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Diffstat (limited to '')
| -rw-r--r-- | modules/metadata/mod_headers.c | 1020 |
1 files changed, 1020 insertions, 0 deletions
diff --git a/modules/metadata/mod_headers.c b/modules/metadata/mod_headers.c new file mode 100644 index 0000000..1ea970d --- /dev/null +++ b/modules/metadata/mod_headers.c @@ -0,0 +1,1020 @@ +/* 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_headers.c: Add/append/remove HTTP response headers + * Written by Paul Sutton, paul@ukweb.com, 1 Oct 1996 + * + * The Header directive can be used to add/replace/remove HTTP headers + * within the response message. The RequestHeader directive can be used + * to add/replace/remove HTTP headers before a request message is processed. + * Valid in both per-server and per-dir configurations. + * + * Syntax is: + * + * Header action header value + * RequestHeader action header value + * + * Where action is one of: + * set - set this header, replacing any old value + * add - add this header, possible resulting in two or more + * headers with the same name + * append - append this text onto any existing header of this same + * merge - merge this text onto any existing header of this same, + * avoiding duplicate values + * unset - remove this header + * edit - transform the header value according to a regexp + * + * Where action is unset, the third argument (value) should not be given. + * The header name can include the colon, or not. + * + * The Header and RequestHeader directives can only be used where allowed + * by the FileInfo override. + * + * When the request is processed, the header directives are processed in + * this order: firstly, the main server, then the virtual server handling + * this request (if any), then any <Directory> sections (working downwards + * from the root dir), then an <Location> sections (working down from + * shortest URL component), the any <File> sections. This order is + * important if any 'set' or 'unset' actions are used. For example, + * the following two directives have different effect if applied in + * the reverse order: + * + * Header append Author "John P. Doe" + * Header unset Author + * + * Examples: + * + * To set the "Author" header, use + * Header add Author "John P. Doe" + * + * To remove a header: + * Header unset Author + * + */ + +#include "apr.h" +#include "apr_lib.h" +#include "apr_strings.h" +#include "apr_buckets.h" + +#include "apr_hash.h" +#define APR_WANT_STRFUNC +#include "apr_want.h" + +#include "httpd.h" +#include "http_config.h" +#include "http_request.h" +#include "http_log.h" +#include "util_filter.h" +#include "http_protocol.h" +#include "ap_expr.h" + +#include "mod_ssl.h" /* for the ssl_var_lookup optional function defn */ + +/* format_tag_hash is initialized during pre-config */ +static apr_hash_t *format_tag_hash; + +typedef enum { + hdr_add = 'a', /* add header (could mean multiple hdrs) */ + hdr_set = 's', /* set (replace old value) */ + hdr_append = 'm', /* append (merge into any old value) */ + hdr_merge = 'g', /* merge (merge, but avoid duplicates) */ + hdr_unset = 'u', /* unset header */ + hdr_echo = 'e', /* echo headers from request to response */ + hdr_edit = 'r', /* change value by regexp, match once */ + hdr_edit_r = 'R', /* change value by regexp, everymatch */ + hdr_setifempty = 'i', /* set value if header not already present*/ + hdr_note = 'n' /* set value of header in a note */ +} hdr_actions; + +/* + * magic cmd->info values + */ +static char hdr_in = '0'; /* RequestHeader */ +static char hdr_out_onsuccess = '1'; /* Header onsuccess */ +static char hdr_out_always = '2'; /* Header always */ + +/* Callback function type. */ +typedef const char *format_tag_fn(request_rec *r, char *a); + +/* + * There is an array of struct format_tag per Header/RequestHeader + * config directive + */ +typedef struct { + format_tag_fn *func; + char *arg; +} format_tag; + +/* 'Magic' condition_var value to run action in post_read_request */ +static const char* condition_early = "early"; +/* + * There is one "header_entry" per Header/RequestHeader config directive + */ +typedef struct { + hdr_actions action; + const char *header; + apr_array_header_t *ta; /* Array of format_tag structs */ + ap_regex_t *regex; + const char *condition_var; + const char *subs; + ap_expr_info_t *expr; + ap_expr_info_t *expr_out; +} header_entry; + +/* echo_do is used for Header echo to iterate through the request headers*/ +typedef struct { + request_rec *r; + header_entry *hdr; +} echo_do; + +/* edit_do is used for Header edit to iterate through the request headers */ +typedef struct { + request_rec *r; + header_entry *hdr; + apr_table_t *t; +} edit_do; + +/* + * headers_conf is our per-module configuration. This is used as both + * a per-dir and per-server config + */ +typedef struct { + apr_array_header_t *fixup_in; + apr_array_header_t *fixup_out; + apr_array_header_t *fixup_err; +} headers_conf; + +module AP_MODULE_DECLARE_DATA headers_module; + +/* Pointer to ssl_var_lookup, if available. */ +static APR_OPTIONAL_FN_TYPE(ssl_var_lookup) *header_ssl_lookup = NULL; + +/* + * Tag formatting functions + */ +static const char *constant_item(request_rec *r, char *stuff) +{ + return stuff; +} +static const char *header_request_duration(request_rec *r, char *a) +{ + return apr_psprintf(r->pool, "D=%" APR_TIME_T_FMT, + (apr_time_now() - r->request_time)); +} +static const char *header_request_time(request_rec *r, char *a) +{ + return apr_psprintf(r->pool, "t=%" APR_TIME_T_FMT, r->request_time); +} + +/* unwrap_header returns HDR with any newlines converted into + * whitespace if necessary. */ +static const char *unwrap_header(apr_pool_t *p, const char *hdr) +{ + if (ap_strchr_c(hdr, APR_ASCII_LF) || ap_strchr_c(hdr, APR_ASCII_CR)) { + char *ptr; + + hdr = ptr = apr_pstrdup(p, hdr); + + do { + if (*ptr == APR_ASCII_LF || *ptr == APR_ASCII_CR) + *ptr = APR_ASCII_BLANK; + } while (*ptr++); + } + return hdr; +} + +static const char *header_request_env_var(request_rec *r, char *a) +{ + const char *s = apr_table_get(r->subprocess_env,a); + + if (s) + return unwrap_header(r->pool, s); + else + return "(null)"; +} + +static const char *header_request_ssl_var(request_rec *r, char *name) +{ + if (header_ssl_lookup) { + const char *val = header_ssl_lookup(r->pool, r->server, + r->connection, r, name); + if (val && val[0]) + return unwrap_header(r->pool, val); + else + return "(null)"; + } + else { + return "(null)"; + } +} + +static const char *header_request_loadavg(request_rec *r, char *a) +{ + ap_loadavg_t t; + ap_get_loadavg(&t); + return apr_psprintf(r->pool, "l=%.2f/%.2f/%.2f", t.loadavg, + t.loadavg5, t.loadavg15); +} + +static const char *header_request_idle(request_rec *r, char *a) +{ + ap_sload_t t; + ap_get_sload(&t); + return apr_psprintf(r->pool, "i=%d", t.idle); +} + +static const char *header_request_busy(request_rec *r, char *a) +{ + ap_sload_t t; + ap_get_sload(&t); + return apr_psprintf(r->pool, "b=%d", t.busy); +} + +/* + * Config routines + */ + +static void *create_headers_dir_config(apr_pool_t *p, char *d) +{ + headers_conf *conf = apr_pcalloc(p, sizeof(*conf)); + + conf->fixup_in = apr_array_make(p, 2, sizeof(header_entry)); + conf->fixup_out = apr_array_make(p, 2, sizeof(header_entry)); + conf->fixup_err = apr_array_make(p, 2, sizeof(header_entry)); + + return conf; +} + +static void *merge_headers_config(apr_pool_t *p, void *basev, void *overridesv) +{ + headers_conf *newconf = apr_pcalloc(p, sizeof(*newconf)); + headers_conf *base = basev; + headers_conf *overrides = overridesv; + + newconf->fixup_in = apr_array_append(p, base->fixup_in, + overrides->fixup_in); + newconf->fixup_out = apr_array_append(p, base->fixup_out, + overrides->fixup_out); + newconf->fixup_err = apr_array_append(p, base->fixup_err, + overrides->fixup_err); + + return newconf; +} + +static char *parse_misc_string(apr_pool_t *p, format_tag *tag, const char **sa) +{ + const char *s; + char *d; + + tag->func = constant_item; + + s = *sa; + while (*s && *s != '%') { + s++; + } + /* + * This might allocate a few chars extra if there's a backslash + * escape in the format string. + */ + tag->arg = apr_palloc(p, s - *sa + 1); + + d = tag->arg; + s = *sa; + while (*s && *s != '%') { + if (*s != '\\') { + *d++ = *s++; + } + else { + s++; + switch (*s) { + case '\\': + *d++ = '\\'; + s++; + break; + case 'r': + *d++ = '\r'; + s++; + break; + case 'n': + *d++ = '\n'; + s++; + break; + case 't': + *d++ = '\t'; + s++; + break; + default: + /* copy verbatim */ + *d++ = '\\'; + /* + * Allow the loop to deal with this *s in the normal + * fashion so that it handles end of string etc. + * properly. + */ + break; + } + } + } + *d = '\0'; + + *sa = s; + return NULL; +} + +static char *parse_format_tag(apr_pool_t *p, format_tag *tag, const char **sa) +{ + const char *s = *sa; + const char * (*tag_handler)(request_rec *,char *); + + /* Handle string literal/conditionals */ + if (*s != '%') { + return parse_misc_string(p, tag, sa); + } + s++; /* skip the % */ + + /* Pass through %% or % at end of string as % */ + if ((*s == '%') || (*s == '\0')) { + tag->func = constant_item; + tag->arg = "%"; + if (*s) + s++; + *sa = s; + return NULL; + } + + tag->arg = "\0"; + /* grab the argument if there is one */ + if (*s == '{') { + ++s; + tag->arg = ap_getword(p,&s,'}'); + } + + tag_handler = (const char * (*)(request_rec *,char *))apr_hash_get(format_tag_hash, s++, 1); + + if (!tag_handler) { + char dummy[2]; + dummy[0] = s[-1]; + dummy[1] = '\0'; + return apr_pstrcat(p, "Unrecognized header format %", dummy, NULL); + } + tag->func = tag_handler; + + *sa = s; + return NULL; +} + +/* + * A format string consists of white space, text and optional format + * tags in any order. E.g., + * + * Header add MyHeader "Free form text %D %t more text" + * + * Decompose the format string into its tags. Each tag (struct format_tag) + * contains a pointer to the function used to format the tag. Then save each + * tag in the tag array anchored in the header_entry. + */ +static char *parse_format_string(cmd_parms *cmd, header_entry *hdr, const char *s) +{ + apr_pool_t *p = cmd->pool; + char *res; + + /* No string to parse with unset and echo commands */ + if (hdr->action == hdr_unset || hdr->action == hdr_echo) { + return NULL; + } + /* Tags are in the replacement value for edit */ + else if (hdr->action == hdr_edit || hdr->action == hdr_edit_r ) { + s = hdr->subs; + } + + if (!strncmp(s, "expr=", 5)) { + const char *err; + hdr->expr_out = ap_expr_parse_cmd(cmd, s+5, + AP_EXPR_FLAG_STRING_RESULT, + &err, NULL); + if (err) { + return apr_pstrcat(cmd->pool, + "Can't parse value expression : ", err, NULL); + } + return NULL; + } + + hdr->ta = apr_array_make(p, 10, sizeof(format_tag)); + + while (*s) { + if ((res = parse_format_tag(p, (format_tag *) apr_array_push(hdr->ta), &s))) { + return res; + } + } + return NULL; +} + +/* handle RequestHeader and Header directive */ +static APR_INLINE const char *header_inout_cmd(cmd_parms *cmd, + void *indirconf, + const char *action, + const char *hdr, + const char *value, + const char *subs, + const char *envclause) +{ + headers_conf *dirconf = indirconf; + const char *condition_var = NULL; + const char *colon; + header_entry *new; + ap_expr_info_t *expr = NULL; + + apr_array_header_t *fixup = (cmd->info == &hdr_in) + ? dirconf->fixup_in : (cmd->info == &hdr_out_always) + ? dirconf->fixup_err + : dirconf->fixup_out; + + new = (header_entry *) apr_array_push(fixup); + + if (!strcasecmp(action, "set")) + new->action = hdr_set; + else if (!strcasecmp(action, "setifempty")) + new->action = hdr_setifempty; + else if (!strcasecmp(action, "add")) + new->action = hdr_add; + else