Fix some long standing bugs in writing to the BPF device attached to

a DLT_NULL interface. In particular:

        1) Consistently use type u_int32_t for the header of a
           DLT_NULL device - it continues to represent the address
           family as always.
        2) In the DLT_NULL case get bpf_movein to store the u_int32_t
           in a sockaddr rather than in the mbuf, to be consistent
           with all the DLT types.
        3) Consequently fix a bug in bpf_movein/bpfwrite which
           only permitted packets up to 4 bytes less than the MTU
           to be written.
        4) Fix all DLT_NULL devices to have the code required to
           allow writing to their bpf devices.
        5) Move the code to allow writing to if_lo from if_simloop
           to looutput, because it only applies to DLT_NULL devices
           but was being applied to other devices that use if_simloop
           possibly incorrectly.

PR:		82157
Submitted by:	Matthew Luckie <mjl@luckie.org.nz>
Approved by:	re (scottl)

1 files changed, 9 insertions, 1 deletions

diff --git a/sys/i4b/driver/i4b_ipr.c b/sys/i4b/driver/i4b_ipr.c
index 60d8a46..1309d73 100644
--- a/sys/i4b/driver/i4b_ipr.c
+++ b/sys/i4b/driver/i4b_ipr.c
@@ -272,7 +272,7 @@ i4biprattach(void *dummy)
 		
 		if_attach(sc->sc_ifp);
 
-		bpfattach(sc->sc_ifp, DLT_NULL, sizeof(u_int));
+		bpfattach(sc->sc_ifp, DLT_NULL, sizeof(u_int32_t));
 	}
 }
 
@@ -288,12 +288,20 @@ i4biproutput(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst,
 	int s;
 	struct ifqueue *ifq;
 	struct ip *ip;
+	u_int32_t af;
 	
 	s = SPLI4B();
 
 	sc = ifp->if_softc;
 	unit = ifp->if_dunit;
 
+	/* BPF writes need to be handled specially. */
+	if(dst->sa_family == AF_UNSPEC)
+	{
+		bcopy(dst->sa_data, &af, sizeof(af));
+		dst->sa_family = af;
+	}
+
 	/* check for IP */
 	
 	if(dst->sa_family != AF_INET)