 	char *progress = NULL;
420 
421 	/*
422 	 * Prevent fetching of references that won't make any
423 	 * sense outside of the remote repository's context.
424 	 */
425 	TAILQ_FOREACH(pe, wanted_refs, entry) {
426 		const char *refname = pe->path;
427 		if (strncmp(refname, "refs/got/", 9) == 0 ||
428 		    strncmp(refname, "got/", 4) == 0 ||
429 		    strncmp(refname, "refs/remotes/", 13) == 0 ||
430 		    strncmp(refname, "remotes/", 8) == 0)
431 			return got_error_path(refname, GOT_ERR_FETCH_BAD_REF);
432 	}
433 
434 	if (!list_refs_only)
435 		repo_path = got_repo_get_path_git_dir(repo);
436 
437 	*pack_hash = NULL;
438 	for (i = 0; i < nitems(tmpfds); i++)
439 		tmpfds[i] = -1;
440 
441 	TAILQ_INIT(&have_refs);
442 	SIMPLEQ_INIT(&my_refs);
443 
444 	if (!mirror_references) {
445 		if (asprintf(&ref_prefix, "refs/remotes/%s/",
446 		    remote_name) == -1)
447 			return got_error_from_errno("asprintf");
448 		ref_prefixlen = strlen(ref_prefix);
449 	}
450 
451 	if (!list_refs_only) {
452 		err = got_ref_list(&my_refs, repo, NULL,
453 		    got_ref_cmp_by_name, NULL);
454 		if (err)
455 			goto done;
456 	}
457 
458 	SIMPLEQ_FOREACH(re, &my_refs, entry) {
459 		struct got_object_id *id;
460 		const char *refname;
461 
462 		if (got_ref_is_symbolic(re->ref))
463 			continue;
464 
465 		refname = got_ref_get_name(re->ref);
466 
467 		if (mirror_references) {
468 			char *name;
469 			err = got_ref_resolve(&id, repo, re->ref);
470 			if (err)
471 				goto done;
472 			name = strdup(refname);
473 			if (name == NULL) {
474 				err = got_error_from_errno("strdup");
475 				goto done;
476 			}
477 			err = got_pathlist_append(&have_refs, name, id);
478 			if (err)
479 				goto done;
480 			continue;
481 		}
482 
483 		if (strncmp("refs/tags/", refname, 10) == 0) {
484 			char *tagname;
485 
486 			err = got_ref_resolve(&id, repo, re->ref);
487 			if (err)
488 				goto done;
489 			tagname = strdup(refname);
490 			if (tagname == NULL) {
491 				err = got_error_from_errno("strdup");
492 				goto done;
493 			}
494 			err = got_pathlist_append(&have_refs, tagname, id);
495 			if (err) {
496 				free(tagname);
497 				goto done;
498 			}
499 		}
500 
501 		if (strncmp(ref_prefix, refname, ref_prefixlen) == 0) {
502 			char *branchname;
503 
504 			err = got_ref_resolve(&id, repo, re->ref);
505 			if (err)
506 				goto done;
507 
508 			if (asprintf(&branchname, "refs/heads/%s",
509 			    refname + ref_prefixlen) == -1) {
510 				err = got_error_from_errno("asprintf");
511 				goto done;
512 			}
513 			err = got_pathlist_append(&have_refs, branchname, id);
514 			if (err) {
515 				free(branchname);
516 				goto done;
517 			}
518 		}
519 	}
520 
521 	if (list_refs_only) {
522 		packfd = got_opentempfd();
523 		if (packfd == -1) {
524 			err = got_error_from_errno("got_opentempfd");
525 			goto done;
526 		}
527 	} else {
528 		if (asprintf(&path, "%s/%s/fetching.pack",
529 		    repo_path, GOT_OBJECTS_PACK_DIR) == -1) {
530 			err = got_error_from_errno("asprintf");
531 			goto done;
532 		}
533 		err = got_opentemp_named_fd(&tmppackpath, &packfd, path);
