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rarpd.c revision 1.26
      1  1.26      mrg /*	$NetBSD: rarpd.c,v 1.26 1998/07/13 06:31:31 mrg Exp $	*/
      2   1.9  thorpej 
      3   1.1  deraadt /*
      4   1.1  deraadt  * Copyright (c) 1990 The Regents of the University of California.
      5   1.1  deraadt  * All rights reserved.
      6   1.1  deraadt  *
      7   1.1  deraadt  * Redistribution and use in source and binary forms, with or without
      8   1.1  deraadt  * modification, are permitted provided that: (1) source code distributions
      9   1.1  deraadt  * retain the above copyright notice and this paragraph in its entirety, (2)
     10   1.1  deraadt  * distributions including binary code include the above copyright notice and
     11   1.1  deraadt  * this paragraph in its entirety in the documentation or other materials
     12   1.1  deraadt  * provided with the distribution, and (3) all advertising materials mentioning
     13   1.1  deraadt  * features or use of this software display the following acknowledgement:
     14   1.1  deraadt  * ``This product includes software developed by the University of California,
     15   1.1  deraadt  * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
     16   1.1  deraadt  * the University nor the names of its contributors may be used to endorse
     17   1.1  deraadt  * or promote products derived from this software without specific prior
     18   1.1  deraadt  * written permission.
     19   1.1  deraadt  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
     20   1.1  deraadt  * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
     21   1.1  deraadt  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
     22   1.1  deraadt  */
     23  1.19    lukem #include <sys/cdefs.h>
     24   1.1  deraadt #ifndef lint
     25  1.19    lukem __COPYRIGHT(
     26  1.19    lukem     "@(#) Copyright (c) 1990 The Regents of the University of California.\n\
     27  1.19    lukem  All rights reserved.\n");
     28  1.19    lukem #endif /* not lint */
     29   1.1  deraadt 
     30   1.1  deraadt #ifndef lint
     31  1.26      mrg __RCSID("$NetBSD: rarpd.c,v 1.26 1998/07/13 06:31:31 mrg Exp $");
     32   1.1  deraadt #endif
     33   1.1  deraadt 
     34   1.1  deraadt 
     35   1.1  deraadt /*
     36   1.1  deraadt  * rarpd - Reverse ARP Daemon
     37   1.1  deraadt  *
     38   1.1  deraadt  * Usage:	rarpd -a [ -d -f ]
     39   1.1  deraadt  *		rarpd [ -d -f ] interface
     40   1.1  deraadt  */
     41   1.1  deraadt 
     42   1.1  deraadt #include <sys/types.h>
     43  1.21    lukem #include <sys/errno.h>
     44  1.21    lukem #include <sys/file.h>
     45   1.1  deraadt #include <sys/time.h>
     46   1.1  deraadt #include <sys/socket.h>
     47   1.1  deraadt #include <sys/ioctl.h>
     48  1.21    lukem 
     49  1.21    lukem #include <net/bpf.h>
     50   1.1  deraadt #include <net/if.h>
     51   1.7  mycroft #include <net/if_dl.h>
     52  1.16       is #ifdef __NetBSD__
     53  1.16       is #include <net/if_ether.h>
     54  1.16       is #endif
     55   1.7  mycroft #include <net/if_types.h>
     56   1.1  deraadt #include <netinet/in.h>
     57  1.16       is #ifdef __NetBSD__
     58  1.16       is #include <netinet/if_inarp.h>
     59  1.16       is #else
     60   1.1  deraadt #include <netinet/if_ether.h>
     61  1.16       is #endif
     62  1.21    lukem 
     63   1.1  deraadt #include <arpa/inet.h>
     64  1.21    lukem 
     65   1.1  deraadt #include <dirent.h>
     66  1.21    lukem #include <netdb.h>
     67  1.21    lukem #include <stdio.h>
     68  1.21    lukem #include <stdlib.h>
     69  1.21    lukem #include <string.h>
     70  1.21    lukem #include <syslog.h>
     71  1.21    lukem #include <unistd.h>
     72   1.1  deraadt 
     73  1.25      mrg #include "pathnames.h"
     74  1.25      mrg 
     75   1.1  deraadt #define FATAL		1	/* fatal error occurred */
     76   1.1  deraadt #define NONFATAL	0	/* non fatal error occurred */
     77   1.1  deraadt 
     78   1.1  deraadt /*
     79   1.1  deraadt  * The structure for each interface.
