Gotweb

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Date:: Mon Apr 15 23:25:11 2024 UTC
Message:: for now, remove a workaround for http fetch that was added for unknown reasons ok op@
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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 
23 #include <stdint.h>
24 #include <errno.h>
25 #include <imsg.h>
26 #include <limits.h>
27 #include <signal.h>
28 #include <stdio.h>
29 #include <stdlib.h>
30 #include <string.h>
31 #include <ctype.h>
32 #include <sha1.h>
33 #include <sha2.h>
34 #include <fcntl.h>
35 #include <unistd.h>
36 #include <zlib.h>
37 #include <err.h>
38 
39 #include "got_error.h"
40 #include "got_object.h"
41 #include "got_path.h"
42 #include "got_version.h"
43 #include "got_fetch.h"
44 #include "got_reference.h"
45 
46 #include "got_lib_hash.h"
47 #include "got_lib_delta.h"
48 #include "got_lib_object.h"
49 #include "got_lib_object_parse.h"
50 #include "got_lib_privsep.h"
51 #include "got_lib_pack.h"
52 #include "got_lib_pkt.h"
53 #include "got_lib_gitproto.h"
54 #include "got_lib_ratelimit.h"
55 
56 #ifndef MIN
57 #define	MIN(_a,_b) ((_a) < (_b) ? (_a) : (_b))
58 #endif
59 
60 #ifndef nitems
61 #define nitems(_a)	(sizeof((_a)) / sizeof((_a)[0]))
62 #endif
63 
64 struct got_object *indexed;
65 static int chattygot;
66 
67 static const struct got_capability got_capabilities[] = {
68 	{ GOT_CAPA_AGENT, "got/" GOT_VERSION_STR },
69 	{ GOT_CAPA_OFS_DELTA, NULL },
70 	{ GOT_CAPA_SIDE_BAND_64K, NULL },
71 };
72 
73 static void
74 match_remote_ref(struct got_pathlist_head *have_refs,
75     struct got_object_id *my_id, const char *refname)
76 {
77 	struct got_pathlist_entry *pe;
78 
79 	/* XXX zero-hash signifies we don't have this ref;
80 	 * we should use a flag instead */
81 	memset(my_id, 0, sizeof(*my_id));
82 
83 	TAILQ_FOREACH(pe, have_refs, entry) {
84 		struct got_object_id *id = pe->data;
85 		if (strcmp(pe->path, refname) == 0) {
86 			memcpy(my_id, id, sizeof(*my_id));
87 			break;
88 		}
89 	}
90 }
91 
92 static int
93 match_branch(const char *branch, const char *wanted_branch)
94 {
95 	if (strncmp(branch, "refs/heads/", 11) != 0)
96 		return 0;
97 
98 	if (strncmp(wanted_branch, "refs/heads/", 11) == 0)
99 		wanted_branch += 11;
100 
101 	return (strcmp(branch + 11, wanted_branch) == 0);
102 }
103 
104 static int
105 match_wanted_ref(const char *refname, const char *wanted_ref)
106 {
107 	if (strncmp(refname, "refs/", 5) != 0)
108 		return 0;
109 	refname += 5;
110 
111 	/*
112 	 * Prevent fetching of references that won't make any
113 	 * sense outside of the remote repository's context.
114 	 */
115 	if (strncmp(refname, "got/", 4) == 0)
116 		return 0;
117 	if (strncmp(refname, "remotes/", 8) == 0)
118 		return 0;
119 
120 	if (strncmp(wanted_ref, "refs/", 5) == 0)
121 		wanted_ref += 5;
122 
123 	/* Allow prefix match. */
124 	if (got_path_is_child(refname, wanted_ref, strlen(wanted_ref)))
125 		return 1;
126 
127 	/* Allow exact match. */
128 	return (strcmp(refname, wanted_ref) == 0);
129 }
130 
131 static const struct got_error *
132 send_fetch_server_progress(struct imsgbuf *ibuf, const char *msg, size_t msglen)
133 {
134 	if (msglen > MAX_IMSGSIZE - IMSG_HEADER_SIZE)
135 		return got_error(GOT_ERR_NO_SPACE);
136 
137 	if (msglen == 0)
138 		return NULL;
139 
140 	if (imsg_compose(ibuf, GOT_IMSG_FETCH_SERVER_PROGRESS, 0, 0, -1,
141 	    msg, msglen) == -1)
142 		return got_error_from_errno(
143 		    "imsg_compose FETCH_SERVER_PROGRESS");
144 
145 	return got_privsep_flush_imsg(ibuf);
146 }
147 
148 static const struct got_error *
149 send_fetch_download_progress(struct imsgbuf *ibuf, off_t bytes,
150     struct got_ratelimit *rl)
151 {
152 	const struct got_error *err;
153 	int elapsed = 0;
154 
155 	if (rl) {
156 		err = got_ratelimit_check(&elapsed, rl);
157 		if (err || !elapsed)
158 			return err;
159 	}
160 
161 	if (imsg_compose(ibuf, GOT_IMSG_FETCH_DOWNLOAD_PROGRESS, 0, 0, -1,
162 	    &bytes, sizeof(bytes)) == -1)
163 		return got_error_from_errno(
164 		    "imsg_compose FETCH_DOWNLOAD_PROGRESS");
165 
166 	return got_privsep_flush_imsg(ibuf);
167 }
168 
169 static const struct got_error *
170 send_fetch_done(struct imsgbuf *ibuf, uint8_t *pack_sha1)
171 {
172 	if (imsg_compose(ibuf, GOT_IMSG_FETCH_DONE, 0, 0, -1,
173 	    pack_sha1, SHA1_DIGEST_LENGTH) == -1)
174 		return got_error_from_errno("imsg_compose FETCH");
175 	return got_privsep_flush_imsg(ibuf);
176 }
177 
178 static const struct got_error *
179 fetch_progress(struct imsgbuf *ibuf, const char *buf, size_t len)
180 {
181 	size_t i;
182 
183 	if (len == 0)
184 		return NULL;
185 
186 	/*
187 	 * Truncate messages which exceed the maximum imsg payload size.
