1 files changed, 5 insertions, 104 deletions

diff --git a/sys/netinet/tcp_input.c b/sys/netinet/tcp_input.c
index 014585b3515a..c1190614a2fd 100644
--- a/sys/netinet/tcp_input.c
+++ b/sys/netinet/tcp_input.c
@@ -561,7 +561,6 @@ tcp_input(struct mbuf **mp, int *offp, int proto)
 	int rstreason = 0;	/* For badport_bandlim accounting purposes */
 	uint8_t iptos;
 	struct m_tag *fwd_tag = NULL;
-	struct epoch_tracker et;
 #ifdef INET6
 	struct ip6_hdr *ip6 = NULL;
 	int isipv6;
@@ -570,7 +569,6 @@ tcp_input(struct mbuf **mp, int *offp, int proto)
 #endif /* INET6 */
 	struct tcpopt to;		/* options in this segment */
 	char *s = NULL;			/* address and port logging */
-	int ti_locked;
 #ifdef TCPDEBUG
 	/*
 	 * The size of tcp_saveipgen must be the size of the max ip header,
@@ -581,6 +579,8 @@ tcp_input(struct mbuf **mp, int *offp, int proto)
 	short ostate = 0;
 #endif
 
+	NET_EPOCH_ASSERT();
+
 #ifdef INET6
 	isipv6 = (mtod(m, struct ip *)->ip_v == 6) ? 1 : 0;
 #endif
@@ -747,19 +747,6 @@ tcp_input(struct mbuf **mp, int *offp, int proto)
 	drop_hdrlen = off0 + off;
 
 	/*
-	 * Locate pcb for segment; if we're likely to add or remove a
-	 * connection then first acquire pcbinfo lock.  There are three cases
-	 * where we might discover later we need a write lock despite the
-	 * flags: ACKs moving a connection out of the syncache, ACKs for a
-	 * connection in TIMEWAIT and SYNs not targeting a listening socket.
-	 */
-	if ((thflags & (TH_FIN | TH_RST)) != 0) {
-		INP_INFO_RLOCK_ET(&V_tcbinfo, et);
-		ti_locked = TI_RLOCKED;
-	} else
-		ti_locked = TI_UNLOCKED;
-
-	/*
 	 * Grab info from PACKET_TAG_IPFORWARD tag prepended to the chain.
 	 */
         if (
@@ -776,13 +763,6 @@ tcp_input(struct mbuf **mp, int *offp, int proto)
 		fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL);
 
 findpcb:
-#ifdef INVARIANTS
-	if (ti_locked == TI_RLOCKED) {
-		INP_INFO_RLOCK_ASSERT(&V_tcbinfo);
-	} else {
-		INP_INFO_WUNLOCK_ASSERT(&V_tcbinfo);
-	}
-#endif
 #ifdef INET6
 	if (isipv6 && fwd_tag != NULL) {
 		struct sockaddr_in6 *next_hop6;
@@ -942,12 +922,6 @@ findpcb:
 	 * XXXRW: It may be time to rethink timewait locking.
 	 */
 	if (inp->inp_flags & INP_TIMEWAIT) {
-		if (ti_locked == TI_UNLOCKED) {
-			INP_INFO_RLOCK_ET(&V_tcbinfo, et);
-			ti_locked = TI_RLOCKED;
-		}
-		INP_INFO_RLOCK_ASSERT(&V_tcbinfo);
-
 		if (thflags & TH_SYN)
 			tcp_dooptions(&to, optp, optlen, TO_SYN);
 		/*
@@ -955,7 +929,6 @@ findpcb:
 		 */
 		if (tcp_twcheck(inp, &to, th, m, tlen))
 			goto findpcb;
-		INP_INFO_RUNLOCK_ET(&V_tcbinfo, et);
 		return (IPPROTO_DONE);
 	}
 	/*
@@ -977,27 +950,6 @@ findpcb:
 	}
 #endif
 
