Andrew's git / gitweb.git / daemon.c
?
daemon.con commit Merge branch 'tr/maint-merge-ours-clarification' (early part) (c50230f)
   1#include "cache.h"
   2#include "pkt-line.h"
   3#include "exec_cmd.h"
   4#include "run-command.h"
   5#include "strbuf.h"
   6
   7#include <syslog.h>
   8
   9#ifndef HOST_NAME_MAX
  10#define HOST_NAME_MAX 256
  11#endif
  12
  13#ifndef NI_MAXSERV
  14#define NI_MAXSERV 32
  15#endif
  16
  17static int log_syslog;
  18static int verbose;
  19static int reuseaddr;
  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] [--detach] [--pid-file=file]\n"
  28"           [--[enable|disable|allow-override|forbid-override]=service]\n"
  29"           [--inetd | [--listen=host_or_ipaddr] [--port=n]\n"
  30"                      [--user=user [--group=group]]\n"
  31"           [directory...]";
  32
  33/* List of acceptable pathname prefixes */
  34static char **ok_paths;
  35static int strict_paths;
  36
  37/* If this is set, git-daemon-export-ok is not required */
  38static int export_all_trees;
  39
  40/* Take all paths relative to this one if non-NULL */
  41static char *base_path;
  42static char *interpolated_path;
  43static int base_path_relaxed;
  44
  45/* Flag indicating client sent extra args. */
  46static int saw_extended_args;
  47
  48/* If defined, ~user notation is allowed and the string is inserted
  49 * after ~user/.  E.g. a request to git://host/~alice/frotz would
  50 * go to /home/alice/pub_git/frotz with --user-path=pub_git.
  51 */
  52static const char *user_path;
  53
  54/* Timeout, and initial timeout */
  55static unsigned int timeout;
  56static unsigned int init_timeout;
  57
  58static char *hostname;
  59static char *canon_hostname;
  60static char *ip_address;
  61static char *tcp_port;
  62
  63static void logreport(int priority, const char *err, va_list params)
  64{
  65        if (log_syslog) {
  66                char buf[1024];
  67                vsnprintf(buf, sizeof(buf), err, params);
  68                syslog(priority, "%s", buf);
  69        } else {
  70                /*
  71                 * Since stderr is set to linebuffered mode, the
  72                 * logging of different processes will not overlap
  73                 */
  74                fprintf(stderr, "[%"PRIuMAX"] ", (uintmax_t)getpid());
  75                vfprintf(stderr, err, params);
  76                fputc('\n', stderr);
  77        }
  78}
  79
  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
  88static void loginfo(const char *err, ...)
  89{
  90        va_list params;
  91        if (!verbose)
  92                return;
  93        va_start(params, err);
  94        logreport(LOG_INFO, err, params);
  95        va_end(params);
  96}
  97
  98static void NORETURN daemon_die(const char *err, va_list params)
  99{
 100        logreport(LOG_ERR, err, params);
 101        exit(1);
 102}
 103
 104static char *path_ok(char *directory)
 105{
 106        static char rpath[PATH_MAX];
 107        static char interp_path[PATH_MAX];
 108        char *path;
 109        char *dir;
 110
 111        dir = directory;
 112
 113        if (daemon_avoid_alias(dir)) {
 114                logerror("'%s': aliased", dir);
 115                return NULL;
 116        }
 117
 118        if (*dir == '~') {
 119                if (!user_path) {
 120                        logerror("'%s': User-path not allowed", dir);
 121                        return NULL;
 122                }
 123                if (*user_path) {
 124                        /* Got either "~alice" or "~alice/foo";
 125                         * rewrite them to "~alice/%s" or
 126                         * "~alice/%s/foo".
