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_ref_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                               int nr_match, char **match,
  67                               unsigned int flags,
  68                               struct extra_have_objects *extra_have)
  69 {
  70         int got_at_least_one_head = 0;
  71
  72         *list = NULL;
  73         for (;;) {
  74                 struct ref *ref;
  75                 unsigned char old_sha1[20];
  76                 static char buffer[1000];
  77                 char *name;
  78                 int len, name_len;
  79
  80                 len = packet_read(in, buffer, sizeof(buffer));
  81                 if (len < 0)
  82                         die_initial_contact(got_at_least_one_head);
  83
  84                 if (!len)
  85                         break;
  86                 if (buffer[len-1] == '\n')
  87                         buffer[--len] = 0;
  88
  89                 if (len > 4 && !prefixcmp(buffer, "ERR "))
  90                         die("remote error: %s", buffer + 4);
  91
  92                 if (len < 42 || get_sha1_hex(buffer, old_sha1) || buffer[40] != ' ')
  93                         die("protocol error: expected sha/ref, got '%s'", buffer);
  94                 name = buffer + 41;
  95
  96                 name_len = strlen(name);
  97                 if (len != name_len + 41) {
  98                         free(server_capabilities);
  99                         server_capabilities = xstrdup(name + name_len + 1);
 100                 }
 101
 102                 if (extra_have &&
 103                     name_len == 5 && !memcmp(".have", name, 5)) {
 104                         add_extra_have(extra_have, old_sha1);
 105                         continue;
 106                 }
 107
 108                 if (!check_ref(name, name_len, flags))
 109                         continue;
 110                 if (nr_match && !path_match(name, nr_match, match))
 111                         continue;
 112                 ref = alloc_ref(buffer + 41);
 113                 hashcpy(ref->old_sha1, old_sha1);
 114                 *list = ref;
 115                 list = &ref->next;
 116                 got_at_least_one_head = 1;
 117         }
 118         return list;
 119 }
 120
 121 int server_supports(const char *feature)
 122 {
 123         return server_capabilities &&
 124                 strstr(server_capabilities, feature) != NULL;
 125 }
 126
 127 int path_match(const char *path, int nr, char **match)
 128 {
 129         int i;
 130         int pathlen = strlen(path);
 131
 132         for (i = 0; i < nr; i++) {
 133                 char *s = match[i];
 134                 int len = strlen(s);
 135
 136                 if (!len || len > pathlen)
 137                         continue;
 138                 if (memcmp(path + pathlen - len, s, len))
 139                         continue;
 140                 if (pathlen > len && path[pathlen - len - 1] != '/')
 141                         continue;
 142                 *s = 0;
 143                 return (i + 1);
 144         }
 145         return 0;
 146 }
 147
 148 enum protocol {
 149         PROTO_LOCAL = 1,
 150         PROTO_SSH,
 151         PROTO_GIT
 152 };
 153
 154 static enum protocol get_protocol(const char *name)
 155 {
 156         if (!strcmp(name, "ssh"))
 157                 return PROTO_SSH;
 158         if (!strcmp(name, "git"))
 159                 return PROTO_GIT;
 160         if (!strcmp(name, "git+ssh"))
 161                 return PROTO_SSH;
 162         if (!strcmp(name, "ssh+git"))
 163                 return PROTO_SSH;
 164         if (!strcmp(name, "file"))
 165                 return PROTO_LOCAL;
 166         die("I don't handle protocol '%s'", name);
 167 }
 168
 169 #define STR_(s) # s
 170 #define STR(s)  STR_(s)
 171
 172 static void get_host_and_port(char **host, const char **port)
 173 {
 174         char *colon, *end;
 175
 176         if (*host[0] == '[') {
 177                 end = strchr(*host + 1, ']');
 178                 if (end) {
 179                         *end = 0;
 180                         end++;
 181                         (*host)++;
 182                 } else
 183                         end = *host;
 184         } else
 185                 end = *host;
 186         colon = strchr(end, ':');
 187
 188         if (colon) {
 189                 *colon = 0;
 190                 *port = colon + 1;
 191         }
 192 }
 193
 194 #ifndef NO_IPV6
 195
 196 static const char *ai_name(const struct addrinfo *ai)
 197 {
 198         static char addr[NI_MAXHOST];
 199         if (getnameinfo(ai->ai_addr, ai->ai_addrlen, addr, sizeof(addr), NULL, 0,
 200                         NI_NUMERICHOST) != 0)
 201                 strcpy(addr, "(unknown)");
 202
 203         return addr;
 204 }
 205
 206 /*
 207  * Returns a connected socket() fd, or else die()s.
