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Date:: Wed Jan 31 22:01:32 2024 UTC
Message:: remove unneded wbuf->fd = -1 There's no need to set the fd to -1 on ibufs created with imsg_create(3), and it was probably never 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 "got_compat.h"
18 
19 #include <sys/types.h>
20 #include <sys/queue.h>
21 #include <sys/uio.h>
22 #include <sys/time.h>
23 #include <sys/stat.h>
24 
25 #include <stdint.h>
26 #include <errno.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 <fcntl.h>
34 #include <unistd.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 #include "got_fetch.h"
43 #include "got_reference.h"
44 
45 #include "got_lib_hash.h"
46 #include "got_lib_delta.h"
47 #include "got_lib_object.h"
48 #include "got_lib_object_parse.h"
49 #include "got_lib_privsep.h"
50 #include "got_lib_pack.h"
51 #include "got_lib_pkt.h"
52 #include "got_lib_gitproto.h"
53 #include "got_lib_ratelimit.h"
54 
55 #ifndef MIN
56 #define	MIN(_a,_b) ((_a) < (_b) ? (_a) : (_b))
57 #endif
58 
59 #ifndef nitems
60 #define nitems(_a)	(sizeof((_a)) / sizeof((_a)[0]))
61 #endif
62 
63 struct got_object *indexed;
64 static int chattygot;
65 
66 static const struct got_capability got_capabilities[] = {
67 	{ GOT_CAPA_AGENT, "got/" GOT_VERSION_STR },
68 	{ GOT_CAPA_OFS_DELTA, NULL },
69 	{ GOT_CAPA_SIDE_BAND_64K, NULL },
70 };
71 
72 static void
73 match_remote_ref(struct got_pathlist_head *have_refs,
74     struct got_object_id *my_id, const char *refname)
75 {
76 	struct got_pathlist_entry *pe;
77 
78 	/* XXX zero-hash signifies we don't have this ref;
79 	 * we should use a flag instead */
80 	memset(my_id, 0, sizeof(*my_id));
81 
82 	TAILQ_FOREACH(pe, have_refs, entry) {
83 		struct got_object_id *id = pe->data;
84 		if (strcmp(pe->path, refname) == 0) {
85 			memcpy(my_id, id, sizeof(*my_id));
86 			break;
87 		}
88 	}
89 }
90 
91 static int
92 match_branch(const char *branch, const char *wanted_branch)
93 {
94 	if (strncmp(branch, "refs/heads/", 11) != 0)
95 		return 0;
96 
97 	if (strncmp(wanted_branch, "refs/heads/", 11) == 0)
98 		wanted_branch += 11;
99 
100 	return (strcmp(branch + 11, wanted_branch) == 0);
101 }
102 
103 static int
104 match_wanted_ref(const char *refname, const char *wanted_ref)
105 {
106 	if (strncmp(refname, "refs/", 5) != 0)
107 		return 0;
108 	refname += 5;
109 
110 	/*
111 	 * Prevent fetching of references that won't make any
112 	 * sense outside of the remote repository's context.
113 	 */
114 	if (strncmp(refname, "got/", 4) == 0)
115 		return 0;
116 	if (strncmp(refname, "remotes/", 8) == 0)
117 		return 0;
118 
119 	if (strncmp(wanted_ref, "refs/", 5) == 0)
120 		wanted_ref += 5;
121 
122 	/* Allow prefix match. */
123 	if (got_path_is_child(refname, wanted_ref, strlen(wanted_ref)))
124 		return 1;
125 
126 	/* Allow exact match. */
127 	return (strcmp(refname, wanted_ref) == 0);
128 }
129 
130 static const struct got_error *
131 send_fetch_server_progress(struct imsgbuf *ibuf, const char *msg, size_t msglen)
132 {
133 	if (msglen > MAX_IMSGSIZE - IMSG_HEADER_SIZE)
134 		return got_error(GOT_ERR_NO_SPACE);
135 
136 	if (msglen == 0)
137 		return NULL;
138 
139 	if (imsg_compose(ibuf, GOT_IMSG_FETCH_SERVER_PROGRESS, 0, 0, -1,
140 	    msg, msglen) == -1)
141 		return got_error_from_errno(
142 		    "imsg_compose FETCH_SERVER_PROGRESS");
143 
144 	return got_privsep_flush_imsg(ibuf);
145 }
146 
147 static const struct got_error *
148 send_fetch_download_progress(struct imsgbuf *ibuf, off_t bytes,
149     struct got_ratelimit *rl)
150 {
151 	const struct got_error *err;
152 	int elapsed = 0;
153 
154 	if (rl) {
155 		err = got_ratelimit_check(&elapsed, rl);
156 		if (err || !elapsed)
157 			return err;
158 	}
159 
160 	if (imsg_compose(ibuf, GOT_IMSG_FETCH_DOWNLOAD_PROGRESS, 0, 0, -1,
161 	    &bytes, sizeof(bytes)) == -1)
162 		return got_error_from_errno(
163 		    "imsg_compose FETCH_DOWNLOAD_PROGRESS");
164 
165 	return got_privsep_flush_imsg(ibuf);
166 }
167 
168 static const struct got_error *
169 send_fetch_done(struct imsgbuf *ibuf, uint8_t *pack_sha1)
170 {
171 	if (imsg_compose(ibuf, GOT_IMSG_FETCH_DONE, 0, 0, -1,
172 	    pack_sha1, SHA1_DIGEST_LENGTH) == -1)
173 		return got_error_from_errno("imsg_compose FETCH");
174 	return got_privsep_flush_imsg(ibuf);
175 }
176 
177 static const struct got_error *
178 fetch_progress(struct imsgbuf *ibuf, const char *buf, size_t len)
179 {
180 	size_t i;
181 
182 	if (len == 0)
183 		return NULL;
184 
185 	/*
186 	 * Truncate messages which exceed the maximum imsg payload size.
