Andrew's git / gitweb.git / http-backend.c
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http-backend.con commit glossary: more precise definition of tree-ish (a.k.a. treeish) (930f302)
   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 int http_config(const char *var, const char *value, void *cb)
 223{
 224        if (!strcmp(var, "http.getanyfile")) {
 225                getanyfile = git_config_bool(var, value);
 226                return 0;
 227        }
 228
 229        if (!prefixcmp(var, "http.")) {
 230                int i;
 231
 232                for (i = 0; i < ARRAY_SIZE(rpc_service); i++) {
 233                        struct rpc_service *svc = &rpc_service[i];
 234                        if (!strcmp(var + 5, svc->config_name)) {
 235                                svc->enabled = git_config_bool(var, value);
 236                                return 0;
 237                        }
 238                }
 239        }
 240
 241        /* we are not interested in parsing any other configuration here */
 242        return 0;
 243}
 244
 245static struct rpc_service *select_service(const char *name)
 246{
 247        struct rpc_service *svc = NULL;
 248        int i;
 249
 250        if (prefixcmp(name, "git-"))
 251                forbidden("Unsupported service: '%s'", name);
 252
 253        for (i = 0; i < ARRAY_SIZE(rpc_service); i++) {
 254                struct rpc_service *s = &rpc_service[i];
 255                if (!strcmp(s->name, name + 4)) {
 256                        svc = s;
 257                        break;
 258                }
 259        }
 260
 261        if (!svc)
 262                forbidden("Unsupported service: '%s'", name);
 263
 264        if (svc->enabled < 0) {
 265                const char *user = getenv("REMOTE_USER");
 266                svc->enabled = (user && *user) ? 1 : 0;
 267        }
 268        if (!svc->enabled)
 269                forbidden("Service not enabled: '%s'", svc->name);
 270        return svc;
 271}
 272
 273static void inflate_request(const char *prog_name, int out)
 274{
 275        git_zstream stream;
 276        unsigned char in_buf[8192];
 277        unsigned char out_buf[8192];
 278        unsigned long cnt = 0;
 279
 280        memset(&stream, 0, sizeof(stream));
 281        git_inflate_init_gzip_only(&stream);
 282
 283        while (1) {
 284                ssize_t n = xread(0, in_buf, sizeof(in_buf));
 285                if (n <= 0)
 286                        die("request ended in the middle of the gzip stream");
 287
 288                stream.next_in = in_buf;
 289                stream.avail_in = n;
 290
 291                while (0 < stream.avail_in) {
 292                        int ret;
 293
 294                        stream.next_out = out_buf;
 295                        stream.avail_out = sizeof(out_buf);
 296
 297                        ret = git_inflate(&stream, Z_NO_FLUSH);
 298                        if (ret != Z_OK && ret != Z_STREAM_END)
 299                                die("zlib error inflating request, result %d", ret);
 300
 301                        n = stream.total_out - cnt;
 302                        if (write_in_full(out, out_buf, n) != n)
 303                                die("%s aborted reading request", prog_name);
 304                        cnt += n;
 305
 306                        if (ret == Z_STREAM_END)
 307                                goto done;
 308                }
 309        }
 310
 311done:
 312        git_inflate_end(&stream);
 313        close(out);
 314}
 315
 316static void run_service(const char **argv)
 317{
 318        const char *encoding = getenv("HTTP_CONTENT_ENCODING");
 319        const char *user = getenv("REMOTE_USER");
 320        const char *host = getenv("REMOTE_ADDR");
 321        struct argv_array env = ARGV_ARRAY_INIT;
 322        int gzipped_request = 0;
 323        struct child_process cld;
 324
 325        if (encoding && !strcmp(encoding, "gzip"))
 326                gzipped_request = 1;
 327        else if (encoding && !strcmp(encoding, "x-gzip"))
 328                gzipped_request = 1;
 329
 330        if (!user || !*user)
 331                user = "anonymous";
 332        if (!host || !*host)
 333                host = "(none)";
 334
 335        if (!getenv("GIT_COMMITTER_NAME"))
 336                argv_array_pushf(&env, "GIT_COMMITTER_NAME=%s", user);
 337        if (!getenv("GIT_COMMITTER_EMAIL"))
 338                argv_array_pushf(&env, "GIT_COMMITTER_EMAIL=%s@http.%s",
 339                                 user, host);
 340
 341        memset(&cld, 0, sizeof(cld));
 342        cld.argv = argv;
 343        cld.env = env.argv;
 344        if (gzipped_request)
 345                cld.in = -1;
 346        cld.git_cmd = 1;
 347        if (start_command(&cld))
 348                exit(1);
 349
 350        close(1);
 351        if (gzipped_request)
 352                inflate_request(argv[0], cld.in);
