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 get_ack(int fd, unsigned char *result_sha1)
 111 {
 112         static char line[1000];
 113         int len = packet_read_line(fd, line, sizeof(line));
 114
 115         if (!len)
 116                 die("git fetch-pack: expected ACK/NAK, got EOF");
 117         if (line[len-1] == '\n')
 118                 line[--len] = 0;
 119         if (!strcmp(line, "NAK"))
 120                 return 0;
 121         if (!prefixcmp(line, "ACK ")) {
 122                 if (!get_sha1_hex(line+4, result_sha1)) {
 123                         if (strstr(line+45, "continue"))
 124                                 return 2;
 125                         return 1;
 126                 }
 127         }
 128         die("git fetch_pack: expected ACK/NAK, got '%s'", line);
 129 }
 130
 131 int path_match(const char *path, int nr, char **match)
 132 {
 133         int i;
 134         int pathlen = strlen(path);
 135
 136         for (i = 0; i < nr; i++) {
 137                 char *s = match[i];
 138                 int len = strlen(s);
 139
 140                 if (!len || len > pathlen)
 141                         continue;
 142                 if (memcmp(path + pathlen - len, s, len))
 143                         continue;
 144                 if (pathlen > len && path[pathlen - len - 1] != '/')
 145                         continue;
 146                 *s = 0;
 147                 return (i + 1);
 148         }
 149         return 0;
 150 }
 151
 152 enum protocol {
 153         PROTO_LOCAL = 1,
 154         PROTO_SSH,
 155         PROTO_GIT,
 156 };
 157
 158 static enum protocol get_protocol(const char *name)
 159 {
 160         if (!strcmp(name, "ssh"))
 161                 return PROTO_SSH;
 162         if (!strcmp(name, "git"))
 163                 return PROTO_GIT;
 164         if (!strcmp(name, "git+ssh"))
 165                 return PROTO_SSH;
 166         if (!strcmp(name, "ssh+git"))
 167                 return PROTO_SSH;
 168         if (!strcmp(name, "file"))
 169                 return PROTO_LOCAL;
 170         die("I don't handle protocol '%s'", name);
 171 }
 172
 173 #define STR_(s) # s
 174 #define STR(s)  STR_(s)
 175
 176 #ifndef NO_IPV6
 177
 178 static const char *ai_name(const struct addrinfo *ai)
 179 {
 180         static char addr[INET_ADDRSTRLEN];
 181         if ( AF_INET == ai->ai_family ) {
 182                 struct sockaddr_in *in;
 183                 in = (struct sockaddr_in *)ai->ai_addr;
 184                 inet_ntop(ai->ai_family, &in->sin_addr, addr, sizeof(addr));
 185         } else if ( AF_INET6 == ai->ai_family ) {
 186                 struct sockaddr_in6 *in;
 187                 in = (struct sockaddr_in6 *)ai->ai_addr;
 188                 inet_ntop(ai->ai_family, &in->sin6_addr, addr, sizeof(addr));
 189         } else {
 190                 strcpy(addr, "(unknown)");
 191         }
 192         return addr;
 193 }
 194
 195 /*
 196  * Returns a connected socket() fd, or else die()s.
 197  */
 198 static int git_tcp_connect_sock(char *host, int flags)
 199 {
 200         int sockfd = -1, saved_errno = 0;
 201         char *colon, *end;
 202         const char *port = STR(DEFAULT_GIT_PORT);
 203         struct addrinfo hints, *ai0, *ai;
 204         int gai;
 205         int cnt = 0;
 206
 207         if (host[0] == '[') {
 208                 end = strchr(host + 1, ']');
 209                 if (end) {
 210                         *end = 0;
 211                         end++;
 212                         host++;
 213                 } else
 214                         end = host;
 215         } else
 216                 end = host;
 217         colon = strchr(end, ':');
 218
 219         if (colon) {
 220                 *colon = 0;
 221                 port = colon + 1;
 222                 if (!*port)
 223                         port = "<none>";
 224         }
 225
 226         memset(&hints, 0, sizeof(hints));
 227         hints.ai_socktype = SOCK_STREAM;
 228         hints.ai_protocol = IPPROTO_TCP;
 229
 230         if (flags & CONNECT_VERBOSE)
 231                 fprintf(stderr, "Looking up %s ... ", host);
 232
 233         gai = getaddrinfo(host, port, &hints, &ai);
 234         if (gai)
 235                 die("Unable to look up %s (port %s) (%s)", host, port, gai_strerror(gai));
 236
 237         if (flags & CONNECT_VERBOSE)
 238                 fprintf(stderr, "done.\nConnecting to %s (port %s) ... ", host, port);
 239
 240         for (ai0 = ai; ai; ai = ai->ai_next) {
 241                 sockfd = socket(ai->ai_family,
 242                                 ai->ai_socktype, ai->ai_protocol);
 243                 if (sockfd < 0) {
 244                         saved_errno = errno;
 245                         continue;
 246                 }
 247                 if (connect(sockfd, ai->ai_addr, ai->ai_addrlen) < 0) {
 248                         saved_errno = errno;
 249                         fprintf(stderr, "%s[%d: %s]: errno=%s\n",
 250                                 host,
 251                                 cnt,
 252                                 ai_name(ai),
 253                                 strerror(saved_errno));
 254                         close(sockfd);
 255                         sockfd = -1;
 256                         continue;
 257                 }
 258                 if (flags & CONNECT_VERBOSE)
 259                         fprintf(stderr, "%s ", ai_name(ai));
 260                 break;
 261         }
 262
 263         freeaddrinfo(ai0);
 264
 265         if (sockfd < 0)
 266                 die("unable to connect a socket (%s)", strerror(saved_errno));
 267
 268         if (flags & CONNECT_VERBOSE)
 269                 fprintf(stderr, "done.\n");
 270
 271         return sockfd;
 272 }
 273
 274 #else /* NO_IPV6 */
 275
 276 /*
 277  * Returns a connected socket() fd, or else die()s.
