Andrew's git / gitweb.git / connect.c
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connect.con commit Merge branch 'master' of git://git.kernel.org/pub/scm/gitk/gitk (11bb2d4)
   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
   9static char *server_capabilities;
  10
  11static int check_ref(const char *name, int len, unsigned int flags)
  12{
  13        if (!flags)
  14                return 1;
  15
  16        if (len < 5 || memcmp(name, "refs/", 5))
  17                return 0;
  18
  19        /* Skip the "refs/" part */
  20        name += 5;
  21        len -= 5;
  22
  23        /* REF_NORMAL means that we don't want the magic fake tag refs */
  24        if ((flags & REF_NORMAL) && check_ref_format(name) < 0)
  25                return 0;
  26
  27        /* REF_HEADS means that we want regular branch heads */
  28        if ((flags & REF_HEADS) && !memcmp(name, "heads/", 6))
  29                return 1;
  30
  31        /* REF_TAGS means that we want tags */
  32        if ((flags & REF_TAGS) && !memcmp(name, "tags/", 5))
  33                return 1;
  34
  35        /* All type bits clear means that we are ok with anything */
  36        return !(flags & ~REF_NORMAL);
  37}
  38
  39/*
  40 * Read all the refs from the other end
  41 */
  42struct ref **get_remote_heads(int in, struct ref **list,
  43                              int nr_match, char **match,
  44                              unsigned int flags)
  45{
  46        *list = NULL;
  47        for (;;) {
  48                struct ref *ref;
  49                unsigned char old_sha1[20];
  50                static char buffer[1000];
  51                char *name;
  52                int len, name_len;
  53
  54                len = packet_read_line(in, buffer, sizeof(buffer));
  55                if (!len)
  56                        break;
  57                if (buffer[len-1] == '\n')
  58                        buffer[--len] = 0;
  59
  60                if (len < 42 || get_sha1_hex(buffer, old_sha1) || buffer[40] != ' ')
  61                        die("protocol error: expected sha/ref, got '%s'", buffer);
  62                name = buffer + 41;
  63
  64                name_len = strlen(name);
  65                if (len != name_len + 41) {
  66                        if (server_capabilities)
  67                                free(server_capabilities);
  68                        server_capabilities = xstrdup(name + name_len + 1);
  69                }
  70
  71                if (!check_ref(name, name_len, flags))
  72                        continue;
  73                if (nr_match && !path_match(name, nr_match, match))
  74                        continue;
  75                ref = alloc_ref(len - 40);
  76                hashcpy(ref->old_sha1, old_sha1);
  77                memcpy(ref->name, buffer + 41, len - 40);
  78                *list = ref;
  79                list = &ref->next;
  80        }
  81        return list;
  82}
  83
  84int server_supports(const char *feature)
  85{
  86        return server_capabilities &&
  87                strstr(server_capabilities, feature) != NULL;
  88}
  89
  90int get_ack(int fd, unsigned char *result_sha1)
  91{
  92        static char line[1000];
  93        int len = packet_read_line(fd, line, sizeof(line));
  94
  95        if (!len)
  96                die("git-fetch-pack: expected ACK/NAK, got EOF");
  97        if (line[len-1] == '\n')
  98                line[--len] = 0;
  99        if (!strcmp(line, "NAK"))
 100                return 0;
 101        if (!prefixcmp(line, "ACK ")) {
 102                if (!get_sha1_hex(line+4, result_sha1)) {
 103                        if (strstr(line+45, "continue"))
 104                                return 2;
 105                        return 1;
 106                }
 107        }
 108        die("git-fetch_pack: expected ACK/NAK, got '%s'", line);
 109}
 110
 111int path_match(const char *path, int nr, char **match)
 112{
 113        int i;
 114        int pathlen = strlen(path);
 115
 116        for (i = 0; i < nr; i++) {
 117                char *s = match[i];
 118                int len = strlen(s);
 119
 120                if (!len || len > pathlen)
 121                        continue;
 122                if (memcmp(path + pathlen - len, s, len))
 123                        continue;
 124                if (pathlen > len && path[pathlen - len - 1] != '/')
