lighttpd1.4/src/mod_magnet.c

#include <ctype.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>

#include "base.h"
#include "log.h"
#include "buffer.h"

#include "plugin.h"

#include "mod_magnet_cache.h"
#include "response.h"
#include "stat_cache.h"
#include "status_counter.h"

#ifdef HAVE_LUA_H
#include <lua.h>
#include <lauxlib.h>

#define MAGNET_CONFIG_RAW_URL       "magnet.attract-raw-url-to"
#define MAGNET_CONFIG_PHYSICAL_PATH "magnet.attract-physical-path-to"
#define MAGNET_RESTART_REQUEST      99

/* plugin config for all request/connections */

typedef struct {
	buffer *url_raw;
	buffer *physical_path;
} plugin_config;

typedef struct {
	PLUGIN_DATA;
	
	script_cache *cache;

	buffer *encode_buf;
	
	plugin_config **config_storage;
	
	plugin_config conf; 
} plugin_data;

/* init the plugin data */
INIT_FUNC(mod_magnet_init) {
	plugin_data *p;
	
	p = calloc(1, sizeof(*p));
	
	p->cache = script_cache_init();
	p->encode_buf = buffer_init();
	
	return p;
}

/* detroy the plugin data */
FREE_FUNC(mod_magnet_free) {
	plugin_data *p = p_d;
	
	UNUSED(srv);

	if (!p) return HANDLER_GO_ON;
	
	if (p->config_storage) {
		size_t i;

		for (i = 0; i < srv->config_context->used; i++) {
			plugin_config *s = p->config_storage[i];

			if (!s) continue;
			
			buffer_free(s->url_raw);
			buffer_free(s->physical_path);
			
			free(s);
		}
		free(p->config_storage);
	}
	
	script_cache_free(p->cache);
	buffer_free(p->encode_buf);
	
	free(p);
	
	return HANDLER_GO_ON;
}

/* handle plugin config and check values */

SETDEFAULTS_FUNC(mod_magnet_set_defaults) {
	plugin_data *p = p_d;
	size_t i = 0;
	
	config_values_t cv[] = { 
		{ MAGNET_CONFIG_RAW_URL,       NULL, T_CONFIG_STRING, T_CONFIG_SCOPE_CONNECTION },       /* 0 */
		{ MAGNET_CONFIG_PHYSICAL_PATH, NULL, T_CONFIG_STRING, T_CONFIG_SCOPE_CONNECTION },       /* 1 */
		{ NULL,                           NULL, T_CONFIG_UNSET, T_CONFIG_SCOPE_UNSET }
	};
	
	if (!p) return HANDLER_ERROR;
	
	p->config_storage = calloc(1, srv->config_context->used * sizeof(specific_config *));
	
	for (i = 0; i < srv->config_context->used; i++) {
		plugin_config *s;
		
		s = calloc(1, sizeof(plugin_config));
		s->url_raw  = buffer_init();
		s->physical_path = buffer_init();
		
		cv[0].destination = s->url_raw;
		cv[1].destination = s->physical_path;
		
		p->config_storage[i] = s;
	
		if (0 != config_insert_values_global(srv, ((data_config *)srv->config_context->data[i])->value, cv)) {
			return HANDLER_ERROR;
		}
	}
	
	return HANDLER_GO_ON;
}

#define PATCH(x) \
	p->conf.x = s->x;
static int mod_magnet_patch_connection(server *srv, connection *con, plugin_data *p) {
	size_t i, j;
	plugin_config *s = p->config_storage[0];
	
	PATCH(url_raw);
	PATCH(physical_path);
	
	/* skip the first, the global context */
	for (i = 1; i < srv->config_context->used; i++) {
		data_config *dc = (data_config *)srv->config_context->data[i];
		s = p->config_storage[i];
		
		/* condition didn't match */
		if (!config_check_cond(srv, con, dc)) continue;
		
