Andrew's git / gitweb.git / connect.c
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connect.con commit archive: re-allow HEAD:Documentation on a remote invocation (0f544ee)
   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        struct strbuf error_message = STRBUF_INIT;
 196        int sockfd = -1;
 197        const char *port = STR(DEFAULT_GIT_PORT);
 198        struct addrinfo hints, *ai0, *ai;
 199        int gai;
 200        int cnt = 0;
 201
 202        get_host_and_port(&host, &port);
 203        if (!*port)
 204                port = "<none>";
 205
 206        memset(&hints, 0, sizeof(hints));
 207        hints.ai_socktype = SOCK_STREAM;
 208        hints.ai_protocol = IPPROTO_TCP;
 209
 210        if (flags & CONNECT_VERBOSE)
 211                fprintf(stderr, "Looking up %s ... ", host);
 212
 213        gai = getaddrinfo(host, port, &hints, &ai);
 214        if (gai)
 215                die("Unable to look up %s (port %s) (%s)", host, port, gai_strerror(gai));
 216
 217        if (flags & CONNECT_VERBOSE)
 218                fprintf(stderr, "done.\nConnecting to %s (port %s) ... ", host, port);
 219
 220        for (ai0 = ai; ai; ai = ai->ai_next, cnt++) {
 221                sockfd = socket(ai->ai_family,
 222                                ai->ai_socktype, ai->ai_protocol);
 223                if ((sockfd < 0) ||
 224                    (connect(sockfd, ai->ai_addr, ai->ai_addrlen) < 0)) {
 225                        strbuf_addf(&error_message, "%s[%d: %s]: errno=%s\n",
 226                                    host, cnt, ai_name(ai), strerror(errno));
 227                        if (0 <= sockfd)
 228                                close(sockfd);
 229                        sockfd = -1;
 230                        continue;
 231                }
 232                if (flags & CONNECT_VERBOSE)
 233                        fprintf(stderr, "%s ", ai_name(ai));
 234                break;
 235        }
 236
 237        freeaddrinfo(ai0);
 238
 239        if (sockfd < 0)
 240                die("unable to connect to %s:\n%s", host, error_message.buf);
 241
 242        if (flags & CONNECT_VERBOSE)
 243                fprintf(stderr, "done.\n");
 244
 245        strbuf_release(&error_message);
 246
 247        return sockfd;
 248}
 249
 250#else /* NO_IPV6 */
 251
 252/*
 253 * Returns a connected socket() fd, or else die()s.
 254 */
 255static int git_tcp_connect_sock(char *host, int flags)
 256{
 257        struct strbuf error_message = STRBUF_INIT;
 258        int sockfd = -1;
 259        const char *port = STR(DEFAULT_GIT_PORT);
 260        char *ep;
 261        struct hostent *he;
 262        struct sockaddr_in sa;
 263        char **ap;
 264        unsigned int nport;
 265        int cnt;
 266
 267        get_host_and_port(&host, &port);
 268
 269        if (flags & CONNECT_VERBOSE)
 270                fprintf(stderr, "Looking up %s ... ", host);
 271
 272        he = gethostbyname(host);
 273        if (!he)
 274                die("Unable to look up %s (%s)", host, hstrerror(h_errno));
 275        nport = strtoul(port, &ep, 10);
 276        if ( ep == port || *ep ) {
 277                /* Not numeric */
 278                struct servent *se = getservbyname(port,"tcp");
 279                if ( !se )
 280                        die("Unknown port %s", port);
 281                nport = se->s_port;
 282        }
 283
 284        if (flags & CONNECT_VERBOSE)
 285                fprintf(stderr, "done.\nConnecting to %s (port %s) ... ", host, port);
 286
 287        for (cnt = 0, ap = he->h_addr_list; *ap; ap++, cnt++) {
 288                memset(&sa, 0, sizeof sa);
 289                sa.sin_family = he->h_addrtype;
 290                sa.sin_port = htons(nport);
 291                memcpy(&sa.sin_addr, *ap, he->h_length);
 292
 293                sockfd = socket(he->h_addrtype, SOCK_STREAM, 0);
 294                if ((sockfd < 0) ||
 295                    connect(sockfd, (struct sockaddr *)&sa, sizeof sa) < 0) {
 296                        strbuf_addf(&error_message, "%s[%d: %s]: errno=%s\n",
 297                                host,
 298                                cnt,
 299                                inet_ntoa(*(struct in_addr *)&sa.sin_addr),
 300                                strerror(errno));
 301                        if (0 <= sockfd)
 302                                close(sockfd);
 303                        sockfd = -1;
 304                        continue;
 305                }
 306                if (flags & CONNECT_VERBOSE)
 307                        fprintf(stderr, "%s ",
 308                                inet_ntoa(*(struct in_addr *)&sa.sin_addr));
 309                break;
