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 < 42 || get_sha1_hex(buffer, old_sha1) || buffer[40] != ' ')
  74                         die("protocol error: expected sha/ref, got '%s'", buffer);
  75                 name = buffer + 41;
  76
  77                 name_len = strlen(name);
  78                 if (len != name_len + 41) {
  79                         free(server_capabilities);
  80                         server_capabilities = xstrdup(name + name_len + 1);
  81                 }
  82
  83                 if (extra_have &&
  84                     name_len == 5 && !memcmp(".have", name, 5)) {
  85                         add_extra_have(extra_have, old_sha1);
  86                         continue;
  87                 }
  88
  89                 if (!check_ref(name, name_len, flags))
  90                         continue;
  91                 if (nr_match && !path_match(name, nr_match, match))
  92                         continue;
  93                 ref = alloc_ref(name_len + 1);
  94                 hashcpy(ref->old_sha1, old_sha1);
  95                 memcpy(ref->name, buffer + 41, name_len + 1);
  96                 *list = ref;
  97                 list = &ref->next;
  98         }
  99         return list;
 100 }
 101
 102 int server_supports(const char *feature)
 103 {
 104         return server_capabilities &&
 105                 strstr(server_capabilities, feature) != NULL;
 106 }
 107
 108 int get_ack(int fd, unsigned char *result_sha1)
 109 {
 110         static char line[1000];
 111         int len = packet_read_line(fd, line, sizeof(line));
 112
 113         if (!len)
 114                 die("git fetch-pack: expected ACK/NAK, got EOF");
 115         if (line[len-1] == '\n')
 116                 line[--len] = 0;
 117         if (!strcmp(line, "NAK"))
 118                 return 0;
 119         if (!prefixcmp(line, "ACK ")) {
 120                 if (!get_sha1_hex(line+4, result_sha1)) {
 121                         if (strstr(line+45, "continue"))
 122                                 return 2;
 123                         return 1;
 124                 }
 125         }
 126         die("git fetch_pack: expected ACK/NAK, got '%s'", line);
 127 }
 128
 129 int path_match(const char *path, int nr, char **match)
 130 {
 131         int i;
 132         int pathlen = strlen(path);
 133
 134         for (i = 0; i < nr; i++) {
 135                 char *s = match[i];
 136                 int len = strlen(s);
 137
 138                 if (!len || len > pathlen)
 139                         continue;
 140                 if (memcmp(path + pathlen - len, s, len))
 141                         continue;
 142                 if (pathlen > len && path[pathlen - len - 1] != '/')
 143                         continue;
 144                 *s = 0;
 145                 return (i + 1);
 146         }
 147         return 0;
 148 }
 149
 150 enum protocol {
 151         PROTO_LOCAL = 1,
 152         PROTO_SSH,
 153         PROTO_GIT,
 154 };
 155
 156 static enum protocol get_protocol(const char *name)
 157 {
 158         if (!strcmp(name, "ssh"))
 159                 return PROTO_SSH;
 160         if (!strcmp(name, "git"))
 161                 return PROTO_GIT;
 162         if (!strcmp(name, "git+ssh"))
 163                 return PROTO_SSH;
 164         if (!strcmp(name, "ssh+git"))
 165                 return PROTO_SSH;
 166         if (!strcmp(name, "file"))
 167                 return PROTO_LOCAL;
 168         die("I don't handle protocol '%s'", name);
 169 }
 170
 171 #define STR_(s) # s
 172 #define STR(s)  STR_(s)
 173
 174 #ifndef NO_IPV6
 175
 176 static const char *ai_name(const struct addrinfo *ai)
 177 {
 178         static char addr[INET_ADDRSTRLEN];
 179         if ( AF_INET == ai->ai_family ) {
 180                 struct sockaddr_in *in;
 181                 in = (struct sockaddr_in *)ai->ai_addr;
 182                 inet_ntop(ai->ai_family, &in->sin_addr, addr, sizeof(addr));
 183         } else if ( AF_INET6 == ai->ai_family ) {
 184                 struct sockaddr_in6 *in;
 185                 in = (struct sockaddr_in6 *)ai->ai_addr;
 186                 inet_ntop(ai->ai_family, &in->sin6_addr, addr, sizeof(addr));
 187         } else {
 188                 strcpy(addr, "(unknown)");
 189         }
 190         return addr;
 191 }
 192
 193 /*
 194  * Returns a connected socket() fd, or else die()s.
