Adding upstream version 2.4.38.upstream/2.4.38upstream

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

1 files changed, 1249 insertions, 0 deletions

diff --git a/modules/metadata/mod_remoteip.c b/modules/metadata/mod_remoteip.c
new file mode 100644
index 0000000..4572ce1
--- /dev/null
+++ b/modules/metadata/mod_remoteip.c
@@ -0,0 +1,1249 @@
+/* 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.
+ *
+ * Portions of the input filter code for PROXY protocol support is
+ * Copyright 2014 Cloudzilla Inc.
+ */
+
+#include "ap_config.h"
+#include "ap_mmn.h"
+#include "ap_listen.h"
+#include "httpd.h"
+#include "http_config.h"
+#include "http_connection.h"
+#include "http_protocol.h"
+#include "http_log.h"
+#include "http_main.h"
+#include "apr_strings.h"
+#include "apr_lib.h"
+#define APR_WANT_BYTEFUNC
+#include "apr_want.h"
+#include "apr_network_io.h"
+#include "apr_version.h"
+
+module AP_MODULE_DECLARE_DATA remoteip_module;
+
+typedef struct {
+    /** A proxy IP mask to match */
+    apr_ipsubnet_t *ip;
+    /** Flagged if internal, otherwise an external trusted proxy */
+    void  *internal;
+} remoteip_proxymatch_t;
+
+typedef struct remoteip_addr_info {
+    struct remoteip_addr_info *next;
+    apr_sockaddr_t *addr;
+    server_rec *source;
+} remoteip_addr_info;
+
+typedef struct {
+    /** The header to retrieve a proxy-via IP list */
+    const char *header_name;
+    /** A header to record the proxied IP's
+     * (removed as the physical connection and
+     * from the proxy-via IP header value list)
+     */
+    const char *proxies_header_name;
+    /** A list of trusted proxies, ideally configured
+     *  with the most commonly encountered listed first
+     */
+    apr_array_header_t *proxymatch_ip;
+
+    remoteip_addr_info *proxy_protocol_enabled;
+    remoteip_addr_info *proxy_protocol_disabled;
+
+    apr_array_header_t *disabled_subnets;
+    apr_pool_t *pool;
+} remoteip_config_t;
+
+typedef struct {
+    apr_sockaddr_t *useragent_addr;
+    char *useragent_ip;
+    /** The list of proxy IP's ignored as remote IP's */
+    const char *proxy_ips;
+    /** The remaining list of untrusted proxied remote IP's */
+    const char *proxied_remote;
+} remoteip_req_t;
+
+/* For PROXY protocol processing */
+static ap_filter_rec_t *remoteip_filter;
+
+typedef struct {
+    char line[108];
+} proxy_v1;
+
+typedef union {
+    struct {        /* for TCP/UDP over IPv4, len = 12 */
+        apr_uint32_t src_addr;
+        apr_uint32_t dst_addr;
+        apr_uint16_t src_port;
+        apr_uint16_t dst_port;
+    } ip4;
+    struct {        /* for TCP/UDP over IPv6, len = 36 */
+         apr_byte_t  src_addr[16];
+         apr_byte_t  dst_addr[16];
+         apr_uint16_t src_port;
+         apr_uint16_t dst_port;
+    } ip6;
+    struct {        /* for AF_UNIX sockets, len = 216 */
+         apr_byte_t src_addr[108];
+         apr_byte_t dst_addr[108];
+    } unx;
+} proxy_v2_addr;
+
+typedef struct {
+    apr_byte_t  sig[12];  /* hex 0D 0A 0D 0A 00 0D 0A 51 55 49 54 0A */
+    apr_byte_t  ver_cmd;  /* protocol version and command */
+    apr_byte_t  fam;      /* protocol family and address */
+    apr_uint16_t len;     /* number of following bytes part of the header */
+    proxy_v2_addr addr;
+} proxy_v2;
+
+typedef union {
+        proxy_v1 v1;
+        proxy_v2 v2;
+} proxy_header;
+
+static const char v2sig[12] = "\x0D\x0A\x0D\x0A\x00\x0D\x0A\x51\x55\x49\x54\x0A";
+#define MIN_V1_HDR_LEN 15
+#define MIN_V2_HDR_LEN 16
+#define MIN_HDR_LEN MIN_V1_HDR_LEN
+
+/* XXX: Unsure if this is needed if v6 support is not available on
+   this platform */
+#ifndef INET6_ADDRSTRLEN
+#define INET6_ADDRSTRLEN 46
+#endif
+
+typedef struct {
+    char header[sizeof(proxy_header)];
+    apr_size_t rcvd;
+    apr_size_t need;
+    int version;
+    ap_input_mode_t mode;
+    apr_bucket_brigade *bb;
+    int done;
+} remoteip_filter_context;
+
+/** Holds the resolved proxy info for this connection and any additional
+  configurable parameters
+*/
+typedef struct {
+    /** The parsed client address in native format */
+    apr_sockaddr_t *client_addr;
+    /** Character representation of the client */
+    char *client_ip;
+} remoteip_conn_config_t;
+
+typedef enum { HDR_DONE, HDR_ERROR, HDR_NEED_MORE } remoteip_parse_status_t;
+
+static void *create_remoteip_server_config(apr_pool_t *p, server_rec *s)
+{
+    remoteip_config_t *config = apr_pcalloc(p, sizeof(*config));
+    config->disabled_subnets = apr_array_make(p, 1, sizeof(apr_ipsubnet_t *));
+    /* config->header_name = NULL;
+     * config->proxies_header_name = NULL;
+     * config->proxy_protocol_enabled = NULL;
+     * config->proxy_protocol_disabled = NULL;
+     */
+    config->pool = p;
+    return config;
+}
+
+static void *merge_remoteip_server_config(apr_pool_t *p, void *globalv,
+                                          void *serverv)
+{
+    remoteip_config_t *global = (remoteip_config_t *) globalv;
+    remoteip_config_t *server = (remoteip_config_t *) serverv;
+    remoteip_config_t *config;
+
+    config = (remoteip_config_t *) apr_palloc(p, sizeof(*config));
+    config->header_name = server->header_name
+                        ? server->header_name
+                        : global->header_name;
+    config->proxies_header_name = server->proxies_header_name
+                                ? server->proxies_header_name
+                                : global->proxies_header_name;
+    config->proxymatch_ip = server->proxymatch_ip
+                          ? server->proxymatch_ip
