Convert the tcp segment reassembly queue to UMA and limit the maximum

amount of segments it will hold.

The following tuneables and sysctls control the behaviour of the tcp
segment reassembly queue:

 net.inet.tcp.reass.maxsegments (loader tuneable)
  specifies the maximum number of segments all tcp reassemly queues can
  hold (defaults to 1/16 of nmbclusters).

 net.inet.tcp.reass.maxqlen
  specifies the maximum number of segments any individual tcp session queue
  can hold (defaults to 48).

 net.inet.tcp.reass.cursegments (readonly)
  counts the number of segments currently in all reassembly queues.

 net.inet.tcp.reass.overflows (readonly)
  counts how often either the global or local queue limit has been reached.

Tested by:	bms, silby
Reviewed by:	bms, silby

1 files changed, 6 insertions, 3 deletions

diff --git a/sys/netinet/tcp_var.h b/sys/netinet/tcp_var.h
index e8aa435..07ebd06 100644
--- a/sys/netinet/tcp_var.h
+++ b/sys/netinet/tcp_var.h
@@ -54,8 +54,9 @@ struct tseg_qent {
 	struct	mbuf	*tqe_m;		/* mbuf contains packet */
 };
 LIST_HEAD(tsegqe_head, tseg_qent);
-#ifdef MALLOC_DECLARE
-MALLOC_DECLARE(M_TSEGQ);
+extern int	tcp_reass_qsize;
+#ifdef VM_UMA_H
+extern uma_zone_t tcp_reass_zone;
 #endif
 
 struct tcptemp {
@@ -70,7 +71,8 @@ struct tcptemp {
  * Organized for 16 byte cacheline efficiency.
  */
 struct tcpcb {
-	struct	tsegqe_head t_segq;
+	struct	tsegqe_head t_segq;	/* segment reassembly queue */
+	int	t_segqlen;		/* segment reassembly queue length */
 	int	t_dupacks;		/* consecutive dup acks recd */
 	struct	tcptemp	*unused;	/* unused */
 
@@ -519,6 +521,7 @@ struct tcpcb *
 void	 tcp_drain(void);
 void	 tcp_fasttimo(void);
 void	 tcp_init(void);
+void	 tcp_reass_init(void);
 void	 tcp_input(struct mbuf *, int);
 u_long	 tcp_maxmtu(struct in_conninfo *);
 u_long	 tcp_maxmtu6(struct in_conninfo *);