| /* 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. |
| */ |
| |
| /* |
| * mod_setenvif.c |
| * Set environment variables based on matching request headers or |
| * attributes against regex strings |
| * |
| * Paul Sutton <paul@ukweb.com> 27 Oct 1996 |
| * Based on mod_browser by Alexei Kosut <akosut@organic.com> |
| */ |
| |
| /* |
| * Used to set environment variables based on the incoming request headers, |
| * or some selected other attributes of the request (e.g., the remote host |
| * name). |
| * |
| * Usage: |
| * |
| * SetEnvIf name regex var ... |
| * |
| * where name is either a HTTP request header name, or one of the |
| * special values (see below). 'name' may be a regex when it is used |
| * to specify an HTTP request header name. The 'value' of the header |
| & (or the value of the special value from below) are compared against |
| * the regex argument. If this is a simple string, a simple sub-string |
| * match is performed. Otherwise, a request expression match is |
| * done. If the value matches the string or regular expression, the |
| * environment variables listed as var ... are set. Each var can |
| * be in one of three formats: var, which sets the named variable |
| * (the value "1"); var=value, which sets the variable to |
| * the given value; or !var, which unsets the variable is it has |
| * been previously set. |
| * |
| * Normally the strings are compared with regard to case. To ignore |
| * case, use the directive SetEnvIfNoCase instead. |
| * |
| * Special values for 'name' are: |
| * |
| * server_addr IP address of interface on which request arrived |
| * (analogous to SERVER_ADDR set in ap_add_common_vars()) |
| * remote_host Remote host name (if available) |
| * remote_addr Remote IP address |
| * request_method Request method (GET, POST, etc) |
| * request_uri Requested URI |
| * |
| * Examples: |
| * |
| * To set the environment variable LOCALHOST if the client is the local |
| * machine: |
| * |
| * SetEnvIf remote_addr 127.0.0.1 LOCALHOST |
| * |
| * To set LOCAL if the client is the local host, or within our company's |
| * domain (192.168.10): |
| * |
| * SetEnvIf remote_addr 192.168.10. LOCAL |
| * SetEnvIf remote_addr 127.0.0.1 LOCALHOST |
| * |
| * This could be written as: |
| * |
| * SetEnvIf remote_addr (127.0.0.1|192.168.10.) LOCAL |
| * |
| * To set HAVE_TS if the client request contains any header beginning |
| * with "TS" with a value beginning with a lower case alphabet: |
| * |
| * SetEnvIf ^TS* ^[a-z].* HAVE_TS |
| */ |
| |
| #include "apr.h" |
| #include "apr_strings.h" |
| #include "apr_strmatch.h" |
| |
| #define APR_WANT_STRFUNC |
| #include "apr_want.h" |
| |
| #include "ap_config.h" |
| #include "httpd.h" |
| #include "http_config.h" |
| #include "http_core.h" |
| #include "http_log.h" |
| #include "http_protocol.h" |
| |
| enum special { |
| SPECIAL_NOT, |
| SPECIAL_REMOTE_ADDR, |
| SPECIAL_REMOTE_HOST, |
| SPECIAL_REQUEST_URI, |
| SPECIAL_REQUEST_METHOD, |
| SPECIAL_REQUEST_PROTOCOL, |
| SPECIAL_SERVER_ADDR |
| }; |
| typedef struct { |
| char *name; /* header name */ |
| ap_regex_t *pnamereg; /* compiled header name regex */ |
| char *regex; /* regex to match against */ |
| ap_regex_t *preg; /* compiled regex */ |
| const apr_strmatch_pattern *pattern; /* non-regex pattern to match */ |
| ap_expr_info_t *expr; /* parsed expression */ |
| apr_table_t *features; /* env vars to set (or unset) */ |
| enum special special_type; /* is it a "special" header ? */ |
| int icase; /* ignoring case? */ |
| } sei_entry; |
| |
| typedef struct { |
| apr_array_header_t *conditionals; |
| } sei_cfg_rec; |
| |
| module AP_MODULE_DECLARE_DATA setenvif_module; |
| |
| /* |
| * These routines, the create- and merge-config functions, are called |
| * for both the server-wide and the per-directory contexts. This is |
