Adding upstream version 2.4.56.upstream/2.4.56upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1330 insertions, 0 deletions

diff --git a/modules/proxy/mod_proxy_fcgi.c b/modules/proxy/mod_proxy_fcgi.c
new file mode 100644
index 0000000..3382b9b
--- /dev/null
+++ b/modules/proxy/mod_proxy_fcgi.c
@@ -0,0 +1,1330 @@
+/* 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 "util_fcgi.h"
+#include "util_script.h"
+#include "ap_expr.h"
+
+module AP_MODULE_DECLARE_DATA proxy_fcgi_module;
+
+typedef struct {
+    ap_expr_info_t *cond;
+    ap_expr_info_t *subst;
+    const char *envname;
+} sei_entry;
+
+typedef struct {
+    int need_dirwalk;
+} fcgi_req_config_t;
+
+/* We will assume FPM, but still differentiate */
+typedef enum {
+    BACKEND_DEFAULT_UNKNOWN = 0,
+    BACKEND_FPM,
+    BACKEND_GENERIC,
+} fcgi_backend_t;
+
+
+#define FCGI_MAY_BE_FPM(dconf)                              \
+        (dconf &&                                           \
+        ((dconf->backend_type == BACKEND_DEFAULT_UNKNOWN) || \
+        (dconf->backend_type == BACKEND_FPM)))
+
+typedef struct {
+    fcgi_backend_t backend_type;
+    apr_array_header_t *env_fixups;
+} fcgi_dirconf_t;
+
+/*
+ * 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_fcgi_canon(request_rec *r, char *url)
+{
+    char *host, sport[7];
+    const char *err;
+    char *path;
+    apr_port_t port, def_port;
+    fcgi_req_config_t *rconf = NULL;
+    const char *pathinfo_type = NULL;
+
+    if (ap_cstr_casecmpn(url, "fcgi:", 5) == 0) {
+        url += 5;
+    }
+    else {
+        return DECLINED;
+    }
+
+    port = def_port = ap_proxy_port_of_scheme("fcgi");
+
+    ap_log_rerror(APLOG_MARK, APLOG_TRACE1, 0, r,
+                 "canonicalising URL %s", url);
+    err = ap_proxy_canon_netloc(r->pool, &url, NULL, NULL, &host, &port);
+    if (err) {
+        ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01059)
+                      "error parsing URL %s: %s", url, err);
+        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);
+    }
+
+    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);
+    }
+    if (path == NULL)
+        return HTTP_BAD_REQUEST;
+
+    r->filename = apr_pstrcat(r->pool, "proxy:fcgi://", host, sport, "/",
+                              path, NULL);
+
+    ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(01060)
+                  "set r->filename to %s", r->filename);
+
+    rconf = ap_get_module_config(r->request_config, &proxy_fcgi_module);
+    if (rconf == NULL) {
+        rconf = apr_pcalloc(r->pool, sizeof(fcgi_req_config_t));
+        ap_set_module_config(r->request_config, &proxy_fcgi_module, rconf);
+    }
+
+    if (NULL != (pathinfo_type = apr_table_get(r->subprocess_env, "proxy-fcgi-pathinfo"))) {
+        /* It has to be on disk for this to work */
+        if (!strcasecmp(pathinfo_type, "full")) {
+            rconf->need_dirwalk = 1;
+            ap_unescape_url_keep2f(path, 0);
+        }
+        else if (!strcasecmp(pathinfo_type, "first-dot")) {
+            char *split = ap_strchr(path, '.');
+            if (split) {
+                char *slash = ap_strchr(split, '/');
+                if (slash) {
+                    r->path_info = apr_pstrdup(r->pool, slash);
+                    ap_unescape_url_keep2f(r->path_info, 0);
+                    *slash = '\0'; /* truncate path */
+                }
+            }
+        }
+        else if (!strcasecmp(pathinfo_type, "last-dot")) {
+            char *split = ap_strrchr(path, '.');
+            if (split) {
+                char *slash = ap_strchr(split, '/');
+                if (slash) {
+                    r->path_info = apr_pstrdup(r->pool, slash);
+                    ap_unescape_url_keep2f(r->path_info, 0);
+                    *slash = '\0'; /* truncate path */
+                }
+            }
+        }
+        else {
+            /* before proxy-fcgi-pathinfo had multi-values. This requires the
+             * the FCGI server to fixup PATH_INFO because it's the entire path
+             */
+            r->path_info = apr_pstrcat(r->pool, "/", path, NULL);
+            if (!strcasecmp(pathinfo_type, "unescape")) {
+                ap_unescape_url_keep2f(r->path_info, 0);
+            }
+            ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(01061)
+                    "set r->path_info to %s", r->path_info);
+        }
+    }
+
+    return OK;
+}
+
+
+/*
+  ProxyFCGISetEnvIf "reqenv('PATH_INFO') =~ m#/foo(\d+)\.php$#" COVENV1 "$1"
+  ProxyFCGISetEnvIf "reqenv('PATH_INFO') =~ m#/foo(\d+)\.php$#" PATH_INFO "/foo.php"
+  ProxyFCGISetEnvIf "reqenv('PATH_TRANSLATED') =~ m#(/.*foo)(\d+)(.*)#" PATH_TRANSLATED "$1$3"
+*/
+static apr_status_t fix_cgivars(request_rec *r, fcgi_dirconf_t *dconf)
+{
+    sei_entry *entries;
+    const char *err, *src;
+    int i = 0, rc = 0;
+    ap_regmatch_t regm[AP_MAX_REG_MATCH];
+
+    entries = (sei_entry *) dconf->env_fixups->elts;
+    for (i = 0; i < dconf->env_fixups->nelts; i++) {
+        sei_entry *entry = &entries[i];
+
+        rc = ap_expr_exec_re(r, entry->cond, AP_MAX_REG_MATCH, regm, &src, &err);
+        if (rc < 0) { 
+            ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(10241) 
+                          "fix_cgivars: Condition eval returned %d: %s", 
+                          rc, err);
+            return APR_EGENERAL;
+        }
+        else if (rc == 0) { 
+            continue; /* evaluated false */
+        }
+
+        if (entry->envname[0] == '!') {
