1#include "git-compat-util.h"
2#include "cache.h"
3#include "pkt-line.h"
4#include "quote.h"
5#include "refs.h"
6#include <sys/wait.h>
7#include <sys/socket.h>
8#include <netinet/in.h>
9#include <arpa/inet.h>
10#include <netdb.h>
11#include <signal.h>
12static char *server_capabilities;
14static int check_ref(const char *name, int len, unsigned int flags)
16{
17 if (!flags)
18 return 1;
19 if (len < 5 || memcmp(name, "refs/", 5))
21 return 0;
22 /* Skip the "refs/" part */
24 name += 5;
25 len -= 5;
26 /* REF_NORMAL means that we don't want the magic fake tag refs */
28 if ((flags & REF_NORMAL) && check_ref_format(name) < 0)
29 return 0;
30 /* REF_HEADS means that we want regular branch heads */
32 if ((flags & REF_HEADS) && !memcmp(name, "heads/", 6))
33 return 1;
34 /* REF_TAGS means that we want tags */
36 if ((flags & REF_TAGS) && !memcmp(name, "tags/", 5))
37 return 1;
38 /* All type bits clear means that we are ok with anything */
40 return !(flags & ~REF_NORMAL);
41}
42/*
44 * Read all the refs from the other end
45 */
46struct ref **get_remote_heads(int in, struct ref **list,
47 int nr_match, char **match,
48 unsigned int flags)
49{
50 *list = NULL;
51 for (;;) {
52 struct ref *ref;
53 unsigned char old_sha1[20];
54 static char buffer[1000];
55 char *name;
56 int len, name_len;
57 len = packet_read_line(in, buffer, sizeof(buffer));
59 if (!len)
60 break;
61 if (buffer[len-1] == '\n')
62 buffer[--len] = 0;
63 if (len < 42 || get_sha1_hex(buffer, old_sha1) || buffer[40] != ' ')
65 die("protocol error: expected sha/ref, got '%s'", buffer);
66 name = buffer + 41;
67 name_len = strlen(name);
69 if (len != name_len + 41) {
70 if (server_capabilities)
71 free(server_capabilities);
72 server_capabilities = xstrdup(name + name_len + 1);
73 }
74 if (!check_ref(name, name_len, flags))
76 continue;
77 if (nr_match && !path_match(name, nr_match, match))
78 continue;
79 ref = xcalloc(1, sizeof(*ref) + len - 40);
80 hashcpy(ref->old_sha1, old_sha1);
81 memcpy(ref->name, buffer + 41, len - 40);
82 *list = ref;
83 list = &ref->next;
84 }
85 return list;
86}
87int server_supports(const char *feature)
89{
90 return server_capabilities &&
91 strstr(server_capabilities, feature) != NULL;
92}
93int get_ack(int fd, unsigned char *result_sha1)
95{
96 static char line[1000];
97 int len = packet_read_line(fd, line, sizeof(line));
98 if (!len)
100 die("git-fetch-pack: expected ACK/NAK, got EOF");
101 if (line[len-1] == '\n')
102 line[--len] = 0;
103 if (!strcmp(line, "NAK"))
104 return 0;
105 if (!strncmp(line, "ACK ", 4)) {
106 if (!get_sha1_hex(line+4, result_sha1)) {
107 if (strstr(line+45, "continue"))
108 return 2;
109 return 1;
110 }
111 }
112 die("git-fetch_pack: expected ACK/NAK, got '%s'", line);
113}
114int path_match(const char *path, int nr, char **match)
116{
117 int i;
118 int pathlen = strlen(path);
119 for (i = 0; i < nr; i++) {
121 char *s = match[i];
122 int len = strlen(s);
123 if (!len || len > pathlen)
125 continue;
126 if (memcmp(path + pathlen - len, s, len))
127 continue;
128 if (pathlen > len && path[pathlen - len - 1] != '/')
129 continue;
130 *s = 0;
131 return (i + 1);
132 }
133 return 0;
134}
135struct refspec {
137 char *src;
138 char *dst;
139 char force;
140};
141/*
143 * A:B means fast forward remote B with local A.
