config.c

Apache HTTP Server 是一个功能强大的灵活的与HTTP/1.1相兼容的web服务器.这里给出的是Apache HTTP服务器的源码。

    parms.temp_pool = ptemp;
    parms.server = s;
    parms.override = (RSRC_CONF | OR_ALL) & ~(OR_AUTHCFG | OR_LIMIT);
    parms.limited = -1;

    errmsg = ap_walk_config(conftree, &parms, s->lookup_defaults);
    if (errmsg) {
        ap_log_perror(APLOG_MARK, APLOG_STARTUP, 0, p,
                     "Syntax error on line %d of %s:",
                     parms.err_directive->line_num,
                     parms.err_directive->filename);
        ap_log_perror(APLOG_MARK, APLOG_STARTUP, 0, p,
                     "%s", errmsg);
        exit(1);
    }
}

AP_CORE_DECLARE(int) ap_parse_htaccess(ap_conf_vector_t **result,
                                       request_rec *r, int override,
                                       const char *d, const char *access_name)
{
    ap_configfile_t *f = NULL;
    cmd_parms parms;
    char *filename = NULL;
    const struct htaccess_result *cache;
    struct htaccess_result *new;
    ap_conf_vector_t *dc = NULL;
    apr_status_t status;

    /* firstly, search cache */
    for (cache = r->htaccess; cache != NULL; cache = cache->next) {
        if (cache->override == override && strcmp(cache->dir, d) == 0) {
            *result = cache->htaccess;
            return OK;
        }
    }

    parms = default_parms;
    parms.override = override;
    parms.pool = r->pool;
    parms.temp_pool = r->pool;
    parms.server = r->server;
    parms.path = apr_pstrdup(r->pool, d);

    /* loop through the access names and find the first one */
    while (access_name[0]) {
        /* AFAICT; there is no use of the actual 'filename' against
         * any canonicalization, so we will simply take the given
         * name, ignoring case sensitivity and aliases
         */
        filename = ap_make_full_path(r->pool, d,
                                     ap_getword_conf(r->pool, &access_name));
        status = ap_pcfg_openfile(&f, r->pool, filename);

        if (status == APR_SUCCESS) {
            const char *errmsg;
            ap_directive_t *temptree = NULL;

            dc = ap_create_per_dir_config(r->pool);

            parms.config_file = f;
            errmsg = ap_build_config(&parms, r->pool, r->pool, &temptree);
            if (errmsg == NULL)
                errmsg = ap_walk_config(temptree, &parms, dc);

            ap_cfg_closefile(f);

            if (errmsg) {
                ap_log_rerror(APLOG_MARK, APLOG_ALERT, 0, r,
                              "%s: %s", filename, errmsg);
                return HTTP_INTERNAL_SERVER_ERROR;
            }

            *result = dc;
            break;
        }
        else {
            if (!APR_STATUS_IS_ENOENT(status)
                && !APR_STATUS_IS_ENOTDIR(status)) {
                ap_log_rerror(APLOG_MARK, APLOG_CRIT, status, r,
                              "%s pcfg_openfile: unable to check htaccess file, "
                              "ensure it is readable",
                              filename);
                apr_table_setn(r->notes, "error-notes",
                               "Server unable to read htaccess file, denying "
                               "access to be safe");
                return HTTP_FORBIDDEN;
            }
        }
    }

    /* cache it */
    new = apr_palloc(r->pool, sizeof(struct htaccess_result));
    new->dir = parms.path;
    new->override = override;
    new->htaccess = dc;

    /* add to head of list */
    new->next = r->htaccess;
    r->htaccess = new;

    return OK;
}

AP_CORE_DECLARE(const char *) ap_init_virtual_host(apr_pool_t *p,
                                                   const char *hostname,
                                                   server_rec *main_server,
                                                   server_rec **ps)
{
    server_rec *s = (server_rec *) apr_pcalloc(p, sizeof(server_rec));

    /* TODO: this crap belongs in http_core */
    s->process = main_server->process;
    s->server_admin = NULL;
    s->server_hostname = NULL;
    s->error_fname = NULL;
    s->timeout = 0;
    s->keep_alive_timeout = 0;
    s->keep_alive = -1;
    s->keep_alive_max = -1;
    s->error_log = main_server->error_log;
    s->loglevel = main_server->loglevel;
    /* useful default, otherwise we get a port of 0 on redirects */
    s->port = main_server->port;
    s->next = NULL;

    s->is_virtual = 1;
    s->names = apr_array_make(p, 4, sizeof(char **));
    s->wild_names = apr_array_make(p, 4, sizeof(char **));

    s->module_config = create_empty_config(p);
    s->lookup_defaults = ap_create_per_dir_config(p);

    s->limit_req_line = main_server->limit_req_line;
    s->limit_req_fieldsize = main_server->limit_req_fieldsize;
    s->limit_req_fields = main_server->limit_req_fields;

