summaryrefslogtreecommitdiff
path: root/receive-pack.c
blob: a971433db155bbac162cece038b73dc64e682ac0 (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
#include "cache.h"
#include "pack.h"
#include "refs.h"
#include "pkt-line.h"
#include "run-command.h"
#include "exec_cmd.h"
#include "commit.h"
#include "object.h"

static const char receive_pack_usage[] = "git-receive-pack <git-dir>";

static int deny_non_fast_forwards = 0;
static int receive_unpack_limit = -1;
static int transfer_unpack_limit = -1;
static int unpack_limit = 100;
static int report_status;

static char capabilities[] = " report-status delete-refs ";
static int capabilities_sent;

static int receive_pack_config(const char *var, const char *value)
{
	if (strcmp(var, "receive.denynonfastforwards") == 0) {
		deny_non_fast_forwards = git_config_bool(var, value);
		return 0;
	}

	if (strcmp(var, "receive.unpacklimit") == 0) {
		receive_unpack_limit = git_config_int(var, value);
		return 0;
	}

	if (strcmp(var, "transfer.unpacklimit") == 0) {
		transfer_unpack_limit = git_config_int(var, value);
		return 0;
	}

	return git_default_config(var, value);
}

static int show_ref(const char *path, const unsigned char *sha1, int flag, void *cb_data)
{
	if (capabilities_sent)
		packet_write(1, "%s %s\n", sha1_to_hex(sha1), path);
	else
		packet_write(1, "%s %s%c%s\n",
			     sha1_to_hex(sha1), path, 0, capabilities);
	capabilities_sent = 1;
	return 0;
}

static void write_head_info(void)
{
	for_each_ref(show_ref, NULL);
	if (!capabilities_sent)
		show_ref("capabilities^{}", null_sha1, 0, NULL);

}

struct command {
	struct command *next;
	const char *error_string;
	unsigned char old_sha1[20];
	unsigned char new_sha1[20];
	char ref_name[FLEX_ARRAY]; /* more */
};

static struct command *commands;

static const char pre_receive_hook[] = "hooks/pre-receive";
static const char post_receive_hook[] = "hooks/post-receive";

static int hook_status(int code, const char *hook_name)
{
	switch (code) {
	case 0:
		return 0;
	case -ERR_RUN_COMMAND_FORK:
		return error("hook fork failed");
	case -ERR_RUN_COMMAND_EXEC:
		return error("hook execute failed");
	case -ERR_RUN_COMMAND_PIPE:
		return error("hook pipe failed");
	case -ERR_RUN_COMMAND_WAITPID:
		return error("waitpid failed");
	case -ERR_RUN_COMMAND_WAITPID_WRONG_PID:
		return error("waitpid is confused");
	case -ERR_RUN_COMMAND_WAITPID_SIGNAL:
		return error("%s died of signal", hook_name);
	case -ERR_RUN_COMMAND_WAITPID_NOEXIT:
		return error("%s died strangely", hook_name);
	default:
		error("%s exited with error code %d", hook_name, -code);
		return -code;
	}
}

static int run_hook(const char *hook_name)
{
	static char buf[sizeof(commands->old_sha1) * 2 + PATH_MAX + 4];
	struct command *cmd;
	struct child_process proc;
	const char *argv[2];
	int have_input = 0, code;

	for (cmd = commands; !have_input && cmd; cmd = cmd->next) {
		if (!cmd->error_string)
			have_input = 1;
	}

	if (!have_input || access(hook_name, X_OK) < 0)
		return 0;

	argv[0] = hook_name;
	argv[1] = NULL;

	memset(&proc, 0, sizeof(proc));
	proc.argv = argv;
	proc.in = -1;
	proc.stdout_to_stderr = 1;

	code = start_command(&proc);
	if (code)
		return hook_status(code, hook_name);
	for (cmd = commands; cmd; cmd = cmd->next) {
		if (!cmd->error_string) {
			size_t n = snprintf(buf, sizeof(buf), "%s %s %s\n",
				sha1_to_hex(cmd->old_sha1),
				sha1_to_hex(cmd->new_sha1),
				cmd->ref_name);
			if (write_in_full(proc.in, buf, n) != n)
				break;
		}
	}
	close(proc.in);
	return hook_status(finish_command(&proc), hook_name);
}

static int run_update_hook(struct command *cmd)
{
	static const char update_hook[] = "hooks/update";
	struct child_process proc;
	const char *argv[5];

	if (access(update_hook, X_OK) < 0)
		return 0;

	argv[0] = update_hook;
	argv[1] = cmd->ref_name;
	argv[2] = sha1_to_hex(cmd->old_sha1);
	argv[3] = sha1_to_hex(cmd->new_sha1);
	argv[4] = NULL;

	memset(&proc, 0, sizeof(proc));
	proc.argv = argv;
	proc.no_stdin = 1;
	proc.stdout_to_stderr = 1;

	return hook_status(run_command(&proc), update_hook);
}

static const char *update(struct command *cmd)
{
	const char *name = cmd->ref_name;
	unsigned char *old_sha1 = cmd->old_sha1;
	unsigned char *new_sha1 = cmd->new_sha1;
	struct ref_lock *lock;