| * because the different definitions are used at different times; the |
| * server-wide ones are used in the post-read-request phase, and the |
| * per-directory ones are used during the header-parse phase (after |
| * the URI has been mapped to a file and we have anything from the |
| * .htaccess file and <Directory> and <Files> containers). |
| */ |
| static void *create_setenvif_config(apr_pool_t *p) |
| { |
| sei_cfg_rec *new = (sei_cfg_rec *) apr_palloc(p, sizeof(sei_cfg_rec)); |
| |
| new->conditionals = apr_array_make(p, 20, sizeof(sei_entry)); |
| return (void *) new; |
| } |
| |
| static void *create_setenvif_config_svr(apr_pool_t *p, server_rec *dummy) |
| { |
| return create_setenvif_config(p); |
| } |
| |
| static void *create_setenvif_config_dir(apr_pool_t *p, char *dummy) |
| { |
| return create_setenvif_config(p); |
| } |
| |
| static void *merge_setenvif_config(apr_pool_t *p, void *basev, void *overridesv) |
| { |
| sei_cfg_rec *a = apr_pcalloc(p, sizeof(sei_cfg_rec)); |
| sei_cfg_rec *base = basev, *overrides = overridesv; |
| |
| a->conditionals = apr_array_append(p, base->conditionals, |
| overrides->conditionals); |
| return a; |
| } |
| |
| /* |
| * any non-NULL magic constant will do... used to indicate if AP_REG_ICASE should |
| * be used |
| */ |
| #define ICASE_MAGIC ((void *)(&setenvif_module)) |
| #define SEI_MAGIC_HEIRLOOM "setenvif-phase-flag" |
| |
| static ap_regex_t *is_header_regex_regex; |
| |
| static int is_header_regex(apr_pool_t *p, const char* name) |
| { |
| /* If a Header name contains characters other than: |
| * -,_,[A-Z\, [a-z] and [0-9]. |
| * assume the header name is a regular expression. |
| */ |
| if (ap_regexec(is_header_regex_regex, name, 0, NULL, 0)) { |
| return 1; |
| } |
| |
| return 0; |
| } |
| |
| /* If the input string does not take advantage of regular |
| * expression metacharacters, return a pointer to an equivalent |
| * string that can be searched using apr_strmatch(). (The |
| * returned string will often be the input string. But if |
| * the input string contains escaped characters, the returned |
| * string will be a copy with the escapes removed.) |
| */ |
| static const char *non_regex_pattern(apr_pool_t *p, const char *s) |
| { |
| const char *src = s; |
| int escapes_found = 0; |
| int in_escape = 0; |
| |
| while (*src) { |
| switch (*src) { |
| case '^': |
| case '.': |
| case '$': |
| case '|': |
| case '(': |
| case ')': |
| case '[': |
| case ']': |
| case '*': |
| case '+': |
| case '?': |
| case '{': |
| case '}': |
| if (!in_escape) { |
| return NULL; |
| } |
| in_escape = 0; |
| break; |
| case '\\': |
| if (!in_escape) { |
| in_escape = 1; |
| escapes_found = 1; |
| } |
| else { |
| in_escape = 0; |
| } |
| break; |
| default: |
| if (in_escape) { |
| return NULL; |
| } |
| break; |
| } |
| src++; |
| } |
| if (!escapes_found) { |
| return s; |
| } |
| else { |
| char *unescaped = (char *)apr_palloc(p, src - s + 1); |
| char *dst = unescaped; |
| src = s; |
| do { |
| if (*src == '\\') { |
| src++; |
| } |
| } while ((*dst++ = *src++)); |
| return unescaped; |
| } |
| } |
| |
| static const char *add_envvars(cmd_parms *cmd, const char *args, sei_entry *new) |
| { |
| const char *feature; |
| int beenhere = 0; |
| char *var; |
| |
| for ( ; ; ) { |
| feature = ap_getword_conf(cmd->pool, &args); |
| if (!*feature) { |
| break; |
| } |
| beenhere++; |
| |
| var = ap_getword(cmd->pool, &feature, '='); |
| if (*feature) { |
| apr_table_setn(new->features, var, feature); |
| } |
| else if (*var == '!') { |
| apr_table_setn(new->features, var + 1, "!"); |
| } |
| else { |
| apr_table_setn(new->features, var, "1"); |
| } |
| } |
| |
| if (!beenhere) { |
| return apr_pstrcat(cmd->pool, "Missing envariable expression for ", |
| cmd->cmd->name, NULL); |
| } |
| |
