1 /* Licensed to the Apache Software Foundation (ASF) under one or more
2 * contributor license agreements. See the NOTICE file distributed with
3 * this work for additional information regarding copyright ownership.
4 * The ASF licenses this file to You under the Apache License, Version 2.0
5 * (the "License"); you may not use this file except in compliance with
6 * the License. You may obtain a copy of the License at
8 * http://www.apache.org/licenses/LICENSE-2.0
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
19 * Set environment variables based on matching request headers or
20 * attributes against regex strings
22 * Paul Sutton <paul@ukweb.com> 27 Oct 1996
23 * Based on mod_browser by Alexei Kosut <akosut@organic.com>
27 * Used to set environment variables based on the incoming request headers,
28 * or some selected other attributes of the request (e.g., the remote host
33 * SetEnvIf name regex var ...
35 * where name is either a HTTP request header name, or one of the
36 * special values (see below). 'name' may be a regex when it is used
37 * to specify an HTTP request header name. The 'value' of the header
38 & (or the value of the special value from below) are compared against
39 * the regex argument. If this is a simple string, a simple sub-string
40 * match is performed. Otherwise, a request expression match is
41 * done. If the value matches the string or regular expression, the
42 * environment variables listed as var ... are set. Each var can
43 * be in one of three formats: var, which sets the named variable
44 * (the value value "1"); var=value, which sets the variable to
45 * the given value; or !var, which unsets the variable is it has
46 * been previously set.
48 * Normally the strings are compared with regard to case. To ignore
49 * case, use the directive SetEnvIfNoCase instead.
51 * Special values for 'name' are:
53 * server_addr IP address of interface on which request arrived
54 * (analogous to SERVER_ADDR set in ap_add_common_vars())
55 * remote_host Remote host name (if available)
56 * remote_addr Remote IP address
57 * request_method Request method (GET, POST, etc)
58 * request_uri Requested URI
62 * To set the enviroment variable LOCALHOST if the client is the local
65 * SetEnvIf remote_addr 127.0.0.1 LOCALHOST
67 * To set LOCAL if the client is the local host, or within our company's
68 * domain (192.168.10):
70 * SetEnvIf remote_addr 192.168.10. LOCAL
71 * SetEnvIf remote_addr 127.0.0.1 LOCALHOST
73 * This could be written as:
75 * SetEnvIf remote_addr (127.0.0.1|192.168.10.) LOCAL
77 * To set HAVE_TS if the client request contains any header beginning
78 * with "TS" with a value beginning with a lower case alphabet:
80 * SetEnvIf ^TS* ^[a-z].* HAVE_TS
84 #include "apr_strings.h"
85 #include "apr_strmatch.h"
87 #define APR_WANT_STRFUNC
90 #include "ap_config.h"
92 #include "http_config.h"
93 #include "http_core.h"
95 #include "http_protocol.h"
103 SPECIAL_REQUEST_METHOD,
104 SPECIAL_REQUEST_PROTOCOL,
108 char *name; /* header name */
109 regex_t *pnamereg; /* compiled header name regex */
110 char *regex; /* regex to match against */
111 regex_t *preg; /* compiled regex */
112 const apr_strmatch_pattern *pattern; /* non-regex pattern to match */
113 apr_table_t *features; /* env vars to set (or unset) */
114 enum special special_type; /* is it a "special" header ? */
115 int icase; /* ignoring case? */
119 apr_array_header_t *conditionals;
122 module AP_MODULE_DECLARE_DATA setenvif_module;
125 * These routines, the create- and merge-config functions, are called
126 * for both the server-wide and the per-directory contexts. This is
127 * because the different definitions are used at different times; the
128 * server-wide ones are used in the post-read-request phase, and the
129 * per-directory ones are used during the header-parse phase (after
130 * the URI has been mapped to a file and we have anything from the
131 * .htaccess file and <Directory> and <Files> containers).
