40595933bea6ddc516a49f7bd5de29b3bb91db16
   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#ifndef NI_MAXSERV
  13#define NI_MAXSERV 32
  14#endif
  15
  16static int log_syslog;
  17static int verbose;
  18static int reuseaddr;
  19
  20static const char daemon_usage[] =
  21"git daemon [--verbose] [--syslog] [--export-all]\n"
  22"           [--timeout=<n>] [--init-timeout=<n>] [--max-connections=<n>]\n"
  23"           [--strict-paths] [--base-path=<path>] [--base-path-relaxed]\n"
  24"           [--user-path | --user-path=<path>]\n"
  25"           [--interpolated-path=<path>]\n"
  26"           [--reuseaddr] [--detach] [--pid-file=<file>]\n"
  27"           [--(enable|disable|allow-override|forbid-override)=<service>]\n"
  28"           [--inetd | [--listen=<host_or_ipaddr>] [--port=<n>]\n"
  29"                      [--user=<user> [--group=<group>]]\n"
  30"           [<directory>...]";
  31
  32/* List of acceptable pathname prefixes */
  33static char **ok_paths;
  34static int strict_paths;
  35
  36/* If this is set, git-daemon-export-ok is not required */
  37static int export_all_trees;
  38
  39/* Take all paths relative to this one if non-NULL */
  40static char *base_path;
  41static char *interpolated_path;
  42static int base_path_relaxed;
  43
  44/* Flag indicating client sent extra args. */
  45static int saw_extended_args;
  46
  47/* If defined, ~user notation is allowed and the string is inserted
  48 * after ~user/.  E.g. a request to git://host/~alice/frotz would
  49 * go to /home/alice/pub_git/frotz with --user-path=pub_git.
  50 */
  51static const char *user_path;
  52
  53/* Timeout, and initial timeout */
  54static unsigned int timeout;
  55static unsigned int init_timeout;
  56
  57static char *hostname;
  58static char *canon_hostname;
  59static char *ip_address;
  60static char *tcp_port;
  61
  62static void logreport(int priority, const char *err, va_list params)
  63{
  64        if (log_syslog) {
  65                char buf[1024];
  66                vsnprintf(buf, sizeof(buf), err, params);
  67                syslog(priority, "%s", buf);
  68        } else {
  69                /*
  70                 * Since stderr is set to linebuffered mode, the
  71                 * logging of different processes will not overlap
  72                 */
  73                fprintf(stderr, "[%"PRIuMAX"] ", (uintmax_t)getpid());
  74                vfprintf(stderr, err, params);
  75                fputc('\n', stderr);
  76        }
  77}
  78
  79__attribute__((format (printf, 1, 2)))
  80static void logerror(const char *err, ...)
  81{
  82        va_list params;
  83        va_start(params, err);
  84        logreport(LOG_ERR, err, params);
  85        va_end(params);
  86}
  87
  88__attribute__((format (printf, 1, 2)))
  89static void loginfo(const char *err, ...)
  90{
  91        va_list params;
  92        if (!verbose)
  93                return;
  94        va_start(params, err);
  95        logreport(LOG_INFO, err, params);
  96        va_end(params);
  97}
  98
  99static void NORETURN daemon_die(const char *err, va_list params)
 100{
 101        logreport(LOG_ERR, err, params);
 102        exit(1);
 103}
 104
 105static char *path_ok(char *directory)
 106{
 107        static char rpath[PATH_MAX];
 108        static char interp_path[PATH_MAX];
 109        char *path;
 110        char *dir;
 111
 112        dir = directory;
 113
 114        if (daemon_avoid_alias(dir)) {
 115                logerror("'%s': aliased", dir);
 116                return NULL;
 117        }
 118
 119        if (*dir == '~') {
 120                if (!user_path) {
 121                        logerror("'%s': User-path not allowed", dir);
 122                        return NULL;
 123                }
 124                if (*user_path) {
 125                        /* Got either "~alice" or "~alice/foo";
 126                         * rewrite them to "~alice/%s" or
 127                         * "~alice/%s/foo".