		/* merge config */
		for (j = 0; j < dc->value->used; j++) {
			data_unset *du = dc->value->data[j];
			
			if (buffer_is_equal_string(du->key, CONST_STR_LEN(MAGNET_CONFIG_RAW_URL))) {
				PATCH(url_raw);
			} else if (buffer_is_equal_string(du->key, CONST_STR_LEN(MAGNET_CONFIG_PHYSICAL_PATH))) {
				PATCH(physical_path);
			}
		}
	}
	
	return 0;
}
#undef PATCH

static int magnet_print(lua_State *L) {
	const char *s = luaL_checkstring(L, 1);
	server *srv;

	lua_pushstring(L, "lighty.srv");
	lua_gettable(L, LUA_REGISTRYINDEX);
	srv = lua_touserdata(L, -1);
	lua_pop(L, 1);

	log_error_write(srv, __FILE__, __LINE__, "ss", 
			"(lua-print)", s);

	return 0;
}

static int magnet_reqhdr_get(lua_State *L) {
	server *srv;
	connection *con;
	data_string *ds;

	const char *key = luaL_checkstring(L, 2);

	lua_pushstring(L, "lighty.srv");
	lua_gettable(L, LUA_REGISTRYINDEX);
	srv = lua_touserdata(L, -1);
	lua_pop(L, 1);

	lua_pushstring(L, "lighty.con");
	lua_gettable(L, LUA_REGISTRYINDEX);
	con = lua_touserdata(L, -1);
	lua_pop(L, 1);

	if (NULL != (ds = (data_string *)array_get_element(con->request.headers, key))) {
		if (ds->value->used) {
			lua_pushlstring(L, ds->value->ptr, ds->value->used - 1);
		} else {
			lua_pushnil(L);
		}
	} else {
		lua_pushnil(L);
	}
	return 1;
}

static int magnet_status_get(lua_State *L) {
	data_integer *di;
	server *srv;
	size_t key_len = 0;

	const char *key = luaL_checklstring(L, 2, &key_len);

	lua_pushstring(L, "lighty.srv");
	lua_gettable(L, LUA_REGISTRYINDEX);
	srv = lua_touserdata(L, -1);
	lua_pop(L, 1);

	di = status_counter_get_counter(srv, key, key_len);

	lua_pushnumber(L, (double)di->value);

	return 1;
}

static int magnet_status_set(lua_State *L) {
	size_t key_len = 0;
	server *srv;

	const char *key = luaL_checklstring(L, 2, &key_len);
	int counter = luaL_checkint(L, 3);

	lua_pushstring(L, "lighty.srv");
	lua_gettable(L, LUA_REGISTRYINDEX);
	srv = lua_touserdata(L, -1);
	lua_pop(L, 1);

	status_counter_set(srv, key, key_len, counter);

	return 0;
}

typedef struct {
	const char *name;
	enum { 
		MAGNET_ENV_UNSET,

		MAGNET_ENV_PHYICAL_PATH,
		MAGNET_ENV_PHYICAL_REL_PATH,
		MAGNET_ENV_PHYICAL_DOC_ROOT,

		MAGNET_ENV_URI_PATH,
		MAGNET_ENV_URI_PATH_RAW,
		MAGNET_ENV_URI_SCHEME,
		MAGNET_ENV_URI_AUTHORITY,
		MAGNET_ENV_URI_QUERY,

		MAGNET_ENV_REQUEST_METHOD,
		MAGNET_ENV_REQUEST_URI,
		MAGNET_ENV_REQUEST_PROTOCOL
       	} type;
} magnet_env_t;

static buffer *magnet_env_get_buffer(server *srv, connection *con, const char *key) {
	buffer *dest = NULL;
	size_t i;

	const magnet_env_t env[] = {
		{ "physical.path", MAGNET_ENV_PHYICAL_PATH },
		{ "physical.rel-path", MAGNET_ENV_PHYICAL_REL_PATH },
		{ "physical.doc-root", MAGNET_ENV_PHYICAL_DOC_ROOT },

