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 int check_ref_type(const struct ref *ref, int flags)
  40 {
  41         return check_ref(ref->name, strlen(ref->name), flags);
  42 }
  43
  44 /*
  45  * Read all the refs from the other end
  46  */
  47 struct ref **get_remote_heads(int in, struct ref **list,
  48                               int nr_match, char **match,
  49                               unsigned int flags)
  50 {
  51         *list = NULL;
  52         for (;;) {
  53                 struct ref *ref;
  54                 unsigned char old_sha1[20];
  55                 static char buffer[1000];
  56                 char *name;
  57                 int len, name_len;
  58
  59                 len = packet_read_line(in, buffer, sizeof(buffer));
  60                 if (!len)
  61                         break;
  62                 if (buffer[len-1] == '\n')
  63                         buffer[--len] = 0;
  64
  65                 if (len < 42 || get_sha1_hex(buffer, old_sha1) || buffer[40] != ' ')
  66                         die("protocol error: expected sha/ref, got '%s'", buffer);
  67                 name = buffer + 41;
  68
  69                 name_len = strlen(name);
  70                 if (len != name_len + 41) {
  71                         if (server_capabilities)
  72                                 free(server_capabilities);
  73                         server_capabilities = xstrdup(name + name_len + 1);
  74                 }
  75
  76                 if (!check_ref(name, name_len, flags))
  77                         continue;
  78                 if (nr_match && !path_match(name, nr_match, match))
  79                         continue;
  80                 ref = alloc_ref(name_len + 1);
  81                 hashcpy(ref->old_sha1, old_sha1);
  82                 memcpy(ref->name, buffer + 41, name_len + 1);
  83                 *list = ref;
  84                 list = &ref->next;
  85         }
  86         return list;
  87 }
  88
  89 int server_supports(const char *feature)
  90 {
  91         return server_capabilities &&
  92                 strstr(server_capabilities, feature) != NULL;
  93 }
  94
  95 int get_ack(int fd, unsigned char *result_sha1)
  96 {
  97         static char line[1000];
  98         int len = packet_read_line(fd, line, sizeof(line));
  99
 100         if (!len)
 101                 die("git-fetch-pack: expected ACK/NAK, got EOF");
 102         if (line[len-1] == '\n')
 103                 line[--len] = 0;
 104         if (!strcmp(line, "NAK"))
 105                 return 0;
 106         if (!prefixcmp(line, "ACK ")) {
 107                 if (!get_sha1_hex(line+4, result_sha1)) {
 108                         if (strstr(line+45, "continue"))
 109                                 return 2;
 110                         return 1;
 111                 }
 112         }
 113         die("git-fetch_pack: expected ACK/NAK, got '%s'", line);
 114 }
 115
 116 int path_match(const char *path, int nr, char **match)
 117 {
 118         int i;
 119         int pathlen = strlen(path);
 120
 121         for (i = 0; i < nr; i++) {
 122                 char *s = match[i];
 123                 int len = strlen(s);
 124
 125                 if (!len || len > pathlen)
 126                         continue;
 127                 if (memcmp(path + pathlen - len, s, len))
 128                         continue;
 129                 if (pathlen > len && path[pathlen - len - 1] != '/')
 130                         continue;
 131                 *s = 0;
 132                 return (i + 1);
 133         }
 134         return 0;
 135 }
 136
 137 enum protocol {
 138         PROTO_LOCAL = 1,
 139         PROTO_SSH,
 140         PROTO_GIT,
 141 };
 142
 143 static enum protocol get_protocol(const char *name)
 144 {
 145         if (!strcmp(name, "ssh"))
 146                 return PROTO_SSH;
 147         if (!strcmp(name, "git"))
 148                 return PROTO_GIT;
 149         if (!strcmp(name, "git+ssh"))
 150                 return PROTO_SSH;
 151         if (!strcmp(name, "ssh+git"))
 152                 return PROTO_SSH;
 153         if (!strcmp(name, "file"))
 154                 return PROTO_LOCAL;
 155         die("I don't handle protocol '%s'", name);
 156 }
 157
 158 #define STR_(s) # s
 159 #define STR(s)  STR_(s)
 160
 161 #ifndef NO_IPV6
 162
 163 static const char *ai_name(const struct addrinfo *ai)
 164 {
 165         static char addr[INET_ADDRSTRLEN];
 166         if ( AF_INET == ai->ai_family ) {
 167                 struct sockaddr_in *in;
 168                 in = (struct sockaddr_in *)ai->ai_addr;
 169                 inet_ntop(ai->ai_family, &in->sin_addr, addr, sizeof(addr));
 170         } else if ( AF_INET6 == ai->ai_family ) {
 171                 struct sockaddr_in6 *in;
 172                 in = (struct sockaddr_in6 *)ai->ai_addr;
 173                 inet_ntop(ai->ai_family, &in->sin6_addr, addr, sizeof(addr));
 174         } else {
 175                 strcpy(addr, "(unknown)");
 176         }
 177         return addr;
 178 }
 179
 180 /*
 181  * Returns a connected socket() fd, or else die()s.
