/* -----------------------------------------------------------------------------
l2tpvpn_refuse - called by vpnd to refuse an incomming connection.
return values: -1 error
socket# launch pppd with next server address
0 handled, do nothing
----------------------------------------------------------------------------- */
int l2tpvpn_refuse(void)
{
u_int8_t recv_buf[1500];
int addrlen;
struct sockaddr_in6 from;
int newSockfd;
/* we should check if there are too many call from the same IP address
in the last xxx minutes, proving a denial of service attack */
/* need t read the packet to empty the socket buffer */
while((newSockfd = socket(PF_PPP, SOCK_DGRAM, PPPPROTO_L2TP)) < 0)
if (errno != EINTR) {
vpnlog(LOG_ERR, "VPND L2TP plugin: Unable to open L2TP socket during refuse\n");
return -1;
}
/* accept the call. it will copy the data to the new socket */
setsockopt(newSockfd, PPPPROTO_L2TP, L2TP_OPT_ACCEPT, 0, 0);
/* and close it right away */
close(newSockfd);
/* read the duplicated SCCRQ from the listen socket and ignore for now */
if (l2tp_sys_recvfrom(listen_sockfd, recv_buf, 1500, MSG_DONTWAIT, (struct sockaddr*)&from, &addrlen) < 0)
return -1;
return 0;
}
/* -----------------------------------------------------------------------------
l2tpvpn_accept
----------------------------------------------------------------------------- */
int l2tpvpn_accept(void)
{
u_int8_t recv_buf[1500];
socklen_t addrlen;
struct sockaddr_in6 from;
int newSockfd;
/* we should check if there are too many call from the same IP address
in the last xxx minutes, proving a denial of service attack */
while((newSockfd = socket(PF_PPP, SOCK_DGRAM, PPPPROTO_L2TP)) < 0)
if (errno != EINTR) {
vpnlog(LOG_ERR, "L2TP plugin: Unable to open L2TP socket during accept\n");
return -1;
}
/* accept the call. it will copy the data to the new socket */
//set_flag(newSockfd, kerneldebug & 1, L2TP_FLAG_DEBUG);
setsockopt(newSockfd, PPPPROTO_L2TP, L2TP_OPT_ACCEPT, 0, 0);
/* read the duplicated SCCRQ from the listen socket and ignore for now */
if (l2tp_sys_recvfrom(listen_sockfd, recv_buf, 1500, MSG_DONTWAIT, (struct sockaddr*)&from, &addrlen) < 0)
return -1;
return newSockfd;
}