+            apr_table_unset(r->subprocess_env, entry->envname+1);
+        }
+        else {
+            const char *val = ap_expr_str_exec_re(r, entry->subst, AP_MAX_REG_MATCH, regm, &src, &err);
+            if (err) {
+                ap_log_rerror(APLOG_MARK, APLOG_INFO, 0, r, APLOGNO(03514)
+                              "Error evaluating expression for replacement of %s: '%s'",
+                               entry->envname, err);
+                continue;
+            }
+            if (APLOGrtrace4(r)) {
+                const char *oldval = apr_table_get(r->subprocess_env, entry->envname);
+                ap_log_rerror(APLOG_MARK, APLOG_TRACE4, 0, r,
+                              "fix_cgivars: override %s from '%s' to '%s'",
+                              entry->envname, oldval, val);
+
+            }
+            apr_table_setn(r->subprocess_env, entry->envname, val);
+        }
+    }
+    return APR_SUCCESS;
+}
+
+/* Wrapper for apr_socket_sendv that handles updating the worker stats. */
+static apr_status_t send_data(proxy_conn_rec *conn,
+                              struct iovec *vec,
+                              int nvec,
+                              apr_size_t *len)
+{
+    apr_status_t rv = APR_SUCCESS;
+    apr_size_t written = 0, to_write = 0;
+    int i, offset;
+    apr_socket_t *s = conn->sock;
+
+    for (i = 0; i < nvec; i++) {
+        to_write += vec[i].iov_len;
+    }
+
+    offset = 0;
+    while (to_write) {
+        apr_size_t n = 0;
+        rv = apr_socket_sendv(s, vec + offset, nvec - offset, &n);
+        if (rv != APR_SUCCESS) {
+            break;
+        }
+        if (n > 0) {
+            written += n;
+            if (written >= to_write)
+                break;                 /* short circuit out */
+            for (i = offset; i < nvec; ) {
+                if (n >= vec[i].iov_len) {
+                    offset++;
+                    n -= vec[i++].iov_len;
+                } else {
+                    vec[i].iov_len -= n;
+                    vec[i].iov_base = (char *) vec[i].iov_base + n;
+                    break;
+                }
+            }
+        }
+    }
+
+    conn->worker->s->transferred += written;
+    *len = written;
+
+    return rv;
+}
+
+/* Wrapper for apr_socket_recv that handles updating the worker stats. */
+static apr_status_t get_data(proxy_conn_rec *conn,
+                             char *buffer,
+                             apr_size_t *buflen)
+{
+    apr_status_t rv = apr_socket_recv(conn->sock, buffer, buflen);
+
+    if (rv == APR_SUCCESS) {
+        conn->worker->s->read += *buflen;
+    }
+
+    return rv;
+}
+
+static apr_status_t get_data_full(proxy_conn_rec *conn,
+                                  char *buffer,
+                                  apr_size_t buflen)
+{
+    apr_size_t readlen;
+    apr_size_t cumulative_len = 0;
+    apr_status_t rv;
+
+    do {
+        readlen = buflen - cumulative_len;
+        rv = get_data(conn, buffer + cumulative_len, &readlen);
+        if (rv != APR_SUCCESS) {
+            return rv;
+        }
+        cumulative_len += readlen;
+    } while (cumulative_len < buflen);
+
+    return APR_SUCCESS;
+}
+
+static apr_status_t send_begin_request(proxy_conn_rec *conn,
+                                       apr_uint16_t request_id)
+{
+    struct iovec vec[2];
+    ap_fcgi_header header;
+    unsigned char farray[AP_FCGI_HEADER_LEN];
+    ap_fcgi_begin_request_body brb;
+    unsigned char abrb[AP_FCGI_HEADER_LEN];
+    apr_size_t len;
+
+    ap_fcgi_fill_in_header(&header, AP_FCGI_BEGIN_REQUEST, request_id,
+                           sizeof(abrb), 0);
+
+    ap_fcgi_fill_in_request_body(&brb, AP_FCGI_RESPONDER,
+                                 ap_proxy_connection_reusable(conn)
+                                     ? AP_FCGI_KEEP_CONN : 0);
+
+    ap_fcgi_header_to_array(&header, farray);
+    ap_fcgi_begin_request_body_to_array(&brb, abrb);
+
+    vec[0].iov_base = (void *)farray;
+    vec[0].iov_len = sizeof(farray);
+    vec[1].iov_base = (void *)abrb;
+    vec[1].iov_len = sizeof(abrb);
+
+    return send_data(conn, vec, 2, &len);
+}
+
+static apr_status_t send_environment(proxy_conn_rec *conn, request_rec *r,
+                                     apr_pool_t *temp_pool,
+                                     apr_uint16_t request_id)
+{
+    const apr_array_header_t *envarr;
+    const apr_table_entry_t *elts;
+    struct iovec vec[2];
+    ap_fcgi_header header;
+    unsigned char farray[AP_FCGI_HEADER_LEN];
+    char *body;
+    apr_status_t rv;
+    apr_size_t avail_len, len, required_len;
+    int next_elem, starting_elem;
+    fcgi_req_config_t *rconf = ap_get_module_config(r->request_config, &proxy_fcgi_module);
+    fcgi_dirconf_t *dconf = ap_get_module_config(r->per_dir_config, &proxy_fcgi_module);
+
+    if (rconf) {
+       if (rconf->need_dirwalk) {
+          ap_directory_walk(r);
+       }
+    }
+
+    /* Strip proxy: prefixes */
+    if (r->filename) {
+        char *newfname = NULL;
+
+        if (!strncmp(r->filename, "proxy:balancer://", 17)) {
+            newfname = apr_pstrdup(r->pool, r->filename+17);
+        }
+
+        if (!FCGI_MAY_BE_FPM(dconf))  {
+            if (!strncmp(r->filename, "proxy:fcgi://", 13)) {
+                /* If we strip this under FPM, and any internal redirect occurs
+                 * on PATH_INFO, FPM may use PATH_TRANSLATED instead of
+                 * SCRIPT_FILENAME (a la mod_fastcgi + Action).
