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748 lines
18 KiB
C
748 lines
18 KiB
C
/*
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* Copyright (c) 1990 The Regents of the University of California.
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that: (1) source code distributions
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* retain the above copyright notice and this paragraph in its entirety, (2)
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* distributions including binary code include the above copyright notice and
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* this paragraph in its entirety in the documentation or other materials
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* provided with the distribution, and (3) all advertising materials mentioning
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* features or use of this software display the following acknowledgement:
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* ``This product includes software developed by the University of California,
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* Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
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* the University nor the names of its contributors may be used to endorse
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* or promote products derived from this software without specific prior
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* written permission.
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* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
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* WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
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* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
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*/
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#ifndef lint
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char copyright[] =
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"@(#) Copyright (c) 1990 The Regents of the University of California.\n\
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All rights reserved.\n";
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#endif /* not lint */
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#ifndef lint
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static char rcsid[] =
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"@(#) $Header: /home/ncvs/src/usr.sbin/rarpd/rarpd.c,v 1.4 1995/05/30 03:51:25 rgrimes Exp $ (LBL)";
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#endif
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/*
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* rarpd - Reverse ARP Daemon
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*
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* Usage: rarpd -a [ -f ] [ hostname ]
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* rarpd [ -f ] interface [ hostname ]
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*
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* 'hostname' is optional solely for backwards compatibility with Sun's rarpd.
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* Currently, the argument is ignored.
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*/
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#include <stdio.h>
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#include <syslog.h>
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#include <string.h>
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#include <strings.h>
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#include <sys/types.h>
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/* SunOS 4.x defines this while 3.x does not. */
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#ifdef __sys_types_h
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#define SUNOS4
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#endif
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#include <sys/time.h>
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#include <net/bpf.h>
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#include <sys/socket.h>
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#include <sys/ioctl.h>
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#include <net/if.h>
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#include <netinet/in.h>
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#include <netinet/if_ether.h>
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#include <sys/errno.h>
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#include <sys/file.h>
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#include <netdb.h>
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#ifdef SUNOS4
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#include <dirent.h>
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#else
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#include <sys/dir.h>
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#endif
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/*
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* Map field names in ether_arp struct. What a pain in the neck.
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*/
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#if !defined(SUNOS4) && !defined(__FreeBSD__)
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#undef arp_sha
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#undef arp_spa
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#undef arp_tha
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#undef arp_tpa
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#define arp_sha arp_xsha
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#define arp_spa arp_xspa
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#define arp_tha arp_xtha
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#define arp_tpa arp_xtpa
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#endif
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#ifndef __GNUC__
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#define inline
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#endif
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extern int errno;
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extern int ether_ntohost __P((char *, struct ether_addr *));
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/*
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* The structure for each interface.
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*/
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struct if_info {
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int ii_fd; /* BPF file descriptor */
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u_char ii_eaddr[6]; /* Ethernet address of this interface */
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u_long ii_ipaddr; /* IP address of this interface */
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u_long ii_netmask; /* subnet or net mask */
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struct if_info *ii_next;
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};
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/*
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* The list of all interfaces that are being listened to. rarp_loop()
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* "selects" on the descriptors in this list.
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*/
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struct if_info *iflist;
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extern char *malloc();
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extern void exit();
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u_long ipaddrtonetmask();
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void init_one();
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void init_all();
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void rarp_loop();
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void lookup_eaddr();
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void lookup_ipaddr();
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void
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main(argc, argv)
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int argc;
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char **argv;
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{
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int op, pid;
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char *ifname, *hostname, *name;
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int aflag = 0; /* listen on "all" interfaces */
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int fflag = 0; /* don't fork */
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extern char *optarg;
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extern int optind, opterr;
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if (name = strrchr(argv[0], '/'))
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++name;
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else
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name = argv[0];
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if (*name == '-')
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++name;
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/*
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* All error reporting is done through syslogs.
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*/
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openlog(name, LOG_PID, LOG_DAEMON);
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opterr = 0;
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while ((op = getopt(argc, argv, "af")) != EOF) {
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switch (op) {
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case 'a':
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++aflag;
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break;
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case 'f':
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++fflag;
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break;
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default:
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usage();
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/* NOTREACHED */
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}
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}
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ifname = argv[optind++];
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hostname = ifname ? argv[optind] : 0;
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if ((aflag && ifname) || (!aflag && ifname == 0))
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usage();
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if (aflag)
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init_all();
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else
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init_one(ifname);
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if (!fflag)
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if (daemon(0,0)) {
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perror("fork");
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exit(0);
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}
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rarp_loop();
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}
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/*
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* Add 'ifname' to the interface list. Lookup its IP address and network
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* mask and Ethernet address, and open a BPF file for it.
