2 * Copyright (c) 1990, 1991, 1992, 1993, 1996
3 * The Regents of the University of California. All rights reserved.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that: (1) source code distributions
7 * retain the above copyright notice and this paragraph in its entirety, (2)
8 * distributions including binary code include the above copyright notice and
9 * this paragraph in its entirety in the documentation or other materials
10 * provided with the distribution, and (3) all advertising materials mentioning
11 * features or use of this software display the following acknowledgement:
12 * ``This product includes software developed by the University of California,
13 * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
14 * the University nor the names of its contributors may be used to endorse
15 * or promote products derived from this software without specific prior
17 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
18 * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
19 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
23 static const char copyright[] =
24 "@(#) Copyright (c) 1990, 1991, 1992, 1993, 1996\n\
25 The Regents of the University of California. All rights reserved.\n";
29 static const char rcsid[] =
30 "$FreeBSD: src/usr.sbin/rarpd/rarpd.c,v 1.23.2.4 2002/12/01 19:19:34 dwmalone Exp $";
34 * rarpd - Reverse ARP Daemon
36 * Usage: rarpd -a [ -dfsv ] [-t directory] [ hostname ]
37 * rarpd [ -dfsv ] [-t directory] interface [ hostname ]
39 * 'hostname' is optional solely for backwards compatibility with Sun's rarpd.
40 * Currently, the argument is ignored.
42 #include <sys/param.h>
44 #include <sys/ioctl.h>
45 #include <sys/socket.h>
49 #include <net/ethernet.h>
51 #include <net/if_types.h>
52 #include <net/if_dl.h>
53 #include <net/route.h>
55 #include <netinet/in.h>
56 #include <netinet/if_ether.h>
58 #include <arpa/inet.h>
69 #if defined(SUNOS4) || defined(__FreeBSD__) /* XXX */
79 /* Cast a struct sockaddr to a structaddr_in */
80 #define SATOSIN(sa) ((struct sockaddr_in *)(sa))
83 #define TFTP_DIR "/tftpboot"
87 #define ARPSECS (20 * 60) /* as per code in netinet/if_ether.c */
88 #define REVARP_REQUEST ARPOP_REVREQUEST
89 #define REVARP_REPLY ARPOP_REVREPLY
92 #ifndef ETHERTYPE_REVARP
93 #define ETHERTYPE_REVARP 0x8035
94 #define REVARP_REQUEST 3
95 #define REVARP_REPLY 4
99 * Map field names in ether_arp struct. What a pain in the neck.
106 #define arp_sha arp_xsha
107 #define arp_spa arp_xspa
108 #define arp_tha arp_xtha
109 #define arp_tpa arp_xtpa
113 * The structure for each interface.
116 struct if_info *ii_next;
117 int ii_fd; /* BPF file descriptor */
118 u_long ii_ipaddr; /* IP address of this interface */
119 u_long ii_netmask; /* subnet or net mask */
120 u_char ii_eaddr[6]; /* Ethernet address of this interface */
121 char ii_ifname[sizeof(((struct ifreq *)0)->ifr_name) + 1];
125 * The list of all interfaces that are being listened to. rarp_loop()
126 * "selects" on the descriptors in this list.
