Andrew's git / gitweb.git / connect.c
?
connect.con commit Merge branch 'kk/maint-commit-tree' (a7fe78a)
   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_refname_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
  52static void die_initial_contact(int got_at_least_one_head)
  53{
  54        if (got_at_least_one_head)
  55                die("The remote end hung up upon initial contact");
  56        else
  57                die("Could not read from remote repository.\n\n"
  58                    "Please make sure you have the correct access rights\n"
  59                    "and the repository exists.");
  60}
  61
  62/*
  63 * Read all the refs from the other end
  64 */
  65struct ref **get_remote_heads(int in, struct ref **list,
  66                              unsigned int flags,
  67                              struct extra_have_objects *extra_have)
  68{
  69        int got_at_least_one_head = 0;
  70
  71        *list = NULL;
  72        for (;;) {
  73                struct ref *ref;
  74                unsigned char old_sha1[20];
  75                static char buffer[1000];
  76                char *name;
  77                int len, name_len;
  78
  79                len = packet_read(in, buffer, sizeof(buffer));
  80                if (len < 0)
  81                        die_initial_contact(got_at_least_one_head);
  82
  83                if (!len)
  84                        break;
  85                if (buffer[len-1] == '\n')
  86                        buffer[--len] = 0;
  87
  88                if (len > 4 && !prefixcmp(buffer, "ERR "))
  89                        die("remote error: %s", buffer + 4);
  90
  91                if (len < 42 || get_sha1_hex(buffer, old_sha1) || buffer[40] != ' ')
  92                        die("protocol error: expected sha/ref, got '%s'", buffer);
  93                name = buffer + 41;
  94
  95                name_len = strlen(name);
  96                if (len != name_len + 41) {
  97                        free(server_capabilities);
  98                        server_capabilities = xstrdup(name + name_len + 1);
  99                }
 100
 101                if (extra_have &&
 102                    name_len == 5 && !memcmp(".have", name, 5)) {
 103                        add_extra_have(extra_have, old_sha1);
 104                        continue;
 105                }
 106
 107                if (!check_ref(name, name_len, flags))
 108                        continue;
 109                ref = alloc_ref(buffer + 41);
 110                hashcpy(ref->old_sha1, old_sha1);
 111                *list = ref;
 112                list = &ref->next;
 113                got_at_least_one_head = 1;
 114        }
 115        return list;
 116}
 117
 118int server_supports(const char *feature)
 119{
 120        return !!parse_feature_request(server_capabilities, feature);
 121}
 122
 123const char *parse_feature_request(const char *feature_list, const char *feature)
 124{
 125        int len;
 126
 127        if (!feature_list)
 128                return NULL;
 129
 130        len = strlen(feature);
 131        while (*feature_list) {
 132                const char *found = strstr(feature_list, feature);
 133                if (!found)
 134                        return NULL;
 135                if ((feature_list == found || isspace(found[-1])) &&
 136                    (!found[len] || isspace(found[len]) || found[len] == '='))
 137                        return found;
 138                feature_list = found + 1;
 139        }
 140        return NULL;
 141}
 142
 143enum protocol {
 144        PROTO_LOCAL = 1,
 145        PROTO_SSH,
 146        PROTO_GIT
 147};
 148
 149static enum protocol get_protocol(const char *name)
 150{
 151        if (!strcmp(name, "ssh"))
 152                return PROTO_SSH;
 153        if (!strcmp(name, "git"))
 154                return PROTO_GIT;
 155        if (!strcmp(name, "git+ssh"))