 127                         */
 128                        int namlen, restlen = strlen(dir);
 129                        char *slash = strchr(dir, '/');
 130                        if (!slash)
 131                                slash = dir + restlen;
 132                        namlen = slash - dir;
 133                        restlen -= namlen;
 134                        loginfo("userpath <%s>, request <%s>, namlen %d, restlen %d, slash <%s>", user_path, dir, namlen, restlen, slash);
 135                        snprintf(rpath, PATH_MAX, "%.*s/%s%.*s",
 136                                 namlen, dir, user_path, restlen, slash);
 137                        dir = rpath;
 138                }
 139        }
 140        else if (interpolated_path && saw_extended_args) {
 141                struct strbuf expanded_path = STRBUF_INIT;
 142                struct strbuf_expand_dict_entry dict[] = {
 143                        { "H", hostname },
 144                        { "CH", canon_hostname },
 145                        { "IP", ip_address },
 146                        { "P", tcp_port },
 147                        { "D", directory },
 148                        { "%", "%" },
 149                        { NULL }
 150                };
 151
 152                if (*dir != '/') {
 153                        /* Allow only absolute */
 154                        logerror("'%s': Non-absolute path denied (interpolated-path active)", dir);
 155                        return NULL;
 156                }
 157
 158                strbuf_expand(&expanded_path, interpolated_path,
 159                                strbuf_expand_dict_cb, &dict);
 160                strlcpy(interp_path, expanded_path.buf, PATH_MAX);
 161                strbuf_release(&expanded_path);
 162                loginfo("Interpolated dir '%s'", interp_path);
 163
 164                dir = interp_path;
 165        }
 166        else if (base_path) {
 167                if (*dir != '/') {
 168                        /* Allow only absolute */
 169                        logerror("'%s': Non-absolute path denied (base-path active)", dir);
 170                        return NULL;
 171                }
 172                snprintf(rpath, PATH_MAX, "%s%s", base_path, dir);
 173                dir = rpath;
 174        }
 175
 176        path = enter_repo(dir, strict_paths);
 177        if (!path && base_path && base_path_relaxed) {
 178                /*
 179                 * if we fail and base_path_relaxed is enabled, try without
 180                 * prefixing the base path
 181                 */
 182                dir = directory;
 183                path = enter_repo(dir, strict_paths);
 184        }
 185
 186        if (!path) {
 187                logerror("'%s' does not appear to be a git repository", dir);
 188                return NULL;
 189        }
 190
 191        if ( ok_paths && *ok_paths ) {
 192                char **pp;
 193                int pathlen = strlen(path);
 194
 195                /* The validation is done on the paths after enter_repo
 196                 * appends optional {.git,.git/.git} and friends, but
 197                 * it does not use getcwd().  So if your /pub is
 198                 * a symlink to /mnt/pub, you can whitelist /pub and
 199                 * do not have to say /mnt/pub.
 200                 * Do not say /pub/.
 201                 */
 202                for ( pp = ok_paths ; *pp ; pp++ ) {
 203                        int len = strlen(*pp);
 204                        if (len <= pathlen &&
 205                            !memcmp(*pp, path, len) &&
 206                            (path[len] == '\0' ||
 207                             (!strict_paths && path[len] == '/')))
 208                                return path;
 209                }
 210        }
 211        else {
 212                /* be backwards compatible */
 213                if (!strict_paths)
 214                        return path;
 215        }
 216
 217        logerror("'%s': not in whitelist", path);
 218        return NULL;            /* Fallthrough. Deny by default */
 219}
 220
 221typedef int (*daemon_service_fn)(void);
 222struct daemon_service {
 223        const char *name;
 224        const char *config_name;
 225        daemon_service_fn fn;
 226        int enabled;
 227        int overridable;
 228};
 229
 230static struct daemon_service *service_looking_at;
 231static int service_enabled;
 232
 233static int git_daemon_config(const char *var, const char *value, void *cb)
 234{
 235        if (!prefixcmp(var, "daemon.") &&
 236            !strcmp(var + 7, service_looking_at->config_name)) {
 237                service_enabled = git_config_bool(var, value);
 238                return 0;
 239        }
 240
 241        /* we are not interested in parsing any other configuration here */
 242        return 0;
 243}
 244
 245static int run_service(char *dir, struct daemon_service *service)
 246{
 247        const char *path;
 248        int enabled = service->enabled;
 249
 250        loginfo("Request %s for '%s'", service->name, dir);
 251
 252        if (!enabled && !service->overridable) {
 253                logerror("'%s': service not enabled.", service->name);
 254                errno = EACCES;
 255                return -1;
 256        }
 257
 258        if (!(path = path_ok(dir)))
 259                return -1;
 260
 261        /*
 262         * Security on the cheap.
 263         *
 264         * We want a readable HEAD, usable "objects" directory, and
 265         * a "git-daemon-export-ok" flag that says that the other side
 266         * is ok with us doing this.
 267         *
 268         * path_ok() uses enter_repo() and does whitelist checking.
 269         * We only need to make sure the repository is exported.
 270         */
 271
 272        if (!export_all_trees && access("git-daemon-export-ok", F_OK)) {
 273                logerror("'%s': repository not exported.", path);
 274                errno = EACCES;
 275                return -1;
 276        }
 277
 278        if (service->overridable) {
 279                service_looking_at = service;
 280                service_enabled = -1;
 281                git_config(git_daemon_config, NULL);
 282                if (0 <= service_enabled)
 283                        enabled = service_enabled;
 284        }
 285        if (!enabled) {
 286                logerror("'%s': service not enabled for '%s'",
 287                         service->name, path);
 288                errno = EACCES;
 289                return -1;
 290        }
 291
 292        /*
 293         * We'll ignore SIGTERM from now on, we have a
 294         * good client.
