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 #include "url.h"
   9
  10 static char *server_capabilities;
  11
  12 static int check_ref(const char *name, int len, unsigned int flags)
  13 {
  14         if (!flags)
  15                 return 1;
  16
  17         if (len < 5 || memcmp(name, "refs/", 5))
  18                 return 0;
  19
  20         /* Skip the "refs/" part */
  21         name += 5;
  22         len -= 5;
  23
  24         /* REF_NORMAL means that we don't want the magic fake tag refs */
  25         if ((flags & REF_NORMAL) && check_refname_format(name, 0))
  26                 return 0;
  27
  28         /* REF_HEADS means that we want regular branch heads */
  29         if ((flags & REF_HEADS) && !memcmp(name, "heads/", 6))
  30                 return 1;
  31
  32         /* REF_TAGS means that we want tags */
  33         if ((flags & REF_TAGS) && !memcmp(name, "tags/", 5))
  34                 return 1;
  35
  36         /* All type bits clear means that we are ok with anything */
  37         return !(flags & ~REF_NORMAL);
  38 }
  39
  40 int check_ref_type(const struct ref *ref, int flags)
  41 {
  42         return check_ref(ref->name, strlen(ref->name), flags);
  43 }
  44
  45 static void add_extra_have(struct extra_have_objects *extra, unsigned char *sha1)
  46 {
  47         ALLOC_GROW(extra->array, extra->nr + 1, extra->alloc);
  48         hashcpy(&(extra->array[extra->nr][0]), sha1);
  49         extra->nr++;
  50 }
  51
  52 /*
  53  * Read all the refs from the other end
  54  */
  55 struct ref **get_remote_heads(int in, struct ref **list,
  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                 ref = alloc_ref(buffer + 41);
  95                 hashcpy(ref->old_sha1, old_sha1);
  96                 *list = ref;
  97                 list = &ref->next;
  98         }
  99         return list;
 100 }
 101
 102 int server_supports(const char *feature)
 103 {
 104         return !!parse_feature_request(server_capabilities, feature);
 105 }
 106
 107 const char *parse_feature_request(const char *feature_list, const char *feature)
 108 {
 109         int len;
 110
 111         if (!feature_list)
 112                 return NULL;
 113
 114         len = strlen(feature);
 115         while (*feature_list) {
 116                 const char *found = strstr(feature_list, feature);
 117                 if (!found)
 118                         return NULL;
 119                 if ((feature_list == found || isspace(found[-1])) &&
 120                     (!found[len] || isspace(found[len]) || found[len] == '='))
 121                         return found;
 122                 feature_list = found + 1;
 123         }
 124         return NULL;
 125 }
 126
 127 enum protocol {
 128         PROTO_LOCAL = 1,
 129         PROTO_SSH,
 130         PROTO_GIT
 131 };
 132
 133 static enum protocol get_protocol(const char *name)
 134 {
 135         if (!strcmp(name, "ssh"))
 136                 return PROTO_SSH;
 137         if (!strcmp(name, "git"))
 138                 return PROTO_GIT;
 139         if (!strcmp(name, "git+ssh"))
 140                 return PROTO_SSH;
 141         if (!strcmp(name, "ssh+git"))
 142                 return PROTO_SSH;
 143         if (!strcmp(name, "file"))
 144                 return PROTO_LOCAL;
 145         die("I don't handle protocol '%s'", name);
 146 }
 147
 148 #define STR_(s) # s
 149 #define STR(s)  STR_(s)
 150
 151 static void get_host_and_port(char **host, const char **port)
 152 {
 153         char *colon, *end;
 154
 155         if (*host[0] == '[') {
 156                 end = strchr(*host + 1, ']');
 157                 if (end) {
 158                         *end = 0;
 159                         end++;
 160                         (*host)++;
 161                 } else
 162                         end = *host;
 163         } else
 164                 end = *host;
 165         colon = strchr(end, ':');
 166
 167         if (colon) {
 168                 *colon = 0;
 169                 *port = colon + 1;
 170         }
 171 }
 172
 173 static void enable_keepalive(int sockfd)
 174 {
 175         int ka = 1;
 176
 177         if (setsockopt(sockfd, SOL_SOCKET, SO_KEEPALIVE, &ka, sizeof(ka)) < 0)
 178                 fprintf(stderr, "unable to set SO_KEEPALIVE on socket: %s\n",
 179                         strerror(errno));
 180 }
 181
 182 #ifndef NO_IPV6
 183
 184 static const char *ai_name(const struct addrinfo *ai)
 185 {
 186         static char addr[NI_MAXHOST];
 187         if (getnameinfo(ai->ai_addr, ai->ai_addrlen, addr, sizeof(addr), NULL, 0,
 188                         NI_NUMERICHOST) != 0)
 189                 strcpy(addr, "(unknown)");
 190
 191         return addr;
 192 }
 193
 194 /*
 195  * Returns a connected socket() fd, or else die()s.
