connect.c

   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
  12 static char *server_capabilities = NULL;
  13
  14 /*
  15  * Read all the refs from the other end
  16  */
  17 struct ref **get_remote_heads(int in, struct ref **list,
  18                               int nr_match, char **match, int ignore_funny)
  19 {
  20         *list = NULL;
  21         for (;;) {
  22                 struct ref *ref;
  23                 unsigned char old_sha1[20];
  24                 static char buffer[1000];
  25                 char *name;
  26                 int len, name_len;
  27
  28                 len = packet_read_line(in, buffer, sizeof(buffer));
  29                 if (!len)
  30                         break;
  31                 if (buffer[len-1] == '\n')
  32                         buffer[--len] = 0;
  33
  34                 if (len < 42 || get_sha1_hex(buffer, old_sha1) || buffer[40] != ' ')
  35                         die("protocol error: expected sha/ref, got '%s'", buffer);
  36                 name = buffer + 41;
  37
  38                 name_len = strlen(name);
  39                 if (len != name_len + 41) {
  40                         if (server_capabilities)
  41                                 free(server_capabilities);
  42                         server_capabilities = strdup(name + name_len + 1);
  43                 }
  44
  45                 if (ignore_funny && 45 < len && !memcmp(name, "refs/", 5) &&
  46                     check_ref_format(name + 5))
  47                         continue;
  48
  49                 if (nr_match && !path_match(name, nr_match, match))
  50                         continue;
  51                 ref = xcalloc(1, sizeof(*ref) + len - 40);
  52                 memcpy(ref->old_sha1, old_sha1, 20);
  53                 memcpy(ref->name, buffer + 41, len - 40);
  54                 *list = ref;
  55                 list = &ref->next;
  56         }
  57         return list;
  58 }
  59
  60 int server_supports(const char *feature)
  61 {
  62         return server_capabilities &&
  63                 strstr(server_capabilities, feature) != NULL;
  64 }
  65
  66 int get_ack(int fd, unsigned char *result_sha1)
  67 {
  68         static char line[1000];
  69         int len = packet_read_line(fd, line, sizeof(line));
  70
  71         if (!len)
  72                 die("git-fetch-pack: expected ACK/NAK, got EOF");
  73         if (line[len-1] == '\n')
  74                 line[--len] = 0;
  75         if (!strcmp(line, "NAK"))
  76                 return 0;
  77         if (!strncmp(line, "ACK ", 4)) {
  78                 if (!get_sha1_hex(line+4, result_sha1)) {
  79                         if (strstr(line+45, "continue"))
  80                                 return 2;
  81                         return 1;
  82                 }
  83         }
  84         die("git-fetch_pack: expected ACK/NAK, got '%s'", line);
  85 }
  86
  87 int path_match(const char *path, int nr, char **match)
  88 {
  89         int i;
  90         int pathlen = strlen(path);
  91
  92         for (i = 0; i < nr; i++) {
  93                 char *s = match[i];
  94                 int len = strlen(s);
  95
  96                 if (!len || len > pathlen)
  97                         continue;
  98                 if (memcmp(path + pathlen - len, s, len))
  99                         continue;
 100                 if (pathlen > len && path[pathlen - len - 1] != '/')
 101                         continue;
 102                 *s = 0;
 103                 return (i + 1);
 104         }
 105         return 0;
 106 }
 107
 108 struct refspec {
 109         char *src;
 110         char *dst;
 111         char force;
 112 };
 113
 114 /*
 115  * A:B means fast forward remote B with local A.
 116  * +A:B means overwrite remote B with local A.
 117  * +A is a shorthand for +A:A.
 118  * A is a shorthand for A:A.