 295         */
 296        signal(SIGTERM, SIG_IGN);
 297
 298        return service->fn();
 299}
 300
 301static void copy_to_log(int fd)
 302{
 303        struct strbuf line = STRBUF_INIT;
 304        FILE *fp;
 305
 306        fp = fdopen(fd, "r");
 307        if (fp == NULL) {
 308                logerror("fdopen of error channel failed");
 309                close(fd);
 310                return;
 311        }
 312
 313        while (strbuf_getline(&line, fp, '\n') != EOF) {
 314                logerror("%s", line.buf);
 315                strbuf_setlen(&line, 0);
 316        }
 317
 318        strbuf_release(&line);
 319        fclose(fp);
 320}
 321
 322static int run_service_command(const char **argv)
 323{
 324        struct child_process cld;
 325
 326        memset(&cld, 0, sizeof(cld));
 327        cld.argv = argv;
 328        cld.git_cmd = 1;
 329        cld.err = -1;
 330        if (start_command(&cld))
 331                return -1;
 332
 333        close(0);
 334        close(1);
 335
 336        copy_to_log(cld.err);
 337
 338        return finish_command(&cld);
 339}
 340
 341static int upload_pack(void)
 342{
 343        /* Timeout as string */
 344        char timeout_buf[64];
 345        const char *argv[] = { "upload-pack", "--strict", timeout_buf, ".", NULL };
 346
 347        snprintf(timeout_buf, sizeof timeout_buf, "--timeout=%u", timeout);
 348        return run_service_command(argv);
 349}
 350
 351static int upload_archive(void)
 352{
 353        static const char *argv[] = { "upload-archive", ".", NULL };
 354        return run_service_command(argv);
 355}
 356
 357static int receive_pack(void)
 358{
 359        static const char *argv[] = { "receive-pack", ".", NULL };
 360        return run_service_command(argv);
 361}
 362
 363static struct daemon_service daemon_service[] = {
 364        { "upload-archive", "uploadarch", upload_archive, 0, 1 },
 365        { "upload-pack", "uploadpack", upload_pack, 1, 1 },
 366        { "receive-pack", "receivepack", receive_pack, 0, 1 },
 367};
 368
 369static void enable_service(const char *name, int ena)
 370{
 371        int i;
 372        for (i = 0; i < ARRAY_SIZE(daemon_service); i++) {
 373                if (!strcmp(daemon_service[i].name, name)) {
 374                        daemon_service[i].enabled = ena;
 375                        return;
 376                }
 377        }
 378        die("No such service %s", name);
 379}
 380
 381static void make_service_overridable(const char *name, int ena)
 382{
 383        int i;
 384        for (i = 0; i < ARRAY_SIZE(daemon_service); i++) {
 385                if (!strcmp(daemon_service[i].name, name)) {
 386                        daemon_service[i].overridable = ena;
 387                        return;
 388                }
 389        }
 390        die("No such service %s", name);
 391}
 392
 393static char *xstrdup_tolower(const char *str)
 394{
 395        char *p, *dup = xstrdup(str);
 396        for (p = dup; *p; p++)
 397                *p = tolower(*p);
 398        return dup;
 399}
 400
 401/*
 402 * Read the host as supplied by the client connection.
 403 */
 404static void parse_host_arg(char *extra_args, int buflen)
 405{
 406        char *val;
 407        int vallen;
 408        char *end = extra_args + buflen;
 409
 410        if (extra_args < end && *extra_args) {
 411                saw_extended_args = 1;
 412                if (strncasecmp("host=", extra_args, 5) == 0) {
 413                        val = extra_args + 5;
 414                        vallen = strlen(val) + 1;
 415                        if (*val) {
 416                                /* Split <host>:<port> at colon. */
 417                                char *host = val;
 418                                char *port = strrchr(host, ':');
 419                                if (port) {
 420                                        *port = 0;
 421                                        port++;
 422                                        free(tcp_port);
 423                                        tcp_port = xstrdup(port);
 424                                }
 425                                free(hostname);
 426                                hostname = xstrdup_tolower(host);
 427                        }
 428
 429                        /* On to the next one */
 430                        extra_args = val + vallen;
 431                }
 432                if (extra_args < end && *extra_args)
 433                        die("Invalid request");
 434        }
 435
 436        /*
 437         * Locate canonical hostname and its IP address.
