implement basic bpf(4) support for qwx(4)

This is sufficient to capture 802.11 frames with tcpdump -y IEEE802_11_RADIO.
Meta-data such as RSSI and channel number is not yet recorded.

diff --git a/sys/dev/ic/qwx.c b/sys/dev/ic/qwx.c
index accad9a..a4319ea 100644 (file)
--- a/sys/dev/ic/qwx.c
+++ b/sys/dev/ic/qwx.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: qwx.c,v 1.17 2024/02/04 17:51:59 kettenis Exp $       */
+/*     $OpenBSD: qwx.c,v 1.18 2024/02/06 14:18:15 stsp Exp $   */
 
 /*
  * Copyright 2023 Stefan Sperling <stsp@openbsd.org>
@@ -54,6 +54,8 @@
  * Driver for Qualcomm Technologies 802.11ax chipset.
  */
 
+#include "bpfilter.h"
+
 #include <sys/types.h>
 #include <sys/param.h>
 #include <sys/device.h>
@@ -72,6 +74,9 @@
 #include <dev/ofw/openfirm.h>
 #endif
 
+#if NBPFILTER > 0
+#include <net/bpf.h>
+#endif
 #include <net/if.h>
 #include <net/if_media.h>
 
@@ -361,6 +366,15 @@ qwx_tx(struct qwx_softc *sc, struct mbuf *m, struct ieee80211_node *ni)
        wh = mtod(m, struct ieee80211_frame *);
        frame_type = wh->i_fc[0] & IEEE80211_FC0_TYPE_MASK;
 
+#if NBPFILTER > 0
+       if (sc->sc_drvbpf != NULL) {
+               struct qwx_tx_radiotap_header *tap = &sc->sc_txtap;
+
+               bpf_mtap_hdr(sc->sc_drvbpf, tap, sc->sc_txtap_len,
+                   m, BPF_DIRECTION_OUT);
+       }
+#endif
+
        if (frame_type == IEEE80211_FC0_TYPE_MGT)
                return qwx_mac_mgmt_tx_wmi(sc, arvif, pdev_id, m);
 
@@ -12636,6 +12650,14 @@ qwx_mgmt_rx_event(struct qwx_softc *sc, struct mbuf *m)
        DNPRINTF(QWX_D_MGMT, "%s: event mgmt rx freq %d chan %d snr %d\n",
            __func__, rx_ev.chan_freq, rx_ev.channel, rx_ev.snr);
 
+#if NBPFILTER > 0
+       if (sc->sc_drvbpf != NULL) {
+               struct qwx_rx_radiotap_header *tap = &sc->sc_rxtap;
+
+               bpf_mtap_hdr(sc->sc_drvbpf, tap, sc->sc_rxtap_len,
+                   m, BPF_DIRECTION_IN);
+       }
+#endif
        ieee80211_input(ifp, m, ni, &rxi);
 exit:
 #ifdef notyet
@@ -15213,8 +15235,14 @@ qwx_dp_rx_deliver_msdu(struct qwx_softc *sc, struct qwx_rx_msdu *msdu)
        wh = mtod(msdu->m, struct ieee80211_frame *);
        ni = ieee80211_find_rxnode(ic, wh);
 
-       /* TODO: bpf */
+#if NBPFILTER > 0
+       if (sc->sc_drvbpf != NULL) {
+               struct qwx_rx_radiotap_header *tap = &sc->sc_rxtap;
 
+               bpf_mtap_hdr(sc->sc_drvbpf, tap, sc->sc_rxtap_len,
+                   msdu->m, BPF_DIRECTION_IN);
+       }
+#endif
        ieee80211_input(ifp, msdu->m, ni, &msdu->rxi);
        ieee80211_release_node(ic, ni);
 }
@@ -23063,6 +23091,23 @@ qwx_run_stop(struct qwx_softc *sc)
        return ENOTSUP;
 }
 
+#if NBPFILTER > 0
+void
+qwx_radiotap_attach(struct qwx_softc *sc)
+{
+       bpfattach(&sc->sc_drvbpf, &sc->sc_ic.ic_if, DLT_IEEE802_11_RADIO,
+           sizeof (struct ieee80211_frame) + IEEE80211_RADIOTAP_HDRLEN);
+
+       sc->sc_rxtap_len = sizeof(sc->sc_rxtapu);
+       sc->sc_rxtap.wr_ihdr.it_len = htole16(sc->sc_rxtap_len);
+       sc->sc_rxtap.wr_ihdr.it_present = htole32(IWX_RX_RADIOTAP_PRESENT);
+
+       sc->sc_txtap_len = sizeof(sc->sc_txtapu);
+       sc->sc_txtap.wt_ihdr.it_len = htole16(sc->sc_txtap_len);
+       sc->sc_txtap.wt_ihdr.it_present = htole32(IWX_TX_RADIOTAP_PRESENT);
+}
+#endif
+
 int
 qwx_attach(struct qwx_softc *sc)
 {
@@ -23073,7 +23118,9 @@ qwx_attach(struct qwx_softc *sc)
        task_set(&sc->init_task, qwx_init_task, sc);
        task_set(&sc->newstate_task, qwx_newstate_task, sc);
        timeout_set_proc(&sc->scan.timeout, qwx_scan_timeout, sc);
-
+#if NBPFILTER > 0
+       qwx_radiotap_attach(sc);
+#endif
        for (i = 0; i < nitems(sc->pdevs); i++)
                sc->pdevs[i].sc = sc;
 

diff --git a/sys/dev/ic/qwxvar.h b/sys/dev/ic/qwxvar.h
index e59d7b7..68fd58d 100644 (file)
--- a/sys/dev/ic/qwxvar.h
+++ b/sys/dev/ic/qwxvar.h
@@ -1,4 +1,4 @@
-/*     $OpenBSD: qwxvar.h,v 1.11 2024/02/03 20:07:19 kettenis Exp $    */
+/*     $OpenBSD: qwxvar.h,v 1.12 2024/02/06 14:18:15 stsp Exp $        */
 
 /*
  * Copyright (c) 2018-2019 The Linux Foundation.
@@ -1624,6 +1624,18 @@ struct qwx_ext_irq_grp {
 #endif
 };
 
+struct qwx_rx_radiotap_header {
+       struct ieee80211_radiotap_header wr_ihdr;
+} __packed;
+
+#define IWX_RX_RADIOTAP_PRESENT        0 /* TODO add more information */
+
+struct qwx_tx_radiotap_header {
+       struct ieee80211_radiotap_header wt_ihdr;
+} __packed;
+
+#define IWX_TX_RADIOTAP_PRESENT        0 /* TODO add more information */
+
 struct qwx_softc {
        struct device                   sc_dev;
        struct ieee80211com             sc_ic;
@@ -1751,6 +1763,24 @@ struct qwx_softc {
        uint32_t                        msi_ce_irqmask;
 
        struct qmi_wlanfw_request_mem_ind_msg_v01 *sc_req_mem_ind;
+
+#if NBPFILTER > 0
+       caddr_t                 sc_drvbpf;
+
+       union {
+               struct qwx_rx_radiotap_header th;
+               uint8_t pad[IEEE80211_RADIOTAP_HDRLEN];
+       } sc_rxtapu;
+#define sc_rxtap       sc_rxtapu.th
+       int                     sc_rxtap_len;
+
+       union {
+               struct qwx_tx_radiotap_header th;
+               uint8_t pad[IEEE80211_RADIOTAP_HDRLEN];
+       } sc_txtapu;
+#define sc_txtap       sc_txtapu.th
+       int                     sc_txtap_len;
+#endif
 };
 
 int    qwx_ce_intr(void *);