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*/
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void
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init_one(ifname)
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char *ifname;
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{
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struct if_info *p;
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p = (struct if_info *)malloc(sizeof(*p));
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p->ii_next = iflist;
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iflist = p;
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p->ii_fd = rarp_open(ifname);
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lookup_eaddr(p->ii_fd, p->ii_eaddr);
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lookup_ipaddr(ifname, &p->ii_ipaddr, &p->ii_netmask);
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}
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/*
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* Initialize all "candidate" interfaces that are in the system
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* configuration list. A "candidate" is up, not loopback and not
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* point to point.
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*/
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void
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init_all()
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{
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int fd;
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int ifflags;
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struct ifreq ibuf[8], tmp_ibuf, *ifptr, *n;
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struct ifconf ifc;
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if ((fd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
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syslog(LOG_ERR, "socket: %m");
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exit(1);
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}
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ifc.ifc_len = sizeof ibuf;
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ifc.ifc_buf = (caddr_t)ibuf;
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if (ioctl(fd, SIOCGIFCONF, (char *)&ifc) < 0 ||
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ifc.ifc_len < sizeof(struct ifreq)) {
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syslog(LOG_ERR, "SIOCGIFCONF: %m");
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exit(1);
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}
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ifptr = ifc.ifc_req;
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ifflags = ifptr->ifr_flags;
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n = (struct ifreq *) (ifc.ifc_buf + ifc.ifc_len);
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while (ifptr < n) {
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bcopy((char *)ifptr, (char *)&tmp_ibuf, sizeof(struct ifreq));
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if (ioctl(fd, SIOCGIFFLAGS, (char *)&tmp_ibuf) < 0) {
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syslog(LOG_ERR, "SIOCGIFFLAGS: %m");
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exit(1);
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}
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if (ifptr->ifr_flags == ifflags && (tmp_ibuf.ifr_flags &
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(IFF_UP | IFF_LOOPBACK | IFF_POINTOPOINT)) == IFF_UP)
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init_one(ifptr->ifr_name);
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if(ifptr->ifr_addr.sa_len) /* Dohw! */
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ifptr = (struct ifreq *) ((caddr_t) ifptr +
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ifptr->ifr_addr.sa_len -
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sizeof(struct sockaddr));
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ifptr++;
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}
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(void)close(fd);
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}
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usage()
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{
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(void)fprintf(stderr, "usage: rarpd [ -af ] [ interface ]\n");
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exit(1);
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}
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static int
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bpf_open()
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{
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int fd;
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int n = 0;
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char device[sizeof "/dev/bpf000"];
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/*
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* Go through all the minors and find one that isn't in use.
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*/
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do {
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(void)sprintf(device, "/dev/bpf%d", n++);
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fd = open(device, O_RDWR);
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} while (fd < 0 && errno == EBUSY);
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if (fd < 0) {
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syslog(LOG_ERR, "%s: %m", device);
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exit(-1);
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}
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return fd;
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}
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/*
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* Open a BPF file and attach it to the interface named 'device'.
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* Set immediate mode, and set a filter that accepts only RARP requests.
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*/
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int
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rarp_open(device)
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char *device;
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{
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int fd;
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struct ifreq ifr;
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int immediate, link_type;
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static struct bpf_insn insns[] = {
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BPF_STMT(BPF_LD+BPF_H+BPF_ABS, 12),
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BPF_JUMP(BPF_JMP+BPF_JEQ+BPF_K, ETHERTYPE_REVARP, 0, 3),
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BPF_STMT(BPF_LD+BPF_H+BPF_ABS, 20),
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BPF_JUMP(BPF_JMP+BPF_JEQ+BPF_K, ARPOP_REVREQUEST, 0, 1),
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BPF_STMT(BPF_RET+BPF_K, sizeof(struct ether_arp) +
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sizeof(struct ether_header)),
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BPF_STMT(BPF_RET+BPF_K, 0),
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};
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static struct bpf_program filter = {
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sizeof insns / sizeof(insns[0]),
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(struct bpf_insn *)&insns
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};
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fd = bpf_open();
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/*
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* Set immediate mode so packets are processed as they arrive.
