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 static void die_initial_contact(int got_at_least_one_head)
  53 {
  54         if (got_at_least_one_head)
  55                 die("The remote end hung up upon initial contact");
  56         else
  57                 die("Could not read from remote repository.\n\n"
  58                     "Please make sure you have the correct access rights\n"
  59                     "and the repository exists.");
  60 }
  61
  62 /*
  63  * Read all the refs from the other end
  64  */
  65 struct ref **get_remote_heads(int in, struct ref **list,
  66                               unsigned int flags,
  67                               struct extra_have_objects *extra_have)
  68 {
  69         int got_at_least_one_head = 0;
  70
  71         *list = NULL;
  72         for (;;) {
  73                 struct ref *ref;
  74                 unsigned char old_sha1[20];
  75                 static char buffer[1000];
  76                 char *name;
  77                 int len, name_len;
  78
  79                 len = packet_read(in, buffer, sizeof(buffer));
  80                 if (len < 0)
  81                         die_initial_contact(got_at_least_one_head);
  82
  83                 if (!len)
  84                         break;
  85                 if (buffer[len-1] == '\n')
  86                         buffer[--len] = 0;
  87
  88                 if (len > 4 && !prefixcmp(buffer, "ERR "))
  89                         die("remote error: %s", buffer + 4);
  90
  91                 if (len < 42 || get_sha1_hex(buffer, old_sha1) || buffer[40] != ' ')
  92                         die("protocol error: expected sha/ref, got '%s'", buffer);
  93                 name = buffer + 41;
  94
  95                 name_len = strlen(name);
  96                 if (len != name_len + 41) {
  97                         free(server_capabilities);
  98                         server_capabilities = xstrdup(name + name_len + 1);
  99                 }
 100
 101                 if (extra_have &&
 102                     name_len == 5 && !memcmp(".have", name, 5)) {
 103                         add_extra_have(extra_have, old_sha1);
 104                         continue;
 105                 }
 106
 107                 if (!check_ref(name, name_len, flags))
 108                         continue;
 109                 ref = alloc_ref(buffer + 41);
 110                 hashcpy(ref->old_sha1, old_sha1);
 111                 *list = ref;
 112                 list = &ref->next;
 113                 got_at_least_one_head = 1;
 114         }
 115         return list;
 116 }
 117
 118 const char *parse_feature_value(const char *feature_list, const char *feature, int *lenp)
 119 {
 120         int len;
 121
 122         if (!feature_list)
 123                 return NULL;
 124
 125         len = strlen(feature);
 126         while (*feature_list) {
 127                 const char *found = strstr(feature_list, feature);
 128                 if (!found)
 129                         return NULL;
 130                 if (feature_list == found || isspace(found[-1])) {
 131                         const char *value = found + len;
 132                         /* feature with no value (e.g., "thin-pack") */
 133                         if (!*value || isspace(*value)) {
 134                                 if (lenp)
 135                                         *lenp = 0;
 136                                 return value;
 137                         }
 138                         /* feature with a value (e.g., "agent=git/1.2.3") */
 139                         else if (*value == '=') {
 140                                 value++;
 141                                 if (lenp)
 142                                         *lenp = strcspn(value, " \t\n");
 143                                 return value;
 144                         }
 145                         /*
 146                          * otherwise we matched a substring of another feature;
 147                          * keep looking
 148                          */
 149                 }
 150                 feature_list = found + 1;
 151         }
 152         return NULL;
 153 }
 154
 155 int parse_feature_request(const char *feature_list, const char *feature)
 156 {
 157         return !!parse_feature_value(feature_list, feature, NULL);
 158 }
 159
 160 const char *server_feature_value(const char *feature, int *len)
 161 {
 162         return parse_feature_value(server_capabilities, feature, len);
