luasocket/src/unixdgram.c
2019-02-25 16:01:33 -07:00

409 lines
14 KiB
C

/*=========================================================================*\
* Unix domain socket dgram submodule
* LuaSocket toolkit
\*=========================================================================*/
#include "luasocket.h"
#include "lua.h"
#include "lauxlib.h"
#include "compat.h"
#include "auxiliar.h"
#include "socket.h"
#include "options.h"
#include "unix.h"
#include <string.h>
#include <stdlib.h>
#include <sys/un.h>
#define UNIXDGRAM_DATAGRAMSIZE 8192
// provide a SUN_LEN macro if sys/un.h doesn't (e.g. Android)
#ifndef SUN_LEN
#define SUN_LEN(ptr) \
((size_t) (((struct sockaddr_un *) 0)->sun_path) \
+ strlen ((ptr)->sun_path))
#endif
/*=========================================================================*\
* Internal function prototypes
\*=========================================================================*/
static int global_create(lua_State *L);
static int meth_connect(lua_State *L);
static int meth_bind(lua_State *L);
static int meth_send(lua_State *L);
static int meth_receive(lua_State *L);
static int meth_close(lua_State *L);
static int meth_setoption(lua_State *L);
static int meth_settimeout(lua_State *L);
static int meth_gettimeout(lua_State *L);
static int meth_getfd(lua_State *L);
static int meth_setfd(lua_State *L);
static int meth_dirty(lua_State *L);
static int meth_receivefrom(lua_State *L);
static int meth_sendto(lua_State *L);
static int meth_getsockname(lua_State *L);
static const char *unixdgram_tryconnect(p_unix un, const char *path);
static const char *unixdgram_trybind(p_unix un, const char *path);
/* unixdgram object methods */
static luaL_Reg unixdgram_methods[] = {
{"__gc", meth_close},
{"__tostring", auxiliar_tostring},
{"bind", meth_bind},
{"close", meth_close},
{"connect", meth_connect},
{"dirty", meth_dirty},
{"getfd", meth_getfd},
{"send", meth_send},
{"sendto", meth_sendto},
{"receive", meth_receive},
{"receivefrom", meth_receivefrom},
{"setfd", meth_setfd},
{"setoption", meth_setoption},
{"setpeername", meth_connect},
{"setsockname", meth_bind},
{"getsockname", meth_getsockname},
{"settimeout", meth_settimeout},
{"gettimeout", meth_gettimeout},
{NULL, NULL}
};
/* socket option handlers */
static t_opt optset[] = {
{"reuseaddr", opt_set_reuseaddr},
{NULL, NULL}
};
/* functions in library namespace */
static luaL_Reg func[] = {
{"dgram", global_create},
{NULL, NULL}
};
/*-------------------------------------------------------------------------*\
* Initializes module
\*-------------------------------------------------------------------------*/
LUASOCKET_PRIVATE int unixdgram_open(lua_State *L)
{
/* create classes */
auxiliar_newclass(L, "unixdgram{connected}", unixdgram_methods);
auxiliar_newclass(L, "unixdgram{unconnected}", unixdgram_methods);
/* create class groups */
auxiliar_add2group(L, "unixdgram{connected}", "unixdgram{any}");
auxiliar_add2group(L, "unixdgram{unconnected}", "unixdgram{any}");
auxiliar_add2group(L, "unixdgram{connected}", "select{able}");
auxiliar_add2group(L, "unixdgram{unconnected}", "select{able}");
luaL_setfuncs(L, func, 0);
return 0;
}
/*=========================================================================*\
* Lua methods
\*=========================================================================*/
static const char *unixdgram_strerror(int err)
{
/* a 'closed' error on an unconnected means the target address was not
* accepted by the transport layer */
if (err == IO_CLOSED) return "refused";
else return socket_strerror(err);
}
static int meth_send(lua_State *L)
{
p_unix un = (p_unix) auxiliar_checkclass(L, "unixdgram{connected}", 1);
p_timeout tm = &un->tm;
size_t count, sent = 0;
int err;
const char *data = luaL_checklstring(L, 2, &count);
timeout_markstart(tm);
err = socket_send(&un->sock, data, count, &sent, tm);
if (err != IO_DONE) {
lua_pushnil(L);
lua_pushstring(L, unixdgram_strerror(err));
return 2;
}
lua_pushnumber(L, (lua_Number) sent);
return 1;
}
/*-------------------------------------------------------------------------*\
* Send data through unconnected unixdgram socket
\*-------------------------------------------------------------------------*/
static int meth_sendto(lua_State *L)
