--- /dev/null
+/* 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.
+ */
+
+/*
+ * Originally written @ BBC by Graham Leggett
+ * (C) 2011 British Broadcasting Corporation
+ */
+
+/*
+ * mod_policy.c --- Enforce specific policies on outgoing requests, logging
+ * or rejecting requests as appropriate.
+ *
+ * To enable, add the corresponding filters like so:
+ *
+ * SetOutputFilter POLICY_TYPE,POLICY_LENGTH
+ *
+ */
+
+#include "util_filter.h"
+#include "httpd.h"
+#include "http_config.h"
+#include "http_core.h"
+#include "http_log.h"
+#include "http_protocol.h"
+
+#include <apr_tables.h>
+#include <apr_strings.h>
+#include <apr_date.h>
+
+module AP_MODULE_DECLARE_DATA policy_module;
+
+#define DEFAULT_TYPE "*/*"
+
+typedef enum policy_result
+{
+ policy_ignore = 0, /* ignore this policy */
+ policy_log, /* log the violation as a warning, but let it through */
+ policy_enforce /* log the violation as an error, and decline */
+} policy_result;
+
+typedef struct policy_conf
+{
+ int policy; /* whether the filters should do anything at all */
+ int policy_set;
+ const char *environment; /* optional name of the subprocess environment variable that
+ * controls whether the policies are enforced.
+ */
+ const char *environment_log; /* value to trigger logging only */
+ const char *environment_ignore; /* value to suspend policy enforcement */
+ int environment_set;
+ policy_result type_action;
+ apr_array_header_t *type_matches; /* content type default patterns to match */
+ int type_set;
+ const char *type_url;
+ int type_url_set;
+ policy_result length_action;
+ int length_set;
+ const char *length_url;
+ int length_url_set;
+ policy_result keepalive_action;
+ int keepalive_set;
+ const char *keepalive_url;
+ int keepalive_url_set;
+ policy_result vary_action;
+ apr_array_header_t *vary_matches; /* Vary default patterns to match */
+ int vary_set;
+ const char *vary_url;
+ int vary_url_set;
+ policy_result validation_action;
+ int validation_set;
+ const char *validation_url;
+ int validation_url_set;
+ policy_result conditional_action;
+ int conditional_set;
+ const char *conditional_url;
+ int conditional_url_set;
+ policy_result nocache_action;
+ int nocache_set;
+ const char *nocache_url;
+ int nocache_url_set;
+ policy_result maxage_action;
+ apr_int64_t maxage;
+ int maxage_set;
+ const char *maxage_url;
+ int maxage_url_set;
+ policy_result version_action;
+ const char *version;
+ int version_num;
+ int version_set;
+ const char *version_url;
+ int version_url_set;
+} policy_conf;
+
+/**
+ * Does the value of a flagpole override the original value?
+ */
+static int check_enabled(request_rec *r, policy_conf *conf,
+ policy_result result)
+{
+ if (conf && !conf->policy) {
+ return policy_ignore;
+ }
+ if (conf && result != policy_ignore && conf->environment) {
+ const char *value = apr_table_get(r->subprocess_env, conf->environment);
+ if (value) {
+ /* downgrade enforce to log? */
+ if (conf->environment_log && !strcmp(value, conf->environment_log)) {
+ if (result == policy_enforce) {
+ return policy_log;
+ }
+ }
+ /* downgrade enforce and log to ignore? */
+ else if (conf->environment_ignore && !strcmp(value,
+ conf->environment_ignore)) {
+ return policy_ignore;
+ }
+ }
+ }
+ return result;
+}
+
+static void handle_policy(request_rec *r, policy_result result,
+ const char *message, const char *url, apr_bucket_brigade *bb,
+ int status)
+{
+ apr_bucket *e;
+
+ switch (result) {
+ case policy_log: {
+ ap_log_rerror(
+ APLOG_MARK,
+ APLOG_WARNING,
+ 0,
+ r,
+ "mod_policy: violation: %s, uri: %s",
+ message, r->uri);
+ apr_table_addn(r->headers_out, "Warning", apr_psprintf(r->pool,
+ "299 %s \"%s\"", ap_get_server_name(r), message));
+ break;
+ }
+ case policy_enforce: {
+
+ ap_log_rerror(
+ APLOG_MARK,
+ APLOG_ERR,
+ 0,
+ r,
+ "mod_policy: violation, rejecting request: %s, uri: %s",
+ message, r->uri);
+ apr_table_addn(r->err_headers_out, "Warning", apr_psprintf(r->pool,
+ "299 %s \"Rejected: %s\"", ap_get_server_name(r), message));
+ apr_table_setn(
+ r->notes, "error-notes",
+ apr_pstrcat(r->pool, url ? apr_pstrcat(r->pool, "<a href=\"",
+ url, "\">", NULL) : "", message, url ? "</a>" : "",
+ NULL));
+
+ apr_brigade_cleanup(bb);
+ e = ap_bucket_error_create(status, NULL, r->pool,
+ r->connection->bucket_alloc);
+ APR_BRIGADE_INSERT_TAIL(bb, e);
+ e = apr_bucket_eos_create(r->connection->bucket_alloc);
+ APR_BRIGADE_INSERT_TAIL(bb, e);
+
+ }
+ case policy_ignore: {
+ }
+ }
+
+}
+
+/**
+ * Policy for Content-Type.
+ *
+ * - It must be present.