 438         */
 439        if (hostname) {
 440#ifndef NO_IPV6
 441                struct addrinfo hints;
 442                struct addrinfo *ai;
 443                int gai;
 444                static char addrbuf[HOST_NAME_MAX + 1];
 445
 446                memset(&hints, 0, sizeof(hints));
 447                hints.ai_flags = AI_CANONNAME;
 448
 449                gai = getaddrinfo(hostname, NULL, &hints, &ai);
 450                if (!gai) {
 451                        struct sockaddr_in *sin_addr = (void *)ai->ai_addr;
 452
 453                        inet_ntop(AF_INET, &sin_addr->sin_addr,
 454                                  addrbuf, sizeof(addrbuf));
 455                        free(ip_address);
 456                        ip_address = xstrdup(addrbuf);
 457
 458                        free(canon_hostname);
 459                        canon_hostname = xstrdup(ai->ai_canonname ?
 460                                                 ai->ai_canonname : ip_address);
 461
 462                        freeaddrinfo(ai);
 463                }
 464#else
 465                struct hostent *hent;
 466                struct sockaddr_in sa;
 467                char **ap;
 468                static char addrbuf[HOST_NAME_MAX + 1];
 469
 470                hent = gethostbyname(hostname);
 471
 472                ap = hent->h_addr_list;
 473                memset(&sa, 0, sizeof sa);
 474                sa.sin_family = hent->h_addrtype;
 475                sa.sin_port = htons(0);
 476                memcpy(&sa.sin_addr, *ap, hent->h_length);
 477
 478                inet_ntop(hent->h_addrtype, &sa.sin_addr,
 479                          addrbuf, sizeof(addrbuf));
 480
 481                free(canon_hostname);
 482                canon_hostname = xstrdup(hent->h_name);
 483                free(ip_address);
 484                ip_address = xstrdup(addrbuf);
 485#endif
 486        }
 487}
 488
 489
 490static int execute(struct sockaddr *addr)
 491{
 492        static char line[1000];
 493        int pktlen, len, i;
 494
 495        if (addr) {
 496                char addrbuf[256] = "";
 497                int port = -1;
 498
 499                if (addr->sa_family == AF_INET) {
 500                        struct sockaddr_in *sin_addr = (void *) addr;
 501                        inet_ntop(addr->sa_family, &sin_addr->sin_addr, addrbuf, sizeof(addrbuf));
 502                        port = ntohs(sin_addr->sin_port);
 503#ifndef NO_IPV6
 504                } else if (addr && addr->sa_family == AF_INET6) {
 505                        struct sockaddr_in6 *sin6_addr = (void *) addr;
 506
 507                        char *buf = addrbuf;
 508                        *buf++ = '['; *buf = '\0'; /* stpcpy() is cool */
 509                        inet_ntop(AF_INET6, &sin6_addr->sin6_addr, buf, sizeof(addrbuf) - 1);
 510                        strcat(buf, "]");
 511
 512                        port = ntohs(sin6_addr->sin6_port);
 513#endif
 514                }
 515                loginfo("Connection from %s:%d", addrbuf, port);
 516                setenv("REMOTE_ADDR", addrbuf, 1);
 517        }
 518        else {
 519                unsetenv("REMOTE_ADDR");
 520        }
 521
 522        alarm(init_timeout ? init_timeout : timeout);
 523        pktlen = packet_read_line(0, line, sizeof(line));
 524        alarm(0);
 525
 526        len = strlen(line);
 527        if (pktlen != len)
 528                loginfo("Extended attributes (%d bytes) exist <%.*s>",
 529                        (int) pktlen - len,
 530                        (int) pktlen - len, line + len + 1);
 531        if (len && line[len-1] == '\n') {
 532                line[--len] = 0;
 533                pktlen--;
 534        }
 535
 536        free(hostname);
 537        free(canon_hostname);
 538        free(ip_address);
 539        free(tcp_port);
 540        hostname = canon_hostname = ip_address = tcp_port = NULL;
 541
 542        if (len != pktlen)
 543                parse_host_arg(line + len + 1, pktlen - len - 1);
 544
 545        for (i = 0; i < ARRAY_SIZE(daemon_service); i++) {
 546                struct daemon_service *s = &(daemon_service[i]);
 547                int namelen = strlen(s->name);
 548                if (!prefixcmp(line, "git-") &&
 549                    !strncmp(s->name, line + 4, namelen) &&
 550                    line[namelen + 4] == ' ') {
 551                        /*
 552                         * Note: The directory here is probably context sensitive,
 553                         * and might depend on the actual service being performed.