 208  */
 209 static int git_tcp_connect_sock(char *host, int flags)
 210 {
 211         struct strbuf error_message = STRBUF_INIT;
 212         int sockfd = -1;
 213         const char *port = STR(DEFAULT_GIT_PORT);
 214         struct addrinfo hints, *ai0, *ai;
 215         int gai;
 216         int cnt = 0;
 217
 218         get_host_and_port(&host, &port);
 219         if (!*port)
 220                 port = "<none>";
 221
 222         memset(&hints, 0, sizeof(hints));
 223         hints.ai_socktype = SOCK_STREAM;
 224         hints.ai_protocol = IPPROTO_TCP;
 225
 226         if (flags & CONNECT_VERBOSE)
 227                 fprintf(stderr, "Looking up %s ... ", host);
 228
 229         gai = getaddrinfo(host, port, &hints, &ai);
 230         if (gai)
 231                 die("Unable to look up %s (port %s) (%s)", host, port, gai_strerror(gai));
 232
 233         if (flags & CONNECT_VERBOSE)
 234                 fprintf(stderr, "done.\nConnecting to %s (port %s) ... ", host, port);
 235
 236         for (ai0 = ai; ai; ai = ai->ai_next, cnt++) {
 237                 sockfd = socket(ai->ai_family,
 238                                 ai->ai_socktype, ai->ai_protocol);
 239                 if ((sockfd < 0) ||
 240                     (connect(sockfd, ai->ai_addr, ai->ai_addrlen) < 0)) {
 241                         strbuf_addf(&error_message, "%s[%d: %s]: errno=%s\n",
 242                                     host, cnt, ai_name(ai), strerror(errno));
 243                         if (0 <= sockfd)
 244                                 close(sockfd);
 245                         sockfd = -1;
 246                         continue;
 247                 }
 248                 if (flags & CONNECT_VERBOSE)
 249                         fprintf(stderr, "%s ", ai_name(ai));
 250                 break;
 251         }
 252
 253         freeaddrinfo(ai0);
 254
 255         if (sockfd < 0)
 256                 die("unable to connect to %s:\n%s", host, error_message.buf);
 257
 258         if (flags & CONNECT_VERBOSE)
 259                 fprintf(stderr, "done.\n");
 260
 261         strbuf_release(&error_message);
 262
 263         return sockfd;
 264 }
 265
 266 #else /* NO_IPV6 */
 267
 268 /*
 269  * Returns a connected socket() fd, or else die()s.
 270  */
 271 static int git_tcp_connect_sock(char *host, int flags)
 272 {
 273         int sockfd = -1, saved_errno = 0;
 274         const char *port = STR(DEFAULT_GIT_PORT);
 275         char *ep;
 276         struct hostent *he;
 277         struct sockaddr_in sa;
 278         char **ap;
 279         unsigned int nport;
 280         int cnt;
 281
 282         get_host_and_port(&host, &port);
 283
 284         if (flags & CONNECT_VERBOSE)
 285                 fprintf(stderr, "Looking up %s ... ", host);
 286
 287         he = gethostbyname(host);
 288         if (!he)
 289                 die("Unable to look up %s (%s)", host, hstrerror(h_errno));
 290         nport = strtoul(port, &ep, 10);
 291         if ( ep == port || *ep ) {
 292                 /* Not numeric */
 293                 struct servent *se = getservbyname(port,"tcp");
 294                 if ( !se )
 295                         die("Unknown port %s", port);
 296                 nport = se->s_port;
 297         }
 298
 299         if (flags & CONNECT_VERBOSE)
 300                 fprintf(stderr, "done.\nConnecting to %s (port %s) ... ", host, port);
 301
