Andrew's git / gitweb.git / daemon.c
?
daemon.con commit git-compat-util.h: Provide missing netdb.h definitions (3b130ad)
   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"           [--inetd | [--listen=<host_or_ipaddr>] [--port=<n>]\n"
  30"                      [--detach] [--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 buffered mode, the
  72                 * logging of different processes will not overlap
  73                 * unless they overflow the (rather big) buffers.
  74                 */
  75                fprintf(stderr, "[%"PRIuMAX"] ", (uintmax_t)getpid());
  76                vfprintf(stderr, err, params);
  77                fputc('\n', stderr);
  78                fflush(stderr);
  79        }
  80}
  81
  82__attribute__((format (printf, 1, 2)))
  83static void logerror(const char *err, ...)
  84{
  85        va_list params;
  86        va_start(params, err);
  87        logreport(LOG_ERR, err, params);
  88        va_end(params);
  89}
  90
  91__attribute__((format (printf, 1, 2)))
  92static void loginfo(const char *err, ...)
  93{
  94        va_list params;
  95        if (!verbose)
  96                return;
  97        va_start(params, err);
  98        logreport(LOG_INFO, err, params);
  99        va_end(params);
 100}
 101
 102static void NORETURN daemon_die(const char *err, va_list params)
 103{
 104        logreport(LOG_ERR, err, params);
 105        exit(1);
 106}
 107
 108static const char *path_ok(char *directory)
 109{
 110        static char rpath[PATH_MAX];
 111        static char interp_path[PATH_MAX];
 112        const char *path;
 113        char *dir;
 114
 115        dir = directory;
 116
 117        if (daemon_avoid_alias(dir)) {
 118                logerror("'%s': aliased", dir);
 119                return NULL;
 120        }
 121
 122        if (*dir == '~') {
 123                if (!user_path) {
 124                        logerror("'%s': User-path not allowed", dir);
 125                        return NULL;
 126                }
 127                if (*user_path) {
 128                        /* Got either "~alice" or "~alice/foo";
 129                         * rewrite them to "~alice/%s" or
 130                         * "~alice/%s/foo".
 131                         */
 132                        int namlen, restlen = strlen(dir);
 133                        char *slash = strchr(dir, '/');
 134                        if (!slash)
 135                                slash = dir + restlen;
 136                        namlen = slash - dir;
 137                        restlen -= namlen;
 138                        loginfo("userpath <%s>, request <%s>, namlen %d, restlen %d, slash <%s>", user_path, dir, namlen, restlen, slash);
 139                        snprintf(rpath, PATH_MAX, "%.*s/%s%.*s",
 140                                 namlen, dir, user_path, restlen, slash);
 141                        dir = rpath;
 142                }
 143        }
 144        else if (interpolated_path && saw_extended_args) {
 145                struct strbuf expanded_path = STRBUF_INIT;
 146                struct strbuf_expand_dict_entry dict[6];
 147
 148                dict[0].placeholder = "H"; dict[0].value = hostname;
 149                dict[1].placeholder = "CH"; dict[1].value = canon_hostname;
 150                dict[2].placeholder = "IP"; dict[2].value = ip_address;
 151                dict[3].placeholder = "P"; dict[3].value = tcp_port;
 152                dict[4].placeholder = "D"; dict[4].value = directory;
 153                dict[5].placeholder = NULL; dict[5].value = NULL;
 154                if (*dir != '/') {
 155                        /* Allow only absolute */
 156                        logerror("'%s': Non-absolute path denied (interpolated-path active)", dir);
 157                        return NULL;
 158                }
 159
 160                strbuf_expand(&expanded_path, interpolated_path,
 161                                strbuf_expand_dict_cb, &dict);
 162                strlcpy(interp_path, expanded_path.buf, PATH_MAX);
 163                strbuf_release(&expanded_path);
 164                loginfo("Interpolated dir '%s'", interp_path);
 165
 166                dir = interp_path;
 167        }
 168        else if (base_path) {
 169                if (*dir != '/') {
 170                        /* Allow only absolute */
 171                        logerror("'%s': Non-absolute path denied (base-path active)", dir);
 172                        return NULL;
 173                }
 174                snprintf(rpath, PATH_MAX, "%s%s", base_path, dir);
 175                dir = rpath;
 176        }
 177
 178        path = enter_repo(dir, strict_paths);
 179        if (!path && base_path && base_path_relaxed) {
 180                /*
 181                 * if we fail and base_path_relaxed is enabled, try without
 182                 * prefixing the base path
 183                 */
 184                dir = directory;
 185                path = enter_repo(dir, strict_paths);
 186        }
 187
 188        if (!path) {
 189                logerror("'%s' does not appear to be a git repository", dir);
 190                return NULL;
 191        }
 192
 193        if ( ok_paths && *ok_paths ) {
 194                char **pp;
 195                int pathlen = strlen(path);
 196
 197                /* The validation is done on the paths after enter_repo
 198                 * appends optional {.git,.git/.git} and friends, but
 199                 * it does not use getcwd().  So if your /pub is
 200                 * a symlink to /mnt/pub, you can whitelist /pub and
 201                 * do not have to say /mnt/pub.
 202                 * Do not say /pub/.