 128                         */
 129                        int namlen, restlen = strlen(dir);
 130                        char *slash = strchr(dir, '/');
 131                        if (!slash)
 132                                slash = dir + restlen;
 133                        namlen = slash - dir;
 134                        restlen -= namlen;
 135                        loginfo("userpath <%s>, request <%s>, namlen %d, restlen %d, slash <%s>", user_path, dir, namlen, restlen, slash);
 136                        snprintf(rpath, PATH_MAX, "%.*s/%s%.*s",
 137                                 namlen, dir, user_path, restlen, slash);
 138                        dir = rpath;
 139                }
 140        }
 141        else if (interpolated_path && saw_extended_args) {
 142                struct strbuf expanded_path = STRBUF_INIT;
 143                struct strbuf_expand_dict_entry dict[6];
 144
 145                dict[0].placeholder = "H"; dict[0].value = hostname;
 146                dict[1].placeholder = "CH"; dict[1].value = canon_hostname;
 147                dict[2].placeholder = "IP"; dict[2].value = ip_address;
 148                dict[3].placeholder = "P"; dict[3].value = tcp_port;
 149                dict[4].placeholder = "D"; dict[4].value = directory;
 150                dict[5].placeholder = NULL; dict[5].value = NULL;
 151                if (*dir != '/') {
 152                        /* Allow only absolute */
 153                        logerror("'%s': Non-absolute path denied (interpolated-path active)", dir);
 154                        return NULL;
 155                }
 156
 157                strbuf_expand(&expanded_path, interpolated_path,
 158                                strbuf_expand_dict_cb, &dict);
 159                strlcpy(interp_path, expanded_path.buf, PATH_MAX);
 160                strbuf_release(&expanded_path);
 161                loginfo("Interpolated dir '%s'", interp_path);
 162
 163                dir = interp_path;
 164        }
 165        else if (base_path) {
 166                if (*dir != '/') {
 167                        /* Allow only absolute */
 168                        logerror("'%s': Non-absolute path denied (base-path active)", dir);
 169                        return NULL;
 170                }
 171                snprintf(rpath, PATH_MAX, "%s%s", base_path, dir);
 172                dir = rpath;
 173        }
 174
 175        path = enter_repo(dir, strict_paths);
 176        if (!path && base_path && base_path_relaxed) {
 177                /*
 178                 * if we fail and base_path_relaxed is enabled, try without
 179                 * prefixing the base path
 180                 */
 181                dir = directory;
 182                path = enter_repo(dir, strict_paths);
 183        }
 184
 185        if (!path) {
 186                logerror("'%s' does not appear to be a git repository", dir);
 187                return NULL;
 188        }
 189
 190        if ( ok_paths && *ok_paths ) {
 191                char **pp;
 192                int pathlen = strlen(path);
 193
 194                /* The validation is done on the paths after enter_repo
 195                 * appends optional {.git,.git/.git} and friends, but
 196                 * it does not use getcwd().  So if your /pub is
 197                 * a symlink to /mnt/pub, you can whitelist /pub and
 198                 * do not have to say /mnt/pub.
 199                 * Do not say /pub/.
 200                 */
 201                for ( pp = ok_paths ; *pp ; pp++ ) {
 202                        int len = strlen(*pp);
 203                        if (len <= pathlen &&
 204                            !memcmp(*pp, path, len) &&
 205                            (path[len] == '\0' ||
 206                             (!strict_paths && path[len] == '/')))
 207                                return path;
 208                }
 209        }
 210        else {
 211                /* be backwards compatible */
 212                if (!strict_paths)
 213                        return path;
 214        }
 215
 216        logerror("'%s': not in whitelist", path);
 217        return NULL;            /* Fallthrough. Deny by default */
 218}
 219
 220typedef int (*daemon_service_fn)(void);
 221struct daemon_service {
 222        const char *name;
 223        const char *config_name;
 224        daemon_service_fn fn;
 225        int enabled;
 226        int overridable;
 227};
 228
 229static struct daemon_service *service_looking_at;
 230static int service_enabled;
 231
 232static int git_daemon_config(const char *var, const char *value, void *cb)
 233{
 234        if (!prefixcmp(var, "daemon.") &&
 235            !strcmp(var + 7, service_looking_at->config_name)) {
 236                service_enabled = git_config_bool(var, value);
 237                return 0;
 238        }
 239
 240        /* we are not interested in parsing any other configuration here */
 241        return 0;
 242}
 243
 244static int run_service(char *dir, struct daemon_service *service)
 245{
 246        const char *path;
 247        int enabled = service->enabled;
 248
 249        loginfo("Request %s for '%s'", service->name, dir);
 250
 251        if (!enabled && !service->overridable) {
 252                logerror("'%s': service not enabled.", service->name);
 253                errno = EACCES;
 254                return -1;
 255        }
 256
 257        if (!(path = path_ok(dir)))
 258                return -1;
 259
 260        /*
 261         * Security on the cheap.
 262         *
 263         * We want a readable HEAD, usable "objects" directory, and
 264         * a "git-daemon-export-ok" flag that says that the other side
 265         * is ok with us doing this.
 266         *
 267         * path_ok() uses enter_repo() and does whitelist checking.
 268         * We only need to make sure the repository is exported.
 269         */
 270
 271        if (!export_all_trees && access("git-daemon-export-ok", F_OK)) {
 272                logerror("'%s': repository not exported.", path);
 273                errno = EACCES;
 274                return -1;
 275        }
 276
 277        if (service->overridable) {
 278                service_looking_at = service;
 279                service_enabled = -1;
 280                git_config(git_daemon_config, NULL);
 281                if (0 <= service_enabled)
 282                        enabled = service_enabled;
 283        }
 284        if (!enabled) {
 285                logerror("'%s': service not enabled for '%s'",
 286                         service->name, path);
 287                errno = EACCES;
 288                return -1;
 289        }
 290
 291        /*
 292         * We'll ignore SIGTERM from now on, we have a
 293         * good client.
