Andrew's git / gitweb.git / connect.c
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connect.con commit documentation: trivial whitespace cleanups (240ae2b)
   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
 118const char *parse_feature_value(const char *feature_list, const char *feature, int *lenp)
 119{
 120        int len;
 121
 122        if (!feature_list)
 123                return NULL;
 124
 125        len = strlen(feature);
 126        while (*feature_list) {
 127                const char *found = strstr(feature_list, feature);
 128                if (!found)
 129                        return NULL;
 130                if (feature_list == found || isspace(found[-1])) {
 131                        const char *value = found + len;
 132                        /* feature with no value (e.g., "thin-pack") */
 133                        if (!*value || isspace(*value)) {
 134                                if (lenp)
 135                                        *lenp = 0;
 136                                return value;
 137                        }
 138                        /* feature with a value (e.g., "agent=git/1.2.3") */
 139                        else if (*value == '=') {
 140                                value++;
 141                                if (lenp)
 142                                        *lenp = strcspn(value, " \t\n");
 143                                return value;
 144                        }
 145                        /*
 146                         * otherwise we matched a substring of another feature;
 147                         * keep looking
 148                         */
 149                }
 150                feature_list = found + 1;
 151        }
 152        return NULL;
 153}
 154
 155int parse_feature_request(const char *feature_list, const char *feature)
 156{
 157        return !!parse_feature_value(feature_list, feature, NULL);
 158}
 159
 160const char *server_feature_value(const char *feature, int *len)
 161{
 162        return parse_feature_value(server_capabilities, feature, len);
 163}
 164
 165int server_supports(const char *feature)
 166{
 167        return !!server_feature_value(feature, NULL);
 168}
 169
 170enum protocol {
 171        PROTO_LOCAL = 1,
 172        PROTO_SSH,
 173        PROTO_GIT
 174};
 175
 176static enum protocol get_protocol(const char *name)
 177{
 178        if (!strcmp(name, "ssh"))
 179                return PROTO_SSH;
 180        if (!strcmp(name, "git"))
 181                return PROTO_GIT;
 182        if (!strcmp(name, "git+ssh"))
 183                return PROTO_SSH;
 184        if (!strcmp(name, "ssh+git"))
 185                return PROTO_SSH;
 186        if (!strcmp(name, "file"))
 187                return PROTO_LOCAL;
 188        die("I don't handle protocol '%s'", name);
 189}
 190
 191#define STR_(s) # s
 192#define STR(s)  STR_(s)
 193
 194static void get_host_and_port(char **host, const char **port)
 195{
 196        char *colon, *end;
 197
 198        if (*host[0] == '[') {
 199                end = strchr(*host + 1, ']');
 200                if (end) {
 201                        *end = 0;
 202                        end++;
 203                        (*host)++;
 204                } else
 205                        end = *host;
 206        } else
 207                end = *host;
 208        colon = strchr(end, ':');
 209
 210        if (colon) {
 211                *colon = 0;
 212                *port = colon + 1;
 213        }
 214}
 215
 216static void enable_keepalive(int sockfd)
 217{
 218        int ka = 1;
 219
 220        if (setsockopt(sockfd, SOL_SOCKET, SO_KEEPALIVE, &ka, sizeof(ka)) < 0)
 221                fprintf(stderr, "unable to set SO_KEEPALIVE on socket: %s\n",
 222                        strerror(errno));
 223}
 224
 225#ifndef NO_IPV6
 226
 227static const char *ai_name(const struct addrinfo *ai)
 228{
 229        static char addr[NI_MAXHOST];
 230        if (getnameinfo(ai->ai_addr, ai->ai_addrlen, addr, sizeof(addr), NULL, 0,
 231                        NI_NUMERICHOST) != 0)
 232                strcpy(addr, "(unknown)");
 233
 234        return addr;
 235}
 236
 237/*
 238 * Returns a connected socket() fd, or else die()s.