 278  */
 279 static int git_tcp_connect_sock(char *host, int flags)
 280 {
 281         int sockfd = -1, saved_errno = 0;
 282         char *colon, *end;
 283         char *port = STR(DEFAULT_GIT_PORT), *ep;
 284         struct hostent *he;
 285         struct sockaddr_in sa;
 286         char **ap;
 287         unsigned int nport;
 288         int cnt;
 289
 290         if (host[0] == '[') {
 291                 end = strchr(host + 1, ']');
 292                 if (end) {
 293                         *end = 0;
 294                         end++;
 295                         host++;
 296                 } else
 297                         end = host;
 298         } else
 299                 end = host;
 300         colon = strchr(end, ':');
 301
 302         if (colon) {
 303                 *colon = 0;
 304                 port = colon + 1;
 305         }
 306
 307         if (flags & CONNECT_VERBOSE)
 308                 fprintf(stderr, "Looking up %s ... ", host);
 309
 310         he = gethostbyname(host);
 311         if (!he)
 312                 die("Unable to look up %s (%s)", host, hstrerror(h_errno));
 313         nport = strtoul(port, &ep, 10);
 314         if ( ep == port || *ep ) {
 315                 /* Not numeric */
 316                 struct servent *se = getservbyname(port,"tcp");
 317                 if ( !se )
 318                         die("Unknown port %s\n", port);
 319                 nport = se->s_port;
 320         }
 321
 322         if (flags & CONNECT_VERBOSE)
 323                 fprintf(stderr, "done.\nConnecting to %s (port %s) ... ", host, port);
 324
 325         for (cnt = 0, ap = he->h_addr_list; *ap; ap++, cnt++) {
 326                 sockfd = socket(he->h_addrtype, SOCK_STREAM, 0);
 327                 if (sockfd < 0) {
 328                         saved_errno = errno;
 329                         continue;
 330                 }
 331
 332                 memset(&sa, 0, sizeof sa);
 333                 sa.sin_family = he->h_addrtype;
 334                 sa.sin_port = htons(nport);
 335                 memcpy(&sa.sin_addr, *ap, he->h_length);
 336
 337                 if (connect(sockfd, (struct sockaddr *)&sa, sizeof sa) < 0) {
 338                         saved_errno = errno;
 339                         fprintf(stderr, "%s[%d: %s]: errno=%s\n",
 340                                 host,
 341                                 cnt,
 342                                 inet_ntoa(*(struct in_addr *)&sa.sin_addr),
 343                                 strerror(saved_errno));
 344                         close(sockfd);
 345                         sockfd = -1;
 346                         continue;
 347                 }
 348                 if (flags & CONNECT_VERBOSE)
 349                         fprintf(stderr, "%s ",
 350                                 inet_ntoa(*(struct in_addr *)&sa.sin_addr));
 351                 break;
 352         }
 353
 354         if (sockfd < 0)
 355                 die("unable to connect a socket (%s)", strerror(saved_errno));
 356
 357         if (flags & CONNECT_VERBOSE)
 358                 fprintf(stderr, "done.\n");
 359
 360         return sockfd;
 361 }
 362
 363 #endif /* NO_IPV6 */
 364
 365
 366 static void git_tcp_connect(int fd[2], char *host, int flags)
 367 {
 368         int sockfd = git_tcp_connect_sock(host, flags);
 369
 370         fd[0] = sockfd;
 371         fd[1] = dup(sockfd);
 372 }
 373
 374
 375 static char *git_proxy_command;
 376 static const char *rhost_name;
 377 static int rhost_len;
 378
 379 static int git_proxy_command_options(const char *var, const char *value,
 380                 void *cb)
 381 {
 382         if (!strcmp(var, "core.gitproxy")) {
 383                 const char *for_pos;
 384                 int matchlen = -1;
 385                 int hostlen;
 386
 387                 if (git_proxy_command)
 388                         return 0;
 389                 if (!value)
 390                         return config_error_nonbool(var);
 391                 /* [core]
 392                  * ;# matches www.kernel.org as well
 393                  * gitproxy = netcatter-1 for kernel.org
 394                  * gitproxy = netcatter-2 for sample.xz
 395                  * gitproxy = netcatter-default
 396                  */
 397                 for_pos = strstr(value, " for ");
 398                 if (!for_pos)
 399                         /* matches everybody */
 400                         matchlen = strlen(value);
 401                 else {
 402                         hostlen = strlen(for_pos + 5);
 403                         if (rhost_len < hostlen)
 404                                 matchlen = -1;
 405                         else if (!strncmp(for_pos + 5,
 406                                           rhost_name + rhost_len - hostlen,
 407                                           hostlen) &&
 408                                  ((rhost_len == hostlen) ||
 409                                   rhost_name[rhost_len - hostlen -1] == '.'))