187 	 * Server may send up to 64k.
188 	 */
189 	if (len > MAX_IMSGSIZE - IMSG_HEADER_SIZE)
190 		len = MAX_IMSGSIZE - IMSG_HEADER_SIZE;
191 
192 	/* Only allow printable ASCII. */
193 	for (i = 0; i < len; i++) {
194 		if (isprint((unsigned char)buf[i]) ||
195 		    isspace((unsigned char)buf[i]))
196 			continue;
197 		return got_error_msg(GOT_ERR_BAD_PACKET,
198 		    "non-printable progress message received from server");
199 	}
200 
201 	return send_fetch_server_progress(ibuf, buf, len);
202 }
203 
204 static const struct got_error *
205 fetch_error(const char *buf, size_t len)
206 {
207 	static char msg[1024];
208 	size_t i;
209 
210 	for (i = 0; i < len && i < sizeof(msg) - 1; i++) {
211 		if (!isprint((unsigned char)buf[i]))
212 			return got_error_msg(GOT_ERR_BAD_PACKET,
213 			    "non-printable error message received from server");
214 		msg[i] = buf[i];
215 	}
216 	msg[i] = '\0';
217 	return got_error_msg(GOT_ERR_FETCH_FAILED, msg);
218 }
219 
220 static const struct got_error *
221 send_fetch_symrefs(struct imsgbuf *ibuf, struct got_pathlist_head *symrefs)
222 {
223 	struct ibuf *wbuf;
224 	size_t len, nsymrefs = 0;
225 	struct got_pathlist_entry *pe;
226 
227 	len = sizeof(struct got_imsg_fetch_symrefs);
228 	TAILQ_FOREACH(pe, symrefs, entry) {
229 		const char *target = pe->data;
230 		len += sizeof(struct got_imsg_fetch_symref) +
231 		    pe->path_len + strlen(target);
232 		nsymrefs++;
233 	}
234 
235 	if (len >= MAX_IMSGSIZE - IMSG_HEADER_SIZE)
236 		return got_error(GOT_ERR_NO_SPACE);
237 
238 	wbuf = imsg_create(ibuf, GOT_IMSG_FETCH_SYMREFS, 0, 0, len);
239 	if (wbuf == NULL)
240 		return got_error_from_errno("imsg_create FETCH_SYMREFS");
241 
242 	/* Keep in sync with struct got_imsg_fetch_symrefs definition! */
243 	if (imsg_add(wbuf, &nsymrefs, sizeof(nsymrefs)) == -1)
244 		return got_error_from_errno("imsg_add FETCH_SYMREFS");
245 
246 	TAILQ_FOREACH(pe, symrefs, entry) {
247 		const char *name = pe->path;
248 		size_t name_len = pe->path_len;
249 		const char *target = pe->data;
250 		size_t target_len = strlen(target);
251 
252 		/* Keep in sync with struct got_imsg_fetch_symref definition! */
253 		if (imsg_add(wbuf, &name_len, sizeof(name_len)) == -1)
254 			return got_error_from_errno("imsg_add FETCH_SYMREFS");
255 		if (imsg_add(wbuf, &target_len, sizeof(target_len)) == -1)
256 			return got_error_from_errno("imsg_add FETCH_SYMREFS");
257 		if (imsg_add(wbuf, name, name_len) == -1)
258 			return got_error_from_errno("imsg_add FETCH_SYMREFS");
259 		if (imsg_add(wbuf, target, target_len) == -1)
260 			return got_error_from_errno("imsg_add FETCH_SYMREFS");
261 	}
262 
263 	imsg_close(ibuf, wbuf);
264 	return got_privsep_flush_imsg(ibuf);
265 }
266 
267 static const struct got_error *
268 send_fetch_ref(struct imsgbuf *ibuf, struct got_object_id *refid,
269     const char *refname)
270 {
271 	struct ibuf *wbuf;
272 	size_t len, reflen = strlen(refname);
273 
274 	len = sizeof(struct got_imsg_fetch_ref) + reflen;
275 	if (len >= MAX_IMSGSIZE - IMSG_HEADER_SIZE)
276 		return got_error(GOT_ERR_NO_SPACE);
277 
278 	wbuf = imsg_create(ibuf, GOT_IMSG_FETCH_REF, 0, 0, len);
279 	if (wbuf == NULL)
280 		return got_error_from_errno("imsg_create FETCH_REF");
281 
282 	/* Keep in sync with struct got_imsg_fetch_ref definition! */
283 	if (imsg_add(wbuf, refid, sizeof(*refid)) == -1)
284 		return got_error_from_errno("imsg_add FETCH_REF");
285 	if (imsg_add(wbuf, refname, reflen) == -1)
286 		return got_error_from_errno("imsg_add FETCH_REF");
287 
288 	imsg_close(ibuf, wbuf);
289 	return got_privsep_flush_imsg(ibuf);
290 }
291 
292 static const struct got_error *
293 fetch_ref(struct imsgbuf *ibuf, struct got_pathlist_head *have_refs,
294     struct got_object_id *have, struct got_object_id *want,
