mod_proxy_http.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.
 */

/* HTTP routines for Apache proxy */

#include "mod_proxy.h"
#include "ap_regex.h"

module AP_MODULE_DECLARE_DATA proxy_http_module;

static int (*ap_proxy_clear_connection_fn)(request_rec *r, apr_table_t *headers) =
        NULL;

static apr_status_t ap_proxy_http_cleanup(const char *scheme,
                                          request_rec *r,
                                          proxy_conn_rec *backend);

/*
 * Canonicalise http-like URLs.
 *  scheme is the scheme for the URL
 *  url    is the URL starting with the first '/'
 *  def_port is the default port for this scheme.
 */
static int proxy_http_canon(request_rec *r, char *url)
{
    char *host, *path, sport[7];
    char *search = NULL;
    const char *err;
    const char *scheme;
    apr_port_t port, def_port;

    /* ap_port_of_scheme() */
    if (strncasecmp(url, "http:", 5) == 0) {
        url += 5;
        scheme = "http";
    }
    else if (strncasecmp(url, "https:", 6) == 0) {
        url += 6;
        scheme = "https";
    }
    else {
        return DECLINED;
    }
    port = def_port = ap_proxy_port_of_scheme(scheme);

    ap_log_rerror(APLOG_MARK, APLOG_TRACE1, 0, r,
                  "HTTP: canonicalising URL %s", url);

    /* do syntatic check.
     * We break the URL into host, port, path, search
     */
    err = ap_proxy_canon_netloc(r->pool, &url, NULL, NULL, &host, &port);
    if (err) {
        ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01083)
                      "error parsing URL %s: %s", url, err);
        return HTTP_BAD_REQUEST;
    }

    /*
     * now parse path/search args, according to rfc1738:
     * process the path.
     *
     * In a reverse proxy, our URL has been processed, so canonicalise
     * unless proxy-nocanon is set to say it's raw
     * In a forward proxy, we have and MUST NOT MANGLE the original.
     */
    switch (r->proxyreq) {
    default: /* wtf are we doing here? */
    case PROXYREQ_REVERSE:
        if (apr_table_get(r->notes, "proxy-nocanon")) {
            path = url;   /* this is the raw path */
        }
        else {
            path = ap_proxy_canonenc(r->pool, url, strlen(url),
                                     enc_path, 0, r->proxyreq);
            search = r->args;
        }
        break;
    case PROXYREQ_PROXY:
        path = url;
        break;
    }

    if (path == NULL)
        return HTTP_BAD_REQUEST;

    if (port != def_port)
        apr_snprintf(sport, sizeof(sport), ":%d", port);
    else
        sport[0] = '\0';

    if (ap_strchr_c(host, ':')) { /* if literal IPv6 address */
        host = apr_pstrcat(r->pool, "[", host, "]", NULL);
    }
    r->filename = apr_pstrcat(r->pool, "proxy:", scheme, "://", host, sport,
            "/", path, (search) ? "?" : "", (search) ? search : "", NULL);
    return OK;
}

/* Clear all connection-based headers from the incoming headers table */
typedef struct header_dptr {
    apr_pool_t *pool;
    apr_table_t *table;
    apr_time_t time;
} header_dptr;
static ap_regex_t *warn_rx;
static int clean_warning_headers(void *data, const char *key, const char *val)
{
    apr_table_t *headers = ((header_dptr*)data)->table;
    apr_pool_t *pool = ((header_dptr*)data)->pool;
    char *warning;
    char *date;
    apr_time_t warn_time;
    const int nmatch = 3;
    ap_regmatch_t pmatch[3];

