Andrew's git - gitweb.git/blob

   1#include "cache.h"
   2#include "config.h"
   3#include "repository.h"
   4#include "refs.h"
   5#include "pkt-line.h"
   6#include "object.h"
   7#include "tag.h"
   8#include "exec-cmd.h"
   9#include "run-command.h"
  10#include "string-list.h"
  11#include "url.h"
  12#include "argv-array.h"
  13#include "packfile.h"
  14#include "object-store.h"
  15#include "protocol.h"
  16
  17static const char content_type[] = "Content-Type";
  18static const char content_length[] = "Content-Length";
  19static const char last_modified[] = "Last-Modified";
  20static int getanyfile = 1;
  21static unsigned long max_request_buffer = 10 * 1024 * 1024;
  22
  23static struct string_list *query_params;
  24
  25struct rpc_service {
  26        const char *name;
  27        const char *config_name;
  28        unsigned buffer_input : 1;
  29        signed enabled : 2;
  30};
  31
  32static struct rpc_service rpc_service[] = {
  33        { "upload-pack", "uploadpack", 1, 1 },
  34        { "receive-pack", "receivepack", 0, -1 },
  35};
  36
  37static struct string_list *get_parameters(void)
  38{
  39        if (!query_params) {
  40                const char *query = getenv("QUERY_STRING");
  41
  42                query_params = xcalloc(1, sizeof(*query_params));
  43                while (query && *query) {
  44                        char *name = url_decode_parameter_name(&query);
  45                        char *value = url_decode_parameter_value(&query);
  46                        struct string_list_item *i;
  47
  48                        i = string_list_lookup(query_params, name);
  49                        if (!i)
  50                                i = string_list_insert(query_params, name);
  51                        else
  52                                free(i->util);
  53                        i->util = value;
  54                }
  55        }
  56        return query_params;
  57}
  58
  59static const char *get_parameter(const char *name)
  60{
  61        struct string_list_item *i;
  62        i = string_list_lookup(get_parameters(), name);
  63        return i ? i->util : NULL;
  64}
  65
  66__attribute__((format (printf, 2, 3)))
  67static void format_write(int fd, const char *fmt, ...)
  68{
  69        static char buffer[1024];
  70
  71        va_list args;
  72        unsigned n;
  73
  74        va_start(args, fmt);
  75        n = vsnprintf(buffer, sizeof(buffer), fmt, args);
  76        va_end(args);
  77        if (n >= sizeof(buffer))
  78                die("protocol error: impossibly long line");
  79
  80        write_or_die(fd, buffer, n);
  81}
  82
  83static void http_status(struct strbuf *hdr, unsigned code, const char *msg)
  84{
  85        strbuf_addf(hdr, "Status: %u %s\r\n", code, msg);
  86}
  87
  88static void hdr_str(struct strbuf *hdr, const char *name, const char *value)
  89{
  90        strbuf_addf(hdr, "%s: %s\r\n", name, value);
  91}
  92
  93static void hdr_int(struct strbuf *hdr, const char *name, uintmax_t value)
  94{
  95        strbuf_addf(hdr, "%s: %" PRIuMAX "\r\n", name, value);
  96}
  97
  98static void hdr_date(struct strbuf *hdr, const char *name, timestamp_t when)
  99{
 100        const char *value = show_date(when, 0, DATE_MODE(RFC2822));
 101        hdr_str(hdr, name, value);
 102}
 103
 104static void hdr_nocache(struct strbuf *hdr)
 105{
 106        hdr_str(hdr, "Expires", "Fri, 01 Jan 1980 00:00:00 GMT");
 107        hdr_str(hdr, "Pragma", "no-cache");
 108        hdr_str(hdr, "Cache-Control", "no-cache, max-age=0, must-revalidate");
 109}
 110
 111static void hdr_cache_forever(struct strbuf *hdr)
 112{
 113        timestamp_t now = time(NULL);
 114        hdr_date(hdr, "Date", now);
 115        hdr_date(hdr, "Expires", now + 31536000);
 116        hdr_str(hdr, "Cache-Control", "public, max-age=31536000");
 117}
 118
 119static void end_headers(struct strbuf *hdr)
 120{
 121        strbuf_add(hdr, "\r\n", 2);
 122        write_or_die(1, hdr->buf, hdr->len);
 123        strbuf_release(hdr);
 124}
 125
 126__attribute__((format (printf, 2, 3)))
 127static NORETURN void not_found(struct strbuf *hdr, const char *err, ...)
