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 "run-command.h"
   7 #include "remote.h"
   8
   9 static char *server_capabilities;
  10
  11 static int check_ref(const char *name, int len, unsigned int flags)
  12 {
  13         if (!flags)
  14                 return 1;
  15
  16         if (len < 5 || memcmp(name, "refs/", 5))
  17                 return 0;
  18
  19         /* Skip the "refs/" part */
  20         name += 5;
  21         len -= 5;
  22
  23         /* REF_NORMAL means that we don't want the magic fake tag refs */
  24         if ((flags & REF_NORMAL) && check_ref_format(name) < 0)
  25                 return 0;
  26
  27         /* REF_HEADS means that we want regular branch heads */
  28         if ((flags & REF_HEADS) && !memcmp(name, "heads/", 6))
  29                 return 1;
  30
  31         /* REF_TAGS means that we want tags */
  32         if ((flags & REF_TAGS) && !memcmp(name, "tags/", 5))
  33                 return 1;
  34
  35         /* All type bits clear means that we are ok with anything */
  36         return !(flags & ~REF_NORMAL);
  37 }
  38
  39 /*
  40  * Read all the refs from the other end
  41  */
  42 struct ref **get_remote_heads(int in, struct ref **list,
  43                               int nr_match, char **match,
  44                               unsigned int flags)
  45 {
  46         *list = NULL;
  47         for (;;) {
  48                 struct ref *ref;
  49                 unsigned char old_sha1[20];
  50                 static char buffer[1000];
  51                 char *name;
  52                 int len, name_len;
  53
  54                 len = packet_read_line(in, buffer, sizeof(buffer));
  55                 if (!len)
  56                         break;
  57                 if (buffer[len-1] == '\n')
  58                         buffer[--len] = 0;
  59
  60                 if (len < 42 || get_sha1_hex(buffer, old_sha1) || buffer[40] != ' ')
  61                         die("protocol error: expected sha/ref, got '%s'", buffer);
  62                 name = buffer + 41;
  63
  64                 name_len = strlen(name);
  65                 if (len != name_len + 41) {
  66                         if (server_capabilities)
  67                                 free(server_capabilities);
  68                         server_capabilities = xstrdup(name + name_len + 1);
  69                 }
  70
  71                 if (!check_ref(name, name_len, flags))
  72                         continue;
  73                 if (nr_match && !path_match(name, nr_match, match))
  74                         continue;
  75                 ref = alloc_ref(len - 40);
  76                 hashcpy(ref->old_sha1, old_sha1);
  77                 memcpy(ref->name, buffer + 41, len - 40);
  78                 *list = ref;
  79                 list = &ref->next;
  80         }
  81         return list;
  82 }
  83
  84 int server_supports(const char *feature)
  85 {
  86         return server_capabilities &&
  87                 strstr(server_capabilities, feature) != NULL;
  88 }
  89
  90 int get_ack(int fd, unsigned char *result_sha1)
  91 {
  92         static char line[1000];
  93         int len = packet_read_line(fd, line, sizeof(line));
  94
  95         if (!len)
  96                 die("git-fetch-pack: expected ACK/NAK, got EOF");
  97         if (line[len-1] == '\n')
  98                 line[--len] = 0;
  99         if (!strcmp(line, "NAK"))
 100                 return 0;
 101         if (!prefixcmp(line, "ACK ")) {
 102                 if (!get_sha1_hex(line+4, result_sha1)) {
 103                         if (strstr(line+45, "continue"))
 104                                 return 2;
 105                         return 1;
 106                 }
 107         }
 108         die("git-fetch_pack: expected ACK/NAK, got '%s'", line);
 109 }
 110
 111 int path_match(const char *path, int nr, char **match)
 112 {
 113         int i;
 114         int pathlen = strlen(path);
 115
 116         for (i = 0; i < nr; i++) {
 117                 char *s = match[i];
 118                 int len = strlen(s);
 119
 120                 if (!len || len > pathlen)
 121                         continue;
 122                 if (memcmp(path + pathlen - len, s, len))
 123                         continue;
 124                 if (pathlen > len && path[pathlen - len - 1] != '/')
 125                         continue;
 126                 *s = 0;
