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