Quelle mod_proxy.c Sprache: C

/* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements.  See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License.  You may obtain a copy of the License at
*
*     http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/

#include "mod_proxy.h"
#include "mod_core.h"
#include "apr_optional.h"
#include "apr_strings.h"
#include "scoreboard.h"
#include "mod_status.h"
#include "proxy_util.h"

#if (MODULE_MAGIC_NUMBER_MAJOR > 20020903)
#include "mod_ssl.h"
#else
APR_DECLARE_OPTIONAL_FN(int, ssl_proxy_enable, (conn_rec *));
APR_DECLARE_OPTIONAL_FN(int, ssl_engine_disable, (conn_rec *));
APR_DECLARE_OPTIONAL_FN(int, ssl_engine_set, (conn_rec *,
                                              ap_conf_vector_t *,
                                              int proxy, int enable));
#endif

#ifndef MAX
#define MAX(x,y) ((x) >= (y) ? (x) : (y))
#endif

/*
* We do health-checks only if that (sub)module is loaded in. This
* allows for us to continue as is w/o requiring mod_watchdog for
* those implementations which aren't using health checks
*/
static APR_OPTIONAL_FN_TYPE(set_worker_hc_param) *set_worker_hc_param_f = NULL;

/* Externals */
proxy_hcmethods_t PROXY_DECLARE_DATA proxy_hcmethods[] = {
    {NONE, "NONE", 1},
    {TCP, "TCP", 1},
    {OPTIONS, "OPTIONS", 1},
    {HEAD, "HEAD", 1},
    {GET, "GET", 1},
    {CPING, "CPING", 0},
    {PROVIDER, "PROVIDER", 0},
    {OPTIONS11, "OPTIONS11", 1},
    {HEAD11, "HEAD11", 1},
    {GET11, "GET11", 1},
    {EOT, NULL, 1}
};

proxy_wstat_t PROXY_DECLARE_DATA proxy_wstat_tbl[] = {
    {PROXY_WORKER_INITIALIZED,   PROXY_WORKER_INITIALIZED_FLAG,   "Init "},
    {PROXY_WORKER_IGNORE_ERRORS, PROXY_WORKER_IGNORE_ERRORS_FLAG, "Ign "},
    {PROXY_WORKER_DRAIN,         PROXY_WORKER_DRAIN_FLAG,         "Drn "},
    {PROXY_WORKER_GENERIC,       PROXY_WORKER_GENERIC_FLAG,       "Gen "},
    {PROXY_WORKER_IN_SHUTDOWN,   PROXY_WORKER_IN_SHUTDOWN_FLAG,   "Shut "},
    {PROXY_WORKER_DISABLED,      PROXY_WORKER_DISABLED_FLAG,      "Dis "},
    {PROXY_WORKER_STOPPED,       PROXY_WORKER_STOPPED_FLAG,       "Stop "},
    {PROXY_WORKER_IN_ERROR,      PROXY_WORKER_IN_ERROR_FLAG,      "Err "},
    {PROXY_WORKER_HOT_STANDBY,   PROXY_WORKER_HOT_STANDBY_FLAG,   "Stby "},
    {PROXY_WORKER_HOT_SPARE,     PROXY_WORKER_HOT_SPARE_FLAG,     "Spar "},
    {PROXY_WORKER_FREE,          PROXY_WORKER_FREE_FLAG,          "Free "},
    {PROXY_WORKER_HC_FAIL,       PROXY_WORKER_HC_FAIL_FLAG,       "HcFl "},
    {0x0, '\0', NULL}
};

static const char * const proxy_id = "proxy";
apr_global_mutex_t *proxy_mutex = NULL;

/*
* A Web proxy module. Stages:
*
*  translate_name: set filename to proxy:<URL>
*  map_to_storage: run proxy_walk (rather than directory_walk/file_walk)
*                  can't trust directory_walk/file_walk since these are
*                  not in our filesystem.  Prevents mod_http from serving
*                  the TRACE request we will set aside to handle later.
*  fix_ups:        convert the URL stored in the filename to the
*                  canonical form.
*  handler:        handle proxy requests
*/

/* -------------------------------------------------------------- */
/* Translate the URL into a 'filename' */

static const char *set_worker_param(apr_pool_t *p,
                                    server_rec *s,
                                    proxy_worker *worker,
                                    const char *key,
                                    const char *val)
{

    int ival;
    apr_interval_time_t timeout;

