Andrew's git / gitweb.git / connect.c
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connect.con commit git-daemon: produce output when ready (f6a34cf)
   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
  52/*
  53 * Read all the refs from the other end
  54 */
  55struct ref **get_remote_heads(int in, struct ref **list,
  56                              unsigned int flags,
  57                              struct extra_have_objects *extra_have)
  58{
  59        *list = NULL;
  60        for (;;) {
  61                struct ref *ref;
  62                unsigned char old_sha1[20];
  63                static char buffer[1000];
  64                char *name;
  65                int len, name_len;
  66
  67                len = packet_read_line(in, buffer, sizeof(buffer));
  68                if (!len)
  69                        break;
  70                if (buffer[len-1] == '\n')
  71                        buffer[--len] = 0;
  72
  73                if (len > 4 && !prefixcmp(buffer, "ERR "))
  74                        die("remote error: %s", buffer + 4);
  75
  76                if (len < 42 || get_sha1_hex(buffer, old_sha1) || buffer[40] != ' ')
  77                        die("protocol error: expected sha/ref, got '%s'", buffer);
  78                name = buffer + 41;
  79
  80                name_len = strlen(name);
  81                if (len != name_len + 41) {
  82                        free(server_capabilities);
  83                        server_capabilities = xstrdup(name + name_len + 1);
  84                }
  85
  86                if (extra_have &&
  87                    name_len == 5 && !memcmp(".have", name, 5)) {
  88                        add_extra_have(extra_have, old_sha1);
  89                        continue;
  90                }
  91
  92                if (!check_ref(name, name_len, flags))
  93                        continue;
  94                ref = alloc_ref(buffer + 41);
  95                hashcpy(ref->old_sha1, old_sha1);
  96                *list = ref;
  97                list = &ref->next;
  98        }
  99        return list;
 100}
 101
 102int server_supports(const char *feature)
 103{
 104        return server_capabilities &&
 105                strstr(server_capabilities, feature) != NULL;
 106}
 107
 108enum protocol {
 109        PROTO_LOCAL = 1,
 110        PROTO_SSH,
 111        PROTO_GIT
 112};
 113
 114static enum protocol get_protocol(const char *name)
 115{
 116        if (!strcmp(name, "ssh"))
 117                return PROTO_SSH;
 118        if (!strcmp(name, "git"))
 119                return PROTO_GIT;
 120        if (!strcmp(name, "git+ssh"))
 121                return PROTO_SSH;
 122        if (!strcmp(name, "ssh+git"))
 123                return PROTO_SSH;
 124        if (!strcmp(name, "file"))
 125                return PROTO_LOCAL;
 126        die("I don't handle protocol '%s'", name);
 127}
 128
 129#define STR_(s) # s
 130#define STR(s)  STR_(s)
 131
 132static void get_host_and_port(char **host, const char **port)
 133{
 134        char *colon, *end;
 135
 136        if (*host[0] == '[') {
 137                end = strchr(*host + 1, ']');
 138                if (end) {
 139                        *end = 0;
 140                        end++;
 141                        (*host)++;
 142                } else
 143                        end = *host;
 144        } else
 145                end = *host;
 146        colon = strchr(end, ':');
 147
 148        if (colon) {
 149                *colon = 0;
 150                *port = colon + 1;
 151        }
 152}
 153
 154static void enable_keepalive(int sockfd)
 155{
 156        int ka = 1;
 157
 158        if (setsockopt(sockfd, SOL_SOCKET, SO_KEEPALIVE, &ka, sizeof(ka)) < 0)
 159                fprintf(stderr, "unable to set SO_KEEPALIVE on socket: %s\n",
 160                        strerror(errno));
 161}
 162
 163#ifndef NO_IPV6
 164
 165static const char *ai_name(const struct addrinfo *ai)
 166{
 167        static char addr[NI_MAXHOST];
 168        if (getnameinfo(ai->ai_addr, ai->ai_addrlen, addr, sizeof(addr), NULL, 0,
 169                        NI_NUMERICHOST) != 0)
 170                strcpy(addr, "(unknown)");
 171
 172        return addr;
 173}
 174
 175/*
 176 * Returns a connected socket() fd, or else die()s.