    if (headers == NULL) {
        ((header_dptr*)data)->table = headers = apr_table_make(pool, 2);
    }
/*
 * Parse this, suckers!
 *
 *    Warning    = "Warning" ":" 1#warning-value
 *
 *    warning-value = warn-code SP warn-agent SP warn-text
 *                                             [SP warn-date]
 *
 *    warn-code  = 3DIGIT
 *    warn-agent = ( host [ ":" port ] ) | pseudonym
 *                    ; the name or pseudonym of the server adding
 *                    ; the Warning header, for use in debugging
 *    warn-text  = quoted-string
 *    warn-date  = <"> HTTP-date <">
 *
 * Buggrit, use a bloomin' regexp!
 * (\d{3}\s+\S+\s+\".*?\"(\s+\"(.*?)\")?)  --> whole in $1, date in $3
 */
    while (!ap_regexec(warn_rx, val, nmatch, pmatch, 0)) {
        warning = apr_pstrndup(pool, val+pmatch[0].rm_so,
                               pmatch[0].rm_eo - pmatch[0].rm_so);
        warn_time = 0;
        if (pmatch[2].rm_eo > pmatch[2].rm_so) {
            /* OK, we have a date here */
            date = apr_pstrndup(pool, val+pmatch[2].rm_so,
                                pmatch[2].rm_eo - pmatch[2].rm_so);
            warn_time = apr_date_parse_http(date);
        }
        if (!warn_time || (warn_time == ((header_dptr*)data)->time)) {
            apr_table_addn(headers, key, warning);
        }
        val += pmatch[0].rm_eo;
    }
    return 1;
}
static apr_table_t *ap_proxy_clean_warnings(apr_pool_t *p, apr_table_t *headers)
{
   header_dptr x;
   x.pool = p;
   x.table = NULL;
   x.time = apr_date_parse_http(apr_table_get(headers, "Date"));
   apr_table_do(clean_warning_headers, &x, headers, "Warning", NULL);
   if (x.table != NULL) {
       apr_table_unset(headers, "Warning");
       return apr_table_overlay(p, headers, x.table);
   }
   else {
        return headers;
   }
}

static void add_te_chunked(apr_pool_t *p,
                           apr_bucket_alloc_t *bucket_alloc,
                           apr_bucket_brigade *header_brigade)
{
    apr_bucket *e;
    char *buf;
    const char te_hdr[] = "Transfer-Encoding: chunked" CRLF;

    buf = apr_pmemdup(p, te_hdr, sizeof(te_hdr)-1);
    ap_xlate_proto_to_ascii(buf, sizeof(te_hdr)-1);

    e = apr_bucket_pool_create(buf, sizeof(te_hdr)-1, p, bucket_alloc);
    APR_BRIGADE_INSERT_TAIL(header_brigade, e);
}

static void add_cl(apr_pool_t *p,
                   apr_bucket_alloc_t *bucket_alloc,
                   apr_bucket_brigade *header_brigade,
                   const char *cl_val)
{
    apr_bucket *e;
    char *buf;

    buf = apr_pstrcat(p, "Content-Length: ",
                      cl_val,
                      CRLF,
                      NULL);
    ap_xlate_proto_to_ascii(buf, strlen(buf));
    e = apr_bucket_pool_create(buf, strlen(buf), p, bucket_alloc);
    APR_BRIGADE_INSERT_TAIL(header_brigade, e);
}

#define ASCII_CRLF  "\015\012"
#define ASCII_ZERO  "\060"

static void terminate_headers(apr_bucket_alloc_t *bucket_alloc,
                              apr_bucket_brigade *header_brigade)
{
    apr_bucket *e;

    /* add empty line at the end of the headers */
    e = apr_bucket_immortal_create(ASCII_CRLF, 2, bucket_alloc);
    APR_BRIGADE_INSERT_TAIL(header_brigade, e);
}


#define MAX_MEM_SPOOL 16384

static int stream_reqbody_chunked(apr_pool_t *p,
                                           request_rec *r,
                                           proxy_conn_rec *p_conn,
                                           conn_rec *origin,
                                           apr_bucket_brigade *header_brigade,
                                           apr_bucket_brigade *input_brigade)
{
    int seen_eos = 0, rv = OK;
    apr_size_t hdr_len;
    apr_off_t bytes;
    apr_status_t status;
    apr_bucket_alloc_t *bucket_alloc = r->connection->bucket_alloc;
    apr_bucket_brigade *bb;
    apr_bucket *e;

    add_te_chunked(p, bucket_alloc, header_brigade);
    terminate_headers(bucket_alloc, header_brigade);

    while (!APR_BUCKET_IS_EOS(APR_BRIGADE_FIRST(input_brigade)))
    {
        char chunk_hdr[20];  /* must be here due to transient bucket. */

        /* If this brigade contains EOS, either stop or remove it. */
        if (APR_BUCKET_IS_EOS(APR_BRIGADE_LAST(input_brigade))) {
            seen_eos = 1;

            /* We can't pass this EOS to the output_filters. */
            e = APR_BRIGADE_LAST(input_brigade);
            apr_bucket_delete(e);
        }

        apr_brigade_length(input_brigade, 1, &bytes);

        hdr_len = apr_snprintf(chunk_hdr, sizeof(chunk_hdr),
                               "%" APR_UINT64_T_HEX_FMT CRLF,
                               (apr_uint64_t)bytes);

        ap_xlate_proto_to_ascii(chunk_hdr, hdr_len);
        e = apr_bucket_transient_create(chunk_hdr, hdr_len,
                                        bucket_alloc);
        APR_BRIGADE_INSERT_HEAD(input_brigade, e);

