Andrew's git / gitweb.git / daemon.c
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daemon.con commit close_lock_file(): exit (successfully) if file is already closed (419f0c0)
   1#include "cache.h"
   2#include "pkt-line.h"
   3#include "exec_cmd.h"
   4#include "run-command.h"
   5#include "strbuf.h"
   6#include "string-list.h"
   7
   8#ifndef HOST_NAME_MAX
   9#define HOST_NAME_MAX 256
  10#endif
  11
  12#ifdef NO_INITGROUPS
  13#define initgroups(x, y) (0) /* nothing */
  14#endif
  15
  16static int log_syslog;
  17static int verbose;
  18static int reuseaddr;
  19static int informative_errors;
  20
  21static const char daemon_usage[] =
  22"git daemon [--verbose] [--syslog] [--export-all]\n"
  23"           [--timeout=<n>] [--init-timeout=<n>] [--max-connections=<n>]\n"
  24"           [--strict-paths] [--base-path=<path>] [--base-path-relaxed]\n"
  25"           [--user-path | --user-path=<path>]\n"
  26"           [--interpolated-path=<path>]\n"
  27"           [--reuseaddr] [--pid-file=<file>]\n"
  28"           [--(enable|disable|allow-override|forbid-override)=<service>]\n"
  29"           [--access-hook=<path>]\n"
  30"           [--inetd | [--listen=<host_or_ipaddr>] [--port=<n>]\n"
  31"                      [--detach] [--user=<user> [--group=<group>]]\n"
  32"           [<directory>...]";
  33
  34/* List of acceptable pathname prefixes */
  35static char **ok_paths;
  36static int strict_paths;
  37
  38/* If this is set, git-daemon-export-ok is not required */
  39static int export_all_trees;
  40
  41/* Take all paths relative to this one if non-NULL */
  42static const char *base_path;
  43static const char *interpolated_path;
  44static int base_path_relaxed;
  45
  46/* Flag indicating client sent extra args. */
  47static int saw_extended_args;
  48
  49/* If defined, ~user notation is allowed and the string is inserted
  50 * after ~user/.  E.g. a request to git://host/~alice/frotz would
  51 * go to /home/alice/pub_git/frotz with --user-path=pub_git.
  52 */
  53static const char *user_path;
  54
  55/* Timeout, and initial timeout */
  56static unsigned int timeout;
  57static unsigned int init_timeout;
  58
  59static char *hostname;
  60static char *canon_hostname;
  61static char *ip_address;
  62static char *tcp_port;
  63
  64static void logreport(int priority, const char *err, va_list params)
  65{
  66        if (log_syslog) {
  67                char buf[1024];
  68                vsnprintf(buf, sizeof(buf), err, params);
  69                syslog(priority, "%s", buf);
  70        } else {
  71                /*
  72                 * Since stderr is set to buffered mode, the
  73                 * logging of different processes will not overlap
  74                 * unless they overflow the (rather big) buffers.
  75                 */
  76                fprintf(stderr, "[%"PRIuMAX"] ", (uintmax_t)getpid());
  77                vfprintf(stderr, err, params);
  78                fputc('\n', stderr);
  79                fflush(stderr);
  80        }
  81}
  82
  83__attribute__((format (printf, 1, 2)))
  84static void logerror(const char *err, ...)
  85{
  86        va_list params;
  87        va_start(params, err);
  88        logreport(LOG_ERR, err, params);
  89        va_end(params);
  90}
  91
  92__attribute__((format (printf, 1, 2)))
  93static void loginfo(const char *err, ...)
  94{
  95        va_list params;
  96        if (!verbose)
  97                return;
  98        va_start(params, err);
  99        logreport(LOG_INFO, err, params);
 100        va_end(params);
 101}
 102
 103static void NORETURN daemon_die(const char *err, va_list params)
 104{
 105        logreport(LOG_ERR, err, params);
 106        exit(1);
 107}
 108
 109static const char *path_ok(const char *directory)
 110{
 111        static char rpath[PATH_MAX];
 112        static char interp_path[PATH_MAX];
 113        const char *path;
 114        const char *dir;
 115
 116        dir = directory;
 117
 118        if (daemon_avoid_alias(dir)) {
 119                logerror("'%s': aliased", dir);
 120                return NULL;
 121        }
 122
 123        if (*dir == '~') {
 124                if (!user_path) {
 125                        logerror("'%s': User-path not allowed", dir);
 126                        return NULL;
 127                }
 128                if (*user_path) {
 129                        /* Got either "~alice" or "~alice/foo";
 130                         * rewrite them to "~alice/%s" or
 131                         * "~alice/%s/foo".