 182  */
 183 static int git_tcp_connect_sock(char *host, int flags)
 184 {
 185         int sockfd = -1, saved_errno = 0;
 186         char *colon, *end;
 187         const char *port = STR(DEFAULT_GIT_PORT);
 188         struct addrinfo hints, *ai0, *ai;
 189         int gai;
 190         int cnt = 0;
 191
 192         if (host[0] == '[') {
 193                 end = strchr(host + 1, ']');
 194                 if (end) {
 195                         *end = 0;
 196                         end++;
 197                         host++;
 198                 } else
 199                         end = host;
 200         } else
 201                 end = host;
 202         colon = strchr(end, ':');
 203
 204         if (colon) {
 205                 *colon = 0;
 206                 port = colon + 1;
 207                 if (!*port)
 208                         port = "<none>";
 209         }
 210
 211         memset(&hints, 0, sizeof(hints));
 212         hints.ai_socktype = SOCK_STREAM;
 213         hints.ai_protocol = IPPROTO_TCP;
 214
 215         if (flags & CONNECT_VERBOSE)
 216                 fprintf(stderr, "Looking up %s ... ", host);
 217
 218         gai = getaddrinfo(host, port, &hints, &ai);
 219         if (gai)
 220                 die("Unable to look up %s (port %s) (%s)", host, port, gai_strerror(gai));
 221
 222         if (flags & CONNECT_VERBOSE)
 223                 fprintf(stderr, "done.\nConnecting to %s (port %s) ... ", host, port);
 224
 225         for (ai0 = ai; ai; ai = ai->ai_next) {
 226                 sockfd = socket(ai->ai_family,
 227                                 ai->ai_socktype, ai->ai_protocol);
 228                 if (sockfd < 0) {
 229                         saved_errno = errno;
 230                         continue;
 231                 }
 232                 if (connect(sockfd, ai->ai_addr, ai->ai_addrlen) < 0) {
 233                         saved_errno = errno;
 234                         fprintf(stderr, "%s[%d: %s]: errno=%s\n",
 235                                 host,
 236                                 cnt,
 237                                 ai_name(ai),
 238                                 strerror(saved_errno));
 239                         close(sockfd);
 240                         sockfd = -1;
 241                         continue;
 242                 }
 243                 if (flags & CONNECT_VERBOSE)
 244                         fprintf(stderr, "%s ", ai_name(ai));
 245                 break;
 246         }
 247
 248         freeaddrinfo(ai0);
 249
 250         if (sockfd < 0)
 251                 die("unable to connect a socket (%s)", strerror(saved_errno));
 252
 253         if (flags & CONNECT_VERBOSE)
 254                 fprintf(stderr, "done.\n");
 255
 256         return sockfd;
 257 }
 258
 259 #else /* NO_IPV6 */
 260
 261 /*
 262  * Returns a connected socket() fd, or else die()s.