if (!strcasecmp(action, "append")) + new->action = hdr_append; + else if (!strcasecmp(action, "merge")) + new->action = hdr_merge; + else if (!strcasecmp(action, "unset")) + new->action = hdr_unset; + else if (!strcasecmp(action, "echo")) + new->action = hdr_echo; + else if (!strcasecmp(action, "edit")) + new->action = hdr_edit; + else if (!strcasecmp(action, "edit*")) + new->action = hdr_edit_r; + else if (!strcasecmp(action, "note")) + new->action = hdr_note; + else + return "first argument must be 'add', 'set', 'setifempty', 'append', 'merge', " + "'unset', 'echo', 'note', 'edit', or 'edit*'."; + + if (new->action == hdr_edit || new->action == hdr_edit_r) { + if (subs == NULL) { + return "Header edit requires a match and a substitution"; + } + new->regex = ap_pregcomp(cmd->pool, value, AP_REG_EXTENDED); + if (new->regex == NULL) { + return "Header edit regex could not be compiled"; + } + new->subs = subs; + } + else { + /* there's no subs, so envclause is really that argument */ + if (envclause != NULL) { + return "Too many arguments to directive"; + } + envclause = subs; + } + if (new->action == hdr_unset) { + if (value) { + if (envclause) { + return "header unset takes two arguments"; + } + envclause = value; + value = NULL; + } + } + else if (new->action == hdr_echo) { + ap_regex_t *regex; + + if (value) { + if (envclause) { + return "Header echo takes two arguments"; + } + envclause = value; + value = NULL; + } + if (cmd->info != &hdr_out_onsuccess && cmd->info != &hdr_out_always) + return "Header echo only valid on Header " + "directives"; + else { + regex = ap_pregcomp(cmd->pool, hdr, AP_REG_EXTENDED | AP_REG_NOSUB); + if (regex == NULL) { + return "Header echo regex could not be compiled"; + } + } + new->regex = regex; + } + else if (!value) + return "Header requires three arguments"; + + /* Handle the envclause on Header */ + if (envclause != NULL) { + if (strcasecmp(envclause, "early") == 0) { + condition_var = condition_early; + } + else if (strncasecmp(envclause, "env=", 4) == 0) { + if ((envclause[4] == '\0') + || ((envclause[4] == '!') && (envclause[5] == '\0'))) { + return "error: missing environment variable name. " + "envclause should be in the form env=envar "; + } + condition_var = envclause + 4; + } + else if (strncasecmp(envclause, "expr=", 5) == 0) { + const char *err = NULL; + expr = ap_expr_parse_cmd(cmd, envclause + 5, 0, &err, NULL); + if (err) { + return apr_pstrcat(cmd->pool, + "Can't parse envclause/expression: ", err, + NULL); + } + } + else { + return apr_pstrcat(cmd->pool, "Unknown parameter: ", envclause, + NULL); + } + } + + if ((colon = ap_strchr_c(hdr, ':'))) { + hdr = apr_pstrmemdup(cmd->pool, hdr, colon-hdr); + } + + new->header = hdr; + new->condition_var = condition_var; + new->expr = expr; + + return parse_format_string(cmd, new, value); +} + +/* Handle all (xxx)Header directives */ +static const char *header_cmd(cmd_parms *cmd, void *indirconf, + const char *args) +{ + const char *action; + const char *hdr; + const char *val; + const char *envclause; + const char *subs; + + action = ap_getword_conf(cmd->temp_pool, &args); + if (cmd->info == &hdr_out_onsuccess) { + if (!strcasecmp(action, "always")) { + cmd->info = &hdr_out_always; + action = ap_getword_conf(cmd->temp_pool, &args); + } + else if (!strcasecmp(action, "onsuccess")) { + action = ap_getword_conf(cmd->temp_pool, &args); + } + } + hdr = ap_getword_conf(cmd->pool, &args); + val = *args ? ap_getword_conf(cmd->pool, &args) : NULL; + subs = *args ? ap_getword_conf(cmd->pool, &args) : NULL; + envclause = *args ? ap_getword_conf(cmd->pool, &args) : NULL; + + if (*args) { + return apr_pstrcat(cmd->pool, cmd->cmd->name, + " has too many arguments", NULL); + } + + return header_inout_cmd(cmd, indirconf, action, hdr, val, subs, envclause); +} + +/* + * Process the tags in the format string. Tags may be format specifiers + * (%D, %t, etc.), whitespace or text strings. For each tag, run the handler + * (formatter) specific to the tag. Handlers return text strings. + * Concatenate the return from each handler into one string that is + * returned from this call. + * If the original value was prefixed with "expr=", processing is + * handled instead by ap_expr. + */ +static char* process_tags(header_entry *hdr, request_rec *r) +{ + int i; + const char *s; + char *str = NULL; + format_tag *tag = NULL; + + if (hdr->expr_out) { + const char *err; + const char *val; + val = ap_expr_str_exec(r, hdr->expr_out, &err); + if (err) { + ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(02557) + "Can't evaluate value expression: %s", err); + return ""; + } + return apr_pstrdup(r->pool, val); + } + + tag = (format_tag*) hdr->ta->elts; + + for (i = 0; i < hdr->ta->nelts; i++) { + s = tag[i].func(r, tag[i].arg); + if (str == NULL) + str = apr_pstrdup(r->pool, s); + else + str = apr_pstrcat(r->pool, str, s, NULL); + } + return str ? str : ""; +} +static const char *process_regexp(header_entry *hdr, const char *value, + request_rec *r) +{ + ap_regmatch_t pmatch[AP_MAX_REG_MATCH]; + const char *subs; + const char *remainder; + char *ret; + int diffsz; + if (ap_regexec(hdr->regex, value, AP_MAX_REG_MATCH, pmatch, 0)) { + /* no match, nothing to do */ + return value; + } + /* Process tags in the input string rather than the resulting + * substitution to avoid surprises + */ + subs = ap_pregsub(r->pool, process_tags(hdr, r), value, AP_MAX_REG_MATCH, pmatch); + if (subs == NULL) + return NULL; + diffsz = strlen(subs) - (pmatch[0].rm_eo - pmatch[0].rm_so); + if (hdr->action == hdr_edit) { + remainder = value + pmatch[0].rm_eo; + } + else { /* recurse to edit multiple matches if applicable */ + remainder = process_regexp(hdr, value + pmatch[0].rm_eo, r); + if (remainder == NULL) + return NULL; + diffsz += strlen(remainder) - strlen(value + pmatch[0].rm_eo); + } + ret = apr_palloc(r->pool, strlen(value) + 1 + diffsz); + memcpy(ret, value, pmatch[0].rm_so); + strcpy(ret + pmatch[0].rm_so, subs); + strcat(ret, remainder); + return ret; +} + +static int echo_header(void *v, const char *key, const char *val) +{ + edit_do *ed = v; + + /* If the input header (key) matches the regex, echo it intact to + * r->headers_out. + */ + if (!ap_regexec(ed->hdr->regex, key, 0, NULL, 0)) { + apr_table_add(ed->r->headers_out, key, val); + } + + return 1; +} + +static int edit_header(void *v, const char *key, const char *val) +{ + edit_do *ed = (edit_do *)v; + const char *repl = process_regexp(ed->hdr, val, ed->r); + if (repl == NULL) + return 0; + + apr_table_addn(ed->t, key, repl); + return 1; +} + +static int add_them_all(void *v, const char *key, const char *val) +{ + apr_table_t *headers = (apr_table_t *)v; + + apr_table_addn(headers, key, val); + return 1; +} + +static int do_headers_fixup(request_rec *r, apr_table_t *headers, + apr_array_header_t *fixup, int early) +{ + echo_do v; + int i; + const char *val; + + for (i = 0; i < fixup->nelts; ++i) { + header_entry *hdr = &((header_entry *) (fixup->elts))[i]; + const char *envar = hdr->condition_var; + + /* ignore early headers in late calls */ + if (!early && (envar == condition_early)) { + continue; + } + /* ignore late headers in early calls */ + else if (early && (envar != condition_early)) { + continue; + } + /* Do we have an expression to evaluate? */ + else if (hdr->expr != NULL) { + const char *err = NULL; + int eval = ap_expr_exec(r, hdr->expr, &err); + if (err) { + ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01501) + "Failed to evaluate expression (%s) - ignoring", + err); + } + else if (!eval) { + continue; + } + } + /* Have any conditional envar-controlled Header processing to do? */ + else if (envar && !early) { + if (*envar != '!') { + if (apr_table_get(r->subprocess_env, envar) == NULL) + continue; + } + else { + if (apr_table_get(r->subprocess_env, &envar[1]) != NULL) + continue; + } + } + + switch (hdr->action) { + case hdr_add: + apr_table_addn(headers, hdr->header, process_tags(hdr, r)); + break; + case hdr_append: + apr_table_mergen(headers, hdr->header, process_tags(hdr, r)); + break; + case hdr_merge: + val = apr_table_get(headers, hdr->header); + if (val == NULL) { + apr_table_addn(headers, hdr->header, process_tags(hdr, r)); + } else { + char *new_val = process_tags(hdr, r); + apr_size_t new_val_len = strlen(new_val); + int tok_found = 0; + + /* modified version of logic in ap_get_token() */ + while (*val) { + const char *tok_start; + + while (apr_isspace(*val)) + ++val; + + tok_start = val; + + while (*val && *val != ',') { + if (*val++ == '"') + while (*val) + if (*val++ == '"') + break; + } + + if (new_val_len == (apr_size_t)(val - tok_start) + && !strncmp(tok_start, new_val, new_val_len)) { + tok_found = 1; + break; + } + + if (*val) + ++val; + } + + if (!tok_found) { + apr_table_mergen(headers, hdr->header, new_val); + } + } + break; + case hdr_set: + if (!strcasecmp(hdr->header, "Content-Type")) { + ap_set_content_type(r, process_tags(hdr, r)); + } + apr_table_setn(headers, hdr->header, process_tags(hdr, r)); + break; + case hdr_setifempty: + if (NULL == apr_table_get(headers, hdr->header)) { + if (!strcasecmp(hdr->header, "Content-Type")) { + ap_set_content_type(r, process_tags(hdr, r)); + } + apr_table_setn(headers, hdr->header, process_tags(hdr, r)); + } + break; + case hdr_unset: + apr_table_unset(headers, hdr->header); + break; + case hdr_echo: + v.r = r; + v.hdr = hdr; + apr_table_do(echo_header, &v, r->headers_in, NULL); + break; + case hdr_edit: + case hdr_edit_r: + if (!strcasecmp(hdr->header, "Content-Type") && r->content_type) { + const char *repl = process_regexp(hdr, r->content_type, r); + if (repl == NULL) + return 0; + ap_set_content_type(r, repl); + } + if (apr_table_get(headers, hdr->header)) { + edit_do ed; + + ed.r = r; + ed.hdr = hdr; + ed.t = apr_table_make(r->pool, 5); + if (!apr_table_do(edit_header, (void *) &ed, headers, + hdr->header, NULL)) + return 0; + apr_table_unset(headers, hdr->header); + apr_table_do(add_them_all, (void *) headers, ed.t, NULL); + } + break; + case hdr_note: + apr_table_setn(r->notes, process_tags(hdr, r), apr_table_get(headers, hdr->header)); + break; + + } + } + return 1; +} + +static void ap_headers_insert_output_filter(request_rec *r) +{ + headers_conf *dirconf = ap_get_module_config(r->per_dir_config, + &headers_module); + + if (dirconf->fixup_out->nelts || dirconf->fixup_err->nelts) { + ap_add_output_filter("FIXUP_HEADERS_OUT", NULL, r, r->connection); + } +} + +/* + * Make sure our error-path filter is in place. + */ +static void ap_headers_insert_error_filter(request_rec *r) +{ + headers_conf *dirconf = ap_get_module_config(r->per_dir_config, + &headers_module); + + if (dirconf->fixup_err->nelts) { + ap_add_output_filter("FIXUP_HEADERS_ERR", NULL, r, r->connection); + } +} + +static apr_status_t ap_headers_output_filter(ap_filter_t *f, + apr_bucket_brigade *in) +{ + headers_conf *dirconf = ap_get_module_config(f->r->per_dir_config, + &headers_module); + + ap_log_error(APLOG_MARK, APLOG_TRACE2, 0, f->r->server, APLOGNO(01502) + "headers: ap_headers_output_filter()"); + + /* do the fixup */ + do_headers_fixup(f->r, f->r->err_headers_out, dirconf->fixup_err, 0); + do_headers_fixup(f->r, f->r->headers_out, dirconf->fixup_out, 0); + + /* remove ourselves from the filter chain */ + ap_remove_output_filter(f); + + /* send the data up the stack */ + return ap_pass_brigade(f->next,in); +} + +/* + * Make sure we propagate any "Header always" settings on the error + * path through http_protocol.c. + */ +static apr_status_t ap_headers_error_filter(ap_filter_t *f, + apr_bucket_brigade *in) +{ + headers_conf *dirconf; + + dirconf = ap_get_module_config(f->r->per_dir_config, + &headers_module); + ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, f->r->server, APLOGNO(01503) + "headers: ap_headers_error_filter()"); + + /* + * Add any header fields defined by "Header always" to r->err_headers_out. + * Server-wide first, then per-directory to allow overriding. + */ + do_headers_fixup(f->r, f->r->err_headers_out, dirconf->fixup_err, 0); + + /* + * We've done our bit; remove ourself from the filter chain so there's + * no possibility we'll be called again. + */ + ap_remove_output_filter(f); + + /* + * Pass the buck. (euro?) + */ + return ap_pass_brigade(f->next, in); +} + +static apr_status_t ap_headers_fixup(request_rec *r) +{ + headers_conf *dirconf = ap_get_module_config(r->per_dir_config, + &headers_module); + + /* do the fixup */ + if (dirconf->fixup_in->nelts) { + do_headers_fixup(r, r->headers_in, dirconf->fixup_in, 0); + } + + return DECLINED; +} +static apr_status_t ap_headers_early(request_rec *r) +{ + headers_conf *dirconf = ap_get_module_config(r->per_dir_config, + &headers_module); + + /* do the fixup */ + if (dirconf->fixup_in->nelts) { + if (!do_headers_fixup(r, r->headers_in, dirconf->fixup_in, 1)) + goto err; + } + if (dirconf->fixup_err->nelts) { + if (!do_headers_fixup(r, r->err_headers_out, dirconf->fixup_err, 1)) + goto err; + } + if (dirconf->fixup_out->nelts) { + if (!do_headers_fixup(r, r->headers_out, dirconf->fixup_out, 1)) + goto err; + } + + return DECLINED; +err: + ap_log_rerror(APLOG_MARK, APLOG_CRIT, 0, r, APLOGNO(01504) + "Regular expression replacement failed (replacement too long?)"); + return HTTP_INTERNAL_SERVER_ERROR; +} + +static const command_rec headers_cmds[] = +{ + AP_INIT_RAW_ARGS("Header", header_cmd, &hdr_out_onsuccess, OR_FILEINFO, + "an optional condition, an action, header and value " + "followed by optional env clause"), + AP_INIT_RAW_ARGS("RequestHeader", header_cmd, &hdr_in, OR_FILEINFO, + "an action, header and value followed by optional env " + "clause"), + {NULL} +}; + +static void register_format_tag_handler(const char *tag, + format_tag_fn *tag_handler) +{ + apr_hash_set(format_tag_hash, tag, 1, tag_handler); +} + +static int header_pre_config(apr_pool_t *p, apr_pool_t *plog, apr_pool_t *ptemp) +{ + format_tag_hash = apr_hash_make(p); + register_format_tag_handler("D", header_request_duration); + register_format_tag_handler("t", header_request_time); + register_format_tag_handler("e", header_request_env_var); + register_format_tag_handler("s", header_request_ssl_var); + register_format_tag_handler("l", header_request_loadavg); + register_format_tag_handler("i", header_request_idle); + register_format_tag_handler("b", header_request_busy); + + return OK; +} + +static int header_post_config(apr_pool_t *pconf, apr_pool_t *plog, + apr_pool_t *ptemp, server_rec *s) +{ + header_ssl_lookup = APR_RETRIEVE_OPTIONAL_FN(ssl_var_lookup); + return OK; +} + +static void register_hooks(apr_pool_t *p) +{ + ap_register_output_filter("FIXUP_HEADERS_OUT", ap_headers_output_filter, + NULL, AP_FTYPE_CONTENT_SET); + ap_register_output_filter("FIXUP_HEADERS_ERR", ap_headers_error_filter, + NULL, AP_FTYPE_CONTENT_SET); + ap_hook_pre_config(header_pre_config,NULL,NULL,APR_HOOK_MIDDLE); + ap_hook_post_config(header_post_config,NULL,NULL,APR_HOOK_MIDDLE); + ap_hook_insert_filter(ap_headers_insert_output_filter, NULL, NULL, APR_HOOK_LAST); + ap_hook_insert_error_filter(ap_headers_insert_error_filter, + NULL, NULL, APR_HOOK_LAST); + ap_hook_fixups(ap_headers_fixup, NULL, NULL, APR_HOOK_LAST); + ap_hook_post_read_request(ap_headers_early, NULL, NULL, APR_HOOK_FIRST); +} + +AP_DECLARE_MODULE(headers) = +{ + STANDARD20_MODULE_STUFF, + create_headers_dir_config, /* dir config creater */ + merge_headers_config, /* dir merger --- default is to override */ + NULL, /* server config */ + NULL, /* merge server configs */ + headers_cmds, /* command apr_table_t */ + register_hooks /* register hooks */ +}; |