 177 */
 178static int git_tcp_connect_sock(char *host, int flags)
 179{
 180        struct strbuf error_message = STRBUF_INIT;
 181        int sockfd = -1;
 182        const char *port = STR(DEFAULT_GIT_PORT);
 183        struct addrinfo hints, *ai0, *ai;
 184        int gai;
 185        int cnt = 0;
 186
 187        get_host_and_port(&host, &port);
 188        if (!*port)
 189                port = "<none>";
 190
 191        memset(&hints, 0, sizeof(hints));
 192        hints.ai_socktype = SOCK_STREAM;
 193        hints.ai_protocol = IPPROTO_TCP;
 194
 195        if (flags & CONNECT_VERBOSE)
 196                fprintf(stderr, "Looking up %s ... ", host);
 197
 198        gai = getaddrinfo(host, port, &hints, &ai);
 199        if (gai)
 200                die("Unable to look up %s (port %s) (%s)", host, port, gai_strerror(gai));
 201
 202        if (flags & CONNECT_VERBOSE)
 203                fprintf(stderr, "done.\nConnecting to %s (port %s) ... ", host, port);
 204
 205        for (ai0 = ai; ai; ai = ai->ai_next, cnt++) {
 206                sockfd = socket(ai->ai_family,
 207                                ai->ai_socktype, ai->ai_protocol);
 208                if ((sockfd < 0) ||
 209                    (connect(sockfd, ai->ai_addr, ai->ai_addrlen) < 0)) {
 210                        strbuf_addf(&error_message, "%s[%d: %s]: errno=%s\n",
 211                                    host, cnt, ai_name(ai), strerror(errno));
 212                        if (0 <= sockfd)
 213                                close(sockfd);
 214                        sockfd = -1;
 215                        continue;
 216                }
 217                if (flags & CONNECT_VERBOSE)
 218                        fprintf(stderr, "%s ", ai_name(ai));
 219                break;
 220        }
 221
 222        freeaddrinfo(ai0);
 223
 224        if (sockfd < 0)
 225                die("unable to connect to %s:\n%s", host, error_message.buf);
 226
 227        enable_keepalive(sockfd);
 228
 229        if (flags & CONNECT_VERBOSE)
 230                fprintf(stderr, "done.\n");
 231
 232        strbuf_release(&error_message);
 233
 234        return sockfd;
 235}
 236
 237#else /* NO_IPV6 */
 238
 239/*
 240 * Returns a connected socket() fd, or else die()s.
 241 */
 242static int git_tcp_connect_sock(char *host, int flags)
 243{
 244        struct strbuf error_message = STRBUF_INIT;
 245        int sockfd = -1;
 246        const char *port = STR(DEFAULT_GIT_PORT);
 247        char *ep;
 248        struct hostent *he;
 249        struct sockaddr_in sa;
 250        char **ap;
 251        unsigned int nport;
 252        int cnt;
 253
 254        get_host_and_port(&host, &port);
 255
 256        if (flags & CONNECT_VERBOSE)
 257                fprintf(stderr, "Looking up %s ... ", host);
 258
 259        he = gethostbyname(host);
 260        if (!he)
 261                die("Unable to look up %s (%s)", host, hstrerror(h_errno));
 262        nport = strtoul(port, &ep, 10);
 263        if ( ep == port || *ep ) {
 264                /* Not numeric */
 265                struct servent *se = getservbyname(port,"tcp");
 266                if ( !se )
 267                        die("Unknown port %s", port);
 268                nport = se->s_port;
 269        }
 270
 271        if (flags & CONNECT_VERBOSE)
 272                fprintf(stderr, "done.\nConnecting to %s (port %s) ... ", host, port);
 273
 274        for (cnt = 0, ap = he->h_addr_list; *ap; ap++, cnt++) {
 275                memset(&sa, 0, sizeof sa);
 276                sa.sin_family = he->h_addrtype;
 277                sa.sin_port = htons(nport);
 278                memcpy(&sa.sin_addr, *ap, he->h_length);
 279
 280                sockfd = socket(he->h_addrtype, SOCK_STREAM, 0);
 281                if ((sockfd < 0) ||
 282                    connect(sockfd, (struct sockaddr *)&sa, sizeof sa) < 0) {
 283                        strbuf_addf(&error_message, "%s[%d: %s]: errno=%s\n",
 284                                host,
 285                                cnt,
 286                                inet_ntoa(*(struct in_addr *)&sa.sin_addr),
 287                                strerror(errno));
 288                        if (0 <= sockfd)
 289                                close(sockfd);
 290                        sockfd = -1;
 291                        continue;
 292                }
 293                if (flags & CONNECT_VERBOSE)
 294                        fprintf(stderr, "%s ",
 295                                inet_ntoa(*(struct in_addr *)&sa.sin_addr));
 296                break;
 297        }
 298
 299        if (sockfd < 0)
 300                die("unable to connect to %s:\n%s", host, error_message.buf);
 301
 302        enable_keepalive(sockfd);
 303
 304        if (flags & CONNECT_VERBOSE)
 305                fprintf(stderr, "done.\n");
 306
 307        return sockfd;
 308}
 309
 310#endif /* NO_IPV6 */
 311
 312
 313static void git_tcp_connect(int fd[2], char *host, int flags)
 314{
 315        int sockfd = git_tcp_connect_sock(host, flags);
 316
 317        fd[0] = sockfd;
 318        fd[1] = dup(sockfd);
 319}
 320
 321
 322static char *git_proxy_command;
 323
 324static int git_proxy_command_options(const char *var, const char *value,
 325                void *cb)
 326{
 327        if (!strcmp(var, "core.gitproxy")) {
 328                const char *for_pos;
 329                int matchlen = -1;
 330                int hostlen;
 331                const char *rhost_name = cb;
 332                int rhost_len = strlen(rhost_name);
 333
 334                if (git_proxy_command)
 335                        return 0;
 336                if (!value)
 337                        return config_error_nonbool(var);
 338                /* [core]
 339                 * ;# matches www.kernel.org as well
 340                 * gitproxy = netcatter-1 for kernel.org
 341                 * gitproxy = netcatter-2 for sample.xz
 342                 * gitproxy = netcatter-default
 343                 */
 344                for_pos = strstr(value, " for ");
 345                if (!for_pos)
 346                        /* matches everybody */
 347                        matchlen = strlen(value);
 348                else {
 349                        hostlen = strlen(for_pos + 5);
 350                        if (rhost_len < hostlen)
 351                                matchlen = -1;
 352                        else if (!strncmp(for_pos + 5,
 353                                          rhost_name + rhost_len - hostlen,
 354                                          hostlen) &&
 355                                 ((rhost_len == hostlen) ||
 356                                  rhost_name[rhost_len - hostlen -1] == '.'))