+                          : global->proxymatch_ip;
+    return config;
+}
+
+static const char *header_name_set(cmd_parms *cmd, void *dummy,
+                                   const char *arg)
+{
+    remoteip_config_t *config = ap_get_module_config(cmd->server->module_config,
+                                                     &remoteip_module);
+    config->header_name = arg;
+    return NULL;
+}
+
+static const char *proxies_header_name_set(cmd_parms *cmd, void *dummy,
+                                           const char *arg)
+{
+    remoteip_config_t *config = ap_get_module_config(cmd->server->module_config,
+                                                     &remoteip_module);
+    config->proxies_header_name = arg;
+    return NULL;
+}
+
+/* Would be quite nice if APR exported this */
+/* apr:network_io/unix/sockaddr.c */
+static int looks_like_ip(const char *ipstr)
+{
+    if (ap_strchr_c(ipstr, ':')) {
+        /* definitely not a hostname; assume it is intended to be an IPv6 address */
+        return 1;
+    }
+
+    /* simple IPv4 address string check */
+    while ((*ipstr == '.') || apr_isdigit(*ipstr))
+        ipstr++;
+    return (*ipstr == '\0');
+}
+
+static const char *proxies_set(cmd_parms *cmd, void *cfg,
+                               const char *arg)
+{
+    remoteip_config_t *config = ap_get_module_config(cmd->server->module_config,
+                                                     &remoteip_module);
+    remoteip_proxymatch_t *match;
+    apr_status_t rv;
+    char *ip = apr_pstrdup(cmd->temp_pool, arg);
+    char *s = ap_strchr(ip, '/');
+    if (s) {
+        *s++ = '\0';
+    }
+
+    if (!config->proxymatch_ip) {
+        config->proxymatch_ip = apr_array_make(cmd->pool, 1, sizeof(*match));
+    }
+    match = (remoteip_proxymatch_t *) apr_array_push(config->proxymatch_ip);
+    match->internal = cmd->info;
+
+    if (looks_like_ip(ip)) {
+        /* Note s may be null, that's fine (explicit host) */
+        rv = apr_ipsubnet_create(&match->ip, ip, s, cmd->pool);
+    }
+    else
+    {
+        apr_sockaddr_t *temp_sa;
+
+        if (s) {
+            return apr_pstrcat(cmd->pool, "RemoteIP: Error parsing IP ", arg,
+                               " the subnet /", s, " is invalid for ",
+                               cmd->cmd->name, NULL);
+        }
+
+        rv = apr_sockaddr_info_get(&temp_sa,  ip, APR_UNSPEC, 0,
+                                   APR_IPV4_ADDR_OK, cmd->temp_pool);
+        while (rv == APR_SUCCESS)
+        {
+            apr_sockaddr_ip_get(&ip, temp_sa);
+            rv = apr_ipsubnet_create(&match->ip, ip, NULL, cmd->pool);
+            if (!(temp_sa = temp_sa->next)) {
+                break;
+            }
+            match = (remoteip_proxymatch_t *)
+                    apr_array_push(config->proxymatch_ip);
+            match->internal = cmd->info;
+        }
+    }
+
+    if (rv != APR_SUCCESS) {
+        return apr_psprintf(cmd->pool,
+                            "RemoteIP: Error parsing IP %s (%pm error) for %s",
+                            arg, &rv, cmd->cmd->name);
+    }
+
+    return NULL;
+}
+
+static const char *proxylist_read(cmd_parms *cmd, void *cfg,
+                                  const char *filename)
+{
+    char lbuf[MAX_STRING_LEN];
+    char *arg;
+    const char *args;
+    const char *errmsg;
+    ap_configfile_t *cfp;
+    apr_status_t rv;
+
+    filename = ap_server_root_relative(cmd->temp_pool, filename);
+    rv = ap_pcfg_openfile(&cfp, cmd->temp_pool, filename);
+    if (rv != APR_SUCCESS) {
+        return apr_psprintf(cmd->pool, "%s: Could not open file %s: %pm",
+                            cmd->cmd->name, filename, &rv);
+    }
+
+    while (!(ap_cfg_getline(lbuf, MAX_STRING_LEN, cfp))) {
+        args = lbuf;
+        while (*(arg = ap_getword_conf(cmd->temp_pool, &args)) != '\0') {
+            if (*arg == '#') {
+                break;
+            }
+            errmsg = proxies_set(cmd, cfg, arg);
+            if (errmsg) {
+                ap_cfg_closefile(cfp);
+                errmsg = apr_psprintf(cmd->pool, "%s at line %d of %s",
+                                      errmsg, cfp->line_number, filename);
+                return errmsg;
+            }
+        }
+    }
+
+    ap_cfg_closefile(cfp);
+    return NULL;
+}
+
+/** Similar to apr_sockaddr_equal, except that it compares ports too. */
+static int remoteip_sockaddr_equal(apr_sockaddr_t *addr1, apr_sockaddr_t *addr2)
+{
+    return (addr1->port == addr2->port && apr_sockaddr_equal(addr1, addr2));
+}
+
+#if !APR_VERSION_AT_LEAST(1,5,0)
+#define apr_sockaddr_is_wildcard sockaddr_is_wildcard
+/* XXX: temp build fix from apr 1.5.x */
+static int sockaddr_is_wildcard(const apr_sockaddr_t *addr)
+{
+    static const char inaddr_any[
+#if APR_HAVE_IPV6
+        sizeof(struct in6_addr)
+#else
+        sizeof(struct in_addr)
+#endif
+    ] = {0};
+
+    if (addr->ipaddr_ptr /* IP address initialized */
+        && addr->ipaddr_len <= sizeof inaddr_any) { /* else bug elsewhere? */
+        if (!memcmp(inaddr_any, addr->ipaddr_ptr, addr->ipaddr_len)) {
+            return 1;
+        }
+#if APR_HAVE_IPV6
+    if (addr->family == AF_INET6
+        && IN6_IS_ADDR_V4MAPPED((struct in6_addr *)addr->ipaddr_ptr)) {
+        struct in_addr *v4 = (struct in_addr *)&((apr_uint32_t *)addr->ipaddr_ptr)[3];
+
+        if (!memcmp(inaddr_any, v4, sizeof *v4)) {
+            return 1;
+        }
+    }
+#endif
+    }
+    return 0;
+}
+#endif
+
+
+/** Similar to remoteip_sockaddr_equal, except that it handles wildcard addresses
+ *  and ports too.
