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 #include <signal.h>
  12
  13 static char *server_capabilities;
  14
  15 static int check_ref(const char *name, int len, unsigned int flags)
  16 {
  17         if (!flags)
  18                 return 1;
  19
  20         if (len < 5 || memcmp(name, "refs/", 5))
  21                 return 0;
  22
  23         /* Skip the "refs/" part */
  24         name += 5;
  25         len -= 5;
  26
  27         /* 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
  31         /* REF_HEADS means that we want regular branch heads */
  32         if ((flags & REF_HEADS) && !memcmp(name, "heads/", 6))
  33                 return 1;
  34
  35         /* REF_TAGS means that we want tags */
  36         if ((flags & REF_TAGS) && !memcmp(name, "tags/", 5))
  37                 return 1;
  38
  39         /* All type bits clear means that we are ok with anything */
  40         return !(flags & ~REF_NORMAL);
  41 }
  42
  43 /*
  44  * Read all the refs from the other end
  45  */
  46 struct 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
  58                 len = packet_read_line(in, buffer, sizeof(buffer));
  59                 if (!len)
  60                         break;
  61                 if (buffer[len-1] == '\n')
  62                         buffer[--len] = 0;
  63
  64                 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
  68                 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
  75                 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 }
  87
  88 int server_supports(const char *feature)
  89 {
  90         return server_capabilities &&
  91                 strstr(server_capabilities, feature) != NULL;
  92 }
  93
  94 int 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
  99         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 }
 114
 115 int path_match(const char *path, int nr, char **match)
 116 {
 117         int i;
 118         int pathlen = strlen(path);
 119
 120         for (i = 0; i < nr; i++) {
 121                 char *s = match[i];
 122                 int len = strlen(s);
 123
 124                 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 }
 135
 136 struct refspec {
 137         char *src;
 138         char *dst;
 139         char force;
 140 };
 141
 142 /*
 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  */
 148 static struct refspec *parse_ref_spec(int nr_refspec, char **refspec)
 149 {
 150         int i;
 151         struct refspec *rs = xcalloc(sizeof(*rs), (nr_refspec + 1));
 152         for (i = 0; i < nr_refspec; i++) {
 153                 char *sp, *dp, *ep;
 154                 sp = refspec[i];
 155                 if (*sp == '+') {
 156                         rs[i].force = 1;
 157                         sp++;
 158                 }
 159                 ep = strchr(sp, ':');
 160                 if (ep) {
 161                         dp = ep + 1;
 162                         *ep = 0;
 163                 }
 164                 else
 165                         dp = sp;
 166                 rs[i].src = sp;
 167                 rs[i].dst = dp;
 168         }
 169         rs[nr_refspec].src = rs[nr_refspec].dst = NULL;
 170         return rs;
 171 }
 172
 173 static int count_refspec_match(const char *pattern,
 174                                struct ref *refs,
 175                                struct ref **matched_ref)
 176 {
 177         int patlen = strlen(pattern);
 178         struct ref *matched_weak = NULL;
 179         struct ref *matched = NULL;
 180         int weak_match = 0;
 181         int match = 0;
 182
 183         for (weak_match = match = 0; refs; refs = refs->next) {
 184                 char *name = refs->name;
 185                 int namelen = strlen(name);
 186                 int weak_match;
 187
 188                 if (namelen < patlen ||
 189                     memcmp(name + namelen - patlen, pattern, patlen))
 190                         continue;
 191                 if (namelen != patlen && name[namelen - patlen - 1] != '/')
 192                         continue;
 193
 194                 /* A match is "weak" if it is with refs outside
 195                  * heads or tags, and did not specify the pattern
 196                  * in full (e.g. "refs/remotes/origin/master") or at
 197                  * least from the toplevel (e.g. "remotes/origin/master");
 198                  * otherwise "git push $URL master" would result in
 199                  * ambiguity between remotes/origin/master and heads/master
 200                  * at the remote site.
