/*
* tcp_detach is called when the socket layer loses its final reference
* to the socket, be it a file descriptor reference, a reference from TCP,
* etc. At this point, there is only one case in which we will keep around
* inpcb state: time wait.
*
* This function can probably be re-absorbed back into tcp_usr_detach() now
* that there is a single detach path.
*/
static void
tcp_detach(struct socket *so, struct inpcb *inp)
{
struct tcpcb *tp;
INP_INFO_WLOCK_ASSERT(&V_tcbinfo);
INP_WLOCK_ASSERT(inp);
KASSERT(so->so_pcb == inp, ("tcp_detach: so_pcb != inp"));
KASSERT(inp->inp_socket == so, ("tcp_detach: inp_socket != so"));
tp = intotcpcb(inp);
if (inp->inp_flags & INP_TIMEWAIT) {
/*
* There are two cases to handle: one in which the time wait
* state is being discarded (INP_DROPPED), and one in which
* this connection will remain in timewait. In the former,
* it is time to discard all state (except tcptw, which has
* already been discarded by the timewait close code, which
* should be further up the call stack somewhere). In the
* latter case, we detach from the socket, but leave the pcb
* present until timewait ends.
*
* XXXRW: Would it be cleaner to free the tcptw here?
*/
if (inp->inp_flags & INP_DROPPED) {
KASSERT(tp == NULL, ("tcp_detach: INP_TIMEWAIT && "
"INP_DROPPED && tp != NULL"));
in_pcbdetach(inp);
in_pcbfree(inp);
} else {
in_pcbdetach(inp);
INP_WUNLOCK(inp);
}
} else {
/*
* If the connection is not in timewait, we consider two
* two conditions: one in which no further processing is
* necessary (dropped || embryonic), and one in which TCP is
* not yet done, but no longer requires the socket, so the
* pcb will persist for the time being.
*
* XXXRW: Does the second case still occur?
*/
if (inp->inp_flags & INP_DROPPED ||
tp->t_state < TCPS_SYN_SENT) {
tcp_discardcb(tp);
in_pcbdetach(inp);
in_pcbfree(inp);
} else
in_pcbdetach(inp);
}
}
/*
* Move a TCP connection into TIME_WAIT state.
* tcbinfo is locked.
* inp is locked, and is unlocked before returning.
*/
void
tcp_twstart(struct tcpcb *tp)
{
struct tcptw *tw;
struct inpcb *inp = tp->t_inpcb;
int acknow;
struct socket *so;
#ifdef INET6
//ScenSim-Port// int isipv6 = inp->inp_inc.inc_flags & INC_ISIPV6;
#endif
//ScenSim-Port// INP_INFO_WLOCK_ASSERT(&V_tcbinfo); /* tcp_tw_2msl_reset(). */
//ScenSim-Port// INP_WLOCK_ASSERT(inp);
//ScenSim-Port// if (V_nolocaltimewait) {
//ScenSim-Port// int error = 0;
//ScenSim-Port//#ifdef INET6
//ScenSim-Port// if (isipv6)
//ScenSim-Port// error = in6_localaddr(&inp->in6p_faddr);
//ScenSim-Port//#endif
//ScenSim-Port//#if defined(INET6) && defined(INET)
//ScenSim-Port// else
//ScenSim-Port//#endif
//ScenSim-Port//#ifdef INET
//ScenSim-Port// error = in_localip(inp->inp_faddr);
//ScenSim-Port//#endif
//ScenSim-Port// if (error) {
//ScenSim-Port// tp = tcp_close(tp);
//ScenSim-Port// if (tp != NULL)
//ScenSim-Port// INP_WUNLOCK(inp);
//ScenSim-Port// return;
//ScenSim-Port// }
//ScenSim-Port// }
//ScenSim-Port// tw = uma_zalloc(V_tcptw_zone, M_NOWAIT);
tw = (struct tcptw *)uma_zalloc(V_tcptw_zone, M_NOWAIT); //ScenSim-Port//
if (tw == NULL) {
tw = tcp_tw_2msl_scan(1);
if (tw == NULL) {
tp = tcp_close(tp);
//ScenSim-Port// if (tp != NULL)
//ScenSim-Port// INP_WUNLOCK(inp);
return;
}
}
tw->tw_inpcb = inp;
/*
* Recover last window size sent.
*/
//ScenSim-Port// KASSERT(SEQ_GEQ(tp->rcv_adv, tp->rcv_nxt),
//ScenSim-Port// ("tcp_twstart negative window: tp %p rcv_nxt %u rcv_adv %u", tp,
//ScenSim-Port// tp->rcv_nxt, tp->rcv_adv));
tw->last_win = (tp->rcv_adv - tp->rcv_nxt) >> tp->rcv_scale;
/*
* Set t_recent if timestamps are used on the connection.
*/
if ((tp->t_flags & (TF_REQ_TSTMP|TF_RCVD_TSTMP|TF_NOOPT)) ==
(TF_REQ_TSTMP|TF_RCVD_TSTMP)) {
tw->t_recent = tp->ts_recent;
tw->ts_offset = tp->ts_offset;
} else {
tw->t_recent = 0;
tw->ts_offset = 0;
}
tw->snd_nxt = tp->snd_nxt;
tw->rcv_nxt = tp->rcv_nxt;
tw->iss = tp->iss;
tw->irs = tp->irs;
tw->t_starttime = tp->t_starttime;
tw->tw_time = 0;
/* XXX
* If this code will
* be used for fin-wait-2 state also, then we may need
* a ts_recent from the last segment.
*/
acknow = tp->t_flags & TF_ACKNOW;
/*
* First, discard tcpcb state, which includes stopping its timers and
* freeing it. tcp_discardcb() used to also release the inpcb, but
* that work is now done in the caller.
*
* Note: soisdisconnected() call used to be made in tcp_discardcb(),
* and might not be needed here any longer.
*/
tcp_discardcb(tp);
so = inp->inp_socket;
soisdisconnected(so);
//ScenSim-Port// tw->tw_cred = crhold(so->so_cred);
//ScenSim-Port// SOCK_LOCK(so);
tw->tw_so_options = so->so_options;
//ScenSim-Port// SOCK_UNLOCK(so);
if (acknow)
tcp_twrespond(tw, TH_ACK);
inp->inp_ppcb = tw;
inp->inp_flags |= INP_TIMEWAIT;
tcp_tw_2msl_reset(tw, 0);
/*
* If the inpcb owns the sole reference to the socket, then we can
* detach and free the socket as it is not needed in time wait.
*/
if (inp->inp_flags & INP_SOCKREF) {
//ScenSim-Port// KASSERT(so->so_state & SS_PROTOREF,
//ScenSim-Port// ("tcp_twstart: !SS_PROTOREF"));
inp->inp_flags &= ~INP_SOCKREF;
//ScenSim-Port// INP_WUNLOCK(inp);
//ScenSim-Port// ACCEPT_LOCK();
//ScenSim-Port// SOCK_LOCK(so);
so->so_state &= ~SS_PROTOREF;
sofree(so);
} else
//ScenSim-Port// INP_WUNLOCK(inp);
; //ScenSim-Port//
}
