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