128 struct if_info *iflist;
130 int verbose; /* verbose messages */
131 int s; /* inet datagram socket */
132 const char *tftp_dir = TFTP_DIR; /* tftp directory */
134 int dflag; /* messages to stdout/stderr, not syslog(3) */
135 int sflag; /* ignore /tftpboot */
137 static u_char zero[6];
139 static int bpf_open(void);
140 static u_long choose_ipaddr(u_long **, u_long, u_long);
141 static char *eatoa(u_char *);
142 static int expand_syslog_m(const char *fmt, char **newfmt);
143 static void init(char *);
144 static void init_one(struct ifreq *, char *);
145 static char *intoa(u_long);
146 static u_long ipaddrtonetmask(u_long);
147 static void logmsg(int, const char *, ...) __printflike(2, 3);
148 static int rarp_bootable(u_long);
149 static int rarp_check(u_char *, u_int);
150 static void rarp_loop(void);
151 static int rarp_open(char *);
152 static void rarp_process(struct if_info *, u_char *, u_int);
153 static void rarp_reply(struct if_info *, struct ether_header *,
155 static void update_arptab(u_char *, u_long);
156 static void usage(void);
159 main(int argc, char *argv[])
162 char *ifname, *hostname, *name;
164 int aflag = 0; /* listen on "all" interfaces */
165 int fflag = 0; /* don't fork */
167 if ((name = strrchr(argv[0], '/')) != NULL)
175 * All error reporting is done through syslog, unless -d is specified
177 openlog(name, LOG_PID | LOG_CONS, LOG_DAEMON);
180 while ((op = getopt(argc, argv, "adfst:v")) != -1) {
211 ifname = argv[optind++];
212 hostname = ifname ? argv[optind] : NULL;
213 if ((aflag && ifname) || (!aflag && ifname == NULL))
223 logmsg(LOG_ERR, "cannot fork");
232 * Add to the interface list.
235 init_one(struct ifreq *ifrp, char *target)
238 struct sockaddr_dl *ll;
242 family = ifrp->ifr_addr.sa_family;
249 (void)strncpy(ifr.ifr_name, ifrp->ifr_name,
250 sizeof(ifrp->ifr_name));
251 if (ioctl(s, SIOCGIFFLAGS, (char *)&ifr) == -1) {
253 "SIOCGIFFLAGS: %.*s: %m",
254 (int)sizeof(ifrp->ifr_name), ifrp->ifr_name);
257 if ((ifr.ifr_flags & IFF_UP) == 0 ||
258 (ifr.ifr_flags & (IFF_LOOPBACK | IFF_POINTOPOINT)) != 0)
267 /* Don't bother going any further if not the target interface */
268 if (target != NULL &&
269 strncmp(ifrp->ifr_name, target, sizeof(ifrp->ifr_name)) != 0)
272 /* Look for interface in list */
273 for (ii = iflist; ii != NULL; ii = ii->ii_next)
274 if (strncmp(ifrp->ifr_name, ii->ii_ifname,
275 sizeof(ifrp->ifr_name)) == 0)
278 /* Allocate a new one if not found */
280 ii = (struct if_info *)malloc(sizeof(*ii));
282 logmsg(LOG_ERR, "malloc: %m");
285 bzero(ii, sizeof(*ii));
287 (void)strncpy(ii->ii_ifname, ifrp->ifr_name,
288 sizeof(ifrp->ifr_name));
289 ii->ii_ifname[sizeof(ii->ii_ifname) - 1] = '\0';
290 ii->ii_next = iflist;
297 if (ioctl(s, SIOCGIFADDR, (char *)&ifr) == -1) {
298 logmsg(LOG_ERR, "ipaddr SIOCGIFADDR: %s: %m",
302 ii->ii_ipaddr = SATOSIN(&ifr.ifr_addr)->sin_addr.s_addr;
303 if (ioctl(s, SIOCGIFNETMASK, (char *)&ifr) == -1) {
304 logmsg(LOG_ERR, "SIOCGIFNETMASK: %m");
307 ii->ii_netmask = SATOSIN(&ifr.ifr_addr)->sin_addr.s_addr;
