summaryrefslogtreecommitdiff
path: root/send-pack.c
blob: 9d2b0c52ed8235425795772db99fc14ea9c2bf2b (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
#include "builtin.h"
#include "commit.h"
#include "refs.h"
#include "pkt-line.h"
#include "sideband.h"
#include "run-command.h"
#include "remote.h"
#include "connect.h"
#include "send-pack.h"
#include "quote.h"
#include "transport.h"
#include "version.h"
#include "sha1-array.h"
#include "gpg-interface.h"

static int feed_object(const unsigned char *sha1, int fd, int negative)
{
	char buf[42];

	if (negative && !has_sha1_file(sha1))
		return 1;

	memcpy(buf + negative, sha1_to_hex(sha1), 40);
	if (negative)
		buf[0] = '^';
	buf[40 + negative] = '\n';
	return write_or_whine(fd, buf, 41 + negative, "send-pack: send refs");
}

/*
 * Make a pack stream and spit it out into file descriptor fd
 */
static int pack_objects(int fd, struct ref *refs, struct sha1_array *extra, struct send_pack_args *args)
{
	/*
	 * The child becomes pack-objects --revs; we feed
	 * the revision parameters to it via its stdin and
	 * let its stdout go back to the other end.
	 */
	const char *argv[] = {
		"pack-objects",
		"--all-progress-implied",
		"--revs",
		"--stdout",
		NULL,
		NULL,
		NULL,
		NULL,
		NULL,
		NULL,
	};
	struct child_process po = CHILD_PROCESS_INIT;
	int i;

	i = 4;
	if (args->use_thin_pack)
		argv[i++] = "--thin";
	if (args->use_ofs_delta)
		argv[i++] = "--delta-base-offset";
	if (args->quiet || !args->progress)
		argv[i++] = "-q";
	if (args->progress)
		argv[i++] = "--progress";
	if (is_repository_shallow())
		argv[i++] = "--shallow";
	po.argv = argv;
	po.in = -1;
	po.out = args->stateless_rpc ? -1 : fd;
	po.git_cmd = 1;
	if (start_command(&po))
		die_errno("git pack-objects failed");

	/*
	 * We feed the pack-objects we just spawned with revision
	 * parameters by writing to the pipe.
	 */
	for (i = 0; i < extra->nr; i++)
		if (!feed_object(extra->sha1[i], po.in, 1))
			break;

	while (refs) {
		if (!is_null_sha1(refs->old_sha1) &&
		    !feed_object(refs->old_sha1, po.in, 1))
			break;
		if (!is_null_sha1(refs->new_sha1) &&
		    !feed_object(refs->new_sha1, po.in, 0))
			break;
		refs = refs->next;
	}

	close(po.in);

	if (args->stateless_rpc) {
		char *buf = xmalloc(LARGE_PACKET_MAX);
		while (1) {
			ssize_t n = xread(po.out, buf, LARGE_PACKET_MAX);
			if (n <= 0)
				break;
			send_sideband(fd, -1, buf, n, LARGE_PACKET_MAX);
		}
		free(buf);
		close(po.out);
		po.out = -1;
	}

	if (finish_command(&po))
		return -1;
	return 0;
}

static int receive_status(int in, struct ref *refs)
{
	struct ref *hint;
	int ret = 0;
	char *line = packet_read_line(in, NULL);
	if (!starts_with(line, "unpack "))
		return error("did not receive remote status");
	if (strcmp(line, "unpack ok")) {
		error("unpack failed: %s", line + 7);
		ret = -1;
	}
	hint = NULL;
	while (1) {
		char *refname;
		char *msg;
		line = packet_read_line(in, NULL);
		if (!line)
			break;
		if (!starts_with(line, "ok ") && !starts_with(line, "ng ")) {
			error("invalid ref status from remote: %s", line);
			ret = -1;
			break;
		}

		refname = line + 3;
		msg = strchr(refname, ' ');
		if (msg)
			*msg++ = '\0';

