summaryrefslogtreecommitdiff
path: root/upload-pack.c
blob: 7e04311027176fc87c1de7dd619000d2a75d4eb9 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
#include "cache.h"
#include "refs.h"
#include "pkt-line.h"
#include "sideband.h"
#include "tag.h"
#include "object.h"
#include "commit.h"
#include "exec_cmd.h"
#include "diff.h"
#include "revision.h"
#include "list-objects.h"
#include "run-command.h"
 
static const char upload_pack_usage[] = "git-upload-pack [--strict] [--timeout=nn] <dir>";
 
/* bits #0..7 in revision.h, #8..10 in commit.c */
#define THEY_HAVE	(1u << 11)
#define OUR_REF		(1u << 12)
#define WANTED		(1u << 13)
#define COMMON_KNOWN	(1u << 14)
#define REACHABLE	(1u << 15)
 
#define SHALLOW		(1u << 16)
#define NOT_SHALLOW	(1u << 17)
#define CLIENT_SHALLOW	(1u << 18)
 
static unsigned long oldest_have;
 
static int multi_ack, nr_our_refs;
static int use_thin_pack, use_ofs_delta, no_progress;
static struct object_array have_obj;
static struct object_array want_obj;
static unsigned int timeout;
/* 0 for no sideband,
 * otherwise maximum packet size (up to 65520 bytes).
 */
static int use_sideband;
 
static void reset_timeout(void)
{
	alarm(timeout);
}
 
static int strip(char *line, int len)
{
	if (len && line[len-1] == '\n')
		line[--len] = 0;
	return len;
}
 
static ssize_t send_client_data(int fd, const char *data, ssize_t sz)
{
	if (use_sideband)
		return send_sideband(1, fd, data, sz, use_sideband);
	if (fd == 3)
		/* emergency quit */
		fd = 2;
	if (fd == 2) {
		/* XXX: are we happy to lose stuff here? */
		xwrite(fd, data, sz);
		return sz;
	}
	return safe_write(fd, data, sz);
}
 
static FILE *pack_pipe = NULL;
static void show_commit(struct commit *commit)
{
	if (commit->object.flags & BOUNDARY)
		fputc('-', pack_pipe);
	if (fputs(sha1_to_hex(commit->object.sha1), pack_pipe) < 0)
		die("broken output pipe");
	fputc('\n', pack_pipe);
	fflush(pack_pipe);
	free(commit->buffer);
	commit->buffer = NULL;
}
 
static void show_object(struct object_array_entry *p)
{
	/* An object with name "foo\n0000000..." can be used to
	 * confuse downstream git-pack-objects very badly.
	 */
	const char *ep = strchr(p->name, '\n');
	if (ep) {
		fprintf(pack_pipe, "%s %.*s\n", sha1_to_hex(p->item->sha1),
		       (int) (ep - p->name),
		       p->name);
	}
	else
		fprintf(pack_pipe, "%s %s\n",
				sha1_to_hex(p->item->sha1), p->name);
}
 
static void show_edge(struct commit *commit)
{
	fprintf(pack_pipe, "-%s\n", sha1_to_hex(commit->object.sha1));
}
 
static int do_rev_list(int fd, void *create_full_pack)
{
	int i;
	struct rev_info revs;
 
	pack_pipe = fdopen(fd, "w");
	if (create_full_pack)
		use_thin_pack = 0; /* no point doing it */
	init_revisions(&revs, NULL);
	revs.tag_objects = 1;
	revs.tree_objects = 1;
	revs.blob_objects = 1;
	if (use_thin_pack)
		revs.edge_hint = 1;
 
	if (create_full_pack) {
		const char *args[] = {"rev-list", "--all", NULL};
		setup_revisions(2, args, &revs, NULL);
	} else {
		for (i = 0; i < want_obj.nr; i++) {
			struct object *o = want_obj.objects[i].item;
			/* why??? */
			o->flags &= ~UNINTERESTING;
			add_pending_object(&revs, o, NULL);
		}
		for (i = 0; i < have_obj.nr; i++) {
			struct object *o = have_obj.objects[i].item;
			o->flags |= UNINTERESTING;
			add_pending_object(&revs, o, NULL);
		}
		setup_revisions(0, NULL, &revs, NULL);
	}
	prepare_revision_walk(&revs);
	mark_edges_uninteresting(revs.commits, &revs, show_edge);
	traverse_commit_list(&revs, show_commit, show_object);
	return 0;
}
 
static void create_pack_file(void)
{
	struct async rev_list;
	struct child_process pack_objects;
	int create_full_pack = (nr_our_refs == want_obj.nr && !have_obj.nr);
	char data[8193], progress[128];
	char abort_msg[] = "aborting due to possible repository "
		"corruption on the remote side.";
	int buffered = -1;
	ssize_t sz;
	const char *argv[10];
	int arg = 0;
 
