File content as of revision 140:9000ea70b220:

#include <stdint.h>

#include   "log.h"
#include   "tcp.h"
#include   "tcb.h"

#define TCB_COUNT 20

struct tcb tcbs[TCB_COUNT];

uint32_t TcbGetIsn()
{
    static uint32_t isn = 0;
    isn += 100000; //Gives each tcb 100,000 packets and won't repeat before 42,940 tcbs.
    return isn;
}
struct tcb* TcbGetExisting(int ipType, int remArIndex, int locIpScope, uint16_t remPort, uint16_t locPort)
{
    for (int i = 0; i < TCB_COUNT; i++)
    {
        struct tcb* pTcb = tcbs + i;
        if (pTcb->state                    && 
            pTcb->ipType     == ipType     &&
            pTcb->remArIndex == remArIndex &&
            pTcb->locIpScope == locIpScope &&
            pTcb->remPort    == remPort    &&
            pTcb->locPort    == locPort) return pTcb;
    }
    return NULL;
}
struct tcb* TcbGetEmpty()
{
    for (int i = 0; i < TCB_COUNT; i++)
    {
        struct tcb* pTcb = tcbs + i;
        if (pTcb->state == TCB_EMPTY) return pTcb;
    }
    return NULL;
}
struct tcb* TcbGetNext(struct tcb* pTcb)
{
    if (!pTcb) return tcbs; //Initialise if passed NULL
    ++pTcb; //Increment
    if (pTcb < tcbs + TCB_COUNT) return pTcb;
    else                         return tcbs;
    
}
void TcbInit()
{
    for (int i = 0; i < TCB_COUNT; i++) tcbs[i].state = TCB_EMPTY;
}