534 		free(path);
535 		if (err)
536 			goto done;
537 	}
538 	if (list_refs_only) {
539 		idxfd = got_opentempfd();
540 		if (idxfd == -1) {
541 			err = got_error_from_errno("got_opentempfd");
542 			goto done;
543 		}
544 	} else {
545 		if (asprintf(&path, "%s/%s/fetching.idx",
546 		    repo_path, GOT_OBJECTS_PACK_DIR) == -1) {
547 			err = got_error_from_errno("asprintf");
548 			goto done;
549 		}
550 		err = got_opentemp_named_fd(&tmpidxpath, &idxfd, path);
551 		free(path);
552 		if (err)
553 			goto done;
554 	}
555 	nidxfd = dup(idxfd);
556 	if (nidxfd == -1) {
557 		err = got_error_from_errno("dup");
558 		goto done;
559 	}
560 
561 	for (i = 0; i < nitems(tmpfds); i++) {
562 		tmpfds[i] = got_opentempfd();
563 		if (tmpfds[i] == -1) {
564 			err = got_error_from_errno("got_opentempfd");
565 			goto done;
566 		}
567 	}
568 
569 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, imsg_fetchfds) == -1) {
570 		err = got_error_from_errno("socketpair");
571 		goto done;
572 	}
573 
574 	fetchpid = fork();
575 	if (fetchpid == -1) {
576 		err = got_error_from_errno("fork");
577 		goto done;
578 	} else if (fetchpid == 0){
579 		got_privsep_exec_child(imsg_fetchfds,
580 		    GOT_PATH_PROG_FETCH_PACK, tmppackpath);
581 	}
582 
583 	if (close(imsg_fetchfds[1]) != 0) {
584 		err = got_error_from_errno("close");
585 		goto done;
586 	}
587 	imsg_init(&fetchibuf, imsg_fetchfds[0]);
588 	nfetchfd = dup(fetchfd);
589 	if (nfetchfd == -1) {
590 		err = got_error_from_errno("dup");
591 		goto done;
592 	}
593 	err = got_privsep_send_fetch_req(&fetchibuf, nfetchfd, &have_refs,
594 	    fetch_all_branches, wanted_branches, wanted_refs,
595 	    list_refs_only, verbosity);
596 	if (err != NULL)
597 		goto done;
598 	nfetchfd = -1;
599 	npackfd = dup(packfd);
600 	if (npackfd == -1) {
601 		err = got_error_from_errno("dup");
602 		goto done;
603 	}
604 	err = got_privsep_send_fetch_outfd(&fetchibuf, npackfd);
605 	if (err != NULL)
606 		goto done;
607 	npackfd = -1;
608 
609 	packfile_size = 0;
610 	progress = calloc(GOT_FETCH_PKTMAX, 1);
611 	if (progress == NULL) {
612 		err = got_error_from_errno("calloc");
613 		goto done;
614 	}
615 	while (!done) {
616 		struct got_object_id *id = NULL;
617 		char *refname = NULL;
618 		char *server_progress = NULL;
619 		off_t packfile_size_cur = 0;
620 
621 		err = got_privsep_recv_fetch_progress(&done,
622 		    &id, &refname, symrefs, &server_progress,
623 		    &packfile_size_cur, &fetchibuf);
624 		if (err != NULL)
625 			goto done;
626 		if (done) {
627 			if (packfile_size > 0)
628 				*pack_hash = id;
629 			else
630 				free(id);
631 		} else if (refname && id) {
632 			err = got_pathlist_insert(NULL, refs, refname, id);
633 			if (err)
634 				goto done;
635 		} else if (server_progress) {
636 			char *p;
637 			/*
638 			 * XXX git-daemon tends to send batched output with
639 			 * lines spanning separate packets. Buffer progress
640 			 * output until we see a CR or LF to avoid giving
641 			 * partial lines of progress output to the callback.
