Add a documentat on how to revert a faulty merge
[git/git.git] / connect.c
CommitLineData
731043fd 1#include "git-compat-util.h"
f7192598 2#include "cache.h"
41cb7488 3#include "pkt-line.h"
b10d0ec7 4#include "quote.h"
6abf5c0c 5#include "refs.h"
15a1c012 6#include "run-command.h"
6b62816c 7#include "remote.h"
f7192598 8
96f1e58f 9static char *server_capabilities;
211b5f9e 10
2718ff09
LT
11static int check_ref(const char *name, int len, unsigned int flags)
12{
13 if (!flags)
14 return 1;
15
c41e20b3 16 if (len < 5 || memcmp(name, "refs/", 5))
2718ff09
LT
17 return 0;
18
19 /* Skip the "refs/" part */
20 name += 5;
21 len -= 5;
22
23 /* REF_NORMAL means that we don't want the magic fake tag refs */
24 if ((flags & REF_NORMAL) && check_ref_format(name) < 0)
25 return 0;
26
27 /* REF_HEADS means that we want regular branch heads */
28 if ((flags & REF_HEADS) && !memcmp(name, "heads/", 6))
29 return 1;
30
31 /* REF_TAGS means that we want tags */
32 if ((flags & REF_TAGS) && !memcmp(name, "tags/", 5))
33 return 1;
34
35 /* All type bits clear means that we are ok with anything */
36 return !(flags & ~REF_NORMAL);
37}
38
4577370e
DB
39int check_ref_type(const struct ref *ref, int flags)
40{
41 return check_ref(ref->name, strlen(ref->name), flags);
42}
43
40c155ff
JH
44static void add_extra_have(struct extra_have_objects *extra, unsigned char *sha1)
45{
46 ALLOC_GROW(extra->array, extra->nr + 1, extra->alloc);
47 hashcpy(&(extra->array[extra->nr][0]), sha1);
48 extra->nr++;
49}
50
d1c133f5
LT
51/*
52 * Read all the refs from the other end
53 */
1a7141ff 54struct ref **get_remote_heads(int in, struct ref **list,
2718ff09 55 int nr_match, char **match,
40c155ff
JH
56 unsigned int flags,
57 struct extra_have_objects *extra_have)
d1c133f5
LT
58{
59 *list = NULL;
60 for (;;) {
61 struct ref *ref;
62 unsigned char old_sha1[20];
63 static char buffer[1000];
64 char *name;
211b5f9e 65 int len, name_len;
d1c133f5
LT
66
67 len = packet_read_line(in, buffer, sizeof(buffer));
68 if (!len)
69 break;
70 if (buffer[len-1] == '\n')
71 buffer[--len] = 0;
72
a8073289
TPW
73 if (len > 4 && !prefixcmp(buffer, "ERR "))
74 die("remote error: %s", buffer + 4);
75
d1c133f5
LT
76 if (len < 42 || get_sha1_hex(buffer, old_sha1) || buffer[40] != ' ')
77 die("protocol error: expected sha/ref, got '%s'", buffer);
78 name = buffer + 41;
1a7141ff 79
211b5f9e
JS
80 name_len = strlen(name);
81 if (len != name_len + 41) {
8e0f7003 82 free(server_capabilities);
9befac47 83 server_capabilities = xstrdup(name + name_len + 1);
211b5f9e
JS
84 }
85
40c155ff
JH
86 if (extra_have &&
87 name_len == 5 && !memcmp(".have", name, 5)) {
88 add_extra_have(extra_have, old_sha1);
89 continue;
90 }
91
2718ff09 92 if (!check_ref(name, name_len, flags))
cfee10a7 93 continue;
d1c133f5