295     const char *refname, const char *id_str)
296 {
297 	const struct got_error *err;
298 	char *theirs = NULL, *mine = NULL;
299 
300 	if (!got_parse_object_id(want, id_str, GOT_HASH_SHA1)) {
301 		err = got_error(GOT_ERR_BAD_OBJ_ID_STR);
302 		goto done;
303 	}
304 
305 	match_remote_ref(have_refs, have, refname);
306 	err = send_fetch_ref(ibuf, want, refname);
307 	if (err)
308 		goto done;
309 
310 	if (chattygot)
311 		fprintf(stderr, "%s: %s will be fetched\n",
312 		    getprogname(), refname);
313 	if (chattygot > 1) {
314 		err = got_object_id_str(&theirs, want);
315 		if (err)
316 			goto done;
317 		err = got_object_id_str(&mine, have);
318 		if (err)
319 			goto done;
320 		fprintf(stderr, "%s: remote: %s\n%s: local:  %s\n",
321 		    getprogname(), theirs, getprogname(), mine);
322 	}
323 done:
324 	free(theirs);
325 	free(mine);
326 	return err;
327 }
328 
329 static const struct got_error *
330 fetch_pack(int fd, int packfd, uint8_t *pack_sha1,
331     struct got_pathlist_head *have_refs, int fetch_all_branches,
332     struct got_pathlist_head *wanted_branches,
333     struct got_pathlist_head *wanted_refs, int list_refs_only,
334     const char *worktree_branch, const char *remote_head,
335     int no_head, struct imsgbuf *ibuf)
336 {
337 	const struct got_error *err = NULL;
338 	char buf[GOT_PKT_MAX];
339 	char hashstr[SHA1_DIGEST_STRING_LENGTH];
340 	struct got_object_id *have, *want;
341 	int is_firstpkt = 1, nref = 0, refsz = 16;
342 	int i, n, nwant = 0, nhave = 0, acked = 0;
343 	off_t packsz = 0, last_reported_packsz = 0;
344 	char *id_str = NULL, *default_id_str = NULL, *refname = NULL;
345 	char *server_capabilities = NULL, *my_capabilities = NULL;
346 	const char *default_branch = NULL;
347 	struct got_pathlist_head symrefs;
348 	struct got_pathlist_entry *pe;
349 	int sent_my_capabilites = 0, have_sidebands = 0;
350 	int found_branch = 0;
351 	struct got_hash ctx;
352 	uint8_t sha1_buf[SHA1_DIGEST_LENGTH];
353 	size_t sha1_buf_len = 0;
354 	ssize_t w;
355 	struct got_ratelimit rl;
356 
357 	TAILQ_INIT(&symrefs);
358 	got_hash_init(&ctx, GOT_HASH_SHA1);
359 	got_ratelimit_init(&rl, 0, 500);
360 
361 	have = malloc(refsz * sizeof(have[0]));
362 	if (have == NULL)
363 		return got_error_from_errno("malloc");
364 	want = malloc(refsz * sizeof(want[0]));
365 	if (want == NULL) {
366 		err = got_error_from_errno("malloc");
367 		goto done;
368 	}
369 	while (1) {
370 		err = got_pkt_readpkt(&n, fd, buf, sizeof(buf), chattygot);
371 		if (err)
372 			goto done;
373 		if (n == 0)
374 			break;
375 		if (n >= 4 && strncmp(buf, "ERR ", 4) == 0) {
376 			err = fetch_error(&buf[4], n - 4);
377 			goto done;
378 		}
379 		free(id_str);
380 		free(refname);
381 		err = got_gitproto_parse_refline(&id_str, &refname,
382 		    &server_capabilities, buf, n);
383 		if (err)
384 			goto done;
385 
386 		if (refsz == nref + 1) {
387 			struct got_object_id *h, *w;
388 
389 			refsz *= 2;
390 			h = reallocarray(have, refsz, sizeof(have[0]));
391 			if (h == NULL) {
392 				err = got_error_from_errno("reallocarray");
393 				goto done;
394 			}
395 			have = h;
396 			w = reallocarray(want, refsz, sizeof(want[0]));
397 			if (w == NULL) {
398 				err = got_error_from_errno("reallocarray");
399 				goto done;
400 			}
401 			want = w;
402 		}
403 
404 		if (is_firstpkt) {
405 			if (chattygot && server_capabilities[0] != '\0')
406 				fprintf(stderr, "%s: server capabilities: %s\n",
407 				    getprogname(), server_capabilities);
408 			err = got_gitproto_match_capabilities(&my_capabilities,
409 			    &symrefs, server_capabilities,
410 			    got_capabilities, nitems(got_capabilities));
411 			if (err)
412 				goto done;
413 			if (chattygot)
414 				fprintf(stderr, "%s: my capabilities:%s\n",
415 				    getprogname(), my_capabilities != NULL ?