 310        }
 311
 312        if (sockfd < 0)
 313                die("unable to connect to %s:\n%s", host, error_message.buf);
 314
 315        if (flags & CONNECT_VERBOSE)
 316                fprintf(stderr, "done.\n");
 317
 318        return sockfd;
 319}
 320
 321#endif /* NO_IPV6 */
 322
 323
 324static void git_tcp_connect(int fd[2], char *host, int flags)
 325{
 326        int sockfd = git_tcp_connect_sock(host, flags);
 327
 328        fd[0] = sockfd;
 329        fd[1] = dup(sockfd);
 330}
 331
 332
 333static char *git_proxy_command;
 334
 335static int git_proxy_command_options(const char *var, const char *value,
 336                void *cb)
 337{
 338        if (!strcmp(var, "core.gitproxy")) {
 339                const char *for_pos;
 340                int matchlen = -1;
 341                int hostlen;
 342                const char *rhost_name = cb;
 343                int rhost_len = strlen(rhost_name);
 344
 345                if (git_proxy_command)
 346                        return 0;
 347                if (!value)
 348                        return config_error_nonbool(var);
 349                /* [core]
 350                 * ;# matches www.kernel.org as well
 351                 * gitproxy = netcatter-1 for kernel.org
 352                 * gitproxy = netcatter-2 for sample.xz
 353                 * gitproxy = netcatter-default
 354                 */
 355                for_pos = strstr(value, " for ");
 356                if (!for_pos)
 357                        /* matches everybody */
 358                        matchlen = strlen(value);
 359                else {
 360                        hostlen = strlen(for_pos + 5);
 361                        if (rhost_len < hostlen)
 362                                matchlen = -1;
 363                        else if (!strncmp(for_pos + 5,
 364                                          rhost_name + rhost_len - hostlen,
 365                                          hostlen) &&
 366                                 ((rhost_len == hostlen) ||
 367                                  rhost_name[rhost_len - hostlen -1] == '.'))
 368                                matchlen = for_pos - value;
 369                        else
 370                                matchlen = -1;
 371                }
 372                if (0 <= matchlen) {
 373                        /* core.gitproxy = none for kernel.org */
 374                        if (matchlen == 4 &&
 375                            !memcmp(value, "none", 4))
 376                                matchlen = 0;
 377                        git_proxy_command = xmemdupz(value, matchlen);
 378                }
 379                return 0;
 380        }
 381
 382        return git_default_config(var, value, cb);
 383}
 384
 385static int git_use_proxy(const char *host)
 386{
 387        git_proxy_command = getenv("GIT_PROXY_COMMAND");
 388        git_config(git_proxy_command_options, (void*)host);
 389        return (git_proxy_command && *git_proxy_command);
 390}
 391
 392static struct child_process *git_proxy_connect(int fd[2], char *host)
 393{
 394        const char *port = STR(DEFAULT_GIT_PORT);
 395        const char **argv;
 396        struct child_process *proxy;
 397
 398        get_host_and_port(&host, &port);
 399
 400        argv = xmalloc(sizeof(*argv) * 4);
 401        argv[0] = git_proxy_command;
 402        argv[1] = host;
 403        argv[2] = port;
 404        argv[3] = NULL;
 405        proxy = xcalloc(1, sizeof(*proxy));
 406        proxy->argv = argv;
 407        proxy->in = -1;
 408        proxy->out = -1;
 409        if (start_command(proxy))
 410                die("cannot start proxy %s", argv[0]);
 411        fd[0] = proxy->out; /* read from proxy stdout */
 412        fd[1] = proxy->in;  /* write to proxy stdin */
 413        return proxy;
 414}
 415
 416#define MAX_CMD_LEN 1024
 417
 418static char *get_port(char *host)
 419{
 420        char *end;
 421        char *p = strchr(host, ':');
 422
 423        if (p) {
 424                long port = strtol(p + 1, &end, 10);
 425                if (end != p + 1 && *end == '\0' && 0 <= port && port < 65536) {
 426                        *p = '\0';
 427                        return p+1;
 428                }
 429        }
 430
 431        return NULL;
 432}
 433
 434static struct child_process no_fork;
 435
 436/*
 437 * This returns a dummy child_process if the transport protocol does not
 438 * need fork(2), or a struct child_process object if it does.  Once done,
 439 * finish the connection with finish_connect() with the value returned from
 440 * this function (it is safe to call finish_connect() with NULL to support
 441 * the former case).