+ * - It must match the optional regex (default .* / .*)
+ */
+static apr_status_t policy_type_out_filter(ap_filter_t *f,
+ apr_bucket_brigade *bb)
+{
+
+ policy_conf *conf = ap_get_module_config(f->r->per_dir_config,
+ &policy_module);
+ policy_result result = check_enabled(f->r, conf, conf->type_action);
+
+ if (result != policy_ignore) {
+ int fail = 1;
+
+ /* content type present and valid? */
+ if (f->r->content_type) {
+ const char *type = f->r->content_type;
+ const char *end = strchr(type, ';');
+ if (end) {
+ type = apr_pstrmemdup(f->r->pool, type, end - type);
+ }
+ if (!conf->type_matches) {
+ if (!ap_strcmp_match(type, DEFAULT_TYPE)) {
+ fail = 0;
+ }
+ }
+ else {
+ int i;
+ for (i = 0; i < conf->type_matches->nelts; i++) {
+ if (!ap_strcmp_match(type,
+ ((char **) conf->type_matches->elts)[i])) {
+ fail = 0;
+ break;
+ }
+ }
+ }
+ }
+
+ if (fail) {
+ const char *types = NULL;
+ if (conf->type_matches) {
+ int i;
+ for (i = 0; i < conf->type_matches->nelts; i++) {
+ types = apr_pstrcat(f->r->pool, types ? ", " : "",
+ ((char **) conf->type_matches->elts)[i], NULL);
+ }
+ }
+ else {
+ types = DEFAULT_TYPE;
+ }
+
+ handle_policy(
+ f->r,
+ result,
+ apr_psprintf(
+ f->r->pool,
+ "Content-Type of '%s' should be RFC compliant and match one of: %s",
+ f->r->content_type, types), conf->type_url, bb, HTTP_BAD_GATEWAY);
+
+ }
+
+ }
+
+ ap_remove_output_filter(f);
+ return ap_pass_brigade(f->next, bb);
+}
+
+/**
+ * Policy for Content-Length.
+ *
+ * - It must be present (missing, or Transfer-Encoding: chunked would be rejected)
+ * - Only applies to 2xx result codes
+ */
+static apr_status_t policy_length_out_filter(ap_filter_t *f,
+ apr_bucket_brigade *bb)
+{
+ request_rec *r = f->r;
+
+ policy_conf *conf = ap_get_module_config(r->per_dir_config,
+ &policy_module);
+ policy_result result = check_enabled(r, conf, conf->length_action);
+
+ if (result != policy_ignore && r->status >= 200 && r->status < 300
+ && r->status != HTTP_NO_CONTENT) {
+
+ if (!apr_table_get(r->headers_out, "Content-Length")) {
+
+ handle_policy(r, result, "Content-Length should be present",
+ conf->length_url, bb, HTTP_BAD_GATEWAY);
+
+ }
+
+ }
+
+ ap_remove_output_filter(f);
+ return ap_pass_brigade(f->next, bb);
+}
+
+/**
+ * Policy for Content-Length / Chunked Encoding.
+ *
+ * We follow a subset of the algorithm httpd uses, which is:
+ *
+ * IF we have not marked this connection as errored;
+ * and the client isn't expecting 100-continue (PR47087 - more
+ * input here could be the client continuing when we're
+ * closing the request).
+ * and the response status does not require a close;
+ * and the response body has a defined length due to the status code
+ * being 304 or 204, the request method being HEAD, already
+ * having defined Content-Length or Transfer-Encoding: chunked, or
+ * the request version being HTTP/1.1 and thus capable of being set
+ * as chunked
+ * THEN we support keepalive.
+ *
+ * Note: The server may choose to turn off keepalive for various reasons,
+ * such as an imminent shutdown, or a Connection: close from the client,
+ * but for our purposes we only care that keepalive was possible from
+ * the application, not that keepalive actually took place.
+ */
+static apr_status_t policy_keepalive_out_filter(ap_filter_t *f,
+ apr_bucket_brigade *bb)
+{
+ request_rec *r = f->r;
+
+ policy_conf *conf = ap_get_module_config(r->per_dir_config,
+ &policy_module);
+ policy_result result = check_enabled(r, conf, conf->keepalive_action);
+
+ if (result != policy_ignore && r->connection->keepalive != AP_CONN_CLOSE
+ && !r->expecting_100 && !ap_status_drops_connection(r->status)) {
+
+ if (!((r->status == HTTP_NOT_MODIFIED)
+ || (r->status == HTTP_NO_CONTENT)
+ || r->header_only
+ || apr_table_get(r->headers_out, "Content-Length")
+ || ap_find_last_token(r->pool, apr_table_get(r->headers_out,
+ "Transfer-Encoding"), "chunked")
+ || r->proto_num >= HTTP_VERSION(1, 1))) {
+
+ handle_policy(r, result, "Keepalive should be possible (supply Content-Length or HTTP/1.1 Transfer-Encoding)",
+ conf->keepalive_url, bb, HTTP_BAD_GATEWAY);
+
+ }
+
+ }
+
+ ap_remove_output_filter(f);
+ return ap_pass_brigade(f->next, bb);
+}
+
+static int vary_test(void *rec, const char *key, const char *value) {
+ request_rec *r = (request_rec *)rec;
+ char *token = apr_pstrdup(r->pool, value);
+ char *last;
+
+ policy_conf *conf = ap_get_module_config(r->per_dir_config,
+ &policy_module);
+
+ token = apr_strtok(token, ", \t", &last);
+ while (token) {
+ int i;
+ for (i = 0; i < conf->vary_matches->nelts; i++) {
+ if (!ap_strcasecmp_match(token,
+ ((char **) conf->vary_matches->elts)[i])) {
+ return 0;
+ }
+ }
+
+ token = apr_strtok(NULL, ", \t", &last);
+ }
+ return 1;
+}
+
+/**
+ * Policy for Vary.
+ *
+ * - If an element matches the optional regex (no default), the request is rejected.
+ * Typically used to reject Varying on User-Agent.