 357                                matchlen = for_pos - value;
 358                        else
 359                                matchlen = -1;
 360                }
 361                if (0 <= matchlen) {
 362                        /* core.gitproxy = none for kernel.org */
 363                        if (matchlen == 4 &&
 364                            !memcmp(value, "none", 4))
 365                                matchlen = 0;
 366                        git_proxy_command = xmemdupz(value, matchlen);
 367                }
 368                return 0;
 369        }
 370
 371        return git_default_config(var, value, cb);
 372}
 373
 374static int git_use_proxy(const char *host)
 375{
 376        git_proxy_command = getenv("GIT_PROXY_COMMAND");
 377        git_config(git_proxy_command_options, (void*)host);
 378        return (git_proxy_command && *git_proxy_command);
 379}
 380
 381static struct child_process *git_proxy_connect(int fd[2], char *host)
 382{
 383        const char *port = STR(DEFAULT_GIT_PORT);
 384        const char **argv;
 385        struct child_process *proxy;
 386
 387        get_host_and_port(&host, &port);
 388
 389        argv = xmalloc(sizeof(*argv) * 4);
 390        argv[0] = git_proxy_command;
 391        argv[1] = host;
 392        argv[2] = port;
 393        argv[3] = NULL;
 394        proxy = xcalloc(1, sizeof(*proxy));
 395        proxy->argv = argv;
 396        proxy->in = -1;
 397        proxy->out = -1;
 398        if (start_command(proxy))
 399                die("cannot start proxy %s", argv[0]);
 400        fd[0] = proxy->out; /* read from proxy stdout */
 401        fd[1] = proxy->in;  /* write to proxy stdin */
 402        return proxy;
 403}
 404
 405#define MAX_CMD_LEN 1024
 406
 407static char *get_port(char *host)
 408{
 409        char *end;
 410        char *p = strchr(host, ':');
 411
 412        if (p) {
 413                long port = strtol(p + 1, &end, 10);
 414                if (end != p + 1 && *end == '\0' && 0 <= port && port < 65536) {
 415                        *p = '\0';
 416                        return p+1;
 417                }
 418        }
 419
 420        return NULL;
 421}
 422
 423static struct child_process no_fork;
 424
 425/*
 426 * This returns a dummy child_process if the transport protocol does not
 427 * need fork(2), or a struct child_process object if it does.  Once done,
 428 * finish the connection with finish_connect() with the value returned from
 429 * this function (it is safe to call finish_connect() with NULL to support
 430 * the former case).
 431 *
 432 * If it returns, the connect is successful; it just dies on errors (this
 433 * will hopefully be changed in a libification effort, to return NULL when
 434 * the connection failed).
 435 */
 436struct child_process *git_connect(int fd[2], const char *url_orig,
 437                                  const char *prog, int flags)
 438{
 439        char *url;
 440        char *host, *path;
 441        char *end;
 442        int c;
 443        struct child_process *conn = &no_fork;
 444        enum protocol protocol = PROTO_LOCAL;
 445        int free_path = 0;
 446        char *port = NULL;
 447        const char **arg;
 448        struct strbuf cmd;
 449
 450        /* Without this we cannot rely on waitpid() to tell
 451         * what happened to our children.