     80   1.1  deraadt  */
     81   1.1  deraadt struct if_info {
     82   1.1  deraadt 	int     ii_fd;		/* BPF file descriptor */
     83   1.1  deraadt 	u_char  ii_eaddr[6];	/* Ethernet address of this interface */
     84   1.1  deraadt 	u_long  ii_ipaddr;	/* IP address of this interface */
     85   1.1  deraadt 	u_long  ii_netmask;	/* subnet or net mask */
     86   1.1  deraadt 	struct if_info *ii_next;
     87   1.1  deraadt };
     88   1.1  deraadt /*
     89   1.1  deraadt  * The list of all interfaces that are being listened to.  rarp_loop()
     90   1.1  deraadt  * "selects" on the descriptors in this list.
     91   1.1  deraadt  */
     92   1.1  deraadt struct if_info *iflist;
     93   1.1  deraadt 
     94  1.19    lukem u_int32_t choose_ipaddr __P((u_int32_t **, u_int32_t, u_int32_t));
     95  1.19    lukem void	debug __P((const char *,...));
     96  1.19    lukem void	init_all __P((void));
     97  1.19    lukem void	init_one __P((char *));
     98  1.19    lukem u_long	ipaddrtonetmask __P((u_long));
     99  1.19    lukem void	lookup_eaddr __P((char *, u_char *));
    100  1.19    lukem void	lookup_ipaddr __P((char *, u_long *, u_long *));
    101  1.19    lukem int	main __P((int, char **));
    102  1.19    lukem void	rarp_loop __P((void));
    103  1.19    lukem int	rarp_open __P((char *));
    104  1.19    lukem void	rarp_process __P((struct if_info *, u_char *));
    105  1.24      mrg void	rarp_reply __P((struct if_info *, struct ether_header *, u_long,
    106  1.24      mrg 			struct hostent *));
    107  1.19    lukem void	rarperr __P((int, const char *,...));
    108  1.22       is 
    109  1.22       is #if defined(__NetBSD__)
    110  1.22       is #include "mkarp.h"
    111  1.22       is #else
    112  1.26      mrg void	update_arptab __P((u_char *, u_long));
    113  1.22       is #endif
    114  1.22       is 
    115  1.19    lukem void	usage __P((void));
    116  1.19    lukem 
    117  1.19    lukem static int	bpf_open __P((void));
    118  1.19    lukem static int	rarp_check __P((u_char *, int));
    119   1.1  deraadt 
    120   1.8  thorpej #ifdef REQUIRE_TFTPBOOT
    121  1.19    lukem int	rarp_bootable __P((u_long));
    122   1.8  thorpej #endif
    123   1.8  thorpej 
    124   1.1  deraadt int     aflag = 0;		/* listen on "all" interfaces  */
    125   1.1  deraadt int     dflag = 0;		/* print debugging messages */
    126   1.1  deraadt int     fflag = 0;		/* don't fork */
    127  1.24      mrg int	lflag = 0;		/* log all replies */
    128   1.1  deraadt 
    129  1.12      jtc int
    130   1.1  deraadt main(argc, argv)
    131   1.1  deraadt 	int     argc;
    132   1.1  deraadt 	char  **argv;
    133   1.1  deraadt {
    134  1.19    lukem 	extern char *__progname;
    135  1.19    lukem 
    136  1.26      mrg 	int     op, pid, devnull;
    137  1.19    lukem 	char   *ifname, *hostname;
    138   1.1  deraadt 
    139   1.1  deraadt 	/* All error reporting is done through syslogs. */