        /*
         * Append the end-of-chunk CRLF
         */
        e = apr_bucket_immortal_create(ASCII_CRLF, 2, bucket_alloc);
        APR_BRIGADE_INSERT_TAIL(input_brigade, e);

        if (header_brigade) {
            /* we never sent the header brigade, so go ahead and
             * take care of that now
             */
            bb = header_brigade;

            /*
             * Save input_brigade in bb brigade. (At least) in the SSL case
             * input_brigade contains transient buckets whose data would get
             * overwritten during the next call of ap_get_brigade in the loop.
             * ap_save_brigade ensures these buckets to be set aside.
             * Calling ap_save_brigade with NULL as filter is OK, because
             * bb brigade already has been created and does not need to get
             * created by ap_save_brigade.
             */
            status = ap_save_brigade(NULL, &bb, &input_brigade, p);
            if (status != APR_SUCCESS) {
                return HTTP_INTERNAL_SERVER_ERROR;
            }

            header_brigade = NULL;
        }
        else {
            bb = input_brigade;
        }

        /* The request is flushed below this loop with chunk EOS header */
        rv = ap_proxy_pass_brigade(bucket_alloc, r, p_conn, origin, bb, 0);
        if (rv != OK) {
            return rv;
        }

        if (seen_eos) {
            break;
        }

        status = ap_get_brigade(r->input_filters, input_brigade,
                                AP_MODE_READBYTES, APR_BLOCK_READ,
                                HUGE_STRING_LEN);

        if (status != APR_SUCCESS) {
            conn_rec *c = r->connection;
            ap_log_rerror(APLOG_MARK, APLOG_ERR, status, r, APLOGNO(02608)
                          "read request body failed to %pI (%s)"
                          " from %s (%s)", p_conn->addr,
                          p_conn->hostname ? p_conn->hostname: "",
                          c->client_ip, c->remote_host ? c->remote_host: "");
            return ap_map_http_request_error(status, HTTP_BAD_REQUEST);
        }
    }

    if (header_brigade) {
        /* we never sent the header brigade because there was no request body;
         * send it now
         */
        bb = header_brigade;
    }
    else {
        if (!APR_BRIGADE_EMPTY(input_brigade)) {
            /* input brigade still has an EOS which we can't pass to the output_filters. */
            e = APR_BRIGADE_LAST(input_brigade);
            AP_DEBUG_ASSERT(APR_BUCKET_IS_EOS(e));
            apr_bucket_delete(e);
        }
        bb = input_brigade;
    }

    e = apr_bucket_immortal_create(ASCII_ZERO ASCII_CRLF
                                   /* <trailers> */
                                   ASCII_CRLF,
                                   5, bucket_alloc);
    APR_BRIGADE_INSERT_TAIL(bb, e);

    if (apr_table_get(r->subprocess_env, "proxy-sendextracrlf")) {
        e = apr_bucket_immortal_create(ASCII_CRLF, 2, bucket_alloc);
        APR_BRIGADE_INSERT_TAIL(bb, e);
    }

    /* Now we have headers-only, or the chunk EOS mark; flush it */
    rv = ap_proxy_pass_brigade(bucket_alloc, r, p_conn, origin, bb, 1);
    return rv;
}

static int stream_reqbody_cl(apr_pool_t *p,
                                      request_rec *r,
                                      proxy_conn_rec *p_conn,
                                      conn_rec *origin,
                                      apr_bucket_brigade *header_brigade,
                                      apr_bucket_brigade *input_brigade,
                                      char *old_cl_val)
{
    int seen_eos = 0, rv = 0;
    apr_status_t status = APR_SUCCESS;
    apr_bucket_alloc_t *bucket_alloc = r->connection->bucket_alloc;
    apr_bucket_brigade *bb;
    apr_bucket *e;
    apr_off_t cl_val = 0;
    apr_off_t bytes;
    apr_off_t bytes_streamed = 0;

    if (old_cl_val) {
        char *endstr;

        add_cl(p, bucket_alloc, header_brigade, old_cl_val);
        status = apr_strtoff(&cl_val, old_cl_val, &endstr, 10);

        if (status || *endstr || endstr == old_cl_val || cl_val < 0) {
            ap_log_rerror(APLOG_MARK, APLOG_ERR, status, r, APLOGNO(01085)
                          "could not parse request Content-Length (%s)",
                          old_cl_val);
            return HTTP_BAD_REQUEST;
        }
    }
    terminate_headers(bucket_alloc, header_brigade);

    while (!APR_BUCKET_IS_EOS(APR_BRIGADE_FIRST(input_brigade)))
    {
        apr_brigade_length(input_brigade, 1, &bytes);
        bytes_streamed += bytes;