 125                        continue;
 126                *s = 0;
 127                return (i + 1);
 128        }
 129        return 0;
 130}
 131
 132enum protocol {
 133        PROTO_LOCAL = 1,
 134        PROTO_SSH,
 135        PROTO_GIT,
 136};
 137
 138static enum protocol get_protocol(const char *name)
 139{
 140        if (!strcmp(name, "ssh"))
 141                return PROTO_SSH;
 142        if (!strcmp(name, "git"))
 143                return PROTO_GIT;
 144        if (!strcmp(name, "git+ssh"))
 145                return PROTO_SSH;
 146        if (!strcmp(name, "ssh+git"))
 147                return PROTO_SSH;
 148        die("I don't handle protocol '%s'", name);
 149}
 150
 151#define STR_(s) # s
 152#define STR(s)  STR_(s)
 153
 154#ifndef NO_IPV6
 155
 156static const char *ai_name(const struct addrinfo *ai)
 157{
 158        static char addr[INET_ADDRSTRLEN];
 159        if ( AF_INET == ai->ai_family ) {
 160                struct sockaddr_in *in;
 161                in = (struct sockaddr_in *)ai->ai_addr;
 162                inet_ntop(ai->ai_family, &in->sin_addr, addr, sizeof(addr));
 163        } else if ( AF_INET6 == ai->ai_family ) {
 164                struct sockaddr_in6 *in;
 165                in = (struct sockaddr_in6 *)ai->ai_addr;
 166                inet_ntop(ai->ai_family, &in->sin6_addr, addr, sizeof(addr));
 167        } else {
 168                strcpy(addr, "(unknown)");
 169        }
 170        return addr;
 171}
 172
 173/*
 174 * Returns a connected socket() fd, or else die()s.
 175 */
 176static int git_tcp_connect_sock(char *host, int flags)
 177{
 178        int sockfd = -1, saved_errno = 0;
 179        char *colon, *end;
 180        const char *port = STR(DEFAULT_GIT_PORT);
 181        struct addrinfo hints, *ai0, *ai;
 182        int gai;
 183        int cnt = 0;
 184
 185        if (host[0] == '[') {
 186                end = strchr(host + 1, ']');
 187                if (end) {
 188                        *end = 0;
 189                        end++;
 190                        host++;
 191                } else
 192                        end = host;
 193        } else
 194                end = host;
 195        colon = strchr(end, ':');
 196
 197        if (colon) {
 198                *colon = 0;
 199                port = colon + 1;
 200                if (!*port)
 201                        port = "<none>";
 202        }
 203
 204        memset(&hints, 0, sizeof(hints));
 205        hints.ai_socktype = SOCK_STREAM;
 206        hints.ai_protocol = IPPROTO_TCP;
 207
 208        if (flags & CONNECT_VERBOSE)
 209                fprintf(stderr, "Looking up %s ... ", host);
 210
 211        gai = getaddrinfo(host, port, &hints, &ai);
 212        if (gai)
 213                die("Unable to look up %s (port %s) (%s)", host, port, gai_strerror(gai));
 214
 215        if (flags & CONNECT_VERBOSE)
 216                fprintf(stderr, "done.\nConnecting to %s (port %s) ... ", host, port);
 217
 218        for (ai0 = ai; ai; ai = ai->ai_next) {
 219                sockfd = socket(ai->ai_family,
 220                                ai->ai_socktype, ai->ai_protocol);
 221                if (sockfd < 0) {
 222                        saved_errno = errno;
 223                        continue;
 224                }
 225                if (connect(sockfd, ai->ai_addr, ai->ai_addrlen) < 0) {
 226                        saved_errno = errno;
 227                        fprintf(stderr, "%s[%d: %s]: errno=%s\n",
 228                                host,
 229                                cnt,
 230                                ai_name(ai),
 231                                strerror(saved_errno));
 232                        close(sockfd);
 233                        sockfd = -1;
 234                        continue;
 235                }
 236                if (flags & CONNECT_VERBOSE)
 237                        fprintf(stderr, "%s ", ai_name(ai));
 238                break;
 239        }
 240
 241        freeaddrinfo(ai0);
 242
 243        if (sockfd < 0)
 244                die("unable to connect a socket (%s)", strerror(saved_errno));
 245
 246        if (flags & CONNECT_VERBOSE)
 247                fprintf(stderr, "done.\n");
 248
 249        return sockfd;
 250}
 251
 252#else /* NO_IPV6 */
 253
 254/*
 255 * Returns a connected socket() fd, or else die()s.