 239 */
 240static int git_tcp_connect_sock(char *host, int flags)
 241{
 242        struct strbuf error_message = STRBUF_INIT;
 243        int sockfd = -1;
 244        const char *port = STR(DEFAULT_GIT_PORT);
 245        struct addrinfo hints, *ai0, *ai;
 246        int gai;
 247        int cnt = 0;
 248
 249        get_host_and_port(&host, &port);
 250        if (!*port)
 251                port = "<none>";
 252
 253        memset(&hints, 0, sizeof(hints));
 254        hints.ai_socktype = SOCK_STREAM;
 255        hints.ai_protocol = IPPROTO_TCP;
 256
 257        if (flags & CONNECT_VERBOSE)
 258                fprintf(stderr, "Looking up %s ... ", host);
 259
 260        gai = getaddrinfo(host, port, &hints, &ai);
 261        if (gai)
 262                die("Unable to look up %s (port %s) (%s)", host, port, gai_strerror(gai));
 263
 264        if (flags & CONNECT_VERBOSE)
 265                fprintf(stderr, "done.\nConnecting to %s (port %s) ... ", host, port);
 266
 267        for (ai0 = ai; ai; ai = ai->ai_next, cnt++) {
 268                sockfd = socket(ai->ai_family,
 269                                ai->ai_socktype, ai->ai_protocol);
 270                if ((sockfd < 0) ||
 271                    (connect(sockfd, ai->ai_addr, ai->ai_addrlen) < 0)) {
 272                        strbuf_addf(&error_message, "%s[%d: %s]: errno=%s\n",
 273                                    host, cnt, ai_name(ai), strerror(errno));
 274                        if (0 <= sockfd)
 275                                close(sockfd);
 276                        sockfd = -1;
 277                        continue;
 278                }
 279                if (flags & CONNECT_VERBOSE)
 280                        fprintf(stderr, "%s ", ai_name(ai));
 281                break;
 282        }
 283
 284        freeaddrinfo(ai0);
 285
 286        if (sockfd < 0)
 287                die("unable to connect to %s:\n%s", host, error_message.buf);
 288
 289        enable_keepalive(sockfd);
 290
 291        if (flags & CONNECT_VERBOSE)
 292                fprintf(stderr, "done.\n");
 293
 294        strbuf_release(&error_message);
 295
 296        return sockfd;
 297}
 298
 299#else /* NO_IPV6 */
 300
 301/*
 302 * Returns a connected socket() fd, or else die()s.
 303 */
 304static int git_tcp_connect_sock(char *host, int flags)
 305{
 306        struct strbuf error_message = STRBUF_INIT;
 307        int sockfd = -1;
 308        const char *port = STR(DEFAULT_GIT_PORT);
 309        char *ep;
 310        struct hostent *he;
 311        struct sockaddr_in sa;
 312        char **ap;
 313        unsigned int nport;
 314        int cnt;
 315
 316        get_host_and_port(&host, &port);
 317
 318        if (flags & CONNECT_VERBOSE)
 319                fprintf(stderr, "Looking up %s ... ", host);
 320
 321        he = gethostbyname(host);
 322        if (!he)
 323                die("Unable to look up %s (%s)", host, hstrerror(h_errno));
 324        nport = strtoul(port, &ep, 10);
 325        if ( ep == port || *ep ) {
 326                /* Not numeric */
 327                struct servent *se = getservbyname(port,"tcp");
 328                if ( !se )
 329                        die("Unknown port %s", port);
 330                nport = se->s_port;
 331        }
 332
 333        if (flags & CONNECT_VERBOSE)
 334                fprintf(stderr, "done.\nConnecting to %s (port %s) ... ", host, port);
 335
 336        for (cnt = 0, ap = he->h_addr_list; *ap; ap++, cnt++) {
 337                memset(&sa, 0, sizeof sa);
 338                sa.sin_family = he->h_addrtype;
 339                sa.sin_port = htons(nport);
 340                memcpy(&sa.sin_addr, *ap, he->h_length);
 341
 342                sockfd = socket(he->h_addrtype, SOCK_STREAM, 0);
 343                if ((sockfd < 0) ||
 344                    connect(sockfd, (struct sockaddr *)&sa, sizeof sa) < 0) {
 345                        strbuf_addf(&error_message, "%s[%d: %s]: errno=%s\n",
 346                                host,
 347                                cnt,
 348                                inet_ntoa(*(struct in_addr *)&sa.sin_addr),
 349                                strerror(errno));
 350                        if (0 <= sockfd)
 351                                close(sockfd);
 352                        sockfd = -1;
 353                        continue;
 354                }
 355                if (flags & CONNECT_VERBOSE)
 356                        fprintf(stderr, "%s ",
 357                                inet_ntoa(*(struct in_addr *)&sa.sin_addr));
 358                break;
 359        }
 360
 361        if (sockfd < 0)
 362                die("unable to connect to %s:\n%s", host, error_message.buf);
 363
 364        enable_keepalive(sockfd);
 365
 366        if (flags & CONNECT_VERBOSE)
 367                fprintf(stderr, "done.\n");
 368
 369        return sockfd;
 370}
 371
 372#endif /* NO_IPV6 */
 373
 374
 375static void git_tcp_connect(int fd[2], char *host, int flags)
 376{
 377        int sockfd = git_tcp_connect_sock(host, flags);
 378
 379        fd[0] = sockfd;
 380        fd[1] = dup(sockfd);
 381}
 382
 383
 384static char *git_proxy_command;
 385
 386static int git_proxy_command_options(const char *var, const char *value,
 387                void *cb)
 388{
 389        if (!strcmp(var, "core.gitproxy")) {
 390                const char *for_pos;
 391                int matchlen = -1;
 392                int hostlen;
 393                const char *rhost_name = cb;
 394                int rhost_len = strlen(rhost_name);
 395
 396                if (git_proxy_command)
 397                        return 0;
 398                if (!value)
 399                        return config_error_nonbool(var);
 400                /* [core]
 401                 * ;# matches www.kernel.org as well
 402                 * gitproxy = netcatter-1 for kernel.org
 403                 * gitproxy = netcatter-2 for sample.xz
 404                 * gitproxy = netcatter-default
 405                 */
 406                for_pos = strstr(value, " for ");
 407                if (!for_pos)
 408                        /* matches everybody */
 409                        matchlen = strlen(value);
 410                else {
 411                        hostlen = strlen(for_pos + 5);
 412                        if (rhost_len < hostlen)
 413                                matchlen = -1;
 414                        else if (!strncmp(for_pos + 5,
 415                                          rhost_name + rhost_len - hostlen,
 416                                          hostlen) &&
 417                                 ((rhost_len == hostlen) ||
 418                                  rhost_name[rhost_len - hostlen -1] == '.'))