    if (!strcasecmp(key, "loadfactor")) {
        /* Normalized load factor. Used with BalancerMember,
         * it is a number between 1 and 100.
         */
        double fval = atof(val);
        ival = fval * 100.0;
        if (ival < 100 || ival > 10000)
            return "LoadFactor must be a number between 1..100";
        worker->s->lbfactor = ival;
    }
    else if (!strcasecmp(key, "retry")) {
        /* If set it will give the retry timeout for the worker
         * The default value is 60 seconds, meaning that if
         * in error state, it will be retried after that timeout.
         */
        ival = atoi(val);
        if (ival < 0)
            return "Retry must be a positive value";
        worker->s->retry = apr_time_from_sec(ival);
        worker->s->retry_set = 1;
    }
    else if (!strcasecmp(key, "ttl")) {
        /* Time in seconds that will destroy all the connections
         * that exceed the smax
         */
        ival = atoi(val);
        if (ival < 1)
            return "TTL must be at least one second";
        worker->s->ttl = apr_time_from_sec(ival);
    }
    else if (!strcasecmp(key, "min")) {
        /* Initial number of connections to remote
         */
        ival = atoi(val);
        if (ival < 0)
            return "Min must be a positive number";
        worker->s->min = ival;
    }
    else if (!strcasecmp(key, "max")) {
        /* Maximum number of connections to remote
         */
        ival = atoi(val);
        if (ival < 0)
            return "Max must be a positive number";
        worker->s->hmax = ival;
    }
    /* XXX: More intelligent naming needed */
    else if (!strcasecmp(key, "smax")) {
        /* Maximum number of connections to remote that
         * will not be destroyed
         */
        ival = atoi(val);
        if (ival < 0)
            return "Smax must be a positive number";
        worker->s->smax = ival;
    }
    else if (!strcasecmp(key, "acquire")) {
        /* Acquire timeout in given unit (default is milliseconds).
         * If set this will be the maximum time to
         * wait for a free connection.
         */
        if (ap_timeout_parameter_parse(val, &timeout, "ms") != APR_SUCCESS)
            return "Acquire timeout has wrong format";
        if (timeout < 1000)
            return "Acquire must be at least one millisecond";
        worker->s->acquire = timeout;
        worker->s->acquire_set = 1;
    }
    else if (!strcasecmp(key, "timeout")) {
        /* Connection timeout in seconds.
         * Defaults to server timeout.
         */
        ival = atoi(val);
        if (ival < 1)
            return "Timeout must be at least one second";
        worker->s->timeout = apr_time_from_sec(ival);
        worker->s->timeout_set = 1;
    }
    else if (!strcasecmp(key, "iobuffersize")) {
        long s = atol(val);
        if (s < 512 && s) {
            return "IOBufferSize must be >= 512 bytes, or 0 for system default.";
        }
        worker->s->io_buffer_size = (s ? s : AP_IOBUFSIZE);
        worker->s->io_buffer_size_set = 1;
    }
    else if (!strcasecmp(key, "receivebuffersize")) {
        ival = atoi(val);
        if (ival < 512 && ival != 0) {
            return "ReceiveBufferSize must be >= 512 bytes, or 0 for system default.";
        }
        worker->s->recv_buffer_size = ival;
        worker->s->recv_buffer_size_set = 1;
    }
    else if (!strcasecmp(key, "keepalive")) {
        if (!strcasecmp(val, "on"))
            worker->s->keepalive = 1;
        else if (!strcasecmp(val, "off"))
            worker->s->keepalive = 0;
        else
            return "KeepAlive must be On|Off";
        worker->s->keepalive_set = 1;
    }
    else if (!strcasecmp(key, "disablereuse")) {
        if (!strcasecmp(val, "on"))
            worker->s->disablereuse = 1;
        else if (!strcasecmp(val, "off"))
            worker->s->disablereuse = 0;
        else
            return "DisableReuse must be On|Off";
        worker->s->disablereuse_set = 1;
    }
    else if (!strcasecmp(key, "enablereuse")) {
        if (!strcasecmp(val, "on"))
            worker->s->disablereuse = 0;
        else if (!strcasecmp(val, "off"))
            worker->s->disablereuse = 1;
        else
            return "EnableReuse must be On|Off";
        worker->s->disablereuse_set = 1;
    }
    else if (!strcasecmp(key, "addressttl")) {
        /* Address TTL in seconds
         */
        apr_interval_time_t ttl;
        if (strcmp(val, "-1") == 0) {
            worker->s->address_ttl = -1;
        }
        else if (ap_timeout_parameter_parse(val, &ttl, "s") == APR_SUCCESS
                 && (ttl <= apr_time_from_sec(APR_INT32_MAX))
                 && (ttl % apr_time_from_sec(1)) == 0) {
            worker->s->address_ttl = apr_time_sec(ttl);
        }
        else {
            return "AddressTTL must be -1 or a number of seconds not "
                   "exceeding " APR_STRINGIFY(APR_INT32_MAX);
        }
        worker->s->address_ttl_set = 1;
    }
    else if (!strcasecmp(key, "route")) {
        /* Worker route.
         */
        if (strlen(val) >= sizeof(worker->s->route))
            return apr_psprintf(p, "Route length must be < %d characters",
                    (int)sizeof(worker->s->route));
        PROXY_STRNCPY(worker->s->route, val);
    }
    else if (!strcasecmp(key, "redirect")) {
        /* Worker redirection route.
         */
        if (strlen(val) >= sizeof(worker->s->redirect))
            return apr_psprintf(p, "Redirect length must be < %d characters",
                    (int)sizeof(worker->s->redirect));
        PROXY_STRNCPY(worker->s->redirect, val);
    }
    else if (!strcasecmp(key, "status")) {
        const char *v;
        int mode = 1;
        apr_status_t rv;
        /* Worker status.
         */
        for (v = val; *v; v++) {
            if (*v == '+') {
                mode = 1;
                v++;
            }
            else if (*v == '-') {
                mode = 0;
                v++;
            }
            rv = ap_proxy_set_wstatus(*v, mode, worker);
            if (rv != APR_SUCCESS)
                return "Unknown status parameter option";
        }
    }
    else if (!strcasecmp(key, "flushpackets")) {
        if (!strcasecmp(val, "on"))
            worker->s->flush_packets = flush_on;
        else if (!strcasecmp(val, "off"))
            worker->s->flush_packets = flush_off;
        else if (!strcasecmp(val, "auto"))
            worker->s->flush_packets = flush_auto;
        else
            return "flushpackets must be on|off|auto";
    }
    else if (!strcasecmp(key, "flushwait")) {
        ival = atoi(val);
        if (ival > 1000 || ival < 0) {
            return "flushwait must be <= 1000, or 0 for system default of 10 millseconds.";
        }
        if (ival == 0)
            worker->s->flush_wait = PROXY_FLUSH_WAIT;
        else
            worker->s->flush_wait = ival * 1000;    /* change to microseconds */
    }
    else if (!strcasecmp(key, "ping")) {
        /* Ping/Pong timeout in given unit (default is second).
         */
        if (ap_timeout_parameter_parse(val, &timeout, "s") != APR_SUCCESS)
            return "Ping/Pong timeout has wrong format";
        if (timeout < 1000)
            return "Ping/Pong timeout must be at least one millisecond";
        worker->s->ping_timeout = timeout;
        worker->s->ping_timeout_set = 1;
    }
    else if (!strcasecmp(key, "lbset")) {
        ival = atoi(val);
        if (ival < 0 || ival > 99)
            return "lbset must be between 0 and 99";
        worker->s->lbset = ival;
    }
    else if (!strcasecmp(key, "connectiontimeout")) {
        /* Request timeout in given unit (default is second).
         * Defaults to connection timeout
         */
        if (ap_timeout_parameter_parse(val, &timeout, "s") != APR_SUCCESS)
            return "Connectiontimeout has wrong format";
        if (timeout < 1000)
            return "Connectiontimeout must be at least one millisecond.";
        worker->s->conn_timeout = timeout;
        worker->s->conn_timeout_set = 1;
    }
    else if (!strcasecmp(key, "flusher")) {
        if (PROXY_STRNCPY(worker->s->flusher, val) != APR_SUCCESS) {
            return apr_psprintf(p, "flusher name length must be < %d characters",
                                (int)sizeof(worker->s->flusher));
        }
    }
    else if (!strcasecmp(key, "upgrade")) {
        if (PROXY_STRNCPY(worker->s->upgrade,
                          strcasecmp(val, "ANY") ? val : "*") != APR_SUCCESS) {
            return apr_psprintf(p, "upgrade protocol length must be < %d characters",
                                (int)sizeof(worker->s->upgrade));
        }
    }
    else if (!strcasecmp(key, "responsefieldsize")) {
        long s = atol(val);
        if (s < 0) {
            return "ResponseFieldSize must be greater than 0 bytes, or 0 for system default.";
        }
        worker->s->response_field_size = (s ? s : HUGE_STRING_LEN);
        worker->s->response_field_size_set = 1;
    }
    else if (!strcasecmp(key, "secret")) {
        if (PROXY_STRNCPY(worker->s->secret, val) != APR_SUCCESS) {
            return apr_psprintf(p, "Secret length must be < %d characters",
                                (int)sizeof(worker->s->secret));
        }
    }
    else {
        if (set_worker_hc_param_f) {
            return set_worker_hc_param_f(p, s, worker, key, val, NULL);
        } else {
            return "unknown Worker parameter";
        }
    }
    return NULL;
}

static const char *set_balancer_param(proxy_server_conf *conf,
                                      apr_pool_t *p,
                                      proxy_balancer *balancer,
                                      const char *key,
                                      const char *val)
{

    int ival;
    if (!strcasecmp(key, "stickysession")) {
        char *path;
        /* Balancer sticky session name.
         * Set to something like JSESSIONID or
         * PHPSESSIONID, etc..,
         */
        if (strlen(val) >= sizeof(balancer->s->sticky_path))
            apr_psprintf(p, "stickysession length must be < %d characters",
                    (int)sizeof(balancer->s->sticky_path));
        PROXY_STRNCPY(balancer->s->sticky_path, val);
        PROXY_STRNCPY(balancer->s->sticky, val);