 195  */
 196 static int git_tcp_connect_sock(char *host, int flags)
 197 {
 198         int sockfd = -1, saved_errno = 0;
 199         char *colon, *end;
 200         const char *port = STR(DEFAULT_GIT_PORT);
 201         struct addrinfo hints, *ai0, *ai;
 202         int gai;
 203         int cnt = 0;
 204
 205         if (host[0] == '[') {
 206                 end = strchr(host + 1, ']');
 207                 if (end) {
 208                         *end = 0;
 209                         end++;
 210                         host++;
 211                 } else
 212                         end = host;
 213         } else
 214                 end = host;
 215         colon = strchr(end, ':');
 216
 217         if (colon) {
 218                 *colon = 0;
 219                 port = colon + 1;
 220                 if (!*port)
 221                         port = "<none>";
 222         }
 223
 224         memset(&hints, 0, sizeof(hints));
 225         hints.ai_socktype = SOCK_STREAM;
 226         hints.ai_protocol = IPPROTO_TCP;
 227
 228         if (flags & CONNECT_VERBOSE)
 229                 fprintf(stderr, "Looking up %s ... ", host);
 230
 231         gai = getaddrinfo(host, port, &hints, &ai);
 232         if (gai)
 233                 die("Unable to look up %s (port %s) (%s)", host, port, gai_strerror(gai));
 234
 235         if (flags & CONNECT_VERBOSE)
 236                 fprintf(stderr, "done.\nConnecting to %s (port %s) ... ", host, port);
 237
 238         for (ai0 = ai; ai; ai = ai->ai_next) {
 239                 sockfd = socket(ai->ai_family,
 240                                 ai->ai_socktype, ai->ai_protocol);
 241                 if (sockfd < 0) {
 242                         saved_errno = errno;
 243                         continue;
 244                 }
 245                 if (connect(sockfd, ai->ai_addr, ai->ai_addrlen) < 0) {
 246                         saved_errno = errno;
 247                         fprintf(stderr, "%s[%d: %s]: errno=%s\n",
 248                                 host,
 249                                 cnt,
 250                                 ai_name(ai),
 251                                 strerror(saved_errno));
 252                         close(sockfd);
 253                         sockfd = -1;
 254                         continue;
 255                 }
 256                 if (flags & CONNECT_VERBOSE)
 257                         fprintf(stderr, "%s ", ai_name(ai));
 258                 break;
 259         }
 260
 261         freeaddrinfo(ai0);
 262
 263         if (sockfd < 0)
 264                 die("unable to connect a socket (%s)", strerror(saved_errno));
 265
 266         if (flags & CONNECT_VERBOSE)
 267                 fprintf(stderr, "done.\n");
 268
 269         return sockfd;
 270 }
 271
 272 #else /* NO_IPV6 */
 273
 274 /*
 275  * Returns a connected socket() fd, or else die()s.