 353        else
 354                close(0);
 355
 356        if (finish_command(&cld))
 357                exit(1);
 358        argv_array_clear(&env);
 359}
 360
 361static int show_text_ref(const char *name, const unsigned char *sha1,
 362        int flag, void *cb_data)
 363{
 364        const char *name_nons = strip_namespace(name);
 365        struct strbuf *buf = cb_data;
 366        struct object *o = parse_object(sha1);
 367        if (!o)
 368                return 0;
 369
 370        strbuf_addf(buf, "%s\t%s\n", sha1_to_hex(sha1), name_nons);
 371        if (o->type == OBJ_TAG) {
 372                o = deref_tag(o, name, 0);
 373                if (!o)
 374                        return 0;
 375                strbuf_addf(buf, "%s\t%s^{}\n", sha1_to_hex(o->sha1),
 376                            name_nons);
 377        }
 378        return 0;
 379}
 380
 381static void get_info_refs(char *arg)
 382{
 383        const char *service_name = get_parameter("service");
 384        struct strbuf buf = STRBUF_INIT;
 385
 386        hdr_nocache();
 387
 388        if (service_name) {
 389                const char *argv[] = {NULL /* service name */,
 390                        "--stateless-rpc", "--advertise-refs",
 391                        ".", NULL};
 392                struct rpc_service *svc = select_service(service_name);
 393
 394                strbuf_addf(&buf, "application/x-git-%s-advertisement",
 395                        svc->name);
 396                hdr_str(content_type, buf.buf);
 397                end_headers();
 398
 399                packet_write(1, "# service=git-%s\n", svc->name);
 400                packet_flush(1);
 401
 402                argv[0] = svc->name;
 403                run_service(argv);
 404
 405        } else {
 406                select_getanyfile();
 407                for_each_namespaced_ref(show_text_ref, &buf);
 408                send_strbuf("text/plain", &buf);
 409        }
 410        strbuf_release(&buf);
 411}
 412
 413static int show_head_ref(const char *refname, const unsigned char *sha1,
 414        int flag, void *cb_data)
 415{
 416        struct strbuf *buf = cb_data;
 417
 418        if (flag & REF_ISSYMREF) {
 419                unsigned char unused[20];
 420                const char *target = resolve_ref_unsafe(refname, unused, 1, NULL);
 421                const char *target_nons = strip_namespace(target);
 422
 423                strbuf_addf(buf, "ref: %s\n", target_nons);
 424        } else {
 425                strbuf_addf(buf, "%s\n", sha1_to_hex(sha1));
 426        }
 427
 428        return 0;
 429}
 430
 431static void get_head(char *arg)
 432{
 433        struct strbuf buf = STRBUF_INIT;
 434
 435        select_getanyfile();
 436        head_ref_namespaced(show_head_ref, &buf);
 437        send_strbuf("text/plain", &buf);
 438        strbuf_release(&buf);
 439}
 440
 441static void get_info_packs(char *arg)
 442{
 443        size_t objdirlen = strlen(get_object_directory());
 444        struct strbuf buf = STRBUF_INIT;
 445        struct packed_git *p;
 446        size_t cnt = 0;
 447
 448        select_getanyfile();
 449        prepare_packed_git();
 450        for (p = packed_git; p; p = p->next) {
 451                if (p->pack_local)
 452                        cnt++;
 453        }
 454
 455        strbuf_grow(&buf, cnt * 53 + 2);
 456        for (p = packed_git; p; p = p->next) {
 457                if (p->pack_local)
 458                        strbuf_addf(&buf, "P %s\n", p->pack_name + objdirlen + 6);
 459        }
 460        strbuf_addch(&buf, '\n');
 461
 462        hdr_nocache();
 463        send_strbuf("text/plain; charset=utf-8", &buf);
 464        strbuf_release(&buf);
 465}
 466
 467static void check_content_type(const char *accepted_type)
 468{
 469        const char *actual_type = getenv("CONTENT_TYPE");
 470
 471        if (!actual_type)
 472                actual_type = "";
 473
 474        if (strcmp(actual_type, accepted_type)) {
 475                http_status(415, "Unsupported Media Type");
 476                hdr_nocache();
 477                end_headers();
 478                format_write(1,
 479                        "Expected POST with Content-Type '%s',"
 480                        " but received '%s' instead.\n",
 481                        accepted_type, actual_type);
 482                exit(0);
 483        }
 484}
 485
 486static void service_rpc(char *service_name)
 487{
 488        const char *argv[] = {NULL, "--stateless-rpc", ".", NULL};
 489        struct rpc_service *svc = select_service(service_name);
 490        struct strbuf buf = STRBUF_INIT;
 491
 492        strbuf_reset(&buf);
 493        strbuf_addf(&buf, "application/x-git-%s-request", svc->name);
 494        check_content_type(buf.buf);
 495
 496        hdr_nocache();
 497
 498        strbuf_reset(&buf);
 499        strbuf_addf(&buf, "application/x-git-%s-result", svc->name);
