blob: 3ad419b39f3bfcd8cc3e4506caec5af9cba83c25 [file] [log] [blame] [raw]
/*
* Copyright (C) Igor Sysoev
*/
#include <ngx_config.h>
#include <ngx_core.h>
#include <ngx_http.h>
#define NGX_HTTP_REFERER_NO_URI_PART ((void *) 4)
typedef struct {
ngx_hash_t hash;
ngx_hash_wildcard_t *dns_wildcards;
ngx_flag_t no_referer;
ngx_flag_t blocked_referer;
ngx_hash_keys_arrays_t *keys;
} ngx_http_referer_conf_t;
static void * ngx_http_referer_create_conf(ngx_conf_t *cf);
static char * ngx_http_referer_merge_conf(ngx_conf_t *cf, void *parent,
void *child);
static char *ngx_http_valid_referers(ngx_conf_t *cf, ngx_command_t *cmd,
void *conf);
static char *ngx_http_add_referer(ngx_conf_t *cf, ngx_hash_keys_arrays_t *keys,
ngx_str_t *value, ngx_str_t *uri);
static int ngx_libc_cdecl ngx_http_cmp_referer_wildcards(const void *one,
const void *two);
static ngx_command_t ngx_http_referer_commands[] = {
{ ngx_string("valid_referers"),
NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_1MORE,
ngx_http_valid_referers,
NGX_HTTP_LOC_CONF_OFFSET,
0,
NULL },
ngx_null_command
};
static ngx_http_module_t ngx_http_referer_module_ctx = {
NULL, /* preconfiguration */
NULL, /* postconfiguration */
NULL, /* create main configuration */
NULL, /* init main configuration */
NULL, /* create server configuration */
NULL, /* merge server configuration */
ngx_http_referer_create_conf, /* create location configuration */
ngx_http_referer_merge_conf /* merge location configuration */
};
ngx_module_t ngx_http_referer_module = {
NGX_MODULE_V1,
&ngx_http_referer_module_ctx, /* module context */
ngx_http_referer_commands, /* module directives */
NGX_HTTP_MODULE, /* module type */
NULL, /* init master */
NULL, /* init module */
NULL, /* init process */
NULL, /* init thread */
NULL, /* exit thread */
NULL, /* exit process */
NULL, /* exit master */
NGX_MODULE_V1_PADDING
};
static ngx_int_t
ngx_http_referer_variable(ngx_http_request_t *r, ngx_http_variable_value_t *v,
uintptr_t data)
{
u_char *p, *ref, *last;
size_t len;
ngx_str_t *uri;
ngx_uint_t i, key;
ngx_http_referer_conf_t *rlcf;
u_char buf[256];
rlcf = ngx_http_get_module_loc_conf(r, ngx_http_referer_module);
if (rlcf->hash.buckets == NULL && rlcf->dns_wildcards == NULL) {
goto valid;
}
if (r->headers_in.referer == NULL) {
if (rlcf->no_referer) {
goto valid;
}
goto invalid;
}
len = r->headers_in.referer->value.len;
ref = r->headers_in.referer->value.data;
if (len < sizeof("http://i.ru") - 1
|| (ngx_strncasecmp(ref, "http://", 7) != 0))
{
if (rlcf->blocked_referer) {
goto valid;
}
goto invalid;
}
last = ref + len;
ref += 7;
i = 0;
key = 0;
for (p = ref; p < last; p++) {
if (*p == '/' || *p == ':') {
break;
}
buf[i] = ngx_tolower(*p);
key = ngx_hash(key, buf[i++]);
if (i == 256) {
goto invalid;
}
}
len = p - ref;
if (rlcf->hash.buckets) {
uri = ngx_hash_find(&rlcf->hash, key, buf, len);
if (uri) {
goto uri;
}
}
if (rlcf->dns_wildcards) {
uri = ngx_hash_find_wildcard(rlcf->dns_wildcards, buf, len);
if (uri) {
goto uri;
}
}
invalid:
*v = ngx_http_variable_true_value;
return NGX_OK;
uri:
for ( /* void */ ; p < last; p++) {
if (*p == '/') {
break;
}
}
len = last - p;
if (uri == NGX_HTTP_REFERER_NO_URI_PART) {
goto valid;
}
if (len < uri->len || ngx_strncmp(uri->data, p, uri->len) != 0) {
goto invalid;
}
valid:
*v = ngx_http_variable_null_value;
return NGX_OK;
}
static void *
ngx_http_referer_create_conf(ngx_conf_t *cf)
{
ngx_http_referer_conf_t *conf;
conf = ngx_pcalloc(cf->pool, sizeof(ngx_http_referer_conf_t));
if (conf == NULL) {
return NGX_CONF_ERROR;
}
conf->no_referer = NGX_CONF_UNSET;
conf->blocked_referer = NGX_CONF_UNSET;
return conf;
}
static char *
ngx_http_referer_merge_conf(ngx_conf_t *cf, void *parent, void *child)
{
ngx_http_referer_conf_t *prev = parent;
ngx_http_referer_conf_t *conf = child;
ngx_hash_init_t hash;
if (conf->keys == NULL) {
conf->hash = prev->hash;
conf->dns_wildcards = prev->dns_wildcards;
ngx_conf_merge_value(conf->no_referer, prev->no_referer, 0);
ngx_conf_merge_value(conf->blocked_referer, prev->blocked_referer, 0);
return NGX_CONF_OK;
}
if ((conf->no_referer == 1 || conf->blocked_referer == 1)
&& conf->keys->keys.nelts == 0 && conf->keys->dns_wildcards.nelts)