 203                 */
 204                for ( pp = ok_paths ; *pp ; pp++ ) {
 205                        int len = strlen(*pp);
 206                        if (len <= pathlen &&
 207                            !memcmp(*pp, path, len) &&
 208                            (path[len] == '\0' ||
 209                             (!strict_paths && path[len] == '/')))
 210                                return path;
 211                }
 212        }
 213        else {
 214                /* be backwards compatible */
 215                if (!strict_paths)
 216                        return path;
 217        }
 218
 219        logerror("'%s': not in whitelist", path);
 220        return NULL;            /* Fallthrough. Deny by default */
 221}
 222
 223typedef int (*daemon_service_fn)(void);
 224struct daemon_service {
 225        const char *name;
 226        const char *config_name;
 227        daemon_service_fn fn;
 228        int enabled;
 229        int overridable;
 230};
 231
 232static struct daemon_service *service_looking_at;
 233static int service_enabled;
 234
 235static int git_daemon_config(const char *var, const char *value, void *cb)
 236{
 237        if (!prefixcmp(var, "daemon.") &&
 238            !strcmp(var + 7, service_looking_at->config_name)) {
 239                service_enabled = git_config_bool(var, value);
 240                return 0;
 241        }
 242
 243        /* we are not interested in parsing any other configuration here */
 244        return 0;
 245}
 246
 247static int daemon_error(const char *dir, const char *msg)
 248{
 249        if (!informative_errors)
 250                msg = "access denied or repository not exported";
 251        packet_write(1, "ERR %s: %s", msg, dir);
 252        return -1;
 253}
 254
 255static int run_service(char *dir, struct daemon_service *service)
 256{
 257        const char *path;
 258        int enabled = service->enabled;
 259
 260        loginfo("Request %s for '%s'", service->name, dir);
 261
 262        if (!enabled && !service->overridable) {
 263                logerror("'%s': service not enabled.", service->name);
 264                errno = EACCES;
 265                return daemon_error(dir, "service not enabled");
 266        }
 267
 268        if (!(path = path_ok(dir)))
 269                return daemon_error(dir, "no such repository");
 270
 271        /*
 272         * Security on the cheap.
 273         *
 274         * We want a readable HEAD, usable "objects" directory, and
 275         * a "git-daemon-export-ok" flag that says that the other side
 276         * is ok with us doing this.
 277         *
 278         * path_ok() uses enter_repo() and does whitelist checking.
 279         * We only need to make sure the repository is exported.
 280         */
 281
 282        if (!export_all_trees && access("git-daemon-export-ok", F_OK)) {
 283                logerror("'%s': repository not exported.", path);
 284                errno = EACCES;
 285                return daemon_error(dir, "repository not exported");
 286        }
 287
 288        if (service->overridable) {
 289                service_looking_at = service;
 290                service_enabled = -1;
 291                git_config(git_daemon_config, NULL);
 292                if (0 <= service_enabled)
 293                        enabled = service_enabled;
 294        }
 295        if (!enabled) {
 296                logerror("'%s': service not enabled for '%s'",
 297                         service->name, path);
 298                errno = EACCES;
 299                return daemon_error(dir, "service not enabled");
 300        }
 301
 302        /*
 303         * We'll ignore SIGTERM from now on, we have a
 304         * good client.
 305         */
 306        signal(SIGTERM, SIG_IGN);
 307
 308        return service->fn();
 309}
 310
 311static void copy_to_log(int fd)
 312{
 313        struct strbuf line = STRBUF_INIT;
 314        FILE *fp;
 315
 316        fp = fdopen(fd, "r");
 317        if (fp == NULL) {
 318                logerror("fdopen of error channel failed");
 319                close(fd);
 320                return;
 321        }
 322
 323        while (strbuf_getline(&line, fp, '\n') != EOF) {
 324                logerror("%s", line.buf);
 325                strbuf_setlen(&line, 0);
 326        }
 327
 328        strbuf_release(&line);
 329        fclose(fp);
 330}
 331
 332static int run_service_command(const char **argv)
 333{
 334        struct child_process cld;
 335
 336        memset(&cld, 0, sizeof(cld));
 337        cld.argv = argv;
 338        cld.git_cmd = 1;
 339        cld.err = -1;
 340        if (start_command(&cld))
 341                return -1;
 342
 343        close(0);
 344        close(1);
 345
 346        copy_to_log(cld.err);
 347
 348        return finish_command(&cld);
 349}
 350
 351static int upload_pack(void)
 352{
 353        /* Timeout as string */
 354        char timeout_buf[64];
 355        const char *argv[] = { "upload-pack", "--strict", NULL, ".", NULL };
 356
 357        argv[2] = timeout_buf;
 358
 359        snprintf(timeout_buf, sizeof timeout_buf, "--timeout=%u", timeout);
 360        return run_service_command(argv);
 361}
 362
 363static int upload_archive(void)
 364{
 365        static const char *argv[] = { "upload-archive", ".", NULL };
 366        return run_service_command(argv);
 367}
 368
 369static int receive_pack(void)
 370{
 371        static const char *argv[] = { "receive-pack", ".", NULL };
 372        return run_service_command(argv);
 373}
 374
 375static struct daemon_service daemon_service[] = {
 376        { "upload-archive", "uploadarch", upload_archive, 0, 1 },
 377        { "upload-pack", "uploadpack", upload_pack, 1, 1 },
 378        { "receive-pack", "receivepack", receive_pack, 0, 1 },
 379};
 380
 381static void enable_service(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].enabled = ena;
 387                        return;
 388                }
 389        }
 390        die("No such service %s", name);
 391}
 392
 393static void make_service_overridable(const char *name, int ena)
 394{
 395        int i;
 396        for (i = 0; i < ARRAY_SIZE(daemon_service); i++) {
 397                if (!strcmp(daemon_service[i].name, name)) {
 398                        daemon_service[i].overridable = ena;