LT
94 if (nr_match && !path_match(name, nr_match, match))
95 continue;
59c69c0c 96 ref = alloc_ref(buffer + 41);
e702496e 97 hashcpy(ref->old_sha1, old_sha1);
d1c133f5
LT
98 *list = ref;
99 list = &ref->next;
100 }
101 return list;
102}
103
211b5f9e
JS
104int server_supports(const char *feature)
105{
1f5881bb
JS
106 return server_capabilities &&
107 strstr(server_capabilities, feature) != NULL;
211b5f9e
JS
108}
109
41cb7488
LT
110int get_ack(int fd, unsigned char *result_sha1)
111{
112 static char line[1000];
113 int len = packet_read_line(fd, line, sizeof(line));
114
115 if (!len)
7e44c935 116 die("git fetch-pack: expected ACK/NAK, got EOF");
41cb7488
LT
117 if (line[len-1] == '\n')
118 line[--len] = 0;
119 if (!strcmp(line, "NAK"))
120 return 0;
cc44c765 121 if (!prefixcmp(line, "ACK ")) {
c4c86f07
JS
122 if (!get_sha1_hex(line+4, result_sha1)) {
123 if (strstr(line+45, "continue"))
124 return 2;
41cb7488 125 return 1;
c4c86f07 126 }
41cb7488 127 }
7e44c935 128 die("git fetch_pack: expected ACK/NAK, got '%s'", line);
41cb7488
LT
129}
130
013e7c7f
LT
131int path_match(const char *path, int nr, char **match)
132{
133 int i;
134 int pathlen = strlen(path);
135
136 for (i = 0; i < nr; i++) {
137 char *s = match[i];
138 int len = strlen(s);
139
140 if (!len || len > pathlen)
141 continue;
142 if (memcmp(path + pathlen - len, s, len))
143 continue;
144 if (pathlen > len && path[pathlen - len - 1] != '/')
145 continue;
146 *s = 0;
9546010b 147 return (i + 1);
013e7c7f
LT
148 }
149 return 0;
150}
151
2386d658
LT
152enum protocol {
153 PROTO_LOCAL = 1,
154 PROTO_SSH,
155 PROTO_GIT,
156};
157
158static enum protocol get_protocol(const char *name)
159{
160 if (!strcmp(name, "ssh"))
161 return PROTO_SSH;
162 if (!strcmp(name, "git"))
163 return PROTO_GIT;
c05186cc
LT
164 if (!strcmp(name, "git+ssh"))
165 return PROTO_SSH;
166 if (!strcmp(name, "ssh+git"))
167 return PROTO_SSH;
72a4f4b6
LT
168 if (!strcmp(name, "file"))
169 return PROTO_LOCAL;
2386d658
LT
170 die("I don't handle protocol '%s'", name);
171}
172
5ba88448
YH
173#define STR_(s) # s
174#define STR(s) STR_(s)
2386d658 175
49744d63 176#ifndef NO_IPV6
4c505f71 177
ba505322
AR
178static const char *ai_name(const struct addrinfo *ai)
179{
180 static char addr[INET_ADDRSTRLEN];
181 if ( AF_INET == ai->ai_family ) {
182 struct sockaddr_in *in;
183 in = (struct sockaddr_in *)ai->ai_addr;
184 inet_ntop(ai->ai_family, &in->sin_addr, addr, sizeof(addr));
185 } else if ( AF_INET6 == ai->ai_family ) {
186 struct sockaddr_in6 *in;
187 in = (struct sockaddr_in6 *)ai->ai_addr;
188 inet_ntop(ai->ai_family, &in->sin6_addr, addr, sizeof(addr));
189 } else {
190 strcpy(addr, "(unknown)");
191 }
192 return addr;
193}
194
5ad312be
JL
195/*
196 * Returns a connected socket() fd, or else die()s.
