/*------------------------------------------------------------------------
* tcpestablished - do ESTABLISHED state input processing
*------------------------------------------------------------------------
*/
int
tcpestablished(struct tcb *ptcb, struct ep *pep)
{
struct ip *pip = (struct ip *)pep->ep_data;
struct tcp *ptcp = (struct tcp *)pip->ip_data;
if (ptcp->tcp_code & TCPF_RST) {
TcpEstabResets++;
TcpCurrEstab--;
return tcpabort(ptcb, TCPE_RESET);
}
if (ptcp->tcp_code & TCPF_SYN) {
TcpEstabResets++;
TcpCurrEstab--;
tcpreset(pep);
return tcpabort(ptcb, TCPE_RESET);
}
if (tcpacked(ptcb, pep) == SYSERR)
return OK;
tcpdata(ptcb, pep);
tcpswindow(ptcb, pep);
if (ptcb->tcb_flags & TCBF_RDONE)
ptcb->tcb_state = TCPS_CLOSEWAIT;
return OK;
}
/*------------------------------------------------------------------------
* tcptimewait - do TIME_WAIT state input processing
*------------------------------------------------------------------------
*/
int
tcptimewait(struct tcb *ptcb, struct ep *pep)
{
struct ip *pip = (struct ip *)pep->ep_data;
struct tcp *ptcp = (struct tcp *)pip->ip_data;
if (ptcp->tcp_code & TCPF_RST)
return tcbdealloc(ptcb);
if (ptcp->tcp_code & TCPF_SYN) {
tcpreset(pep);
return tcbdealloc(ptcb);
}
tcpacked(ptcb, pep);
tcpdata(ptcb, pep); /* just ACK any packets */
tcpwait(ptcb);
return OK;
}
/*------------------------------------------------------------------------
* tcpinp - handle TCP segment coming in from IP
*------------------------------------------------------------------------
*/
PROCESS
tcpinp(void)
{
struct ep *pep;
struct ip *pip;
struct tcp *ptcp;
struct tcb *ptcb;
tcps_iport = pcreate(TCPQLEN);
signal(Net.sema);
while (TRUE) {
pep = (struct ep *)preceive(tcps_iport);
if ((int)pep == SYSERR)
break;
pip = (struct ip *)pep->ep_data;
if (tcpcksum(pep, pip->ip_len - IP_HLEN(pip))) {
++TcpInErrs;
freebuf(pep);
continue;
}
ptcp = (struct tcp *)pip->ip_data;
tcpnet2h(ptcp); /* convert all fields to host order */
pep->ep_order |= EPO_TCP;
ptcb = tcpdemux(pep);
if (ptcb == 0) {
++TcpInErrs;
tcpreset(pep);
freebuf(pep);
continue;
}
if (!tcpok(ptcb, pep))
tcpackit(ptcb, pep);
else {
tcpopts(ptcb, pep);
tcpswitch[ptcb->tcb_state](ptcb, pep);
}
if (ptcb->tcb_state != TCPS_FREE)
signal(ptcb->tcb_mutex);
freebuf(pep);
}
}
/*------------------------------------------------------------------------
* tcpfin2 - do FIN_WAIT_2 state input processing
*------------------------------------------------------------------------
*/
int
tcpfin2(struct tcb *ptcb, struct ep *pep)
{
struct ip *pip = (struct ip *)pep->ep_data;
struct tcp *ptcp = (struct tcp *)pip->ip_data;
if (ptcp->tcp_code & TCPF_RST)
return tcpabort(ptcb, TCPE_RESET);
if (ptcp->tcp_code & TCPF_SYN) {
tcpreset(pep);
return tcpabort(ptcb, TCPE_RESET);
}
if (tcpacked(ptcb, pep) == SYSERR)
return OK;
tcpdata(ptcb, pep); /* for data + FIN ACKing */
if (ptcb->tcb_flags & TCBF_RDONE) {
ptcb->tcb_state = TCPS_TIMEWAIT;
tcpwait(ptcb);
}
return OK;
}
/*------------------------------------------------------------------------
* tcpclosed - do CLOSED state processing
*------------------------------------------------------------------------
*/
int
tcpclosed(struct tcb *ptcb, struct ep *pep)
{
tcpreset(pep);
return SYSERR;
}