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*/
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immediate = 1;
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if (ioctl(fd, BIOCIMMEDIATE, &immediate) < 0) {
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syslog(LOG_ERR, "BIOCIMMEDIATE: %m");
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exit(1);
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}
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(void)strncpy(ifr.ifr_name, device, sizeof ifr.ifr_name);
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if (ioctl(fd, BIOCSETIF, (caddr_t)&ifr) < 0) {
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syslog(LOG_ERR, "BIOCSETIF: %m");
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exit(1);
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}
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/*
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* Check that the data link layer is an Ethernet; this code won't
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* work with anything else.
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*/
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if (ioctl(fd, BIOCGDLT, &link_type) < 0) {
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syslog(LOG_ERR, "BIOCGDLP: %m");
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exit(1);
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}
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if (link_type != DLT_EN10MB) {
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syslog(LOG_ERR, "%s not on ethernet", device);
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exit(1);
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}
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/*
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* Set filter program.
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*/
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if (ioctl(fd, BIOCSETF, (caddr_t)&filter) < 0) {
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syslog(LOG_ERR, "BIOCSETF: %m");
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exit(1);
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}
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return fd;
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}
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/*
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* Perform various sanity checks on the RARP request packet. Return
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* false on failure and log the reason.
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*/
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static int
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rarp_check(p, len)
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u_char *p;
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int len;
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{
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struct ether_header *ep = (struct ether_header *)p;
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struct ether_arp *ap = (struct ether_arp *)(p + sizeof(*ep));
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if (len < sizeof(*ep) + sizeof(*ap)) {
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syslog(LOG_ERR, "truncated request");
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return 0;
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}
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/*
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* XXX This test might be better off broken out...
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*/
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if (ep->ether_type != htons(ETHERTYPE_REVARP) ||
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ap->arp_hrd != htons(ARPHRD_ETHER) ||
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ap->arp_op != htons(ARPOP_REVREQUEST) ||
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ap->arp_pro != htons(ETHERTYPE_IP) ||
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ap->arp_hln != 6 || ap->arp_pln != 4) {
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syslog(LOG_DEBUG, "request fails sanity check");
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return 0;
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}
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if (bcmp((char *)&ep->ether_shost, (char *)&ap->arp_sha, 6) != 0) {
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syslog(LOG_DEBUG, "ether/arp sender address mismatch");
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return 0;
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}
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if (bcmp((char *)&ap->arp_sha, (char *)&ap->arp_tha, 6) != 0) {
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syslog(LOG_DEBUG, "ether/arp target address mismatch");
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return 0;
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}
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return 1;
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}
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#ifndef FD_SETSIZE
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#define FD_SET(n, fdp) ((fdp)->fds_bits[0] |= (1 << (n)))
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#define FD_ISSET(n, fdp) ((fdp)->fds_bits[0] & (1 << (n)))
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#define FD_ZERO(fdp) ((fdp)->fds_bits[0] = 0)
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#endif
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/*
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* Loop indefinitely listening for RARP requests on the
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* interfaces in 'iflist'.
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*/
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void
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rarp_loop()
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{
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struct bpf_hdr *bhp;
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u_char *pkt;
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int cc, fd;
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fd_set fds, listeners;
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int bufsize, maxfd = 0;
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struct if_info *ii;
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if (iflist == 0) {
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syslog(LOG_ERR, "no interfaces");
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exit(1);
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}
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if (ioctl(iflist->ii_fd, BIOCGBLEN, (caddr_t)&bufsize) < 0) {
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syslog(LOG_ERR, "BIOCGBLEN: %m");
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exit(1);
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}
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bhp = (struct bpf_hdr *)malloc((unsigned)bufsize);
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/*
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* Find the highest numbered file descriptor for select().
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* Initialize the set of descriptors to listen to.
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*/
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FD_ZERO(&fds);
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for (ii = iflist; ii; ii = ii->ii_next) {
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FD_SET(ii->ii_fd, &fds);
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if (ii->ii_fd > maxfd)
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maxfd = ii->ii_fd;
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}
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while (1) {
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listeners = fds;
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if (select(maxfd + 1, &listeners, (struct fd_set *)0,
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(struct fd_set *)0, (struct timeval *)0) < 0) {
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syslog(LOG_ERR, "select: %m");
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exit(1);
|
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}
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for (ii = iflist; ii; ii = ii->ii_next) {
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fd = ii->ii_fd;
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if (FD_ISSET(fd, &listeners)) {
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again:
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cc = read(fd, (char *)bhp, bufsize);
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/*
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* Due to a SunOS bug, after 2^31 bytes, the
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* file offset overflows and read fails with
|
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* EINVAL. The lseek() to 0 will fix things.