 156                return PROTO_SSH;
 157        if (!strcmp(name, "ssh+git"))
 158                return PROTO_SSH;
 159        if (!strcmp(name, "file"))
 160                return PROTO_LOCAL;
 161        die("I don't handle protocol '%s'", name);
 162}
 163
 164#define STR_(s) # s
 165#define STR(s)  STR_(s)
 166
 167static void get_host_and_port(char **host, const char **port)
 168{
 169        char *colon, *end;
 170
 171        if (*host[0] == '[') {
 172                end = strchr(*host + 1, ']');
 173                if (end) {
 174                        *end = 0;
 175                        end++;
 176                        (*host)++;
 177                } else
 178                        end = *host;
 179        } else
 180                end = *host;
 181        colon = strchr(end, ':');
 182
 183        if (colon) {
 184                *colon = 0;
 185                *port = colon + 1;
 186        }
 187}
 188
 189static void enable_keepalive(int sockfd)
 190{
 191        int ka = 1;
 192
 193        if (setsockopt(sockfd, SOL_SOCKET, SO_KEEPALIVE, &ka, sizeof(ka)) < 0)
 194                fprintf(stderr, "unable to set SO_KEEPALIVE on socket: %s\n",
 195                        strerror(errno));
 196}
 197
 198#ifndef NO_IPV6
 199
 200static const char *ai_name(const struct addrinfo *ai)
 201{
 202        static char addr[NI_MAXHOST];
 203        if (getnameinfo(ai->ai_addr, ai->ai_addrlen, addr, sizeof(addr), NULL, 0,
 204                        NI_NUMERICHOST) != 0)
 205                strcpy(addr, "(unknown)");
 206
 207        return addr;
 208}
 209
 210/*
 211 * Returns a connected socket() fd, or else die()s.
 212 */
 213static int git_tcp_connect_sock(char *host, int flags)
 214{
 215        struct strbuf error_message = STRBUF_INIT;
 216        int sockfd = -1;
 217        const char *port = STR(DEFAULT_GIT_PORT);
 218        struct addrinfo hints, *ai0, *ai;
 219        int gai;
 220        int cnt = 0;
 221
 222        get_host_and_port(&host, &port);
 223        if (!*port)
 224                port = "<none>";
 225
 226        memset(&hints, 0, sizeof(hints));
 227        hints.ai_socktype = SOCK_STREAM;
 228        hints.ai_protocol = IPPROTO_TCP;
 229
 230        if (flags & CONNECT_VERBOSE)
 231                fprintf(stderr, "Looking up %s ... ", host);
 232
 233        gai = getaddrinfo(host, port, &hints, &ai);
 234        if (gai)
 235                die("Unable to look up %s (port %s) (%s)", host, port, gai_strerror(gai));
 236
 237        if (flags & CONNECT_VERBOSE)
 238                fprintf(stderr, "done.\nConnecting to %s (port %s) ... ", host, port);
 239
 240        for (ai0 = ai; ai; ai = ai->ai_next, cnt++) {
 241                sockfd = socket(ai->ai_family,
 242                                ai->ai_socktype, ai->ai_protocol);
 243                if ((sockfd < 0) ||
 244                    (connect(sockfd, ai->ai_addr, ai->ai_addrlen) < 0)) {
 245                        strbuf_addf(&error_message, "%s[%d: %s]: errno=%s\n",
 246                                    host, cnt, ai_name(ai), strerror(errno));
 247                        if (0 <= sockfd)
 248                                close(sockfd);
 249                        sockfd = -1;
 250                        continue;
 251                }
 252                if (flags & CONNECT_VERBOSE)
 253                        fprintf(stderr, "%s ", ai_name(ai));
 254                break;
 255        }
 256
 257        freeaddrinfo(ai0);
 258
 259        if (sockfd < 0)
 260                die("unable to connect to %s:\n%s", host, error_message.buf);
 261
 262        enable_keepalive(sockfd);
 263
 264        if (flags & CONNECT_VERBOSE)
 265                fprintf(stderr, "done.\n");
 266
 267        strbuf_release(&error_message);
 268
 269        return sockfd;
 270}
 271
 272#else /* NO_IPV6 */
 273
 274/*
 275 * Returns a connected socket() fd, or else die()s.