        /* If this brigade contains EOS, either stop or remove it. */
        if (APR_BUCKET_IS_EOS(APR_BRIGADE_LAST(input_brigade))) {
            seen_eos = 1;

            /* We can't pass this EOS to the output_filters. */
            e = APR_BRIGADE_LAST(input_brigade);
            apr_bucket_delete(e);

            if (apr_table_get(r->subprocess_env, "proxy-sendextracrlf")) {
                e = apr_bucket_immortal_create(ASCII_CRLF, 2, bucket_alloc);
                APR_BRIGADE_INSERT_TAIL(input_brigade, e);
            }
        }

        /* C-L < bytes streamed?!?
         * We will error out after the body is completely
         * consumed, but we can't stream more bytes at the
         * back end since they would in part be interpreted
         * as another request!  If nothing is sent, then
         * just send nothing.
         *
         * Prevents HTTP Response Splitting.
         */
        if (bytes_streamed > cl_val) {
            ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01086)
                          "read more bytes of request body than expected "
                          "(got %" APR_OFF_T_FMT ", expected %" APR_OFF_T_FMT ")",
                          bytes_streamed, cl_val);
            return HTTP_INTERNAL_SERVER_ERROR;
        }

        if (header_brigade) {
            /* we never sent the header brigade, so go ahead and
             * take care of that now
             */
            bb = header_brigade;

            /*
             * Save input_brigade in bb brigade. (At least) in the SSL case
             * input_brigade contains transient buckets whose data would get
             * overwritten during the next call of ap_get_brigade in the loop.
             * ap_save_brigade ensures these buckets to be set aside.
             * Calling ap_save_brigade with NULL as filter is OK, because
             * bb brigade already has been created and does not need to get
             * created by ap_save_brigade.
             */
            status = ap_save_brigade(NULL, &bb, &input_brigade, p);
            if (status != APR_SUCCESS) {
                return HTTP_INTERNAL_SERVER_ERROR;
            }

            header_brigade = NULL;
        }
        else {
            bb = input_brigade;
        }

        /* Once we hit EOS, we are ready to flush. */
        rv = ap_proxy_pass_brigade(bucket_alloc, r, p_conn, origin, bb, seen_eos);
        if (rv != OK) {
            return rv ;
        }

        if (seen_eos) {
            break;
        }

        status = ap_get_brigade(r->input_filters, input_brigade,
                                AP_MODE_READBYTES, APR_BLOCK_READ,
                                HUGE_STRING_LEN);

        if (status != APR_SUCCESS) {
            conn_rec *c = r->connection;
            ap_log_rerror(APLOG_MARK, APLOG_ERR, status, r, APLOGNO(02609)
                          "read request body failed to %pI (%s)"
                          " from %s (%s)", p_conn->addr,
                          p_conn->hostname ? p_conn->hostname: "",
                          c->client_ip, c->remote_host ? c->remote_host: "");
            return ap_map_http_request_error(status, HTTP_BAD_REQUEST);
        }
    }

    if (bytes_streamed != cl_val) {
        ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01087)
                      "client %s given Content-Length did not match"
                      " number of body bytes read", r->connection->client_ip);
        return HTTP_BAD_REQUEST;
    }

    if (header_brigade) {
        /* we never sent the header brigade since there was no request
         * body; send it now with the flush flag
         */
        bb = header_brigade;
        return(ap_proxy_pass_brigade(bucket_alloc, r, p_conn, origin, bb, 1));
    }

    return OK;
}

static int spool_reqbody_cl(apr_pool_t *p,
                                     request_rec *r,
                                     proxy_conn_rec *p_conn,
                                     conn_rec *origin,
                                     apr_bucket_brigade *header_brigade,
                                     apr_bucket_brigade *input_brigade,
                                     int force_cl)
{
    int seen_eos = 0;
    apr_status_t status;
    apr_bucket_alloc_t *bucket_alloc = r->connection->bucket_alloc;
    apr_bucket_brigade *body_brigade;
    apr_bucket *e;
    apr_off_t bytes, bytes_spooled = 0, fsize = 0;
    apr_file_t *tmpfile = NULL;
    apr_off_t limit;

    body_brigade = apr_brigade_create(p, bucket_alloc);

    limit = ap_get_limit_req_body(r);

    while (!APR_BUCKET_IS_EOS(APR_BRIGADE_FIRST(input_brigade)))
    {
        /* If this brigade contains EOS, either stop or remove it. */
        if (APR_BUCKET_IS_EOS(APR_BRIGADE_LAST(input_brigade))) {
            seen_eos = 1;