+ */
+static int remoteip_sockaddr_compat(apr_sockaddr_t *addr1, apr_sockaddr_t *addr2)
+{
+    /* test exact address equality */
+    if (apr_sockaddr_equal(addr1, addr2) &&
+        (addr1->port == addr2->port || addr1->port == 0 || addr2->port == 0)) {
+        return 1;
+    }
+
+    /* test address wildcards */
+    if (apr_sockaddr_is_wildcard(addr1) &&
+        (addr1->port == 0 || addr1->port == addr2->port)) {
+        return 1;
+    }
+
+    if (apr_sockaddr_is_wildcard(addr2) &&
+        (addr2->port == 0 || addr2->port == addr1->port)) {
+        return 1;
+    }
+
+    return 0;
+}
+
+static int remoteip_addr_in_list(remoteip_addr_info *list, apr_sockaddr_t *addr)
+{
+    for (; list; list = list->next) {
+        if (remoteip_sockaddr_compat(list->addr, addr)) {
+            return 1;
+        }
+    }
+
+    return 0;
+}
+
+static void remoteip_warn_enable_conflict(remoteip_addr_info *prev, server_rec *new, int flag)
+{
+    char buf[INET6_ADDRSTRLEN];
+
+    apr_sockaddr_ip_getbuf(buf, sizeof(buf), prev->addr);
+
+    ap_log_error(APLOG_MARK, APLOG_NOTICE, 0, new, APLOGNO(03491)
+                 "RemoteIPProxyProtocol: previous setting for %s:%hu from virtual "
+                 "host {%s:%hu in %s} is being overriden by virtual host "
+                 "{%s:%hu in %s}; new setting is '%s'",
+                 buf, prev->addr->port, prev->source->server_hostname,
+                 prev->source->addrs->host_port, prev->source->defn_name,
+                 new->server_hostname, new->addrs->host_port, new->defn_name,
+                 flag ? "On" : "Off");
+}
+
+static const char *remoteip_enable_proxy_protocol(cmd_parms *cmd, void *config,
+                                                  int flag)
+{
+    remoteip_config_t *conf;
+    server_addr_rec *addr;
+    remoteip_addr_info **add;
+    remoteip_addr_info **rem;
+    remoteip_addr_info *list;
+
+    conf = ap_get_module_config(ap_server_conf->module_config,
+                                &remoteip_module);
+
+    if (flag) {
+        add = &conf->proxy_protocol_enabled;
+        rem = &conf->proxy_protocol_disabled;
+    }
+    else {
+        add = &conf->proxy_protocol_disabled;
+        rem = &conf->proxy_protocol_enabled;
+    }
+
+    for (addr = cmd->server->addrs; addr; addr = addr->next) {
+        /* remove address from opposite list */
+        if (*rem) {
+            if (remoteip_sockaddr_equal((*rem)->addr, addr->host_addr)) {
+                remoteip_warn_enable_conflict(*rem, cmd->server, flag);
+                *rem = (*rem)->next;
+            }
+            else {
+                for (list = *rem; list->next; list = list->next) {
+                    if (remoteip_sockaddr_equal(list->next->addr, addr->host_addr)) {
+                        remoteip_warn_enable_conflict(list->next, cmd->server, flag);
+                        list->next = list->next->next;
+                        break;
+                    }
+                }
+            }
+        }
+
+        /* add address to desired list */
+        if (!remoteip_addr_in_list(*add, addr->host_addr)) {
+            remoteip_addr_info *info = apr_palloc(conf->pool, sizeof(*info));
+            info->addr = addr->host_addr;
+            info->source = cmd->server;
+            info->next = *add;
+            *add = info;
+        }
+    }
+
+    return NULL;
+}
+
+static const char *remoteip_disable_networks(cmd_parms *cmd, void *d,
+                                             int argc, char *const argv[])
+{
+    int i;
+    apr_pool_t *ptemp = cmd->temp_pool;
+    apr_pool_t *p = cmd->pool;
+    remoteip_config_t *conf = ap_get_module_config(ap_server_conf->module_config,
+                                &remoteip_module);
+
+    if (argc == 0)
+        return apr_pstrcat(p, cmd->cmd->name, " requires an argument", NULL);
+
+
+    for (i=0; i<argc; i++) {
+        char *addr = apr_pstrdup(ptemp, argv[i]);
+        char *mask;
+        apr_status_t rv;
+        apr_ipsubnet_t **ip = apr_pcalloc(p, sizeof(apr_ipsubnet_t *));
+
+        if ((mask = ap_strchr(addr, '/')))
+            *mask++ = '\0';
+
+        rv = apr_ipsubnet_create(ip, addr, mask, p);
+
+        if (APR_STATUS_IS_EINVAL(rv)) {
+            /* looked nothing like an IP address */
+            return apr_psprintf(p, "ip address '%s' appears to be invalid", addr);
+        }
+        else if (rv != APR_SUCCESS) {
+            return apr_psprintf(p, "ip address '%s' appears to be invalid: %pm",
+                                addr, &rv);
+        }
+
+        *(apr_ipsubnet_t**)apr_array_push(conf->disabled_subnets) = *ip;
+    }
+
+    return NULL;
+}
+
+static int remoteip_hook_post_config(apr_pool_t *pconf, apr_pool_t *plog,
+                               apr_pool_t *ptemp, server_rec *s)
+{
+    remoteip_config_t *conf;
+    remoteip_addr_info *info;
+    char buf[INET6_ADDRSTRLEN];
+
+    conf = ap_get_module_config(ap_server_conf->module_config,
+                                &remoteip_module);
+
+    for (info = conf->proxy_protocol_enabled; info; info = info->next) {
+        apr_sockaddr_ip_getbuf(buf, sizeof(buf), info->addr);
+        ap_log_error(APLOG_MARK, APLOG_NOTICE, 0, s, APLOGNO(03492)
+                     "RemoteIPProxyProtocol: enabled on %s:%hu", buf, info->addr->port);
+    }
+    for (info = conf->proxy_protocol_disabled; info; info = info->next) {
+        apr_sockaddr_ip_getbuf(buf, sizeof(buf), info->addr);
+        ap_log_error(APLOG_MARK, APLOG_NOTICE, 0, s, APLOGNO(03494)
+                     "RemoteIPProxyProtocol: disabled on %s:%hu", buf, info->addr->port);
+    }
+
+    return OK;
+}
+
+static int remoteip_modify_request(request_rec *r)
+{
+    conn_rec *c = r->connection;
+    remoteip_config_t *config = (remoteip_config_t *)
+        ap_get_module_config(r->server->module_config, &remoteip_module);
+    remoteip_conn_config_t *conn_config = (remoteip_conn_config_t *)
+        ap_get_module_config(r->connection->conn_config, &remoteip_module);
+
+    remoteip_req_t *req = NULL;
+    apr_sockaddr_t *temp_sa;
+
+    apr_status_t rv;
+    char *remote;
+    char *proxy_ips = NULL;
+    char *parse_remote;
+    char *eos;
+    unsigned char *addrbyte;
+
+    /* If no RemoteIPInternalProxy, RemoteIPInternalProxyList, RemoteIPTrustedProxy
+       or RemoteIPTrustedProxyList directive is configured,
+       all proxies will be considered as external trusted proxies.