 410                                 matchlen = for_pos - value;
 411                         else
 412                                 matchlen = -1;
 413                 }
 414                 if (0 <= matchlen) {
 415                         /* core.gitproxy = none for kernel.org */
 416                         if (matchlen == 4 &&
 417                             !memcmp(value, "none", 4))
 418                                 matchlen = 0;
 419                         git_proxy_command = xmemdupz(value, matchlen);
 420                 }
 421                 return 0;
 422         }
 423
 424         return git_default_config(var, value, cb);
 425 }
 426
 427 static int git_use_proxy(const char *host)
 428 {
 429         rhost_name = host;
 430         rhost_len = strlen(host);
 431         git_proxy_command = getenv("GIT_PROXY_COMMAND");
 432         git_config(git_proxy_command_options, NULL);
 433         rhost_name = NULL;
 434         return (git_proxy_command && *git_proxy_command);
 435 }
 436
 437 static void git_proxy_connect(int fd[2], char *host)
 438 {
 439         const char *port = STR(DEFAULT_GIT_PORT);
 440         char *colon, *end;
 441         const char *argv[4];
 442         struct child_process proxy;
 443
 444         if (host[0] == '[') {
 445                 end = strchr(host + 1, ']');
 446                 if (end) {
 447                         *end = 0;
 448                         end++;
 449                         host++;
 450                 } else
 451                         end = host;
 452         } else
 453                 end = host;
 454         colon = strchr(end, ':');
 455
 456         if (colon) {
 457                 *colon = 0;
 458                 port = colon + 1;
 459         }
 460
 461         argv[0] = git_proxy_command;
 462         argv[1] = host;
 463         argv[2] = port;
 464         argv[3] = NULL;
 465         memset(&proxy, 0, sizeof(proxy));
 466         proxy.argv = argv;
 467         proxy.in = -1;
 468         proxy.out = -1;
 469         if (start_command(&proxy))
 470                 die("cannot start proxy %s", argv[0]);
 471         fd[0] = proxy.out; /* read from proxy stdout */
 472         fd[1] = proxy.in;  /* write to proxy stdin */
 473 }
 474
 475 #define MAX_CMD_LEN 1024
 476
 477 char *get_port(char *host)
 478 {
 479         char *end;
 480         char *p = strchr(host, ':');
 481
 482         if (p) {
 483                 long port = strtol(p + 1, &end, 10);
 484                 if (end != p + 1 && *end == '\0' && 0 <= port && port < 65536) {
 485                         *p = '\0';
 486                         return p+1;
 487                 }
 488         }
 489
 490         return NULL;
 491 }
 492
 493 static struct child_process no_fork;
 494
 495 /*
 496  * This returns a dummy child_process if the transport protocol does not
 497  * need fork(2), or a struct child_process object if it does.  Once done,
 498  * finish the connection with finish_connect() with the value returned from
 499  * this function (it is safe to call finish_connect() with NULL to support
 500  * the former case).
 501  *
 502  * If it returns, the connect is successful; it just dies on errors (this
 503  * will hopefully be changed in a libification effort, to return NULL when
 504  * the connection failed).
 505  */
 506 struct child_process *git_connect(int fd[2], const char *url_orig,
 507                                   const char *prog, int flags)
 508 {
 509         char *url = xstrdup(url_orig);
 510         char *host, *path = url;
 511         char *end;
 512         int c;
 513         struct child_process *conn;
 514         enum protocol protocol = PROTO_LOCAL;
 515         int free_path = 0;
 516         char *port = NULL;
 517         const char **arg;
 518         struct strbuf cmd;
 519
 520         /* Without this we cannot rely on waitpid() to tell
 521          * what happened to our children.