        if ((path = strchr((char *)balancer->s->sticky, '|'))) {
            *path++ = '\0';
            PROXY_STRNCPY(balancer->s->sticky_path, path);
        }
    }
    else if (!strcasecmp(key, "stickysessionsep")) {
        /* separator/delimiter for sessionid and route,
         * normally '.'
         */
        if (strlen(val) != 1) {
            if (!strcasecmp(val, "off"))
                balancer->s->sticky_separator = 0;
            else
                return "stickysessionsep must be a single character or Off";
        }
        else
            balancer->s->sticky_separator = *val;
        balancer->s->sticky_separator_set = 1;
    }
    else if (!strcasecmp(key, "nofailover")) {
        /* If set to 'on' the session will break
         * if the worker is in error state or
         * disabled.
         */
        if (!strcasecmp(val, "on"))
            balancer->s->sticky_force = 1;
        else if (!strcasecmp(val, "off"))
            balancer->s->sticky_force = 0;
        else
            return "failover must be On|Off";
        balancer->s->sticky_force_set = 1;
    }
    else if (!strcasecmp(key, "timeout")) {
        /* Balancer timeout in seconds.
         * If set this will be the maximum time to
         * wait for a free worker.
         * Default is not to wait.
         */
        ival = atoi(val);
        if (ival < 1)
            return "timeout must be at least one second";
        balancer->s->timeout = apr_time_from_sec(ival);
    }
    else if (!strcasecmp(key, "maxattempts")) {
        /* Maximum number of failover attempts before
         * giving up.
         */
        ival = atoi(val);
        if (ival < 0)
            return "maximum number of attempts must be a positive number";
        balancer->s->max_attempts = ival;
        balancer->s->max_attempts_set = 1;
    }
    else if (!strcasecmp(key, "lbmethod")) {
        proxy_balancer_method *provider;
        if (strlen(val) > (sizeof(balancer->s->lbpname)-1))
            return "unknown lbmethod";
        provider = ap_lookup_provider(PROXY_LBMETHOD, val, "0");
        if (provider) {
            balancer->lbmethod = provider;
            if (PROXY_STRNCPY(balancer->s->lbpname, val) == APR_SUCCESS) {
                balancer->lbmethod_set = 1;
                return NULL;
            }
            else {
                return "lbmethod name too large";
            }
        }
        return "unknown lbmethod";
    }
    else if (!strcasecmp(key, "scolonpathdelim")) {
        /* If set to 'on' then ';' will also be
         * used as a session path separator/delim (ala
         * mod_jk)
         */
        if (!strcasecmp(val, "on"))
            balancer->s->scolonsep = 1;
        else if (!strcasecmp(val, "off"))
            balancer->s->scolonsep = 0;
        else
            return "scolonpathdelim must be On|Off";
        balancer->s->scolonsep_set = 1;
    }
    else if (!strcasecmp(key, "failonstatus")) {
        char *val_split;
        char *status;
        char *tok_state;

        val_split = apr_pstrdup(p, val);

        balancer->errstatuses = apr_array_make(p, 1, sizeof(int));

        status = apr_strtok(val_split, ", ", &tok_state);
        while (status != NULL) {
            ival = atoi(status);
            if (ap_is_HTTP_VALID_RESPONSE(ival)) {
                *(int *)apr_array_push(balancer->errstatuses) = ival;
            }
            else {
                return "failonstatus must be one or more HTTP response codes";
            }
            status = apr_strtok(NULL, ", ", &tok_state);
        }

    }
    else if (!strcasecmp(key, "failontimeout")) {
        if (!strcasecmp(val, "on"))
            balancer->failontimeout = 1;
        else if (!strcasecmp(val, "off"))
            balancer->failontimeout = 0;
        else
            return "failontimeout must be On|Off";
        balancer->failontimeout_set = 1;
    }
    else if (!strcasecmp(key, "nonce")) {
        if (!strcasecmp(val, "None")) {
            *balancer->s->nonce = '\0';
        }
        else {
            if (PROXY_STRNCPY(balancer->s->nonce, val) != APR_SUCCESS) {
                return "Provided nonce is too large";
            }
        }
        balancer->s->nonce_set = 1;
    }
    else if (!strcasecmp(key, "growth")) {
        ival = atoi(val);
        if (ival < 1 || ival > 100)   /* arbitrary limit here */
            return "growth must be between 1 and 100";
        balancer->growth = ival;
        balancer->growth_set = 1;
    }
    else if (!strcasecmp(key, "forcerecovery")) {
        if (!strcasecmp(val, "on"))
            balancer->s->forcerecovery = 1;
        else if (!strcasecmp(val, "off"))
            balancer->s->forcerecovery = 0;
        else
            return "forcerecovery must be On|Off";
        balancer->s->forcerecovery_set = 1;
    }
    else {
        return "unknown Balancer parameter";
    }
    return NULL;
}

static int alias_match(const char *uri, const char *alias_fakename)
{
    const char *end_fakename = alias_fakename + strlen(alias_fakename);
    const char *aliasp = alias_fakename, *urip = uri;
    const char *end_uri = uri + strlen(uri);

    while (aliasp < end_fakename && urip < end_uri) {
        if (*aliasp == '/') {
            /* any number of '/' in the alias matches any number in
             * the supplied URI, but there must be at least one...
             */
            if (*urip != '/')
                return 0;

            while (*aliasp == '/')
                ++aliasp;
            while (*urip == '/')
                ++urip;
        }
        else {
            /* Other characters are compared literally */
            if (*urip++ != *aliasp++)
                return 0;
        }
    }

    /* fixup badly encoded stuff (e.g. % as last character) */
    if (aliasp > end_fakename) {
        aliasp = end_fakename;
    }
    if (urip > end_uri) {
        urip = end_uri;
    }

   /* We reach the end of the uri before the end of "alias_fakename"
    * for example uri is "/" and alias_fakename "/examples"
    */
   if (urip == end_uri && aliasp != end_fakename) {
       return 0;
   }

    /* Check last alias path component matched all the way */
    if (aliasp[-1] != '/' && *urip != '\0' && *urip != '/')
        return 0;

    /* Return number of characters from URI which matched (may be
     * greater than length of alias, since we may have matched
     * doubled slashes)
     */

    return urip - uri;
}

/*
* Inspired by mod_jk's jk_servlet_normalize().
*/
static int alias_match_servlet(apr_pool_t *p,
                               const char **urip,
                               const char *alias)
{
    char *map;
    const char *uri = *urip;
    apr_array_header_t *stack;
    int map_pos, uri_pos, alias_pos, first_pos;
    int alias_depth = 0, depth;

    /* Both uri and alias should start with '/' */
    if (uri[0] != '/' || alias[0] != '/') {
        return 0;
    }

    stack = apr_array_make(p, 5, sizeof(int));
    map = apr_palloc(p, strlen(uri) + 1);
    map[0] = '/';
    map[1] = '\0';

    map_pos = uri_pos = alias_pos = first_pos = 1;
    while (uri[uri_pos] != '\0') {
        /* Remove path parameters ;foo=bar/ from any path segment */
        if (uri[uri_pos] == ';') {
            do {
                uri_pos++;
            } while (uri[uri_pos] != '/' && uri[uri_pos] != '\0');
            continue;
        }

        if (map[map_pos - 1] == '/') {
            /* Collapse ///// sequences to / */
            if (uri[uri_pos] == '/') {
                do {
                    uri_pos++;
                } while (uri[uri_pos] == '/');
                continue;
            }

            if (uri[uri_pos] == '.') {
                /* Remove /./ segments */
                if (uri[uri_pos + 1] == '/'
                        || uri[uri_pos + 1] == ';'
                        || uri[uri_pos + 1] == '\0') {
                    uri_pos++;
                    if (uri[uri_pos] == '/') {
                        uri_pos++;
                    }
                    continue;
                }

                /* Remove /xx/../ segments */
                if (uri[uri_pos + 1] == '.'
                    && (uri[uri_pos + 2] == '/'
                        || uri[uri_pos + 2] == ';'
                        || uri[uri_pos + 2] == '\0')) {
                    /* Wind map segment back the previous one */
                    if (map_pos == 1) {
                        /* Above root */
                        return 0;
                    }
                    do {
                        map_pos--;
                    } while (map[map_pos - 1] != '/');
                    map[map_pos] = '\0';

                    /* Wind alias segment back, unless in deeper segment */
                    if (alias_depth == stack->nelts) {
                        if (alias[alias_pos] == '\0') {
                            alias_pos--;
                        }
                        while (alias_pos > 0 && alias[alias_pos] == '/') {
                            alias_pos--;
                        }
                        while (alias_pos > 0 && alias[alias_pos - 1] != '/') {
                            alias_pos--;
                        }
                        AP_DEBUG_ASSERT(alias_pos > 0);
                        alias_depth--;
                    }
                    apr_array_pop(stack);

                    /* Move uri forward to the next segment */
                    uri_pos += 2;
                    if (uri[uri_pos] == '/') {
                        uri_pos++;
                    }
                    first_pos = 0;
                    continue;
                }
            }
            if (first_pos) {
                while (uri[first_pos] == '/') {
                    first_pos++;
                }
            }

