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