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 static void die_initial_contact(int got_at_least_one_head)
  53 {
  54         if (got_at_least_one_head)
  55                 die("The remote end hung up upon initial contact");
  56         else
  57                 die("Could not read from remote repository.\n\n"
  58                     "Please make sure you have the correct access rights\n"
  59                     "and the repository exists.");
  60 }
  61
  62 /*
  63  * Read all the refs from the other end
  64  */
  65 struct ref **get_remote_heads(int in, struct ref **list,
  66                               unsigned int flags,
  67                               struct extra_have_objects *extra_have)
  68 {
  69         int got_at_least_one_head = 0;
  70
  71         *list = NULL;
  72         for (;;) {
  73                 struct ref *ref;
  74                 unsigned char old_sha1[20];
  75                 static char buffer[1000];
  76                 char *name;
  77                 int len, name_len;
  78
  79                 len = packet_read(in, buffer, sizeof(buffer));
  80                 if (len < 0)
  81                         die_initial_contact(got_at_least_one_head);
  82
  83                 if (!len)
  84                         break;
  85                 if (buffer[len-1] == '\n')
  86                         buffer[--len] = 0;
  87
  88                 if (len > 4 && !prefixcmp(buffer, "ERR "))
  89                         die("remote error: %s", buffer + 4);
  90
  91                 if (len < 42 || get_sha1_hex(buffer, old_sha1) || buffer[40] != ' ')
  92                         die("protocol error: expected sha/ref, got '%s'", buffer);
  93                 name = buffer + 41;
  94
  95                 name_len = strlen(name);
  96                 if (len != name_len + 41) {
  97                         free(server_capabilities);
  98                         server_capabilities = xstrdup(name + name_len + 1);
  99                 }
 100
 101                 if (extra_have &&
 102                     name_len == 5 && !memcmp(".have", name, 5)) {
 103                         add_extra_have(extra_have, old_sha1);
 104                         continue;
 105                 }
 106
 107                 if (!check_ref(name, name_len, flags))
 108                         continue;
 109                 ref = alloc_ref(buffer + 41);
 110                 hashcpy(ref->old_sha1, old_sha1);
 111                 *list = ref;
 112                 list = &ref->next;
 113                 got_at_least_one_head = 1;
 114         }
 115         return list;
 116 }
 117
 118 int server_supports(const char *feature)
 119 {
 120         return !!parse_feature_request(server_capabilities, feature);
 121 }
 122
 123 const char *parse_feature_request(const char *feature_list, const char *feature)
 124 {
 125         int len;
 126
 127         if (!feature_list)
 128                 return NULL;
 129
 130         len = strlen(feature);
 131         while (*feature_list) {
 132                 const char *found = strstr(feature_list, feature);
 133                 if (!found)
 134                         return NULL;
 135                 if ((feature_list == found || isspace(found[-1])) &&
 136                     (!found[len] || isspace(found[len]) || found[len] == '='))
 137                         return found;
 138                 feature_list = found + 1;
 139         }
 140         return NULL;
 141 }
 142
 143 enum protocol {
 144         PROTO_LOCAL = 1,
 145         PROTO_SSH,
 146         PROTO_GIT
 147 };
 148
 149 static enum protocol get_protocol(const char *name)
 150 {
 151         if (!strcmp(name, "ssh"))
 152                 return PROTO_SSH;
 153         if (!strcmp(name, "git"))
 154                 return PROTO_GIT;
 155         if (!strcmp(name, "git+ssh"))
 156                 return PROTO_SSH;
 157         if (!strcmp(name, "ssh+git"))
 158                 return PROTO_SSH;
 159         if (!strcmp(name, "file"))
 160                 return PROTO_LOCAL;
 161         die("I don't handle protocol '%s'", name);
 162 }
 163
 164 #define STR_(s) # s
 165 #define STR(s)  STR_(s)
 166
 167 static void get_host_and_port(char **host, const char **port)
 168 {
 169         char *colon, *end;
 170
 171         if (*host[0] == '[') {
 172                 end = strchr(*host + 1, ']');
 173                 if (end) {
 174                         *end = 0;
 175                         end++;
 176                         (*host)++;
 177                 } else
 178                         end = *host;
 179         } else
 180                 end = *host;
 181         colon = strchr(end, ':');
 182
 183         if (colon) {
 184                 *colon = 0;
 185                 *port = colon + 1;
 186         }
 187 }
 188
 189 static void enable_keepalive(int sockfd)
 190 {
 191         int ka = 1;
 192
 193         if (setsockopt(sockfd, SOL_SOCKET, SO_KEEPALIVE, &ka, sizeof(ka)) < 0)
 194                 fprintf(stderr, "unable to set SO_KEEPALIVE on socket: %s\n",
 195                         strerror(errno));
 196 }
 197
 198 #ifndef NO_IPV6
 199
 200 static const char *ai_name(const struct addrinfo *ai)
 201 {
 202         static char addr[NI_MAXHOST];
 203         if (getnameinfo(ai->ai_addr, ai->ai_addrlen, addr, sizeof(addr), NULL, 0,
 204                         NI_NUMERICHOST) != 0)
 205                 strcpy(addr, "(unknown)");
 206
 207         return addr;
 208 }
 209
 210 /*
 211  * Returns a connected socket() fd, or else die()s.
