Andrew's git / gitweb.git / connect.c
?
connect.con commit Refactor git_tcp_connect() functions a little. (5ad312b)
   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
  12static char *server_capabilities = NULL;
  13
  14/*
  15 * Read all the refs from the other end
  16 */
  17struct ref **get_remote_heads(int in, struct ref **list,
  18                              int nr_match, char **match, int ignore_funny)
  19{
  20        *list = NULL;
  21        for (;;) {
  22                struct ref *ref;
  23                unsigned char old_sha1[20];
  24                static char buffer[1000];
  25                char *name;
  26                int len, name_len;
  27
  28                len = packet_read_line(in, buffer, sizeof(buffer));
  29                if (!len)
  30                        break;
  31                if (buffer[len-1] == '\n')
  32                        buffer[--len] = 0;
  33
  34                if (len < 42 || get_sha1_hex(buffer, old_sha1) || buffer[40] != ' ')
  35                        die("protocol error: expected sha/ref, got '%s'", buffer);
  36                name = buffer + 41;
  37
  38                name_len = strlen(name);
  39                if (len != name_len + 41) {
  40                        if (server_capabilities)
  41                                free(server_capabilities);
  42                        server_capabilities = strdup(name + name_len + 1);
  43                }
  44
  45                if (ignore_funny && 45 < len && !memcmp(name, "refs/", 5) &&
  46                    check_ref_format(name + 5))
  47                        continue;
  48
  49                if (nr_match && !path_match(name, nr_match, match))
  50                        continue;
  51                ref = xcalloc(1, sizeof(*ref) + len - 40);
  52                memcpy(ref->old_sha1, old_sha1, 20);
  53                memcpy(ref->name, buffer + 41, len - 40);
  54                *list = ref;
  55                list = &ref->next;
  56        }
  57        return list;
  58}
  59
  60int server_supports(const char *feature)
  61{
  62        return server_capabilities &&
  63                strstr(server_capabilities, feature) != NULL;
  64}
  65
  66int get_ack(int fd, unsigned char *result_sha1)
  67{
  68        static char line[1000];
  69        int len = packet_read_line(fd, line, sizeof(line));
  70
  71        if (!len)
  72                die("git-fetch-pack: expected ACK/NAK, got EOF");
  73        if (line[len-1] == '\n')
  74                line[--len] = 0;
  75        if (!strcmp(line, "NAK"))
  76                return 0;
  77        if (!strncmp(line, "ACK ", 4)) {
  78                if (!get_sha1_hex(line+4, result_sha1)) {
  79                        if (strstr(line+45, "continue"))
  80                                return 2;
  81                        return 1;
  82                }
  83        }
  84        die("git-fetch_pack: expected ACK/NAK, got '%s'", line);
  85}
  86
  87int path_match(const char *path, int nr, char **match)
  88{
  89        int i;
  90        int pathlen = strlen(path);
  91
  92        for (i = 0; i < nr; i++) {
  93                char *s = match[i];
  94                int len = strlen(s);
  95
  96                if (!len || len > pathlen)
  97                        continue;
  98                if (memcmp(path + pathlen - len, s, len))
  99                        continue;
 100                if (pathlen > len && path[pathlen - len - 1] != '/')
 101                        continue;
 102                *s = 0;
 103                return (i + 1);
 104        }
 105        return 0;
 106}
 107
 108struct refspec {
 109        char *src;
 110        char *dst;
 111        char force;
 112};
 113
 114/*
 115 * A:B means fast forward remote B with local A.
 116 * +A:B means overwrite remote B with local A.
 117 * +A is a shorthand for +A:A.
 118 * A is a shorthand for A:A.