 201                  */
 202                 if (namelen != patlen &&
 203                     patlen != namelen - 5 &&
 204                     strncmp(name, "refs/heads/", 11) &&
 205                     strncmp(name, "refs/tags/", 10)) {
 206                         /* We want to catch the case where only weak
 207                          * matches are found and there are multiple
 208                          * matches, and where more than one strong
 209                          * matches are found, as ambiguous.  One
 210                          * strong match with zero or more weak matches
 211                          * are acceptable as a unique match.
 212                          */
 213                         matched_weak = refs;
 214                         weak_match++;
 215                 }
 216                 else {
 217                         matched = refs;
 218                         match++;
 219                 }
 220         }
 221         if (!matched) {
 222                 *matched_ref = matched_weak;
 223                 return weak_match;
 224         }
 225         else {
 226                 *matched_ref = matched;
 227                 return match;
 228         }
 229 }
 230
 231 static void link_dst_tail(struct ref *ref, struct ref ***tail)
 232 {
 233         **tail = ref;
 234         *tail = &ref->next;
 235         **tail = NULL;
 236 }
 237
 238 static struct ref *try_explicit_object_name(const char *name)
 239 {
 240         unsigned char sha1[20];
 241         struct ref *ref;
 242         int len;
 243         if (get_sha1(name, sha1))
 244                 return NULL;
 245         len = strlen(name) + 1;
 246         ref = xcalloc(1, sizeof(*ref) + len);
 247         memcpy(ref->name, name, len);
 248         hashcpy(ref->new_sha1, sha1);
 249         return ref;
 250 }
 251
 252 static int match_explicit_refs(struct ref *src, struct ref *dst,
 253                                struct ref ***dst_tail, struct refspec *rs)
 254 {
 255         int i, errs;
 256         for (i = errs = 0; rs[i].src; i++) {
 257                 struct ref *matched_src, *matched_dst;
 258
 259                 matched_src = matched_dst = NULL;
 260                 switch (count_refspec_match(rs[i].src, src, &matched_src)) {
 261                 case 1:
 262                         break;
 263                 case 0:
 264                         /* The source could be in the get_sha1() format
 265                          * not a reference name.
 266                          */
 267                         matched_src = try_explicit_object_name(rs[i].src);
 268                         if (matched_src)
 269                                 break;
 270                         errs = 1;
 271                         error("src refspec %s does not match any.",
 272                               rs[i].src);
 273                         break;
 274                 default:
 275                         errs = 1;
 276                         error("src refspec %s matches more than one.",
 277                               rs[i].src);
 278                         break;
 279                 }
 280                 switch (count_refspec_match(rs[i].dst, dst, &matched_dst)) {
 281                 case 1:
 282                         break;
 283                 case 0:
 284                         if (!memcmp(rs[i].dst, "refs/", 5)) {
 285                                 int len = strlen(rs[i].dst) + 1;
 286                                 matched_dst = xcalloc(1, sizeof(*dst) + len);
 287                                 memcpy(matched_dst->name, rs[i].dst, len);
 288                                 link_dst_tail(matched_dst, dst_tail);
 289                         }
 290                         else if (!strcmp(rs[i].src, rs[i].dst) &&
 291                                  matched_src) {
 292                                 /* pushing "master:master" when
 293                                  * remote does not have master yet.
