proxy_util.c

Apache官方在今天放出产品系列2.2的最新版本2.2.11的源码包 最流行的HTTP服务器软件之一

    c = strchr(uri, ':');
    if (c == NULL || c[1] != '/' || c[2] != '/' || c[3] == '\0') {
       return NULL;
    }
    /* remove path from uri */
    if ((c = strchr(c + 3, '/'))) {
        *c = '\0';
    }
    balancer = (proxy_balancer *)conf->balancers->elts;
    for (i = 0; i < conf->balancers->nelts; i++) {
        if (strcasecmp(balancer->name, uri) == 0) {
            return balancer;
        }
        balancer++;
    }
    return NULL;
}

PROXY_DECLARE(const char *) ap_proxy_add_balancer(proxy_balancer **balancer,
                                                  apr_pool_t *p,
                                                  proxy_server_conf *conf,
                                                  const char *url)
{
    char *c, *q, *uri = apr_pstrdup(p, url);
    proxy_balancer_method *lbmethod;

    c = strchr(uri, ':');
    if (c == NULL || c[1] != '/' || c[2] != '/' || c[3] == '\0')
       return "Bad syntax for a balancer name";
    /* remove path from uri */
    if ((q = strchr(c + 3, '/')))
        *q = '\0';

    ap_str_tolower(uri);
    *balancer = apr_array_push(conf->balancers);
    memset(*balancer, 0, sizeof(proxy_balancer));

    /*
     * NOTE: The default method is byrequests, which we assume
     * exists!
     */
    lbmethod = ap_lookup_provider(PROXY_LBMETHOD, "byrequests", "0");
    if (!lbmethod) {
        return "Can't find 'byrequests' lb method";
    }

    (*balancer)->name = uri;
    (*balancer)->lbmethod = lbmethod;
    (*balancer)->workers = apr_array_make(p, 5, sizeof(proxy_worker));
    /* XXX Is this a right place to create mutex */
#if APR_HAS_THREADS
    if (apr_thread_mutex_create(&((*balancer)->mutex),
                APR_THREAD_MUTEX_DEFAULT, p) != APR_SUCCESS) {
        /* XXX: Do we need to log something here */
        return "can not create thread mutex";
    }
#endif

    return NULL;
}

PROXY_DECLARE(proxy_worker *) ap_proxy_get_worker(apr_pool_t *p,
                                                  proxy_server_conf *conf,
                                                  const char *url)
{
    proxy_worker *worker;
    proxy_worker *max_worker = NULL;
    int max_match = 0;
    int url_length;
    int min_match;
    int worker_name_length;
    const char *c;
    char *url_copy;
    int i;

    c = ap_strchr_c(url, ':');
    if (c == NULL || c[1] != '/' || c[2] != '/' || c[3] == '\0') {
       return NULL;
    }

    url_copy = apr_pstrdup(p, url);
    url_length = strlen(url);

    /*
     * We need to find the start of the path and
     * therefore we know the length of the scheme://hostname/
     * part to we can force-lowercase everything up to
     * the start of the path.
     */
    c = ap_strchr_c(c+3, '/');
    if (c) {
        char *pathstart;
        pathstart = url_copy + (c - url);
        *pathstart = '\0';
        ap_str_tolower(url_copy);
        min_match = strlen(url_copy);
        *pathstart = '/';
    }
    else {
        ap_str_tolower(url_copy);
        min_match = strlen(url_copy);
    }

    worker = (proxy_worker *)conf->workers->elts;

    /*
     * Do a "longest match" on the worker name to find the worker that
     * fits best to the URL, but keep in mind that we must have at least
     * a minimum matching of length min_match such that
     * scheme://hostname[:port] matches between worker and url.
     */
    for (i = 0; i < conf->workers->nelts; i++) {
        if ( ((worker_name_length = strlen(worker->name)) <= url_length)
           && (worker_name_length >= min_match)
           && (worker_name_length > max_match)
           && (strncmp(url_copy, worker->name, worker_name_length) == 0) ) {
            max_worker = worker;
            max_match = worker_name_length;
        }
        worker++;
    }
    return max_worker;
}

#if APR_HAS_THREADS
static apr_status_t conn_pool_cleanup(void *theworker)
{
    proxy_worker *worker = (proxy_worker *)theworker;
    if (worker->cp->res) {
        worker->cp->pool = NULL;
    }
    return APR_SUCCESS;
}
#endif

static void init_conn_pool(apr_pool_t *p, proxy_worker *worker)
{
    apr_pool_t *pool;
    proxy_conn_pool *cp;