416 				    my_capabilities : "");
417 			err = send_fetch_symrefs(ibuf, &symrefs);
418 			if (err)
419 				goto done;
420 			is_firstpkt = 0;
421 			if (!fetch_all_branches) {
422 				TAILQ_FOREACH(pe, &symrefs, entry) {
423 					const char *name = pe->path;
424 					const char *symref_target = pe->data;
425 					if (strcmp(name, GOT_REF_HEAD) != 0)
426 						continue;
427 					default_branch = symref_target;
428 					break;
429 				}
430 			}
431 			if (default_branch)
432 				continue;
433 		}
434 		if (strstr(refname, "^{}")) {
435 			if (chattygot) {
436 				fprintf(stderr, "%s: ignoring %s\n",
437 				    getprogname(), refname);
438 			}
439 			continue;
440 		}
441 		if (default_branch && default_id_str == NULL &&
442 		    strcmp(refname, default_branch) == 0) {
443 			default_id_str = strdup(id_str);
444 			if (default_id_str == NULL) {
445 				err = got_error_from_errno("strdup");
446 				goto done;
447 			}
448 		}
449 
450 		if (list_refs_only || strncmp(refname, "refs/tags/", 10) == 0) {
451 			err = fetch_ref(ibuf, have_refs, &have[nref],
452 			    &want[nref], refname, id_str);
453 			if (err)
454 				goto done;
455 			nref++;
456 		} else if (strncmp(refname, "refs/heads/", 11) == 0) {
457 			if (fetch_all_branches) {
458 				err = fetch_ref(ibuf, have_refs, &have[nref],
459 				    &want[nref], refname, id_str);
460 				if (err)
461 					goto done;
462 				nref++;
463 				found_branch = 1;
464 				continue;
465 			}
466 			TAILQ_FOREACH(pe, wanted_branches, entry) {
467 				if (match_branch(refname, pe->path))
468 					break;
469 			}
470 			if (pe != NULL || (worktree_branch != NULL &&
471 			    match_branch(refname, worktree_branch))) {
472 				err = fetch_ref(ibuf, have_refs, &have[nref],
473 				    &want[nref], refname, id_str);
474 				if (err)
475 					goto done;
476 				nref++;
477 				found_branch = 1;
478 			} else if (chattygot) {
479 				fprintf(stderr, "%s: ignoring %s\n",
480 				    getprogname(), refname);
481 			}
482 		} else {
483 			TAILQ_FOREACH(pe, wanted_refs, entry) {
484 				if (match_wanted_ref(refname, pe->path))
485 					break;
486 			}
487 			if (pe != NULL) {
488 				err = fetch_ref(ibuf, have_refs, &have[nref],
489 				    &want[nref], refname, id_str);
490 				if (err)
491 					goto done;
492 				nref++;
493 			} else if (chattygot) {
494 				fprintf(stderr, "%s: ignoring %s\n",
495 				    getprogname(), refname);
496 			}
497 		}
498 	}
499 
500 	if (list_refs_only)
501 		goto done;
502 
503 	/*
504 	 * If -b was not used and either none of the requested branches
505 	 * (got.conf, worktree) were found or the client already has the
506 	 * remote HEAD symref but its target changed, fetch remote's HEAD.
507 	 */
508 	if (!no_head && default_branch && default_id_str &&
509 	    strncmp(default_branch, "refs/heads/", 11) == 0) {
510 		int remote_head_changed = 0;
511 
512 		if (remote_head) {
513 			if (strcmp(remote_head, default_branch + 11) != 0)
514 				remote_head_changed = 1;
515 		}
516 
517 		if (!found_branch || remote_head_changed) {
518 			err = fetch_ref(ibuf, have_refs, &have[nref],
519 			    &want[nref], default_branch, default_id_str);
520 			if (err)
521 				goto done;
522 			nref++;
523 		}
524 	}
525 
526 	/* Abort if we haven't found anything to fetch. */
527 	if (nref == 0) {
528 		struct got_pathlist_entry *pe;
529 		static char msg[PATH_MAX + 33];
530 
531 		pe = TAILQ_FIRST(wanted_branches);
532 		if (pe) {
533 			snprintf(msg, sizeof(msg),
534 			    "branch \"%s\" not found on server", pe->path);
535 			err = got_error_msg(GOT_ERR_FETCH_NO_BRANCH, msg);
536 			goto done;
537 		}
538 
539 		pe = TAILQ_FIRST(wanted_refs);
540 		if (pe) {
541 			snprintf(msg, sizeof(msg),
542 			    "reference \"%s\" not found on server", pe->path);
543 			err = got_error_msg(GOT_ERR_FETCH_NO_BRANCH, msg);
544 			goto done;
545 		}
546 
547 		err = got_error(GOT_ERR_FETCH_NO_BRANCH);
548 		goto done;
549 	}
550 
551 	for (i = 0; i < nref; i++) {
552 		if (got_object_id_cmp(&have[i], &want[i]) == 0)
553 			continue;
554 		got_sha1_digest_to_str(want[i].sha1, hashstr, sizeof(hashstr));
555 		n = snprintf(buf, sizeof(buf), "want %s%s\n", hashstr,
556 		    sent_my_capabilites || my_capabilities == NULL ?
