Index: stable/12/sys/netinet/tcp_timewait.c
===================================================================
--- stable/12/sys/netinet/tcp_timewait.c	(revision 347093)
+++ stable/12/sys/netinet/tcp_timewait.c	(revision 347094)
@@ -1,769 +1,769 @@
 /*-
  * SPDX-License-Identifier: BSD-3-Clause
  *
  * Copyright (c) 1982, 1986, 1988, 1990, 1993, 1995
  *	The Regents of the University of California.  All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  * 3. Neither the name of the University nor the names of its contributors
  *    may be used to endorse or promote products derived from this software
  *    without specific prior written permission.
  *
  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
  *	@(#)tcp_subr.c	8.2 (Berkeley) 5/24/95
  */
 
 #include <sys/cdefs.h>
 __FBSDID("$FreeBSD$");
 
 #include "opt_inet.h"
 #include "opt_inet6.h"
 #include "opt_tcpdebug.h"
 
 #include <sys/param.h>
 #include <sys/systm.h>
 #include <sys/callout.h>
 #include <sys/kernel.h>
 #include <sys/sysctl.h>
 #include <sys/malloc.h>
 #include <sys/mbuf.h>
 #include <sys/priv.h>
 #include <sys/proc.h>
 #include <sys/socket.h>
 #include <sys/socketvar.h>
 #ifndef INVARIANTS
 #include <sys/syslog.h>
 #endif
 #include <sys/protosw.h>
 #include <sys/random.h>
 
 #include <vm/uma.h>
 
 #include <net/route.h>
 #include <net/if.h>
 #include <net/if_var.h>
 #include <net/vnet.h>
 
 #include <netinet/in.h>
 #include <netinet/in_kdtrace.h>
 #include <netinet/in_pcb.h>
 #include <netinet/in_systm.h>
 #include <netinet/in_var.h>
 #include <netinet/ip.h>
 #include <netinet/ip_icmp.h>
 #include <netinet/ip_var.h>
 #ifdef INET6
 #include <netinet/ip6.h>
 #include <netinet6/in6_pcb.h>
 #include <netinet6/ip6_var.h>
 #include <netinet6/scope6_var.h>
 #include <netinet6/nd6.h>
 #endif
 #include <netinet/tcp.h>
 #include <netinet/tcp_fsm.h>
 #include <netinet/tcp_seq.h>
 #include <netinet/tcp_timer.h>
 #include <netinet/tcp_var.h>
 #ifdef INET6
 #include <netinet6/tcp6_var.h>
 #endif
 #include <netinet/tcpip.h>
 #ifdef TCPDEBUG
 #include <netinet/tcp_debug.h>
 #endif
 #ifdef INET6
 #include <netinet6/ip6protosw.h>
 #endif
 
 #include <machine/in_cksum.h>
 
 #include <security/mac/mac_framework.h>
 
 VNET_DEFINE_STATIC(uma_zone_t, tcptw_zone);
 #define	V_tcptw_zone		VNET(tcptw_zone)
 static int	maxtcptw;
 
 /*
  * The timed wait queue contains references to each of the TCP sessions
  * currently in the TIME_WAIT state.  The queue pointers, including the
  * queue pointers in each tcptw structure, are protected using the global
  * timewait lock, which must be held over queue iteration and modification.
  *
  * Rules on tcptw usage:
  *  - a inpcb is always freed _after_ its tcptw
  *  - a tcptw relies on its inpcb reference counting for memory stability
  *  - a tcptw is dereferenceable only while its inpcb is locked
  */
 VNET_DEFINE_STATIC(TAILQ_HEAD(, tcptw), twq_2msl);
 #define	V_twq_2msl		VNET(twq_2msl)
 
 /* Global timewait lock */
 VNET_DEFINE_STATIC(struct rwlock, tw_lock);
 #define	V_tw_lock		VNET(tw_lock)
 