| return NULL; |
| } |
| |
| static const char *add_setenvif_core(cmd_parms *cmd, void *mconfig, |
| char *fname, const char *args) |
| { |
| char *regex; |
| const char *simple_pattern; |
| sei_cfg_rec *sconf; |
| sei_entry *new; |
| sei_entry *entries; |
| int i; |
| int icase; |
| |
| /* |
| * Determine from our context into which record to put the entry. |
| * cmd->path == NULL means we're in server-wide context; otherwise, |
| * we're dealing with a per-directory setting. |
| */ |
| sconf = (cmd->path != NULL) |
| ? (sei_cfg_rec *) mconfig |
| : (sei_cfg_rec *) ap_get_module_config(cmd->server->module_config, |
| &setenvif_module); |
| entries = (sei_entry *) sconf->conditionals->elts; |
| /* get regex */ |
| regex = ap_getword_conf(cmd->pool, &args); |
| if (!*regex) { |
| return apr_pstrcat(cmd->pool, "Missing regular expression for ", |
| cmd->cmd->name, NULL); |
| } |
| |
| /* |
| * If we've already got a sei_entry with the same name we want to |
| * just copy the name pointer... so that later on we can compare |
| * two header names just by comparing the pointers. |
| */ |
| for (i = 0; i < sconf->conditionals->nelts; ++i) { |
| new = &entries[i]; |
| if (new->name && !strcasecmp(new->name, fname)) { |
| fname = new->name; |
| break; |
| } |
| } |
| |
| /* if the last entry has an identical headername and regex then |
| * merge with it |
| */ |
| i = sconf->conditionals->nelts - 1; |
| icase = cmd->info == ICASE_MAGIC; |
| if (i < 0 |
| || entries[i].name != fname |
| || entries[i].icase != icase |
| || strcmp(entries[i].regex, regex)) { |
| |
| /* no match, create a new entry */ |
| new = apr_array_push(sconf->conditionals); |
| new->name = fname; |
| new->regex = regex; |
| new->icase = icase; |
| if ((simple_pattern = non_regex_pattern(cmd->pool, regex))) { |
| new->pattern = apr_strmatch_precompile(cmd->pool, |
| simple_pattern, !icase); |
| if (new->pattern == NULL) { |
| return apr_pstrcat(cmd->pool, cmd->cmd->name, |
| " pattern could not be compiled.", NULL); |
| } |
| new->preg = NULL; |
| } |
| else { |
| new->preg = ap_pregcomp(cmd->pool, regex, |
| (AP_REG_EXTENDED | (icase ? AP_REG_ICASE : 0))); |
| if (new->preg == NULL) { |
| return apr_pstrcat(cmd->pool, cmd->cmd->name, |
| " regex could not be compiled.", NULL); |
| } |
| new->pattern = NULL; |
| } |
| new->features = apr_table_make(cmd->pool, 2); |
| |
| if (!strcasecmp(fname, "remote_addr")) { |
| new->special_type = SPECIAL_REMOTE_ADDR; |
| } |
| else if (!strcasecmp(fname, "remote_host")) { |
| new->special_type = SPECIAL_REMOTE_HOST; |
| } |
| else if (!strcasecmp(fname, "request_uri")) { |
| new->special_type = SPECIAL_REQUEST_URI; |
| } |
| else if (!strcasecmp(fname, "request_method")) { |
| new->special_type = SPECIAL_REQUEST_METHOD; |
| } |
| else if (!strcasecmp(fname, "request_protocol")) { |
| new->special_type = SPECIAL_REQUEST_PROTOCOL; |
| } |
| else if (!strcasecmp(fname, "server_addr")) { |
| new->special_type = SPECIAL_SERVER_ADDR; |
| } |
| else { |
| new->special_type = SPECIAL_NOT; |
| /* Handle fname as a regular expression. |
| * If fname a simple header string, identify as such |
| * (new->pnamereg = NULL) to avoid the overhead of searching |
| * through headers_in for a regex match. |
| */ |
| if (is_header_regex(cmd->temp_pool, fname)) { |
| new->pnamereg = ap_pregcomp(cmd->pool, fname, |
| (AP_REG_EXTENDED | AP_REG_NOSUB |
| | (icase ? AP_REG_ICASE : 0))); |
| if (new->pnamereg == NULL) |
| return apr_pstrcat(cmd->pool, cmd->cmd->name, |
| "Header name regex could not be " |
| "compiled.", NULL); |
| } |
| else { |
| new->pnamereg = NULL; |
| } |
| } |
| } |
| else { |
| new = &entries[i]; |
| } |
| |
| return add_envvars(cmd, args, new); |
| } |
| |
| static const char *add_setenvif(cmd_parms *cmd, void *mconfig, |
| const char *args) |
| { |
