/*
* Copyright (C) Xiaozhe Wang (chaoslawful)
* Copyright (C) Yichun Zhang (agentzh)
*/
#ifndef DDEBUG
#define DDEBUG 0
#endif
#include "ddebug.h"
#include "ngx_http_lua_variable.h"
#include "ngx_http_lua_util.h"
static int ngx_http_lua_var_get(lua_State *L);
static int ngx_http_lua_var_set(lua_State *L);
void
ngx_http_lua_inject_variable_api(lua_State *L)
{
/* {{{ register reference maps */
lua_newtable(L); /* ngx.var */
lua_createtable(L, 0, 2 /* nrec */); /* metatable for .var */
lua_pushcfunction(L, ngx_http_lua_var_get);
lua_setfield(L, -2, "__index");
lua_pushcfunction(L, ngx_http_lua_var_set);
lua_setfield(L, -2, "__newindex");
lua_setmetatable(L, -2);
lua_setfield(L, -2, "var");
}
/**
* Get nginx internal variables content
*
* @retval Always return a string or nil on Lua stack. Return nil when failed
* to get content, and actual content string when found the specified variable.
* @seealso ngx_http_lua_var_set
* */
static int
ngx_http_lua_var_get(lua_State *L)
{
ngx_http_request_t *r;
u_char *p, *lowcase;
size_t len;
ngx_uint_t hash;
ngx_str_t name;
ngx_http_variable_value_t *vv;
#if (NGX_PCRE)
u_char *val;
ngx_uint_t n;
LUA_NUMBER index;
int *cap;
#endif
r = ngx_http_lua_get_req(L);
if (r == NULL) {
return luaL_error(L, "no request object found");
}
ngx_http_lua_check_fake_request(L, r);
#if (NGX_PCRE)
if (lua_type(L, -1) == LUA_TNUMBER) {
/* it is a regex capturing variable */
index = lua_tonumber(L, -1);
if (index <= 0) {
lua_pushnil(L);
return 1;
}
n = (ngx_uint_t) index * 2;
dd("n = %d, ncaptures = %d", (int) n, (int) r->ncaptures);
if (r->captures == NULL
|| r->captures_data == NULL
|| n >= r->ncaptures)
{
lua_pushnil(L);
return 1;
}
/* n >= 0 && n < r->ncaptures */
cap = r->captures;
p = r->captures_data;
val = &p[cap[n]];
lua_pushlstring(L, (const char *) val, (size_t) (cap[n + 1] - cap[n]));
return 1;
}
#endif
if (lua_type(L, -1) != LUA_TSTRING) {
return luaL_error(L, "bad variable name");
}
p = (u_char *) lua_tolstring(L, -1, &len);
lowcase = lua_newuserdata(L, len);
hash = ngx_hash_strlow(lowcase, p, len);
name.len = len;
name.data = lowcase;
vv = ngx_http_get_variable(r, &name, hash);
if (vv == NULL || vv->not_found) {
lua_pushnil(L);
return 1;
}
lua_pushlstring(L, (const char *) vv->data, (size_t) vv->len);
return 1;
}
/**
* Set nginx internal variable content
*
* @retval Always return a boolean on Lua stack. Return true when variable
* content was modified successfully, false otherwise.