 522          */
 523         signal(SIGCHLD, SIG_DFL);
 524
 525         host = strstr(url, "://");
 526         if(host) {
 527                 *host = '\0';
 528                 protocol = get_protocol(url);
 529                 host += 3;
 530                 c = '/';
 531         } else {
 532                 host = url;
 533                 c = ':';
 534         }
 535
 536         if (host[0] == '[') {
 537                 end = strchr(host + 1, ']');
 538                 if (end) {
 539                         *end = 0;
 540                         end++;
 541                         host++;
 542                 } else
 543                         end = host;
 544         } else
 545                 end = host;
 546
 547         path = strchr(end, c);
 548         if (path && !has_dos_drive_prefix(end)) {
 549                 if (c == ':') {
 550                         protocol = PROTO_SSH;
 551                         *path++ = '\0';
 552                 }
 553         } else
 554                 path = end;
 555
 556         if (!path || !*path)
 557                 die("No path specified. See 'man git-pull' for valid url syntax");
 558
 559         /*
 560          * null-terminate hostname and point path to ~ for URL's like this:
 561          *    ssh://host.xz/~user/repo
 562          */
 563         if (protocol != PROTO_LOCAL && host != url) {
 564                 char *ptr = path;
 565                 if (path[1] == '~')
 566                         path++;
 567                 else {
 568                         path = xstrdup(ptr);
 569                         free_path = 1;
 570                 }
 571
 572                 *ptr = '\0';
 573         }
 574
 575         /*
 576          * Add support for ssh port: ssh://host.xy:<port>/...
 577          */
 578         if (protocol == PROTO_SSH && host != url)
 579                 port = get_port(host);
 580
 581         if (protocol == PROTO_GIT) {
 582                 /* These underlying connection commands die() if they
 583                  * cannot connect.
 584                  */
 585                 char *target_host = xstrdup(host);
 586                 if (git_use_proxy(host))
 587                         git_proxy_connect(fd, host);
 588                 else
 589                         git_tcp_connect(fd, host, flags);
 590                 /*
 591                  * Separate original protocol components prog and path
 592                  * from extended components with a NUL byte.
 593                  */
 594                 packet_write(fd[1],
 595                              "%s %s%chost=%s%c",
 596                              prog, path, 0,
 597                              target_host, 0);
 598                 free(target_host);
 599                 free(url);
 600                 if (free_path)
 601                         free(path);
 602                 return &no_fork;
 603         }
 604
 605         conn = xcalloc(1, sizeof(*conn));
 606
 607         strbuf_init(&cmd, MAX_CMD_LEN);
 608         strbuf_addstr(&cmd, prog);
 609         strbuf_addch(&cmd, ' ');
 610         sq_quote_buf(&cmd, path);
 611         if (cmd.len >= MAX_CMD_LEN)
 612                 die("command line too long");
 613
 614         conn->in = conn->out = -1;
 615         conn->argv = arg = xcalloc(6, sizeof(*arg));
 616         if (protocol == PROTO_SSH) {
 617                 const char *ssh = getenv("GIT_SSH");
 618                 if (!ssh) ssh = "ssh";
 619
 620                 *arg++ = ssh;
 621                 if (port) {
 622                         *arg++ = "-p";
 623                         *arg++ = port;
 624                 }
 625                 *arg++ = host;
 626         }
 627         else {
 628                 /* remove these from the environment */
 629                 const char *env[] = {
 630                         ALTERNATE_DB_ENVIRONMENT,
 631                         DB_ENVIRONMENT,
 632                         GIT_DIR_ENVIRONMENT,
 633                         GIT_WORK_TREE_ENVIRONMENT,
 634                         GRAFT_ENVIRONMENT,
 635                         INDEX_ENVIRONMENT,
 636                         NULL
 637                 };
 638                 conn->env = env;
 639                 *arg++ = "sh";
 640                 *arg++ = "-c";
 641         }
 642         *arg++ = cmd.buf;
 643         *arg = NULL;
 644
 645         if (start_command(conn))
 646                 die("unable to fork");
 647
 648         fd[0] = conn->out; /* read from child's stdout */
 649         fd[1] = conn->in;  /* write to child's stdin */
 650         strbuf_release(&cmd);
 651         free(url);
 652         if (free_path)
 653                 free(path);
 654         return conn;
 655 }
 656
 657 int finish_connect(struct child_process *conn)
 658 {
 659         int code;
 660         if (!conn || conn == &no_fork)
 661                 return 0;
 662
 663         code = finish_command(conn);
 664         free(conn->argv);
 665         free(conn);
 666         return code;
 667 }