 276 */
 277static int git_tcp_connect_sock(char *host, int flags)
 278{
 279        struct strbuf error_message = STRBUF_INIT;
 280        int sockfd = -1;
 281        const char *port = STR(DEFAULT_GIT_PORT);
 282        char *ep;
 283        struct hostent *he;
 284        struct sockaddr_in sa;
 285        char **ap;
 286        unsigned int nport;
 287        int cnt;
 288
 289        get_host_and_port(&host, &port);
 290
 291        if (flags & CONNECT_VERBOSE)
 292                fprintf(stderr, "Looking up %s ... ", host);
 293
 294        he = gethostbyname(host);
 295        if (!he)
 296                die("Unable to look up %s (%s)", host, hstrerror(h_errno));
 297        nport = strtoul(port, &ep, 10);
 298        if ( ep == port || *ep ) {
 299                /* Not numeric */
 300                struct servent *se = getservbyname(port,"tcp");
 301                if ( !se )
 302                        die("Unknown port %s", port);
 303                nport = se->s_port;
 304        }
 305
 306        if (flags & CONNECT_VERBOSE)
 307                fprintf(stderr, "done.\nConnecting to %s (port %s) ... ", host, port);
 308
 309        for (cnt = 0, ap = he->h_addr_list; *ap; ap++, cnt++) {
 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                sockfd = socket(he->h_addrtype, SOCK_STREAM, 0);
 316                if ((sockfd < 0) ||
 317                    connect(sockfd, (struct sockaddr *)&sa, sizeof sa) < 0) {
 318                        strbuf_addf(&error_message, "%s[%d: %s]: errno=%s\n",
 319                                host,
 320                                cnt,
 321                                inet_ntoa(*(struct in_addr *)&sa.sin_addr),
 322                                strerror(errno));
 323                        if (0 <= sockfd)
 324                                close(sockfd);
 325                        sockfd = -1;
 326                        continue;
 327                }
 328                if (flags & CONNECT_VERBOSE)
 329                        fprintf(stderr, "%s ",
 330                                inet_ntoa(*(struct in_addr *)&sa.sin_addr));
 331                break;
 332        }
 333
 334        if (sockfd < 0)
 335                die("unable to connect to %s:\n%s", host, error_message.buf);
 336
 337        enable_keepalive(sockfd);
 338
 339        if (flags & CONNECT_VERBOSE)
 340                fprintf(stderr, "done.\n");
 341
 342        return sockfd;
 343}
 344
 345#endif /* NO_IPV6 */
 346
 347
 348static void git_tcp_connect(int fd[2], char *host, int flags)
 349{
 350        int sockfd = git_tcp_connect_sock(host, flags);
 351
 352        fd[0] = sockfd;
 353        fd[1] = dup(sockfd);
 354}
 355
 356
 357static char *git_proxy_command;
 358
 359static int git_proxy_command_options(const char *var, const char *value,
 360                void *cb)
 361{
 362        if (!strcmp(var, "core.gitproxy")) {
 363                const char *for_pos;
 364                int matchlen = -1;
 365                int hostlen;
 366                const char *rhost_name = cb;
 367                int rhost_len = strlen(rhost_name);
 368
 369                if (git_proxy_command)
 370                        return 0;
 371                if (!value)
 372                        return config_error_nonbool(var);
 373                /* [core]
 374                 * ;# matches www.kernel.org as well
 375                 * gitproxy = netcatter-1 for kernel.org
 376                 * gitproxy = netcatter-2 for sample.xz
 377                 * gitproxy = netcatter-default
 378                 */
 379                for_pos = strstr(value, " for ");
 380                if (!for_pos)
 381                        /* matches everybody */
 382                        matchlen = strlen(value);
 383                else {
 384                        hostlen = strlen(for_pos + 5);
 385                        if (rhost_len < hostlen)
 386                                matchlen = -1;
 387                        else if (!strncmp(for_pos + 5,
 388                                          rhost_name + rhost_len - hostlen,
 389                                          hostlen) &&
 390                                 ((rhost_len == hostlen) ||
 391                                  rhost_name[rhost_len - hostlen -1] == '.'))