 276  */
 277 static int git_tcp_connect_sock(char *host, int flags)
 278 {
 279         int sockfd = -1, saved_errno = 0;
 280         char *colon, *end;
 281         char *port = STR(DEFAULT_GIT_PORT), *ep;
 282         struct hostent *he;
 283         struct sockaddr_in sa;
 284         char **ap;
 285         unsigned int nport;
 286         int cnt;
 287
 288         if (host[0] == '[') {
 289                 end = strchr(host + 1, ']');
 290                 if (end) {
 291                         *end = 0;
 292                         end++;
 293                         host++;
 294                 } else
 295                         end = host;
 296         } else
 297                 end = host;
 298         colon = strchr(end, ':');
 299
 300         if (colon) {
 301                 *colon = 0;
 302                 port = colon + 1;
 303         }
 304
 305         if (flags & CONNECT_VERBOSE)
 306                 fprintf(stderr, "Looking up %s ... ", host);
 307
 308         he = gethostbyname(host);
 309         if (!he)
 310                 die("Unable to look up %s (%s)", host, hstrerror(h_errno));
 311         nport = strtoul(port, &ep, 10);
 312         if ( ep == port || *ep ) {
 313                 /* Not numeric */
 314                 struct servent *se = getservbyname(port,"tcp");
 315                 if ( !se )
 316                         die("Unknown port %s\n", port);
 317                 nport = se->s_port;
 318         }
 319
 320         if (flags & CONNECT_VERBOSE)
 321                 fprintf(stderr, "done.\nConnecting to %s (port %s) ... ", host, port);
 322
 323         for (cnt = 0, ap = he->h_addr_list; *ap; ap++, cnt++) {
 324                 sockfd = socket(he->h_addrtype, SOCK_STREAM, 0);
 325                 if (sockfd < 0) {
 326                         saved_errno = errno;
 327                         continue;
 328                 }
 329
 330                 memset(&sa, 0, sizeof sa);
 331                 sa.sin_family = he->h_addrtype;
 332                 sa.sin_port = htons(nport);
 333                 memcpy(&sa.sin_addr, *ap, he->h_length);
 334
 335                 if (connect(sockfd, (struct sockaddr *)&sa, sizeof sa) < 0) {
 336                         saved_errno = errno;
 337                         fprintf(stderr, "%s[%d: %s]: errno=%s\n",
 338                                 host,
 339                                 cnt,
 340                                 inet_ntoa(*(struct in_addr *)&sa.sin_addr),
 341                                 strerror(saved_errno));
 342                         close(sockfd);
 343                         sockfd = -1;
 344                         continue;
 345                 }
 346                 if (flags & CONNECT_VERBOSE)
 347                         fprintf(stderr, "%s ",
 348                                 inet_ntoa(*(struct in_addr *)&sa.sin_addr));
 349                 break;
 350         }
 351
 352         if (sockfd < 0)
 353                 die("unable to connect a socket (%s)", strerror(saved_errno));
 354
 355         if (flags & CONNECT_VERBOSE)
 356                 fprintf(stderr, "done.\n");
 357
 358         return sockfd;
 359 }
 360
 361 #endif /* NO_IPV6 */
 362
 363
 364 static void git_tcp_connect(int fd[2], char *host, int flags)
 365 {
 366         int sockfd = git_tcp_connect_sock(host, flags);
 367
 368         fd[0] = sockfd;
 369         fd[1] = dup(sockfd);
 370 }
 371
 372
 373 static char *git_proxy_command;
 374 static const char *rhost_name;
 375 static int rhost_len;
 376
 377 static int git_proxy_command_options(const char *var, const char *value,
 378                 void *cb)
 379 {
 380         if (!strcmp(var, "core.gitproxy")) {
 381                 const char *for_pos;
 382                 int matchlen = -1;
 383                 int hostlen;
 384
 385                 if (git_proxy_command)
 386                         return 0;
 387                 if (!value)
 388                         return config_error_nonbool(var);
 389                 /* [core]
 390                  * ;# matches www.kernel.org as well
 391                  * gitproxy = netcatter-1 for kernel.org
 392                  * gitproxy = netcatter-2 for sample.xz
 393                  * gitproxy = netcatter-default
 394                  */
 395                 for_pos = strstr(value, " for ");
 396                 if (!for_pos)
 397                         /* matches everybody */
 398                         matchlen = strlen(value);
 399                 else {
 400                         hostlen = strlen(for_pos + 5);
 401                         if (rhost_len < hostlen)
 402                                 matchlen = -1;
 403                         else if (!strncmp(for_pos + 5,
 404                                           rhost_name + rhost_len - hostlen,
 405                                           hostlen) &&
 406                                  ((rhost_len == hostlen) ||
 407                                   rhost_name[rhost_len - hostlen -1] == '.'))