 263  */
 264 static int git_tcp_connect_sock(char *host, int flags)
 265 {
 266         int sockfd = -1, saved_errno = 0;
 267         char *colon, *end;
 268         char *port = STR(DEFAULT_GIT_PORT), *ep;
 269         struct hostent *he;
 270         struct sockaddr_in sa;
 271         char **ap;
 272         unsigned int nport;
 273         int cnt;
 274
 275         if (host[0] == '[') {
 276                 end = strchr(host + 1, ']');
 277                 if (end) {
 278                         *end = 0;
 279                         end++;
 280                         host++;
 281                 } else
 282                         end = host;
 283         } else
 284                 end = host;
 285         colon = strchr(end, ':');
 286
 287         if (colon) {
 288                 *colon = 0;
 289                 port = colon + 1;
 290         }
 291
 292         if (flags & CONNECT_VERBOSE)
 293                 fprintf(stderr, "Looking up %s ... ", host);
 294
 295         he = gethostbyname(host);
 296         if (!he)
 297                 die("Unable to look up %s (%s)", host, hstrerror(h_errno));
 298         nport = strtoul(port, &ep, 10);
 299         if ( ep == port || *ep ) {
 300                 /* Not numeric */
 301                 struct servent *se = getservbyname(port,"tcp");
 302                 if ( !se )
 303                         die("Unknown port %s\n", port);
 304                 nport = se->s_port;
 305         }
 306
 307         if (flags & CONNECT_VERBOSE)
 308                 fprintf(stderr, "done.\nConnecting to %s (port %s) ... ", host, port);
 309
 310         for (cnt = 0, ap = he->h_addr_list; *ap; ap++, cnt++) {
 311                 sockfd = socket(he->h_addrtype, SOCK_STREAM, 0);
 312                 if (sockfd < 0) {
 313                         saved_errno = errno;
 314                         continue;
 315                 }
 316
 317                 memset(&sa, 0, sizeof sa);
 318                 sa.sin_family = he->h_addrtype;
 319                 sa.sin_port = htons(nport);
 320                 memcpy(&sa.sin_addr, *ap, he->h_length);
 321
 322                 if (connect(sockfd, (struct sockaddr *)&sa, sizeof sa) < 0) {
 323                         saved_errno = errno;
 324                         fprintf(stderr, "%s[%d: %s]: errno=%s\n",
 325                                 host,
 326                                 cnt,
 327                                 inet_ntoa(*(struct in_addr *)&sa.sin_addr),
 328                                 strerror(saved_errno));
 329                         close(sockfd);
 330                         sockfd = -1;
 331                         continue;
 332                 }
 333                 if (flags & CONNECT_VERBOSE)
 334                         fprintf(stderr, "%s ",
 335                                 inet_ntoa(*(struct in_addr *)&sa.sin_addr));
 336                 break;
 337         }
 338
 339         if (sockfd < 0)
 340                 die("unable to connect a socket (%s)", strerror(saved_errno));
 341
 342         if (flags & CONNECT_VERBOSE)
 343                 fprintf(stderr, "done.\n");
 344
 345         return sockfd;
 346 }
 347
 348 #endif /* NO_IPV6 */
 349
 350
 351 static void git_tcp_connect(int fd[2], char *host, int flags)
 352 {
 353         int sockfd = git_tcp_connect_sock(host, flags);
 354
 355         fd[0] = sockfd;
 356         fd[1] = dup(sockfd);
 357 }
 358
 359
 360 static char *git_proxy_command;
 361 static const char *rhost_name;
 362 static int rhost_len;
 363
 364 static int git_proxy_command_options(const char *var, const char *value)
 365 {
 366         if (!strcmp(var, "core.gitproxy")) {
 367                 const char *for_pos;
 368                 int matchlen = -1;
 369                 int hostlen;
 370
 371                 if (git_proxy_command)
 372                         return 0;
 373                 if (!value)
 374                         return config_error_nonbool(var);
 375                 /* [core]
 376                  * ;# matches www.kernel.org as well
 377                  * gitproxy = netcatter-1 for kernel.org
 378                  * gitproxy = netcatter-2 for sample.xz
 379                  * gitproxy = netcatter-default
 380                  */
 381                 for_pos = strstr(value, " for ");
 382                 if (!for_pos)
 383                         /* matches everybody */
 384                         matchlen = strlen(value);
 385                 else {
 386                         hostlen = strlen(for_pos + 5);
 387                         if (rhost_len < hostlen)
 388                                 matchlen = -1;
 389                         else if (!strncmp(for_pos + 5,
 390                                           rhost_name + rhost_len - hostlen,
 391                                           hostlen) &&
 392                                  ((rhost_len == hostlen) ||
 393                                   rhost_name[rhost_len - hostlen -1] == '.'))