197 */
7841ce79 198static int git_tcp_connect_sock(char *host, int flags)
2386d658 199{
ac3bc6c1 200 int sockfd = -1, saved_errno = 0;
5ba88448 201 char *colon, *end;
554fe20d 202 const char *port = STR(DEFAULT_GIT_PORT);
5ba88448
YH
203 struct addrinfo hints, *ai0, *ai;
204 int gai;
ba505322 205 int cnt = 0;
5ba88448
YH
206
207 if (host[0] == '[') {
208 end = strchr(host + 1, ']');
209 if (end) {
210 *end = 0;
211 end++;
212 host++;
213 } else
214 end = host;
215 } else
216 end = host;
217 colon = strchr(end, ':');
218
ce6f8e7e
LT
219 if (colon) {
220 *colon = 0;
5ba88448 221 port = colon + 1;
608d48b2
LT
222 if (!*port)
223 port = "<none>";
ce6f8e7e 224 }
5ba88448
YH
225
226 memset(&hints, 0, sizeof(hints));
227 hints.ai_socktype = SOCK_STREAM;
228 hints.ai_protocol = IPPROTO_TCP;
229
7841ce79
MT
230 if (flags & CONNECT_VERBOSE)
231 fprintf(stderr, "Looking up %s ... ", host);
232
5ba88448
YH
233 gai = getaddrinfo(host, port, &hints, &ai);
234 if (gai)
608d48b2 235 die("Unable to look up %s (port %s) (%s)", host, port, gai_strerror(gai));
5ba88448 236
7841ce79
MT
237 if (flags & CONNECT_VERBOSE)
238 fprintf(stderr, "done.\nConnecting to %s (port %s) ... ", host, port);
239
5ba88448 240 for (ai0 = ai; ai; ai = ai->ai_next) {
5ad312be
JL
241 sockfd = socket(ai->ai_family,
242 ai->ai_socktype, ai->ai_protocol);
ac3bc6c1
PB
243 if (sockfd < 0) {
244 saved_errno = errno;
5ba88448 245 continue;
ac3bc6c1 246 }
5ba88448 247 if (connect(sockfd, ai->ai_addr, ai->ai_addrlen) < 0) {
ac3bc6c1 248 saved_errno = errno;
7cbf2f24 249 fprintf(stderr, "%s[%d: %s]: errno=%s\n",
ba505322
AR
250 host,
251 cnt,
252 ai_name(ai),
ba505322 253 strerror(saved_errno));
5ba88448
YH
254 close(sockfd);
255 sockfd = -1;
256 continue;
2386d658 257 }
ba505322
AR
258 if (flags & CONNECT_VERBOSE)
259 fprintf(stderr, "%s ", ai_name(ai));
5ba88448 260 break;
2386d658
LT
261 }
262
5ba88448 263 freeaddrinfo(ai0);
2386d658 264
2386d658 265 if (sockfd < 0)
ac3bc6c1 266 die("unable to connect a socket (%s)", strerror(saved_errno));
5ba88448 267
7841ce79
MT
268 if (flags & CONNECT_VERBOSE)
269 fprintf(stderr, "done.\n");
270
5ad312be 271 return sockfd;
2386d658
LT
272}
273
49744d63 274#else /* NO_IPV6 */
4c505f71 275
5ad312be
JL
276/*
277 * Returns a connected socket() fd, or else die()s.
278 */
7841ce79 279static int git_tcp_connect_sock(char *host, int flags)
4c505f71 280{
ac3bc6c1 281 int sockfd = -1, saved_errno = 0;
4c505f71
PA
282 char *colon, *end;
283 char *port = STR(DEFAULT_GIT_PORT), *ep;
284 struct hostent *he;
285 struct sockaddr_in sa;
286 char **ap;
287 unsigned int nport;
ba505322 288 int cnt;
4c505f71
PA
289
290 if (host[0] == '[') {
291 end = strchr(host + 1, ']');
292 if (end) {
293 *end = 0;
294 end++;
295 host++;
296 } else
297 end = host;
298 } else
299 end = host;
300 colon = strchr(end, ':');
301
302 if (colon) {
303 *colon = 0;
304 port = colon + 1;
305 }
306
7841ce79
MT
307 if (flags & CONNECT_VERBOSE)
308 fprintf(stderr, "Looking up %s ... ", host);
309
