Differential D16471 Diff 45916 FreeBSD/sys/netinet/tcp_reass.c

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FreeBSD/sys/netinet/tcp_reass.c

Show First 20 Lines • Show All 158 Lines • ▼ Show 20 Lines	tcp_reass(struct tcpcb tp, struct tcphdr th, int tlenp, struct mbuf m)

/*		/*
* Call with th==NULL after become established to		* Call with th==NULL after become established to
* force pre-ESTABLISHED data up to user socket.		* force pre-ESTABLISHED data up to user socket.
*/		*/
if (th == NULL)		if (th == NULL)
goto present;		goto present;

		KASSERT(SEQ_GEQ(th->th_seq, tp->rcv_nxt),
		("Attempt to add old entry to reassembly queue (th=%p, tp=%p)",
		th, tp));

/*		/*
* Limit the number of segments that can be queued to reduce the		* Limit the number of segments that can be queued to reduce the
* potential for mbuf exhaustion. For best performance, we want to be		* potential for mbuf exhaustion. For best performance, we want to be
* able to queue a full window's worth of segments. The size of the		* able to queue a full window's worth of segments. The size of the
* socket receive buffer determines our advertised window and grows		* socket receive buffer determines our advertised window and grows
* automatically when socket buffer autotuning is enabled. Use it as the		* automatically when socket buffer autotuning is enabled. Use it as the
* basis for our queue limit.		* basis for our queue limit.
* Always let the missing segment through which caused this queue.		* Always let the missing segment through which caused this queue.
▲ Show 20 Lines • Show All 65 Lines • ▼ Show 20 Lines	tcp_reass(struct tcpcb tp, struct tcphdr th, int tlenp, struct mbuf m)
* If there is a preceding segment, it may provide some of		* If there is a preceding segment, it may provide some of
* our data already. If so, drop the data from the incoming		* our data already. If so, drop the data from the incoming
* segment. If it provides all of our data, drop us.		* segment. If it provides all of our data, drop us.
*/		*/
if (p != NULL) {		if (p != NULL) {
int i;		int i;
/* conversion to int (in i) handles seq wraparound */		/* conversion to int (in i) handles seq wraparound */
i = p->tqe_th->th_seq + p->tqe_len - th->th_seq;		i = p->tqe_th->th_seq + p->tqe_len - th->th_seq;
if (i > 0) {		if (i >= 0) {
if (i >= *tlenp) {		if (i >= *tlenp) {
TCPSTAT_INC(tcps_rcvduppack);		TCPSTAT_INC(tcps_rcvduppack);
TCPSTAT_ADD(tcps_rcvdupbyte, *tlenp);		TCPSTAT_ADD(tcps_rcvdupbyte, *tlenp);
		p->tqe_th->th_flags \|= (th->th_seq & TH_FIN);
m_freem(m);		m_freem(m);
if (te != &tqs)		if (te != &tqs)
uma_zfree(tcp_reass_zone, te);		uma_zfree(tcp_reass_zone, te);
tp->t_segqlen--;		tp->t_segqlen--;
/*		/*
* Try to present any queued data		* Try to present any queued data
* at the left window edge to the user.		* at the left window edge to the user.
* This is needed after the 3-WHS		* This is needed after the 3-WHS
* completes.		* completes.
*/		*/
goto present; /* ??? */		goto present; /* ??? */
}		}
		if (i > 0) {
m_adj(m, i);		m_adj(m, i);
*tlenp -= i;		*tlenp -= i;
th->th_seq += i;		th->th_seq += i;
}		}
}		}
		}
tp->t_rcvoopack++;		tp->t_rcvoopack++;
TCPSTAT_INC(tcps_rcvoopack);		TCPSTAT_INC(tcps_rcvoopack);
TCPSTAT_ADD(tcps_rcvoobyte, *tlenp);		TCPSTAT_ADD(tcps_rcvoobyte, *tlenp);

/*		/*
* While we overlap succeeding segments trim them or,		* While we overlap succeeding segments trim them or,
* if they are completely covered, dequeue them.		* if they are completely covered, dequeue them.
*/		*/
Show All 21 Lines	tcp_reass(struct tcpcb tp, struct tcphdr th, int tlenp, struct mbuf m)
te->tqe_th = th;		te->tqe_th = th;
te->tqe_len = *tlenp;		te->tqe_len = *tlenp;

if (p == NULL) {		if (p == NULL) {
LIST_INSERT_HEAD(&tp->t_segq, te, tqe_q);		LIST_INSERT_HEAD(&tp->t_segq, te, tqe_q);
} else {		} else {
KASSERT(te != &tqs, ("%s: temporary stack based entry not "		KASSERT(te != &tqs, ("%s: temporary stack based entry not "
"first element in queue", __func__));		"first element in queue", __func__));
		if (te == &tqs)
		tp->t_segqlen--;
		else
LIST_INSERT_AFTER(p, te, tqe_q);		LIST_INSERT_AFTER(p, te, tqe_q);
}		}

present:		present:
/*		/*
* Present data to user, advancing rcv_nxt through		* Present data to user, advancing rcv_nxt through
* completed sequence space.		* completed sequence space.
*/		*/
if (!TCPS_HAVEESTABLISHED(tp->t_state))		if (!TCPS_HAVEESTABLISHED(tp->t_state))
return (0);		return (0);
q = LIST_FIRST(&tp->t_segq);		q = LIST_FIRST(&tp->t_segq);
		KASSERT(q == NULL \|\| SEQ_GEQ(q->tqe_th->th_seq, tp->rcv_nxt),
		("Reassembly queue for %p has stale entry at head", tp));
if (!q \|\| q->tqe_th->th_seq != tp->rcv_nxt)		if (!q \|\| q->tqe_th->th_seq != tp->rcv_nxt)
return (0);		return (0);
SOCKBUF_LOCK(&so->so_rcv);		SOCKBUF_LOCK(&so->so_rcv);
do {		do {
tp->rcv_nxt += q->tqe_len;		tp->rcv_nxt += q->tqe_len;
flags = q->tqe_th->th_flags & TH_FIN;		flags = q->tqe_th->th_flags & TH_FIN;
nq = LIST_NEXT(q, tqe_q);		nq = LIST_NEXT(q, tqe_q);
LIST_REMOVE(q, tqe_q);		LIST_REMOVE(q, tqe_q);
Show All 12 Lines