 294         */
 295        signal(SIGTERM, SIG_IGN);
 296
 297        return service->fn();
 298}
 299
 300static void copy_to_log(int fd)
 301{
 302        struct strbuf line = STRBUF_INIT;
 303        FILE *fp;
 304
 305        fp = fdopen(fd, "r");
 306        if (fp == NULL) {
 307                logerror("fdopen of error channel failed");
 308                close(fd);
 309                return;
 310        }
 311
 312        while (strbuf_getline(&line, fp, '\n') != EOF) {
 313                logerror("%s", line.buf);
 314                strbuf_setlen(&line, 0);
 315        }
 316
 317        strbuf_release(&line);
 318        fclose(fp);
 319}
 320
 321static int run_service_command(const char **argv)
 322{
 323        struct child_process cld;
 324
 325        memset(&cld, 0, sizeof(cld));
 326        cld.argv = argv;
 327        cld.git_cmd = 1;
 328        cld.err = -1;
 329        if (start_command(&cld))
 330                return -1;
 331
 332        close(0);
 333        close(1);
 334
 335        copy_to_log(cld.err);
 336
 337        return finish_command(&cld);
 338}
 339
 340static int upload_pack(void)
 341{
 342        /* Timeout as string */
 343        char timeout_buf[64];
 344        const char *argv[] = { "upload-pack", "--strict", NULL, ".", NULL };
 345
 346        argv[2] = timeout_buf;
 347
 348        snprintf(timeout_buf, sizeof timeout_buf, "--timeout=%u", timeout);
 349        return run_service_command(argv);
 350}
 351
 352static int upload_archive(void)
 353{
 354        static const char *argv[] = { "upload-archive", ".", NULL };
 355        return run_service_command(argv);
 356}
 357
 358static int receive_pack(void)
 359{
 360        static const char *argv[] = { "receive-pack", ".", NULL };
 361        return run_service_command(argv);
 362}
 363
 364static struct daemon_service daemon_service[] = {
 365        { "upload-archive", "uploadarch", upload_archive, 0, 1 },
 366        { "upload-pack", "uploadpack", upload_pack, 1, 1 },
 367        { "receive-pack", "receivepack", receive_pack, 0, 1 },
 368};
 369
 370static void enable_service(const char *name, int ena)
 371{
 372        int i;
 373        for (i = 0; i < ARRAY_SIZE(daemon_service); i++) {
 374                if (!strcmp(daemon_service[i].name, name)) {
 375                        daemon_service[i].enabled = ena;
 376                        return;
 377                }
 378        }
 379        die("No such service %s", name);
 380}
 381
 382static void make_service_overridable(const char *name, int ena)
 383{
 384        int i;
 385        for (i = 0; i < ARRAY_SIZE(daemon_service); i++) {
 386                if (!strcmp(daemon_service[i].name, name)) {
 387                        daemon_service[i].overridable = ena;
 388                        return;
 389                }
 390        }
 391        die("No such service %s", name);
 392}
 393
 394static char *xstrdup_tolower(const char *str)
 395{
 396        char *p, *dup = xstrdup(str);
 397        for (p = dup; *p; p++)
 398                *p = tolower(*p);
 399        return dup;
 400}
 401
 402static void parse_host_and_port(char *hostport, char **host,
 403        char **port)
 404{
 405        if (*hostport == '[') {
 406                char *end;
 407
 408                end = strchr(hostport, ']');
 409                if (!end)
 410                        die("Invalid request ('[' without ']')");
 411                *end = '\0';
 412                *host = hostport + 1;
 413                if (!end[1])
 414                        *port = NULL;
 415                else if (end[1] == ':')
 416                        *port = end + 2;
 417                else
 418                        die("Garbage after end of host part");
 419        } else {
 420                *host = hostport;
 421                *port = strrchr(hostport, ':');
 422                if (*port) {
 423                        **port = '\0';
 424                        ++*port;
 425                }
 426        }
 427}
 428
 429/*
 430 * Read the host as supplied by the client connection.
 431 */
 432static void parse_host_arg(char *extra_args, int buflen)
 433{
 434        char *val;
 435        int vallen;
 436        char *end = extra_args + buflen;
 437
 438        if (extra_args < end && *extra_args) {
 439                saw_extended_args = 1;
 440                if (strncasecmp("host=", extra_args, 5) == 0) {
 441                        val = extra_args + 5;
 442                        vallen = strlen(val) + 1;
 443                        if (*val) {
 444                                /* Split <host>:<port> at colon. */
 445                                char *host;
 446                                char *port;
 447                                parse_host_and_port(val, &host, &port);
 448                                if (port) {
 449                                        free(tcp_port);
 450                                        tcp_port = xstrdup(port);
 451                                }
 452                                free(hostname);
 453                                hostname = xstrdup_tolower(host);
 454                        }
 455
 456                        /* On to the next one */
 457                        extra_args = val + vallen;
 458                }
 459                if (extra_args < end && *extra_args)
 460                        die("Invalid request");
 461        }
 462
 463        /*
 464         * Locate canonical hostname and its IP address.