642 			 */
643 			if (strlcat(progress, server_progress,
644 			    GOT_FETCH_PKTMAX) >= GOT_FETCH_PKTMAX) {
645 				progress[0] = '\0'; /* discard */
646 				continue;
647 			}
648 			while ((p = strchr(progress, '\r')) != NULL ||
649 			    (p = strchr(progress, '\n')) != NULL) {
650 				char *s;
651 				size_t n;
652 				char c = *p;
653 				*p = '\0';
654 				if (asprintf(&s, "%s%s", progress,
655 				    c == '\n' ? "\n" : "") == -1) {
656 					err = got_error_from_errno("asprintf");
657 					goto done;
658 				}
659 				err = progress_cb(progress_arg, s,
660 				    packfile_size_cur, 0, 0, 0, 0);
661 				free(s);
662 				if (err)
663 					break;
664 				n = strlen(progress);
665 				if (n < GOT_FETCH_PKTMAX - 1) {
666 					memmove(progress, &progress[n + 1],
667 					    GOT_FETCH_PKTMAX - n - 1);
668 				} else
669 					progress[0] = '\0';
670 			}
671 			free(server_progress);
672 			if (err)
673 				goto done;
674 		} else if (packfile_size_cur != packfile_size) {
675 			err = progress_cb(progress_arg, NULL,
676 			    packfile_size_cur, 0, 0, 0, 0);
677 			if (err)
678 				break;
679 			packfile_size = packfile_size_cur;
680 		}
681 	}
682 	if (waitpid(fetchpid, &fetchstatus, 0) == -1) {
683 		err = got_error_from_errno("waitpid");
684 		goto done;
685 	}
686 
687 	if (lseek(packfd, 0, SEEK_SET) == -1) {
688 		err = got_error_from_errno("lseek");
689 		goto done;
690 	}
691 
692 	/* If zero data was fetched without error we are already up-to-date. */
693 	if (packfile_size == 0)
694 		goto done;
695 	else if (packfile_size < sizeof(pack_hdr) + SHA1_DIGEST_LENGTH) {
696 		err = got_error_msg(GOT_ERR_BAD_PACKFILE, "short pack file");
697 		goto done;
698 	} else {
699 		ssize_t n;
700 
701 		n = read(packfd, &pack_hdr, sizeof(pack_hdr));
702 		if (n == -1) {
703 			err = got_error_from_errno("read");
704 			goto done;
705 		}
706 		if (n != sizeof(pack_hdr)) {
707 			err = got_error(GOT_ERR_IO);
708 			goto done;
709 		}
710 		if (pack_hdr.signature != htobe32(GOT_PACKFILE_SIGNATURE)) {
711 			err = got_error_msg(GOT_ERR_BAD_PACKFILE,
712 			    "bad pack file signature");
713 			goto done;
714 		}
715 		if (pack_hdr.version != htobe32(GOT_PACKFILE_VERSION)) {
716 			err = got_error_msg(GOT_ERR_BAD_PACKFILE,
717 			    "bad pack file version");
718 			goto done;
719 		}
720 		nobj = betoh32(pack_hdr.nobjects);
721 		if (nobj == 0 &&
722 		    packfile_size > sizeof(pack_hdr) + SHA1_DIGEST_LENGTH)
723 			return got_error_msg(GOT_ERR_BAD_PACKFILE,
724 			    "bad pack file with zero objects");
725 		if (nobj != 0 &&
726 		    packfile_size <= sizeof(pack_hdr) + SHA1_DIGEST_LENGTH)
727 			return got_error_msg(GOT_ERR_BAD_PACKFILE,
728 			    "empty pack file with non-zero object count");
729 	}
730 
731 	/*
732 	 * If the pack file contains no objects, we may only need to update
733 	 * references in our repository. The caller will take care of that.
734 	 */
735 	if (nobj == 0)
736 		goto done;
737 
738 	if (lseek(packfd, 0, SEEK_SET) == -1) {
739 		err = got_error_from_errno("lseek");
740 		goto done;
741 	}
742 
743 	err = check_pack_hash(packfd, packfile_size, (*pack_hash)->sha1);
744 	if (err)
745 		goto done;
746 
747 	if (lseek(packfd, 0, SEEK_SET) == -1) {
748 		err = got_error_from_errno("lseek");
749 		goto done;
750 	}
751  
752 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, imsg_idxfds) == -1) {
753 		err = got_error_from_errno("socketpair");
754 		goto done;
755 	}
756 	idxpid = fork();
757 	if (idxpid == -1) {
758 		err= got_error_from_errno("fork");
759 		goto done;
760 	} else if (idxpid == 0)
761 		got_privsep_exec_child(imsg_idxfds,
762 		    GOT_PATH_PROG_INDEX_PACK, tmppackpath);
763 	if (close(imsg_idxfds[1]) != 0) {
764 		err = got_error_from_errno("close");