            /* New segment */
            APR_ARRAY_PUSH(stack, int) = first_pos ? first_pos : uri_pos;
            if (alias[alias_pos] != '\0') {
                if (alias[alias_pos - 1] != '/') {
                    /* Remain in pair with uri segments */
                    do {
                        alias_pos++;
                    } while (alias[alias_pos - 1] != '/' && alias[alias_pos]);
                }
                while (alias[alias_pos] == '/') {
                    alias_pos++;
                }
                if (alias[alias_pos] != '\0') {
                    alias_depth++;
                }
            }
        }

        if (alias[alias_pos] != '\0') {
            int *match = &APR_ARRAY_IDX(stack, alias_depth - 1, int);
            if (*match) {
                if (alias[alias_pos] != uri[uri_pos]) {
                    /* Current segment does not match */
                    *match = 0;
                }
                else if (alias[alias_pos + 1] == '\0'
                         && alias[alias_pos] != '/') {
                    if (uri[uri_pos + 1] == ';') {
                        /* We'll preserve the parameters of the last
                         * segment if it does not end with '/', so mark
                         * the match as negative for below handling.
                         */
                        *match = -(uri_pos + 1);
                    }
                    else if (uri[uri_pos + 1] != '/'
                             && uri[uri_pos + 1] != '\0') {
                        /* Last segment does not match all the way */
                        *match = 0;
                    }
                }
            }
            /* Don't go past the segment if the uri isn't there yet */
            if (alias[alias_pos] != '/' || uri[uri_pos] == '/') {
                alias_pos++;
            }
        }

        if (uri[uri_pos] == '/') {
            first_pos = uri_pos + 1;
        }
        map[map_pos++] = uri[uri_pos++];
        map[map_pos] = '\0';
    }

    /* Can't reach the end of uri before the end of the alias,
     * for example if uri is "/" and alias is "/examples"
     */
    if (alias[alias_pos] != '\0') {
        return 0;
    }

    /* Check whether each alias segment matched */
    for (depth = 0; depth < alias_depth; ++depth) {
        if (!APR_ARRAY_IDX(stack, depth, int)) {
            return 0;
        }
    }

    /* If alias_depth == stack->nelts we have a full match, i.e.
     * uri == alias so we can return uri_pos as is (the end of uri)
     */
    if (alias_depth < stack->nelts) {
        /* Return the segment following the alias */
        uri_pos = APR_ARRAY_IDX(stack, alias_depth, int);
        if (alias_depth) {
            /* But if the last segment of the alias does not end with '/'
             * and the corresponding segment of the uri has parameters,
             * we want to forward those parameters (see above for the
             * negative pos trick/mark).
             */
            int pos = APR_ARRAY_IDX(stack, alias_depth - 1, int);
            if (pos < 0) {
                uri_pos = -pos;
            }
        }
    }
    /* If the alias lacks a trailing slash, take it from the uri (if any) */
    if (alias[alias_pos - 1] != '/' && uri[uri_pos - 1] == '/') {
        uri_pos--;
    }

    *urip = map;
    return uri_pos;
}

/* Detect if an absoluteURI should be proxied or not.  Note that we
* have to do this during this phase because later phases are
* "short-circuiting"... i.e. translate_names will end when the first
* module returns OK.  So for example, if the request is something like:
*
* GET http://othervhost/cgi-bin/printenv HTTP/1.0
*
* mod_alias will notice the /cgi-bin part and ScriptAlias it and
* short-circuit the proxy... just because of the ordering in the
* configuration file.
*/
static int proxy_detect(request_rec *r)
{
    void *sconf = r->server->module_config;
    proxy_server_conf *conf =
        (proxy_server_conf *) ap_get_module_config(sconf, &proxy_module);

    /* Ick... msvc (perhaps others) promotes ternary short results to int */

    if (conf->req && r->parsed_uri.scheme) {
        /* but it might be something vhosted */
        if (!r->parsed_uri.hostname
            || ap_cstr_casecmp(r->parsed_uri.scheme, ap_http_scheme(r)) != 0
            || !ap_matches_request_vhost(r, r->parsed_uri.hostname,
                                         (apr_port_t)(r->parsed_uri.port_str
                                                      ? r->parsed_uri.port
                                                      : ap_default_port(r)))) {
            r->proxyreq = PROXYREQ_PROXY;
            r->uri = r->unparsed_uri;
            r->filename = apr_pstrcat(r->pool, "proxy:", r->uri, NULL);
            r->handler = "proxy-server";
        }
    }
    /* We need special treatment for CONNECT proxying: it has no scheme part */
    else if (conf->req && r->method_number == M_CONNECT
             && r->parsed_uri.hostname
             && r->parsed_uri.port_str) {
        r->proxyreq = PROXYREQ_PROXY;
        r->uri = r->unparsed_uri;
        r->filename = apr_pstrcat(r->pool, "proxy:", r->uri, NULL);
        r->handler = "proxy-server";
    }
    return DECLINED;
}

PROXY_DECLARE(int) ap_proxy_trans_match(request_rec *r, struct proxy_alias *ent,
                                        proxy_dir_conf *dconf)
{
    int len;
    const char *fake;
    const char *real;
    ap_regmatch_t regm[AP_MAX_REG_MATCH];
    ap_regmatch_t reg1[AP_MAX_REG_MATCH];
    char *found = NULL;
    int mismatch = 0;
    unsigned int nocanon = ent->flags & PROXYPASS_NOCANON;
    const char *use_uri = nocanon ? r->unparsed_uri : r->uri;
    const char *servlet_uri = NULL;

    if (dconf && (dconf->interpolate_env == 1) && (ent->flags & PROXYPASS_INTERPOLATE)) {
        fake = ap_proxy_interpolate(r, ent->fake);
        real = ap_proxy_interpolate(r, ent->real);
    }
    else {
        fake = ent->fake;
        real = ent->real;
    }

    ap_log_rerror(APLOG_MARK, APLOG_TRACE2, 0, r, APLOGNO(03461)
                  "attempting to match URI path '%s' against %s '%s' for "
                  "proxying", r->uri, (ent->regex ? "pattern" : "prefix"),
                  fake);

    if (ent->regex) {
        if (!ap_regexec(ent->regex, r->uri, AP_MAX_REG_MATCH, regm, 0)) {
            if ((real[0] == '!') && (real[1] == '\0')) {
                ap_log_rerror(APLOG_MARK, APLOG_TRACE1, 0, r, APLOGNO(03462)
                              "proxying is explicitly disabled for URI path "
                              "'%s'; declining", r->uri);
                return DECLINED;
            }
            /* test that we haven't reduced the URI */
            if (nocanon && ap_regexec(ent->regex, r->unparsed_uri,
                    AP_MAX_REG_MATCH, reg1, 0)) {
                mismatch = 1;
                use_uri = r->uri;
            }
            found = ap_pregsub(r->pool, real, use_uri, AP_MAX_REG_MATCH,
                    (use_uri == r->uri) ? regm : reg1);
            if (!found) {
                ap_log_rerror(APLOG_MARK, APLOG_CRIT, 0, r, APLOGNO(01135)
                              "Substitution in regular expression failed. "
                              "Replacement too long?");
                return HTTP_INTERNAL_SERVER_ERROR;
            }