 465         */
 466        if (hostname) {
 467#ifndef NO_IPV6
 468                struct addrinfo hints;
 469                struct addrinfo *ai;
 470                int gai;
 471                static char addrbuf[HOST_NAME_MAX + 1];
 472
 473                memset(&hints, 0, sizeof(hints));
 474                hints.ai_flags = AI_CANONNAME;
 475
 476                gai = getaddrinfo(hostname, NULL, &hints, &ai);
 477                if (!gai) {
 478                        struct sockaddr_in *sin_addr = (void *)ai->ai_addr;
 479
 480                        inet_ntop(AF_INET, &sin_addr->sin_addr,
 481                                  addrbuf, sizeof(addrbuf));
 482                        free(ip_address);
 483                        ip_address = xstrdup(addrbuf);
 484
 485                        free(canon_hostname);
 486                        canon_hostname = xstrdup(ai->ai_canonname ?
 487                                                 ai->ai_canonname : ip_address);
 488
 489                        freeaddrinfo(ai);
 490                }
 491#else
 492                struct hostent *hent;
 493                struct sockaddr_in sa;
 494                char **ap;
 495                static char addrbuf[HOST_NAME_MAX + 1];
 496
 497                hent = gethostbyname(hostname);
 498
 499                ap = hent->h_addr_list;
 500                memset(&sa, 0, sizeof sa);
 501                sa.sin_family = hent->h_addrtype;
 502                sa.sin_port = htons(0);
 503                memcpy(&sa.sin_addr, *ap, hent->h_length);
 504
 505                inet_ntop(hent->h_addrtype, &sa.sin_addr,
 506                          addrbuf, sizeof(addrbuf));
 507
 508                free(canon_hostname);
 509                canon_hostname = xstrdup(hent->h_name);
 510                free(ip_address);
 511                ip_address = xstrdup(addrbuf);
 512#endif
 513        }
 514}
 515
 516
 517static int execute(struct sockaddr *addr)
 518{
 519        static char line[1000];
 520        int pktlen, len, i;
 521
 522        if (addr) {
 523                char addrbuf[256] = "";
 524                int port = -1;
 525
 526                if (addr->sa_family == AF_INET) {
 527                        struct sockaddr_in *sin_addr = (void *) addr;
 528                        inet_ntop(addr->sa_family, &sin_addr->sin_addr, addrbuf, sizeof(addrbuf));
 529                        port = ntohs(sin_addr->sin_port);
 530#ifndef NO_IPV6
 531                } else if (addr && addr->sa_family == AF_INET6) {
 532                        struct sockaddr_in6 *sin6_addr = (void *) addr;
 533
 534                        char *buf = addrbuf;
 535                        *buf++ = '['; *buf = '\0'; /* stpcpy() is cool */
 536                        inet_ntop(AF_INET6, &sin6_addr->sin6_addr, buf, sizeof(addrbuf) - 1);
 537                        strcat(buf, "]");
 538
 539                        port = ntohs(sin6_addr->sin6_port);
 540#endif
 541                }
 542                loginfo("Connection from %s:%d", addrbuf, port);
 543                setenv("REMOTE_ADDR", addrbuf, 1);
 544        }
 545        else {
 546                unsetenv("REMOTE_ADDR");
 547        }
 548
 549        alarm(init_timeout ? init_timeout : timeout);
 550        pktlen = packet_read_line(0, line, sizeof(line));
 551        alarm(0);
 552
 553        len = strlen(line);
 554        if (pktlen != len)
 555                loginfo("Extended attributes (%d bytes) exist <%.*s>",
 556                        (int) pktlen - len,
 557                        (int) pktlen - len, line + len + 1);
 558        if (len && line[len-1] == '\n') {
 559                line[--len] = 0;
 560                pktlen--;
 561        }
 562
 563        free(hostname);
 564        free(canon_hostname);
 565        free(ip_address);
 566        free(tcp_port);
 567        hostname = canon_hostname = ip_address = tcp_port = NULL;
 568
 569        if (len != pktlen)
 570                parse_host_arg(line + len + 1, pktlen - len - 1);
 571
 572        for (i = 0; i < ARRAY_SIZE(daemon_service); i++) {
 573                struct daemon_service *s = &(daemon_service[i]);
 574                int namelen = strlen(s->name);
 575                if (!prefixcmp(line, "git-") &&
 576                    !strncmp(s->name, line + 4, namelen) &&
 577                    line[namelen + 4] == ' ') {
 578                        /*
 579                         * Note: The directory here is probably context sensitive,
 580                         * and might depend on the actual service being performed.