144 * +A:B means overwrite remote B with local A.
145 * +A is a shorthand for +A:A.
146 * A is a shorthand for A:A.
147 * :B means delete remote B.
148 */
149static struct refspec *parse_ref_spec(int nr_refspec, char **refspec)
150{
151 int i;
152 struct refspec *rs = xcalloc(sizeof(*rs), (nr_refspec + 1));
153 for (i = 0; i < nr_refspec; i++) {
154 char *sp, *dp, *ep;
155 sp = refspec[i];
156 if (*sp == '+') {
157 rs[i].force = 1;
158 sp++;
159 }
160 ep = strchr(sp, ':');
161 if (ep) {
162 dp = ep + 1;
163 *ep = 0;
164 }
165 else
166 dp = sp;
167 rs[i].src = sp;
168 rs[i].dst = dp;
169 }
170 rs[nr_refspec].src = rs[nr_refspec].dst = NULL;
171 return rs;
172}
173static int count_refspec_match(const char *pattern,
175 struct ref *refs,
176 struct ref **matched_ref)
177{
178 int patlen = strlen(pattern);
179 struct ref *matched_weak = NULL;
180 struct ref *matched = NULL;
181 int weak_match = 0;
182 int match = 0;
183 for (weak_match = match = 0; refs; refs = refs->next) {
185 char *name = refs->name;
186 int namelen = strlen(name);
187 int weak_match;
188 if (namelen < patlen ||
190 memcmp(name + namelen - patlen, pattern, patlen))
191 continue;
192 if (namelen != patlen && name[namelen - patlen - 1] != '/')
193 continue;
194 /* A match is "weak" if it is with refs outside
196 * heads or tags, and did not specify the pattern
197 * in full (e.g. "refs/remotes/origin/master") or at
198 * least from the toplevel (e.g. "remotes/origin/master");
199 * otherwise "git push $URL master" would result in
200 * ambiguity between remotes/origin/master and heads/master
201 * at the remote site.
202 */
203 if (namelen != patlen &&
204 patlen != namelen - 5 &&
205 strncmp(name, "refs/heads/", 11) &&
206 strncmp(name, "refs/tags/", 10)) {
207 /* We want to catch the case where only weak
208 * matches are found and there are multiple
209 * matches, and where more than one strong
210 * matches are found, as ambiguous. One
211 * strong match with zero or more weak matches
212 * are acceptable as a unique match.
213 */
214 matched_weak = refs;
215 weak_match++;
216 }
217 else {
218 matched = refs;
219 match++;
220 }
221 }
222 if (!matched) {
223 *matched_ref = matched_weak;
224 return weak_match;
225 }
226 else {
227 *matched_ref = matched;
228 return match;
229 }
230}
231static void link_dst_tail(struct ref *ref, struct ref ***tail)
233{
234 **tail = ref;
235 *tail = &ref->next;
236 **tail = NULL;
237}
238static struct ref *try_explicit_object_name(const char *name)
240{
241 unsigned char sha1[20];
242 struct ref *ref;
243 int len;
244 if (!*name) {
246 ref = xcalloc(1, sizeof(*ref) + 20);
247 strcpy(ref->name, "(delete)");
248 hashclr(ref->new_sha1);
249 return ref;
250 }
251 if (get_sha1(name, sha1))
252 return NULL;
253 len = strlen(name) + 1;
254 ref = xcalloc(1, sizeof(*ref) + len);
255 memcpy(ref->name, name, len);
256 hashcpy(ref->new_sha1, sha1);
257 return ref;
258}
259static int match_explicit_refs(struct ref *src, struct ref *dst,
261 struct ref ***dst_tail, struct refspec *rs)
262{
263 int i, errs;
264 for (i = errs = 0; rs[i].src; i++) {
265 struct ref *matched_src, *matched_dst;
266 matched_src = matched_dst = NULL;
268 switch (count_refspec_match(rs[i].src, src, &matched_src)) {
269 case 1:
270 break;
271 case 0:
272 /* The source could be in the get_sha1() format
273 * not a reference name. :refs/other is a
274 * way to delete 'other' ref at the remote end.
