svn commit: r214878 - stable/7/sys/netinet

[Lawrence Stewart]

Author: lstewart
Date: Sat Nov  6 13:46:58 2010
New Revision: 214878
URL: http://svn.freebsd.org/changeset/base/214878

Log:
  MFC r213158:
  
  Internalise reassembly queue related functionality and variables which should
  not be used outside of the reassembly queue implementation. Provide a new
  function to flush all segments from a reassembly queue and call it from the
  appropriate places instead of manipulating the queue directly.
  
  The base code from r213158 was modified as part of this MFC in order to work
  correctly on FreeBSD 7.
  
  Sponsored by:	FreeBSD Foundation
  Reviewed by:	andre, gnn, rpaulo

Modified:
  stable/7/sys/netinet/tcp_reass.c
  stable/7/sys/netinet/tcp_subr.c
  stable/7/sys/netinet/tcp_var.h
Directory Properties:
  stable/7/sys/   (props changed)
  stable/7/sys/cddl/contrib/opensolaris/   (props changed)
  stable/7/sys/contrib/dev/acpica/   (props changed)
  stable/7/sys/contrib/pf/   (props changed)

Modified: stable/7/sys/netinet/tcp_reass.c
==============================================================================
--- stable/7/sys/netinet/tcp_reass.c	Sat Nov  6 13:43:18 2010	(r214877)
+++ stable/7/sys/netinet/tcp_reass.c	Sat Nov  6 13:46:58 2010	(r214878)
@@ -81,7 +81,7 @@ SYSCTL_INT(_net_inet_tcp_reass, OID_AUTO
     &tcp_reass_maxseg, 0,
     "Global maximum number of TCP Segments in Reassembly Queue");
 
-int tcp_reass_qsize = 0;
+static int tcp_reass_qsize = 0;
 SYSCTL_INT(_net_inet_tcp_reass, OID_AUTO, cursegments, CTLFLAG_RD,
     &tcp_reass_qsize, 0,
     "Global number of TCP Segments currently in Reassembly Queue");
@@ -96,6 +96,8 @@ SYSCTL_INT(_net_inet_tcp_reass, OID_AUTO
     &tcp_reass_overflows, 0,
     "Global number of TCP Segment Reassembly Queue Overflows");
 
+static uma_zone_t	tcp_reass_zone;
+
 /* Initialize TCP reassembly queue */
 static void
 tcp_reass_zone_change(void *tag)
@@ -105,8 +107,6 @@ tcp_reass_zone_change(void *tag)
 	uma_zone_set_max(tcp_reass_zone, tcp_reass_maxseg);
 }
 
-uma_zone_t	tcp_reass_zone;
-
 void
 tcp_reass_init(void)
 {
@@ -121,6 +121,26 @@ tcp_reass_init(void)
 	    tcp_reass_zone_change, NULL, EVENTHANDLER_PRI_ANY);
 }
 
+void
+tcp_reass_flush(struct tcpcb *tp)
+{
+	struct tseg_qent *qe;
+
+	INP_WLOCK_ASSERT(tp->t_inpcb);
+
+	while ((qe = LIST_FIRST(&tp->t_segq)) != NULL) {
+		LIST_REMOVE(qe, tqe_q);
+		m_freem(qe->tqe_m);
+		uma_zfree(tcp_reass_zone, qe);
+		tp->t_segqlen--;
+		tcp_reass_qsize--;
+	}
+
+	KASSERT((tp->t_segqlen == 0),
+	    ("TCP reass queue %p segment count is %d instead of 0 after flush.",
+	    tp, tp->t_segqlen));
+}
+
 int
 tcp_reass(struct tcpcb *tp, struct tcphdr *th, int *tlenp, struct mbuf *m)
 {

Modified: stable/7/sys/netinet/tcp_subr.c
==============================================================================
--- stable/7/sys/netinet/tcp_subr.c	Sat Nov  6 13:43:18 2010	(r214877)
+++ stable/7/sys/netinet/tcp_subr.c	Sat Nov  6 13:46:58 2010	(r214878)
@@ -704,7 +704,6 @@ tcp_drop(struct tcpcb *tp, int errno)
 void
 tcp_discardcb(struct tcpcb *tp)
 {
-	struct tseg_qent *q;
 	struct inpcb *inp = tp->t_inpcb;
 	struct socket *so = inp->inp_socket;
 #ifdef INET6
@@ -782,13 +781,7 @@ tcp_discardcb(struct tcpcb *tp)
 	}
 
 	/* free the reassembly queue, if any */
-	while ((q = LIST_FIRST(&tp->t_segq)) != NULL) {
-		LIST_REMOVE(q, tqe_q);
-		m_freem(q->tqe_m);
-		uma_zfree(tcp_reass_zone, q);
-		tp->t_segqlen--;
-		tcp_reass_qsize--;
-	}
+	tcp_reass_flush(tp);
 	/* Disconnect offload device, if any. */
 	tcp_offload_detach(tp);
 		
@@ -840,7 +833,6 @@ tcp_drain(void)
 	if (do_tcpdrain) {
 		struct inpcb *inpb;
 		struct tcpcb *tcpb;
-		struct tseg_qent *te;
 
 	/*
 	 * Walk the tcpbs, if existing, and flush the reassembly queue,
@@ -856,14 +848,7 @@ tcp_drain(void)
 				continue;
 			INP_WLOCK(inpb);
 			if ((tcpb = intotcpcb(inpb)) != NULL) {
-				while ((te = LIST_FIRST(&tcpb->t_segq))
-			            != NULL) {
-					LIST_REMOVE(te, tqe_q);
-					m_freem(te->tqe_m);
-					uma_zfree(tcp_reass_zone, te);
-					tcpb->t_segqlen--;
-					tcp_reass_qsize--;
-				}
+				tcp_reass_flush(tcpb);
 				tcp_clean_sackreport(tcpb);
 			}
 			INP_WUNLOCK(inpb);

Modified: stable/7/sys/netinet/tcp_var.h
==============================================================================
--- stable/7/sys/netinet/tcp_var.h	Sat Nov  6 13:43:18 2010	(r214877)
+++ stable/7/sys/netinet/tcp_var.h	Sat Nov  6 13:46:58 2010	(r214878)
@@ -48,8 +48,6 @@ struct tseg_qent {
 	struct	mbuf	*tqe_m;		/* mbuf contains packet */
 };
 LIST_HEAD(tsegqe_head, tseg_qent);
-extern int	tcp_reass_qsize;
-extern struct uma_zone *tcp_reass_zone;
 
 struct sackblk {
 	tcp_seq start;		/* start seq no. of sack block */
@@ -543,6 +541,7 @@ char	*tcp_log_vain(struct in_conninfo *,
 	    const void *);
 int	 tcp_reass(struct tcpcb *, struct tcphdr *, int *, struct mbuf *);
 void	 tcp_reass_init(void);
+void	 tcp_reass_flush(struct tcpcb *);
 void	 tcp_input(struct mbuf *, int);
 u_long	 tcp_maxmtu(struct in_conninfo *, int *);
 u_long	 tcp_maxmtu6(struct in_conninfo *, int *);