188 	 * Server may send up to 64k.
189 	 */
190 	if (len > MAX_IMSGSIZE - IMSG_HEADER_SIZE)
191 		len = MAX_IMSGSIZE - IMSG_HEADER_SIZE;
192 
193 	/* Only allow printable ASCII. */
194 	for (i = 0; i < len; i++) {
195 		if (isprint((unsigned char)buf[i]) ||
196 		    isspace((unsigned char)buf[i]))
197 			continue;
198 		return got_error_msg(GOT_ERR_BAD_PACKET,
199 		    "non-printable progress message received from server");
200 	}
201 
202 	return send_fetch_server_progress(ibuf, buf, len);
203 }
204 
205 static const struct got_error *
206 fetch_error(const char *buf, size_t len)
207 {
208 	static char msg[1024];
209 	size_t i;
210 
211 	for (i = 0; i < len && i < sizeof(msg) - 1; i++) {
212 		if (!isprint((unsigned char)buf[i]))
213 			return got_error_msg(GOT_ERR_BAD_PACKET,
214 			    "non-printable error message received from server");
215 		msg[i] = buf[i];
216 	}
217 	msg[i] = '\0';
218 	return got_error_msg(GOT_ERR_FETCH_FAILED, msg);
219 }
220 
221 static const struct got_error *
222 send_fetch_symrefs(struct imsgbuf *ibuf, struct got_pathlist_head *symrefs)
223 {
224 	struct ibuf *wbuf;
225 	size_t len, nsymrefs = 0;
226 	struct got_pathlist_entry *pe;
227 
228 	len = sizeof(struct got_imsg_fetch_symrefs);
229 	TAILQ_FOREACH(pe, symrefs, entry) {
230 		const char *target = pe->data;
231 		len += sizeof(struct got_imsg_fetch_symref) +
232 		    pe->path_len + strlen(target);
233 		nsymrefs++;
234 	}
235 
236 	if (len >= MAX_IMSGSIZE - IMSG_HEADER_SIZE)
237 		return got_error(GOT_ERR_NO_SPACE);
238 
239 	wbuf = imsg_create(ibuf, GOT_IMSG_FETCH_SYMREFS, 0, 0, len);
240 	if (wbuf == NULL)
241 		return got_error_from_errno("imsg_create FETCH_SYMREFS");
242 
243 	/* Keep in sync with struct got_imsg_fetch_symrefs definition! */
244 	if (imsg_add(wbuf, &nsymrefs, sizeof(nsymrefs)) == -1)
245 		return got_error_from_errno("imsg_add FETCH_SYMREFS");
246 
247 	TAILQ_FOREACH(pe, symrefs, entry) {
248 		const char *name = pe->path;
249 		size_t name_len = pe->path_len;
250 		const char *target = pe->data;
251 		size_t target_len = strlen(target);
252 
253 		/* Keep in sync with struct got_imsg_fetch_symref definition! */
254 		if (imsg_add(wbuf, &name_len, sizeof(name_len)) == -1)
255 			return got_error_from_errno("imsg_add FETCH_SYMREFS");
256 		if (imsg_add(wbuf, &target_len, sizeof(target_len)) == -1)
257 			return got_error_from_errno("imsg_add FETCH_SYMREFS");
258 		if (imsg_add(wbuf, name, name_len) == -1)
259 			return got_error_from_errno("imsg_add FETCH_SYMREFS");
260 		if (imsg_add(wbuf, target, target_len) == -1)
261 			return got_error_from_errno("imsg_add FETCH_SYMREFS");
262 	}
263 
264 	imsg_close(ibuf, wbuf);
265 	return got_privsep_flush_imsg(ibuf);
266 }
267 
268 static const struct got_error *
269 send_fetch_ref(struct imsgbuf *ibuf, struct got_object_id *refid,
270     const char *refname)
271 {
272 	struct ibuf *wbuf;
273 	size_t len, reflen = strlen(refname);
274 
275 	len = sizeof(struct got_imsg_fetch_ref) + reflen;
276 	if (len >= MAX_IMSGSIZE - IMSG_HEADER_SIZE)
277 		return got_error(GOT_ERR_NO_SPACE);
278 
279 	wbuf = imsg_create(ibuf, GOT_IMSG_FETCH_REF, 0, 0, len);
280 	if (wbuf == NULL)
281 		return got_error_from_errno("imsg_create FETCH_REF");
282 
283 	/* Keep in sync with struct got_imsg_fetch_ref definition! */
284 	if (imsg_add(wbuf, refid, sizeof(*refid)) == -1)
285 		return got_error_from_errno("imsg_add FETCH_REF");
286 	if (imsg_add(wbuf, refname, reflen) == -1)
287 		return got_error_from_errno("imsg_add FETCH_REF");
288 
289 	imsg_close(ibuf, wbuf);
290 	return got_privsep_flush_imsg(ibuf);
291 }
292 
293 static const struct got_error *
294 fetch_ref(struct imsgbuf *ibuf, struct got_pathlist_head *have_refs,
295     struct got_object_id *have, struct got_object_id *want,