275 */
276 matched_src = try_explicit_object_name(rs[i].src);
277 if (matched_src)
278 break;
279 errs = 1;
280 error("src refspec %s does not match any.",
281 rs[i].src);
282 break;
283 default:
284 errs = 1;
285 error("src refspec %s matches more than one.",
286 rs[i].src);
287 break;
288 }
289 switch (count_refspec_match(rs[i].dst, dst, &matched_dst)) {
290 case 1:
291 break;
292 case 0:
293 if (!memcmp(rs[i].dst, "refs/", 5)) {
294 int len = strlen(rs[i].dst) + 1;
295 matched_dst = xcalloc(1, sizeof(*dst) + len);
296 memcpy(matched_dst->name, rs[i].dst, len);
297 link_dst_tail(matched_dst, dst_tail);
298 }
299 else if (!strcmp(rs[i].src, rs[i].dst) &&
300 matched_src) {
301 /* pushing "master:master" when
302 * remote does not have master yet.
303 */
304 int len = strlen(matched_src->name) + 1;
305 matched_dst = xcalloc(1, sizeof(*dst) + len);
306 memcpy(matched_dst->name, matched_src->name,
307 len);
308 link_dst_tail(matched_dst, dst_tail);
309 }
310 else {
311 errs = 1;
312 error("dst refspec %s does not match any "
313 "existing ref on the remote and does "
314 "not start with refs/.", rs[i].dst);
315 }
316 break;
317 default:
318 errs = 1;
319 error("dst refspec %s matches more than one.",
320 rs[i].dst);
321 break;
322 }
323 if (errs)
324 continue;
325 if (matched_dst->peer_ref) {
326 errs = 1;
327 error("dst ref %s receives from more than one src.",
328 matched_dst->name);
329 }
330 else {
331 matched_dst->peer_ref = matched_src;
332 matched_dst->force = rs[i].force;
333 }
334 }
335 return -errs;
336}
337static struct ref *find_ref_by_name(struct ref *list, const char *name)
339{
340 for ( ; list; list = list->next)
341 if (!strcmp(list->name, name))
342 return list;
343 return NULL;
344}
345int match_refs(struct ref *src, struct ref *dst, struct ref ***dst_tail,
347 int nr_refspec, char **refspec, int all)
348{
349 struct refspec *rs = parse_ref_spec(nr_refspec, refspec);
350 if (nr_refspec)
352 return match_explicit_refs(src, dst, dst_tail, rs);
353 /* pick the remainder */
355 for ( ; src; src = src->next) {
356 struct ref *dst_peer;
357 if (src->peer_ref)
358 continue;
359 dst_peer = find_ref_by_name(dst, src->name);
360 if ((dst_peer && dst_peer->peer_ref) || (!dst_peer && !all))
361 continue;
362 if (!dst_peer) {
363 /* Create a new one and link it */
364 int len = strlen(src->name) + 1;
365 dst_peer = xcalloc(1, sizeof(*dst_peer) + len);
366 memcpy(dst_peer->name, src->name, len);
367 hashcpy(dst_peer->new_sha1, src->new_sha1);
368 link_dst_tail(dst_peer, dst_tail);
369 }
370 dst_peer->peer_ref = src;
371 }
372 return 0;
373}
374enum protocol {
376 PROTO_LOCAL = 1,
377 PROTO_SSH,
378 PROTO_GIT,
379};
380static enum protocol get_protocol(const char *name)
382{
383 if (!strcmp(name, "ssh"))
384 return PROTO_SSH;
385 if (!strcmp(name, "git"))
386 return PROTO_GIT;
387 if (!strcmp(name, "git+ssh"))
388 return PROTO_SSH;
389 if (!strcmp(name, "ssh+git"))
390 return PROTO_SSH;
391 die("I don't handle protocol '%s'", name);
392}
393#define STR_(s) # s
395#define STR(s) STR_(s)
396#ifndef NO_IPV6
398/*
400 * Returns a connected socket() fd, or else die()s.