		/* first try searching at our hint, falling back to all refs */
		if (hint)
			hint = find_ref_by_name(hint, refname);
		if (!hint)
			hint = find_ref_by_name(refs, refname);
		if (!hint) {
			warning("remote reported status on unknown ref: %s",
					refname);
			continue;
		}
		if (hint->status != REF_STATUS_EXPECTING_REPORT) {
			warning("remote reported status on unexpected ref: %s",
					refname);
			continue;
		}

		if (line[0] == 'o' && line[1] == 'k')
			hint->status = REF_STATUS_OK;
		else {
			hint->status = REF_STATUS_REMOTE_REJECT;
			ret = -1;
		}
		if (msg)
			hint->remote_status = xstrdup(msg);
		/* start our next search from the next ref */
		hint = hint->next;
	}
	return ret;
}

static int sideband_demux(int in, int out, void *data)
{
	int *fd = data, ret;
#ifdef NO_PTHREADS
	close(fd[1]);
#endif
	ret = recv_sideband("send-pack", fd[0], out);
	close(out);
	return ret;
}

static int advertise_shallow_grafts_cb(const struct commit_graft *graft, void *cb)
{
	struct strbuf *sb = cb;
	if (graft->nr_parent == -1)
		packet_buf_write(sb, "shallow %s\n", sha1_to_hex(graft->sha1));
	return 0;
}

static void advertise_shallow_grafts_buf(struct strbuf *sb)
{
	if (!is_repository_shallow())
		return;
	for_each_commit_graft(advertise_shallow_grafts_cb, sb);
}

#define CHECK_REF_NO_PUSH -1
#define CHECK_REF_STATUS_REJECTED -2
#define CHECK_REF_UPTODATE -3
static int check_to_send_update(const struct ref *ref, const struct send_pack_args *args)
{
	if (!ref->peer_ref && !args->send_mirror)
		return CHECK_REF_NO_PUSH;

	/* Check for statuses set by set_ref_status_for_push() */
	switch (ref->status) {
	case REF_STATUS_REJECT_NONFASTFORWARD:
	case REF_STATUS_REJECT_ALREADY_EXISTS:
	case REF_STATUS_REJECT_FETCH_FIRST:
	case REF_STATUS_REJECT_NEEDS_FORCE:
	case REF_STATUS_REJECT_STALE:
	case REF_STATUS_REJECT_NODELETE:
		return CHECK_REF_STATUS_REJECTED;
	case REF_STATUS_UPTODATE:
		return CHECK_REF_UPTODATE;
	default:
		return 0;
	}
}

/*
 * the beginning of the next line, or the end of buffer.
 *
 * NEEDSWORK: perhaps move this to git-compat-util.h or somewhere and
 * convert many similar uses found by "git grep -A4 memchr".
 */
static const char *next_line(const char *line, size_t len)
{
	const char *nl = memchr(line, '\n', len);
	if (!nl)
		return line + len; /* incomplete line */
	return nl + 1;
}

static int generate_push_cert(struct strbuf *req_buf,
			      const struct ref *remote_refs,
			      struct send_pack_args *args,
			      const char *cap_string,
			      const char *push_cert_nonce)
{
	const struct ref *ref;
	char *signing_key = xstrdup(get_signing_key());
	const char *cp, *np;
	struct strbuf cert = STRBUF_INIT;
	int update_seen = 0;

	strbuf_addf(&cert, "certificate version 0.1\n");
	strbuf_addf(&cert, "pusher %s ", signing_key);
	datestamp(&cert);
	strbuf_addch(&cert, '\n');
	if (args->url && *args->url) {
		char *anon_url = transport_anonymize_url(args->url);
		strbuf_addf(&cert, "pushee %s\n", anon_url);
		free(anon_url);
	}
	if (push_cert_nonce[0])
		strbuf_addf(&cert, "nonce %s\n", push_cert_nonce);
	strbuf_addstr(&cert, "\n");

	for (ref = remote_refs; ref; ref = ref->next) {
		if (check_to_send_update(ref, args) < 0)
			continue;
		update_seen = 1;
		strbuf_addf(&cert, "%s %s %s\n",
			    sha1_to_hex(ref->old_sha1),
			    sha1_to_hex(ref->new_sha1),
			    ref->name);
	}
	if (!update_seen)
		goto free_return;