 302         for (cnt = 0, ap = he->h_addr_list; *ap; ap++, cnt++) {
 303                 sockfd = socket(he->h_addrtype, SOCK_STREAM, 0);
 304                 if (sockfd < 0) {
 305                         saved_errno = errno;
 306                         continue;
 307                 }
 308
 309                 memset(&sa, 0, sizeof sa);
 310                 sa.sin_family = he->h_addrtype;
 311                 sa.sin_port = htons(nport);
 312                 memcpy(&sa.sin_addr, *ap, he->h_length);
 313
 314                 if (connect(sockfd, (struct sockaddr *)&sa, sizeof sa) < 0) {
 315                         saved_errno = errno;
 316                         fprintf(stderr, "%s[%d: %s]: errno=%s\n",
 317                                 host,
 318                                 cnt,
 319                                 inet_ntoa(*(struct in_addr *)&sa.sin_addr),
 320                                 strerror(saved_errno));
 321                         close(sockfd);
 322                         sockfd = -1;
 323                         continue;
 324                 }
 325                 if (flags & CONNECT_VERBOSE)
 326                         fprintf(stderr, "%s ",
 327                                 inet_ntoa(*(struct in_addr *)&sa.sin_addr));
 328                 break;
 329         }
 330
 331         if (sockfd < 0)
 332                 die("unable to connect a socket (%s)", strerror(saved_errno));
 333
 334         if (flags & CONNECT_VERBOSE)
 335                 fprintf(stderr, "done.\n");
 336
 337         return sockfd;
 338 }
 339
 340 #endif /* NO_IPV6 */
 341
 342
 343 static void git_tcp_connect(int fd[2], char *host, int flags)
 344 {
 345         int sockfd = git_tcp_connect_sock(host, flags);
 346
 347         fd[0] = sockfd;
 348         fd[1] = dup(sockfd);
 349 }
 350
 351
 352 static char *git_proxy_command;
 353
 354 static int git_proxy_command_options(const char *var, const char *value,
 355                 void *cb)
 356 {
 357         if (!strcmp(var, "core.gitproxy")) {
 358                 const char *for_pos;
 359                 int matchlen = -1;
 360                 int hostlen;
 361                 const char *rhost_name = cb;
 362                 int rhost_len = strlen(rhost_name);
 363
 364                 if (git_proxy_command)
 365                         return 0;
 366                 if (!value)
 367                         return config_error_nonbool(var);
 368                 /* [core]
 369                  * ;# matches www.kernel.org as well
 370                  * gitproxy = netcatter-1 for kernel.org
 371                  * gitproxy = netcatter-2 for sample.xz
 372                  * gitproxy = netcatter-default
 373                  */
 374                 for_pos = strstr(value, " for ");
 375                 if (!for_pos)
 376                         /* matches everybody */
 377                         matchlen = strlen(value);
 378                 else {
 379                         hostlen = strlen(for_pos + 5);
 380                         if (rhost_len < hostlen)
 381                                 matchlen = -1;
 382                         else if (!strncmp(for_pos + 5,
 383                                           rhost_name + rhost_len - hostlen,
 384                                           hostlen) &&
 385                                  ((rhost_len == hostlen) ||
 386                                   rhost_name[rhost_len - hostlen -1] == '.'))
