summaryrefslogtreecommitdiff
path: root/connect.c
blob: 7a417e5a73f3228af00d2e143b16e24004083341 (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
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
#include "cache.h"
#include "pkt-line.h"
#include "quote.h"
#include "refs.h"
#include <sys/wait.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netdb.h>

static char *server_capabilities = NULL;

/*
 * Read all the refs from the other end
 */
struct ref **get_remote_heads(int in, struct ref **list,
			      int nr_match, char **match, int ignore_funny)
{
	*list = NULL;
	for (;;) {
		struct ref *ref;
		unsigned char old_sha1[20];
		static char buffer[1000];
		char *name;
		int len, name_len;

		len = packet_read_line(in, buffer, sizeof(buffer));
		if (!len)
			break;
		if (buffer[len-1] == '\n')
			buffer[--len] = 0;

		if (len < 42 || get_sha1_hex(buffer, old_sha1) || buffer[40] != ' ')
			die("protocol error: expected sha/ref, got '%s'", buffer);
		name = buffer + 41;

		if (ignore_funny && 45 < len && !memcmp(name, "refs/", 5) &&
		    check_ref_format(name + 5))
			continue;

		name_len = strlen(name);
		if (len != name_len + 41) {
			if (server_capabilities)
				free(server_capabilities);
			server_capabilities = strdup(name + name_len + 1);
		}

		if (nr_match && !path_match(name, nr_match, match))
			continue;
		ref = xcalloc(1, sizeof(*ref) + len - 40);
		memcpy(ref->old_sha1, old_sha1, 20);
		memcpy(ref->name, buffer + 41, len - 40);
		*list = ref;
		list = &ref->next;
	}
	return list;
}

int server_supports(const char *feature)
{
	return server_capabilities &&
		strstr(server_capabilities, feature) != NULL;
}

int get_ack(int fd, unsigned char *result_sha1)
{
	static char line[1000];
	int len = packet_read_line(fd, line, sizeof(line));

	if (!len)
		die("git-fetch-pack: expected ACK/NAK, got EOF");
	if (line[len-1] == '\n')
		line[--len] = 0;
	if (!strcmp(line, "NAK"))
		return 0;
	if (!strncmp(line, "ACK ", 3)) {
		if (!get_sha1_hex(line+4, result_sha1)) {
			if (strstr(line+45, "continue"))
				return 2;
			return 1;
		}
	}
	die("git-fetch_pack: expected ACK/NAK, got '%s'", line);
}

int path_match(const char *path, int nr, char **match)
{
	int i;
	int pathlen = strlen(path);

	for (i = 0; i < nr; i++) {
		char *s = match[i];
		int len = strlen(s);

		if (!len || len > pathlen)
			continue;
		if (memcmp(path + pathlen - len, s, len))
			continue;
		if (pathlen > len && path[pathlen - len - 1] != '/')
			continue;
		*s = 0;
		return 1;
	}
	return 0;
}

struct refspec {
	char *src;
	char *dst;
	char force;
};

/*
 * A:B means fast forward remote B with local A.
 * +A:B means overwrite remote B with local A.
 * +A is a shorthand for +A:A.
 * A is a shorthand for A:A.
 */
static struct refspec *parse_ref_spec(int nr_refspec, char **refspec)
{
	int i;
	struct refspec *rs = xcalloc(sizeof(*rs), (nr_refspec + 1));
	for (i = 0; i < nr_refspec; i++) {
		char *sp, *dp, *ep;
		sp = refspec[i];
		if (*sp == '+') {
			rs[i].force = 1;
			sp++;
		}
		ep = strchr(sp, ':');
		if (ep) {
			dp = ep + 1;
			*ep = 0;
		}
		else
			dp = sp;
		rs[i].src = sp;
		rs[i].dst = dp;
	}
	rs[nr_refspec].src = rs[nr_refspec].dst = NULL;
	return rs;
}

static int count_refspec_match(const char *pattern,
			       struct ref *refs,
			       struct ref **matched_ref)
{
	int match;
	int patlen = strlen(pattern);

	for (match = 0; refs; refs = refs->next) {
		char *name = refs->name;
		int namelen = strlen(name);
		if (namelen < patlen ||
		    memcmp(name + namelen - patlen, pattern, patlen))
			continue;
		if (namelen != patlen && name[namelen - patlen - 1] != '/')
			continue;
		match++;
		*matched_ref = refs;
	}
	return match;
}

static void link_dst_tail(struct ref *ref, struct ref ***tail)
{
	**tail = ref;
	*tail = &ref->next;
	**tail = NULL;
}

