Andrew's git / gitweb.git / connect.c
?
connect.con commit t3306,t5304: avoid clock skew issues (e3b02bc)
   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
  10static char *server_capabilities;
  11
  12static 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_ref_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
  40int check_ref_type(const struct ref *ref, int flags)
  41{
  42        return check_ref(ref->name, strlen(ref->name), flags);
  43}
  44
  45static 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 */
  55struct ref **get_remote_heads(int in, struct ref **list,
  56                              int nr_match, char **match,
  57                              unsigned int flags,
  58                              struct extra_have_objects *extra_have)
  59{
  60        *list = NULL;
  61        for (;;) {
  62                struct ref *ref;
  63                unsigned char old_sha1[20];
  64                static char buffer[1000];
  65                char *name;
  66                int len, name_len;
  67
  68                len = packet_read_line(in, buffer, sizeof(buffer));
  69                if (!len)
  70                        break;
  71                if (buffer[len-1] == '\n')
  72                        buffer[--len] = 0;
  73
  74                if (len > 4 && !prefixcmp(buffer, "ERR "))
  75                        die("remote error: %s", buffer + 4);
  76
  77                if (len < 42 || get_sha1_hex(buffer, old_sha1) || buffer[40] != ' ')
  78                        die("protocol error: expected sha/ref, got '%s'", buffer);
  79                name = buffer + 41;
  80
  81                name_len = strlen(name);
  82                if (len != name_len + 41) {
  83                        free(server_capabilities);
  84                        server_capabilities = xstrdup(name + name_len + 1);
  85                }
  86
  87                if (extra_have &&
  88                    name_len == 5 && !memcmp(".have", name, 5)) {
  89                        add_extra_have(extra_have, old_sha1);
  90                        continue;
  91                }
  92
  93                if (!check_ref(name, name_len, flags))
  94                        continue;
  95                if (nr_match && !path_match(name, nr_match, match))
  96                        continue;
  97                ref = alloc_ref(buffer + 41);
  98                hashcpy(ref->old_sha1, old_sha1);
  99                *list = ref;
 100                list = &ref->next;
 101        }
 102        return list;
 103}
 104
 105int server_supports(const char *feature)
 106{
 107        return server_capabilities &&
 108                strstr(server_capabilities, feature) != NULL;
 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        if (!strcmp(name, "file"))
 149                return PROTO_LOCAL;
 150        die("I don't handle protocol '%s'", name);
 151}
 152
 153#define STR_(s) # s
 154#define STR(s)  STR_(s)
 155
 156static void get_host_and_port(char **host, const char **port)
 157{
 158        char *colon, *end;
 159
 160        if (*host[0] == '[') {
 161                end = strchr(*host + 1, ']');
 162                if (end) {
 163                        *end = 0;
 164                        end++;
 165                        (*host)++;
 166                } else
 167                        end = *host;
 168        } else
 169                end = *host;
 170        colon = strchr(end, ':');
 171
 172        if (colon) {
 173                *colon = 0;
 174                *port = colon + 1;
 175        }
 176}
 177
 178#ifndef NO_IPV6
 179
 180static const char *ai_name(const struct addrinfo *ai)
 181{
 182        static char addr[NI_MAXHOST];
 183        if (getnameinfo(ai->ai_addr, ai->ai_addrlen, addr, sizeof(addr), NULL, 0,
 184                        NI_NUMERICHOST) != 0)
 185                strcpy(addr, "(unknown)");
 186
 187        return addr;
 188}
 189
 190/*
 191 * Returns a connected socket() fd, or else die()s.
