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                               int nr_match, char **match,
  57                               unsigned int flags,
  58                               struct extra_have_objects *extra_have)
  59 {
  60         *list = NULL;
  61         for (;;) {
  62                 struct ref *ref;
  63                 unsigned char old_sha1[20];
  64                 static char buffer[1000];
  65                 char *name;
  66                 int len, name_len;
  67
  68                 len = packet_read_line(in, buffer, sizeof(buffer));
  69                 if (!len)
  70                         break;
  71                 if (buffer[len-1] == '\n')
  72                         buffer[--len] = 0;
  73
  74                 if (len > 4 && !prefixcmp(buffer, "ERR "))
  75                         die("remote error: %s", buffer + 4);
  76
  77                 if (len < 42 || get_sha1_hex(buffer, old_sha1) || buffer[40] != ' ')
  78                         die("protocol error: expected sha/ref, got '%s'", buffer);
  79                 name = buffer + 41;
  80
  81                 name_len = strlen(name);
  82                 if (len != name_len + 41) {
  83                         free(server_capabilities);
  84                         server_capabilities = xstrdup(name + name_len + 1);
  85                 }
  86
  87                 if (extra_have &&
  88                     name_len == 5 && !memcmp(".have", name, 5)) {
  89                         add_extra_have(extra_have, old_sha1);
  90                         continue;
  91                 }
  92
  93                 if (!check_ref(name, name_len, flags))
  94                         continue;
  95                 if (nr_match && !path_match(name, nr_match, match))
  96                         continue;
  97                 ref = alloc_ref(buffer + 41);
  98                 hashcpy(ref->old_sha1, old_sha1);
  99                 *list = ref;
 100                 list = &ref->next;
 101         }
 102         return list;
 103 }
 104
 105 int server_supports(const char *feature)
 106 {
 107         return server_capabilities &&
 108                 strstr(server_capabilities, feature) != NULL;
 109 }
 110
 111 int path_match(const char *path, int nr, char **match)
 112 {
 113         int i;
 114         int pathlen = strlen(path);
 115
 116         for (i = 0; i < nr; i++) {
 117                 char *s = match[i];
 118                 int len = strlen(s);
 119
 120                 if (!len || len > pathlen)
 121                         continue;
 122                 if (memcmp(path + pathlen - len, s, len))
 123                         continue;
 124                 if (pathlen > len && path[pathlen - len - 1] != '/')
 125                         continue;
 126                 *s = 0;
 127                 return (i + 1);
 128         }
 129         return 0;
 130 }
 131
 132 enum protocol {
 133         PROTO_LOCAL = 1,
 134         PROTO_SSH,
 135         PROTO_GIT
 136 };
 137
 138 static enum protocol get_protocol(const char *name)
 139 {
 140         if (!strcmp(name, "ssh"))
 141                 return PROTO_SSH;
 142         if (!strcmp(name, "git"))
 143                 return PROTO_GIT;
 144         if (!strcmp(name, "git+ssh"))
 145                 return PROTO_SSH;
 146         if (!strcmp(name, "ssh+git"))
 147                 return PROTO_SSH;
 148         if (!strcmp(name, "file"))
 149                 return PROTO_LOCAL;
 150         die("I don't handle protocol '%s'", name);
 151 }
 152
 153 #define STR_(s) # s
 154 #define STR(s)  STR_(s)
 155
 156 static void get_host_and_port(char **host, const char **port)
 157 {
 158         char *colon, *end;
 159
 160         if (*host[0] == '[') {
 161                 end = strchr(*host + 1, ']');
 162                 if (end) {
 163                         *end = 0;
 164                         end++;
 165                         (*host)++;
 166                 } else
 167                         end = *host;
 168         } else
 169                 end = *host;
 170         colon = strchr(end, ':');
 171
 172         if (colon) {
 173                 *colon = 0;
 174                 *port = colon + 1;
 175         }
 176 }
 177
 178 static void enable_keepalive(int sockfd)
 179 {
 180         int ka = 1;
 181
 182         if (setsockopt(sockfd, SOL_SOCKET, SO_KEEPALIVE, &ka, sizeof(ka)) < 0)
 183                 fprintf(stderr, "unable to set SO_KEEPALIVE on socket: %s\n",
 184                         strerror(errno));
 185 }
 186
 187 #ifndef NO_IPV6
 188
 189 static const char *ai_name(const struct addrinfo *ai)
 190 {
 191         static char addr[NI_MAXHOST];
 192         if (getnameinfo(ai->ai_addr, ai->ai_addrlen, addr, sizeof(addr), NULL, 0,
 193                         NI_NUMERICHOST) != 0)
 194                 strcpy(addr, "(unknown)");
 195
 196         return addr;
 197 }
 198
 199 /*
 200  * Returns a connected socket() fd, or else die()s.
