Andrew's git / gitweb.git / connect.c
?
connect.con commit Git.pm: Implement Git::exec_path() (eca1f6f)
   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 <sys/wait.h>
   7#include <sys/socket.h>
   8#include <netinet/in.h>
   9#include <arpa/inet.h>
  10#include <netdb.h>
  11#include <signal.h>
  12
  13static char *server_capabilities = NULL;
  14
  15/*
  16 * Read all the refs from the other end
  17 */
  18struct ref **get_remote_heads(int in, struct ref **list,
  19                              int nr_match, char **match, int ignore_funny)
  20{
  21        *list = NULL;
  22        for (;;) {
  23                struct ref *ref;
  24                unsigned char old_sha1[20];
  25                static char buffer[1000];
  26                char *name;
  27                int len, name_len;
  28
  29                len = packet_read_line(in, buffer, sizeof(buffer));
  30                if (!len)
  31                        break;
  32                if (buffer[len-1] == '\n')
  33                        buffer[--len] = 0;
  34
  35                if (len < 42 || get_sha1_hex(buffer, old_sha1) || buffer[40] != ' ')
  36                        die("protocol error: expected sha/ref, got '%s'", buffer);
  37                name = buffer + 41;
  38
  39                name_len = strlen(name);
  40                if (len != name_len + 41) {
  41                        if (server_capabilities)
  42                                free(server_capabilities);
  43                        server_capabilities = strdup(name + name_len + 1);
  44                }
  45
  46                if (ignore_funny && 45 < len && !memcmp(name, "refs/", 5) &&
  47                    check_ref_format(name + 5))
  48                        continue;
  49
  50                if (nr_match && !path_match(name, nr_match, match))
  51                        continue;
  52                ref = xcalloc(1, sizeof(*ref) + len - 40);
  53                memcpy(ref->old_sha1, old_sha1, 20);
  54                memcpy(ref->name, buffer + 41, len - 40);
  55                *list = ref;
  56                list = &ref->next;
  57        }
  58        return list;
  59}
  60
  61int server_supports(const char *feature)
  62{
  63        return server_capabilities &&
  64                strstr(server_capabilities, feature) != NULL;
  65}
  66
  67int get_ack(int fd, unsigned char *result_sha1)
  68{
  69        static char line[1000];
  70        int len = packet_read_line(fd, line, sizeof(line));
  71
  72        if (!len)
  73                die("git-fetch-pack: expected ACK/NAK, got EOF");
  74        if (line[len-1] == '\n')
  75                line[--len] = 0;
  76        if (!strcmp(line, "NAK"))
  77                return 0;
  78        if (!strncmp(line, "ACK ", 4)) {
  79                if (!get_sha1_hex(line+4, result_sha1)) {
  80                        if (strstr(line+45, "continue"))
  81                                return 2;
  82                        return 1;
  83                }
  84        }
  85        die("git-fetch_pack: expected ACK/NAK, got '%s'", line);
  86}
  87
  88int path_match(const char *path, int nr, char **match)
  89{
  90        int i;
  91        int pathlen = strlen(path);
  92
  93        for (i = 0; i < nr; i++) {
  94                char *s = match[i];
  95                int len = strlen(s);
  96
  97                if (!len || len > pathlen)
  98                        continue;
  99                if (memcmp(path + pathlen - len, s, len))
 100                        continue;
 101                if (pathlen > len && path[pathlen - len - 1] != '/')
 102                        continue;
 103                *s = 0;
 104                return (i + 1);
 105        }
 106        return 0;
 107}
 108
 109struct refspec {
 110        char *src;
 111        char *dst;
 112        char force;
 113};
 114
 115/*
 116 * A:B means fast forward remote B with local A.
 117 * +A:B means overwrite remote B with local A.
 118 * +A is a shorthand for +A:A.
 119 * A is a shorthand for A:A.