            /* We can't pass this EOS to the output_filters. */
            e = APR_BRIGADE_LAST(input_brigade);
            apr_bucket_delete(e);
        }

        apr_brigade_length(input_brigade, 1, &bytes);

        if (bytes_spooled + bytes > MAX_MEM_SPOOL) {
            /*
             * LimitRequestBody does not affect Proxy requests (Should it?).
             * Let it take effect if we decide to store the body in a
             * temporary file on disk.
             */
            if (limit && (bytes_spooled + bytes > limit)) {
                ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01088)
                              "Request body is larger than the configured "
                              "limit of %" APR_OFF_T_FMT, limit);
                return HTTP_REQUEST_ENTITY_TOO_LARGE;
            }
            /* can't spool any more in memory; write latest brigade to disk */
            if (tmpfile == NULL) {
                const char *temp_dir;
                char *template;

                status = apr_temp_dir_get(&temp_dir, p);
                if (status != APR_SUCCESS) {
                    ap_log_rerror(APLOG_MARK, APLOG_ERR, status, r, APLOGNO(01089)
                                  "search for temporary directory failed");
                    return HTTP_INTERNAL_SERVER_ERROR;
                }
                apr_filepath_merge(&template, temp_dir,
                                   "modproxy.tmp.XXXXXX",
                                   APR_FILEPATH_NATIVE, p);
                status = apr_file_mktemp(&tmpfile, template, 0, p);
                if (status != APR_SUCCESS) {
                    ap_log_rerror(APLOG_MARK, APLOG_ERR, status, r, APLOGNO(01090)
                                  "creation of temporary file in directory "
                                  "%s failed", temp_dir);
                    return HTTP_INTERNAL_SERVER_ERROR;
                }
            }
            for (e = APR_BRIGADE_FIRST(input_brigade);
                 e != APR_BRIGADE_SENTINEL(input_brigade);
                 e = APR_BUCKET_NEXT(e)) {
                const char *data;
                apr_size_t bytes_read, bytes_written;

                apr_bucket_read(e, &data, &bytes_read, APR_BLOCK_READ);
                status = apr_file_write_full(tmpfile, data, bytes_read, &bytes_written);
                if (status != APR_SUCCESS) {
                    const char *tmpfile_name;

                    if (apr_file_name_get(&tmpfile_name, tmpfile) != APR_SUCCESS) {
                        tmpfile_name = "(unknown)";
                    }
                    ap_log_rerror(APLOG_MARK, APLOG_ERR, status, r, APLOGNO(01091)
                                  "write to temporary file %s failed",
                                  tmpfile_name);
                    return HTTP_INTERNAL_SERVER_ERROR;
                }
                AP_DEBUG_ASSERT(bytes_read == bytes_written);
                fsize += bytes_written;
            }
            apr_brigade_cleanup(input_brigade);
        }
        else {

            /*
             * Save input_brigade in body_brigade. (At least) in the SSL case
             * input_brigade contains transient buckets whose data would get
             * overwritten during the next call of ap_get_brigade in the loop.
             * ap_save_brigade ensures these buckets to be set aside.
             * Calling ap_save_brigade with NULL as filter is OK, because
             * body_brigade already has been created and does not need to get
             * created by ap_save_brigade.
             */
            status = ap_save_brigade(NULL, &body_brigade, &input_brigade, p);
            if (status != APR_SUCCESS) {
                return HTTP_INTERNAL_SERVER_ERROR;
            }

        }

        bytes_spooled += bytes;

        if (seen_eos) {
            break;
        }

        status = ap_get_brigade(r->input_filters, input_brigade,
                                AP_MODE_READBYTES, APR_BLOCK_READ,
                                HUGE_STRING_LEN);

        if (status != APR_SUCCESS) {
            conn_rec *c = r->connection;
            ap_log_rerror(APLOG_MARK, APLOG_ERR, status, r, APLOGNO(02610)
                          "read request body failed to %pI (%s)"
                          " from %s (%s)", p_conn->addr,
                          p_conn->hostname ? p_conn->hostname: "",
                          c->client_ip, c->remote_host ? c->remote_host: "");
            return ap_map_http_request_error(status, HTTP_BAD_REQUEST);
        }
    }

    if (bytes_spooled || force_cl) {
        add_cl(p, bucket_alloc, header_brigade, apr_off_t_toa(p, bytes_spooled));
    }
    terminate_headers(bucket_alloc, header_brigade);
    APR_BRIGADE_CONCAT(header_brigade, body_brigade);
    if (tmpfile) {
        apr_brigade_insert_file(header_brigade, tmpfile, 0, fsize, p);
    }
    if (apr_table_get(r->subprocess_env, "proxy-sendextracrlf")) {
        e = apr_bucket_immortal_create(ASCII_CRLF, 2, bucket_alloc);
        APR_BRIGADE_INSERT_TAIL(header_brigade, e);
    }
    /* This is all a single brigade, pass with flush flagged */
    return(ap_proxy_pass_brigade(bucket_alloc, r, p_conn, origin, header_brigade, 1));
}