 163 }
 164
 165 int server_supports(const char *feature)
 166 {
 167         return !!server_feature_value(feature, NULL);
 168 }
 169
 170 enum protocol {
 171         PROTO_LOCAL = 1,
 172         PROTO_SSH,
 173         PROTO_GIT
 174 };
 175
 176 static enum protocol get_protocol(const char *name)
 177 {
 178         if (!strcmp(name, "ssh"))
 179                 return PROTO_SSH;
 180         if (!strcmp(name, "git"))
 181                 return PROTO_GIT;
 182         if (!strcmp(name, "git+ssh"))
 183                 return PROTO_SSH;
 184         if (!strcmp(name, "ssh+git"))
 185                 return PROTO_SSH;
 186         if (!strcmp(name, "file"))
 187                 return PROTO_LOCAL;
 188         die("I don't handle protocol '%s'", name);
 189 }
 190
 191 #define STR_(s) # s
 192 #define STR(s)  STR_(s)
 193
 194 static void get_host_and_port(char **host, const char **port)
 195 {
 196         char *colon, *end;
 197
 198         if (*host[0] == '[') {
 199                 end = strchr(*host + 1, ']');
 200                 if (end) {
 201                         *end = 0;
 202                         end++;
 203                         (*host)++;
 204                 } else
 205                         end = *host;
 206         } else
 207                 end = *host;
 208         colon = strchr(end, ':');
 209
 210         if (colon) {
 211                 *colon = 0;
 212                 *port = colon + 1;
 213         }
 214 }
 215
 216 static void enable_keepalive(int sockfd)
 217 {
 218         int ka = 1;
 219
 220         if (setsockopt(sockfd, SOL_SOCKET, SO_KEEPALIVE, &ka, sizeof(ka)) < 0)
 221                 fprintf(stderr, "unable to set SO_KEEPALIVE on socket: %s\n",
 222                         strerror(errno));
 223 }
 224
 225 #ifndef NO_IPV6
 226
 227 static const char *ai_name(const struct addrinfo *ai)
 228 {
 229         static char addr[NI_MAXHOST];
 230         if (getnameinfo(ai->ai_addr, ai->ai_addrlen, addr, sizeof(addr), NULL, 0,
 231                         NI_NUMERICHOST) != 0)
 232                 strcpy(addr, "(unknown)");
 233
 234         return addr;
 235 }
 236
 237 /*
 238  * Returns a connected socket() fd, or else die()s.
 239  */
 240 static int git_tcp_connect_sock(char *host, int flags)
 241 {
 242         struct strbuf error_message = STRBUF_INIT;
 243         int sockfd = -1;
 244         const char *port = STR(DEFAULT_GIT_PORT);
 245         struct addrinfo hints, *ai0, *ai;
 246         int gai;
 247         int cnt = 0;
 248
 249         get_host_and_port(&host, &port);
 250         if (!*port)
 251                 port = "<none>";
 252
 253         memset(&hints, 0, sizeof(hints));
 254         hints.ai_socktype = SOCK_STREAM;
 255         hints.ai_protocol = IPPROTO_TCP;
 256
 257         if (flags & CONNECT_VERBOSE)
 258                 fprintf(stderr, "Looking up %s ... ", host);
 259
 260         gai = getaddrinfo(host, port, &hints, &ai);
 261         if (gai)
 262                 die("Unable to look up %s (port %s) (%s)", host, port, gai_strerror(gai));
 263
 264         if (flags & CONNECT_VERBOSE)
 265                 fprintf(stderr, "done.\nConnecting to %s (port %s) ... ", host, port);
 266
 267         for (ai0 = ai; ai; ai = ai->ai_next, cnt++) {
 268                 sockfd = socket(ai->ai_family,
 269                                 ai->ai_socktype, ai->ai_protocol);
 270                 if ((sockfd < 0) ||
 271                     (connect(sockfd, ai->ai_addr, ai->ai_addrlen) < 0)) {
 272                         strbuf_addf(&error_message, "%s[%d: %s]: errno=%s\n",
 273                                     host, cnt, ai_name(ai), strerror(errno));
 274                         if (0 <= sockfd)
 275                                 close(sockfd);
 276                         sockfd = -1;
 277                         continue;
 278                 }
 279                 if (flags & CONNECT_VERBOSE)
 280                         fprintf(stderr, "%s ", ai_name(ai));
 281                 break;
 282         }
 283
 284         freeaddrinfo(ai0);
 285
 286         if (sockfd < 0)
 287                 die("unable to connect to %s:\n%s", host, error_message.buf);
 288
 289         enable_keepalive(sockfd);
 290
 291         if (flags & CONNECT_VERBOSE)
 292                 fprintf(stderr, "done.\n");
 293
 294         strbuf_release(&error_message);
 295
 296         return sockfd;
 297 }
 298
 299 #else /* NO_IPV6 */
 300
 301 /*
 302  * Returns a connected socket() fd, or else die()s.