 120 */
 121static struct refspec *parse_ref_spec(int nr_refspec, char **refspec)
 122{
 123        int i;
 124        struct refspec *rs = xcalloc(sizeof(*rs), (nr_refspec + 1));
 125        for (i = 0; i < nr_refspec; i++) {
 126                char *sp, *dp, *ep;
 127                sp = refspec[i];
 128                if (*sp == '+') {
 129                        rs[i].force = 1;
 130                        sp++;
 131                }
 132                ep = strchr(sp, ':');
 133                if (ep) {
 134                        dp = ep + 1;
 135                        *ep = 0;
 136                }
 137                else
 138                        dp = sp;
 139                rs[i].src = sp;
 140                rs[i].dst = dp;
 141        }
 142        rs[nr_refspec].src = rs[nr_refspec].dst = NULL;
 143        return rs;
 144}
 145
 146static int count_refspec_match(const char *pattern,
 147                               struct ref *refs,
 148                               struct ref **matched_ref)
 149{
 150        int match;
 151        int patlen = strlen(pattern);
 152
 153        for (match = 0; refs; refs = refs->next) {
 154                char *name = refs->name;
 155                int namelen = strlen(name);
 156                if (namelen < patlen ||
 157                    memcmp(name + namelen - patlen, pattern, patlen))
 158                        continue;
 159                if (namelen != patlen && name[namelen - patlen - 1] != '/')
 160                        continue;
 161                match++;
 162                *matched_ref = refs;
 163        }
 164        return match;
 165}
 166
 167static void link_dst_tail(struct ref *ref, struct ref ***tail)
 168{
 169        **tail = ref;
 170        *tail = &ref->next;
 171        **tail = NULL;
 172}
 173
 174static struct ref *try_explicit_object_name(const char *name)
 175{
 176        unsigned char sha1[20];
 177        struct ref *ref;
 178        int len;
 179        if (get_sha1(name, sha1))
 180                return NULL;
 181        len = strlen(name) + 1;
 182        ref = xcalloc(1, sizeof(*ref) + len);
 183        memcpy(ref->name, name, len);
 184        memcpy(ref->new_sha1, sha1, 20);
 185        return ref;
 186}
 187
 188static int match_explicit_refs(struct ref *src, struct ref *dst,
 189                               struct ref ***dst_tail, struct refspec *rs)
 190{
 191        int i, errs;
 192        for (i = errs = 0; rs[i].src; i++) {
 193                struct ref *matched_src, *matched_dst;
 194
 195                matched_src = matched_dst = NULL;
 196                switch (count_refspec_match(rs[i].src, src, &matched_src)) {
 197                case 1:
 198                        break;
 199                case 0:
 200                        /* The source could be in the get_sha1() format
 201                         * not a reference name.
 202                         */
 203                        matched_src = try_explicit_object_name(rs[i].src);
 204                        if (matched_src)
 205                                break;
 206                        errs = 1;
 207                        error("src refspec %s does not match any.",
 208                              rs[i].src);
 209                        break;
 210                default:
 211                        errs = 1;
 212                        error("src refspec %s matches more than one.",
 213                              rs[i].src);
 214                        break;
 215                }
 216                switch (count_refspec_match(rs[i].dst, dst, &matched_dst)) {
 217                case 1:
 218                        break;
 219                case 0:
 220                        if (!memcmp(rs[i].dst, "refs/", 5)) {
 221                                int len = strlen(rs[i].dst) + 1;
 222                                matched_dst = xcalloc(1, sizeof(*dst) + len);
 223                                memcpy(matched_dst->name, rs[i].dst, len);
 224                                link_dst_tail(matched_dst, dst_tail);
 225                        }
 226                        else if (!strcmp(rs[i].src, rs[i].dst) &&
 227                                 matched_src) {
 228                                /* pushing "master:master" when
 229                                 * remote does not have master yet.