    /*
     * Create a connection pool's subpool.
     * This pool is used for connection recycling.
     * Once the worker is added it is never removed but
     * it can be disabled.
     */
    apr_pool_create(&pool, p);
    apr_pool_tag(pool, "proxy_worker_cp");
    /*
     * Alloc from the same pool as worker.
     * proxy_conn_pool is permanently attached to the worker.
     */
    cp = (proxy_conn_pool *)apr_pcalloc(p, sizeof(proxy_conn_pool));
    cp->pool = pool;
    worker->cp = cp;
}

PROXY_DECLARE(const char *) ap_proxy_add_worker(proxy_worker **worker,
                                                apr_pool_t *p,
                                                proxy_server_conf *conf,
                                                const char *url)
{
    int rv;
    apr_uri_t uri;

    rv = apr_uri_parse(p, url, &uri);

    if (rv != APR_SUCCESS) {
        return "Unable to parse URL";
    }
    if (!uri.hostname || !uri.scheme) {
        return "URL must be absolute!";
    }

    ap_str_tolower(uri.hostname);
    ap_str_tolower(uri.scheme);
    *worker = apr_array_push(conf->workers);
    memset(*worker, 0, sizeof(proxy_worker));
    (*worker)->name = apr_uri_unparse(p, &uri, APR_URI_UNP_REVEALPASSWORD);
    (*worker)->scheme = uri.scheme;
    (*worker)->hostname = uri.hostname;
    (*worker)->port = uri.port;
    (*worker)->id   = proxy_lb_workers;
    (*worker)->flush_packets = flush_off;
    (*worker)->flush_wait = PROXY_FLUSH_WAIT;
    (*worker)->smax = -1;
    /* Increase the total worker count */
    proxy_lb_workers++;
    init_conn_pool(p, *worker);
#if APR_HAS_THREADS
    if (apr_thread_mutex_create(&((*worker)->mutex),
                APR_THREAD_MUTEX_DEFAULT, p) != APR_SUCCESS) {
        /* XXX: Do we need to log something here */
        return "can not create thread mutex";
    }
#endif

    return NULL;
}

PROXY_DECLARE(proxy_worker *) ap_proxy_create_worker(apr_pool_t *p)
{

    proxy_worker *worker;
    worker = (proxy_worker *)apr_pcalloc(p, sizeof(proxy_worker));
    worker->id = proxy_lb_workers;
    worker->smax = -1;
    /* Increase the total worker count */
    proxy_lb_workers++;
    init_conn_pool(p, worker);

    return worker;
}

PROXY_DECLARE(void)
ap_proxy_add_worker_to_balancer(apr_pool_t *pool, proxy_balancer *balancer,
                                proxy_worker *worker)
{
    proxy_worker *runtime;

    runtime = apr_array_push(balancer->workers);
    memcpy(runtime, worker, sizeof(proxy_worker));
    runtime->id = proxy_lb_workers;
    /* Increase the total runtime count */
    proxy_lb_workers++;

}

PROXY_DECLARE(int) ap_proxy_pre_request(proxy_worker **worker,
                                        proxy_balancer **balancer,
                                        request_rec *r,
                                        proxy_server_conf *conf, char **url)
{
    int access_status;

    access_status = proxy_run_pre_request(worker, balancer, r, conf, url);
    if (access_status == DECLINED && *balancer == NULL) {
        *worker = ap_proxy_get_worker(r->pool, conf, *url);
        if (*worker) {
            ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r,
                          "proxy: %s: found worker %s for %s",
                           (*worker)->scheme, (*worker)->name, *url);

            *balancer = NULL;
            access_status = OK;
        }
        else if (r->proxyreq == PROXYREQ_PROXY) {
            if (conf->forward) {
                ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r,
                              "proxy: *: found forward proxy worker for %s",
                               *url);
                *balancer = NULL;
                *worker = conf->forward;
                access_status = OK;
            }
        }
        else if (r->proxyreq == PROXYREQ_REVERSE) {
            if (conf->reverse) {
                ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r,
                              "proxy: *: found reverse proxy worker for %s",
                               *url);
                *balancer = NULL;
                *worker = conf->reverse;
                access_status = OK;
            }
        }
    }
    else if (access_status == DECLINED && *balancer != NULL) {
        /* All the workers are busy */
        ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r,
          "proxy: all workers are busy.  Unable to serve %s",
          *url);
        access_status = HTTP_SERVICE_UNAVAILABLE;
    }
    return access_status;
}