 196  */
 197 static int git_tcp_connect_sock(char *host, int flags)
 198 {
 199         struct strbuf error_message = STRBUF_INIT;
 200         int sockfd = -1;
 201         const char *port = STR(DEFAULT_GIT_PORT);
 202         struct addrinfo hints, *ai0, *ai;
 203         int gai;
 204         int cnt = 0;
 205
 206         get_host_and_port(&host, &port);
 207         if (!*port)
 208                 port = "<none>";
 209
 210         memset(&hints, 0, sizeof(hints));
 211         hints.ai_socktype = SOCK_STREAM;
 212         hints.ai_protocol = IPPROTO_TCP;
 213
 214         if (flags & CONNECT_VERBOSE)
 215                 fprintf(stderr, "Looking up %s ... ", host);
 216
 217         gai = getaddrinfo(host, port, &hints, &ai);
 218         if (gai)
 219                 die("Unable to look up %s (port %s) (%s)", host, port, gai_strerror(gai));
 220
 221         if (flags & CONNECT_VERBOSE)
 222                 fprintf(stderr, "done.\nConnecting to %s (port %s) ... ", host, port);
 223
 224         for (ai0 = ai; ai; ai = ai->ai_next, cnt++) {
 225                 sockfd = socket(ai->ai_family,
 226                                 ai->ai_socktype, ai->ai_protocol);
 227                 if ((sockfd < 0) ||
 228                     (connect(sockfd, ai->ai_addr, ai->ai_addrlen) < 0)) {
 229                         strbuf_addf(&error_message, "%s[%d: %s]: errno=%s\n",
 230                                     host, cnt, ai_name(ai), strerror(errno));
 231                         if (0 <= sockfd)
 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 to %s:\n%s", host, error_message.buf);
 245
 246         enable_keepalive(sockfd);
 247
 248         if (flags & CONNECT_VERBOSE)
 249                 fprintf(stderr, "done.\n");
 250
 251         strbuf_release(&error_message);
 252
 253         return sockfd;
 254 }
 255
 256 #else /* NO_IPV6 */
 257
 258 /*
 259  * Returns a connected socket() fd, or else die()s.
