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 "run-command.h"
7#include "remote.h"
8#include "connect.h"
9#include "url.h"
10#include "string-list.h"
11#include "sha1-array.h"
12
13static char *server_capabilities;
14static const char *parse_feature_value(const char *, const char *, int *);
15
16static int check_ref(const char *name, int len, unsigned int flags)
17{
18 if (!flags)
19 return 1;
20
21 if (len < 5 || memcmp(name, "refs/", 5))
22 return 0;
23
24 /* Skip the "refs/" part */
25 name += 5;
26 len -= 5;
27
28 /* REF_NORMAL means that we don't want the magic fake tag refs */
29 if ((flags & REF_NORMAL) && check_refname_format(name, 0))
30 return 0;
31
32 /* REF_HEADS means that we want regular branch heads */
33 if ((flags & REF_HEADS) && !memcmp(name, "heads/", 6))
34 return 1;
35
36 /* REF_TAGS means that we want tags */
37 if ((flags & REF_TAGS) && !memcmp(name, "tags/", 5))
38 return 1;
39
40 /* All type bits clear means that we are ok with anything */
41 return !(flags & ~REF_NORMAL);
42}
43
44int check_ref_type(const struct ref *ref, int flags)
45{
46 return check_ref(ref->name, strlen(ref->name), flags);
47}
48
49static void die_initial_contact(int got_at_least_one_head)
50{
51 if (got_at_least_one_head)
52 die("The remote end hung up upon initial contact");
53 else
54 die("Could not read from remote repository.\n\n"
55 "Please make sure you have the correct access rights\n"
56 "and the repository exists.");
57}
58
59static void parse_one_symref_info(struct string_list *symref, const char *val, int len)
60{
61 char *sym, *target;
62 struct string_list_item *item;
63
64 if (!len)
65 return; /* just "symref" */
66 /* e.g. "symref=HEAD:refs/heads/master" */
67 sym = xmemdupz(val, len);
68 target = strchr(sym, ':');
69 if (!target)
70 /* just "symref=something" */
71 goto reject;
72 *(target++) = '\0';
73 if (check_refname_format(sym, REFNAME_ALLOW_ONELEVEL) ||
74 check_refname_format(target, REFNAME_ALLOW_ONELEVEL))
75 /* "symref=bogus:pair */
76 goto reject;
77 item = string_list_append(symref, sym);
78 item->util = target;
79 return;
80reject:
81 free(sym);
82 return;
83}
84
85static void annotate_refs_with_symref_info(struct ref *ref)
86{
87 struct string_list symref = STRING_LIST_INIT_DUP;
88 const char *feature_list = server_capabilities;
89
90 while (feature_list) {
91 int len;
92 const char *val;
93
94 val = parse_feature_value(feature_list, "symref", &len);
95 if (!val)
96 break;
97 parse_one_symref_info(&symref, val, len);
98 feature_list = val + 1;
99 }
100 sort_string_list(&symref);
101
102 for (; ref; ref = ref->next) {
103 struct string_list_item *item;
104 item = string_list_lookup(&symref, ref->name);
105 if (!item)
106 continue;
107 ref->symref = xstrdup((char *)item->util);
108 }
109 string_list_clear(&symref, 0);
110}
111
112/*
113 * Read all the refs from the other end
114 */
115struct ref **get_remote_heads(int in, char *src_buf, size_t src_len,
116 struct ref **list, unsigned int flags,
117 struct sha1_array *extra_have,
118 struct sha1_array *shallow_points)
119{
120 struct ref **orig_list = list;
121 int got_at_least_one_head = 0;
122
123 *list = NULL;
124 for (;;) {
125 struct ref *ref;
126 unsigned char old_sha1[20];