308 if (ii->ii_netmask == 0)
309 ii->ii_netmask = ipaddrtonetmask(ii->ii_ipaddr);
311 ii->ii_fd = rarp_open(ii->ii_ifname);
313 /* Use BPF descriptor to get ethernet address. */
314 if (ioctl(ii->ii_fd, SIOCGIFADDR, (char *)&ifr) == -1) {
315 logmsg(LOG_ERR, "eaddr SIOCGIFADDR: %s: %m",
319 bcopy(&ifr.ifr_addr.sa_data[0], ii->ii_eaddr, 6);
326 ll = (struct sockaddr_dl *)&ifrp->ifr_addr;
327 if (ll->sdl_type == IFT_ETHER)
328 bcopy(LLADDR(ll), ii->ii_eaddr, 6);
334 * Initialize all "candidate" interfaces that are in the system
335 * configuration list. A "candidate" is up, not loopback and not
342 struct ifreq *ifrp, *ifend;
343 struct if_info *ii, *nii, *lii;
345 struct ifreq ibuf[16];
347 if ((s = socket(AF_INET, SOCK_DGRAM, 0)) == -1) {
348 logmsg(LOG_ERR, "socket: %m");
351 ifc.ifc_len = sizeof ibuf;
352 ifc.ifc_buf = (caddr_t)ibuf;
353 if ((ioctl(s, SIOCGIFCONF, (char *)&ifc) == -1) ||
354 ((u_int)ifc.ifc_len < sizeof(struct ifreq))) {
355 logmsg(LOG_ERR, "SIOCGIFCONF: %m");
359 ifend = (struct ifreq *)((char *)ibuf + ifc.ifc_len);
360 while (ifrp < ifend) {
361 init_one(ifrp, target);
364 n = ifrp->ifr_addr.sa_len + sizeof(ifrp->ifr_name);
365 if (n < sizeof(*ifrp))
367 ifrp = (struct ifreq *)((char *)ifrp + n);
373 /* Throw away incomplete interfaces */
375 for (ii = iflist; ii != NULL; ii = nii) {
377 if (ii->ii_ipaddr == 0 ||
378 bcmp(ii->ii_eaddr, zero, 6) == 0) {
393 for (ii = iflist; ii != NULL; ii = ii->ii_next)
394 logmsg(LOG_DEBUG, "%s %s 0x%08lx %s",
395 ii->ii_ifname, intoa(ntohl(ii->ii_ipaddr)),
396 (u_long)ntohl(ii->ii_netmask), eatoa(ii->ii_eaddr));
402 (void)fprintf(stderr, "usage: rarpd [-adfsv] [-t directory] [interface]\n");
411 char device[sizeof "/dev/bpf000"];
414 * Go through all the minors and find one that isn't in use.
417 (void)sprintf(device, "/dev/bpf%d", n++);
418 fd = open(device, O_RDWR);
419 } while ((fd == -1) && (errno == EBUSY));
422 logmsg(LOG_ERR, "%s: %m", device);
429 * Open a BPF file and attach it to the interface named 'device'.
430 * Set immediate mode, and set a filter that accepts only RARP requests.
433 rarp_open(char *device)
440 static struct bpf_insn insns[] = {
441 BPF_STMT(BPF_LD|BPF_H|BPF_ABS, 12),
442 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, ETHERTYPE_REVARP, 0, 3),
443 BPF_STMT(BPF_LD|BPF_H|BPF_ABS, 20),
444 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, REVARP_REQUEST, 0, 1),
445 BPF_STMT(BPF_RET|BPF_K, sizeof(struct ether_arp) +
446 sizeof(struct ether_header)),
447 BPF_STMT(BPF_RET|BPF_K, 0),
449 static struct bpf_program filter = {
450 sizeof insns / sizeof(insns[0]),
456 * Set immediate mode so packets are processed as they arrive.
459 if (ioctl(fd, BIOCIMMEDIATE, &immediate) == -1) {
460 logmsg(LOG_ERR, "BIOCIMMEDIATE: %m");
463 (void)strncpy(ifr.ifr_name, device, sizeof ifr.ifr_name);
464 if (ioctl(fd, BIOCSETIF, (caddr_t)&ifr) == -1) {
465 logmsg(LOG_ERR, "BIOCSETIF: %m");
469 * Check that the data link layer is an Ethernet; this code won't
470 * work with anything else.