 230                                 */
 231                                int len = strlen(matched_src->name) + 1;
 232                                matched_dst = xcalloc(1, sizeof(*dst) + len);
 233                                memcpy(matched_dst->name, matched_src->name,
 234                                       len);
 235                                link_dst_tail(matched_dst, dst_tail);
 236                        }
 237                        else {
 238                                errs = 1;
 239                                error("dst refspec %s does not match any "
 240                                      "existing ref on the remote and does "
 241                                      "not start with refs/.", rs[i].dst);
 242                        }
 243                        break;
 244                default:
 245                        errs = 1;
 246                        error("dst refspec %s matches more than one.",
 247                              rs[i].dst);
 248                        break;
 249                }
 250                if (errs)
 251                        continue;
 252                if (matched_dst->peer_ref) {
 253                        errs = 1;
 254                        error("dst ref %s receives from more than one src.",
 255                              matched_dst->name);
 256                }
 257                else {
 258                        matched_dst->peer_ref = matched_src;
 259                        matched_dst->force = rs[i].force;
 260                }
 261        }
 262        return -errs;
 263}
 264
 265static struct ref *find_ref_by_name(struct ref *list, const char *name)
 266{
 267        for ( ; list; list = list->next)
 268                if (!strcmp(list->name, name))
 269                        return list;
 270        return NULL;
 271}
 272
 273int match_refs(struct ref *src, struct ref *dst, struct ref ***dst_tail,
 274               int nr_refspec, char **refspec, int all)
 275{
 276        struct refspec *rs = parse_ref_spec(nr_refspec, refspec);
 277
 278        if (nr_refspec)
 279                return match_explicit_refs(src, dst, dst_tail, rs);
 280
 281        /* pick the remainder */
 282        for ( ; src; src = src->next) {
 283                struct ref *dst_peer;
 284                if (src->peer_ref)
 285                        continue;
 286                dst_peer = find_ref_by_name(dst, src->name);
 287                if ((dst_peer && dst_peer->peer_ref) || (!dst_peer && !all))
 288                        continue;
 289                if (!dst_peer) {
 290                        /* Create a new one and link it */
 291                        int len = strlen(src->name) + 1;
 292                        dst_peer = xcalloc(1, sizeof(*dst_peer) + len);
 293                        memcpy(dst_peer->name, src->name, len);
 294                        memcpy(dst_peer->new_sha1, src->new_sha1, 20);
 295                        link_dst_tail(dst_peer, dst_tail);
 296                }
 297                dst_peer->peer_ref = src;
 298        }
 299        return 0;
 300}
 301
 302enum protocol {
 303        PROTO_LOCAL = 1,
 304        PROTO_SSH,
 305        PROTO_GIT,
 306};
 307
 308static enum protocol get_protocol(const char *name)
 309{
 310        if (!strcmp(name, "ssh"))
 311                return PROTO_SSH;
 312        if (!strcmp(name, "git"))
 313                return PROTO_GIT;
 314        if (!strcmp(name, "git+ssh"))
 315                return PROTO_SSH;
 316        if (!strcmp(name, "ssh+git"))
 317                return PROTO_SSH;
 318        die("I don't handle protocol '%s'", name);
 319}
 320
 321#define STR_(s) # s
 322#define STR(s)  STR_(s)
 323
 324#ifndef NO_IPV6
 325
 326/*
 327 * Returns a connected socket() fd, or else die()s.
