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