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 const char *parse_feature_value(const char *feature_list, const char *feature, int *lenp)
 103 {
 104         int len;
 105
 106         if (!feature_list)
 107                 return NULL;
 108
 109         len = strlen(feature);
 110         while (*feature_list) {
 111                 const char *found = strstr(feature_list, feature);
 112                 if (!found)
 113                         return NULL;
 114                 if (feature_list == found || isspace(found[-1])) {
 115                         const char *value = found + len;
 116                         /* feature with no value (e.g., "thin-pack") */
 117                         if (!*value || isspace(*value)) {
 118                                 if (lenp)
 119                                         *lenp = 0;
 120                                 return value;
 121                         }
 122                         /* feature with a value (e.g., "agent=git/1.2.3") */
 123                         else if (*value == '=') {
 124                                 value++;
 125                                 if (lenp)
 126                                         *lenp = strcspn(value, " \t\n");
 127                                 return value;
 128                         }
 129                         /*
 130                          * otherwise we matched a substring of another feature;
 131                          * keep looking
 132                          */
 133                 }
 134                 feature_list = found + 1;
 135         }
 136         return NULL;
 137 }
 138
 139 int parse_feature_request(const char *feature_list, const char *feature)
 140 {
 141         return !!parse_feature_value(feature_list, feature, NULL);
 142 }
 143
 144 const char *server_feature_value(const char *feature, int *len)
 145 {
 146         return parse_feature_value(server_capabilities, feature, len);
 147 }
 148
 149 int server_supports(const char *feature)
 150 {
 151         return !!server_feature_value(feature, NULL);
 152 }
 153
 154 enum protocol {
 155         PROTO_LOCAL = 1,
 156         PROTO_SSH,
 157         PROTO_GIT
 158 };
 159
 160 static enum protocol get_protocol(const char *name)
 161 {
 162         if (!strcmp(name, "ssh"))
 163                 return PROTO_SSH;
 164         if (!strcmp(name, "git"))
 165                 return PROTO_GIT;
 166         if (!strcmp(name, "git+ssh"))
 167                 return PROTO_SSH;
 168         if (!strcmp(name, "ssh+git"))
 169                 return PROTO_SSH;
 170         if (!strcmp(name, "file"))
 171                 return PROTO_LOCAL;
 172         die("I don't handle protocol '%s'", name);
 173 }
 174
 175 #define STR_(s) # s
 176 #define STR(s)  STR_(s)
 177
 178 static void get_host_and_port(char **host, const char **port)
 179 {
 180         char *colon, *end;
 181
 182         if (*host[0] == '[') {
 183                 end = strchr(*host + 1, ']');
 184                 if (end) {
 185                         *end = 0;
 186                         end++;
 187                         (*host)++;
 188                 } else
 189                         end = *host;
 190         } else
 191                 end = *host;
 192         colon = strchr(end, ':');
 193
 194         if (colon) {
 195                 *colon = 0;
 196                 *port = colon + 1;
 197         }
 198 }
 199
 200 static void enable_keepalive(int sockfd)
 201 {
 202         int ka = 1;
 203
 204         if (setsockopt(sockfd, SOL_SOCKET, SO_KEEPALIVE, &ka, sizeof(ka)) < 0)
 205                 fprintf(stderr, "unable to set SO_KEEPALIVE on socket: %s\n",
 206                         strerror(errno));
 207 }
 208
 209 #ifndef NO_IPV6
 210
 211 static const char *ai_name(const struct addrinfo *ai)
 212 {
 213         static char addr[NI_MAXHOST];
 214         if (getnameinfo(ai->ai_addr, ai->ai_addrlen, addr, sizeof(addr), NULL, 0,
 215                         NI_NUMERICHOST) != 0)
 216                 strcpy(addr, "(unknown)");
 217
 218         return addr;
 219 }
 220
 221 /*
 222  * Returns a connected socket() fd, or else die()s.