 328 */
 329static int git_tcp_connect_sock(char *host)
 330{
 331        int sockfd = -1, saved_errno = 0;
 332        char *colon, *end;
 333        const char *port = STR(DEFAULT_GIT_PORT);
 334        struct addrinfo hints, *ai0, *ai;
 335        int gai;
 336
 337        if (host[0] == '[') {
 338                end = strchr(host + 1, ']');
 339                if (end) {
 340                        *end = 0;
 341                        end++;
 342                        host++;
 343                } else
 344                        end = host;
 345        } else
 346                end = host;
 347        colon = strchr(end, ':');
 348
 349        if (colon) {
 350                *colon = 0;
 351                port = colon + 1;
 352        }
 353
 354        memset(&hints, 0, sizeof(hints));
 355        hints.ai_socktype = SOCK_STREAM;
 356        hints.ai_protocol = IPPROTO_TCP;
 357
 358        gai = getaddrinfo(host, port, &hints, &ai);
 359        if (gai)
 360                die("Unable to look up %s (%s)", host, gai_strerror(gai));
 361
 362        for (ai0 = ai; ai; ai = ai->ai_next) {
 363                sockfd = socket(ai->ai_family,
 364                                ai->ai_socktype, ai->ai_protocol);
 365                if (sockfd < 0) {
 366                        saved_errno = errno;
 367                        continue;
 368                }
 369                if (connect(sockfd, ai->ai_addr, ai->ai_addrlen) < 0) {
 370                        saved_errno = errno;
 371                        close(sockfd);
 372                        sockfd = -1;
 373                        continue;
 374                }
 375                break;
 376        }
 377
 378        freeaddrinfo(ai0);
 379
 380        if (sockfd < 0)
 381                die("unable to connect a socket (%s)", strerror(saved_errno));
 382
 383        return sockfd;
 384}
 385
 386#else /* NO_IPV6 */
 387
 388/*
 389 * Returns a connected socket() fd, or else die()s.
 390 */
 391static int git_tcp_connect_sock(char *host)
 392{
 393        int sockfd = -1, saved_errno = 0;
 394        char *colon, *end;
 395        char *port = STR(DEFAULT_GIT_PORT), *ep;
 396        struct hostent *he;
 397        struct sockaddr_in sa;
 398        char **ap;
 399        unsigned int nport;
 400
 401        if (host[0] == '[') {
 402                end = strchr(host + 1, ']');
 403                if (end) {
 404                        *end = 0;
 405                        end++;
 406                        host++;
 407                } else
 408                        end = host;
 409        } else
 410                end = host;
 411        colon = strchr(end, ':');
 412
 413        if (colon) {
 414                *colon = 0;
 415                port = colon + 1;
 416        }
 417
 418        he = gethostbyname(host);
 419        if (!he)
 420                die("Unable to look up %s (%s)", host, hstrerror(h_errno));
 421        nport = strtoul(port, &ep, 10);
 422        if ( ep == port || *ep ) {
 423                /* Not numeric */
 424                struct servent *se = getservbyname(port,"tcp");
 425                if ( !se )
 426                        die("Unknown port %s\n", port);
 427                nport = se->s_port;
 428        }
 429
 430        for (ap = he->h_addr_list; *ap; ap++) {
 431                sockfd = socket(he->h_addrtype, SOCK_STREAM, 0);
 432                if (sockfd < 0) {
 433                        saved_errno = errno;
 434                        continue;
 435                }
 436
 437                memset(&sa, 0, sizeof sa);
 438                sa.sin_family = he->h_addrtype;
 439                sa.sin_port = htons(nport);
 440                memcpy(&sa.sin_addr, *ap, he->h_length);
 441
 442                if (connect(sockfd, (struct sockaddr *)&sa, sizeof sa) < 0) {
 443                        saved_errno = errno;
 444                        close(sockfd);
 445                        sockfd = -1;
 446                        continue;
 447                }
 448                break;
 449        }
 450
 451        if (sockfd < 0)
 452                die("unable to connect a socket (%s)", strerror(saved_errno));
 453
 454        return sockfd;
 455}
 456
 457#endif /* NO_IPV6 */
 458
 459
 460static void git_tcp_connect(int fd[2], char *host)
 461{
 462        int sockfd = git_tcp_connect_sock(host);
 463
 464        fd[0] = sockfd;
 465        fd[1] = sockfd;
 466}
 467
 468
 469static char *git_proxy_command = NULL;
 470static const char *rhost_name = NULL;
 471static int rhost_len;
 472
 473static int git_proxy_command_options(const char *var, const char *value)
 474{
 475        if (!strcmp(var, "core.gitproxy")) {
 476                const char *for_pos;
 477                int matchlen = -1;
 478                int hostlen;
 479
 480                if (git_proxy_command)
 481                        return 0;
 482                /* [core]
 483                 * ;# matches www.kernel.org as well
 484                 * gitproxy = netcatter-1 for kernel.org
 485                 * gitproxy = netcatter-2 for sample.xz
 486                 * gitproxy = netcatter-default
 487                 */
 488                for_pos = strstr(value, " for ");
 489                if (!for_pos)
 490                        /* matches everybody */
 491                        matchlen = strlen(value);
 492                else {
 493                        hostlen = strlen(for_pos + 5);
 494                        if (rhost_len < hostlen)
 495                                matchlen = -1;
 496                        else if (!strncmp(for_pos + 5,
 497                                          rhost_name + rhost_len - hostlen,
 498                                          hostlen) &&
 499                                 ((rhost_len == hostlen) ||
 500                                  rhost_name[rhost_len - hostlen -1] == '.'))