 212  */
 213 static int git_tcp_connect_sock(char *host, int flags)
 214 {
 215         struct strbuf error_message = STRBUF_INIT;
 216         int sockfd = -1;
 217         const char *port = STR(DEFAULT_GIT_PORT);
 218         struct addrinfo hints, *ai0, *ai;
 219         int gai;
 220         int cnt = 0;
 221
 222         get_host_and_port(&host, &port);
 223         if (!*port)
 224                 port = "<none>";
 225
 226         memset(&hints, 0, sizeof(hints));
 227         hints.ai_socktype = SOCK_STREAM;
 228         hints.ai_protocol = IPPROTO_TCP;
 229
 230         if (flags & CONNECT_VERBOSE)
 231                 fprintf(stderr, "Looking up %s ... ", host);
 232
 233         gai = getaddrinfo(host, port, &hints, &ai);
 234         if (gai)
 235                 die("Unable to look up %s (port %s) (%s)", host, port, gai_strerror(gai));
 236
 237         if (flags & CONNECT_VERBOSE)
 238                 fprintf(stderr, "done.\nConnecting to %s (port %s) ... ", host, port);
 239
 240         for (ai0 = ai; ai; ai = ai->ai_next, cnt++) {
 241                 sockfd = socket(ai->ai_family,
 242                                 ai->ai_socktype, ai->ai_protocol);
 243                 if ((sockfd < 0) ||
 244                     (connect(sockfd, ai->ai_addr, ai->ai_addrlen) < 0)) {
 245                         strbuf_addf(&error_message, "%s[%d: %s]: errno=%s\n",
 246                                     host, cnt, ai_name(ai), strerror(errno));
 247                         if (0 <= sockfd)
 248                                 close(sockfd);
 249                         sockfd = -1;
 250                         continue;
 251                 }
 252                 if (flags & CONNECT_VERBOSE)
 253                         fprintf(stderr, "%s ", ai_name(ai));
 254                 break;
 255         }
 256
 257         freeaddrinfo(ai0);
 258
 259         if (sockfd < 0)
 260                 die("unable to connect to %s:\n%s", host, error_message.buf);
 261
 262         enable_keepalive(sockfd);
 263
 264         if (flags & CONNECT_VERBOSE)
 265                 fprintf(stderr, "done.\n");
 266
 267         strbuf_release(&error_message);
 268
 269         return sockfd;
 270 }
 271
 272 #else /* NO_IPV6 */
 273
 274 /*
 275  * Returns a connected socket() fd, or else die()s.