557 		    "" : my_capabilities);
558 		if (n < 0 || (size_t)n >= sizeof(buf)) {
559 			err = got_error(GOT_ERR_NO_SPACE);
560 			goto done;
561 		}
562 		err = got_pkt_writepkt(fd, buf, n, chattygot);
563 		if (err)
564 			goto done;
565 		sent_my_capabilites = 1;
566 		nwant++;
567 	}
568 	err = got_pkt_flushpkt(fd, chattygot);
569 	if (err)
570 		goto done;
571 
572 	if (nwant == 0)
573 		goto done;
574 
575 	TAILQ_FOREACH(pe, have_refs, entry) {
576 		struct got_object_id *id = pe->data;
577 		got_sha1_digest_to_str(id->sha1, hashstr, sizeof(hashstr));
578 		n = snprintf(buf, sizeof(buf), "have %s\n", hashstr);
579 		if (n < 0 || (size_t)n >= sizeof(buf)) {
580 			err = got_error(GOT_ERR_NO_SPACE);
581 			goto done;
582 		}
583 		err = got_pkt_writepkt(fd, buf, n, chattygot);
584 		if (err)
585 			goto done;
586 		nhave++;
587 	}
588 
589 	n = strlcpy(buf, "done\n", sizeof(buf));
590 	err = got_pkt_writepkt(fd, buf, n, chattygot);
591 	if (err)
592 		goto done;
593 
594 	while (nhave > 0 && !acked) {
595 		struct got_object_id common_id;
596 
597 		/* The server should ACK the object IDs we need. */
598 		err = got_pkt_readpkt(&n, fd, buf, sizeof(buf), chattygot);
599 		if (err)
600 			goto done;
601 		if (n >= 4 && strncmp(buf, "ERR ", 4) == 0) {
602 			err = fetch_error(&buf[4], n - 4);
603 			goto done;
604 		}
605 		if (n >= 4 && strncmp(buf, "NAK\n", 4) == 0) {
606 			/*
607 			 * Server could not find a common ancestor.
608 			 * Perhaps it is an out-of-date mirror, or there
609 			 * is a repository with unrelated history.
610 			 */
611 			break;
612 		}
613 		if (n < 4 + SHA1_DIGEST_STRING_LENGTH ||
614 		    strncmp(buf, "ACK ", 4) != 0) {
615 			err = got_error_msg(GOT_ERR_BAD_PACKET,
616 			    "unexpected message from server");
617 			goto done;
618 		}
619 		if (!got_parse_object_id(&common_id, buf + 4,
620 		    GOT_HASH_SHA1)) {
621 			err = got_error_msg(GOT_ERR_BAD_PACKET,
622 			    "bad object ID in ACK packet from server");
623 			goto done;
624 		}
625 		acked++;
626 	}
627 
628 	if (nhave == 0) {
629 		err = got_pkt_readpkt(&n, fd, buf, sizeof(buf), chattygot);
630 		if (err)
631 			goto done;
632 		if (n != 4 || strncmp(buf, "NAK\n", n) != 0) {
633 			err = got_error_msg(GOT_ERR_BAD_PACKET,
634 			    "unexpected message from server");
635 			goto done;
636 		}
637 	}
638 
639 	if (chattygot)
640 		fprintf(stderr, "%s: fetching...\n", getprogname());
641 
642 	if (my_capabilities != NULL &&
643 	    strstr(my_capabilities, GOT_CAPA_SIDE_BAND_64K) != NULL)
644 		have_sidebands = 1;
645 
646 	while (1) {
647 		ssize_t r = 0;
648 		int datalen = -1;
649 
650 		if (have_sidebands) {
651 			err = got_pkt_readhdr(&datalen, fd, chattygot);
652 			if (err)
653 				goto done;
654 			if (datalen <= 0)
655 				break;
656 
657 			/* Read sideband channel ID (one byte). */
658 			r = read(fd, buf, 1);
659 			if (r == -1) {
660 				err = got_error_from_errno("read");
661 				goto done;
662 			}
663 			if (r != 1) {
664 				err = got_error_msg(GOT_ERR_BAD_PACKET,
665 				    "short packet");
666 				goto done;
667 			}
668 			if (datalen > sizeof(buf) - 5) {
669 				err = got_error_msg(GOT_ERR_BAD_PACKET,
670 				    "bad packet length");
671 				goto done;
672 			}
673 			datalen--; /* sideband ID has been read */
674 			if (buf[0] == GOT_SIDEBAND_PACKFILE_DATA) {
675 				/* Read packfile data. */
676 				err = got_pkt_readn(&r, fd, buf, datalen);
677 				if (err)
678 					goto done;
679 				if (r != datalen) {
680 					err = got_error_msg(GOT_ERR_BAD_PACKET,
681 					    "packet too short");
682 					goto done;
683 				}
684 			} else if (buf[0] == GOT_SIDEBAND_PROGRESS_INFO) {
685 				err = got_pkt_readn(&r, fd, buf, datalen);
686 				if (err)
687 					goto done;
688 				if (r != datalen) {
689 					err = got_error_msg(GOT_ERR_BAD_PACKET,
690 					    "packet too short");
691 					goto done;
692 				}
693 				err = fetch_progress(ibuf, buf, r);
694 				if (err)
695 					goto done;
696 				continue;
697 			} else if (buf[0] == GOT_SIDEBAND_ERROR_INFO) {
698 				err = got_pkt_readn(&r, fd, buf, datalen);
699 				if (err)
700 					goto done;
701 				if (r != datalen) {
702 					err = got_error_msg(GOT_ERR_BAD_PACKET,
703 					    "packet too short");
704 					goto done;
705 				}
706 				err = fetch_error(buf, r);
707 				goto done;
708 			} else if (buf[0] == 'A') {
709 				err = got_pkt_readn(&r, fd, buf, datalen);
710 				if (err)
711 					goto done;
712 				if (r != datalen) {
713 					err = got_error_msg(GOT_ERR_BAD_PACKET,
714 					    "packet too short");
715 					goto done;
716 				}
717 				/*
718 				 * Git server responds with ACK after 'done'
719 				 * even though multi_ack is disabled?!?