 399                        return;
 400                }
 401        }
 402        die("No such service %s", name);
 403}
 404
 405static char *xstrdup_tolower(const char *str)
 406{
 407        char *p, *dup = xstrdup(str);
 408        for (p = dup; *p; p++)
 409                *p = tolower(*p);
 410        return dup;
 411}
 412
 413static void parse_host_and_port(char *hostport, char **host,
 414        char **port)
 415{
 416        if (*hostport == '[') {
 417                char *end;
 418
 419                end = strchr(hostport, ']');
 420                if (!end)
 421                        die("Invalid request ('[' without ']')");
 422                *end = '\0';
 423                *host = hostport + 1;
 424                if (!end[1])
 425                        *port = NULL;
 426                else if (end[1] == ':')
 427                        *port = end + 2;
 428                else
 429                        die("Garbage after end of host part");
 430        } else {
 431                *host = hostport;
 432                *port = strrchr(hostport, ':');
 433                if (*port) {
 434                        **port = '\0';
 435                        ++*port;
 436                }
 437        }
 438}
 439
 440/*
 441 * Read the host as supplied by the client connection.
 442 */
 443static void parse_host_arg(char *extra_args, int buflen)
 444{
 445        char *val;
 446        int vallen;
 447        char *end = extra_args + buflen;
 448
 449        if (extra_args < end && *extra_args) {
 450                saw_extended_args = 1;
 451                if (strncasecmp("host=", extra_args, 5) == 0) {
 452                        val = extra_args + 5;
 453                        vallen = strlen(val) + 1;
 454                        if (*val) {
 455                                /* Split <host>:<port> at colon. */
 456                                char *host;
 457                                char *port;
 458                                parse_host_and_port(val, &host, &port);
 459                                if (port) {
 460                                        free(tcp_port);
 461                                        tcp_port = xstrdup(port);
 462                                }
 463                                free(hostname);
 464                                hostname = xstrdup_tolower(host);
 465                        }
 466
 467                        /* On to the next one */
 468                        extra_args = val + vallen;
 469                }
 470                if (extra_args < end && *extra_args)
 471                        die("Invalid request");
 472        }
 473
 474        /*
 475         * Locate canonical hostname and its IP address.
 476         */
 477        if (hostname) {
 478#ifndef NO_IPV6
 479                struct addrinfo hints;
 480                struct addrinfo *ai;
 481                int gai;
 482                static char addrbuf[HOST_NAME_MAX + 1];
 483
 484                memset(&hints, 0, sizeof(hints));
 485                hints.ai_flags = AI_CANONNAME;
 486
 487                gai = getaddrinfo(hostname, NULL, &hints, &ai);
 488                if (!gai) {
 489                        struct sockaddr_in *sin_addr = (void *)ai->ai_addr;
 490
 491                        inet_ntop(AF_INET, &sin_addr->sin_addr,
 492                                  addrbuf, sizeof(addrbuf));
 493                        free(ip_address);
 494                        ip_address = xstrdup(addrbuf);
 495
 496                        free(canon_hostname);
 497                        canon_hostname = xstrdup(ai->ai_canonname ?
 498                                                 ai->ai_canonname : ip_address);
 499
 500                        freeaddrinfo(ai);
 501                }
 502#else
 503                struct hostent *hent;
 504                struct sockaddr_in sa;
 505                char **ap;
 506                static char addrbuf[HOST_NAME_MAX + 1];
 507
 508                hent = gethostbyname(hostname);
 509
 510                ap = hent->h_addr_list;
 511                memset(&sa, 0, sizeof sa);
 512                sa.sin_family = hent->h_addrtype;
 513                sa.sin_port = htons(0);
 514                memcpy(&sa.sin_addr, *ap, hent->h_length);
 515
 516                inet_ntop(hent->h_addrtype, &sa.sin_addr,
 517                          addrbuf, sizeof(addrbuf));
 518
 519                free(canon_hostname);
 520                canon_hostname = xstrdup(hent->h_name);
 521                free(ip_address);
 522                ip_address = xstrdup(addrbuf);
 523#endif
 524        }
 525}
 526
 527
 528static int execute(void)
 529{
 530        static char line[1000];
 531        int pktlen, len, i;
 532        char *addr = getenv("REMOTE_ADDR"), *port = getenv("REMOTE_PORT");
 533
 534        if (addr)
 535                loginfo("Connection from %s:%s", addr, port);
 536
 537        alarm(init_timeout ? init_timeout : timeout);
 538        pktlen = packet_read_line(0, line, sizeof(line));
 539        alarm(0);
 540
 541        len = strlen(line);
 542        if (pktlen != len)
 543                loginfo("Extended attributes (%d bytes) exist <%.*s>",
 544                        (int) pktlen - len,
 545                        (int) pktlen - len, line + len + 1);
 546        if (len && line[len-1] == '\n') {
 547                line[--len] = 0;
 548                pktlen--;
 549        }
 550
 551        free(hostname);
 552        free(canon_hostname);
 553        free(ip_address);
 554        free(tcp_port);
 555        hostname = canon_hostname = ip_address = tcp_port = NULL;
 556
 557        if (len != pktlen)
 558                parse_host_arg(line + len + 1, pktlen - len - 1);
 559
 560        for (i = 0; i < ARRAY_SIZE(daemon_service); i++) {
 561                struct daemon_service *s = &(daemon_service[i]);
 562                int namelen = strlen(s->name);
 563                if (!prefixcmp(line, "git-") &&
 564                    !strncmp(s->name, line + 4, namelen) &&
 565                    line[namelen + 4] == ' ') {
 566                        /*
 567                         * Note: The directory here is probably context sensitive,
 568                         * and might depend on the actual service being performed.