	if (sign_buffer(&cert, &cert, signing_key))
		die(_("failed to sign the push certificate"));

	packet_buf_write(req_buf, "push-cert%c%s", 0, cap_string);
	for (cp = cert.buf; cp < cert.buf + cert.len; cp = np) {
		np = next_line(cp, cert.buf + cert.len - cp);
		packet_buf_write(req_buf,
				 "%.*s", (int)(np - cp), cp);
	}
	packet_buf_write(req_buf, "push-cert-end\n");

free_return:
	free(signing_key);
	strbuf_release(&cert);
	return update_seen;
}


static int atomic_push_failure(struct send_pack_args *args,
			       struct ref *remote_refs,
			       struct ref *failing_ref)
{
	struct ref *ref;
	/* Mark other refs as failed */
	for (ref = remote_refs; ref; ref = ref->next) {
		if (!ref->peer_ref && !args->send_mirror)
			continue;

		switch (ref->status) {
		case REF_STATUS_EXPECTING_REPORT:
			ref->status = REF_STATUS_ATOMIC_PUSH_FAILED;
			continue;
		default:
			break; /* do nothing */
		}
	}
	return error("atomic push failed for ref %s. status: %d\n",
		     failing_ref->name, failing_ref->status);
}

int send_pack(struct send_pack_args *args,
	      int fd[], struct child_process *conn,
	      struct ref *remote_refs,
	      struct sha1_array *extra_have)
{
	int in = fd[0];
	int out = fd[1];
	struct strbuf req_buf = STRBUF_INIT;
	struct strbuf cap_buf = STRBUF_INIT;
	struct ref *ref;
	int need_pack_data = 0;
	int allow_deleting_refs = 0;
	int status_report = 0;
	int use_sideband = 0;
	int quiet_supported = 0;
	int agent_supported = 0;
	int use_atomic = 0;
	int atomic_supported = 0;
	unsigned cmds_sent = 0;
	int ret;
	struct async demux;
	const char *push_cert_nonce = NULL;

	/* Does the other end support the reporting? */
	if (server_supports("report-status"))
		status_report = 1;
	if (server_supports("delete-refs"))
		allow_deleting_refs = 1;
	if (server_supports("ofs-delta"))
		args->use_ofs_delta = 1;
	if (server_supports("side-band-64k"))
		use_sideband = 1;
	if (server_supports("quiet"))
		quiet_supported = 1;
	if (server_supports("agent"))
		agent_supported = 1;
	if (server_supports("no-thin"))
		args->use_thin_pack = 0;
	if (server_supports("atomic"))
		atomic_supported = 1;
	if (args->push_cert) {
		int len;

		push_cert_nonce = server_feature_value("push-cert", &len);
		if (!push_cert_nonce)
			die(_("the receiving end does not support --signed push"));
		push_cert_nonce = xmemdupz(push_cert_nonce, len);
	}

	if (!remote_refs) {
		fprintf(stderr, "No refs in common and none specified; doing nothing.\n"
			"Perhaps you should specify a branch such as 'master'.\n");
		return 0;
	}
	if (args->atomic && !atomic_supported)
		die(_("server does not support --atomic push"));

	use_atomic = atomic_supported && args->atomic;

	if (status_report)
		strbuf_addstr(&cap_buf, " report-status");
	if (use_sideband)
		strbuf_addstr(&cap_buf, " side-band-64k");
	if (quiet_supported && (args->quiet || !args->progress))
		strbuf_addstr(&cap_buf, " quiet");
	if (use_atomic)
		strbuf_addstr(&cap_buf, " atomic");
	if (agent_supported)
		strbuf_addf(&cap_buf, " agent=%s", git_user_agent_sanitized());