+     */
+    void *internal = NULL;
+
+    /* No header defined or results from our input filter */
+    if (!config->header_name && !conn_config) {
+        return DECLINED;
+    }
+ 
+    /* Easy parsing case - just position the data we already have from PROXY
+       protocol handling allowing it to take precedence and return
+    */
+    if (conn_config) {
+        if (!conn_config->client_addr) {
+            ap_log_rerror(APLOG_MARK, APLOG_WARNING, 0, r, APLOGNO(03496)
+                          "RemoteIPProxyProtocol data is missing, but required! Aborting request.");
+            return HTTP_BAD_REQUEST;
+        }
+
+        r->useragent_addr = conn_config->client_addr;
+        r->useragent_ip = conn_config->client_ip;
+
+        ap_log_rerror(APLOG_MARK, APLOG_TRACE1, 0, r,
+                      "Using %s as client's IP from PROXY protocol", r->useragent_ip);
+        return OK;
+    }
+
+    if (config->proxymatch_ip) {
+        /* This indicates that a RemoteIPInternalProxy, RemoteIPInternalProxyList, RemoteIPTrustedProxy
+           or RemoteIPTrustedProxyList directive is configured.
+           In this case, default to internal proxy.
+         */
+        internal = (void *) 1;
+    }
+
+    remote = (char *) apr_table_get(r->headers_in, config->header_name);
+    if (!remote) {
+        return OK;
+    }
+    remote = apr_pstrdup(r->pool, remote);
+
+    temp_sa = r->useragent_addr ? r->useragent_addr : c->client_addr;
+
+    while (remote) {
+
+        /* verify user agent IP against the trusted proxy list
+         */
+        if (config->proxymatch_ip) {
+            int i;
+            remoteip_proxymatch_t *match;
+            match = (remoteip_proxymatch_t *)config->proxymatch_ip->elts;
+            for (i = 0; i < config->proxymatch_ip->nelts; ++i) {
+                if (apr_ipsubnet_test(match[i].ip, temp_sa)) {
+                    if (internal) {
+                        /* Allow an internal proxy to present an external proxy,
+                           but do not allow an external proxy to present an internal proxy.
+                           In this case, the presented internal proxy will be considered external.
+                         */
+                        internal = match[i].internal;
+                    }
+                    break;
+                }
+            }
+            if (i && i >= config->proxymatch_ip->nelts) {
+                break;
+            }
+        }
+
+        if ((parse_remote = strrchr(remote, ',')) == NULL) {
+            parse_remote = remote;
+            remote = NULL;
+        }
+        else {
+            *(parse_remote++) = '\0';
+        }
+
+        while (*parse_remote == ' ') {
+            ++parse_remote;
+        }
+
+        eos = parse_remote + strlen(parse_remote) - 1;
+        while (eos >= parse_remote && *eos == ' ') {
+            *(eos--) = '\0';
+        }
+
+        if (eos < parse_remote) {
+            if (remote) {
+                *(remote + strlen(remote)) = ',';
+            }
+            else {
+                remote = parse_remote;
+            }
+            break;
+        }
+
+        /* We map as IPv4 rather than IPv6 for equivalent host names
+         * or IPV4OVERIPV6
+         */
+        rv = apr_sockaddr_info_get(&temp_sa,  parse_remote,
+                                   APR_UNSPEC, temp_sa->port,
+                                   APR_IPV4_ADDR_OK, r->pool);
+        if (rv != APR_SUCCESS) {
+            ap_log_rerror(APLOG_MARK, APLOG_DEBUG,  rv, r, APLOGNO(01568)
+                          "RemoteIP: Header %s value of %s cannot be parsed "
+                          "as a client IP",
+                          config->header_name, parse_remote);
+
+            if (remote) {
+                *(remote + strlen(remote)) = ',';
+            }
+            else {
+                remote = parse_remote;
+            }
+            break;
+        }
+
+        addrbyte = (unsigned char *) &temp_sa->sa.sin.sin_addr;
+
+        /* For intranet (Internal proxies) ignore all restrictions below */
+        if (!internal
+              && ((temp_sa->family == APR_INET
+                   /* For internet (non-Internal proxies) deny all
+                    * RFC3330 designated local/private subnets:
+                    * 10.0.0.0/8   169.254.0.0/16  192.168.0.0/16
+                    * 127.0.0.0/8  172.16.0.0/12
+                    */
+                      && (addrbyte[0] == 10
+                       || addrbyte[0] == 127
+                       || (addrbyte[0] == 169 && addrbyte[1] == 254)
+                       || (addrbyte[0] == 172 && (addrbyte[1] & 0xf0) == 16)
+                       || (addrbyte[0] == 192 && addrbyte[1] == 168)))
+#if APR_HAVE_IPV6
+               || (temp_sa->family == APR_INET6
+                   /* For internet (non-Internal proxies) we translated
+                    * IPv4-over-IPv6-mapped addresses as IPv4, above.