    *ps = s;

    return ap_parse_vhost_addrs(p, hostname, s);
}


AP_DECLARE(void) ap_fixup_virtual_hosts(apr_pool_t *p, server_rec *main_server)
{
    server_rec *virt;

    for (virt = main_server->next; virt; virt = virt->next) {
        merge_server_configs(p, main_server->module_config,
                             virt->module_config);

        virt->lookup_defaults =
            ap_merge_per_dir_configs(p, main_server->lookup_defaults,
                                     virt->lookup_defaults);

        if (virt->server_admin == NULL)
            virt->server_admin = main_server->server_admin;

        if (virt->timeout == 0)
            virt->timeout = main_server->timeout;

        if (virt->keep_alive_timeout == 0)
            virt->keep_alive_timeout = main_server->keep_alive_timeout;

        if (virt->keep_alive == -1)
            virt->keep_alive = main_server->keep_alive;

        if (virt->keep_alive_max == -1)
            virt->keep_alive_max = main_server->keep_alive_max;

        /* XXX: this is really something that should be dealt with by a
         * post-config api phase
         */
        ap_core_reorder_directories(p, virt);
    }

    ap_core_reorder_directories(p, main_server);
}

/*****************************************************************
 *
 * Getting *everything* configured...
 */

static void init_config_globals(apr_pool_t *p)
{
    /* Global virtual host hash bucket pointers.  Init to null. */
    ap_init_vhost_config(p);
}

static server_rec *init_server_config(process_rec *process, apr_pool_t *p)
{
    apr_status_t rv;
    server_rec *s = (server_rec *) apr_pcalloc(p, sizeof(server_rec));

    apr_file_open_stderr(&s->error_log, p);
    s->process = process;
    s->port = 0;
    s->server_admin = DEFAULT_ADMIN;
    s->server_hostname = NULL;
    s->error_fname = DEFAULT_ERRORLOG;
    s->loglevel = DEFAULT_LOGLEVEL;
    s->limit_req_line = DEFAULT_LIMIT_REQUEST_LINE;
    s->limit_req_fieldsize = DEFAULT_LIMIT_REQUEST_FIELDSIZE;
    s->limit_req_fields = DEFAULT_LIMIT_REQUEST_FIELDS;
    s->timeout = apr_time_from_sec(DEFAULT_TIMEOUT);
    s->keep_alive_timeout = apr_time_from_sec(DEFAULT_KEEPALIVE_TIMEOUT);
    s->keep_alive_max = DEFAULT_KEEPALIVE;
    s->keep_alive = 1;
    s->next = NULL;
    s->addrs = apr_pcalloc(p, sizeof(server_addr_rec));

    /* NOT virtual host; don't match any real network interface */
    rv = apr_sockaddr_info_get(&s->addrs->host_addr,
                               NULL, APR_INET, 0, 0, p);
    ap_assert(rv == APR_SUCCESS); /* otherwise: bug or no storage */

    s->addrs->host_port = 0; /* matches any port */
    s->addrs->virthost = ""; /* must be non-NULL */
    s->names = s->wild_names = NULL;

    s->module_config = create_server_config(p, s);
    s->lookup_defaults = create_default_per_dir_config(p);

    return s;
}


AP_DECLARE(server_rec*) ap_read_config(process_rec *process, apr_pool_t *ptemp,
                                       const char *filename,
                                       ap_directive_t **conftree)
{
    const char *confname;
    apr_pool_t *p = process->pconf;
    server_rec *s = init_server_config(process, p);

    init_config_globals(p);

    /* All server-wide config files now have the SAME syntax... */
    process_command_config(s, ap_server_pre_read_config, conftree,
                           p, ptemp);

