/*      $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);
                       }
               }
       }
}