+                 */
+                newfname = apr_pstrdup(r->pool, r->filename+13);
+            }
+            /* Query string in environment only */
+            if (newfname && r->args && *r->args) {
+                char *qs = strrchr(newfname, '?');
+                if (qs && !strcmp(qs+1, r->args)) {
+                    *qs = '\0';
+                }
+            }
+        }
+
+        if (newfname) {
+            newfname = ap_strchr(newfname, '/');
+            r->filename = newfname;
+        }
+    }
+
+    ap_add_common_vars(r);
+    ap_add_cgi_vars(r);
+
+    /* XXX are there any FastCGI specific env vars we need to send? */
+
+    /* Give admins final option to fine-tune env vars */
+    if (APR_SUCCESS != (rv = fix_cgivars(r, dconf))) { 
+        return rv;
+    }
+
+    /* XXX mod_cgi/mod_cgid use ap_create_environment here, which fills in
+     *     the TZ value specially.  We could use that, but it would mean
+     *     parsing the key/value pairs back OUT of the allocated env array,
+     *     not to mention allocating a totally useless array in the first
+     *     place, which would suck. */
+
+    envarr = apr_table_elts(r->subprocess_env);
+    elts = (const apr_table_entry_t *) envarr->elts;
+
+    if (APLOGrtrace8(r)) {
+        int i;
+
+        for (i = 0; i < envarr->nelts; ++i) {
+            ap_log_rerror(APLOG_MARK, APLOG_TRACE8, 0, r, APLOGNO(01062)
+                          "sending env var '%s' value '%s'",
+                          elts[i].key, elts[i].val);
+        }
+    }
+
+    /* Send envvars over in as many FastCGI records as it takes, */
+    next_elem = 0; /* starting with the first one */
+
+    avail_len = 16 * 1024; /* our limit per record, which could have been up
+                            * to AP_FCGI_MAX_CONTENT_LEN
+                            */
+
+    while (next_elem < envarr->nelts) {
+        starting_elem = next_elem;
+        required_len = ap_fcgi_encoded_env_len(r->subprocess_env,
+                                               avail_len,
+                                               &next_elem);
+
+        if (!required_len) {
+            if (next_elem < envarr->nelts) {
+                ap_log_rerror(APLOG_MARK, APLOG_WARNING, 0, r,
+                              APLOGNO(02536) "couldn't encode envvar '%s' in %"
+                              APR_SIZE_T_FMT " bytes",
+                              elts[next_elem].key, avail_len);
+                /* skip this envvar and continue */
+                ++next_elem;
+                continue;
+            }
+            /* only an unused element at the end of the array */
+            break;
+        }
+
+        body = apr_palloc(temp_pool, required_len);
+        rv = ap_fcgi_encode_env(r, r->subprocess_env, body, required_len,
+                                &starting_elem);
+        /* we pre-compute, so we can't run out of space */
+        ap_assert(rv == APR_SUCCESS);
+        /* compute and encode must be in sync */
+        ap_assert(starting_elem == next_elem);
+
+        ap_fcgi_fill_in_header(&header, AP_FCGI_PARAMS, request_id,
+                               (apr_uint16_t)required_len, 0);
+        ap_fcgi_header_to_array(&header, farray);
+
+        vec[0].iov_base = (void *)farray;
+        vec[0].iov_len = sizeof(farray);
+        vec[1].iov_base = body;
+        vec[1].iov_len = required_len;
+
+        rv = send_data(conn, vec, 2, &len);
+        apr_pool_clear(temp_pool);
+
+        if (rv) {
+            return rv;
+        }
+    }
+
+    /* Envvars sent, so say we're done */
+    ap_fcgi_fill_in_header(&header, AP_FCGI_PARAMS, request_id, 0, 0);
+    ap_fcgi_header_to_array(&header, farray);
+
+    vec[0].iov_base = (void *)farray;
+    vec[0].iov_len = sizeof(farray);
+
+    return send_data(conn, vec, 1, &len);
+}
+
+enum {
+  HDR_STATE_READING_HEADERS,
+  HDR_STATE_GOT_CR,
+  HDR_STATE_GOT_CRLF,
+  HDR_STATE_GOT_CRLFCR,
+  HDR_STATE_GOT_LF,
+  HDR_STATE_DONE_WITH_HEADERS
+};
+
+/* Try to find the end of the script headers in the response from the back
+ * end fastcgi server. STATE holds the current header parsing state for this
+ * request.