* @seealso ngx_http_lua_var_get
* */
static int
ngx_http_lua_var_set(lua_State *L)
{
ngx_http_variable_t *v;
ngx_http_variable_value_t *vv;
ngx_http_core_main_conf_t *cmcf;
u_char *p, *lowcase, *val;
size_t len;
ngx_str_t name;
ngx_uint_t hash;
ngx_http_request_t *r;
int value_type;
const char *msg;
r = ngx_http_lua_get_req(L);
if (r == NULL) {
return luaL_error(L, "no request object found");
}
ngx_http_lua_check_fake_request(L, r);
/* we skip the first argument that is the table */
/* we read the variable name */
if (lua_type(L, 2) != LUA_TSTRING) {
return luaL_error(L, "bad variable name");
}
p = (u_char *) lua_tolstring(L, 2, &len);
lowcase = lua_newuserdata(L, len + 1);
hash = ngx_hash_strlow(lowcase, p, len);
lowcase[len] = '\0';
name.len = len;
name.data = lowcase;
/* we read the variable new value */
value_type = lua_type(L, 3);
switch (value_type) {
case LUA_TNUMBER:
case LUA_TSTRING:
p = (u_char *) luaL_checklstring(L, 3, &len);
val = ngx_palloc(r->pool, len);
if (val == NULL) {
return luaL_error(L, "memory allocation error");
}
ngx_memcpy(val, p, len);
break;
case LUA_TNIL:
/* undef the variable */
val = NULL;
len = 0;
break;
default:
msg = lua_pushfstring(L, "string, number, or nil expected, "
"but got %s", lua_typename(L, value_type));
return luaL_argerror(L, 1, msg);
}
/* we fetch the variable itself */
cmcf = ngx_http_get_module_main_conf(r, ngx_http_core_module);
v = ngx_hash_find(&cmcf->variables_hash, hash, name.data, name.len);
if (v) {
if (!(v->flags & NGX_HTTP_VAR_CHANGEABLE)) {
return luaL_error(L, "variable \"%s\" not changeable", lowcase);
}
if (v->set_handler) {
dd("set variables with set_handler");
vv = ngx_palloc(r->pool, sizeof(ngx_http_variable_value_t));
if (vv == NULL) {
return luaL_error(L, "no memory");
}
if (value_type == LUA_TNIL) {
vv->valid = 0;
vv->not_found = 1;
vv->no_cacheable = 0;
vv->data = NULL;
vv->len = 0;
} else {
vv->valid = 1;
vv->not_found = 0;
vv->no_cacheable = 0;
vv->data = val;
vv->len = len;
}
v->set_handler(r, vv, v->data);
return 0;
}
if (v->flags & NGX_HTTP_VAR_INDEXED) {
vv = &r->variables[v->index];
dd("set indexed variable");
if (value_type == LUA_TNIL) {
vv->valid = 0;
vv->not_found = 1;
vv->no_cacheable = 0;
vv->data = NULL;
vv->len = 0;
} else {
vv->valid = 1;
vv->not_found = 0;
vv->no_cacheable = 0;
vv->data = val;
vv->len = len;
}
return 0;
}
return luaL_error(L, "variable \"%s\" cannot be assigned a value",
lowcase);
}
/* variable not found */
return luaL_error(L, "variable \"%s\" not found for writing; "
"maybe it is a built-in variable that is not changeable "
"or you forgot to use \"set $%s '';\" "
"in the config file to define it first",
lowcase, lowcase);
}
#ifndef NGX_LUA_NO_FFI_API
int
ngx_http_lua_ffi_var_get(ngx_http_request_t *r, u_char *name_data,
size_t name_len, u_char *lowcase_buf, int capture_id, u_char **value,
size_t *value_len, char **err)
{
ngx_uint_t hash;
ngx_str_t name;
ngx_http_variable_value_t *vv;
#if (NGX_PCRE)
u_char *p;
ngx_uint_t n;
int *cap;
#endif
if (r == NULL) {
*err = "no request object found";
return NGX_ERROR;
}
if ((r)->connection->fd == (ngx_socket_t) -1) {
*err = "API disabled in the current context";
return NGX_ERROR;
}
#if (NGX_PCRE)
if (name_data == 0) {
if (capture_id <= 0) {
return NGX_DECLINED;
}
/* it is a regex capturing variable */
n = (ngx_uint_t) capture_id * 2;
dd("n = %d, ncaptures = %d", (int) n, (int) r->ncaptures);