127 char *name;
128 int len, name_len;
129 char *buffer = packet_buffer;
130 const char *arg;
131
132 len = packet_read(in, &src_buf, &src_len,
133 packet_buffer, sizeof(packet_buffer),
134 PACKET_READ_GENTLE_ON_EOF |
135 PACKET_READ_CHOMP_NEWLINE);
136 if (len < 0)
137 die_initial_contact(got_at_least_one_head);
138
139 if (!len)
140 break;
141
142 if (len > 4 && skip_prefix(buffer, "ERR ", &arg))
143 die("remote error: %s", arg);
144
145 if (len == 48 && skip_prefix(buffer, "shallow ", &arg)) {
146 if (get_sha1_hex(arg, old_sha1))
147 die("protocol error: expected shallow sha-1, got '%s'", arg);
148 if (!shallow_points)
149 die("repository on the other end cannot be shallow");
150 sha1_array_append(shallow_points, old_sha1);
151 continue;
152 }
153
154 if (len < 42 || get_sha1_hex(buffer, old_sha1) || buffer[40] != ' ')
155 die("protocol error: expected sha/ref, got '%s'", buffer);
156 name = buffer + 41;
157
158 name_len = strlen(name);
159 if (len != name_len + 41) {
160 free(server_capabilities);
161 server_capabilities = xstrdup(name + name_len + 1);
162 }
163
164 if (extra_have &&
165 name_len == 5 && !memcmp(".have", name, 5)) {
166 sha1_array_append(extra_have, old_sha1);
167 continue;
168 }
169
170 if (!check_ref(name, name_len, flags))
171 continue;
172 ref = alloc_ref(buffer + 41);
173 hashcpy(ref->old_sha1, old_sha1);
174 *list = ref;
175 list = &ref->next;
176 got_at_least_one_head = 1;
177 }
178
179 annotate_refs_with_symref_info(*orig_list);
180
181 return list;
182}
183
184static const char *parse_feature_value(const char *feature_list, const char *feature, int *lenp)
185{
186 int len;
187
188 if (!feature_list)
189 return NULL;
190
191 len = strlen(feature);
192 while (*feature_list) {
193 const char *found = strstr(feature_list, feature);
194 if (!found)
195 return NULL;
196 if (feature_list == found || isspace(found[-1])) {
197 const char *value = found + len;
198 /* feature with no value (e.g., "thin-pack") */
199 if (!*value || isspace(*value)) {
200 if (lenp)
201 *lenp = 0;
202 return value;
203 }
204 /* feature with a value (e.g., "agent=git/1.2.3") */
205 else if (*value == '=') {
206 value++;
207 if (lenp)
208 *lenp = strcspn(value, " \t\n");
209 return value;
210 }
211 /*
212 * otherwise we matched a substring of another feature;
213 * keep looking
214 */
215 }
216 feature_list = found + 1;
217 }
218 return NULL;
219}
220
221int parse_feature_request(const char *feature_list, const char *feature)
222{
223 return !!parse_feature_value(feature_list, feature, NULL);
224}
225
226const char *server_feature_value(const char *feature, int *len)
227{
228 return parse_feature_value(server_capabilities, feature, len);
229}
230
231int server_supports(const char *feature)
232{
233 return !!server_feature_value(feature, NULL);
234}
235
236enum protocol {
237 PROTO_LOCAL = 1,
238 PROTO_FILE,
239 PROTO_SSH,
240 PROTO_GIT
241};
242
243int url_is_local_not_ssh(const char *url)
244{
245 const char *colon = strchr(url, ':');
246 const char *slash = strchr(url, '/');
247 return !colon || (slash && slash < colon) ||
248 has_dos_drive_prefix(url);
249}
250
251static const char *prot_name(enum protocol protocol)
252{
253 switch (protocol) {
254 case PROTO_LOCAL:
255 case PROTO_FILE:
256 return "file";
257 case PROTO_SSH:
258 return "ssh";
259 case PROTO_GIT:
260 return "git";
261 default:
262 return "unkown protocol";
263 }
264}
265
266static enum protocol get_protocol(const char *name)
267{
268 if (!strcmp(name, "ssh"))
269 return PROTO_SSH;
270 if (!strcmp(name, "git"))
271 return PROTO_GIT;
272 if (!strcmp(name, "git+ssh"))
273 return PROTO_SSH;
274 if (!strcmp(name, "ssh+git"))
275 return PROTO_SSH;
276 if (!strcmp(name, "file"))
277 return PROTO_FILE;
278 die("I don't handle protocol '%s'", name);
279}
280
281#define STR_(s) # s
282#define STR(s) STR_(s)
283
284static void get_host_and_port(char **host, const char **port)
285{
286 char *colon, *end;
287
288 if (*host[0] == '[') {
289 end = strchr(*host + 1, ']');
290 if (end) {
291 *end = 0;
292 end++;
293 (*host)++;
294 } else
295 end = *host;
296 } else
297 end = *host;
298 colon = strchr(end, ':');
299
300 if (colon) {
301 *colon = 0;
302 *port = colon + 1;
303 }
304}
305
306static void enable_keepalive(int sockfd)
307{
308 int ka = 1;
309
310 if (setsockopt(sockfd, SOL_SOCKET, SO_KEEPALIVE, &ka, sizeof(ka)) < 0)
311 fprintf(stderr, "unable to set SO_KEEPALIVE on socket: %s\n",
312 strerror(errno));
313}
314
315#ifndef NO_IPV6
316
317static const char *ai_name(const struct addrinfo *ai)
318{
319 static char addr[NI_MAXHOST];
320 if (getnameinfo(ai->ai_addr, ai->ai_addrlen, addr, sizeof(addr), NULL, 0,
321 NI_NUMERICHOST) != 0)
322 strcpy(addr, "(unknown)");
323
324 return addr;
325}
326
327/*
328 * Returns a connected socket() fd, or else die()s.
329 */
330static int git_tcp_connect_sock(char *host, int flags)
331{
332 struct strbuf error_message = STRBUF_INIT;
333 int sockfd = -1;
334 const char *port = STR(DEFAULT_GIT_PORT);
335 struct addrinfo hints, *ai0, *ai;
336 int gai;
337 int cnt = 0;
338
339 get_host_and_port(&host, &port);
340 if (!*port)
341 port = "<none>";
342
343 memset(&hints, 0, sizeof(hints));
344 hints.ai_socktype = SOCK_STREAM;
345 hints.ai_protocol = IPPROTO_TCP;
346
347 if (flags & CONNECT_VERBOSE)
348 fprintf(stderr, "Looking up %s ... ", host);
349
350 gai = getaddrinfo(host, port, &hints, &ai);
351 if (gai)
352 die("Unable to look up %s (port %s) (%s)", host, port, gai_strerror(gai));
353
354 if (flags & CONNECT_VERBOSE)
355 fprintf(stderr, "done.\nConnecting to %s (port %s) ... ", host, port);
356
357 for (ai0 = ai; ai; ai = ai->ai_next, cnt++) {
358 sockfd = socket(ai->ai_family,
359 ai->ai_socktype, ai->ai_protocol);
360 if ((sockfd < 0) ||
361 (connect(sockfd, ai->ai_addr, ai->ai_addrlen) < 0)) {
362 strbuf_addf(&error_message, "%s[%d: %s]: errno=%s\n",
363 host, cnt, ai_name(ai), strerror(errno));
364 if (0 <= sockfd)
365 close(sockfd);
366 sockfd = -1;
367 continue;
368 }
369 if (flags & CONNECT_VERBOSE)
370 fprintf(stderr, "%s ", ai_name(ai));
371 break;
372 }
373
374 freeaddrinfo(ai0);
375
376 if (sockfd < 0)
377 die("unable to connect to %s:\n%s", host, error_message.buf);
378
379 enable_keepalive(sockfd);
380
381 if (flags & CONNECT_VERBOSE)
382 fprintf(stderr, "done.\n");
383
384 strbuf_release(&error_message);
385
386 return sockfd;
387}
388
389#else /* NO_IPV6 */
390
391/*
392 * Returns a connected socket() fd, or else die()s.