 119 */
 120static struct refspec *parse_ref_spec(int nr_refspec, char **refspec)
 121{
 122        int i;
 123        struct refspec *rs = xcalloc(sizeof(*rs), (nr_refspec + 1));
 124        for (i = 0; i < nr_refspec; i++) {
 125                char *sp, *dp, *ep;
 126                sp = refspec[i];
 127                if (*sp == '+') {
 128                        rs[i].force = 1;
 129                        sp++;
 130                }
 131                ep = strchr(sp, ':');
 132                if (ep) {
 133                        dp = ep + 1;
 134                        *ep = 0;
 135                }
 136                else
 137                        dp = sp;
 138                rs[i].src = sp;
 139                rs[i].dst = dp;
 140        }
 141        rs[nr_refspec].src = rs[nr_refspec].dst = NULL;
 142        return rs;
 143}
 144
 145static int count_refspec_match(const char *pattern,
 146                               struct ref *refs,
 147                               struct ref **matched_ref)
 148{
 149        int match;
 150        int patlen = strlen(pattern);
 151
 152        for (match = 0; refs; refs = refs->next) {
 153                char *name = refs->name;
 154                int namelen = strlen(name);
 155                if (namelen < patlen ||
 156                    memcmp(name + namelen - patlen, pattern, patlen))
 157                        continue;
 158                if (namelen != patlen && name[namelen - patlen - 1] != '/')
 159                        continue;
 160                match++;
 161                *matched_ref = refs;
 162        }
 163        return match;
 164}
 165
 166static void link_dst_tail(struct ref *ref, struct ref ***tail)
 167{
 168        **tail = ref;
 169        *tail = &ref->next;
 170        **tail = NULL;
 171}
 172
 173static struct ref *try_explicit_object_name(const char *name)
 174{
 175        unsigned char sha1[20];
 176        struct ref *ref;
 177        int len;
 178        if (get_sha1(name, sha1))
 179                return NULL;
 180        len = strlen(name) + 1;
 181        ref = xcalloc(1, sizeof(*ref) + len);
 182        memcpy(ref->name, name, len);
 183        memcpy(ref->new_sha1, sha1, 20);
 184        return ref;
 185}
 186
 187static int match_explicit_refs(struct ref *src, struct ref *dst,
 188                               struct ref ***dst_tail, struct refspec *rs)
 189{
 190        int i, errs;
 191        for (i = errs = 0; rs[i].src; i++) {
 192                struct ref *matched_src, *matched_dst;
 193
 194                matched_src = matched_dst = NULL;
 195                switch (count_refspec_match(rs[i].src, src, &matched_src)) {
 196                case 1:
 197                        break;
 198                case 0:
 199                        /* The source could be in the get_sha1() format
 200                         * not a reference name.
 201                         */
 202                        matched_src = try_explicit_object_name(rs[i].src);
 203                        if (matched_src)
 204                                break;
 205                        errs = 1;
 206                        error("src refspec %s does not match any.",
 207                              rs[i].src);
 208                        break;
 209                default:
 210                        errs = 1;
 211                        error("src refspec %s matches more than one.",
 212                              rs[i].src);
 213                        break;
 214                }
 215                switch (count_refspec_match(rs[i].dst, dst, &matched_dst)) {
 216                case 1:
 217                        break;
 218                case 0:
 219                        if (!memcmp(rs[i].dst, "refs/", 5)) {
 220                                int len = strlen(rs[i].dst) + 1;
 221                                matched_dst = xcalloc(1, sizeof(*dst) + len);
 222                                memcpy(matched_dst->name, rs[i].dst, len);
 223                                link_dst_tail(matched_dst, dst_tail);
 224                        }
 225                        else if (!strcmp(rs[i].src, rs[i].dst) &&
 226                                 matched_src) {
 227                                /* pushing "master:master" when
 228                                 * remote does not have master yet.