401 */
402static int git_tcp_connect_sock(char *host)
403{
404 int sockfd = -1, saved_errno = 0;
405 char *colon, *end;
406 const char *port = STR(DEFAULT_GIT_PORT);
407 struct addrinfo hints, *ai0, *ai;
408 int gai;
409 if (host[0] == '[') {
411 end = strchr(host + 1, ']');
412 if (end) {
413 *end = 0;
414 end++;
415 host++;
416 } else
417 end = host;
418 } else
419 end = host;
420 colon = strchr(end, ':');
421 if (colon) {
423 *colon = 0;
424 port = colon + 1;
425 }
426 memset(&hints, 0, sizeof(hints));
428 hints.ai_socktype = SOCK_STREAM;
429 hints.ai_protocol = IPPROTO_TCP;
430 gai = getaddrinfo(host, port, &hints, &ai);
432 if (gai)
433 die("Unable to look up %s (%s)", host, gai_strerror(gai));
434 for (ai0 = ai; ai; ai = ai->ai_next) {
436 sockfd = socket(ai->ai_family,
437 ai->ai_socktype, ai->ai_protocol);
438 if (sockfd < 0) {
439 saved_errno = errno;
440 continue;
441 }
442 if (connect(sockfd, ai->ai_addr, ai->ai_addrlen) < 0) {
443 saved_errno = errno;
444 close(sockfd);
445 sockfd = -1;
446 continue;
447 }
448 break;
449 }
450 freeaddrinfo(ai0);
452 if (sockfd < 0)
454 die("unable to connect a socket (%s)", strerror(saved_errno));
455 return sockfd;
457}
458#else /* NO_IPV6 */
460/*
462 * Returns a connected socket() fd, or else die()s.
463 */
464static int git_tcp_connect_sock(char *host)
465{
466 int sockfd = -1, saved_errno = 0;
467 char *colon, *end;
468 char *port = STR(DEFAULT_GIT_PORT), *ep;
469 struct hostent *he;
470 struct sockaddr_in sa;
471 char **ap;
472 unsigned int nport;
473 if (host[0] == '[') {
475 end = strchr(host + 1, ']');
476 if (end) {
477 *end = 0;
478 end++;
479 host++;
480 } else
481 end = host;
482 } else
483 end = host;
484 colon = strchr(end, ':');
485 if (colon) {
487 *colon = 0;
488 port = colon + 1;
489 }
490 he = gethostbyname(host);
492 if (!he)
493 die("Unable to look up %s (%s)", host, hstrerror(h_errno));
494 nport = strtoul(port, &ep, 10);
495 if ( ep == port || *ep ) {
496 /* Not numeric */
497 struct servent *se = getservbyname(port,"tcp");
498 if ( !se )
499 die("Unknown port %s\n", port);
500 nport = se->s_port;
501 }
502 for (ap = he->h_addr_list; *ap; ap++) {
504 sockfd = socket(he->h_addrtype, SOCK_STREAM, 0);
505 if (sockfd < 0) {
506 saved_errno = errno;
507 continue;
508 }
509 memset(&sa, 0, sizeof sa);
511 sa.sin_family = he->h_addrtype;
512 sa.sin_port = htons(nport);
513 memcpy(&sa.sin_addr, *ap, he->h_length);
514 if (connect(sockfd, (struct sockaddr *)&sa, sizeof sa) < 0) {
516 saved_errno = errno;
517 close(sockfd);
518 sockfd = -1;
519 continue;
520 }
521 break;
522 }
523 if (sockfd < 0)
525 die("unable to connect a socket (%s)", strerror(saved_errno));
526 return sockfd;
528}
529#endif /* NO_IPV6 */
531static void git_tcp_connect(int fd[2], char *host)
534{
535 int sockfd = git_tcp_connect_sock(host);
536 fd[0] = sockfd;
538 fd[1] = sockfd;
539}
540static char *git_proxy_command;
543static const char *rhost_name;
544static int rhost_len;
545static int git_proxy_command_options(const char *var, const char *value)
547{
548 if (!strcmp(var, "core.gitproxy")) {
549 const char *for_pos;
550 int matchlen = -1;
551 int hostlen;
552 if (git_proxy_command)
554 return 0;
555 /* [core]
556 * ;# matches www.kernel.org as well
557 * gitproxy = netcatter-1 for kernel.org
558 * gitproxy = netcatter-2 for sample.xz
559 * gitproxy = netcatter-default
560 */
561 for_pos = strstr(value, " for ");
562 if (!for_pos)
563 /* matches everybody */
564 matchlen = strlen(value);
565 else {
566 hostlen = strlen(for_pos + 5);
567 if (rhost_len < hostlen)
568 matchlen = -1;
569 else if (!strncmp(for_pos + 5,
570 rhost_name + rhost_len - hostlen,
571 hostlen) &&
572 ((rhost_len == hostlen) ||
573 rhost_name[rhost_len - hostlen -1] == '.'))