 442 *
 443 * If it returns, the connect is successful; it just dies on errors (this
 444 * will hopefully be changed in a libification effort, to return NULL when
 445 * the connection failed).
 446 */
 447struct child_process *git_connect(int fd[2], const char *url_orig,
 448                                  const char *prog, int flags)
 449{
 450        char *url;
 451        char *host, *path;
 452        char *end;
 453        int c;
 454        struct child_process *conn = &no_fork;
 455        enum protocol protocol = PROTO_LOCAL;
 456        int free_path = 0;
 457        char *port = NULL;
 458        const char **arg;
 459        struct strbuf cmd;
 460
 461        /* Without this we cannot rely on waitpid() to tell
 462         * what happened to our children.
 463         */
 464        signal(SIGCHLD, SIG_DFL);
 465
 466        if (is_url(url_orig))
 467                url = url_decode(url_orig);
 468        else
 469                url = xstrdup(url_orig);
 470
 471        host = strstr(url, "://");
 472        if (host) {
 473                *host = '\0';
 474                protocol = get_protocol(url);
 475                host += 3;
 476                c = '/';
 477        } else {
 478                host = url;
 479                c = ':';
 480        }
 481
 482        /*
 483         * Don't do destructive transforms with git:// as that
 484         * protocol code does '[]' unwrapping of its own.
 485         */
 486        if (host[0] == '[') {
 487                end = strchr(host + 1, ']');
 488                if (end) {
 489                        if (protocol != PROTO_GIT) {
 490                                *end = 0;
 491                                host++;
 492                        }
 493                        end++;
 494                } else
 495                        end = host;
 496        } else
 497                end = host;
 498
 499        path = strchr(end, c);
 500        if (path && !has_dos_drive_prefix(end)) {
 501                if (c == ':') {
 502                        protocol = PROTO_SSH;
 503                        *path++ = '\0';
 504                }
 505        } else
 506                path = end;
 507
 508        if (!path || !*path)
 509                die("No path specified. See 'man git-pull' for valid url syntax");
 510
 511        /*
 512         * null-terminate hostname and point path to ~ for URL's like this:
 513         *    ssh://host.xz/~user/repo
 514         */
 515        if (protocol != PROTO_LOCAL && host != url) {
 516                char *ptr = path;
 517                if (path[1] == '~')
 518                        path++;
 519                else {
 520                        path = xstrdup(ptr);
 521                        free_path = 1;
 522                }
 523
 524                *ptr = '\0';
 525        }
 526
 527        /*
 528         * Add support for ssh port: ssh://host.xy:<port>/...
 529         */
 530        if (protocol == PROTO_SSH && host != url)
 531                port = get_port(host);
 532
 533        if (protocol == PROTO_GIT) {
 534                /* These underlying connection commands die() if they
 535                 * cannot connect.