 229                                 */
 230                                int len = strlen(matched_src->name) + 1;
 231                                matched_dst = xcalloc(1, sizeof(*dst) + len);
 232                                memcpy(matched_dst->name, matched_src->name,
 233                                       len);
 234                                link_dst_tail(matched_dst, dst_tail);
 235                        }
 236                        else {
 237                                errs = 1;
 238                                error("dst refspec %s does not match any "
 239                                      "existing ref on the remote and does "
 240                                      "not start with refs/.", rs[i].dst);
 241                        }
 242                        break;
 243                default:
 244                        errs = 1;
 245                        error("dst refspec %s matches more than one.",
 246                              rs[i].dst);
 247                        break;
 248                }
 249                if (errs)
 250                        continue;
 251                if (matched_dst->peer_ref) {
 252                        errs = 1;
 253                        error("dst ref %s receives from more than one src.",
 254                              matched_dst->name);
 255                }
 256                else {
 257                        matched_dst->peer_ref = matched_src;
 258                        matched_dst->force = rs[i].force;
 259                }
 260        }
 261        return -errs;
 262}
 263
 264static struct ref *find_ref_by_name(struct ref *list, const char *name)
 265{
 266        for ( ; list; list = list->next)
 267                if (!strcmp(list->name, name))
 268                        return list;
 269        return NULL;
 270}
 271
 272int match_refs(struct ref *src, struct ref *dst, struct ref ***dst_tail,
 273               int nr_refspec, char **refspec, int all)
 274{
 275        struct refspec *rs = parse_ref_spec(nr_refspec, refspec);
 276
 277        if (nr_refspec)
 278                return match_explicit_refs(src, dst, dst_tail, rs);
 279
 280        /* pick the remainder */
 281        for ( ; src; src = src->next) {
 282                struct ref *dst_peer;
 283                if (src->peer_ref)
 284                        continue;
 285                dst_peer = find_ref_by_name(dst, src->name);
 286                if ((dst_peer && dst_peer->peer_ref) || (!dst_peer && !all))
 287                        continue;
 288                if (!dst_peer) {
 289                        /* Create a new one and link it */
 290                        int len = strlen(src->name) + 1;
 291                        dst_peer = xcalloc(1, sizeof(*dst_peer) + len);
 292                        memcpy(dst_peer->name, src->name, len);
 293                        memcpy(dst_peer->new_sha1, src->new_sha1, 20);
 294                        link_dst_tail(dst_peer, dst_tail);
 295                }
 296                dst_peer->peer_ref = src;
 297        }
 298        return 0;
 299}
 300
 301enum protocol {
 302        PROTO_LOCAL = 1,
 303        PROTO_SSH,
 304        PROTO_GIT,
 305};
 306
 307static enum protocol get_protocol(const char *name)
 308{
 309        if (!strcmp(name, "ssh"))
 310                return PROTO_SSH;
 311        if (!strcmp(name, "git"))
 312                return PROTO_GIT;
 313        if (!strcmp(name, "git+ssh"))
 314                return PROTO_SSH;
 315        if (!strcmp(name, "ssh+git"))
 316                return PROTO_SSH;
 317        die("I don't handle protocol '%s'", name);
 318}
 319
 320#define STR_(s) # s
 321#define STR(s)  STR_(s)
 322
 323#ifndef NO_IPV6
 324
 325/*
 326 * Returns a connected socket() fd, or else die()s.