 569                         */
 570                        return run_service(line + namelen + 5, s);
 571                }
 572        }
 573
 574        logerror("Protocol error: '%s'", line);
 575        return -1;
 576}
 577
 578static int addrcmp(const struct sockaddr_storage *s1,
 579    const struct sockaddr_storage *s2)
 580{
 581        const struct sockaddr *sa1 = (const struct sockaddr*) s1;
 582        const struct sockaddr *sa2 = (const struct sockaddr*) s2;
 583
 584        if (sa1->sa_family != sa2->sa_family)
 585                return sa1->sa_family - sa2->sa_family;
 586        if (sa1->sa_family == AF_INET)
 587                return memcmp(&((struct sockaddr_in *)s1)->sin_addr,
 588                    &((struct sockaddr_in *)s2)->sin_addr,
 589                    sizeof(struct in_addr));
 590#ifndef NO_IPV6
 591        if (sa1->sa_family == AF_INET6)
 592                return memcmp(&((struct sockaddr_in6 *)s1)->sin6_addr,
 593                    &((struct sockaddr_in6 *)s2)->sin6_addr,
 594                    sizeof(struct in6_addr));
 595#endif
 596        return 0;
 597}
 598
 599static int max_connections = 32;
 600
 601static unsigned int live_children;
 602
 603static struct child {
 604        struct child *next;
 605        struct child_process cld;
 606        struct sockaddr_storage address;
 607} *firstborn;
 608
 609static void add_child(struct child_process *cld, struct sockaddr *addr, socklen_t addrlen)
 610{
 611        struct child *newborn, **cradle;
 612
 613        newborn = xcalloc(1, sizeof(*newborn));
 614        live_children++;
 615        memcpy(&newborn->cld, cld, sizeof(*cld));
 616        memcpy(&newborn->address, addr, addrlen);
 617        for (cradle = &firstborn; *cradle; cradle = &(*cradle)->next)
 618                if (!addrcmp(&(*cradle)->address, &newborn->address))
 619                        break;
 620        newborn->next = *cradle;
 621        *cradle = newborn;
 622}
 623
 624/*
 625 * This gets called if the number of connections grows
 626 * past "max_connections".
 627 *
 628 * We kill the newest connection from a duplicate IP.
 629 */
 630static void kill_some_child(void)
 631{
 632        const struct child *blanket, *next;
 633
 634        if (!(blanket = firstborn))
 635                return;
 636
 637        for (; (next = blanket->next); blanket = next)
 638                if (!addrcmp(&blanket->address, &next->address)) {
 639                        kill(blanket->cld.pid, SIGTERM);
 640                        break;
 641                }
 642}
 643
 644static void check_dead_children(void)
 645{
 646        int status;
 647        pid_t pid;
 648
 649        struct child **cradle, *blanket;
 650        for (cradle = &firstborn; (blanket = *cradle);)
 651                if ((pid = waitpid(blanket->cld.pid, &status, WNOHANG)) > 1) {
 652                        const char *dead = "";
 653                        if (status)
 654                                dead = " (with error)";
 655                        loginfo("[%"PRIuMAX"] Disconnected%s", (uintmax_t)pid, dead);
 656
 657                        /* remove the child */
 658                        *cradle = blanket->next;
 659                        live_children--;
 660                        free(blanket);
 661                } else
 662                        cradle = &blanket->next;
 663}
 664
 665static char **cld_argv;
 666static void handle(int incoming, struct sockaddr *addr, socklen_t addrlen)
 667{
 668        struct child_process cld = { NULL };
 669        char addrbuf[300] = "REMOTE_ADDR=", portbuf[300];
 670        char *env[] = { addrbuf, portbuf, NULL };
 671
 672        if (max_connections && live_children >= max_connections) {
 673                kill_some_child();
 674                sleep(1);  /* give it some time to die */
 675                check_dead_children();
 676                if (live_children >= max_connections) {
 677                        close(incoming);
 678                        logerror("Too many children, dropping connection");
 679                        return;
 680                }
 681        }
 682
 683        if (addr->sa_family == AF_INET) {
 684                struct sockaddr_in *sin_addr = (void *) addr;
 685                inet_ntop(addr->sa_family, &sin_addr->sin_addr, addrbuf + 12,
 686                    sizeof(addrbuf) - 12);
 687                snprintf(portbuf, sizeof(portbuf), "REMOTE_PORT=%d",
 688                    ntohs(sin_addr->sin_port));
 689#ifndef NO_IPV6
 690        } else if (addr && addr->sa_family == AF_INET6) {
 691                struct sockaddr_in6 *sin6_addr = (void *) addr;
 692
 693                char *buf = addrbuf + 12;
 694                *buf++ = '['; *buf = '\0'; /* stpcpy() is cool */
 695                inet_ntop(AF_INET6, &sin6_addr->sin6_addr, buf,
 696                    sizeof(addrbuf) - 13);
 697                strcat(buf, "]");
 698
 699                snprintf(portbuf, sizeof(portbuf), "REMOTE_PORT=%d",
 700                    ntohs(sin6_addr->sin6_port));
 701#endif
 702        }
 703
 704        cld.env = (const char **)env;
 705        cld.argv = (const char **)cld_argv;
 706        cld.in = incoming;
 707        cld.out = dup(incoming);
