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 ", 3)) {
  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 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 static int git_tcp_connect(int fd[2], const char *prog, char *host, char *path)
 326 {
 327         int sockfd = -1;
 328         char *colon, *end;
 329         char *port = STR(DEFAULT_GIT_PORT);
 330         struct addrinfo hints, *ai0, *ai;
 331         int gai;
 332
 333         if (host[0] == '[') {
 334                 end = strchr(host + 1, ']');
 335                 if (end) {
 336                         *end = 0;
 337                         end++;
 338                         host++;
 339                 } else
 340                         end = host;
 341         } else
 342                 end = host;
 343         colon = strchr(end, ':');
 344
 345         if (colon) {
 346                 *colon = 0;
 347                 port = colon + 1;
 348         }
 349
 350         memset(&hints, 0, sizeof(hints));
 351         hints.ai_socktype = SOCK_STREAM;
 352         hints.ai_protocol = IPPROTO_TCP;
 353
 354         gai = getaddrinfo(host, port, &hints, &ai);
 355         if (gai)
 356                 die("Unable to look up %s (%s)", host, gai_strerror(gai));
 357
 358         for (ai0 = ai; ai; ai = ai->ai_next) {
 359                 sockfd = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
 360                 if (sockfd < 0)
 361                         continue;
 362                 if (connect(sockfd, ai->ai_addr, ai->ai_addrlen) < 0) {
 363                         close(sockfd);
 364                         sockfd = -1;
 365                         continue;
 366                 }
 367                 break;
 368         }
 369
 370         freeaddrinfo(ai0);
 371
 372         if (sockfd < 0)
 373                 die("unable to connect a socket (%s)", strerror(errno));
 374
 375         fd[0] = sockfd;
 376         fd[1] = sockfd;
 377         packet_write(sockfd, "%s %s\n", prog, path);
 378         return 0;
 379 }
 380
 381 #else /* NO_IPV6 */
 382
 383 static int git_tcp_connect(int fd[2], const char *prog, char *host, char *path)
 384 {
 385         int sockfd = -1;
 386         char *colon, *end;
 387         char *port = STR(DEFAULT_GIT_PORT), *ep;
 388         struct hostent *he;
 389         struct sockaddr_in sa;
 390         char **ap;
 391         unsigned int nport;
 392
 393         if (host[0] == '[') {
 394                 end = strchr(host + 1, ']');
 395                 if (end) {
 396                         *end = 0;
 397                         end++;
 398                         host++;
 399                 } else
 400                         end = host;
 401         } else
 402                 end = host;
 403         colon = strchr(end, ':');
 404
 405         if (colon) {
 406                 *colon = 0;
 407                 port = colon + 1;
 408         }
 409
 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\n", port);
 420                 nport = se->s_port;
 421         }
 422
 423         for (ap = he->h_addr_list; *ap; ap++) {
 424                 sockfd = socket(he->h_addrtype, SOCK_STREAM, 0);
 425                 if (sockfd < 0)
 426                         continue;
 427
 428                 memset(&sa, 0, sizeof sa);
 429                 sa.sin_family = he->h_addrtype;
 430                 sa.sin_port = htons(nport);
 431                 memcpy(&sa.sin_addr, *ap, he->h_length);
 432
 433                 if (connect(sockfd, (struct sockaddr *)&sa, sizeof sa) < 0) {
 434                         close(sockfd);
 435                         sockfd = -1;
 436                         continue;
 437                 }
 438                 break;
 439         }
 440
 441         if (sockfd < 0)
 442                 die("unable to connect a socket (%s)", strerror(errno));
 443
 444         fd[0] = sockfd;
 445         fd[1] = sockfd;
 446         packet_write(sockfd, "%s %s\n", prog, path);
 447         return 0;
 448 }
 449
 450 #endif /* NO_IPV6 */
 451
 452 static char *git_proxy_command = NULL;
 453 static const char *rhost_name = NULL;
 454 static int rhost_len;
 455
 456 static int git_proxy_command_options(const char *var, const char *value)
 457 {
 458         if (!strcmp(var, "core.gitproxy")) {
 459                 const char *for_pos;
 460                 int matchlen = -1;
 461                 int hostlen;
 462
 463                 if (git_proxy_command)
 464                         return 0;
 465                 /* [core]
 466                  * ;# matches www.kernel.org as well
 467                  * gitproxy = netcatter-1 for kernel.org
 468                  * gitproxy = netcatter-2 for sample.xz
 469                  * gitproxy = netcatter-default
 470                  */
 471                 for_pos = strstr(value, " for ");
 472                 if (!for_pos)
 473                         /* matches everybody */
 474                         matchlen = strlen(value);
 475                 else {
 476                         hostlen = strlen(for_pos + 5);
 477                         if (rhost_len < hostlen)
 478                                 matchlen = -1;
 479                         else if (!strncmp(for_pos + 5,
 480                                           rhost_name + rhost_len - hostlen,
 481                                           hostlen) &&
 482                                  ((rhost_len == hostlen) ||
 483                                   rhost_name[rhost_len - hostlen -1] == '.'))