296     const char *refname, const char *id_str)
297 {
298 	const struct got_error *err;
299 	char *theirs = NULL, *mine = NULL;
300 
301 	if (!got_parse_object_id(want, id_str, GOT_HASH_SHA1)) {
302 		err = got_error(GOT_ERR_BAD_OBJ_ID_STR);
303 		goto done;
304 	}
305 
306 	match_remote_ref(have_refs, have, refname);
307 	err = send_fetch_ref(ibuf, want, refname);
308 	if (err)
309 		goto done;
310 
311 	if (chattygot)
312 		fprintf(stderr, "%s: %s will be fetched\n",
313 		    getprogname(), refname);
314 	if (chattygot > 1) {
315 		err = got_object_id_str(&theirs, want);
316 		if (err)
317 			goto done;
318 		err = got_object_id_str(&mine, have);
319 		if (err)
320 			goto done;
321 		fprintf(stderr, "%s: remote: %s\n%s: local:  %s\n",
322 		    getprogname(), theirs, getprogname(), mine);
323 	}
324 done:
325 	free(theirs);
326 	free(mine);
327 	return err;
328 }
329 
330 static const struct got_error *
331 fetch_pack(int fd, int packfd, uint8_t *pack_sha1,
332     struct got_pathlist_head *have_refs, int fetch_all_branches,
333     struct got_pathlist_head *wanted_branches,
334     struct got_pathlist_head *wanted_refs, int list_refs_only,
335     const char *worktree_branch, const char *remote_head,
336     int no_head, struct imsgbuf *ibuf)
337 {
338 	const struct got_error *err = NULL;
339 	char buf[GOT_PKT_MAX];
340 	char hashstr[SHA1_DIGEST_STRING_LENGTH];
341 	struct got_object_id *have, *want;
342 	int is_firstpkt = 1, nref = 0, refsz = 16;
343 	int i, n, nwant = 0, nhave = 0, acked = 0;
344 	off_t packsz = 0, last_reported_packsz = 0;
345 	char *id_str = NULL, *default_id_str = NULL, *refname = NULL;
346 	char *server_capabilities = NULL, *my_capabilities = NULL;
347 	const char *default_branch = NULL;
348 	struct got_pathlist_head symrefs;
349 	struct got_pathlist_entry *pe;
350 	int sent_my_capabilites = 0, have_sidebands = 0;
351 	int found_branch = 0;
352 	struct got_hash ctx;
353 	uint8_t sha1_buf[SHA1_DIGEST_LENGTH];
354 	size_t sha1_buf_len = 0;
355 	ssize_t w;
356 	struct got_ratelimit rl;
357 
358 	TAILQ_INIT(&symrefs);
359 	got_hash_init(&ctx, GOT_HASH_SHA1);
360 	got_ratelimit_init(&rl, 0, 500);
361 
362 	have = malloc(refsz * sizeof(have[0]));
363 	if (have == NULL)
364 		return got_error_from_errno("malloc");
365 	want = malloc(refsz * sizeof(want[0]));
366 	if (want == NULL) {
367 		err = got_error_from_errno("malloc");
368 		goto done;
369 	}
370 	while (1) {
371 		err = got_pkt_readpkt(&n, fd, buf, sizeof(buf), chattygot);
372 		if (err)
373 			goto done;
374 		if (n == 0)
375 			break;
376 		if (n >= 4 && strncmp(buf, "ERR ", 4) == 0) {
377 			err = fetch_error(&buf[4], n - 4);
378 			goto done;
379 		}
380 		free(id_str);
381 		free(refname);
382 		err = got_gitproto_parse_refline(&id_str, &refname,
383 		    &server_capabilities, buf, n);
384 		if (err)
385 			goto done;
386 
387 		if (refsz == nref + 1) {
388 			struct got_object_id *h, *w;
389 
390 			refsz *= 2;
391 			h = reallocarray(have, refsz, sizeof(have[0]));
392 			if (h == NULL) {
393 				err = got_error_from_errno("reallocarray");
394 				goto done;
395 			}
396 			have = h;
397 			w = reallocarray(want, refsz, sizeof(want[0]));
398 			if (w == NULL) {
399 				err = got_error_from_errno("reallocarray");
400 				goto done;
401 			}
402 			want = w;
403 		}
404 
405 		if (is_firstpkt) {
406 			if (chattygot && server_capabilities[0] != '\0')
407 				fprintf(stderr, "%s: server capabilities: %s\n",
408 				    getprogname(), server_capabilities);
409 			err = got_gitproto_match_capabilities(&my_capabilities,
410 			    &symrefs, server_capabilities,
411 			    got_capabilities, nitems(got_capabilities));
412 			if (err)
413 				goto done;
414 			if (chattygot)
415 				fprintf(stderr, "%s: my capabilities:%s\n",
416 				    getprogname(), my_capabilities != NULL ?