 501                                matchlen = for_pos - value;
 502                        else
 503                                matchlen = -1;
 504                }
 505                if (0 <= matchlen) {
 506                        /* core.gitproxy = none for kernel.org */
 507                        if (matchlen == 4 && 
 508                            !memcmp(value, "none", 4))
 509                                matchlen = 0;
 510                        git_proxy_command = xmalloc(matchlen + 1);
 511                        memcpy(git_proxy_command, value, matchlen);
 512                        git_proxy_command[matchlen] = 0;
 513                }
 514                return 0;
 515        }
 516
 517        return git_default_config(var, value);
 518}
 519
 520static int git_use_proxy(const char *host)
 521{
 522        rhost_name = host;
 523        rhost_len = strlen(host);
 524        git_proxy_command = getenv("GIT_PROXY_COMMAND");
 525        git_config(git_proxy_command_options);
 526        rhost_name = NULL;
 527        return (git_proxy_command && *git_proxy_command);
 528}
 529
 530static void git_proxy_connect(int fd[2], char *host)
 531{
 532        const char *port = STR(DEFAULT_GIT_PORT);
 533        char *colon, *end;
 534        int pipefd[2][2];
 535        pid_t pid;
 536
 537        if (host[0] == '[') {
 538                end = strchr(host + 1, ']');
 539                if (end) {
 540                        *end = 0;
 541                        end++;
 542                        host++;
 543                } else
 544                        end = host;
 545        } else
 546                end = host;
 547        colon = strchr(end, ':');
 548
 549        if (colon) {
 550                *colon = 0;
 551                port = colon + 1;
 552        }
 553
 554        if (pipe(pipefd[0]) < 0 || pipe(pipefd[1]) < 0)
 555                die("unable to create pipe pair for communication");
 556        pid = fork();
 557        if (!pid) {
 558                dup2(pipefd[1][0], 0);
 559                dup2(pipefd[0][1], 1);
 560                close(pipefd[0][0]);
 561                close(pipefd[0][1]);
 562                close(pipefd[1][0]);
 563                close(pipefd[1][1]);
 564                execlp(git_proxy_command, git_proxy_command, host, port, NULL);
 565                die("exec failed");
 566        }
 567        if (pid < 0)
 568                die("fork failed");
 569        fd[0] = pipefd[0][0];
 570        fd[1] = pipefd[1][1];
 571        close(pipefd[0][1]);
 572        close(pipefd[1][0]);
 573}
 574
 575/*
 576 * Yeah, yeah, fixme. Need to pass in the heads etc.
 577 */
 578int git_connect(int fd[2], char *url, const char *prog)
 579{
 580        char command[1024];
 581        char *host, *path = url;
 582        char *end;
 583        int c;
 584        int pipefd[2][2];
 585        pid_t pid;
 586        enum protocol protocol = PROTO_LOCAL;
 587        int free_path = 0;
 588
 589        /* Without this we cannot rely on waitpid() to tell
 590         * what happened to our children.