+ *
+ * Returns 0 if it can't find the end of the headers, and 1 if it found the
+ * end of the headers. */
+static int handle_headers(request_rec *r, int *state,
+                          const char *readbuf, apr_size_t readlen)
+{
+    const char *itr = readbuf;
+
+    while (readlen--) {
+        if (*itr == '\r') {
+            switch (*state) {
+                case HDR_STATE_GOT_CRLF:
+                    *state = HDR_STATE_GOT_CRLFCR;
+                    break;
+
+                default:
+                    *state = HDR_STATE_GOT_CR;
+                    break;
+            }
+        }
+        else if (*itr == '\n') {
+            switch (*state) {
+                 case HDR_STATE_GOT_LF:
+                     *state = HDR_STATE_DONE_WITH_HEADERS;
+                     break;
+
+                 case HDR_STATE_GOT_CR:
+                     *state = HDR_STATE_GOT_CRLF;
+                     break;
+
+                 case HDR_STATE_GOT_CRLFCR:
+                     *state = HDR_STATE_DONE_WITH_HEADERS;
+                     break;
+
+                 default:
+                     *state = HDR_STATE_GOT_LF;
+                     break;
+            }
+        }
+        else {
+            *state = HDR_STATE_READING_HEADERS;
+        }
+
+        if (*state == HDR_STATE_DONE_WITH_HEADERS)
+            break;
+
+        ++itr;
+    }
+
+    if (*state == HDR_STATE_DONE_WITH_HEADERS) {
+        return 1;
+    }
+
+    return 0;
+}
+
+static apr_status_t dispatch(proxy_conn_rec *conn, proxy_dir_conf *conf,
+                             request_rec *r, apr_pool_t *setaside_pool,
+                             apr_uint16_t request_id, const char **err,
+                             int *bad_request, int *has_responded,
+                             apr_bucket_brigade *input_brigade)
+{
+    apr_bucket_brigade *ib, *ob;
+    int seen_end_of_headers = 0, done = 0, ignore_body = 0;
+    apr_status_t rv = APR_SUCCESS;
+    int script_error_status = HTTP_OK;
+    conn_rec *c = r->connection;
+    struct iovec vec[2];
+    ap_fcgi_header header;
+    unsigned char farray[AP_FCGI_HEADER_LEN];
+    apr_pollfd_t pfd;
+    apr_pollfd_t *flushpoll = NULL;
+    apr_int32_t flushpoll_fd;
+    int header_state = HDR_STATE_READING_HEADERS;
+    char stack_iobuf[AP_IOBUFSIZE];
+    apr_size_t iobuf_size = AP_IOBUFSIZE;
+    char *iobuf = stack_iobuf;
+
+    *err = NULL;
+    if (conn->worker->s->io_buffer_size_set) {
+        iobuf_size = conn->worker->s->io_buffer_size;
+        iobuf = apr_palloc(r->pool, iobuf_size);
+    }
+
+    pfd.desc_type = APR_POLL_SOCKET;
+    pfd.desc.s = conn->sock;
+    pfd.p = r->pool;
+    pfd.reqevents = APR_POLLIN | APR_POLLOUT;
+
+    if (conn->worker->s->flush_packets == flush_auto) {
+        flushpoll = apr_pcalloc(r->pool, sizeof(apr_pollfd_t));
+        flushpoll->reqevents = APR_POLLIN;
+        flushpoll->desc_type = APR_POLL_SOCKET;
+        flushpoll->desc.s = conn->sock;
+    }
+
+    ib = apr_brigade_create(r->pool, c->bucket_alloc);
+    ob = apr_brigade_create(r->pool, c->bucket_alloc);
+
+    while (! done) {
+        apr_interval_time_t timeout;
+        apr_size_t len;
+        int n;
+
+        /* We need SOME kind of timeout here, or virtually anything will
+         * cause timeout errors. */
+        apr_socket_timeout_get(conn->sock, &timeout);
+
+        rv = apr_poll(&pfd, 1, &n, timeout);
+        if (rv != APR_SUCCESS) {
+            if (APR_STATUS_IS_EINTR(rv)) {
+                continue;
+            }
+            *err = "polling";
+            break;
+        }
+
+        if (pfd.rtnevents & APR_POLLOUT) {
+            apr_size_t to_send, writebuflen;
+            int last_stdin = 0;
+            char *iobuf_cursor;
+
+            if (APR_BRIGADE_EMPTY(input_brigade)) {
+                rv = ap_get_brigade(r->input_filters, ib,
+                                    AP_MODE_READBYTES, APR_BLOCK_READ,
+                                    iobuf_size);
+            }
+            else {
+                apr_bucket *e;
+                APR_BRIGADE_CONCAT(ib, input_brigade);
+                rv = apr_brigade_partition(ib, iobuf_size, &e);
+                if (rv == APR_SUCCESS) {
+                    while (e != APR_BRIGADE_SENTINEL(ib)
+                           && APR_BUCKET_IS_METADATA(e)) {
+                        e = APR_BUCKET_NEXT(e);
+                    }
+                    apr_brigade_split_ex(ib, e, input_brigade);
+                }
+                else if (rv == APR_INCOMPLETE) {
+                    rv = APR_SUCCESS;
+                }
+            }
+            if (rv != APR_SUCCESS) {
+                *err = "reading input brigade";
+                *bad_request = 1;
+                break;
+            }
+
+            if (APR_BUCKET_IS_EOS(APR_BRIGADE_LAST(ib))) {
+                last_stdin = 1;
+            }
+
+            writebuflen = iobuf_size;
+
+            rv = apr_brigade_flatten(ib, iobuf, &writebuflen);
+
+            apr_brigade_cleanup(ib);
+
+            if (rv != APR_SUCCESS) {
+                *err = "flattening brigade";
+                break;
+            }
+
+            to_send = writebuflen;
+            iobuf_cursor = iobuf;
+            while (to_send > 0) {
+                int nvec = 0;
+                apr_size_t write_this_time;
+
+                write_this_time =
+                    to_send < AP_FCGI_MAX_CONTENT_LEN ? to_send : AP_FCGI_MAX_CONTENT_LEN;
+
+                ap_fcgi_fill_in_header(&header, AP_FCGI_STDIN, request_id,
+                                       (apr_uint16_t)write_this_time, 0);
+                ap_fcgi_header_to_array(&header, farray);
+
+                vec[nvec].iov_base = (void *)farray;
+                vec[nvec].iov_len = sizeof(farray);
+                ++nvec;
+                if (writebuflen) {
+                    vec[nvec].iov_base = iobuf_cursor;
+                    vec[nvec].iov_len = write_this_time;
+                    ++nvec;
+                }
+
+                rv = send_data(conn, vec, nvec, &len);
+                if (rv != APR_SUCCESS) {
+                    *err = "sending stdin";
+                    break;
+                }
+
+                to_send -= write_this_time;
+                iobuf_cursor += write_this_time;
+            }
+            if (rv != APR_SUCCESS) {
+                break;
+            }
+
+            if (last_stdin) {
+                pfd.reqevents = APR_POLLIN; /* Done with input data */
+