133 static void *create_setenvif_config(apr_pool_t *p)
135 sei_cfg_rec *new = (sei_cfg_rec *) apr_palloc(p, sizeof(sei_cfg_rec));
137 new->conditionals = apr_array_make(p, 20, sizeof(sei_entry));
141 static void *create_setenvif_config_svr(apr_pool_t *p, server_rec *dummy)
143 return create_setenvif_config(p);
146 static void *create_setenvif_config_dir(apr_pool_t *p, char *dummy)
148 return create_setenvif_config(p);
151 static void *merge_setenvif_config(apr_pool_t *p, void *basev, void *overridesv)
153 sei_cfg_rec *a = apr_pcalloc(p, sizeof(sei_cfg_rec));
154 sei_cfg_rec *base = basev, *overrides = overridesv;
156 a->conditionals = apr_array_append(p, base->conditionals,
157 overrides->conditionals);
162 * any non-NULL magic constant will do... used to indicate if REG_ICASE should
165 #define ICASE_MAGIC ((void *)(&setenvif_module))
166 #define SEI_MAGIC_HEIRLOOM "setenvif-phase-flag"
168 static int is_header_regex(apr_pool_t *p, const char* name)
170 /* If a Header name contains characters other than:
171 * -,_,[A-Z\, [a-z] and [0-9].
172 * assume the header name is a regular expression.
174 regex_t *preg = ap_pregcomp(p, "^[-A-Za-z0-9_]*$",
175 (REG_EXTENDED | REG_NOSUB ));
176 ap_assert(preg != NULL);
178 if (ap_regexec(preg, name, 0, NULL, 0)) {
185 /* If the input string does not take advantage of regular
186 * expression metacharacters, return a pointer to an equivalent
187 * string that can be searched using apr_strmatch(). (The
188 * returned string will often be the input string. But if
189 * the input string contains escaped characters, the returned
190 * string will be a copy with the escapes removed.)
192 static const char *non_regex_pattern(apr_pool_t *p, const char *s)
195 int escapes_found = 0;
235 if (!escapes_found) {
239 char *unescaped = (char *)apr_palloc(p, src - s + 1);
240 char *dst = unescaped;
246 } while ((*dst++ = *src++));
251 static const char *add_setenvif_core(cmd_parms *cmd, void *mconfig,
252 char *fname, const char *args)
255 const char *simple_pattern;
266 * Determine from our context into which record to put the entry.
267 * cmd->path == NULL means we're in server-wide context; otherwise,
268 * we're dealing with a per-directory setting.
270 sconf = (cmd->path != NULL)
271 ? (sei_cfg_rec *) mconfig
272 : (sei_cfg_rec *) ap_get_module_config(cmd->server->module_config,
274 entries = (sei_entry *) sconf->conditionals->elts;
276 regex = ap_getword_conf(cmd->pool, &args);
278 return apr_pstrcat(cmd->pool, "Missing regular expression for ",
279 cmd->cmd->name, NULL);
283 * If we've already got a sei_entry with the same name we want to
284 * just copy the name pointer... so that later on we can compare
285 * two header names just by comparing the pointers.
