Index: share/man/man4/divert.4
===================================================================
--- share/man/man4/divert.4
+++ share/man/man4/divert.4
@@ -51,10 +51,19 @@
 By reading from and writing to a divert socket, matching packets
 can be passed through an arbitrary ``filter'' as they travel through
 the host machine, special routing tricks can be done, etc.
+.Pp
+The following sysctls are relevant to the operation of
+.Nm :
+.Bl -tag -width indent
+.It Va net.inet.divert.recvspace
+Receive buffer size for divert sockets (default: 65536).
+.It Va net.inet.divert.sendspace
+Send buffer size for divert sockets (default: 65536).
 .Sh READING PACKETS
 Packets are diverted either as they are ``incoming'' or ``outgoing.''
 Incoming packets are diverted after reception on an IP interface,
 whereas outgoing packets are diverted before next hop forwarding.
+.El
 .Pp
 Diverted packets may be read unaltered via
 .Xr read 2 ,
Index: sys/netinet/ip_divert.c
===================================================================
--- sys/netinet/ip_divert.c
+++ sys/netinet/ip_divert.c
@@ -117,8 +117,8 @@
 #define	V_divcb				VNET(divcb)
 #define	V_divcbinfo			VNET(divcbinfo)
 
-static u_long	div_sendspace = DIVSNDQ;	/* XXX sysctl ? */
-static u_long	div_recvspace = DIVRCVQ;	/* XXX sysctl ? */
+static u_long	div_sendspace = DIVSNDQ;
+static u_long	div_recvspace = DIVRCVQ;
 
 static eventhandler_tag ip_divert_event_tag;
 
@@ -741,6 +741,10 @@
     "IPDIVERT");
 SYSCTL_PROC(_net_inet_divert, OID_AUTO, pcblist, CTLTYPE_OPAQUE | CTLFLAG_RD,
     NULL, 0, div_pcblist, "S,xinpcb", "List of active divert sockets");
+SYSCTL_ULONG(_net_inet_divert, OID_AUTO, sendspace, CTLFLAG_RW,
+    &div_sendspace, 0, "Send buffer size for divert sockets");
+SYSCTL_ULONG(_net_inet_divert, OID_AUTO, recvspace, CTLFLAG_RW,
+    &div_recvspace, 0, "Receive buffer size for divert sockets");
 #endif
 
 struct pr_usrreqs div_usrreqs = {