Andrew's git / gitweb.git / connect.c
?
connect.con commit archive: refactor file extension format-guessing (08716b3)
   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 struct child_process *git_proxy_connect(int fd[2], char *host)
 399{
 400        const char *port = STR(DEFAULT_GIT_PORT);
 401        const char **argv;
 402        struct child_process *proxy;
 403
 404        get_host_and_port(&host, &port);
 405
 406        argv = xmalloc(sizeof(*argv) * 4);
 407        argv[0] = git_proxy_command;
 408        argv[1] = host;
 409        argv[2] = port;
 410        argv[3] = NULL;
 411        proxy = xcalloc(1, sizeof(*proxy));
 412        proxy->argv = argv;
 413        proxy->in = -1;
 414        proxy->out = -1;
 415        if (start_command(proxy))
 416                die("cannot start proxy %s", argv[0]);
 417        fd[0] = proxy->out; /* read from proxy stdout */
 418        fd[1] = proxy->in;  /* write to proxy stdin */
 419        return proxy;
 420}
 421
 422#define MAX_CMD_LEN 1024
 423
 424static char *get_port(char *host)
 425{
 426        char *end;
 427        char *p = strchr(host, ':');
 428
 429        if (p) {
 430                long port = strtol(p + 1, &end, 10);
 431                if (end != p + 1 && *end == '\0' && 0 <= port && port < 65536) {
 432                        *p = '\0';
 433                        return p+1;
 434                }
 435        }
 436
 437        return NULL;
 438}
 439
 440static struct child_process no_fork;
 441
 442/*
 443 * This returns a dummy child_process if the transport protocol does not
 444 * need fork(2), or a struct child_process object if it does.  Once done,
 445 * finish the connection with finish_connect() with the value returned from
 446 * this function (it is safe to call finish_connect() with NULL to support
 447 * the former case).
 448 *
 449 * If it returns, the connect is successful; it just dies on errors (this
 450 * will hopefully be changed in a libification effort, to return NULL when
 451 * the connection failed).
 452 */
 453struct child_process *git_connect(int fd[2], const char *url_orig,
 454                                  const char *prog, int flags)
 455{
 456        char *url;
 457        char *host, *path;
 458        char *end;
 459        int c;
 460        struct child_process *conn = &no_fork;
 461        enum protocol protocol = PROTO_LOCAL;
 462        int free_path = 0;
 463        char *port = NULL;
 464        const char **arg;
 465        struct strbuf cmd;
 466
 467        /* Without this we cannot rely on waitpid() to tell
 468         * what happened to our children.
 469         */
 470        signal(SIGCHLD, SIG_DFL);
 471
 472        if (is_url(url_orig))
 473                url = url_decode(url_orig);
 474        else
 475                url = xstrdup(url_orig);
 476
 477        host = strstr(url, "://");
 478        if (host) {
 479                *host = '\0';
 480                protocol = get_protocol(url);
 481                host += 3;
 482                c = '/';
 483        } else {
 484                host = url;
 485                c = ':';
 486        }
 487
 488        /*
 489         * Don't do destructive transforms with git:// as that
 490         * protocol code does '[]' unwrapping of its own.
 491         */
 492        if (host[0] == '[') {
 493                end = strchr(host + 1, ']');
 494                if (end) {
 495                        if (protocol != PROTO_GIT) {
 496                                *end = 0;
 497                                host++;
 498                        }
 499                        end++;
 500                } else
 501                        end = host;
 502        } else
 503                end = host;
 504
 505        path = strchr(end, c);
 506        if (path && !has_dos_drive_prefix(end)) {
 507                if (c == ':') {
 508                        protocol = PROTO_SSH;
 509                        *path++ = '\0';
 510                }
 511        } else
 512                path = end;
 513
 514        if (!path || !*path)
 515                die("No path specified. See 'man git-pull' for valid url syntax");
 516
 517        /*
 518         * null-terminate hostname and point path to ~ for URL's like this:
 519         *    ssh://host.xz/~user/repo
 520         */
 521        if (protocol != PROTO_LOCAL && host != url) {
 522                char *ptr = path;
 523                if (path[1] == '~')
 524                        path++;
 525                else {
 526                        path = xstrdup(ptr);
 527                        free_path = 1;
 528                }
 529
 530                *ptr = '\0';
 531        }
 532
 533        /*
 534         * Add support for ssh port: ssh://host.xy:<port>/...