574 matchlen = for_pos - value;
575 else
576 matchlen = -1;
577 }
578 if (0 <= matchlen) {
579 /* core.gitproxy = none for kernel.org */
580 if (matchlen == 4 &&
581 !memcmp(value, "none", 4))
582 matchlen = 0;
583 git_proxy_command = xmalloc(matchlen + 1);
584 memcpy(git_proxy_command, value, matchlen);
585 git_proxy_command[matchlen] = 0;
586 }
587 return 0;
588 }
589 return git_default_config(var, value);
591}
592static int git_use_proxy(const char *host)
594{
595 rhost_name = host;
596 rhost_len = strlen(host);
597 git_proxy_command = getenv("GIT_PROXY_COMMAND");
598 git_config(git_proxy_command_options);
599 rhost_name = NULL;
600 return (git_proxy_command && *git_proxy_command);
601}
602static void git_proxy_connect(int fd[2], char *host)
604{
605 const char *port = STR(DEFAULT_GIT_PORT);
606 char *colon, *end;
607 int pipefd[2][2];
608 pid_t pid;
609 if (host[0] == '[') {
611 end = strchr(host + 1, ']');
612 if (end) {
613 *end = 0;
614 end++;
615 host++;
616 } else
617 end = host;
618 } else
619 end = host;
620 colon = strchr(end, ':');
621 if (colon) {
623 *colon = 0;
624 port = colon + 1;
625 }
626 if (pipe(pipefd[0]) < 0 || pipe(pipefd[1]) < 0)
628 die("unable to create pipe pair for communication");
629 pid = fork();
630 if (!pid) {
631 dup2(pipefd[1][0], 0);
632 dup2(pipefd[0][1], 1);
633 close(pipefd[0][0]);
634 close(pipefd[0][1]);
635 close(pipefd[1][0]);
636 close(pipefd[1][1]);
637 execlp(git_proxy_command, git_proxy_command, host, port, NULL);
638 die("exec failed");
639 }
640 if (pid < 0)
641 die("fork failed");
642 fd[0] = pipefd[0][0];
643 fd[1] = pipefd[1][1];
644 close(pipefd[0][1]);
645 close(pipefd[1][0]);
646}
647#define MAX_CMD_LEN 1024
649/*
651 * This returns 0 if the transport protocol does not need fork(2),
652 * or a process id if it does. Once done, finish the connection
653 * with finish_connect() with the value returned from this function
654 * (it is safe to call finish_connect() with 0 to support the former
655 * case).
656 *
657 * Does not return a negative value on error; it just dies.
658 */
659pid_t git_connect(int fd[2], char *url, const char *prog)
660{
661 char *host, *path = url;
662 char *end;
663 int c;
664 int pipefd[2][2];
665 pid_t pid;
666 enum protocol protocol = PROTO_LOCAL;
667 int free_path = 0;
668 /* Without this we cannot rely on waitpid() to tell
670 * what happened to our children.
