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, 7 insertions, 1 deletions

diff --git a/sys/dev/iicbus/if_ic.c b/sys/dev/iicbus/if_ic.c
index d0068bb..fba21d1 100644
--- a/sys/dev/iicbus/if_ic.c
+++ b/sys/dev/iicbus/if_ic.c
@@ -374,7 +374,13 @@ icoutput(struct ifnet *ifp, struct mbuf *m,
 	int s, len, sent;
 	struct mbuf *mm;
 	u_char *cp;
-	u_int32_t hdr = dst->sa_family;
+	u_int32_t hdr;
+
+	/* BPF writes need to be handled specially. */ 
+	if (dst->sa_family == AF_UNSPEC)
+		bcopy(dst->sa_data, &hdr, sizeof(hdr));
+	else 
+		hdr = dst->sa_family;
 
 	ifp->if_flags |= IFF_RUNNING;