 294                                  */
 295                                 int len = strlen(matched_src->name) + 1;
 296                                 matched_dst = xcalloc(1, sizeof(*dst) + len);
 297                                 memcpy(matched_dst->name, matched_src->name,
 298                                        len);
 299                                 link_dst_tail(matched_dst, dst_tail);
 300                         }
 301                         else {
 302                                 errs = 1;
 303                                 error("dst refspec %s does not match any "
 304                                       "existing ref on the remote and does "
 305                                       "not start with refs/.", rs[i].dst);
 306                         }
 307                         break;
 308                 default:
 309                         errs = 1;
 310                         error("dst refspec %s matches more than one.",
 311                               rs[i].dst);
 312                         break;
 313                 }
 314                 if (errs)
 315                         continue;
 316                 if (matched_dst->peer_ref) {
 317                         errs = 1;
 318                         error("dst ref %s receives from more than one src.",
 319                               matched_dst->name);
 320                 }
 321                 else {
 322                         matched_dst->peer_ref = matched_src;
 323                         matched_dst->force = rs[i].force;
 324                 }
 325         }
 326         return -errs;
 327 }
 328
 329 static struct ref *find_ref_by_name(struct ref *list, const char *name)
 330 {
 331         for ( ; list; list = list->next)
 332                 if (!strcmp(list->name, name))
 333                         return list;
 334         return NULL;
 335 }
 336
 337 int match_refs(struct ref *src, struct ref *dst, struct ref ***dst_tail,
 338                int nr_refspec, char **refspec, int all)
 339 {
 340         struct refspec *rs = parse_ref_spec(nr_refspec, refspec);
 341
 342         if (nr_refspec)
 343                 return match_explicit_refs(src, dst, dst_tail, rs);
 344
 345         /* pick the remainder */
 346         for ( ; src; src = src->next) {
 347                 struct ref *dst_peer;
 348                 if (src->peer_ref)
 349                         continue;
 350                 dst_peer = find_ref_by_name(dst, src->name);
 351                 if ((dst_peer && dst_peer->peer_ref) || (!dst_peer && !all))
 352                         continue;
 353                 if (!dst_peer) {
 354                         /* Create a new one and link it */
 355                         int len = strlen(src->name) + 1;
 356                         dst_peer = xcalloc(1, sizeof(*dst_peer) + len);
 357                         memcpy(dst_peer->name, src->name, len);
 358                         hashcpy(dst_peer->new_sha1, src->new_sha1);
 359                         link_dst_tail(dst_peer, dst_tail);
 360                 }
 361                 dst_peer->peer_ref = src;
 362         }
 363         return 0;
 364 }
 365
 366 enum protocol {
 367         PROTO_LOCAL = 1,
 368         PROTO_SSH,
 369         PROTO_GIT,
 370 };
 371
 372 static enum protocol get_protocol(const char *name)
 373 {
 374         if (!strcmp(name, "ssh"))
 375                 return PROTO_SSH;
 376         if (!strcmp(name, "git"))
 377                 return PROTO_GIT;
 378         if (!strcmp(name, "git+ssh"))
 379                 return PROTO_SSH;
 380         if (!strcmp(name, "ssh+git"))
 381                 return PROTO_SSH;
 382         die("I don't handle protocol '%s'", name);
 383 }
 384
 385 #define STR_(s) # s
 386 #define STR(s)  STR_(s)
 387
 388 #ifndef NO_IPV6
 389
 390 /*
 391  * Returns a connected socket() fd, or else die()s.
 392  */
 393 static int git_tcp_connect_sock(char *host)
 394 {
 395         int sockfd = -1, saved_errno = 0;
 396         char *colon, *end;
 397         const char *port = STR(DEFAULT_GIT_PORT);
 398         struct addrinfo hints, *ai0, *ai;
 399         int gai;
 400
 401         if (host[0] == '[') {
 402                 end = strchr(host + 1, ']');
 403                 if (end) {
 404                         *end = 0;
 405                         end++;
 406                         host++;
 407                 } else
 408                         end = host;
 409         } else
 410                 end = host;
 411         colon = strchr(end, ':');
 412
 413         if (colon) {
 414                 *colon = 0;
 415                 port = colon + 1;
 416         }
 417
 418         memset(&hints, 0, sizeof(hints));
 419         hints.ai_socktype = SOCK_STREAM;
 420         hints.ai_protocol = IPPROTO_TCP;
 421
 422         gai = getaddrinfo(host, port, &hints, &ai);
 423         if (gai)
 424                 die("Unable to look up %s (%s)", host, gai_strerror(gai));
 425
 426         for (ai0 = ai; ai; ai = ai->ai_next) {
 427                 sockfd = socket(ai->ai_family,
 428                                 ai->ai_socktype, ai->ai_protocol);
 429                 if (sockfd < 0) {
 430                         saved_errno = errno;
 431                         continue;
 432                 }
 433                 if (connect(sockfd, ai->ai_addr, ai->ai_addrlen) < 0) {
 434                         saved_errno = errno;
 435                         close(sockfd);
 436                         sockfd = -1;
 437                         continue;
 438                 }
 439                 break;
 440         }
 441
 442         freeaddrinfo(ai0);
 443
 444         if (sockfd < 0)
 445                 die("unable to connect a socket (%s)", strerror(saved_errno));
 446
 447         return sockfd;
 448 }
 449
 450 #else /* NO_IPV6 */
 451
 452 /*
 453  * Returns a connected socket() fd, or else die()s.