417 				    my_capabilities : "");
418 			err = send_fetch_symrefs(ibuf, &symrefs);
419 			if (err)
420 				goto done;
421 			is_firstpkt = 0;
422 			if (!fetch_all_branches) {
423 				TAILQ_FOREACH(pe, &symrefs, entry) {
424 					const char *name = pe->path;
425 					const char *symref_target = pe->data;
426 					if (strcmp(name, GOT_REF_HEAD) != 0)
427 						continue;
428 					default_branch = symref_target;
429 					break;
430 				}
431 			}
432 			if (default_branch)
433 				continue;
434 		}
435 		if (strstr(refname, "^{}")) {
436 			if (chattygot) {
437 				fprintf(stderr, "%s: ignoring %s\n",
438 				    getprogname(), refname);
439 			}
440 			continue;
441 		}
442 		if (default_branch && default_id_str == NULL &&
443 		    strcmp(refname, default_branch) == 0) {
444 			default_id_str = strdup(id_str);
445 			if (default_id_str == NULL) {
446 				err = got_error_from_errno("strdup");
447 				goto done;
448 			}
449 		}
450 
451 		if (list_refs_only || strncmp(refname, "refs/tags/", 10) == 0) {
452 			err = fetch_ref(ibuf, have_refs, &have[nref],
453 			    &want[nref], refname, id_str);
454 			if (err)
455 				goto done;
456 			nref++;
457 		} else if (strncmp(refname, "refs/heads/", 11) == 0) {
458 			if (fetch_all_branches) {
459 				err = fetch_ref(ibuf, have_refs, &have[nref],
460 				    &want[nref], refname, id_str);
461 				if (err)
462 					goto done;
463 				nref++;
464 				found_branch = 1;
465 				continue;
466 			}
467 			TAILQ_FOREACH(pe, wanted_branches, entry) {
468 				if (match_branch(refname, pe->path))
469 					break;
470 			}
471 			if (pe != NULL || (worktree_branch != NULL &&
472 			    match_branch(refname, worktree_branch))) {
473 				err = fetch_ref(ibuf, have_refs, &have[nref],
474 				    &want[nref], refname, id_str);
475 				if (err)
476 					goto done;
477 				nref++;
478 				found_branch = 1;
479 			} else if (chattygot) {
480 				fprintf(stderr, "%s: ignoring %s\n",
481 				    getprogname(), refname);
482 			}
483 		} else {
484 			TAILQ_FOREACH(pe, wanted_refs, entry) {
485 				if (match_wanted_ref(refname, pe->path))
486 					break;
487 			}
488 			if (pe != NULL) {
489 				err = fetch_ref(ibuf, have_refs, &have[nref],
490 				    &want[nref], refname, id_str);
491 				if (err)
492 					goto done;
493 				nref++;
494 			} else if (chattygot) {
495 				fprintf(stderr, "%s: ignoring %s\n",
496 				    getprogname(), refname);
497 			}
498 		}
499 	}
500 
501 	if (list_refs_only)
502 		goto done;
503 
504 	/*
505 	 * If -b was not used and either none of the requested branches
506 	 * (got.conf, worktree) were found or the client already has the
507 	 * remote HEAD symref but its target changed, fetch remote's HEAD.
508 	 */
509 	if (!no_head && default_branch && default_id_str &&
510 	    strncmp(default_branch, "refs/heads/", 11) == 0) {
511 		int remote_head_changed = 0;
512 
513 		if (remote_head) {
514 			if (strcmp(remote_head, default_branch + 11) != 0)
515 				remote_head_changed = 1;
516 		}
517 
518 		if (!found_branch || remote_head_changed) {
519 			err = fetch_ref(ibuf, have_refs, &have[nref],
520 			    &want[nref], default_branch, default_id_str);
521 			if (err)
522 				goto done;
523 			nref++;
524 		}
525 	}
526 
527 	/* Abort if we haven't found anything to fetch. */
528 	if (nref == 0) {
529 		struct got_pathlist_entry *pe;
530 		static char msg[PATH_MAX + 33];
531 
532 		pe = TAILQ_FIRST(wanted_branches);
533 		if (pe) {
534 			snprintf(msg, sizeof(msg),
535 			    "branch \"%s\" not found on server", pe->path);
536 			err = got_error_msg(GOT_ERR_FETCH_NO_BRANCH, msg);
537 			goto done;
538 		}
539 
540 		pe = TAILQ_FIRST(wanted_refs);
541 		if (pe) {
542 			snprintf(msg, sizeof(msg),
543 			    "reference \"%s\" not found on server", pe->path);
544 			err = got_error_msg(GOT_ERR_FETCH_NO_BRANCH, msg);
545 			goto done;
546 		}
547 
548 		err = got_error(GOT_ERR_FETCH_NO_BRANCH);
549 		goto done;
550 	}
551 
552 	for (i = 0; i < nref; i++) {
553 		if (got_object_id_cmp(&have[i], &want[i]) == 0)
554 			continue;
555 		got_sha1_digest_to_str(want[i].sha1, hashstr, sizeof(hashstr));
556 		n = snprintf(buf, sizeof(buf), "want %s%s\n", hashstr,
557 		    sent_my_capabilites || my_capabilities == NULL ?
