http-backend.con commit Merge branch 'nd/maint-hide-checkout-index-from-error' (6a79be3)
   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
  11static const char content_type[] = "Content-Type";
  12static const char content_length[] = "Content-Length";
  13static const char last_modified[] = "Last-Modified";
  14static int getanyfile = 1;
  15
  16static struct string_list *query_params;
  17
  18struct rpc_service {
  19        const char *name;
  20        const char *config_name;
  21        signed enabled : 2;
  22};
  23
  24static struct rpc_service rpc_service[] = {
  25        { "upload-pack", "uploadpack", 1 },
  26        { "receive-pack", "receivepack", -1 },
  27};
  28
  29static struct string_list *get_parameters(void)
  30{
  31        if (!query_params) {
  32                const char *query = getenv("QUERY_STRING");
  33
  34                query_params = xcalloc(1, sizeof(*query_params));
  35                while (query && *query) {
  36                        char *name = url_decode_parameter_name(&query);
  37                        char *value = url_decode_parameter_value(&query);
  38                        struct string_list_item *i;
  39
  40                        i = string_list_lookup(query_params, name);
  41                        if (!i)
  42                                i = string_list_insert(query_params, name);
  43                        else
  44                                free(i->util);
  45                        i->util = value;
  46                }
  47        }
  48        return query_params;
  49}
  50
  51static const char *get_parameter(const char *name)
  52{
  53        struct string_list_item *i;
  54        i = string_list_lookup(get_parameters(), name);
  55        return i ? i->util : NULL;
  56}
  57
  58__attribute__((format (printf, 2, 3)))
  59static void format_write(int fd, const char *fmt, ...)
  60{
  61        static char buffer[1024];
  62
  63        va_list args;
  64        unsigned n;
  65
  66        va_start(args, fmt);
  67        n = vsnprintf(buffer, sizeof(buffer), fmt, args);
  68        va_end(args);
  69        if (n >= sizeof(buffer))
  70                die("protocol error: impossibly long line");
  71
  72        safe_write(fd, buffer, n);
  73}
  74
  75static void http_status(unsigned code, const char *msg)
  76{
  77        format_write(1, "Status: %u %s\r\n", code, msg);
  78}
  79
  80static void hdr_str(const char *name, const char *value)
  81{
  82        format_write(1, "%s: %s\r\n", name, value);
  83}
  84
  85static void hdr_int(const char *name, uintmax_t value)
  86{
  87        format_write(1, "%s: %" PRIuMAX "\r\n", name, value);
  88}
  89
  90static void hdr_date(const char *name, unsigned long when)
  91{
  92        const char *value = show_date(when, 0, DATE_RFC2822);
  93        hdr_str(name, value);
  94}
  95
  96static void hdr_nocache(void)
  97{
  98        hdr_str("Expires", "Fri, 01 Jan 1980 00:00:00 GMT");
  99        hdr_str("Pragma", "no-cache");
 100        hdr_str("Cache-Control", "no-cache, max-age=0, must-revalidate");
 101}
 102
 103static void hdr_cache_forever(void)
 104{
 105        unsigned long now = time(NULL);
 106        hdr_date("Date", now);
 107        hdr_date("Expires", now + 31536000);
 108        hdr_str("Cache-Control", "public, max-age=31536000");
 109}
 110
 111static void end_headers(void)
 112{
 113        safe_write(1, "\r\n", 2);
 114}
 115
 116__attribute__((format (printf, 1, 2)))
 117static NORETURN void not_found(const char *err, ...)
 118{
 119        va_list params;
 120
 121        http_status(404, "Not Found");
 122        hdr_nocache();
 123        end_headers();
 124
 125        va_start(params, err);
 126        if (err && *err)
 127                vfprintf(stderr, err, params);
 128        va_end(params);
 129        exit(0);
 130}
 131
 132__attribute__((format (printf, 1, 2)))
 133static NORETURN void forbidden(const char *err, ...)