 132                         */
 133                        int namlen, restlen = strlen(dir);
 134                        const char *slash = strchr(dir, '/');
 135                        if (!slash)
 136                                slash = dir + restlen;
 137                        namlen = slash - dir;
 138                        restlen -= namlen;
 139                        loginfo("userpath <%s>, request <%s>, namlen %d, restlen %d, slash <%s>", user_path, dir, namlen, restlen, slash);
 140                        snprintf(rpath, PATH_MAX, "%.*s/%s%.*s",
 141                                 namlen, dir, user_path, restlen, slash);
 142                        dir = rpath;
 143                }
 144        }
 145        else if (interpolated_path && saw_extended_args) {
 146                struct strbuf expanded_path = STRBUF_INIT;
 147                struct strbuf_expand_dict_entry dict[6];
 148
 149                dict[0].placeholder = "H"; dict[0].value = hostname;
 150                dict[1].placeholder = "CH"; dict[1].value = canon_hostname;
 151                dict[2].placeholder = "IP"; dict[2].value = ip_address;
 152                dict[3].placeholder = "P"; dict[3].value = tcp_port;
 153                dict[4].placeholder = "D"; dict[4].value = directory;
 154                dict[5].placeholder = NULL; dict[5].value = NULL;
 155                if (*dir != '/') {
 156                        /* Allow only absolute */
 157                        logerror("'%s': Non-absolute path denied (interpolated-path active)", dir);
 158                        return NULL;
 159                }
 160
 161                strbuf_expand(&expanded_path, interpolated_path,
 162                                strbuf_expand_dict_cb, &dict);
 163                strlcpy(interp_path, expanded_path.buf, PATH_MAX);
 164                strbuf_release(&expanded_path);
 165                loginfo("Interpolated dir '%s'", interp_path);
 166
 167                dir = interp_path;
 168        }
 169        else if (base_path) {
 170                if (*dir != '/') {
 171                        /* Allow only absolute */
 172                        logerror("'%s': Non-absolute path denied (base-path active)", dir);
 173                        return NULL;
 174                }
 175                snprintf(rpath, PATH_MAX, "%s%s", base_path, dir);
 176                dir = rpath;
 177        }
 178
 179        path = enter_repo(dir, strict_paths);
 180        if (!path && base_path && base_path_relaxed) {
 181                /*
 182                 * if we fail and base_path_relaxed is enabled, try without
 183                 * prefixing the base path
 184                 */
 185                dir = directory;
 186                path = enter_repo(dir, strict_paths);
 187        }
 188
 189        if (!path) {
 190                logerror("'%s' does not appear to be a git repository", dir);
 191                return NULL;
 192        }
 193
 194        if ( ok_paths && *ok_paths ) {
 195                char **pp;
 196                int pathlen = strlen(path);
 197
 198                /* The validation is done on the paths after enter_repo
 199                 * appends optional {.git,.git/.git} and friends, but
 200                 * it does not use getcwd().  So if your /pub is
 201                 * a symlink to /mnt/pub, you can whitelist /pub and
 202                 * do not have to say /mnt/pub.
 203                 * Do not say /pub/.
 204                 */
 205                for ( pp = ok_paths ; *pp ; pp++ ) {
 206                        int len = strlen(*pp);
 207                        if (len <= pathlen &&
 208                            !memcmp(*pp, path, len) &&
 209                            (path[len] == '\0' ||
 210                             (!strict_paths && path[len] == '/')))
 211                                return path;
 212                }
 213        }
 214        else {
 215                /* be backwards compatible */
 216                if (!strict_paths)
 217                        return path;
 218        }
 219
 220        logerror("'%s': not in whitelist", path);
 221        return NULL;            /* Fallthrough. Deny by default */
 222}
 223
 224typedef int (*daemon_service_fn)(void);
 225struct daemon_service {
 226        const char *name;
 227        const char *config_name;
 228        daemon_service_fn fn;
 229        int enabled;
 230        int overridable;
 231};
 232
 233static int daemon_error(const char *dir, const char *msg)
 234{
 235        if (!informative_errors)
 236                msg = "access denied or repository not exported";
 237        packet_write(1, "ERR %s: %s", msg, dir);
 238        return -1;
 239}
 240
 241static const char *access_hook;
 242
 243static int run_access_hook(struct daemon_service *service, const char *dir, const char *path)
 244{
 245        struct child_process child = CHILD_PROCESS_INIT;
 246        struct strbuf buf = STRBUF_INIT;
 247        const char *argv[8];
 248        const char **arg = argv;
 249        char *eol;
 250        int seen_errors = 0;
 251
 252#define STRARG(x) ((x) ? (x) : "")
 253        *arg++ = access_hook;
 254        *arg++ = service->name;
 255        *arg++ = path;
 256        *arg++ = STRARG(hostname);
 257        *arg++ = STRARG(canon_hostname);
 258        *arg++ = STRARG(ip_address);
 259        *arg++ = STRARG(tcp_port);
 260        *arg = NULL;
 261#undef STRARG
 262
 263        child.use_shell = 1;
 264        child.argv = argv;
 265        child.no_stdin = 1;
 266        child.no_stderr = 1;
 267        child.out = -1;
 268        if (start_command(&child)) {
 269                logerror("daemon access hook '%s' failed to start",
 270                         access_hook);
 271                goto error_return;
 272        }
 273        if (strbuf_read(&buf, child.out, 0) < 0) {
 274                logerror("failed to read from pipe to daemon access hook '%s'",
 275                         access_hook);
 276                strbuf_reset(&buf);
 277                seen_errors = 1;
 278        }
 279        if (close(child.out) < 0) {
 280                logerror("failed to close pipe to daemon access hook '%s'",
 281                         access_hook);
 282                seen_errors = 1;
 283        }
 284        if (finish_command(&child))
 285                seen_errors = 1;
 286
 287        if (!seen_errors) {
 288                strbuf_release(&buf);
 289                return 0;
 290        }
 291
 292error_return:
 293        strbuf_ltrim(&buf);
 294        if (!buf.len)
 295                strbuf_addstr(&buf, "service rejected");
 296        eol = strchr(buf.buf, '\n');
 297        if (eol)
 298                *eol = '\0';
 299        errno = EACCES;
 300        daemon_error(dir, buf.buf);
 301        strbuf_release(&buf);
 302        return -1;
 303}
 304
 305static int run_service(const char *dir, struct daemon_service *service)
 306{
 307        const char *path;
 308        int enabled = service->enabled;
 309        struct strbuf var = STRBUF_INIT;
 310
 311        loginfo("Request %s for '%s'", service->name, dir);
 312
 313        if (!enabled && !service->overridable) {
 314                logerror("'%s': service not enabled.", service->name);
 315                errno = EACCES;
 316                return daemon_error(dir, "service not enabled");
 317        }
 318
 319        if (!(path = path_ok(dir)))
 320                return daemon_error(dir, "no such repository");
 321
 322        /*
 323         * Security on the cheap.