            /* Note: The strcmp() below catches cases where there
             * was no regex substitution. This is so cases like:
             *
             *    ProxyPassMatch \.gif balancer://foo
             *
             * will work "as expected". The upshot is that the 2
             * directives below act the exact same way (ie: $1 is implied):
             *
             *    ProxyPassMatch ^(/.*\.gif)$ balancer://foo
             *    ProxyPassMatch ^(/.*\.gif)$ balancer://foo$1
             *
             * which may be confusing.
             */
            if (strcmp(found, real) != 0) {
                found = apr_pstrcat(r->pool, "proxy:", found, NULL);
            }
            else {
                found = apr_pstrcat(r->pool, "proxy:", real, use_uri, NULL);
            }
        }
    }
    else {
        if ((ent->flags & PROXYPASS_MAP_SERVLET) == PROXYPASS_MAP_SERVLET) {
            servlet_uri = r->uri;
            len = alias_match_servlet(r->pool, &servlet_uri, fake);
            nocanon = 0; /* ignored since servlet's normalization applies */
        }
        else {
            len = alias_match(r->uri, fake);
        }

        if (len != 0) {
            if ((real[0] == '!') && (real[1] == '\0')) {
                ap_log_rerror(APLOG_MARK, APLOG_TRACE1, 0, r, APLOGNO(03463)
                              "proxying is explicitly disabled for URI path "
                              "'%s'; declining", r->uri);
                return DECLINED;
            }
            if (nocanon && len != alias_match(r->unparsed_uri, fake)) {
                mismatch = 1;
                use_uri = r->uri;
            }
            found = apr_pstrcat(r->pool, "proxy:", real, use_uri + len, NULL);
        }
    }
    if (mismatch) {
        /* We made a reducing transformation, so we can't safely use
         * unparsed_uri.  Safe fallback is to ignore nocanon.
         */
        ap_log_rerror(APLOG_MARK, APLOG_WARNING, 0, r, APLOGNO(01136)
                "Unescaped URL path matched ProxyPass; ignoring unsafe nocanon");
    }

    if (found) {
        unsigned int encoded = ent->flags & PROXYPASS_MAP_ENCODED;

        /* A proxy module is assigned this URL, check whether it's interested
         * in the request itself (e.g. proxy_wstunnel cares about Upgrade
         * requests only, and could hand over to proxy_http otherwise).
         */
        int rc = proxy_run_check_trans(r, found + 6);
        if (rc != OK && rc != DECLINED) {
            return HTTP_CONTINUE;
        }

        r->filename = found;
        r->handler = "proxy-server";
        r->proxyreq = PROXYREQ_REVERSE;
        if (nocanon && !mismatch) {
            /* mod_proxy_http needs to be told.  Different module. */
            apr_table_setn(r->notes, "proxy-nocanon", "1");
        }
        if (ent->flags & PROXYPASS_NOQUERY) {
            apr_table_setn(r->notes, "proxy-noquery", "1");
        }
        if (encoded) {
            apr_table_setn(r->notes, "proxy-noencode", "1");
        }

        if (servlet_uri) {
            ap_log_rerror(APLOG_MARK, APLOG_TRACE1, 0, r, APLOGNO(10248)
                          "Servlet path '%s' (%s) matches proxy handler '%s'",
                          r->uri, servlet_uri, found);
            /* Apply servlet normalization to r->uri so that <Location> or any
             * directory context match does not have to handle path parameters.
             * We change r->uri in-place so that r->parsed_uri.path is updated
             * too. Since normalized servlet_uri is necessarily shorter than
             * the original r->uri, strcpy() is fine.
             */
            AP_DEBUG_ASSERT(strlen(r->uri) >= strlen(servlet_uri));
            strcpy(r->uri, servlet_uri);
        }
        else {
            ap_log_rerror(APLOG_MARK, APLOG_TRACE1, 0, r, APLOGNO(03464)
                          "URI path '%s' matches proxy handler '%s'", r->uri,
                          found);
        }
        return (encoded) ? DONE : OK;
    }

    return HTTP_CONTINUE;
}

static int proxy_trans(request_rec *r, int pre_trans)
{
    int i, enc;
    struct proxy_alias *ent;
    proxy_dir_conf *dconf;
    proxy_server_conf *conf;

    if (r->proxyreq) {
        /* someone has already set up the proxy, it was possibly ourselves
         * in proxy_detect (DONE will prevent further decoding of r->uri,
         * only if proxyreq is set before pre_trans already).
         */
        return pre_trans ? DONE : OK;
    }

    /* In early pre_trans hook, r->uri was not manipulated yet so we are
     * compliant with RFC1945 at this point. Otherwise, it probably isn't
     * an issue because this is a hybrid proxy/origin server.
     */

    dconf = ap_get_module_config(r->per_dir_config, &proxy_module);
    conf = (proxy_server_conf *) ap_get_module_config(r->server->module_config,
                                                      &proxy_module);

    /* Always and only do PROXY_MAP_ENCODED mapping in pre_trans, when
     * r->uri is still encoded, or we might consider for instance that
     * a decoded sub-delim is now a delimiter (e.g. "%3B" => ';' for
     * path parameters), which it's not.
     */
    if ((pre_trans && !conf->map_encoded_one)
            || (!pre_trans && conf->map_encoded_all)) {
        /* Fast path, nothing at this stage */
        return DECLINED;
    }

    if ((r->unparsed_uri[0] == '*' && r->unparsed_uri[1] == '\0')
        || !r->uri || r->uri[0] != '/') {
        return DECLINED;
    }

    if (apr_table_get(r->subprocess_env, "no-proxy")) {
        return DECLINED;
    }

    /* short way - this location is reverse proxied? */
    if (dconf->alias) {
        enc = (dconf->alias->flags & PROXYPASS_MAP_ENCODED) != 0;
        if (!(pre_trans ^ enc)) {
            int rv = ap_proxy_trans_match(r, dconf->alias, dconf);
            if (rv != HTTP_CONTINUE) {
                return rv;
            }
        }
    }

    /* long way - walk the list of aliases, find a match */
    for (i = 0; i < conf->aliases->nelts; i++) {
        ent = &((struct proxy_alias *)conf->aliases->elts)[i];
        enc = (ent->flags & PROXYPASS_MAP_ENCODED) != 0;
        if (!(pre_trans ^ enc)) {
            int rv = ap_proxy_trans_match(r, ent, dconf);
            if (rv != HTTP_CONTINUE) {
                return rv;
            }
        }
    }

    return DECLINED;
}

static int proxy_pre_translate_name(request_rec *r)
{
    return proxy_trans(r, 1);
}

static int proxy_translate_name(request_rec *r)
{
    return proxy_trans(r, 0);
}

static int proxy_walk(request_rec *r)
{
    proxy_server_conf *sconf = ap_get_module_config(r->server->module_config,
                                                    &proxy_module);
    ap_conf_vector_t *per_dir_defaults = r->per_dir_config;
    ap_conf_vector_t **sec_proxy = (ap_conf_vector_t **) sconf->sec_proxy->elts;
    ap_conf_vector_t *entry_config;
    proxy_dir_conf *entry_proxy;
    int num_sec = sconf->sec_proxy->nelts;
    /* XXX: shouldn't we use URI here?  Canonicalize it first?
     * Pass over "proxy:" prefix
     */
    const char *proxyname = r->filename + 6;
    int j;
    apr_pool_t *rxpool = NULL;

    for (j = 0; j < num_sec; ++j)
    {
        int nmatch = 0;
        int i;
        ap_regmatch_t *pmatch = NULL;

        entry_config = sec_proxy[j];
        entry_proxy = ap_get_module_config(entry_config, &proxy_module);

        if (entry_proxy->r) {

            if (entry_proxy->refs && entry_proxy->refs->nelts) {
                if (!rxpool) {
                    apr_pool_create(&rxpool, r->pool);
                    apr_pool_tag(rxpool, "proxy_rxpool");
                }
                nmatch = entry_proxy->refs->nelts;
                pmatch = apr_palloc(rxpool, nmatch*sizeof(ap_regmatch_t));
            }

            if (ap_regexec(entry_proxy->r, proxyname, nmatch, pmatch, 0)) {
                continue;
            }

            for (i = 0; i < nmatch; i++) {
                if (pmatch[i].rm_so >= 0 && pmatch[i].rm_eo >= 0 &&
                        ((const char **)entry_proxy->refs->elts)[i]) {
                    apr_table_setn(r->subprocess_env,
                            ((const char **)entry_proxy->refs->elts)[i],
                            apr_pstrndup(r->pool,
                                    proxyname + pmatch[i].rm_so,
                                    pmatch[i].rm_eo - pmatch[i].rm_so));
                }
            }
        }

        else if (
            /* XXX: What about case insensitive matching ???
             * Compare regex, fnmatch or string as appropriate
             * If the entry doesn't relate, then continue
             */
            entry_proxy->p_is_fnmatch ? apr_fnmatch(entry_proxy->p,
                    proxyname, 0) :
                    strncmp(proxyname, entry_proxy->p,
                            strlen(entry_proxy->p))) {
            continue;
        }
        per_dir_defaults = ap_merge_per_dir_configs(r->pool, per_dir_defaults,
                                                             entry_config);
    }

    r->per_dir_config = per_dir_defaults;

    if (rxpool) {
        apr_pool_destroy(rxpool);
    }

    return OK;
}

static int proxy_map_location(request_rec *r)
{
    int access_status;

    if (!r->proxyreq || !r->filename || strncmp(r->filename, "proxy:", 6) != 0)
        return DECLINED;