static struct ref *try_explicit_object_name(const char *name)
{
	unsigned char sha1[20];
	struct ref *ref;
	int len;
	if (get_sha1(name, sha1))
		return NULL;
	len = strlen(name) + 1;
	ref = xcalloc(1, sizeof(*ref) + len);
	memcpy(ref->name, name, len);
	memcpy(ref->new_sha1, sha1, 20);
	return ref;
}

static int match_explicit_refs(struct ref *src, struct ref *dst,
			       struct ref ***dst_tail, struct refspec *rs)
{
	int i, errs;
	for (i = errs = 0; rs[i].src; i++) {
		struct ref *matched_src, *matched_dst;

		matched_src = matched_dst = NULL;
		switch (count_refspec_match(rs[i].src, src, &matched_src)) {
		case 1:
			break;
		case 0:
			/* The source could be in the get_sha1() format
			 * not a reference name.
			 */
			matched_src = try_explicit_object_name(rs[i].src);
			if (matched_src)
				break;
			errs = 1;
			error("src refspec %s does not match any.",
			      rs[i].src);
			break;
		default:
			errs = 1;
			error("src refspec %s matches more than one.",
			      rs[i].src);
			break;
		}
		switch (count_refspec_match(rs[i].dst, dst, &matched_dst)) {
		case 1:
			break;
		case 0:
			if (!memcmp(rs[i].dst, "refs/", 5)) {
				int len = strlen(rs[i].dst) + 1;
				matched_dst = xcalloc(1, sizeof(*dst) + len);
				memcpy(matched_dst->name, rs[i].dst, len);
				link_dst_tail(matched_dst, dst_tail);
			}
			else if (!strcmp(rs[i].src, rs[i].dst) &&
				 matched_src) {
				/* pushing "master:master" when
				 * remote does not have master yet.
				 */
				int len = strlen(matched_src->name) + 1;
				matched_dst = xcalloc(1, sizeof(*dst) + len);
				memcpy(matched_dst->name, matched_src->name,
				       len);
				link_dst_tail(matched_dst, dst_tail);
			}
			else {
				errs = 1;
				error("dst refspec %s does not match any "
				      "existing ref on the remote and does "
				      "not start with refs/.", rs[i].dst);
			}
			break;
		default:
			errs = 1;
			error("dst refspec %s matches more than one.",
			      rs[i].dst);
			break;
		}
		if (errs)
			continue;
		if (matched_dst->peer_ref) {
			errs = 1;
			error("dst ref %s receives from more than one src.",
			      matched_dst->name);
		}
		else {
			matched_dst->peer_ref = matched_src;
			matched_dst->force = rs[i].force;
		}
	}
	return -errs;
}

static struct ref *find_ref_by_name(struct ref *list, const char *name)
{
	for ( ; list; list = list->next)
		if (!strcmp(list->name, name))
			return list;
	return NULL;
}

int match_refs(struct ref *src, struct ref *dst, struct ref ***dst_tail,
	       int nr_refspec, char **refspec, int all)
{
	struct refspec *rs = parse_ref_spec(nr_refspec, refspec);

	if (nr_refspec)
		return match_explicit_refs(src, dst, dst_tail, rs);

	/* pick the remainder */
	for ( ; src; src = src->next) {
		struct ref *dst_peer;
		if (src->peer_ref)
			continue;
		dst_peer = find_ref_by_name(dst, src->name);
		if ((dst_peer && dst_peer->peer_ref) || (!dst_peer && !all))
			continue;
		if (!dst_peer) {
			/* Create a new one and link it */
			int len = strlen(src->name) + 1;
			dst_peer = xcalloc(1, sizeof(*dst_peer) + len);
			memcpy(dst_peer->name, src->name, len);
			memcpy(dst_peer->new_sha1, src->new_sha1, 20);
			link_dst_tail(dst_peer, dst_tail);
		}
		dst_peer->peer_ref = src;
	}
	return 0;
}

enum protocol {
	PROTO_LOCAL = 1,
	PROTO_SSH,
	PROTO_GIT,
};

static enum protocol get_protocol(const char *name)
{
	if (!strcmp(name, "ssh"))
		return PROTO_SSH;
	if (!strcmp(name, "git"))
		return PROTO_GIT;
	if (!strcmp(name, "git+ssh"))
		return PROTO_SSH;
	if (!strcmp(name, "ssh+git"))
		return PROTO_SSH;
	die("I don't handle protocol '%s'", name);
}

#define STR_(s)	# s
#define STR(s)	STR_(s)