 324         *
 325         * We want a readable HEAD, usable "objects" directory, and
 326         * a "git-daemon-export-ok" flag that says that the other side
 327         * is ok with us doing this.
 328         *
 329         * path_ok() uses enter_repo() and does whitelist checking.
 330         * We only need to make sure the repository is exported.
 331         */
 332
 333        if (!export_all_trees && access("git-daemon-export-ok", F_OK)) {
 334                logerror("'%s': repository not exported.", path);
 335                errno = EACCES;
 336                return daemon_error(dir, "repository not exported");
 337        }
 338
 339        if (service->overridable) {
 340                strbuf_addf(&var, "daemon.%s", service->config_name);
 341                git_config_get_bool(var.buf, &enabled);
 342                strbuf_release(&var);
 343        }
 344        if (!enabled) {
 345                logerror("'%s': service not enabled for '%s'",
 346                         service->name, path);
 347                errno = EACCES;
 348                return daemon_error(dir, "service not enabled");
 349        }
 350
 351        /*
 352         * Optionally, a hook can choose to deny access to the
 353         * repository depending on the phase of the moon.
 354         */
 355        if (access_hook && run_access_hook(service, dir, path))
 356                return -1;
 357
 358        /*
 359         * We'll ignore SIGTERM from now on, we have a
 360         * good client.
 361         */
 362        signal(SIGTERM, SIG_IGN);
 363
 364        return service->fn();
 365}
 366
 367static void copy_to_log(int fd)
 368{
 369        struct strbuf line = STRBUF_INIT;
 370        FILE *fp;
 371
 372        fp = fdopen(fd, "r");
 373        if (fp == NULL) {
 374                logerror("fdopen of error channel failed");
 375                close(fd);
 376                return;
 377        }
 378
 379        while (strbuf_getline(&line, fp, '\n') != EOF) {
 380                logerror("%s", line.buf);
 381                strbuf_setlen(&line, 0);
 382        }
 383
 384        strbuf_release(&line);
 385        fclose(fp);
 386}
 387
 388static int run_service_command(const char **argv)
 389{
 390        struct child_process cld = CHILD_PROCESS_INIT;
 391
 392        cld.argv = argv;
 393        cld.git_cmd = 1;
 394        cld.err = -1;
 395        if (start_command(&cld))
 396                return -1;
 397
 398        close(0);
 399        close(1);
 400
 401        copy_to_log(cld.err);
 402
 403        return finish_command(&cld);
 404}
 405
 406static int upload_pack(void)
 407{
 408        /* Timeout as string */
 409        char timeout_buf[64];
 410        const char *argv[] = { "upload-pack", "--strict", NULL, ".", NULL };
 411
 412        argv[2] = timeout_buf;
 413
 414        snprintf(timeout_buf, sizeof timeout_buf, "--timeout=%u", timeout);
 415        return run_service_command(argv);
 416}
 417
 418static int upload_archive(void)
 419{
 420        static const char *argv[] = { "upload-archive", ".", NULL };
 421        return run_service_command(argv);
 422}
 423
 424static int receive_pack(void)
 425{
 426        static const char *argv[] = { "receive-pack", ".", NULL };
 427        return run_service_command(argv);
 428}
 429
 430static struct daemon_service daemon_service[] = {
 431        { "upload-archive", "uploadarch", upload_archive, 0, 1 },
 432        { "upload-pack", "uploadpack", upload_pack, 1, 1 },
 433        { "receive-pack", "receivepack", receive_pack, 0, 1 },
 434};
 435
 436static void enable_service(const char *name, int ena)
 437{
 438        int i;
 439        for (i = 0; i < ARRAY_SIZE(daemon_service); i++) {
 440                if (!strcmp(daemon_service[i].name, name)) {
 441                        daemon_service[i].enabled = ena;
 442                        return;
 443                }
 444        }
 445        die("No such service %s", name);
 446}
 447
 448static void make_service_overridable(const char *name, int ena)
 449{
 450        int i;
 451        for (i = 0; i < ARRAY_SIZE(daemon_service); i++) {
 452                if (!strcmp(daemon_service[i].name, name)) {
 453                        daemon_service[i].overridable = ena;
 454                        return;
 455                }
 456        }
 457        die("No such service %s", name);
 458}
 459
 460static void parse_host_and_port(char *hostport, char **host,
 461        char **port)
 462{
 463        if (*hostport == '[') {
 464                char *end;
 465
 466                end = strchr(hostport, ']');
 467                if (!end)
 468                        die("Invalid request ('[' without ']')");
 469                *end = '\0';
 470                *host = hostport + 1;
 471                if (!end[1])
 472                        *port = NULL;
 473                else if (end[1] == ':')
 474                        *port = end + 2;
 475                else
 476                        die("Garbage after end of host part");
 477        } else {
 478                *host = hostport;
 479                *port = strrchr(hostport, ':');
 480                if (*port) {
 481                        **port = '\0';
 482                        ++*port;
 483                }
 484        }
 485}
 486
 487/*
 488 * Read the host as supplied by the client connection.