 192 */
 193static int git_tcp_connect_sock(char *host, int flags)
 194{
 195        int sockfd = -1, saved_errno = 0;
 196        const char *port = STR(DEFAULT_GIT_PORT);
 197        struct addrinfo hints, *ai0, *ai;
 198        int gai;
 199        int cnt = 0;
 200
 201        get_host_and_port(&host, &port);
 202        if (!*port)
 203                port = "<none>";
 204
 205        memset(&hints, 0, sizeof(hints));
 206        hints.ai_socktype = SOCK_STREAM;
 207        hints.ai_protocol = IPPROTO_TCP;
 208
 209        if (flags & CONNECT_VERBOSE)
 210                fprintf(stderr, "Looking up %s ... ", host);
 211
 212        gai = getaddrinfo(host, port, &hints, &ai);
 213        if (gai)
 214                die("Unable to look up %s (port %s) (%s)", host, port, gai_strerror(gai));
 215
 216        if (flags & CONNECT_VERBOSE)
 217                fprintf(stderr, "done.\nConnecting to %s (port %s) ... ", host, port);
 218
 219        for (ai0 = ai; ai; ai = ai->ai_next) {
 220                sockfd = socket(ai->ai_family,
 221                                ai->ai_socktype, ai->ai_protocol);
 222                if (sockfd < 0) {
 223                        saved_errno = errno;
 224                        continue;
 225                }
 226                if (connect(sockfd, ai->ai_addr, ai->ai_addrlen) < 0) {
 227                        saved_errno = errno;
 228                        fprintf(stderr, "%s[%d: %s]: errno=%s\n",
 229                                host,
 230                                cnt,
 231                                ai_name(ai),
 232                                strerror(saved_errno));
 233                        close(sockfd);
 234                        sockfd = -1;
 235                        continue;
 236                }
 237                if (flags & CONNECT_VERBOSE)
 238                        fprintf(stderr, "%s ", ai_name(ai));
 239                break;
 240        }
 241
 242        freeaddrinfo(ai0);
 243
 244        if (sockfd < 0)
 245                die("unable to connect a socket (%s)", strerror(saved_errno));
 246
 247        if (flags & CONNECT_VERBOSE)
 248                fprintf(stderr, "done.\n");
 249
 250        return sockfd;
 251}
 252
 253#else /* NO_IPV6 */
 254
 255/*
 256 * Returns a connected socket() fd, or else die()s.
 257 */
 258static int git_tcp_connect_sock(char *host, int flags)
 259{
 260        int sockfd = -1, saved_errno = 0;
 261        const char *port = STR(DEFAULT_GIT_PORT);
 262        char *ep;
 263        struct hostent *he;
 264        struct sockaddr_in sa;
 265        char **ap;
 266        unsigned int nport;
 267        int cnt;
 268
 269        get_host_and_port(&host, &port);
 270
 271        if (flags & CONNECT_VERBOSE)
 272                fprintf(stderr, "Looking up %s ... ", host);
 273
 274        he = gethostbyname(host);
 275        if (!he)
 276                die("Unable to look up %s (%s)", host, hstrerror(h_errno));
 277        nport = strtoul(port, &ep, 10);
 278        if ( ep == port || *ep ) {
 279                /* Not numeric */
 280                struct servent *se = getservbyname(port,"tcp");
 281                if ( !se )
 282                        die("Unknown port %s", port);
 283                nport = se->s_port;
 284        }
 285
 286        if (flags & CONNECT_VERBOSE)
 287                fprintf(stderr, "done.\nConnecting to %s (port %s) ... ", host, port);
 288
 289        for (cnt = 0, ap = he->h_addr_list; *ap; ap++, cnt++) {
 290                sockfd = socket(he->h_addrtype, SOCK_STREAM, 0);
 291                if (sockfd < 0) {
 292                        saved_errno = errno;
 293                        continue;
 294                }
 295
 296                memset(&sa, 0, sizeof sa);
 297                sa.sin_family = he->h_addrtype;
 298                sa.sin_port = htons(nport);
 299                memcpy(&sa.sin_addr, *ap, he->h_length);
 300
 301                if (connect(sockfd, (struct sockaddr *)&sa, sizeof sa) < 0) {
 302                        saved_errno = errno;
 303                        fprintf(stderr, "%s[%d: %s]: errno=%s\n",
 304                                host,
 305                                cnt,
 306                                inet_ntoa(*(struct in_addr *)&sa.sin_addr),
 307                                strerror(saved_errno));
 308                        close(sockfd);
 309                        sockfd = -1;
 310                        continue;
 311                }
 312                if (flags & CONNECT_VERBOSE)
 313                        fprintf(stderr, "%s ",
 314                                inet_ntoa(*(struct in_addr *)&sa.sin_addr));