 201  */
 202 static int git_tcp_connect_sock(char *host, int flags)
 203 {
 204         struct strbuf error_message = STRBUF_INIT;
 205         int sockfd = -1;
 206         const char *port = STR(DEFAULT_GIT_PORT);
 207         struct addrinfo hints, *ai0, *ai;
 208         int gai;
 209         int cnt = 0;
 210
 211         get_host_and_port(&host, &port);
 212         if (!*port)
 213                 port = "<none>";
 214
 215         memset(&hints, 0, sizeof(hints));
 216         hints.ai_socktype = SOCK_STREAM;
 217         hints.ai_protocol = IPPROTO_TCP;
 218
 219         if (flags & CONNECT_VERBOSE)
 220                 fprintf(stderr, "Looking up %s ... ", host);
 221
 222         gai = getaddrinfo(host, port, &hints, &ai);
 223         if (gai)
 224                 die("Unable to look up %s (port %s) (%s)", host, port, gai_strerror(gai));
 225
 226         if (flags & CONNECT_VERBOSE)
 227                 fprintf(stderr, "done.\nConnecting to %s (port %s) ... ", host, port);
 228
 229         for (ai0 = ai; ai; ai = ai->ai_next, cnt++) {
 230                 sockfd = socket(ai->ai_family,
 231                                 ai->ai_socktype, ai->ai_protocol);
 232                 if ((sockfd < 0) ||
 233                     (connect(sockfd, ai->ai_addr, ai->ai_addrlen) < 0)) {
 234                         strbuf_addf(&error_message, "%s[%d: %s]: errno=%s\n",
 235                                     host, cnt, ai_name(ai), strerror(errno));
 236                         if (0 <= sockfd)
 237                                 close(sockfd);
 238                         sockfd = -1;
 239                         continue;
 240                 }
 241                 if (flags & CONNECT_VERBOSE)
 242                         fprintf(stderr, "%s ", ai_name(ai));
 243                 break;
 244         }
 245
 246         freeaddrinfo(ai0);
 247
 248         if (sockfd < 0)
 249                 die("unable to connect to %s:\n%s", host, error_message.buf);
 250
 251         enable_keepalive(sockfd);
 252
 253         if (flags & CONNECT_VERBOSE)
 254                 fprintf(stderr, "done.\n");
 255
 256         strbuf_release(&error_message);
 257
 258         return sockfd;
 259 }
 260
 261 #else /* NO_IPV6 */
 262
 263 /*
 264  * Returns a connected socket() fd, or else die()s.