 489 */
 490static void parse_host_arg(char *extra_args, int buflen)
 491{
 492        char *val;
 493        int vallen;
 494        char *end = extra_args + buflen;
 495
 496        if (extra_args < end && *extra_args) {
 497                saw_extended_args = 1;
 498                if (strncasecmp("host=", extra_args, 5) == 0) {
 499                        val = extra_args + 5;
 500                        vallen = strlen(val) + 1;
 501                        if (*val) {
 502                                /* Split <host>:<port> at colon. */
 503                                char *host;
 504                                char *port;
 505                                parse_host_and_port(val, &host, &port);
 506                                if (port) {
 507                                        free(tcp_port);
 508                                        tcp_port = xstrdup(port);
 509                                }
 510                                free(hostname);
 511                                hostname = xstrdup_tolower(host);
 512                        }
 513
 514                        /* On to the next one */
 515                        extra_args = val + vallen;
 516                }
 517                if (extra_args < end && *extra_args)
 518                        die("Invalid request");
 519        }
 520
 521        /*
 522         * Locate canonical hostname and its IP address.
 523         */
 524        if (hostname) {
 525#ifndef NO_IPV6
 526                struct addrinfo hints;
 527                struct addrinfo *ai;
 528                int gai;
 529                static char addrbuf[HOST_NAME_MAX + 1];
 530
 531                memset(&hints, 0, sizeof(hints));
 532                hints.ai_flags = AI_CANONNAME;
 533
 534                gai = getaddrinfo(hostname, NULL, &hints, &ai);
 535                if (!gai) {
 536                        struct sockaddr_in *sin_addr = (void *)ai->ai_addr;
 537
 538                        inet_ntop(AF_INET, &sin_addr->sin_addr,
 539                                  addrbuf, sizeof(addrbuf));
 540                        free(ip_address);
 541                        ip_address = xstrdup(addrbuf);
 542
 543                        free(canon_hostname);
 544                        canon_hostname = xstrdup(ai->ai_canonname ?
 545                                                 ai->ai_canonname : ip_address);
 546
 547                        freeaddrinfo(ai);
 548                }
 549#else
 550                struct hostent *hent;
 551                struct sockaddr_in sa;
 552                char **ap;
 553                static char addrbuf[HOST_NAME_MAX + 1];
 554
 555                hent = gethostbyname(hostname);
 556
 557                ap = hent->h_addr_list;
 558                memset(&sa, 0, sizeof sa);
 559                sa.sin_family = hent->h_addrtype;
 560                sa.sin_port = htons(0);
 561                memcpy(&sa.sin_addr, *ap, hent->h_length);
 562
 563                inet_ntop(hent->h_addrtype, &sa.sin_addr,
 564                          addrbuf, sizeof(addrbuf));
 565
 566                free(canon_hostname);
 567                canon_hostname = xstrdup(hent->h_name);
 568                free(ip_address);
 569                ip_address = xstrdup(addrbuf);
 570#endif
 571        }
 572}
 573
 574
 575static int execute(void)
 576{
 577        char *line = packet_buffer;
 578        int pktlen, len, i;
 579        char *addr = getenv("REMOTE_ADDR"), *port = getenv("REMOTE_PORT");
 580
 581        if (addr)
 582                loginfo("Connection from %s:%s", addr, port);
 583
 584        alarm(init_timeout ? init_timeout : timeout);
 585        pktlen = packet_read(0, NULL, NULL, packet_buffer, sizeof(packet_buffer), 0);
 586        alarm(0);
 587
 588        len = strlen(line);
 589        if (pktlen != len)
 590                loginfo("Extended attributes (%d bytes) exist <%.*s>",
 591                        (int) pktlen - len,
 592                        (int) pktlen - len, line + len + 1);
 593        if (len && line[len-1] == '\n') {
 594                line[--len] = 0;
 595                pktlen--;
 596        }
 597
 598        free(hostname);
 599        free(canon_hostname);
 600        free(ip_address);
 601        free(tcp_port);
 602        hostname = canon_hostname = ip_address = tcp_port = NULL;
 603
 604        if (len != pktlen)
 605                parse_host_arg(line + len + 1, pktlen - len - 1);
 606
 607        for (i = 0; i < ARRAY_SIZE(daemon_service); i++) {
 608                struct daemon_service *s = &(daemon_service[i]);
 609                const char *arg;
 610
 611                if (skip_prefix(line, "git-", &arg) &&
 612                    skip_prefix(arg, s->name, &arg) &&
 613                    *arg++ == ' ') {
 614                        /*
 615                         * Note: The directory here is probably context sensitive,
 616                         * and might depend on the actual service being performed.
 617                         */
 618                        return run_service(arg, s);
 619                }
 620        }
 621
 622        logerror("Protocol error: '%s'", line);
 623        return -1;
 624}
 625
 626static int addrcmp(const struct sockaddr_storage *s1,
 627    const struct sockaddr_storage *s2)
 628{
 629        const struct sockaddr *sa1 = (const struct sockaddr*) s1;
 630        const struct sockaddr *sa2 = (const struct sockaddr*) s2;
 631
 632        if (sa1->sa_family != sa2->sa_family)
 633                return sa1->sa_family - sa2->sa_family;
 634        if (sa1->sa_family == AF_INET)
 635                return memcmp(&((struct sockaddr_in *)s1)->sin_addr,
 636                    &((struct sockaddr_in *)s2)->sin_addr,
 637                    sizeof(struct in_addr));
 638#ifndef NO_IPV6
 639        if (sa1->sa_family == AF_INET6)
 640                return memcmp(&((struct sockaddr_in6 *)s1)->sin6_addr,
 641                    &((struct sockaddr_in6 *)s2)->sin6_addr,
 642                    sizeof(struct in6_addr));
 643#endif
 644        return 0;
 645}
 646
 647static int max_connections = 32;
 648
 649static unsigned int live_children;
 650
 651static struct child {
 652        struct child *next;
 653        struct child_process cld;
 654        struct sockaddr_storage address;
 655} *firstborn;
 656
 657static void add_child(struct child_process *cld, struct sockaddr *addr, socklen_t addrlen)
 658{
 659        struct child *newborn, **cradle;
 660
 661        newborn = xcalloc(1, sizeof(*newborn));
 662        live_children++;
 663        memcpy(&newborn->cld, cld, sizeof(*cld));
 664        memcpy(&newborn->address, addr, addrlen);
 665        for (cradle = &firstborn; *cradle; cradle = &(*cradle)->next)
 666                if (!addrcmp(&(*cradle)->address, &newborn->address))
 667                        break;
 668        newborn->next = *cradle;
 669        *cradle = newborn;
 670}
 671
 672/*
 673 * This gets called if the number of connections grows
 674 * past "max_connections".