| char *fname; |
| |
| /* get header name */ |
| fname = ap_getword_conf(cmd->pool, &args); |
| if (!*fname) { |
| return apr_pstrcat(cmd->pool, "Missing header-field name for ", |
| cmd->cmd->name, NULL); |
| } |
| return add_setenvif_core(cmd, mconfig, fname, args); |
| } |
| |
| static const char *add_setenvifexpr(cmd_parms *cmd, void *mconfig, |
| const char *args) |
| { |
| char *expr; |
| sei_cfg_rec *sconf; |
| sei_entry *new; |
| const char *err; |
| |
| /* |
| * Determine from our context into which record to put the entry. |
| * cmd->path == NULL means we're in server-wide context; otherwise, |
| * we're dealing with a per-directory setting. |
| */ |
| sconf = (cmd->path != NULL) |
| ? (sei_cfg_rec *) mconfig |
| : (sei_cfg_rec *) ap_get_module_config(cmd->server->module_config, |
| &setenvif_module); |
| /* get expr */ |
| expr = ap_getword_conf(cmd->pool, &args); |
| if (!*expr) { |
| return apr_pstrcat(cmd->pool, "Missing expression for ", |
| cmd->cmd->name, NULL); |
| } |
| |
| new = apr_array_push(sconf->conditionals); |
| new->features = apr_table_make(cmd->pool, 2); |
| new->name = NULL; |
| new->regex = NULL; |
| new->pattern = NULL; |
| new->preg = NULL; |
| new->expr = ap_expr_parse_cmd(cmd, expr, 0, &err, NULL); |
| if (err) |
| return apr_psprintf(cmd->pool, "Could not parse expression \"%s\": %s", |
| expr, err); |
| |
| return add_envvars(cmd, args, new); |
| } |
| |
| /* |
| * This routine handles the BrowserMatch* directives. It simply turns around |
| * and feeds them, with the appropriate embellishments, to the general-purpose |
| * command handler. |
| */ |
| static const char *add_browser(cmd_parms *cmd, void *mconfig, const char *args) |
| { |
| return add_setenvif_core(cmd, mconfig, "User-Agent", args); |
| } |
| |
| static const command_rec setenvif_module_cmds[] = |
| { |
| AP_INIT_RAW_ARGS("SetEnvIf", add_setenvif, NULL, OR_FILEINFO, |
| "A header-name, regex and a list of variables."), |
| AP_INIT_RAW_ARGS("SetEnvIfNoCase", add_setenvif, ICASE_MAGIC, OR_FILEINFO, |
| "a header-name, regex and a list of variables."), |
| AP_INIT_RAW_ARGS("SetEnvIfExpr", add_setenvifexpr, NULL, OR_FILEINFO, |
| "an expression and a list of variables."), |
| AP_INIT_RAW_ARGS("BrowserMatch", add_browser, NULL, OR_FILEINFO, |
| "A browser regex and a list of variables."), |
| AP_INIT_RAW_ARGS("BrowserMatchNoCase", add_browser, ICASE_MAGIC, |
| OR_FILEINFO, |
| "A browser regex and a list of variables."), |
| { NULL }, |
| }; |
| |
| /* |
| * This routine gets called at two different points in request processing: |
| * once before the URI has been translated (during the post-read-request |
| * phase) and once after (during the header-parse phase). We use different |
| * config records for the two different calls to reduce overhead (by not |
| * re-doing the server-wide settings during directory processing), and |
| * signal which call it is by having the earlier one pass a flag to the |
| * later one. |
| */ |
| static int match_headers(request_rec *r) |
| { |
| sei_cfg_rec *sconf; |
| sei_entry *entries; |
| const apr_table_entry_t *elts; |
| const char *val, *err; |
| apr_size_t val_len = 0; |
| int i, j; |
| char *last_name; |
| ap_regmatch_t regm[AP_MAX_REG_MATCH]; |
| |
| if (!ap_get_module_config(r->request_config, &setenvif_module)) { |
| ap_set_module_config(r->request_config, &setenvif_module, |
| SEI_MAGIC_HEIRLOOM); |
| sconf = (sei_cfg_rec *) ap_get_module_config(r->server->module_config, |
| &setenvif_module); |
| } |
| else { |
| sconf = (sei_cfg_rec *) ap_get_module_config(r->per_dir_config, |
| &setenvif_module); |
| } |
| entries = (sei_entry *) sconf->conditionals->elts; |
| last_name = NULL; |
| val = NULL; |
| for (i = 0; i < sconf->conditionals->nelts; ++i) { |
| sei_entry *b = &entries[i]; |
| |
| if (!b->expr) { |