 315                break;
 316        }
 317
 318        if (sockfd < 0)
 319                die("unable to connect a socket (%s)", strerror(saved_errno));
 320
 321        if (flags & CONNECT_VERBOSE)
 322                fprintf(stderr, "done.\n");
 323
 324        return sockfd;
 325}
 326
 327#endif /* NO_IPV6 */
 328
 329
 330static void git_tcp_connect(int fd[2], char *host, int flags)
 331{
 332        int sockfd = git_tcp_connect_sock(host, flags);
 333
 334        fd[0] = sockfd;
 335        fd[1] = dup(sockfd);
 336}
 337
 338
 339static char *git_proxy_command;
 340
 341static int git_proxy_command_options(const char *var, const char *value,
 342                void *cb)
 343{
 344        if (!strcmp(var, "core.gitproxy")) {
 345                const char *for_pos;
 346                int matchlen = -1;
 347                int hostlen;
 348                const char *rhost_name = cb;
 349                int rhost_len = strlen(rhost_name);
 350
 351                if (git_proxy_command)
 352                        return 0;
 353                if (!value)
 354                        return config_error_nonbool(var);
 355                /* [core]
 356                 * ;# matches www.kernel.org as well
 357                 * gitproxy = netcatter-1 for kernel.org
 358                 * gitproxy = netcatter-2 for sample.xz
 359                 * gitproxy = netcatter-default
 360                 */
 361                for_pos = strstr(value, " for ");
 362                if (!for_pos)
 363                        /* matches everybody */
 364                        matchlen = strlen(value);
 365                else {
 366                        hostlen = strlen(for_pos + 5);
 367                        if (rhost_len < hostlen)
 368                                matchlen = -1;
 369                        else if (!strncmp(for_pos + 5,
 370                                          rhost_name + rhost_len - hostlen,
 371                                          hostlen) &&
 372                                 ((rhost_len == hostlen) ||
 373                                  rhost_name[rhost_len - hostlen -1] == '.'))
 374                                matchlen = for_pos - value;
 375                        else
 376                                matchlen = -1;
 377                }
 378                if (0 <= matchlen) {
 379                        /* core.gitproxy = none for kernel.org */
 380                        if (matchlen == 4 &&
 381                            !memcmp(value, "none", 4))
 382                                matchlen = 0;
 383                        git_proxy_command = xmemdupz(value, matchlen);
 384                }
 385                return 0;
 386        }
 387
 388        return git_default_config(var, value, cb);
 389}
 390
 391static int git_use_proxy(const char *host)
 392{
 393        git_proxy_command = getenv("GIT_PROXY_COMMAND");
 394        git_config(git_proxy_command_options, (void*)host);
 395        return (git_proxy_command && *git_proxy_command);
 396}
 397
 398static void git_proxy_connect(int fd[2], char *host)
 399{
 400        const char *port = STR(DEFAULT_GIT_PORT);
 401        const char *argv[4];
 402        struct child_process proxy;
 403
 404        get_host_and_port(&host, &port);
 405
 406        argv[0] = git_proxy_command;
 407        argv[1] = host;
 408        argv[2] = port;
 409        argv[3] = NULL;
 410        memset(&proxy, 0, sizeof(proxy));
 411        proxy.argv = argv;
 412        proxy.in = -1;
 413        proxy.out = -1;
 414        if (start_command(&proxy))
 415                die("cannot start proxy %s", argv[0]);
 416        fd[0] = proxy.out; /* read from proxy stdout */
 417        fd[1] = proxy.in;  /* write to proxy stdin */
 418}
 419
 420#define MAX_CMD_LEN 1024
 421
 422static char *get_port(char *host)
 423{
 424        char *end;
 425        char *p = strchr(host, ':');
 426
 427        if (p) {
 428                long port = strtol(p + 1, &end, 10);
 429                if (end != p + 1 && *end == '\0' && 0 <= port && port < 65536) {
 430                        *p = '\0';
 431                        return p+1;
 432                }
 433        }
 434
 435        return NULL;
 436}
 437
 438static struct child_process no_fork;
 439
 440/*
 441 * This returns a dummy child_process if the transport protocol does not
 442 * need fork(2), or a struct child_process object if it does.  Once done,
 443 * finish the connection with finish_connect() with the value returned from
 444 * this function (it is safe to call finish_connect() with NULL to support
 445 * the former case).