472 if (ioctl(fd, BIOCGDLT, (caddr_t)&dlt) == -1) {
473 logmsg(LOG_ERR, "BIOCGDLT: %m");
476 if (dlt != DLT_EN10MB) {
477 logmsg(LOG_ERR, "%s is not an ethernet", device);
481 * Set filter program.
483 if (ioctl(fd, BIOCSETF, (caddr_t)&filter) == -1) {
484 logmsg(LOG_ERR, "BIOCSETF: %m");
491 * Perform various sanity checks on the RARP request packet. Return
492 * false on failure and log the reason.
495 rarp_check(u_char *p, u_int len)
497 struct ether_header *ep = (struct ether_header *)p;
498 struct ether_arp *ap = (struct ether_arp *)(p + sizeof(*ep));
500 if (len < sizeof(*ep) + sizeof(*ap)) {
501 logmsg(LOG_ERR, "truncated request, got %u, expected %lu",
502 len, (u_long)(sizeof(*ep) + sizeof(*ap)));
506 * XXX This test might be better off broken out...
508 if (ntohs(ep->ether_type) != ETHERTYPE_REVARP ||
509 ntohs(ap->arp_hrd) != ARPHRD_ETHER ||
510 ntohs(ap->arp_op) != REVARP_REQUEST ||
511 ntohs(ap->arp_pro) != ETHERTYPE_IP ||
512 ap->arp_hln != 6 || ap->arp_pln != 4) {
513 logmsg(LOG_DEBUG, "request fails sanity check");
516 if (bcmp((char *)&ep->ether_shost, (char *)&ap->arp_sha, 6) != 0) {
517 logmsg(LOG_DEBUG, "ether/arp sender address mismatch");
520 if (bcmp((char *)&ap->arp_sha, (char *)&ap->arp_tha, 6) != 0) {
521 logmsg(LOG_DEBUG, "ether/arp target address mismatch");
528 #define FD_SET(n, fdp) ((fdp)->fds_bits[0] |= (1 << (n)))
529 #define FD_ISSET(n, fdp) ((fdp)->fds_bits[0] & (1 << (n)))
530 #define FD_ZERO(fdp) ((fdp)->fds_bits[0] = 0)
534 * Loop indefinitely listening for RARP requests on the
535 * interfaces in 'iflist'.
540 u_char *buf, *bp, *ep;
542 fd_set fds, listeners;
543 int bufsize, maxfd = 0;
546 if (iflist == NULL) {
547 logmsg(LOG_ERR, "no interfaces");
550 if (ioctl(iflist->ii_fd, BIOCGBLEN, (caddr_t)&bufsize) == -1) {
551 logmsg(LOG_ERR, "BIOCGBLEN: %m");
554 buf = malloc(bufsize);
556 logmsg(LOG_ERR, "malloc: %m");
562 * Find the highest numbered file descriptor for select().
563 * Initialize the set of descriptors to listen to.
566 for (ii = iflist; ii != NULL; ii = ii->ii_next) {
567 FD_SET(ii->ii_fd, &fds);
568 if (ii->ii_fd > maxfd)
572 if (select(maxfd + 1, &listeners, NULL, NULL, NULL) == -1) {
573 /* Don't choke when we get ptraced */
576 logmsg(LOG_ERR, "select: %m");
579 for (ii = iflist; ii != NULL; ii = ii->ii_next) {
581 if (!FD_ISSET(fd, &listeners))
584 cc = read(fd, (char *)buf, bufsize);
585 /* Don't choke when we get ptraced */
586 if ((cc == -1) && (errno == EINTR))
588 #if defined(SUNOS3) || defined(SUNOS4)
590 * Due to a SunOS bug, after 2^31 bytes, the
591 * file offset overflows and read fails with
592 * EINVAL. The lseek() to 0 will fix things.