{
p_unix un = (p_unix) auxiliar_checkclass(L, "unixdgram{unconnected}", 1);
size_t count, sent = 0;
const char *data = luaL_checklstring(L, 2, &count);
const char *path = luaL_checkstring(L, 3);
p_timeout tm = &un->tm;
int err;
struct sockaddr_un remote;
size_t len = strlen(path);
if (len >= sizeof(remote.sun_path)) {
lua_pushnil(L);
lua_pushstring(L, "path too long");
return 2;
}
memset(&remote, 0, sizeof(remote));
strcpy(remote.sun_path, path);
remote.sun_family = AF_UNIX;
timeout_markstart(tm);
#ifdef UNIX_HAS_SUN_LEN
remote.sun_len = sizeof(remote.sun_family) + sizeof(remote.sun_len)
+ len + 1;
err = socket_sendto(&un->sock, data, count, &sent, (SA *) &remote, remote.sun_len, tm);
#else
err = socket_sendto(&un->sock, data, count, &sent, (SA *) &remote,
sizeof(remote.sun_family) + len, tm);
#endif
if (err != IO_DONE) {
lua_pushnil(L);
lua_pushstring(L, unixdgram_strerror(err));
return 2;
}
lua_pushnumber(L, (lua_Number) sent);
return 1;
}
static int meth_receive(lua_State *L) {
p_unix un = (p_unix) auxiliar_checkgroup(L, "unixdgram{any}", 1);
char buf[UNIXDGRAM_DATAGRAMSIZE];
size_t got, wanted = (size_t) luaL_optnumber(L, 2, sizeof(buf));
char *dgram = wanted > sizeof(buf)? (char *) malloc(wanted): buf;
int err;
p_timeout tm = &un->tm;
timeout_markstart(tm);
if (!dgram) {
lua_pushnil(L);
lua_pushliteral(L, "out of memory");
return 2;
}
err = socket_recv(&un->sock, dgram, wanted, &got, tm);
/* Unlike STREAM, recv() of zero is not closed, but a zero-length packet. */
if (err != IO_DONE && err != IO_CLOSED) {
lua_pushnil(L);
lua_pushstring(L, unixdgram_strerror(err));
if (wanted > sizeof(buf)) free(dgram);
return 2;
}
lua_pushlstring(L, dgram, got);
if (wanted > sizeof(buf)) free(dgram);
return 1;
}
/*-------------------------------------------------------------------------*\
* Receives data and sender from a DGRAM socket
\*-------------------------------------------------------------------------*/
static int meth_receivefrom(lua_State *L) {
p_unix un = (p_unix) auxiliar_checkclass(L, "unixdgram{unconnected}", 1);
char buf[UNIXDGRAM_DATAGRAMSIZE];
size_t got, wanted = (size_t) luaL_optnumber(L, 2, sizeof(buf));
char *dgram = wanted > sizeof(buf)? (char *) malloc(wanted): buf;
struct sockaddr_un addr;
socklen_t addr_len = sizeof(addr);
int err;
p_timeout tm = &un->tm;
timeout_markstart(tm);
if (!dgram) {
lua_pushnil(L);
lua_pushliteral(L, "out of memory");
return 2;
}
addr.sun_path[0] = '\0';
err = socket_recvfrom(&un->sock, dgram, wanted, &got, (SA *) &addr,
&addr_len, tm);
/* Unlike STREAM, recv() of zero is not closed, but a zero-length packet. */
if (err != IO_DONE && err != IO_CLOSED) {
lua_pushnil(L);
lua_pushstring(L, unixdgram_strerror(err));
if (wanted > sizeof(buf)) free(dgram);
return 2;
}
lua_pushlstring(L, dgram, got);
/* the path may be empty, when client send without bind */
lua_pushstring(L, addr.sun_path);
if (wanted > sizeof(buf)) free(dgram);
return 2;
}
/*-------------------------------------------------------------------------*\
* Just call option handler
\*-------------------------------------------------------------------------*/
static int meth_setoption(lua_State *L) {
p_unix un = (p_unix) auxiliar_checkgroup(L, "unixdgram{any}", 1);
return opt_meth_setoption(L, optset, &un->sock);
}
/*-------------------------------------------------------------------------*\
* Select support methods
\*-------------------------------------------------------------------------*/
static int meth_getfd(lua_State *L) {
p_unix un = (p_unix) auxiliar_checkgroup(L, "unixdgram{any}", 1);
lua_pushnumber(L, (int) un->sock);
return 1;
}
/* this is very dangerous, but can be handy for those that are brave enough */
static int meth_setfd(lua_State *L) {
p_unix un = (p_unix) auxiliar_checkgroup(L, "unixdgram{any}", 1);
un->sock = (t_socket) luaL_checknumber(L, 2);
return 0;
}
static int meth_dirty(lua_State *L) {
p_unix un = (p_unix) auxiliar_checkgroup(L, "unixdgram{any}", 1);
(void) un;
lua_pushboolean(L, 0);
return 1;
}
/*-------------------------------------------------------------------------*\
* Binds an object to an address
\*-------------------------------------------------------------------------*/