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|
*/
|
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if (cc < 0) {
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if (errno == EINVAL &&
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(long)(lseek(fd, 0L, SEEK_CUR) + bufsize) < 0) {
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(void)lseek(fd, 0, 0);
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goto again;
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}
|
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syslog(LOG_ERR, "read: %m");
|
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exit(1);
|
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}
|
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pkt = (u_char *)bhp + bhp->bh_hdrlen;
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|
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if (rarp_check(pkt, (int)bhp->bh_datalen))
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rarp_process(ii, pkt);
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}
|
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}
|
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}
|
|
}
|
|
|
|
#ifndef TFTP_DIR
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#define TFTP_DIR "/tftpboot"
|
|
#endif
|
|
|
|
/*
|
|
* True if this server can boot the host whose IP address is 'addr'.
|
|
* This check is made by looking in the tftp directory for the
|
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* configuration file.
|
|
*/
|
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rarp_bootable(addr)
|
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u_long addr;
|
|
{
|
|
|
|
#ifdef SUNOS4
|
|
register struct dirent *dent;
|
|
#else
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register struct direct *dent;
|
|
#endif
|
|
register DIR *d;
|
|
char ipname[9];
|
|
static DIR *dd = 0;
|
|
|
|
/*
|
|
* XXX Need to htonl() the IP address or it'll
|
|
* come out backwards.
|
|
*/
|
|
(void)sprintf(ipname, "%08X", htonl(addr));
|
|
/*
|
|
* If directory is already open, rewind it. Otherwise, open it.
|
|
*/
|
|
if (d = dd)
|
|
rewinddir(d);
|
|
else {
|
|
if (chdir(TFTP_DIR) == -1) {
|
|
syslog(LOG_ERR, "chdir: %m");
|
|
exit(1);
|
|
}
|
|
d = opendir(".");
|
|
if (d == 0) {
|
|
syslog(LOG_ERR, "opendir: %m");
|
|
exit(1);
|
|
}
|
|
dd = d;
|
|
}
|
|
while (dent = readdir(d))
|
|
if (strncmp(dent->d_name, ipname, 8) == 0)
|
|
return 1;
|
|
return 0;
|
|
|
|
}
|
|
|
|
/*
|
|
* Given a list of IP addresses, 'alist', return the first address that
|
|
* is on network 'net'; 'netmask' is a mask indicating the network portion
|
|
* of the address.
|
|
*/
|
|
u_long
|
|
choose_ipaddr(alist, net, netmask)
|
|
u_long **alist;
|
|
u_long net;
|
|
u_long netmask;
|
|
{
|
|
for (; *alist; ++alist) {
|
|
if ((**alist & netmask) == net)
|
|
return **alist;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* A one entry ip/ethernet address cache.
|
|
*/
|
|
static u_long cache_ipaddr;
|
|
static u_char cache_eaddr[6];
|
|
|
|
/*
|
|
* Answer the RARP request in 'pkt', on the interface 'ii'. 'pkt' has
|
|
* already been checked for validity. The reply is overlaid on the request.
|
|
*/
|
|
rarp_process(ii, pkt)
|
|
struct if_info *ii;
|
|
u_char *pkt;
|
|
{
|
|
struct ether_header *ep;
|
|
struct hostent *hp;
|
|
u_long target_ipaddr;
|
|
char ename[256];
|
|
|
|
ep = (struct ether_header *)pkt;
|
|
/*
|
|
* If the address in the one element cache, don't bother
|
|
* looking up names.
|
|
*/
|
|
if (bcmp((char *)cache_eaddr, (char *)&ep->ether_shost, 6) == 0)
|
|
target_ipaddr = cache_ipaddr;
|
|
else {
|
|
if (ether_ntohost(ename, (struct ether_addr *)&ep->ether_shost) != 0 ||
|
|
(hp = gethostbyname(ename)) == 0)
|
|
return;
|
|
/*
|
|
* Choose correct address from list.