 265  */
 266 static int git_tcp_connect_sock(char *host, int flags)
 267 {
 268         struct strbuf error_message = STRBUF_INIT;
 269         int sockfd = -1;
 270         const char *port = STR(DEFAULT_GIT_PORT);
 271         char *ep;
 272         struct hostent *he;
 273         struct sockaddr_in sa;
 274         char **ap;
 275         unsigned int nport;
 276         int cnt;
 277
 278         get_host_and_port(&host, &port);
 279
 280         if (flags & CONNECT_VERBOSE)
 281                 fprintf(stderr, "Looking up %s ... ", host);
 282
 283         he = gethostbyname(host);
 284         if (!he)
 285                 die("Unable to look up %s (%s)", host, hstrerror(h_errno));
 286         nport = strtoul(port, &ep, 10);
 287         if ( ep == port || *ep ) {
 288                 /* Not numeric */
 289                 struct servent *se = getservbyname(port,"tcp");
 290                 if ( !se )
 291                         die("Unknown port %s", port);
 292                 nport = se->s_port;
 293         }
 294
 295         if (flags & CONNECT_VERBOSE)
 296                 fprintf(stderr, "done.\nConnecting to %s (port %s) ... ", host, port);
 297
 298         for (cnt = 0, ap = he->h_addr_list; *ap; ap++, cnt++) {
 299                 memset(&sa, 0, sizeof sa);
 300                 sa.sin_family = he->h_addrtype;
 301                 sa.sin_port = htons(nport);
 302                 memcpy(&sa.sin_addr, *ap, he->h_length);
 303
 304                 sockfd = socket(he->h_addrtype, SOCK_STREAM, 0);
 305                 if ((sockfd < 0) ||
 306                     connect(sockfd, (struct sockaddr *)&sa, sizeof sa) < 0) {
 307                         strbuf_addf(&error_message, "%s[%d: %s]: errno=%s\n",
 308                                 host,
 309                                 cnt,
 310                                 inet_ntoa(*(struct in_addr *)&sa.sin_addr),
 311                                 strerror(errno));
 312                         if (0 <= sockfd)
 313                                 close(sockfd);
 314                         sockfd = -1;
 315                         continue;
 316                 }
 317                 if (flags & CONNECT_VERBOSE)
 318                         fprintf(stderr, "%s ",
 319                                 inet_ntoa(*(struct in_addr *)&sa.sin_addr));
 320                 break;
 321         }
 322
 323         if (sockfd < 0)
 324                 die("unable to connect to %s:\n%s", host, error_message.buf);
 325
 326         enable_keepalive(sockfd);
 327
 328         if (flags & CONNECT_VERBOSE)
 329                 fprintf(stderr, "done.\n");
 330
 331         return sockfd;
 332 }
 333
 334 #endif /* NO_IPV6 */
 335
 336
 337 static void git_tcp_connect(int fd[2], char *host, int flags)
 338 {
 339         int sockfd = git_tcp_connect_sock(host, flags);
 340
 341         fd[0] = sockfd;
 342         fd[1] = dup(sockfd);
 343 }
 344
 345
 346 static char *git_proxy_command;
 347
 348 static int git_proxy_command_options(const char *var, const char *value,
 349                 void *cb)
 350 {
 351         if (!strcmp(var, "core.gitproxy")) {
 352                 const char *for_pos;
 353                 int matchlen = -1;
 354                 int hostlen;
 355                 const char *rhost_name = cb;
 356                 int rhost_len = strlen(rhost_name);
 357
 358                 if (git_proxy_command)
 359                         return 0;
 360                 if (!value)
 361                         return config_error_nonbool(var);
 362                 /* [core]
 363                  * ;# matches www.kernel.org as well
 364                  * gitproxy = netcatter-1 for kernel.org
 365                  * gitproxy = netcatter-2 for sample.xz
 366                  * gitproxy = netcatter-default
 367                  */
 368                 for_pos = strstr(value, " for ");
 369                 if (!for_pos)
 370                         /* matches everybody */
 371                         matchlen = strlen(value);
 372                 else {
 373                         hostlen = strlen(for_pos + 5);
 374                         if (rhost_len < hostlen)
 375                                 matchlen = -1;
 376                         else if (!strncmp(for_pos + 5,
 377                                           rhost_name + rhost_len - hostlen,
 378                                           hostlen) &&
 379                                  ((rhost_len == hostlen) ||
 380                                   rhost_name[rhost_len - hostlen -1] == '.'))