558 		    "" : my_capabilities);
559 		if (n < 0 || (size_t)n >= sizeof(buf)) {
560 			err = got_error(GOT_ERR_NO_SPACE);
561 			goto done;
562 		}
563 		err = got_pkt_writepkt(fd, buf, n, chattygot);
564 		if (err)
565 			goto done;
566 		sent_my_capabilites = 1;
567 		nwant++;
568 	}
569 	err = got_pkt_flushpkt(fd, chattygot);
570 	if (err)
571 		goto done;
572 
573 	if (nwant == 0)
574 		goto done;
575 
576 	TAILQ_FOREACH(pe, have_refs, entry) {
577 		struct got_object_id *id = pe->data;
578 		got_sha1_digest_to_str(id->sha1, hashstr, sizeof(hashstr));
579 		n = snprintf(buf, sizeof(buf), "have %s\n", hashstr);
580 		if (n < 0 || (size_t)n >= sizeof(buf)) {
581 			err = got_error(GOT_ERR_NO_SPACE);
582 			goto done;
583 		}
584 		err = got_pkt_writepkt(fd, buf, n, chattygot);
585 		if (err)
586 			goto done;
587 		nhave++;
588 	}
589 
590 	n = strlcpy(buf, "done\n", sizeof(buf));
591 	err = got_pkt_writepkt(fd, buf, n, chattygot);
592 	if (err)
593 		goto done;
594 
595 	while (nhave > 0 && !acked) {
596 		struct got_object_id common_id;
597 
598 		/* The server should ACK the object IDs we need. */
599 		err = got_pkt_readpkt(&n, fd, buf, sizeof(buf), chattygot);
600 		if (err)
601 			goto done;
602 		if (n >= 4 && strncmp(buf, "ERR ", 4) == 0) {
603 			err = fetch_error(&buf[4], n - 4);
604 			goto done;
605 		}
606 		if (n >= 4 && strncmp(buf, "NAK\n", 4) == 0) {
607 			/*
608 			 * Server could not find a common ancestor.
609 			 * Perhaps it is an out-of-date mirror, or there
610 			 * is a repository with unrelated history.
611 			 */
612 			break;
613 		}
614 		if (n < 4 + SHA1_DIGEST_STRING_LENGTH ||
615 		    strncmp(buf, "ACK ", 4) != 0) {
616 			err = got_error_msg(GOT_ERR_BAD_PACKET,
617 			    "unexpected message from server");
618 			goto done;
619 		}
620 		if (!got_parse_object_id(&common_id, buf + 4,
621 		    GOT_HASH_SHA1)) {
622 			err = got_error_msg(GOT_ERR_BAD_PACKET,
623 			    "bad object ID in ACK packet from server");
624 			goto done;
625 		}
626 		acked++;
627 	}
628 
629 	if (nhave == 0) {
630 		err = got_pkt_readpkt(&n, fd, buf, sizeof(buf), chattygot);
631 		if (err)
632 			goto done;
633 		if (n != 4 || strncmp(buf, "NAK\n", n) != 0) {
634 			err = got_error_msg(GOT_ERR_BAD_PACKET,
635 			    "unexpected message from server");
636 			goto done;
637 		}
638 	}
639 
640 	if (chattygot)
641 		fprintf(stderr, "%s: fetching...\n", getprogname());
642 
643 	if (my_capabilities != NULL &&
644 	    strstr(my_capabilities, GOT_CAPA_SIDE_BAND_64K) != NULL)
645 		have_sidebands = 1;
646 
647 	while (1) {
648 		ssize_t r = 0;
649 		int datalen = -1;
650 
651 		if (have_sidebands) {
652 			err = got_pkt_readhdr(&datalen, fd, chattygot);
653 			if (err)
654 				goto done;
655 			if (datalen <= 0)
656 				break;
657 
658 			/* Read sideband channel ID (one byte). */
659 			r = read(fd, buf, 1);
660 			if (r == -1) {
661 				err = got_error_from_errno("read");
662 				goto done;
663 			}
664 			if (r != 1) {
665 				err = got_error_msg(GOT_ERR_BAD_PACKET,
666 				    "short packet");
667 				goto done;
668 			}
669 			if (datalen > sizeof(buf) - 5) {
670 				err = got_error_msg(GOT_ERR_BAD_PACKET,
671 				    "bad packet length");
672 				goto done;
673 			}
674 			datalen--; /* sideband ID has been read */
675 			if (buf[0] == GOT_SIDEBAND_PACKFILE_DATA) {
676 				/* Read packfile data. */
677 				err = got_pkt_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 			} else if (buf[0] == GOT_SIDEBAND_PROGRESS_INFO) {
686 				err = got_pkt_readn(&r, fd, buf, datalen);
687 				if (err)
688 					goto done;
689 				if (r != datalen) {
690 					err = got_error_msg(GOT_ERR_BAD_PACKET,
691 					    "packet too short");
692 					goto done;
693 				}
694 				err = fetch_progress(ibuf, buf, r);
695 				if (err)
696 					goto done;
697 				continue;
698 			} else if (buf[0] == GOT_SIDEBAND_ERROR_INFO) {
699 				err = got_pkt_readn(&r, fd, buf, datalen);
700 				if (err)
701 					goto done;
702 				if (r != datalen) {
703 					err = got_error_msg(GOT_ERR_BAD_PACKET,
704 					    "packet too short");
705 					goto done;
706 				}
707 				err = fetch_error(buf, r);
708 				goto done;
709 			} else if (buf[0] == 'A') {
710 				err = got_pkt_readn(&r, fd, buf, datalen);
711 				if (err)
712 					goto done;
713 				if (r != datalen) {
714 					err = got_error_msg(GOT_ERR_BAD_PACKET,
715 					    "packet too short");
716 					goto done;
717 				}
718 				/*
719 				 * Git server responds with ACK after 'done'
720 				 * even though multi_ack is disabled?!?