static
int ap_proxy_http_request(apr_pool_t *p, request_rec *r,
                                   proxy_conn_rec *p_conn, proxy_worker *worker,
                                   proxy_server_conf *conf,
                                   apr_uri_t *uri,
                                   char *url, char *server_portstr)
{
    conn_rec *c = r->connection;
    apr_bucket_alloc_t *bucket_alloc = c->bucket_alloc;
    apr_bucket_brigade *header_brigade;
    apr_bucket_brigade *input_brigade;
    apr_bucket_brigade *temp_brigade;
    apr_bucket *e;
    char *buf;
    apr_status_t status;
    enum rb_methods {RB_INIT, RB_STREAM_CL, RB_STREAM_CHUNKED, RB_SPOOL_CL};
    enum rb_methods rb_method = RB_INIT;
    char *old_cl_val = NULL;
    char *old_te_val = NULL;
    apr_off_t bytes_read = 0;
    apr_off_t bytes;
    int force10, rv;
    conn_rec *origin = p_conn->connection;

    if (apr_table_get(r->subprocess_env, "force-proxy-request-1.0")) {
        if (r->expecting_100) {
            return HTTP_EXPECTATION_FAILED;
        }
        force10 = 1;
    } else {
        force10 = 0;
    }

    header_brigade = apr_brigade_create(p, bucket_alloc);
    rv = ap_proxy_create_hdrbrgd(p, header_brigade, r, p_conn,
                                 worker, conf, uri, url, server_portstr,
                                 &old_cl_val, &old_te_val);
    if (rv != OK) {
        return rv;
    }

    /* We have headers, let's figure out our request body... */
    input_brigade = apr_brigade_create(p, bucket_alloc);

    /* sub-requests never use keepalives, and mustn't pass request bodies.
     * Because the new logic looks at input_brigade, we will self-terminate
     * input_brigade and jump past all of the request body logic...
     * Reading anything with ap_get_brigade is likely to consume the
     * main request's body or read beyond EOS - which would be unplesant.
     *
     * An exception: when a kept_body is present, then subrequest CAN use
     * pass request bodies, and we DONT skip the body.
     */
    if (!r->kept_body && r->main) {
        /* XXX: Why DON'T sub-requests use keepalives? */
        p_conn->close = 1;
        old_cl_val = NULL;
        old_te_val = NULL;
        rb_method = RB_STREAM_CL;
        e = apr_bucket_eos_create(input_brigade->bucket_alloc);
        APR_BRIGADE_INSERT_TAIL(input_brigade, e);
        goto skip_body;
    }

    /* WE only understand chunked.  Other modules might inject
     * (and therefore, decode) other flavors but we don't know
     * that the can and have done so unless they remove
     * their decoding from the headers_in T-E list.
     * XXX: Make this extensible, but in doing so, presume the
     * encoding has been done by the extensions' handler, and
     * do not modify add_te_chunked's logic
     */
    if (old_te_val && strcasecmp(old_te_val, "chunked") != 0) {
        ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01093)
                      "%s Transfer-Encoding is not supported", old_te_val);
        return HTTP_INTERNAL_SERVER_ERROR;
    }

    if (old_cl_val && old_te_val) {
        ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(01094)
                      "client %s (%s) requested Transfer-Encoding "
                      "chunked body with Content-Length (C-L ignored)",
                      c->client_ip, c->remote_host ? c->remote_host: "");
        old_cl_val = NULL;
        origin->keepalive = AP_CONN_CLOSE;
        p_conn->close = 1;
    }

    /* Prefetch MAX_MEM_SPOOL bytes
     *
     * This helps us avoid any election of C-L v.s. T-E
     * request bodies, since we are willing to keep in
     * memory this much data, in any case.  This gives
     * us an instant C-L election if the body is of some
     * reasonable size.
     */
    temp_brigade = apr_brigade_create(p, bucket_alloc);
    do {
        status = ap_get_brigade(r->input_filters, temp_brigade,
                                AP_MODE_READBYTES, APR_BLOCK_READ,
                                MAX_MEM_SPOOL - bytes_read);
        if (status != APR_SUCCESS) {
            ap_log_rerror(APLOG_MARK, APLOG_ERR, status, r, APLOGNO(01095)
                          "prefetch request body failed to %pI (%s)"
                          " from %s (%s)",
                          p_conn->addr, p_conn->hostname ? p_conn->hostname: "",
                          c->client_ip, c->remote_host ? c->remote_host: "");
            return ap_map_http_request_error(status, HTTP_BAD_REQUEST);
        }

        apr_brigade_length(temp_brigade, 1, &bytes);
        bytes_read += bytes;

