http-backend.con commit Squelch warning about an integer overflow (8f77442)
   1#include "cache.h"
   2#include "refs.h"
   3#include "pkt-line.h"
   4#include "object.h"
   5#include "tag.h"
   6#include "exec_cmd.h"
   7#include "run-command.h"
   8#include "string-list.h"
   9#include "url.h"
  10#include "argv-array.h"
  11
  12static const char content_type[] = "Content-Type";
  13static const char content_length[] = "Content-Length";
  14static const char last_modified[] = "Last-Modified";
  15static int getanyfile = 1;
  16
  17static struct string_list *query_params;
  18
  19struct rpc_service {
  20        const char *name;
  21        const char *config_name;
  22        signed enabled : 2;
  23};
  24
  25static struct rpc_service rpc_service[] = {
  26        { "upload-pack", "uploadpack", 1 },
  27        { "receive-pack", "receivepack", -1 },
  28};
  29
  30static struct string_list *get_parameters(void)
  31{
  32        if (!query_params) {
  33                const char *query = getenv("QUERY_STRING");
  34
  35                query_params = xcalloc(1, sizeof(*query_params));
  36                while (query && *query) {
  37                        char *name = url_decode_parameter_name(&query);
  38                        char *value = url_decode_parameter_value(&query);
  39                        struct string_list_item *i;
  40
  41                        i = string_list_lookup(query_params, name);
  42                        if (!i)
  43                                i = string_list_insert(query_params, name);
  44                        else
  45                                free(i->util);
  46                        i->util = value;
  47                }
  48        }
  49        return query_params;
  50}
  51
  52static const char *get_parameter(const char *name)
  53{
  54        struct string_list_item *i;
  55        i = string_list_lookup(get_parameters(), name);
  56        return i ? i->util : NULL;
  57}
  58
  59__attribute__((format (printf, 2, 3)))
  60static void format_write(int fd, const char *fmt, ...)
  61{
  62        static char buffer[1024];
  63
  64        va_list args;
  65        unsigned n;
  66
  67        va_start(args, fmt);
  68        n = vsnprintf(buffer, sizeof(buffer), fmt, args);
  69        va_end(args);
  70        if (n >= sizeof(buffer))
  71                die("protocol error: impossibly long line");
  72
  73        write_or_die(fd, buffer, n);
  74}
  75
  76static void http_status(unsigned code, const char *msg)
  77{
  78        format_write(1, "Status: %u %s\r\n", code, msg);
  79}
  80
  81static void hdr_str(const char *name, const char *value)
  82{
  83        format_write(1, "%s: %s\r\n", name, value);
  84}
  85
  86static void hdr_int(const char *name, uintmax_t value)
  87{
  88        format_write(1, "%s: %" PRIuMAX "\r\n", name, value);
  89}
  90
  91static void hdr_date(const char *name, unsigned long when)
  92{
  93        const char *value = show_date(when, 0, DATE_RFC2822);
  94        hdr_str(name, value);
  95}
  96
  97static void hdr_nocache(void)
  98{
  99        hdr_str("Expires", "Fri, 01 Jan 1980 00:00:00 GMT");
 100        hdr_str("Pragma", "no-cache");
 101        hdr_str("Cache-Control", "no-cache, max-age=0, must-revalidate");
 102}
 103
 104static void hdr_cache_forever(void)
 105{
 106        unsigned long now = time(NULL);
 107        hdr_date("Date", now);
 108        hdr_date("Expires", now + 31536000);
 109        hdr_str("Cache-Control", "public, max-age=31536000");
 110}
 111
 112static void end_headers(void)
 113{
 114        write_or_die(1, "\r\n", 2);
 115}
 116
 117__attribute__((format (printf, 1, 2)))
 118static NORETURN void not_found(const char *err, ...)
 119{
 120        va_list params;
 121
 122        http_status(404, "Not Found");
 123        hdr_nocache();
 124        end_headers();
 125
 126        va_start(params, err);
 127        if (err && *err)
 128                vfprintf(stderr, err, params);
 129        va_end(params);
 130        exit(0);
 131}
 132
 133__attribute__((format (printf, 1, 2)))
 134static NORETURN void forbidden(const char *err, ...)