 260  */
 261 static int git_tcp_connect_sock(char *host, int flags)
 262 {
 263         struct strbuf error_message = STRBUF_INIT;
 264         int sockfd = -1;
 265         const char *port = STR(DEFAULT_GIT_PORT);
 266         char *ep;
 267         struct hostent *he;
 268         struct sockaddr_in sa;
 269         char **ap;
 270         unsigned int nport;
 271         int cnt;
 272
 273         get_host_and_port(&host, &port);
 274
 275         if (flags & CONNECT_VERBOSE)
 276                 fprintf(stderr, "Looking up %s ... ", host);
 277
 278         he = gethostbyname(host);
 279         if (!he)
 280                 die("Unable to look up %s (%s)", host, hstrerror(h_errno));
 281         nport = strtoul(port, &ep, 10);
 282         if ( ep == port || *ep ) {
 283                 /* Not numeric */
 284                 struct servent *se = getservbyname(port,"tcp");
 285                 if ( !se )
 286                         die("Unknown port %s", port);
 287                 nport = se->s_port;
 288         }
 289
 290         if (flags & CONNECT_VERBOSE)
 291                 fprintf(stderr, "done.\nConnecting to %s (port %s) ... ", host, port);
 292
 293         for (cnt = 0, ap = he->h_addr_list; *ap; ap++, cnt++) {
 294                 memset(&sa, 0, sizeof sa);
 295                 sa.sin_family = he->h_addrtype;
 296                 sa.sin_port = htons(nport);
 297                 memcpy(&sa.sin_addr, *ap, he->h_length);
 298
 299                 sockfd = socket(he->h_addrtype, SOCK_STREAM, 0);
 300                 if ((sockfd < 0) ||
 301                     connect(sockfd, (struct sockaddr *)&sa, sizeof sa) < 0) {
 302                         strbuf_addf(&error_message, "%s[%d: %s]: errno=%s\n",
 303                                 host,
 304                                 cnt,
 305                                 inet_ntoa(*(struct in_addr *)&sa.sin_addr),
 306                                 strerror(errno));
 307                         if (0 <= sockfd)
 308                                 close(sockfd);
 309                         sockfd = -1;
 310                         continue;
 311                 }
 312                 if (flags & CONNECT_VERBOSE)
 313                         fprintf(stderr, "%s ",
 314                                 inet_ntoa(*(struct in_addr *)&sa.sin_addr));
 315                 break;
 316         }
 317
 318         if (sockfd < 0)
 319                 die("unable to connect to %s:\n%s", host, error_message.buf);
 320
 321         enable_keepalive(sockfd);
 322
 323         if (flags & CONNECT_VERBOSE)
 324                 fprintf(stderr, "done.\n");
 325
 326         return sockfd;
 327 }
 328
 329 #endif /* NO_IPV6 */
 330
 331
 332 static void git_tcp_connect(int fd[2], char *host, int flags)
 333 {
 334         int sockfd = git_tcp_connect_sock(host, flags);
 335
 336         fd[0] = sockfd;
 337         fd[1] = dup(sockfd);
 338 }
 339
 340
 341 static char *git_proxy_command;
 342
 343 static int git_proxy_command_options(const char *var, const char *value,
 344                 void *cb)
 345 {
 346         if (!strcmp(var, "core.gitproxy")) {
 347                 const char *for_pos;
 348                 int matchlen = -1;
 349                 int hostlen;
 350                 const char *rhost_name = cb;
 351                 int rhost_len = strlen(rhost_name);
 352
 353                 if (git_proxy_command)
 354                         return 0;
 355                 if (!value)
 356                         return config_error_nonbool(var);
 357                 /* [core]
 358                  * ;# matches www.kernel.org as well
 359                  * gitproxy = netcatter-1 for kernel.org
 360                  * gitproxy = netcatter-2 for sample.xz
 361                  * gitproxy = netcatter-default
 362                  */
 363                 for_pos = strstr(value, " for ");
 364                 if (!for_pos)
 365                         /* matches everybody */
 366                         matchlen = strlen(value);
 367                 else {
 368                         hostlen = strlen(for_pos + 5);
 369                         if (rhost_len < hostlen)
 370                                 matchlen = -1;
 371                         else if (!strncmp(for_pos + 5,
 372                                           rhost_name + rhost_len - hostlen,
 373                                           hostlen) &&
 374                                  ((rhost_len == hostlen) ||
 375                                   rhost_name[rhost_len - hostlen -1] == '.'))