| /* Optimize the case where a bunch of directives in a row use the |
| * same header. Remember we don't need to strcmp the two header |
| * names because we made sure the pointers were equal during |
| * configuration. |
| */ |
| if (b->name != last_name) { |
| last_name = b->name; |
| switch (b->special_type) { |
| case SPECIAL_REMOTE_ADDR: |
| val = r->useragent_ip; |
| break; |
| case SPECIAL_SERVER_ADDR: |
| val = r->connection->local_ip; |
| break; |
| case SPECIAL_REMOTE_HOST: |
| val = ap_get_useragent_host(r, REMOTE_NAME, NULL); |
| break; |
| case SPECIAL_REQUEST_URI: |
| val = r->uri; |
| break; |
| case SPECIAL_REQUEST_METHOD: |
| val = r->method; |
| break; |
| case SPECIAL_REQUEST_PROTOCOL: |
| val = r->protocol; |
| break; |
| case SPECIAL_NOT: |
| if (b->pnamereg) { |
| /* Matching headers_in against a regex. Iterate through |
| * the headers_in until we find a match or run out of |
| * headers. |
| */ |
| const apr_array_header_t |
| *arr = apr_table_elts(r->headers_in); |
| |
| elts = (const apr_table_entry_t *) arr->elts; |
| val = NULL; |
| for (j = 0; j < arr->nelts; ++j) { |
| if (!ap_regexec(b->pnamereg, elts[j].key, 0, NULL, 0)) { |
| val = elts[j].val; |
| } |
| } |
| } |
| else { |
| /* Not matching against a regex */ |
| val = apr_table_get(r->headers_in, b->name); |
| if (val == NULL) { |
| val = apr_table_get(r->subprocess_env, b->name); |
| } |
| } |
| } |
| val_len = val ? strlen(val) : 0; |
| } |
| |
| } |
| |
| /* |
| * A NULL value indicates that the header field or special entity |
| * wasn't present or is undefined. Represent that as an empty string |
| * so that REs like "^$" will work and allow envariable setting |
| * based on missing or empty field. This is also necessary to make |
| * ap_pregsub work after evaluating an ap_expr_t which does set the |
| * regexp backref data. |
| */ |
| if (val == NULL) { |
| val = ""; |
| val_len = 0; |
| } |
| |
| if ((b->pattern && apr_strmatch(b->pattern, val, val_len)) || |
| (b->preg && !ap_regexec(b->preg, val, AP_MAX_REG_MATCH, regm, 0)) || |
| (b->expr && ap_expr_exec_re(r, b->expr, AP_MAX_REG_MATCH, regm, &val, &err) > 0)) |
| { |
| const apr_array_header_t *arr = apr_table_elts(b->features); |
| elts = (const apr_table_entry_t *) arr->elts; |
| |
| for (j = 0; j < arr->nelts; ++j) { |
| if (*(elts[j].val) == '!') { |
| apr_table_unset(r->subprocess_env, elts[j].key); |
| } |
| else { |
| if (!b->pattern) { |
| char *replaced = ap_pregsub(r->pool, elts[j].val, val, |
| AP_MAX_REG_MATCH, regm); |
| if (replaced) { |
| apr_table_setn(r->subprocess_env, elts[j].key, |
| replaced); |
| } |
| else { |
| ap_log_rerror(APLOG_MARK, APLOG_CRIT, 0, r, APLOGNO(01505) |
| "Regular expression replacement " |
| "failed for '%s', value too long?", |
| elts[j].key); |
| return HTTP_INTERNAL_SERVER_ERROR; |
| } |
| } |
| else { |
| apr_table_setn(r->subprocess_env, elts[j].key, |
| elts[j].val); |
| } |
| } |
| ap_log_rerror(APLOG_MARK, APLOG_TRACE2, 0, r, "Setting %s", |
| elts[j].key); |
| } |
| } |
| } |
| |
| return DECLINED; |
| } |
| |
| static void register_hooks(apr_pool_t *p) |
| { |
| ap_hook_header_parser(match_headers, NULL, NULL, APR_HOOK_MIDDLE); |
| ap_hook_post_read_request(match_headers, NULL, NULL, APR_HOOK_MIDDLE); |
| |
| is_header_regex_regex = ap_pregcomp(p, "^[-A-Za-z0-9_]*$", |
| (AP_REG_EXTENDED | AP_REG_NOSUB )); |
| ap_assert(is_header_regex_regex != NULL); |
| } |
| |
| AP_DECLARE_MODULE(setenvif) = |
| { |
| STANDARD20_MODULE_STUFF, |
| create_setenvif_config_dir, /* dir config creater */ |
| merge_setenvif_config, /* dir merger --- default is to override */ |
| create_setenvif_config_svr, /* server config */ |
| merge_setenvif_config, /* merge server configs */ |
| setenvif_module_cmds, /* command apr_table_t */ |
| register_hooks /* register hooks */ |
| }; |