 135{
 136        va_list params;
 137
 138        http_status(403, "Forbidden");
 139        hdr_nocache();
 140        end_headers();
 141
 142        va_start(params, err);
 143        if (err && *err)
 144                vfprintf(stderr, err, params);
 145        va_end(params);
 146        exit(0);
 147}
 148
 149static void select_getanyfile(void)
 150{
 151        if (!getanyfile)
 152                forbidden("Unsupported service: getanyfile");
 153}
 154
 155static void send_strbuf(const char *type, struct strbuf *buf)
 156{
 157        hdr_int(content_length, buf->len);
 158        hdr_str(content_type, type);
 159        end_headers();
 160        write_or_die(1, buf->buf, buf->len);
 161}
 162
 163static void send_local_file(const char *the_type, const char *name)
 164{
 165        const char *p = git_path("%s", name);
 166        size_t buf_alloc = 8192;
 167        char *buf = xmalloc(buf_alloc);
 168        int fd;
 169        struct stat sb;
 170
 171        fd = open(p, O_RDONLY);
 172        if (fd < 0)
 173                not_found("Cannot open '%s': %s", p, strerror(errno));
 174        if (fstat(fd, &sb) < 0)
 175                die_errno("Cannot stat '%s'", p);
 176
 177        hdr_int(content_length, sb.st_size);
 178        hdr_str(content_type, the_type);
 179        hdr_date(last_modified, sb.st_mtime);
 180        end_headers();
 181
 182        for (;;) {
 183                ssize_t n = xread(fd, buf, buf_alloc);
 184                if (n < 0)
 185                        die_errno("Cannot read '%s'", p);
 186                if (!n)
 187                        break;
 188                write_or_die(1, buf, n);
 189        }
 190        close(fd);
 191        free(buf);
 192}
 193
 194static void get_text_file(char *name)
 195{
 196        select_getanyfile();
 197        hdr_nocache();
 198        send_local_file("text/plain", name);
 199}
 200
 201static void get_loose_object(char *name)
 202{
 203        select_getanyfile();
 204        hdr_cache_forever();
 205        send_local_file("application/x-git-loose-object", name);
 206}
 207
 208static void get_pack_file(char *name)
 209{
 210        select_getanyfile();
 211        hdr_cache_forever();
 212        send_local_file("application/x-git-packed-objects", name);
 213}
 214
 215static void get_idx_file(char *name)
 216{
 217        select_getanyfile();
 218        hdr_cache_forever();
 219        send_local_file("application/x-git-packed-objects-toc", name);
 220}
 221
 222static void http_config(void)
 223{
 224        int i, value = 0;
 225        struct strbuf var = STRBUF_INIT;
 226
 227        git_config_get_bool("http.getanyfile", &getanyfile);
 228
 229        for (i = 0; i < ARRAY_SIZE(rpc_service); i++) {
 230                struct rpc_service *svc = &rpc_service[i];
 231                strbuf_addf(&var, "http.%s", svc->config_name);
 232                if (!git_config_get_bool(var.buf, &value))
 233                        svc->enabled = value;
 234                strbuf_reset(&var);
 235        }
 236
 237        strbuf_release(&var);
 238}
 239
 240static struct rpc_service *select_service(const char *name)
 241{
 242        const char *svc_name;
 243        struct rpc_service *svc = NULL;
 244        int i;
 245
 246        if (!skip_prefix(name, "git-", &svc_name))
 247                forbidden("Unsupported service: '%s'", name);
 248
 249        for (i = 0; i < ARRAY_SIZE(rpc_service); i++) {
 250                struct rpc_service *s = &rpc_service[i];
 251                if (!strcmp(s->name, svc_name)) {
 252                        svc = s;
 253                        break;
 254                }
 255        }
 256
 257        if (!svc)
 258                forbidden("Unsupported service: '%s'", name);
 259
 260        if (svc->enabled < 0) {
 261                const char *user = getenv("REMOTE_USER");
 262                svc->enabled = (user && *user) ? 1 : 0;
 263        }
 264        if (!svc->enabled)
 265                forbidden("Service not enabled: '%s'", svc->name);
 266        return svc;
 267}
 268
 269static void inflate_request(const char *prog_name, int out)
 270{
 271        git_zstream stream;
 272        unsigned char in_buf[8192];
