don't hand roll bpf_mtap_hdr functionality, just use bpf_mtap_hdr.

the radiotap code prepends a big struct to the packets, and wires
them up with the packet by putting an mbuf on the stack and using
that as the head of an mbuf chain. bpf_mtap_hdr does the chain head
thing for us, so shrink this code by calling the bpf function.

there's some other drivers that do this too, so if anyone wants a
free commit they should go looking in the other wireless drivers
and do the same change.

ok claudio@

1 files changed, 5 insertions, 17 deletions

diff --git a/sys/dev/pci/if_iwi.c b/sys/dev/pci/if_iwi.c
index be8d57baecd..8b5f9119a60 100644
--- a/sys/dev/pci/if_iwi.c
+++ b/sys/dev/pci/if_iwi.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: if_iwi.c,v 1.141 2019/09/12 12:55:07 stsp Exp $	*/
+/*	$OpenBSD: if_iwi.c,v 1.142 2019/09/18 23:52:32 dlg Exp $	*/
 
 /*-
  * Copyright (c) 2004-2008
@@ -923,7 +923,6 @@ iwi_frame_intr(struct iwi_softc *sc, struct iwi_rx_data *data,
 
 #if NBPFILTER > 0
 	if (sc->sc_drvbpf != NULL) {
-		struct mbuf mb;
 		struct iwi_rx_radiotap_header *tap = &sc->sc_rxtap;
 
 		tap->wr_flags = 0;
@@ -937,13 +936,8 @@ iwi_frame_intr(struct iwi_softc *sc, struct iwi_rx_data *data,
 		if (frame->antenna & 0x40)
 			tap->wr_flags |= IEEE80211_RADIOTAP_F_SHORTPRE;
 
-		mb.m_data = (caddr_t)tap;
-		mb.m_len = sc->sc_rxtap_len;
-		mb.m_next = m;
-		mb.m_nextpkt = NULL;
-		mb.m_type = 0;
-		mb.m_flags = 0;
-		bpf_mtap(sc->sc_drvbpf, &mb, BPF_DIRECTION_IN);
+		bpf_mtap_hdr(sc->sc_drvbpf, tap, sc->sc_rxtap_len,
+		    m, BPF_DIRECTION_IN, NULL);
 	}
 #endif
 
@@ -1267,20 +1261,14 @@ iwi_tx_start(struct ifnet *ifp, struct mbuf *m0, struct ieee80211_node *ni)
 
 #if NBPFILTER > 0
 	if (sc->sc_drvbpf != NULL) {
-		struct mbuf mb;
 		struct iwi_tx_radiotap_header *tap = &sc->sc_txtap;
 
 		tap->wt_flags = 0;
 		tap->wt_chan_freq = htole16(ic->ic_bss->ni_chan->ic_freq);
 		tap->wt_chan_flags = htole16(ic->ic_bss->ni_chan->ic_flags);
 
-		mb.m_data = (caddr_t)tap;
-		mb.m_len = sc->sc_txtap_len;
-		mb.m_next = m0;
-		mb.m_nextpkt = NULL;
-		mb.m_type = 0;
-		mb.m_flags = 0;
-		bpf_mtap(sc->sc_drvbpf, &mb, BPF_DIRECTION_OUT);
+		bpf_mtap_hdr(sc->sc_drvbpf, tap, sc->sc_txtap_len,
+		    m0, BPF_DIRECTION_OUT, NULL);
 	}
 #endif