    /* Don't let the core or mod_http map_to_storage hooks handle this,
     * We don't need directory/file_walk, and we want to TRACE on our own.
     */
    if ((access_status = proxy_walk(r))) {
        ap_die(access_status, r);
        return access_status;
    }

    return OK;
}

/* -------------------------------------------------------------- */
/* Fixup the filename */

/*
* Canonicalise the URL
*/
static int proxy_fixup(request_rec *r)
{
    if (!r->proxyreq || !r->filename || strncmp(r->filename, "proxy:", 6) != 0)
        return DECLINED;

    /* XXX: Shouldn't we try this before we run the proxy_walk? */

    return ap_proxy_canon_url(r);
}

/* Send a redirection if the request contains a hostname which is not */
/* fully qualified, i.e. doesn't have a domain name appended. Some proxy */
/* servers like Netscape's allow this and access hosts from the local */
/* domain in this case. I think it is better to redirect to a FQDN, since */
/* these will later be found in the bookmarks files. */
/* The "ProxyDomain" directive determines what domain will be appended */
static int proxy_needsdomain(request_rec *r, const char *url, const char *domain)
{
    char *nuri;
    const char *ref;

    /* We only want to worry about GETs */
    if (!r->proxyreq || r->method_number != M_GET || !r->parsed_uri.hostname)
        return DECLINED;

    /* If host does contain a dot already, or it is "localhost", decline */
    if (strchr(r->parsed_uri.hostname, '.') != NULL /* has domain, or IPv4 literal */
     || strchr(r->parsed_uri.hostname, ':') != NULL /* IPv6 literal */
     || ap_cstr_casecmp(r->parsed_uri.hostname, "localhost") == 0)
        return DECLINED;    /* host name has a dot already */

    ref = apr_table_get(r->headers_in, "Referer");

    /* Reassemble the request, but insert the domain after the host name */
    /* Note that the domain name always starts with a dot */
    r->parsed_uri.hostname = apr_pstrcat(r->pool, r->parsed_uri.hostname,
                                         domain, NULL);
    nuri = apr_uri_unparse(r->pool,
                           &r->parsed_uri,
                           APR_URI_UNP_REVEALPASSWORD);

    apr_table_setn(r->headers_out, "Location", nuri);
    ap_log_rerror(APLOG_MARK, APLOG_INFO, 0, r, APLOGNO(01138)
                  "Domain missing: %s sent to %s%s%s", r->uri,
                  apr_uri_unparse(r->pool, &r->parsed_uri,
                                  APR_URI_UNP_OMITUSERINFO),
                  ref ? " from " : "", ref ? ref : "");

    return HTTP_MOVED_PERMANENTLY;
}

/* -------------------------------------------------------------- */
/* Invoke handler */

static int proxy_handler(request_rec *r)
{
    char *uri, *scheme, *p;
    const char *p2;
    void *sconf = r->server->module_config;
    proxy_server_conf *conf = (proxy_server_conf *)
        ap_get_module_config(sconf, &proxy_module);
    apr_array_header_t *proxies = conf->proxies;
    struct proxy_remote *ents = (struct proxy_remote *) proxies->elts;
    int rc = DECLINED, access_status, i;
    int direct_connect = 0;
    const char *str;
    apr_int64_t maxfwd;
    proxy_balancer *balancer = NULL;
    proxy_worker *worker = NULL;
    int attempts = 0, max_attempts = 0;
    struct dirconn_entry *list = (struct dirconn_entry *)conf->dirconn->elts;
    int saved_status;

    /* is this for us? */
    if (!r->filename) {
        return DECLINED;
    }

    /* We may have forced the proxy handler via config or .htaccess */
    if (!r->proxyreq && r->handler && strncmp(r->handler, "proxy:", 6) == 0) {
        char *old_filename = r->filename;

        r->proxyreq = PROXYREQ_REVERSE;
        r->filename = apr_pstrcat(r->pool, r->handler, r->filename, NULL);
        apr_table_setn(r->notes, "proxy-sethandler", "1");

        /* Still need to canonicalize r->filename */
        rc = ap_proxy_canon_url(r);
        if (rc != OK) {
            r->filename = old_filename;
            r->proxyreq = 0;
        }
    }
    else if (r->proxyreq && strncmp(r->filename, "proxy:", 6) == 0) {
        apr_table_unset(r->notes, "proxy-sethandler");
        rc = OK;
    }
    if (rc != OK) {
        return rc;
    }

    uri = r->filename + 6;
    p = strchr(uri, ':');
    if (p == NULL) {
        ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(01141)
                      "proxy_handler no URL in %s", r->filename);
        return HTTP_BAD_REQUEST;
    }
    scheme = apr_pstrmemdup(r->pool, uri, p - uri);

    /* handle max-forwards / OPTIONS / TRACE */
    if ((str = apr_table_get(r->headers_in, "Max-Forwards"))) {
        char *end;
        maxfwd = apr_strtoi64(str, &end, 10);
        if (maxfwd < 0 || maxfwd == APR_INT64_MAX || *end) {
            ap_log_rerror(APLOG_MARK, APLOG_WARNING, 0, r, APLOGNO(10188)
                          "Max-Forwards value '%s' could not be parsed", str);
            return ap_proxyerror(r, HTTP_BAD_REQUEST,
                          "Max-Forwards request header could not be parsed");
        }
        else if (maxfwd == 0) {
            switch (r->method_number) {
            case M_TRACE: {
                int access_status;
                r->proxyreq = PROXYREQ_NONE;
                access_status = ap_send_http_trace(r);
                ap_die(access_status, r);
                return OK;
            }
            case M_OPTIONS: {
                int access_status;
                r->proxyreq = PROXYREQ_NONE;
                access_status = ap_send_http_options(r);
                ap_die(access_status, r);
                return OK;
            }
            default: {
                return ap_proxyerror(r, HTTP_BAD_REQUEST,
                                     "Max-Forwards has reached zero - proxy loop?");
            }
            }
        }
        maxfwd = (maxfwd > 0) ? maxfwd - 1 : 0;
    }
    else {
        /* set configured max-forwards */
        maxfwd = conf->maxfwd;
    }
    if (maxfwd >= 0) {
        apr_table_setn(r->headers_in, "Max-Forwards",
                       apr_psprintf(r->pool, "%" APR_INT64_T_FMT, maxfwd));
    }

    if (r->method_number == M_TRACE) {
        core_server_config *coreconf = (core_server_config *)
                                       ap_get_core_module_config(sconf);

        if (coreconf->trace_enable == AP_TRACE_DISABLE)
        {
            /* Allow "error-notes" string to be printed by ap_send_error_response()
             * Note; this goes nowhere, canned error response need an overhaul.
             */
            apr_table_setn(r->notes, "error-notes",
                           "TRACE forbidden by server configuration");
            apr_table_setn(r->notes, "verbose-error-to", "*");
            ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01139)
                          "TRACE forbidden by server configuration");
            return HTTP_METHOD_NOT_ALLOWED;
        }

        /* Can't test ap_should_client_block, we aren't ready to send
         * the client a 100 Continue response till the connection has
         * been established
         */
        if (coreconf->trace_enable != AP_TRACE_EXTENDED
            && (r->read_length || r->read_chunked || r->remaining))
        {
            /* Allow "error-notes" string to be printed by ap_send_error_response()
             * Note; this goes nowhere, canned error response need an overhaul.
             */
            apr_table_setn(r->notes, "error-notes",
                           "TRACE with request body is not allowed");
            apr_table_setn(r->notes, "verbose-error-to", "*");
            ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01140)
                          "TRACE with request body is not allowed");
            return HTTP_REQUEST_ENTITY_TOO_LARGE;
        }
    }