 394                                 matchlen = for_pos - value;
 395                         else
 396                                 matchlen = -1;
 397                 }
 398                 if (0 <= matchlen) {
 399                         /* core.gitproxy = none for kernel.org */
 400                         if (matchlen == 4 &&
 401                             !memcmp(value, "none", 4))
 402                                 matchlen = 0;
 403                         git_proxy_command = xmemdupz(value, matchlen);
 404                 }
 405                 return 0;
 406         }
 407
 408         return git_default_config(var, value);
 409 }
 410
 411 static int git_use_proxy(const char *host)
 412 {
 413         rhost_name = host;
 414         rhost_len = strlen(host);
 415         git_proxy_command = getenv("GIT_PROXY_COMMAND");
 416         git_config(git_proxy_command_options);
 417         rhost_name = NULL;
 418         return (git_proxy_command && *git_proxy_command);
 419 }
 420
 421 static void git_proxy_connect(int fd[2], char *host)
 422 {
 423         const char *port = STR(DEFAULT_GIT_PORT);
 424         char *colon, *end;
 425         const char *argv[4];
 426         struct child_process proxy;
 427
 428         if (host[0] == '[') {
 429                 end = strchr(host + 1, ']');
 430                 if (end) {
 431                         *end = 0;
 432                         end++;
 433                         host++;
 434                 } else
 435                         end = host;
 436         } else
 437                 end = host;
 438         colon = strchr(end, ':');
 439
 440         if (colon) {
 441                 *colon = 0;
 442                 port = colon + 1;
 443         }
 444
 445         argv[0] = git_proxy_command;
 446         argv[1] = host;
 447         argv[2] = port;
 448         argv[3] = NULL;
 449         memset(&proxy, 0, sizeof(proxy));
 450         proxy.argv = argv;
 451         proxy.in = -1;
 452         proxy.out = -1;
 453         if (start_command(&proxy))
 454                 die("cannot start proxy %s", argv[0]);
 455         fd[0] = proxy.out; /* read from proxy stdout */
 456         fd[1] = proxy.in;  /* write to proxy stdin */
 457 }
 458
 459 #define MAX_CMD_LEN 1024
 460
 461 char *get_port(char *host)
 462 {
 463         char *end;
 464         char *p = strchr(host, ':');
 465
 466         if (p) {
 467                 strtol(p+1, &end, 10);
 468                 if (*end == '\0') {
 469                         *p = '\0';
 470                         return p+1;
 471                 }
 472         }
 473
 474         return NULL;
 475 }
 476
 477 static struct child_process no_fork;
 478
 479 /*
 480  * This returns a dummy child_process if the transport protocol does not
 481  * need fork(2), or a struct child_process object if it does.  Once done,
 482  * finish the connection with finish_connect() with the value returned from
 483  * this function (it is safe to call finish_connect() with NULL to support
 484  * the former case).
 485  *
 486  * If it returns, the connect is successful; it just dies on errors (this
 487  * will hopefully be changed in a libification effort, to return NULL when
 488  * the connection failed).
 489  */
 490 struct child_process *git_connect(int fd[2], const char *url_orig,
 491                                   const char *prog, int flags)
 492 {
 493         char *url = xstrdup(url_orig);
 494         char *host, *path = url;
 495         char *end;
 496         int c;
 497         struct child_process *conn;
 498         enum protocol protocol = PROTO_LOCAL;
 499         int free_path = 0;
 500         char *port = NULL;
 501         const char **arg;
 502         struct strbuf cmd;
 503
 504         /* Without this we cannot rely on waitpid() to tell
 505          * what happened to our children.