	rev_list.proc = do_rev_list;
	/* .data is just a boolean: any non-NULL value will do */
	rev_list.data = create_full_pack ? &rev_list : NULL;
	if (start_async(&rev_list))
		die("git-upload-pack: unable to fork git-rev-list");
 
	argv[arg++] = "pack-objects";
	argv[arg++] = "--stdout";
	if (!no_progress)
		argv[arg++] = "--progress";
	if (use_ofs_delta)
		argv[arg++] = "--delta-base-offset";
	argv[arg++] = NULL;
 
	memset(&pack_objects, 0, sizeof(pack_objects));
	pack_objects.in = rev_list.out;	/* start_command closes it */
	pack_objects.out = -1;
	pack_objects.err = -1;
	pack_objects.git_cmd = 1;
	pack_objects.argv = argv;
 
	if (start_command(&pack_objects))
		die("git-upload-pack: unable to fork git-pack-objects");
 
	/* We read from pack_objects.err to capture stderr output for
	 * progress bar, and pack_objects.out to capture the pack data.
	 */
 
	while (1) {
		struct pollfd pfd[2];
		int pe, pu, pollsize;
 
		reset_timeout();
 
		pollsize = 0;
		pe = pu = -1;
 
		if (0 <= pack_objects.out) {
			pfd[pollsize].fd = pack_objects.out;
			pfd[pollsize].events = POLLIN;
			pu = pollsize;
			pollsize++;
		}
		if (0 <= pack_objects.err) {
			pfd[pollsize].fd = pack_objects.err;
			pfd[pollsize].events = POLLIN;
			pe = pollsize;
			pollsize++;
		}
 
		if (!pollsize)
			break;
 
		if (poll(pfd, pollsize, -1) < 0) {
			if (errno != EINTR) {
				error("poll failed, resuming: %s",
				      strerror(errno));
				sleep(1);
			}
			continue;
		}
		if (0 <= pu && (pfd[pu].revents & (POLLIN|POLLHUP))) {
			/* Data ready; we keep the last byte to ourselves
			 * in case we detect broken rev-list, so that we
			 * can leave the stream corrupted.  This is
			 * unfortunate -- unpack-objects would happily
			 * accept a valid packdata with trailing garbage,
			 * so appending garbage after we pass all the
			 * pack data is not good enough to signal
			 * breakage to downstream.
			 */
			char *cp = data;
			ssize_t outsz = 0;
			if (0 <= buffered) {
				*cp++ = buffered;
				outsz++;
			}
			sz = xread(pack_objects.out, cp,
				  sizeof(data) - outsz);
			if (0 < sz)
					;
			else if (sz == 0) {
				close(pack_objects.out);
				pack_objects.out = -1;
			}
			else
				goto fail;
			sz += outsz;
			if (1 < sz) {
				buffered = data[sz-1] & 0xFF;
				sz--;
			}
			else
				buffered = -1;
			sz = send_client_data(1, data, sz);
			if (sz < 0)
				goto fail;
		}
		if (0 <= pe && (pfd[pe].revents & (POLLIN|POLLHUP))) {
			/* Status ready; we ship that in the side-band
			 * or dump to the standard error.
			 */
			sz = xread(pack_objects.err, progress,
				  sizeof(progress));
			if (0 < sz)
				send_client_data(2, progress, sz);
			else if (sz == 0) {
				close(pack_objects.err);
				pack_objects.err = -1;
			}
			else
				goto fail;
		}
	}
 
	if (finish_command(&pack_objects)) {
		error("git-upload-pack: git-pack-objects died with error.");
		goto fail;
	}
	if (finish_async(&rev_list))
		goto fail;	/* error was already reported */
 
	/* flush the data */
	if (0 <= buffered) {
		data[0] = buffered;
		sz = send_client_data(1, data, 1);
		if (sz < 0)
			goto fail;
		fprintf(stderr, "flushed.\n");
	}
	if (use_sideband)
		packet_flush(1);
	return;
 
 fail:
	send_client_data(3, abort_msg, sizeof(abort_msg));
	die("git-upload-pack: %s", abort_msg);
}
 
static int got_sha1(char *hex, unsigned char *sha1)
{
	struct object *o;
	int we_knew_they_have = 0;
 
	if (get_sha1_hex(hex, sha1))
		die("git-upload-pack: expected SHA1 object, got '%s'", hex);
	if (!has_sha1_file(sha1))
		return -1;
 