        /*
         * Save temp_brigade in input_brigade. (At least) in the SSL case
         * temp_brigade contains transient buckets whose data would get
         * overwritten during the next call of ap_get_brigade in the loop.
         * ap_save_brigade ensures these buckets to be set aside.
         * Calling ap_save_brigade with NULL as filter is OK, because
         * input_brigade already has been created and does not need to get
         * created by ap_save_brigade.
         */
        status = ap_save_brigade(NULL, &input_brigade, &temp_brigade, p);
        if (status != APR_SUCCESS) {
            ap_log_rerror(APLOG_MARK, APLOG_ERR, status, r, APLOGNO(01096)
                          "processing prefetched request body failed"
                          " to %pI (%s) from %s (%s)",
                          p_conn->addr, p_conn->hostname ? p_conn->hostname: "",
                          c->client_ip, c->remote_host ? c->remote_host: "");
            return HTTP_INTERNAL_SERVER_ERROR;
        }

    /* Ensure we don't hit a wall where we have a buffer too small
     * for ap_get_brigade's filters to fetch us another bucket,
     * surrender once we hit 80 bytes less than MAX_MEM_SPOOL
     * (an arbitrary value.)
     */
    } while ((bytes_read < MAX_MEM_SPOOL - 80)
              && !APR_BUCKET_IS_EOS(APR_BRIGADE_LAST(input_brigade)));

    /* Use chunked request body encoding or send a content-length body?
     *
     * Prefer C-L when:
     *
     *   We have no request body (handled by RB_STREAM_CL)
     *
     *   We have a request body length <= MAX_MEM_SPOOL
     *
     *   The administrator has setenv force-proxy-request-1.0
     *
     *   The client sent a C-L body, and the administrator has
     *   not setenv proxy-sendchunked or has set setenv proxy-sendcl
     *
     *   The client sent a T-E body, and the administrator has
     *   setenv proxy-sendcl, and not setenv proxy-sendchunked
     *
     * If both proxy-sendcl and proxy-sendchunked are set, the
     * behavior is the same as if neither were set, large bodies
     * that can't be read will be forwarded in their original
     * form of C-L, or T-E.
     *
     * To ensure maximum compatibility, setenv proxy-sendcl
     * To reduce server resource use,   setenv proxy-sendchunked
     *
     * Then address specific servers with conditional setenv
     * options to restore the default behavior where desireable.
     *
     * We have to compute content length by reading the entire request
     * body; if request body is not small, we'll spool the remaining
     * input to a temporary file.  Chunked is always preferable.
     *
     * We can only trust the client-provided C-L if the T-E header
     * is absent, and the filters are unchanged (the body won't
     * be resized by another content filter).
     */
    if (APR_BUCKET_IS_EOS(APR_BRIGADE_LAST(input_brigade))) {
        /* The whole thing fit, so our decision is trivial, use
         * the filtered bytes read from the client for the request
         * body Content-Length.
         *
         * If we expected no body, and read no body, do not set
         * the Content-Length.
         */
        if (old_cl_val || old_te_val || bytes_read) {
            old_cl_val = apr_off_t_toa(r->pool, bytes_read);
        }
        rb_method = RB_STREAM_CL;
    }
    else if (old_te_val) {
        if (force10
             || (apr_table_get(r->subprocess_env, "proxy-sendcl")
                  && !apr_table_get(r->subprocess_env, "proxy-sendchunks")
                  && !apr_table_get(r->subprocess_env, "proxy-sendchunked"))) {
            rb_method = RB_SPOOL_CL;
        }
        else {
            rb_method = RB_STREAM_CHUNKED;
        }
    }
    else if (old_cl_val) {
        if (r->input_filters == r->proto_input_filters) {
            rb_method = RB_STREAM_CL;
        }
        else if (!force10
                  && (apr_table_get(r->subprocess_env, "proxy-sendchunks")
                      || apr_table_get(r->subprocess_env, "proxy-sendchunked"))
                  && !apr_table_get(r->subprocess_env, "proxy-sendcl")) {
            rb_method = RB_STREAM_CHUNKED;
        }
        else {
            rb_method = RB_SPOOL_CL;
        }
    }
    else {
        /* This is an appropriate default; very efficient for no-body
         * requests, and has the behavior that it will not add any C-L
         * when the old_cl_val is NULL.
         */
        rb_method = RB_SPOOL_CL;
    }