+                    * Accept only Global Unicast 2000::/3 defined by RFC4291
+                    */
+                      && ((temp_sa->sa.sin6.sin6_addr.s6_addr[0] & 0xe0) != 0x20))
+#endif
+        )) {
+            ap_log_rerror(APLOG_MARK, APLOG_DEBUG,  rv, r, APLOGNO(01569)
+                          "RemoteIP: Header %s value of %s appears to be "
+                          "a private IP or nonsensical.  Ignored",
+                          config->header_name, parse_remote);
+            if (remote) {
+                *(remote + strlen(remote)) = ',';
+            }
+            else {
+                remote = parse_remote;
+            }
+
+            break;
+        }
+
+        /* save away our results */
+        if (!req) {
+            req = (remoteip_req_t *) apr_palloc(r->pool, sizeof(remoteip_req_t));
+            req->useragent_ip = r->useragent_ip;
+        }
+
+        /* Set useragent_ip string */
+        if (!internal) {
+            if (proxy_ips) {
+                proxy_ips = apr_pstrcat(r->pool, proxy_ips, ", ",
+                                        req->useragent_ip, NULL);
+            }
+            else {
+                proxy_ips = req->useragent_ip;
+            }
+        }
+
+        req->useragent_addr = temp_sa;
+        apr_sockaddr_ip_get(&req->useragent_ip, req->useragent_addr);
+    }
+
+    /* Nothing happened? */
+    if (!req) {
+        return OK;
+    }
+
+    /* Port is not known so set it to zero; otherwise it can be misleading */
+    req->useragent_addr->port = 0;
+
+    req->proxied_remote = remote;
+    req->proxy_ips = proxy_ips;
+
+    if (req->proxied_remote) {
+        apr_table_setn(r->headers_in, config->header_name,
+                       req->proxied_remote);
+    }
+    else {
+        apr_table_unset(r->headers_in, config->header_name);
+    }
+    if (req->proxy_ips) {
+        apr_table_setn(r->notes, "remoteip-proxy-ip-list", req->proxy_ips);
+        if (config->proxies_header_name) {
+            apr_table_setn(r->headers_in, config->proxies_header_name,
+                           req->proxy_ips);
+        }
+    }
+
+    r->useragent_addr = req->useragent_addr;
+    r->useragent_ip = req->useragent_ip;
+
+    ap_log_rerror(APLOG_MARK, APLOG_TRACE1, 0, r,
+                  req->proxy_ips
+                      ? "Using %s as client's IP by proxies %s"
+                      : "Using %s as client's IP by internal proxies%s",
+                  req->useragent_ip,
+                  (req->proxy_ips ? req->proxy_ips : ""));
+    return OK;
+}
+
+static int remoteip_is_server_port(apr_port_t port)
+{
+    ap_listen_rec *lr;
+
+    for (lr = ap_listeners; lr; lr = lr->next) {
+        if (lr->bind_addr && lr->bind_addr->port == port) {
+            return 1;
+        }
+    }
+
+    return 0;
+}
+
+/*
+ * Human readable format:
+ * PROXY {TCP4|TCP6|UNKNOWN} <client-ip-addr> <dest-ip-addr> <client-port> <dest-port><CR><LF>
+ */
+static remoteip_parse_status_t remoteip_process_v1_header(conn_rec *c,
+                                                          remoteip_conn_config_t *conn_conf,
+                                                          proxy_header *hdr, apr_size_t len,
+                                                          apr_size_t *hdr_len)
+{
+    char *end, *word, *host, *valid_addr_chars, *saveptr;
+    char buf[sizeof(hdr->v1.line)];
+    apr_port_t port;
+    apr_status_t ret;
+    apr_int32_t family;
+
+#define GET_NEXT_WORD(field) \
+    word = apr_strtok(NULL, " ", &saveptr); \
+    if (!word) { \
+        ap_log_cerror(APLOG_MARK, APLOG_ERR, 0, c, APLOGNO(03497) \
+                      "RemoteIPProxyProtocol: no " field " found in header '%s'", \
+                      hdr->v1.line); \
+        return HDR_ERROR; \
+    }
+
+    end = memchr(hdr->v1.line, '\r', len - 1);
+    if (!end || end[1] != '\n') {
+        return HDR_NEED_MORE; /* partial or invalid header */
+    }
+
+    *end = '\0';
+    *hdr_len = end + 2 - hdr->v1.line; /* skip header + CRLF */
+
+    /* parse in separate buffer so have the original for error messages */
+    strcpy(buf, hdr->v1.line);
+
+    apr_strtok(buf, " ", &saveptr);
+
+    /* parse family */
+    GET_NEXT_WORD("family")
+    if (strcmp(word, "UNKNOWN") == 0) {
+        conn_conf->client_addr = c->client_addr;
+        conn_conf->client_ip = c->client_ip;
+        return HDR_DONE;
+    }
+    else if (strcmp(word, "TCP4") == 0) {
+        family = APR_INET;
+        valid_addr_chars = "0123456789.";
+    }
+    else if (strcmp(word, "TCP6") == 0) {
+#if APR_HAVE_IPV6
+        family = APR_INET6;
+        valid_addr_chars = "0123456789abcdefABCDEF:";
+#else
+        ap_log_cerror(APLOG_MARK, APLOG_ERR, 0, c, APLOGNO(03498)
+                      "RemoteIPProxyProtocol: Unable to parse v6 address - APR is not compiled with IPv6 support");