4c505f71
PA
310 he = gethostbyname(host);
311 if (!he)
312 die("Unable to look up %s (%s)", host, hstrerror(h_errno));
313 nport = strtoul(port, &ep, 10);
314 if ( ep == port || *ep ) {
315 /* Not numeric */
316 struct servent *se = getservbyname(port,"tcp");
317 if ( !se )
318 die("Unknown port %s\n", port);
319 nport = se->s_port;
320 }
321
7841ce79
MT
322 if (flags & CONNECT_VERBOSE)
323 fprintf(stderr, "done.\nConnecting to %s (port %s) ... ", host, port);
324
ba505322 325 for (cnt = 0, ap = he->h_addr_list; *ap; ap++, cnt++) {
4c505f71 326 sockfd = socket(he->h_addrtype, SOCK_STREAM, 0);
ac3bc6c1
PB
327 if (sockfd < 0) {
328 saved_errno = errno;
4c505f71 329 continue;
ac3bc6c1 330 }
4c505f71
PA
331
332 memset(&sa, 0, sizeof sa);
333 sa.sin_family = he->h_addrtype;
6573faff 334 sa.sin_port = htons(nport);
c6164218 335 memcpy(&sa.sin_addr, *ap, he->h_length);
4c505f71
PA
336
337 if (connect(sockfd, (struct sockaddr *)&sa, sizeof sa) < 0) {
ac3bc6c1 338 saved_errno = errno;
7cbf2f24 339 fprintf(stderr, "%s[%d: %s]: errno=%s\n",
ba505322
AR
340 host,
341 cnt,
342 inet_ntoa(*(struct in_addr *)&sa.sin_addr),
ba505322 343 strerror(saved_errno));
4c505f71
PA
344 close(sockfd);
345 sockfd = -1;
346 continue;
347 }
ba505322
AR
348 if (flags & CONNECT_VERBOSE)
349 fprintf(stderr, "%s ",
350 inet_ntoa(*(struct in_addr *)&sa.sin_addr));
4c505f71
PA
351 break;
352 }
353
354 if (sockfd < 0)
ac3bc6c1 355 die("unable to connect a socket (%s)", strerror(saved_errno));
4c505f71 356
7841ce79
MT
357 if (flags & CONNECT_VERBOSE)
358 fprintf(stderr, "done.\n");
359
5ad312be
JL
360 return sockfd;
361}
362
363#endif /* NO_IPV6 */
364
365
7841ce79 366static void git_tcp_connect(int fd[2], char *host, int flags)
5ad312be 367{
7841ce79 368 int sockfd = git_tcp_connect_sock(host, flags);
5ad312be 369
4c505f71 370 fd[0] = sockfd;
ec587fde 371 fd[1] = dup(sockfd);
4c505f71
PA
372}
373
4c505f71 374
96f1e58f
DR
375static char *git_proxy_command;
376static const char *rhost_name;
e814bc4d 377static int rhost_len;
f8014776 378
ef90d6d4
JS
379static int git_proxy_command_options(const char *var, const char *value,
380 void *cb)
f8014776 381{
e814bc4d 382 if (!strcmp(var, "core.gitproxy")) {
c3df8568
YH
383 const char *for_pos;
384 int matchlen = -1;
385 int hostlen;
386
e814bc4d 387 if (git_proxy_command)
f8014776 388 return 0;
c64b9ad0
JH
389 if (!value)
390 return config_error_nonbool(var);
e814bc4d
JH
391 /* [core]
392 * ;# matches www.kernel.org as well
393 * gitproxy = netcatter-1 for kernel.org
394 * gitproxy = netcatter-2 for sample.xz
395 * gitproxy = netcatter-default
396 */
c3df8568 397 for_pos = strstr(value, " for ");
e814bc4d
JH
398 if (!for_pos)
399 /* matches everybody */
400 matchlen = strlen(value);
401 else {
402 hostlen = strlen(for_pos + 5);
403 if (rhost_len < hostlen)
404 matchlen = -1;
405 else if (!strncmp(for_pos + 5,
406 rhost_name + rhost_len - hostlen,
407 hostlen) &&
408 ((rhost_len == hostlen) ||
409 rhost_name[rhost_len - hostlen -1] == '.'))