 134{
 135        va_list params;
 136
 137        http_status(403, "Forbidden");
 138        hdr_nocache();
 139        end_headers();
 140
 141        va_start(params, err);
 142        if (err && *err)
 143                vfprintf(stderr, err, params);
 144        va_end(params);
 145        exit(0);
 146}
 147
 148static void select_getanyfile(void)
 149{
 150        if (!getanyfile)
 151                forbidden("Unsupported service: getanyfile");
 152}
 153
 154static void send_strbuf(const char *type, struct strbuf *buf)
 155{
 156        hdr_int(content_length, buf->len);
 157        hdr_str(content_type, type);
 158        end_headers();
 159        safe_write(1, buf->buf, buf->len);
 160}
 161
 162static void send_local_file(const char *the_type, const char *name)
 163{
 164        const char *p = git_path("%s", name);
 165        size_t buf_alloc = 8192;
 166        char *buf = xmalloc(buf_alloc);
 167        int fd;
 168        struct stat sb;
 169
 170        fd = open(p, O_RDONLY);
 171        if (fd < 0)
 172                not_found("Cannot open '%s': %s", p, strerror(errno));
 173        if (fstat(fd, &sb) < 0)
 174                die_errno("Cannot stat '%s'", p);
 175
 176        hdr_int(content_length, sb.st_size);
 177        hdr_str(content_type, the_type);
 178        hdr_date(last_modified, sb.st_mtime);
 179        end_headers();
 180
 181        for (;;) {
 182                ssize_t n = xread(fd, buf, buf_alloc);
 183                if (n < 0)
 184                        die_errno("Cannot read '%s'", p);
 185                if (!n)
 186                        break;
 187                safe_write(1, buf, n);
 188        }
 189        close(fd);
 190        free(buf);
 191}
 192
 193static void get_text_file(char *name)
 194{
 195        select_getanyfile();
 196        hdr_nocache();
 197        send_local_file("text/plain", name);
 198}
 199
 200static void get_loose_object(char *name)
 201{
 202        select_getanyfile();
 203        hdr_cache_forever();
 204        send_local_file("application/x-git-loose-object", name);
 205}
 206
 207static void get_pack_file(char *name)
 208{
 209        select_getanyfile();
 210        hdr_cache_forever();
 211        send_local_file("application/x-git-packed-objects", name);
 212}
 213
 214static void get_idx_file(char *name)
 215{
 216        select_getanyfile();
 217        hdr_cache_forever();
 218        send_local_file("application/x-git-packed-objects-toc", name);
 219}
 220
 221static int http_config(const char *var, const char *value, void *cb)
 222{
 223        if (!strcmp(var, "http.getanyfile")) {
 224                getanyfile = git_config_bool(var, value);
 225                return 0;
 226        }
 227
 228        if (!prefixcmp(var, "http.")) {
 229                int i;
 230
 231                for (i = 0; i < ARRAY_SIZE(rpc_service); i++) {
 232                        struct rpc_service *svc = &rpc_service[i];
 233                        if (!strcmp(var + 5, svc->config_name)) {
 234                                svc->enabled = git_config_bool(var, value);
 235                                return 0;
 236                        }
 237                }
 238        }
 239
 240        /* we are not interested in parsing any other configuration here */
 241        return 0;
 242}
 243
 244static struct rpc_service *select_service(const char *name)
 245{
 246        struct rpc_service *svc = NULL;
 247        int i;
 248
 249        if (prefixcmp(name, "git-"))
 250                forbidden("Unsupported service: '%s'", name);
 251
 252        for (i = 0; i < ARRAY_SIZE(rpc_service); i++) {
 253                struct rpc_service *s = &rpc_service[i];
 254                if (!strcmp(s->name, name + 4)) {
 255                        svc = s;
 256                        break;
 257                }
 258        }
 259
 260        if (!svc)
 261                forbidden("Unsupported service: '%s'", name);
 262
 263        if (svc->enabled < 0) {
 264                const char *user = getenv("REMOTE_USER");