 446 *
 447 * If it returns, the connect is successful; it just dies on errors (this
 448 * will hopefully be changed in a libification effort, to return NULL when
 449 * the connection failed).
 450 */
 451struct child_process *git_connect(int fd[2], const char *url_orig,
 452                                  const char *prog, int flags)
 453{
 454        char *url;
 455        char *host, *path;
 456        char *end;
 457        int c;
 458        struct child_process *conn;
 459        enum protocol protocol = PROTO_LOCAL;
 460        int free_path = 0;
 461        char *port = NULL;
 462        const char **arg;
 463        struct strbuf cmd;
 464
 465        /* Without this we cannot rely on waitpid() to tell
 466         * what happened to our children.
 467         */
 468        signal(SIGCHLD, SIG_DFL);
 469
 470        if (is_url(url_orig))
 471                url = url_decode(url_orig);
 472        else
 473                url = xstrdup(url_orig);
 474
 475        host = strstr(url, "://");
 476        if (host) {
 477                *host = '\0';
 478                protocol = get_protocol(url);
 479                host += 3;
 480                c = '/';
 481        } else {
 482                host = url;
 483                c = ':';
 484        }
 485
 486        /*
 487         * Don't do destructive transforms with git:// as that
 488         * protocol code does '[]' unwrapping of its own.
 489         */
 490        if (host[0] == '[') {
 491                end = strchr(host + 1, ']');
 492                if (end) {
 493                        if (protocol != PROTO_GIT) {
 494                                *end = 0;
 495                                host++;
 496                        }
 497                        end++;
 498                } else
 499                        end = host;
 500        } else
 501                end = host;
 502
 503        path = strchr(end, c);
 504        if (path && !has_dos_drive_prefix(end)) {
 505                if (c == ':') {
 506                        protocol = PROTO_SSH;
 507                        *path++ = '\0';
 508                }
 509        } else
 510                path = end;
 511
 512        if (!path || !*path)
 513                die("No path specified. See 'man git-pull' for valid url syntax");
 514
 515        /*
 516         * null-terminate hostname and point path to ~ for URL's like this:
 517         *    ssh://host.xz/~user/repo
 518         */
 519        if (protocol != PROTO_LOCAL && host != url) {
 520                char *ptr = path;
 521                if (path[1] == '~')
 522                        path++;
 523                else {
 524                        path = xstrdup(ptr);
 525                        free_path = 1;
 526                }
 527
 528                *ptr = '\0';
 529        }
 530
 531        /*
 532         * Add support for ssh port: ssh://host.xy:<port>/...
 533         */
 534        if (protocol == PROTO_SSH && host != url)
 535                port = get_port(host);
 536
 537        if (protocol == PROTO_GIT) {
 538                /* These underlying connection commands die() if they
 539                 * cannot connect.
