int connection_tracking(packetinfo *pi)
{
struct in6_addr *ip_src;
struct in6_addr *ip_dst;
struct in6_addr ips;
struct in6_addr ipd;
uint16_t src_port = pi->s_port;
uint16_t dst_port = pi->d_port;
int af = pi->af;
connection *cxt = NULL;
connection *head = NULL;
uint32_t hash;
if(af == AF_INET6){
ip_src = &PI_IP6SRC(pi);
ip_dst = &PI_IP6DST(pi);
}
else {
ips.s6_addr32[0] = pi->ip4->ip_src;
ipd.s6_addr32[0] = pi->ip4->ip_dst;
ip_src = &ips;
ip_dst = &ipd;
}
/* Find the right connection bucket */
if (af == AF_INET) {
hash = CXT_HASH4(IP4ADDR(ip_src), IP4ADDR(ip_dst), src_port, dst_port,
pi->proto);
}
else if (af == AF_INET6) {
hash = CXT_HASH6(ip_src, ip_dst, src_port, dst_port, pi->proto);
}
else {
dlog("[D] Only CTX with AF_INET and AF_INET6 are supported: %d\n", af);
return 0;
}
cxt = bucket[hash];
head = cxt;
/* Search through the bucket */
while (cxt != NULL)
{
/* Two-way compare of given connection against connection table */
if (af == AF_INET) {
if (CMP_CXT4(cxt, IP4ADDR(ip_src), src_port, IP4ADDR(ip_dst), dst_port)) {
/* Client sends first packet (TCP/SYN - UDP?) hence this is a client */
dlog("[D] Found existing v4 client connection.\n");
return cxt_update_client(cxt, pi);
}
else if (CMP_CXT4(cxt, IP4ADDR(ip_dst), dst_port, IP4ADDR(ip_src), src_port)) {
if (pi->sc == SC_SERVER) {
/* This is a server */
dlog("[D] Found existing v4 server connection.\n");
return cxt_update_server(cxt, pi);
} else {
/* This is a client, where we saw a mid-stream DNS response first */
dlog("[D] Found existing unknown v4 server connection.\n");
return cxt_update_client(cxt, pi);
}
}
}
else if (af == AF_INET6) {
if (CMP_CXT6(cxt, ip_src, src_port, ip_dst, dst_port)) {
dlog("[D] Found existing v6 client connection.\n");
return cxt_update_client(cxt, pi);
}
else if (CMP_CXT6(cxt, ip_dst, dst_port, ip_src, src_port)) {
dlog("[D] Found existing v6 client connection.\n");
return cxt_update_server(cxt, pi);
}
}
cxt = cxt->next;
}
/* Bucket turned upside down didn't yield anything. New connection */
dlog("[D] New connection.\n");
cxt = cxt_new(pi);
/* New connections are pushed on to the head of bucket[s_hash] */
cxt->next = head;
if (head != NULL) {
/* Are we double linked? */
head->prev = cxt;
}
bucket[hash] = cxt;
pi->cxt = cxt;
return cxt_update_unknown(cxt, pi);
}
int cx_track(packetinfo *pi) {
struct in6_addr *ip_src;
struct in6_addr *ip_dst;
struct in6_addr ips;
struct in6_addr ipd;
uint16_t src_port = pi->s_port;
uint16_t dst_port = pi->d_port;
int af = pi->af;
connection *cxt = NULL;
connection *head = NULL;
uint32_t hash;
if(af== AF_INET6){
ip_src = &PI_IP6SRC(pi);
ip_dst = &PI_IP6DST(pi);
}else {
// ugly hack :(
// the way we do ip4/6 is DIRTY
// FIX IT?!!?