 408                                 matchlen = for_pos - value;
 409                         else
 410                                 matchlen = -1;
 411                 }
 412                 if (0 <= matchlen) {
 413                         /* core.gitproxy = none for kernel.org */
 414                         if (matchlen == 4 &&
 415                             !memcmp(value, "none", 4))
 416                                 matchlen = 0;
 417                         git_proxy_command = xmemdupz(value, matchlen);
 418                 }
 419                 return 0;
 420         }
 421
 422         return git_default_config(var, value, cb);
 423 }
 424
 425 static int git_use_proxy(const char *host)
 426 {
 427         rhost_name = host;
 428         rhost_len = strlen(host);
 429         git_proxy_command = getenv("GIT_PROXY_COMMAND");
 430         git_config(git_proxy_command_options, NULL);
 431         rhost_name = NULL;
 432         return (git_proxy_command && *git_proxy_command);
 433 }
 434
 435 static void git_proxy_connect(int fd[2], char *host)
 436 {
 437         const char *port = STR(DEFAULT_GIT_PORT);
 438         char *colon, *end;
 439         const char *argv[4];
 440         struct child_process proxy;
 441
 442         if (host[0] == '[') {
 443                 end = strchr(host + 1, ']');
 444                 if (end) {
 445                         *end = 0;
 446                         end++;
 447                         host++;
 448                 } else
 449                         end = host;
 450         } else
 451                 end = host;
 452         colon = strchr(end, ':');
 453
 454         if (colon) {
 455                 *colon = 0;
 456                 port = colon + 1;
 457         }
 458
 459         argv[0] = git_proxy_command;
 460         argv[1] = host;
 461         argv[2] = port;
 462         argv[3] = NULL;
 463         memset(&proxy, 0, sizeof(proxy));
 464         proxy.argv = argv;
 465         proxy.in = -1;
 466         proxy.out = -1;
 467         if (start_command(&proxy))
 468                 die("cannot start proxy %s", argv[0]);
 469         fd[0] = proxy.out; /* read from proxy stdout */
 470         fd[1] = proxy.in;  /* write to proxy stdin */
 471 }
 472
 473 #define MAX_CMD_LEN 1024
 474
 475 char *get_port(char *host)
 476 {
 477         char *end;
 478         char *p = strchr(host, ':');
 479
 480         if (p) {
 481                 strtol(p+1, &end, 10);
 482                 if (*end == '\0') {
 483                         *p = '\0';
 484                         return p+1;
 485                 }
 486         }
 487
 488         return NULL;
 489 }
 490
 491 static struct child_process no_fork;
 492
 493 /*
 494  * This returns a dummy child_process if the transport protocol does not
 495  * need fork(2), or a struct child_process object if it does.  Once done,
 496  * finish the connection with finish_connect() with the value returned from
 497  * this function (it is safe to call finish_connect() with NULL to support
 498  * the former case).
 499  *
 500  * If it returns, the connect is successful; it just dies on errors (this
 501  * will hopefully be changed in a libification effort, to return NULL when
 502  * the connection failed).
 503  */
 504 struct child_process *git_connect(int fd[2], const char *url_orig,
 505                                   const char *prog, int flags)
 506 {
 507         char *url = xstrdup(url_orig);
 508         char *host, *path = url;
 509         char *end;
 510         int c;
 511         struct child_process *conn;
 512         enum protocol protocol = PROTO_LOCAL;
 513         int free_path = 0;
 514         char *port = NULL;
 515         const char **arg;
 516         struct strbuf cmd;
 517
 518         /* Without this we cannot rely on waitpid() to tell
 519          * what happened to our children.