-	/*
-	 * We've identified a valid inpcb, but it could be that we need an
-	 * inpcbinfo write lock but don't hold it.  In this case, attempt to
-	 * acquire using the same strategy as the TIMEWAIT case above.  If we
-	 * relock, we have to jump back to 'relocked' as the connection might
-	 * now be in TIMEWAIT.
-	 */
-#ifdef INVARIANTS
-	if ((thflags & (TH_FIN | TH_RST)) != 0)
-		INP_INFO_RLOCK_ASSERT(&V_tcbinfo);
-#endif
-	if (!((tp->t_state == TCPS_ESTABLISHED && (thflags & TH_SYN) == 0) ||
-	      (tp->t_state == TCPS_LISTEN && (thflags & TH_SYN) &&
-	       !IS_FASTOPEN(tp->t_flags)))) {
-		if (ti_locked == TI_UNLOCKED) {
-			INP_INFO_RLOCK_ET(&V_tcbinfo, et);
-			ti_locked = TI_RLOCKED;
-		}
-		INP_INFO_RLOCK_ASSERT(&V_tcbinfo);
-	}
-
 #ifdef MAC
 	INP_WLOCK_ASSERT(inp);
 	if (mac_inpcb_check_deliver(inp, m))
@@ -1052,7 +1004,6 @@ findpcb:
 		 */
 		if ((thflags & (TH_RST|TH_ACK|TH_SYN)) == TH_ACK) {
 
-			INP_INFO_RLOCK_ASSERT(&V_tcbinfo);
 			/*
 			 * Parse the TCP options here because
 			 * syncookies need access to the reflected
@@ -1130,8 +1081,6 @@ tfo_socket_result:
 			TCP_PROBE5(receive, NULL, tp, m, tp, th);
 			tp->t_fb->tfb_tcp_do_segment(m, th, so, tp, drop_hdrlen, tlen,
 			    iptos);
-			if (ti_locked == TI_RLOCKED)
-				INP_INFO_RUNLOCK_ET(&V_tcbinfo, et);
 			return (IPPROTO_DONE);
 		}
 		/*
@@ -1334,10 +1283,6 @@ tfo_socket_result:
 		 * Entry added to syncache and mbuf consumed.
 		 * Only the listen socket is unlocked by syncache_add().
 		 */
-		if (ti_locked == TI_RLOCKED) {
-			INP_INFO_RUNLOCK_ET(&V_tcbinfo, et);
-			ti_locked = TI_UNLOCKED;
-		}
 		INP_INFO_WUNLOCK_ASSERT(&V_tcbinfo);
 		return (IPPROTO_DONE);
 	} else if (tp->t_state == TCPS_LISTEN) {
@@ -1370,25 +1315,11 @@ tfo_socket_result:
 	 * the inpcb, and unlocks pcbinfo.
 	 */
 	tp->t_fb->tfb_tcp_do_segment(m, th, so, tp, drop_hdrlen, tlen, iptos);
-	if (ti_locked == TI_RLOCKED)
-		INP_INFO_RUNLOCK_ET(&V_tcbinfo, et);
 	return (IPPROTO_DONE);
 
 dropwithreset:
 	TCP_PROBE5(receive, NULL, tp, m, tp, th);
 
-	if (ti_locked == TI_RLOCKED) {
-		INP_INFO_RUNLOCK_ET(&V_tcbinfo, et);
-		ti_locked = TI_UNLOCKED;
-	}
-#ifdef INVARIANTS
-	else {
-		KASSERT(ti_locked == TI_UNLOCKED, ("%s: dropwithreset "
-		    "ti_locked: %d", __func__, ti_locked));
-		INP_INFO_WUNLOCK_ASSERT(&V_tcbinfo);
-	}
-#endif
-
 	if (inp != NULL) {
 		tcp_dropwithreset(m, th, tp, tlen, rstreason);
 		INP_WUNLOCK(inp);
@@ -1401,18 +1332,6 @@ dropunlock:
 	if (m != NULL)
 		TCP_PROBE5(receive, NULL, tp, m, tp, th);
 
-	if (ti_locked == TI_RLOCKED) {
-		INP_INFO_RUNLOCK_ET(&V_tcbinfo, et);
-		ti_locked = TI_UNLOCKED;
-	}
-#ifdef INVARIANTS
-	else {
-		KASSERT(ti_locked == TI_UNLOCKED, ("%s: dropunlock "
-		    "ti_locked: %d", __func__, ti_locked));
-		INP_INFO_WUNLOCK_ASSERT(&V_tcbinfo);
-	}
-#endif
-
 	if (inp != NULL)
 		INP_WUNLOCK(inp);
 