 303  */
 304 static int git_tcp_connect_sock(char *host, int flags)
 305 {
 306         struct strbuf error_message = STRBUF_INIT;
 307         int sockfd = -1;
 308         const char *port = STR(DEFAULT_GIT_PORT);
 309         char *ep;
 310         struct hostent *he;
 311         struct sockaddr_in sa;
 312         char **ap;
 313         unsigned int nport;
 314         int cnt;
 315
 316         get_host_and_port(&host, &port);
 317
 318         if (flags & CONNECT_VERBOSE)
 319                 fprintf(stderr, "Looking up %s ... ", host);
 320
 321         he = gethostbyname(host);
 322         if (!he)
 323                 die("Unable to look up %s (%s)", host, hstrerror(h_errno));
 324         nport = strtoul(port, &ep, 10);
 325         if ( ep == port || *ep ) {
 326                 /* Not numeric */
 327                 struct servent *se = getservbyname(port,"tcp");
 328                 if ( !se )
 329                         die("Unknown port %s", port);
 330                 nport = se->s_port;
 331         }
 332
 333         if (flags & CONNECT_VERBOSE)
 334                 fprintf(stderr, "done.\nConnecting to %s (port %s) ... ", host, port);
 335
 336         for (cnt = 0, ap = he->h_addr_list; *ap; ap++, cnt++) {
 337                 memset(&sa, 0, sizeof sa);
 338                 sa.sin_family = he->h_addrtype;
 339                 sa.sin_port = htons(nport);
 340                 memcpy(&sa.sin_addr, *ap, he->h_length);
 341
 342                 sockfd = socket(he->h_addrtype, SOCK_STREAM, 0);
 343                 if ((sockfd < 0) ||
 344                     connect(sockfd, (struct sockaddr *)&sa, sizeof sa) < 0) {
 345                         strbuf_addf(&error_message, "%s[%d: %s]: errno=%s\n",
 346                                 host,
 347                                 cnt,
 348                                 inet_ntoa(*(struct in_addr *)&sa.sin_addr),
 349                                 strerror(errno));
 350                         if (0 <= sockfd)
 351                                 close(sockfd);
 352                         sockfd = -1;
 353                         continue;
 354                 }
 355                 if (flags & CONNECT_VERBOSE)
 356                         fprintf(stderr, "%s ",
 357                                 inet_ntoa(*(struct in_addr *)&sa.sin_addr));
 358                 break;
 359         }
 360
 361         if (sockfd < 0)
 362                 die("unable to connect to %s:\n%s", host, error_message.buf);
 363
 364         enable_keepalive(sockfd);
 365
 366         if (flags & CONNECT_VERBOSE)
 367                 fprintf(stderr, "done.\n");
 368
 369         return sockfd;
 370 }
 371
 372 #endif /* NO_IPV6 */
 373
 374
 375 static void git_tcp_connect(int fd[2], char *host, int flags)
 376 {
 377         int sockfd = git_tcp_connect_sock(host, flags);
 378
 379         fd[0] = sockfd;
 380         fd[1] = dup(sockfd);
 381 }
 382
 383
 384 static char *git_proxy_command;
 385
 386 static int git_proxy_command_options(const char *var, const char *value,
 387                 void *cb)
 388 {
 389         if (!strcmp(var, "core.gitproxy")) {
 390                 const char *for_pos;
 391                 int matchlen = -1;
 392                 int hostlen;
 393                 const char *rhost_name = cb;
 394                 int rhost_len = strlen(rhost_name);
 395
 396                 if (git_proxy_command)
 397                         return 0;
 398                 if (!value)
 399                         return config_error_nonbool(var);
 400                 /* [core]
 401                  * ;# matches www.kernel.org as well
 402                  * gitproxy = netcatter-1 for kernel.org
 403                  * gitproxy = netcatter-2 for sample.xz
 404                  * gitproxy = netcatter-default
 405                  */
 406                 for_pos = strstr(value, " for ");
 407                 if (!for_pos)
 408                         /* matches everybody */
 409                         matchlen = strlen(value);
 410                 else {
 411                         hostlen = strlen(for_pos + 5);
 412                         if (rhost_len < hostlen)
 413                                 matchlen = -1;
 414                         else if (!strncmp(for_pos + 5,
 415                                           rhost_name + rhost_len - hostlen,
 416                                           hostlen) &&
 417                                  ((rhost_len == hostlen) ||
 418                                   rhost_name[rhost_len - hostlen -1] == '.'))