 536                 */
 537                char *target_host = xstrdup(host);
 538                if (git_use_proxy(host))
 539                        conn = git_proxy_connect(fd, host);
 540                else
 541                        git_tcp_connect(fd, host, flags);
 542                /*
 543                 * Separate original protocol components prog and path
 544                 * from extended host header with a NUL byte.
 545                 *
 546                 * Note: Do not add any other headers here!  Doing so
 547                 * will cause older git-daemon servers to crash.
 548                 */
 549                packet_write(fd[1],
 550                             "%s %s%chost=%s%c",
 551                             prog, path, 0,
 552                             target_host, 0);
 553                free(target_host);
 554                free(url);
 555                if (free_path)
 556                        free(path);
 557                return conn;
 558        }
 559
 560        conn = xcalloc(1, sizeof(*conn));
 561
 562        strbuf_init(&cmd, MAX_CMD_LEN);
 563        strbuf_addstr(&cmd, prog);
 564        strbuf_addch(&cmd, ' ');
 565        sq_quote_buf(&cmd, path);
 566        if (cmd.len >= MAX_CMD_LEN)
 567                die("command line too long");
 568
 569        conn->in = conn->out = -1;
 570        conn->argv = arg = xcalloc(7, sizeof(*arg));
 571        if (protocol == PROTO_SSH) {
 572                const char *ssh = getenv("GIT_SSH");
 573                int putty = ssh && strcasestr(ssh, "plink");
 574                if (!ssh) ssh = "ssh";
 575
 576                *arg++ = ssh;
 577                if (putty && !strcasestr(ssh, "tortoiseplink"))
 578                        *arg++ = "-batch";
 579                if (port) {
 580                        /* P is for PuTTY, p is for OpenSSH */
 581                        *arg++ = putty ? "-P" : "-p";
 582                        *arg++ = port;
 583                }
 584                *arg++ = host;
 585        }
 586        else {
 587                /* remove repo-local variables from the environment */
 588                conn->env = local_repo_env;
 589                conn->use_shell = 1;
 590        }
 591        *arg++ = cmd.buf;
 592        *arg = NULL;
 593
 594        if (start_command(conn))
 595                die("unable to fork");
 596
 597        fd[0] = conn->out; /* read from child's stdout */
 598        fd[1] = conn->in;  /* write to child's stdin */
 599        strbuf_release(&cmd);
 600        free(url);
 601        if (free_path)
 602                free(path);
 603        return conn;
 604}
 605
 606int git_connection_is_socket(struct child_process *conn)
 607{
 608        return conn == &no_fork;
 609}
 610
 611int finish_connect(struct child_process *conn)
 612{
 613        int code;
 614        if (!conn || git_connection_is_socket(conn))
 615                return 0;
 616
 617        code = finish_command(conn);
 618        free(conn->argv);
 619        free(conn);
 620        return code;
 621}
 622
 623char *git_getpass(const char *prompt)
 624{
 625        const char *askpass;
 626        struct child_process pass;
 627        const char *args[3];
 628        static struct strbuf buffer = STRBUF_INIT;
 629
 630        askpass = getenv("GIT_ASKPASS");
 631        if (!askpass)
 632                askpass = askpass_program;
 633        if (!askpass)
 634                askpass = getenv("SSH_ASKPASS");
 635        if (!askpass || !(*askpass)) {
 636                char *result = getpass(prompt);
 637                if (!result)
 638                        die_errno("Could not read password");
 639                return result;
 640        }
 641
 642        args[0] = askpass;
 643        args[1] = prompt;
 644        args[2] = NULL;
 645
 646        memset(&pass, 0, sizeof(pass));
 647        pass.argv = args;
 648        pass.out = -1;
 649
 650        if (start_command(&pass))
 651                exit(1);
 652
 653        strbuf_reset(&buffer);
 654        if (strbuf_read(&buffer, pass.out, 20) < 0)
 655                die("failed to read password from %s\n", askpass);
 656
 657        close(pass.out);
 658
 659        if (finish_command(&pass))
 660                exit(1);
 661
 662        strbuf_setlen(&buffer, strcspn(buffer.buf, "\r\n"));
 663
 664        return buffer.buf;
 665}