+ */
+static apr_status_t policy_vary_out_filter(ap_filter_t *f,
+ apr_bucket_brigade *bb)
+{
+
+ policy_conf *conf = ap_get_module_config(f->r->per_dir_config,
+ &policy_module);
+ policy_result result = check_enabled(f->r, conf, conf->vary_action);
+
+ if (result != policy_ignore) {
+
+ /* Vary present and valid? */
+ if (!apr_table_do(vary_test, f->r, f->r->headers_out, "Vary", NULL)) {
+ const char *varys = NULL;
+ if (conf->vary_matches) {
+ int i;
+ for (i = 0; i < conf->vary_matches->nelts; i++) {
+ varys = apr_pstrcat(f->r->pool, varys ? ", " : "",
+ ((char **) conf->vary_matches->elts)[i], NULL);
+ }
+ }
+
+ handle_policy(f->r, result, apr_psprintf(f->r->pool,
+ "Vary header(s) should NOT match any of: %s", varys),
+ conf->vary_url, bb, HTTP_BAD_GATEWAY);
+
+ }
+
+ }
+
+ ap_remove_output_filter(f);
+ return ap_pass_brigade(f->next, bb);
+}
+
+/**
+ * Policy for Validation.
+ *
+ * Validation is possible through either the ETag or Last-Modified header, as described
+ * in http://www.w3.org/Protocols/rfc2616/rfc2616-sec13.html#sec13.3.
+ *
+ * - Either must be present
+ * - Last-Modified, if present, must parse to a valid date
+ * - ETag, if present, must parse to a valid ETag.
+ */
+static apr_status_t policy_validation_out_filter(ap_filter_t *f,
+ apr_bucket_brigade *bb)
+{
+
+ policy_conf *conf = ap_get_module_config(f->r->per_dir_config,
+ &policy_module);
+ policy_result result = check_enabled(f->r, conf, conf->validation_action);
+
+ if (result != policy_ignore) {
+ int fail = 1, etagfail = 0, lmfail = 0;
+ const char *etag = apr_table_get(f->r->headers_out, "ETag");
+ const char *lastmodified = apr_table_get(f->r->headers_out,
+ "Last-Modified");
+
+ if (etag) {
+ int len = strlen(etag);
+ if (len > 1) {
+ if (etag[0] == '\"' && etag[len - 1] == '\"') {
+ fail = 0;
+ }
+ else if (etag[0] == 'W' && etag[1] == '/' && etag[2] == '\"'
+ && etag[len - 1] == '\"') {
+ fail = 0;
+ }
+ }
+ if (fail) {
+ etagfail = 1;
+ }
+ }
+
+ if (lastmodified) {
+ apr_time_t lastmod = apr_date_parse_http(lastmodified);
+ if (lastmod != APR_DATE_BAD) {
+ fail = 0;
+ }
+ if (fail) {
+ lmfail = 1;
+ }
+ }
+
+ if (fail) {
+ const char *error = NULL;
+ if (!etag && !lastmodified) {
+ error = apr_psprintf(f->r->pool,
+ "Etag and Last Modified missing");
+ }
+ else {
+ error = apr_pstrcat(f->r->pool,
+ (etagfail ? "ETag syntax error (check quotes)" : ""),
+ (etagfail && lmfail ? " / " : ""),
+ (lmfail ? "Last-Modified could not be parsed" : ""),
+ NULL);
+ }
+
+ handle_policy(f->r, result, error, conf->validation_url, bb,
+ HTTP_BAD_GATEWAY);
+
+ }
+
+ }
+
+ ap_remove_output_filter(f);
+ return ap_pass_brigade(f->next, bb);
+}
+
+/**
+ * Policy for Revalidation through Conditional Requests.
+ *
+ * The If-None-Match header is described in
+ * http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.26. Over and above the
+ * checks done in the validation filter, the conditional filter detects when an
+ * If-None-Match header is present in the request, an ETag is present in the response,
+ * and the response code is unexpected given the match. A result code is unexpected
+ * where a 304 Not Modified or 412 Precondition Failed was expected, but a 200 response
+ * was seen instead.
+ */
+static apr_status_t policy_conditional_out_filter(ap_filter_t *f,
+ apr_bucket_brigade *bb)
+{
+
+ policy_conf *conf = ap_get_module_config(f->r->per_dir_config,
+ &policy_module);
+ policy_result result = check_enabled(f->r, conf, conf->conditional_action);
+
+ if (result != policy_ignore) {
+ int code = ap_meets_conditions(f->r);
+
+ if (OK != code && code != f->r->status) {
+
+ handle_policy(
+ f->r,
+ result,
+ apr_psprintf(
+ f->r->pool,
+ "Conditional request should have returned %d, instead returned %d",
+ code, f->r->status), conf->conditional_url, bb,
+ HTTP_BAD_GATEWAY);
+
+ }
+
+ }
+
+ ap_remove_output_filter(f);
+ return ap_pass_brigade(f->next, bb);
+}
+
+/**
+ * Policy for No-Cache Requests.
+ *
+ * If the Cache-Control and/or Pragma header specifies that the content is not
+ * cacheable, the request will be rejected.