 119  */
 120 static struct refspec *parse_ref_spec(int nr_refspec, char **refspec)
 121 {
 122         int i;
 123         struct refspec *rs = xcalloc(sizeof(*rs), (nr_refspec + 1));
 124         for (i = 0; i < nr_refspec; i++) {
 125                 char *sp, *dp, *ep;
 126                 sp = refspec[i];
 127                 if (*sp == '+') {
 128                         rs[i].force = 1;
 129                         sp++;
 130                 }
 131                 ep = strchr(sp, ':');
 132                 if (ep) {
 133                         dp = ep + 1;
 134                         *ep = 0;
 135                 }
 136                 else
 137                         dp = sp;
 138                 rs[i].src = sp;
 139                 rs[i].dst = dp;
 140         }
 141         rs[nr_refspec].src = rs[nr_refspec].dst = NULL;
 142         return rs;
 143 }
 144
 145 static int count_refspec_match(const char *pattern,
 146                                struct ref *refs,
 147                                struct ref **matched_ref)
 148 {
 149         int match;
 150         int patlen = strlen(pattern);
 151
 152         for (match = 0; refs; refs = refs->next) {
 153                 char *name = refs->name;
 154                 int namelen = strlen(name);
 155                 if (namelen < patlen ||
 156                     memcmp(name + namelen - patlen, pattern, patlen))
 157                         continue;
 158                 if (namelen != patlen && name[namelen - patlen - 1] != '/')
 159                         continue;
 160                 match++;
 161                 *matched_ref = refs;
 162         }
 163         return match;
 164 }
 165
 166 static void link_dst_tail(struct ref *ref, struct ref ***tail)
 167 {
 168         **tail = ref;
 169         *tail = &ref->next;
 170         **tail = NULL;
 171 }
 172
 173 static struct ref *try_explicit_object_name(const char *name)
 174 {
 175         unsigned char sha1[20];
 176         struct ref *ref;
 177         int len;
 178         if (get_sha1(name, sha1))
 179                 return NULL;
 180         len = strlen(name) + 1;
 181         ref = xcalloc(1, sizeof(*ref) + len);
 182         memcpy(ref->name, name, len);
 183         memcpy(ref->new_sha1, sha1, 20);
 184         return ref;
 185 }
 186
 187 static int match_explicit_refs(struct ref *src, struct ref *dst,
 188                                struct ref ***dst_tail, struct refspec *rs)
 189 {
 190         int i, errs;
 191         for (i = errs = 0; rs[i].src; i++) {
 192                 struct ref *matched_src, *matched_dst;
 193
 194                 matched_src = matched_dst = NULL;
 195                 switch (count_refspec_match(rs[i].src, src, &matched_src)) {
 196                 case 1:
 197                         break;
 198                 case 0:
 199                         /* The source could be in the get_sha1() format
 200                          * not a reference name.
 201                          */
 202                         matched_src = try_explicit_object_name(rs[i].src);
 203                         if (matched_src)
 204                                 break;
 205                         errs = 1;
 206                         error("src refspec %s does not match any.",
 207                               rs[i].src);
 208                         break;
 209                 default:
 210                         errs = 1;
 211                         error("src refspec %s matches more than one.",
 212                               rs[i].src);
 213                         break;
 214                 }
 215                 switch (count_refspec_match(rs[i].dst, dst, &matched_dst)) {
 216                 case 1:
 217                         break;
 218                 case 0:
 219                         if (!memcmp(rs[i].dst, "refs/", 5)) {
 220                                 int len = strlen(rs[i].dst) + 1;
 221                                 matched_dst = xcalloc(1, sizeof(*dst) + len);
 222                                 memcpy(matched_dst->name, rs[i].dst, len);
 223                                 link_dst_tail(matched_dst, dst_tail);
 224                         }
 225                         else if (!strcmp(rs[i].src, rs[i].dst) &&
 226                                  matched_src) {
 227                                 /* pushing "master:master" when
 228                                  * remote does not have master yet.
