Allow loadable interface drivers with BPF support to be loaded into a kernel

that doesn't have it.  This is achieved by having minimal do-nothing stubs
enabled when there are no bpfilter devices configured.

Driver modules should be built with BPF enabled for maximum
convenience (but can be built without it for maximum performance).

6 files changed, 51 insertions, 12 deletions

diff --git a/sys/conf/files b/sys/conf/files
index 7e427c1..bbf2f6a 100644
--- a/sys/conf/files
+++ b/sys/conf/files
@@ -387,7 +387,7 @@ ntfs/ntfs_vnops.c		optional ntfs
 ntfs/ntfs_subr.c		optional ntfs
 ntfs/ntfs_compr.c		optional ntfs
 ntfs/ntfs_ihash.c		optional ntfs
-net/bpf.c		optional bpfilter
+net/bpf.c		standard
 net/bpf_filter.c	optional bpfilter
 net/bridge.c		optional bridge
 net/bsd_comp.c		optional ppp_bsdcomp
diff --git a/sys/modules/if_disc/Makefile b/sys/modules/if_disc/Makefile
index b95b478..a2f5323 100644
--- a/sys/modules/if_disc/Makefile
+++ b/sys/modules/if_disc/Makefile
@@ -1,11 +1,11 @@
-#       $Id: Makefile,v 1.5 1998/02/01 18:12:13 bde Exp $
+#       $Id: Makefile,v 1.6 1998/10/16 04:30:44 peter Exp $
 
 .PATH:  ${.CURDIR}/../../net
 KMOD=   if_disc
 SRCS=   if_disc.c bpfilter.h	opt_inet.h
 NOMAN=
 
-NBPFILTER?=	0
+NBPFILTER?=	1
 
 CFLAGS+= ${PROTOS}
 CLEANFILES+=	bpfilter.h	opt_inet.h
diff --git a/sys/modules/if_ppp/Makefile b/sys/modules/if_ppp/Makefile
index 97c3b3c..6be6fdb 100644
--- a/sys/modules/if_ppp/Makefile
+++ b/sys/modules/if_ppp/Makefile
@@ -1,4 +1,4 @@
-#       $Id: Makefile,v 1.15 1998/10/16 04:30:44 peter Exp $
+#       $Id: Makefile,v 1.16 1999/01/17 20:53:48 peter Exp $
 
 .PATH:  ${.CURDIR}/../../net
 KMOD=   if_ppp
@@ -10,7 +10,7 @@ CLEANFILES+=	vnode_if.c vnode_if.h
 NPPP?=		2
 PPP_BSDCOMP?=	1	# 0/1
 PPP_DEFLATE?=	1	# 0/1
-PPP_FILTER?=	0	# 0/1 - requires bpf to be configured in kernel
+PPP_FILTER?=	1	# 0/1 - requires bpf to be configured in kernel
 PPP_INET?=	1	# 0/1 - requires INET to be configured in kernel
 PPP_IPX?=	0	# 0/1 - requires IPX to be configured in kernel
 
diff --git a/sys/modules/if_sl/Makefile b/sys/modules/if_sl/Makefile
index 6d14477..9ce708a 100644
--- a/sys/modules/if_sl/Makefile
+++ b/sys/modules/if_sl/Makefile
@@ -1,11 +1,11 @@
-#       $Id: Makefile,v 1.6 1998/02/01 18:12:14 bde Exp $
+#       $Id: Makefile,v 1.7 1998/10/16 04:30:45 peter Exp $
 
 .PATH:  ${.CURDIR}/../../net
 KMOD=   if_sl
 SRCS=   if_sl.c slcompress.c bpfilter.h opt_inet.h sl.h
 NOMAN=
 
-NBPFILTER?=	0
+NBPFILTER?=	1
 NSL?=		2
 PROTOS?=	-DINET
 
diff --git a/sys/modules/if_tun/Makefile b/sys/modules/if_tun/Makefile
index 7fadb7f..1f33fe2 100644
--- a/sys/modules/if_tun/Makefile
+++ b/sys/modules/if_tun/Makefile
@@ -1,4 +1,4 @@
-#       $Id: Makefile,v 1.7 1998/10/16 04:30:45 peter Exp $
+#       $Id: Makefile,v 1.8 1999/01/17 20:53:47 peter Exp $
 
 .PATH:  ${.CURDIR}/../../net
 KMOD=   if_tun
@@ -6,7 +6,7 @@ SRCS=   if_tun.c bpfilter.h opt_devfs.h opt_inet.h tun.h vnode_if.h
 NOMAN=
 CLEANFILES+=	vnode_if.h vnode_if.c
 
-NBPFILTER?=	0
+NBPFILTER?=	1
 NTUN?=		2
 
 CFLAGS+= ${PROTOS}
diff --git a/sys/net/bpf.c b/sys/net/bpf.c
index a49ac6d..0c37a7a 100644
--- a/sys/net/bpf.c
+++ b/sys/net/bpf.c
@@ -37,13 +37,11 @@
  *
  *      @(#)bpf.c	8.2 (Berkeley) 3/28/94
  *
- * $Id: bpf.c,v 1.46 1998/12/07 21:58:36 archie Exp $
+ * $Id: bpf.c,v 1.47 1999/01/27 22:42:13 dillon Exp $
  */
 
 #include "bpfilter.h"
 
-#if NBPFILTER > 0
-
 #ifndef __GNUC__
 #define inline
 #else
@@ -86,6 +84,7 @@
 #include <sys/devfsext.h>
 #endif /*DEVFS*/
 
+#if NBPFILTER > 0
 
 /*
  * Older BSDs don't have kernel malloc.
@@ -1309,4 +1308,44 @@ bpf_drvinit(unused)
 
 SYSINIT(bpfdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR,bpf_drvinit,NULL)
 
+#else /* !BPFILTER */
+/*
+ * NOP stubs to allow bpf-using drivers to load and function.
+ *
+ * A 'better' implementation would allow the core bpf functionality
+ * to be loaded at runtime.
+ */
+
+void
+bpf_tap(ifp, pkt, pktlen)
+	struct ifnet *ifp;
+	register u_char *pkt;
+	register u_int pktlen;
+{
+}
+
+void
+bpf_mtap(ifp, m)
+	struct ifnet *ifp;
+	struct mbuf *m;
+{
+}
+
+void
+bpfattach(ifp, dlt, hdrlen)
+	struct ifnet *ifp;
+	u_int dlt, hdrlen;
+{
+}
+
+u_int
+bpf_filter(pc, p, wirelen, buflen)
+	register struct bpf_insn *pc;
+	register u_char *p;
+	u_int wirelen;
+	register u_int buflen;
+{
+	return -1;	/* "no filter" behaviour */
+}
+
 #endif