 127                 return (i + 1);
 128         }
 129         return 0;
 130 }
 131
 132 enum protocol {
 133         PROTO_LOCAL = 1,
 134         PROTO_SSH,
 135         PROTO_GIT,
 136 };
 137
 138 static enum protocol get_protocol(const char *name)
 139 {
 140         if (!strcmp(name, "ssh"))
 141                 return PROTO_SSH;
 142         if (!strcmp(name, "git"))
 143                 return PROTO_GIT;
 144         if (!strcmp(name, "git+ssh"))
 145                 return PROTO_SSH;
 146         if (!strcmp(name, "ssh+git"))
 147                 return PROTO_SSH;
 148         if (!strcmp(name, "file"))
 149                 return PROTO_LOCAL;
 150         die("I don't handle protocol '%s'", name);
 151 }
 152
 153 #define STR_(s) # s
 154 #define STR(s)  STR_(s)
 155
 156 #ifndef NO_IPV6
 157
 158 static const char *ai_name(const struct addrinfo *ai)
 159 {
 160         static char addr[INET_ADDRSTRLEN];
 161         if ( AF_INET == ai->ai_family ) {
 162                 struct sockaddr_in *in;
 163                 in = (struct sockaddr_in *)ai->ai_addr;
 164                 inet_ntop(ai->ai_family, &in->sin_addr, addr, sizeof(addr));
 165         } else if ( AF_INET6 == ai->ai_family ) {
 166                 struct sockaddr_in6 *in;
 167                 in = (struct sockaddr_in6 *)ai->ai_addr;
 168                 inet_ntop(ai->ai_family, &in->sin6_addr, addr, sizeof(addr));
 169         } else {
 170                 strcpy(addr, "(unknown)");
 171         }
 172         return addr;
 173 }
 174
 175 /*
 176  * Returns a connected socket() fd, or else die()s.
 177  */
 178 static int git_tcp_connect_sock(char *host, int flags)
 179 {
 180         int sockfd = -1, saved_errno = 0;
 181         char *colon, *end;
 182         const char *port = STR(DEFAULT_GIT_PORT);
 183         struct addrinfo hints, *ai0, *ai;
 184         int gai;
 185         int cnt = 0;
 186
 187         if (host[0] == '[') {
 188                 end = strchr(host + 1, ']');
 189                 if (end) {
 190                         *end = 0;
 191                         end++;
 192                         host++;
 193                 } else
 194                         end = host;
 195         } else
 196                 end = host;
 197         colon = strchr(end, ':');
 198
 199         if (colon) {
 200                 *colon = 0;
 201                 port = colon + 1;
 202                 if (!*port)
 203                         port = "<none>";
 204         }
 205
 206         memset(&hints, 0, sizeof(hints));
 207         hints.ai_socktype = SOCK_STREAM;
 208         hints.ai_protocol = IPPROTO_TCP;
 209
 210         if (flags & CONNECT_VERBOSE)
 211                 fprintf(stderr, "Looking up %s ... ", host);
 212
 213         gai = getaddrinfo(host, port, &hints, &ai);
 214         if (gai)
 215                 die("Unable to look up %s (port %s) (%s)", host, port, gai_strerror(gai));
 216
 217         if (flags & CONNECT_VERBOSE)
 218                 fprintf(stderr, "done.\nConnecting to %s (port %s) ... ", host, port);
 219
 220         for (ai0 = ai; ai; ai = ai->ai_next) {
 221                 sockfd = socket(ai->ai_family,
 222                                 ai->ai_socktype, ai->ai_protocol);
 223                 if (sockfd < 0) {
 224                         saved_errno = errno;
 225                         continue;
 226                 }
 227                 if (connect(sockfd, ai->ai_addr, ai->ai_addrlen) < 0) {
 228                         saved_errno = errno;
 229                         fprintf(stderr, "%s[%d: %s]: errno=%s\n",
 230                                 host,
 231                                 cnt,
 232                                 ai_name(ai),
 233                                 strerror(saved_errno));
 234                         close(sockfd);
 235                         sockfd = -1;
 236                         continue;
 237                 }
 238                 if (flags & CONNECT_VERBOSE)
 239                         fprintf(stderr, "%s ", ai_name(ai));
 240                 break;
 241         }
 242
 243         freeaddrinfo(ai0);
 244
 245         if (sockfd < 0)
 246                 die("unable to connect a socket (%s)", strerror(saved_errno));
 247
 248         if (flags & CONNECT_VERBOSE)
 249                 fprintf(stderr, "done.\n");
 250
 251         return sockfd;
 252 }
 253
 254 #else /* NO_IPV6 */
 255
 256 /*
 257  * Returns a connected socket() fd, or else die()s.
