/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2005 Christian S.J. Peron
 * 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 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 AUTHOR 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/types.h>
#include <sys/protosw.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/sysctl.h>
#include <sys/param.h>
#include <sys/user.h>

#include <net/if.h>
#include <net/bpf.h>
#include <net/bpfdesc.h>
#include <arpa/inet.h>

#include <errno.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include <string.h>
#include <unistd.h>
#include <libxo/xo.h>

#include "netstat.h"

/* print bpf stats */

static char *
bpf_pidname(pid_t pid)
{
        struct kinfo_proc newkp;
        int error, mib[4];
        size_t size;

        mib[0] = CTL_KERN;
        mib[1] = KERN_PROC;
        mib[2] = KERN_PROC_PID;
        mib[3] = pid;
        size = sizeof(newkp);
        error = sysctl(mib, 4, &newkp, &size, NULL, 0);
        if (error < 0) {
                xo_warn("kern.proc.pid failed");
                return (strdup("??????"));
        }
        return (strdup(newkp.ki_comm));
}

static void
bpf_flags(struct xbpf_d *bd, char *flagbuf)
{

        *flagbuf++ = bd->bd_promisc ? 'p' : '-';
        *flagbuf++ = bd->bd_immediate ? 'i' : '-';
        *flagbuf++ = bd->bd_hdrcmplt ? '-' : 'f';
        *flagbuf++ = (bd->bd_direction == BPF_D_IN) ? '-' :
            ((bd->bd_direction == BPF_D_OUT) ? 'o' : 's');
        *flagbuf++ = bd->bd_feedback ? 'b' : '-';
        *flagbuf++ = bd->bd_async ? 'a' : '-';
        *flagbuf++ = bd->bd_locked ? 'l' : '-';
        *flagbuf++ = '\0';

        if (bd->bd_promisc)
                xo_emit("{e:promiscuous/}");
        if (bd->bd_immediate)
                xo_emit("{e:immediate/}");
        if (bd->bd_hdrcmplt)
                xo_emit("{e:header-complete/}");
        xo_emit("{e:direction}", (bd->bd_direction == BPF_D_IN) ? "input" :
            (bd->bd_direction == BPF_D_OUT) ? "output" : "bidirectional");
        if (bd->bd_feedback)
                xo_emit("{e:feedback/}");
        if (bd->bd_async)
                xo_emit("{e:async/}");
        if (bd->bd_locked)
                xo_emit("{e:locked/}");
}

void
bpf_stats(char *ifname)
{
        struct xbpf_d *d, *bd, zerostat;
        char *pname, flagbuf[12];
        size_t size;

        if (zflag) {
                bzero(&zerostat, sizeof(zerostat));
                if (sysctlbyname("net.bpf.stats", NULL, NULL,
                    &zerostat, sizeof(zerostat)) < 0)
                        xo_warn("failed to zero bpf counters");
                return;
        }
        if (sysctlbyname("net.bpf.stats", NULL, &size,
            NULL, 0) < 0) {
                xo_warn("net.bpf.stats");
                return;
        }
        if (size == 0)
                return;
        bd = malloc(size);
        if (bd == NULL) {
                xo_warn("malloc failed");
                return;
        }
        if (sysctlbyname("net.bpf.stats", bd, &size,
            NULL, 0) < 0) {
                xo_warn("net.bpf.stats");
                free(bd);
                return;
        }
        xo_emit("{T:/%5s} {T:/%6s} {T:/%7s} {T:/%9s} {T:/%9s} {T:/%9s} "
            "{T:/%5s} {T:/%5s} {T:/%s}\n",
            "Pid", "Netif", "Flags", "Recv", "Drop", "Match",
            "Sblen", "Hblen", "Command");
        xo_open_container("bpf-statistics");
        xo_open_list("bpf-entry");
        for (d = &bd[0]; d < &bd[size / sizeof(*d)]; d++) {
                if (d->bd_structsize != sizeof(*d)) {
                        xo_warnx("bpf_stats_extended: version mismatch");
                        return;
                }
                if (ifname && strcmp(ifname, d->bd_ifname) != 0)
                        continue;
                xo_open_instance("bpf-entry");
                pname = bpf_pidname(d->bd_pid);
                xo_emit("{k:pid/%5d} {k:interface-name/%6s} ",
                    d->bd_pid, d->bd_ifname);
                bpf_flags(d, flagbuf);
                xo_emit("{d:flags/%7s} {:received-packets/%9ju} "
                    "{:dropped-packets/%9ju} {:filter-packets/%9ju} "
                    "{:store-buffer-length/%5d} {:hold-buffer-length/%5d} "
                    "{:process/%s}\n",
                    flagbuf, (uintmax_t)d->bd_rcount, (uintmax_t)d->bd_dcount,
                    (uintmax_t)d->bd_fcount, d->bd_slen, d->bd_hlen, pname);
                free(pname);
                xo_close_instance("bpf-entry");
        }
        xo_close_list("bpf-entry");
        xo_close_container("bpf-statistics");
        free(bd);
}