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 static void add_extra_have(struct extra_have_objects *extra, unsigned char *sha1)
  45 {
  46         ALLOC_GROW(extra->array, extra->nr + 1, extra->alloc);
  47         hashcpy(&(extra->array[extra->nr][0]), sha1);
  48         extra->nr++;
  49 }
  50
  51 /*
  52  * Read all the refs from the other end
  53  */
  54 struct ref **get_remote_heads(int in, struct ref **list,
  55                               int nr_match, char **match,
  56                               unsigned int flags,
  57                               struct extra_have_objects *extra_have)
  58 {
  59         *list = NULL;
  60         for (;;) {
  61                 struct ref *ref;
  62                 unsigned char old_sha1[20];
  63                 static char buffer[1000];
  64                 char *name;
  65                 int len, name_len;
  66
  67                 len = packet_read_line(in, buffer, sizeof(buffer));
  68                 if (!len)
  69                         break;
  70                 if (buffer[len-1] == '\n')
  71                         buffer[--len] = 0;
  72
  73                 if (len > 4 && !prefixcmp(buffer, "ERR "))
  74                         die("remote error: %s", buffer + 4);
  75
  76                 if (len < 42 || get_sha1_hex(buffer, old_sha1) || buffer[40] != ' ')
  77                         die("protocol error: expected sha/ref, got '%s'", buffer);
  78                 name = buffer + 41;
  79
  80                 name_len = strlen(name);
  81                 if (len != name_len + 41) {
  82                         free(server_capabilities);
  83                         server_capabilities = xstrdup(name + name_len + 1);
  84                 }
  85
  86                 if (extra_have &&
  87                     name_len == 5 && !memcmp(".have", name, 5)) {
  88                         add_extra_have(extra_have, old_sha1);
  89                         continue;
  90                 }
  91
  92                 if (!check_ref(name, name_len, flags))
  93                         continue;
  94                 if (nr_match && !path_match(name, nr_match, match))
  95                         continue;
  96                 ref = alloc_ref(buffer + 41);
  97                 hashcpy(ref->old_sha1, old_sha1);
  98                 *list = ref;
  99                 list = &ref->next;
 100         }
 101         return list;
 102 }
 103
 104 int server_supports(const char *feature)
 105 {
 106         return server_capabilities &&
 107                 strstr(server_capabilities, feature) != NULL;
 108 }
 109
 110 int path_match(const char *path, int nr, char **match)
 111 {
 112         int i;
 113         int pathlen = strlen(path);
 114
 115         for (i = 0; i < nr; i++) {
 116                 char *s = match[i];
 117                 int len = strlen(s);
 118
 119                 if (!len || len > pathlen)
 120                         continue;
 121                 if (memcmp(path + pathlen - len, s, len))
 122                         continue;
 123                 if (pathlen > len && path[pathlen - len - 1] != '/')
 124                         continue;
 125                 *s = 0;
 126                 return (i + 1);
 127         }
 128         return 0;
 129 }
 130
 131 enum protocol {
 132         PROTO_LOCAL = 1,
 133         PROTO_SSH,
 134         PROTO_GIT,
 135 };
 136
 137 static enum protocol get_protocol(const char *name)
 138 {
 139         if (!strcmp(name, "ssh"))
 140                 return PROTO_SSH;
 141         if (!strcmp(name, "git"))
 142                 return PROTO_GIT;
 143         if (!strcmp(name, "git+ssh"))
 144                 return PROTO_SSH;
 145         if (!strcmp(name, "ssh+git"))
 146                 return PROTO_SSH;
 147         if (!strcmp(name, "file"))
 148                 return PROTO_LOCAL;
 149         die("I don't handle protocol '%s'", name);
 150 }
 151
 152 #define STR_(s) # s
 153 #define STR(s)  STR_(s)
 154
 155 #ifndef NO_IPV6
 156
 157 static const char *ai_name(const struct addrinfo *ai)
 158 {
 159         static char addr[NI_MAXHOST];
 160         if (getnameinfo(ai->ai_addr, ai->ai_addrlen, addr, sizeof(addr), NULL, 0,
 161                         NI_NUMERICHOST) != 0)
 162                 strcpy(addr, "(unknown)");
 163
 164         return addr;
 165 }
 166
 167 /*
 168  * Returns a connected socket() fd, or else die()s.