 675 *
 676 * We kill the newest connection from a duplicate IP.
 677 */
 678static void kill_some_child(void)
 679{
 680        const struct child *blanket, *next;
 681
 682        if (!(blanket = firstborn))
 683                return;
 684
 685        for (; (next = blanket->next); blanket = next)
 686                if (!addrcmp(&blanket->address, &next->address)) {
 687                        kill(blanket->cld.pid, SIGTERM);
 688                        break;
 689                }
 690}
 691
 692static void check_dead_children(void)
 693{
 694        int status;
 695        pid_t pid;
 696
 697        struct child **cradle, *blanket;
 698        for (cradle = &firstborn; (blanket = *cradle);)
 699                if ((pid = waitpid(blanket->cld.pid, &status, WNOHANG)) > 1) {
 700                        const char *dead = "";
 701                        if (status)
 702                                dead = " (with error)";
 703                        loginfo("[%"PRIuMAX"] Disconnected%s", (uintmax_t)pid, dead);
 704
 705                        /* remove the child */
 706                        *cradle = blanket->next;
 707                        live_children--;
 708                        free(blanket);
 709                } else
 710                        cradle = &blanket->next;
 711}
 712
 713static char **cld_argv;
 714static void handle(int incoming, struct sockaddr *addr, socklen_t addrlen)
 715{
 716        struct child_process cld = CHILD_PROCESS_INIT;
 717        char addrbuf[300] = "REMOTE_ADDR=", portbuf[300];
 718        char *env[] = { addrbuf, portbuf, NULL };
 719
 720        if (max_connections && live_children >= max_connections) {
 721                kill_some_child();
 722                sleep(1);  /* give it some time to die */
 723                check_dead_children();
 724                if (live_children >= max_connections) {
 725                        close(incoming);
 726                        logerror("Too many children, dropping connection");
 727                        return;
 728                }
 729        }
 730
 731        if (addr->sa_family == AF_INET) {
 732                struct sockaddr_in *sin_addr = (void *) addr;
 733                inet_ntop(addr->sa_family, &sin_addr->sin_addr, addrbuf + 12,
 734                    sizeof(addrbuf) - 12);
 735                snprintf(portbuf, sizeof(portbuf), "REMOTE_PORT=%d",
 736                    ntohs(sin_addr->sin_port));
 737#ifndef NO_IPV6
 738        } else if (addr->sa_family == AF_INET6) {
 739                struct sockaddr_in6 *sin6_addr = (void *) addr;
 740
 741                char *buf = addrbuf + 12;
 742                *buf++ = '['; *buf = '\0'; /* stpcpy() is cool */
 743                inet_ntop(AF_INET6, &sin6_addr->sin6_addr, buf,
 744                    sizeof(addrbuf) - 13);
 745                strcat(buf, "]");
 746
 747                snprintf(portbuf, sizeof(portbuf), "REMOTE_PORT=%d",
 748                    ntohs(sin6_addr->sin6_port));
 749#endif
 750        }
 751
 752        cld.env = (const char **)env;
 753        cld.argv = (const char **)cld_argv;
 754        cld.in = incoming;
 755        cld.out = dup(incoming);
 756
 757        if (start_command(&cld))
 758                logerror("unable to fork");
 759        else
 760                add_child(&cld, addr, addrlen);
 761}
 762
 763static void child_handler(int signo)
 764{
 765        /*
 766         * Otherwise empty handler because systemcalls will get interrupted
 767         * upon signal receipt
 768         * SysV needs the handler to be rearmed
 769         */
 770        signal(SIGCHLD, child_handler);
 771}
 772
 773static int set_reuse_addr(int sockfd)
 774{
 775        int on = 1;
 776
 777        if (!reuseaddr)
 778                return 0;
 779        return setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR,
 780                          &on, sizeof(on));
 781}
 782
 783struct socketlist {
 784        int *list;
 785        size_t nr;
 786        size_t alloc;
 787};
 788
 789static const char *ip2str(int family, struct sockaddr *sin, socklen_t len)
 790{
 791#ifdef NO_IPV6
 792        static char ip[INET_ADDRSTRLEN];
 793#else
 794        static char ip[INET6_ADDRSTRLEN];
 795#endif
 796
 797        switch (family) {
 798#ifndef NO_IPV6
 799        case AF_INET6:
 800                inet_ntop(family, &((struct sockaddr_in6*)sin)->sin6_addr, ip, len);
 801                break;
 802#endif
 803        case AF_INET:
 804                inet_ntop(family, &((struct sockaddr_in*)sin)->sin_addr, ip, len);
 805                break;
 806        default:
 807                strcpy(ip, "<unknown>");
 808        }
 809        return ip;
 810}
 811
 812#ifndef NO_IPV6
 813
 814static int setup_named_sock(char *listen_addr, int listen_port, struct socketlist *socklist)
 815{
 816        int socknum = 0;
 817        int maxfd = -1;
 818        char pbuf[NI_MAXSERV];
 819        struct addrinfo hints, *ai0, *ai;
 820        int gai;
 821        long flags;
 822
 823        sprintf(pbuf, "%d", listen_port);
 824        memset(&hints, 0, sizeof(hints));
 825        hints.ai_family = AF_UNSPEC;
 826        hints.ai_socktype = SOCK_STREAM;
 827        hints.ai_protocol = IPPROTO_TCP;
 828        hints.ai_flags = AI_PASSIVE;
 829
 830        gai = getaddrinfo(listen_addr, pbuf, &hints, &ai0);
 831        if (gai) {
 832                logerror("getaddrinfo() for %s failed: %s", listen_addr, gai_strerror(gai));
 833                return 0;
 834        }
 835
 836        for (ai = ai0; ai; ai = ai->ai_next) {
 837                int sockfd;
 838
 839                sockfd = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
 840                if (sockfd < 0)
 841                        continue;
 842                if (sockfd >= FD_SETSIZE) {