393 */
394static int git_tcp_connect_sock(char *host, int flags)
395{
396 struct strbuf error_message = STRBUF_INIT;
397 int sockfd = -1;
398 const char *port = STR(DEFAULT_GIT_PORT);
399 char *ep;
400 struct hostent *he;
401 struct sockaddr_in sa;
402 char **ap;
403 unsigned int nport;
404 int cnt;
405
406 get_host_and_port(&host, &port);
407
408 if (flags & CONNECT_VERBOSE)
409 fprintf(stderr, "Looking up %s ... ", host);
410
411 he = gethostbyname(host);
412 if (!he)
413 die("Unable to look up %s (%s)", host, hstrerror(h_errno));
414 nport = strtoul(port, &ep, 10);
415 if ( ep == port || *ep ) {
416 /* Not numeric */
417 struct servent *se = getservbyname(port,"tcp");
418 if ( !se )
419 die("Unknown port %s", port);
420 nport = se->s_port;
421 }
422
423 if (flags & CONNECT_VERBOSE)
424 fprintf(stderr, "done.\nConnecting to %s (port %s) ... ", host, port);
425
426 for (cnt = 0, ap = he->h_addr_list; *ap; ap++, cnt++) {
427 memset(&sa, 0, sizeof sa);
428 sa.sin_family = he->h_addrtype;
429 sa.sin_port = htons(nport);
430 memcpy(&sa.sin_addr, *ap, he->h_length);
431
432 sockfd = socket(he->h_addrtype, SOCK_STREAM, 0);
433 if ((sockfd < 0) ||
434 connect(sockfd, (struct sockaddr *)&sa, sizeof sa) < 0) {
435 strbuf_addf(&error_message, "%s[%d: %s]: errno=%s\n",
436 host,
437 cnt,
438 inet_ntoa(*(struct in_addr *)&sa.sin_addr),
439 strerror(errno));
440 if (0 <= sockfd)
441 close(sockfd);
442 sockfd = -1;
443 continue;
444 }
445 if (flags & CONNECT_VERBOSE)
446 fprintf(stderr, "%s ",
447 inet_ntoa(*(struct in_addr *)&sa.sin_addr));
448 break;
449 }
450
451 if (sockfd < 0)
452 die("unable to connect to %s:\n%s", host, error_message.buf);
453
454 enable_keepalive(sockfd);
455
456 if (flags & CONNECT_VERBOSE)
457 fprintf(stderr, "done.\n");
458
459 return sockfd;
460}
461
462#endif /* NO_IPV6 */
463
464
465static void git_tcp_connect(int fd[2], char *host, int flags)
466{
467 int sockfd = git_tcp_connect_sock(host, flags);
468
469 fd[0] = sockfd;
470 fd[1] = dup(sockfd);
471}
472
473
474static char *git_proxy_command;
475
476static int git_proxy_command_options(const char *var, const char *value,
477 void *cb)
478{
479 if (!strcmp(var, "core.gitproxy")) {
480 const char *for_pos;
481 int matchlen = -1;
482 int hostlen;
483 const char *rhost_name = cb;
484 int rhost_len = strlen(rhost_name);
485
486 if (git_proxy_command)
487 return 0;
488 if (!value)
489 return config_error_nonbool(var);
490 /* [core]
491 * ;# matches www.kernel.org as well
492 * gitproxy = netcatter-1 for kernel.org
493 * gitproxy = netcatter-2 for sample.xz
494 * gitproxy = netcatter-default
495 */
496 for_pos = strstr(value, " for ");
497 if (!for_pos)
498 /* matches everybody */
499 matchlen = strlen(value);
500 else {
501 hostlen = strlen(for_pos + 5);
502 if (rhost_len < hostlen)
503 matchlen = -1;
504 else if (!strncmp(for_pos + 5,
505 rhost_name + rhost_len - hostlen,
506 hostlen) &&
507 ((rhost_len == hostlen) ||
508 rhost_name[rhost_len - hostlen -1] == '.'))