595 if (errno == EINVAL &&
596 (long)(tell(fd) + bufsize) < 0) {
597 (void)lseek(fd, 0, 0);
600 logmsg(LOG_ERR, "read: %m");
605 /* Loop through the packet(s) */
606 #define bhp ((struct bpf_hdr *)bp)
610 u_int caplen, hdrlen;
612 caplen = bhp->bh_caplen;
613 hdrlen = bhp->bh_hdrlen;
614 if (rarp_check(bp + hdrlen, caplen))
615 rarp_process(ii, bp + hdrlen, caplen);
616 bp += BPF_WORDALIGN(hdrlen + caplen);
624 * True if this server can boot the host whose IP address is 'addr'.
625 * This check is made by looking in the tftp directory for the
626 * configuration file.
629 rarp_bootable(u_long addr)
638 static DIR *dd = NULL;
640 (void)sprintf(ipname, "%08lX", (u_long)ntohl(addr));
643 * If directory is already open, rewind it. Otherwise, open it.
645 if ((d = dd) != NULL)
648 if (chdir(tftp_dir) == -1) {
649 logmsg(LOG_ERR, "chdir: %s: %m", tftp_dir);
654 logmsg(LOG_ERR, "opendir: %m");
659 while ((dent = readdir(d)) != NULL)
660 if (strncmp(dent->d_name, ipname, 8) == 0)
666 * Given a list of IP addresses, 'alist', return the first address that
667 * is on network 'net'; 'netmask' is a mask indicating the network portion
671 choose_ipaddr(u_long **alist, u_long net, u_long netmask)
673 for (; *alist; ++alist)
674 if ((**alist & netmask) == net)
680 * Answer the RARP request in 'pkt', on the interface 'ii'. 'pkt' has
681 * already been checked for validity. The reply is overlaid on the request.
684 rarp_process(struct if_info *ii, u_char *pkt, u_int len)
686 struct ether_header *ep;
688 u_long target_ipaddr;
691 ep = (struct ether_header *)pkt;
692 /* should this be arp_tha? */
693 if (ether_ntohost(ename, (struct ether_addr *)&ep->ether_shost) != 0) {
694 logmsg(LOG_ERR, "cannot map %s to name",
695 eatoa(ep->ether_shost));
699 if ((hp = gethostbyname(ename)) == NULL) {
700 logmsg(LOG_ERR, "cannot map %s to IP address", ename);
705 * Choose correct address from list.
707 if (hp->h_addrtype != AF_INET) {
708 logmsg(LOG_ERR, "cannot handle non IP addresses for %s",
712 target_ipaddr = choose_ipaddr((u_long **)hp->h_addr_list,
713 ii->ii_ipaddr & ii->ii_netmask,
715 if (target_ipaddr == 0) {
716 logmsg(LOG_ERR, "cannot find %s on net %s",
717 ename, intoa(ntohl(ii->ii_ipaddr & ii->ii_netmask)));
720 if (sflag || rarp_bootable(target_ipaddr))
721 rarp_reply(ii, ep, target_ipaddr, len);
722 else if (verbose > 1)
723 logmsg(LOG_INFO, "%s %s at %s DENIED (not bootable)",
725 eatoa(ep->ether_shost),
726 intoa(ntohl(target_ipaddr)));
730 * Poke the kernel arp tables with the ethernet/ip address combinataion
731 * given. When processing a reply, we must do this so that the booting
732 * host (i.e. the guy running rarpd), won't try to ARP for the hardware
733 * address of the guy being booted (he cannot answer the ARP).