 276  */
 277 static int git_tcp_connect_sock(char *host, int flags)
 278 {
 279         struct strbuf error_message = STRBUF_INIT;
 280         int sockfd = -1;
 281         const char *port = STR(DEFAULT_GIT_PORT);
 282         char *ep;
 283         struct hostent *he;
 284         struct sockaddr_in sa;
 285         char **ap;
 286         unsigned int nport;
 287         int cnt;
 288
 289         get_host_and_port(&host, &port);
 290
 291         if (flags & CONNECT_VERBOSE)
 292                 fprintf(stderr, "Looking up %s ... ", host);
 293
 294         he = gethostbyname(host);
 295         if (!he)
 296                 die("Unable to look up %s (%s)", host, hstrerror(h_errno));
 297         nport = strtoul(port, &ep, 10);
 298         if ( ep == port || *ep ) {
 299                 /* Not numeric */
 300                 struct servent *se = getservbyname(port,"tcp");
 301                 if ( !se )
 302                         die("Unknown port %s", port);
 303                 nport = se->s_port;
 304         }
 305
 306         if (flags & CONNECT_VERBOSE)
 307                 fprintf(stderr, "done.\nConnecting to %s (port %s) ... ", host, port);
 308
 309         for (cnt = 0, ap = he->h_addr_list; *ap; ap++, cnt++) {
 310                 memset(&sa, 0, sizeof sa);
 311                 sa.sin_family = he->h_addrtype;
 312                 sa.sin_port = htons(nport);
 313                 memcpy(&sa.sin_addr, *ap, he->h_length);
 314
 315                 sockfd = socket(he->h_addrtype, SOCK_STREAM, 0);
 316                 if ((sockfd < 0) ||
 317                     connect(sockfd, (struct sockaddr *)&sa, sizeof sa) < 0) {
 318                         strbuf_addf(&error_message, "%s[%d: %s]: errno=%s\n",
 319                                 host,
 320                                 cnt,
 321                                 inet_ntoa(*(struct in_addr *)&sa.sin_addr),
 322                                 strerror(errno));
 323                         if (0 <= sockfd)
 324                                 close(sockfd);
 325                         sockfd = -1;
 326                         continue;
 327                 }
 328                 if (flags & CONNECT_VERBOSE)
 329                         fprintf(stderr, "%s ",
 330                                 inet_ntoa(*(struct in_addr *)&sa.sin_addr));
 331                 break;
 332         }
 333
 334         if (sockfd < 0)
 335                 die("unable to connect to %s:\n%s", host, error_message.buf);
 336
 337         enable_keepalive(sockfd);
 338
 339         if (flags & CONNECT_VERBOSE)
 340                 fprintf(stderr, "done.\n");
 341
 342         return sockfd;
 343 }
 344
 345 #endif /* NO_IPV6 */
 346
 347
 348 static void git_tcp_connect(int fd[2], char *host, int flags)
 349 {
 350         int sockfd = git_tcp_connect_sock(host, flags);
 351
 352         fd[0] = sockfd;
 353         fd[1] = dup(sockfd);
 354 }
 355
 356
 357 static char *git_proxy_command;
 358
 359 static int git_proxy_command_options(const char *var, const char *value,
 360                 void *cb)
 361 {
 362         if (!strcmp(var, "core.gitproxy")) {
 363                 const char *for_pos;
 364                 int matchlen = -1;
 365                 int hostlen;
 366                 const char *rhost_name = cb;
 367                 int rhost_len = strlen(rhost_name);
 368
 369                 if (git_proxy_command)
 370                         return 0;
 371                 if (!value)
 372                         return config_error_nonbool(var);
 373                 /* [core]
 374                  * ;# matches www.kernel.org as well
 375                  * gitproxy = netcatter-1 for kernel.org
 376                  * gitproxy = netcatter-2 for sample.xz
 377                  * gitproxy = netcatter-default
 378                  */
 379                 for_pos = strstr(value, " for ");
 380                 if (!for_pos)
 381                         /* matches everybody */
 382                         matchlen = strlen(value);
 383                 else {
 384                         hostlen = strlen(for_pos + 5);
 385                         if (rhost_len < hostlen)
 386                                 matchlen = -1;
 387                         else if (!strncmp(for_pos + 5,
 388                                           rhost_name + rhost_len - hostlen,
 389                                           hostlen) &&
 390                                  ((rhost_len == hostlen) ||
 391                                   rhost_name[rhost_len - hostlen -1] == '.'))