 708
 709        if (start_command(&cld))
 710                logerror("unable to fork");
 711        else
 712                add_child(&cld, addr, addrlen);
 713        close(incoming);
 714}
 715
 716static void child_handler(int signo)
 717{
 718        /*
 719         * Otherwise empty handler because systemcalls will get interrupted
 720         * upon signal receipt
 721         * SysV needs the handler to be rearmed
 722         */
 723        signal(SIGCHLD, child_handler);
 724}
 725
 726static int set_reuse_addr(int sockfd)
 727{
 728        int on = 1;
 729
 730        if (!reuseaddr)
 731                return 0;
 732        return setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR,
 733                          &on, sizeof(on));
 734}
 735
 736struct socketlist {
 737        int *list;
 738        size_t nr;
 739        size_t alloc;
 740};
 741
 742static const char *ip2str(int family, struct sockaddr *sin, socklen_t len)
 743{
 744#ifdef NO_IPV6
 745        static char ip[INET_ADDRSTRLEN];
 746#else
 747        static char ip[INET6_ADDRSTRLEN];
 748#endif
 749
 750        switch (family) {
 751#ifndef NO_IPV6
 752        case AF_INET6:
 753                inet_ntop(family, &((struct sockaddr_in6*)sin)->sin6_addr, ip, len);
 754                break;
 755#endif
 756        case AF_INET:
 757                inet_ntop(family, &((struct sockaddr_in*)sin)->sin_addr, ip, len);
 758                break;
 759        default:
 760                strcpy(ip, "<unknown>");
 761        }
 762        return ip;
 763}
 764
 765#ifndef NO_IPV6
 766
 767static int setup_named_sock(char *listen_addr, int listen_port, struct socketlist *socklist)
 768{
 769        int socknum = 0;
 770        int maxfd = -1;
 771        char pbuf[NI_MAXSERV];
 772        struct addrinfo hints, *ai0, *ai;
 773        int gai;
 774        long flags;
 775
 776        sprintf(pbuf, "%d", listen_port);
 777        memset(&hints, 0, sizeof(hints));
 778        hints.ai_family = AF_UNSPEC;
 779        hints.ai_socktype = SOCK_STREAM;
 780        hints.ai_protocol = IPPROTO_TCP;
 781        hints.ai_flags = AI_PASSIVE;
 782
 783        gai = getaddrinfo(listen_addr, pbuf, &hints, &ai0);
 784        if (gai) {
 785                logerror("getaddrinfo() for %s failed: %s", listen_addr, gai_strerror(gai));
 786                return 0;
 787        }
 788
 789        for (ai = ai0; ai; ai = ai->ai_next) {
 790                int sockfd;
 791
 792                sockfd = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
 793                if (sockfd < 0)
 794                        continue;
 795                if (sockfd >= FD_SETSIZE) {
 796                        logerror("Socket descriptor too large");
 797                        close(sockfd);
 798                        continue;
 799                }
 800
 801#ifdef IPV6_V6ONLY
 802                if (ai->ai_family == AF_INET6) {
 803                        int on = 1;
 804                        setsockopt(sockfd, IPPROTO_IPV6, IPV6_V6ONLY,
 805                                   &on, sizeof(on));
 806                        /* Note: error is not fatal */
 807                }
 808#endif
 809
 810                if (set_reuse_addr(sockfd)) {
 811                        logerror("Could not set SO_REUSEADDR: %s", strerror(errno));
 812                        close(sockfd);
 813                        continue;
 814                }
 815
 816                if (bind(sockfd, ai->ai_addr, ai->ai_addrlen) < 0) {
 817                        logerror("Could not bind to %s: %s",
 818                                 ip2str(ai->ai_family, ai->ai_addr, ai->ai_addrlen),
 819                                 strerror(errno));
 820                        close(sockfd);
 821                        continue;       /* not fatal */
 822                }
 823                if (listen(sockfd, 5) < 0) {
 824                        logerror("Could not listen to %s: %s",
 825                                 ip2str(ai->ai_family, ai->ai_addr, ai->ai_addrlen),
 826                                 strerror(errno));
 827                        close(sockfd);
 828                        continue;       /* not fatal */
 829                }
 830
 831                flags = fcntl(sockfd, F_GETFD, 0);
 832                if (flags >= 0)
 833                        fcntl(sockfd, F_SETFD, flags | FD_CLOEXEC);
 834
 835                ALLOC_GROW(socklist->list, socklist->nr + 1, socklist->alloc);
 836                socklist->list[socklist->nr++] = sockfd;
 837                socknum++;
 838
 839                if (maxfd < sockfd)
 840                        maxfd = sockfd;
 841        }
 842
 843        freeaddrinfo(ai0);
 844
 845        return socknum;
 846}
 847
 848#else /* NO_IPV6 */
 849
 850static int setup_named_sock(char *listen_addr, int listen_port, struct socketlist *socklist)
 851{
 852        struct sockaddr_in sin;
 853        int sockfd;
 854        long flags;
 855
 856        memset(&sin, 0, sizeof sin);
 857        sin.sin_family = AF_INET;
 858        sin.sin_port = htons(listen_port);
 859
 860        if (listen_addr) {
 861                /* Well, host better be an IP address here. */