 506          */
 507         signal(SIGCHLD, SIG_DFL);
 508
 509         host = strstr(url, "://");
 510         if(host) {
 511                 *host = '\0';
 512                 protocol = get_protocol(url);
 513                 host += 3;
 514                 c = '/';
 515         } else {
 516                 host = url;
 517                 c = ':';
 518         }
 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
 531         path = strchr(end, c);
 532         if (path) {
 533                 if (c == ':') {
 534                         protocol = PROTO_SSH;
 535                         *path++ = '\0';
 536                 }
 537         } else
 538                 path = end;
 539
 540         if (!path || !*path)
 541                 die("No path specified. See 'man git-pull' for valid url syntax");
 542
 543         /*
 544          * null-terminate hostname and point path to ~ for URL's like this:
 545          *    ssh://host.xz/~user/repo
 546          */
 547         if (protocol != PROTO_LOCAL && host != url) {
 548                 char *ptr = path;
 549                 if (path[1] == '~')
 550                         path++;
 551                 else {
 552                         path = xstrdup(ptr);
 553                         free_path = 1;
 554                 }
 555
 556                 *ptr = '\0';
 557         }
 558
 559         /*
 560          * Add support for ssh port: ssh://host.xy:<port>/...
 561          */
 562         if (protocol == PROTO_SSH && host != url)
 563                 port = get_port(host);
 564
 565         if (protocol == PROTO_GIT) {
 566                 /* These underlying connection commands die() if they
 567                  * cannot connect.
 568                  */
 569                 char *target_host = xstrdup(host);
 570                 if (git_use_proxy(host))
 571                         git_proxy_connect(fd, host);
 572                 else
 573                         git_tcp_connect(fd, host, flags);
 574                 /*
 575                  * Separate original protocol components prog and path
 576                  * from extended components with a NUL byte.
 577                  */
 578                 packet_write(fd[1],
 579                              "%s %s%chost=%s%c",
 580                              prog, path, 0,
 581                              target_host, 0);
 582                 free(target_host);
 583                 free(url);
 584                 if (free_path)
 585                         free(path);
 586                 return &no_fork;
 587         }
 588
 589         conn = xcalloc(1, sizeof(*conn));
 590
 591         strbuf_init(&cmd, MAX_CMD_LEN);
 592         strbuf_addstr(&cmd, prog);
 593         strbuf_addch(&cmd, ' ');
 594         sq_quote_buf(&cmd, path);
 595         if (cmd.len >= MAX_CMD_LEN)
 596                 die("command line too long");
 597
 598         conn->in = conn->out = -1;
 599         conn->argv = arg = xcalloc(6, sizeof(*arg));
 600         if (protocol == PROTO_SSH) {
 601                 const char *ssh = getenv("GIT_SSH");
 602                 if (!ssh) ssh = "ssh";
 603
 604                 *arg++ = ssh;
 605                 if (port) {
 606                         *arg++ = "-p";
 607                         *arg++ = port;
 608                 }
 609                 *arg++ = host;
 610         }
 611         else {
 612                 /* remove these from the environment */
 613                 const char *env[] = {
 614                         ALTERNATE_DB_ENVIRONMENT,
 615                         DB_ENVIRONMENT,
 616                         GIT_DIR_ENVIRONMENT,
 617                         GIT_WORK_TREE_ENVIRONMENT,
 618                         GRAFT_ENVIRONMENT,
 619                         INDEX_ENVIRONMENT,
 620                         NULL
 621                 };
 622                 conn->env = env;
 623                 *arg++ = "sh";
 624                 *arg++ = "-c";
 625         }
 626         *arg++ = cmd.buf;
 627         *arg = NULL;
 628
 629         if (start_command(conn))
 630                 die("unable to fork");
 631
 632         fd[0] = conn->out; /* read from child's stdout */
 633         fd[1] = conn->in;  /* write to child's stdin */
 634         strbuf_release(&cmd);
 635         free(url);
 636         if (free_path)
 637                 free(path);
 638         return conn;
 639 }
 640
 641 int finish_connect(struct child_process *conn)
 642 {
 643         int code;
 644         if (!conn || conn == &no_fork)
 645                 return 0;
 646
 647         code = finish_command(conn);
 648         free(conn->argv);
 649         free(conn);
 650         return code;
 651 }