+ *
+ * - If Cache-Control: no-cache
+ * - If Pragma: no-cache
+ * - If Cache-Control: no-store
+ * - If Cache-Control: private
+ */
+static apr_status_t policy_nocache_out_filter(ap_filter_t *f,
+ apr_bucket_brigade *bb)
+{
+
+ policy_conf *conf = ap_get_module_config(f->r->per_dir_config,
+ &policy_module);
+ policy_result result = check_enabled(f->r, conf, conf->nocache_action);
+
+ if (result != policy_ignore) {
+ request_rec *r = f->r;
+ const char *cc_header = apr_table_get(r->headers_out, "Cache-Control");
+ const char *pragma_header = apr_table_get(r->headers_out, "Pragma");
+ int fail = 0;
+ char *last;
+
+ if (pragma_header) {
+ char *header = apr_pstrdup(r->pool, pragma_header);
+ const char *token = apr_strtok(header, ", ", &last);
+ while (token) {
+ /* handle most common quickest case... */
+ if (!strcmp(token, "no-cache")) {
+ fail = 1;
+ }
+ /* ...then try slowest case */
+ else if (!strcasecmp(token, "no-cache")) {
+ fail = 1;
+ }
+ token = apr_strtok(NULL, ", ", &last);
+ }
+ }
+
+ if (cc_header) {
+ char *header = apr_pstrdup(r->pool, cc_header);
+ const char *token = apr_strtok(header, ", ", &last);
+ while (token) {
+ switch (token[0]) {
+ case 'n':
+ case 'N': {
+ /* handle most common quickest cases... */
+ if (!strcmp(token, "no-cache")) {
+ fail = 1;
+ }
+ else if (!strcmp(token, "no-store")) {
+ fail = 1;
+ }
+ /* ...then try slowest cases */
+ else if (!strncasecmp(token, "no-cache", 8)) {
+ if (token[8] == '=') {
+ }
+ else if (!token[8]) {
+ fail = 1;
+ }
+ break;
+ }
+ else if (!strcasecmp(token, "no-store")) {
+ fail = 1;
+ }
+ break;
+ }
+ case 'p':
+ case 'P': {
+ /* handle most common quickest cases... */
+ if (!strcmp(token, "private")) {
+ fail = 1;
+ }
+ /* ...then try slowest cases */
+ else if (!strncasecmp(token, "private", 7)) {
+ if (token[7] == '=') {
+ }
+ else if (!token[7]) {
+ fail = 1;
+ }
+ break;
+ }
+ break;
+ }
+ }
+ token = apr_strtok(NULL, ", ", &last);
+ }
+ }
+
+ if (fail) {
+
+ handle_policy(r, result, "Response is marked uncacheable",
+ conf->nocache_url, bb, HTTP_BAD_GATEWAY);
+
+ }
+
+ }
+
+ ap_remove_output_filter(f);
+ return ap_pass_brigade(f->next, bb);
+}
+
+/**
+ * Policy for Maxage.
+ *
+ * If the effective maxage of the request is less than the parameter provided,
+ * the request will be rejected.
+ *
+ * - If Cache-Control: s-maxage is less than the limit
+ * - If Cache-Control: maxage is less than the limit
+ * - If Expires - Date is less than the limit
+ * - If none of the above, reject the request, as maxage is heuristic
+ *
+ * As soon as a test passes, we stop, as HTTP maxage handling follows a given
+ * set of priorities (s-maxage beats maxage, maxage beats Expires).
+ */
+static apr_status_t policy_maxage_out_filter(ap_filter_t *f,
+ apr_bucket_brigade *bb)
+{
+
+ policy_conf *conf = ap_get_module_config(f->r->per_dir_config,
+ &policy_module);
+ policy_result result = check_enabled(f->r, conf, conf->maxage_action);
+
+ if (result != policy_ignore) {
+ request_rec *r = f->r;
+ const char *cc_header;
+ const char *expires_header;
+ const char *date_header;
+ char *last;
+
+ int max_age = 0;
+ apr_int64_t max_age_value = 0;
+ int s_maxage = 0;
+ apr_int64_t s_maxage_value = 0;
+
+ /* parse Cache-Control */
+ cc_header = apr_table_get(r->headers_out, "Cache-Control");
+ if (cc_header) {
+ char *header = apr_pstrdup(r->pool, cc_header);
+ const char *token = apr_strtok(header, ", ", &last);
+ while (token) {
+ switch (token[0]) {
+ case 'm':
+ case 'M': {
+ /* handle most common quickest cases... */
+ if (!strncmp(token, "max-age", 7)) {
+ max_age = 1;
+ max_age_value = apr_atoi64(token + 8);
+ }
+ /* ...then try slowest cases */
+ else if (!strncasecmp(token, "max-age", 7)) {
+ if (token[7] == '=') {
+ max_age = 1;
+ max_age_value = apr_atoi64(token + 8);
+ }
+ break;
+ }
+ break;
+ }
+ case 's':
+ case 'S': {
+ if (!strncmp(token, "s-maxage", 8)) {
+ if (token[8] == '=') {
+ s_maxage = 1;
+ s_maxage_value = apr_atoi64(token + 9);
+ }
+ break;
+ }
+ else if (!strncasecmp(token, "s-maxage", 8)) {
+ if (token[8] == '=') {
+ s_maxage = 1;
+ s_maxage_value = apr_atoi64(token + 9);
+ }
+ break;
+ }
+ break;
+ }
+ }
+ token = apr_strtok(NULL, ", ", &last);
+ }
+ }
+
+ /* test s-maxage, if present */
+ if (s_maxage) {
+ if (s_maxage_value < conf->maxage) {
+
+ handle_policy(
+ f->r,
+ result,
+ apr_psprintf(
+ f->r->pool,
+ "Response s-maxage of %" APR_INT64_T_FMT " must be at least %" APR_INT64_T_FMT,
+ s_maxage_value, conf->maxage), conf->maxage_url,
+ bb, HTTP_BAD_GATEWAY);