 327 */
 328static int git_tcp_connect_sock(char *host)
 329{
 330        int sockfd = -1;
 331        char *colon, *end;
 332        char *port = STR(DEFAULT_GIT_PORT);
 333        struct addrinfo hints, *ai0, *ai;
 334        int gai;
 335
 336        if (host[0] == '[') {
 337                end = strchr(host + 1, ']');
 338                if (end) {
 339                        *end = 0;
 340                        end++;
 341                        host++;
 342                } else
 343                        end = host;
 344        } else
 345                end = host;
 346        colon = strchr(end, ':');
 347
 348        if (colon) {
 349                *colon = 0;
 350                port = colon + 1;
 351        }
 352
 353        memset(&hints, 0, sizeof(hints));
 354        hints.ai_socktype = SOCK_STREAM;
 355        hints.ai_protocol = IPPROTO_TCP;
 356
 357        gai = getaddrinfo(host, port, &hints, &ai);
 358        if (gai)
 359                die("Unable to look up %s (%s)", host, gai_strerror(gai));
 360
 361        for (ai0 = ai; ai; ai = ai->ai_next) {
 362                sockfd = socket(ai->ai_family,
 363                                ai->ai_socktype, ai->ai_protocol);
 364                if (sockfd < 0)
 365                        continue;
 366                if (connect(sockfd, ai->ai_addr, ai->ai_addrlen) < 0) {
 367                        close(sockfd);
 368                        sockfd = -1;
 369                        continue;
 370                }
 371                break;
 372        }
 373
 374        freeaddrinfo(ai0);
 375
 376        if (sockfd < 0)
 377                die("unable to connect a socket (%s)", strerror(errno));
 378
 379        return sockfd;
 380}
 381
 382#else /* NO_IPV6 */
 383
 384/*
 385 * Returns a connected socket() fd, or else die()s.
 386 */
 387static int git_tcp_connect_sock(char *host)
 388{
 389        int sockfd = -1;
 390        char *colon, *end;
 391        char *port = STR(DEFAULT_GIT_PORT), *ep;
 392        struct hostent *he;
 393        struct sockaddr_in sa;
 394        char **ap;
 395        unsigned int nport;
 396
 397        if (host[0] == '[') {
 398                end = strchr(host + 1, ']');
 399                if (end) {
 400                        *end = 0;
 401                        end++;
 402                        host++;
 403                } else
 404                        end = host;
 405        } else
 406                end = host;
 407        colon = strchr(end, ':');
 408
 409        if (colon) {
 410                *colon = 0;
 411                port = colon + 1;
 412        }
 413
 414        he = gethostbyname(host);
 415        if (!he)
 416                die("Unable to look up %s (%s)", host, hstrerror(h_errno));
 417        nport = strtoul(port, &ep, 10);
 418        if ( ep == port || *ep ) {
 419                /* Not numeric */
 420                struct servent *se = getservbyname(port,"tcp");
 421                if ( !se )
 422                        die("Unknown port %s\n", port);
 423                nport = se->s_port;
 424        }
 425
 426        for (ap = he->h_addr_list; *ap; ap++) {
 427                sockfd = socket(he->h_addrtype, SOCK_STREAM, 0);
 428                if (sockfd < 0)
 429                        continue;
 430
 431                memset(&sa, 0, sizeof sa);
 432                sa.sin_family = he->h_addrtype;
 433                sa.sin_port = htons(nport);
 434                memcpy(&sa.sin_addr, *ap, he->h_length);
 435
 436                if (connect(sockfd, (struct sockaddr *)&sa, sizeof sa) < 0) {
 437                        close(sockfd);
 438                        sockfd = -1;
 439                        continue;
 440                }
 441                break;
 442        }
 443
 444        if (sockfd < 0)
 445                die("unable to connect a socket (%s)", strerror(errno));
 446
 447        return sockfd;
 448}
 449
 450#endif /* NO_IPV6 */
 451
 452
 453static void git_tcp_connect(int fd[2],
 454                            const char *prog, char *host, char *path)
 455{
 456        int sockfd = git_tcp_connect_sock(host);
 457
 458        fd[0] = sockfd;
 459        fd[1] = sockfd;
 460}
 461
 462
 463static char *git_proxy_command = NULL;
 464static const char *rhost_name = NULL;
 465static int rhost_len;
 466
 467static int git_proxy_command_options(const char *var, const char *value)
 468{
 469        if (!strcmp(var, "core.gitproxy")) {
 470                const char *for_pos;
 471                int matchlen = -1;
 472                int hostlen;
 473
 474                if (git_proxy_command)
 475                        return 0;
 476                /* [core]
 477                 * ;# matches www.kernel.org as well
 478                 * gitproxy = netcatter-1 for kernel.org
 479                 * gitproxy = netcatter-2 for sample.xz
 480                 * gitproxy = netcatter-default
 481                 */
 482                for_pos = strstr(value, " for ");
 483                if (!for_pos)
 484                        /* matches everybody */
 485                        matchlen = strlen(value);
 486                else {
 487                        hostlen = strlen(for_pos + 5);
 488                        if (rhost_len < hostlen)
 489                                matchlen = -1;
 490                        else if (!strncmp(for_pos + 5,
 491                                          rhost_name + rhost_len - hostlen,
 492                                          hostlen) &&
 493                                 ((rhost_len == hostlen) ||
 494                                  rhost_name[rhost_len - hostlen -1] == '.'))