ips.s6_addr32[0] = pi->ip4->ip_src;
ipd.s6_addr32[0] = pi->ip4->ip_dst;
ip_src = &ips;
ip_dst = &ipd;
}
// find the right connection bucket
if (af == AF_INET) {
hash = CXT_HASH4(IP4ADDR(ip_src),IP4ADDR(ip_dst));
} else if (af == AF_INET6) {
hash = CXT_HASH6(ip_src,ip_dst);
}
cxt = bucket[hash];
head = cxt;
// search through the bucket
while (cxt != NULL) {
// Two-way compare of given connection against connection table
if (af == AF_INET) {
if (CMP_CXT4(cxt,IP4ADDR(ip_src),src_port,IP4ADDR(ip_dst),dst_port)){
// Client sends first packet (TCP/SYN - UDP?) hence this is a client
return cxt_update_client(cxt, pi);
} else if (CMP_CXT4(cxt,IP4ADDR(ip_dst),dst_port,IP4ADDR(ip_src),src_port)) {
// This is a server (Maybe not when we start up but in the long run)
return cxt_update_server(cxt, pi);
}
} else if (af == AF_INET6) {
if (CMP_CXT6(cxt,ip_src,src_port,ip_dst,dst_port)){
return cxt_update_client(cxt, pi);
} else if (CMP_CXT6(cxt,ip_dst,dst_port,ip_src,src_port)){
return cxt_update_server(cxt, pi);
}
}
cxt = cxt->next;
}
// bucket turned upside down didn't yeild anything. new connection
cxt = cxt_new(pi);
if(config.cflags & CONFIG_CXWRITE)
log_connection(cxt, stdout, CX_NEW);
/* * New connections are pushed on to the head of bucket[s_hash] */
cxt->next = head;
if (head != NULL) {
// are we doubly linked?
head->prev = cxt;
}
bucket[hash] = cxt;
pi->cxt = cxt;
/* * Return value should be 1, telling to do client service fingerprinting */
return 1;
}
int connection_tracking(packetinfo *pi) {
struct in6_addr *ip_src;
struct in6_addr *ip_dst;
struct in6_addr ips;
struct in6_addr ipd;
uint16_t src_port = pi->s_port;
uint16_t dst_port = pi->d_port;
int af = pi->af;
connection *cxt = NULL;
connection *head = NULL;
uint32_t hash;
if(af== AF_INET6){
ip_src = &PI_IP6SRC(pi);
ip_dst = &PI_IP6DST(pi);
}else {
ips.s6_addr32[0] = pi->ip4->ip_src;
ipd.s6_addr32[0] = pi->ip4->ip_dst;
ip_src = &ips;
ip_dst = &ipd;
}
// find the right connection bucket
if (af == AF_INET) {
hash = CXT_HASH4(IP4ADDR(ip_src),IP4ADDR(ip_dst),src_port,dst_port,pi->proto);
} else if (af == AF_INET6) {
hash = CXT_HASH6(ip_src,ip_dst,src_port,dst_port,pi->proto);
}
cxt = bucket[hash];
head = cxt;
// search through the bucket
while (cxt != NULL) {
// Two-way compare of given connection against connection table
if (af == AF_INET) {
if (CMP_CXT4(cxt,IP4ADDR(ip_src),src_port,IP4ADDR(ip_dst),dst_port)){
// Client sends first packet (TCP/SYN - UDP?) hence this is a client
return cxt_update_client(cxt, pi);
} else if (CMP_CXT4(cxt,IP4ADDR(ip_dst),dst_port,IP4ADDR(ip_src),src_port)) {
// This is a server (Maybe not when we start up but in the long run)
return cxt_update_server(cxt, pi);
}
} else if (af == AF_INET6) {
if (CMP_CXT6(cxt,ip_src,src_port,ip_dst,dst_port)){
return cxt_update_client(cxt, pi);
} else if (CMP_CXT6(cxt,ip_dst,dst_port,ip_src,src_port)){
return cxt_update_server(cxt, pi);
}
}
cxt = cxt->next;
}
// bucket turned upside down didn't yeild anything. new connection
cxt = cxt_new(pi);
/* New connections are pushed on to the head of bucket[s_hash] */
cxt->next = head;
if (head != NULL) {
// are we doubly linked?