 229                                  */
 230                                 int len = strlen(matched_src->name) + 1;
 231                                 matched_dst = xcalloc(1, sizeof(*dst) + len);
 232                                 memcpy(matched_dst->name, matched_src->name,
 233                                        len);
 234                                 link_dst_tail(matched_dst, dst_tail);
 235                         }
 236                         else {
 237                                 errs = 1;
 238                                 error("dst refspec %s does not match any "
 239                                       "existing ref on the remote and does "
 240                                       "not start with refs/.", rs[i].dst);
 241                         }
 242                         break;
 243                 default:
 244                         errs = 1;
 245                         error("dst refspec %s matches more than one.",
 246                               rs[i].dst);
 247                         break;
 248                 }
 249                 if (errs)
 250                         continue;
 251                 if (matched_dst->peer_ref) {
 252                         errs = 1;
 253                         error("dst ref %s receives from more than one src.",
 254                               matched_dst->name);
 255                 }
 256                 else {
 257                         matched_dst->peer_ref = matched_src;
 258                         matched_dst->force = rs[i].force;
 259                 }
 260         }
 261         return -errs;
 262 }
 263
 264 static struct ref *find_ref_by_name(struct ref *list, const char *name)
 265 {
 266         for ( ; list; list = list->next)
 267                 if (!strcmp(list->name, name))
 268                         return list;
 269         return NULL;
 270 }
 271
 272 int match_refs(struct ref *src, struct ref *dst, struct ref ***dst_tail,
 273                int nr_refspec, char **refspec, int all)
 274 {
 275         struct refspec *rs = parse_ref_spec(nr_refspec, refspec);
 276
 277         if (nr_refspec)
 278                 return match_explicit_refs(src, dst, dst_tail, rs);
 279
 280         /* pick the remainder */
 281         for ( ; src; src = src->next) {
 282                 struct ref *dst_peer;
 283                 if (src->peer_ref)
 284                         continue;
 285                 dst_peer = find_ref_by_name(dst, src->name);
 286                 if ((dst_peer && dst_peer->peer_ref) || (!dst_peer && !all))
 287                         continue;
 288                 if (!dst_peer) {
 289                         /* Create a new one and link it */
 290                         int len = strlen(src->name) + 1;
 291                         dst_peer = xcalloc(1, sizeof(*dst_peer) + len);
 292                         memcpy(dst_peer->name, src->name, len);
 293                         memcpy(dst_peer->new_sha1, src->new_sha1, 20);
 294                         link_dst_tail(dst_peer, dst_tail);
 295                 }
 296                 dst_peer->peer_ref = src;
 297         }
 298         return 0;
 299 }
 300
 301 enum protocol {
 302         PROTO_LOCAL = 1,
 303         PROTO_SSH,
 304         PROTO_GIT,
 305 };
 306
 307 static enum protocol get_protocol(const char *name)
 308 {
 309         if (!strcmp(name, "ssh"))
 310                 return PROTO_SSH;
 311         if (!strcmp(name, "git"))
 312                 return PROTO_GIT;
 313         if (!strcmp(name, "git+ssh"))
 314                 return PROTO_SSH;
 315         if (!strcmp(name, "ssh+git"))
 316                 return PROTO_SSH;
 317         die("I don't handle protocol '%s'", name);
 318 }
 319
 320 #define STR_(s) # s
 321 #define STR(s)  STR_(s)
 322
 323 #ifndef NO_IPV6
 324
 325 /*
 326  * Returns a connected socket() fd, or else die()s.
 327  */
 328 static int git_tcp_connect_sock(char *host)
 329 {
 330         int sockfd = -1;
 331         char *colon, *end;
 332         char *port = STR(DEFAULT_GIT_PORT);
 333         struct addrinfo hints, *ai0, *ai;
 334         int gai;
 335
 336         if (host[0] == '[') {
 337                 end = strchr(host + 1, ']');
 338                 if (end) {
 339                         *end = 0;
 340                         end++;
 341                         host++;
 342                 } else
 343                         end = host;
 344         } else
 345                 end = host;
 346         colon = strchr(end, ':');
 347
 348         if (colon) {
 349                 *colon = 0;
 350                 port = colon + 1;
 351         }
 352
 353         memset(&hints, 0, sizeof(hints));
 354         hints.ai_socktype = SOCK_STREAM;
 355         hints.ai_protocol = IPPROTO_TCP;
 356
 357         gai = getaddrinfo(host, port, &hints, &ai);
 358         if (gai)
 359                 die("Unable to look up %s (%s)", host, gai_strerror(gai));
 360
 361         for (ai0 = ai; ai; ai = ai->ai_next) {
 362                 sockfd = socket(ai->ai_family,
 363                                 ai->ai_socktype, ai->ai_protocol);
 364                 if (sockfd < 0)
 365                         continue;
 366                 if (connect(sockfd, ai->ai_addr, ai->ai_addrlen) < 0) {
 367                         close(sockfd);
 368                         sockfd = -1;
 369                         continue;
 370                 }
 371                 break;
 372         }
 373
 374         freeaddrinfo(ai0);
 375
 376         if (sockfd < 0)
 377                 die("unable to connect a socket (%s)", strerror(errno));
 378
 379         return sockfd;
 380 }
 381
 382 #else /* NO_IPV6 */
 383
 384 /*
 385  * Returns a connected socket() fd, or else die()s.