 #define	TW_LOCK_INIT(tw, d)	rw_init_flags(&(tw), (d), 0)
 #define	TW_LOCK_DESTROY(tw)	rw_destroy(&(tw))
 #define	TW_RLOCK(tw)		rw_rlock(&(tw))
 #define	TW_WLOCK(tw)		rw_wlock(&(tw))
 #define	TW_RUNLOCK(tw)		rw_runlock(&(tw))
 #define	TW_WUNLOCK(tw)		rw_wunlock(&(tw))
 #define	TW_LOCK_ASSERT(tw)	rw_assert(&(tw), RA_LOCKED)
 #define	TW_RLOCK_ASSERT(tw)	rw_assert(&(tw), RA_RLOCKED)
 #define	TW_WLOCK_ASSERT(tw)	rw_assert(&(tw), RA_WLOCKED)
 #define	TW_UNLOCK_ASSERT(tw)	rw_assert(&(tw), RA_UNLOCKED)
 
 static void	tcp_tw_2msl_reset(struct tcptw *, int);
 static void	tcp_tw_2msl_stop(struct tcptw *, int);
 static int	tcp_twrespond(struct tcptw *, int);
 
 static int
 tcptw_auto_size(void)
 {
 	int halfrange;
 
 	/*
 	 * Max out at half the ephemeral port range so that TIME_WAIT
 	 * sockets don't tie up too many ephemeral ports.
 	 */
 	if (V_ipport_lastauto > V_ipport_firstauto)
 		halfrange = (V_ipport_lastauto - V_ipport_firstauto) / 2;
 	else
 		halfrange = (V_ipport_firstauto - V_ipport_lastauto) / 2;
 	/* Protect against goofy port ranges smaller than 32. */
 	return (imin(imax(halfrange, 32), maxsockets / 5));
 }
 
 static int
 sysctl_maxtcptw(SYSCTL_HANDLER_ARGS)
 {
 	int error, new;
 
 	if (maxtcptw == 0)
 		new = tcptw_auto_size();
 	else
 		new = maxtcptw;
 	error = sysctl_handle_int(oidp, &new, 0, req);
 	if (error == 0 && req->newptr)
 		if (new >= 32) {
 			maxtcptw = new;
 			uma_zone_set_max(V_tcptw_zone, maxtcptw);
 		}
 	return (error);
 }
 
 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, maxtcptw, CTLTYPE_INT|CTLFLAG_RW,
     &maxtcptw, 0, sysctl_maxtcptw, "IU",
     "Maximum number of compressed TCP TIME_WAIT entries");
 
 VNET_DEFINE_STATIC(int, nolocaltimewait) = 0;
 #define	V_nolocaltimewait	VNET(nolocaltimewait)
 SYSCTL_INT(_net_inet_tcp, OID_AUTO, nolocaltimewait, CTLFLAG_VNET | CTLFLAG_RW,
     &VNET_NAME(nolocaltimewait), 0,
     "Do not create compressed TCP TIME_WAIT entries for local connections");
 
 void
 tcp_tw_zone_change(void)
 {
 
 	if (maxtcptw == 0)
 		uma_zone_set_max(V_tcptw_zone, tcptw_auto_size());
 }
 
 void
 tcp_tw_init(void)
 {
 
 	V_tcptw_zone = uma_zcreate("tcptw", sizeof(struct tcptw),
 	    NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0);
 	TUNABLE_INT_FETCH("net.inet.tcp.maxtcptw", &maxtcptw);
 	if (maxtcptw == 0)
 		uma_zone_set_max(V_tcptw_zone, tcptw_auto_size());
 	else
 		uma_zone_set_max(V_tcptw_zone, maxtcptw);
 	TAILQ_INIT(&V_twq_2msl);
 	TW_LOCK_INIT(V_tw_lock, "tcptw");
 }
 
 #ifdef VIMAGE
 void
 tcp_tw_destroy(void)
 {
 	struct tcptw *tw;
 	struct epoch_tracker et;
 