 256 */
 257static int git_tcp_connect_sock(char *host, int flags)
 258{
 259        int sockfd = -1, saved_errno = 0;
 260        char *colon, *end;
 261        char *port = STR(DEFAULT_GIT_PORT), *ep;
 262        struct hostent *he;
 263        struct sockaddr_in sa;
 264        char **ap;
 265        unsigned int nport;
 266        int cnt;
 267
 268        if (host[0] == '[') {
 269                end = strchr(host + 1, ']');
 270                if (end) {
 271                        *end = 0;
 272                        end++;
 273                        host++;
 274                } else
 275                        end = host;
 276        } else
 277                end = host;
 278        colon = strchr(end, ':');
 279
 280        if (colon) {
 281                *colon = 0;
 282                port = colon + 1;
 283        }
 284
 285        if (flags & CONNECT_VERBOSE)
 286                fprintf(stderr, "Looking up %s ... ", host);
 287
 288        he = gethostbyname(host);
 289        if (!he)
 290                die("Unable to look up %s (%s)", host, hstrerror(h_errno));
 291        nport = strtoul(port, &ep, 10);
 292        if ( ep == port || *ep ) {
 293                /* Not numeric */
 294                struct servent *se = getservbyname(port,"tcp");
 295                if ( !se )
 296                        die("Unknown port %s\n", port);
 297                nport = se->s_port;
 298        }
 299
 300        if (flags & CONNECT_VERBOSE)
 301                fprintf(stderr, "done.\nConnecting to %s (port %s) ... ", host, port);
 302
 303        for (cnt = 0, ap = he->h_addr_list; *ap; ap++, cnt++) {
 304                sockfd = socket(he->h_addrtype, SOCK_STREAM, 0);
 305                if (sockfd < 0) {
 306                        saved_errno = errno;
 307                        continue;
 308                }
 309
 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                if (connect(sockfd, (struct sockaddr *)&sa, sizeof sa) < 0) {
 316                        saved_errno = errno;
 317                        fprintf(stderr, "%s[%d: %s]: errno=%s\n",
 318                                host,
 319                                cnt,
 320                                inet_ntoa(*(struct in_addr *)&sa.sin_addr),
 321                                strerror(saved_errno));
 322                        close(sockfd);
 323                        sockfd = -1;
 324                        continue;
 325                }
 326                if (flags & CONNECT_VERBOSE)
 327                        fprintf(stderr, "%s ",
 328                                inet_ntoa(*(struct in_addr *)&sa.sin_addr));
 329                break;
 330        }
 331
 332        if (sockfd < 0)
 333                die("unable to connect a socket (%s)", strerror(saved_errno));
 334
 335        if (flags & CONNECT_VERBOSE)
 336                fprintf(stderr, "done.\n");
 337
 338        return sockfd;
 339}
 340
 341#endif /* NO_IPV6 */
 342
 343
 344static void git_tcp_connect(int fd[2], char *host, int flags)
 345{
 346        int sockfd = git_tcp_connect_sock(host, flags);
 347
 348        fd[0] = sockfd;
 349        fd[1] = dup(sockfd);
 350}
 351
 352
 353static char *git_proxy_command;
 354static const char *rhost_name;
 355static int rhost_len;
 356
 357static int git_proxy_command_options(const char *var, const char *value)
 358{
 359        if (!strcmp(var, "core.gitproxy")) {
 360                const char *for_pos;
 361                int matchlen = -1;
 362                int hostlen;
 363
 364                if (git_proxy_command)
 365                        return 0;
 366                /* [core]
 367                 * ;# matches www.kernel.org as well
 368                 * gitproxy = netcatter-1 for kernel.org
 369                 * gitproxy = netcatter-2 for sample.xz
 370                 * gitproxy = netcatter-default
 371                 */
 372                for_pos = strstr(value, " for ");
 373                if (!for_pos)
 374                        /* matches everybody */
 375                        matchlen = strlen(value);
 376                else {
 377                        hostlen = strlen(for_pos + 5);
 378                        if (rhost_len < hostlen)
 379                                matchlen = -1;
 380                        else if (!strncmp(for_pos + 5,
 381                                          rhost_name + rhost_len - hostlen,
 382                                          hostlen) &&
 383                                 ((rhost_len == hostlen) ||
 384                                  rhost_name[rhost_len - hostlen -1] == '.'))