 495                                matchlen = for_pos - value;
 496                        else
 497                                matchlen = -1;
 498                }
 499                if (0 <= matchlen) {
 500                        /* core.gitproxy = none for kernel.org */
 501                        if (matchlen == 4 && 
 502                            !memcmp(value, "none", 4))
 503                                matchlen = 0;
 504                        git_proxy_command = xmalloc(matchlen + 1);
 505                        memcpy(git_proxy_command, value, matchlen);
 506                        git_proxy_command[matchlen] = 0;
 507                }
 508                return 0;
 509        }
 510
 511        return git_default_config(var, value);
 512}
 513
 514static int git_use_proxy(const char *host)
 515{
 516        rhost_name = host;
 517        rhost_len = strlen(host);
 518        git_proxy_command = getenv("GIT_PROXY_COMMAND");
 519        git_config(git_proxy_command_options);
 520        rhost_name = NULL;
 521        return (git_proxy_command && *git_proxy_command);
 522}
 523
 524static void git_proxy_connect(int fd[2],
 525                              const char *prog, char *host, char *path)
 526{
 527        char *port = STR(DEFAULT_GIT_PORT);
 528        char *colon, *end;
 529        int pipefd[2][2];
 530        pid_t pid;
 531
 532        if (host[0] == '[') {
 533                end = strchr(host + 1, ']');
 534                if (end) {
 535                        *end = 0;
 536                        end++;
 537                        host++;
 538                } else
 539                        end = host;
 540        } else
 541                end = host;
 542        colon = strchr(end, ':');
 543
 544        if (colon) {
 545                *colon = 0;
 546                port = colon + 1;
 547        }
 548
 549        if (pipe(pipefd[0]) < 0 || pipe(pipefd[1]) < 0)
 550                die("unable to create pipe pair for communication");
 551        pid = fork();
 552        if (!pid) {
 553                dup2(pipefd[1][0], 0);
 554                dup2(pipefd[0][1], 1);
 555                close(pipefd[0][0]);
 556                close(pipefd[0][1]);
 557                close(pipefd[1][0]);
 558                close(pipefd[1][1]);
 559                execlp(git_proxy_command, git_proxy_command, host, port, NULL);
 560                die("exec failed");
 561        }
 562        if (pid < 0)
 563                die("fork failed");
 564        fd[0] = pipefd[0][0];
 565        fd[1] = pipefd[1][1];
 566        close(pipefd[0][1]);
 567        close(pipefd[1][0]);
 568}
 569
 570/*
 571 * Yeah, yeah, fixme. Need to pass in the heads etc.