 169  */
 170 static int git_tcp_connect_sock(char *host, int flags)
 171 {
 172         int sockfd = -1, saved_errno = 0;
 173         char *colon, *end;
 174         const char *port = STR(DEFAULT_GIT_PORT);
 175         struct addrinfo hints, *ai0, *ai;
 176         int gai;
 177         int cnt = 0;
 178
 179         if (host[0] == '[') {
 180                 end = strchr(host + 1, ']');
 181                 if (end) {
 182                         *end = 0;
 183                         end++;
 184                         host++;
 185                 } else
 186                         end = host;
 187         } else
 188                 end = host;
 189         colon = strchr(end, ':');
 190
 191         if (colon) {
 192                 *colon = 0;
 193                 port = colon + 1;
 194                 if (!*port)
 195                         port = "<none>";
 196         }
 197
 198         memset(&hints, 0, sizeof(hints));
 199         hints.ai_socktype = SOCK_STREAM;
 200         hints.ai_protocol = IPPROTO_TCP;
 201
 202         if (flags & CONNECT_VERBOSE)
 203                 fprintf(stderr, "Looking up %s ... ", host);
 204
 205         gai = getaddrinfo(host, port, &hints, &ai);
 206         if (gai)
 207                 die("Unable to look up %s (port %s) (%s)", host, port, gai_strerror(gai));
 208
 209         if (flags & CONNECT_VERBOSE)
 210                 fprintf(stderr, "done.\nConnecting to %s (port %s) ... ", host, port);
 211
 212         for (ai0 = ai; ai; ai = ai->ai_next) {
 213                 sockfd = socket(ai->ai_family,
 214                                 ai->ai_socktype, ai->ai_protocol);
 215                 if (sockfd < 0) {
 216                         saved_errno = errno;
 217                         continue;
 218                 }
 219                 if (connect(sockfd, ai->ai_addr, ai->ai_addrlen) < 0) {
 220                         saved_errno = errno;
 221                         fprintf(stderr, "%s[%d: %s]: errno=%s\n",
 222                                 host,
 223                                 cnt,
 224                                 ai_name(ai),
 225                                 strerror(saved_errno));
 226                         close(sockfd);
 227                         sockfd = -1;
 228                         continue;
 229                 }
 230                 if (flags & CONNECT_VERBOSE)
 231                         fprintf(stderr, "%s ", ai_name(ai));
 232                 break;
 233         }
 234
 235         freeaddrinfo(ai0);
 236
 237         if (sockfd < 0)
 238                 die("unable to connect a socket (%s)", strerror(saved_errno));
 239
 240         if (flags & CONNECT_VERBOSE)
 241                 fprintf(stderr, "done.\n");
 242
 243         return sockfd;
 244 }
 245
 246 #else /* NO_IPV6 */
 247
 248 /*
 249  * Returns a connected socket() fd, or else die()s.