 273        unsigned char out_buf[8192];
 274        unsigned long cnt = 0;
 275
 276        memset(&stream, 0, sizeof(stream));
 277        git_inflate_init_gzip_only(&stream);
 278
 279        while (1) {
 280                ssize_t n = xread(0, in_buf, sizeof(in_buf));
 281                if (n <= 0)
 282                        die("request ended in the middle of the gzip stream");
 283
 284                stream.next_in = in_buf;
 285                stream.avail_in = n;
 286
 287                while (0 < stream.avail_in) {
 288                        int ret;
 289
 290                        stream.next_out = out_buf;
 291                        stream.avail_out = sizeof(out_buf);
 292
 293                        ret = git_inflate(&stream, Z_NO_FLUSH);
 294                        if (ret != Z_OK && ret != Z_STREAM_END)
 295                                die("zlib error inflating request, result %d", ret);
 296
 297                        n = stream.total_out - cnt;
 298                        if (write_in_full(out, out_buf, n) != n)
 299                                die("%s aborted reading request", prog_name);
 300                        cnt += n;
 301
 302                        if (ret == Z_STREAM_END)
 303                                goto done;
 304                }
 305        }
 306
 307done:
 308        git_inflate_end(&stream);
 309        close(out);
 310}
 311
 312static void run_service(const char **argv)
 313{
 314        const char *encoding = getenv("HTTP_CONTENT_ENCODING");
 315        const char *user = getenv("REMOTE_USER");
 316        const char *host = getenv("REMOTE_ADDR");
 317        int gzipped_request = 0;
 318        struct child_process cld = CHILD_PROCESS_INIT;
 319
 320        if (encoding && !strcmp(encoding, "gzip"))
 321                gzipped_request = 1;
 322        else if (encoding && !strcmp(encoding, "x-gzip"))
 323                gzipped_request = 1;
 324
 325        if (!user || !*user)
 326                user = "anonymous";
 327        if (!host || !*host)
 328                host = "(none)";
 329
 330        if (!getenv("GIT_COMMITTER_NAME"))
 331                argv_array_pushf(&cld.env_array, "GIT_COMMITTER_NAME=%s", user);
 332        if (!getenv("GIT_COMMITTER_EMAIL"))
 333                argv_array_pushf(&cld.env_array,
 334                                 "GIT_COMMITTER_EMAIL=%s@http.%s", user, host);
 335
 336        cld.argv = argv;
 337        if (gzipped_request)
 338                cld.in = -1;
 339        cld.git_cmd = 1;
 340        if (start_command(&cld))
 341                exit(1);
 342
 343        close(1);
 344        if (gzipped_request)
 345                inflate_request(argv[0], cld.in);
 346        else
 347                close(0);
 348
 349        if (finish_command(&cld))
 350                exit(1);
 351}
 352
 353static int show_text_ref(const char *name, const unsigned char *sha1,
 354        int flag, void *cb_data)
 355{
 356        const char *name_nons = strip_namespace(name);
 357        struct strbuf *buf = cb_data;
 358        struct object *o = parse_object(sha1);
 359        if (!o)
 360                return 0;
 361
 362        strbuf_addf(buf, "%s\t%s\n", sha1_to_hex(sha1), name_nons);
 363        if (o->type == OBJ_TAG) {
 364                o = deref_tag(o, name, 0);
 365                if (!o)
 366                        return 0;
 367                strbuf_addf(buf, "%s\t%s^{}\n", sha1_to_hex(o->sha1),
 368                            name_nons);
 369        }
 370        return 0;
 371}
 372
 373static void get_info_refs(char *arg)
 374{
 375        const char *service_name = get_parameter("service");
 376        struct strbuf buf = STRBUF_INIT;
 377
 378        hdr_nocache();
 379
 380        if (service_name) {
 381                const char *argv[] = {NULL /* service name */,
 382                        "--stateless-rpc", "--advertise-refs",
 383                        ".", NULL};
 384                struct rpc_service *svc = select_service(service_name);
 385
 386                strbuf_addf(&buf, "application/x-git-%s-advertisement",
 387                        svc->name);
 388                hdr_str(content_type, buf.buf);
 389                end_headers();
 390