 419                                matchlen = for_pos - value;
 420                        else
 421                                matchlen = -1;
 422                }
 423                if (0 <= matchlen) {
 424                        /* core.gitproxy = none for kernel.org */
 425                        if (matchlen == 4 &&
 426                            !memcmp(value, "none", 4))
 427                                matchlen = 0;
 428                        git_proxy_command = xmemdupz(value, matchlen);
 429                }
 430                return 0;
 431        }
 432
 433        return git_default_config(var, value, cb);
 434}
 435
 436static int git_use_proxy(const char *host)
 437{
 438        git_proxy_command = getenv("GIT_PROXY_COMMAND");
 439        git_config(git_proxy_command_options, (void*)host);
 440        return (git_proxy_command && *git_proxy_command);
 441}
 442
 443static struct child_process *git_proxy_connect(int fd[2], char *host)
 444{
 445        const char *port = STR(DEFAULT_GIT_PORT);
 446        const char **argv;
 447        struct child_process *proxy;
 448
 449        get_host_and_port(&host, &port);
 450
 451        argv = xmalloc(sizeof(*argv) * 4);
 452        argv[0] = git_proxy_command;
 453        argv[1] = host;
 454        argv[2] = port;
 455        argv[3] = NULL;
 456        proxy = xcalloc(1, sizeof(*proxy));
 457        proxy->argv = argv;
 458        proxy->in = -1;
 459        proxy->out = -1;
 460        if (start_command(proxy))
 461                die("cannot start proxy %s", argv[0]);
 462        fd[0] = proxy->out; /* read from proxy stdout */
 463        fd[1] = proxy->in;  /* write to proxy stdin */
 464        return proxy;
 465}
 466
 467#define MAX_CMD_LEN 1024
 468
 469static char *get_port(char *host)
 470{
 471        char *end;
 472        char *p = strchr(host, ':');
 473
 474        if (p) {
 475                long port = strtol(p + 1, &end, 10);
 476                if (end != p + 1 && *end == '\0' && 0 <= port && port < 65536) {
 477                        *p = '\0';
 478                        return p+1;
 479                }
 480        }
 481
 482        return NULL;
 483}
 484
 485static struct child_process no_fork;
 486
 487/*
 488 * This returns a dummy child_process if the transport protocol does not
 489 * need fork(2), or a struct child_process object if it does.  Once done,
 490 * finish the connection with finish_connect() with the value returned from
 491 * this function (it is safe to call finish_connect() with NULL to support
 492 * the former case).
 493 *
 494 * If it returns, the connect is successful; it just dies on errors (this
 495 * will hopefully be changed in a libification effort, to return NULL when
 496 * the connection failed).
 497 */
 498struct child_process *git_connect(int fd[2], const char *url_orig,
 499                                  const char *prog, int flags)
 500{
 501        char *url;
 502        char *host, *path;
 503        char *end;
 504        int c;
 505        struct child_process *conn = &no_fork;
 506        enum protocol protocol = PROTO_LOCAL;
 507        int free_path = 0;
 508        char *port = NULL;
 509        const char **arg;
 510        struct strbuf cmd;
 511
 512        /* Without this we cannot rely on waitpid() to tell
 513         * what happened to our children.