720 				 */
721 				buf[r] = '\0';
722 				if (strncmp(buf, "CK ", 3) == 0)
723 					continue; /* ignore */
724 				err = got_error_msg(GOT_ERR_BAD_PACKET,
725 				    "unexpected message from server");
726 				goto done;
727 			} else {
728 				err = got_error_msg(GOT_ERR_BAD_PACKET,
729 				    "unknown side-band received from server");
730 				goto done;
731 			}
732 		} else {
733 			/* No sideband channel. Every byte is packfile data. */
734 			err = got_pkt_readn(&r, fd, buf, sizeof buf);
735 			if (err)
736 				goto done;
737 			if (r <= 0)
738 				break;
739 		}
740 
741 		/*
742 		 * An expected SHA1 checksum sits at the end of the pack file.
743 		 * Since we don't know the file size ahead of time we have to
744 		 * keep SHA1_DIGEST_LENGTH bytes buffered and avoid mixing
745 		 * those bytes into our SHA1 checksum computation until we
746 		 * know for sure that additional pack file data bytes follow.
747 		 *
748 		 * We can assume r > 0 since otherwise the loop would exit.
749 		 */
750 		if (r < SHA1_DIGEST_LENGTH) {
751 			if (sha1_buf_len < SHA1_DIGEST_LENGTH) {
752 				/*
753 				 * If there's enough buffered + read data to
754 				 * fill up the buffer then shift a sufficient
755 				 * amount of bytes out at the front to make
756 				 * room, mixing those bytes into the checksum.
757 				 */
758 				if (sha1_buf_len > 0 &&
759 				    sha1_buf_len + r > SHA1_DIGEST_LENGTH) {
760 					size_t nshift = MIN(sha1_buf_len + r -
761 					    SHA1_DIGEST_LENGTH, sha1_buf_len);
762 					got_hash_update(&ctx, sha1_buf,
763 					    nshift);
764 					memmove(sha1_buf, sha1_buf + nshift,
765 					    sha1_buf_len - nshift);
766 					sha1_buf_len -= nshift;
767 				}
768 
769 				/* Buffer potential checksum bytes. */
770 				memcpy(sha1_buf + sha1_buf_len, buf, r);
771 				sha1_buf_len += r;
772 			} else {
773 				/*
774 				 * Mix in previously buffered bytes which
775 				 * are not part of the checksum after all.
776 				 */
777 				got_hash_update(&ctx, sha1_buf, r);
778 
779 				/* Update potential checksum buffer. */
780 				memmove(sha1_buf, sha1_buf + r,
781 				    sha1_buf_len - r);
782 				memcpy(sha1_buf + sha1_buf_len - r, buf, r);
783 			}
784 		} else {
785 			/* Mix in any previously buffered bytes. */
786 			got_hash_update(&ctx, sha1_buf, sha1_buf_len);
787 
788 			/* Mix in bytes read minus potential checksum bytes. */
789 			got_hash_update(&ctx, buf, r - SHA1_DIGEST_LENGTH);
790 
791 			/* Buffer potential checksum bytes. */
792 			memcpy(sha1_buf, buf + r - SHA1_DIGEST_LENGTH,
793 			    SHA1_DIGEST_LENGTH);
794 			sha1_buf_len = SHA1_DIGEST_LENGTH;
795 		}
796 
797 		/* Write packfile data to temporary pack file. */
798 		w = write(packfd, buf, r);
799 		if (w == -1) {
800 			err = got_error_from_errno("write");
801 			goto done;
802 		}
803 		if (w != r) {
804 			err = got_error(GOT_ERR_IO);
805 			goto done;
806 		}
807 		packsz += w;
808 
809 		/* Don't send too many progress privsep messages. */
810 		if (packsz > last_reported_packsz + 1024) {
811 			err = send_fetch_download_progress(ibuf, packsz, &rl);
812 			if (err)
813 				goto done;
814 			last_reported_packsz = packsz;
815 		}
816 	}
817 	err = send_fetch_download_progress(ibuf, packsz, NULL);
818 	if (err)
819 		goto done;
820 
821 	got_hash_final(&ctx, pack_sha1);
822 	if (sha1_buf_len != SHA1_DIGEST_LENGTH ||
823 	    memcmp(pack_sha1, sha1_buf, sha1_buf_len) != 0) {
824 		err = got_error_msg(GOT_ERR_BAD_PACKFILE,
825 		    "pack file checksum mismatch");
826 	}
827 done:
828 	got_pathlist_free(&symrefs, GOT_PATHLIST_FREE_ALL);
829 	free(have);
830 	free(want);
831 	free(id_str);
832 	free(default_id_str);
833 	free(refname);
834 	free(server_capabilities);
835 	return err;
836 }
837 
838 
839 int
840 main(int argc, char **argv)
841 {
842 	const struct got_error *err = NULL;
843 	int fetchfd = -1, packfd = -1;
