ieee80211_alq.c

/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2011 Adrian Chadd, Xenion Lty Ltd
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/*
 * net80211 fast-logging support, primarily for debugging.
 *
 * This implements a single debugging queue which includes
 * per-device enumeration where needed.
 */

#include "opt_wlan.h"

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/mbuf.h>
#include <sys/malloc.h>
#include <sys/endian.h>
#include <sys/kernel.h>
#include <sys/sysctl.h>
#include <sys/pcpu.h>
#include <sys/proc.h>
#include <sys/ucred.h>
#include <sys/alq.h>

#include <sys/socket.h>

#include <net/if.h>
#include <net/if_var.h>
#include <net/if_media.h>
#include <net/ethernet.h>

#include <net80211/ieee80211_var.h>
#include <net80211/ieee80211_freebsd.h>
#include <net80211/ieee80211_alq.h>

static struct alq *ieee80211_alq;
static int ieee80211_alq_lost;
static int ieee80211_alq_logged;
static char ieee80211_alq_logfile[MAXPATHLEN] = "/tmp/net80211.log";
static unsigned int ieee80211_alq_qsize = 64*1024;

static int
ieee80211_alq_setlogging(int enable)
{
	int error;

	if (enable) {
		if (ieee80211_alq)
			alq_close(ieee80211_alq);

		error = alq_open(&ieee80211_alq,
		    ieee80211_alq_logfile,
		    curthread->td_ucred,
		    ALQ_DEFAULT_CMODE,
		    ieee80211_alq_qsize, 0);
		ieee80211_alq_lost = 0;
		ieee80211_alq_logged = 0;
		net80211_printf("net80211: logging to %s enabled; "
		    "struct size %d bytes\n",
		    ieee80211_alq_logfile,
		    (int) sizeof(struct ieee80211_alq_rec));
	} else {
		if (ieee80211_alq)
			alq_close(ieee80211_alq);
		ieee80211_alq = NULL;
		net80211_printf("net80211: logging disabled\n");
		error = 0;
	}
	return (error);
}

static int
sysctl_ieee80211_alq_log(SYSCTL_HANDLER_ARGS)
{
	int error, enable;

	enable = (ieee80211_alq != NULL);
	error = sysctl_handle_int(oidp, &enable, 0, req);
	if (error || !req->newptr)
		return (error);
	else
		return (ieee80211_alq_setlogging(enable));
}

SYSCTL_PROC(_net_wlan, OID_AUTO, alq,
    CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_NEEDGIANT, 0, 0,
    sysctl_ieee80211_alq_log, "I",
    "Enable net80211 alq logging");
SYSCTL_INT(_net_wlan, OID_AUTO, alq_size, CTLFLAG_RW,
	&ieee80211_alq_qsize, 0, "In-memory log size (bytes)");
SYSCTL_INT(_net_wlan, OID_AUTO, alq_lost, CTLFLAG_RW,
	&ieee80211_alq_lost, 0, "Debugging operations not logged");
SYSCTL_INT(_net_wlan, OID_AUTO, alq_logged, CTLFLAG_RW,
	&ieee80211_alq_logged, 0, "Debugging operations logged");

static struct ale *
ieee80211_alq_get(size_t len)
{
	struct ale *ale;

	ale = alq_getn(ieee80211_alq, len + sizeof(struct ieee80211_alq_rec),
	    ALQ_NOWAIT);
	if (!ale)
		ieee80211_alq_lost++;
	else
		ieee80211_alq_logged++;
	return ale;
}

int
ieee80211_alq_log(struct ieee80211com *ic, struct ieee80211vap *vap,
    uint32_t op, uint32_t flags, uint16_t srcid, const uint8_t *src,
    size_t len)
{
	struct ale *ale;
	struct ieee80211_alq_rec *r;
	char *dst;

	/* Don't log if we're disabled */
	if (ieee80211_alq == NULL)
		return (0);

	if (len > IEEE80211_ALQ_MAX_PAYLOAD)
		return (ENOMEM);

	ale = ieee80211_alq_get(len);
	if (! ale)
		return (ENOMEM);

	r = (struct ieee80211_alq_rec *) ale->ae_data;
	dst = ((char *) r) + sizeof(struct ieee80211_alq_rec);
	r->r_timestamp = htobe64(ticks);
	if (vap != NULL) {
		r->r_wlan = htobe16(vap->iv_ifp->if_dunit);
	} else {
		r->r_wlan = 0xffff;
	}
	r->r_src = htobe16(srcid);
	r->r_flags = htobe32(flags);
	r->r_op = htobe32(op);
	r->r_len = htobe32(len + sizeof(struct ieee80211_alq_rec));
	r->r_threadid = htobe32((uint32_t) curthread->td_tid);

	if (src != NULL)
		memcpy(dst, src, len);

	alq_post(ieee80211_alq, ale);

	return (0);
}