 554                         */
 555                        return run_service(line + namelen + 5, s);
 556                }
 557        }
 558
 559        logerror("Protocol error: '%s'", line);
 560        return -1;
 561}
 562
 563static int max_connections = 32;
 564
 565static unsigned int live_children;
 566
 567static struct child {
 568        struct child *next;
 569        pid_t pid;
 570        struct sockaddr_storage address;
 571} *firstborn;
 572
 573static void add_child(pid_t pid, struct sockaddr *addr, int addrlen)
 574{
 575        struct child *newborn, **cradle;
 576
 577        /*
 578         * This must be xcalloc() -- we'll compare the whole sockaddr_storage
 579         * but individual address may be shorter.
 580         */
 581        newborn = xcalloc(1, sizeof(*newborn));
 582        live_children++;
 583        newborn->pid = pid;
 584        memcpy(&newborn->address, addr, addrlen);
 585        for (cradle = &firstborn; *cradle; cradle = &(*cradle)->next)
 586                if (!memcmp(&(*cradle)->address, &newborn->address,
 587                            sizeof(newborn->address)))
 588                        break;
 589        newborn->next = *cradle;
 590        *cradle = newborn;
 591}
 592
 593static void remove_child(pid_t pid)
 594{
 595        struct child **cradle, *blanket;
 596
 597        for (cradle = &firstborn; (blanket = *cradle); cradle = &blanket->next)
 598                if (blanket->pid == pid) {
 599                        *cradle = blanket->next;
 600                        live_children--;
 601                        free(blanket);
 602                        break;
 603                }
 604}
 605
 606/*
 607 * This gets called if the number of connections grows
 608 * past "max_connections".
 609 *
 610 * We kill the newest connection from a duplicate IP.
 611 */
 612static void kill_some_child(void)
 613{
 614        const struct child *blanket, *next;
 615
 616        if (!(blanket = firstborn))
 617                return;
 618
 619        for (; (next = blanket->next); blanket = next)
 620                if (!memcmp(&blanket->address, &next->address,
 621                            sizeof(next->address))) {
 622                        kill(blanket->pid, SIGTERM);
 623                        break;
 624                }
 625}
 626
 627static void check_dead_children(void)
 628{
 629        int status;
 630        pid_t pid;
 631
 632        while ((pid = waitpid(-1, &status, WNOHANG)) > 0) {
 633                const char *dead = "";
 634                remove_child(pid);
 635                if (!WIFEXITED(status) || (WEXITSTATUS(status) > 0))
 636                        dead = " (with error)";
 637                loginfo("[%"PRIuMAX"] Disconnected%s", (uintmax_t)pid, dead);
 638        }
 639}
 640
 641static void handle(int incoming, struct sockaddr *addr, int addrlen)
 642{
 643        pid_t pid;
 644
 645        if (max_connections && live_children >= max_connections) {
 646                kill_some_child();
 647                sleep(1);  /* give it some time to die */
 648                check_dead_children();
 649                if (live_children >= max_connections) {
 650                        close(incoming);
 651                        logerror("Too many children, dropping connection");
 652                        return;
 653                }
 654        }
 655
 656        if ((pid = fork())) {
 657                close(incoming);
 658                if (pid < 0) {
 659                        logerror("Couldn't fork %s", strerror(errno));
 660                        return;
 661                }
 662
 663                add_child(pid, addr, addrlen);
 664                return;
 665        }
 666
 667        dup2(incoming, 0);
 668        dup2(incoming, 1);
 669        close(incoming);
 670
 671        exit(execute(addr));
 672}
 673
 674static void child_handler(int signo)
 675{
 676        /*
 677         * Otherwise empty handler because systemcalls will get interrupted
 678         * upon signal receipt
 679         * SysV needs the handler to be rearmed
 680         */
 681        signal(SIGCHLD, child_handler);
 682}
 683
 684static int set_reuse_addr(int sockfd)
 685{
 686        int on = 1;
 687
 688        if (!reuseaddr)
 689                return 0;
 690        return setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR,
 691                          &on, sizeof(on));
 692}
 693
 694#ifndef NO_IPV6
 695
 696static int socksetup(char *listen_addr, int listen_port, int **socklist_p)
 697{
 698        int socknum = 0, *socklist = NULL;
 699        int maxfd = -1;
 700        char pbuf[NI_MAXSERV];
 701        struct addrinfo hints, *ai0, *ai;
 702        int gai;
 703        long flags;
 704
 705        sprintf(pbuf, "%d", listen_port);
 706        memset(&hints, 0, sizeof(hints));
 707        hints.ai_family = AF_UNSPEC;
 708        hints.ai_socktype = SOCK_STREAM;
 709        hints.ai_protocol = IPPROTO_TCP;
 710        hints.ai_flags = AI_PASSIVE;
 711