765 		goto done;
766 	}
767 	imsg_init(&idxibuf, imsg_idxfds[0]);
768 
769 	npackfd = dup(packfd);
770 	if (npackfd == -1) {
771 		err = got_error_from_errno("dup");
772 		goto done;
773 	}
774 	err = got_privsep_send_index_pack_req(&idxibuf, (*pack_hash)->sha1,
775 	    npackfd);
776 	if (err != NULL)
777 		goto done;
778 	npackfd = -1;
779 	err = got_privsep_send_index_pack_outfd(&idxibuf, nidxfd);
780 	if (err != NULL)
781 		goto done;
782 	nidxfd = -1;
783 	for (i = 0; i < nitems(tmpfds); i++) {
784 		err = got_privsep_send_tmpfd(&idxibuf, tmpfds[i]);
785 		if (err != NULL)
786 			goto done;
787 		tmpfds[i] = -1;
788 	}
789 	done = 0;
790 	while (!done) {
791 		int nobj_total, nobj_indexed, nobj_loose, nobj_resolved;
792 
793 		err = got_privsep_recv_index_progress(&done, &nobj_total,
794 		    &nobj_indexed, &nobj_loose, &nobj_resolved,
795 		    &idxibuf);
796 		if (err != NULL)
797 			goto done;
798 		if (nobj_indexed != 0) {
799 			err = progress_cb(progress_arg, NULL,
800 			    packfile_size, nobj_total,
801 			    nobj_indexed, nobj_loose, nobj_resolved);
802 			if (err)
803 				break;
804 		}
805 		imsg_clear(&idxibuf);
806 	}
807 	if (close(imsg_idxfds[0]) == -1) {
808 		err = got_error_from_errno("close");
809 		goto done;
810 	}
811 	if (waitpid(idxpid, &idxstatus, 0) == -1) {
812 		err = got_error_from_errno("waitpid");
813 		goto done;
814 	}
815 
816 	err = got_object_id_str(&id_str, *pack_hash);
817 	if (err)
818 		goto done;
819 	if (asprintf(&packpath, "%s/%s/pack-%s.pack",
820 	    repo_path, GOT_OBJECTS_PACK_DIR, id_str) == -1) {
821 		err = got_error_from_errno("asprintf");
822 		goto done;
823 	}
824 
825 	if (asprintf(&idxpath, "%s/%s/pack-%s.idx",
826 	    repo_path, GOT_OBJECTS_PACK_DIR, id_str) == -1) {
827 		err = got_error_from_errno("asprintf");
828 		goto done;
829 	}
830 
831 	if (rename(tmppackpath, packpath) == -1) {
832 		err = got_error_from_errno3("rename", tmppackpath, packpath);
833 		goto done;
834 	}
835 	free(tmppackpath);
836 	tmppackpath = NULL;
837 	if (rename(tmpidxpath, idxpath) == -1) {
838 		err = got_error_from_errno3("rename", tmpidxpath, idxpath);
839 		goto done;
840 	}
841 	free(tmpidxpath);
842 	tmpidxpath = NULL;
843 
844 done:
845 	if (tmppackpath && unlink(tmppackpath) == -1 && err == NULL)
846 		err = got_error_from_errno2("unlink", tmppackpath);
847 	if (tmpidxpath && unlink(tmpidxpath) == -1 && err == NULL)
848 		err = got_error_from_errno2("unlink", tmpidxpath);
849 	if (nfetchfd != -1 && close(nfetchfd) == -1 && err == NULL)
850 		err = got_error_from_errno("close");
851 	if (npackfd != -1 && close(npackfd) == -1 && err == NULL)
852 		err = got_error_from_errno("close");
853 	if (packfd != -1 && close(packfd) == -1 && err == NULL)
854 		err = got_error_from_errno("close");
855 	if (idxfd != -1 && close(idxfd) == -1 && err == NULL)
856 		err = got_error_from_errno("close");
857 	for (i = 0; i < nitems(tmpfds); i++) {
858 		if (tmpfds[i] != -1 && close(tmpfds[i]) == -1 && err == NULL)
859 			err = got_error_from_errno("close");
860 	}
861 	free(tmppackpath);
862 	free(tmpidxpath);
863 	free(idxpath);
864 	free(packpath);
865 	free(ref_prefix);
866 	free(progress);
867 
868 	TAILQ_FOREACH(pe, &have_refs, entry) {
869 		free((char *)pe->path);
870 		free(pe->data);
871 	}
872 	got_pathlist_free(&have_refs);
873 	got_ref_list_free(&my_refs);
874 	if (err) {
875 		free(*pack_hash);
876 		*pack_hash = NULL;
877 		TAILQ_FOREACH(pe, refs, entry) {
878 			free((void *)pe->path);
879 			free(pe->data);
880 		}
881 		got_pathlist_free(refs);
882 		TAILQ_FOREACH(pe, symrefs, entry) {
883 			free((void *)pe->path);
884 			free(pe->data);
885 		}
886 		got_pathlist_free(symrefs);
887 	}
888 	return err;
889 }