736 struct sockaddr_inarp sin_inarp = {
737 sizeof(struct sockaddr_inarp), AF_INET, 0,
742 struct sockaddr_dl sin_dl = {
743 sizeof(struct sockaddr_dl), AF_LINK, 0, IFT_ETHER, 0, 6,
747 struct rt_msghdr rthdr;
752 update_arptab(u_char *ep, u_long ipaddr)
755 struct sockaddr_inarp *ar, *ar2;
756 struct sockaddr_dl *ll, *ll2;
757 struct rt_msghdr *rt;
763 r = socket(PF_ROUTE, SOCK_RAW, 0);
765 logmsg(LOG_ERR, "raw route socket: %m");
771 ar->sin_addr.s_addr = ipaddr;
773 bcopy(ep, LLADDR(ll), 6);
775 /* Get the type and interface index */
777 bzero(rt, sizeof(rtmsg));
778 rt->rtm_version = RTM_VERSION;
779 rt->rtm_addrs = RTA_DST;
780 rt->rtm_type = RTM_GET;
782 ar2 = (struct sockaddr_inarp *)rtmsg.rtspace;
783 bcopy(ar, ar2, sizeof(*ar));
784 rt->rtm_msglen = sizeof(*rt) + sizeof(*ar);
786 if ((write(r, rt, rt->rtm_msglen) == -1) && (errno != ESRCH)) {
787 logmsg(LOG_ERR, "rtmsg get write: %m");
792 cc = read(r, rt, sizeof(rtmsg));
793 } while (cc > 0 && (rt->rtm_seq != seq || rt->rtm_pid != pid));
795 logmsg(LOG_ERR, "rtmsg get read: %m");
799 ll2 = (struct sockaddr_dl *)((u_char *)ar2 + ar2->sin_len);
800 if (ll2->sdl_family != AF_LINK) {
802 * XXX I think this means the ip address is not on a
803 * directly connected network (the family is AF_INET in
806 logmsg(LOG_ERR, "bogus link family (%d) wrong net for %08lX?\n",
807 ll2->sdl_family, ipaddr);
811 xtype = ll2->sdl_type;
812 xindex = ll2->sdl_index;
814 /* Set the new arp entry */
815 bzero(rt, sizeof(rtmsg));
816 rt->rtm_version = RTM_VERSION;
817 rt->rtm_addrs = RTA_DST | RTA_GATEWAY;
818 rt->rtm_inits = RTV_EXPIRE;
819 rt->rtm_rmx.rmx_expire = time(0) + ARPSECS;
820 rt->rtm_flags = RTF_HOST | RTF_STATIC;
821 rt->rtm_type = RTM_ADD;
824 bcopy(ar, ar2, sizeof(*ar));
826 ll2 = (struct sockaddr_dl *)((u_char *)ar2 + sizeof(*ar2));
827 bcopy(ll, ll2, sizeof(*ll));
828 ll2->sdl_type = xtype;
829 ll2->sdl_index = xindex;
831 rt->rtm_msglen = sizeof(*rt) + sizeof(*ar2) + sizeof(*ll2);
833 if ((write(r, rt, rt->rtm_msglen) == -1) && (errno != EEXIST)) {
834 logmsg(LOG_ERR, "rtmsg add write: %m");
839 cc = read(r, rt, sizeof(rtmsg));
840 } while (cc > 0 && (rt->rtm_seq != seq || rt->rtm_pid != pid));
843 logmsg(LOG_ERR, "rtmsg add read: %m");
849 update_arptab(u_char *ep, u_long ipaddr)
851 struct arpreq request;
852 struct sockaddr_in *sin;
854 request.arp_flags = 0;
855 sin = (struct sockaddr_in *)&request.arp_pa;
856 sin->sin_family = AF_INET;
857 sin->sin_addr.s_addr = ipaddr;
858 request.arp_ha.sa_family = AF_UNSPEC;
859 bcopy((char *)ep, (char *)request.arp_ha.sa_data, 6);
861 if (ioctl(s, SIOCSARP, (caddr_t)&request) == -1)
862 logmsg(LOG_ERR, "SIOCSARP: %m");
867 * Build a reverse ARP packet and sent it out on the interface.
868 * 'ep' points to a valid REVARP_REQUEST. The REVARP_REPLY is built
869 * on top of the request, then written to the network.
871 * RFC 903 defines the ether_arp fields as follows. The following comments
872 * are taken (more or less) straight from this document.