 392                                matchlen = for_pos - value;
 393                        else
 394                                matchlen = -1;
 395                }
 396                if (0 <= matchlen) {
 397                        /* core.gitproxy = none for kernel.org */
 398                        if (matchlen == 4 &&
 399                            !memcmp(value, "none", 4))
 400                                matchlen = 0;
 401                        git_proxy_command = xmemdupz(value, matchlen);
 402                }
 403                return 0;
 404        }
 405
 406        return git_default_config(var, value, cb);
 407}
 408
 409static int git_use_proxy(const char *host)
 410{
 411        git_proxy_command = getenv("GIT_PROXY_COMMAND");
 412        git_config(git_proxy_command_options, (void*)host);
 413        return (git_proxy_command && *git_proxy_command);
 414}
 415
 416static struct child_process *git_proxy_connect(int fd[2], char *host)
 417{
 418        const char *port = STR(DEFAULT_GIT_PORT);
 419        const char **argv;
 420        struct child_process *proxy;
 421
 422        get_host_and_port(&host, &port);
 423
 424        argv = xmalloc(sizeof(*argv) * 4);
 425        argv[0] = git_proxy_command;
 426        argv[1] = host;
 427        argv[2] = port;
 428        argv[3] = NULL;
 429        proxy = xcalloc(1, sizeof(*proxy));
 430        proxy->argv = argv;
 431        proxy->in = -1;
 432        proxy->out = -1;
 433        if (start_command(proxy))
 434                die("cannot start proxy %s", argv[0]);
 435        fd[0] = proxy->out; /* read from proxy stdout */
 436        fd[1] = proxy->in;  /* write to proxy stdin */
 437        return proxy;
 438}
 439
 440#define MAX_CMD_LEN 1024
 441
 442static char *get_port(char *host)
 443{
 444        char *end;
 445        char *p = strchr(host, ':');
 446
 447        if (p) {
 448                long port = strtol(p + 1, &end, 10);
 449                if (end != p + 1 && *end == '\0' && 0 <= port && port < 65536) {
 450                        *p = '\0';
 451                        return p+1;
 452                }
 453        }
 454
 455        return NULL;
 456}
 457
 458static struct child_process no_fork;
 459
 460/*
 461 * This returns a dummy child_process if the transport protocol does not
 462 * need fork(2), or a struct child_process object if it does.  Once done,
 463 * finish the connection with finish_connect() with the value returned from
 464 * this function (it is safe to call finish_connect() with NULL to support
 465 * the former case).
 466 *
 467 * If it returns, the connect is successful; it just dies on errors (this
 468 * will hopefully be changed in a libification effort, to return NULL when
 469 * the connection failed).
 470 */
 471struct child_process *git_connect(int fd[2], const char *url_orig,
 472                                  const char *prog, int flags)
 473{
 474        char *url;
 475        char *host, *path;
 476        char *end;
 477        int c;
 478        struct child_process *conn = &no_fork;
 479        enum protocol protocol = PROTO_LOCAL;
 480        int free_path = 0;
 481        char *port = NULL;
 482        const char **arg;
 483        struct strbuf cmd;
 484
 485        /* Without this we cannot rely on waitpid() to tell
 486         * what happened to our children.
 487         */
 488        signal(SIGCHLD, SIG_DFL);
 489
 490        if (is_url(url_orig))
 491                url = url_decode(url_orig);
 492        else
 493                url = xstrdup(url_orig);
 494
 495        host = strstr(url, "://");
 496        if (host) {
 497                *host = '\0';
 498                protocol = get_protocol(url);
 499                host += 3;
 500                c = '/';
 501        } else {
 502                host = url;
 503                c = ':';
 504        }
 505
 506        /*
 507         * Don't do destructive transforms with git:// as that
 508         * protocol code does '[]' unwrapping of its own.