+                /* signal EOF (empty FCGI_STDIN) */
+                ap_fcgi_fill_in_header(&header, AP_FCGI_STDIN, request_id,
+                                       0, 0);
+                ap_fcgi_header_to_array(&header, farray);
+
+                vec[0].iov_base = (void *)farray;
+                vec[0].iov_len = sizeof(farray);
+
+                rv = send_data(conn, vec, 1, &len);
+                if (rv != APR_SUCCESS) {
+                    *err = "sending empty stdin";
+                    break;
+                }
+            }
+        }
+
+        if (pfd.rtnevents & APR_POLLIN) {
+            apr_size_t readbuflen;
+            apr_uint16_t clen, rid;
+            apr_bucket *b;
+            unsigned char plen;
+            unsigned char type, version;
+            int mayflush = 0;
+
+            /* First, we grab the header... */
+            rv = get_data_full(conn, (char *) farray, AP_FCGI_HEADER_LEN);
+            if (rv != APR_SUCCESS) {
+                ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01067)
+                              "Failed to read FastCGI header");
+                break;
+            }
+
+            ap_log_rdata(APLOG_MARK, APLOG_TRACE8, r, "FastCGI header",
+                         farray, AP_FCGI_HEADER_LEN, 0);
+
+            ap_fcgi_header_fields_from_array(&version, &type, &rid,
+                                             &clen, &plen, farray);
+
+            if (version != AP_FCGI_VERSION_1) {
+                ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01068)
+                              "Got bogus version %d", (int)version);
+                rv = APR_EINVAL;
+                break;
+            }
+
+            if (rid != request_id) {
+                ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01069)
+                              "Got bogus rid %d, expected %d",
+                              rid, request_id);
+                rv = APR_EINVAL;
+                break;
+            }
+
+recv_again:
+            if (clen > iobuf_size) {
+                readbuflen = iobuf_size;
+            } else {
+                readbuflen = clen;
+            }
+
+            /* Now get the actual data.  Yes it sucks to do this in a second
+             * recv call, this will eventually change when we move to real
+             * nonblocking recv calls. */
+            if (readbuflen != 0) {
+                rv = get_data(conn, iobuf, &readbuflen);
+                if (rv != APR_SUCCESS) {
+                    *err = "reading response body";
+                    break;
+                }
+            }
+
+            switch (type) {
+            case AP_FCGI_STDOUT:
+                if (clen != 0) {
+                    b = apr_bucket_transient_create(iobuf,
+                                                    readbuflen,
+                                                    c->bucket_alloc);
+
+                    APR_BRIGADE_INSERT_TAIL(ob, b);
+
+                    if (! seen_end_of_headers) {
+                        int st = handle_headers(r, &header_state,
+                                                iobuf, readbuflen);
+
+                        if (st == 1) {
+                            int status;
+                            seen_end_of_headers = 1;
+
+                            status = ap_scan_script_header_err_brigade_ex(r, ob,
+                                NULL, APLOG_MODULE_INDEX);
+                            /* suck in all the rest */
+                            if (status != OK) {
+                                apr_bucket *tmp_b;
+                                apr_brigade_cleanup(ob);
+                                tmp_b = apr_bucket_eos_create(c->bucket_alloc);
+                                APR_BRIGADE_INSERT_TAIL(ob, tmp_b);
+
+                                *has_responded = 1;
+                                r->status = status;
+                                rv = ap_pass_brigade(r->output_filters, ob);
+                                if (rv != APR_SUCCESS) {
+                                    *err = "passing headers brigade to output filters";
+                                    break;
+                                }
+                                else if (status == HTTP_NOT_MODIFIED
+                                         || status == HTTP_PRECONDITION_FAILED) {
+                                    /* Special 'status' cases handled:
+                                     * 1) HTTP 304 response MUST NOT contain
+                                     *    a message-body, ignore it.
+                                     * 2) HTTP 412 response.
+                                     * The break is not added since there might
+                                     * be more bytes to read from the FCGI
+                                     * connection. Even if the message-body is
+                                     * ignored (and the EOS bucket has already
+                                     * been sent) we want to avoid subsequent
+                                     * bogus reads. */
+                                    ignore_body = 1;
+                                }
+                                else {
+                                    ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01070)
+                                                    "Error parsing script headers");
+                                    rv = APR_EINVAL;
+                                    break;
+                                }
+                            }
+
+                            if (ap_proxy_should_override(conf, r->status) && ap_is_initial_req(r)) {
+                                /*
+                                 * set script_error_status to discard
+                                 * everything after the headers
+                                 */
+                                script_error_status = r->status;
+                                /*
+                                 * prevent ap_die() from treating this as a
+                                 * recursive error, initially:
+                                 */
+                                r->status = HTTP_OK;
+                            }
+
+                            if (script_error_status == HTTP_OK
+                                && !APR_BRIGADE_EMPTY(ob) && !ignore_body) {
+                                /* Send the part of the body that we read while
+                                 * reading the headers.