 452         */
 453        signal(SIGCHLD, SIG_DFL);
 454
 455        if (is_url(url_orig))
 456                url = url_decode(url_orig);
 457        else
 458                url = xstrdup(url_orig);
 459
 460        host = strstr(url, "://");
 461        if (host) {
 462                *host = '\0';
 463                protocol = get_protocol(url);
 464                host += 3;
 465                c = '/';
 466        } else {
 467                host = url;
 468                c = ':';
 469        }
 470
 471        /*
 472         * Don't do destructive transforms with git:// as that
 473         * protocol code does '[]' unwrapping of its own.
 474         */
 475        if (host[0] == '[') {
 476                end = strchr(host + 1, ']');
 477                if (end) {
 478                        if (protocol != PROTO_GIT) {
 479                                *end = 0;
 480                                host++;
 481                        }
 482                        end++;
 483                } else
 484                        end = host;
 485        } else
 486                end = host;
 487
 488        path = strchr(end, c);
 489        if (path && !has_dos_drive_prefix(end)) {
 490                if (c == ':') {
 491                        protocol = PROTO_SSH;
 492                        *path++ = '\0';
 493                }
 494        } else
 495                path = end;
 496
 497        if (!path || !*path)
 498                die("No path specified. See 'man git-pull' for valid url syntax");
 499
 500        /*
 501         * null-terminate hostname and point path to ~ for URL's like this:
 502         *    ssh://host.xz/~user/repo
 503         */
 504        if (protocol != PROTO_LOCAL && host != url) {
 505                char *ptr = path;
 506                if (path[1] == '~')
 507                        path++;
 508                else {
 509                        path = xstrdup(ptr);
 510                        free_path = 1;
 511                }
 512
 513                *ptr = '\0';
 514        }
 515
 516        /*
 517         * Add support for ssh port: ssh://host.xy:<port>/...
 518         */
 519        if (protocol == PROTO_SSH && host != url)
 520                port = get_port(host);
 521
 522        if (protocol == PROTO_GIT) {
 523                /* These underlying connection commands die() if they
 524                 * cannot connect.
 525                 */
 526                char *target_host = xstrdup(host);
 527                if (git_use_proxy(host))
 528                        conn = git_proxy_connect(fd, host);
 529                else
 530                        git_tcp_connect(fd, host, flags);
 531                /*
 532                 * Separate original protocol components prog and path
 533                 * from extended host header with a NUL byte.
 534                 *
 535                 * Note: Do not add any other headers here!  Doing so
 536                 * will cause older git-daemon servers to crash.
 537                 */
 538                packet_write(fd[1],
 539                             "%s %s%chost=%s%c",
 540                             prog, path, 0,
 541                             target_host, 0);
 542                free(target_host);
 543                free(url);
 544                if (free_path)
 545                        free(path);
 546                return conn;
 547        }
 548
 549        conn = xcalloc(1, sizeof(*conn));
 550
 551        strbuf_init(&cmd, MAX_CMD_LEN);
 552        strbuf_addstr(&cmd, prog);
 553        strbuf_addch(&cmd, ' ');
 554        sq_quote_buf(&cmd, path);
 555        if (cmd.len >= MAX_CMD_LEN)
 556                die("command line too long");
 557
 558        conn->in = conn->out = -1;
 559        conn->argv = arg = xcalloc(7, sizeof(*arg));
 560        if (protocol == PROTO_SSH) {
 561                const char *ssh = getenv("GIT_SSH");
 562                int putty = ssh && strcasestr(ssh, "plink");
 563                if (!ssh) ssh = "ssh";
 564
 565                *arg++ = ssh;
 566                if (putty && !strcasestr(ssh, "tortoiseplink"))
 567                        *arg++ = "-batch";
 568                if (port) {
 569                        /* P is for PuTTY, p is for OpenSSH */
 570                        *arg++ = putty ? "-P" : "-p";
 571                        *arg++ = port;
 572                }
 573                *arg++ = host;
 574        }
 575        else {
 576                /* remove repo-local variables from the environment */
 577                conn->env = local_repo_env;
 578                conn->use_shell = 1;
 579        }
 580        *arg++ = cmd.buf;
 581        *arg = NULL;
 582
 583        if (start_command(conn))
 584                die("unable to fork");
 585
 586        fd[0] = conn->out; /* read from child's stdout */
 587        fd[1] = conn->in;  /* write to child's stdin */
 588        strbuf_release(&cmd);
 589        free(url);
 590        if (free_path)
 591                free(path);
 592        return conn;
 593}
 594
 595int git_connection_is_socket(struct child_process *conn)
 596{
 597        return conn == &no_fork;
 598}
 599
 600int finish_connect(struct child_process *conn)
 601{
 602        int code;
 603        if (!conn || git_connection_is_socket(conn))
 604                return 0;
 605
 606        code = finish_command(conn);
 607        free(conn->argv);
 608        free(conn);
 609        return code;
 610}