 454  */
 455 static int git_tcp_connect_sock(char *host)
 456 {
 457         int sockfd = -1, saved_errno = 0;
 458         char *colon, *end;
 459         char *port = STR(DEFAULT_GIT_PORT), *ep;
 460         struct hostent *he;
 461         struct sockaddr_in sa;
 462         char **ap;
 463         unsigned int nport;
 464
 465         if (host[0] == '[') {
 466                 end = strchr(host + 1, ']');
 467                 if (end) {
 468                         *end = 0;
 469                         end++;
 470                         host++;
 471                 } else
 472                         end = host;
 473         } else
 474                 end = host;
 475         colon = strchr(end, ':');
 476
 477         if (colon) {
 478                 *colon = 0;
 479                 port = colon + 1;
 480         }
 481
 482         he = gethostbyname(host);
 483         if (!he)
 484                 die("Unable to look up %s (%s)", host, hstrerror(h_errno));
 485         nport = strtoul(port, &ep, 10);
 486         if ( ep == port || *ep ) {
 487                 /* Not numeric */
 488                 struct servent *se = getservbyname(port,"tcp");
 489                 if ( !se )
 490                         die("Unknown port %s\n", port);
 491                 nport = se->s_port;
 492         }
 493
 494         for (ap = he->h_addr_list; *ap; ap++) {
 495                 sockfd = socket(he->h_addrtype, SOCK_STREAM, 0);
 496                 if (sockfd < 0) {
 497                         saved_errno = errno;
 498                         continue;
 499                 }
 500
 501                 memset(&sa, 0, sizeof sa);
 502                 sa.sin_family = he->h_addrtype;
 503                 sa.sin_port = htons(nport);
 504                 memcpy(&sa.sin_addr, *ap, he->h_length);
 505
 506                 if (connect(sockfd, (struct sockaddr *)&sa, sizeof sa) < 0) {
 507                         saved_errno = errno;
 508                         close(sockfd);
 509                         sockfd = -1;
 510                         continue;
 511                 }
 512                 break;
 513         }
 514
 515         if (sockfd < 0)
 516                 die("unable to connect a socket (%s)", strerror(saved_errno));
 517
 518         return sockfd;
 519 }
 520
 521 #endif /* NO_IPV6 */
 522
 523
 524 static void git_tcp_connect(int fd[2], char *host)
 525 {
 526         int sockfd = git_tcp_connect_sock(host);
 527
 528         fd[0] = sockfd;
 529         fd[1] = sockfd;
 530 }
 531
 532
 533 static char *git_proxy_command;
 534 static const char *rhost_name;
 535 static int rhost_len;
 536
 537 static int git_proxy_command_options(const char *var, const char *value)
 538 {
 539         if (!strcmp(var, "core.gitproxy")) {
 540                 const char *for_pos;
 541                 int matchlen = -1;
 542                 int hostlen;
 543
 544                 if (git_proxy_command)
 545                         return 0;
 546                 /* [core]
 547                  * ;# matches www.kernel.org as well
 548                  * gitproxy = netcatter-1 for kernel.org
 549                  * gitproxy = netcatter-2 for sample.xz
 550                  * gitproxy = netcatter-default
 551                  */
 552                 for_pos = strstr(value, " for ");
 553                 if (!for_pos)
 554                         /* matches everybody */
 555                         matchlen = strlen(value);
 556                 else {
 557                         hostlen = strlen(for_pos + 5);
 558                         if (rhost_len < hostlen)
 559                                 matchlen = -1;
 560                         else if (!strncmp(for_pos + 5,
 561                                           rhost_name + rhost_len - hostlen,
 562                                           hostlen) &&
 563                                  ((rhost_len == hostlen) ||
 564                                   rhost_name[rhost_len - hostlen -1] == '.'))