+        return HDR_ERROR;
+#endif
+    }
+    else {
+        ap_log_cerror(APLOG_MARK, APLOG_ERR, 0, c, APLOGNO(03499)
+                      "RemoteIPProxyProtocol: unknown family '%s' in header '%s'",
+                      word, hdr->v1.line);
+        return HDR_ERROR;
+    }
+
+    /* parse client-addr */
+    GET_NEXT_WORD("client-address")
+
+    if (strspn(word, valid_addr_chars) != strlen(word)) {
+        ap_log_cerror(APLOG_MARK, APLOG_ERR, 0, c, APLOGNO(03500)
+                      "RemoteIPProxyProtocol: invalid client-address '%s' found in "
+                      "header '%s'", word, hdr->v1.line);
+        return HDR_ERROR;
+    }
+
+    host = word;
+
+    /* parse dest-addr */
+    GET_NEXT_WORD("destination-address")
+
+    /* parse client-port */
+    GET_NEXT_WORD("client-port")
+    if (sscanf(word, "%hu", &port) != 1) {
+        ap_log_cerror(APLOG_MARK, APLOG_ERR, 0, c, APLOGNO(03501)
+                      "RemoteIPProxyProtocol: error parsing port '%s' in header '%s'",
+                      word, hdr->v1.line);
+        return HDR_ERROR;
+    }
+
+    /* parse dest-port */
+    /* GET_NEXT_WORD("destination-port") - no-op since we don't care about it */
+
+    /* create a socketaddr from the info */
+    ret = apr_sockaddr_info_get(&conn_conf->client_addr, host, family, port, 0,
+                                c->pool);
+    if (ret != APR_SUCCESS) {
+        conn_conf->client_addr = NULL;
+        ap_log_cerror(APLOG_MARK, APLOG_ERR, ret, c, APLOGNO(03502)
+                      "RemoteIPProxyProtocol: error converting family '%d', host '%s',"
+                      " and port '%hu' to sockaddr; header was '%s'",
+                      family, host, port, hdr->v1.line);
+        return HDR_ERROR;
+    }
+
+    conn_conf->client_ip = apr_pstrdup(c->pool, host);
+
+    return HDR_DONE;
+}
+
+/** Add our filter to the connection if it is requested
+ */
+static int remoteip_hook_pre_connection(conn_rec *c, void *csd)
+{
+    remoteip_config_t *conf;
+    remoteip_conn_config_t *conn_conf;
+    int i;
+
+    /* Establish master config in slave connections, so that request processing
+     * finds it. */
+    if (c->master != NULL) {
+        conn_conf = ap_get_module_config(c->master->conn_config, &remoteip_module);
+        if (conn_conf) {
+            ap_set_module_config(c->conn_config, &remoteip_module, conn_conf);
+        }
+        return DECLINED;
+    }
+
+    conf = ap_get_module_config(ap_server_conf->module_config,
+                                &remoteip_module);
+
+    /* check if we're enabled for this connection */
+    if (!remoteip_addr_in_list(conf->proxy_protocol_enabled, c->local_addr)
+        || remoteip_addr_in_list(conf->proxy_protocol_disabled, c->local_addr)) {
+
+        return DECLINED;
+    }
+
+    /* We are enabled for this IP/port, but check that we aren't
+       explicitly disabled */
+    for (i = 0; i < conf->disabled_subnets->nelts; i++) {
+        apr_ipsubnet_t *ip = ((apr_ipsubnet_t**)conf->disabled_subnets->elts)[i];
+
+        if (ip && apr_ipsubnet_test(ip, c->client_addr))
+            return DECLINED;
+    }
+
+    /* mod_proxy creates outgoing connections - we don't want those */
+    if (!remoteip_is_server_port(c->local_addr->port)) {
+        return DECLINED;
+    }
+
+    /* add our filter */
+    if (!ap_add_input_filter_handle(remoteip_filter, NULL, NULL, c)) {
+        /* XXX: Shouldn't this WARN in log? */
+        return DECLINED;
+    }
+
+    ap_log_cerror(APLOG_MARK, APLOG_DEBUG, 0, c, APLOGNO(03503)
+                  "RemoteIPProxyProtocol: enabled on connection to %s:%hu",
+                  c->local_ip, c->local_addr->port);
+
+    /* this holds the resolved proxy info for this connection */
+    conn_conf = apr_pcalloc(c->pool, sizeof(*conn_conf));
+
+    ap_set_module_config(c->conn_config, &remoteip_module, conn_conf);
+
+    return OK;
+}
+
+/* Binary format:
+ * <sig><cmd><proto><addr-len><addr>
+ * sig = \x0D \x0A \x0D \x0A \x00 \x0D \x0A \x51 \x55 \x49 \x54 \x0A
+ * cmd = <4-bits-version><4-bits-command>
+ * 4-bits-version = \x02
+ * 4-bits-command = {\x00|\x01}  (\x00 = LOCAL: discard con info; \x01 = PROXY)
+ * proto = <4-bits-family><4-bits-protocol>
+ * 4-bits-family = {\x00|\x01|\x02|\x03}  (AF_UNSPEC, AF_INET, AF_INET6, AF_UNIX)
+ * 4-bits-protocol = {\x00|\x01|\x02}  (UNSPEC, STREAM, DGRAM)
+ */
+static remoteip_parse_status_t remoteip_process_v2_header(conn_rec *c,
+                                              remoteip_conn_config_t *conn_conf,
+                                              proxy_header *hdr)
+{
+    apr_status_t ret;
+
+    switch (hdr->v2.ver_cmd & 0xF) {
+        case 0x01: /* PROXY command */
+            switch (hdr->v2.fam) {
+                case 0x11:  /* TCPv4 */