 381                                 matchlen = for_pos - value;
 382                         else
 383                                 matchlen = -1;
 384                 }
 385                 if (0 <= matchlen) {
 386                         /* core.gitproxy = none for kernel.org */
 387                         if (matchlen == 4 &&
 388                             !memcmp(value, "none", 4))
 389                                 matchlen = 0;
 390                         git_proxy_command = xmemdupz(value, matchlen);
 391                 }
 392                 return 0;
 393         }
 394
 395         return git_default_config(var, value, cb);
 396 }
 397
 398 static int git_use_proxy(const char *host)
 399 {
 400         git_proxy_command = getenv("GIT_PROXY_COMMAND");
 401         git_config(git_proxy_command_options, (void*)host);
 402         return (git_proxy_command && *git_proxy_command);
 403 }
 404
 405 static struct child_process *git_proxy_connect(int fd[2], char *host)
 406 {
 407         const char *port = STR(DEFAULT_GIT_PORT);
 408         const char **argv;
 409         struct child_process *proxy;
 410
 411         get_host_and_port(&host, &port);
 412
 413         argv = xmalloc(sizeof(*argv) * 4);
 414         argv[0] = git_proxy_command;
 415         argv[1] = host;
 416         argv[2] = port;
 417         argv[3] = NULL;
 418         proxy = xcalloc(1, sizeof(*proxy));
 419         proxy->argv = argv;
 420         proxy->in = -1;
 421         proxy->out = -1;
 422         if (start_command(proxy))
 423                 die("cannot start proxy %s", argv[0]);
 424         fd[0] = proxy->out; /* read from proxy stdout */
 425         fd[1] = proxy->in;  /* write to proxy stdin */
 426         return proxy;
 427 }
 428
 429 #define MAX_CMD_LEN 1024
 430
 431 static char *get_port(char *host)
 432 {
 433         char *end;
 434         char *p = strchr(host, ':');
 435
 436         if (p) {
 437                 long port = strtol(p + 1, &end, 10);
 438                 if (end != p + 1 && *end == '\0' && 0 <= port && port < 65536) {
 439                         *p = '\0';
 440                         return p+1;
 441                 }
 442         }
 443
 444         return NULL;
 445 }
 446
 447 static struct child_process no_fork;
 448
 449 /*
 450  * This returns a dummy child_process if the transport protocol does not
 451  * need fork(2), or a struct child_process object if it does.  Once done,
 452  * finish the connection with finish_connect() with the value returned from
 453  * this function (it is safe to call finish_connect() with NULL to support
 454  * the former case).
 455  *
 456  * If it returns, the connect is successful; it just dies on errors (this
 457  * will hopefully be changed in a libification effort, to return NULL when
 458  * the connection failed).
 459  */
 460 struct child_process *git_connect(int fd[2], const char *url_orig,
 461                                   const char *prog, int flags)
 462 {
 463         char *url;
 464         char *host, *path;
 465         char *end;
 466         int c;
 467         struct child_process *conn = &no_fork;
 468         enum protocol protocol = PROTO_LOCAL;
 469         int free_path = 0;
 470         char *port = NULL;
 471         const char **arg;
 472         struct strbuf cmd;
 473
 474         /* Without this we cannot rely on waitpid() to tell
 475          * what happened to our children.
 476          */
 477         signal(SIGCHLD, SIG_DFL);
 478
 479         if (is_url(url_orig))
 480                 url = url_decode(url_orig);
 481         else
 482                 url = xstrdup(url_orig);
 483
 484         host = strstr(url, "://");
 485         if (host) {
 486                 *host = '\0';
 487                 protocol = get_protocol(url);
 488                 host += 3;
 489                 c = '/';
 490         } else {
 491                 host = url;
 492                 c = ':';
 493         }
 494
 495         /*
 496          * Don't do destructive transforms with git:// as that
 497          * protocol code does '[]' unwrapping of its own.
 498          */
 499         if (host[0] == '[') {
 500                 end = strchr(host + 1, ']');
 501                 if (end) {
 502                         if (protocol != PROTO_GIT) {
 503                                 *end = 0;
 504                                 host++;
 505                         }
 506                         end++;
 507                 } else
 508                         end = host;
 509         } else
 510                 end = host;
 511
 512         path = strchr(end, c);
 513         if (path && !has_dos_drive_prefix(end)) {
 514                 if (c == ':') {
 515                         protocol = PROTO_SSH;
 516                         *path++ = '\0';
 517                 }
 518         } else
 519                 path = end;
 520
 521         if (!path || !*path)
 522                 die("No path specified. See 'man git-pull' for valid url syntax");
 523
 524         /*
 525          * null-terminate hostname and point path to ~ for URL's like this:
 526          *    ssh://host.xz/~user/repo
 527          */
 528         if (protocol != PROTO_LOCAL && host != url) {
 529                 char *ptr = path;
 530                 if (path[1] == '~')
 531                         path++;
 532                 else {
 533                         path = xstrdup(ptr);
 534                         free_path = 1;
 535                 }
 536
 537                 *ptr = '\0';
 538         }
 539
 540         /*
 541          * Add support for ssh port: ssh://host.xy:<port>/...
 542          */
 543         if (protocol == PROTO_SSH && host != url)
 544                 port = get_port(host);
 545
 546         if (protocol == PROTO_GIT) {
 547                 /* These underlying connection commands die() if they
 548                  * cannot connect.