721 				 */
722 				buf[r] = '\0';
723 				if (strncmp(buf, "CK ", 3) == 0)
724 					continue; /* ignore */
725 				err = got_error_msg(GOT_ERR_BAD_PACKET,
726 				    "unexpected message from server");
727 				goto done;
728 			} else {
729 				err = got_error_msg(GOT_ERR_BAD_PACKET,
730 				    "unknown side-band received from server");
731 				goto done;
732 			}
733 		} else {
734 			/* No sideband channel. Every byte is packfile data. */
735 			err = got_pkt_readn(&r, fd, buf, sizeof buf);
736 			if (err)
737 				goto done;
738 			if (r <= 0)
739 				break;
740 		}
741 
742 		/*
743 		 * An expected SHA1 checksum sits at the end of the pack file.
744 		 * Since we don't know the file size ahead of time we have to
745 		 * keep SHA1_DIGEST_LENGTH bytes buffered and avoid mixing
746 		 * those bytes into our SHA1 checksum computation until we
747 		 * know for sure that additional pack file data bytes follow.
748 		 *
749 		 * We can assume r > 0 since otherwise the loop would exit.
750 		 */
751 		if (r < SHA1_DIGEST_LENGTH) {
752 			if (sha1_buf_len < SHA1_DIGEST_LENGTH) {
753 				/*
754 				 * If there's enough buffered + read data to
755 				 * fill up the buffer then shift a sufficient
756 				 * amount of bytes out at the front to make
757 				 * room, mixing those bytes into the checksum.
758 				 */
759 				if (sha1_buf_len > 0 &&
760 				    sha1_buf_len + r > SHA1_DIGEST_LENGTH) {
761 					size_t nshift = MIN(sha1_buf_len + r -
762 					    SHA1_DIGEST_LENGTH, sha1_buf_len);
763 					got_hash_update(&ctx, sha1_buf,
764 					    nshift);
765 					memmove(sha1_buf, sha1_buf + nshift,
766 					    sha1_buf_len - nshift);
767 					sha1_buf_len -= nshift;
768 				}
769 
770 				/* Buffer potential checksum bytes. */
771 				memcpy(sha1_buf + sha1_buf_len, buf, r);
772 				sha1_buf_len += r;
773 			} else {
774 				/*
775 				 * Mix in previously buffered bytes which
776 				 * are not part of the checksum after all.
777 				 */
778 				got_hash_update(&ctx, sha1_buf, r);
779 
780 				/* Update potential checksum buffer. */
781 				memmove(sha1_buf, sha1_buf + r,
782 				    sha1_buf_len - r);
783 				memcpy(sha1_buf + sha1_buf_len - r, buf, r);
784 			}
785 		} else {
786 			/* Mix in any previously buffered bytes. */
787 			got_hash_update(&ctx, sha1_buf, sha1_buf_len);
788 
789 			/* Mix in bytes read minus potential checksum bytes. */
790 			got_hash_update(&ctx, buf, r - SHA1_DIGEST_LENGTH);
791 
792 			/* Buffer potential checksum bytes. */
793 			memcpy(sha1_buf, buf + r - SHA1_DIGEST_LENGTH,
794 			    SHA1_DIGEST_LENGTH);
795 			sha1_buf_len = SHA1_DIGEST_LENGTH;
796 		}
797 
798 		/* Write packfile data to temporary pack file. */
799 		w = write(packfd, buf, r);
800 		if (w == -1) {
801 			err = got_error_from_errno("write");
802 			goto done;
803 		}
804 		if (w != r) {
805 			err = got_error(GOT_ERR_IO);
806 			goto done;
807 		}
808 		packsz += w;
809 
810 		/* Don't send too many progress privsep messages. */
811 		if (packsz > last_reported_packsz + 1024) {
812 			err = send_fetch_download_progress(ibuf, packsz, &rl);
813 			if (err)
814 				goto done;
815 			last_reported_packsz = packsz;
816 		}
817 	}
818 	err = send_fetch_download_progress(ibuf, packsz, NULL);
819 	if (err)
820 		goto done;
821 
822 	got_hash_final(&ctx, pack_sha1);
823 	if (sha1_buf_len != SHA1_DIGEST_LENGTH ||
824 	    memcmp(pack_sha1, sha1_buf, sha1_buf_len) != 0) {
825 		err = got_error_msg(GOT_ERR_BAD_PACKFILE,
826 		    "pack file checksum mismatch");
827 	}
828 done:
829 	got_pathlist_free(&symrefs, GOT_PATHLIST_FREE_ALL);
830 	free(have);
831 	free(want);
832 	free(id_str);
833 	free(default_id_str);
834 	free(refname);
835 	free(server_capabilities);
836 	return err;
837 }
838 
839 
840 int