 258  */
 259 static int git_tcp_connect_sock(char *host, int flags)
 260 {
 261         int sockfd = -1, saved_errno = 0;
 262         char *colon, *end;
 263         char *port = STR(DEFAULT_GIT_PORT), *ep;
 264         struct hostent *he;
 265         struct sockaddr_in sa;
 266         char **ap;
 267         unsigned int nport;
 268         int cnt;
 269
 270         if (host[0] == '[') {
 271                 end = strchr(host + 1, ']');
 272                 if (end) {
 273                         *end = 0;
 274                         end++;
 275                         host++;
 276                 } else
 277                         end = host;
 278         } else
 279                 end = host;
 280         colon = strchr(end, ':');
 281
 282         if (colon) {
 283                 *colon = 0;
 284                 port = colon + 1;
 285         }
 286
 287         if (flags & CONNECT_VERBOSE)
 288                 fprintf(stderr, "Looking up %s ... ", host);
 289
 290         he = gethostbyname(host);
 291         if (!he)
 292                 die("Unable to look up %s (%s)", host, hstrerror(h_errno));
 293         nport = strtoul(port, &ep, 10);
 294         if ( ep == port || *ep ) {
 295                 /* Not numeric */
 296                 struct servent *se = getservbyname(port,"tcp");
 297                 if ( !se )
 298                         die("Unknown port %s\n", port);
 299                 nport = se->s_port;
 300         }
 301
 302         if (flags & CONNECT_VERBOSE)
 303                 fprintf(stderr, "done.\nConnecting to %s (port %s) ... ", host, port);
 304
 305         for (cnt = 0, ap = he->h_addr_list; *ap; ap++, cnt++) {
 306                 sockfd = socket(he->h_addrtype, SOCK_STREAM, 0);
 307                 if (sockfd < 0) {
 308                         saved_errno = errno;
 309                         continue;
 310                 }
 311
 312                 memset(&sa, 0, sizeof sa);
 313                 sa.sin_family = he->h_addrtype;
 314                 sa.sin_port = htons(nport);
 315                 memcpy(&sa.sin_addr, *ap, he->h_length);
 316
 317                 if (connect(sockfd, (struct sockaddr *)&sa, sizeof sa) < 0) {
 318                         saved_errno = errno;
 319                         fprintf(stderr, "%s[%d: %s]: errno=%s\n",
 320                                 host,
 321                                 cnt,
 322                                 inet_ntoa(*(struct in_addr *)&sa.sin_addr),
 323                                 strerror(saved_errno));
 324                         close(sockfd);
 325                         sockfd = -1;
 326                         continue;
 327                 }
 328                 if (flags & CONNECT_VERBOSE)
 329                         fprintf(stderr, "%s ",
 330                                 inet_ntoa(*(struct in_addr *)&sa.sin_addr));
 331                 break;
 332         }
 333
 334         if (sockfd < 0)
 335                 die("unable to connect a socket (%s)", strerror(saved_errno));
 336
 337         if (flags & CONNECT_VERBOSE)
 338                 fprintf(stderr, "done.\n");
 339
 340         return sockfd;
 341 }
 342
 343 #endif /* NO_IPV6 */
 344
 345
 346 static void git_tcp_connect(int fd[2], char *host, int flags)
 347 {
 348         int sockfd = git_tcp_connect_sock(host, flags);
 349
 350         fd[0] = sockfd;
 351         fd[1] = dup(sockfd);
 352 }
 353
 354
 355 static char *git_proxy_command;
 356 static const char *rhost_name;
 357 static int rhost_len;
 358
 359 static int git_proxy_command_options(const char *var, const char *value)
 360 {
 361         if (!strcmp(var, "core.gitproxy")) {
 362                 const char *for_pos;
 363                 int matchlen = -1;
 364                 int hostlen;
 365
 366                 if (git_proxy_command)
 367                         return 0;
 368                 /* [core]
 369                  * ;# matches www.kernel.org as well
 370                  * gitproxy = netcatter-1 for kernel.org
 371                  * gitproxy = netcatter-2 for sample.xz
 372                  * gitproxy = netcatter-default
 373                  */
 374                 for_pos = strstr(value, " for ");
 375                 if (!for_pos)
 376                         /* matches everybody */
 377                         matchlen = strlen(value);
 378                 else {
 379                         hostlen = strlen(for_pos + 5);
 380                         if (rhost_len < hostlen)
 381                                 matchlen = -1;
 382                         else if (!strncmp(for_pos + 5,
 383                                           rhost_name + rhost_len - hostlen,
 384                                           hostlen) &&
 385                                  ((rhost_len == hostlen) ||
 386                                   rhost_name[rhost_len - hostlen -1] == '.'))