 	INP_INFO_RLOCK_ET(&V_tcbinfo, et);
 	while ((tw = TAILQ_FIRST(&V_twq_2msl)) != NULL)
 		tcp_twclose(tw, 0);
 	INP_INFO_RUNLOCK_ET(&V_tcbinfo, et);
 
 	TW_LOCK_DESTROY(V_tw_lock);
 	uma_zdestroy(V_tcptw_zone);
 }
 #endif
 
 /*
  * 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 twlocal, *tw;
 	struct inpcb *inp = tp->t_inpcb;
 	struct socket *so;
 	uint32_t recwin;
 	bool acknow, local;
 #ifdef INET6
 	bool isipv6 = inp->inp_inc.inc_flags & INC_ISIPV6;
 #endif
 
 	INP_INFO_RLOCK_ASSERT(&V_tcbinfo);
 	INP_WLOCK_ASSERT(inp);
 
 	/* A dropped inp should never transition to TIME_WAIT state. */
 	KASSERT((inp->inp_flags & INP_DROPPED) == 0, ("tcp_twstart: "
 	    "(inp->inp_flags & INP_DROPPED) != 0"));
 
 	if (V_nolocaltimewait) {
 #ifdef INET6
 		if (isipv6)
 			local = in6_localaddr(&inp->in6p_faddr);
 		else
 #endif
 #ifdef INET
 			local = in_localip(inp->inp_faddr);
 #else
 			local = false;
 #endif
 	} else
 		local = false;
 
 	/*
 	 * For use only by DTrace.  We do not reference the state
 	 * after this point so modifying it in place is not a problem.
 	 */
 	tcp_state_change(tp, TCPS_TIME_WAIT);
 
 	if (local)
 		tw = &twlocal;
 	else
 		tw = uma_zalloc(V_tcptw_zone, M_NOWAIT);
 	if (tw == NULL) {
 		/*
 		 * Reached limit on total number of TIMEWAIT connections
 		 * allowed. Remove a connection from TIMEWAIT queue in LRU
 		 * fashion to make room for this connection.
 		 *
 		 * XXX:  Check if it possible to always have enough room
 		 * in advance based on guarantees provided by uma_zalloc().
 		 */
 		tw = tcp_tw_2msl_scan(1);
 		if (tw == NULL) {
 			tp = tcp_close(tp);
 			if (tp != NULL)
 				INP_WUNLOCK(inp);
 			return;
 		}
 	}
 	/*
 	 * For !local case the tcptw will hold a reference on its inpcb
 	 * until tcp_twclose is called.
 	 */
 	tw->tw_inpcb = inp;
 
 	/*
 	 * Recover last window size sent.
 	 */
 	so = inp->inp_socket;
 	recwin = lmin(lmax(sbspace(&so->so_rcv), 0),
 	    (long)TCP_MAXWIN << tp->rcv_scale);
 	if (recwin < (so->so_rcv.sb_hiwat / 4) &&
 	    recwin < tp->t_maxseg)
 		recwin = 0;
 	if (SEQ_GT(tp->rcv_adv, tp->rcv_nxt) &&
 	    recwin < (tp->rcv_adv - tp->rcv_nxt))
 		recwin = (tp->rcv_adv - tp->rcv_nxt);
-	tw->last_win = htons((u_short)(recwin >> tp->rcv_scale));
+	tw->last_win = (u_short)(recwin >> 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);
 	soisdisconnected(so);
 	tw->tw_so_options = so->so_options;
 	inp->inp_flags |= INP_TIMEWAIT;
 	if (acknow)
 		tcp_twrespond(tw, TH_ACK);
 	if (local)
 		in_pcbdrop(inp);
 	else {
 		in_pcbref(inp);	/* Reference from tw */
 		tw->tw_cred = crhold(so->so_cred);
 		inp->inp_ppcb = tw;
 		TCPSTATES_INC(TCPS_TIME_WAIT);
 		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) {
 		KASSERT(so->so_state & SS_PROTOREF,
 		    ("tcp_twstart: !SS_PROTOREF"));
 		inp->inp_flags &= ~INP_SOCKREF;
 		INP_WUNLOCK(inp);
 		SOCK_LOCK(so);
 		so->so_state &= ~SS_PROTOREF;
 		sofree(so);
 	} else
 		INP_WUNLOCK(inp);
 }
 