+
+ }
+
+ /* decision is made, leave */
+ ap_remove_output_filter(f);
+ return ap_pass_brigade(f->next, bb);
+ }
+
+ /* test max-age, if present */
+ if (max_age) {
+ if (max_age_value < conf->maxage) {
+
+ handle_policy(
+ f->r,
+ result,
+ apr_psprintf(
+ f->r->pool,
+ "Response max-age of %" APR_INT64_T_FMT " must be at least %" APR_INT64_T_FMT,
+ max_age_value, conf->maxage), conf->maxage_url,
+ bb, HTTP_BAD_GATEWAY);
+
+ }
+
+ /* decision is made, leave */
+ ap_remove_output_filter(f);
+ return ap_pass_brigade(f->next, bb);
+ }
+
+ /* test expires, if present */
+ expires_header = apr_table_get(r->headers_out, "Expires");
+ date_header = apr_table_get(r->headers_out, "Date");
+ if (expires_header && date_header) {
+ apr_time_t expires = apr_date_parse_http(expires_header);
+ apr_time_t date = apr_date_parse_http(date_header);
+ apr_int64_t fresh = apr_time_sec(expires - date);
+
+ if (expires == APR_DATE_BAD) {
+
+ handle_policy(
+ f->r,
+ result,
+ apr_psprintf(
+ f->r->pool,
+ "Response Expires of '%s' is invalid, maxage %" APR_INT64_T_FMT " required",
+ expires_header, conf->maxage),
+ conf->maxage_url, bb, HTTP_BAD_GATEWAY);
+
+ }
+
+ else if (date == APR_DATE_BAD) {
+
+ handle_policy(
+ f->r,
+ result,
+ apr_psprintf(
+ f->r->pool,
+ "Response Date of '%s' is invalid, maxage %" APR_INT64_T_FMT " required",
+ date_header, conf->maxage),
+ conf->maxage_url, bb, HTTP_BAD_GATEWAY);
+
+ }
+
+ else if (conf->maxage > 0 && fresh < conf->maxage) {
+
+ handle_policy(
+ f->r,
+ result,
+ apr_psprintf(
+ f->r->pool,
+ "Response expires in %" APR_INT64_T_FMT " seconds, must be at least %" APR_INT64_T_FMT,
+ fresh, conf->maxage),
+ conf->maxage_url, bb, HTTP_BAD_GATEWAY);
+
+ }
+
+ /* decision is made, leave */
+ ap_remove_output_filter(f);
+ return ap_pass_brigade(f->next, bb);
+ }
+
+ /* no explicit maxage defined, so fail */
+ handle_policy(r, result, "Response has no explicit freshness lifetime (s-maxage, max-age or Expires/Date)",
+ conf->maxage_url, bb, HTTP_BAD_GATEWAY);
+
+ }
+
+ ap_remove_output_filter(f);
+ return ap_pass_brigade(f->next, bb);
+}
+
+static const char *version_string(int proto_num)
+{
+ switch (proto_num) {
+ case HTTP_VERSION(0, 9): {
+ return "HTTP/0.9";
+ }
+ case HTTP_VERSION(1, 0): {
+ return "HTTP/1.0";
+ }
+ case HTTP_VERSION(1, 1): {
+ return "HTTP/1.1";
+ }
+ default: {
+ return "(unknown)";
+ }
+ }
+}
+
+/**
+ * Policy for HTTP Version.
+ *
+ * - The HTTP version of the response must be at least the level specified.
+ */
+static apr_status_t policy_version_out_filter(ap_filter_t *f,
+ apr_bucket_brigade *bb)
+{
+ request_rec *r = f->r;
+
+ policy_conf *conf = ap_get_module_config(r->per_dir_config,
+ &policy_module);
+ policy_result result = check_enabled(r, conf, conf->version_action);
+
+ if (result != policy_ignore) {
+
+ if (r->proto_num > 0 && r->proto_num < conf->version_num) {
+
+ handle_policy(f->r, result, apr_psprintf(f->r->pool,
+ "Request HTTP version '%s' should be at least '%s'",
+ version_string(r->proto_num), conf->version),
+ conf->version_url, bb, HTTP_VERSION_NOT_SUPPORTED);
+
+ }
+
+ }
+
+ ap_remove_output_filter(f);
+ return ap_pass_brigade(f->next, bb);
+}
+
+static void *create_policy_config(apr_pool_t *p, char *dummy)
+{
+ policy_conf *new = (policy_conf *) apr_pcalloc(p, sizeof(policy_conf));
+
+ new->policy = 1;
+ new->type_action = policy_log;
+ new->length_action = policy_log;
+ new->vary_action = policy_log;
+ new->validation_action = policy_log;
+ new->conditional_action = policy_log;
+ new->nocache_action = policy_log;
+ new->maxage_action = policy_log;
+ new->version_action = policy_log;
+ new->version_num = HTTP_VERSION(0, 9);
+ new->version = "HTTP/0.9";
+
+ return (void *) new;
+}
+
+static void *merge_policy_config(apr_pool_t *p, void *basev, void *addv)
+{
+ policy_conf *new = (policy_conf *) apr_pcalloc(p, sizeof(policy_conf));
+ policy_conf *add = (policy_conf *) addv;
+ policy_conf *base = (policy_conf *) basev;
+
+ new->policy = (add->policy_set == 0) ? base->policy : add->policy;
+ new->policy_set = add->policy_set || base->policy_set;
+ new->environment = (add->environment_set == 0) ? base->environment : add->environment;
+ new->environment_log = (add->environment_set == 0) ? base->environment_log
+ : add->environment_log;
+ new->environment_ignore = (add->environment_set == 0) ? base->environment_ignore
+ : add->environment_ignore;
+ new->environment_set = add->environment_set || base->environment_set;
+ new->type_action = (add->type_set == 0) ? base->type_action