 565                                 matchlen = for_pos - value;
 566                         else
 567                                 matchlen = -1;
 568                 }
 569                 if (0 <= matchlen) {
 570                         /* core.gitproxy = none for kernel.org */
 571                         if (matchlen == 4 &&
 572                             !memcmp(value, "none", 4))
 573                                 matchlen = 0;
 574                         git_proxy_command = xmalloc(matchlen + 1);
 575                         memcpy(git_proxy_command, value, matchlen);
 576                         git_proxy_command[matchlen] = 0;
 577                 }
 578                 return 0;
 579         }
 580
 581         return git_default_config(var, value);
 582 }
 583
 584 static int git_use_proxy(const char *host)
 585 {
 586         rhost_name = host;
 587         rhost_len = strlen(host);
 588         git_proxy_command = getenv("GIT_PROXY_COMMAND");
 589         git_config(git_proxy_command_options);
 590         rhost_name = NULL;
 591         return (git_proxy_command && *git_proxy_command);
 592 }
 593
 594 static void git_proxy_connect(int fd[2], char *host)
 595 {
 596         const char *port = STR(DEFAULT_GIT_PORT);
 597         char *colon, *end;
 598         int pipefd[2][2];
 599         pid_t pid;
 600
 601         if (host[0] == '[') {
 602                 end = strchr(host + 1, ']');
 603                 if (end) {
 604                         *end = 0;
 605                         end++;
 606                         host++;
 607                 } else
 608                         end = host;
 609         } else
 610                 end = host;
 611         colon = strchr(end, ':');
 612
 613         if (colon) {
 614                 *colon = 0;
 615                 port = colon + 1;
 616         }
 617
 618         if (pipe(pipefd[0]) < 0 || pipe(pipefd[1]) < 0)
 619                 die("unable to create pipe pair for communication");
 620         pid = fork();
 621         if (!pid) {
 622                 dup2(pipefd[1][0], 0);
 623                 dup2(pipefd[0][1], 1);
 624                 close(pipefd[0][0]);
 625                 close(pipefd[0][1]);
 626                 close(pipefd[1][0]);
 627                 close(pipefd[1][1]);
 628                 execlp(git_proxy_command, git_proxy_command, host, port, NULL);
 629                 die("exec failed");
 630         }
 631         if (pid < 0)
 632                 die("fork failed");
 633         fd[0] = pipefd[0][0];
 634         fd[1] = pipefd[1][1];
 635         close(pipefd[0][1]);
 636         close(pipefd[1][0]);
 637 }
 638
 639 #define MAX_CMD_LEN 1024
 640
 641 /*
 642  * This returns 0 if the transport protocol does not need fork(2),
 643  * or a process id if it does.  Once done, finish the connection
 644  * with finish_connect() with the value returned from this function
 645  * (it is safe to call finish_connect() with 0 to support the former
 646  * case).
 647  *
 648  * Does not return a negative value on error; it just dies.
 649  */
 650 pid_t git_connect(int fd[2], char *url, const char *prog)
 651 {
 652         char *host, *path = url;
 653         char *end;
 654         int c;
 655         int pipefd[2][2];
 656         pid_t pid;
 657         enum protocol protocol = PROTO_LOCAL;
 658         int free_path = 0;
 659
 660         /* Without this we cannot rely on waitpid() to tell
 661          * what happened to our children.