|
|
*/
|
|
if (hp->h_addrtype != AF_INET) {
|
|
syslog(LOG_ERR, "cannot handle non IP addresses");
|
|
exit(1);
|
|
}
|
|
target_ipaddr = choose_ipaddr((u_long **)hp->h_addr_list,
|
|
ii->ii_ipaddr & ii->ii_netmask,
|
|
ii->ii_netmask);
|
|
if (target_ipaddr == 0) {
|
|
syslog(LOG_ERR, "cannot find %s on %08x",
|
|
ename, ii->ii_ipaddr & ii->ii_netmask);
|
|
return;
|
|
}
|
|
bcopy((char *)&ep->ether_shost, (char *)cache_eaddr, 6);
|
|
cache_ipaddr = target_ipaddr;
|
|
}
|
|
if (rarp_bootable(target_ipaddr))
|
|
rarp_reply(ii, ep, target_ipaddr);
|
|
}
|
|
|
|
/*
|
|
* Lookup the ethernet address of the interface attached to the BPF
|
|
* file descriptor 'fd'; return it in 'eaddr'.
|
|
*/
|
|
void
|
|
lookup_eaddr(fd, eaddr)
|
|
int fd;
|
|
u_char *eaddr;
|
|
{
|
|
struct ifreq ifr;
|
|
|
|
/* Use BPF descriptor to get ethernet address. */
|
|
if (ioctl(fd, SIOCGIFADDR, (char *)&ifr) < 0) {
|
|
syslog(LOG_ERR, "SIOCGIFADDR: %m");
|
|
exit(1);
|
|
}
|
|
bcopy((char *)&ifr.ifr_addr.sa_data[0], (char *)eaddr, 6);
|
|
}
|
|
|
|
/*
|
|
* Lookup the IP address and network mask of the interface named 'ifname'.
|
|
*/
|
|
void
|
|
lookup_ipaddr(ifname, addrp, netmaskp)
|
|
char *ifname;
|
|
u_long *addrp;
|
|
u_long *netmaskp;
|
|
{
|
|
int fd;
|
|
struct ifreq ifr;
|
|
|
|
/* Use data gram socket to get IP address. */
|
|
if ((fd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
|
|
syslog(LOG_ERR, "socket: %m");
|
|
exit(1);
|
|
}
|
|
(void)strncpy(ifr.ifr_name, ifname, sizeof ifr.ifr_name);
|
|
if (ioctl(fd, SIOCGIFADDR, (char *)&ifr) < 0) {
|
|
syslog(LOG_ERR, "SIOCGIFADDR: %m");
|
|
exit(1);
|
|
}
|
|
*addrp = ((struct sockaddr_in *)&ifr.ifr_addr)->sin_addr.s_addr;
|
|
if (ioctl(fd, SIOCGIFNETMASK, (char *)&ifr) < 0) {
|
|
perror("SIOCGIFNETMASK");
|
|
exit(1);
|
|
}
|
|
*netmaskp = ((struct sockaddr_in *)&ifr.ifr_addr)->sin_addr.s_addr;
|
|
/*
|
|
* If SIOCGIFNETMASK didn't work, figure out a mask from
|
|
* the IP address class.
|
|
*/
|
|
if (*netmaskp == 0)
|
|
*netmaskp = ipaddrtonetmask(*addrp);
|
|
|
|
(void)close(fd);
|
|
}
|
|
|
|
/*
|
|
* Poke the kernel arp tables with the ethernet/ip address combinataion
|
|
* given. When processing a reply, we must do this so that the booting
|
|
* host (i.e. the guy running rarpd), won't try to ARP for the hardware
|
|
* address of the guy being booted (he cannot answer the ARP).
|
|
*/
|
|
update_arptab(ep, ipaddr)
|
|
u_char *ep;
|
|
u_long ipaddr;
|
|
{
|
|
#ifdef SIOCSARP
|
|
int s;
|
|
struct arpreq request;
|
|
struct sockaddr_in *sin;
|
|
|
|
request.arp_flags = 0;
|
|
sin = (struct sockaddr_in *)&request.arp_pa;
|
|
sin->sin_family = AF_INET;
|
|
sin->sin_addr.s_addr = ipaddr;
|
|
request.arp_ha.sa_family = AF_UNSPEC;
|
|
bcopy((char *)ep, (char *)request.arp_ha.sa_data, 6);
|
|
|
|
s = socket(AF_INET, SOCK_DGRAM, 0);
|
|
if (ioctl(s, SIOCSARP, (caddr_t)&request) < 0)
|
|
syslog(LOG_ERR, "SIOCSARP: %m");
|
|
(void)close(s);
|
|
#else
|
|
if (arptab_set(ep, ipaddr) > 0)
|
|
syslog(LOG_ERR, "couldn't update arp table");
|
|
#endif
|
|
}
|
|
|
|
/*
|
|
* Build a reverse ARP packet and sent it out on the interface.