+ : add->type_action;
+ new->type_matches = (add->type_set == 0) ? base->type_matches
+ : add->type_matches;
+ new->type_set = add->type_set || base->type_set;
+ new->type_url = (add->type_url_set == 0) ? base->type_url : add->type_url;
+ new->type_url_set = add->type_url_set || base->type_url_set;
+ new->length_action = (add->length_set == 0) ? base->length_action
+ : add->length_action;
+ new->length_set = add->length_set || base->length_set;
+ new->length_url = (add->length_url_set == 0) ? base->length_url
+ : add->length_url;
+ new->length_url_set = add->length_url_set || base->length_url_set;
+ new->vary_action = (add->vary_set == 0) ? base->vary_action
+ : add->vary_action;
+ new->vary_matches = (add->vary_set == 0) ? base->vary_matches
+ : add->vary_matches;
+ new->vary_set = add->vary_set || base->vary_set;
+ new->vary_url = (add->vary_url_set == 0) ? base->vary_url : add->vary_url;
+ new->vary_url_set = add->vary_url_set || base->vary_url_set;
+ new->validation_action
+ = (add->validation_set == 0) ? base->validation_action
+ : add->validation_action;
+ new->validation_set = add->validation_set || base->validation_set;
+ new->validation_url = (add->validation_url_set == 0) ? base->validation_url
+ : add->validation_url;
+ new->validation_url_set = add->validation_url_set
+ || base->validation_url_set;
+ new->conditional_action
+ = (add->conditional_set == 0) ? base->conditional_action
+ : add->conditional_action;
+ new->conditional_set = add->conditional_set || base->conditional_set;
+ new->conditional_url
+ = (add->conditional_url_set == 0) ? base->conditional_url
+ : add->conditional_url;
+ new->conditional_url_set = add->conditional_url_set
+ || base->conditional_url_set;
+ new->nocache_action = (add->nocache_set == 0) ? base->nocache_action
+ : add->nocache_action;
+ new->nocache_set = add->nocache_set || base->nocache_set;
+ new->nocache_url = (add->nocache_url_set == 0) ? base->nocache_url
+ : add->nocache_url;
+ new->nocache_url_set = add->nocache_url_set || base->nocache_url_set;
+ new->maxage_action = (add->maxage_set == 0) ? base->maxage_action
+ : add->maxage_action;
+ new->maxage = (add->maxage_set == 0) ? base->maxage : add->maxage;
+ new->maxage_set = add->maxage_set || base->maxage_set;
+ new->maxage_url = (add->maxage_url_set == 0) ? base->maxage_url
+ : add->maxage_url;
+ new->maxage_url_set = add->maxage_url_set || base->maxage_url_set;
+ new->version_action = (add->version_set == 0) ? base->version_action
+ : add->version_action;
+ new->version = (add->version_set == 0) ? base->version : add->version;
+ new->version_num = (add->version_set == 0) ? base->version_num : add->version_num;
+ new->version_set = add->version_set || base->version_set;
+ new->version_url = (add->version_url_set == 0) ? base->version_url
+ : add->version_url;
+ new->version_url_set = add->version_url_set || base->version_url_set;
+
+
+ return new;
+}
+
+static const char *parse_action(apr_pool_t *pool, const char *action,
+ policy_result *result)
+{
+ if (!strcmp(action, "enforce")) {
+ *result = policy_enforce;
+ }
+ else if (!strcmp(action, "log")) {
+ *result = policy_log;
+ }
+ else if (!strcmp(action, "ignore")) {
+ *result = policy_ignore;
+ }
+ else {
+ return apr_psprintf(pool,
+ "'%s' must be one of 'enforce, 'log' or 'ignore'.", action);
+ }
+ return NULL;
+}
+
+static const char *set_policy(cmd_parms *cmd, void *dconf, int flag)
+{
+ policy_conf *conf = dconf;
+
+ conf->policy = flag;
+ conf->policy_set = 1;
+
+ return NULL;
+}
+
+static const char *set_environment(cmd_parms *cmd, void *dconf,
+ const char *environment, const char *log, const char *ignore)
+{
+ policy_conf *conf = dconf;
+
+ conf->environment = environment;
+ conf->environment_log = log;
+ conf->environment_ignore = ignore;
+ conf->environment_set = 1;
+
+ return NULL;
+}
+
+static const char *set_type(cmd_parms *cmd, void *dconf, const char *action,
+ const char *type)
+{
+ policy_conf *conf = dconf;
+
+ if (type) {
+ const char **match_ptr;
+ if (!conf->type_matches) {
+ conf->type_matches = apr_array_make(cmd->pool, 2,
+ sizeof(const char *));
+ }
+ match_ptr = apr_array_push(conf->type_matches);
+ *match_ptr = type;
+ }
+ conf->type_set = 1;
+
+ return parse_action(cmd->pool, action, &conf->type_action);
+}
+
+static const char *set_type_url(cmd_parms *cmd, void *dconf, const char *url)
+{
+ policy_conf *conf = dconf;
+
+ conf->type_url = url;
+ conf->type_url_set = 1;
+
+ return NULL;
+}
+
