Imported Upstream version 2.3.16-beta

1 files changed, 447 insertions, 0 deletions

diff --git a/modules/metadata/mod_remoteip.c b/modules/metadata/mod_remoteip.c
new file mode 100644
index 00000000..d2858cc1
--- /dev/null
+++ b/modules/metadata/mod_remoteip.c
@@ -0,0 +1,447 @@
+/* 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 "ap_config.h"
+#include "ap_mmn.h"
+#include "httpd.h"
+#include "http_config.h"
+#include "http_connection.h"
+#include "http_protocol.h"
+#include "http_log.h"
+#include "apr_strings.h"
+#include "apr_lib.h"
+#define APR_WANT_BYTEFUNC
+#include "apr_want.h"
+#include "apr_network_io.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 {
+    /** 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_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;
+
+static void *create_remoteip_server_config(apr_pool_t *p, server_rec *s)
+{
+    remoteip_config_t *config = apr_pcalloc(p, sizeof *config);
+    /* config->header_name = NULL;
+     * config->proxies_header_name = NULL;
+     */
+    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) {
+        char msgbuf[128];
+        apr_strerror(rv, msgbuf, sizeof(msgbuf));
+        return apr_pstrcat(cmd->pool, "RemoteIP: Error parsing IP ", arg,
+                           " (", msgbuf, " error) for ", cmd->cmd->name, NULL);
+    }
+
+    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: %s",
+                            cmd->cmd->name, filename,
+                            apr_strerror(rv, lbuf, sizeof(lbuf)));
+    }
+
+    while (!(ap_cfg_getline(lbuf, MAX_STRING_LEN, cfp))) {
+        args = lbuf;
+        while (*(arg = ap_getword_conf(cmd->temp_pool, &args)) != '\0') {
+            if (*arg == '#' || *arg == '\0') {
+                break;
+            }
+            errmsg = proxies_set(cmd, cfg, arg);
+            if (errmsg) {
+                errmsg = apr_psprintf(cmd->pool, "%s at line %d of %s",
+                                      errmsg, cfp->line_number, filename);
+                return errmsg;
+            }
+        }
+    }
+
+    ap_cfg_closefile(cfp);
+    return NULL;
+}
+
+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_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;
+    void *internal = NULL;
+
+    if (!config->header_name) {
+        return DECLINED;
+    }
+
+    remote = (char *) apr_table_get(r->headers_in, config->header_name);
+    if (!remote) {
+        return OK;
+    }
+    remote = apr_pstrdup(r->pool, remote);
+
+    temp_sa = c->client_addr;
+
+    while (remote) {
+
+        /* verify c->client_addr is trusted if there is a 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, c->client_addr)) {
+                    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 equivilant 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));
+        }
+
+        /* Set useragent_ip string */
+        if (!internal) {
+            if (proxy_ips) {
+                proxy_ips = apr_pstrcat(r->pool, proxy_ips, ", ",
+                                        c->client_ip, NULL);
+            }
+            else {
+                proxy_ips = c->client_ip;
+            }
+        }
+
+        req->useragent_addr = temp_sa;
+        apr_sockaddr_ip_get(&req->useragent_ip, req->useragent_addr);
+    }
+
+    /* Nothing happened? */
+    if (!req) {
+        return OK;
+    }
+
+    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_INFO, 0, r,
+                  req->proxy_ips
+                      ? "Using %s as client's IP by proxies %s"
+                      : "Using %s as client's IP by internal proxies",
+                  req->useragent_ip, req->proxy_ips);
+    return OK;
+}
+
+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"),
+    { NULL }
+};
+
+static void register_hooks(apr_pool_t *p)
+{
+    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 */
+};