 520          */
 521         signal(SIGCHLD, SIG_DFL);
 522
 523         host = strstr(url, "://");
 524         if(host) {
 525                 *host = '\0';
 526                 protocol = get_protocol(url);
 527                 host += 3;
 528                 c = '/';
 529         } else {
 530                 host = url;
 531                 c = ':';
 532         }
 533
 534         if (host[0] == '[') {
 535                 end = strchr(host + 1, ']');
 536                 if (end) {
 537                         *end = 0;
 538                         end++;
 539                         host++;
 540                 } else
 541                         end = host;
 542         } else
 543                 end = host;
 544
 545         path = strchr(end, c);
 546         if (path && !has_dos_drive_prefix(end)) {
 547                 if (c == ':') {
 548                         protocol = PROTO_SSH;
 549                         *path++ = '\0';
 550                 }
 551         } else
 552                 path = end;
 553
 554         if (!path || !*path)
 555                 die("No path specified. See 'man git-pull' for valid url syntax");
 556
 557         /*
 558          * null-terminate hostname and point path to ~ for URL's like this:
 559          *    ssh://host.xz/~user/repo
 560          */
 561         if (protocol != PROTO_LOCAL && host != url) {
 562                 char *ptr = path;
 563                 if (path[1] == '~')
 564                         path++;
 565                 else {
 566                         path = xstrdup(ptr);
 567                         free_path = 1;
 568                 }
 569
 570                 *ptr = '\0';
 571         }
 572
 573         /*
 574          * Add support for ssh port: ssh://host.xy:<port>/...
 575          */
 576         if (protocol == PROTO_SSH && host != url)
 577                 port = get_port(host);
 578
 579         if (protocol == PROTO_GIT) {
 580                 /* These underlying connection commands die() if they
 581                  * cannot connect.
 582                  */
 583                 char *target_host = xstrdup(host);
 584                 if (git_use_proxy(host))
 585                         git_proxy_connect(fd, host);
 586                 else
 587                         git_tcp_connect(fd, host, flags);
 588                 /*
 589                  * Separate original protocol components prog and path
 590                  * from extended components with a NUL byte.
 591                  */
 592                 packet_write(fd[1],
 593                              "%s %s%chost=%s%c",
 594                              prog, path, 0,
 595                              target_host, 0);
 596                 free(target_host);
 597                 free(url);
 598                 if (free_path)
 599                         free(path);
 600                 return &no_fork;
 601         }
 602
 603         conn = xcalloc(1, sizeof(*conn));
 604
 605         strbuf_init(&cmd, MAX_CMD_LEN);
 606         strbuf_addstr(&cmd, prog);
 607         strbuf_addch(&cmd, ' ');
 608         sq_quote_buf(&cmd, path);
 609         if (cmd.len >= MAX_CMD_LEN)
 610                 die("command line too long");
 611
 612         conn->in = conn->out = -1;
 613         conn->argv = arg = xcalloc(6, sizeof(*arg));
 614         if (protocol == PROTO_SSH) {
 615                 const char *ssh = getenv("GIT_SSH");
 616                 if (!ssh) ssh = "ssh";
 617
 618                 *arg++ = ssh;
 619                 if (port) {
 620                         *arg++ = "-p";
 621                         *arg++ = port;
 622                 }
 623                 *arg++ = host;
 624         }
 625         else {
 626                 /* remove these from the environment */
 627                 const char *env[] = {
 628                         ALTERNATE_DB_ENVIRONMENT,
 629                         DB_ENVIRONMENT,
 630                         GIT_DIR_ENVIRONMENT,
 631                         GIT_WORK_TREE_ENVIRONMENT,
 632                         GRAFT_ENVIRONMENT,
 633                         INDEX_ENVIRONMENT,
 634                         NULL
 635                 };
 636                 conn->env = env;
 637                 *arg++ = "sh";
 638                 *arg++ = "-c";
 639         }
 640         *arg++ = cmd.buf;
 641         *arg = NULL;
 642
 643         if (start_command(conn))
 644                 die("unable to fork");
 645
 646         fd[0] = conn->out; /* read from child's stdout */
 647         fd[1] = conn->in;  /* write to child's stdin */
 648         strbuf_release(&cmd);
 649         free(url);
 650         if (free_path)
 651                 free(path);
 652         return conn;
 653 }
 654
 655 int finish_connect(struct child_process *conn)
 656 {
 657         int code;
 658         if (!conn || conn == &no_fork)
 659                 return 0;
 660
 661         code = finish_command(conn);
 662         free(conn->argv);
 663         free(conn);
 664         return code;
 665 }