    140  1.19    lukem 	openlog(__progname, LOG_PID, LOG_DAEMON);
    141   1.1  deraadt 
    142   1.1  deraadt 	opterr = 0;
    143  1.24      mrg 	while ((op = getopt(argc, argv, "adfl")) != -1) {
    144   1.1  deraadt 		switch (op) {
    145   1.1  deraadt 		case 'a':
    146   1.1  deraadt 			++aflag;
    147   1.1  deraadt 			break;
    148   1.1  deraadt 
    149   1.1  deraadt 		case 'd':
    150   1.1  deraadt 			++dflag;
    151   1.1  deraadt 			break;
    152   1.1  deraadt 
    153   1.1  deraadt 		case 'f':
    154   1.1  deraadt 			++fflag;
    155   1.1  deraadt 			break;
    156   1.1  deraadt 
    157  1.24      mrg 		case 'l':
    158  1.24      mrg 			++lflag;
    159  1.24      mrg 			break;
    160  1.24      mrg 
    161   1.1  deraadt 		default:
    162   1.1  deraadt 			usage();
    163   1.1  deraadt 			/* NOTREACHED */
    164   1.1  deraadt 		}
    165   1.1  deraadt 	}
    166   1.1  deraadt 	ifname = argv[optind++];
    167   1.1  deraadt 	hostname = ifname ? argv[optind] : 0;
    168   1.1  deraadt 	if ((aflag && ifname) || (!aflag && ifname == 0))
    169   1.1  deraadt 		usage();
    170   1.1  deraadt 
    171   1.1  deraadt 	if (aflag)
    172   1.1  deraadt 		init_all();
    173   1.1  deraadt 	else
    174   1.1  deraadt 		init_one(ifname);
    175   1.1  deraadt 
    176   1.1  deraadt 	if ((!fflag) && (!dflag)) {
    177  1.25      mrg 		FILE *fp;
    178  1.25      mrg 
    179   1.1  deraadt 		pid = fork();
    180   1.1  deraadt 		if (pid > 0)
    181   1.1  deraadt 			/* Parent exits, leaving child in background. */
    182   1.1  deraadt 			exit(0);
    183   1.1  deraadt 		else
    184   1.1  deraadt 			if (pid == -1) {
    185  1.19    lukem 				rarperr(FATAL, "cannot fork");
    186   1.1  deraadt 				/* NOTREACHED */
    187   1.1  deraadt 			}
    188  1.25      mrg 
    189  1.25      mrg 		/* write pid file */
    190  1.25      mrg 		if ((fp = fopen(_PATH_RARPDPID, "w")) != NULL) {
    191  1.25      mrg 			fprintf(fp, "%u\n", getpid());
    192  1.25      mrg 			(void)fclose(fp);
    193  1.25      mrg 		}
    194  1.25      mrg 
    195   1.1  deraadt 		/* Fade into the background */
    196  1.26      mrg 		(void)setsid();
    197  1.26      mrg 		(void)chdir("/");
    198   1.1  deraadt 		devnull = open("/dev/null", O_RDWR);
    199   1.1  deraadt 		if (devnull >= 0) {
    200  1.26      mrg 			(void)dup2(devnull, 0);
    201  1.26      mrg 			(void)dup2(devnull, 1);
    202  1.26      mrg 			(void)dup2(devnull, 2);
    203   1.1  deraadt 			if (devnull > 2)
    204  1.26      mrg 				(void)close(devnull);
    205   1.1  deraadt 		}
    206   1.1  deraadt 	}
    207   1.1  deraadt 	rarp_loop();
    208  1.19    lukem 	/* NOTREACHED */
    209  1.19    lukem 	return (0);
    210   1.1  deraadt }
    211  1.19    lukem 
    212   1.1  deraadt /*
    213   1.1  deraadt  * Add 'ifname' to the interface list.  Lookup its IP address and network
    214   1.1  deraadt  * mask and Ethernet address, and open a BPF file for it.