 549                  */
 550                 char *target_host = xstrdup(host);
 551                 if (git_use_proxy(host))
 552                         conn = git_proxy_connect(fd, host);
 553                 else
 554                         git_tcp_connect(fd, host, flags);
 555                 /*
 556                  * Separate original protocol components prog and path
 557                  * from extended host header with a NUL byte.
 558                  *
 559                  * Note: Do not add any other headers here!  Doing so
 560                  * will cause older git-daemon servers to crash.
 561                  */
 562                 packet_write(fd[1],
 563                              "%s %s%chost=%s%c",
 564                              prog, path, 0,
 565                              target_host, 0);
 566                 free(target_host);
 567                 free(url);
 568                 if (free_path)
 569                         free(path);
 570                 return conn;
 571         }
 572
 573         conn = xcalloc(1, sizeof(*conn));
 574
 575         strbuf_init(&cmd, MAX_CMD_LEN);
 576         strbuf_addstr(&cmd, prog);
 577         strbuf_addch(&cmd, ' ');
 578         sq_quote_buf(&cmd, path);
 579         if (cmd.len >= MAX_CMD_LEN)
 580                 die("command line too long");
 581
 582         conn->in = conn->out = -1;
 583         conn->argv = arg = xcalloc(7, sizeof(*arg));
 584         if (protocol == PROTO_SSH) {
 585                 const char *ssh = getenv("GIT_SSH");
 586                 int putty = ssh && strcasestr(ssh, "plink");
 587                 if (!ssh) ssh = "ssh";
 588
 589                 *arg++ = ssh;
 590                 if (putty && !strcasestr(ssh, "tortoiseplink"))
 591                         *arg++ = "-batch";
 592                 if (port) {
 593                         /* P is for PuTTY, p is for OpenSSH */
 594                         *arg++ = putty ? "-P" : "-p";
 595                         *arg++ = port;
 596                 }
 597                 *arg++ = host;
 598         }
 599         else {
 600                 /* remove repo-local variables from the environment */
 601                 conn->env = local_repo_env;
 602                 conn->use_shell = 1;
 603         }
 604         *arg++ = cmd.buf;
 605         *arg = NULL;
 606
 607         if (start_command(conn))
 608                 die("unable to fork");
 609
 610         fd[0] = conn->out; /* read from child's stdout */
 611         fd[1] = conn->in;  /* write to child's stdin */
 612         strbuf_release(&cmd);
 613         free(url);
 614         if (free_path)
 615                 free(path);
 616         return conn;
 617 }
 618
 619 int git_connection_is_socket(struct child_process *conn)
 620 {
 621         return conn == &no_fork;
 622 }
 623
 624 int finish_connect(struct child_process *conn)
 625 {
 626         int code;
 627         if (!conn || git_connection_is_socket(conn))
 628                 return 0;
 629
 630         code = finish_command(conn);
 631         free(conn->argv);
 632         free(conn);
 633         return code;
 634 }
 635
 636 char *git_getpass(const char *prompt)
 637 {
 638         const char *askpass;
 639         struct child_process pass;
 640         const char *args[3];
 641         static struct strbuf buffer = STRBUF_INIT;
 642
 643         askpass = getenv("GIT_ASKPASS");
 644         if (!askpass)
 645                 askpass = askpass_program;
 646         if (!askpass)
 647                 askpass = getenv("SSH_ASKPASS");
 648         if (!askpass || !(*askpass)) {
 649                 char *result = getpass(prompt);
 650                 if (!result)
 651                         die_errno("Could not read password");
 652                 return result;
 653         }
 654
 655         args[0] = askpass;
 656         args[1] = prompt;
 657         args[2] = NULL;
 658
 659         memset(&pass, 0, sizeof(pass));
 660         pass.argv = args;
 661         pass.out = -1;
 662
 663         if (start_command(&pass))
 664                 exit(1);
 665
 666         strbuf_reset(&buffer);
 667         if (strbuf_read(&buffer, pass.out, 20) < 0)
 668                 die("failed to read password from %s\n", askpass);
 669
 670         close(pass.out);
 671
 672         if (finish_command(&pass))
 673                 exit(1);
 674
 675         strbuf_setlen(&buffer, strcspn(buffer.buf, "\r\n"));
 676
 677         return buffer.buf;
 678 }