int nl_init_event_handler(void)
{
STATE(event) = nfct_open(CONNTRACK, NFCT_ALL_CT_GROUPS);
if (!STATE(event))
return -1;
fcntl(nfct_fd(STATE(event)), F_SETFL, O_NONBLOCK);
/* set up socket buffer size */
if (CONFIG(netlink_buffer_size))
nfnl_rcvbufsiz(nfct_nfnlh(STATE(event)),
CONFIG(netlink_buffer_size));
else {
socklen_t socklen = sizeof(unsigned int);
unsigned int read_size;
/* get current buffer size */
getsockopt(nfct_fd(STATE(event)), SOL_SOCKET,
SO_RCVBUF, &read_size, &socklen);
CONFIG(netlink_buffer_size) = read_size;
}
/* ensure that maximum grown size is >= than maximum size */
if (CONFIG(netlink_buffer_size_max_grown) < CONFIG(netlink_buffer_size))
CONFIG(netlink_buffer_size_max_grown) =
CONFIG(netlink_buffer_size);
/* register callback for events */
nfct_callback_register(STATE(event), NFCT_T_ALL, event_handler, NULL);
return 0;
}
/*-
-- cthandle = nfct.setblocking(cthandle, [blocking])
blocking is true to set blocking, and false to set non-blocking (default is false)
Return is cthandle on success, or nil,emsg,errno on failure.
*/
static int setblocking(lua_State* L)
{
return nfsetblocking(L, nfct_fd(check_cthandle(L)));
}
/*-
-- fd = nfct.fd(cthandle)
Return the underlying fd used by the conntrack handle, useful for
selecting on.
*/
static int fd(lua_State* L)
{
struct nfct_handle* cthandle = check_cthandle(L);
lua_pushinteger(L, nfct_fd(cthandle));
return 1;
}
struct nfct_handle *nl_init_event_handler(void)
{
struct nfct_handle *h;
h = nfct_open(CONFIG(netlink).subsys_id, CONFIG(netlink).groups);
if (h == NULL)
return NULL;
if (CONFIG(netlink).events_reliable) {
int on = 1;
setsockopt(nfct_fd(h), SOL_NETLINK,
NETLINK_BROADCAST_SEND_ERROR, &on, sizeof(int));
setsockopt(nfct_fd(h), SOL_NETLINK,
NETLINK_NO_ENOBUFS, &on, sizeof(int));
dlog(LOG_NOTICE, "reliable ctnetlink event delivery "
"is ENABLED.");
}
if (STATE(filter)) {
if (CONFIG(filter_from_kernelspace)) {
if (nfct_filter_attach(nfct_fd(h),
STATE(filter)) == -1) {
dlog(LOG_ERR, "cannot set event filtering: %s",
strerror(errno));
}
dlog(LOG_NOTICE, "using kernel-space event filtering");
} else
dlog(LOG_NOTICE, "using user-space event filtering");
nfct_filter_destroy(STATE(filter));
}
fcntl(nfct_fd(h), F_SETFL, O_NONBLOCK);
/* set up socket buffer size */
if (CONFIG(netlink_buffer_size) &&
CONFIG(netlink_buffer_size) <=
CONFIG(netlink_buffer_size_max_grown)) {
/* we divide netlink_buffer_size by 2 here since value passed
to kernel gets doubled in SO_RCVBUF; see net/core/sock.c */
CONFIG(netlink_buffer_size) =
nfnl_rcvbufsiz(nfct_nfnlh(h), CONFIG(netlink_buffer_size)/2);
} else {
dlog(LOG_NOTICE, "NetlinkBufferSize is either not set or "
"is greater than NetlinkBufferSizeMaxGrowth. "
"Using current system buffer size");
socklen_t socklen = sizeof(unsigned int);
unsigned int read_size;
/* get current buffer size */
getsockopt(nfct_fd(h), SOL_SOCKET,
SO_RCVBUF, &read_size, &socklen);
CONFIG(netlink_buffer_size) = read_size;
}
dlog(LOG_NOTICE, "netlink event socket buffer size has been set "
"to %u bytes", CONFIG(netlink_buffer_size));
return h;
}