 250  */
 251 static int git_tcp_connect_sock(char *host, int flags)
 252 {
 253         int sockfd = -1, saved_errno = 0;
 254         char *colon, *end;
 255         char *port = STR(DEFAULT_GIT_PORT), *ep;
 256         struct hostent *he;
 257         struct sockaddr_in sa;
 258         char **ap;
 259         unsigned int nport;
 260         int cnt;
 261
 262         if (host[0] == '[') {
 263                 end = strchr(host + 1, ']');
 264                 if (end) {
 265                         *end = 0;
 266                         end++;
 267                         host++;
 268                 } else
 269                         end = host;
 270         } else
 271                 end = host;
 272         colon = strchr(end, ':');
 273
 274         if (colon) {
 275                 *colon = 0;
 276                 port = colon + 1;
 277         }
 278
 279         if (flags & CONNECT_VERBOSE)
 280                 fprintf(stderr, "Looking up %s ... ", host);
 281
 282         he = gethostbyname(host);
 283         if (!he)
 284                 die("Unable to look up %s (%s)", host, hstrerror(h_errno));
 285         nport = strtoul(port, &ep, 10);
 286         if ( ep == port || *ep ) {
 287                 /* Not numeric */
 288                 struct servent *se = getservbyname(port,"tcp");
 289                 if ( !se )
 290                         die("Unknown port %s", port);
 291                 nport = se->s_port;
 292         }
 293
 294         if (flags & CONNECT_VERBOSE)
 295                 fprintf(stderr, "done.\nConnecting to %s (port %s) ... ", host, port);
 296
 297         for (cnt = 0, ap = he->h_addr_list; *ap; ap++, cnt++) {
 298                 sockfd = socket(he->h_addrtype, SOCK_STREAM, 0);
 299                 if (sockfd < 0) {
 300                         saved_errno = errno;
 301                         continue;
 302                 }
 303
 304                 memset(&sa, 0, sizeof sa);
 305                 sa.sin_family = he->h_addrtype;
 306                 sa.sin_port = htons(nport);
 307                 memcpy(&sa.sin_addr, *ap, he->h_length);
 308
 309                 if (connect(sockfd, (struct sockaddr *)&sa, sizeof sa) < 0) {
 310                         saved_errno = errno;
 311                         fprintf(stderr, "%s[%d: %s]: errno=%s\n",
 312                                 host,
 313                                 cnt,
 314                                 inet_ntoa(*(struct in_addr *)&sa.sin_addr),
 315                                 strerror(saved_errno));
 316                         close(sockfd);
 317                         sockfd = -1;
 318                         continue;
 319                 }
 320                 if (flags & CONNECT_VERBOSE)
 321                         fprintf(stderr, "%s ",
 322                                 inet_ntoa(*(struct in_addr *)&sa.sin_addr));
 323                 break;
 324         }
 325
 326         if (sockfd < 0)
 327                 die("unable to connect a socket (%s)", strerror(saved_errno));
 328
 329         if (flags & CONNECT_VERBOSE)
 330                 fprintf(stderr, "done.\n");
 331
 332         return sockfd;
 333 }
 334
 335 #endif /* NO_IPV6 */
 336
 337
 338 static void git_tcp_connect(int fd[2], char *host, int flags)
 339 {
 340         int sockfd = git_tcp_connect_sock(host, flags);
 341
 342         fd[0] = sockfd;
 343         fd[1] = dup(sockfd);
 344 }
 345
 346
 347 static char *git_proxy_command;
 348
 349 static int git_proxy_command_options(const char *var, const char *value,
 350                 void *cb)
 351 {
 352         if (!strcmp(var, "core.gitproxy")) {
 353                 const char *for_pos;
 354                 int matchlen = -1;
 355                 int hostlen;
 356                 const char *rhost_name = cb;
 357                 int rhost_len = strlen(rhost_name);
 358
 359                 if (git_proxy_command)
 360                         return 0;
 361                 if (!value)
 362                         return config_error_nonbool(var);
 363                 /* [core]
 364                  * ;# matches www.kernel.org as well
 365                  * gitproxy = netcatter-1 for kernel.org
 366                  * gitproxy = netcatter-2 for sample.xz
 367                  * gitproxy = netcatter-default
 368                  */
 369                 for_pos = strstr(value, " for ");
 370                 if (!for_pos)
 371                         /* matches everybody */
 372                         matchlen = strlen(value);
 373                 else {
 374                         hostlen = strlen(for_pos + 5);
 375                         if (rhost_len < hostlen)
 376                                 matchlen = -1;
 377                         else if (!strncmp(for_pos + 5,
 378                                           rhost_name + rhost_len - hostlen,
 379                                           hostlen) &&
 380                                  ((rhost_len == hostlen) ||
 381                                   rhost_name[rhost_len - hostlen -1] == '.'))