 843                        logerror("Socket descriptor too large");
 844                        close(sockfd);
 845                        continue;
 846                }
 847
 848#ifdef IPV6_V6ONLY
 849                if (ai->ai_family == AF_INET6) {
 850                        int on = 1;
 851                        setsockopt(sockfd, IPPROTO_IPV6, IPV6_V6ONLY,
 852                                   &on, sizeof(on));
 853                        /* Note: error is not fatal */
 854                }
 855#endif
 856
 857                if (set_reuse_addr(sockfd)) {
 858                        logerror("Could not set SO_REUSEADDR: %s", strerror(errno));
 859                        close(sockfd);
 860                        continue;
 861                }
 862
 863                if (bind(sockfd, ai->ai_addr, ai->ai_addrlen) < 0) {
 864                        logerror("Could not bind to %s: %s",
 865                                 ip2str(ai->ai_family, ai->ai_addr, ai->ai_addrlen),
 866                                 strerror(errno));
 867                        close(sockfd);
 868                        continue;       /* not fatal */
 869                }
 870                if (listen(sockfd, 5) < 0) {
 871                        logerror("Could not listen to %s: %s",
 872                                 ip2str(ai->ai_family, ai->ai_addr, ai->ai_addrlen),
 873                                 strerror(errno));
 874                        close(sockfd);
 875                        continue;       /* not fatal */
 876                }
 877
 878                flags = fcntl(sockfd, F_GETFD, 0);
 879                if (flags >= 0)
 880                        fcntl(sockfd, F_SETFD, flags | FD_CLOEXEC);
 881
 882                ALLOC_GROW(socklist->list, socklist->nr + 1, socklist->alloc);
 883                socklist->list[socklist->nr++] = sockfd;
 884                socknum++;
 885
 886                if (maxfd < sockfd)
 887                        maxfd = sockfd;
 888        }
 889
 890        freeaddrinfo(ai0);
 891
 892        return socknum;
 893}
 894
 895#else /* NO_IPV6 */
 896
 897static int setup_named_sock(char *listen_addr, int listen_port, struct socketlist *socklist)
 898{
 899        struct sockaddr_in sin;
 900        int sockfd;
 901        long flags;
 902
 903        memset(&sin, 0, sizeof sin);
 904        sin.sin_family = AF_INET;
 905        sin.sin_port = htons(listen_port);
 906
 907        if (listen_addr) {
 908                /* Well, host better be an IP address here. */
 909                if (inet_pton(AF_INET, listen_addr, &sin.sin_addr.s_addr) <= 0)
 910                        return 0;
 911        } else {
 912                sin.sin_addr.s_addr = htonl(INADDR_ANY);
 913        }
 914
 915        sockfd = socket(AF_INET, SOCK_STREAM, 0);
 916        if (sockfd < 0)
 917                return 0;
 918
 919        if (set_reuse_addr(sockfd)) {
 920                logerror("Could not set SO_REUSEADDR: %s", strerror(errno));
 921                close(sockfd);
 922                return 0;
 923        }
 924
 925        if ( bind(sockfd, (struct sockaddr *)&sin, sizeof sin) < 0 ) {
 926                logerror("Could not listen to %s: %s",
 927                         ip2str(AF_INET, (struct sockaddr *)&sin, sizeof(sin)),
 928                         strerror(errno));
 929                close(sockfd);
 930                return 0;
 931        }
 932
 933        if (listen(sockfd, 5) < 0) {
 934                logerror("Could not listen to %s: %s",
 935                         ip2str(AF_INET, (struct sockaddr *)&sin, sizeof(sin)),
 936                         strerror(errno));
 937                close(sockfd);
 938                return 0;
 939        }
 940
 941        flags = fcntl(sockfd, F_GETFD, 0);
 942        if (flags >= 0)
 943                fcntl(sockfd, F_SETFD, flags | FD_CLOEXEC);
 944
 945        ALLOC_GROW(socklist->list, socklist->nr + 1, socklist->alloc);
 946        socklist->list[socklist->nr++] = sockfd;
 947        return 1;
 948}
 949
 950#endif
 951
 952static void socksetup(struct string_list *listen_addr, int listen_port, struct socketlist *socklist)
 953{
 954        if (!listen_addr->nr)
 955                setup_named_sock(NULL, listen_port, socklist);
 956        else {
 957                int i, socknum;
 958                for (i = 0; i < listen_addr->nr; i++) {
 959                        socknum = setup_named_sock(listen_addr->items[i].string,
 960                                                   listen_port, socklist);
 961
 962                        if (socknum == 0)
 963                                logerror("unable to allocate any listen sockets for host %s on port %u",
 964                                         listen_addr->items[i].string, listen_port);
 965                }
 966        }
 967}
 968
 969static int service_loop(struct socketlist *socklist)
 970{
 971        struct pollfd *pfd;
 972        int i;
 973
 974        pfd = xcalloc(socklist->nr, sizeof(struct pollfd));
 975
 976        for (i = 0; i < socklist->nr; i++) {
 977                pfd[i].fd = socklist->list[i];
 978                pfd[i].events = POLLIN;
 979        }
 980
 981        signal(SIGCHLD, child_handler);
 982
 983        for (;;) {
 984                int i;
 985
 986                check_dead_children();
 987
 988                if (poll(pfd, socklist->nr, -1) < 0) {
 989                        if (errno != EINTR) {
 990                                logerror("Poll failed, resuming: %s",
 991                                      strerror(errno));
 992                                sleep(1);
 993                        }
 994                        continue;
 995                }
 996
 997                for (i = 0; i < socklist->nr; i++) {
 998                        if (pfd[i].revents & POLLIN) {