		{ "uri.path", MAGNET_ENV_URI_PATH },
		{ "uri.path-raw", MAGNET_ENV_URI_PATH_RAW },
		{ "uri.scheme", MAGNET_ENV_URI_SCHEME },
		{ "uri.authority", MAGNET_ENV_URI_AUTHORITY },
		{ "uri.query", MAGNET_ENV_URI_QUERY },

		{ "request.method", MAGNET_ENV_REQUEST_METHOD },
		{ "request.uri", MAGNET_ENV_REQUEST_URI },
		{ "request.protocol", MAGNET_ENV_REQUEST_PROTOCOL },
	
		{ NULL, MAGNET_ENV_UNSET }
	};


	/**
	 * map all internal variables to lua 
	 *
	 */

	for (i = 0; env[i].name; i++) {
		if (0 == strcmp(key, env[i].name)) break;
	}

	switch (env[i].type) {
	case MAGNET_ENV_PHYICAL_PATH: dest = con->physical.path; break;
	case MAGNET_ENV_PHYICAL_REL_PATH: dest = con->physical.rel_path; break;
	case MAGNET_ENV_PHYICAL_DOC_ROOT: dest = con->physical.doc_root; break;

	case MAGNET_ENV_URI_PATH: dest = con->uri.path; break;
	case MAGNET_ENV_URI_PATH_RAW: dest = con->uri.path_raw; break;
	case MAGNET_ENV_URI_SCHEME: dest = con->uri.scheme; break;
	case MAGNET_ENV_URI_AUTHORITY: dest = con->uri.authority; break;
	case MAGNET_ENV_URI_QUERY: dest = con->uri.query; break;

	case MAGNET_ENV_REQUEST_METHOD:   break;
	case MAGNET_ENV_REQUEST_URI:      dest = con->request.uri; break;
	case MAGNET_ENV_REQUEST_PROTOCOL: break;

	case MAGNET_ENV_UNSET: break;
	}

	return dest;
}

static int magnet_env_get(lua_State *L) {
	server *srv;
	connection *con;

	const char *key = luaL_checkstring(L, 2);
	buffer *dest = NULL;

	lua_pushstring(L, "lighty.srv");
	lua_gettable(L, LUA_REGISTRYINDEX);
	srv = lua_touserdata(L, -1);
	lua_pop(L, 1);

	lua_pushstring(L, "lighty.con");
	lua_gettable(L, LUA_REGISTRYINDEX);
	con = lua_touserdata(L, -1);
	lua_pop(L, 1);

	dest = magnet_env_get_buffer(srv, con, key);

	if (dest && dest->used) {
		lua_pushlstring(L, dest->ptr, dest->used - 1);
	} else {
		lua_pushnil(L);
	}

	return 1;
}

static int magnet_env_set(lua_State *L) {
	server *srv;
	connection *con;

	const char *key = luaL_checkstring(L, 2);
	const char *val = luaL_checkstring(L, 3);
	buffer *dest = NULL;

	lua_pushstring(L, "lighty.srv");
	lua_gettable(L, LUA_REGISTRYINDEX);
	srv = lua_touserdata(L, -1);
	lua_pop(L, 1);

	lua_pushstring(L, "lighty.con");
	lua_gettable(L, LUA_REGISTRYINDEX);
	con = lua_touserdata(L, -1);
	lua_pop(L, 1);

	if (NULL != (dest = magnet_env_get_buffer(srv, con, key))) {
		buffer_copy_string(dest, val);
	} else {
		/* couldn't save */

		return luaL_error(L, "couldn't store '%s' in lighty.env[]", key);
	}

	return 0;
}


static int magnet_copy_response_header(server *srv, connection *con, plugin_data *p, lua_State *L) {
	/**
	 * get the environment of the function
	 */

	lua_getfenv(L, -1); /* -1 is the function */

	/* lighty.header */

	lua_getfield(L, -1, "lighty"); /* lighty.* from the env  */
	assert(lua_istable(L, -1));

