diff options
Diffstat (limited to 'sys/net/bpf.c')
| -rw-r--r-- | sys/net/bpf.c | 41 |
1 files changed, 40 insertions, 1 deletions
diff --git a/sys/net/bpf.c b/sys/net/bpf.c index 2d3795199f0..af7406e1d00 100644 --- a/sys/net/bpf.c +++ b/sys/net/bpf.c @@ -1,4 +1,4 @@ -/* $OpenBSD: bpf.c,v 1.166 2018/01/24 00:25:17 dlg Exp $ */ +/* $OpenBSD: bpf.c,v 1.167 2018/02/01 12:10:27 dlg Exp $ */ /* $NetBSD: bpf.c,v 1.33 1997/02/21 23:59:35 thorpej Exp $ */ /* @@ -1291,6 +1291,45 @@ _bpf_mtap(caddr_t arg, const struct mbuf *m, u_int direction, } /* + * Incoming linkage from device drivers, where a data buffer should be + * prepended by an arbitrary header. In this situation we already have a + * way of representing a chain of memory buffers, ie, mbufs, so reuse + * the existing functionality by attaching the buffers to mbufs. + * + * Con up a minimal mbuf chain to pacify bpf by allocating (only) a + * struct m_hdr each for the header and data on the stack. + */ +int +bpf_tap_hdr(caddr_t arg, const void *hdr, unsigned int hdrlen, + const void *buf, unsigned int buflen, u_int direction) +{ + struct m_hdr mh, md; + struct mbuf *m0 = NULL; + struct mbuf **mp = &m0; + + if (hdr != NULL) { + mh.mh_flags = 0; + mh.mh_next = NULL; + mh.mh_len = hdrlen; + mh.mh_data = (void *)hdr; + + *mp = (struct mbuf *)&mh; + mp = &mh.mh_next; + } + + if (buf != NULL) { + md.mh_flags = 0; + md.mh_next = NULL; + md.mh_len = buflen; + md.mh_data = (void *)buf; + + *mp = (struct mbuf *)&md; + } + + return _bpf_mtap(arg, m0, direction, bpf_mcopy); +} + +/* * Incoming linkage from device drivers, when packet is in an mbuf chain. */ int |