/* Yes I hate gotos.  This is the subrequest shortcut */
skip_body:
    /*
     * Handle Connection: header if we do HTTP/1.1 request:
     * If we plan to close the backend connection sent Connection: close
     * otherwise sent Connection: Keep-Alive.
     */
    if (!force10) {
        if (!ap_proxy_connection_reusable(p_conn)) {
            buf = apr_pstrdup(p, "Connection: close" CRLF);
        }
        else {
            buf = apr_pstrdup(p, "Connection: Keep-Alive" CRLF);
        }
        ap_xlate_proto_to_ascii(buf, strlen(buf));
        e = apr_bucket_pool_create(buf, strlen(buf), p, c->bucket_alloc);
        APR_BRIGADE_INSERT_TAIL(header_brigade, e);
    }

    /* send the request body, if any. */
    switch(rb_method) {
    case RB_STREAM_CHUNKED:
        rv = stream_reqbody_chunked(p, r, p_conn, origin, header_brigade,
                                        input_brigade);
        break;
    case RB_STREAM_CL:
        rv = stream_reqbody_cl(p, r, p_conn, origin, header_brigade,
                                   input_brigade, old_cl_val);
        break;
    case RB_SPOOL_CL:
        rv = spool_reqbody_cl(p, r, p_conn, origin, header_brigade,
                                  input_brigade, (old_cl_val != NULL)
                                              || (old_te_val != NULL)
                                              || (bytes_read > 0));
        break;
    default:
        /* shouldn't be possible */
        rv = HTTP_INTERNAL_SERVER_ERROR;
        break;
    }

    if (rv != OK) {
        /* apr_status_t value has been logged in lower level method */
        ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01097)
                      "pass request body failed to %pI (%s) from %s (%s)",
                      p_conn->addr, p_conn->hostname ? p_conn->hostname: "",
                      c->client_ip, c->remote_host ? c->remote_host: "");
        return rv;
    }

    return OK;
}

/*
 * If the date is a valid RFC 850 date or asctime() date, then it
 * is converted to the RFC 1123 format.
 */
static const char *date_canon(apr_pool_t *p, const char *date)
{
    apr_status_t rv;
    char* ndate;

    apr_time_t time = apr_date_parse_http(date);
    if (!time) {
        return date;
    }

    ndate = apr_palloc(p, APR_RFC822_DATE_LEN);
    rv = apr_rfc822_date(ndate, time);
    if (rv != APR_SUCCESS) {
        return date;
    }

    return ndate;
}

static request_rec *make_fake_req(conn_rec *c, request_rec *r)
{
    apr_pool_t *pool;
    request_rec *rp;

    apr_pool_create(&pool, c->pool);

    rp = apr_pcalloc(pool, sizeof(*r));

    rp->pool            = pool;
    rp->status          = HTTP_OK;

    rp->headers_in      = apr_table_make(pool, 50);
    rp->trailers_in     = apr_table_make(pool, 5);

    rp->subprocess_env  = apr_table_make(pool, 50);
    rp->headers_out     = apr_table_make(pool, 12);
    rp->trailers_out    = apr_table_make(pool, 5);
    rp->err_headers_out = apr_table_make(pool, 5);
    rp->notes           = apr_table_make(pool, 5);

    rp->server = r->server;
    rp->log = r->log;
    rp->proxyreq = r->proxyreq;
    rp->request_time = r->request_time;
    rp->connection      = c;
    rp->output_filters  = c->output_filters;
    rp->input_filters   = c->input_filters;
    rp->proto_output_filters  = c->output_filters;
    rp->proto_input_filters   = c->input_filters;
    rp->useragent_ip = c->client_ip;
    rp->useragent_addr = c->client_addr;

    rp->request_config  = ap_create_request_config(pool);
    proxy_run_create_req(r, rp);

    return rp;
}

static void process_proxy_header(request_rec *r, proxy_dir_conf *c,
                                 const char *key, const char *value)
{
    static const char *date_hdrs[]
        = { "Date", "Expires", "Last-Modified", NULL };
    static const struct {
        const char *name;
        ap_proxy_header_reverse_map_fn func;
    } transform_hdrs[] = {
        { "Location", ap_proxy_location_reverse_map },
        { "Content-Location", ap_proxy_location_reverse_map },
        { "URI", ap_proxy_location_reverse_map },
        { "Destination", ap_proxy_location_reverse_map },
        { "Set-Cookie", ap_proxy_cookie_reverse_map },
        { NULL, NULL }
    };
    int i;
    for (i = 0; date_hdrs[i]; ++i) {