 392                                 matchlen = for_pos - value;
 393                         else
 394                                 matchlen = -1;
 395                 }
 396                 if (0 <= matchlen) {
 397                         /* core.gitproxy = none for kernel.org */
 398                         if (matchlen == 4 &&
 399                             !memcmp(value, "none", 4))
 400                                 matchlen = 0;
 401                         git_proxy_command = xmemdupz(value, matchlen);
 402                 }
 403                 return 0;
 404         }
 405
 406         return git_default_config(var, value, cb);
 407 }
 408
 409 static int git_use_proxy(const char *host)
 410 {
 411         git_proxy_command = getenv("GIT_PROXY_COMMAND");
 412         git_config(git_proxy_command_options, (void*)host);
 413         return (git_proxy_command && *git_proxy_command);
 414 }
 415
 416 static struct child_process *git_proxy_connect(int fd[2], char *host)
 417 {
 418         const char *port = STR(DEFAULT_GIT_PORT);
 419         const char **argv;
 420         struct child_process *proxy;
 421
 422         get_host_and_port(&host, &port);
 423
 424         argv = xmalloc(sizeof(*argv) * 4);
 425         argv[0] = git_proxy_command;
 426         argv[1] = host;
 427         argv[2] = port;
 428         argv[3] = NULL;
 429         proxy = xcalloc(1, sizeof(*proxy));
 430         proxy->argv = argv;
 431         proxy->in = -1;
 432         proxy->out = -1;
 433         if (start_command(proxy))
 434                 die("cannot start proxy %s", argv[0]);
 435         fd[0] = proxy->out; /* read from proxy stdout */
 436         fd[1] = proxy->in;  /* write to proxy stdin */
 437         return proxy;
 438 }
 439
 440 #define MAX_CMD_LEN 1024
 441
 442 static char *get_port(char *host)
 443 {
 444         char *end;
 445         char *p = strchr(host, ':');
 446
 447         if (p) {
 448                 long port = strtol(p + 1, &end, 10);
 449                 if (end != p + 1 && *end == '\0' && 0 <= port && port < 65536) {
 450                         *p = '\0';
 451                         return p+1;
 452                 }
 453         }
 454
 455         return NULL;
 456 }
 457
 458 static struct child_process no_fork;
 459
 460 /*
 461  * This returns a dummy child_process if the transport protocol does not
 462  * need fork(2), or a struct child_process object if it does.  Once done,
 463  * finish the connection with finish_connect() with the value returned from
 464  * this function (it is safe to call finish_connect() with NULL to support
 465  * the former case).
 466  *
 467  * If it returns, the connect is successful; it just dies on errors (this
 468  * will hopefully be changed in a libification effort, to return NULL when
 469  * the connection failed).
 470  */
 471 struct child_process *git_connect(int fd[2], const char *url_orig,
 472                                   const char *prog, int flags)
 473 {
 474         char *url;
 475         char *host, *path;
 476         char *end;
 477         int c;
 478         struct child_process *conn = &no_fork;
 479         enum protocol protocol = PROTO_LOCAL;
 480         int free_path = 0;
 481         char *port = NULL;
 482         const char **arg;
 483         struct strbuf cmd;
 484
 485         /* Without this we cannot rely on waitpid() to tell
 486          * what happened to our children.
 487          */
 488         signal(SIGCHLD, SIG_DFL);
 489
 490         if (is_url(url_orig))
 491                 url = url_decode(url_orig);
 492         else
 493                 url = xstrdup(url_orig);
 494
 495         host = strstr(url, "://");
 496         if (host) {
 497                 *host = '\0';
 498                 protocol = get_protocol(url);
 499                 host += 3;
 500                 c = '/';
 501         } else {
 502                 host = url;
 503                 c = ':';
 504         }
 505
 506         /*
 507          * Don't do destructive transforms with git:// as that
 508          * protocol code does '[]' unwrapping of its own.