 387                                 matchlen = for_pos - value;
 388                         else
 389                                 matchlen = -1;
 390                 }
 391                 if (0 <= matchlen) {
 392                         /* core.gitproxy = none for kernel.org */
 393                         if (matchlen == 4 &&
 394                             !memcmp(value, "none", 4))
 395                                 matchlen = 0;
 396                         git_proxy_command = xmemdupz(value, matchlen);
 397                 }
 398                 return 0;
 399         }
 400
 401         return git_default_config(var, value, cb);
 402 }
 403
 404 static int git_use_proxy(const char *host)
 405 {
 406         git_proxy_command = getenv("GIT_PROXY_COMMAND");
 407         git_config(git_proxy_command_options, (void*)host);
 408         return (git_proxy_command && *git_proxy_command);
 409 }
 410
 411 static struct child_process *git_proxy_connect(int fd[2], char *host)
 412 {
 413         const char *port = STR(DEFAULT_GIT_PORT);
 414         const char **argv;
 415         struct child_process *proxy;
 416
 417         get_host_and_port(&host, &port);
 418
 419         argv = xmalloc(sizeof(*argv) * 4);
 420         argv[0] = git_proxy_command;
 421         argv[1] = host;
 422         argv[2] = port;
 423         argv[3] = NULL;
 424         proxy = xcalloc(1, sizeof(*proxy));
 425         proxy->argv = argv;
 426         proxy->in = -1;
 427         proxy->out = -1;
 428         if (start_command(proxy))
 429                 die("cannot start proxy %s", argv[0]);
 430         fd[0] = proxy->out; /* read from proxy stdout */
 431         fd[1] = proxy->in;  /* write to proxy stdin */
 432         return proxy;
 433 }
 434
 435 #define MAX_CMD_LEN 1024
 436
 437 static char *get_port(char *host)
 438 {
 439         char *end;
 440         char *p = strchr(host, ':');
 441
 442         if (p) {
 443                 long port = strtol(p + 1, &end, 10);
 444                 if (end != p + 1 && *end == '\0' && 0 <= port && port < 65536) {
 445                         *p = '\0';
 446                         return p+1;
 447                 }
 448         }
 449
 450         return NULL;
 451 }
 452
 453 static struct child_process no_fork;
 454
 455 /*
 456  * This returns a dummy child_process if the transport protocol does not
 457  * need fork(2), or a struct child_process object if it does.  Once done,
 458  * finish the connection with finish_connect() with the value returned from
 459  * this function (it is safe to call finish_connect() with NULL to support
 460  * the former case).
 461  *
 462  * If it returns, the connect is successful; it just dies on errors (this
 463  * will hopefully be changed in a libification effort, to return NULL when
 464  * the connection failed).
 465  */
 466 struct child_process *git_connect(int fd[2], const char *url_orig,
 467                                   const char *prog, int flags)
 468 {
 469         char *url;
 470         char *host, *path;
 471         char *end;
 472         int c;
 473         struct child_process *conn = &no_fork;
 474         enum protocol protocol = PROTO_LOCAL;
 475         int free_path = 0;
 476         char *port = NULL;
 477         const char **arg;
 478         struct strbuf cmd;
 479
 480         /* Without this we cannot rely on waitpid() to tell
 481          * what happened to our children.
 482          */
 483         signal(SIGCHLD, SIG_DFL);
 484
 485         if (is_url(url_orig))
 486                 url = url_decode(url_orig);
 487         else
 488                 url = xstrdup(url_orig);
 489
 490         host = strstr(url, "://");
 491         if (host) {
 492                 *host = '\0';
 493                 protocol = get_protocol(url);
 494                 host += 3;
 495                 c = '/';
 496         } else {
 497                 host = url;
 498                 c = ':';
 499         }
 500
 501         /*
 502          * Don't do destructive transforms with git:// as that
 503          * protocol code does '[]' unwrapping of its own.
 504          */
 505         if (host[0] == '[') {
 506                 end = strchr(host + 1, ']');
 507                 if (end) {
 508                         if (protocol != PROTO_GIT) {
 509                                 *end = 0;
 510                                 host++;
 511                         }
 512                         end++;
 513                 } else
 514                         end = host;
 515         } else
 516                 end = host;
 517
 518         path = strchr(end, c);
 519         if (path && !has_dos_drive_prefix(end)) {
 520                 if (c == ':') {
 521                         protocol = PROTO_SSH;
 522                         *path++ = '\0';
 523                 }
 524         } else
 525                 path = end;
 526
 527         if (!path || !*path)
 528                 die("No path specified. See 'man git-pull' for valid url syntax");
 529
 530         /*
 531          * null-terminate hostname and point path to ~ for URL's like this:
 532          *    ssh://host.xz/~user/repo
 533          */
 534         if (protocol != PROTO_LOCAL && host != url) {
 535                 char *ptr = path;
 536                 if (path[1] == '~')
 537                         path++;
 538                 else {
 539                         path = xstrdup(ptr);
 540                         free_path = 1;
 541                 }
 542
 543                 *ptr = '\0';
 544         }
 545
 546         /*
 547          * Add support for ssh port: ssh://host.xy:<port>/...
 548          */
 549         if (protocol == PROTO_SSH && host != url)
 550                 port = get_port(host);
 551
 552         if (protocol == PROTO_GIT) {
 553                 /* These underlying connection commands die() if they
 554                  * cannot connect.
