/*      $NetBSD: loop-bsd.c,v 1.13 2020/04/22 23:55:29 joerg Exp $      */

/*
 * Copyright (c) 1993-95 Mats O Jansson.  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.
 */

#include "port.h"
#ifndef lint
__RCSID("$NetBSD: loop-bsd.c,v 1.13 2020/04/22 23:55:29 joerg Exp $");
#endif

#include <errno.h>
#include <stdlib.h>
#include <strings.h>
#include <unistd.h>
#if defined(__bsdi__) || defined(__FreeBSD__) || defined(__NetBSD__)
#include <sys/time.h>
#endif
#include <net/bpf.h>
#include <sys/ioctl.h>
#include <sys/poll.h>
#include <assert.h>

#include "os.h"
#include "common.h"
#include "device.h"
#include "mopdef.h"
#include "log.h"

int
mopOpenRC(struct if_info *p, int trans)
{
#ifndef NORC
        return (*(p->iopen))(p->if_name,
                             O_RDWR,
                             MOP_K_PROTO_RC,
                             trans);
#else
        return -1;
#endif
}

int
mopOpenDL(struct if_info *p, int trans)
{
#ifndef NODL
        return (*(p->iopen))(p->if_name,
                             O_RDWR,
                             MOP_K_PROTO_DL,
                             trans);
#else
        return -1;
#endif
}

void
mopReadRC(void)
{
}

void
mopReadDL(void)
{
}

/*
 * The list of all interfaces that are being listened to.  loop()
 * "polls" on the descriptors in this list.
 */
extern struct if_info *iflist;

void   mopProcess(struct if_info *, u_char *);

/*
 * Loop indefinitely listening for MOP requests on the
 * interfaces in 'iflist'.
 */
void
Loop(void)
{
        u_char *buf, *bp, *ep;
        int     cc, n, m;
        struct  pollfd *set;
        int     bufsize;
        struct  if_info *ii;

        if (iflist == 0)
                mopLogErrX("no interfaces");
        if (iflist->fd != -1) {
                if (ioctl(iflist->fd, BIOCGBLEN, (caddr_t) & bufsize) < 0)
                        mopLogErr("BIOCGBLEN");
        } else
                mopLogErrX("cannot get buffer size");
        buf = (u_char *) malloc((unsigned) bufsize);
        if (buf == 0)
                mopLogErr("malloc");
        /*
         * Find the highest numbered file descriptor for poll().
         * Initialize the set of descriptors to listen to.
         */
        for (ii = iflist, n = 0; ii; ii = ii->next, n++)
                ;
        set = malloc(n * sizeof(*set));
        for (ii = iflist, m = 0; ii; ii = ii->next, m++) {
                assert(ii->fd != -1);
                set[m].fd = ii->fd;
                set[m].events = POLLIN;
        }
        for (;;) {
                if (poll(set, n, INFTIM) < 0)
                        mopLogErr("poll");
                for (ii = iflist, m = 0; ii; ii = ii->next, m++) {
                        if (!(set[m].revents & POLLIN))
                                continue;
        again:
                        cc = read(ii->fd, (char *) buf, bufsize);
                        /* Don't choke when we get ptraced */
                        if (cc < 0 && errno == EINTR)
                                goto again;
                        /* Due to a SunOS bug, after 2^31 bytes, the file
                         * offset overflows and read fails with EINVAL.  The
                         * lseek() to 0 will fix things. */
                        if (cc < 0) {
                                if (errno == EINVAL &&
                                    (lseek(ii->fd, 0, SEEK_CUR) + bufsize) < 0) {
                                        (void) lseek(ii->fd, 0, 0);
                                        goto again;
                                }
                                mopLogErr("read");
                        }
                        /* Loop through the packet(s) */
#define bhp ((struct bpf_hdr *)bp)
                        bp = buf;
                        ep = bp + cc;
                        while (bp < ep) {
                                int caplen, hdrlen;

                                caplen = bhp->bh_caplen;
                                hdrlen = bhp->bh_hdrlen;
                                mopProcess(ii, bp + hdrlen);
                                bp += BPF_WORDALIGN(hdrlen + caplen);
                        }
                }
        }
}