 712        gai = getaddrinfo(listen_addr, pbuf, &hints, &ai0);
 713        if (gai)
 714                die("getaddrinfo() failed: %s", gai_strerror(gai));
 715
 716        for (ai = ai0; ai; ai = ai->ai_next) {
 717                int sockfd;
 718
 719                sockfd = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
 720                if (sockfd < 0)
 721                        continue;
 722                if (sockfd >= FD_SETSIZE) {
 723                        logerror("Socket descriptor too large");
 724                        close(sockfd);
 725                        continue;
 726                }
 727
 728#ifdef IPV6_V6ONLY
 729                if (ai->ai_family == AF_INET6) {
 730                        int on = 1;
 731                        setsockopt(sockfd, IPPROTO_IPV6, IPV6_V6ONLY,
 732                                   &on, sizeof(on));
 733                        /* Note: error is not fatal */
 734                }
 735#endif
 736
 737                if (set_reuse_addr(sockfd)) {
 738                        close(sockfd);
 739                        continue;
 740                }
 741
 742                if (bind(sockfd, ai->ai_addr, ai->ai_addrlen) < 0) {
 743                        close(sockfd);
 744                        continue;       /* not fatal */
 745                }
 746                if (listen(sockfd, 5) < 0) {
 747                        close(sockfd);
 748                        continue;       /* not fatal */
 749                }
 750
 751                flags = fcntl(sockfd, F_GETFD, 0);
 752                if (flags >= 0)
 753                        fcntl(sockfd, F_SETFD, flags | FD_CLOEXEC);
 754
 755                socklist = xrealloc(socklist, sizeof(int) * (socknum + 1));
 756                socklist[socknum++] = sockfd;
 757
 758                if (maxfd < sockfd)
 759                        maxfd = sockfd;
 760        }
 761
 762        freeaddrinfo(ai0);
 763
 764        *socklist_p = socklist;
 765        return socknum;
 766}
 767
 768#else /* NO_IPV6 */
 769
 770static int socksetup(char *listen_addr, int listen_port, int **socklist_p)
 771{
 772        struct sockaddr_in sin;
 773        int sockfd;
 774        long flags;
 775
 776        memset(&sin, 0, sizeof sin);
 777        sin.sin_family = AF_INET;
 778        sin.sin_port = htons(listen_port);
 779
 780        if (listen_addr) {
 781                /* Well, host better be an IP address here. */
 782                if (inet_pton(AF_INET, listen_addr, &sin.sin_addr.s_addr) <= 0)
 783                        return 0;
 784        } else {
 785                sin.sin_addr.s_addr = htonl(INADDR_ANY);
 786        }
 787
 788        sockfd = socket(AF_INET, SOCK_STREAM, 0);
 789        if (sockfd < 0)
 790                return 0;
 791
 792        if (set_reuse_addr(sockfd)) {
 793                close(sockfd);
 794                return 0;
 795        }
 796
 797        if ( bind(sockfd, (struct sockaddr *)&sin, sizeof sin) < 0 ) {
 798                close(sockfd);
 799                return 0;
 800        }
 801
 802        if (listen(sockfd, 5) < 0) {
 803                close(sockfd);
 804                return 0;
 805        }
 806
 807        flags = fcntl(sockfd, F_GETFD, 0);
 808        if (flags >= 0)
 809                fcntl(sockfd, F_SETFD, flags | FD_CLOEXEC);
 810
 811        *socklist_p = xmalloc(sizeof(int));
 812        **socklist_p = sockfd;
 813        return 1;
 814}
 815
 816#endif
 817
 818static int service_loop(int socknum, int *socklist)
 819{
 820        struct pollfd *pfd;
 821        int i;
 822
 823        pfd = xcalloc(socknum, sizeof(struct pollfd));
 824
 825        for (i = 0; i < socknum; i++) {
 826                pfd[i].fd = socklist[i];
 827                pfd[i].events = POLLIN;
 828        }
 829
 830        signal(SIGCHLD, child_handler);
 831
 832        for (;;) {
 833                int i;
 834
 835                check_dead_children();
 836
 837                if (poll(pfd, socknum, -1) < 0) {
 838                        if (errno != EINTR) {
 839                                logerror("Poll failed, resuming: %s",
 840                                      strerror(errno));
 841                                sleep(1);
 842                        }
 843                        continue;
 844                }
 845
 846                for (i = 0; i < socknum; i++) {
 847                        if (pfd[i].revents & POLLIN) {
 848                                struct sockaddr_storage ss;
 849                                unsigned int sslen = sizeof(ss);
 850                                int incoming = accept(pfd[i].fd, (struct sockaddr *)&ss, &sslen);
 851                                if (incoming < 0) {
 852                                        switch (errno) {
 853                                        case EAGAIN:
 854                                        case EINTR:
 855                                        case ECONNABORTED:
 856                                                continue;
