#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;
ap_regex_t *pnamereg;
char *regex;
ap_regex_t *preg;
const apr_strmatch_pattern *pattern;
apr_table_t *features;
enum special special_type;
int icase;
} sei_entry;
typedef struct {
apr_array_header_t *conditionals;
} sei_cfg_rec;
module AP_MODULE_DECLARE_DATA setenvif_module;
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;
}
#define ICASE_MAGIC ((void *)(&setenvif_module))
#define SEI_MAGIC_HEIRLOOM "setenvif-phase-flag"
static int is_header_regex(apr_pool_t *p, const char* name)
{
ap_regex_t *preg = ap_pregcomp(p, "^[-A-Za-z0-9_]*$",
(AP_REG_EXTENDED | AP_REG_NOSUB ));
ap_assert(preg != NULL);
if (ap_regexec(preg, name, 0, NULL, 0)) {
return 1;
}
return 0;
}
static const char *non_regex_pattern(apr_pool_t *p, const char *s)
{
const char *src = s;
int escapes_found = 0;
int in_escape = 0;
while (*src) {
switch (*src) {
case '^':
case '.':
case '$':
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_setenvif_core(cmd_parms *cmd, void *mconfig,
char *fname, const char *args)
{
char *regex;
const char *simple_pattern;
const char *feature;
sei_cfg_rec *sconf;
sei_entry *new;
sei_entry *entries;
char *var;
int i;
int beenhere = 0;
int icase;
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;
regex = ap_getword_conf(cmd->pool, &args);
if (!*regex) {
return apr_pstrcat(cmd->pool, "Missing regular expression for ",
cmd->cmd->name, NULL);
}
for (i = 0; i < sconf->conditionals->nelts; ++i) {
new = &entries[i];
if (!strcasecmp(new->name, fname)) {
fname = new->name;
break;
}
}
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)) {
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;
if (is_header_regex(cmd->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];
}
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(cmd_parms *cmd, void *mconfig,
const char *args)
{
char *fname;
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_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("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 },
};
static int match_headers(request_rec *r)
{
sei_cfg_rec *sconf;
sei_entry *entries;
const apr_table_entry_t *elts;
const char *val;
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->name != last_name) {
last_name = b->name;
switch (b->special_type) {
case SPECIAL_REMOTE_ADDR:
val = r->connection->remote_ip;
break;
case SPECIAL_SERVER_ADDR:
val = r->connection->local_ip;
break;
case SPECIAL_REMOTE_HOST:
val = ap_get_remote_host(r->connection, r->per_dir_config,
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) {
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 {
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;
}
if (val == NULL) {
val = "";
val_len = 0;
}
if ((b->pattern && apr_strmatch(b->pattern, val, val_len)) ||
(!b->pattern && !ap_regexec(b->preg, val, AP_MAX_REG_MATCH, regm,
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 {
apr_table_setn(r->subprocess_env, elts[j].key,
elts[j].val);
}
}
}
}
}
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);
}
module AP_MODULE_DECLARE_DATA setenvif_module =
{
STANDARD20_MODULE_STUFF,
create_setenvif_config_dir,
merge_setenvif_config,
create_setenvif_config_svr,
merge_setenvif_config,
setenvif_module_cmds,
register_hooks
};