diff options
Diffstat (limited to 'modules/metadata/mod_remoteip.c')
| -rw-r--r-- | modules/metadata/mod_remoteip.c | 1267 |
1 files changed, 1267 insertions, 0 deletions
diff --git a/modules/metadata/mod_remoteip.c b/modules/metadata/mod_remoteip.c new file mode 100644 index 0000000..045e988 --- /dev/null +++ b/modules/metadata/mod_remoteip.c @@ -0,0 +1,1267 @@ +/* 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 overridden 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 */ + ap_log_cerror(APLOG_MARK, APLOG_ERR, 0, c, APLOGNO(10183) + "RemoteIPProxyProtocol: unsupported protocol %.2hx", + (unsigned short)hdr->v2.fam); + return HDR_ERROR; + } + break; /* we got a sockaddr now */ + 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)) { + apr_off_t got, want = ctx->need - ctx->rcvd; + + ret = ap_get_brigade(f->next, ctx->bb, ctx->mode, block, want); + if (ret != APR_SUCCESS) { + ap_log_cerror(APLOG_MARK, APLOG_ERR, ret, f->c, APLOGNO(10184) + "failed reading input"); + return ret; + } + + ret = apr_brigade_length(ctx->bb, 1, &got); + if (ret || got > want) { + ap_log_cerror(APLOG_MARK, APLOG_ERR, ret, f->c, APLOGNO(10185) + "RemoteIPProxyProtocol header too long, " + "got %" APR_OFF_T_FMT " expected %" APR_OFF_T_FMT, + got, want); + f->c->aborted = 1; + return APR_ECONNABORTED; + } + } + 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->need > sizeof(proxy_v2)) { + ap_log_cerror(APLOG_MARK, APLOG_ERR, 0, f->c, APLOGNO(10186) + "RemoteIPProxyProtocol protocol header length too long"); + f->c->aborted = 1; + apr_brigade_destroy(ctx->bb); + return APR_ECONNABORTED; + } + } + 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 */ +}; |