	/*
	 * NEEDSWORK: why does delete-refs have to be so specific to
	 * send-pack machinery that set_ref_status_for_push() cannot
	 * set this bit for us???
	 */
	for (ref = remote_refs; ref; ref = ref->next)
		if (ref->deletion && !allow_deleting_refs)
			ref->status = REF_STATUS_REJECT_NODELETE;

	if (!args->dry_run)
		advertise_shallow_grafts_buf(&req_buf);

	if (!args->dry_run && args->push_cert)
		cmds_sent = generate_push_cert(&req_buf, remote_refs, args,
					       cap_buf.buf, push_cert_nonce);

	/*
	 * Clear the status for each ref and see if we need to send
	 * the pack data.
	 */
	for (ref = remote_refs; ref; ref = ref->next) {
		switch (check_to_send_update(ref, args)) {
		case 0: /* no error */
			break;
		case CHECK_REF_STATUS_REJECTED:
			/*
			 * When we know the server would reject a ref update if
			 * we were to send it and we're trying to send the refs
			 * atomically, abort the whole operation.
			 */
			if (use_atomic)
				return atomic_push_failure(args, remote_refs, ref);
			/* Fallthrough for non atomic case. */
		default:
			continue;
		}
		if (!ref->deletion)
			need_pack_data = 1;

		if (args->dry_run || !status_report)
			ref->status = REF_STATUS_OK;
		else
			ref->status = REF_STATUS_EXPECTING_REPORT;
	}

	/*
	 * Finally, tell the other end!
	 */
	for (ref = remote_refs; ref; ref = ref->next) {
		char *old_hex, *new_hex;

		if (args->dry_run || args->push_cert)
			continue;

		if (check_to_send_update(ref, args) < 0)
			continue;

		old_hex = sha1_to_hex(ref->old_sha1);
		new_hex = sha1_to_hex(ref->new_sha1);
		if (!cmds_sent) {
			packet_buf_write(&req_buf,
					 "%s %s %s%c%s",
					 old_hex, new_hex, ref->name, 0,
					 cap_buf.buf);
			cmds_sent = 1;
		} else {
			packet_buf_write(&req_buf, "%s %s %s",
					 old_hex, new_hex, ref->name);
		}
	}

	if (args->stateless_rpc) {
		if (!args->dry_run && (cmds_sent || is_repository_shallow())) {
			packet_buf_flush(&req_buf);
			send_sideband(out, -1, req_buf.buf, req_buf.len, LARGE_PACKET_MAX);
		}
	} else {
		write_or_die(out, req_buf.buf, req_buf.len);
		packet_flush(out);
	}
	strbuf_release(&req_buf);
	strbuf_release(&cap_buf);

	if (use_sideband && cmds_sent) {
		memset(&demux, 0, sizeof(demux));
		demux.proc = sideband_demux;
		demux.data = fd;
		demux.out = -1;
		if (start_async(&demux))
			die("send-pack: unable to fork off sideband demultiplexer");
		in = demux.out;
	}

	if (need_pack_data && cmds_sent) {
		if (pack_objects(out, remote_refs, extra_have, args) < 0) {
			for (ref = remote_refs; ref; ref = ref->next)
				ref->status = REF_STATUS_NONE;
			if (args->stateless_rpc)
				close(out);
			if (git_connection_is_socket(conn))
				shutdown(fd[0], SHUT_WR);
			if (use_sideband)
				finish_async(&demux);
			fd[1] = -1;
			return -1;
		}
		if (!args->stateless_rpc)
			/* Closed by pack_objects() via start_command() */
			fd[1] = -1;
	}
	if (args->stateless_rpc && cmds_sent)
		packet_flush(out);

	if (status_report && cmds_sent)
		ret = receive_status(in, remote_refs);
	else
		ret = 0;
	if (args->stateless_rpc)
		packet_flush(out);

	if (use_sideband && cmds_sent) {
		if (finish_async(&demux)) {
			error("error in sideband demultiplexer");
			ret = -1;
		}
		close(demux.out);
	}

	if (ret < 0)
		return ret;

	if (args->porcelain)
		return 0;

	for (ref = remote_refs; ref; ref = ref->next) {
		switch (ref->status) {
		case REF_STATUS_NONE:
		case REF_STATUS_UPTODATE:
		case REF_STATUS_OK:
			break;
		default:
			return -1;
		}
	}
	return 0;
}