 223  */
 224 static int git_tcp_connect_sock(char *host, int flags)
 225 {
 226         struct strbuf error_message = STRBUF_INIT;
 227         int sockfd = -1;
 228         const char *port = STR(DEFAULT_GIT_PORT);
 229         struct addrinfo hints, *ai0, *ai;
 230         int gai;
 231         int cnt = 0;
 232
 233         get_host_and_port(&host, &port);
 234         if (!*port)
 235                 port = "<none>";
 236
 237         memset(&hints, 0, sizeof(hints));
 238         hints.ai_socktype = SOCK_STREAM;
 239         hints.ai_protocol = IPPROTO_TCP;
 240
 241         if (flags & CONNECT_VERBOSE)
 242                 fprintf(stderr, "Looking up %s ... ", host);
 243
 244         gai = getaddrinfo(host, port, &hints, &ai);
 245         if (gai)
 246                 die("Unable to look up %s (port %s) (%s)", host, port, gai_strerror(gai));
 247
 248         if (flags & CONNECT_VERBOSE)
 249                 fprintf(stderr, "done.\nConnecting to %s (port %s) ... ", host, port);
 250
 251         for (ai0 = ai; ai; ai = ai->ai_next, cnt++) {
 252                 sockfd = socket(ai->ai_family,
 253                                 ai->ai_socktype, ai->ai_protocol);
 254                 if ((sockfd < 0) ||
 255                     (connect(sockfd, ai->ai_addr, ai->ai_addrlen) < 0)) {
 256                         strbuf_addf(&error_message, "%s[%d: %s]: errno=%s\n",
 257                                     host, cnt, ai_name(ai), strerror(errno));
 258                         if (0 <= sockfd)
 259                                 close(sockfd);
 260                         sockfd = -1;
 261                         continue;
 262                 }
 263                 if (flags & CONNECT_VERBOSE)
 264                         fprintf(stderr, "%s ", ai_name(ai));
 265                 break;
 266         }
 267
 268         freeaddrinfo(ai0);
 269
 270         if (sockfd < 0)
 271                 die("unable to connect to %s:\n%s", host, error_message.buf);
 272
 273         enable_keepalive(sockfd);
 274
 275         if (flags & CONNECT_VERBOSE)
 276                 fprintf(stderr, "done.\n");
 277
 278         strbuf_release(&error_message);
 279
 280         return sockfd;
 281 }
 282
 283 #else /* NO_IPV6 */
 284
 285 /*
 286  * Returns a connected socket() fd, or else die()s.
 287  */
 288 static int git_tcp_connect_sock(char *host, int flags)
 289 {
 290         struct strbuf error_message = STRBUF_INIT;
 291         int sockfd = -1;
 292         const char *port = STR(DEFAULT_GIT_PORT);
 293         char *ep;
 294         struct hostent *he;
 295         struct sockaddr_in sa;
 296         char **ap;
 297         unsigned int nport;
 298         int cnt;
 299
 300         get_host_and_port(&host, &port);
 301
 302         if (flags & CONNECT_VERBOSE)
 303                 fprintf(stderr, "Looking up %s ... ", host);
 304
 305         he = gethostbyname(host);
 306         if (!he)
 307                 die("Unable to look up %s (%s)", host, hstrerror(h_errno));
 308         nport = strtoul(port, &ep, 10);
 309         if ( ep == port || *ep ) {
 310                 /* Not numeric */
 311                 struct servent *se = getservbyname(port,"tcp");
 312                 if ( !se )
 313                         die("Unknown port %s", port);
 314                 nport = se->s_port;
 315         }
 316
 317         if (flags & CONNECT_VERBOSE)
 318                 fprintf(stderr, "done.\nConnecting to %s (port %s) ... ", host, port);
 319
 320         for (cnt = 0, ap = he->h_addr_list; *ap; ap++, cnt++) {
 321                 memset(&sa, 0, sizeof sa);
 322                 sa.sin_family = he->h_addrtype;
 323                 sa.sin_port = htons(nport);
 324                 memcpy(&sa.sin_addr, *ap, he->h_length);
 325
 326                 sockfd = socket(he->h_addrtype, SOCK_STREAM, 0);
 327                 if ((sockfd < 0) ||
 328                     connect(sockfd, (struct sockaddr *)&sa, sizeof sa) < 0) {
 329                         strbuf_addf(&error_message, "%s[%d: %s]: errno=%s\n",
 330                                 host,
 331                                 cnt,
 332                                 inet_ntoa(*(struct in_addr *)&sa.sin_addr),
 333                                 strerror(errno));
 334                         if (0 <= sockfd)
 335                                 close(sockfd);
 336                         sockfd = -1;
 337                         continue;
 338                 }
 339                 if (flags & CONNECT_VERBOSE)
 340                         fprintf(stderr, "%s ",
 341                                 inet_ntoa(*(struct in_addr *)&sa.sin_addr));
 342                 break;
 343         }
 344
 345         if (sockfd < 0)
 346                 die("unable to connect to %s:\n%s", host, error_message.buf);
 347
 348         enable_keepalive(sockfd);
 349
 350         if (flags & CONNECT_VERBOSE)
 351                 fprintf(stderr, "done.\n");
 352
 353         return sockfd;
 354 }
 355
 356 #endif /* NO_IPV6 */
 357
 358
 359 static void git_tcp_connect(int fd[2], char *host, int flags)
 360 {
 361         int sockfd = git_tcp_connect_sock(host, flags);
 362
 363         fd[0] = sockfd;
 364         fd[1] = dup(sockfd);
 365 }
 366
 367
 368 static char *git_proxy_command;
 369
 370 static int git_proxy_command_options(const char *var, const char *value,
 371                 void *cb)
 372 {
 373         if (!strcmp(var, "core.gitproxy")) {
 374                 const char *for_pos;
 375                 int matchlen = -1;
 376                 int hostlen;
 377                 const char *rhost_name = cb;
 378                 int rhost_len = strlen(rhost_name);
 379
 380                 if (git_proxy_command)
 381                         return 0;
 382                 if (!value)
 383                         return config_error_nonbool(var);
 384                 /* [core]
 385                  * ;# matches www.kernel.org as well
 386                  * gitproxy = netcatter-1 for kernel.org
 387                  * gitproxy = netcatter-2 for sample.xz
 388                  * gitproxy = netcatter-default
 389                  */
 390                 for_pos = strstr(value, " for ");
 391                 if (!for_pos)
 392                         /* matches everybody */
 393                         matchlen = strlen(value);
 394                 else {
 395                         hostlen = strlen(for_pos + 5);
 396                         if (rhost_len < hostlen)
 397                                 matchlen = -1;
 398                         else if (!strncmp(for_pos + 5,
 399                                           rhost_name + rhost_len - hostlen,
 400                                           hostlen) &&
 401                                  ((rhost_len == hostlen) ||
 402                                   rhost_name[rhost_len - hostlen -1] == '.'))