 514         */
 515        signal(SIGCHLD, SIG_DFL);
 516
 517        if (is_url(url_orig))
 518                url = url_decode(url_orig);
 519        else
 520                url = xstrdup(url_orig);
 521
 522        host = strstr(url, "://");
 523        if (host) {
 524                *host = '\0';
 525                protocol = get_protocol(url);
 526                host += 3;
 527                c = '/';
 528        } else {
 529                host = url;
 530                c = ':';
 531        }
 532
 533        /*
 534         * Don't do destructive transforms with git:// as that
 535         * protocol code does '[]' unwrapping of its own.
 536         */
 537        if (host[0] == '[') {
 538                end = strchr(host + 1, ']');
 539                if (end) {
 540                        if (protocol != PROTO_GIT) {
 541                                *end = 0;
 542                                host++;
 543                        }
 544                        end++;
 545                } else
 546                        end = host;
 547        } else
 548                end = host;
 549
 550        path = strchr(end, c);
 551        if (path && !has_dos_drive_prefix(end)) {
 552                if (c == ':') {
 553                        protocol = PROTO_SSH;
 554                        *path++ = '\0';
 555                }
 556        } else
 557                path = end;
 558
 559        if (!path || !*path)
 560                die("No path specified. See 'man git-pull' for valid url syntax");
 561
 562        /*
 563         * null-terminate hostname and point path to ~ for URL's like this:
 564         *    ssh://host.xz/~user/repo
 565         */
 566        if (protocol != PROTO_LOCAL && host != url) {
 567                char *ptr = path;
 568                if (path[1] == '~')
 569                        path++;
 570                else {
 571                        path = xstrdup(ptr);
 572                        free_path = 1;
 573                }
 574
 575                *ptr = '\0';
 576        }
 577
 578        /*
 579         * Add support for ssh port: ssh://host.xy:<port>/...
 580         */
 581        if (protocol == PROTO_SSH && host != url)
 582                port = get_port(end);
 583
 584        if (protocol == PROTO_GIT) {
 585                /* These underlying connection commands die() if they
 586                 * cannot connect.
 587                 */
 588                char *target_host = xstrdup(host);
 589                if (git_use_proxy(host))
 590                        conn = git_proxy_connect(fd, host);
 591                else
 592                        git_tcp_connect(fd, host, flags);
 593                /*
 594                 * Separate original protocol components prog and path
 595                 * from extended host header with a NUL byte.
 596                 *
 597                 * Note: Do not add any other headers here!  Doing so
 598                 * will cause older git-daemon servers to crash.
 599                 */
 600                packet_write(fd[1],
 601                             "%s %s%chost=%s%c",
 602                             prog, path, 0,
 603                             target_host, 0);
 604                free(target_host);
 605                free(url);
 606                if (free_path)
 607                        free(path);
 608                return conn;
 609        }
 610
 611        conn = xcalloc(1, sizeof(*conn));
 612
 613        strbuf_init(&cmd, MAX_CMD_LEN);
 614        strbuf_addstr(&cmd, prog);
 615        strbuf_addch(&cmd, ' ');
 616        sq_quote_buf(&cmd, path);
 617        if (cmd.len >= MAX_CMD_LEN)
 618                die("command line too long");
 619
 620        conn->in = conn->out = -1;
 621        conn->argv = arg = xcalloc(7, sizeof(*arg));
 622        if (protocol == PROTO_SSH) {
 623                const char *ssh = getenv("GIT_SSH");
 624                int putty = ssh && strcasestr(ssh, "plink");
 625                if (!ssh) ssh = "ssh";
 626
 627                *arg++ = ssh;
 628                if (putty && !strcasestr(ssh, "tortoiseplink"))
 629                        *arg++ = "-batch";
 630                if (port) {
 631                        /* P is for PuTTY, p is for OpenSSH */
 632                        *arg++ = putty ? "-P" : "-p";
 633                        *arg++ = port;
 634                }
 635                *arg++ = host;
 636        }
 637        else {
 638                /* remove repo-local variables from the environment */
 639                conn->env = local_repo_env;
 640                conn->use_shell = 1;
 641        }
 642        *arg++ = cmd.buf;
 643        *arg = NULL;
 644
 645        if (start_command(conn))
 646                die("unable to fork");
 647
 648        fd[0] = conn->out; /* read from child's stdout */
 649        fd[1] = conn->in;  /* write to child's stdin */
 650        strbuf_release(&cmd);
 651        free(url);
 652        if (free_path)
 653                free(path);
 654        return conn;
 655}
 656
 657int git_connection_is_socket(struct child_process *conn)
 658{
 659        return conn == &no_fork;
 660}
 661
 662int finish_connect(struct child_process *conn)
 663{
 664        int code;
 665        if (!conn || git_connection_is_socket(conn))
 666                return 0;
 667
 668        code = finish_command(conn);
 669        free(conn->argv);
 670        free(conn);
 671        return code;
 672}