 128{
 129        va_list params;
 130
 131        http_status(hdr, 404, "Not Found");
 132        hdr_nocache(hdr);
 133        end_headers(hdr);
 134
 135        va_start(params, err);
 136        if (err && *err)
 137                vfprintf(stderr, err, params);
 138        va_end(params);
 139        exit(0);
 140}
 141
 142__attribute__((format (printf, 2, 3)))
 143static NORETURN void forbidden(struct strbuf *hdr, const char *err, ...)
 144{
 145        va_list params;
 146
 147        http_status(hdr, 403, "Forbidden");
 148        hdr_nocache(hdr);
 149        end_headers(hdr);
 150
 151        va_start(params, err);
 152        if (err && *err)
 153                vfprintf(stderr, err, params);
 154        va_end(params);
 155        exit(0);
 156}
 157
 158static void select_getanyfile(struct strbuf *hdr)
 159{
 160        if (!getanyfile)
 161                forbidden(hdr, "Unsupported service: getanyfile");
 162}
 163
 164static void send_strbuf(struct strbuf *hdr,
 165                        const char *type, struct strbuf *buf)
 166{
 167        hdr_int(hdr, content_length, buf->len);
 168        hdr_str(hdr, content_type, type);
 169        end_headers(hdr);
 170        write_or_die(1, buf->buf, buf->len);
 171}
 172
 173static void send_local_file(struct strbuf *hdr, const char *the_type,
 174                                const char *name)
 175{
 176        char *p = git_pathdup("%s", name);
 177        size_t buf_alloc = 8192;
 178        char *buf = xmalloc(buf_alloc);
 179        int fd;
 180        struct stat sb;
 181
 182        fd = open(p, O_RDONLY);
 183        if (fd < 0)
 184                not_found(hdr, "Cannot open '%s': %s", p, strerror(errno));
 185        if (fstat(fd, &sb) < 0)
 186                die_errno("Cannot stat '%s'", p);
 187
 188        hdr_int(hdr, content_length, sb.st_size);
 189        hdr_str(hdr, content_type, the_type);
 190        hdr_date(hdr, last_modified, sb.st_mtime);
 191        end_headers(hdr);
 192
 193        for (;;) {
 194                ssize_t n = xread(fd, buf, buf_alloc);
 195                if (n < 0)
 196                        die_errno("Cannot read '%s'", p);
 197                if (!n)
 198                        break;
 199                write_or_die(1, buf, n);
 200        }
 201        close(fd);
 202        free(buf);
 203        free(p);
 204}
 205
 206static void get_text_file(struct strbuf *hdr, char *name)
 207{
 208        select_getanyfile(hdr);
 209        hdr_nocache(hdr);
 210        send_local_file(hdr, "text/plain", name);
 211}
 212
 213static void get_loose_object(struct strbuf *hdr, char *name)
 214{
 215        select_getanyfile(hdr);
 216        hdr_cache_forever(hdr);
 217        send_local_file(hdr, "application/x-git-loose-object", name);
 218}
 219
 220static void get_pack_file(struct strbuf *hdr, char *name)
 221{
 222        select_getanyfile(hdr);
 223        hdr_cache_forever(hdr);
 224        send_local_file(hdr, "application/x-git-packed-objects", name);
 225}
 226
 227static void get_idx_file(struct strbuf *hdr, char *name)
 228{
 229        select_getanyfile(hdr);
 230        hdr_cache_forever(hdr);
 231        send_local_file(hdr, "application/x-git-packed-objects-toc", name);
 232}
 233
 234static void http_config(void)
 235{
 236        int i, value = 0;
 237        struct strbuf var = STRBUF_INIT;
 238
 239        git_config_get_bool("http.getanyfile", &getanyfile);
 240        git_config_get_ulong("http.maxrequestbuffer", &max_request_buffer);
 241
 242        for (i = 0; i < ARRAY_SIZE(rpc_service); i++) {
 243                struct rpc_service *svc = &rpc_service[i];
 244                strbuf_addf(&var, "http.%s", svc->config_name);
 245                if (!git_config_get_bool(var.buf, &value))
 246                        svc->enabled = value;
 247                strbuf_reset(&var);
 248        }
 249
 250        strbuf_release(&var);
 251}
 252
 253static struct rpc_service *select_service(struct strbuf *hdr, const char *name)
 254{
 255        const char *svc_name;
 256        struct rpc_service *svc = NULL;
 257        int i;
 258
 259        if (!skip_prefix(name, "git-", &svc_name))