 403                                 matchlen = for_pos - value;
 404                         else
 405                                 matchlen = -1;
 406                 }
 407                 if (0 <= matchlen) {
 408                         /* core.gitproxy = none for kernel.org */
 409                         if (matchlen == 4 &&
 410                             !memcmp(value, "none", 4))
 411                                 matchlen = 0;
 412                         git_proxy_command = xmemdupz(value, matchlen);
 413                 }
 414                 return 0;
 415         }
 416
 417         return git_default_config(var, value, cb);
 418 }
 419
 420 static int git_use_proxy(const char *host)
 421 {
 422         git_proxy_command = getenv("GIT_PROXY_COMMAND");
 423         git_config(git_proxy_command_options, (void*)host);
 424         return (git_proxy_command && *git_proxy_command);
 425 }
 426
 427 static struct child_process *git_proxy_connect(int fd[2], char *host)
 428 {
 429         const char *port = STR(DEFAULT_GIT_PORT);
 430         const char **argv;
 431         struct child_process *proxy;
 432
 433         get_host_and_port(&host, &port);
 434
 435         argv = xmalloc(sizeof(*argv) * 4);
 436         argv[0] = git_proxy_command;
 437         argv[1] = host;
 438         argv[2] = port;
 439         argv[3] = NULL;
 440         proxy = xcalloc(1, sizeof(*proxy));
 441         proxy->argv = argv;
 442         proxy->in = -1;
 443         proxy->out = -1;
 444         if (start_command(proxy))
 445                 die("cannot start proxy %s", argv[0]);
 446         fd[0] = proxy->out; /* read from proxy stdout */
 447         fd[1] = proxy->in;  /* write to proxy stdin */
 448         return proxy;
 449 }
 450
 451 #define MAX_CMD_LEN 1024
 452
 453 static char *get_port(char *host)
 454 {
 455         char *end;
 456         char *p = strchr(host, ':');
 457
 458         if (p) {
 459                 long port = strtol(p + 1, &end, 10);
 460                 if (end != p + 1 && *end == '\0' && 0 <= port && port < 65536) {
 461                         *p = '\0';
 462                         return p+1;
 463                 }
 464         }
 465
 466         return NULL;
 467 }
 468
 469 static struct child_process no_fork;
 470
 471 /*
 472  * This returns a dummy child_process if the transport protocol does not
 473  * need fork(2), or a struct child_process object if it does.  Once done,
 474  * finish the connection with finish_connect() with the value returned from
 475  * this function (it is safe to call finish_connect() with NULL to support
 476  * the former case).
 477  *
 478  * If it returns, the connect is successful; it just dies on errors (this
 479  * will hopefully be changed in a libification effort, to return NULL when
 480  * the connection failed).
 481  */
 482 struct child_process *git_connect(int fd[2], const char *url_orig,
 483                                   const char *prog, int flags)
 484 {
 485         char *url;
 486         char *host, *path;
 487         char *end;
 488         int c;
 489         struct child_process *conn = &no_fork;
 490         enum protocol protocol = PROTO_LOCAL;
 491         int free_path = 0;
 492         char *port = NULL;
 493         const char **arg;
 494         struct strbuf cmd;
 495
 496         /* Without this we cannot rely on waitpid() to tell
 497          * what happened to our children.