    215   1.1  deraadt  */
    216   1.1  deraadt void
    217   1.1  deraadt init_one(ifname)
    218   1.1  deraadt 	char   *ifname;
    219   1.1  deraadt {
    220   1.1  deraadt 	struct if_info *p;
    221  1.23     fair 	int fd;
    222  1.23     fair 
    223  1.23     fair 	fd = rarp_open(ifname);
    224  1.23     fair 	if (fd < 0)
    225  1.23     fair 		return;
    226   1.1  deraadt 
    227   1.7  mycroft 	p = (struct if_info *)malloc(sizeof(*p));
    228   1.1  deraadt 	if (p == 0) {
    229  1.19    lukem 		rarperr(FATAL, "malloc: %s", strerror(errno));
    230   1.1  deraadt 		/* NOTREACHED */
    231   1.1  deraadt 	}
    232   1.1  deraadt 	p->ii_next = iflist;
    233   1.1  deraadt 	iflist = p;
    234   1.1  deraadt 
    235  1.23     fair 	p->ii_fd = fd;
    236   1.1  deraadt 	lookup_eaddr(ifname, p->ii_eaddr);
    237   1.1  deraadt 	lookup_ipaddr(ifname, &p->ii_ipaddr, &p->ii_netmask);
    238   1.1  deraadt }
    239  1.19    lukem 
    240   1.1  deraadt /*
    241   1.1  deraadt  * Initialize all "candidate" interfaces that are in the system
    242   1.1  deraadt  * configuration list.  A "candidate" is up, not loopback and not
    243   1.1  deraadt  * point to point.
    244   1.1  deraadt  */
    245   1.1  deraadt void
    246   1.1  deraadt init_all()
    247   1.1  deraadt {
    248  1.26      mrg 	char inbuf[8192*2];
    249   1.1  deraadt 	struct ifconf ifc;
    250  1.10  hpeyerl 	struct ifreq ifreq, *ifr;
    251   1.7  mycroft 	int fd;
    252   1.7  mycroft 	int i, len;
    253   1.1  deraadt 
    254   1.1  deraadt 	if ((fd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
    255  1.19    lukem 		rarperr(FATAL, "socket: %s", strerror(errno));
    256   1.1  deraadt 		/* NOTREACHED */
    257   1.1  deraadt 	}
    258   1.7  mycroft 
    259   1.7  mycroft 	ifc.ifc_len = sizeof(inbuf);
    260   1.7  mycroft 	ifc.ifc_buf = inbuf;
    261   1.7  mycroft 	if (ioctl(fd, SIOCGIFCONF, (caddr_t)&ifc) < 0 ||
    262   1.1  deraadt 	    ifc.ifc_len < sizeof(struct ifreq)) {
    263  1.19    lukem 		rarperr(FATAL, "init_all: SIOCGIFCONF: %s", strerror(errno));
    264   1.1  deraadt 		/* NOTREACHED */
    265   1.1  deraadt 	}
    266   1.7  mycroft 	ifr = ifc.ifc_req;
    267  1.10  hpeyerl 	ifreq.ifr_name[0] = '\0';
    268   1.7  mycroft 	for (i = 0; i < ifc.ifc_len;
    269   1.7  mycroft 	     i += len, ifr = (struct ifreq *)((caddr_t)ifr + len)) {
    270   1.7  mycroft 		len = sizeof(ifr->ifr_name) + ifr->ifr_addr.sa_len;
    271  1.10  hpeyerl 		if (!strncmp(ifreq.ifr_name, ifr->ifr_name, sizeof(ifr->ifr_name)))
    272  1.10  hpeyerl 			continue;
    273  1.10  hpeyerl 		ifreq = *ifr;
    274   1.7  mycroft 		if (ioctl(fd, SIOCGIFFLAGS, (caddr_t)ifr) < 0) {
    275  1.19    lukem 			rarperr(FATAL, "init_all: SIOCGIFFLAGS: %s",
    276   1.7  mycroft 			    strerror(errno));
    277   1.1  deraadt 			/* NOTREACHED */
    278   1.1  deraadt 		}
    279   1.7  mycroft 		if ((ifr->ifr_flags &