 387                                 matchlen = for_pos - value;
 388                         else
 389                                 matchlen = -1;
 390                 }
 391                 if (0 <= matchlen) {
 392                         /* core.gitproxy = none for kernel.org */
 393                         if (matchlen == 4 &&
 394                             !memcmp(value, "none", 4))
 395                                 matchlen = 0;
 396                         git_proxy_command = xmemdupz(value, matchlen);
 397                 }
 398                 return 0;
 399         }
 400
 401         return git_default_config(var, value);
 402 }
 403
 404 static int git_use_proxy(const char *host)
 405 {
 406         rhost_name = host;
 407         rhost_len = strlen(host);
 408         git_proxy_command = getenv("GIT_PROXY_COMMAND");
 409         git_config(git_proxy_command_options);
 410         rhost_name = NULL;
 411         return (git_proxy_command && *git_proxy_command);
 412 }
 413
 414 static void git_proxy_connect(int fd[2], char *host)
 415 {
 416         const char *port = STR(DEFAULT_GIT_PORT);
 417         char *colon, *end;
 418         const char *argv[4];
 419         struct child_process proxy;
 420
 421         if (host[0] == '[') {
 422                 end = strchr(host + 1, ']');
 423                 if (end) {
 424                         *end = 0;
 425                         end++;
 426                         host++;
 427                 } else
 428                         end = host;
 429         } else
 430                 end = host;
 431         colon = strchr(end, ':');
 432
 433         if (colon) {
 434                 *colon = 0;
 435                 port = colon + 1;
 436         }
 437
 438         argv[0] = git_proxy_command;
 439         argv[1] = host;
 440         argv[2] = port;
 441         argv[3] = NULL;
 442         memset(&proxy, 0, sizeof(proxy));
 443         proxy.argv = argv;
 444         proxy.in = -1;
 445         proxy.out = -1;
 446         if (start_command(&proxy))
 447                 die("cannot start proxy %s", argv[0]);
 448         fd[0] = proxy.out; /* read from proxy stdout */
 449         fd[1] = proxy.in;  /* write to proxy stdin */
 450 }
 451
 452 #define MAX_CMD_LEN 1024
 453
 454 char *get_port(char *host)
 455 {
 456         char *end;
 457         char *p = strchr(host, ':');
 458
 459         if (p) {
 460                 strtol(p+1, &end, 10);
 461                 if (*end == '\0') {
 462                         *p = '\0';
 463                         return p+1;
 464                 }
 465         }
 466
 467         return NULL;
 468 }
 469
 470 /*
 471  * This returns 0 if the transport protocol does not need fork(2),
 472  * or a process id if it does.  Once done, finish the connection
 473  * with finish_connect() with the value returned from this function
 474  * (it is safe to call finish_connect() with 0 to support the former
 475  * case).
 476  *
 477  * Does not return a negative value on error; it just dies.
 478  */
 479 pid_t git_connect(int fd[2], char *url, const char *prog, int flags)
 480 {
 481         char *host, *path = url;
 482         char *end;
 483         int c;
 484         int pipefd[2][2];
 485         pid_t pid;
 486         enum protocol protocol = PROTO_LOCAL;
 487         int free_path = 0;
 488         char *port = NULL;
 489
 490         /* Without this we cannot rely on waitpid() to tell
 491          * what happened to our children.