 265                svc->enabled = (user && *user) ? 1 : 0;
 266        }
 267        if (!svc->enabled)
 268                forbidden("Service not enabled: '%s'", svc->name);
 269        return svc;
 270}
 271
 272static void inflate_request(const char *prog_name, int out)
 273{
 274        z_stream stream;
 275        unsigned char in_buf[8192];
 276        unsigned char out_buf[8192];
 277        unsigned long cnt = 0;
 278        int ret;
 279
 280        memset(&stream, 0, sizeof(stream));
 281        ret = inflateInit2(&stream, (15 + 16));
 282        if (ret != Z_OK)
 283                die("cannot start zlib inflater, zlib err %d", ret);
 284
 285        while (1) {
 286                ssize_t n = xread(0, in_buf, sizeof(in_buf));
 287                if (n <= 0)
 288                        die("request ended in the middle of the gzip stream");
 289
 290                stream.next_in = in_buf;
 291                stream.avail_in = n;
 292
 293                while (0 < stream.avail_in) {
 294                        int ret;
 295
 296                        stream.next_out = out_buf;
 297                        stream.avail_out = sizeof(out_buf);
 298
 299                        ret = inflate(&stream, Z_NO_FLUSH);
 300                        if (ret != Z_OK && ret != Z_STREAM_END)
 301                                die("zlib error inflating request, result %d", ret);
 302
 303                        n = stream.total_out - cnt;
 304                        if (write_in_full(out, out_buf, n) != n)
 305                                die("%s aborted reading request", prog_name);
 306                        cnt += n;
 307
 308                        if (ret == Z_STREAM_END)
 309                                goto done;
 310                }
 311        }
 312
 313done:
 314        inflateEnd(&stream);
 315        close(out);
 316}
 317
 318static void run_service(const char **argv)
 319{
 320        const char *encoding = getenv("HTTP_CONTENT_ENCODING");
 321        const char *user = getenv("REMOTE_USER");
 322        const char *host = getenv("REMOTE_ADDR");
 323        char *env[3];
 324        struct strbuf buf = STRBUF_INIT;
 325        int gzipped_request = 0;
 326        struct child_process cld;
 327
 328        if (encoding && !strcmp(encoding, "gzip"))
 329                gzipped_request = 1;
 330        else if (encoding && !strcmp(encoding, "x-gzip"))
 331                gzipped_request = 1;
 332
 333        if (!user || !*user)
 334                user = "anonymous";
 335        if (!host || !*host)
 336                host = "(none)";
 337
 338        memset(&env, 0, sizeof(env));
 339        strbuf_addf(&buf, "GIT_COMMITTER_NAME=%s", user);
 340        env[0] = strbuf_detach(&buf, NULL);
 341
 342        strbuf_addf(&buf, "GIT_COMMITTER_EMAIL=%s@http.%s", user, host);
 343        env[1] = strbuf_detach(&buf, NULL);
 344        env[2] = NULL;
 345
 346        memset(&cld, 0, sizeof(cld));
 347        cld.argv = argv;
 348        cld.env = (const char *const *)env;
 349        if (gzipped_request)
 350                cld.in = -1;
 351        cld.git_cmd = 1;
 352        if (start_command(&cld))
 353                exit(1);
 354
 355        close(1);
 356        if (gzipped_request)
 357                inflate_request(argv[0], cld.in);
 358        else
 359                close(0);
 360
 361        if (finish_command(&cld))
 362                exit(1);
 363        free(env[0]);
 364        free(env[1]);
 365        strbuf_release(&buf);
 366}
 367
 368static int show_text_ref(const char *name, const unsigned char *sha1,
 369        int flag, void *cb_data)
 370{
 371        struct strbuf *buf = cb_data;
 372        struct object *o = parse_object(sha1);
 373        if (!o)
 374                return 0;
 375
 376        strbuf_addf(buf, "%s\t%s\n", sha1_to_hex(sha1), name);
 377        if (o->type == OBJ_TAG) {
 378                o = deref_tag(o, name, 0);
 379                if (!o)
 380                        return 0;
 381                strbuf_addf(buf, "%s\t%s^{}\n", sha1_to_hex(o->sha1), name);