+static const char *set_length(cmd_parms *cmd, void *dconf, const char *action)
+{
+ policy_conf *conf = dconf;
+
+ conf->length_set = 1;
+
+ return parse_action(cmd->pool, action, &conf->length_action);
+}
+
+static const char *set_length_url(cmd_parms *cmd, void *dconf, const char *url)
+{
+ policy_conf *conf = dconf;
+
+ conf->length_url = url;
+ conf->length_url_set = 1;
+
+ return NULL;
+}
+
+static const char *set_keepalive(cmd_parms *cmd, void *dconf, const char *action)
+{
+ policy_conf *conf = dconf;
+
+ conf->keepalive_set = 1;
+
+ return parse_action(cmd->pool, action, &conf->keepalive_action);
+}
+
+static const char *set_keepalive_url(cmd_parms *cmd, void *dconf, const char *url)
+{
+ policy_conf *conf = dconf;
+
+ conf->keepalive_url = url;
+ conf->keepalive_url_set = 1;
+
+ return NULL;
+}
+
+static const char *set_vary(cmd_parms *cmd, void *dconf, const char *action,
+ const char *vary)
+{
+ policy_conf *conf = dconf;
+
+ if (vary) {
+ const char **match_ptr;
+ if (!conf->vary_matches) {
+ conf->vary_matches = apr_array_make(cmd->pool, 2,
+ sizeof(const char *));
+ }
+ match_ptr = apr_array_push(conf->vary_matches);
+ *match_ptr = vary;
+ }
+ conf->vary_set = 1;
+
+ return parse_action(cmd->pool, action, &conf->vary_action);
+}
+
+static const char *set_vary_url(cmd_parms *cmd, void *dconf, const char *url)
+{
+ policy_conf *conf = dconf;
+
+ conf->vary_url = url;
+ conf->vary_url_set = 1;
+
+ return NULL;
+}
+
+static const char *set_validation(cmd_parms *cmd, void *dconf,
+ const char *action)
+{
+ policy_conf *conf = dconf;
+
+ conf->validation_set = 1;
+
+ return parse_action(cmd->pool, action, &conf->validation_action);
+}
+
+static const char *set_validation_url(cmd_parms *cmd, void *dconf,
+ const char *url)
+{
+ policy_conf *conf = dconf;
+
+ conf->validation_url = url;
+ conf->validation_url_set = 1;
+
+ return NULL;
+}
+
+static const char *set_conditional(cmd_parms *cmd, void *dconf,
+ const char *action)
+{
+ policy_conf *conf = dconf;
+
+ conf->conditional_set = 1;
+
+ return parse_action(cmd->pool, action, &conf->conditional_action);
+}
+
+static const char *set_conditional_url(cmd_parms *cmd, void *dconf,
+ const char *url)
+{
+ policy_conf *conf = dconf;
+
+ conf->conditional_url = url;
+ conf->conditional_url_set = 1;
+
+ return NULL;
+}
+
+static const char *set_nocache(cmd_parms *cmd, void *dconf, const char *action)
+{
+ policy_conf *conf = dconf;
+
+ conf->nocache_set = 1;
+
+ return parse_action(cmd->pool, action, &conf->nocache_action);
+}
+
+static const char *set_nocache_url(cmd_parms *cmd, void *dconf, const char *url)
+{
+ policy_conf *conf = dconf;
+
+ conf->nocache_url = url;
+ conf->nocache_url_set = 1;
+
+ return NULL;
+}
+
+static const char *set_maxage(cmd_parms *cmd, void *dconf, const char *action, const char *maxage)
+{
+ policy_conf *conf = dconf;
+
+ conf->maxage_set = 1;
+ conf->maxage = apr_atoi64(maxage);
+ if (conf->maxage < 0) {
+ return apr_psprintf(cmd->pool,
+ "'%s' must be a positive integer.", maxage);
+ }
+
+ return parse_action(cmd->pool, action, &conf->maxage_action);
+}
+
+static const char *set_maxage_url(cmd_parms *cmd, void *dconf, const char *url)
+{
+ policy_conf *conf = dconf;
+
+ conf->maxage_url = url;
+ conf->maxage_url_set = 1;
+
+ return NULL;
+}
+
+static const char *set_version(cmd_parms *cmd, void *dconf, const char *action, const char *version)
+{
+ policy_conf *conf = dconf;
+
+ conf->version_set = 1;
+
+ if (!strcmp(version, "HTTP/1.1")) {
+ conf->version = "HTTP/1.1";
+ conf->version_num = HTTP_VERSION(1, 1);
+ }
+ else if (!strcmp(version, "HTTP/1.0")) {
+ conf->version = "HTTP/1.0";
+ conf->version_num = HTTP_VERSION(1, 0);
+ }
+ else if (!strcmp(version, "HTTP/0.9")) {
+ conf->version = "HTTP/0.9";
+ conf->version_num = HTTP_VERSION(0, 9);
+ }
+ else {
+ return apr_psprintf(cmd->pool,
+ "'%s' must be one of 'HTTP/1.1', 'HTTP/1.0' or 'HTTP/0.9'.", version);
+ }
+
+ return parse_action(cmd->pool, action, &conf->version_action);
+}
+
+static const char *set_version_url(cmd_parms *cmd, void *dconf, const char *url)
+{
+ policy_conf *conf = dconf;
+
+ conf->version_url = url;
+ conf->version_url_set = 1;
+
+ return NULL;
+}
+
+static const command_rec
+ policy_cmds[] =
+ {
+ AP_INIT_FLAG("PolicyFilter", set_policy, NULL, RSRC_CONF
+ | ACCESS_CONF,
+ "Whether policies should be applied. Defaults to 'on'."),
+ AP_INIT_TAKE1(
+ "PolicyConditional",
+ set_conditional,
+ NULL,
+ RSRC_CONF | ACCESS_CONF,
+ "Action to take (enforce, ignore, log) if a conditional request was not honoured. Defaults to 'log'."),