 382                                 matchlen = for_pos - value;
 383                         else
 384                                 matchlen = -1;
 385                 }
 386                 if (0 <= matchlen) {
 387                         /* core.gitproxy = none for kernel.org */
 388                         if (matchlen == 4 &&
 389                             !memcmp(value, "none", 4))
 390                                 matchlen = 0;
 391                         git_proxy_command = xmemdupz(value, matchlen);
 392                 }
 393                 return 0;
 394         }
 395
 396         return git_default_config(var, value, cb);
 397 }
 398
 399 static int git_use_proxy(const char *host)
 400 {
 401         git_proxy_command = getenv("GIT_PROXY_COMMAND");
 402         git_config(git_proxy_command_options, (void*)host);
 403         return (git_proxy_command && *git_proxy_command);
 404 }
 405
 406 static void git_proxy_connect(int fd[2], char *host)
 407 {
 408         const char *port = STR(DEFAULT_GIT_PORT);
 409         char *colon, *end;
 410         const char *argv[4];
 411         struct child_process proxy;
 412
 413         if (host[0] == '[') {
 414                 end = strchr(host + 1, ']');
 415                 if (end) {
 416                         *end = 0;
 417                         end++;
 418                         host++;
 419                 } else
 420                         end = host;
 421         } else
 422                 end = host;
 423         colon = strchr(end, ':');
 424
 425         if (colon) {
 426                 *colon = 0;
 427                 port = colon + 1;
 428         }
 429
 430         argv[0] = git_proxy_command;
 431         argv[1] = host;
 432         argv[2] = port;
 433         argv[3] = NULL;
 434         memset(&proxy, 0, sizeof(proxy));
 435         proxy.argv = argv;
 436         proxy.in = -1;
 437         proxy.out = -1;
 438         if (start_command(&proxy))
 439                 die("cannot start proxy %s", argv[0]);
 440         fd[0] = proxy.out; /* read from proxy stdout */
 441         fd[1] = proxy.in;  /* write to proxy stdin */
 442 }
 443
 444 #define MAX_CMD_LEN 1024
 445
 446 static char *get_port(char *host)
 447 {
 448         char *end;
 449         char *p = strchr(host, ':');
 450
 451         if (p) {
 452                 long port = strtol(p + 1, &end, 10);
 453                 if (end != p + 1 && *end == '\0' && 0 <= port && port < 65536) {
 454                         *p = '\0';
 455                         return p+1;
 456                 }
 457         }
 458
 459         return NULL;
 460 }
 461
 462 static struct child_process no_fork;
 463
 464 /*
 465  * This returns a dummy child_process if the transport protocol does not
 466  * need fork(2), or a struct child_process object if it does.  Once done,
 467  * finish the connection with finish_connect() with the value returned from
 468  * this function (it is safe to call finish_connect() with NULL to support
 469  * the former case).
 470  *
 471  * If it returns, the connect is successful; it just dies on errors (this
 472  * will hopefully be changed in a libification effort, to return NULL when
 473  * the connection failed).
 474  */
 475 struct child_process *git_connect(int fd[2], const char *url_orig,
 476                                   const char *prog, int flags)
 477 {
 478         char *url = xstrdup(url_orig);
 479         char *host, *path;
 480         char *end;
 481         int c;
 482         struct child_process *conn;
 483         enum protocol protocol = PROTO_LOCAL;
 484         int free_path = 0;
 485         char *port = NULL;
 486         const char **arg;
 487         struct strbuf cmd;
 488
 489         /* Without this we cannot rely on waitpid() to tell
 490          * what happened to our children.
 491          */
 492         signal(SIGCHLD, SIG_DFL);
 493
 494         host = strstr(url, "://");
 495         if (host) {
 496                 *host = '\0';
 497                 protocol = get_protocol(url);
 498                 host += 3;
 499                 c = '/';
 500         } else {
 501                 host = url;
 502                 c = ':';
 503         }
 504
 505         /*
 506          * Don't do destructive transforms with git:// as that
 507          * protocol code does '[]' unwrapping of its own.