static const char *unixdgram_trybind(p_unix un, const char *path) {
struct sockaddr_un local;
size_t len = strlen(path);
if (len >= sizeof(local.sun_path)) return "path too long";
memset(&local, 0, sizeof(local));
strcpy(local.sun_path, path);
local.sun_family = AF_UNIX;
size_t addrlen = SUN_LEN(&local);
#ifdef UNIX_HAS_SUN_LEN
local.sun_len = addrlen + 1;
#endif
int err = socket_bind(&un->sock, (SA *) &local, addrlen);
if (err != IO_DONE) socket_destroy(&un->sock);
return socket_strerror(err);
}
static int meth_bind(lua_State *L)
{
p_unix un = (p_unix) auxiliar_checkclass(L, "unixdgram{unconnected}", 1);
const char *path = luaL_checkstring(L, 2);
const char *err = unixdgram_trybind(un, path);
if (err) {
lua_pushnil(L);
lua_pushstring(L, err);
return 2;
}
lua_pushnumber(L, 1);
return 1;
}
static int meth_getsockname(lua_State *L)
{
p_unix un = (p_unix) auxiliar_checkgroup(L, "unixdgram{any}", 1);
struct sockaddr_un peer = {0};
socklen_t peer_len = sizeof(peer);
if (getsockname(un->sock, (SA *) &peer, &peer_len) < 0) {
lua_pushnil(L);
lua_pushstring(L, socket_strerror(errno));
return 2;
}
lua_pushstring(L, peer.sun_path);
return 1;
}
/*-------------------------------------------------------------------------*\
* Turns a master unixdgram object into a client object.
\*-------------------------------------------------------------------------*/
static const char *unixdgram_tryconnect(p_unix un, const char *path)
{
struct sockaddr_un remote;
size_t len = strlen(path);
if (len >= sizeof(remote.sun_path)) return "path too long";
memset(&remote, 0, sizeof(remote));
strcpy(remote.sun_path, path);
remote.sun_family = AF_UNIX;
timeout_markstart(&un->tm);
size_t addrlen = SUN_LEN(&remote);
#ifdef UNIX_HAS_SUN_LEN
remote.sun_len = addrlen + 1;
#endif
int err = socket_connect(&un->sock, (SA *) &remote, addrlen, &un->tm);
if (err != IO_DONE) socket_destroy(&un->sock);
return socket_strerror(err);
}
static int meth_connect(lua_State *L)
{
p_unix un = (p_unix) auxiliar_checkgroup(L, "unixdgram{any}", 1);
const char *path = luaL_checkstring(L, 2);
const char *err = unixdgram_tryconnect(un, path);
if (err) {
lua_pushnil(L);
lua_pushstring(L, err);
return 2;
}
/* turn unconnected object into a connected object */
auxiliar_setclass(L, "unixdgram{connected}", 1);
lua_pushnumber(L, 1);
return 1;
}
/*-------------------------------------------------------------------------*\
* Closes socket used by object
\*-------------------------------------------------------------------------*/
static int meth_close(lua_State *L)
{
p_unix un = (p_unix) auxiliar_checkgroup(L, "unixdgram{any}", 1);
socket_destroy(&un->sock);
lua_pushnumber(L, 1);
return 1;
}
/*-------------------------------------------------------------------------*\
* Just call tm methods
\*-------------------------------------------------------------------------*/
static int meth_settimeout(lua_State *L)
{
p_unix un = (p_unix) auxiliar_checkgroup(L, "unixdgram{any}", 1);
return timeout_meth_settimeout(L, &un->tm);
}
static int meth_gettimeout(lua_State *L)
{
p_unix un = (p_unix) auxiliar_checkgroup(L, "unixdgram{any}", 1);
return timeout_meth_gettimeout(L, &un->tm);
}
/*=========================================================================*\
* Library functions
\*=========================================================================*/
/*-------------------------------------------------------------------------*\
* Creates a master unixdgram object
\*-------------------------------------------------------------------------*/
static int global_create(lua_State *L)
{
t_socket sock;
int err = socket_create(&sock, AF_UNIX, SOCK_DGRAM, 0);
/* try to allocate a system socket */
if (err == IO_DONE) {
/* allocate unixdgram object */
p_unix un = (p_unix) lua_newuserdata(L, sizeof(t_unix));
/* set its type as master object */
auxiliar_setclass(L, "unixdgram{unconnected}", -1);
/* initialize remaining structure fields */
socket_setnonblocking(&sock);
un->sock = sock;
io_init(&un->io, (p_send) socket_send, (p_recv) socket_recv,
(p_error) socket_ioerror, &un->sock);
timeout_init(&un->tm, -1, -1);
buffer_init(&un->buf, &un->io, &un->tm);
return 1;
} else {
lua_pushnil(L);
lua_pushstring(L, socket_strerror(err));
return 2;
}
}