844 	uint8_t pack_sha1[SHA1_DIGEST_LENGTH];
845 	struct imsgbuf ibuf;
846 	struct imsg imsg;
847 	struct got_pathlist_head have_refs;
848 	struct got_pathlist_head wanted_branches;
849 	struct got_pathlist_head wanted_refs;
850 	struct got_imsg_fetch_request fetch_req;
851 	struct got_imsg_fetch_have_ref href;
852 	struct got_imsg_fetch_wanted_branch wbranch;
853 	struct got_imsg_fetch_wanted_ref wref;
854 	size_t datalen, i;
855 	char *remote_head = NULL, *worktree_branch = NULL;
856 #if 0
857 	static int attached;
858 	while (!attached)
859 		sleep (1);
860 #endif
861 
862 	TAILQ_INIT(&have_refs);
863 	TAILQ_INIT(&wanted_branches);
864 	TAILQ_INIT(&wanted_refs);
865 
866 	imsg_init(&ibuf, GOT_IMSG_FD_CHILD);
867 #ifndef PROFILE
868 	/* revoke access to most system calls */
869 	if (pledge("stdio recvfd", NULL) == -1) {
870 		err = got_error_from_errno("pledge");
871 		got_privsep_send_error(&ibuf, err);
872 		return 1;
873 	}
874 
875 	/* revoke fs access */
876 	if (landlock_no_fs() == -1) {
877 		err = got_error_from_errno("landlock_no_fs");
878 		got_privsep_send_error(&ibuf, err);
879 		return 1;
880 	}
881 	if (cap_enter() == -1) {
882 		err = got_error_from_errno("cap_enter");
883 		got_privsep_send_error(&ibuf, err);
884 		return 1;
885 	}
886 #endif
887 	err = got_privsep_recv_imsg(&imsg, &ibuf, 0);
888 	if (err) {
889 		if (err->code == GOT_ERR_PRIVSEP_PIPE)
890 			err = NULL;
891 		goto done;
892 	}
893 	if (imsg.hdr.type == GOT_IMSG_STOP)
894 		goto done;
895 	if (imsg.hdr.type != GOT_IMSG_FETCH_REQUEST) {
896 		err = got_error(GOT_ERR_PRIVSEP_MSG);
897 		goto done;
898 	}
899 	datalen = imsg.hdr.len - IMSG_HEADER_SIZE;
900 	if (datalen < sizeof(fetch_req)) {
901 		err = got_error(GOT_ERR_PRIVSEP_LEN);
902 		goto done;
903 	}
904 	memcpy(&fetch_req, imsg.data, sizeof(fetch_req));
905 	fetchfd = imsg_get_fd(&imsg);
906 
907 	if (datalen != sizeof(fetch_req) +
908 	    fetch_req.worktree_branch_len + fetch_req.remote_head_len) {
909 		err = got_error(GOT_ERR_PRIVSEP_LEN);
910 		goto done;
911 	}
912 
913 	if (fetch_req.worktree_branch_len != 0) {
914 		worktree_branch = strndup(imsg.data +
915 		    sizeof(fetch_req), fetch_req.worktree_branch_len);
916 		if (worktree_branch == NULL) {
917 			err = got_error_from_errno("strndup");
918 			goto done;
919 		}
920 	}
921 
922 	if (fetch_req.remote_head_len != 0) {
923 		remote_head = strndup(imsg.data + sizeof(fetch_req) +
924 		    fetch_req.worktree_branch_len, fetch_req.remote_head_len);
925 		if (remote_head == NULL) {
926 			err = got_error_from_errno("strndup");
927 			goto done;
928 		}
929 	}
930 
931 	imsg_free(&imsg);
932 
933 	if (fetch_req.verbosity > 0)
934 		chattygot += fetch_req.verbosity;
935 
936 	for (i = 0; i < fetch_req.n_have_refs; i++) {
937 		struct got_object_id *id;
938 		char *refname;
939 
940 		err = got_privsep_recv_imsg(&imsg, &ibuf, 0);
941 		if (err) {
942 			if (err->code == GOT_ERR_PRIVSEP_PIPE)
943 				err = NULL;
944 			goto done;
945 		}
946 		if (imsg.hdr.type == GOT_IMSG_STOP)
947 			goto done;
948 		if (imsg.hdr.type != GOT_IMSG_FETCH_HAVE_REF) {
949 			err = got_error(GOT_ERR_PRIVSEP_MSG);
950 			goto done;
951 		}
952 		datalen = imsg.hdr.len - IMSG_HEADER_SIZE;
953 		if (datalen < sizeof(href)) {
954 			err = got_error(GOT_ERR_PRIVSEP_LEN);
955 			goto done;
956 		}
957 		memcpy(&href, imsg.data, sizeof(href));
958 		if (datalen - sizeof(href) < href.name_len) {
959 			err = got_error(GOT_ERR_PRIVSEP_LEN);
960 			goto done;
961 		}
962 		refname = strndup(imsg.data + sizeof(href), href.name_len);
963 		if (refname == NULL) {
964 			err = got_error_from_errno("strndup");
965 			goto done;
966 		}
967 
968 		id = malloc(sizeof(*id));
969 		if (id == NULL) {
970 			free(refname);
971 			err = got_error_from_errno("malloc");
972 			goto done;
973 		}
974 		memcpy(id, &href.id, sizeof(*id));