 260                forbidden(hdr, "Unsupported service: '%s'", name);
 261
 262        for (i = 0; i < ARRAY_SIZE(rpc_service); i++) {
 263                struct rpc_service *s = &rpc_service[i];
 264                if (!strcmp(s->name, svc_name)) {
 265                        svc = s;
 266                        break;
 267                }
 268        }
 269
 270        if (!svc)
 271                forbidden(hdr, "Unsupported service: '%s'", name);
 272
 273        if (svc->enabled < 0) {
 274                const char *user = getenv("REMOTE_USER");
 275                svc->enabled = (user && *user) ? 1 : 0;
 276        }
 277        if (!svc->enabled)
 278                forbidden(hdr, "Service not enabled: '%s'", svc->name);
 279        return svc;
 280}
 281
 282/*
 283 * This is basically strbuf_read(), except that if we
 284 * hit max_request_buffer we die (we'd rather reject a
 285 * maliciously large request than chew up infinite memory).
 286 */
 287static ssize_t read_request(int fd, unsigned char **out)
 288{
 289        size_t len = 0, alloc = 8192;
 290        unsigned char *buf = xmalloc(alloc);
 291
 292        if (max_request_buffer < alloc)
 293                max_request_buffer = alloc;
 294
 295        while (1) {
 296                ssize_t cnt;
 297
 298                cnt = read_in_full(fd, buf + len, alloc - len);
 299                if (cnt < 0) {
 300                        free(buf);
 301                        return -1;
 302                }
 303
 304                /* partial read from read_in_full means we hit EOF */
 305                len += cnt;
 306                if (len < alloc) {
 307                        *out = buf;
 308                        return len;
 309                }
 310
 311                /* otherwise, grow and try again (if we can) */
 312                if (alloc == max_request_buffer)
 313                        die("request was larger than our maximum size (%lu);"
 314                            " try setting GIT_HTTP_MAX_REQUEST_BUFFER",
 315                            max_request_buffer);
 316
 317                alloc = alloc_nr(alloc);
 318                if (alloc > max_request_buffer)
 319                        alloc = max_request_buffer;
 320                REALLOC_ARRAY(buf, alloc);
 321        }
 322}
 323
 324static void inflate_request(const char *prog_name, int out, int buffer_input)
 325{
 326        git_zstream stream;
 327        unsigned char *full_request = NULL;
 328        unsigned char in_buf[8192];
 329        unsigned char out_buf[8192];
 330        unsigned long cnt = 0;
 331
 332        memset(&stream, 0, sizeof(stream));
 333        git_inflate_init_gzip_only(&stream);
 334
 335        while (1) {
 336                ssize_t n;
 337
 338                if (buffer_input) {
 339                        if (full_request)
 340                                n = 0; /* nothing left to read */
 341                        else
 342                                n = read_request(0, &full_request);
 343                        stream.next_in = full_request;
 344                } else {
 345                        n = xread(0, in_buf, sizeof(in_buf));
 346                        stream.next_in = in_buf;
 347                }
 348
 349                if (n <= 0)
 350                        die("request ended in the middle of the gzip stream");
 351                stream.avail_in = n;
 352
 353                while (0 < stream.avail_in) {
 354                        int ret;
 355
 356                        stream.next_out = out_buf;
 357                        stream.avail_out = sizeof(out_buf);
 358
 359                        ret = git_inflate(&stream, Z_NO_FLUSH);
 360                        if (ret != Z_OK && ret != Z_STREAM_END)
 361                                die("zlib error inflating request, result %d", ret);
 362
 363                        n = stream.total_out - cnt;
 364                        if (write_in_full(out, out_buf, n) < 0)
 365                                die("%s aborted reading request", prog_name);
 366                        cnt += n;
 367
 368                        if (ret == Z_STREAM_END)
 369                                goto done;