	o = lookup_object(sha1);
	if (!(o && o->parsed))
		o = parse_object(sha1);
	if (!o)
		die("oops (%s)", sha1_to_hex(sha1));
	if (o->type == OBJ_COMMIT) {
		struct commit_list *parents;
		struct commit *commit = (struct commit *)o;
		if (o->flags & THEY_HAVE)
			we_knew_they_have = 1;
		else
			o->flags |= THEY_HAVE;
		if (!oldest_have || (commit->date < oldest_have))
			oldest_have = commit->date;
		for (parents = commit->parents;
		     parents;
		     parents = parents->next)
			parents->item->object.flags |= THEY_HAVE;
	}
	if (!we_knew_they_have) {
		add_object_array(o, NULL, &have_obj);
		return 1;
	}
	return 0;
}
 
static int reachable(struct commit *want)
{
	struct commit_list *work = NULL;
 
	insert_by_date(want, &work);
	while (work) {
		struct commit_list *list = work->next;
		struct commit *commit = work->item;
		free(work);
		work = list;
 
		if (commit->object.flags & THEY_HAVE) {
			want->object.flags |= COMMON_KNOWN;
			break;
		}
		if (!commit->object.parsed)
			parse_object(commit->object.sha1);
		if (commit->object.flags & REACHABLE)
			continue;
		commit->object.flags |= REACHABLE;
		if (commit->date < oldest_have)
			continue;
		for (list = commit->parents; list; list = list->next) {
			struct commit *parent = list->item;
			if (!(parent->object.flags & REACHABLE))
				insert_by_date(parent, &work);
		}
	}
	want->object.flags |= REACHABLE;
	clear_commit_marks(want, REACHABLE);
	free_commit_list(work);
	return (want->object.flags & COMMON_KNOWN);
}
 
static int ok_to_give_up(void)
{
	int i;
 
	if (!have_obj.nr)
		return 0;
 
	for (i = 0; i < want_obj.nr; i++) {
		struct object *want = want_obj.objects[i].item;
 
		if (want->flags & COMMON_KNOWN)
			continue;
		want = deref_tag(want, "a want line", 0);
		if (!want || want->type != OBJ_COMMIT) {
			/* no way to tell if this is reachable by
			 * looking at the ancestry chain alone, so
			 * leave a note to ourselves not to worry about
			 * this object anymore.
			 */
			want_obj.objects[i].item->flags |= COMMON_KNOWN;
			continue;
		}
		if (!reachable((struct commit *)want))
			return 0;
	}
	return 1;
}
 
static int get_common_commits(void)
{
	static char line[1000];
	unsigned char sha1[20];
	char hex[41], last_hex[41];
	int len;
 
	track_object_refs = 0;
	save_commit_buffer = 0;
 
	for(;;) {
		len = packet_read_line(0, line, sizeof(line));
		reset_timeout();
 
		if (!len) {
			if (have_obj.nr == 0 || multi_ack)
				packet_write(1, "NAK\n");
			continue;
		}
		len = strip(line, len);
		if (!prefixcmp(line, "have ")) {
			switch (got_sha1(line+5, sha1)) {
			case -1: /* they have what we do not */
				if (multi_ack && ok_to_give_up())
					packet_write(1, "ACK %s continue\n",
						     sha1_to_hex(sha1));
				break;
			default:
				memcpy(hex, sha1_to_hex(sha1), 41);
				if (multi_ack) {
					const char *msg = "ACK %s continue\n";
					packet_write(1, msg, hex);
					memcpy(last_hex, hex, 41);
				}
				else if (have_obj.nr == 1)
					packet_write(1, "ACK %s\n", hex);
				break;
			}
			continue;
		}
		if (!strcmp(line, "done")) {
			if (have_obj.nr > 0) {
				if (multi_ack)
					packet_write(1, "ACK %s\n", last_hex);
				return 0;
			}
			packet_write(1, "NAK\n");
			return -1;
		}
		die("git-upload-pack: expected SHA1 list, got '%s'", line);
	}
}
 
static void receive_needs(void)
{
	struct object_array shallows = {0, 0, NULL};
	static char line[1000];
	int len, depth = 0;
 
	for (;;) {
		struct object *o;
		unsigned char sha1_buf[20];
		len = packet_read_line(0, line, sizeof(line));
		reset_timeout();
		if (!len)
			break;
 
		if (!prefixcmp(line, "shallow ")) {
			unsigned char sha1[20];
			struct object *object;
			use_thin_pack = 0;
			if (get_sha1(line + 8, sha1))
				die("invalid shallow line: %s", line);
			object = parse_object(sha1);
			if (!object)
				die("did not find object for %s", line);
			object->flags |= CLIENT_SHALLOW;
			add_object_array(object, NULL, &shallows);
			continue;
		}
		if (!prefixcmp(line, "deepen ")) {
			char *end;
			use_thin_pack = 0;
			depth = strtol(line + 7, &end, 0);
			if (end == line + 7 || depth <= 0)
				die("Invalid deepen: %s", line);
			continue;
		}
		if (prefixcmp(line, "want ") ||
		    get_sha1_hex(line+5, sha1_buf))
			die("git-upload-pack: protocol error, "
			    "expected to get sha, not '%s'", line);
		if (strstr(line+45, "multi_ack"))
			multi_ack = 1;
		if (strstr(line+45, "thin-pack"))
			use_thin_pack = 1;
		if (strstr(line+45, "ofs-delta"))
			use_ofs_delta = 1;
		if (strstr(line+45, "side-band-64k"))
			use_sideband = LARGE_PACKET_MAX;
		else if (strstr(line+45, "side-band"))
			use_sideband = DEFAULT_PACKET_MAX;
		if (strstr(line+45, "no-progress"))
			no_progress = 1;
 