 572 */
 573int git_connect(int fd[2], char *url, const char *prog)
 574{
 575        char command[1024];
 576        char *host, *path = url;
 577        char *end;
 578        int c;
 579        int pipefd[2][2];
 580        pid_t pid;
 581        enum protocol protocol = PROTO_LOCAL;
 582        int free_path = 0;
 583
 584        host = strstr(url, "://");
 585        if(host) {
 586                *host = '\0';
 587                protocol = get_protocol(url);
 588                host += 3;
 589                c = '/';
 590        } else {
 591                host = url;
 592                c = ':';
 593        }
 594
 595        if (host[0] == '[') {
 596                end = strchr(host + 1, ']');
 597                if (end) {
 598                        *end = 0;
 599                        end++;
 600                        host++;
 601                } else
 602                        end = host;
 603        } else
 604                end = host;
 605
 606        path = strchr(end, c);
 607        if (c == ':') {
 608                if (path) {
 609                        protocol = PROTO_SSH;
 610                        *path++ = '\0';
 611                } else
 612                        path = host;
 613        }
 614
 615        if (!path || !*path)
 616                die("No path specified. See 'man git-pull' for valid url syntax");
 617
 618        /*
 619         * null-terminate hostname and point path to ~ for URL's like this:
 620         *    ssh://host.xz/~user/repo
 621         */
 622        if (protocol != PROTO_LOCAL && host != url) {
 623                char *ptr = path;
 624                if (path[1] == '~')
 625                        path++;
 626                else {
 627                        path = strdup(ptr);
 628                        free_path = 1;
 629                }
 630
 631                *ptr = '\0';
 632        }
 633
 634        if (protocol == PROTO_GIT) {
 635                /* These underlying connection commands die() if they
 636                 * cannot connect.
 637                 */
 638                char *target_host = strdup(host);
 639                if (git_use_proxy(host))
 640                        git_proxy_connect(fd, prog, host, path);
 641                else
 642                        git_tcp_connect(fd, prog, host, path);
 643                /*
 644                 * Separate original protocol components prog and path
 645                 * from extended components with a NUL byte.
 646                 */
 647                packet_write(fd[1],
 648                             "%s %s%chost=%s%c",
 649                             prog, path, 0,
 650                             target_host, 0);
 651                free(target_host);
 652                if (free_path)
 653                        free(path);
 654                return 0;
 655        }
 656
 657        if (pipe(pipefd[0]) < 0 || pipe(pipefd[1]) < 0)
 658                die("unable to create pipe pair for communication");
 659        pid = fork();
 660        if (!pid) {
 661                snprintf(command, sizeof(command), "%s %s", prog,
 662                         sq_quote(path));
 663                dup2(pipefd[1][0], 0);
 664                dup2(pipefd[0][1], 1);
 665                close(pipefd[0][0]);
 666                close(pipefd[0][1]);
 667                close(pipefd[1][0]);
 668                close(pipefd[1][1]);
 669                if (protocol == PROTO_SSH) {
 670                        const char *ssh, *ssh_basename;
 671                        ssh = getenv("GIT_SSH");
 672                        if (!ssh) ssh = "ssh";
 673                        ssh_basename = strrchr(ssh, '/');
 674                        if (!ssh_basename)
 675                                ssh_basename = ssh;
 676                        else
 677                                ssh_basename++;
 678                        execlp(ssh, ssh_basename, host, command, NULL);
 679                }
 680                else {
 681                        unsetenv(ALTERNATE_DB_ENVIRONMENT);
 682                        unsetenv(DB_ENVIRONMENT);
 683                        unsetenv(GIT_DIR_ENVIRONMENT);
 684                        unsetenv(GRAFT_ENVIRONMENT);
 685                        unsetenv(INDEX_ENVIRONMENT);
 686                        execlp("sh", "sh", "-c", command, NULL);
 687                }
 688                die("exec failed");
 689        }
 690        fd[0] = pipefd[0][0];
 691        fd[1] = pipefd[1][1];
 692        close(pipefd[0][1]);
 693        close(pipefd[1][0]);
 694        if (free_path)
 695                free(path);
 696        return pid;
 697}
 698
 699int finish_connect(pid_t pid)
 700{
 701        int ret;
 702
 703        for (;;) {
 704                ret = waitpid(pid, NULL, 0);
 705                if (!ret)
 706                        break;
 707                if (errno != EINTR)
 708                        break;
 709        }
 710        return ret;
 711}