 857                                        default:
 858                                                die_errno("accept returned");
 859                                        }
 860                                }
 861                                handle(incoming, (struct sockaddr *)&ss, sslen);
 862                        }
 863                }
 864        }
 865}
 866
 867/* if any standard file descriptor is missing open it to /dev/null */
 868static void sanitize_stdfds(void)
 869{
 870        int fd = open("/dev/null", O_RDWR, 0);
 871        while (fd != -1 && fd < 2)
 872                fd = dup(fd);
 873        if (fd == -1)
 874                die_errno("open /dev/null or dup failed");
 875        if (fd > 2)
 876                close(fd);
 877}
 878
 879static void daemonize(void)
 880{
 881        switch (fork()) {
 882                case 0:
 883                        break;
 884                case -1:
 885                        die_errno("fork failed");
 886                default:
 887                        exit(0);
 888        }
 889        if (setsid() == -1)
 890                die_errno("setsid failed");
 891        close(0);
 892        close(1);
 893        close(2);
 894        sanitize_stdfds();
 895}
 896
 897static void store_pid(const char *path)
 898{
 899        FILE *f = fopen(path, "w");
 900        if (!f)
 901                die_errno("cannot open pid file '%s'", path);
 902        if (fprintf(f, "%"PRIuMAX"\n", (uintmax_t) getpid()) < 0 || fclose(f) != 0)
 903                die_errno("failed to write pid file '%s'", path);
 904}
 905
 906static int serve(char *listen_addr, int listen_port, struct passwd *pass, gid_t gid)
 907{
 908        int socknum, *socklist;
 909
 910        socknum = socksetup(listen_addr, listen_port, &socklist);
 911        if (socknum == 0)
 912                die("unable to allocate any listen sockets on host %s port %u",
 913                    listen_addr, listen_port);
 914
 915        if (pass && gid &&
 916            (initgroups(pass->pw_name, gid) || setgid (gid) ||
 917             setuid(pass->pw_uid)))
 918                die("cannot drop privileges");
 919
 920        return service_loop(socknum, socklist);
 921}
 922
 923int main(int argc, char **argv)
 924{
 925        int listen_port = 0;
 926        char *listen_addr = NULL;
 927        int inetd_mode = 0;
 928        const char *pid_file = NULL, *user_name = NULL, *group_name = NULL;
 929        int detach = 0;
 930        struct passwd *pass = NULL;
 931        struct group *group;
 932        gid_t gid = 0;
 933        int i;
 934
 935        git_extract_argv0_path(argv[0]);
 936
 937        for (i = 1; i < argc; i++) {
 938                char *arg = argv[i];
 939
 940                if (!prefixcmp(arg, "--listen=")) {
 941                        listen_addr = xstrdup_tolower(arg + 9);
 942                        continue;
 943                }
 944                if (!prefixcmp(arg, "--port=")) {
 945                        char *end;
 946                        unsigned long n;
 947                        n = strtoul(arg+7, &end, 0);
 948                        if (arg[7] && !*end) {
 949                                listen_port = n;
 950                                continue;
 951                        }
 952                }
 953                if (!strcmp(arg, "--inetd")) {
 954                        inetd_mode = 1;
 955                        log_syslog = 1;
 956                        continue;
 957                }
 958                if (!strcmp(arg, "--verbose")) {
 959                        verbose = 1;
 960                        continue;
 961                }
 962                if (!strcmp(arg, "--syslog")) {
 963                        log_syslog = 1;
 964                        continue;
 965                }
 966                if (!strcmp(arg, "--export-all")) {
 967                        export_all_trees = 1;
 968                        continue;
 969                }
 970                if (!prefixcmp(arg, "--timeout=")) {
 971                        timeout = atoi(arg+10);
 972                        continue;
 973                }
 974                if (!prefixcmp(arg, "--init-timeout=")) {
 975                        init_timeout = atoi(arg+15);
 976                        continue;
 977                }
 978                if (!prefixcmp(arg, "--max-connections=")) {
 979                        max_connections = atoi(arg+18);
 980                        if (max_connections < 0)
 981                                max_connections = 0;            /* unlimited */
 982                        continue;
 983                }
 984                if (!strcmp(arg, "--strict-paths")) {
 985                        strict_paths = 1;
 986                        continue;
 987                }
 988                if (!prefixcmp(arg, "--base-path=")) {
 989                        base_path = arg+12;
 990                        continue;
 991                }
 992                if (!strcmp(arg, "--base-path-relaxed")) {