 509         */
 510        if (host[0] == '[') {
 511                end = strchr(host + 1, ']');
 512                if (end) {
 513                        if (protocol != PROTO_GIT) {
 514                                *end = 0;
 515                                host++;
 516                        }
 517                        end++;
 518                } else
 519                        end = host;
 520        } else
 521                end = host;
 522
 523        path = strchr(end, c);
 524        if (path && !has_dos_drive_prefix(end)) {
 525                if (c == ':') {
 526                        protocol = PROTO_SSH;
 527                        *path++ = '\0';
 528                }
 529        } else
 530                path = end;
 531
 532        if (!path || !*path)
 533                die("No path specified. See 'man git-pull' for valid url syntax");
 534
 535        /*
 536         * null-terminate hostname and point path to ~ for URL's like this:
 537         *    ssh://host.xz/~user/repo
 538         */
 539        if (protocol != PROTO_LOCAL && host != url) {
 540                char *ptr = path;
 541                if (path[1] == '~')
 542                        path++;
 543                else {
 544                        path = xstrdup(ptr);
 545                        free_path = 1;
 546                }
 547
 548                *ptr = '\0';
 549        }
 550
 551        /*
 552         * Add support for ssh port: ssh://host.xy:<port>/...
 553         */
 554        if (protocol == PROTO_SSH && host != url)
 555                port = get_port(end);
 556
 557        if (protocol == PROTO_GIT) {
 558                /* These underlying connection commands die() if they
 559                 * cannot connect.
 560                 */
 561                char *target_host = xstrdup(host);
 562                if (git_use_proxy(host))
 563                        conn = git_proxy_connect(fd, host);
 564                else
 565                        git_tcp_connect(fd, host, flags);
 566                /*
 567                 * Separate original protocol components prog and path
 568                 * from extended host header with a NUL byte.
 569                 *
 570                 * Note: Do not add any other headers here!  Doing so
 571                 * will cause older git-daemon servers to crash.
 572                 */
 573                packet_write(fd[1],
 574                             "%s %s%chost=%s%c",
 575                             prog, path, 0,
 576                             target_host, 0);
 577                free(target_host);
 578                free(url);
 579                if (free_path)
 580                        free(path);
 581                return conn;
 582        }
 583
 584        conn = xcalloc(1, sizeof(*conn));
 585
 586        strbuf_init(&cmd, MAX_CMD_LEN);
 587        strbuf_addstr(&cmd, prog);
 588        strbuf_addch(&cmd, ' ');
 589        sq_quote_buf(&cmd, path);
 590        if (cmd.len >= MAX_CMD_LEN)
 591                die("command line too long");
 592
 593        conn->in = conn->out = -1;
 594        conn->argv = arg = xcalloc(7, sizeof(*arg));
 595        if (protocol == PROTO_SSH) {
 596                const char *ssh = getenv("GIT_SSH");
 597                int putty = ssh && strcasestr(ssh, "plink");
 598                if (!ssh) ssh = "ssh";
 599
 600                *arg++ = ssh;
 601                if (putty && !strcasestr(ssh, "tortoiseplink"))
 602                        *arg++ = "-batch";
 603                if (port) {
 604                        /* P is for PuTTY, p is for OpenSSH */
 605                        *arg++ = putty ? "-P" : "-p";
 606                        *arg++ = port;
 607                }
 608                *arg++ = host;
 609        }
 610        else {
 611                /* remove repo-local variables from the environment */
 612                conn->env = local_repo_env;
 613                conn->use_shell = 1;
 614        }
 615        *arg++ = cmd.buf;
 616        *arg = NULL;
 617
 618        if (start_command(conn))
 619                die("unable to fork");
 620
 621        fd[0] = conn->out; /* read from child's stdout */
 622        fd[1] = conn->in;  /* write to child's stdin */
 623        strbuf_release(&cmd);
 624        free(url);
 625        if (free_path)
 626                free(path);
 627        return conn;
 628}
 629
 630int git_connection_is_socket(struct child_process *conn)
 631{
 632        return conn == &no_fork;
 633}
 634
 635int finish_connect(struct child_process *conn)
 636{
 637        int code;
 638        if (!conn || git_connection_is_socket(conn))
 639                return 0;
 640
 641        code = finish_command(conn);
 642        free(conn->argv);
 643        free(conn);
 644        return code;
 645}