841 main(int argc, char **argv)
842 {
843 	const struct got_error *err = NULL;
844 	int fetchfd = -1, packfd = -1;
845 	uint8_t pack_sha1[SHA1_DIGEST_LENGTH];
846 	struct imsgbuf ibuf;
847 	struct imsg imsg;
848 	struct got_pathlist_head have_refs;
849 	struct got_pathlist_head wanted_branches;
850 	struct got_pathlist_head wanted_refs;
851 	struct got_imsg_fetch_request fetch_req;
852 	struct got_imsg_fetch_have_ref href;
853 	struct got_imsg_fetch_wanted_branch wbranch;
854 	struct got_imsg_fetch_wanted_ref wref;
855 	size_t datalen, i;
856 	char *remote_head = NULL, *worktree_branch = NULL;
857 #if 0
858 	static int attached;
859 	while (!attached)
860 		sleep (1);
861 #endif
862 
863 	TAILQ_INIT(&have_refs);
864 	TAILQ_INIT(&wanted_branches);
865 	TAILQ_INIT(&wanted_refs);
866 
867 	imsg_init(&ibuf, GOT_IMSG_FD_CHILD);
868 #ifndef PROFILE
869 	/* revoke access to most system calls */
870 	if (pledge("stdio recvfd", NULL) == -1) {
871 		err = got_error_from_errno("pledge");
872 		got_privsep_send_error(&ibuf, err);
873 		return 1;
874 	}
875 #endif
876 	err = got_privsep_recv_imsg(&imsg, &ibuf, 0);
877 	if (err) {
878 		if (err->code == GOT_ERR_PRIVSEP_PIPE)
879 			err = NULL;
880 		goto done;
881 	}
882 	if (imsg.hdr.type == GOT_IMSG_STOP)
883 		goto done;
884 	if (imsg.hdr.type != GOT_IMSG_FETCH_REQUEST) {
885 		err = got_error(GOT_ERR_PRIVSEP_MSG);
886 		goto done;
887 	}
888 	datalen = imsg.hdr.len - IMSG_HEADER_SIZE;
889 	if (datalen < sizeof(fetch_req)) {
890 		err = got_error(GOT_ERR_PRIVSEP_LEN);
891 		goto done;
892 	}
893 	memcpy(&fetch_req, imsg.data, sizeof(fetch_req));
894 	fetchfd = imsg_get_fd(&imsg);
895 
896 	if (datalen != sizeof(fetch_req) +
897 	    fetch_req.worktree_branch_len + fetch_req.remote_head_len) {
898 		err = got_error(GOT_ERR_PRIVSEP_LEN);
899 		goto done;
900 	}
901 
902 	if (fetch_req.worktree_branch_len != 0) {
903 		worktree_branch = strndup(imsg.data +
904 		    sizeof(fetch_req), fetch_req.worktree_branch_len);
905 		if (worktree_branch == NULL) {
906 			err = got_error_from_errno("strndup");
907 			goto done;
908 		}
909 	}
910 
911 	if (fetch_req.remote_head_len != 0) {
912 		remote_head = strndup(imsg.data + sizeof(fetch_req) +
913 		    fetch_req.worktree_branch_len, fetch_req.remote_head_len);
914 		if (remote_head == NULL) {
915 			err = got_error_from_errno("strndup");
916 			goto done;
917 		}
918 	}
919 
920 	imsg_free(&imsg);
921 
922 	if (fetch_req.verbosity > 0)
923 		chattygot += fetch_req.verbosity;
924 
925 	for (i = 0; i < fetch_req.n_have_refs; i++) {
926 		struct got_object_id *id;
927 		char *refname;
928 
929 		err = got_privsep_recv_imsg(&imsg, &ibuf, 0);
930 		if (err) {
931 			if (err->code == GOT_ERR_PRIVSEP_PIPE)
932 				err = NULL;
933 			goto done;
934 		}
935 		if (imsg.hdr.type == GOT_IMSG_STOP)
936 			goto done;
937 		if (imsg.hdr.type != GOT_IMSG_FETCH_HAVE_REF) {
938 			err = got_error(GOT_ERR_PRIVSEP_MSG);
939 			goto done;
940 		}
941 		datalen = imsg.hdr.len - IMSG_HEADER_SIZE;
942 		if (datalen < sizeof(href)) {
943 			err = got_error(GOT_ERR_PRIVSEP_LEN);
944 			goto done;
945 		}
946 		memcpy(&href, imsg.data, sizeof(href));
947 		if (datalen - sizeof(href) < href.name_len) {
948 			err = got_error(GOT_ERR_PRIVSEP_LEN);
949 			goto done;
950 		}
951 		refname = strndup(imsg.data + sizeof(href), href.name_len);
952 		if (refname == NULL) {
953 			err = got_error_from_errno("strndup");
954 			goto done;
955 		}
956 
957 		id = malloc(sizeof(*id));
958 		if (id == NULL) {
959 			free(refname);
960 			err = got_error_from_errno("malloc");
961 			goto done;
962 		}
963 		memcpy(id, &href.id, sizeof(*id));
964 		err = got_pathlist_append(&have_refs, refname, id);
965 		if (err) {
966 			free(refname);
967 			free(id);
968 			goto done;