410 matchlen = for_pos - value;
411 else
412 matchlen = -1;
413 }
414 if (0 <= matchlen) {
415 /* core.gitproxy = none for kernel.org */
a6080a0a 416 if (matchlen == 4 &&
e814bc4d
JH
417 !memcmp(value, "none", 4))
418 matchlen = 0;
182af834 419 git_proxy_command = xmemdupz(value, matchlen);
f8014776 420 }
e814bc4d 421 return 0;
f8014776
PC
422 }
423
ef90d6d4 424 return git_default_config(var, value, cb);
f8014776
PC
425}
426
e814bc4d 427static int git_use_proxy(const char *host)
f8014776 428{
e814bc4d
JH
429 rhost_name = host;
430 rhost_len = strlen(host);
f8014776 431 git_proxy_command = getenv("GIT_PROXY_COMMAND");
ef90d6d4 432 git_config(git_proxy_command_options, NULL);
e814bc4d
JH
433 rhost_name = NULL;
434 return (git_proxy_command && *git_proxy_command);
f8014776
PC
435}
436
c78963d2 437static void git_proxy_connect(int fd[2], char *host)
f8014776 438{
554fe20d 439 const char *port = STR(DEFAULT_GIT_PORT);
f8014776 440 char *colon, *end;
15a1c012
SP
441 const char *argv[4];
442 struct child_process proxy;
f8014776
PC
443
444 if (host[0] == '[') {
445 end = strchr(host + 1, ']');
446 if (end) {
447 *end = 0;
448 end++;
449 host++;
450 } else
451 end = host;
452 } else
453 end = host;
454 colon = strchr(end, ':');
455
456 if (colon) {
457 *colon = 0;
458 port = colon + 1;
459 }
460
15a1c012
SP
461 argv[0] = git_proxy_command;
462 argv[1] = host;
463 argv[2] = port;
464 argv[3] = NULL;
465 memset(&proxy, 0, sizeof(proxy));
466 proxy.argv = argv;
467 proxy.in = -1;
468 proxy.out = -1;
469 if (start_command(&proxy))
470 die("cannot start proxy %s", argv[0]);
471 fd[0] = proxy.out; /* read from proxy stdout */
472 fd[1] = proxy.in; /* write to proxy stdin */
f8014776
PC
473}
474
0f503d77
CC
475#define MAX_CMD_LEN 1024
476
2e776665
LT
477char *get_port(char *host)
478{
479 char *end;
480 char *p = strchr(host, ':');
481
482 if (p) {
483 strtol(p+1, &end, 10);
484 if (*end == '\0') {
485 *p = '\0';
486 return p+1;
487 }
488 }
489
490 return NULL;
491}
492
fb32c917
JS
493static struct child_process no_fork;
494
f7192598 495/*
fb32c917
JS
496 * This returns a dummy child_process if the transport protocol does not
497 * need fork(2), or a struct child_process object if it does. Once done,
498 * finish the connection with finish_connect() with the value returned from
499 * this function (it is safe to call finish_connect() with NULL to support
500 * the former case).
f42a5c4e 501 *
fb32c917
JS
502 * If it returns, the connect is successful; it just dies on errors (this
503 * will hopefully be changed in a libification effort, to return NULL when
504 * the connection failed).
f7192598 505 */
4577370e 506struct child_process *git_connect(int fd[2], const char *url_orig,
98158e9c 507 const char *prog, int flags)
f7192598 508{
4577370e 509 char *url = xstrdup(url_orig);
faea9ccb 510 char *host, *path = url;
356bece0
YH
511 char *end;
512 int c;
98158e9c 513 struct child_process *conn;
faea9ccb 514 enum protocol protocol = PROTO_LOCAL;
da2a95b2 515 int free_path = 0;
2e776665 516 char *port = NULL;
f364cb88
JS
517 const char **arg;
518 struct strbuf cmd;
faea9ccb 519
f0b7367c
JH
520 /* Without this we cannot rely on waitpid() to tell
521 * what happened to our children.