876 * arp_sha is the hardware address of the sender of the packet.
877 * arp_spa is undefined.
878 * arp_tha is the 'target' hardware address.
879 * In the case where the sender wishes to determine his own
880 * protocol address, this, like arp_sha, will be the hardware
881 * address of the sender.
882 * arp_tpa is undefined.
886 * arp_sha is the hardware address of the responder (the sender of the
888 * arp_spa is the protocol address of the responder (see the note below).
889 * arp_tha is the hardware address of the target, and should be the same as
890 * that which was given in the request.
891 * arp_tpa is the protocol address of the target, that is, the desired address.
893 * Note that the requirement that arp_spa be filled in with the responder's
894 * protocol is purely for convenience. For instance, if a system were to use
895 * both ARP and RARP, then the inclusion of the valid protocol-hardware
896 * address pair (arp_spa, arp_sha) may eliminate the need for a subsequent
900 rarp_reply(struct if_info *ii, struct ether_header *ep, u_long ipaddr,
904 struct ether_arp *ap = (struct ether_arp *)(ep + 1);
906 update_arptab((u_char *)&ap->arp_sha, ipaddr);
909 * Build the rarp reply by modifying the rarp request in place.
911 ap->arp_op = htons(REVARP_REPLY);
914 ep->ether_type = ETHERTYPE_REVARP;
916 bcopy((char *)&ap->arp_sha, (char *)&ep->ether_dhost, 6);
917 bcopy((char *)ii->ii_eaddr, (char *)&ep->ether_shost, 6);
918 bcopy((char *)ii->ii_eaddr, (char *)&ap->arp_sha, 6);
920 bcopy((char *)&ipaddr, (char *)ap->arp_tpa, 4);
921 /* Target hardware is unchanged. */
922 bcopy((char *)&ii->ii_ipaddr, (char *)ap->arp_spa, 4);
924 /* Zero possible garbage after packet. */
925 bzero((char *)ep + (sizeof(*ep) + sizeof(*ap)),
926 len - (sizeof(*ep) + sizeof(*ap)));
927 n = write(ii->ii_fd, (char *)ep, len);
929 logmsg(LOG_ERR, "write: only %d of %d bytes written", n, len);
931 logmsg(LOG_INFO, "%s %s at %s REPLIED", ii->ii_ifname,
933 intoa(ntohl(ipaddr)));
937 * Get the netmask of an IP address. This routine is used if
938 * SIOCGIFNETMASK doesn't work.
941 ipaddrtonetmask(u_long addr)
945 return htonl(IN_CLASSA_NET);
947 return htonl(IN_CLASSB_NET);
949 return htonl(IN_CLASSC_NET);
950 logmsg(LOG_DEBUG, "unknown IP address class: %08lX", addr);
951 return htonl(0xffffffff);
955 * A faster replacement for inet_ntoa().
963 static char buf[sizeof(".xxx.xxx.xxx.xxx")];
965 cp = &buf[sizeof buf];
971 *--cp = byte % 10 + '0';
974 *--cp = byte % 10 + '0';
989 static char buf[sizeof("xx:xx:xx:xx:xx:xx")];
991 (void)sprintf(buf, "%x:%x:%x:%x:%x:%x",
992 ea[0], ea[1], ea[2], ea[3], ea[4], ea[5]);
997 logmsg(int pri, const char *fmt, ...)
1009 if (expand_syslog_m(fmt, &newfmt) == -1) {
1010 vfprintf(fp, fmt, v);
1012 vfprintf(fp, newfmt, v);
1018 vsyslog(pri, fmt, v);
1024 expand_syslog_m(const char *fmt, char **newfmt) {
1025 const char *str, *m;
1030 while ((m = strstr(str, "%m")) != NULL) {
1031 asprintf(&np, "%s%.*s%s", p, (int)(m - str),
1032 str, strerror(errno));
1043 asprintf(&np, "%s%s", p, str);