 498          */
 499         signal(SIGCHLD, SIG_DFL);
 500
 501         if (is_url(url_orig))
 502                 url = url_decode(url_orig);
 503         else
 504                 url = xstrdup(url_orig);
 505
 506         host = strstr(url, "://");
 507         if (host) {
 508                 *host = '\0';
 509                 protocol = get_protocol(url);
 510                 host += 3;
 511                 c = '/';
 512         } else {
 513                 host = url;
 514                 c = ':';
 515         }
 516
 517         /*
 518          * Don't do destructive transforms with git:// as that
 519          * protocol code does '[]' unwrapping of its own.
 520          */
 521         if (host[0] == '[') {
 522                 end = strchr(host + 1, ']');
 523                 if (end) {
 524                         if (protocol != PROTO_GIT) {
 525                                 *end = 0;
 526                                 host++;
 527                         }
 528                         end++;
 529                 } else
 530                         end = host;
 531         } else
 532                 end = host;
 533
 534         path = strchr(end, c);
 535         if (path && !has_dos_drive_prefix(end)) {
 536                 if (c == ':') {
 537                         protocol = PROTO_SSH;
 538                         *path++ = '\0';
 539                 }
 540         } else
 541                 path = end;
 542
 543         if (!path || !*path)
 544                 die("No path specified. See 'man git-pull' for valid url syntax");
 545
 546         /*
 547          * null-terminate hostname and point path to ~ for URL's like this:
 548          *    ssh://host.xz/~user/repo
 549          */
 550         if (protocol != PROTO_LOCAL && host != url) {
 551                 char *ptr = path;
 552                 if (path[1] == '~')
 553                         path++;
 554                 else {
 555                         path = xstrdup(ptr);
 556                         free_path = 1;
 557                 }
 558
 559                 *ptr = '\0';
 560         }
 561
 562         /*
 563          * Add support for ssh port: ssh://host.xy:<port>/...
 564          */
 565         if (protocol == PROTO_SSH && host != url)
 566                 port = get_port(host);
 567
 568         if (protocol == PROTO_GIT) {
 569                 /* These underlying connection commands die() if they
 570                  * cannot connect.
 571                  */
 572                 char *target_host = xstrdup(host);
 573                 if (git_use_proxy(host))
 574                         conn = git_proxy_connect(fd, host);
 575                 else
 576                         git_tcp_connect(fd, host, flags);
 577                 /*
 578                  * Separate original protocol components prog and path
 579                  * from extended host header with a NUL byte.
 580                  *
 581                  * Note: Do not add any other headers here!  Doing so
 582                  * will cause older git-daemon servers to crash.
 583                  */
 584                 packet_write(fd[1],
 585                              "%s %s%chost=%s%c",
 586                              prog, path, 0,
 587                              target_host, 0);
 588                 free(target_host);
 589                 free(url);
 590                 if (free_path)
 591                         free(path);
 592                 return conn;
 593         }
 594
 595         conn = xcalloc(1, sizeof(*conn));
 596
 597         strbuf_init(&cmd, MAX_CMD_LEN);
 598         strbuf_addstr(&cmd, prog);
 599         strbuf_addch(&cmd, ' ');
 600         sq_quote_buf(&cmd, path);
 601         if (cmd.len >= MAX_CMD_LEN)
 602                 die("command line too long");
 603
 604         conn->in = conn->out = -1;
 605         conn->argv = arg = xcalloc(7, sizeof(*arg));
 606         if (protocol == PROTO_SSH) {
 607                 const char *ssh = getenv("GIT_SSH");
 608                 int putty = ssh && strcasestr(ssh, "plink");
 609                 if (!ssh) ssh = "ssh";
 610
 611                 *arg++ = ssh;
 612                 if (putty && !strcasestr(ssh, "tortoiseplink"))
 613                         *arg++ = "-batch";
 614                 if (port) {
 615                         /* P is for PuTTY, p is for OpenSSH */
 616                         *arg++ = putty ? "-P" : "-p";
 617                         *arg++ = port;
 618                 }
 619                 *arg++ = host;
 620         }
 621         else {
 622                 /* remove repo-local variables from the environment */
 623                 conn->env = local_repo_env;
 624                 conn->use_shell = 1;
 625         }
 626         *arg++ = cmd.buf;
 627         *arg = NULL;
 628
 629         if (start_command(conn))
 630                 die("unable to fork");
 631
 632         fd[0] = conn->out; /* read from child's stdout */
 633         fd[1] = conn->in;  /* write to child's stdin */
 634         strbuf_release(&cmd);
 635         free(url);
 636         if (free_path)
 637                 free(path);
 638         return conn;
 639 }
 640
 641 int git_connection_is_socket(struct child_process *conn)
 642 {
 643         return conn == &no_fork;
 644 }
 645
 646 int finish_connect(struct child_process *conn)
 647 {
 648         int code;
 649         if (!conn || git_connection_is_socket(conn))
 650                 return 0;
 651
 652         code = finish_command(conn);
 653         free(conn->argv);
 654         free(conn);
 655         return code;
 656 }