 386  */
 387 static int git_tcp_connect_sock(char *host)
 388 {
 389         int sockfd = -1;
 390         char *colon, *end;
 391         char *port = STR(DEFAULT_GIT_PORT), *ep;
 392         struct hostent *he;
 393         struct sockaddr_in sa;
 394         char **ap;
 395         unsigned int nport;
 396
 397         if (host[0] == '[') {
 398                 end = strchr(host + 1, ']');
 399                 if (end) {
 400                         *end = 0;
 401                         end++;
 402                         host++;
 403                 } else
 404                         end = host;
 405         } else
 406                 end = host;
 407         colon = strchr(end, ':');
 408
 409         if (colon) {
 410                 *colon = 0;
 411                 port = colon + 1;
 412         }
 413
 414         he = gethostbyname(host);
 415         if (!he)
 416                 die("Unable to look up %s (%s)", host, hstrerror(h_errno));
 417         nport = strtoul(port, &ep, 10);
 418         if ( ep == port || *ep ) {
 419                 /* Not numeric */
 420                 struct servent *se = getservbyname(port,"tcp");
 421                 if ( !se )
 422                         die("Unknown port %s\n", port);
 423                 nport = se->s_port;
 424         }
 425
 426         for (ap = he->h_addr_list; *ap; ap++) {
 427                 sockfd = socket(he->h_addrtype, SOCK_STREAM, 0);
 428                 if (sockfd < 0)
 429                         continue;
 430
 431                 memset(&sa, 0, sizeof sa);
 432                 sa.sin_family = he->h_addrtype;
 433                 sa.sin_port = htons(nport);
 434                 memcpy(&sa.sin_addr, *ap, he->h_length);
 435
 436                 if (connect(sockfd, (struct sockaddr *)&sa, sizeof sa) < 0) {
 437                         close(sockfd);
 438                         sockfd = -1;
 439                         continue;
 440                 }
 441                 break;
 442         }
 443
 444         if (sockfd < 0)
 445                 die("unable to connect a socket (%s)", strerror(errno));
 446
 447         return sockfd;
 448 }
 449
 450 #endif /* NO_IPV6 */
 451
 452
 453 static void git_tcp_connect(int fd[2],
 454                             const char *prog, char *host, char *path)
 455 {
 456         int sockfd = git_tcp_connect_sock(host);
 457
 458         fd[0] = sockfd;
 459         fd[1] = sockfd;
 460 }
 461
 462
 463 static char *git_proxy_command = NULL;
 464 static const char *rhost_name = NULL;
 465 static int rhost_len;
 466
 467 static int git_proxy_command_options(const char *var, const char *value)
 468 {
 469         if (!strcmp(var, "core.gitproxy")) {
 470                 const char *for_pos;
 471                 int matchlen = -1;
 472                 int hostlen;
 473
 474                 if (git_proxy_command)
 475                         return 0;
 476                 /* [core]
 477                  * ;# matches www.kernel.org as well
 478                  * gitproxy = netcatter-1 for kernel.org
 479                  * gitproxy = netcatter-2 for sample.xz
 480                  * gitproxy = netcatter-default
 481                  */
 482                 for_pos = strstr(value, " for ");
 483                 if (!for_pos)
 484                         /* matches everybody */
 485                         matchlen = strlen(value);
 486                 else {
 487                         hostlen = strlen(for_pos + 5);
 488                         if (rhost_len < hostlen)
 489                                 matchlen = -1;
 490                         else if (!strncmp(for_pos + 5,
 491                                           rhost_name + rhost_len - hostlen,
 492                                           hostlen) &&
 493                                  ((rhost_len == hostlen) ||
 494                                   rhost_name[rhost_len - hostlen -1] == '.'))