 540                 */
 541                char *target_host = xstrdup(host);
 542                if (git_use_proxy(host))
 543                        git_proxy_connect(fd, host);
 544                else
 545                        git_tcp_connect(fd, host, flags);
 546                /*
 547                 * Separate original protocol components prog and path
 548                 * from extended host header with a NUL byte.
 549                 *
 550                 * Note: Do not add any other headers here!  Doing so
 551                 * will cause older git-daemon servers to crash.
 552                 */
 553                packet_write(fd[1],
 554                             "%s %s%chost=%s%c",
 555                             prog, path, 0,
 556                             target_host, 0);
 557                free(target_host);
 558                free(url);
 559                if (free_path)
 560                        free(path);
 561                return &no_fork;
 562        }
 563
 564        conn = xcalloc(1, sizeof(*conn));
 565
 566        strbuf_init(&cmd, MAX_CMD_LEN);
 567        strbuf_addstr(&cmd, prog);
 568        strbuf_addch(&cmd, ' ');
 569        sq_quote_buf(&cmd, path);
 570        if (cmd.len >= MAX_CMD_LEN)
 571                die("command line too long");
 572
 573        conn->in = conn->out = -1;
 574        conn->argv = arg = xcalloc(7, sizeof(*arg));
 575        if (protocol == PROTO_SSH) {
 576                const char *ssh = getenv("GIT_SSH");
 577                int putty = ssh && strcasestr(ssh, "plink");
 578                if (!ssh) ssh = "ssh";
 579
 580                *arg++ = ssh;
 581                if (putty && !strcasestr(ssh, "tortoiseplink"))
 582                        *arg++ = "-batch";
 583                if (port) {
 584                        /* P is for PuTTY, p is for OpenSSH */
 585                        *arg++ = putty ? "-P" : "-p";
 586                        *arg++ = port;
 587                }
 588                *arg++ = host;
 589        }
 590        else {
 591                /* remove repo-local variables from the environment */
 592                conn->env = local_repo_env;
 593                conn->use_shell = 1;
 594        }
 595        *arg++ = cmd.buf;
 596        *arg = NULL;
 597
 598        if (start_command(conn))
 599                die("unable to fork");
 600
 601        fd[0] = conn->out; /* read from child's stdout */
 602        fd[1] = conn->in;  /* write to child's stdin */
 603        strbuf_release(&cmd);
 604        free(url);
 605        if (free_path)
 606                free(path);
 607        return conn;
 608}
 609
 610int finish_connect(struct child_process *conn)
 611{
 612        int code;
 613        if (!conn || conn == &no_fork)
 614                return 0;
 615
 616        code = finish_command(conn);
 617        free(conn->argv);
 618        free(conn);
 619        return code;
 620}
 621
 622char *git_getpass(const char *prompt)
 623{
 624        const char *askpass;
 625        struct child_process pass;
 626        const char *args[3];
 627        static struct strbuf buffer = STRBUF_INIT;
 628
 629        askpass = getenv("GIT_ASKPASS");
 630        if (!askpass)
 631                askpass = askpass_program;
 632        if (!askpass)
 633                askpass = getenv("SSH_ASKPASS");
 634        if (!askpass || !(*askpass)) {
 635                char *result = getpass(prompt);
 636                if (!result)
 637                        die_errno("Could not read password");
 638                return result;
 639        }
 640
 641        args[0] = askpass;
 642        args[1] = prompt;
 643        args[2] = NULL;
 644
 645        memset(&pass, 0, sizeof(pass));
 646        pass.argv = args;
 647        pass.out = -1;
 648
 649        if (start_command(&pass))
 650                exit(1);
 651
 652        strbuf_reset(&buffer);
 653        if (strbuf_read(&buffer, pass.out, 20) < 0)
 654                die("failed to read password from %s\n", askpass);
 655
 656        close(pass.out);
 657
 658        if (finish_command(&pass))
 659                exit(1);
 660
 661        strbuf_setlen(&buffer, strcspn(buffer.buf, "\r\n"));
 662
 663        return buffer.buf;
 664}