+                                 */
+                                *has_responded = 1;
+                                rv = ap_pass_brigade(r->output_filters, ob);
+                                if (rv != APR_SUCCESS) {
+                                    *err = "passing brigade to output filters";
+                                    break;
+                                }
+                                mayflush = 1;
+                            }
+                            apr_brigade_cleanup(ob);
+
+                            apr_pool_clear(setaside_pool);
+                        }
+                        else {
+                            /* We're still looking for the end of the
+                             * headers, so this part of the data will need
+                             * to persist. */
+                            apr_bucket_setaside(b, setaside_pool);
+                        }
+                    } else {
+                        /* we've already passed along the headers, so now pass
+                         * through the content.  we could simply continue to
+                         * setaside the content and not pass until we see the
+                         * 0 content-length (below, where we append the EOS),
+                         * but that could be a huge amount of data; so we pass
+                         * along smaller chunks
+                         */
+                        if (script_error_status == HTTP_OK && !ignore_body) {
+                            *has_responded = 1;
+                            rv = ap_pass_brigade(r->output_filters, ob);
+                            if (rv != APR_SUCCESS) {
+                                *err = "passing brigade to output filters";
+                                break;
+                            }
+                            mayflush = 1;
+                        }
+                        apr_brigade_cleanup(ob);
+                    }
+
+                    /* If we didn't read all the data, go back and get the
+                     * rest of it. */
+                    if (clen > readbuflen) {
+                        clen -= readbuflen;
+                        goto recv_again;
+                    }
+                } else {
+                    /* XXX what if we haven't seen end of the headers yet? */
+
+                    if (script_error_status == HTTP_OK) {
+                        b = apr_bucket_eos_create(c->bucket_alloc);
+                        APR_BRIGADE_INSERT_TAIL(ob, b);
+
+                        *has_responded = 1;
+                        rv = ap_pass_brigade(r->output_filters, ob);
+                        if (rv != APR_SUCCESS) {
+                            *err = "passing brigade to output filters";
+                            break;
+                        }
+                    }
+
+                    /* XXX Why don't we cleanup here?  (logic from AJP) */
+                }
+                break;
+
+            case AP_FCGI_STDERR:
+                /* TODO: Should probably clean up this logging a bit... */
+                if (clen) {
+                    ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01071)
+                                  "Got error '%.*s'", (int)readbuflen, iobuf);
+                }
+
+                if (clen > readbuflen) {
+                    clen -= readbuflen;
+                    goto recv_again;
+                }
+                break;
+
+            case AP_FCGI_END_REQUEST:
+                done = 1;
+                break;
+
+            default:
+                ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01072)
+                              "Got bogus record %d", type);
+                break;
+            }
+            /* Leave on above switch's inner error. */
+            if (rv != APR_SUCCESS) {
+                break;
+            }
+
+            if (plen) {
+                rv = get_data_full(conn, iobuf, plen);
+                if (rv != APR_SUCCESS) {
+                    ap_log_rerror(APLOG_MARK, APLOG_ERR, rv, r, APLOGNO(02537)
+                                  "Error occurred reading padding");
+                    break;
+                }
+            }
+
+            if (mayflush && ((conn->worker->s->flush_packets == flush_on) ||
+                             ((conn->worker->s->flush_packets == flush_auto) && 
+                              (apr_poll(flushpoll, 1, &flushpoll_fd,
+                               conn->worker->s->flush_wait) == APR_TIMEUP)))) {
+                apr_bucket* flush_b = apr_bucket_flush_create(r->connection->bucket_alloc);
+                APR_BRIGADE_INSERT_TAIL(ob, flush_b);
+                rv = ap_pass_brigade(r->output_filters, ob);
+                if (rv != APR_SUCCESS) {
+                    *err = "passing headers brigade to output filters";
+                    break;
+                }
+                mayflush = 0;
+            }
+        }
+    }
+
+    apr_brigade_destroy(ib);
+    apr_brigade_destroy(ob);
+
+    if (script_error_status != HTTP_OK) {
+        ap_die(script_error_status, r); /* send ErrorDocument */
+        *has_responded = 1;
+    }
+
+    return rv;
+}
+
+/*
+ * process the request and write the response.
+ */
+static int fcgi_do_request(apr_pool_t *p, request_rec *r,
+                           proxy_conn_rec *conn,
+                           conn_rec *origin,
+                           proxy_dir_conf *conf,
+                           apr_uri_t *uri,
+                           char *url, char *server_portstr,
+                           apr_bucket_brigade *input_brigade)
+{
+    /* Request IDs are arbitrary numbers that we assign to a
+     * single request. This would allow multiplex/pipelining of
+     * multiple requests to the same FastCGI connection, but
+     * we don't support that, and always use a value of '1' to
+     * keep things simple. */
+    apr_uint16_t request_id = 1;
+    apr_status_t rv;
+    apr_pool_t *temp_pool;
+    const char *err;
+    int bad_request = 0,
+        has_responded = 0;
+
+    /* Step 1: Send AP_FCGI_BEGIN_REQUEST */
+    rv = send_begin_request(conn, request_id);
+    if (rv != APR_SUCCESS) {
+        ap_log_rerror(APLOG_MARK, APLOG_ERR, rv, r, APLOGNO(01073)
+                      "Failed Writing Request to %s:", server_portstr);
+        conn->close = 1;
+        return HTTP_SERVICE_UNAVAILABLE;
+    }
+
+    apr_pool_create(&temp_pool, r->pool);
+    apr_pool_tag(temp_pool, "proxy_fcgi_do_request");
+
+    /* Step 2: Send Environment via FCGI_PARAMS */
+    rv = send_environment(conn, r, temp_pool, request_id);
+    if (rv != APR_SUCCESS) {
+        ap_log_rerror(APLOG_MARK, APLOG_ERR, rv, r, APLOGNO(01074)
+                      "Failed writing Environment to %s:", server_portstr);
+        conn->close = 1;
+        return HTTP_SERVICE_UNAVAILABLE;
+    }
+
+    /* Step 3: Read records from the back end server and handle them. */
+    rv = dispatch(conn, conf, r, temp_pool, request_id,
+                  &err, &bad_request, &has_responded,
+                  input_brigade);
+    if (rv != APR_SUCCESS) {
+        /* If the client aborted the connection during retrieval or (partially)
+         * sending the response, don't return a HTTP_SERVICE_UNAVAILABLE, since
+         * this is not a backend problem. */
+        if (r->connection->aborted) {
+            ap_log_rerror(APLOG_MARK, APLOG_TRACE1, rv, r,