 993                        base_path_relaxed = 1;
 994                        continue;
 995                }
 996                if (!prefixcmp(arg, "--interpolated-path=")) {
 997                        interpolated_path = arg+20;
 998                        continue;
 999                }
1000                if (!strcmp(arg, "--reuseaddr")) {
1001                        reuseaddr = 1;
1002                        continue;
1003                }
1004                if (!strcmp(arg, "--user-path")) {
1005                        user_path = "";
1006                        continue;
1007                }
1008                if (!prefixcmp(arg, "--user-path=")) {
1009                        user_path = arg + 12;
1010                        continue;
1011                }
1012                if (!prefixcmp(arg, "--pid-file=")) {
1013                        pid_file = arg + 11;
1014                        continue;
1015                }
1016                if (!strcmp(arg, "--detach")) {
1017                        detach = 1;
1018                        log_syslog = 1;
1019                        continue;
1020                }
1021                if (!prefixcmp(arg, "--user=")) {
1022                        user_name = arg + 7;
1023                        continue;
1024                }
1025                if (!prefixcmp(arg, "--group=")) {
1026                        group_name = arg + 8;
1027                        continue;
1028                }
1029                if (!prefixcmp(arg, "--enable=")) {
1030                        enable_service(arg + 9, 1);
1031                        continue;
1032                }
1033                if (!prefixcmp(arg, "--disable=")) {
1034                        enable_service(arg + 10, 0);
1035                        continue;
1036                }
1037                if (!prefixcmp(arg, "--allow-override=")) {
1038                        make_service_overridable(arg + 17, 1);
1039                        continue;
1040                }
1041                if (!prefixcmp(arg, "--forbid-override=")) {
1042                        make_service_overridable(arg + 18, 0);
1043                        continue;
1044                }
1045                if (!strcmp(arg, "--")) {
1046                        ok_paths = &argv[i+1];
1047                        break;
1048                } else if (arg[0] != '-') {
1049                        ok_paths = &argv[i];
1050                        break;
1051                }
1052
1053                usage(daemon_usage);
1054        }
1055
1056        if (log_syslog) {
1057                openlog("git-daemon", LOG_PID, LOG_DAEMON);
1058                set_die_routine(daemon_die);
1059        } else
1060                /* avoid splitting a message in the middle */
1061                setvbuf(stderr, NULL, _IOLBF, 0);
1062
1063        if (inetd_mode && (group_name || user_name))
1064                die("--user and --group are incompatible with --inetd");
1065
1066        if (inetd_mode && (listen_port || listen_addr))
1067                die("--listen= and --port= are incompatible with --inetd");
1068        else if (listen_port == 0)
1069                listen_port = DEFAULT_GIT_PORT;
1070
1071        if (group_name && !user_name)
1072                die("--group supplied without --user");
1073
1074        if (user_name) {
1075                pass = getpwnam(user_name);
1076                if (!pass)
1077                        die("user not found - %s", user_name);
1078
1079                if (!group_name)
1080                        gid = pass->pw_gid;
1081                else {
1082                        group = getgrnam(group_name);
1083                        if (!group)
1084                                die("group not found - %s", group_name);
1085
1086                        gid = group->gr_gid;
1087                }
1088        }
1089
1090        if (strict_paths && (!ok_paths || !*ok_paths))
1091                die("option --strict-paths requires a whitelist");
1092
1093        if (base_path && !is_directory(base_path))
1094                die("base-path '%s' does not exist or is not a directory",
1095                    base_path);
1096
1097        if (inetd_mode) {
1098                struct sockaddr_storage ss;
1099                struct sockaddr *peer = (struct sockaddr *)&ss;
1100                socklen_t slen = sizeof(ss);
1101
1102                if (!freopen("/dev/null", "w", stderr))
1103                        die_errno("failed to redirect stderr to /dev/null");
1104
1105                if (getpeername(0, peer, &slen))
1106                        peer = NULL;
1107
1108                return execute(peer);
1109        }
1110
1111        if (detach) {
1112                daemonize();
1113                loginfo("Ready to rumble");
1114        }
1115        else
1116                sanitize_stdfds();
1117
1118        if (pid_file)
1119                store_pid(pid_file);
1120
1121        return serve(listen_addr, listen_port, pass, gid);
1122}