		/* We have sent all our refs already, and the other end
		 * should have chosen out of them; otherwise they are
		 * asking for nonsense.
		 *
		 * Hmph.  We may later want to allow "want" line that
		 * asks for something like "master~10" (symbolic)...
		 * would it make sense?  I don't know.
		 */
		o = lookup_object(sha1_buf);
		if (!o || !(o->flags & OUR_REF))
			die("git-upload-pack: not our ref %s", line+5);
		if (!(o->flags & WANTED)) {
			o->flags |= WANTED;
			add_object_array(o, NULL, &want_obj);
		}
	}
	if (depth == 0 && shallows.nr == 0)
		return;
	if (depth > 0) {
		struct commit_list *result, *backup;
		int i;
		backup = result = get_shallow_commits(&want_obj, depth,
			SHALLOW, NOT_SHALLOW);
		while (result) {
			struct object *object = &result->item->object;
			if (!(object->flags & (CLIENT_SHALLOW|NOT_SHALLOW))) {
				packet_write(1, "shallow %s",
						sha1_to_hex(object->sha1));
				register_shallow(object->sha1);
			}
			result = result->next;
		}
		free_commit_list(backup);
		for (i = 0; i < shallows.nr; i++) {
			struct object *object = shallows.objects[i].item;
			if (object->flags & NOT_SHALLOW) {
				struct commit_list *parents;
				packet_write(1, "unshallow %s",
					sha1_to_hex(object->sha1));
				object->flags &= ~CLIENT_SHALLOW;
				/* make sure the real parents are parsed */
				unregister_shallow(object->sha1);
				object->parsed = 0;
				parse_commit((struct commit *)object);
				parents = ((struct commit *)object)->parents;
				while (parents) {
					add_object_array(&parents->item->object,
							NULL, &want_obj);
					parents = parents->next;
				}
			}
			/* make sure commit traversal conforms to client */
			register_shallow(object->sha1);
		}
		packet_flush(1);
	} else
		if (shallows.nr > 0) {
			int i;
			for (i = 0; i < shallows.nr; i++)
				register_shallow(shallows.objects[i].item->sha1);
		}
	free(shallows.objects);
}
 
static int send_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
{
	static const char *capabilities = "multi_ack thin-pack side-band"
		" side-band-64k ofs-delta shallow no-progress";
	struct object *o = parse_object(sha1);
 
	if (!o)
		die("git-upload-pack: cannot find object %s:", sha1_to_hex(sha1));
 
	if (capabilities)
		packet_write(1, "%s %s%c%s\n", sha1_to_hex(sha1), refname,
			0, capabilities);
	else
		packet_write(1, "%s %s\n", sha1_to_hex(sha1), refname);
	capabilities = NULL;
	if (!(o->flags & OUR_REF)) {
		o->flags |= OUR_REF;
		nr_our_refs++;
	}
	if (o->type == OBJ_TAG) {
		o = deref_tag(o, refname, 0);
		packet_write(1, "%s %s^{}\n", sha1_to_hex(o->sha1), refname);
	}
	return 0;
}
 
static void upload_pack(void)
{
	reset_timeout();
	head_ref(send_ref, NULL);
	for_each_ref(send_ref, NULL);
	packet_flush(1);
	receive_needs();
	if (want_obj.nr) {
		get_common_commits();
		create_pack_file();
	}
}
 
int main(int argc, char **argv)
{
	char *dir;
	int i;
	int strict = 0;
 
	for (i = 1; i < argc; i++) {
		char *arg = argv[i];
 
		if (arg[0] != '-')
			break;
		if (!strcmp(arg, "--strict")) {
			strict = 1;
			continue;
		}
		if (!prefixcmp(arg, "--timeout=")) {
			timeout = atoi(arg+10);
			continue;
		}
		if (!strcmp(arg, "--")) {
			i++;
			break;
		}
	}
 
	if (i != argc-1)
		usage(upload_pack_usage);
	dir = argv[i];
 
	if (!enter_repo(dir, strict))
		die("'%s': unable to chdir or not a git archive", dir);
	if (is_repository_shallow())
		die("attempt to fetch/clone from a shallow repository");
	upload_pack();
	return 0;
}