 382        }
 383        return 0;
 384}
 385
 386static void get_info_refs(char *arg)
 387{
 388        const char *service_name = get_parameter("service");
 389        struct strbuf buf = STRBUF_INIT;
 390
 391        hdr_nocache();
 392
 393        if (service_name) {
 394                const char *argv[] = {NULL /* service name */,
 395                        "--stateless-rpc", "--advertise-refs",
 396                        ".", NULL};
 397                struct rpc_service *svc = select_service(service_name);
 398
 399                strbuf_addf(&buf, "application/x-git-%s-advertisement",
 400                        svc->name);
 401                hdr_str(content_type, buf.buf);
 402                end_headers();
 403
 404                packet_write(1, "# service=git-%s\n", svc->name);
 405                packet_flush(1);
 406
 407                argv[0] = svc->name;
 408                run_service(argv);
 409
 410        } else {
 411                select_getanyfile();
 412                for_each_ref(show_text_ref, &buf);
 413                send_strbuf("text/plain", &buf);
 414        }
 415        strbuf_release(&buf);
 416}
 417
 418static void get_info_packs(char *arg)
 419{
 420        size_t objdirlen = strlen(get_object_directory());
 421        struct strbuf buf = STRBUF_INIT;
 422        struct packed_git *p;
 423        size_t cnt = 0;
 424
 425        select_getanyfile();
 426        prepare_packed_git();
 427        for (p = packed_git; p; p = p->next) {
 428                if (p->pack_local)
 429                        cnt++;
 430        }
 431
 432        strbuf_grow(&buf, cnt * 53 + 2);
 433        for (p = packed_git; p; p = p->next) {
 434                if (p->pack_local)
 435                        strbuf_addf(&buf, "P %s\n", p->pack_name + objdirlen + 6);
 436        }
 437        strbuf_addch(&buf, '\n');
 438
 439        hdr_nocache();
 440        send_strbuf("text/plain; charset=utf-8", &buf);
 441        strbuf_release(&buf);
 442}
 443
 444static void check_content_type(const char *accepted_type)
 445{
 446        const char *actual_type = getenv("CONTENT_TYPE");
 447
 448        if (!actual_type)
 449                actual_type = "";
 450
 451        if (strcmp(actual_type, accepted_type)) {
 452                http_status(415, "Unsupported Media Type");
 453                hdr_nocache();
 454                end_headers();
 455                format_write(1,
 456                        "Expected POST with Content-Type '%s',"
 457                        " but received '%s' instead.\n",
 458                        accepted_type, actual_type);
 459                exit(0);
 460        }
 461}
 462
 463static void service_rpc(char *service_name)
 464{
 465        const char *argv[] = {NULL, "--stateless-rpc", ".", NULL};
 466        struct rpc_service *svc = select_service(service_name);
 467        struct strbuf buf = STRBUF_INIT;
 468
 469        strbuf_reset(&buf);
 470        strbuf_addf(&buf, "application/x-git-%s-request", svc->name);
 471        check_content_type(buf.buf);
 472
 473        hdr_nocache();
 474
 475        strbuf_reset(&buf);
 476        strbuf_addf(&buf, "application/x-git-%s-result", svc->name);
 477        hdr_str(content_type, buf.buf);
 478
 479        end_headers();
 480
 481        argv[0] = svc->name;
 482        run_service(argv);
 483        strbuf_release(&buf);
 484}
 485
 486static NORETURN void die_webcgi(const char *err, va_list params)
 487{
 488        static int dead;
 489
 490        if (!dead) {
 491                dead = 1;
 492                http_status(500, "Internal Server Error");
 493                hdr_nocache();
 494                end_headers();
 495
 496                vreportf("fatal: ", err, params);
 497        }
 498        exit(0); /* we successfully reported a failure ;-) */
 499}
 500
 501static char* getdir(void)
 502{
 503        struct strbuf buf = STRBUF_INIT;
 504        char *pathinfo = getenv("PATH_INFO");
 505        char *root = getenv("GIT_PROJECT_ROOT");
