int
tcp_reass(struct tcpcb *tp,struct tcpiphdr *ti, usn_mbuf_t *m)
{
struct tcpiphdr *q;
struct usn_socket *so = tp->t_inpcb->inp_socket;
int flags;
// Call with ti==0 after become established to
// force pre-ESTABLISHED data up to user socket.
if (ti == 0)
goto present;
// Find a segment which begins after this one does.
for (q = tp->seg_next; q != (struct tcpiphdr *)tp;
q = (struct tcpiphdr *)q->ti_next)
if (SEQ_GT(q->ti_seq, ti->ti_seq))
break;
// If there is a preceding segment, it may provide some of
// our data already. If so, drop the data from the incoming
// segment. If it provides all of our data, drop us.
if ((struct tcpiphdr *)q->ti_prev != (struct tcpiphdr *)tp) {
int i;
q = (struct tcpiphdr *)q->ti_prev;
// conversion to int (in i) handles seq wraparound
i = q->ti_seq + q->ti_len - ti->ti_seq;
if (i > 0) {
if (i >= ti->ti_len) {
g_tcpstat.tcps_rcvduppack++;
g_tcpstat.tcps_rcvdupbyte += ti->ti_len;
usn_free_mbuf(m);
return (0);
}
m_adj(m, i);
ti->ti_len -= i;
ti->ti_seq += i;
}
q = (struct tcpiphdr *)(q->ti_next);
}
g_tcpstat.tcps_rcvoopack++;
g_tcpstat.tcps_rcvoobyte += ti->ti_len;
REASS_MBUF(ti) = m; // XXX: wrong assumtion dst and src port for mbuf pointer
// While we overlap succeeding segments trim them or,
// if they are completely covered, dequeue them.
while (q != (struct tcpiphdr *)tp) {
int i = (ti->ti_seq + ti->ti_len) - q->ti_seq;
if (i <= 0)
break;
if (i < q->ti_len) {
q->ti_seq += i;
q->ti_len -= i;
m_adj(REASS_MBUF(q), i);
break;
}
q = (struct tcpiphdr *)q->ti_next;
m = REASS_MBUF((struct tcpiphdr *)q->ti_prev);
// FIXME
//remque(q->ti_prev);
usn_free_mbuf(m);
}
// FIXME: Stick new segment in its place.
//insque(ti, q->ti_prev);
present:
// Present data to user, advancing rcv_nxt through
// completed sequence space.
if (TCPS_HAVERCVDSYN(tp->t_state) == 0)
return (0);
ti = tp->seg_next;
if (ti == (struct tcpiphdr *)tp || ti->ti_seq != tp->rcv_nxt)
return (0);
if (tp->t_state == TCPS_SYN_RECEIVED && ti->ti_len)
return (0);
do {
tp->rcv_nxt += ti->ti_len;
flags = ti->ti_flags & TH_FIN;
// FIXME
//remque(ti);
m = REASS_MBUF(ti);
ti = (struct tcpiphdr *)ti->ti_next;
if (so->so_state & USN_CANTRCVMORE) {
usn_free_mbuf(m);
} else {
sbappend(so->so_rcv, m);
}
} while (ti != (struct tcpiphdr *)tp && ti->ti_seq == tp->rcv_nxt);
sorwakeup(so);
usnet_tcpin_rwakeup(so, USN_TCP_IN, USN_TCPEV_READ, m);
return (flags);
}
int tcp_reass(struct tcpcb *tp, struct tcpiphdr *ti, struct mbuf *m)
{
register struct tcpiphdr *q;
struct socket *so = tp->t_socket;
int flags;
/*
* Call with ti==0 after become established to
* force pre-ESTABLISHED data up to user socket.
*/
if (ti == 0)
goto present;
/*
* Find a segment which begins after this one does.
*/
for (q = (struct tcpiphdr *)tp->seg_next; q != (struct tcpiphdr *)tp;
q = (struct tcpiphdr *)q->ti_next)
if (SEQ_GT(q->ti_seq, ti->ti_seq))
break;
/*
* If there is a preceding segment, it may provide some of
* our data already. If so, drop the data from the incoming
* segment. If it provides all of our data, drop us.
*/
if ((struct tcpiphdr *)q->ti_prev != (struct tcpiphdr *)tp) {
register int i;
q = (struct tcpiphdr *)q->ti_prev;
/* conversion to int (in i) handles seq wraparound */
i = q->ti_seq + q->ti_len - ti->ti_seq;
if (i > 0) {
if (i >= ti->ti_len) {
tcpstat.tcps_rcvduppack++;
tcpstat.tcps_rcvdupbyte += ti->ti_len;
m_freem(m);
/*
* Try to present any queued data
* at the left window edge to the user.
* This is needed after the 3-WHS
* completes.
*/
goto present; /* ??? */
}
m_adj(m, i);
ti->ti_len -= i;
ti->ti_seq += i;
}
q = (struct tcpiphdr *)(q->ti_next);
}
tcpstat.tcps_rcvoopack++;
tcpstat.tcps_rcvoobyte += ti->ti_len;
REASS_MBUF(ti) = (mbufp_32) m; /* XXX */
/*
* While we overlap succeeding segments trim them or,
* if they are completely covered, dequeue them.
*/
while (q != (struct tcpiphdr *)tp) {
register int i = (ti->ti_seq + ti->ti_len) - q->ti_seq;
if (i <= 0)
break;
if (i < q->ti_len) {
q->ti_seq += i;
q->ti_len -= i;
m_adj((struct mbuf *) REASS_MBUF(q), i);
break;
}
q = (struct tcpiphdr *)q->ti_next;
m = (struct mbuf *) REASS_MBUF((struct tcpiphdr *)q->ti_prev);
slirp_remque((void *)(q->ti_prev));
m_freem(m);
}
/*
* Stick new segment in its place.
*/
slirp_insque(ti, (void *)(q->ti_prev));
present:
/*
* Present data to user, advancing rcv_nxt through
* completed sequence space.
*/
if (!TCPS_HAVEESTABLISHED(tp->t_state))
return (0);
ti = (struct tcpiphdr *) tp->seg_next;
if (ti == (struct tcpiphdr *)tp || ti->ti_seq != tp->rcv_nxt)
return (0);
if (tp->t_state == TCPS_SYN_RECEIVED && ti->ti_len)
return (0);
do {
tp->rcv_nxt += ti->ti_len;
flags = ti->ti_flags & TH_FIN;
slirp_remque(ti);
m = (struct mbuf *) REASS_MBUF(ti); /* XXX */
ti = (struct tcpiphdr *)ti->ti_next;
/* if (so->so_state & SS_FCANTRCVMORE) */
if (so->so_state & SS_FCANTSENDMORE)
m_freem(m);
else {
if (so->so_emu) {
if (tcp_emu(so,m)) sbappend(so, m);
} else
sbappend(so, m);
}
} while (ti != (struct tcpiphdr *)tp && ti->ti_seq == tp->rcv_nxt);
/* sorwakeup(so); */
return (flags);
}