 385                                matchlen = for_pos - value;
 386                        else
 387                                matchlen = -1;
 388                }
 389                if (0 <= matchlen) {
 390                        /* core.gitproxy = none for kernel.org */
 391                        if (matchlen == 4 &&
 392                            !memcmp(value, "none", 4))
 393                                matchlen = 0;
 394                        git_proxy_command = xmalloc(matchlen + 1);
 395                        memcpy(git_proxy_command, value, matchlen);
 396                        git_proxy_command[matchlen] = 0;
 397                }
 398                return 0;
 399        }
 400
 401        return git_default_config(var, value);
 402}
 403
 404static int git_use_proxy(const char *host)
 405{
 406        rhost_name = host;
 407        rhost_len = strlen(host);
 408        git_proxy_command = getenv("GIT_PROXY_COMMAND");
 409        git_config(git_proxy_command_options);
 410        rhost_name = NULL;
 411        return (git_proxy_command && *git_proxy_command);
 412}
 413
 414static void git_proxy_connect(int fd[2], char *host)
 415{
 416        const char *port = STR(DEFAULT_GIT_PORT);
 417        char *colon, *end;
 418        const char *argv[4];
 419        struct child_process proxy;
 420
 421        if (host[0] == '[') {
 422                end = strchr(host + 1, ']');
 423                if (end) {
 424                        *end = 0;
 425                        end++;
 426                        host++;
 427                } else
 428                        end = host;
 429        } else
 430                end = host;
 431        colon = strchr(end, ':');
 432
 433        if (colon) {
 434                *colon = 0;
 435                port = colon + 1;
 436        }
 437
 438        argv[0] = git_proxy_command;
 439        argv[1] = host;
 440        argv[2] = port;
 441        argv[3] = NULL;
 442        memset(&proxy, 0, sizeof(proxy));
 443        proxy.argv = argv;
 444        proxy.in = -1;
 445        proxy.out = -1;
 446        if (start_command(&proxy))
 447                die("cannot start proxy %s", argv[0]);
 448        fd[0] = proxy.out; /* read from proxy stdout */
 449        fd[1] = proxy.in;  /* write to proxy stdin */
 450}
 451
 452#define MAX_CMD_LEN 1024
 453
 454/*
 455 * This returns 0 if the transport protocol does not need fork(2),
 456 * or a process id if it does.  Once done, finish the connection
 457 * with finish_connect() with the value returned from this function
 458 * (it is safe to call finish_connect() with 0 to support the former
 459 * case).
 460 *
 461 * Does not return a negative value on error; it just dies.
 462 */
 463pid_t git_connect(int fd[2], char *url, const char *prog, int flags)
 464{
 465        char *host, *path = url;
 466        char *end;
 467        int c;
 468        int pipefd[2][2];
 469        pid_t pid;
 470        enum protocol protocol = PROTO_LOCAL;
 471        int free_path = 0;
 472
 473        /* Without this we cannot rely on waitpid() to tell
 474         * what happened to our children.