 484                                 matchlen = for_pos - value;
 485                         else
 486                                 matchlen = -1;
 487                 }
 488                 if (0 <= matchlen) {
 489                         /* core.gitproxy = none for kernel.org */
 490                         if (matchlen == 4 &&
 491                             !memcmp(value, "none", 4))
 492                                 matchlen = 0;
 493                         git_proxy_command = xmalloc(matchlen + 1);
 494                         memcpy(git_proxy_command, value, matchlen);
 495                         git_proxy_command[matchlen] = 0;
 496                 }
 497                 return 0;
 498         }
 499
 500         return git_default_config(var, value);
 501 }
 502
 503 static int git_use_proxy(const char *host)
 504 {
 505         rhost_name = host;
 506         rhost_len = strlen(host);
 507         git_proxy_command = getenv("GIT_PROXY_COMMAND");
 508         git_config(git_proxy_command_options);
 509         rhost_name = NULL;
 510         return (git_proxy_command && *git_proxy_command);
 511 }
 512
 513 static int git_proxy_connect(int fd[2], const char *prog, char *host, char *path)
 514 {
 515         char *port = STR(DEFAULT_GIT_PORT);
 516         char *colon, *end;
 517         int pipefd[2][2];
 518         pid_t pid;
 519
 520         if (host[0] == '[') {
 521                 end = strchr(host + 1, ']');
 522                 if (end) {
 523                         *end = 0;
 524                         end++;
 525                         host++;
 526                 } else
 527                         end = host;
 528         } else
 529                 end = host;
 530         colon = strchr(end, ':');
 531
 532         if (colon) {
 533                 *colon = 0;
 534                 port = colon + 1;
 535         }
 536
 537         if (pipe(pipefd[0]) < 0 || pipe(pipefd[1]) < 0)
 538                 die("unable to create pipe pair for communication");
 539         pid = fork();
 540         if (!pid) {
 541                 dup2(pipefd[1][0], 0);
 542                 dup2(pipefd[0][1], 1);
 543                 close(pipefd[0][0]);
 544                 close(pipefd[0][1]);
 545                 close(pipefd[1][0]);
 546                 close(pipefd[1][1]);
 547                 execlp(git_proxy_command, git_proxy_command, host, port, NULL);
 548                 die("exec failed");
 549         }
 550         fd[0] = pipefd[0][0];
 551         fd[1] = pipefd[1][1];
 552         close(pipefd[0][1]);
 553         close(pipefd[1][0]);
 554         packet_write(fd[1], "%s %s\n", prog, path);
 555         return pid;
 556 }
 557
 558 /*
 559  * Yeah, yeah, fixme. Need to pass in the heads etc.
 560  */
 561 int git_connect(int fd[2], char *url, const char *prog)
 562 {
 563         char command[1024];
 564         char *host, *path = url;
 565         char *end;
 566         int c;
 567         int pipefd[2][2];
 568         pid_t pid;
 569         enum protocol protocol = PROTO_LOCAL;
 570
 571         host = strstr(url, "://");
 572         if(host) {
 573                 *host = '\0';
 574                 protocol = get_protocol(url);
 575                 host += 3;
 576                 c = '/';
 577         } else {
 578                 host = url;
 579                 c = ':';
 580         }
 581
 582         if (host[0] == '[') {
 583                 end = strchr(host + 1, ']');
 584                 if (end) {
 585                         *end = 0;
 586                         end++;
 587                         host++;
 588                 } else
 589                         end = host;
 590         } else
 591                 end = host;
 592
 593         path = strchr(end, c);
 594         if (c == ':') {
 595                 if (path) {
 596                         protocol = PROTO_SSH;
 597                         *path++ = '\0';
 598                 } else
 599                         path = host;
 600         }
 601
 602         if (!path || !*path)
 603                 die("No path specified. See 'man git-pull' for valid url syntax");
 604
 605         /*
 606          * null-terminate hostname and point path to ~ for URL's like this:
 607          *    ssh://host.xz/~user/repo
 608          */
 609         if (protocol != PROTO_LOCAL && host != url) {
 610                 char *ptr = path;
 611                 if (path[1] == '~')
 612                         path++;
 613                 else
 614                         path = strdup(ptr);
 615
 616                 *ptr = '\0';
 617         }
 618
 619         if (protocol == PROTO_GIT) {
 620                 if (git_use_proxy(host))
 621                         return git_proxy_connect(fd, prog, host, path);
 622                 return git_tcp_connect(fd, prog, host, path);
 623         }
 624
 625         if (pipe(pipefd[0]) < 0 || pipe(pipefd[1]) < 0)
 626                 die("unable to create pipe pair for communication");
 627         pid = fork();
 628         if (!pid) {
 629                 snprintf(command, sizeof(command), "%s %s", prog,
 630                          sq_quote(path));
 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                 if (protocol == PROTO_SSH) {
 638                         const char *ssh, *ssh_basename;
 639                         ssh = getenv("GIT_SSH");
 640                         if (!ssh) ssh = "ssh";
 641                         ssh_basename = strrchr(ssh, '/');
 642                         if (!ssh_basename)
 643                                 ssh_basename = ssh;
 644                         else
 645                                 ssh_basename++;
 646                         execlp(ssh, ssh_basename, host, command, NULL);
 647                 }
 648                 else {
 649                         unsetenv(ALTERNATE_DB_ENVIRONMENT);
 650                         unsetenv(DB_ENVIRONMENT);
 651                         unsetenv(GIT_DIR_ENVIRONMENT);
 652                         unsetenv(GRAFT_ENVIRONMENT);
 653                         unsetenv(INDEX_ENVIRONMENT);
 654                         execlp("sh", "sh", "-c", command, NULL);
 655                 }
 656                 die("exec failed");
 657         }
 658         fd[0] = pipefd[0][0];
 659         fd[1] = pipefd[1][1];
 660         close(pipefd[0][1]);
 661         close(pipefd[1][0]);
 662         return pid;
 663 }
 664
 665 int finish_connect(pid_t pid)
 666 {
 667         int ret;
 668
 669         for (;;) {
 670                 ret = waitpid(pid, NULL, 0);
 671                 if (!ret)
 672                         break;
 673                 if (errno != EINTR)
 674                         break;
 675         }
 676         return ret;
 677 }