 999                                union {
1000                                        struct sockaddr sa;
1001                                        struct sockaddr_in sai;
1002#ifndef NO_IPV6
1003                                        struct sockaddr_in6 sai6;
1004#endif
1005                                } ss;
1006                                socklen_t sslen = sizeof(ss);
1007                                int incoming = accept(pfd[i].fd, &ss.sa, &sslen);
1008                                if (incoming < 0) {
1009                                        switch (errno) {
1010                                        case EAGAIN:
1011                                        case EINTR:
1012                                        case ECONNABORTED:
1013                                                continue;
1014                                        default:
1015                                                die_errno("accept returned");
1016                                        }
1017                                }
1018                                handle(incoming, &ss.sa, sslen);
1019                        }
1020                }
1021        }
1022}
1023
1024#ifdef NO_POSIX_GOODIES
1025
1026struct credentials;
1027
1028static void drop_privileges(struct credentials *cred)
1029{
1030        /* nothing */
1031}
1032
1033static struct credentials *prepare_credentials(const char *user_name,
1034    const char *group_name)
1035{
1036        die("--user not supported on this platform");
1037}
1038
1039#else
1040
1041struct credentials {
1042        struct passwd *pass;
1043        gid_t gid;
1044};
1045
1046static void drop_privileges(struct credentials *cred)
1047{
1048        if (cred && (initgroups(cred->pass->pw_name, cred->gid) ||
1049            setgid (cred->gid) || setuid(cred->pass->pw_uid)))
1050                die("cannot drop privileges");
1051}
1052
1053static struct credentials *prepare_credentials(const char *user_name,
1054    const char *group_name)
1055{
1056        static struct credentials c;
1057
1058        c.pass = getpwnam(user_name);
1059        if (!c.pass)
1060                die("user not found - %s", user_name);
1061
1062        if (!group_name)
1063                c.gid = c.pass->pw_gid;
1064        else {
1065                struct group *group = getgrnam(group_name);
1066                if (!group)
1067                        die("group not found - %s", group_name);
1068
1069                c.gid = group->gr_gid;
1070        }
1071
1072        return &c;
1073}
1074#endif
1075
1076static void store_pid(const char *path)
1077{
1078        FILE *f = fopen(path, "w");
1079        if (!f)
1080                die_errno("cannot open pid file '%s'", path);
1081        if (fprintf(f, "%"PRIuMAX"\n", (uintmax_t) getpid()) < 0 || fclose(f) != 0)
1082                die_errno("failed to write pid file '%s'", path);
1083}
1084
1085static int serve(struct string_list *listen_addr, int listen_port,
1086    struct credentials *cred)
1087{
1088        struct socketlist socklist = { NULL, 0, 0 };
1089
1090        socksetup(listen_addr, listen_port, &socklist);
1091        if (socklist.nr == 0)
1092                die("unable to allocate any listen sockets on port %u",
1093                    listen_port);
1094
1095        drop_privileges(cred);
1096
1097        loginfo("Ready to rumble");
1098
1099        return service_loop(&socklist);
1100}
1101
1102int main(int argc, char **argv)
1103{
1104        int listen_port = 0;
1105        struct string_list listen_addr = STRING_LIST_INIT_NODUP;
1106        int serve_mode = 0, inetd_mode = 0;
1107        const char *pid_file = NULL, *user_name = NULL, *group_name = NULL;
1108        int detach = 0;
1109        struct credentials *cred = NULL;
1110        int i;
1111
1112        git_setup_gettext();
1113
1114        git_extract_argv0_path(argv[0]);
1115
1116        for (i = 1; i < argc; i++) {
1117                char *arg = argv[i];
1118                const char *v;
1119
1120                if (skip_prefix(arg, "--listen=", &v)) {
1121                        string_list_append(&listen_addr, xstrdup_tolower(v));
1122                        continue;
1123                }
1124                if (skip_prefix(arg, "--port=", &v)) {
1125                        char *end;
1126                        unsigned long n;
1127                        n = strtoul(v, &end, 0);
1128                        if (*v && !*end) {
1129                                listen_port = n;
1130                                continue;
1131                        }
1132                }
1133                if (!strcmp(arg, "--serve")) {
1134                        serve_mode = 1;
1135                        continue;
1136                }
1137                if (!strcmp(arg, "--inetd")) {
1138                        inetd_mode = 1;
1139                        log_syslog = 1;
1140                        continue;
1141                }
1142                if (!strcmp(arg, "--verbose")) {
1143                        verbose = 1;
1144                        continue;
1145                }
1146                if (!strcmp(arg, "--syslog")) {
1147                        log_syslog = 1;
1148                        continue;
1149                }
1150                if (!strcmp(arg, "--export-all")) {
1151                        export_all_trees = 1;
1152                        continue;
1153                }
1154                if (skip_prefix(arg, "--access-hook=", &v)) {
1155                        access_hook = v;
1156                        continue;
1157                }
1158                if (skip_prefix(arg, "--timeout=", &v)) {
1159                        timeout = atoi(v);
1160                        continue;
1161                }
1162                if (skip_prefix(arg, "--init-timeout=", &v)) {