522 */
523 signal(SIGCHLD, SIG_DFL);
524
faea9ccb
AE
525 host = strstr(url, "://");
526 if(host) {
527 *host = '\0';
528 protocol = get_protocol(url);
529 host += 3;
356bece0
YH
530 c = '/';
531 } else {
f7192598 532 host = url;
356bece0
YH
533 c = ':';
534 }
535
536 if (host[0] == '[') {
537 end = strchr(host + 1, ']');
538 if (end) {
539 *end = 0;
540 end++;
541 host++;
542 } else
543 end = host;
544 } else
545 end = host;
546
547 path = strchr(end, c);
be501813 548 if (path && !has_dos_drive_prefix(end)) {
72a4f4b6 549 if (c == ':') {
faea9ccb 550 protocol = PROTO_SSH;
356bece0 551 *path++ = '\0';
72a4f4b6
LT
552 }
553 } else
554 path = end;
2386d658 555
faea9ccb
AE
556 if (!path || !*path)
557 die("No path specified. See 'man git-pull' for valid url syntax");
558
559 /*
560 * null-terminate hostname and point path to ~ for URL's like this:
561 * ssh://host.xz/~user/repo
562 */
563 if (protocol != PROTO_LOCAL && host != url) {
564 char *ptr = path;
565 if (path[1] == '~')
566 path++;
da2a95b2 567 else {
9befac47 568 path = xstrdup(ptr);
da2a95b2
SH
569 free_path = 1;
570 }
faea9ccb
AE
571
572 *ptr = '\0';
573 }
574
2e776665
LT
575 /*
576 * Add support for ssh port: ssh://host.xy:<port>/...
577 */
578 if (protocol == PROTO_SSH && host != url)
579 port = get_port(host);
580
f8014776 581 if (protocol == PROTO_GIT) {
5ad312be
JL
582 /* These underlying connection commands die() if they
583 * cannot connect.
584 */
9befac47 585 char *target_host = xstrdup(host);
e814bc4d 586 if (git_use_proxy(host))
c78963d2 587 git_proxy_connect(fd, host);
da2a95b2 588 else
7841ce79 589 git_tcp_connect(fd, host, flags);
5ad312be
JL
590 /*
591 * Separate original protocol components prog and path
592 * from extended components with a NUL byte.
593 */
594 packet_write(fd[1],
595 "%s %s%chost=%s%c",
596 prog, path, 0,
597 target_host, 0);
598 free(target_host);
4577370e 599 free(url);
da2a95b2
SH
600 if (free_path)
601 free(path);
fb32c917 602 return &no_fork;
f8014776 603 }
2386d658 604
98158e9c 605 conn = xcalloc(1, sizeof(*conn));
2e776665 606
f364cb88
JS
607 strbuf_init(&cmd, MAX_CMD_LEN);
608 strbuf_addstr(&cmd, prog);
609 strbuf_addch(&cmd, ' ');
610 sq_quote_buf(&cmd, path);
611 if (cmd.len >= MAX_CMD_LEN)
612 die("command line too long");
613
614 conn->in = conn->out = -1;
615 conn->argv = arg = xcalloc(6, sizeof(*arg));
616 if (protocol == PROTO_SSH) {
617 const char *ssh = getenv("GIT_SSH");
618 if (!ssh) ssh = "ssh";
619
620 *arg++ = ssh;
621 if (port) {
622 *arg++ = "-p";
623 *arg++ = port;
4852f723 624 }
f364cb88
JS
625 *arg++ = host;
626 }
627 else {
628 /* remove these from the environment */
629 const char *env[] = {
630 ALTERNATE_DB_ENVIRONMENT,
631 DB_ENVIRONMENT,
632 GIT_DIR_ENVIRONMENT,
633 GIT_WORK_TREE_ENVIRONMENT,
634 GRAFT_ENVIRONMENT,
635 INDEX_ENVIRONMENT,
636 NULL
637 };
638 conn->env = env;
639 *arg++ = "sh";
640 *arg++ = "-c";
016fb48b 641 }
f364cb88
JS
642 *arg++ = cmd.buf;
643 *arg = NULL;
644
645 if (start_command(conn))
646 die("unable to fork");
647
648 fd[0] = conn->out; /* read from child's stdout */
649 fd[1] = conn->in; /* write to child's stdin */
650 strbuf_release(&cmd);
4577370e 651 free(url);
da2a95b2
SH
652 if (free_path)
653 free(path);
98158e9c 654 return conn;
f7192598
LT
655}
656
98158e9c 657int finish_connect(struct child_process *conn)
f7192598 658{
f364cb88 659 int code;
fb32c917 660 if (!conn || conn == &no_fork)
f42a5c4e
FBH
661 return 0;
662
f364cb88
JS
663 code = finish_command(conn);
664 free(conn->argv);
98158e9c 665 free(conn);
f364cb88 666 return code;
f7192598 667}