 506        char *path = getenv("PATH_TRANSLATED");
 507
 508        if (root && *root) {
 509                if (!pathinfo || !*pathinfo)
 510                        die("GIT_PROJECT_ROOT is set but PATH_INFO is not");
 511                if (daemon_avoid_alias(pathinfo))
 512                        die("'%s': aliased", pathinfo);
 513                end_url_with_slash(&buf, root);
 514                if (pathinfo[0] == '/')
 515                        pathinfo++;
 516                strbuf_addstr(&buf, pathinfo);
 517                return strbuf_detach(&buf, NULL);
 518        } else if (path && *path) {
 519                return xstrdup(path);
 520        } else
 521                die("No GIT_PROJECT_ROOT or PATH_TRANSLATED from server");
 522        return NULL;
 523}
 524
 525static struct service_cmd {
 526        const char *method;
 527        const char *pattern;
 528        void (*imp)(char *);
 529} services[] = {
 530        {"GET", "/HEAD$", get_text_file},
 531        {"GET", "/info/refs$", get_info_refs},
 532        {"GET", "/objects/info/alternates$", get_text_file},
 533        {"GET", "/objects/info/http-alternates$", get_text_file},
 534        {"GET", "/objects/info/packs$", get_info_packs},
 535        {"GET", "/objects/[0-9a-f]{2}/[0-9a-f]{38}$", get_loose_object},
 536        {"GET", "/objects/pack/pack-[0-9a-f]{40}\\.pack$", get_pack_file},
 537        {"GET", "/objects/pack/pack-[0-9a-f]{40}\\.idx$", get_idx_file},
 538
 539        {"POST", "/git-upload-pack$", service_rpc},
 540        {"POST", "/git-receive-pack$", service_rpc}
 541};
 542
 543int main(int argc, char **argv)
 544{
 545        char *method = getenv("REQUEST_METHOD");
 546        char *dir;
 547        struct service_cmd *cmd = NULL;
 548        char *cmd_arg = NULL;
 549        int i;
 550
 551        git_extract_argv0_path(argv[0]);
 552        set_die_routine(die_webcgi);
 553
 554        if (!method)
 555                die("No REQUEST_METHOD from server");
 556        if (!strcmp(method, "HEAD"))
 557                method = "GET";
 558        dir = getdir();
 559
 560        for (i = 0; i < ARRAY_SIZE(services); i++) {
 561                struct service_cmd *c = &services[i];
 562                regex_t re;
 563                regmatch_t out[1];
 564
 565                if (regcomp(&re, c->pattern, REG_EXTENDED))
 566                        die("Bogus regex in service table: %s", c->pattern);
 567                if (!regexec(&re, dir, 1, out, 0)) {
 568                        size_t n;
 569
 570                        if (strcmp(method, c->method)) {
 571                                const char *proto = getenv("SERVER_PROTOCOL");
 572                                if (proto && !strcmp(proto, "HTTP/1.1"))
 573                                        http_status(405, "Method Not Allowed");
 574                                else
 575                                        http_status(400, "Bad Request");
 576                                hdr_nocache();
 577                                end_headers();
 578                                return 0;
 579                        }
 580
 581                        cmd = c;
 582                        n = out[0].rm_eo - out[0].rm_so;
 583                        cmd_arg = xmalloc(n);
 584                        memcpy(cmd_arg, dir + out[0].rm_so + 1, n-1);
 585                        cmd_arg[n-1] = '\0';
 586                        dir[out[0].rm_so] = 0;
 587                        break;
 588                }
 589                regfree(&re);
 590        }
 591
 592        if (!cmd)
 593                not_found("Request not supported: '%s'", dir);
 594
 595        setup_path();
 596        if (!enter_repo(dir, 0))
 597                not_found("Not a git repository: '%s'", dir);
 598        if (!getenv("GIT_HTTP_EXPORT_ALL") &&
 599            access("git-daemon-export-ok", F_OK) )
 600                not_found("Repository not exported: '%s'", dir);
 601
 602        git_config(http_config, NULL);
 603        cmd->imp(cmd_arg);
 604        return 0;
 605}