+                    ret = apr_sockaddr_info_get(&conn_conf->client_addr, NULL,
+                                                APR_INET,
+                                                ntohs(hdr->v2.addr.ip4.src_port),
+                                                0, c->pool);
+                    if (ret != APR_SUCCESS) {
+                        conn_conf->client_addr = NULL;
+                        ap_log_cerror(APLOG_MARK, APLOG_ERR, ret, c, APLOGNO(03504)
+                                      "RemoteIPPProxyProtocol: error creating sockaddr");
+                        return HDR_ERROR;
+                    }
+
+                    conn_conf->client_addr->sa.sin.sin_addr.s_addr =
+                            hdr->v2.addr.ip4.src_addr;
+                    break;
+
+                case 0x21:  /* TCPv6 */
+#if APR_HAVE_IPV6
+                    ret = apr_sockaddr_info_get(&conn_conf->client_addr, NULL,
+                                                APR_INET6,
+                                                ntohs(hdr->v2.addr.ip6.src_port),
+                                                0, c->pool);
+                    if (ret != APR_SUCCESS) {
+                        conn_conf->client_addr = NULL;
+                        ap_log_cerror(APLOG_MARK, APLOG_ERR, ret, c, APLOGNO(03505)
+                                      "RemoteIPProxyProtocol: error creating sockaddr");
+                        return HDR_ERROR;
+                    }
+                    memcpy(&conn_conf->client_addr->sa.sin6.sin6_addr.s6_addr,
+                           hdr->v2.addr.ip6.src_addr, 16);
+                    break;
+#else
+                    ap_log_cerror(APLOG_MARK, APLOG_ERR, 0, c, APLOGNO(03506)
+                                  "RemoteIPProxyProtocol: APR is not compiled with IPv6 support");
+                    return HDR_ERROR;
+#endif
+                default:
+                    /* unsupported protocol, keep local connection address */
+                    return HDR_DONE;
+            }
+            break;  /* we got a sockaddr now */
+
+        case 0x00: /* LOCAL command */
+            /* keep local connection address for LOCAL */
+            return HDR_DONE;
+
+        default:
+            /* not a supported command */
+            ap_log_cerror(APLOG_MARK, APLOG_ERR, 0, c, APLOGNO(03507)
+                          "RemoteIPProxyProtocol: unsupported command %.2hx",
+                          (unsigned short)hdr->v2.ver_cmd);
+            return HDR_ERROR;
+    }
+
+    /* got address - compute the client_ip from it */
+    ret = apr_sockaddr_ip_get(&conn_conf->client_ip, conn_conf->client_addr);
+    if (ret != APR_SUCCESS) {
+        conn_conf->client_addr = NULL;
+        ap_log_cerror(APLOG_MARK, APLOG_ERR, ret, c, APLOGNO(03508)
+                      "RemoteIPProxyProtocol: error converting address to string");
+        return HDR_ERROR;
+    }
+
+    return HDR_DONE;
+}
+
+/** Return length for a v2 protocol header. */
+static apr_size_t remoteip_get_v2_len(proxy_header *hdr)
+{
+    return ntohs(hdr->v2.len);
+}
+
+/** Determine if this is a v1 or v2 PROXY header.
+ */
+static int remoteip_determine_version(conn_rec *c, const char *ptr)
+{
+    proxy_header *hdr = (proxy_header *) ptr;
+
+    /* assert len >= 14 */
+
+    if (memcmp(&hdr->v2, v2sig, sizeof(v2sig)) == 0 &&
+        (hdr->v2.ver_cmd & 0xF0) == 0x20) {
+        return 2;
+    }
+    else if (memcmp(hdr->v1.line, "PROXY ", 6) == 0) {
+        return 1;
+    }
+    else {
+        return -1;
+    }
+}
+
+/* Capture the first bytes on the protocol and parse the PROXY protocol header.
+ * Removes itself when the header is complete.
+ */
+static apr_status_t remoteip_input_filter(ap_filter_t *f,
+                                    apr_bucket_brigade *bb_out,
+                                    ap_input_mode_t mode,
+                                    apr_read_type_e block,
+                                    apr_off_t readbytes)
+{
+    apr_status_t ret;
+    remoteip_filter_context *ctx = f->ctx;
+    remoteip_conn_config_t *conn_conf;
+    apr_bucket *b;
+    remoteip_parse_status_t psts = HDR_NEED_MORE;
+    const char *ptr;
+    apr_size_t len;
+
+    if (f->c->aborted) {
+        return APR_ECONNABORTED;
+    }
+
+    /* allocate/retrieve the context that holds our header */
+    if (!ctx) {
+        ctx = f->ctx = apr_palloc(f->c->pool, sizeof(*ctx));
+        ctx->rcvd = 0;
+        ctx->need = MIN_HDR_LEN;
+        ctx->version = 0;
+        ctx->mode = AP_MODE_READBYTES;
+        ctx->bb = apr_brigade_create(f->c->pool, f->c->bucket_alloc);
+        ctx->done = 0;
+    }
+
+    if (ctx->done) {
+        /* Note: because we're a connection filter we can't remove ourselves
+         * when we're done, so we have to stay in the chain and just go into
+         * passthrough mode.