 508          */
 509         if (host[0] == '[') {
 510                 end = strchr(host + 1, ']');
 511                 if (end) {
 512                         if (protocol != PROTO_GIT) {
 513                                 *end = 0;
 514                                 host++;
 515                         }
 516                         end++;
 517                 } else
 518                         end = host;
 519         } else
 520                 end = host;
 521
 522         path = strchr(end, c);
 523         if (path && !has_dos_drive_prefix(end)) {
 524                 if (c == ':') {
 525                         protocol = PROTO_SSH;
 526                         *path++ = '\0';
 527                 }
 528         } else
 529                 path = end;
 530
 531         if (!path || !*path)
 532                 die("No path specified. See 'man git-pull' for valid url syntax");
 533
 534         /*
 535          * null-terminate hostname and point path to ~ for URL's like this:
 536          *    ssh://host.xz/~user/repo
 537          */
 538         if (protocol != PROTO_LOCAL && host != url) {
 539                 char *ptr = path;
 540                 if (path[1] == '~')
 541                         path++;
 542                 else {
 543                         path = xstrdup(ptr);
 544                         free_path = 1;
 545                 }
 546
 547                 *ptr = '\0';
 548         }
 549
 550         /*
 551          * Add support for ssh port: ssh://host.xy:<port>/...
 552          */
 553         if (protocol == PROTO_SSH && host != url)
 554                 port = get_port(host);
 555
 556         if (protocol == PROTO_GIT) {
 557                 /* These underlying connection commands die() if they
 558                  * cannot connect.
 559                  */
 560                 char *target_host = xstrdup(host);
 561                 if (git_use_proxy(host))
 562                         git_proxy_connect(fd, host);
 563                 else
 564                         git_tcp_connect(fd, host, flags);
 565                 /*
 566                  * Separate original protocol components prog and path
 567                  * from extended host header with a NUL byte.
 568                  *
 569                  * Note: Do not add any other headers here!  Doing so
 570                  * will cause older git-daemon servers to crash.
 571                  */
 572                 packet_write(fd[1],
 573                              "%s %s%chost=%s%c",
 574                              prog, path, 0,
 575                              target_host, 0);
 576                 free(target_host);
 577                 free(url);
 578                 if (free_path)
 579                         free(path);
 580                 return &no_fork;
 581         }
 582
 583         conn = xcalloc(1, sizeof(*conn));
 584
 585         strbuf_init(&cmd, MAX_CMD_LEN);
 586         strbuf_addstr(&cmd, prog);
 587         strbuf_addch(&cmd, ' ');
 588         sq_quote_buf(&cmd, path);
 589         if (cmd.len >= MAX_CMD_LEN)
 590                 die("command line too long");
 591
 592         conn->in = conn->out = -1;
 593         conn->argv = arg = xcalloc(7, sizeof(*arg));
 594         if (protocol == PROTO_SSH) {
 595                 const char *ssh = getenv("GIT_SSH");
 596                 int putty = ssh && strcasestr(ssh, "plink");
 597                 if (!ssh) ssh = "ssh";
 598
 599                 *arg++ = ssh;
 600                 if (putty && !strcasestr(ssh, "tortoiseplink"))
 601                         *arg++ = "-batch";
 602                 if (port) {
 603                         /* P is for PuTTY, p is for OpenSSH */
 604                         *arg++ = putty ? "-P" : "-p";
 605                         *arg++ = port;
 606                 }
 607                 *arg++ = host;
 608         }
 609         else {
 610                 /* remove these from the environment */
 611                 const char *env[] = {
 612                         ALTERNATE_DB_ENVIRONMENT,
 613                         DB_ENVIRONMENT,
 614                         GIT_DIR_ENVIRONMENT,
 615                         GIT_WORK_TREE_ENVIRONMENT,
 616                         GRAFT_ENVIRONMENT,
 617                         INDEX_ENVIRONMENT,
 618                         NO_REPLACE_OBJECTS_ENVIRONMENT,
 619                         NULL
 620                 };
 621                 conn->env = env;
 622                 conn->use_shell = 1;
 623         }
 624         *arg++ = cmd.buf;
 625         *arg = NULL;
 626
 627         if (start_command(conn))
 628                 die("unable to fork");
 629
 630         fd[0] = conn->out; /* read from child's stdout */
 631         fd[1] = conn->in;  /* write to child's stdin */
 632         strbuf_release(&cmd);
 633         free(url);
 634         if (free_path)
 635                 free(path);
 636         return conn;
 637 }
 638
 639 int finish_connect(struct child_process *conn)
 640 {
 641         int code;
 642         if (!conn || conn == &no_fork)
 643                 return 0;
 644
 645         code = finish_command(conn);
 646         free(conn->argv);
 647         free(conn);
 648         return code;
 649 }