 /*
  * Returns 1 if the TIME_WAIT state was killed and we should start over,
  * looking for a pcb in the listen state.  Returns 0 otherwise.
  */
 int
 tcp_twcheck(struct inpcb *inp, struct tcpopt *to __unused, struct tcphdr *th,
     struct mbuf *m, int tlen)
 {
 	struct tcptw *tw;
 	int thflags;
 	tcp_seq seq;
 
 	INP_INFO_RLOCK_ASSERT(&V_tcbinfo);
 	INP_WLOCK_ASSERT(inp);
 
 	/*
 	 * XXXRW: Time wait state for inpcb has been recycled, but inpcb is
 	 * still present.  This is undesirable, but temporarily necessary
 	 * until we work out how to handle inpcb's who's timewait state has
 	 * been removed.
 	 */
 	tw = intotw(inp);
 	if (tw == NULL)
 		goto drop;
 
 	thflags = th->th_flags;
 
 	/*
 	 * NOTE: for FIN_WAIT_2 (to be added later),
 	 * must validate sequence number before accepting RST
 	 */
 
 	/*
 	 * If the segment contains RST:
 	 *	Drop the segment - see Stevens, vol. 2, p. 964 and
 	 *      RFC 1337.
 	 */
 	if (thflags & TH_RST)
 		goto drop;
 
 #if 0
 /* PAWS not needed at the moment */
 	/*
 	 * RFC 1323 PAWS: If we have a timestamp reply on this segment
 	 * and it's less than ts_recent, drop it.
 	 */
 	if ((to.to_flags & TOF_TS) != 0 && tp->ts_recent &&
 	    TSTMP_LT(to.to_tsval, tp->ts_recent)) {
 		if ((thflags & TH_ACK) == 0)
 			goto drop;
 		goto ack;
 	}
 	/*
 	 * ts_recent is never updated because we never accept new segments.
 	 */
 #endif
 
 	/*
 	 * If a new connection request is received
 	 * while in TIME_WAIT, drop the old connection
 	 * and start over if the sequence numbers
 	 * are above the previous ones.
 	 */
 	if ((thflags & TH_SYN) && SEQ_GT(th->th_seq, tw->rcv_nxt)) {
 		tcp_twclose(tw, 0);
 		return (1);
 	}
 
 	/*
 	 * Drop the segment if it does not contain an ACK.
 	 */
 	if ((thflags & TH_ACK) == 0)
 		goto drop;
 
 	/*
 	 * Reset the 2MSL timer if this is a duplicate FIN.
 	 */
 	if (thflags & TH_FIN) {
 		seq = th->th_seq + tlen + (thflags & TH_SYN ? 1 : 0);
 		if (seq + 1 == tw->rcv_nxt)
 			tcp_tw_2msl_reset(tw, 1);
 	}
 
 	/*
 	 * Acknowledge the segment if it has data or is not a duplicate ACK.
 	 */
 	if (thflags != TH_ACK || tlen != 0 ||
 	    th->th_seq != tw->rcv_nxt || th->th_ack != tw->snd_nxt) {
 		TCP_PROBE5(receive, NULL, NULL, m, NULL, th);
 		tcp_twrespond(tw, TH_ACK);
 		goto dropnoprobe;
 	}
 drop:
 	TCP_PROBE5(receive, NULL, NULL, m, NULL, th);
 dropnoprobe:
 	INP_WUNLOCK(inp);
 	m_freem(m);
 	return (0);
 }
 
 void
 tcp_twclose(struct tcptw *tw, int reuse)
 {
 	struct socket *so;
 	struct inpcb *inp;
 