 862                if (inet_pton(AF_INET, listen_addr, &sin.sin_addr.s_addr) <= 0)
 863                        return 0;
 864        } else {
 865                sin.sin_addr.s_addr = htonl(INADDR_ANY);
 866        }
 867
 868        sockfd = socket(AF_INET, SOCK_STREAM, 0);
 869        if (sockfd < 0)
 870                return 0;
 871
 872        if (set_reuse_addr(sockfd)) {
 873                logerror("Could not set SO_REUSEADDR: %s", strerror(errno));
 874                close(sockfd);
 875                return 0;
 876        }
 877
 878        if ( bind(sockfd, (struct sockaddr *)&sin, sizeof sin) < 0 ) {
 879                logerror("Could not listen to %s: %s",
 880                         ip2str(AF_INET, (struct sockaddr *)&sin, sizeof(sin)),
 881                         strerror(errno));
 882                close(sockfd);
 883                return 0;
 884        }
 885
 886        if (listen(sockfd, 5) < 0) {
 887                logerror("Could not listen to %s: %s",
 888                         ip2str(AF_INET, (struct sockaddr *)&sin, sizeof(sin)),
 889                         strerror(errno));
 890                close(sockfd);
 891                return 0;
 892        }
 893
 894        flags = fcntl(sockfd, F_GETFD, 0);
 895        if (flags >= 0)
 896                fcntl(sockfd, F_SETFD, flags | FD_CLOEXEC);
 897
 898        ALLOC_GROW(socklist->list, socklist->nr + 1, socklist->alloc);
 899        socklist->list[socklist->nr++] = sockfd;
 900        return 1;
 901}
 902
 903#endif
 904
 905static void socksetup(struct string_list *listen_addr, int listen_port, struct socketlist *socklist)
 906{
 907        if (!listen_addr->nr)
 908                setup_named_sock(NULL, listen_port, socklist);
 909        else {
 910                int i, socknum;
 911                for (i = 0; i < listen_addr->nr; i++) {
 912                        socknum = setup_named_sock(listen_addr->items[i].string,
 913                                                   listen_port, socklist);
 914
 915                        if (socknum == 0)
 916                                logerror("unable to allocate any listen sockets for host %s on port %u",
 917                                         listen_addr->items[i].string, listen_port);
 918                }
 919        }
 920}
 921
 922static int service_loop(struct socketlist *socklist)
 923{
 924        struct pollfd *pfd;
 925        int i;
 926
 927        pfd = xcalloc(socklist->nr, sizeof(struct pollfd));
 928
 929        for (i = 0; i < socklist->nr; i++) {
 930                pfd[i].fd = socklist->list[i];
 931                pfd[i].events = POLLIN;
 932        }
 933
 934        signal(SIGCHLD, child_handler);
 935
 936        for (;;) {
 937                int i;
 938
 939                check_dead_children();
 940
 941                if (poll(pfd, socklist->nr, -1) < 0) {
 942                        if (errno != EINTR) {
 943                                logerror("Poll failed, resuming: %s",
 944                                      strerror(errno));
 945                                sleep(1);
 946                        }
 947                        continue;
 948                }
 949
 950                for (i = 0; i < socklist->nr; i++) {
 951                        if (pfd[i].revents & POLLIN) {
 952                                union {
 953                                        struct sockaddr sa;
 954                                        struct sockaddr_in sai;
 955#ifndef NO_IPV6
 956                                        struct sockaddr_in6 sai6;
 957#endif
 958                                } ss;
 959                                socklen_t sslen = sizeof(ss);
 960                                int incoming = accept(pfd[i].fd, &ss.sa, &sslen);
 961                                if (incoming < 0) {
 962                                        switch (errno) {
 963                                        case EAGAIN:
 964                                        case EINTR:
 965                                        case ECONNABORTED:
 966                                                continue;
 967                                        default:
 968                                                die_errno("accept returned");
 969                                        }
 970                                }
 971                                handle(incoming, &ss.sa, sslen);
 972                        }
 973                }
 974        }
 975}
 976
 977/* if any standard file descriptor is missing open it to /dev/null */
 978static void sanitize_stdfds(void)
 979{
 980        int fd = open("/dev/null", O_RDWR, 0);
 981        while (fd != -1 && fd < 2)
 982                fd = dup(fd);
 983        if (fd == -1)
 984                die_errno("open /dev/null or dup failed");
 985        if (fd > 2)
 986                close(fd);
 987}
 988
 989#ifdef NO_POSIX_GOODIES
 990
 991struct credentials;
 992
 993static void drop_privileges(struct credentials *cred)
 994{
 995        /* nothing */
 996}
 997
 998static void daemonize(void)
 999{
1000        die("--detach not supported on this platform");
1001}
1002
1003static struct credentials *prepare_credentials(const char *user_name,
1004    const char *group_name)