 475         */
 476        signal(SIGCHLD, SIG_DFL);
 477
 478        host = strstr(url, "://");
 479        if(host) {
 480                *host = '\0';
 481                protocol = get_protocol(url);
 482                host += 3;
 483                c = '/';
 484        } else {
 485                host = url;
 486                c = ':';
 487        }
 488
 489        if (host[0] == '[') {
 490                end = strchr(host + 1, ']');
 491                if (end) {
 492                        *end = 0;
 493                        end++;
 494                        host++;
 495                } else
 496                        end = host;
 497        } else
 498                end = host;
 499
 500        path = strchr(end, c);
 501        if (c == ':') {
 502                if (path) {
 503                        protocol = PROTO_SSH;
 504                        *path++ = '\0';
 505                } else
 506                        path = host;
 507        }
 508
 509        if (!path || !*path)
 510                die("No path specified. See 'man git-pull' for valid url syntax");
 511
 512        /*
 513         * null-terminate hostname and point path to ~ for URL's like this:
 514         *    ssh://host.xz/~user/repo
 515         */
 516        if (protocol != PROTO_LOCAL && host != url) {
 517                char *ptr = path;
 518                if (path[1] == '~')
 519                        path++;
 520                else {
 521                        path = xstrdup(ptr);
 522                        free_path = 1;
 523                }
 524
 525                *ptr = '\0';
 526        }
 527
 528        if (protocol == PROTO_GIT) {
 529                /* These underlying connection commands die() if they
 530                 * cannot connect.
 531                 */
 532                char *target_host = xstrdup(host);
 533                if (git_use_proxy(host))
 534                        git_proxy_connect(fd, host);
 535                else
 536                        git_tcp_connect(fd, host, flags);
 537                /*
 538                 * Separate original protocol components prog and path
 539                 * from extended components with a NUL byte.
 540                 */
 541                packet_write(fd[1],
 542                             "%s %s%chost=%s%c",
 543                             prog, path, 0,
 544                             target_host, 0);
 545                free(target_host);
 546                if (free_path)
 547                        free(path);
 548                return 0;
 549        }
 550
 551        if (pipe(pipefd[0]) < 0 || pipe(pipefd[1]) < 0)
 552                die("unable to create pipe pair for communication");
 553        pid = fork();
 554        if (pid < 0)
 555                die("unable to fork");
 556        if (!pid) {
 557                char command[MAX_CMD_LEN];
 558                char *posn = command;
 559                int size = MAX_CMD_LEN;
 560                int of = 0;
 561
 562                of |= add_to_string(&posn, &size, prog, 0);
 563                of |= add_to_string(&posn, &size, " ", 0);
 564                of |= add_to_string(&posn, &size, path, 1);
 565
 566                if (of)
 567                        die("command line too long");
 568
 569                dup2(pipefd[1][0], 0);
 570                dup2(pipefd[0][1], 1);
 571                close(pipefd[0][0]);
 572                close(pipefd[0][1]);
 573                close(pipefd[1][0]);
 574                close(pipefd[1][1]);
 575                if (protocol == PROTO_SSH) {
 576                        const char *ssh, *ssh_basename;
 577                        ssh = getenv("GIT_SSH");
 578                        if (!ssh) ssh = "ssh";
 579                        ssh_basename = strrchr(ssh, '/');
 580                        if (!ssh_basename)
 581                                ssh_basename = ssh;
 582                        else
 583                                ssh_basename++;
 584                        execlp(ssh, ssh_basename, host, command, NULL);
 585                }
 586                else {
 587                        unsetenv(ALTERNATE_DB_ENVIRONMENT);
 588                        unsetenv(DB_ENVIRONMENT);
 589                        unsetenv(GIT_DIR_ENVIRONMENT);
 590                        unsetenv(GIT_WORK_TREE_ENVIRONMENT);
 591                        unsetenv(GRAFT_ENVIRONMENT);
 592                        unsetenv(INDEX_ENVIRONMENT);
 593                        execlp("sh", "sh", "-c", command, NULL);
 594                }
 595                die("exec failed");
 596        }
 597        fd[0] = pipefd[0][0];
 598        fd[1] = pipefd[1][1];
 599        close(pipefd[0][1]);
 600        close(pipefd[1][0]);
 601        if (free_path)
 602                free(path);
 603        return pid;
 604}
 605
 606int finish_connect(pid_t pid)
 607{
 608        if (pid == 0)
 609                return 0;
 610
 611        while (waitpid(pid, NULL, 0) < 0) {
 612                if (errno != EINTR)
 613                        return -1;
 614        }
 615        return 0;
 616}