 370                }
 371        }
 372
 373done:
 374        git_inflate_end(&stream);
 375        close(out);
 376        free(full_request);
 377}
 378
 379static void copy_request(const char *prog_name, int out)
 380{
 381        unsigned char *buf;
 382        ssize_t n = read_request(0, &buf);
 383        if (n < 0)
 384                die_errno("error reading request body");
 385        if (write_in_full(out, buf, n) < 0)
 386                die("%s aborted reading request", prog_name);
 387        close(out);
 388        free(buf);
 389}
 390
 391static void run_service(const char **argv, int buffer_input)
 392{
 393        const char *encoding = getenv("HTTP_CONTENT_ENCODING");
 394        const char *user = getenv("REMOTE_USER");
 395        const char *host = getenv("REMOTE_ADDR");
 396        int gzipped_request = 0;
 397        struct child_process cld = CHILD_PROCESS_INIT;
 398
 399        if (encoding && !strcmp(encoding, "gzip"))
 400                gzipped_request = 1;
 401        else if (encoding && !strcmp(encoding, "x-gzip"))
 402                gzipped_request = 1;
 403
 404        if (!user || !*user)
 405                user = "anonymous";
 406        if (!host || !*host)
 407                host = "(none)";
 408
 409        if (!getenv("GIT_COMMITTER_NAME"))
 410                argv_array_pushf(&cld.env_array, "GIT_COMMITTER_NAME=%s", user);
 411        if (!getenv("GIT_COMMITTER_EMAIL"))
 412                argv_array_pushf(&cld.env_array,
 413                                 "GIT_COMMITTER_EMAIL=%s@http.%s", user, host);
 414
 415        cld.argv = argv;
 416        if (buffer_input || gzipped_request)
 417                cld.in = -1;
 418        cld.git_cmd = 1;
 419        if (start_command(&cld))
 420                exit(1);
 421
 422        close(1);
 423        if (gzipped_request)
 424                inflate_request(argv[0], cld.in, buffer_input);
 425        else if (buffer_input)
 426                copy_request(argv[0], cld.in);
 427        else
 428                close(0);
 429
 430        if (finish_command(&cld))
 431                exit(1);
 432}
 433
 434static int show_text_ref(const char *name, const struct object_id *oid,
 435                         int flag, void *cb_data)
 436{
 437        const char *name_nons = strip_namespace(name);
 438        struct strbuf *buf = cb_data;
 439        struct object *o = parse_object(oid);
 440        if (!o)
 441                return 0;
 442
 443        strbuf_addf(buf, "%s\t%s\n", oid_to_hex(oid), name_nons);
 444        if (o->type == OBJ_TAG) {
 445                o = deref_tag(o, name, 0);
 446                if (!o)
 447                        return 0;
 448                strbuf_addf(buf, "%s\t%s^{}\n", oid_to_hex(&o->oid),
 449                            name_nons);
 450        }
 451        return 0;
 452}
 453
 454static void get_info_refs(struct strbuf *hdr, char *arg)
 455{
 456        const char *service_name = get_parameter("service");
 457        struct strbuf buf = STRBUF_INIT;
 458
 459        hdr_nocache(hdr);
 460
 461        if (service_name) {
 462                const char *argv[] = {NULL /* service name */,
 463                        "--stateless-rpc", "--advertise-refs",
 464                        ".", NULL};
 465                struct rpc_service *svc = select_service(hdr, service_name);
 466
 467                strbuf_addf(&buf, "application/x-git-%s-advertisement",
 468                        svc->name);
 469                hdr_str(hdr, content_type, buf.buf);
 470                end_headers(hdr);
 471
 472
 473                if (determine_protocol_version_server() != protocol_v2) {
 474                        packet_write_fmt(1, "# service=git-%s\n", svc->name);
 475                        packet_flush(1);
 476                }
 477
 478                argv[0] = svc->name;
 479                run_service(argv, 0);
 480
 481        } else {
 482                select_getanyfile(hdr);
 483                for_each_namespaced_ref(show_text_ref, &buf);
 484                send_strbuf(hdr, "text/plain", &buf);
 485        }
 486        strbuf_release(&buf);
 487}
 488