+                          "The client aborted the connection.");
+            conn->close = 1;
+            return OK;
+        }
+
+        ap_log_rerror(APLOG_MARK, APLOG_ERR, rv, r, APLOGNO(01075)
+                      "Error dispatching request to %s: %s%s%s",
+                      server_portstr,
+                      err ? "(" : "",
+                      err ? err : "",
+                      err ? ")" : "");
+        conn->close = 1;
+        if (has_responded) {
+            return AP_FILTER_ERROR;
+        }
+        if (bad_request) {
+            return ap_map_http_request_error(rv, HTTP_BAD_REQUEST);
+        }
+        if (APR_STATUS_IS_TIMEUP(rv)) {
+            return HTTP_GATEWAY_TIME_OUT;
+        }
+        return HTTP_SERVICE_UNAVAILABLE;
+    }
+
+    return OK;
+}
+
+#define FCGI_SCHEME "FCGI"
+
+#define MAX_MEM_SPOOL 16384
+
+/*
+ * This handles fcgi:(dest) URLs
+ */
+static int proxy_fcgi_handler(request_rec *r, proxy_worker *worker,
+                              proxy_server_conf *conf,
+                              char *url, const char *proxyname,
+                              apr_port_t proxyport)
+{
+    int status;
+    char server_portstr[32];
+    conn_rec *origin = NULL;
+    proxy_conn_rec *backend = NULL;
+    apr_bucket_brigade *input_brigade;
+    apr_off_t input_bytes = 0;
+    apr_uri_t *uri;
+
+    proxy_dir_conf *dconf = ap_get_module_config(r->per_dir_config,
+                                                 &proxy_module);
+
+    apr_pool_t *p = r->pool;
+
+
+    ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(01076)
+                  "url: %s proxyname: %s proxyport: %d",
+                  url, proxyname, proxyport);
+
+    if (ap_cstr_casecmpn(url, "fcgi:", 5) != 0) {
+        ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(01077) "declining URL %s", url);
+        return DECLINED;
+    }
+
+    ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(01078) "serving URL %s", url);
+
+    /* Create space for state information */
+    status = ap_proxy_acquire_connection(FCGI_SCHEME, &backend, worker,
+                                         r->server);
+    if (status != OK) {
+        if (backend) {
+            backend->close = 1;
+            ap_proxy_release_connection(FCGI_SCHEME, backend, r->server);
+        }
+        return status;
+    }
+
+    backend->is_ssl = 0;
+
+    /* Step One: Determine Who To Connect To */
+    uri = apr_palloc(p, sizeof(*uri));
+    status = ap_proxy_determine_connection(p, r, conf, worker, backend,
+                                           uri, &url, proxyname, proxyport,
+                                           server_portstr,
+                                           sizeof(server_portstr));
+    if (status != OK) {
+        goto cleanup;
+    }
+
+    /* We possibly reuse input data prefetched in previous call(s), e.g. for a
+     * balancer fallback scenario.
+     */
+    apr_pool_userdata_get((void **)&input_brigade, "proxy-fcgi-input", p);
+    if (input_brigade == NULL) {
+        const char *old_te = apr_table_get(r->headers_in, "Transfer-Encoding");
+        const char *old_cl = NULL;
+        if (old_te) {
+            apr_table_unset(r->headers_in, "Content-Length");
+        }
+        else {
+            old_cl = apr_table_get(r->headers_in, "Content-Length");
+        }
+
+        input_brigade = apr_brigade_create(p, r->connection->bucket_alloc);
+        apr_pool_userdata_setn(input_brigade, "proxy-fcgi-input", NULL, p);
+
+        /* Prefetch (nonlocking) the request body so to increase the chance
+         * to get the whole (or enough) body and determine Content-Length vs
+         * chunked or spooled. By doing this before connecting or reusing the
+         * backend, we want to minimize the delay between this connection is
+         * considered alive and the first bytes sent (should the client's link
+         * be slow or some input filter retain the data). This is a best effort
+         * to prevent the backend from closing (from under us) what it thinks is
+         * an idle connection, hence to reduce to the minimum the unavoidable
+         * local is_socket_connected() vs remote keepalive race condition.
+         */
+        status = ap_proxy_prefetch_input(r, backend, input_brigade,
+                                         APR_NONBLOCK_READ, &input_bytes,
+                                         MAX_MEM_SPOOL);
+        if (status != OK) {
+            goto cleanup;
+        }
+
+        /*
+         * The request body is streamed by default, using either C-L or
+         * chunked T-E, like this:
+         *
+         *   The whole body (including no body) was received on prefetch, i.e.
+         *   the input brigade ends with EOS => C-L = input_bytes.
+         *
+         *   C-L is known and reliable, i.e. only protocol filters in the input
+         *   chain thus none should change the body => use C-L from client.
+         *
+         *   The administrator has not "proxy-sendcl" which prevents T-E => use
+         *   T-E and chunks.
+         *
+         *   Otherwise we need to determine and set a content-length, so spool
+         *   the entire request body to memory/temporary file (MAX_MEM_SPOOL),
+         *   such that we finally know its length => C-L = input_bytes.
+         */
+        if (!APR_BRIGADE_EMPTY(input_brigade)
+                && APR_BUCKET_IS_EOS(APR_BRIGADE_LAST(input_brigade))) {
+            /* The whole thing fit, so our decision is trivial, use the input
+             * bytes for the Content-Length. If we expected no body, and read
+             * no body, do not set the Content-Length.
+             */
+            if (old_cl || old_te || input_bytes) {
+                apr_table_setn(r->headers_in, "Content-Length",
+                               apr_off_t_toa(p, input_bytes));
+                if (old_te) {
+                    apr_table_unset(r->headers_in, "Transfer-Encoding");
+                }
+            }
+        }
+        else if (old_cl && r->input_filters == r->proto_input_filters) {
+            /* Streaming is possible by preserving the existing C-L */
+        }
+        else if (!apr_table_get(r->subprocess_env, "proxy-sendcl")) {
+            /* Streaming is possible using T-E: chunked */
+        }
+        else {
+            /* No streaming, C-L is the only option so spool to memory/file */
+            apr_bucket_brigade *tmp_bb;
+            apr_off_t remaining_bytes = 0;
+
+            AP_DEBUG_ASSERT(MAX_MEM_SPOOL >= input_bytes);
+            tmp_bb = apr_brigade_create(p, r->connection->bucket_alloc);
+            status = ap_proxy_spool_input(r, backend, tmp_bb, &remaining_bytes,
+                                          MAX_MEM_SPOOL - input_bytes);
+            if (status != OK) {
+                goto cleanup;
+            }
+
+            APR_BRIGADE_CONCAT(input_brigade, tmp_bb);
+            input_bytes += remaining_bytes;
+
+            apr_table_setn(r->headers_in, "Content-Length",
+                           apr_off_t_toa(p, input_bytes));
+            if (old_te) {
+                apr_table_unset(r->headers_in, "Transfer-Encoding");
+            }
+        }
+    }
+
+    /* This scheme handler does not reuse connections by default, to
+     * avoid tying up a fastcgi that isn't expecting to work on
+     * parallel requests.  But if the user went out of their way to
+     * type the default value of disablereuse=off, we'll allow it.