{
ngx_log_error(NGX_LOG_EMERG, cf->log, 0,
"the \"none\" or \"blocked\" referers are specified "
"in the \"valid_referers\" directive "
"without any valid referer");
return NGX_CONF_ERROR;
}
hash.key = ngx_hash_key_lc;
hash.max_size = 2048; /* TODO: referer_hash_max_size; */
hash.bucket_size = 64; /* TODO: referer_hash_bucket_size; */
hash.name = "referers_hash";
hash.pool = cf->pool;
if (conf->keys->keys.nelts) {
hash.hash = &conf->hash;
hash.temp_pool = NULL;
if (ngx_hash_init(&hash, conf->keys->keys.elts, conf->keys->keys.nelts)
!= NGX_OK)
{
return NGX_CONF_ERROR;
}
}
if (conf->keys->dns_wildcards.nelts) {
ngx_qsort(conf->keys->dns_wildcards.elts,
(size_t) conf->keys->dns_wildcards.nelts,
sizeof(ngx_hash_key_t),
ngx_http_cmp_referer_wildcards);
hash.hash = NULL;
hash.temp_pool = cf->temp_pool;
if (ngx_hash_wildcard_init(&hash, conf->keys->dns_wildcards.elts,
conf->keys->dns_wildcards.nelts)
!= NGX_OK)
{
return NGX_CONF_ERROR;
}
conf->dns_wildcards = (ngx_hash_wildcard_t *) hash.hash;
}
if (conf->no_referer == NGX_CONF_UNSET) {
conf->no_referer = 0;
}
if (conf->blocked_referer == NGX_CONF_UNSET) {
conf->blocked_referer = 0;
}
conf->keys = NULL;
return NGX_CONF_OK;
}
static char *
ngx_http_valid_referers(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
{
ngx_http_referer_conf_t *rlcf = conf;
u_char *p;
ngx_str_t *value, uri, name;
ngx_uint_t i, n;
ngx_http_variable_t *var;
ngx_http_server_name_t *sn;
ngx_http_core_srv_conf_t *cscf;
name.len = sizeof("invalid_referer") - 1;
name.data = (u_char *) "invalid_referer";
var = ngx_http_add_variable(cf, &name,
NGX_HTTP_VAR_CHANGABLE|NGX_HTTP_VAR_NOHASH);
if (var == NULL) {
return NGX_CONF_ERROR;
}
var->handler = ngx_http_referer_variable;
if (rlcf->keys == NULL) {
rlcf->keys = ngx_pcalloc(cf->temp_pool, sizeof(ngx_hash_keys_arrays_t));
if (rlcf->keys == NULL) {
return NGX_CONF_ERROR;
}
rlcf->keys->pool = cf->pool;
rlcf->keys->temp_pool = cf->pool;
if (ngx_hash_keys_array_init(rlcf->keys, NGX_HASH_SMALL) != NGX_OK) {
return NGX_CONF_ERROR;
}
}
value = cf->args->elts;
for (i = 1; i < cf->args->nelts; i++) {
if (value[i].len == 0) {
ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
"invalid referer \"%V\"", &value[i]);
return NGX_CONF_ERROR;
}
if (ngx_strcmp(value[i].data, "none") == 0) {
rlcf->no_referer = 1;
continue;
}
if (ngx_strcmp(value[i].data, "blocked") == 0) {
rlcf->blocked_referer = 1;
continue;
}
uri.len = 0;
uri.data = NULL;
if (ngx_strcmp(value[i].data, "server_names") == 0) {
cscf = ngx_http_conf_get_module_srv_conf(cf, ngx_http_core_module);
sn = cscf->server_names.elts;
for (n = 0; n < cscf->server_names.nelts; n++) {
if (ngx_http_add_referer(cf, rlcf->keys, &sn[n].name, &uri)
!= NGX_OK)
{
return NGX_CONF_ERROR;
}
}
continue;
}
p = (u_char *) ngx_strstr(value[i].data, "/");
if (p) {
uri.len = (value[i].data + value[i].len) - p;
uri.data = p;
value[i].len = p - value[i].data;
}
if (ngx_http_add_referer(cf, rlcf->keys, &value[i], &uri) != NGX_OK) {
return NGX_CONF_ERROR;
}
}
return NGX_CONF_OK;
}
static char *
ngx_http_add_referer(ngx_conf_t *cf, ngx_hash_keys_arrays_t *keys,
ngx_str_t *value, ngx_str_t *uri)
{
u_char ch;
ngx_int_t rc;
ngx_str_t *u;
ngx_uint_t flags;
ch = value->data[0];
if ((ch == '*' && (value->len < 3 || value->data[1] != '.'))
|| (ch == '.' && value->len < 2))
{
ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
"invalid DNS wildcard \"%V\"", value);
return NGX_CONF_ERROR;
}
flags = (ch == '*' || ch == '.') ? NGX_HASH_WILDCARD_KEY : 0;
if (uri->len == 0) {
u = NGX_HTTP_REFERER_NO_URI_PART;
} else {
u = ngx_palloc(cf->pool, sizeof(ngx_str_t));
if (u == NULL) {
return NGX_CONF_ERROR;
}
*u = *uri;
}
rc = ngx_hash_add_key(keys, value, u, flags);
if (rc == NGX_OK) {
return NGX_CONF_OK;
}
if (rc == NGX_BUSY) {
ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
"conflicting parameter \"%V\"", value);
}
return NGX_CONF_ERROR;
}
static int ngx_libc_cdecl
ngx_http_cmp_referer_wildcards(const void *one, const void *two)
{
ngx_hash_key_t *first, *second;
first = (ngx_hash_key_t *) one;
second = (ngx_hash_key_t *) two;
return ngx_strcmp(first->key.data, second->key.data);
}