 489static int show_head_ref(const char *refname, const struct object_id *oid,
 490                         int flag, void *cb_data)
 491{
 492        struct strbuf *buf = cb_data;
 493
 494        if (flag & REF_ISSYMREF) {
 495                const char *target = resolve_ref_unsafe(refname,
 496                                                        RESOLVE_REF_READING,
 497                                                        NULL, NULL);
 498
 499                if (target)
 500                        strbuf_addf(buf, "ref: %s\n", strip_namespace(target));
 501        } else {
 502                strbuf_addf(buf, "%s\n", oid_to_hex(oid));
 503        }
 504
 505        return 0;
 506}
 507
 508static void get_head(struct strbuf *hdr, char *arg)
 509{
 510        struct strbuf buf = STRBUF_INIT;
 511
 512        select_getanyfile(hdr);
 513        head_ref_namespaced(show_head_ref, &buf);
 514        send_strbuf(hdr, "text/plain", &buf);
 515        strbuf_release(&buf);
 516}
 517
 518static void get_info_packs(struct strbuf *hdr, char *arg)
 519{
 520        size_t objdirlen = strlen(get_object_directory());
 521        struct strbuf buf = STRBUF_INIT;
 522        struct packed_git *p;
 523        size_t cnt = 0;
 524
 525        select_getanyfile(hdr);
 526        for (p = get_packed_git(the_repository); p; p = p->next) {
 527                if (p->pack_local)
 528                        cnt++;
 529        }
 530
 531        strbuf_grow(&buf, cnt * 53 + 2);
 532        for (p = get_packed_git(the_repository); p; p = p->next) {
 533                if (p->pack_local)
 534                        strbuf_addf(&buf, "P %s\n", p->pack_name + objdirlen + 6);
 535        }
 536        strbuf_addch(&buf, '\n');
 537
 538        hdr_nocache(hdr);
 539        send_strbuf(hdr, "text/plain; charset=utf-8", &buf);
 540        strbuf_release(&buf);
 541}
 542
 543static void check_content_type(struct strbuf *hdr, const char *accepted_type)
 544{
 545        const char *actual_type = getenv("CONTENT_TYPE");
 546
 547        if (!actual_type)
 548                actual_type = "";
 549
 550        if (strcmp(actual_type, accepted_type)) {
 551                http_status(hdr, 415, "Unsupported Media Type");
 552                hdr_nocache(hdr);
 553                end_headers(hdr);
 554                format_write(1,
 555                        "Expected POST with Content-Type '%s',"
 556                        " but received '%s' instead.\n",
 557                        accepted_type, actual_type);
 558                exit(0);
 559        }
 560}
 561
 562static void service_rpc(struct strbuf *hdr, char *service_name)
 563{
 564        const char *argv[] = {NULL, "--stateless-rpc", ".", NULL};
 565        struct rpc_service *svc = select_service(hdr, service_name);
 566        struct strbuf buf = STRBUF_INIT;
 567
 568        strbuf_reset(&buf);
 569        strbuf_addf(&buf, "application/x-git-%s-request", svc->name);
 570        check_content_type(hdr, buf.buf);
 571
 572        hdr_nocache(hdr);
 573
 574        strbuf_reset(&buf);
 575        strbuf_addf(&buf, "application/x-git-%s-result", svc->name);
 576        hdr_str(hdr, content_type, buf.buf);
 577
 578        end_headers(hdr);
 579
 580        argv[0] = svc->name;
 581        run_service(argv, svc->buffer_input);
 582        strbuf_release(&buf);
 583}
 584
 585static int dead;
 586static NORETURN void die_webcgi(const char *err, va_list params)
 587{
 588        if (dead <= 1) {
 589                struct strbuf hdr = STRBUF_INIT;
 590
 591                vreportf("fatal: ", err, params);
 592
 593                http_status(&hdr, 500, "Internal Server Error");
 594                hdr_nocache(&hdr);
 595                end_headers(&hdr);
 596        }
 597        exit(0); /* we successfully reported a failure ;-) */
 598}
 599
 600static int die_webcgi_recursing(void)
 601{
 602        return dead++ > 1;
 603}
 604
 605static char* getdir(void)
 606{
 607        struct strbuf buf = STRBUF_INIT;
 608        char *pathinfo = getenv("PATH_INFO");
 609        char *root = getenv("GIT_PROJECT_ROOT");
 610        char *path = getenv("PATH_TRANSLATED");
 611
 612        if (root && *root) {