 495                                 matchlen = for_pos - value;
 496                         else
 497                                 matchlen = -1;
 498                 }
 499                 if (0 <= matchlen) {
 500                         /* core.gitproxy = none for kernel.org */
 501                         if (matchlen == 4 &&
 502                             !memcmp(value, "none", 4))
 503                                 matchlen = 0;
 504                         git_proxy_command = xmalloc(matchlen + 1);
 505                         memcpy(git_proxy_command, value, matchlen);
 506                         git_proxy_command[matchlen] = 0;
 507                 }
 508                 return 0;
 509         }
 510
 511         return git_default_config(var, value);
 512 }
 513
 514 static int git_use_proxy(const char *host)
 515 {
 516         rhost_name = host;
 517         rhost_len = strlen(host);
 518         git_proxy_command = getenv("GIT_PROXY_COMMAND");
 519         git_config(git_proxy_command_options);
 520         rhost_name = NULL;
 521         return (git_proxy_command && *git_proxy_command);
 522 }
 523
 524 static void git_proxy_connect(int fd[2],
 525                               const char *prog, char *host, char *path)
 526 {
 527         char *port = STR(DEFAULT_GIT_PORT);
 528         char *colon, *end;
 529         int pipefd[2][2];
 530         pid_t pid;
 531
 532         if (host[0] == '[') {
 533                 end = strchr(host + 1, ']');
 534                 if (end) {
 535                         *end = 0;
 536                         end++;
 537                         host++;
 538                 } else
 539                         end = host;
 540         } else
 541                 end = host;
 542         colon = strchr(end, ':');
 543
 544         if (colon) {
 545                 *colon = 0;
 546                 port = colon + 1;
 547         }
 548
 549         if (pipe(pipefd[0]) < 0 || pipe(pipefd[1]) < 0)
 550                 die("unable to create pipe pair for communication");
 551         pid = fork();
 552         if (!pid) {
 553                 dup2(pipefd[1][0], 0);
 554                 dup2(pipefd[0][1], 1);
 555                 close(pipefd[0][0]);
 556                 close(pipefd[0][1]);
 557                 close(pipefd[1][0]);
 558                 close(pipefd[1][1]);
 559                 execlp(git_proxy_command, git_proxy_command, host, port, NULL);
 560                 die("exec failed");
 561         }
 562         if (pid < 0)
 563                 die("fork failed");
 564         fd[0] = pipefd[0][0];
 565         fd[1] = pipefd[1][1];
 566         close(pipefd[0][1]);
 567         close(pipefd[1][0]);
 568 }
 569
 570 /*
 571  * Yeah, yeah, fixme. Need to pass in the heads etc.
 572  */
 573 int git_connect(int fd[2], char *url, const char *prog)
 574 {
 575         char command[1024];
 576         char *host, *path = url;
 577         char *end;
 578         int c;
 579         int pipefd[2][2];
 580         pid_t pid;
 581         enum protocol protocol = PROTO_LOCAL;
 582         int free_path = 0;
 583
 584         /* Without this we cannot rely on waitpid() to tell
 585          * what happened to our children.