 376                                 matchlen = for_pos - value;
 377                         else
 378                                 matchlen = -1;
 379                 }
 380                 if (0 <= matchlen) {
 381                         /* core.gitproxy = none for kernel.org */
 382                         if (matchlen == 4 &&
 383                             !memcmp(value, "none", 4))
 384                                 matchlen = 0;
 385                         git_proxy_command = xmemdupz(value, matchlen);
 386                 }
 387                 return 0;
 388         }
 389
 390         return git_default_config(var, value, cb);
 391 }
 392
 393 static int git_use_proxy(const char *host)
 394 {
 395         git_proxy_command = getenv("GIT_PROXY_COMMAND");
 396         git_config(git_proxy_command_options, (void*)host);
 397         return (git_proxy_command && *git_proxy_command);
 398 }
 399
 400 static struct child_process *git_proxy_connect(int fd[2], char *host)
 401 {
 402         const char *port = STR(DEFAULT_GIT_PORT);
 403         const char **argv;
 404         struct child_process *proxy;
 405
 406         get_host_and_port(&host, &port);
 407
 408         argv = xmalloc(sizeof(*argv) * 4);
 409         argv[0] = git_proxy_command;
 410         argv[1] = host;
 411         argv[2] = port;
 412         argv[3] = NULL;
 413         proxy = xcalloc(1, sizeof(*proxy));
 414         proxy->argv = argv;
 415         proxy->in = -1;
 416         proxy->out = -1;
 417         if (start_command(proxy))
 418                 die("cannot start proxy %s", argv[0]);
 419         fd[0] = proxy->out; /* read from proxy stdout */
 420         fd[1] = proxy->in;  /* write to proxy stdin */
 421         return proxy;
 422 }
 423
 424 #define MAX_CMD_LEN 1024
 425
 426 static char *get_port(char *host)
 427 {
 428         char *end;
 429         char *p = strchr(host, ':');
 430
 431         if (p) {
 432                 long port = strtol(p + 1, &end, 10);
 433                 if (end != p + 1 && *end == '\0' && 0 <= port && port < 65536) {
 434                         *p = '\0';
 435                         return p+1;
 436                 }
 437         }
 438
 439         return NULL;
 440 }
 441
 442 static struct child_process no_fork;
 443
 444 /*
 445  * This returns a dummy child_process if the transport protocol does not
 446  * need fork(2), or a struct child_process object if it does.  Once done,
 447  * finish the connection with finish_connect() with the value returned from
 448  * this function (it is safe to call finish_connect() with NULL to support
 449  * the former case).
 450  *
 451  * If it returns, the connect is successful; it just dies on errors (this
 452  * will hopefully be changed in a libification effort, to return NULL when
 453  * the connection failed).
 454  */
 455 struct child_process *git_connect(int fd[2], const char *url_orig,
 456                                   const char *prog, int flags)
 457 {
 458         char *url;
 459         char *host, *path;
 460         char *end;
 461         int c;
 462         struct child_process *conn = &no_fork;
 463         enum protocol protocol = PROTO_LOCAL;
 464         int free_path = 0;
 465         char *port = NULL;
 466         const char **arg;
 467         struct strbuf cmd;
 468
 469         /* Without this we cannot rely on waitpid() to tell
 470          * what happened to our children.
 471          */
 472         signal(SIGCHLD, SIG_DFL);
 473
 474         if (is_url(url_orig))
 475                 url = url_decode(url_orig);
 476         else
 477                 url = xstrdup(url_orig);
 478
 479         host = strstr(url, "://");
 480         if (host) {
 481                 *host = '\0';
 482                 protocol = get_protocol(url);
 483                 host += 3;
 484                 c = '/';
 485         } else {
 486                 host = url;
 487                 c = ':';
 488         }
 489
 490         /*
 491          * Don't do destructive transforms with git:// as that
 492          * protocol code does '[]' unwrapping of its own.