	lua_getfield(L, -1, "header"); /* lighty.header */
	if (lua_istable(L, -1)) {
		/* header is found, and is a table */

		lua_pushnil(L);
		while (lua_next(L, -2) != 0) {
			if (lua_isstring(L, -1) && lua_isstring(L, -2)) {
				const char *key, *val;
				size_t key_len, val_len;

				key = lua_tolstring(L, -2, &key_len);
				val = lua_tolstring(L, -1, &val_len);

				response_header_overwrite(srv, con, key, key_len, val, val_len);
			}

			lua_pop(L, 1);
		}
	} 

	lua_pop(L, 1); /* pop the header-table */
	lua_pop(L, 1); /* pop the lighty-env */
	lua_pop(L, 1); /* pop the function env */

	return 0;
}

/**
 * walk through the content array 
 *
 * content = { "<pre>", { file = "/content" } , "</pre>" } 
 *
 * header["Content-Type"] = "text/html"
 * 
 * return 200
 */
static int magnet_attach_content(lua_State *L) {
	/**
	 * get the environment of the function
	 */
	server *srv;
	connection *con;
	int i;

	lua_pushstring(L, "lighty.srv");
	lua_gettable(L, LUA_REGISTRYINDEX);
	srv = lua_touserdata(L, -1);
	lua_pop(L, 1);

	lua_pushstring(L, "lighty.con");
	lua_gettable(L, LUA_REGISTRYINDEX);
	con = lua_touserdata(L, -1);
	lua_pop(L, 1);

	assert(lua_isfunction(L, -1)); /* this would be error in lighty */
	lua_getfenv(L, -1); /* get the script-env */

	lua_getfield(L, -1, "lighty"); /* lighty.* from the env  */
	if (!lua_istable(L, -1)) {
		return luaL_error(L, "lighty.* was a table and get overwritten in your script");
	}

	lua_getfield(L, -1, "content"); /* lighty.content */
	if (!lua_istable(L, -1)) {
		return luaL_error(L, "lighty.content was a table and get overwritten in your script");
	}
		/* header is found, and is a table */

	for (i = 1; ; i++) {
		lua_rawgeti(L, -1, i);

		/* -1 is the value and should be the value ... aka a table */
		if (lua_isstring(L, -1)) {
			size_t s_len = 0;
			const char *s = lua_tolstring(L, -1, &s_len);

			chunkqueue_append_mem(con->write_queue, s, s_len + 1);
		} else if (lua_istable(L, -1)) {
			stat_cache_entry *sce;
			buffer *fn;

			lua_getfield(L, -1, "filename");
			lua_getfield(L, -2, "length");
			lua_getfield(L, -3, "offset");

			if (!lua_isstring(L, -3)) { /* filename has to be a string */
				return luaL_error(L, "lighty.content[%d] is a table and requires the field \"filename\"", i);
			}
			fn = buffer_init();

			buffer_copy_string(fn, lua_tostring(L, -3));

			if (HANDLER_GO_ON == stat_cache_get_entry(srv, con, fn, &sce)) {
				off_t off = 0;
				off_t len = 0;

				if (lua_isnumber(L, -1)) {
					off = lua_tonumber(L, -1);
				}

				if (lua_isnumber(L, -2)) {
					len = lua_tonumber(L, -2);
				} else {
					len = sce->st.st_size;
				}

				if (off < 0) {
					/* fn leaks mem */
					return luaL_error(L, "offset for '%s' is negative", fn->ptr);
				}

				if (len < off) {
					/* fn leaks mem */
					return luaL_error(L, "offset > length for '%s'", fn->ptr);
				}
				
				chunkqueue_append_file(con->write_queue, fn, off, len - off);
			}

			buffer_free(fn);
		} else if (lua_isnil(L, -1)) {
			/* oops, end of list */

			break;
		} else {
			return luaL_error(L, "lighty.content[%d] is neither a string nor a table: ", i);
		}
	}

	return 0;
}

static handler_t magnet_attract(server *srv, connection *con, plugin_data *p, buffer *name) {
	lua_State *L;
	int lua_return_value = -1;
	/* get the script-context */