 419                                 matchlen = for_pos - value;
 420                         else
 421                                 matchlen = -1;
 422                 }
 423                 if (0 <= matchlen) {
 424                         /* core.gitproxy = none for kernel.org */
 425                         if (matchlen == 4 &&
 426                             !memcmp(value, "none", 4))
 427                                 matchlen = 0;
 428                         git_proxy_command = xmemdupz(value, matchlen);
 429                 }
 430                 return 0;
 431         }
 432
 433         return git_default_config(var, value, cb);
 434 }
 435
 436 static int git_use_proxy(const char *host)
 437 {
 438         git_proxy_command = getenv("GIT_PROXY_COMMAND");
 439         git_config(git_proxy_command_options, (void*)host);
 440         return (git_proxy_command && *git_proxy_command);
 441 }
 442
 443 static struct child_process *git_proxy_connect(int fd[2], char *host)
 444 {
 445         const char *port = STR(DEFAULT_GIT_PORT);
 446         const char **argv;
 447         struct child_process *proxy;
 448
 449         get_host_and_port(&host, &port);
 450
 451         argv = xmalloc(sizeof(*argv) * 4);
 452         argv[0] = git_proxy_command;
 453         argv[1] = host;
 454         argv[2] = port;
 455         argv[3] = NULL;
 456         proxy = xcalloc(1, sizeof(*proxy));
 457         proxy->argv = argv;
 458         proxy->in = -1;
 459         proxy->out = -1;
 460         if (start_command(proxy))
 461                 die("cannot start proxy %s", argv[0]);
 462         fd[0] = proxy->out; /* read from proxy stdout */
 463         fd[1] = proxy->in;  /* write to proxy stdin */
 464         return proxy;
 465 }
 466
 467 #define MAX_CMD_LEN 1024
 468
 469 static char *get_port(char *host)
 470 {
 471         char *end;
 472         char *p = strchr(host, ':');
 473
 474         if (p) {
 475                 long port = strtol(p + 1, &end, 10);
 476                 if (end != p + 1 && *end == '\0' && 0 <= port && port < 65536) {
 477                         *p = '\0';
 478                         return p+1;
 479                 }
 480         }
 481
 482         return NULL;
 483 }
 484
 485 static struct child_process no_fork;
 486
 487 /*
 488  * This returns a dummy child_process if the transport protocol does not
 489  * need fork(2), or a struct child_process object if it does.  Once done,
 490  * finish the connection with finish_connect() with the value returned from
 491  * this function (it is safe to call finish_connect() with NULL to support
 492  * the former case).
 493  *
 494  * If it returns, the connect is successful; it just dies on errors (this
 495  * will hopefully be changed in a libification effort, to return NULL when
 496  * the connection failed).
 497  */
 498 struct child_process *git_connect(int fd[2], const char *url_orig,
 499                                   const char *prog, int flags)
 500 {
 501         char *url;
 502         char *host, *path;
 503         char *end;
 504         int c;
 505         struct child_process *conn = &no_fork;
 506         enum protocol protocol = PROTO_LOCAL;
 507         int free_path = 0;
 508         char *port = NULL;
 509         const char **arg;
 510         struct strbuf cmd;
 511
 512         /* Without this we cannot rely on waitpid() to tell
 513          * what happened to our children.
 514          */
 515         signal(SIGCHLD, SIG_DFL);
 516
 517         if (is_url(url_orig))
 518                 url = url_decode(url_orig);
 519         else
 520                 url = xstrdup(url_orig);
 521
 522         host = strstr(url, "://");
 523         if (host) {
 524                 *host = '\0';
 525                 protocol = get_protocol(url);
 526                 host += 3;
 527                 c = '/';
 528         } else {
 529                 host = url;
 530                 c = ':';
 531         }
 532
 533         /*
 534          * Don't do destructive transforms with git:// as that
 535          * protocol code does '[]' unwrapping of its own.