 	/*
 	 * At this point, we are in one of two situations:
 	 *
 	 * (1) We have no socket, just an inpcb<->twtcp pair.  We can free
 	 *     all state.
 	 *
 	 * (2) We have a socket -- if we own a reference, release it and
 	 *     notify the socket layer.
 	 */
 	inp = tw->tw_inpcb;
 	KASSERT((inp->inp_flags & INP_TIMEWAIT), ("tcp_twclose: !timewait"));
 	KASSERT(intotw(inp) == tw, ("tcp_twclose: inp_ppcb != tw"));
 	INP_INFO_RLOCK_ASSERT(&V_tcbinfo);	/* in_pcbfree() */
 	INP_WLOCK_ASSERT(inp);
 
 	tcp_tw_2msl_stop(tw, reuse);
 	inp->inp_ppcb = NULL;
 	in_pcbdrop(inp);
 
 	so = inp->inp_socket;
 	if (so != NULL) {
 		/*
 		 * If there's a socket, handle two cases: first, we own a
 		 * strong reference, which we will now release, or we don't
 		 * in which case another reference exists (XXXRW: think
 		 * about this more), and we don't need to take action.
 		 */
 		if (inp->inp_flags & INP_SOCKREF) {
 			inp->inp_flags &= ~INP_SOCKREF;
 			INP_WUNLOCK(inp);
 			SOCK_LOCK(so);
 			KASSERT(so->so_state & SS_PROTOREF,
 			    ("tcp_twclose: INP_SOCKREF && !SS_PROTOREF"));
 			so->so_state &= ~SS_PROTOREF;
 			sofree(so);
 		} else {
 			/*
 			 * If we don't own the only reference, the socket and
 			 * inpcb need to be left around to be handled by
 			 * tcp_usr_detach() later.
 			 */
 			INP_WUNLOCK(inp);
 		}
 	} else {
 		/*
 		 * The socket has been already cleaned-up for us, only free the
 		 * inpcb.
 		 */
 		in_pcbfree(inp);
 	}
 	TCPSTAT_INC(tcps_closed);
 }
 
 static int
 tcp_twrespond(struct tcptw *tw, int flags)
 {
 	struct inpcb *inp = tw->tw_inpcb;
 #if defined(INET6) || defined(INET)
 	struct tcphdr *th = NULL;
 #endif
 	struct mbuf *m;
 #ifdef INET
 	struct ip *ip = NULL;
 #endif
 	u_int hdrlen, optlen;
 	int error = 0;			/* Keep compiler happy */
 	struct tcpopt to;
 #ifdef INET6
 	struct ip6_hdr *ip6 = NULL;
 	int isipv6 = inp->inp_inc.inc_flags & INC_ISIPV6;
 #endif
 	hdrlen = 0;                     /* Keep compiler happy */
 
 	INP_WLOCK_ASSERT(inp);
 
 	m = m_gethdr(M_NOWAIT, MT_DATA);
 	if (m == NULL)
 		return (ENOBUFS);
 	m->m_data += max_linkhdr;
 
 #ifdef MAC
 	mac_inpcb_create_mbuf(inp, m);
 #endif
 
 #ifdef INET6
 	if (isipv6) {
 		hdrlen = sizeof(struct ip6_hdr) + sizeof(struct tcphdr);
 		ip6 = mtod(m, struct ip6_hdr *);
 		th = (struct tcphdr *)(ip6 + 1);
 		tcpip_fillheaders(inp, ip6, th);
 	}
 #endif
 #if defined(INET6) && defined(INET)
 	else
 #endif
 #ifdef INET
 	{
 		hdrlen = sizeof(struct tcpiphdr);
 		ip = mtod(m, struct ip *);
 		th = (struct tcphdr *)(ip + 1);
 		tcpip_fillheaders(inp, ip, th);
 	}
 #endif
 	to.to_flags = 0;
 