 391                packet_write(1, "# service=git-%s\n", svc->name);
 392                packet_flush(1);
 393
 394                argv[0] = svc->name;
 395                run_service(argv);
 396
 397        } else {
 398                select_getanyfile();
 399                for_each_namespaced_ref(show_text_ref, &buf);
 400                send_strbuf("text/plain", &buf);
 401        }
 402        strbuf_release(&buf);
 403}
 404
 405static int show_head_ref(const char *refname, const unsigned char *sha1,
 406        int flag, void *cb_data)
 407{
 408        struct strbuf *buf = cb_data;
 409
 410        if (flag & REF_ISSYMREF) {
 411                unsigned char unused[20];
 412                const char *target = resolve_ref_unsafe(refname,
 413                                                        RESOLVE_REF_READING,
 414                                                        unused, NULL);
 415                const char *target_nons = strip_namespace(target);
 416
 417                strbuf_addf(buf, "ref: %s\n", target_nons);
 418        } else {
 419                strbuf_addf(buf, "%s\n", sha1_to_hex(sha1));
 420        }
 421
 422        return 0;
 423}
 424
 425static void get_head(char *arg)
 426{
 427        struct strbuf buf = STRBUF_INIT;
 428
 429        select_getanyfile();
 430        head_ref_namespaced(show_head_ref, &buf);
 431        send_strbuf("text/plain", &buf);
 432        strbuf_release(&buf);
 433}
 434
 435static void get_info_packs(char *arg)
 436{
 437        size_t objdirlen = strlen(get_object_directory());
 438        struct strbuf buf = STRBUF_INIT;
 439        struct packed_git *p;
 440        size_t cnt = 0;
 441
 442        select_getanyfile();
 443        prepare_packed_git();
 444        for (p = packed_git; p; p = p->next) {
 445                if (p->pack_local)
 446                        cnt++;
 447        }
 448
 449        strbuf_grow(&buf, cnt * 53 + 2);
 450        for (p = packed_git; p; p = p->next) {
 451                if (p->pack_local)
 452                        strbuf_addf(&buf, "P %s\n", p->pack_name + objdirlen + 6);
 453        }
 454        strbuf_addch(&buf, '\n');
 455
 456        hdr_nocache();
 457        send_strbuf("text/plain; charset=utf-8", &buf);
 458        strbuf_release(&buf);
 459}
 460
 461static void check_content_type(const char *accepted_type)
 462{
 463        const char *actual_type = getenv("CONTENT_TYPE");
 464
 465        if (!actual_type)
 466                actual_type = "";
 467
 468        if (strcmp(actual_type, accepted_type)) {
 469                http_status(415, "Unsupported Media Type");
 470                hdr_nocache();
 471                end_headers();
 472                format_write(1,
 473                        "Expected POST with Content-Type '%s',"
 474                        " but received '%s' instead.\n",
 475                        accepted_type, actual_type);
 476                exit(0);
 477        }
 478}
 479
 480static void service_rpc(char *service_name)
 481{
 482        const char *argv[] = {NULL, "--stateless-rpc", ".", NULL};
 483        struct rpc_service *svc = select_service(service_name);
 484        struct strbuf buf = STRBUF_INIT;
 485
 486        strbuf_reset(&buf);
 487        strbuf_addf(&buf, "application/x-git-%s-request", svc->name);
 488        check_content_type(buf.buf);
 489
 490        hdr_nocache();
 491
 492        strbuf_reset(&buf);
 493        strbuf_addf(&buf, "application/x-git-%s-result", svc->name);
 494        hdr_str(content_type, buf.buf);
 495
 496        end_headers();
 497
 498        argv[0] = svc->name;
 499        run_service(argv);
 500        strbuf_release(&buf);
 501}
 502
 503static NORETURN void die_webcgi(const char *err, va_list params)
 504{
 505        static int dead;
 506
 507        if (!dead) {
 508                dead = 1;
 509                http_status(500, "Internal Server Error");
 510                hdr_nocache();
 511                end_headers();
 512
 513                vreportf("fatal: ", err, params);
 514        }
 515        exit(0); /* we successfully reported a failure ;-) */
 516}
 517
 518static char* getdir(void)
 519{
 520        struct strbuf buf = STRBUF_INIT;
 521        char *pathinfo = getenv("PATH_INFO");