 492          */
 493         signal(SIGCHLD, SIG_DFL);
 494
 495         host = strstr(url, "://");
 496         if(host) {
 497                 *host = '\0';
 498                 protocol = get_protocol(url);
 499                 host += 3;
 500                 c = '/';
 501         } else {
 502                 host = url;
 503                 c = ':';
 504         }
 505
 506         if (host[0] == '[') {
 507                 end = strchr(host + 1, ']');
 508                 if (end) {
 509                         *end = 0;
 510                         end++;
 511                         host++;
 512                 } else
 513                         end = host;
 514         } else
 515                 end = host;
 516
 517         path = strchr(end, c);
 518         if (path) {
 519                 if (c == ':') {
 520                         protocol = PROTO_SSH;
 521                         *path++ = '\0';
 522                 }
 523         } else
 524                 path = end;
 525
 526         if (!path || !*path)
 527                 die("No path specified. See 'man git-pull' for valid url syntax");
 528
 529         /*
 530          * null-terminate hostname and point path to ~ for URL's like this:
 531          *    ssh://host.xz/~user/repo
 532          */
 533         if (protocol != PROTO_LOCAL && host != url) {
 534                 char *ptr = path;
 535                 if (path[1] == '~')
 536                         path++;
 537                 else {
 538                         path = xstrdup(ptr);
 539                         free_path = 1;
 540                 }
 541
 542                 *ptr = '\0';
 543         }
 544
 545         /*
 546          * Add support for ssh port: ssh://host.xy:<port>/...
 547          */
 548         if (protocol == PROTO_SSH && host != url)
 549                 port = get_port(host);
 550
 551         if (protocol == PROTO_GIT) {
 552                 /* These underlying connection commands die() if they
 553                  * cannot connect.
 554                  */
 555                 char *target_host = xstrdup(host);
 556                 if (git_use_proxy(host))
 557                         git_proxy_connect(fd, host);
 558                 else
 559                         git_tcp_connect(fd, host, flags);
 560                 /*
 561                  * Separate original protocol components prog and path
 562                  * from extended components with a NUL byte.
 563                  */
 564                 packet_write(fd[1],
 565                              "%s %s%chost=%s%c",
 566                              prog, path, 0,
 567                              target_host, 0);
 568                 free(target_host);
 569                 if (free_path)
 570                         free(path);
 571                 return 0;
 572         }
 573
 574         if (pipe(pipefd[0]) < 0 || pipe(pipefd[1]) < 0)
 575                 die("unable to create pipe pair for communication");
 576         pid = fork();
 577         if (pid < 0)
 578                 die("unable to fork");
 579         if (!pid) {
 580                 char command[MAX_CMD_LEN];
 581                 char *posn = command;
 582                 int size = MAX_CMD_LEN;
 583                 int of = 0;
 584
 585                 of |= add_to_string(&posn, &size, prog, 0);
 586                 of |= add_to_string(&posn, &size, " ", 0);
 587                 of |= add_to_string(&posn, &size, path, 1);
 588
 589                 if (of)
 590                         die("command line too long");
 591
 592                 dup2(pipefd[1][0], 0);
 593                 dup2(pipefd[0][1], 1);
 594                 close(pipefd[0][0]);
 595                 close(pipefd[0][1]);
 596                 close(pipefd[1][0]);
 597                 close(pipefd[1][1]);
 598                 if (protocol == PROTO_SSH) {
 599                         const char *ssh, *ssh_basename;
 600                         ssh = getenv("GIT_SSH");
 601                         if (!ssh) ssh = "ssh";
 602                         ssh_basename = strrchr(ssh, '/');
 603                         if (!ssh_basename)
 604                                 ssh_basename = ssh;
 605                         else
 606                                 ssh_basename++;
 607
 608                         if (!port)
 609                                 execlp(ssh, ssh_basename, host, command, NULL);
 610                         else
 611                                 execlp(ssh, ssh_basename, "-p", port, host,
 612                                        command, NULL);
 613                 }
 614                 else {
 615                         unsetenv(ALTERNATE_DB_ENVIRONMENT);
 616                         unsetenv(DB_ENVIRONMENT);
 617                         unsetenv(GIT_DIR_ENVIRONMENT);
 618                         unsetenv(GIT_WORK_TREE_ENVIRONMENT);
 619                         unsetenv(GRAFT_ENVIRONMENT);
 620                         unsetenv(INDEX_ENVIRONMENT);
 621                         execlp("sh", "sh", "-c", command, NULL);
 622                 }
 623                 die("exec failed");
 624         }
 625         fd[0] = pipefd[0][0];
 626         fd[1] = pipefd[1][1];
 627         close(pipefd[0][1]);
 628         close(pipefd[1][0]);
 629         if (free_path)
 630                 free(path);
 631         return pid;
 632 }
 633
 634 int finish_connect(pid_t pid)
 635 {
 636         if (pid == 0)
 637                 return 0;
 638
 639         while (waitpid(pid, NULL, 0) < 0) {
 640                 if (errno != EINTR)
 641                         return -1;
 642         }
 643         return 0;
 644 }