 591         */
 592        signal(SIGCHLD, SIG_DFL);
 593
 594        host = strstr(url, "://");
 595        if(host) {
 596                *host = '\0';
 597                protocol = get_protocol(url);
 598                host += 3;
 599                c = '/';
 600        } else {
 601                host = url;
 602                c = ':';
 603        }
 604
 605        if (host[0] == '[') {
 606                end = strchr(host + 1, ']');
 607                if (end) {
 608                        *end = 0;
 609                        end++;
 610                        host++;
 611                } else
 612                        end = host;
 613        } else
 614                end = host;
 615
 616        path = strchr(end, c);
 617        if (c == ':') {
 618                if (path) {
 619                        protocol = PROTO_SSH;
 620                        *path++ = '\0';
 621                } else
 622                        path = host;
 623        }
 624
 625        if (!path || !*path)
 626                die("No path specified. See 'man git-pull' for valid url syntax");
 627
 628        /*
 629         * null-terminate hostname and point path to ~ for URL's like this:
 630         *    ssh://host.xz/~user/repo
 631         */
 632        if (protocol != PROTO_LOCAL && host != url) {
 633                char *ptr = path;
 634                if (path[1] == '~')
 635                        path++;
 636                else {
 637                        path = strdup(ptr);
 638                        free_path = 1;
 639                }
 640
 641                *ptr = '\0';
 642        }
 643
 644        if (protocol == PROTO_GIT) {
 645                /* These underlying connection commands die() if they
 646                 * cannot connect.
 647                 */
 648                char *target_host = strdup(host);
 649                if (git_use_proxy(host))
 650                        git_proxy_connect(fd, host);
 651                else
 652                        git_tcp_connect(fd, host);
 653                /*
 654                 * Separate original protocol components prog and path
 655                 * from extended components with a NUL byte.
 656                 */
 657                packet_write(fd[1],
 658                             "%s %s%chost=%s%c",
 659                             prog, path, 0,
 660                             target_host, 0);
 661                free(target_host);
 662                if (free_path)
 663                        free(path);
 664                return 0;
 665        }
 666
 667        if (pipe(pipefd[0]) < 0 || pipe(pipefd[1]) < 0)
 668                die("unable to create pipe pair for communication");
 669        pid = fork();
 670        if (pid < 0)
 671                die("unable to fork");
 672        if (!pid) {
 673                snprintf(command, sizeof(command), "%s %s", prog,
 674                         sq_quote(path));
 675                dup2(pipefd[1][0], 0);
 676                dup2(pipefd[0][1], 1);
 677                close(pipefd[0][0]);
 678                close(pipefd[0][1]);
 679                close(pipefd[1][0]);
 680                close(pipefd[1][1]);
 681                if (protocol == PROTO_SSH) {
 682                        const char *ssh, *ssh_basename;
 683                        ssh = getenv("GIT_SSH");
 684                        if (!ssh) ssh = "ssh";
 685                        ssh_basename = strrchr(ssh, '/');
 686                        if (!ssh_basename)
 687                                ssh_basename = ssh;
 688                        else
 689                                ssh_basename++;
 690                        execlp(ssh, ssh_basename, host, command, NULL);
 691                }
 692                else {
 693                        unsetenv(ALTERNATE_DB_ENVIRONMENT);
 694                        unsetenv(DB_ENVIRONMENT);
 695                        unsetenv(GIT_DIR_ENVIRONMENT);
 696                        unsetenv(GRAFT_ENVIRONMENT);
 697                        unsetenv(INDEX_ENVIRONMENT);
 698                        execlp("sh", "sh", "-c", command, NULL);
 699                }
 700                die("exec failed");
 701        }
 702        fd[0] = pipefd[0][0];
 703        fd[1] = pipefd[1][1];
 704        close(pipefd[0][1]);
 705        close(pipefd[1][0]);
 706        if (free_path)
 707                free(path);
 708        return pid;
 709}
 710
 711int finish_connect(pid_t pid)
 712{
 713        int ret;
 714
 715        for (;;) {
 716                ret = waitpid(pid, NULL, 0);
 717                if (!ret)
 718                        break;
 719                if (errno != EINTR)
 720                        break;
 721        }
 722        return ret;
 723}