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      1 /*	$NetBSD: loop-bsd.c,v 1.13 2020/04/22 23:55:29 joerg Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1993-95 Mats O Jansson.  All rights reserved.
      5  *
      6  * Redistribution and use in source and binary forms, with or without
      7  * modification, are permitted provided that the following conditions
      8  * are met:
      9  * 1. Redistributions of source code must retain the above copyright
     10  *    notice, this list of conditions and the following disclaimer.
     11  * 2. Redistributions in binary form must reproduce the above copyright
     12  *    notice, this list of conditions and the following disclaimer in the
     13  *    documentation and/or other materials provided with the distribution.
     14  *
     15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     18  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
     20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
     24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     25  */
     26 
     27 #include "port.h"
     28 #ifndef lint
     29 __RCSID("$NetBSD: loop-bsd.c,v 1.13 2020/04/22 23:55:29 joerg Exp $");
     30 #endif
     31 
     32 #include <errno.h>
     33 #include <stdlib.h>
     34 #include <strings.h>
     35 #include <unistd.h>
     36 #if defined(__bsdi__) || defined(__FreeBSD__) || defined(__NetBSD__)
     37 #include <sys/time.h>
     38 #endif
     39 #include <net/bpf.h>
     40 #include <sys/ioctl.h>
     41 #include <sys/poll.h>
     42 #include <assert.h>
     43 
     44 #include "os.h"
     45 #include "common.h"
     46 #include "device.h"
     47 #include "mopdef.h"
     48 #include "log.h"
     49 
     50 int
     51 mopOpenRC(struct if_info *p, int trans)
     52 {
     53 #ifndef NORC
     54 	return (*(p->iopen))(p->if_name,
     55 			     O_RDWR,
     56 			     MOP_K_PROTO_RC,
     57 			     trans);
     58 #else
     59 	return -1;
     60 #endif
     61 }
     62 
     63 int
     64 mopOpenDL(struct if_info *p, int trans)
     65 {
     66 #ifndef NODL
     67 	return (*(p->iopen))(p->if_name,
     68 			     O_RDWR,
     69 			     MOP_K_PROTO_DL,
     70 			     trans);
     71 #else
     72 	return -1;
     73 #endif
     74 }
     75 
     76 void
     77 mopReadRC(void)
     78 {
     79 }
     80 
     81 void
     82 mopReadDL(void)
     83 {
     84 }
     85 
     86 /*
     87  * The list of all interfaces that are being listened to.  loop()
     88  * "polls" on the descriptors in this list.
     89  */
     90 extern struct if_info *iflist;
     91 
     92 void   mopProcess(struct if_info *, u_char *);
     93 
     94 /*
     95  * Loop indefinitely listening for MOP requests on the
     96  * interfaces in 'iflist'.
     97  */
     98 void
     99 Loop(void)
    100 {
    101 	u_char *buf, *bp, *ep;
    102 	int     cc, n, m;
    103 	struct	pollfd *set;
    104 	int     bufsize;
    105 	struct	if_info *ii;
    106 
    107 	if (iflist == 0)
    108 		mopLogErrX("no interfaces");
    109 	if (iflist->fd != -1) {
    110 		if (ioctl(iflist->fd, BIOCGBLEN, (caddr_t) & bufsize) < 0)
    111 			mopLogErr("BIOCGBLEN");
    112 	} else
    113 		mopLogErrX("cannot get buffer size");
    114 	buf = (u_char *) malloc((unsigned) bufsize);
    115 	if (buf == 0)
    116 		mopLogErr("malloc");
    117 	/*
    118          * Find the highest numbered file descriptor for poll().
    119          * Initialize the set of descriptors to listen to.
    120          */
    121 	for (ii = iflist, n = 0; ii; ii = ii->next, n++)
    122 		;
    123 	set = malloc(n * sizeof(*set));
    124 	for (ii = iflist, m = 0; ii; ii = ii->next, m++) {
    125 		assert(ii->fd != -1);
    126 		set[m].fd = ii->fd;
    127 		set[m].events = POLLIN;
    128 	}
    129 	for (;;) {
    130 		if (poll(set, n, INFTIM) < 0)
    131 			mopLogErr("poll");
    132 		for (ii = iflist, m = 0; ii; ii = ii->next, m++) {
    133 			if (!(set[m].revents & POLLIN))
    134 				continue;
    135 	again:
    136 			cc = read(ii->fd, (char *) buf, bufsize);
    137 			/* Don't choke when we get ptraced */
    138 			if (cc < 0 && errno == EINTR)
    139 				goto again;
    140 			/* Due to a SunOS bug, after 2^31 bytes, the file
    141 			 * offset overflows and read fails with EINVAL.  The
    142 			 * lseek() to 0 will fix things. */
    143 			if (cc < 0) {
    144 				if (errno == EINVAL &&
    145 				    (lseek(ii->fd, 0, SEEK_CUR) + bufsize) < 0) {
    146 					(void) lseek(ii->fd, 0, 0);
    147 					goto again;
    148 				}
    149 				mopLogErr("read");
    150 			}
    151 			/* Loop through the packet(s) */
    152 #define bhp ((struct bpf_hdr *)bp)
    153 			bp = buf;
    154 			ep = bp + cc;
    155 			while (bp < ep) {
    156 				int caplen, hdrlen;
    157 
    158 				caplen = bhp->bh_caplen;
    159 				hdrlen = bhp->bh_hdrlen;
    160 				mopProcess(ii, bp + hdrlen);
    161 				bp += BPF_WORDALIGN(hdrlen + caplen);
    162 			}
    163 		}
    164 	}
    165 }
    166