@@ -1501,7 +1420,7 @@ tcp_do_segment(struct mbuf *m, struct tcphdr *th, struct socket *so,
 	struct mbuf *mfree;
 	struct tcpopt to;
 	int tfo_syn;
-	
+
 #ifdef TCPDEBUG
 	/*
 	 * The size of tcp_saveipgen must be the size of the max ip header,
@@ -1516,16 +1435,8 @@ tcp_do_segment(struct mbuf *m, struct tcphdr *th, struct socket *so,
 	tp->sackhint.last_sack_ack = 0;
 	sack_changed = 0;
 	nsegs = max(1, m->m_pkthdr.lro_nsegs);
-	/*
-	 * If this is either a state-changing packet or current state isn't
-	 * established, we require a write lock on tcbinfo.  Otherwise, we
-	 * allow the tcbinfo to be in either alocked or unlocked, as the
-	 * caller may have unnecessarily acquired a write lock due to a race.
-	 */
-	if ((thflags & (TH_SYN | TH_FIN | TH_RST)) != 0 ||
-	    tp->t_state != TCPS_ESTABLISHED) {
-		INP_INFO_RLOCK_ASSERT(&V_tcbinfo);
-	}
+
+	NET_EPOCH_ASSERT();
 	INP_WLOCK_ASSERT(tp->t_inpcb);
 	KASSERT(tp->t_state > TCPS_LISTEN, ("%s: TCPS_LISTEN",
 	    __func__));
@@ -2047,7 +1958,6 @@ tcp_do_segment(struct mbuf *m, struct tcphdr *th, struct socket *so,
 			tcp_state_change(tp, TCPS_SYN_RECEIVED);
 		}
 
-		INP_INFO_RLOCK_ASSERT(&V_tcbinfo);
 		INP_WLOCK_ASSERT(tp->t_inpcb);
 
 		/*
@@ -2120,7 +2030,6 @@ tcp_do_segment(struct mbuf *m, struct tcphdr *th, struct socket *so,
 		    SEQ_LT(th->th_seq, tp->last_ack_sent + tp->rcv_wnd)) ||
 		    (tp->rcv_wnd == 0 && tp->last_ack_sent == th->th_seq)) {
 
-			INP_INFO_RLOCK_ASSERT(&V_tcbinfo);
 			KASSERT(tp->t_state != TCPS_SYN_SENT,
 			    ("%s: TH_RST for TCPS_SYN_SENT th %p tp %p",
 			    __func__, th, tp));
@@ -2163,8 +2072,6 @@ tcp_do_segment(struct mbuf *m, struct tcphdr *th, struct socket *so,
 	 */
 	if ((thflags & TH_SYN) && tp->t_state != TCPS_SYN_SENT &&
 	    tp->t_state != TCPS_SYN_RECEIVED) {
-		INP_INFO_RLOCK_ASSERT(&V_tcbinfo);
-
 		TCPSTAT_INC(tcps_badsyn);
 		if (V_tcp_insecure_syn &&
 		    SEQ_GEQ(th->th_seq, tp->last_ack_sent) &&
@@ -2288,8 +2195,6 @@ tcp_do_segment(struct mbuf *m, struct tcphdr *th, struct socket *so,
 	 */
 	if ((so->so_state & SS_NOFDREF) &&
 	    tp->t_state > TCPS_CLOSE_WAIT && tlen) {
-		INP_INFO_RLOCK_ASSERT(&V_tcbinfo);
-
 		if ((s = tcp_log_addrs(inc, th, NULL, NULL))) {
 			log(LOG_DEBUG, "%s; %s: %s: Received %d bytes of data "
 			    "after socket was closed, "
@@ -2875,7 +2780,6 @@ process_ACK:
 		 */
 		case TCPS_CLOSING:
 			if (ourfinisacked) {
-				INP_INFO_RLOCK_ASSERT(&V_tcbinfo);
 				tcp_twstart(tp);
 				m_freem(m);
 				return;
@@ -2890,7 +2794,6 @@ process_ACK:
 		 */
 		case TCPS_LAST_ACK:
 			if (ourfinisacked) {
-				INP_INFO_RLOCK_ASSERT(&V_tcbinfo);
 				tp = tcp_close(tp);
 				goto drop;
 			}
@@ -3139,8 +3042,6 @@ dodata:							/* XXX */
 		 * standard timers.
 		 */
 		case TCPS_FIN_WAIT_2:
-			INP_INFO_RLOCK_ASSERT(&V_tcbinfo);
-
 			tcp_twstart(tp);
 			return;
 		}