	/* only refs/... are allowed */
	if (prefixcmp(name, "refs/") || check_ref_format(name + 5)) {
		error("refusing to create funny ref '%s' remotely", name);
		return "funny refname";
	}

	if (!is_null_sha1(new_sha1) && !has_sha1_file(new_sha1)) {
		error("unpack should have generated %s, "
		      "but I can't find it!", sha1_to_hex(new_sha1));
		return "bad pack";
	}
	if (deny_non_fast_forwards && !is_null_sha1(new_sha1) &&
	    !is_null_sha1(old_sha1) &&
	    !prefixcmp(name, "refs/heads/")) {
		struct object *old_object, *new_object;
		struct commit *old_commit, *new_commit;
		struct commit_list *bases, *ent;

		old_object = parse_object(old_sha1);
		new_object = parse_object(new_sha1);

		if (!old_object || !new_object ||
		    old_object->type != OBJ_COMMIT ||
		    new_object->type != OBJ_COMMIT) {
			error("bad sha1 objects for %s", name);
			return "bad ref";
		}
		old_commit = (struct commit *)old_object;
		new_commit = (struct commit *)new_object;
		bases = get_merge_bases(old_commit, new_commit, 1);
		for (ent = bases; ent; ent = ent->next)
			if (!hashcmp(old_sha1, ent->item->object.sha1))
				break;
		free_commit_list(bases);
		if (!ent) {
			error("denying non-fast forward %s"
			      " (you should pull first)", name);
			return "non-fast forward";
		}
	}
	if (run_update_hook(cmd)) {
		error("hook declined to update %s", name);
		return "hook declined";
	}

	if (is_null_sha1(new_sha1)) {
		if (!parse_object(old_sha1)) {
			warning ("Allowing deletion of corrupt ref.");
			old_sha1 = NULL;
		}
		if (delete_ref(name, old_sha1)) {
			error("failed to delete %s", name);
			return "failed to delete";
		}
		return NULL; /* good */
	}
	else {
		lock = lock_any_ref_for_update(name, old_sha1, 0);
		if (!lock) {
			error("failed to lock %s", name);
			return "failed to lock";
		}
		if (write_ref_sha1(lock, new_sha1, "push")) {
			return "failed to write"; /* error() already called */
		}
		return NULL; /* good */
	}
}

static char update_post_hook[] = "hooks/post-update";

static void run_update_post_hook(struct command *cmd)
{
	struct command *cmd_p;
	int argc;
	const char **argv;

	for (argc = 0, cmd_p = cmd; cmd_p; cmd_p = cmd_p->next) {
		if (cmd_p->error_string)
			continue;
		argc++;
	}
	if (!argc || access(update_post_hook, X_OK) < 0)
		return;
	argv = xmalloc(sizeof(*argv) * (2 + argc));
	argv[0] = update_post_hook;

	for (argc = 1, cmd_p = cmd; cmd_p; cmd_p = cmd_p->next) {
		char *p;
		if (cmd_p->error_string)
			continue;
		p = xmalloc(strlen(cmd_p->ref_name) + 1);
		strcpy(p, cmd_p->ref_name);
		argv[argc] = p;
		argc++;
	}
	argv[argc] = NULL;
	run_command_v_opt(argv, RUN_COMMAND_NO_STDIN
		| RUN_COMMAND_STDOUT_TO_STDERR);
}

static void execute_commands(const char *unpacker_error)
{
	struct command *cmd = commands;

	if (unpacker_error) {
		while (cmd) {
			cmd->error_string = "n/a (unpacker error)";
			cmd = cmd->next;
		}
		return;
	}

	if (run_hook(pre_receive_hook)) {
		while (cmd) {
			cmd->error_string = "pre-receive hook declined";
			cmd = cmd->next;
		}
		return;
	}

	while (cmd) {
		cmd->error_string = update(cmd);
		cmd = cmd->next;
	}
}

static void read_head_info(void)
{
	struct command **p = &commands;
	for (;;) {
		static char line[1000];
		unsigned char old_sha1[20], new_sha1[20];
		struct command *cmd;
		char *refname;
		int len, reflen;

		len = packet_read_line(0, line, sizeof(line));
		if (!len)
			break;
		if (line[len-1] == '\n')
			line[--len] = 0;
		if (len < 83 ||
		    line[40] != ' ' ||
		    line[81] != ' ' ||
		    get_sha1_hex(line, old_sha1) ||
		    get_sha1_hex(line + 41, new_sha1))
			die("protocol error: expected old/new/ref, got '%s'",
			    line);

		refname = line + 82;
		reflen = strlen(refname);
		if (reflen + 82 < len) {
			if (strstr(refname + reflen + 1, "report-status"))
				report_status = 1;
		}
		cmd = xmalloc(sizeof(struct command) + len - 80);
		hashcpy(cmd->old_sha1, old_sha1);
		hashcpy(cmd->new_sha1, new_sha1);
		memcpy(cmd->ref_name, line + 82, len - 81);
		cmd->error_string = NULL;
		cmd->next = NULL;
		*p = cmd;
		p = &cmd->next;
	}
}