 	/*
 	 * Send a timestamp and echo-reply if both our side and our peer
 	 * have sent timestamps in our SYN's and this is not a RST.
 	 */
 	if (tw->t_recent && flags == TH_ACK) {
 		to.to_flags |= TOF_TS;
 		to.to_tsval = tcp_ts_getticks() + tw->ts_offset;
 		to.to_tsecr = tw->t_recent;
 	}
 	optlen = tcp_addoptions(&to, (u_char *)(th + 1));
 
 	m->m_len = hdrlen + optlen;
 	m->m_pkthdr.len = m->m_len;
 
 	KASSERT(max_linkhdr + m->m_len <= MHLEN, ("tcptw: mbuf too small"));
 
 	th->th_seq = htonl(tw->snd_nxt);
 	th->th_ack = htonl(tw->rcv_nxt);
 	th->th_off = (sizeof(struct tcphdr) + optlen) >> 2;
 	th->th_flags = flags;
 	th->th_win = htons(tw->last_win);
 
 	m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
 #ifdef INET6
 	if (isipv6) {
 		m->m_pkthdr.csum_flags = CSUM_TCP_IPV6;
 		th->th_sum = in6_cksum_pseudo(ip6,
 		    sizeof(struct tcphdr) + optlen, IPPROTO_TCP, 0);
 		ip6->ip6_hlim = in6_selecthlim(inp, NULL);
 		TCP_PROBE5(send, NULL, NULL, ip6, NULL, th);
 		error = ip6_output(m, inp->in6p_outputopts, NULL,
 		    (tw->tw_so_options & SO_DONTROUTE), NULL, NULL, inp);
 	}
 #endif
 #if defined(INET6) && defined(INET)
 	else
 #endif
 #ifdef INET
 	{
 		m->m_pkthdr.csum_flags = CSUM_TCP;
 		th->th_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr,
 		    htons(sizeof(struct tcphdr) + optlen + IPPROTO_TCP));
 		ip->ip_len = htons(m->m_pkthdr.len);
 		if (V_path_mtu_discovery)
 			ip->ip_off |= htons(IP_DF);
 		TCP_PROBE5(send, NULL, NULL, ip, NULL, th);
 		error = ip_output(m, inp->inp_options, NULL,
 		    ((tw->tw_so_options & SO_DONTROUTE) ? IP_ROUTETOIF : 0),
 		    NULL, inp);
 	}
 #endif
 	if (flags & TH_ACK)
 		TCPSTAT_INC(tcps_sndacks);
 	else
 		TCPSTAT_INC(tcps_sndctrl);
 	TCPSTAT_INC(tcps_sndtotal);
 	return (error);
 }
 
 static void
 tcp_tw_2msl_reset(struct tcptw *tw, int rearm)
 {
 
 	INP_INFO_RLOCK_ASSERT(&V_tcbinfo);
 	INP_WLOCK_ASSERT(tw->tw_inpcb);
 
 	TW_WLOCK(V_tw_lock);
 	if (rearm)
 		TAILQ_REMOVE(&V_twq_2msl, tw, tw_2msl);
 	tw->tw_time = ticks + 2 * tcp_msl;
 	TAILQ_INSERT_TAIL(&V_twq_2msl, tw, tw_2msl);
 	TW_WUNLOCK(V_tw_lock);
 }
 
 static void
 tcp_tw_2msl_stop(struct tcptw *tw, int reuse)
 {
 	struct ucred *cred;
 	struct inpcb *inp;
 	int released __unused;
 
 	INP_INFO_RLOCK_ASSERT(&V_tcbinfo);
 
 	TW_WLOCK(V_tw_lock);
 	inp = tw->tw_inpcb;
 	tw->tw_inpcb = NULL;
 