 536          */
 537         if (host[0] == '[') {
 538                 end = strchr(host + 1, ']');
 539                 if (end) {
 540                         if (protocol != PROTO_GIT) {
 541                                 *end = 0;
 542                                 host++;
 543                         }
 544                         end++;
 545                 } else
 546                         end = host;
 547         } else
 548                 end = host;
 549
 550         path = strchr(end, c);
 551         if (path && !has_dos_drive_prefix(end)) {
 552                 if (c == ':') {
 553                         protocol = PROTO_SSH;
 554                         *path++ = '\0';
 555                 }
 556         } else
 557                 path = end;
 558
 559         if (!path || !*path)
 560                 die("No path specified. See 'man git-pull' for valid url syntax");
 561
 562         /*
 563          * null-terminate hostname and point path to ~ for URL's like this:
 564          *    ssh://host.xz/~user/repo
 565          */
 566         if (protocol != PROTO_LOCAL && host != url) {
 567                 char *ptr = path;
 568                 if (path[1] == '~')
 569                         path++;
 570                 else {
 571                         path = xstrdup(ptr);
 572                         free_path = 1;
 573                 }
 574
 575                 *ptr = '\0';
 576         }
 577
 578         /*
 579          * Add support for ssh port: ssh://host.xy:<port>/...
 580          */
 581         if (protocol == PROTO_SSH && host != url)
 582                 port = get_port(end);
 583
 584         if (protocol == PROTO_GIT) {
 585                 /* These underlying connection commands die() if they
 586                  * cannot connect.
 587                  */
 588                 char *target_host = xstrdup(host);
 589                 if (git_use_proxy(host))
 590                         conn = git_proxy_connect(fd, host);
 591                 else
 592                         git_tcp_connect(fd, host, flags);
 593                 /*
 594                  * Separate original protocol components prog and path
 595                  * from extended host header with a NUL byte.
 596                  *
 597                  * Note: Do not add any other headers here!  Doing so
 598                  * will cause older git-daemon servers to crash.
 599                  */
 600                 packet_write(fd[1],
 601                              "%s %s%chost=%s%c",
 602                              prog, path, 0,
 603                              target_host, 0);
 604                 free(target_host);
 605                 free(url);
 606                 if (free_path)
 607                         free(path);
 608                 return conn;
 609         }
 610
 611         conn = xcalloc(1, sizeof(*conn));
 612
 613         strbuf_init(&cmd, MAX_CMD_LEN);
 614         strbuf_addstr(&cmd, prog);
 615         strbuf_addch(&cmd, ' ');
 616         sq_quote_buf(&cmd, path);
 617         if (cmd.len >= MAX_CMD_LEN)
 618                 die("command line too long");
 619
 620         conn->in = conn->out = -1;
 621         conn->argv = arg = xcalloc(7, sizeof(*arg));
 622         if (protocol == PROTO_SSH) {
 623                 const char *ssh = getenv("GIT_SSH");
 624                 int putty = ssh && strcasestr(ssh, "plink");
 625                 if (!ssh) ssh = "ssh";
 626
 627                 *arg++ = ssh;
 628                 if (putty && !strcasestr(ssh, "tortoiseplink"))
 629                         *arg++ = "-batch";
 630                 if (port) {
 631                         /* P is for PuTTY, p is for OpenSSH */
 632                         *arg++ = putty ? "-P" : "-p";
 633                         *arg++ = port;
 634                 }
 635                 *arg++ = host;
 636         }
 637         else {
 638                 /* remove repo-local variables from the environment */
 639                 conn->env = local_repo_env;
 640                 conn->use_shell = 1;
 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 git_connection_is_socket(struct child_process *conn)
 658 {
 659         return conn == &no_fork;
 660 }
 661
 662 int finish_connect(struct child_process *conn)
 663 {
 664         int code;
 665         if (!conn || git_connection_is_socket(conn))
 666                 return 0;
 667
 668         code = finish_command(conn);
 669         free(conn->argv);
 670         free(conn);
 671         return code;
 672 }