    /* If the host doesn't have a domain name, add one and redirect. */
    if (conf->domain != NULL) {
        rc = proxy_needsdomain(r, uri, conf->domain);
        if (ap_is_HTTP_REDIRECT(rc))
            return HTTP_MOVED_PERMANENTLY;
    }

    /* Check URI's destination host against NoProxy hosts */
    /* Bypass ProxyRemote server lookup if configured as NoProxy */
    for (direct_connect = i = 0; i < conf->dirconn->nelts &&
                                        !direct_connect; i++) {
        direct_connect = list[i].matcher(&list[i], r);
    }
#if DEBUGGING
    ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r,
                (direct_connect) ? APLOGNO(03231) "NoProxy for %s" : APLOGNO(03232) "UseProxy for %s",
                r->uri);
#endif

    do {
        char *url = uri;
        /* Try to obtain the most suitable worker */
        access_status = ap_proxy_pre_request(&worker, &balancer, r, conf, &url);
        if (access_status != OK) {
            /*
             * Only return if access_status is not HTTP_SERVICE_UNAVAILABLE
             * This gives other modules the chance to hook into the
             * request_status hook and decide what to do in this situation.
             */
            if (access_status != HTTP_SERVICE_UNAVAILABLE)
                return access_status;
            /*
             * Ensure that balancer is NULL if worker is NULL to prevent
             * potential problems in the post_request hook.
             */
            if (!worker)
                balancer = NULL;
            goto cleanup;
        }

        /* Initialise worker if needed, note the shared area must be initialized by the balancer logic */
        if (balancer) {
            ap_proxy_initialize_worker(worker, r->server, conf->pool);
        }

        if (balancer && balancer->s->max_attempts_set && !max_attempts)
            max_attempts = balancer->s->max_attempts;
        /* firstly, try a proxy, unless a NoProxy directive is active */
        if (!direct_connect) {
            for (i = 0; i < proxies->nelts; i++) {
                p2 = ap_strchr_c(ents[i].scheme, ':');  /* is it a partial URL? */
                if (strcmp(ents[i].scheme, "*") == 0 ||
                    (ents[i].use_regex &&
                     ap_regexec(ents[i].regexp, url, 0, NULL, 0) == 0) ||
                    (p2 == NULL && ap_cstr_casecmp(scheme, ents[i].scheme) == 0) ||
                    (p2 != NULL &&
                    ap_cstr_casecmpn(url, ents[i].scheme,
                                strlen(ents[i].scheme)) == 0)) {

                    /* handle the scheme */
                    ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(01142)
                                  "Trying to run scheme_handler against proxy");

                    if (ents[i].creds) {
                        apr_table_set(r->notes, "proxy-basic-creds", ents[i].creds);
                        ap_log_rerror(APLOG_MARK, APLOG_TRACE1, 0, r,
                                      "Using proxy auth creds %s", ents[i].creds);
                    }

                    access_status = proxy_run_scheme_handler(r, worker,
                                                             conf, url,
                                                             ents[i].hostname,
                                                             ents[i].port);

                    if (ents[i].creds) apr_table_unset(r->notes, "proxy-basic-creds");

                    /* Did the scheme handler process the request? */
                    if (access_status != DECLINED) {
                        const char *cl_a;
                        apr_off_t cl;

                        /*
                         * An fatal error or success, so no point in
                         * retrying with a direct connection.
                         */
                        if (access_status != HTTP_BAD_GATEWAY) {
                            goto cleanup;
                        }

                        cl_a = apr_table_get(r->headers_in, "Content-Length");
                        if (cl_a && (!ap_parse_strict_length(&cl, cl_a)
                                     || cl > 0)) {
                            /*
                             * The request body is of length > 0. We cannot
                             * retry with a direct connection since we already
                             * sent (parts of) the request body to the proxy
                             * and do not have any longer.
                             */
                            goto cleanup;
                        }
                        /*
                         * Transfer-Encoding was set as input header, so we had
                         * a request body. We cannot retry with a direct
                         * connection for the same reason as above.
                         */
                        if (apr_table_get(r->headers_in, "Transfer-Encoding")) {
                            goto cleanup;
                        }
                    }
                }
            }
        }

        /* otherwise, try it direct */
        /* N.B. what if we're behind a firewall, where we must use a proxy or
        * give up??
        */

        /* handle the scheme */
        ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(01143)
                      "Running scheme %s handler (attempt %d)",
                      scheme, attempts);
        AP_PROXY_RUN(r, worker, conf, url, attempts);
        access_status = proxy_run_scheme_handler(r, worker, conf,
                                                 url, NULL, 0);
        if (access_status == OK
                || apr_table_get(r->notes, "proxy-error-override"))
            break;
        else if (access_status == HTTP_INTERNAL_SERVER_ERROR) {
            /* Unrecoverable server error.
             * We can not failover to another worker.
             * Mark the worker as unusable if member of load balancer
             */
            if (balancer
                && !(worker->s->status & PROXY_WORKER_IGNORE_ERRORS)) {
                worker->s->status |= PROXY_WORKER_IN_ERROR;
                worker->s->error_time = apr_time_now();
            }
            break;
        }
        else if (access_status == HTTP_SERVICE_UNAVAILABLE) {
            /* Recoverable server error.
             * We can failover to another worker
             * Mark the worker as unusable if member of load balancer
             */
            if (balancer
                && !(worker->s->status & PROXY_WORKER_IGNORE_ERRORS)) {
                worker->s->status |= PROXY_WORKER_IN_ERROR;
                worker->s->error_time = apr_time_now();
            }
        }
        else {
            /* Unrecoverable error.
             * Return the origin status code to the client.
             */
            break;
        }
        /* Try again if the worker is unusable and the service is
         * unavailable.
         */
    } while (!PROXY_WORKER_IS_USABLE(worker) &&
             max_attempts > attempts++);

    if (DECLINED == access_status) {
        ap_log_rerror(APLOG_MARK, APLOG_WARNING, 0, r, APLOGNO(01144)
                      "No protocol handler was valid for the URL %s "
                      "(scheme '%s'). "
                      "If you are using a DSO version of mod_proxy, make sure "
                      "the proxy submodules are included in the configuration "
                      "using LoadModule.", r->uri, scheme);
        access_status = HTTP_INTERNAL_SERVER_ERROR;
        goto cleanup;
    }
cleanup:
    /*
     * Save current r->status and set it to the value of access_status which
     * might be different (e.g. r->status could be HTTP_OK if e.g. we override
     * the error page on the proxy or if the error was not generated by the
     * backend itself but by the proxy e.g. a bad gateway) in order to give
     * ap_proxy_post_request a chance to act correctly on the status code.
     * But only do the above if access_status is not OK and not DONE, because
     * in this case r->status might contain the true status and overwriting
     * it with OK or DONE would be wrong.
     */
    if ((access_status != OK) && (access_status != DONE)) {
        saved_status = r->status;
        r->status = access_status;
        ap_proxy_post_request(worker, balancer, r, conf);
        /*
         * Only restore r->status if it has not been changed by
         * ap_proxy_post_request as we assume that this change was intentional.
         */
        if (r->status == access_status) {
            r->status = saved_status;
        }
    }
    else {
        ap_proxy_post_request(worker, balancer, r, conf);
    }

    proxy_run_request_status(&access_status, r);
    AP_PROXY_RUN_FINISHED(r, attempts, access_status);

    return access_status;
}

/* -------------------------------------------------------------- */
/* Setup configurable data */

static void * create_proxy_config(apr_pool_t *p, server_rec *s)
{
    proxy_server_conf *ps = apr_pcalloc(p, sizeof(proxy_server_conf));