 	TAILQ_REMOVE(&V_twq_2msl, tw, tw_2msl);
 	cred = tw->tw_cred;
 	tw->tw_cred = NULL;
 	TW_WUNLOCK(V_tw_lock);
 
 	if (cred != NULL)
 		crfree(cred);
 
 	released = in_pcbrele_wlocked(inp);
 	KASSERT(!released, ("%s: inp should not be released here", __func__));
 
 	if (!reuse)
 		uma_zfree(V_tcptw_zone, tw);
 	TCPSTATES_DEC(TCPS_TIME_WAIT);
 }
 
 struct tcptw *
 tcp_tw_2msl_scan(int reuse)
 {
 	struct tcptw *tw;
 	struct inpcb *inp;
 	struct epoch_tracker et;
 
 #ifdef INVARIANTS
 	if (reuse) {
 		/*
 		 * Exclusive pcbinfo lock is not required in reuse case even if
 		 * two inpcb locks can be acquired simultaneously:
 		 *  - the inpcb transitioning to TIME_WAIT state in
 		 *    tcp_tw_start(),
 		 *  - the inpcb closed by tcp_twclose().
 		 *
 		 * It is because only inpcbs in FIN_WAIT2 or CLOSING states can
 		 * transition in TIME_WAIT state.  Then a pcbcb cannot be in
 		 * TIME_WAIT list and transitioning to TIME_WAIT state at same
 		 * time.
 		 */
 		INP_INFO_RLOCK_ASSERT(&V_tcbinfo);
 	}
 #endif
 
 	for (;;) {
 		TW_RLOCK(V_tw_lock);
 		tw = TAILQ_FIRST(&V_twq_2msl);
 		if (tw == NULL || (!reuse && (tw->tw_time - ticks) > 0)) {
 			TW_RUNLOCK(V_tw_lock);
 			break;
 		}
 		KASSERT(tw->tw_inpcb != NULL, ("%s: tw->tw_inpcb == NULL",
 		    __func__));
 
 		inp = tw->tw_inpcb;
 		in_pcbref(inp);
 		TW_RUNLOCK(V_tw_lock);
 
 		INP_INFO_RLOCK_ET(&V_tcbinfo, et);
 		INP_WLOCK(inp);
 		tw = intotw(inp);
 		if (in_pcbrele_wlocked(inp)) {
 			if (__predict_true(tw == NULL)) {
 				INP_INFO_RUNLOCK_ET(&V_tcbinfo, et);
 				continue;
 			} else {
 				/* This should not happen as in TIMEWAIT
 				 * state the inp should not be destroyed
 				 * before its tcptw. If INVARIANTS is
 				 * defined panic.
 				 */
 #ifdef INVARIANTS
 				panic("%s: Panic before an infinite "
 					  "loop: INP_TIMEWAIT && (INP_FREED "
 					  "|| inp last reference) && tw != "
 					  "NULL", __func__);
 #else
 				log(LOG_ERR, "%s: Avoid an infinite "
 					"loop: INP_TIMEWAIT && (INP_FREED "
 					"|| inp last reference) && tw != "
 					"NULL", __func__);
 #endif
 				INP_INFO_RUNLOCK_ET(&V_tcbinfo, et);
 				break;
 			}
 		}
 
 		if (tw == NULL) {
 			/* tcp_twclose() has already been called */
 			INP_WUNLOCK(inp);
 			INP_INFO_RUNLOCK_ET(&V_tcbinfo, et);
 			continue;
 		}
 
 		tcp_twclose(tw, reuse);
 		INP_INFO_RUNLOCK_ET(&V_tcbinfo, et);
 		if (reuse)
 			return tw;
 	}
 
 	return NULL;
 }
Index: stable/12
===================================================================
--- stable/12	(revision 347093)
+++ stable/12	(revision 347094)

Property changes on: stable/12
___________________________________________________________________
Modified: svn:mergeinfo
## -0,0 +0,1 ##
   Merged /head:r344148