PROXY_DECLARE(int) ap_proxy_post_request(proxy_worker *worker,
                                         proxy_balancer *balancer,
                                         request_rec *r,
                                         proxy_server_conf *conf)
{
    int access_status;
    if (balancer) {
        access_status = proxy_run_post_request(worker, balancer, r, conf);
    }
    else {
        access_status = OK;
    }

    return access_status;
}

/* DEPRECATED */
PROXY_DECLARE(int) ap_proxy_connect_to_backend(apr_socket_t **newsock,
                                               const char *proxy_function,
                                               apr_sockaddr_t *backend_addr,
                                               const char *backend_name,
                                               proxy_server_conf *conf,
                                               server_rec *s,
                                               apr_pool_t *p)
{
    apr_status_t rv;
    int connected = 0;
    int loglevel;

    while (backend_addr && !connected) {
        if ((rv = apr_socket_create(newsock, backend_addr->family,
                                    SOCK_STREAM, 0, p)) != APR_SUCCESS) {
            loglevel = backend_addr->next ? APLOG_DEBUG : APLOG_ERR;
            ap_log_error(APLOG_MARK, loglevel, rv, s,
                         "proxy: %s: error creating fam %d socket for target %s",
                         proxy_function,
                         backend_addr->family,
                         backend_name);
            /*
             * this could be an IPv6 address from the DNS but the
             * local machine won't give us an IPv6 socket; hopefully the
             * DNS returned an additional address to try
             */
            backend_addr = backend_addr->next;
            continue;
        }

#if !defined(TPF) && !defined(BEOS)
        if (conf->recv_buffer_size > 0 &&
            (rv = apr_socket_opt_set(*newsock, APR_SO_RCVBUF,
                                     conf->recv_buffer_size))) {
            ap_log_error(APLOG_MARK, APLOG_ERR, rv, s,
                         "apr_socket_opt_set(SO_RCVBUF): Failed to set "
                         "ProxyReceiveBufferSize, using default");
        }
#endif

        rv = apr_socket_opt_set(*newsock, APR_TCP_NODELAY, 1);
        if (rv != APR_SUCCESS && rv != APR_ENOTIMPL) {
             ap_log_error(APLOG_MARK, APLOG_ERR, rv, s,
                          "apr_socket_opt_set(APR_TCP_NODELAY): "
                          "Failed to set");
        }

        /* Set a timeout on the socket */
        if (conf->timeout_set == 1) {
            apr_socket_timeout_set(*newsock, conf->timeout);
        }
        else {
             apr_socket_timeout_set(*newsock, s->timeout);
        }

        ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s,
                     "proxy: %s: fam %d socket created to connect to %s",
                     proxy_function, backend_addr->family, backend_name);

        /* make the connection out of the socket */
        rv = apr_socket_connect(*newsock, backend_addr);

        /* if an error occurred, loop round and try again */
        if (rv != APR_SUCCESS) {
            apr_socket_close(*newsock);
            loglevel = backend_addr->next ? APLOG_DEBUG : APLOG_ERR;
            ap_log_error(APLOG_MARK, loglevel, rv, s,
                         "proxy: %s: attempt to connect to %pI (%s) failed",
                         proxy_function,
                         backend_addr,
                         backend_name);
            backend_addr = backend_addr->next;
            continue;
        }
        connected = 1;
    }
    return connected ? 0 : 1;
}

static apr_status_t connection_cleanup(void *theconn)
{
    proxy_conn_rec *conn = (proxy_conn_rec *)theconn;
    proxy_worker *worker = conn->worker;

    /*
     * If the connection pool is NULL the worker
     * cleanup has been run. Just return.
     */
    if (!worker->cp) {
        return APR_SUCCESS;
    }

#if APR_HAS_THREADS
    /* Sanity check: Did we already return the pooled connection? */
    if (conn->inreslist) {
        ap_log_perror(APLOG_MARK, APLOG_ERR, 0, conn->pool,
                      "proxy: Pooled connection 0x%pp for worker %s has been"
                      " already returned to the connection pool.", conn,
                      worker->name);
        return APR_SUCCESS;
    }
#endif

    /* determine if the connection need to be closed */
    if (conn->close_on_recycle || conn->close || worker->disablereuse ||
        !worker->is_address_reusable) {
        apr_pool_t *p = conn->pool;
        apr_pool_clear(p);
        conn = apr_pcalloc(p, sizeof(proxy_conn_rec));
        conn->pool = p;
        conn->worker = worker;
        apr_pool_create(&(conn->scpool), p);
        apr_pool_tag(conn->scpool, "proxy_conn_scpool");
    }
#if APR_HAS_THREADS
    if (worker->hmax && worker->cp->res) {
        conn->inreslist = 1;
        apr_reslist_release(worker->cp->res, (void *)conn);
    }
    else
#endif