 555                  */
 556                 char *target_host = xstrdup(host);
 557                 if (git_use_proxy(host))
 558                         conn = git_proxy_connect(fd, host);
 559                 else
 560                         git_tcp_connect(fd, host, flags);
 561                 /*
 562                  * Separate original protocol components prog and path
 563                  * from extended host header with a NUL byte.
 564                  *
 565                  * Note: Do not add any other headers here!  Doing so
 566                  * will cause older git-daemon servers to crash.
 567                  */
 568                 packet_write(fd[1],
 569                              "%s %s%chost=%s%c",
 570                              prog, path, 0,
 571                              target_host, 0);
 572                 free(target_host);
 573                 free(url);
 574                 if (free_path)
 575                         free(path);
 576                 return conn;
 577         }
 578
 579         conn = xcalloc(1, sizeof(*conn));
 580
 581         strbuf_init(&cmd, MAX_CMD_LEN);
 582         strbuf_addstr(&cmd, prog);
 583         strbuf_addch(&cmd, ' ');
 584         sq_quote_buf(&cmd, path);
 585         if (cmd.len >= MAX_CMD_LEN)
 586                 die("command line too long");
 587
 588         conn->in = conn->out = -1;
 589         conn->argv = arg = xcalloc(7, sizeof(*arg));
 590         if (protocol == PROTO_SSH) {
 591                 const char *ssh = getenv("GIT_SSH");
 592                 int putty = ssh && strcasestr(ssh, "plink");
 593                 if (!ssh) ssh = "ssh";
 594
 595                 *arg++ = ssh;
 596                 if (putty && !strcasestr(ssh, "tortoiseplink"))
 597                         *arg++ = "-batch";
 598                 if (port) {
 599                         /* P is for PuTTY, p is for OpenSSH */
 600                         *arg++ = putty ? "-P" : "-p";
 601                         *arg++ = port;
 602                 }
 603                 *arg++ = host;
 604         }
 605         else {
 606                 /* remove repo-local variables from the environment */
 607                 conn->env = local_repo_env;
 608                 conn->use_shell = 1;
 609         }
 610         *arg++ = cmd.buf;
 611         *arg = NULL;
 612
 613         if (start_command(conn))
 614                 die("unable to fork");
 615
 616         fd[0] = conn->out; /* read from child's stdout */
 617         fd[1] = conn->in;  /* write to child's stdin */
 618         strbuf_release(&cmd);
 619         free(url);
 620         if (free_path)
 621                 free(path);
 622         return conn;
 623 }
 624
 625 int git_connection_is_socket(struct child_process *conn)
 626 {
 627         return conn == &no_fork;
 628 }
 629
 630 int finish_connect(struct child_process *conn)
 631 {
 632         int code;
 633         if (!conn || git_connection_is_socket(conn))
 634                 return 0;
 635
 636         code = finish_command(conn);
 637         free(conn->argv);
 638         free(conn);
 639         return code;
 640 }
 641
 642 char *git_getpass(const char *prompt)
 643 {
 644         const char *askpass;
 645         struct child_process pass;
 646         const char *args[3];
 647         static struct strbuf buffer = STRBUF_INIT;
 648
 649         askpass = getenv("GIT_ASKPASS");
 650         if (!askpass)
 651                 askpass = askpass_program;
 652         if (!askpass)
 653                 askpass = getenv("SSH_ASKPASS");
 654         if (!askpass || !(*askpass)) {
 655                 char *result = getpass(prompt);
 656                 if (!result)
 657                         die_errno("Could not read password");
 658                 return result;
 659         }
 660
 661         args[0] = askpass;
 662         args[1] = prompt;
 663         args[2] = NULL;
 664
 665         memset(&pass, 0, sizeof(pass));
 666         pass.argv = args;
 667         pass.out = -1;
 668
 669         if (start_command(&pass))
 670                 exit(1);
 671
 672         strbuf_reset(&buffer);
 673         if (strbuf_read(&buffer, pass.out, 20) < 0)
 674                 die("failed to read password from %s\n", askpass);
 675
 676         close(pass.out);
 677
 678         if (finish_command(&pass))
 679                 exit(1);
 680
 681         strbuf_setlen(&buffer, strcspn(buffer.buf, "\r\n"));
 682
 683         return buffer.buf;
 684 }