|
|
* 'ep' points to a valid ARPOP_REVREQUEST. The ARPOP_REVREPLY is built
|
|
* on top of the request, then written to the network.
|
|
*
|
|
* RFC 903 defines the ether_arp fields as follows. The following comments
|
|
* are taken (more or less) straight from this document.
|
|
*
|
|
* ARPOP_REVREQUEST
|
|
*
|
|
* arp_sha is the hardware address of the sender of the packet.
|
|
* arp_spa is undefined.
|
|
* arp_tha is the 'target' hardware address.
|
|
* In the case where the sender wishes to determine his own
|
|
* protocol address, this, like arp_sha, will be the hardware
|
|
* address of the sender.
|
|
* arp_tpa is undefined.
|
|
*
|
|
* ARPOP_REVREPLY
|
|
*
|
|
* arp_sha is the hardware address of the responder (the sender of the
|
|
* reply packet).
|
|
* arp_spa is the protocol address of the responder (see the note below).
|
|
* arp_tha is the hardware address of the target, and should be the same as
|
|
* that which was given in the request.
|
|
* arp_tpa is the protocol address of the target, that is, the desired address.
|
|
*
|
|
* Note that the requirement that arp_spa be filled in with the responder's
|
|
* protocol is purely for convenience. For instance, if a system were to use
|
|
* both ARP and RARP, then the inclusion of the valid protocol-hardware
|
|
* address pair (arp_spa, arp_sha) may eliminate the need for a subsequent
|
|
* ARP request.
|
|
*/
|
|
rarp_reply(ii, ep, ipaddr)
|
|
struct if_info *ii;
|
|
struct ether_header *ep;
|
|
u_long ipaddr;
|
|
{
|
|
int n;
|
|
struct ether_arp *ap = (struct ether_arp *)(ep + 1);
|
|
int len, raw_sock;
|
|
|
|
update_arptab((u_char *)&ap->arp_sha, ipaddr);
|
|
|
|
/*
|
|
* Build the rarp reply by modifying the rarp request in place.
|
|
*/
|
|
ap->arp_op = htons(ARPOP_REVREPLY);
|
|
|
|
/*
|
|
* XXX Using htons(ETHERTYPE_REVARP) doesn't work: you wind
|
|
* up transmitting 0x3580 instead of the correct value of
|
|
* 0x8035. What makes no sense is that the NetBSD people
|
|
* do in fact use htons(ETHERTYPE_REVARP) in their rarpd.
|
|
* (Thank god for tcpdump or I would never have figured this
|
|
* out.)
|
|
*/
|
|
ep->ether_type = ETHERTYPE_REVARP;
|
|
|
|
bcopy((char *)&ap->arp_sha, (char *)&ep->ether_dhost, 6);
|
|
bcopy((char *)ii->ii_eaddr, (char *)&ep->ether_shost, 6);
|
|
bcopy((char *)ii->ii_eaddr, (char *)&ap->arp_sha, 6);
|
|
|
|
bcopy((char *)&ipaddr, (char *)ap->arp_tpa, 4);
|
|
/* Target hardware is unchanged. */
|
|
bcopy((char *)&ii->ii_ipaddr, (char *)ap->arp_spa, 4);
|
|
|
|
len = sizeof(*ep) + sizeof(*ap);
|
|
n = write(ii->ii_fd, (char *)ep, len);
|
|
if (n != len) {
|
|
syslog(LOG_ERR, "write: only %d of %d bytes written", n, len);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Get the netmask of an IP address. This routine is used if
|
|
* SIOCGIFNETMASK doesn't work.
|
|
*/
|
|
u_long
|
|
ipaddrtonetmask(addr)
|
|
u_long addr;
|
|
{
|
|
if (IN_CLASSA(addr))
|
|
return IN_CLASSA_NET;
|
|
if (IN_CLASSB(addr))
|
|
return IN_CLASSB_NET;
|
|
if (IN_CLASSC(addr))
|
|
return IN_CLASSC_NET;
|
|
syslog(LOG_DEBUG, "unknown IP address class: %08X", addr);
|
|
exit(1);
|
|
/* NOTREACHED */
|
|
}
|