969 		}
970 
971 		imsg_free(&imsg);
972 	}
973 
974 	for (i = 0; i < fetch_req.n_wanted_branches; i++) {
975 		char *refname;
976 
977 		err = got_privsep_recv_imsg(&imsg, &ibuf, 0);
978 		if (err) {
979 			if (err->code == GOT_ERR_PRIVSEP_PIPE)
980 				err = NULL;
981 			goto done;
982 		}
983 		if (imsg.hdr.type == GOT_IMSG_STOP)
984 			goto done;
985 		if (imsg.hdr.type != GOT_IMSG_FETCH_WANTED_BRANCH) {
986 			err = got_error(GOT_ERR_PRIVSEP_MSG);
987 			goto done;
988 		}
989 		datalen = imsg.hdr.len - IMSG_HEADER_SIZE;
990 		if (datalen < sizeof(wbranch)) {
991 			err = got_error(GOT_ERR_PRIVSEP_LEN);
992 			goto done;
993 		}
994 		memcpy(&wbranch, imsg.data, sizeof(wbranch));
995 		if (datalen - sizeof(wbranch) < wbranch.name_len) {
996 			err = got_error(GOT_ERR_PRIVSEP_LEN);
997 			goto done;
998 		}
999 		refname = strndup(imsg.data + sizeof(wbranch),
1000 		    wbranch.name_len);
1001 		if (refname == NULL) {
1002 			err = got_error_from_errno("strndup");
1003 			goto done;
1004 		}
1005 
1006 		err = got_pathlist_append(&wanted_branches, refname, NULL);
1007 		if (err) {
1008 			free(refname);
1009 			goto done;
1010 		}
1011 
1012 		imsg_free(&imsg);
1013 	}
1014 
1015 	for (i = 0; i < fetch_req.n_wanted_refs; i++) {
1016 		char *refname;
1017 
1018 		err = got_privsep_recv_imsg(&imsg, &ibuf, 0);
1019 		if (err) {
1020 			if (err->code == GOT_ERR_PRIVSEP_PIPE)
1021 				err = NULL;
1022 			goto done;
1023 		}
1024 		if (imsg.hdr.type == GOT_IMSG_STOP)
1025 			goto done;
1026 		if (imsg.hdr.type != GOT_IMSG_FETCH_WANTED_REF) {
1027 			err = got_error(GOT_ERR_PRIVSEP_MSG);
1028 			goto done;
1029 		}
1030 		datalen = imsg.hdr.len - IMSG_HEADER_SIZE;
1031 		if (datalen < sizeof(wref)) {
1032 			err = got_error(GOT_ERR_PRIVSEP_LEN);
1033 			goto done;
1034 		}
1035 		memcpy(&wref, imsg.data, sizeof(wref));
1036 		if (datalen - sizeof(wref) < wref.name_len) {
1037 			err = got_error(GOT_ERR_PRIVSEP_LEN);
1038 			goto done;
1039 		}
1040 		refname = strndup(imsg.data + sizeof(wref), wref.name_len);
1041 		if (refname == NULL) {
1042 			err = got_error_from_errno("strndup");
1043 			goto done;
1044 		}
1045 
1046 		err = got_pathlist_append(&wanted_refs, refname, NULL);
1047 		if (err) {
1048 			free(refname);
1049 			goto done;
1050 		}
1051 
1052 		imsg_free(&imsg);
1053 	}
1054 
1055 	err = got_privsep_recv_imsg(&imsg, &ibuf, 0);
1056 	if (err) {
1057 		if (err->code == GOT_ERR_PRIVSEP_PIPE)
1058 			err = NULL;
1059 		goto done;
1060 	}
1061 	if (imsg.hdr.type == GOT_IMSG_STOP)
1062 		goto done;
1063 	if (imsg.hdr.type != GOT_IMSG_FETCH_OUTFD) {
1064 		err = got_error(GOT_ERR_PRIVSEP_MSG);
1065 		goto done;
1066 	}
1067 	if (imsg.hdr.len - IMSG_HEADER_SIZE != 0) {
1068 		err = got_error(GOT_ERR_PRIVSEP_LEN);
1069 		goto done;
1070 	}
1071 	packfd = imsg_get_fd(&imsg);
1072 
1073 	err = fetch_pack(fetchfd, packfd, pack_sha1, &have_refs,
1074 	    fetch_req.fetch_all_branches, &wanted_branches,
1075 	    &wanted_refs, fetch_req.list_refs_only,
1076 	    worktree_branch, remote_head, fetch_req.no_head, &ibuf);
1077 done:
1078 	free(worktree_branch);
1079 	free(remote_head);
1080 	got_pathlist_free(&have_refs, GOT_PATHLIST_FREE_ALL);
1081 	got_pathlist_free(&wanted_branches, GOT_PATHLIST_FREE_PATH);
1082 	if (fetchfd != -1 && close(fetchfd) == -1 && err == NULL)
1083 		err = got_error_from_errno("close");
1084 	if (packfd != -1 && close(packfd) == -1 && err == NULL)
1085 		err = got_error_from_errno("close");
1086 	if (err != NULL)
1087 		got_privsep_send_error(&ibuf, err);
1088 	else
1089 		err = send_fetch_done(&ibuf, pack_sha1);
1090 	if (err != NULL) {
1091 		fprintf(stderr, "%s: %s\n", getprogname(), err->msg);
1092 		got_privsep_send_error(&ibuf, err);
1093 	}
1094 
1095 	exit(0);
1096 }