 509          */
 510         if (host[0] == '[') {
 511                 end = strchr(host + 1, ']');
 512                 if (end) {
 513                         if (protocol != PROTO_GIT) {
 514                                 *end = 0;
 515                                 host++;
 516                         }
 517                         end++;
 518                 } else
 519                         end = host;
 520         } else
 521                 end = host;
 522
 523         path = strchr(end, c);
 524         if (path && !has_dos_drive_prefix(end)) {
 525                 if (c == ':') {
 526                         protocol = PROTO_SSH;
 527                         *path++ = '\0';
 528                 }
 529         } else
 530                 path = end;
 531
 532         if (!path || !*path)
 533                 die("No path specified. See 'man git-pull' for valid url syntax");
 534
 535         /*
 536          * null-terminate hostname and point path to ~ for URL's like this:
 537          *    ssh://host.xz/~user/repo
 538          */
 539         if (protocol != PROTO_LOCAL && host != url) {
 540                 char *ptr = path;
 541                 if (path[1] == '~')
 542                         path++;
 543                 else {
 544                         path = xstrdup(ptr);
 545                         free_path = 1;
 546                 }
 547
 548                 *ptr = '\0';
 549         }
 550
 551         /*
 552          * Add support for ssh port: ssh://host.xy:<port>/...
 553          */
 554         if (protocol == PROTO_SSH && host != url)
 555                 port = get_port(end);
 556
 557         if (protocol == PROTO_GIT) {
 558                 /* These underlying connection commands die() if they
 559                  * cannot connect.
 560                  */
 561                 char *target_host = xstrdup(host);
 562                 if (git_use_proxy(host))
 563                         conn = git_proxy_connect(fd, host);
 564                 else
 565                         git_tcp_connect(fd, host, flags);
 566                 /*
 567                  * Separate original protocol components prog and path
 568                  * from extended host header with a NUL byte.
 569                  *
 570                  * Note: Do not add any other headers here!  Doing so
 571                  * will cause older git-daemon servers to crash.
 572                  */
 573                 packet_write(fd[1],
 574                              "%s %s%chost=%s%c",
 575                              prog, path, 0,
 576                              target_host, 0);
 577                 free(target_host);
 578                 free(url);
 579                 if (free_path)
 580                         free(path);
 581                 return conn;
 582         }
 583
 584         conn = xcalloc(1, sizeof(*conn));
 585
 586         strbuf_init(&cmd, MAX_CMD_LEN);
 587         strbuf_addstr(&cmd, prog);
 588         strbuf_addch(&cmd, ' ');
 589         sq_quote_buf(&cmd, path);
 590         if (cmd.len >= MAX_CMD_LEN)
 591                 die("command line too long");
 592
 593         conn->in = conn->out = -1;
 594         conn->argv = arg = xcalloc(7, sizeof(*arg));
 595         if (protocol == PROTO_SSH) {
 596                 const char *ssh = getenv("GIT_SSH");
 597                 int putty = ssh && strcasestr(ssh, "plink");
 598                 if (!ssh) ssh = "ssh";
 599
 600                 *arg++ = ssh;
 601                 if (putty && !strcasestr(ssh, "tortoiseplink"))
 602                         *arg++ = "-batch";
 603                 if (port) {
 604                         /* P is for PuTTY, p is for OpenSSH */
 605                         *arg++ = putty ? "-P" : "-p";
 606                         *arg++ = port;
 607                 }
 608                 *arg++ = host;
 609         }
 610         else {
 611                 /* remove repo-local variables from the environment */
 612                 conn->env = local_repo_env;
 613                 conn->use_shell = 1;
 614         }
 615         *arg++ = cmd.buf;
 616         *arg = NULL;
 617
 618         if (start_command(conn))
 619                 die("unable to fork");
 620
 621         fd[0] = conn->out; /* read from child's stdout */
 622         fd[1] = conn->in;  /* write to child's stdin */
 623         strbuf_release(&cmd);
 624         free(url);
 625         if (free_path)
 626                 free(path);
 627         return conn;
 628 }
 629
 630 int git_connection_is_socket(struct child_process *conn)
 631 {
 632         return conn == &no_fork;
 633 }
 634
 635 int finish_connect(struct child_process *conn)
 636 {
 637         int code;
 638         if (!conn || git_connection_is_socket(conn))
 639                 return 0;
 640
 641         code = finish_command(conn);
 642         free(conn->argv);
 643         free(conn);
 644         return code;
 645 }