 493          */
 494         if (host[0] == '[') {
 495                 end = strchr(host + 1, ']');
 496                 if (end) {
 497                         if (protocol != PROTO_GIT) {
 498                                 *end = 0;
 499                                 host++;
 500                         }
 501                         end++;
 502                 } else
 503                         end = host;
 504         } else
 505                 end = host;
 506
 507         path = strchr(end, c);
 508         if (path && !has_dos_drive_prefix(end)) {
 509                 if (c == ':') {
 510                         protocol = PROTO_SSH;
 511                         *path++ = '\0';
 512                 }
 513         } else
 514                 path = end;
 515
 516         if (!path || !*path)
 517                 die("No path specified. See 'man git-pull' for valid url syntax");
 518
 519         /*
 520          * null-terminate hostname and point path to ~ for URL's like this:
 521          *    ssh://host.xz/~user/repo
 522          */
 523         if (protocol != PROTO_LOCAL && host != url) {
 524                 char *ptr = path;
 525                 if (path[1] == '~')
 526                         path++;
 527                 else {
 528                         path = xstrdup(ptr);
 529                         free_path = 1;
 530                 }
 531
 532                 *ptr = '\0';
 533         }
 534
 535         /*
 536          * Add support for ssh port: ssh://host.xy:<port>/...
 537          */
 538         if (protocol == PROTO_SSH && host != url)
 539                 port = get_port(end);
 540
 541         if (protocol == PROTO_GIT) {
 542                 /* These underlying connection commands die() if they
 543                  * cannot connect.
 544                  */
 545                 char *target_host = xstrdup(host);
 546                 if (git_use_proxy(host))
 547                         conn = git_proxy_connect(fd, host);
 548                 else
 549                         git_tcp_connect(fd, host, flags);
 550                 /*
 551                  * Separate original protocol components prog and path
 552                  * from extended host header with a NUL byte.
 553                  *
 554                  * Note: Do not add any other headers here!  Doing so
 555                  * will cause older git-daemon servers to crash.
 556                  */
 557                 packet_write(fd[1],
 558                              "%s %s%chost=%s%c",
 559                              prog, path, 0,
 560                              target_host, 0);
 561                 free(target_host);
 562                 free(url);
 563                 if (free_path)
 564                         free(path);
 565                 return conn;
 566         }
 567
 568         conn = xcalloc(1, sizeof(*conn));
 569
 570         strbuf_init(&cmd, MAX_CMD_LEN);
 571         strbuf_addstr(&cmd, prog);
 572         strbuf_addch(&cmd, ' ');
 573         sq_quote_buf(&cmd, path);
 574         if (cmd.len >= MAX_CMD_LEN)
 575                 die("command line too long");
 576
 577         conn->in = conn->out = -1;
 578         conn->argv = arg = xcalloc(7, sizeof(*arg));
 579         if (protocol == PROTO_SSH) {
 580                 const char *ssh = getenv("GIT_SSH");
 581                 int putty = ssh && strcasestr(ssh, "plink");
 582                 if (!ssh) ssh = "ssh";
 583
 584                 *arg++ = ssh;
 585                 if (putty && !strcasestr(ssh, "tortoiseplink"))
 586                         *arg++ = "-batch";
 587                 if (port) {
 588                         /* P is for PuTTY, p is for OpenSSH */
 589                         *arg++ = putty ? "-P" : "-p";
 590                         *arg++ = port;
 591                 }
 592                 *arg++ = host;
 593         }
 594         else {
 595                 /* remove repo-local variables from the environment */
 596                 conn->env = local_repo_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 git_connection_is_socket(struct child_process *conn)
 615 {
 616         return conn == &no_fork;
 617 }
 618
 619 int finish_connect(struct child_process *conn)
 620 {
 621         int code;
 622         if (!conn || git_connection_is_socket(conn))
 623                 return 0;
 624
 625         code = finish_command(conn);
 626         free(conn->argv);
 627         free(conn);
 628         return code;
 629 }