287 for (i = 0; i < sconf->conditionals->nelts; ++i) {
289 if (!strcasecmp(new->name, fname)) {
295 /* if the last entry has an identical headername and regex then
298 i = sconf->conditionals->nelts - 1;
299 icase = cmd->info == ICASE_MAGIC;
301 || entries[i].name != fname
302 || entries[i].icase != icase
303 || strcmp(entries[i].regex, regex)) {
305 /* no match, create a new entry */
306 new = apr_array_push(sconf->conditionals);
310 if ((simple_pattern = non_regex_pattern(cmd->pool, regex))) {
311 new->pattern = apr_strmatch_precompile(cmd->pool,
312 simple_pattern, !icase);
313 if (new->pattern == NULL) {
314 return apr_pstrcat(cmd->pool, cmd->cmd->name,
315 " pattern could not be compiled.", NULL);
320 new->preg = ap_pregcomp(cmd->pool, regex,
321 (REG_EXTENDED | (icase ? REG_ICASE : 0)));
322 if (new->preg == NULL) {
323 return apr_pstrcat(cmd->pool, cmd->cmd->name,
324 " regex could not be compiled.", NULL);
328 new->features = apr_table_make(cmd->pool, 2);
330 if (!strcasecmp(fname, "remote_addr")) {
331 new->special_type = SPECIAL_REMOTE_ADDR;
333 else if (!strcasecmp(fname, "remote_host")) {
334 new->special_type = SPECIAL_REMOTE_HOST;
336 else if (!strcasecmp(fname, "request_uri")) {
337 new->special_type = SPECIAL_REQUEST_URI;
339 else if (!strcasecmp(fname, "request_method")) {
340 new->special_type = SPECIAL_REQUEST_METHOD;
342 else if (!strcasecmp(fname, "request_protocol")) {
343 new->special_type = SPECIAL_REQUEST_PROTOCOL;
345 else if (!strcasecmp(fname, "server_addr")) {
346 new->special_type = SPECIAL_SERVER_ADDR;
349 new->special_type = SPECIAL_NOT;
350 /* Handle fname as a regular expression.
351 * If fname a simple header string, identify as such
352 * (new->pnamereg = NULL) to avoid the overhead of searching
353 * through headers_in for a regex match.
355 if (is_header_regex(cmd->pool, fname)) {
356 new->pnamereg = ap_pregcomp(cmd->pool, fname,
357 (REG_EXTENDED | REG_NOSUB
358 | (icase ? REG_ICASE : 0)));
359 if (new->pnamereg == NULL)
360 return apr_pstrcat(cmd->pool, cmd->cmd->name,
361 "Header name regex could not be "
365 new->pnamereg = NULL;
374 feature = ap_getword_conf(cmd->pool, &args);
380 var = ap_getword(cmd->pool, &feature, '=');
382 apr_table_setn(new->features, var, feature);
384 else if (*var == '!') {
385 apr_table_setn(new->features, var + 1, "!");
388 apr_table_setn(new->features, var, "1");
393 return apr_pstrcat(cmd->pool, "Missing envariable expression for ",
394 cmd->cmd->name, NULL);
400 static const char *add_setenvif(cmd_parms *cmd, void *mconfig,
405 /* get header name */
406 fname = ap_getword_conf(cmd->pool, &args);
408 return apr_pstrcat(cmd->pool, "Missing header-field name for ",
409 cmd->cmd->name, NULL);
411 return add_setenvif_core(cmd, mconfig, fname, args);
415 * This routine handles the BrowserMatch* directives. It simply turns around
416 * and feeds them, with the appropriate embellishments, to the general-purpose
419 static const char *add_browser(cmd_parms *cmd, void *mconfig, const char *args)
421 return add_setenvif_core(cmd, mconfig, "User-Agent", args);
424 static const command_rec setenvif_module_cmds[] =
426 AP_INIT_RAW_ARGS("SetEnvIf", add_setenvif, NULL, OR_FILEINFO,
427 "A header-name, regex and a list of variables."),
428 AP_INIT_RAW_ARGS("SetEnvIfNoCase", add_setenvif, ICASE_MAGIC, OR_FILEINFO,
429 "a header-name, regex and a list of variables."),
430 AP_INIT_RAW_ARGS("BrowserMatch", add_browser, NULL, OR_FILEINFO,
431 "A browser regex and a list of variables."),
432 AP_INIT_RAW_ARGS("BrowserMatchNoCase", add_browser, ICASE_MAGIC,