 586          */
 587         signal(SIGCHLD, SIG_DFL);
 588
 589         host = strstr(url, "://");
 590         if(host) {
 591                 *host = '\0';
 592                 protocol = get_protocol(url);
 593                 host += 3;
 594                 c = '/';
 595         } else {
 596                 host = url;
 597                 c = ':';
 598         }
 599
 600         if (host[0] == '[') {
 601                 end = strchr(host + 1, ']');
 602                 if (end) {
 603                         *end = 0;
 604                         end++;
 605                         host++;
 606                 } else
 607                         end = host;
 608         } else
 609                 end = host;
 610
 611         path = strchr(end, c);
 612         if (c == ':') {
 613                 if (path) {
 614                         protocol = PROTO_SSH;
 615                         *path++ = '\0';
 616                 } else
 617                         path = host;
 618         }
 619
 620         if (!path || !*path)
 621                 die("No path specified. See 'man git-pull' for valid url syntax");
 622
 623         /*
 624          * null-terminate hostname and point path to ~ for URL's like this:
 625          *    ssh://host.xz/~user/repo
 626          */
 627         if (protocol != PROTO_LOCAL && host != url) {
 628                 char *ptr = path;
 629                 if (path[1] == '~')
 630                         path++;
 631                 else {
 632                         path = strdup(ptr);
 633                         free_path = 1;
 634                 }
 635
 636                 *ptr = '\0';
 637         }
 638
 639         if (protocol == PROTO_GIT) {
 640                 /* These underlying connection commands die() if they
 641                  * cannot connect.
 642                  */
 643                 char *target_host = strdup(host);
 644                 if (git_use_proxy(host))
 645                         git_proxy_connect(fd, prog, host, path);
 646                 else
 647                         git_tcp_connect(fd, prog, host, path);
 648                 /*
 649                  * Separate original protocol components prog and path
 650                  * from extended components with a NUL byte.
 651                  */
 652                 packet_write(fd[1],
 653                              "%s %s%chost=%s%c",
 654                              prog, path, 0,
 655                              target_host, 0);
 656                 free(target_host);
 657                 if (free_path)
 658                         free(path);
 659                 return 0;
 660         }
 661
 662         if (pipe(pipefd[0]) < 0 || pipe(pipefd[1]) < 0)
 663                 die("unable to create pipe pair for communication");
 664         pid = fork();
 665         if (pid < 0)
 666                 die("unable to fork");
 667         if (!pid) {
 668                 snprintf(command, sizeof(command), "%s %s", prog,
 669                          sq_quote(path));
 670                 dup2(pipefd[1][0], 0);
 671                 dup2(pipefd[0][1], 1);
 672                 close(pipefd[0][0]);
 673                 close(pipefd[0][1]);
 674                 close(pipefd[1][0]);
 675                 close(pipefd[1][1]);
 676                 if (protocol == PROTO_SSH) {
 677                         const char *ssh, *ssh_basename;
 678                         ssh = getenv("GIT_SSH");
 679                         if (!ssh) ssh = "ssh";
 680                         ssh_basename = strrchr(ssh, '/');
 681                         if (!ssh_basename)
 682                                 ssh_basename = ssh;
 683                         else
 684                                 ssh_basename++;
 685                         execlp(ssh, ssh_basename, host, command, NULL);
 686                 }
 687                 else {
 688                         unsetenv(ALTERNATE_DB_ENVIRONMENT);
 689                         unsetenv(DB_ENVIRONMENT);
 690                         unsetenv(GIT_DIR_ENVIRONMENT);
 691                         unsetenv(GRAFT_ENVIRONMENT);
 692                         unsetenv(INDEX_ENVIRONMENT);
 693                         execlp("sh", "sh", "-c", command, NULL);
 694                 }
 695                 die("exec failed");
 696         }
 697         fd[0] = pipefd[0][0];
 698         fd[1] = pipefd[1][1];
 699         close(pipefd[0][1]);
 700         close(pipefd[1][0]);
 701         if (free_path)
 702                 free(path);
 703         return pid;
 704 }
 705
 706 int finish_connect(pid_t pid)
 707 {
 708         int ret;
 709
 710         for (;;) {
 711                 ret = waitpid(pid, NULL, 0);
 712                 if (!ret)
 713                         break;
 714                 if (errno != EINTR)
 715                         break;
 716         }
 717         return ret;
 718 }