	L = script_cache_get_script(srv, con, p->cache, name);

	if (lua_isstring(L, -1)) {
		log_error_write(srv, __FILE__, __LINE__, 
				"sbss",
				"loading script",
				name,
				"failed:",
				lua_tostring(L, -1));

		lua_pop(L, 1);
		
		assert(lua_gettop(L) == 0); /* only the function should be on the stack */

		con->http_status = 500;

		return HANDLER_FINISHED;
	}

	lua_pushstring(L, "lighty.srv"); 
	lua_pushlightuserdata(L, srv);
	lua_settable(L, LUA_REGISTRYINDEX); /* registery[<id>] = srv */

	lua_pushstring(L, "lighty.con"); 
	lua_pushlightuserdata(L, con);
	lua_settable(L, LUA_REGISTRYINDEX); /* registery[<id>] = con */

	/**
	 * we want to create empty environment for our script 
	 * 
	 * setmetatable({}, {__index = _G})
	 * 
	 * if a function, symbol is not defined in our env, __index will lookup 
	 * in the global env.
	 *
	 * all variables created in the script-env will be thrown 
	 * away at the end of the script run.
	 */
	lua_newtable(L); /* my empty environment aka {}              (sp += 1) */

	/* we have to overwrite the print function */
	lua_pushcfunction(L, magnet_print);                       /* (sp += 1) */
	lua_setfield(L, -2, "print"); /* -1 is the env we want to set(sp -= 1) */

	/**
	 * lighty.request[] has the HTTP-request headers 
	 * lighty.content[] is a table of string/file 
	 * lighty.header[] is a array to set response headers
	 */

	lua_newtable(L); /* lighty.*                                 (sp += 1) */

	lua_newtable(L); /*  {}                                      (sp += 1) */
	lua_newtable(L); /* the meta-table for the request-table     (sp += 1) */
	lua_pushcfunction(L, magnet_reqhdr_get);                  /* (sp += 1) */
	lua_setfield(L, -2, "__index");                           /* (sp -= 1) */    
	lua_setmetatable(L, -2); /* tie the metatable to request     (sp -= 1) */
	lua_setfield(L, -2, "request"); /* content = {}              (sp -= 1) */

	lua_newtable(L); /*  {}                                      (sp += 1) */
	lua_newtable(L); /* the meta-table for the request-table     (sp += 1) */
	lua_pushcfunction(L, magnet_env_get);                     /* (sp += 1) */
	lua_setfield(L, -2, "__index");                           /* (sp -= 1) */    
	lua_pushcfunction(L, magnet_env_set);                     /* (sp += 1) */
	lua_setfield(L, -2, "__newindex");                        /* (sp -= 1) */    
	lua_setmetatable(L, -2); /* tie the metatable to request     (sp -= 1) */
	lua_setfield(L, -2, "env"); /* content = {}                  (sp -= 1) */

	lua_newtable(L); /*  {}                                      (sp += 1) */
	lua_newtable(L); /* the meta-table for the request-table     (sp += 1) */
	lua_pushcfunction(L, magnet_status_get);                  /* (sp += 1) */
	lua_setfield(L, -2, "__index");                           /* (sp -= 1) */    
	lua_pushcfunction(L, magnet_status_set);                  /* (sp += 1) */
	lua_setfield(L, -2, "__newindex");                        /* (sp -= 1) */    
	lua_setmetatable(L, -2); /* tie the metatable to request     (sp -= 1) */
	lua_setfield(L, -2, "status"); /* content = {}               (sp -= 1) */