434 "A browser regex and a list of variables."),
439 * This routine gets called at two different points in request processing:
440 * once before the URI has been translated (during the post-read-request
441 * phase) and once after (during the header-parse phase). We use different
442 * config records for the two different calls to reduce overhead (by not
443 * re-doing the server-wide settings during directory processing), and
444 * signal which call it is by having the earlier one pass a flag to the
447 static int match_headers(request_rec *r)
451 const apr_table_entry_t *elts;
453 apr_size_t val_len = 0;
456 regmatch_t regm[AP_MAX_REG_MATCH];
458 if (!ap_get_module_config(r->request_config, &setenvif_module)) {
459 ap_set_module_config(r->request_config, &setenvif_module,
461 sconf = (sei_cfg_rec *) ap_get_module_config(r->server->module_config,
465 sconf = (sei_cfg_rec *) ap_get_module_config(r->per_dir_config,
468 entries = (sei_entry *) sconf->conditionals->elts;
471 for (i = 0; i < sconf->conditionals->nelts; ++i) {
472 sei_entry *b = &entries[i];
474 /* Optimize the case where a bunch of directives in a row use the
475 * same header. Remember we don't need to strcmp the two header
476 * names because we made sure the pointers were equal during
479 if (b->name != last_name) {
481 switch (b->special_type) {
482 case SPECIAL_REMOTE_ADDR:
483 val = r->connection->remote_ip;
485 case SPECIAL_SERVER_ADDR:
486 val = r->connection->local_ip;
488 case SPECIAL_REMOTE_HOST:
489 val = ap_get_remote_host(r->connection, r->per_dir_config,
492 case SPECIAL_REQUEST_URI:
495 case SPECIAL_REQUEST_METHOD:
498 case SPECIAL_REQUEST_PROTOCOL:
503 /* Matching headers_in against a regex. Iterate through
504 * the headers_in until we find a match or run out of
507 const apr_array_header_t
508 *arr = apr_table_elts(r->headers_in);
510 elts = (const apr_table_entry_t *) arr->elts;
512 for (j = 0; j < arr->nelts; ++j) {
513 if (!ap_regexec(b->pnamereg, elts[j].key, 0, NULL, 0)) {
519 /* Not matching against a regex */
520 val = apr_table_get(r->headers_in, b->name);
522 val = apr_table_get(r->subprocess_env, b->name);
526 val_len = val ? strlen(val) : 0;
530 * A NULL value indicates that the header field or special entity
531 * wasn't present or is undefined. Represent that as an empty string
532 * so that REs like "^$" will work and allow envariable setting
533 * based on missing or empty field.
540 if ((b->pattern && apr_strmatch(b->pattern, val, val_len)) ||
541 (!b->pattern && !ap_regexec(b->preg, val, AP_MAX_REG_MATCH, regm,
543 const apr_array_header_t *arr = apr_table_elts(b->features);
544 elts = (const apr_table_entry_t *) arr->elts;
546 for (j = 0; j < arr->nelts; ++j) {
547 if (*(elts[j].val) == '!') {
548 apr_table_unset(r->subprocess_env, elts[j].key);
552 char *replaced = ap_pregsub(r->pool, elts[j].val, val,
553 AP_MAX_REG_MATCH, regm);
555 apr_table_setn(r->subprocess_env, elts[j].key,
560 apr_table_setn(r->subprocess_env, elts[j].key,
571 static void register_hooks(apr_pool_t *p)
573 ap_hook_header_parser(match_headers, NULL, NULL, APR_HOOK_MIDDLE);
574 ap_hook_post_read_request(match_headers, NULL, NULL, APR_HOOK_MIDDLE);
577 module AP_MODULE_DECLARE_DATA setenvif_module =
579 STANDARD20_MODULE_STUFF,
580 create_setenvif_config_dir, /* dir config creater */
581 merge_setenvif_config, /* dir merger --- default is to override */
582 create_setenvif_config_svr, /* server config */
583 merge_setenvif_config, /* merge server configs */
584 setenvif_module_cmds, /* command apr_table_t */
585 register_hooks /* register hooks */