 581                         */
 582                        return run_service(line + namelen + 5, s);
 583                }
 584        }
 585
 586        logerror("Protocol error: '%s'", line);
 587        return -1;
 588}
 589
 590static int addrcmp(const struct sockaddr_storage *s1,
 591    const struct sockaddr_storage *s2)
 592{
 593        const struct sockaddr *sa1 = (const struct sockaddr*) s1;
 594        const struct sockaddr *sa2 = (const struct sockaddr*) s2;
 595
 596        if (sa1->sa_family != sa2->sa_family)
 597                return sa1->sa_family - sa2->sa_family;
 598        if (sa1->sa_family == AF_INET)
 599                return memcmp(&((struct sockaddr_in *)s1)->sin_addr,
 600                    &((struct sockaddr_in *)s2)->sin_addr,
 601                    sizeof(struct in_addr));
 602#ifndef NO_IPV6
 603        if (sa1->sa_family == AF_INET6)
 604                return memcmp(&((struct sockaddr_in6 *)s1)->sin6_addr,
 605                    &((struct sockaddr_in6 *)s2)->sin6_addr,
 606                    sizeof(struct in6_addr));
 607#endif
 608        return 0;
 609}
 610
 611static int max_connections = 32;
 612
 613static unsigned int live_children;
 614
 615static struct child {
 616        struct child *next;
 617        struct child_process cld;
 618        struct sockaddr_storage address;
 619} *firstborn;
 620
 621static void add_child(struct child_process *cld, struct sockaddr *addr, int addrlen)
 622{
 623        struct child *newborn, **cradle;
 624
 625        newborn = xcalloc(1, sizeof(*newborn));
 626        live_children++;
 627        memcpy(&newborn->cld, cld, sizeof(*cld));
 628        memcpy(&newborn->address, addr, addrlen);
 629        for (cradle = &firstborn; *cradle; cradle = &(*cradle)->next)
 630                if (!addrcmp(&(*cradle)->address, &newborn->address))
 631                        break;
 632        newborn->next = *cradle;
 633        *cradle = newborn;
 634}
 635
 636/*
 637 * This gets called if the number of connections grows
 638 * past "max_connections".
 639 *
 640 * We kill the newest connection from a duplicate IP.
 641 */
 642static void kill_some_child(void)
 643{
 644        const struct child *blanket, *next;
 645
 646        if (!(blanket = firstborn))
 647                return;
 648
 649        for (; (next = blanket->next); blanket = next)
 650                if (!addrcmp(&blanket->address, &next->address)) {
 651                        kill(blanket->cld.pid, SIGTERM);
 652                        break;
 653                }
 654}
 655
 656static void check_dead_children(void)
 657{
 658        int status;
 659        pid_t pid;
 660
 661        struct child **cradle, *blanket;
 662        for (cradle = &firstborn; (blanket = *cradle);)
 663                if ((pid = waitpid(blanket->cld.pid, &status, WNOHANG)) > 1) {
 664                        const char *dead = "";
 665                        if (status)
 666                                dead = " (with error)";
 667                        loginfo("[%"PRIuMAX"] Disconnected%s", (uintmax_t)pid, dead);
 668
 669                        /* remove the child */
 670                        *cradle = blanket->next;
 671                        live_children--;
 672                        free(blanket);
 673                } else
 674                        cradle = &blanket->next;
 675}
 676
 677static char **cld_argv;
 678static void handle(int incoming, struct sockaddr *addr, int addrlen)
 679{
 680        struct child_process cld = { 0 };
 681
 682        if (max_connections && live_children >= max_connections) {
 683                kill_some_child();
 684                sleep(1);  /* give it some time to die */
 685                check_dead_children();
 686                if (live_children >= max_connections) {
 687                        close(incoming);
 688                        logerror("Too many children, dropping connection");
 689                        return;
 690                }
 691        }
 692
 693        cld.argv = (const char **)cld_argv;
 694        cld.in = incoming;
 695        cld.out = dup(incoming);
 696
 697        if (start_command(&cld))
 698                logerror("unable to fork");
 699        else
 700                add_child(&cld, addr, addrlen);
 701        close(incoming);
 702}
 703
 704static void child_handler(int signo)
 705{
 706        /*
 707         * Otherwise empty handler because systemcalls will get interrupted
 708         * upon signal receipt
 709         * SysV needs the handler to be rearmed
 710         */
 711        signal(SIGCHLD, child_handler);
 712}
 713
 714static int set_reuse_addr(int sockfd)
 715{
 716        int on = 1;
 717
 718        if (!reuseaddr)
 719                return 0;
 720        return setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR,
 721                          &on, sizeof(on));
 722}
 723
 724struct socketlist {
 725        int *list;
 726        size_t nr;
 727        size_t alloc;
 728};
 729
 730#ifndef NO_IPV6
 731
 732static int setup_named_sock(char *listen_addr, int listen_port, struct socketlist *socklist)
 733{
 734        int socknum = 0;
 735        int maxfd = -1;
 736        char pbuf[NI_MAXSERV];
 737        struct addrinfo hints, *ai0, *ai;
 738        int gai;
 739        long flags;
 740
 741        sprintf(pbuf, "%d", listen_port);
 742        memset(&hints, 0, sizeof(hints));
 743        hints.ai_family = AF_UNSPEC;
 744        hints.ai_socktype = SOCK_STREAM;
 745        hints.ai_protocol = IPPROTO_TCP;
 746        hints.ai_flags = AI_PASSIVE;