509 matchlen = for_pos - value;
510 else
511 matchlen = -1;
512 }
513 if (0 <= matchlen) {
514 /* core.gitproxy = none for kernel.org */
515 if (matchlen == 4 &&
516 !memcmp(value, "none", 4))
517 matchlen = 0;
518 git_proxy_command = xmemdupz(value, matchlen);
519 }
520 return 0;
521 }
522
523 return git_default_config(var, value, cb);
524}
525
526static int git_use_proxy(const char *host)
527{
528 git_proxy_command = getenv("GIT_PROXY_COMMAND");
529 git_config(git_proxy_command_options, (void*)host);
530 return (git_proxy_command && *git_proxy_command);
531}
532
533static struct child_process *git_proxy_connect(int fd[2], char *host)
534{
535 const char *port = STR(DEFAULT_GIT_PORT);
536 struct child_process *proxy;
537
538 get_host_and_port(&host, &port);
539
540 proxy = xmalloc(sizeof(*proxy));
541 child_process_init(proxy);
542 argv_array_push(&proxy->args, git_proxy_command);
543 argv_array_push(&proxy->args, host);
544 argv_array_push(&proxy->args, port);
545 proxy->in = -1;
546 proxy->out = -1;
547 if (start_command(proxy))
548 die("cannot start proxy %s", git_proxy_command);
549 fd[0] = proxy->out; /* read from proxy stdout */
550 fd[1] = proxy->in; /* write to proxy stdin */
551 return proxy;
552}
553
554static const char *get_port_numeric(const char *p)
555{
556 char *end;
557 if (p) {
558 long port = strtol(p + 1, &end, 10);
559 if (end != p + 1 && *end == '\0' && 0 <= port && port < 65536) {
560 return p;
561 }
562 }
563
564 return NULL;
565}
566
567/*
568 * Extract protocol and relevant parts from the specified connection URL.
569 * The caller must free() the returned strings.
570 */
571static enum protocol parse_connect_url(const char *url_orig, char **ret_host,
572 char **ret_path)
573{
574 char *url;
575 char *host, *path;
576 char *end;
577 int separator = '/';
578 enum protocol protocol = PROTO_LOCAL;
579
580 if (is_url(url_orig))
581 url = url_decode(url_orig);
582 else
583 url = xstrdup(url_orig);
584
585 host = strstr(url, "://");
586 if (host) {
587 *host = '\0';
588 protocol = get_protocol(url);
589 host += 3;
590 } else {
591 host = url;
592 if (!url_is_local_not_ssh(url)) {
593 protocol = PROTO_SSH;
594 separator = ':';
595 }
596 }
597
598 /*
599 * Don't do destructive transforms as protocol code does
600 * '[]' unwrapping in get_host_and_port()
601 */
602 if (host[0] == '[') {
603 end = strchr(host + 1, ']');
604 if (end) {
605 end++;
606 } else
607 end = host;
608 } else
609 end = host;
610
611 if (protocol == PROTO_LOCAL)
612 path = end;
613 else if (protocol == PROTO_FILE && has_dos_drive_prefix(end))
614 path = end; /* "file://$(pwd)" may be "file://C:/projects/repo" */
615 else
616 path = strchr(end, separator);
617
618 if (!path || !*path)
619 die("No path specified. See 'man git-pull' for valid url syntax");
620
621 /*
622 * null-terminate hostname and point path to ~ for URL's like this:
623 * ssh://host.xz/~user/repo
624 */
625
626 end = path; /* Need to \0 terminate host here */
627 if (separator == ':')
628 path++; /* path starts after ':' */
629 if (protocol == PROTO_GIT || protocol == PROTO_SSH) {
630 if (path[1] == '~')
631 path++;
632 }
633
634 path = xstrdup(path);
635 *end = '\0';
636
637 *ret_host = xstrdup(host);
638 *ret_path = path;
639 free(url);
640 return protocol;
641}
642
643static struct child_process no_fork = CHILD_PROCESS_INIT;
644
645/*
646 * This returns a dummy child_process if the transport protocol does not
647 * need fork(2), or a struct child_process object if it does. Once done,
648 * finish the connection with finish_connect() with the value returned from
649 * this function (it is safe to call finish_connect() with NULL to support
650 * the former case).