 500        hdr_str(content_type, buf.buf);
 501
 502        end_headers();
 503
 504        argv[0] = svc->name;
 505        run_service(argv);
 506        strbuf_release(&buf);
 507}
 508
 509static NORETURN void die_webcgi(const char *err, va_list params)
 510{
 511        static int dead;
 512
 513        if (!dead) {
 514                dead = 1;
 515                http_status(500, "Internal Server Error");
 516                hdr_nocache();
 517                end_headers();
 518
 519                vreportf("fatal: ", err, params);
 520        }
 521        exit(0); /* we successfully reported a failure ;-) */
 522}
 523
 524static char* getdir(void)
 525{
 526        struct strbuf buf = STRBUF_INIT;
 527        char *pathinfo = getenv("PATH_INFO");
 528        char *root = getenv("GIT_PROJECT_ROOT");
 529        char *path = getenv("PATH_TRANSLATED");
 530
 531        if (root && *root) {
 532                if (!pathinfo || !*pathinfo)
 533                        die("GIT_PROJECT_ROOT is set but PATH_INFO is not");
 534                if (daemon_avoid_alias(pathinfo))
 535                        die("'%s': aliased", pathinfo);
 536                end_url_with_slash(&buf, root);
 537                if (pathinfo[0] == '/')
 538                        pathinfo++;
 539                strbuf_addstr(&buf, pathinfo);
 540                return strbuf_detach(&buf, NULL);
 541        } else if (path && *path) {
 542                return xstrdup(path);
 543        } else
 544                die("No GIT_PROJECT_ROOT or PATH_TRANSLATED from server");
 545        return NULL;
 546}
 547
 548static struct service_cmd {
 549        const char *method;
 550        const char *pattern;
 551        void (*imp)(char *);
 552} services[] = {
 553        {"GET", "/HEAD$", get_head},
 554        {"GET", "/info/refs$", get_info_refs},
 555        {"GET", "/objects/info/alternates$", get_text_file},
 556        {"GET", "/objects/info/http-alternates$", get_text_file},
 557        {"GET", "/objects/info/packs$", get_info_packs},
 558        {"GET", "/objects/[0-9a-f]{2}/[0-9a-f]{38}$", get_loose_object},
 559        {"GET", "/objects/pack/pack-[0-9a-f]{40}\\.pack$", get_pack_file},
 560        {"GET", "/objects/pack/pack-[0-9a-f]{40}\\.idx$", get_idx_file},
 561
 562        {"POST", "/git-upload-pack$", service_rpc},
 563        {"POST", "/git-receive-pack$", service_rpc}
 564};
 565
 566int main(int argc, char **argv)
 567{
 568        char *method = getenv("REQUEST_METHOD");
 569        char *dir;
 570        struct service_cmd *cmd = NULL;
 571        char *cmd_arg = NULL;
 572        int i;
 573
 574        git_setup_gettext();
 575
 576        git_extract_argv0_path(argv[0]);
 577        set_die_routine(die_webcgi);
 578
 579        if (!method)
 580                die("No REQUEST_METHOD from server");
 581        if (!strcmp(method, "HEAD"))
 582                method = "GET";
 583        dir = getdir();
 584
 585        for (i = 0; i < ARRAY_SIZE(services); i++) {
 586                struct service_cmd *c = &services[i];
 587                regex_t re;
 588                regmatch_t out[1];
 589
 590                if (regcomp(&re, c->pattern, REG_EXTENDED))
 591                        die("Bogus regex in service table: %s", c->pattern);
 592                if (!regexec(&re, dir, 1, out, 0)) {
 593                        size_t n;
 594
 595                        if (strcmp(method, c->method)) {
 596                                const char *proto = getenv("SERVER_PROTOCOL");
 597                                if (proto && !strcmp(proto, "HTTP/1.1"))
 598                                        http_status(405, "Method Not Allowed");
 599                                else
 600                                        http_status(400, "Bad Request");
 601                                hdr_nocache();
 602                                end_headers();
 603                                return 0;
 604                        }
 605
 606                        cmd = c;
 607                        n = out[0].rm_eo - out[0].rm_so;
 608                        cmd_arg = xmalloc(n);
 609                        memcpy(cmd_arg, dir + out[0].rm_so + 1, n-1);
 610                        cmd_arg[n-1] = '\0';
 611                        dir[out[0].rm_so] = 0;
 612                        break;
 613                }
 614                regfree(&re);
 615        }
 616
 617        if (!cmd)
 618                not_found("Request not supported: '%s'", dir);
 619
 620        setup_path();
 621        if (!enter_repo(dir, 0))
 622                not_found("Not a git repository: '%s'", dir);
 623        if (!getenv("GIT_HTTP_EXPORT_ALL") &&
 624            access("git-daemon-export-ok", F_OK) )
 625                not_found("Repository not exported: '%s'", dir);
 626
 627        git_config(http_config, NULL);
 628        cmd->imp(cmd_arg);
 629        return 0;
 630}