#ifndef NO_IPV6

static int git_tcp_connect(int fd[2], const char *prog, char *host, char *path)
{
	int sockfd = -1;
	char *colon, *end;
	char *port = STR(DEFAULT_GIT_PORT);
	struct addrinfo hints, *ai0, *ai;
	int gai;

	if (host[0] == '[') {
		end = strchr(host + 1, ']');
		if (end) {
			*end = 0;
			end++;
			host++;
		} else
			end = host;
	} else
		end = host;
	colon = strchr(end, ':');

	if (colon) {
		*colon = 0;
		port = colon + 1;
	}

	memset(&hints, 0, sizeof(hints));
	hints.ai_socktype = SOCK_STREAM;
	hints.ai_protocol = IPPROTO_TCP;

	gai = getaddrinfo(host, port, &hints, &ai);
	if (gai)
		die("Unable to look up %s (%s)", host, gai_strerror(gai));

	for (ai0 = ai; ai; ai = ai->ai_next) {
		sockfd = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
		if (sockfd < 0)
			continue;
		if (connect(sockfd, ai->ai_addr, ai->ai_addrlen) < 0) {
			close(sockfd);
			sockfd = -1;
			continue;
		}
		break;
	}

	freeaddrinfo(ai0);

	if (sockfd < 0)
		die("unable to connect a socket (%s)", strerror(errno));

	fd[0] = sockfd;
	fd[1] = sockfd;
	packet_write(sockfd, "%s %s\n", prog, path);
	return 0;
}

#else /* NO_IPV6 */

static int git_tcp_connect(int fd[2], const char *prog, char *host, char *path)
{
	int sockfd = -1;
	char *colon, *end;
	char *port = STR(DEFAULT_GIT_PORT), *ep;
	struct hostent *he;
	struct sockaddr_in sa;
	char **ap;
	unsigned int nport;

	if (host[0] == '[') {
		end = strchr(host + 1, ']');
		if (end) {
			*end = 0;
			end++;
			host++;
		} else
			end = host;
	} else
		end = host;
	colon = strchr(end, ':');

	if (colon) {
		*colon = 0;
		port = colon + 1;
	}


	he = gethostbyname(host);
	if (!he)
		die("Unable to look up %s (%s)", host, hstrerror(h_errno));
	nport = strtoul(port, &ep, 10);
	if ( ep == port || *ep ) {
		/* Not numeric */
		struct servent *se = getservbyname(port,"tcp");
		if ( !se )
			die("Unknown port %s\n", port);
		nport = se->s_port;
	}

	for (ap = he->h_addr_list; *ap; ap++) {
		sockfd = socket(he->h_addrtype, SOCK_STREAM, 0);
		if (sockfd < 0)
			continue;

		memset(&sa, 0, sizeof sa);
		sa.sin_family = he->h_addrtype;
		sa.sin_port = htons(nport);
		memcpy(&sa.sin_addr, ap, he->h_length);

		if (connect(sockfd, (struct sockaddr *)&sa, sizeof sa) < 0) {
			close(sockfd);
			sockfd = -1;
			continue;
		}
		break;
	}

	if (sockfd < 0)
		die("unable to connect a socket (%s)", strerror(errno));

	fd[0] = sockfd;
	fd[1] = sockfd;
	packet_write(sockfd, "%s %s\n", prog, path);
	return 0;
}

#endif /* NO_IPV6 */

static char *git_proxy_command = NULL;
static const char *rhost_name = NULL;
static int rhost_len;

static int git_proxy_command_options(const char *var, const char *value)
{
	if (!strcmp(var, "core.gitproxy")) {
		const char *for_pos;
		int matchlen = -1;
		int hostlen;

		if (git_proxy_command)
			return 0;
		/* [core]
		 * ;# matches www.kernel.org as well
		 * gitproxy = netcatter-1 for kernel.org
		 * gitproxy = netcatter-2 for sample.xz
		 * gitproxy = netcatter-default
		 */
		for_pos = strstr(value, " for ");
		if (!for_pos)
			/* matches everybody */
			matchlen = strlen(value);
		else {
			hostlen = strlen(for_pos + 5);
			if (rhost_len < hostlen)
				matchlen = -1;
			else if (!strncmp(for_pos + 5,
					  rhost_name + rhost_len - hostlen,
					  hostlen) &&
				 ((rhost_len == hostlen) ||
				  rhost_name[rhost_len - hostlen -1] == '.'))
				matchlen = for_pos - value;
			else
				matchlen = -1;
		}
		if (0 <= matchlen) {
			/* core.gitproxy = none for kernel.org */
			if (matchlen == 4 && 
			    !memcmp(value, "none", 4))
				matchlen = 0;
			git_proxy_command = xmalloc(matchlen + 1);
			memcpy(git_proxy_command, value, matchlen);
			git_proxy_command[matchlen] = 0;
		}
		return 0;
	}