+ AP_INIT_TAKE1("PolicyConditionalURL", set_conditional_url,
+ NULL, RSRC_CONF | ACCESS_CONF,
+ "URL describing the conditional request policy."),
+ AP_INIT_TAKE3(
+ "PolicyEnvironment",
+ set_environment,
+ NULL,
+ RSRC_CONF | ACCESS_CONF,
+ "Environment variable to control policy enforcement, followed by the variable value for logging only, and the value for policy suspension."),
+ AP_INIT_TAKE1(
+ "PolicyLength",
+ set_length,
+ NULL,
+ RSRC_CONF | ACCESS_CONF,
+ "Action to take (enforce, ignore, log) if Content-Length missing. Defaults to 'log'."),
+ AP_INIT_TAKE1("PolicyLengthURL", set_length_url, NULL,
+ RSRC_CONF | ACCESS_CONF,
+ "URL describing the content length policy."),
+ AP_INIT_TAKE1(
+ "PolicyKeepalive",
+ set_keepalive,
+ NULL,
+ RSRC_CONF | ACCESS_CONF,
+ "Action to take (enforce, ignore, log) if keepalive is not possible. Defaults to 'log'."),
+ AP_INIT_TAKE1("PolicyKeepaliveURL", set_keepalive_url, NULL,
+ RSRC_CONF | ACCESS_CONF,
+ "URL describing the keepalive policy."),
+ AP_INIT_ITERATE2(
+ "PolicyType",
+ set_type,
+ NULL,
+ RSRC_CONF | ACCESS_CONF,
+ "Action to take (enforce, ignore, log), followed by one or more valid content types containing optional wildcards ? and *"),
+ AP_INIT_TAKE1("PolicyTypeURL", set_type_url, NULL, RSRC_CONF
+ | ACCESS_CONF,
+ "URL describing the content type policy."),
+ AP_INIT_ITERATE2(
+ "PolicyVary",
+ set_vary,
+ NULL,
+ RSRC_CONF | ACCESS_CONF,
+ "Action to take (enforce, ignore, log), followed by one or more headers containing optional wildcards ? and * that are NOT to appear in a Vary header"),
+ AP_INIT_TAKE1("PolicyVaryURL", set_vary_url, NULL, RSRC_CONF
+ | ACCESS_CONF,
+ "URL describing the vary header policy."),
+ AP_INIT_TAKE1(
+ "PolicyValidation",
+ set_validation,
+ NULL,
+ RSRC_CONF | ACCESS_CONF,
+ "Action to take (enforce, ignore, log) if Last-Modified or Etag is missing or invalid. Defaults to 'log'."),
+ AP_INIT_TAKE1("PolicyValidationURL", set_validation_url, NULL,
+ RSRC_CONF | ACCESS_CONF,
+ "URL describing the content validation policy."),
+ AP_INIT_TAKE1(
+ "PolicyNocache",
+ set_nocache,
+ NULL,
+ RSRC_CONF | ACCESS_CONF,
+ "Action to take (enforce, ignore, log) if a response is not cacheable. Defaults to 'log'."),
+ AP_INIT_TAKE1("PolicyNocacheURL", set_nocache_url, NULL,
+ RSRC_CONF | ACCESS_CONF,
+ "URL describing the no cache policy."),
+ AP_INIT_TAKE2(
+ "PolicyMaxage",
+ set_maxage,
+ NULL,
+ RSRC_CONF | ACCESS_CONF,
+ "Action to take (enforce, ignore, log) if a response has an effective maxage less than the age provided. Defaults to 'log'."),
+ AP_INIT_TAKE1("PolicyMaxageURL", set_maxage_url, NULL,
+ RSRC_CONF | ACCESS_CONF,
+ "URL describing the maxage policy."),
+ AP_INIT_TAKE2(
+ "PolicyVersion",
+ set_version,
+ NULL,
+ RSRC_CONF | ACCESS_CONF,
+ "Action to take (enforce, ignore, log) if a response has an HTTP version less than the version provided. Defaults to 'log HTTP/0.9'."),
+ AP_INIT_TAKE1("PolicyVersionURL", set_version_url, NULL,
+ RSRC_CONF | ACCESS_CONF,
+ "URL describing the version policy."),
+ { NULL } };
+
+static void register_hooks(apr_pool_t *p)
+{
+ ap_register_output_filter("POLICY_TYPE", policy_type_out_filter, NULL,
+ AP_FTYPE_CONTENT_SET + 5);
+ ap_register_output_filter("POLICY_LENGTH", policy_length_out_filter, NULL,
+ AP_FTYPE_CONTENT_SET + 5);
+ ap_register_output_filter("POLICY_KEEPALIVE", policy_keepalive_out_filter, NULL,
+ AP_FTYPE_CONTENT_SET + 5);
+ ap_register_output_filter("POLICY_VARY", policy_vary_out_filter, NULL,
+ AP_FTYPE_CONTENT_SET + 5);
+ ap_register_output_filter("POLICY_VALIDATION",
+ policy_validation_out_filter, NULL, AP_FTYPE_CONTENT_SET + 5);
+ ap_register_output_filter("POLICY_CONDITIONAL",
+ policy_conditional_out_filter, NULL, AP_FTYPE_CONTENT_SET + 5);
+ ap_register_output_filter("POLICY_NOCACHE", policy_nocache_out_filter,
+ NULL, AP_FTYPE_CONTENT_SET + 5);
+ ap_register_output_filter("POLICY_MAXAGE", policy_maxage_out_filter,
+ NULL, AP_FTYPE_CONTENT_SET + 5);
+ ap_register_output_filter("POLICY_VERSION", policy_version_out_filter,
+ NULL, AP_FTYPE_CONTENT_SET + 5);
+}
+
+AP_DECLARE_MODULE(policy) =
+{
+ STANDARD20_MODULE_STUFF, create_policy_config, /* create per-directory config structure */
+ merge_policy_config, /* merge per-directory config structures */
+ NULL, /* create per-server config structure */
+ NULL, /* merge per-server config structures */
+ policy_cmds, /* command apr_table_t */
+ register_hooks /* register hooks */
+};
projects / apache / commitdiff