 613                if (!pathinfo || !*pathinfo)
 614                        die("GIT_PROJECT_ROOT is set but PATH_INFO is not");
 615                if (daemon_avoid_alias(pathinfo))
 616                        die("'%s': aliased", pathinfo);
 617                end_url_with_slash(&buf, root);
 618                if (pathinfo[0] == '/')
 619                        pathinfo++;
 620                strbuf_addstr(&buf, pathinfo);
 621                return strbuf_detach(&buf, NULL);
 622        } else if (path && *path) {
 623                return xstrdup(path);
 624        } else
 625                die("No GIT_PROJECT_ROOT or PATH_TRANSLATED from server");
 626        return NULL;
 627}
 628
 629static struct service_cmd {
 630        const char *method;
 631        const char *pattern;
 632        void (*imp)(struct strbuf *, char *);
 633} services[] = {
 634        {"GET", "/HEAD$", get_head},
 635        {"GET", "/info/refs$", get_info_refs},
 636        {"GET", "/objects/info/alternates$", get_text_file},
 637        {"GET", "/objects/info/http-alternates$", get_text_file},
 638        {"GET", "/objects/info/packs$", get_info_packs},
 639        {"GET", "/objects/[0-9a-f]{2}/[0-9a-f]{38}$", get_loose_object},
 640        {"GET", "/objects/pack/pack-[0-9a-f]{40}\\.pack$", get_pack_file},
 641        {"GET", "/objects/pack/pack-[0-9a-f]{40}\\.idx$", get_idx_file},
 642
 643        {"POST", "/git-upload-pack$", service_rpc},
 644        {"POST", "/git-receive-pack$", service_rpc}
 645};
 646
 647static int bad_request(struct strbuf *hdr, const struct service_cmd *c)
 648{
 649        const char *proto = getenv("SERVER_PROTOCOL");
 650
 651        if (proto && !strcmp(proto, "HTTP/1.1")) {
 652                http_status(hdr, 405, "Method Not Allowed");
 653                hdr_str(hdr, "Allow",
 654                        !strcmp(c->method, "GET") ? "GET, HEAD" : c->method);
 655        } else
 656                http_status(hdr, 400, "Bad Request");
 657        hdr_nocache(hdr);
 658        end_headers(hdr);
 659        return 0;
 660}
 661
 662int cmd_main(int argc, const char **argv)
 663{
 664        char *method = getenv("REQUEST_METHOD");
 665        char *dir;
 666        struct service_cmd *cmd = NULL;
 667        char *cmd_arg = NULL;
 668        int i;
 669        struct strbuf hdr = STRBUF_INIT;
 670
 671        set_die_routine(die_webcgi);
 672        set_die_is_recursing_routine(die_webcgi_recursing);
 673
 674        if (!method)
 675                die("No REQUEST_METHOD from server");
 676        if (!strcmp(method, "HEAD"))
 677                method = "GET";
 678        dir = getdir();
 679
 680        for (i = 0; i < ARRAY_SIZE(services); i++) {
 681                struct service_cmd *c = &services[i];
 682                regex_t re;
 683                regmatch_t out[1];
 684
 685                if (regcomp(&re, c->pattern, REG_EXTENDED))
 686                        die("Bogus regex in service table: %s", c->pattern);
 687                if (!regexec(&re, dir, 1, out, 0)) {
 688                        size_t n;
 689
 690                        if (strcmp(method, c->method))
 691                                return bad_request(&hdr, c);
 692
 693                        cmd = c;
 694                        n = out[0].rm_eo - out[0].rm_so;
 695                        cmd_arg = xmemdupz(dir + out[0].rm_so + 1, n - 1);
 696                        dir[out[0].rm_so] = 0;
 697                        break;
 698                }
 699                regfree(&re);
 700        }
 701
 702        if (!cmd)
 703                not_found(&hdr, "Request not supported: '%s'", dir);
 704
 705        setup_path();
 706        if (!enter_repo(dir, 0))
 707                not_found(&hdr, "Not a git repository: '%s'", dir);
 708        if (!getenv("GIT_HTTP_EXPORT_ALL") &&
 709            access("git-daemon-export-ok", F_OK) )
 710                not_found(&hdr, "Repository not exported: '%s'", dir);
 711
 712        http_config();
 713        max_request_buffer = git_env_ulong("GIT_HTTP_MAX_REQUEST_BUFFER",
 714                                           max_request_buffer);
 715
 716        cmd->imp(&hdr, cmd_arg);
 717        return 0;
 718}