    /* process_command_config may change the ServerRoot so
     * compute this config file name afterwards.
     */
    confname = ap_server_root_relative(p, filename);

    if (!confname) {
        ap_log_error(APLOG_MARK, APLOG_STARTUP|APLOG_CRIT,
                     APR_EBADPATH, NULL, "Invalid config file path %s",
                     filename);
        exit(1);
    }

    ap_process_resource_config(s, confname, conftree, p, ptemp);

    process_command_config(s, ap_server_post_read_config, conftree,
                           p, ptemp);

    return s;
}

AP_DECLARE(void) ap_single_module_configure(apr_pool_t *p, server_rec *s,
                                            module *m)
{
    if (m->create_server_config)
        ap_set_module_config(s->module_config, m,
                             (*m->create_server_config)(p, s));

    if (m->create_dir_config)
        ap_set_module_config(s->lookup_defaults, m,
                             (*m->create_dir_config)(p, NULL));
}

AP_DECLARE(void) ap_run_rewrite_args(process_rec *process)
{
    module *m;

    for (m = ap_top_module; m; m = m->next) {
        if (m->rewrite_args) {
            (*m->rewrite_args)(process);
        }
    }
}

/********************************************************************
 * Configuration directives are restricted in terms of where they may
 * appear in the main configuration files and/or .htaccess files according
 * to the bitmask req_override in the command_rec structure.
 * If any of the overrides set in req_override are also allowed in the
 * context in which the command is read, then the command is allowed.
 * The context is determined as follows:
 *
 *    inside *.conf --> override = (RSRC_CONF|OR_ALL)&~(OR_AUTHCFG|OR_LIMIT);
 *    within <Directory> or <Location> --> override = OR_ALL|ACCESS_CONF;
 *    within .htaccess --> override = AllowOverride for current directory;
 *
 * the result is, well, a rather confusing set of possibilities for when
 * a particular directive is allowed to be used.  This procedure prints
 * in English where the given (pc) directive can be used.
 */
static void show_overrides(const command_rec *pc, module *pm)
{
    int n = 0;

    printf("\tAllowed in *.conf ");
    if ((pc->req_override & (OR_OPTIONS | OR_FILEINFO | OR_INDEXES))
        || ((pc->req_override & RSRC_CONF)
        && ((pc->req_override & (ACCESS_CONF | OR_AUTHCFG | OR_LIMIT))))) {
        printf("anywhere");
    }
    else if (pc->req_override & RSRC_CONF) {
        printf("only outside <Directory>, <Files> or <Location>");
    }
    else {
        printf("only inside <Directory>, <Files> or <Location>");
    }

    /* Warn if the directive is allowed inside <Directory> or .htaccess
     * but module doesn't support per-dir configuration
     */
    if ((pc->req_override & (OR_ALL | ACCESS_CONF)) && !pm->create_dir_config)
        printf(" [no per-dir config]");

    if (pc->req_override & OR_ALL) {
        printf(" and in .htaccess\n\twhen AllowOverride");

        if ((pc->req_override & OR_ALL) == OR_ALL) {
            printf(" isn't None");
        }
        else {
            printf(" includes ");

            if (pc->req_override & OR_AUTHCFG) {
                if (n++)
                    printf(" or ");

                printf("AuthConfig");
            }

            if (pc->req_override & OR_LIMIT) {
                if (n++)
                    printf(" or ");

                printf("Limit");
            }

            if (pc->req_override & OR_OPTIONS) {
                if (n++)
                    printf(" or ");

                printf("Options");
            }

            if (pc->req_override & OR_FILEINFO) {
                if (n++)
                    printf(" or ");

                printf("FileInfo");
            }

            if (pc->req_override & OR_INDEXES) {
                if (n++)
                    printf(" or ");

                printf("Indexes");
            }
        }
    }

    printf("\n");
}

/* Show the preloaded configuration directives, the help string explaining
 * the directive arguments, in what module they are handled, and in
 * what parts of the configuration they are allowed.  Used for httpd -L.
 */
AP_DECLARE(void) ap_show_directives(void)
{
    const command_rec *pc;
    int n;

    for (n = 0; ap_loaded_modules[n]; ++n) {
        for (pc = ap_loaded_modules[n]->cmds; pc && pc->name; ++pc) {
            printf("%s (%s)\n", pc->name, ap_loaded_modules[n]->name);

            if (pc->errmsg)
                printf("\t%s\n", pc->errmsg);

            show_overrides(pc, ap_loaded_modules[n]);
        }
    }
}

/* Show the preloaded module names.  Used for httpd -l. */
AP_DECLARE(void) ap_show_modules(void)
{
    int n;

    printf("Compiled in modules:\n");
    for (n = 0; ap_loaded_modules[n]; ++n)
        printf("  %s\n", ap_loaded_modules[n]->name);
}

AP_DECLARE(const char *) ap_show_mpm(void)
{
    return MPM_NAME;
}