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