if (r->captures == NULL
|| r->captures_data == NULL
|| n >= r->ncaptures)
{
return NGX_DECLINED;
}
/* n >= 0 && n < r->ncaptures */
cap = r->captures;
p = r->captures_data;
*value = &p[cap[n]];
*value_len = (size_t) (cap[n + 1] - cap[n]);
return NGX_OK;
}
#endif
hash = ngx_hash_strlow(lowcase_buf, name_data, name_len);
name.data = lowcase_buf;
name.len = name_len;
dd("variable name: %.*s", (int) name_len, lowcase_buf);
vv = ngx_http_get_variable(r, &name, hash);
if (vv == NULL || vv->not_found) {
return NGX_DECLINED;
}
*value = vv->data;
*value_len = vv->len;
return NGX_OK;
}
int
ngx_http_lua_ffi_var_set(ngx_http_request_t *r, u_char *name_data,
size_t name_len, u_char *lowcase_buf, u_char *value, size_t value_len,
u_char *errbuf, size_t *errlen)
{
u_char *p;
ngx_uint_t hash;
ngx_http_variable_t *v;
ngx_http_variable_value_t *vv;
ngx_http_core_main_conf_t *cmcf;
if (r == NULL) {
*errlen = ngx_snprintf(errbuf, *errlen, "no request object found")
- errbuf;
return NGX_ERROR;
}
if ((r)->connection->fd == (ngx_socket_t) -1) {
*errlen = ngx_snprintf(errbuf, *errlen,
"API disabled in the current context")
- errbuf;
return NGX_ERROR;
}
hash = ngx_hash_strlow(lowcase_buf, name_data, name_len);
dd("variable name: %.*s", (int) name_len, lowcase_buf);
/* we fetch the variable itself */
cmcf = ngx_http_get_module_main_conf(r, ngx_http_core_module);
v = ngx_hash_find(&cmcf->variables_hash, hash, lowcase_buf, name_len);
if (v) {
if (!(v->flags & NGX_HTTP_VAR_CHANGEABLE)) {
dd("variable not changeable");
*errlen = ngx_snprintf(errbuf, *errlen,
"variable \"%*s\" not changeable",
name_len, lowcase_buf)
- errbuf;
return NGX_ERROR;
}
if (v->set_handler) {
dd("set variables with set_handler");
if (value != NULL && value_len) {
vv = ngx_palloc(r->pool, sizeof(ngx_http_variable_value_t)
+ value_len);
if (vv == NULL) {
goto nomem;
}
p = (u_char *) vv + sizeof(ngx_http_variable_value_t);
ngx_memcpy(p, value, value_len);
value = p;
} else {
vv = ngx_palloc(r->pool, sizeof(ngx_http_variable_value_t));
if (vv == NULL) {
goto nomem;
}
}
if (value == NULL) {
vv->valid = 0;
vv->not_found = 1;
vv->no_cacheable = 0;
vv->data = NULL;
vv->len = 0;
} else {
vv->valid = 1;
vv->not_found = 0;
vv->no_cacheable = 0;
vv->data = value;
vv->len = value_len;
}
v->set_handler(r, vv, v->data);
return NGX_OK;
}
if (v->flags & NGX_HTTP_VAR_INDEXED) {
vv = &r->variables[v->index];
dd("set indexed variable");
if (value == NULL) {
vv->valid = 0;
vv->not_found = 1;
vv->no_cacheable = 0;
vv->data = NULL;
vv->len = 0;
} else {
p = ngx_palloc(r->pool, value_len);
if (p == NULL) {
goto nomem;
}
ngx_memcpy(p, value, value_len);
value = p;
vv->valid = 1;
vv->not_found = 0;
vv->no_cacheable = 0;
vv->data = value;
vv->len = value_len;
}
return NGX_OK;
}
*errlen = ngx_snprintf(errbuf, *errlen,
"variable \"%*s\" cannot be assigned "
"a value", name_len, lowcase_buf)
- errbuf;
return NGX_ERROR;
}
/* variable not found */
*errlen = ngx_snprintf(errbuf, *errlen,
"variable \"%*s\" not found for writing; "
"maybe it is a built-in variable that is not "
"changeable or you forgot to use \"set $%*s '';\" "
"in the config file to define it first",
name_len, lowcase_buf, name_len, lowcase_buf)
- errbuf;
return NGX_ERROR;
nomem:
*errlen = ngx_snprintf(errbuf, *errlen, "no memory") - errbuf;
return NGX_ERROR;
}
#endif /* NGX_LUA_NO_FFI_API */
/* vi:set ft=c ts=4 sw=4 et fdm=marker: */