static const char *parse_pack_header(struct pack_header *hdr)
{
	switch (read_pack_header(0, hdr)) {
	case PH_ERROR_EOF:
		return "eof before pack header was fully read";

	case PH_ERROR_PACK_SIGNATURE:
		return "protocol error (pack signature mismatch detected)";

	case PH_ERROR_PROTOCOL:
		return "protocol error (pack version unsupported)";

	default:
		return "unknown error in parse_pack_header";

	case 0:
		return NULL;
	}
}

static const char *pack_lockfile;

static const char *unpack(void)
{
	struct pack_header hdr;
	const char *hdr_err;
	char hdr_arg[38];

	hdr_err = parse_pack_header(&hdr);
	if (hdr_err)
		return hdr_err;
	snprintf(hdr_arg, sizeof(hdr_arg), "--pack_header=%u,%u",
			ntohl(hdr.hdr_version), ntohl(hdr.hdr_entries));

	if (ntohl(hdr.hdr_entries) < unpack_limit) {
		int code;
		const char *unpacker[3];
		unpacker[0] = "unpack-objects";
		unpacker[1] = hdr_arg;
		unpacker[2] = NULL;
		code = run_command_v_opt(unpacker, RUN_GIT_CMD);
		switch (code) {
		case 0:
			return NULL;
		case -ERR_RUN_COMMAND_FORK:
			return "unpack fork failed";
		case -ERR_RUN_COMMAND_EXEC:
			return "unpack execute failed";
		case -ERR_RUN_COMMAND_WAITPID:
			return "waitpid failed";
		case -ERR_RUN_COMMAND_WAITPID_WRONG_PID:
			return "waitpid is confused";
		case -ERR_RUN_COMMAND_WAITPID_SIGNAL:
			return "unpacker died of signal";
		case -ERR_RUN_COMMAND_WAITPID_NOEXIT:
			return "unpacker died strangely";
		default:
			return "unpacker exited with error code";
		}
	} else {
		const char *keeper[6];
		int s, status;
		char keep_arg[256];
		struct child_process ip;

		s = sprintf(keep_arg, "--keep=receive-pack %i on ", getpid());
		if (gethostname(keep_arg + s, sizeof(keep_arg) - s))
			strcpy(keep_arg + s, "localhost");

		keeper[0] = "index-pack";
		keeper[1] = "--stdin";
		keeper[2] = "--fix-thin";
		keeper[3] = hdr_arg;
		keeper[4] = keep_arg;
		keeper[5] = NULL;
		memset(&ip, 0, sizeof(ip));
		ip.argv = keeper;
		ip.out = -1;
		ip.git_cmd = 1;
		if (start_command(&ip))
			return "index-pack fork failed";
		pack_lockfile = index_pack_lockfile(ip.out);
		close(ip.out);
		status = finish_command(&ip);
		if (!status) {
			reprepare_packed_git();
			return NULL;
		}
		return "index-pack abnormal exit";
	}
}

static void report(const char *unpack_status)
{
	struct command *cmd;
	packet_write(1, "unpack %s\n",
		     unpack_status ? unpack_status : "ok");
	for (cmd = commands; cmd; cmd = cmd->next) {
		if (!cmd->error_string)
			packet_write(1, "ok %s\n",
				     cmd->ref_name);
		else
			packet_write(1, "ng %s %s\n",
				     cmd->ref_name, cmd->error_string);
	}
	packet_flush(1);
}

static int delete_only(struct command *cmd)
{
	while (cmd) {
		if (!is_null_sha1(cmd->new_sha1))
			return 0;
		cmd = cmd->next;
	}
	return 1;
}

int main(int argc, char **argv)
{
	int i;
	char *dir = NULL;

	argv++;
	for (i = 1; i < argc; i++) {
		char *arg = *argv++;

		if (*arg == '-') {
			/* Do flag handling here */
			usage(receive_pack_usage);
		}
		if (dir)
			usage(receive_pack_usage);
		dir = arg;
	}
	if (!dir)
		usage(receive_pack_usage);

	if (!enter_repo(dir, 0))
		die("'%s': unable to chdir or not a git archive", dir);

	if (is_repository_shallow())
		die("attempt to push into a shallow repository");

	git_config(receive_pack_config);

	if (0 <= transfer_unpack_limit)
		unpack_limit = transfer_unpack_limit;
	else if (0 <= receive_unpack_limit)
		unpack_limit = receive_unpack_limit;

	write_head_info();

	/* EOF */
	packet_flush(1);

	read_head_info();
	if (commands) {
		const char *unpack_status = NULL;

		if (!delete_only(commands))
			unpack_status = unpack();
		execute_commands(unpack_status);
		if (pack_lockfile)
			unlink(pack_lockfile);
		if (report_status)
			report(unpack_status);
		run_hook(post_receive_hook);
		run_update_post_hook(commands);
	}
	return 0;
}