	/* add empty 'content' and 'header' tables */
	lua_newtable(L); /*  {}                                      (sp += 1) */
	lua_setfield(L, -2, "content"); /* content = {}              (sp -= 1) */

	lua_newtable(L); /*  {}                                      (sp += 1) */
	lua_setfield(L, -2, "header"); /* header = {}                (sp -= 1) */

	lua_pushinteger(L, MAGNET_RESTART_REQUEST);
	lua_setfield(L, -2, "RESTART_REQUEST");

	lua_setfield(L, -2, "lighty"); /* lighty.*                   (sp -= 1) */
	
	lua_newtable(L); /* the meta-table for the new env           (sp += 1) */
	lua_pushvalue(L, LUA_GLOBALSINDEX);                       /* (sp += 1) */
	lua_setfield(L, -2, "__index"); /* { __index = _G }          (sp -= 1) */
	lua_setmetatable(L, -2); /* setmetatable({}, {__index = _G}) (sp -= 1) */
	

	lua_setfenv(L, -2); /* on the stack should be a modified env (sp -= 1) */

	if (lua_pcall(L, 0, 1, 0)) {
		log_error_write(srv, __FILE__, __LINE__, 
			"ss", 
			"lua_pcall():",
			lua_tostring(L, -1));
		lua_pop(L, 1); /* remove the error-msg and the function copy from the stack */

		assert(lua_gettop(L) == 1); /* only the function should be on the stack */

		con->http_status = 500;

		return HANDLER_FINISHED;
	}

	/* we should have the function-copy and the return value on the stack */
	assert(lua_gettop(L) == 2);

	if (lua_isnumber(L, -1)) {
		/* if the ret-value is a number, take it */
		lua_return_value = (int)lua_tonumber(L, -1);
	}
	lua_pop(L, 1); /* pop the ret-value */

	magnet_copy_response_header(srv, con, p, L);

	/* everything 3-digit number is a status-code */
	if (lua_return_value > 99 && lua_return_value < 1000) {
		con->http_status = lua_return_value;
		con->file_finished = 1;

		/* use the lua-system to call a lua-c-function
		 * that way I can use luaL_error() without problems 
		 */	
		if (lua_cpcall(L, magnet_attach_content, NULL)) {
			log_error_write(srv, __FILE__, __LINE__, 
				"ss", 
				"magnet_attach_content():",
				lua_tostring(L, -1));

			con->http_status = 500;
		}

		assert(lua_gettop(L) == 1); /* only the function should be on the stack */

		/* we are finished */
		return HANDLER_FINISHED;
	} else if (MAGNET_RESTART_REQUEST == lua_return_value) {
		assert(lua_gettop(L) == 1); /* only the function should be on the stack */

		return HANDLER_COMEBACK;
	} else {
		assert(lua_gettop(L) == 1); /* only the function should be on the stack */
	
		return HANDLER_GO_ON;
	}
}

URIHANDLER_FUNC(mod_magnet_uri_handler) {
	plugin_data *p = p_d;
	
	mod_magnet_patch_connection(srv, con, p);

	if (buffer_is_empty(p->conf.url_raw)) return HANDLER_GO_ON;

	/* looks like we have a handler for this request */

	return magnet_attract(srv, con, p, p->conf.url_raw);
}

URIHANDLER_FUNC(mod_magnet_physical) {
	plugin_data *p = p_d;
	
	mod_magnet_patch_connection(srv, con, p);

	if (buffer_is_empty(p->conf.physical_path)) return HANDLER_GO_ON;

	/* looks like we have a handler for this request */

	return magnet_attract(srv, con, p, p->conf.physical_path);
}


/* this function is called at dlopen() time and inits the callbacks */

int mod_magnet_plugin_init(plugin *p) {
	p->version     = LIGHTTPD_VERSION_ID;
	p->name        = buffer_init_string("magnet");
	
	p->init        = mod_magnet_init;
	p->handle_uri_clean  = mod_magnet_uri_handler;
	p->handle_physical   = mod_magnet_physical;
	p->set_defaults  = mod_magnet_set_defaults;
	p->cleanup     = mod_magnet_free;
	
	p->data        = NULL;
	
	return 0;
}

#else
int mod_magnet_plugin_init(plugin *p) {
	return -1;
}
#endif