+         */
+        return ap_get_brigade(f->next, bb_out, mode, block, readbytes);
+    }
+
+    conn_conf = ap_get_module_config(f->c->conn_config, &remoteip_module);
+
+    /* try to read a header's worth of data */
+    while (!ctx->done) {
+        if (APR_BRIGADE_EMPTY(ctx->bb)) {
+            ret = ap_get_brigade(f->next, ctx->bb, ctx->mode, block,
+                                 ctx->need - ctx->rcvd);
+            if (ret != APR_SUCCESS) {
+                return ret;
+            }
+        }
+        if (APR_BRIGADE_EMPTY(ctx->bb)) {
+            return block == APR_NONBLOCK_READ ? APR_SUCCESS : APR_EOF;
+        }
+
+        while (!ctx->done && !APR_BRIGADE_EMPTY(ctx->bb)) {
+            b = APR_BRIGADE_FIRST(ctx->bb);
+
+            ret = apr_bucket_read(b, &ptr, &len, block);
+            if (APR_STATUS_IS_EAGAIN(ret) && block == APR_NONBLOCK_READ) {
+                return APR_SUCCESS;
+            }
+            if (ret != APR_SUCCESS) {
+                return ret;
+            }
+
+            memcpy(ctx->header + ctx->rcvd, ptr, len);
+            ctx->rcvd += len;
+
+            apr_bucket_delete(b);
+            psts = HDR_NEED_MORE;
+
+            if (ctx->version == 0) {
+                /* reading initial chunk */
+                if (ctx->rcvd >= MIN_HDR_LEN) {
+                    ctx->version = remoteip_determine_version(f->c, ctx->header);
+                    if (ctx->version < 0) {
+                        psts = HDR_ERROR;
+                    }
+                    else if (ctx->version == 1) {
+                        ctx->mode = AP_MODE_GETLINE;
+                        ctx->need = sizeof(proxy_v1);
+                    }
+                    else if (ctx->version == 2) {
+                        ctx->need = MIN_V2_HDR_LEN;
+                    }
+                }
+            }
+            else if (ctx->version == 1) {
+                psts = remoteip_process_v1_header(f->c, conn_conf,
+                                            (proxy_header *) ctx->header,
+                                            ctx->rcvd, &ctx->need);
+            }
+            else if (ctx->version == 2) {
+                if (ctx->rcvd >= MIN_V2_HDR_LEN) {
+                    ctx->need = MIN_V2_HDR_LEN +
+                        remoteip_get_v2_len((proxy_header *) ctx->header);
+                }
+                if (ctx->rcvd >= ctx->need) {
+                    psts = remoteip_process_v2_header(f->c, conn_conf,
+                                                (proxy_header *) ctx->header);
+                }
+            }
+            else {
+                ap_log_cerror(APLOG_MARK, APLOG_ERR, 0, f->c, APLOGNO(03509)
+                              "RemoteIPProxyProtocol: internal error: unknown version "
+                              "%d", ctx->version);
+                f->c->aborted = 1;
+                apr_brigade_destroy(ctx->bb);
+                return APR_ECONNABORTED;
+            }
+
+            switch (psts) {
+                case HDR_ERROR:
+                    f->c->aborted = 1;
+                    apr_brigade_destroy(ctx->bb);
+                    return APR_ECONNABORTED;
+
+                case HDR_DONE:
+                    ctx->done = 1;
+                    break;
+
+                case HDR_NEED_MORE:
+                    break;
+            }
+        }
+    }
+
+    /* we only get here when done == 1 */
+    ap_log_cerror(APLOG_MARK, APLOG_DEBUG, 0, f->c, APLOGNO(03511)
+                  "RemoteIPProxyProtocol: received valid PROXY header: %s:%hu",
+                  conn_conf->client_ip, conn_conf->client_addr->port);
+
+    if (ctx->rcvd > ctx->need || !APR_BRIGADE_EMPTY(ctx->bb)) {
+        ap_log_cerror(APLOG_MARK, APLOG_ERR, 0, f->c, APLOGNO(03513)
+                      "RemoteIPProxyProtocol: internal error: have data left over; "
+                      " need=%" APR_SIZE_T_FMT ", rcvd=%" APR_SIZE_T_FMT
+                      ", brigade-empty=%d", ctx->need, ctx->rcvd,
+                      APR_BRIGADE_EMPTY(ctx->bb));
+        f->c->aborted = 1;
+        apr_brigade_destroy(ctx->bb);
+        return APR_ECONNABORTED;
+    }
+
+    /* clean up */
+    apr_brigade_destroy(ctx->bb);
+    ctx->bb = NULL;
+
+    /* now do the real read for the upper layer */
+    return ap_get_brigade(f->next, bb_out, mode, block, readbytes);
+}
+
+static const command_rec remoteip_cmds[] =
+{
+    AP_INIT_TAKE1("RemoteIPHeader", header_name_set, NULL, RSRC_CONF,
+                  "Specifies a request header to trust as the client IP, "
+                  "e.g. X-Forwarded-For"),
+    AP_INIT_TAKE1("RemoteIPProxiesHeader", proxies_header_name_set,
+                  NULL, RSRC_CONF,
+                  "Specifies a request header to record proxy IP's, "
+                  "e.g. X-Forwarded-By; if not given then do not record"),
+    AP_INIT_ITERATE("RemoteIPTrustedProxy", proxies_set, 0, RSRC_CONF,
+                    "Specifies one or more proxies which are trusted "
+                    "to present IP headers"),
+    AP_INIT_ITERATE("RemoteIPInternalProxy", proxies_set, (void*)1, RSRC_CONF,
+                    "Specifies one or more internal (transparent) proxies "
+                    "which are trusted to present IP headers"),
+    AP_INIT_TAKE1("RemoteIPTrustedProxyList", proxylist_read, 0,
+                  RSRC_CONF | EXEC_ON_READ,
+                  "The filename to read the list of trusted proxies, "
+                  "see the RemoteIPTrustedProxy directive"),
+    AP_INIT_TAKE1("RemoteIPInternalProxyList", proxylist_read, (void*)1,
+                  RSRC_CONF | EXEC_ON_READ,
+                  "The filename to read the list of internal proxies, "
+                  "see the RemoteIPInternalProxy directive"),
+    AP_INIT_FLAG("RemoteIPProxyProtocol", remoteip_enable_proxy_protocol, NULL,
+                  RSRC_CONF, "Enable PROXY protocol handling ('on', 'off')"),
+    AP_INIT_TAKE_ARGV("RemoteIPProxyProtocolExceptions",
+                  remoteip_disable_networks, NULL, RSRC_CONF, "Disable PROXY "
+                  "protocol handling for this list of networks in CIDR format"),
+    { NULL }
+};
+
+static void register_hooks(apr_pool_t *p)
+{
+    /* mod_ssl is CONNECTION + 5, so we want something higher (earlier);
+     * mod_reqtimeout is CONNECTION + 8, so we want something lower (later) */
+    remoteip_filter = 
+        ap_register_input_filter("REMOTEIP_INPUT", remoteip_input_filter, NULL,
+                                 AP_FTYPE_CONNECTION + 7);
+
+    ap_hook_post_config(remoteip_hook_post_config, NULL, NULL, APR_HOOK_MIDDLE);
+    ap_hook_pre_connection(remoteip_hook_pre_connection, NULL, NULL, APR_HOOK_MIDDLE);
+    ap_hook_post_read_request(remoteip_modify_request, NULL, NULL, APR_HOOK_FIRST);
+}
+
+AP_DECLARE_MODULE(remoteip) = {
+    STANDARD20_MODULE_STUFF,
+    NULL,                          /* create per-directory config structure */
+    NULL,                          /* merge per-directory config structures */
+    create_remoteip_server_config, /* create per-server config structure */
+    merge_remoteip_server_config,  /* merge per-server config structures */
+    remoteip_cmds,                 /* command apr_table_t */
+    register_hooks                 /* register hooks */
+};