 522        char *root = getenv("GIT_PROJECT_ROOT");
 523        char *path = getenv("PATH_TRANSLATED");
 524
 525        if (root && *root) {
 526                if (!pathinfo || !*pathinfo)
 527                        die("GIT_PROJECT_ROOT is set but PATH_INFO is not");
 528                if (daemon_avoid_alias(pathinfo))
 529                        die("'%s': aliased", pathinfo);
 530                end_url_with_slash(&buf, root);
 531                if (pathinfo[0] == '/')
 532                        pathinfo++;
 533                strbuf_addstr(&buf, pathinfo);
 534                return strbuf_detach(&buf, NULL);
 535        } else if (path && *path) {
 536                return xstrdup(path);
 537        } else
 538                die("No GIT_PROJECT_ROOT or PATH_TRANSLATED from server");
 539        return NULL;
 540}
 541
 542static struct service_cmd {
 543        const char *method;
 544        const char *pattern;
 545        void (*imp)(char *);
 546} services[] = {
 547        {"GET", "/HEAD$", get_head},
 548        {"GET", "/info/refs$", get_info_refs},
 549        {"GET", "/objects/info/alternates$", get_text_file},
 550        {"GET", "/objects/info/http-alternates$", get_text_file},
 551        {"GET", "/objects/info/packs$", get_info_packs},
 552        {"GET", "/objects/[0-9a-f]{2}/[0-9a-f]{38}$", get_loose_object},
 553        {"GET", "/objects/pack/pack-[0-9a-f]{40}\\.pack$", get_pack_file},
 554        {"GET", "/objects/pack/pack-[0-9a-f]{40}\\.idx$", get_idx_file},
 555
 556        {"POST", "/git-upload-pack$", service_rpc},
 557        {"POST", "/git-receive-pack$", service_rpc}
 558};
 559
 560int main(int argc, char **argv)
 561{
 562        char *method = getenv("REQUEST_METHOD");
 563        char *dir;
 564        struct service_cmd *cmd = NULL;
 565        char *cmd_arg = NULL;
 566        int i;
 567
 568        git_setup_gettext();
 569
 570        git_extract_argv0_path(argv[0]);
 571        set_die_routine(die_webcgi);
 572
 573        if (!method)
 574                die("No REQUEST_METHOD from server");
 575        if (!strcmp(method, "HEAD"))
 576                method = "GET";
 577        dir = getdir();
 578
 579        for (i = 0; i < ARRAY_SIZE(services); i++) {
 580                struct service_cmd *c = &services[i];
 581                regex_t re;
 582                regmatch_t out[1];
 583
 584                if (regcomp(&re, c->pattern, REG_EXTENDED))
 585                        die("Bogus regex in service table: %s", c->pattern);
 586                if (!regexec(&re, dir, 1, out, 0)) {
 587                        size_t n;
 588
 589                        if (strcmp(method, c->method)) {
 590                                const char *proto = getenv("SERVER_PROTOCOL");
 591                                if (proto && !strcmp(proto, "HTTP/1.1")) {
 592                                        http_status(405, "Method Not Allowed");
 593                                        hdr_str("Allow", !strcmp(c->method, "GET") ?
 594                                                "GET, HEAD" : c->method);
 595                                } else
 596                                        http_status(400, "Bad Request");
 597                                hdr_nocache();
 598                                end_headers();
 599                                return 0;
 600                        }
 601
 602                        cmd = c;
 603                        n = out[0].rm_eo - out[0].rm_so;
 604                        cmd_arg = xmemdupz(dir + out[0].rm_so + 1, n - 1);
 605                        dir[out[0].rm_so] = 0;
 606                        break;
 607                }
 608                regfree(&re);
 609        }
 610
 611        if (!cmd)
 612                not_found("Request not supported: '%s'", dir);
 613
 614        setup_path();
 615        if (!enter_repo(dir, 0))
 616                not_found("Not a git repository: '%s'", dir);
 617        if (!getenv("GIT_HTTP_EXPORT_ALL") &&
 618            access("git-daemon-export-ok", F_OK) )
 619                not_found("Repository not exported: '%s'", dir);
 620
 621        http_config();
 622        cmd->imp(cmd_arg);
 623        return 0;
 624}