head->prev = cxt;
}
bucket[hash] = cxt;
pi->cxt = cxt;
return cxt_update_client(cxt, pi);
}
inline void cxt_update (packetinfo *pi, uint32_t hash)
{
connection *cxt = NULL;
int ret = 0;
/* get our hash bucket and lock it */
cxtbucket *cb = &cxt_hash[hash];
/* see if the bucket already has a connection */
if (cb->cxt == NULL) {
/* no, so get a new one */
cxt = cb->cxt = cxt_dequeue(&cxt_spare_q);
if (cxt == NULL) {
cxt = cb->cxt = connection_alloc();
if (cxt == NULL) {
return;
}
}
/* these are protected by the bucket lock */
cxt->hnext = NULL;
cxt->hprev = NULL;
/* got one, initialize and return */
cxt_new(cxt,pi);
cxt_requeue(cxt, NULL, &cxt_est_q);
cxt->cb = cb;
cxt_update_src(cxt, pi);
pi->cxt = cxt;
return;
}
/* ok, we have a flow in the bucket. Let's find out if it is our flow */
cxt = cb->cxt;
/* see if this is the flow we are looking for */
if (pi->af == AF_INET) {
if (CMP_CXT4(cxt, PI_IP4SRC(pi), pi->s_port, PI_IP4DST(pi), pi->d_port)) {
cxt_update_src(cxt, pi);
ret = 1;
} else if (CMP_CXT4(cxt, PI_IP4DST(pi), pi->d_port, PI_IP4SRC(pi), pi->s_port)) {
cxt_update_dst(cxt, pi);
ret = 1;
}
} else if (pi->af == AF_INET6){
if (CMP_CXT6(cxt, &PI_IP6SRC(pi), pi->s_port, &PI_IP6DST(pi), pi->d_port)) {
cxt_update_src(cxt, pi);
ret = 1;
} else if (CMP_CXT6(cxt, &PI_IP6DST(pi), pi->d_port, &PI_IP6SRC(pi), pi->s_port)) {
cxt_update_dst(cxt, pi);
ret = 1;
}
}
if (ret == 0) {
connection *pcxt = NULL; /* previous connection */
while (cxt != NULL) {
pcxt = cxt; /* pf is not locked at this point */
cxt = cxt->hnext;
if (cxt == NULL) {
/* get us a new one and put it and the list tail */
cxt = pcxt->hnext = cxt_dequeue(&cxt_spare_q);
if (cxt == NULL) {
cxt = cb->cxt = connection_alloc();
if (cxt == NULL) {
return;
}
}
cxt->hnext = NULL;
cxt->hprev = pcxt;
/* initialize and return */
cxt_new(cxt,pi);
cxt_requeue(cxt, NULL, &cxt_est_q);
cxt->cb = cb;
cxt_update_src(cxt, pi);
pi->cxt = cxt;
return;
}
if (pi->af == AF_INET) {
if (CMP_CXT4(cxt, PI_IP4SRC(pi), pi->s_port, PI_IP4DST(pi), pi->d_port)) {
cxt_update_src(cxt, pi);
ret = 1;
} else if (CMP_CXT4(cxt, PI_IP4DST(pi), pi->d_port, PI_IP4SRC(pi), pi->s_port)) {
cxt_update_dst(cxt, pi);
ret = 1;
}
} else if (pi->af == AF_INET6) {
if (CMP_CXT6(cxt, &PI_IP6SRC(pi), pi->s_port, &PI_IP6DST(pi), pi->d_port)) {
cxt_update_src(cxt, pi);
ret = 1;
} else if (CMP_CXT6(cxt, &PI_IP6DST(pi), pi->d_port, &PI_IP6SRC(pi), pi->s_port)) {
cxt_update_dst(cxt, pi);
ret = 1;
}
}
if ( ret != 0) {
/* we found our flow, lets put it on top of the
* hash list -- this rewards active flows */
if (cxt->hnext) cxt->hnext->hprev = cxt->hprev;
if (cxt->hprev) cxt->hprev->hnext = cxt->hnext;
cxt->hnext = cb->cxt;
cxt->hprev = NULL;
cb->cxt->hprev = cxt;
cb->cxt = cxt;
/* found our connection */
pi->cxt = cxt;
return;
}
/* not found, try the next... */
}
}
pi->cxt = cxt;
/* The 'root' connection was our connection, return it. */
return;
}