 662          */
 663         signal(SIGCHLD, SIG_DFL);
 664
 665         host = strstr(url, "://");
 666         if(host) {
 667                 *host = '\0';
 668                 protocol = get_protocol(url);
 669                 host += 3;
 670                 c = '/';
 671         } else {
 672                 host = url;
 673                 c = ':';
 674         }
 675
 676         if (host[0] == '[') {
 677                 end = strchr(host + 1, ']');
 678                 if (end) {
 679                         *end = 0;
 680                         end++;
 681                         host++;
 682                 } else
 683                         end = host;
 684         } else
 685                 end = host;
 686
 687         path = strchr(end, c);
 688         if (c == ':') {
 689                 if (path) {
 690                         protocol = PROTO_SSH;
 691                         *path++ = '\0';
 692                 } else
 693                         path = host;
 694         }
 695
 696         if (!path || !*path)
 697                 die("No path specified. See 'man git-pull' for valid url syntax");
 698
 699         /*
 700          * null-terminate hostname and point path to ~ for URL's like this:
 701          *    ssh://host.xz/~user/repo
 702          */
 703         if (protocol != PROTO_LOCAL && host != url) {
 704                 char *ptr = path;
 705                 if (path[1] == '~')
 706                         path++;
 707                 else {
 708                         path = xstrdup(ptr);
 709                         free_path = 1;
 710                 }
 711
 712                 *ptr = '\0';
 713         }
 714
 715         if (protocol == PROTO_GIT) {
 716                 /* These underlying connection commands die() if they
 717                  * cannot connect.
 718                  */
 719                 char *target_host = xstrdup(host);
 720                 if (git_use_proxy(host))
 721                         git_proxy_connect(fd, host);
 722                 else
 723                         git_tcp_connect(fd, host);
 724                 /*
 725                  * Separate original protocol components prog and path
 726                  * from extended components with a NUL byte.
 727                  */
 728                 packet_write(fd[1],
 729                              "%s %s%chost=%s%c",
 730                              prog, path, 0,
 731                              target_host, 0);
 732                 free(target_host);
 733                 if (free_path)
 734                         free(path);
 735                 return 0;
 736         }
 737
 738         if (pipe(pipefd[0]) < 0 || pipe(pipefd[1]) < 0)
 739                 die("unable to create pipe pair for communication");
 740         pid = fork();
 741         if (pid < 0)
 742                 die("unable to fork");
 743         if (!pid) {
 744                 char command[MAX_CMD_LEN];
 745                 char *posn = command;
 746                 int size = MAX_CMD_LEN;
 747                 int of = 0;
 748
 749                 of |= add_to_string(&posn, &size, prog, 0);
 750                 of |= add_to_string(&posn, &size, " ", 0);
 751                 of |= add_to_string(&posn, &size, path, 1);
 752
 753                 if (of)
 754                         die("command line too long");
 755
 756                 dup2(pipefd[1][0], 0);
 757                 dup2(pipefd[0][1], 1);
 758                 close(pipefd[0][0]);
 759                 close(pipefd[0][1]);
 760                 close(pipefd[1][0]);
 761                 close(pipefd[1][1]);
 762                 if (protocol == PROTO_SSH) {
 763                         const char *ssh, *ssh_basename;
 764                         ssh = getenv("GIT_SSH");
 765                         if (!ssh) ssh = "ssh";
 766                         ssh_basename = strrchr(ssh, '/');
 767                         if (!ssh_basename)
 768                                 ssh_basename = ssh;
 769                         else
 770                                 ssh_basename++;
 771                         execlp(ssh, ssh_basename, host, command, NULL);
 772                 }
 773                 else {
 774                         unsetenv(ALTERNATE_DB_ENVIRONMENT);
 775                         unsetenv(DB_ENVIRONMENT);
 776                         unsetenv(GIT_DIR_ENVIRONMENT);
 777                         unsetenv(GRAFT_ENVIRONMENT);
 778                         unsetenv(INDEX_ENVIRONMENT);
 779                         execlp("sh", "sh", "-c", command, NULL);
 780                 }
 781                 die("exec failed");
 782         }
 783         fd[0] = pipefd[0][0];
 784         fd[1] = pipefd[1][1];
 785         close(pipefd[0][1]);
 786         close(pipefd[1][0]);
 787         if (free_path)
 788                 free(path);
 789         return pid;
 790 }
 791
 792 int finish_connect(pid_t pid)
 793 {
 794         if (pid == 0)
 795                 return 0;
 796
 797         while (waitpid(pid, NULL, 0) < 0) {
 798                 if (errno != EINTR)
 799                         return -1;
 800         }
 801         return 0;
 802 }