1005{
1006        die("--user not supported on this platform");
1007}
1008
1009#else
1010
1011struct credentials {
1012        struct passwd *pass;
1013        gid_t gid;
1014};
1015
1016static void drop_privileges(struct credentials *cred)
1017{
1018        if (cred && (initgroups(cred->pass->pw_name, cred->gid) ||
1019            setgid (cred->gid) || setuid(cred->pass->pw_uid)))
1020                die("cannot drop privileges");
1021}
1022
1023static struct credentials *prepare_credentials(const char *user_name,
1024    const char *group_name)
1025{
1026        static struct credentials c;
1027
1028        c.pass = getpwnam(user_name);
1029        if (!c.pass)
1030                die("user not found - %s", user_name);
1031
1032        if (!group_name)
1033                c.gid = c.pass->pw_gid;
1034        else {
1035                struct group *group = getgrnam(group_name);
1036                if (!group)
1037                        die("group not found - %s", group_name);
1038
1039                c.gid = group->gr_gid;
1040        }
1041
1042        return &c;
1043}
1044
1045static void daemonize(void)
1046{
1047        switch (fork()) {
1048                case 0:
1049                        break;
1050                case -1:
1051                        die_errno("fork failed");
1052                default:
1053                        exit(0);
1054        }
1055        if (setsid() == -1)
1056                die_errno("setsid failed");
1057        close(0);
1058        close(1);
1059        close(2);
1060        sanitize_stdfds();
1061}
1062#endif
1063
1064static void store_pid(const char *path)
1065{
1066        FILE *f = fopen(path, "w");
1067        if (!f)
1068                die_errno("cannot open pid file '%s'", path);
1069        if (fprintf(f, "%"PRIuMAX"\n", (uintmax_t) getpid()) < 0 || fclose(f) != 0)
1070                die_errno("failed to write pid file '%s'", path);
1071}
1072
1073static int serve(struct string_list *listen_addr, int listen_port,
1074    struct credentials *cred)
1075{
1076        struct socketlist socklist = { NULL, 0, 0 };
1077
1078        socksetup(listen_addr, listen_port, &socklist);
1079        if (socklist.nr == 0)
1080                die("unable to allocate any listen sockets on port %u",
1081                    listen_port);
1082
1083        drop_privileges(cred);
1084
1085        loginfo("Ready to rumble");
1086
1087        return service_loop(&socklist);
1088}
1089
1090int main(int argc, char **argv)
1091{
1092        int listen_port = 0;
1093        struct string_list listen_addr = STRING_LIST_INIT_NODUP;
1094        int serve_mode = 0, inetd_mode = 0;
1095        const char *pid_file = NULL, *user_name = NULL, *group_name = NULL;
1096        int detach = 0;
1097        struct credentials *cred = NULL;
1098        int i;
1099
1100        git_setup_gettext();
1101
1102        git_extract_argv0_path(argv[0]);
1103
1104        for (i = 1; i < argc; i++) {
1105                char *arg = argv[i];
1106
1107                if (!prefixcmp(arg, "--listen=")) {
1108                        string_list_append(&listen_addr, xstrdup_tolower(arg + 9));
1109                        continue;
1110                }
1111                if (!prefixcmp(arg, "--port=")) {
1112                        char *end;
1113                        unsigned long n;
1114                        n = strtoul(arg+7, &end, 0);
1115                        if (arg[7] && !*end) {
1116                                listen_port = n;
1117                                continue;
1118                        }
1119                }
1120                if (!strcmp(arg, "--serve")) {
1121                        serve_mode = 1;
1122                        continue;
1123                }
1124                if (!strcmp(arg, "--inetd")) {
1125                        inetd_mode = 1;
1126                        log_syslog = 1;
1127                        continue;
1128                }
1129                if (!strcmp(arg, "--verbose")) {
1130                        verbose = 1;
1131                        continue;
1132                }
1133                if (!strcmp(arg, "--syslog")) {
1134                        log_syslog = 1;
1135                        continue;
1136                }
1137                if (!strcmp(arg, "--export-all")) {
1138                        export_all_trees = 1;
1139                        continue;
1140                }
1141                if (!prefixcmp(arg, "--timeout=")) {
1142                        timeout = atoi(arg+10);
1143                        continue;
1144                }
1145                if (!prefixcmp(arg, "--init-timeout=")) {
1146                        init_timeout = atoi(arg+15);
1147                        continue;
1148                }
1149                if (!prefixcmp(arg, "--max-connections=")) {
1150                        max_connections = atoi(arg+18);
1151                        if (max_connections < 0)
1152                                max_connections = 0;            /* unlimited */
1153                        continue;
1154                }
1155                if (!strcmp(arg, "--strict-paths")) {
1156                        strict_paths = 1;
1157                        continue;