671 */
672 signal(SIGCHLD, SIG_DFL);
673 host = strstr(url, "://");
675 if(host) {
676 *host = '\0';
677 protocol = get_protocol(url);
678 host += 3;
679 c = '/';
680 } else {
681 host = url;
682 c = ':';
683 }
684 if (host[0] == '[') {
686 end = strchr(host + 1, ']');
687 if (end) {
688 *end = 0;
689 end++;
690 host++;
691 } else
692 end = host;
693 } else
694 end = host;
695 path = strchr(end, c);
697 if (c == ':') {
698 if (path) {
699 protocol = PROTO_SSH;
700 *path++ = '\0';
701 } else
702 path = host;
703 }
704 if (!path || !*path)
706 die("No path specified. See 'man git-pull' for valid url syntax");
707 /*
709 * null-terminate hostname and point path to ~ for URL's like this:
710 * ssh://host.xz/~user/repo
711 */
712 if (protocol != PROTO_LOCAL && host != url) {
713 char *ptr = path;
714 if (path[1] == '~')
715 path++;
716 else {
717 path = xstrdup(ptr);
718 free_path = 1;
719 }
720 *ptr = '\0';
722 }
723 if (protocol == PROTO_GIT) {
725 /* These underlying connection commands die() if they
726 * cannot connect.
727 */
728 char *target_host = xstrdup(host);
729 if (git_use_proxy(host))
730 git_proxy_connect(fd, host);
731 else
732 git_tcp_connect(fd, host);
733 /*
734 * Separate original protocol components prog and path
735 * from extended components with a NUL byte.
736 */
737 packet_write(fd[1],
738 "%s %s%chost=%s%c",
739 prog, path, 0,
740 target_host, 0);
741 free(target_host);
742 if (free_path)
743 free(path);
744 return 0;
745 }
746 if (pipe(pipefd[0]) < 0 || pipe(pipefd[1]) < 0)
748 die("unable to create pipe pair for communication");
749 pid = fork();
750 if (pid < 0)
751 die("unable to fork");
752 if (!pid) {
753 char command[MAX_CMD_LEN];
754 char *posn = command;
755 int size = MAX_CMD_LEN;
756 int of = 0;
757 of |= add_to_string(&posn, &size, prog, 0);
759 of |= add_to_string(&posn, &size, " ", 0);
760 of |= add_to_string(&posn, &size, path, 1);
761 if (of)
763 die("command line too long");
764 dup2(pipefd[1][0], 0);
766 dup2(pipefd[0][1], 1);
767 close(pipefd[0][0]);
768 close(pipefd[0][1]);
769 close(pipefd[1][0]);
770 close(pipefd[1][1]);
771 if (protocol == PROTO_SSH) {
772 const char *ssh, *ssh_basename;
773 ssh = getenv("GIT_SSH");
774 if (!ssh) ssh = "ssh";
775 ssh_basename = strrchr(ssh, '/');
776 if (!ssh_basename)
777 ssh_basename = ssh;
778 else
779 ssh_basename++;
780 execlp(ssh, ssh_basename, host, command, NULL);
781 }
782 else {
783 unsetenv(ALTERNATE_DB_ENVIRONMENT);
784 unsetenv(DB_ENVIRONMENT);
785 unsetenv(GIT_DIR_ENVIRONMENT);
786 unsetenv(GRAFT_ENVIRONMENT);
787 unsetenv(INDEX_ENVIRONMENT);
788 execlp("sh", "sh", "-c", command, NULL);
789 }
790 die("exec failed");
791 }
792 fd[0] = pipefd[0][0];
793 fd[1] = pipefd[1][1];
794 close(pipefd[0][1]);
795 close(pipefd[1][0]);
796 if (free_path)
797 free(path);
798 return pid;
799}
800int finish_connect(pid_t pid)
802{
803 if (pid == 0)
804 return 0;
805 while (waitpid(pid, NULL, 0) < 0) {
807 if (errno != EINTR)
808 return -1;
809 }
810 return 0;
811}