 747
 748        gai = getaddrinfo(listen_addr, pbuf, &hints, &ai0);
 749        if (gai) {
 750                logerror("getaddrinfo() for %s failed: %s", listen_addr, gai_strerror(gai));
 751                return 0;
 752        }
 753
 754        for (ai = ai0; ai; ai = ai->ai_next) {
 755                int sockfd;
 756
 757                sockfd = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
 758                if (sockfd < 0)
 759                        continue;
 760                if (sockfd >= FD_SETSIZE) {
 761                        logerror("Socket descriptor too large");
 762                        close(sockfd);
 763                        continue;
 764                }
 765
 766#ifdef IPV6_V6ONLY
 767                if (ai->ai_family == AF_INET6) {
 768                        int on = 1;
 769                        setsockopt(sockfd, IPPROTO_IPV6, IPV6_V6ONLY,
 770                                   &on, sizeof(on));
 771                        /* Note: error is not fatal */
 772                }
 773#endif
 774
 775                if (set_reuse_addr(sockfd)) {
 776                        close(sockfd);
 777                        continue;
 778                }
 779
 780                if (bind(sockfd, ai->ai_addr, ai->ai_addrlen) < 0) {
 781                        close(sockfd);
 782                        continue;       /* not fatal */
 783                }
 784                if (listen(sockfd, 5) < 0) {
 785                        close(sockfd);
 786                        continue;       /* not fatal */
 787                }
 788
 789                flags = fcntl(sockfd, F_GETFD, 0);
 790                if (flags >= 0)
 791                        fcntl(sockfd, F_SETFD, flags | FD_CLOEXEC);
 792
 793                ALLOC_GROW(socklist->list, socklist->nr + 1, socklist->alloc);
 794                socklist->list[socklist->nr++] = sockfd;
 795                socknum++;
 796
 797                if (maxfd < sockfd)
 798                        maxfd = sockfd;
 799        }
 800
 801        freeaddrinfo(ai0);
 802
 803        return socknum;
 804}
 805
 806#else /* NO_IPV6 */
 807
 808static int setup_named_sock(char *listen_addr, int listen_port, struct socketlist *socklist)
 809{
 810        struct sockaddr_in sin;
 811        int sockfd;
 812        long flags;
 813
 814        memset(&sin, 0, sizeof sin);
 815        sin.sin_family = AF_INET;
 816        sin.sin_port = htons(listen_port);
 817
 818        if (listen_addr) {
 819                /* Well, host better be an IP address here. */
 820                if (inet_pton(AF_INET, listen_addr, &sin.sin_addr.s_addr) <= 0)
 821                        return 0;
 822        } else {
 823                sin.sin_addr.s_addr = htonl(INADDR_ANY);
 824        }
 825
 826        sockfd = socket(AF_INET, SOCK_STREAM, 0);
 827        if (sockfd < 0)
 828                return 0;
 829
 830        if (set_reuse_addr(sockfd)) {
 831                close(sockfd);
 832                return 0;
 833        }
 834
 835        if ( bind(sockfd, (struct sockaddr *)&sin, sizeof sin) < 0 ) {
 836                close(sockfd);
 837                return 0;
 838        }
 839
 840        if (listen(sockfd, 5) < 0) {
 841                close(sockfd);
 842                return 0;
 843        }
 844
 845        flags = fcntl(sockfd, F_GETFD, 0);
 846        if (flags >= 0)
 847                fcntl(sockfd, F_SETFD, flags | FD_CLOEXEC);
 848
 849        ALLOC_GROW(socklist->list, socklist->nr + 1, socklist->alloc);
 850        socklist->list[socklist->nr++] = sockfd;
 851        return 1;
 852}
 853
 854#endif
 855
 856static void socksetup(struct string_list *listen_addr, int listen_port, struct socketlist *socklist)
 857{
 858        if (!listen_addr->nr)
 859                setup_named_sock(NULL, listen_port, socklist);
 860        else {
 861                int i, socknum;
 862                for (i = 0; i < listen_addr->nr; i++) {
 863                        socknum = setup_named_sock(listen_addr->items[i].string,
 864                                                   listen_port, socklist);
 865
 866                        if (socknum == 0)
 867                                logerror("unable to allocate any listen sockets for host %s on port %u",
 868                                         listen_addr->items[i].string, listen_port);
 869                }
 870        }
 871}
 872
 873static int service_loop(struct socketlist *socklist)
 874{
 875        struct pollfd *pfd;
 876        int i;
 877
 878        pfd = xcalloc(socklist->nr, sizeof(struct pollfd));
 879
 880        for (i = 0; i < socklist->nr; i++) {
 881                pfd[i].fd = socklist->list[i];
 882                pfd[i].events = POLLIN;
 883        }
 884
 885        signal(SIGCHLD, child_handler);
 886
 887        for (;;) {
 888                int i;
 889
 890                check_dead_children();
 891
 892                if (poll(pfd, socklist->nr, -1) < 0) {
 893                        if (errno != EINTR) {
 894                                logerror("Poll failed, resuming: %s",
 895                                      strerror(errno));
 896                                sleep(1);
 897                        }
 898                        continue;
 899                }
 900
 901                for (i = 0; i < socklist->nr; i++) {
 902                        if (pfd[i].revents & POLLIN) {
 903                                struct sockaddr_storage ss;
 904                                unsigned int sslen = sizeof(ss);
