/*      $NetBSD: net_stats.c,v 1.6 2020/02/07 12:35:33 thorpej Exp $    */

/*-
* Copyright (c) 2008 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Jason R. Thorpe.
*
* 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 NETBSD FOUNDATION, INC. AND CONTRIBUTORS
* ``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 FOUNDATION OR CONTRIBUTORS
* 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.
*/

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: net_stats.c,v 1.6 2020/02/07 12:35:33 thorpej Exp $");

#include <sys/types.h>
#include <sys/systm.h>
#include <sys/sysctl.h>
#include <sys/kmem.h>
#include <sys/xcall.h>

#include <net/net_stats.h>

typedef struct {
       uint64_t        *ctx_counters;  /* pointer to collated counter array */
       u_int            ctx_ncounters; /* number of counters in array */
} netstat_sysctl_context;

/*
* netstat_convert_to_user_cb --
*      Internal routine used as a call-back for percpu data enumeration.
*/
static void
netstat_convert_to_user_cb(void *v1, void *v2, struct cpu_info *ci)
{
       const uint64_t *local_counters = v1;
       netstat_sysctl_context *ctx = v2;
       u_int i;

       for (i = 0; i < ctx->ctx_ncounters; i++)
               ctx->ctx_counters[i] += local_counters[i];
}

/*
* netstat_sysctl --
*      Common routine for collating and reporting network statistics
*      that are gathered per-CPU.  Statistics counters are assumed
*      to be arrays of uint64_t's.
*/
int
netstat_sysctl(percpu_t *stat, u_int ncounters, SYSCTLFN_ARGS)
{
       netstat_sysctl_context ctx;
       struct sysctlnode node;
       uint64_t *counters;
       size_t countersize;
       int rv;

       countersize = sizeof(uint64_t) * ncounters;

       counters = kmem_zalloc(countersize, KM_SLEEP);
       ctx.ctx_counters = counters;
       ctx.ctx_ncounters = ncounters;

       percpu_foreach_xcall(stat, XC_HIGHPRI_IPL(IPL_SOFTNET),
           netstat_convert_to_user_cb, &ctx);

       node = *rnode;
       node.sysctl_data = counters;
       node.sysctl_size = countersize;
       rv = sysctl_lookup(SYSCTLFN_CALL(&node));

       kmem_free(counters, countersize);

       return (rv);
}