1158                }
1159                if (!prefixcmp(arg, "--base-path=")) {
1160                        base_path = arg+12;
1161                        continue;
1162                }
1163                if (!strcmp(arg, "--base-path-relaxed")) {
1164                        base_path_relaxed = 1;
1165                        continue;
1166                }
1167                if (!prefixcmp(arg, "--interpolated-path=")) {
1168                        interpolated_path = arg+20;
1169                        continue;
1170                }
1171                if (!strcmp(arg, "--reuseaddr")) {
1172                        reuseaddr = 1;
1173                        continue;
1174                }
1175                if (!strcmp(arg, "--user-path")) {
1176                        user_path = "";
1177                        continue;
1178                }
1179                if (!prefixcmp(arg, "--user-path=")) {
1180                        user_path = arg + 12;
1181                        continue;
1182                }
1183                if (!prefixcmp(arg, "--pid-file=")) {
1184                        pid_file = arg + 11;
1185                        continue;
1186                }
1187                if (!strcmp(arg, "--detach")) {
1188                        detach = 1;
1189                        log_syslog = 1;
1190                        continue;
1191                }
1192                if (!prefixcmp(arg, "--user=")) {
1193                        user_name = arg + 7;
1194                        continue;
1195                }
1196                if (!prefixcmp(arg, "--group=")) {
1197                        group_name = arg + 8;
1198                        continue;
1199                }
1200                if (!prefixcmp(arg, "--enable=")) {
1201                        enable_service(arg + 9, 1);
1202                        continue;
1203                }
1204                if (!prefixcmp(arg, "--disable=")) {
1205                        enable_service(arg + 10, 0);
1206                        continue;
1207                }
1208                if (!prefixcmp(arg, "--allow-override=")) {
1209                        make_service_overridable(arg + 17, 1);
1210                        continue;
1211                }
1212                if (!prefixcmp(arg, "--forbid-override=")) {
1213                        make_service_overridable(arg + 18, 0);
1214                        continue;
1215                }
1216                if (!prefixcmp(arg, "--informative-errors")) {
1217                        informative_errors = 1;
1218                        continue;
1219                }
1220                if (!prefixcmp(arg, "--no-informative-errors")) {
1221                        informative_errors = 0;
1222                        continue;
1223                }
1224                if (!strcmp(arg, "--")) {
1225                        ok_paths = &argv[i+1];
1226                        break;
1227                } else if (arg[0] != '-') {
1228                        ok_paths = &argv[i];
1229                        break;
1230                }
1231
1232                usage(daemon_usage);
1233        }
1234
1235        if (log_syslog) {
1236                openlog("git-daemon", LOG_PID, LOG_DAEMON);
1237                set_die_routine(daemon_die);
1238        } else
1239                /* avoid splitting a message in the middle */
1240                setvbuf(stderr, NULL, _IOFBF, 4096);
1241
1242        if (inetd_mode && (detach || group_name || user_name))
1243                die("--detach, --user and --group are incompatible with --inetd");
1244
1245        if (inetd_mode && (listen_port || (listen_addr.nr > 0)))
1246                die("--listen= and --port= are incompatible with --inetd");
1247        else if (listen_port == 0)
1248                listen_port = DEFAULT_GIT_PORT;
1249
1250        if (group_name && !user_name)
1251                die("--group supplied without --user");
1252
1253        if (user_name)
1254                cred = prepare_credentials(user_name, group_name);
1255
1256        if (strict_paths && (!ok_paths || !*ok_paths))
1257                die("option --strict-paths requires a whitelist");
1258
1259        if (base_path && !is_directory(base_path))
1260                die("base-path '%s' does not exist or is not a directory",
1261                    base_path);
1262
1263        if (inetd_mode) {
1264                if (!freopen("/dev/null", "w", stderr))
1265                        die_errno("failed to redirect stderr to /dev/null");
1266        }
1267
1268        if (inetd_mode || serve_mode)
1269                return execute();
1270
1271        if (detach)
1272                daemonize();
1273        else
1274                sanitize_stdfds();
1275
1276        if (pid_file)
1277                store_pid(pid_file);
1278
1279        /* prepare argv for serving-processes */
1280        cld_argv = xmalloc(sizeof (char *) * (argc + 2));
1281        cld_argv[0] = argv[0];  /* git-daemon */
1282        cld_argv[1] = "--serve";
1283        for (i = 1; i < argc; ++i)
1284                cld_argv[i+1] = argv[i];
1285        cld_argv[argc+1] = NULL;
1286
1287        return serve(&listen_addr, listen_port, cred);
1288}