 905                                int incoming = accept(pfd[i].fd, (struct sockaddr *)&ss, &sslen);
 906                                if (incoming < 0) {
 907                                        switch (errno) {
 908                                        case EAGAIN:
 909                                        case EINTR:
 910                                        case ECONNABORTED:
 911                                                continue;
 912                                        default:
 913                                                die_errno("accept returned");
 914                                        }
 915                                }
 916                                handle(incoming, (struct sockaddr *)&ss, sslen);
 917                        }
 918                }
 919        }
 920}
 921
 922/* if any standard file descriptor is missing open it to /dev/null */
 923static void sanitize_stdfds(void)
 924{
 925        int fd = open("/dev/null", O_RDWR, 0);
 926        while (fd != -1 && fd < 2)
 927                fd = dup(fd);
 928        if (fd == -1)
 929                die_errno("open /dev/null or dup failed");
 930        if (fd > 2)
 931                close(fd);
 932}
 933
 934static void daemonize(void)
 935{
 936        switch (fork()) {
 937                case 0:
 938                        break;
 939                case -1:
 940                        die_errno("fork failed");
 941                default:
 942                        exit(0);
 943        }
 944        if (setsid() == -1)
 945                die_errno("setsid failed");
 946        close(0);
 947        close(1);
 948        close(2);
 949        sanitize_stdfds();
 950}
 951
 952static void store_pid(const char *path)
 953{
 954        FILE *f = fopen(path, "w");
 955        if (!f)
 956                die_errno("cannot open pid file '%s'", path);
 957        if (fprintf(f, "%"PRIuMAX"\n", (uintmax_t) getpid()) < 0 || fclose(f) != 0)
 958                die_errno("failed to write pid file '%s'", path);
 959}
 960
 961static int serve(struct string_list *listen_addr, int listen_port, struct passwd *pass, gid_t gid)
 962{
 963        struct socketlist socklist = { NULL, 0, 0 };
 964
 965        socksetup(listen_addr, listen_port, &socklist);
 966        if (socklist.nr == 0)
 967                die("unable to allocate any listen sockets on port %u",
 968                    listen_port);
 969
 970        if (pass && gid &&
 971            (initgroups(pass->pw_name, gid) || setgid (gid) ||
 972             setuid(pass->pw_uid)))
 973                die("cannot drop privileges");
 974
 975        return service_loop(&socklist);
 976}
 977
 978int main(int argc, char **argv)
 979{
 980        int listen_port = 0;
 981        struct string_list listen_addr = STRING_LIST_INIT_NODUP;
 982        int serve_mode = 0, inetd_mode = 0;
 983        const char *pid_file = NULL, *user_name = NULL, *group_name = NULL;
 984        int detach = 0;
 985        struct passwd *pass = NULL;
 986        struct group *group;
 987        gid_t gid = 0;
 988        int i;
 989
 990        git_extract_argv0_path(argv[0]);
 991
 992        for (i = 1; i < argc; i++) {
 993                char *arg = argv[i];
 994
 995                if (!prefixcmp(arg, "--listen=")) {
 996                        string_list_append(&listen_addr, xstrdup_tolower(arg + 9));
 997                        continue;
 998                }
 999                if (!prefixcmp(arg, "--port=")) {
1000                        char *end;
1001                        unsigned long n;
1002                        n = strtoul(arg+7, &end, 0);
1003                        if (arg[7] && !*end) {
1004                                listen_port = n;
1005                                continue;
1006                        }
1007                }
1008                if (!strcmp(arg, "--serve")) {
1009                        serve_mode = 1;
1010                        continue;
1011                }
1012                if (!strcmp(arg, "--inetd")) {
1013                        inetd_mode = 1;
1014                        log_syslog = 1;
1015                        continue;
1016                }
1017                if (!strcmp(arg, "--verbose")) {
1018                        verbose = 1;
1019                        continue;
1020                }
1021                if (!strcmp(arg, "--syslog")) {
1022                        log_syslog = 1;
1023                        continue;
1024                }
1025                if (!strcmp(arg, "--export-all")) {
1026                        export_all_trees = 1;
1027                        continue;
1028                }
1029                if (!prefixcmp(arg, "--timeout=")) {
1030                        timeout = atoi(arg+10);
1031                        continue;
1032                }
1033                if (!prefixcmp(arg, "--init-timeout=")) {
1034                        init_timeout = atoi(arg+15);
1035                        continue;
1036                }
1037                if (!prefixcmp(arg, "--max-connections=")) {
1038                        max_connections = atoi(arg+18);
1039                        if (max_connections < 0)
1040                                max_connections = 0;            /* unlimited */
1041                        continue;
1042                }
1043                if (!strcmp(arg, "--strict-paths")) {
1044                        strict_paths = 1;
1045                        continue;
1046                }
1047                if (!prefixcmp(arg, "--base-path=")) {