+     */
+    backend->close = 1;
+    if (worker->s->disablereuse_set && !worker->s->disablereuse) {
+        backend->close = 0;
+    }
+
+    /* Step Two: Make the Connection */
+    if (ap_proxy_check_connection(FCGI_SCHEME, backend, r->server, 0,
+                                  PROXY_CHECK_CONN_EMPTY)
+            && ap_proxy_connect_backend(FCGI_SCHEME, backend, worker,
+                                        r->server)) {
+        ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01079)
+                      "failed to make connection to backend: %s",
+                      backend->hostname);
+        status = HTTP_SERVICE_UNAVAILABLE;
+        goto cleanup;
+    }
+
+    /* Step Three: Process the Request */
+    status = fcgi_do_request(p, r, backend, origin, dconf, uri, url,
+                             server_portstr, input_brigade);
+
+cleanup:
+    ap_proxy_release_connection(FCGI_SCHEME, backend, r->server);
+    return status;
+}
+
+static void *fcgi_create_dconf(apr_pool_t *p, char *path)
+{
+    fcgi_dirconf_t *a;
+
+    a = (fcgi_dirconf_t *)apr_pcalloc(p, sizeof(fcgi_dirconf_t));
+    a->backend_type = BACKEND_DEFAULT_UNKNOWN;
+    a->env_fixups = apr_array_make(p, 20, sizeof(sei_entry));
+
+    return a;
+}
+
+static void *fcgi_merge_dconf(apr_pool_t *p, void *basev, void *overridesv)
+{
+    fcgi_dirconf_t *a, *base, *over;
+
+    a     = (fcgi_dirconf_t *)apr_pcalloc(p, sizeof(fcgi_dirconf_t));
+    base  = (fcgi_dirconf_t *)basev;
+    over  = (fcgi_dirconf_t *)overridesv;
+
+    a->backend_type = (over->backend_type != BACKEND_DEFAULT_UNKNOWN)
+                      ? over->backend_type
+                      : base->backend_type;
+    a->env_fixups = apr_array_append(p, base->env_fixups, over->env_fixups);
+    return a;
+}
+
+static const char *cmd_servertype(cmd_parms *cmd, void *in_dconf,
+                                   const char *val)
+{
+    fcgi_dirconf_t *dconf = in_dconf;
+
+    if (!strcasecmp(val, "GENERIC")) {
+       dconf->backend_type = BACKEND_GENERIC;
+    }
+    else if (!strcasecmp(val, "FPM")) {
+       dconf->backend_type = BACKEND_FPM;
+    }
+    else {
+        return "ProxyFCGIBackendType requires one of the following arguments: "
+               "'GENERIC', 'FPM'";
+    }
+
+    return NULL;
+}
+
+
+static const char *cmd_setenv(cmd_parms *cmd, void *in_dconf,
+                              const char *arg1, const char *arg2,
+                              const char *arg3)
+{
+    fcgi_dirconf_t *dconf = in_dconf;
+    const char *err;
+    sei_entry *new;
+    const char *envvar = arg2;
+
+    new = apr_array_push(dconf->env_fixups);
+    new->cond = ap_expr_parse_cmd(cmd, arg1, 0, &err, NULL);
+    if (err) {
+        return apr_psprintf(cmd->pool, "Could not parse expression \"%s\": %s",
+                            arg1, err);
+    }
+
+    if (envvar[0] == '!') {
+        /* Unset mode. */
+        if (arg3) {
+            return apr_psprintf(cmd->pool, "Third argument (\"%s\") is not "
+                                "allowed when using ProxyFCGISetEnvIf's unset "
+                                "mode (%s)", arg3, envvar);
+        }
+        else if (!envvar[1]) {
+            /* i.e. someone tried to give us a name of just "!" */
+            return "ProxyFCGISetEnvIf: \"!\" is not a valid variable name";
+        }
+
+        new->subst = NULL;
+    }
+    else {
+        /* Set mode. */
+        if (!arg3) {
+            /* A missing expr-value should be treated as empty. */
+            arg3 = "";
+        }
+
+        new->subst = ap_expr_parse_cmd(cmd, arg3, AP_EXPR_FLAG_STRING_RESULT, &err, NULL);
+        if (err) {
+            return apr_psprintf(cmd->pool, "Could not parse expression \"%s\": %s",
+                                arg3, err);
+        }
+    }
+
+    new->envname = envvar;
+
+    return NULL;
+}
+static void register_hooks(apr_pool_t *p)
+{
+    proxy_hook_scheme_handler(proxy_fcgi_handler, NULL, NULL, APR_HOOK_FIRST);
+    proxy_hook_canon_handler(proxy_fcgi_canon, NULL, NULL, APR_HOOK_FIRST);
+}
+
+static const command_rec command_table[] = {
+    AP_INIT_TAKE1("ProxyFCGIBackendType", cmd_servertype, NULL, OR_FILEINFO,
+                  "Specify the type of FastCGI server: 'Generic', 'FPM'"),
+    AP_INIT_TAKE23("ProxyFCGISetEnvIf", cmd_setenv, NULL, OR_FILEINFO,
+                  "expr-condition env-name expr-value"),
+    { NULL }
+};
+
+AP_DECLARE_MODULE(proxy_fcgi) = {
+    STANDARD20_MODULE_STUFF,
+    fcgi_create_dconf,          /* create per-directory config structure */
+    fcgi_merge_dconf,           /* merge per-directory config structures */
+    NULL,                       /* create per-server config structure */
+    NULL,                       /* merge per-server config structures */
+    command_table,              /* command apr_table_t */
+    register_hooks              /* register hooks */
+};