    ps->sec_proxy = apr_array_make(p, 10, sizeof(ap_conf_vector_t *));
    ps->proxies = apr_array_make(p, 10, sizeof(struct proxy_remote));
    ps->aliases = apr_array_make(p, 10, sizeof(struct proxy_alias));
    ps->noproxies = apr_array_make(p, 10, sizeof(struct noproxy_entry));
    ps->dirconn = apr_array_make(p, 10, sizeof(struct dirconn_entry));
    ps->workers = apr_array_make(p, 10, sizeof(proxy_worker));
    ps->balancers = apr_array_make(p, 10, sizeof(proxy_balancer));
    ps->forward = NULL;
    ps->reverse = NULL;
    ps->domain = NULL;
    ps->map_encoded_one = 0;
    ps->map_encoded_all = 1;
    ps->id = apr_psprintf(p, "p%x", 1); /* simply for storage size */
    ps->viaopt = via_off; /* initially backward compatible with 1.3.1 */
    ps->viaopt_set = 0; /* 0 means default */
    ps->req = 0;
    ps->max_balancers = 0;
    ps->bal_persist = 0;
    ps->inherit = 1;
    ps->inherit_set = 0;
    ps->ppinherit = 1;
    ps->ppinherit_set = 0;
    ps->bgrowth = 5;
    ps->bgrowth_set = 0;
    ps->req_set = 0;
    ps->recv_buffer_size = 0; /* this default was left unset for some reason */
    ps->recv_buffer_size_set = 0;
    ps->io_buffer_size = AP_IOBUFSIZE;
    ps->io_buffer_size_set = 0;
    ps->maxfwd = DEFAULT_MAX_FORWARDS;
    ps->maxfwd_set = 0;
    ps->timeout = 0;
    ps->timeout_set = 0;
    ps->badopt = bad_error;
    ps->badopt_set = 0;
    ps->source_address = NULL;
    ps->source_address_set = 0;
    apr_pool_create_ex(&ps->pool, p, NULL, NULL);
    apr_pool_tag(ps->pool, "proxy_server_conf");

    return ps;
}

static apr_array_header_t *merge_balancers(apr_pool_t *p,
                                           apr_array_header_t *base,
                                           apr_array_header_t *overrides)
{
    proxy_balancer *b1;
    proxy_balancer *b2;
    proxy_balancer tmp;
    int x, y, found;
    apr_array_header_t *tocopy = apr_array_make(p, 1, sizeof(proxy_balancer));

    /* Check if the balancer is defined in both override and base configs:
     * a) If it is, Create copy of base balancer and change the configuration
     *    which can be changed by ProxyPass.
     * b) Otherwise, copy the balancer to tocopy array and merge it later.
     */
    b1 = (proxy_balancer *) base->elts;
    for (y = 0; y < base->nelts; y++) {
        b2 = (proxy_balancer *) overrides->elts;
        for (x = 0, found = 0; x < overrides->nelts; x++) {
            if (b1->hash.def == b2->hash.def && b1->hash.fnv == b2->hash.fnv) {
                tmp = *b2;
                *b2 = *b1;
                b2->s = tmp.s;

                /* For shared memory entries, b2->s belongs to override
                 * balancer, so if some entry is not set there, we have to
                 * update it according to the base balancer. */
                if (*b2->s->sticky == 0 && *b1->s->sticky) {
                    PROXY_STRNCPY(b2->s->sticky_path, b1->s->sticky_path);
                    PROXY_STRNCPY(b2->s->sticky, b1->s->sticky);
                }
                if (!b2->s->sticky_separator_set
                    && b1->s->sticky_separator_set) {
                    b2->s->sticky_separator_set = b1->s->sticky_separator_set;
                    b2->s->sticky_separator = b1->s->sticky_separator;
                }
                if (!b2->s->timeout && b1->s->timeout) {
                    b2->s->timeout = b1->s->timeout;
                }
                if (!b2->s->max_attempts_set && b1->s->max_attempts_set) {
                    b2->s->max_attempts_set = b1->s->max_attempts_set;
                    b2->s->max_attempts = b1->s->max_attempts;
                }
                if (!b2->s->nonce_set && b1->s->nonce_set) {
                    b2->s->nonce_set = b1->s->nonce_set;
                    PROXY_STRNCPY(b2->s->nonce, b1->s->nonce);
                }
                if (!b2->s->sticky_force_set && b1->s->sticky_force_set) {
                    b2->s->sticky_force_set = b1->s->sticky_force_set;
                    b2->s->sticky_force = b1->s->sticky_force;
                }
                if (!b2->s->scolonsep_set && b1->s->scolonsep_set) {
                    b2->s->scolonsep_set = b1->s->scolonsep_set;
                    b2->s->scolonsep = b1->s->scolonsep;
                }
                if (!b2->s->forcerecovery_set && b1->s->forcerecovery_set) {
                    b2->s->forcerecovery_set = b1->s->forcerecovery_set;
                    b2->s->forcerecovery = b1->s->forcerecovery;
                }

                /* For non-shared memory entries, b2 is copy of b1, so we have
                 * to use tmp copy of b1 to detect changes done in override. */
                if (tmp.lbmethod_set) {
                    b2->lbmethod_set = tmp.lbmethod_set;
                    b2->lbmethod = tmp.lbmethod;
                }
                if (tmp.growth_set) {
                    b2->growth_set = tmp.growth_set;
                    b2->growth = tmp.growth;
                }
                if (tmp.failontimeout_set) {
                    b2->failontimeout_set = tmp.failontimeout_set;
                    b2->failontimeout = tmp.failontimeout;
                }
                if (!apr_is_empty_array(tmp.errstatuses)) {
                    apr_array_cat(tmp.errstatuses, b2->errstatuses);
                    b2->errstatuses = tmp.errstatuses;
                }

                found = 1;
                break;
            }
            b2++;
        }
        if (!found) {
            *(proxy_balancer *)apr_array_push(tocopy) = *b1;
        }
        b1++;
    }

    return apr_array_append(p, tocopy, overrides);
}

static void * merge_proxy_config(apr_pool_t *p, void *basev, void *overridesv)
{
    proxy_server_conf *ps = apr_pcalloc(p, sizeof(proxy_server_conf));
    proxy_server_conf *base = (proxy_server_conf *) basev;
    proxy_server_conf *overrides = (proxy_server_conf *) overridesv;

    ps->inherit = (overrides->inherit_set == 0) ? base->inherit : overrides->inherit;
    ps->inherit_set = overrides->inherit_set || base->inherit_set;

    ps->ppinherit = (overrides->ppinherit_set == 0) ? base->ppinherit : overrides->ppinherit;
    ps->ppinherit_set = overrides->ppinherit_set || base->ppinherit_set;

    if (ps->ppinherit) {
        ps->proxies = apr_array_append(p, base->proxies, overrides->proxies);
    }
    else {
        ps->proxies = overrides->proxies;
    }
    ps->sec_proxy = apr_array_append(p, base->sec_proxy, overrides->sec_proxy);
    ps->aliases = apr_array_append(p, base->aliases, overrides->aliases);
    ps->noproxies = apr_array_append(p, base->noproxies, overrides->noproxies);
    ps->dirconn = apr_array_append(p, base->dirconn, overrides->dirconn);
    if (ps->inherit || ps->ppinherit) {
        ps->workers = apr_array_append(p, base->workers, overrides->workers);
        ps->balancers = merge_balancers(p, base->balancers, overrides->balancers);
    }
    else {
        ps->workers = overrides->workers;
        ps->balancers = overrides->balancers;
    }
    ps->forward = overrides->forward ? overrides->forward : base->forward;
    ps->reverse = overrides->reverse ? overrides->reverse : base->reverse;

    ps->map_encoded_one = overrides->map_encoded_one || base->map_encoded_one;
    ps->map_encoded_all = overrides->map_encoded_all && base->map_encoded_all;

    ps->domain = (overrides->domain == NULL) ? base->domain : overrides->domain;
    ps->id = (overrides->id == NULL) ? base->id : overrides->id;
    ps->viaopt = (overrides->viaopt_set == 0) ? base->viaopt : overrides->viaopt;
--> --------------------

--> maximum size reached

--> --------------------

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