975 		err = got_pathlist_append(&have_refs, refname, id);
976 		if (err) {
977 			free(refname);
978 			free(id);
979 			goto done;
980 		}
981 
982 		imsg_free(&imsg);
983 	}
984 
985 	for (i = 0; i < fetch_req.n_wanted_branches; i++) {
986 		char *refname;
987 
988 		err = got_privsep_recv_imsg(&imsg, &ibuf, 0);
989 		if (err) {
990 			if (err->code == GOT_ERR_PRIVSEP_PIPE)
991 				err = NULL;
992 			goto done;
993 		}
994 		if (imsg.hdr.type == GOT_IMSG_STOP)
995 			goto done;
996 		if (imsg.hdr.type != GOT_IMSG_FETCH_WANTED_BRANCH) {
997 			err = got_error(GOT_ERR_PRIVSEP_MSG);
998 			goto done;
999 		}
1000 		datalen = imsg.hdr.len - IMSG_HEADER_SIZE;
1001 		if (datalen < sizeof(wbranch)) {
1002 			err = got_error(GOT_ERR_PRIVSEP_LEN);
1003 			goto done;
1004 		}
1005 		memcpy(&wbranch, imsg.data, sizeof(wbranch));
1006 		if (datalen - sizeof(wbranch) < wbranch.name_len) {
1007 			err = got_error(GOT_ERR_PRIVSEP_LEN);
1008 			goto done;
1009 		}
1010 		refname = strndup(imsg.data + sizeof(wbranch),
1011 		    wbranch.name_len);
1012 		if (refname == NULL) {
1013 			err = got_error_from_errno("strndup");
1014 			goto done;
1015 		}
1016 
1017 		err = got_pathlist_append(&wanted_branches, refname, NULL);
1018 		if (err) {
1019 			free(refname);
1020 			goto done;
1021 		}
1022 
1023 		imsg_free(&imsg);
1024 	}
1025 
1026 	for (i = 0; i < fetch_req.n_wanted_refs; i++) {
1027 		char *refname;
1028 
1029 		err = got_privsep_recv_imsg(&imsg, &ibuf, 0);
1030 		if (err) {
1031 			if (err->code == GOT_ERR_PRIVSEP_PIPE)
1032 				err = NULL;
1033 			goto done;
1034 		}
1035 		if (imsg.hdr.type == GOT_IMSG_STOP)
1036 			goto done;
1037 		if (imsg.hdr.type != GOT_IMSG_FETCH_WANTED_REF) {
1038 			err = got_error(GOT_ERR_PRIVSEP_MSG);
1039 			goto done;
1040 		}
1041 		datalen = imsg.hdr.len - IMSG_HEADER_SIZE;
1042 		if (datalen < sizeof(wref)) {
1043 			err = got_error(GOT_ERR_PRIVSEP_LEN);
1044 			goto done;
1045 		}
1046 		memcpy(&wref, imsg.data, sizeof(wref));
1047 		if (datalen - sizeof(wref) < wref.name_len) {
1048 			err = got_error(GOT_ERR_PRIVSEP_LEN);
1049 			goto done;
1050 		}
1051 		refname = strndup(imsg.data + sizeof(wref), wref.name_len);
1052 		if (refname == NULL) {
1053 			err = got_error_from_errno("strndup");
1054 			goto done;
1055 		}
1056 
1057 		err = got_pathlist_append(&wanted_refs, refname, NULL);
1058 		if (err) {
1059 			free(refname);
1060 			goto done;
1061 		}
1062 
1063 		imsg_free(&imsg);
1064 	}
1065 
1066 	err = got_privsep_recv_imsg(&imsg, &ibuf, 0);
1067 	if (err) {
1068 		if (err->code == GOT_ERR_PRIVSEP_PIPE)
1069 			err = NULL;
1070 		goto done;
1071 	}
1072 	if (imsg.hdr.type == GOT_IMSG_STOP)
1073 		goto done;
1074 	if (imsg.hdr.type != GOT_IMSG_FETCH_OUTFD) {
1075 		err = got_error(GOT_ERR_PRIVSEP_MSG);
1076 		goto done;
1077 	}
1078 	if (imsg.hdr.len - IMSG_HEADER_SIZE != 0) {
1079 		err = got_error(GOT_ERR_PRIVSEP_LEN);
1080 		goto done;
1081 	}
1082 	packfd = imsg_get_fd(&imsg);
1083 
1084 	err = fetch_pack(fetchfd, packfd, pack_sha1, &have_refs,
1085 	    fetch_req.fetch_all_branches, &wanted_branches,
1086 	    &wanted_refs, fetch_req.list_refs_only,
1087 	    worktree_branch, remote_head, fetch_req.no_head, &ibuf);
1088 done:
1089 	free(worktree_branch);
1090 	free(remote_head);
1091 	got_pathlist_free(&have_refs, GOT_PATHLIST_FREE_ALL);
1092 	got_pathlist_free(&wanted_branches, GOT_PATHLIST_FREE_PATH);
1093 	if (fetchfd != -1 && close(fetchfd) == -1 && err == NULL)
1094 		err = got_error_from_errno("close");
1095 	if (packfd != -1 && close(packfd) == -1 && err == NULL)
1096 		err = got_error_from_errno("close");
1097 	if (err != NULL)
1098 		got_privsep_send_error(&ibuf, err);
1099 	else
1100 		err = send_fetch_done(&ibuf, pack_sha1);
1101 	if (err != NULL) {
1102 		fprintf(stderr, "%s: %s\n", getprogname(), err->msg);
1103 		got_privsep_send_error(&ibuf, err);
1104 	}
1105 
1106 	exit(0);
1107 }