1163                        init_timeout = atoi(v);
1164                        continue;
1165                }
1166                if (skip_prefix(arg, "--max-connections=", &v)) {
1167                        max_connections = atoi(v);
1168                        if (max_connections < 0)
1169                                max_connections = 0;            /* unlimited */
1170                        continue;
1171                }
1172                if (!strcmp(arg, "--strict-paths")) {
1173                        strict_paths = 1;
1174                        continue;
1175                }
1176                if (skip_prefix(arg, "--base-path=", &v)) {
1177                        base_path = v;
1178                        continue;
1179                }
1180                if (!strcmp(arg, "--base-path-relaxed")) {
1181                        base_path_relaxed = 1;
1182                        continue;
1183                }
1184                if (skip_prefix(arg, "--interpolated-path=", &v)) {
1185                        interpolated_path = v;
1186                        continue;
1187                }
1188                if (!strcmp(arg, "--reuseaddr")) {
1189                        reuseaddr = 1;
1190                        continue;
1191                }
1192                if (!strcmp(arg, "--user-path")) {
1193                        user_path = "";
1194                        continue;
1195                }
1196                if (skip_prefix(arg, "--user-path=", &v)) {
1197                        user_path = v;
1198                        continue;
1199                }
1200                if (skip_prefix(arg, "--pid-file=", &v)) {
1201                        pid_file = v;
1202                        continue;
1203                }
1204                if (!strcmp(arg, "--detach")) {
1205                        detach = 1;
1206                        log_syslog = 1;
1207                        continue;
1208                }
1209                if (skip_prefix(arg, "--user=", &v)) {
1210                        user_name = v;
1211                        continue;
1212                }
1213                if (skip_prefix(arg, "--group=", &v)) {
1214                        group_name = v;
1215                        continue;
1216                }
1217                if (skip_prefix(arg, "--enable=", &v)) {
1218                        enable_service(v, 1);
1219                        continue;
1220                }
1221                if (skip_prefix(arg, "--disable=", &v)) {
1222                        enable_service(v, 0);
1223                        continue;
1224                }
1225                if (skip_prefix(arg, "--allow-override=", &v)) {
1226                        make_service_overridable(v, 1);
1227                        continue;
1228                }
1229                if (skip_prefix(arg, "--forbid-override=", &v)) {
1230                        make_service_overridable(v, 0);
1231                        continue;
1232                }
1233                if (!strcmp(arg, "--informative-errors")) {
1234                        informative_errors = 1;
1235                        continue;
1236                }
1237                if (!strcmp(arg, "--no-informative-errors")) {
1238                        informative_errors = 0;
1239                        continue;
1240                }
1241                if (!strcmp(arg, "--")) {
1242                        ok_paths = &argv[i+1];
1243                        break;
1244                } else if (arg[0] != '-') {
1245                        ok_paths = &argv[i];
1246                        break;
1247                }
1248
1249                usage(daemon_usage);
1250        }
1251
1252        if (log_syslog) {
1253                openlog("git-daemon", LOG_PID, LOG_DAEMON);
1254                set_die_routine(daemon_die);
1255        } else
1256                /* avoid splitting a message in the middle */
1257                setvbuf(stderr, NULL, _IOFBF, 4096);
1258
1259        if (inetd_mode && (detach || group_name || user_name))
1260                die("--detach, --user and --group are incompatible with --inetd");
1261
1262        if (inetd_mode && (listen_port || (listen_addr.nr > 0)))
1263                die("--listen= and --port= are incompatible with --inetd");
1264        else if (listen_port == 0)
1265                listen_port = DEFAULT_GIT_PORT;
1266
1267        if (group_name && !user_name)
1268                die("--group supplied without --user");
1269
1270        if (user_name)
1271                cred = prepare_credentials(user_name, group_name);
1272
1273        if (strict_paths && (!ok_paths || !*ok_paths))
1274                die("option --strict-paths requires a whitelist");
1275
1276        if (base_path && !is_directory(base_path))
1277                die("base-path '%s' does not exist or is not a directory",
1278                    base_path);
1279
1280        if (inetd_mode) {
1281                if (!freopen("/dev/null", "w", stderr))
1282                        die_errno("failed to redirect stderr to /dev/null");
1283        }
1284
1285        if (inetd_mode || serve_mode)
1286                return execute();
1287
1288        if (detach) {
1289                if (daemonize())
1290                        die("--detach not supported on this platform");
1291        } else
1292                sanitize_stdfds();
1293
1294        if (pid_file)
1295                store_pid(pid_file);
1296
1297        /* prepare argv for serving-processes */
1298        cld_argv = xmalloc(sizeof (char *) * (argc + 2));
1299        cld_argv[0] = argv[0];  /* git-daemon */
1300        cld_argv[1] = "--serve";
1301        for (i = 1; i < argc; ++i)
1302                cld_argv[i+1] = argv[i];
1303        cld_argv[argc+1] = NULL;
1304
1305        return serve(&listen_addr, listen_port, cred);
1306}