/*-
- ptag = n:ipv4{len=int, protocol=int, src=ipaddr, dst=ipaddr, payload=str, ptag=int, options=ip_options}
ptag is optional, defaults to creating a new protocol block
options is optional
*/
static int lnet_ipv4 (lua_State *L)
{
libnet_t** ud = luaL_checkudata(L, 1, L_NET_REGID);
luaL_argcheck(L, *ud, 1, "net has been destroyed");
int len = v_arg_integer(L, 2, "len"); // FIXME - should be optional!
int tos = 0;
int id = 0;
int offset = 0;
int ttl = 64;
int protocol = v_arg_integer(L, 2, "protocol");
int cksum = 0; // 0 is a flag requesting libnet to fill in correct cksum
const char* src = v_arg_string(L, 2, "src");
const char* dst = v_arg_string(L, 2, "dst");
size_t payloadsz = 0;
const char* payload = v_arg_lstring(L, 2, "payload", &payloadsz, "");
int ptag = lnet_arg_ptag(L, 2);
int options_ptag = 0;
size_t optionsz = 0;
const char* options = v_arg_lstring(L, 2, "options", &optionsz, "");
if(payloadsz == 0) {
payload = NULL;
}
#ifdef NET_DUMP
printf("net ipv4 src %s dst %s len %d payloadsz %lu ptag %d optionsz %lu\n", src, dst, len, payloadsz, ptag, optionsz);
#endif
uint32_t src_n = check_ip_pton(L, src, "src");
uint32_t dst_n = check_ip_pton(L, dst, "dst");
if(ptag) {
/* Modifying exist IPv4 packet, so find the preceeding options block (we
* _always_ push an options block, perhaps empty, to make this easy).
*/
libnet_pblock_t* p = libnet_pblock_find(*ud, ptag);
if(!p)
return check_error(L, *ud, -1);
options_ptag = p->prev->ptag;
}
#ifdef NET_DUMP
printf(" options_ptag %d optionsz %lu\n", options_ptag, optionsz);
#endif
options_ptag = libnet_build_ipv4_options((uint8_t*) options,
optionsz, *ud, options_ptag);
check_error(L, *ud, options_ptag);
ptag = libnet_build_ipv4(len, tos, id, offset, ttl, protocol, cksum, src_n,
dst_n, (uint8_t*) payload, payloadsz, *ud, ptag);
check_error(L, *ud, ptag);
lua_pushinteger(L, ptag);
return 1;
}
/*-
- ptag = n:eth{src=ethmac, dst=ethmac, type=int, payload=str, ptag=int}
type is optional, defaults to IP
ptag is optional, defaults to creating a new protocol block
*/
static int lnet_eth (lua_State *L)
{
libnet_t** ud = luaL_checkudata(L, 1, L_NET_REGID);
luaL_argcheck(L, *ud, 1, "net has been destroyed");
const char* src = v_arg_string(L, 2, "src");
const char* dst = v_arg_string(L, 2, "dst");
int type = v_arg_integer_opt(L, 2, "type", ETHERTYPE_IP);
size_t payloadsz = 0;
const char* payload = v_arg_lstring(L, 2, "payload", &payloadsz, "");
int ptag = lnet_arg_ptag(L, 2);
if(payloadsz == 0) {
payload = NULL;
}
#ifdef NET_DUMP
printf("net eth src %s dst %s type %d payloadsz %lu ptag %d\n", src, dst, type, payloadsz, ptag);
#endif
eth_addr_t src_n = check_eth_pton(L, src, "src");
eth_addr_t dst_n = check_eth_pton(L, dst, "dst");
ptag = libnet_build_ethernet(dst_n.data, src_n.data, type, (uint8_t*)payload, payloadsz, *ud, ptag);
check_error(L, *ud, ptag);
lua_pushinteger(L, ptag);
return 1;
}
static const uint8_t*
checklbuffer(lua_State* L, int argt, const char* field, uint32_t* size)
{
size_t payloadsz = 0;
const char* payload = v_arg_lstring(L, argt, field, &payloadsz, "");
if(payloadsz == 0) {
payload = NULL;
}
*size = payloadsz;
return (const uint8_t*) payload;
}
/*-
- ptag = net:udp{src=NUM, dst=NUM, len=NUM, payload=STR, ptag=int}
Build UDP packet inside net context.
ptag is optional, defaults to creating a new protocol block
*/
static int lnet_udp (lua_State *L)
{
libnet_t** ud = luaL_checkudata(L, 1, L_NET_REGID);
luaL_argcheck(L, *ud, 1, "net has been destroyed");
int src = v_arg_integer(L, 2, "src");
int dst = v_arg_integer(L, 2, "dst");
size_t payloadsz = 0;
const char* payload = v_arg_lstring(L, 2, "payload", &payloadsz, "");
int len = v_arg_integer_opt(L, 2, "len", LIBNET_UDP_H + payloadsz);
int cksum = 0;
int ptag = lnet_arg_ptag(L, 2);
if(payloadsz == 0) {
payload = NULL;
}
ptag = libnet_build_udp(src, dst, len, cksum, (uint8_t*)payload, payloadsz, *ud, ptag);
check_error(L, *ud, ptag);
lua_pushinteger(L, ptag);
return 1;
}
static const char* v_arg_string(lua_State* L, int argt, const char* field)
{
return v_arg_lstring(L, argt, field, NULL, NULL);
}