651 *
652 * If it returns, the connect is successful; it just dies on errors (this
653 * will hopefully be changed in a libification effort, to return NULL when
654 * the connection failed).
655 */
656struct child_process *git_connect(int fd[2], const char *url,
657 const char *prog, int flags)
658{
659 char *hostandport, *path;
660 struct child_process *conn = &no_fork;
661 enum protocol protocol;
662 struct strbuf cmd = STRBUF_INIT;
663
664 /* Without this we cannot rely on waitpid() to tell
665 * what happened to our children.
666 */
667 signal(SIGCHLD, SIG_DFL);
668
669 protocol = parse_connect_url(url, &hostandport, &path);
670 if (flags & CONNECT_DIAG_URL) {
671 printf("Diag: url=%s\n", url ? url : "NULL");
672 printf("Diag: protocol=%s\n", prot_name(protocol));
673 printf("Diag: hostandport=%s\n", hostandport ? hostandport : "NULL");
674 printf("Diag: path=%s\n", path ? path : "NULL");
675 conn = NULL;
676 } else if (protocol == PROTO_GIT) {
677 /* These underlying connection commands die() if they
678 * cannot connect.
679 */
680 char *target_host = xstrdup(hostandport);
681 if (git_use_proxy(hostandport))
682 conn = git_proxy_connect(fd, hostandport);
683 else
684 git_tcp_connect(fd, hostandport, flags);
685 /*
686 * Separate original protocol components prog and path
687 * from extended host header with a NUL byte.
688 *
689 * Note: Do not add any other headers here! Doing so
690 * will cause older git-daemon servers to crash.
691 */
692 packet_write(fd[1],
693 "%s %s%chost=%s%c",
694 prog, path, 0,
695 target_host, 0);
696 free(target_host);
697 } else {
698 conn = xmalloc(sizeof(*conn));
699 child_process_init(conn);
700
701 strbuf_addstr(&cmd, prog);
702 strbuf_addch(&cmd, ' ');
703 sq_quote_buf(&cmd, path);
704
705 conn->in = conn->out = -1;
706 if (protocol == PROTO_SSH) {
707 const char *ssh = getenv("GIT_SSH");
708 int putty = ssh && strcasestr(ssh, "plink");
709 char *ssh_host = hostandport;
710 const char *port = NULL;
711 get_host_and_port(&ssh_host, &port);
712 port = get_port_numeric(port);
713
714 if (!ssh) ssh = "ssh";
715
716 argv_array_push(&conn->args, ssh);
717 if (putty && !strcasestr(ssh, "tortoiseplink"))
718 argv_array_push(&conn->args, "-batch");
719 if (port) {
720 /* P is for PuTTY, p is for OpenSSH */
721 argv_array_push(&conn->args, putty ? "-P" : "-p");
722 argv_array_push(&conn->args, port);
723 }
724 argv_array_push(&conn->args, ssh_host);
725 } else {
726 /* remove repo-local variables from the environment */
727 conn->env = local_repo_env;
728 conn->use_shell = 1;
729 }
730 argv_array_push(&conn->args, cmd.buf);
731
732 if (start_command(conn))
733 die("unable to fork");
734
735 fd[0] = conn->out; /* read from child's stdout */
736 fd[1] = conn->in; /* write to child's stdin */
737 strbuf_release(&cmd);
738 }
739 free(hostandport);
740 free(path);
741 return conn;
742}
743
744int git_connection_is_socket(struct child_process *conn)
745{
746 return conn == &no_fork;
747}
748
749int finish_connect(struct child_process *conn)
750{
751 int code;
752 if (!conn || git_connection_is_socket(conn))
753 return 0;
754
755 code = finish_command(conn);
756 free(conn);
757 return code;
758}