1048                        base_path = arg+12;
1049                        continue;
1050                }
1051                if (!strcmp(arg, "--base-path-relaxed")) {
1052                        base_path_relaxed = 1;
1053                        continue;
1054                }
1055                if (!prefixcmp(arg, "--interpolated-path=")) {
1056                        interpolated_path = arg+20;
1057                        continue;
1058                }
1059                if (!strcmp(arg, "--reuseaddr")) {
1060                        reuseaddr = 1;
1061                        continue;
1062                }
1063                if (!strcmp(arg, "--user-path")) {
1064                        user_path = "";
1065                        continue;
1066                }
1067                if (!prefixcmp(arg, "--user-path=")) {
1068                        user_path = arg + 12;
1069                        continue;
1070                }
1071                if (!prefixcmp(arg, "--pid-file=")) {
1072                        pid_file = arg + 11;
1073                        continue;
1074                }
1075                if (!strcmp(arg, "--detach")) {
1076                        detach = 1;
1077                        log_syslog = 1;
1078                        continue;
1079                }
1080                if (!prefixcmp(arg, "--user=")) {
1081                        user_name = arg + 7;
1082                        continue;
1083                }
1084                if (!prefixcmp(arg, "--group=")) {
1085                        group_name = arg + 8;
1086                        continue;
1087                }
1088                if (!prefixcmp(arg, "--enable=")) {
1089                        enable_service(arg + 9, 1);
1090                        continue;
1091                }
1092                if (!prefixcmp(arg, "--disable=")) {
1093                        enable_service(arg + 10, 0);
1094                        continue;
1095                }
1096                if (!prefixcmp(arg, "--allow-override=")) {
1097                        make_service_overridable(arg + 17, 1);
1098                        continue;
1099                }
1100                if (!prefixcmp(arg, "--forbid-override=")) {
1101                        make_service_overridable(arg + 18, 0);
1102                        continue;
1103                }
1104                if (!strcmp(arg, "--")) {
1105                        ok_paths = &argv[i+1];
1106                        break;
1107                } else if (arg[0] != '-') {
1108                        ok_paths = &argv[i];
1109                        break;
1110                }
1111
1112                usage(daemon_usage);
1113        }
1114
1115        if (log_syslog) {
1116                openlog("git-daemon", LOG_PID, LOG_DAEMON);
1117                set_die_routine(daemon_die);
1118        } else
1119                /* avoid splitting a message in the middle */
1120                setvbuf(stderr, NULL, _IOLBF, 0);
1121
1122        if (inetd_mode && (group_name || user_name))
1123                die("--user and --group are incompatible with --inetd");
1124
1125        if (inetd_mode && (listen_port || (listen_addr.nr > 0)))
1126                die("--listen= and --port= are incompatible with --inetd");
1127        else if (listen_port == 0)
1128                listen_port = DEFAULT_GIT_PORT;
1129
1130        if (group_name && !user_name)
1131                die("--group supplied without --user");
1132
1133        if (user_name) {
1134                pass = getpwnam(user_name);
1135                if (!pass)
1136                        die("user not found - %s", user_name);
1137
1138                if (!group_name)
1139                        gid = pass->pw_gid;
1140                else {
1141                        group = getgrnam(group_name);
1142                        if (!group)
1143                                die("group not found - %s", group_name);
1144
1145                        gid = group->gr_gid;
1146                }
1147        }
1148
1149        if (strict_paths && (!ok_paths || !*ok_paths))
1150                die("option --strict-paths requires a whitelist");
1151
1152        if (base_path && !is_directory(base_path))
1153                die("base-path '%s' does not exist or is not a directory",
1154                    base_path);
1155
1156        if (inetd_mode) {
1157                if (!freopen("/dev/null", "w", stderr))
1158                        die_errno("failed to redirect stderr to /dev/null");
1159        }
1160
1161        if (inetd_mode || serve_mode) {
1162                struct sockaddr_storage ss;
1163                struct sockaddr *peer = (struct sockaddr *)&ss;
1164                socklen_t slen = sizeof(ss);
1165
1166                if (getpeername(0, peer, &slen))
1167                        return execute(NULL);
1168                else
1169                        return execute(peer);
1170        }
1171
1172        if (detach) {
1173                daemonize();
1174                loginfo("Ready to rumble");
1175        }
1176        else
1177                sanitize_stdfds();
1178
1179        if (pid_file)
1180                store_pid(pid_file);
1181
1182        /* prepare argv for serving-processes */
1183        cld_argv = xmalloc(sizeof (char *) * (argc + 2));
1184        for (i = 0; i < argc; ++i)
1185                cld_argv[i] = argv[i];
1186        cld_argv[argc] = "--serve";
1187        cld_argv[argc+1] = NULL;
1188
1189        return serve(&listen_addr, listen_port, pass, gid);
1190}