	return git_default_config(var, value);
}

static int git_use_proxy(const char *host)
{
	rhost_name = host;
	rhost_len = strlen(host);
	git_proxy_command = getenv("GIT_PROXY_COMMAND");
	git_config(git_proxy_command_options);
	rhost_name = NULL;
	return (git_proxy_command && *git_proxy_command);
}

static int git_proxy_connect(int fd[2], const char *prog, char *host, char *path)
{
	char *port = STR(DEFAULT_GIT_PORT);
	char *colon, *end;
	int pipefd[2][2];
	pid_t pid;

	if (host[0] == '[') {
		end = strchr(host + 1, ']');
		if (end) {
			*end = 0;
			end++;
			host++;
		} else
			end = host;
	} else
		end = host;
	colon = strchr(end, ':');

	if (colon) {
		*colon = 0;
		port = colon + 1;
	}

	if (pipe(pipefd[0]) < 0 || pipe(pipefd[1]) < 0)
		die("unable to create pipe pair for communication");
	pid = fork();
	if (!pid) {
		dup2(pipefd[1][0], 0);
		dup2(pipefd[0][1], 1);
		close(pipefd[0][0]);
		close(pipefd[0][1]);
		close(pipefd[1][0]);
		close(pipefd[1][1]);
		execlp(git_proxy_command, git_proxy_command, host, port, NULL);
		die("exec failed");
	}
	fd[0] = pipefd[0][0];
	fd[1] = pipefd[1][1];
	close(pipefd[0][1]);
	close(pipefd[1][0]);
	packet_write(fd[1], "%s %s\n", prog, path);
	return pid;
}

/*
 * Yeah, yeah, fixme. Need to pass in the heads etc.
 */
int git_connect(int fd[2], char *url, const char *prog)
{
	char command[1024];
	char *host, *path = url;
	char *colon = NULL;
	int pipefd[2][2];
	pid_t pid;
	enum protocol protocol = PROTO_LOCAL;

	host = strstr(url, "://");
	if(host) {
		*host = '\0';
		protocol = get_protocol(url);
		host += 3;
		path = strchr(host, '/');
	}
	else {
		host = url;
		if ((colon = strchr(host, ':'))) {
			protocol = PROTO_SSH;
			*colon = '\0';
			path = colon + 1;
		}
	}

	if (!path || !*path)
		die("No path specified. See 'man git-pull' for valid url syntax");

	/*
	 * null-terminate hostname and point path to ~ for URL's like this:
	 *    ssh://host.xz/~user/repo
	 */
	if (protocol != PROTO_LOCAL && host != url) {
		char *ptr = path;
		if (path[1] == '~')
			path++;
		else
			path = strdup(ptr);

		*ptr = '\0';
	}

	if (protocol == PROTO_GIT) {
		if (git_use_proxy(host))
			return git_proxy_connect(fd, prog, host, path);
		return git_tcp_connect(fd, prog, host, path);
	}

	if (pipe(pipefd[0]) < 0 || pipe(pipefd[1]) < 0)
		die("unable to create pipe pair for communication");
	pid = fork();
	if (!pid) {
		snprintf(command, sizeof(command), "%s %s", prog,
			 sq_quote(path));
		dup2(pipefd[1][0], 0);
		dup2(pipefd[0][1], 1);
		close(pipefd[0][0]);
		close(pipefd[0][1]);
		close(pipefd[1][0]);
		close(pipefd[1][1]);
		if (protocol == PROTO_SSH) {
			const char *ssh, *ssh_basename;
			ssh = getenv("GIT_SSH");
			if (!ssh) ssh = "ssh";
			ssh_basename = strrchr(ssh, '/');
			if (!ssh_basename)
				ssh_basename = ssh;
			else
				ssh_basename++;
			execlp(ssh, ssh_basename, host, command, NULL);
		}
		else
			execlp("sh", "sh", "-c", command, NULL);
		die("exec failed");
	}		
	fd[0] = pipefd[0][0];
	fd[1] = pipefd[1][1];
	close(pipefd[0][1]);
	close(pipefd[1][0]);
	return pid;
}

int finish_connect(pid_t pid)
{
	int ret;

	for (;;) {
		ret = waitpid(pid, NULL, 0);
		if (!ret)
			break;
		if (errno != EINTR)
			break;
	}
	return ret;
}