 535         */
 536        if (protocol == PROTO_SSH && host != url)
 537                port = get_port(host);
 538
 539        if (protocol == PROTO_GIT) {
 540                /* These underlying connection commands die() if they
 541                 * cannot connect.
 542                 */
 543                char *target_host = xstrdup(host);
 544                if (git_use_proxy(host))
 545                        conn = git_proxy_connect(fd, host);
 546                else
 547                        git_tcp_connect(fd, host, flags);
 548                /*
 549                 * Separate original protocol components prog and path
 550                 * from extended host header with a NUL byte.
 551                 *
 552                 * Note: Do not add any other headers here!  Doing so
 553                 * will cause older git-daemon servers to crash.
 554                 */
 555                packet_write(fd[1],
 556                             "%s %s%chost=%s%c",
 557                             prog, path, 0,
 558                             target_host, 0);
 559                free(target_host);
 560                free(url);
 561                if (free_path)
 562                        free(path);
 563                return conn;
 564        }
 565
 566        conn = xcalloc(1, sizeof(*conn));
 567
 568        strbuf_init(&cmd, MAX_CMD_LEN);
 569        strbuf_addstr(&cmd, prog);
 570        strbuf_addch(&cmd, ' ');
 571        sq_quote_buf(&cmd, path);
 572        if (cmd.len >= MAX_CMD_LEN)
 573                die("command line too long");
 574
 575        conn->in = conn->out = -1;
 576        conn->argv = arg = xcalloc(7, sizeof(*arg));
 577        if (protocol == PROTO_SSH) {
 578                const char *ssh = getenv("GIT_SSH");
 579                int putty = ssh && strcasestr(ssh, "plink");
 580                if (!ssh) ssh = "ssh";
 581
 582                *arg++ = ssh;
 583                if (putty && !strcasestr(ssh, "tortoiseplink"))
 584                        *arg++ = "-batch";
 585                if (port) {
 586                        /* P is for PuTTY, p is for OpenSSH */
 587                        *arg++ = putty ? "-P" : "-p";
 588                        *arg++ = port;
 589                }
 590                *arg++ = host;
 591        }
 592        else {
 593                /* remove repo-local variables from the environment */
 594                conn->env = local_repo_env;
 595                conn->use_shell = 1;
 596        }
 597        *arg++ = cmd.buf;
 598        *arg = NULL;
 599
 600        if (start_command(conn))
 601                die("unable to fork");
 602
 603        fd[0] = conn->out; /* read from child's stdout */
 604        fd[1] = conn->in;  /* write to child's stdin */
 605        strbuf_release(&cmd);
 606        free(url);
 607        if (free_path)
 608                free(path);
 609        return conn;
 610}
 611
 612int git_connection_is_socket(struct child_process *conn)
 613{
 614        return conn == &no_fork;
 615}
 616
 617int finish_connect(struct child_process *conn)
 618{
 619        int code;
 620        if (!conn || git_connection_is_socket(conn))
 621                return 0;
 622
 623        code = finish_command(conn);
 624        free(conn->argv);
 625        free(conn);
 626        return code;
 627}
 628
 629char *git_getpass(const char *prompt)
 630{
 631        const char *askpass;
 632        struct child_process pass;
 633        const char *args[3];
 634        static struct strbuf buffer = STRBUF_INIT;
 635
 636        askpass = getenv("GIT_ASKPASS");
 637        if (!askpass)
 638                askpass = askpass_program;
 639        if (!askpass)
 640                askpass = getenv("SSH_ASKPASS");
 641        if (!askpass || !(*askpass)) {
 642                char *result = getpass(prompt);
 643                if (!result)
 644                        die_errno("Could not read password");
 645                return result;
 646        }
 647
 648        args[0] = askpass;
 649        args[1] = prompt;
 650        args[2] = NULL;
 651
 652        memset(&pass, 0, sizeof(pass));
 653        pass.argv = args;
 654        pass.out = -1;
 655
 656        if (start_command(&pass))
 657                exit(1);
 658
 659        strbuf_reset(&buffer);
 660        if (strbuf_read(&buffer, pass.out, 20) < 0)
 661                die("failed to read password from %s\n", askpass);
 662
 663        close(pass.out);
 664
 665        if (finish_command(&pass))
 666                exit(1);
 667
 668        strbuf_setlen(&buffer, strcspn(buffer.buf, "\r\n"));
 669
 670        return buffer.buf;
 671}