    280   1.7  mycroft 		    (IFF_UP | IFF_LOOPBACK | IFF_POINTOPOINT)) != IFF_UP)
    281   1.1  deraadt 			continue;
    282   1.7  mycroft 		init_one(ifr->ifr_name);
    283   1.1  deraadt 	}
    284  1.26      mrg 	(void)close(fd);
    285   1.1  deraadt }
    286   1.1  deraadt 
    287   1.1  deraadt void
    288   1.1  deraadt usage()
    289   1.1  deraadt {
    290  1.26      mrg 	(void)fprintf(stderr, "usage: rarpd -a [ -d -f ]\n");
    291  1.26      mrg 	(void)fprintf(stderr, "       rarpd [ -d -f ] interface\n");
    292   1.1  deraadt 	exit(1);
    293   1.1  deraadt }
    294   1.1  deraadt 
    295   1.1  deraadt static int
    296   1.1  deraadt bpf_open()
    297   1.1  deraadt {
    298   1.1  deraadt 	int     fd;
    299   1.1  deraadt 	int     n = 0;
    300   1.1  deraadt 	char    device[sizeof "/dev/bpf000"];
    301   1.1  deraadt 
    302   1.1  deraadt 	/* Go through all the minors and find one that isn't in use. */
    303   1.1  deraadt 	do {
    304  1.26      mrg 		(void)sprintf(device, "/dev/bpf%d", n++);
    305   1.1  deraadt 		fd = open(device, O_RDWR);
    306   1.1  deraadt 	} while (fd < 0 && errno == EBUSY);
    307   1.1  deraadt 
    308   1.1  deraadt 	if (fd < 0) {
    309  1.19    lukem 		rarperr(FATAL, "%s: %s", device, strerror(errno));
    310   1.1  deraadt 		/* NOTREACHED */
    311   1.1  deraadt 	}
    312   1.1  deraadt 	return fd;
    313   1.1  deraadt }
    314   1.1  deraadt /*
    315   1.1  deraadt  * Open a BPF file and attach it to the interface named 'device'.
    316   1.1  deraadt  * Set immediate mode, and set a filter that accepts only RARP requests.
    317   1.1  deraadt  */
    318   1.1  deraadt int
    319   1.1  deraadt rarp_open(device)
    320   1.1  deraadt 	char   *device;
    321   1.1  deraadt {
    322   1.1  deraadt 	int     fd;
    323   1.1  deraadt 	struct ifreq ifr;
    324   1.1  deraadt 	u_int   dlt;
    325   1.1  deraadt 	int     immediate;
    326   1.1  deraadt 
    327   1.1  deraadt 	static struct bpf_insn insns[] = {
    328   1.1  deraadt 		BPF_STMT(BPF_LD | BPF_H | BPF_ABS, 12),
    329   1.1  deraadt 		BPF_JUMP(BPF_JMP | BPF_JEQ | BPF_K, ETHERTYPE_REVARP, 0, 3),
    330   1.1  deraadt 		BPF_STMT(BPF_LD | BPF_H | BPF_ABS, 20),
    331   1.6      cgd 		BPF_JUMP(BPF_JMP | BPF_JEQ | BPF_K, ARPOP_REVREQUEST, 0, 1),
    332  1.16       is 		BPF_STMT(BPF_RET | BPF_K,
    333  1.16       is 		    sizeof(struct arphdr) +
    334  1.16       is 		    2 * ETHER_ADDR_LEN + 2 * sizeof(struct in_addr) +
    335   1.1  deraadt 		    sizeof(struct ether_header)),
    336   1.1  deraadt 		BPF_STMT(BPF_RET | BPF_K, 0),
    337   1.1  deraadt 	};
    338   1.1  deraadt 	static struct bpf_program filter = {
    339   1.1  deraadt 		sizeof insns / sizeof(insns[0]),
    340   1.1  deraadt 		insns
    341   1.1  deraadt 	};
    342   1.1  deraadt 
    343   1.1  deraadt 	fd = bpf_open();
    344   1.1  deraadt 
    345   1.1  deraadt 	/* Set immediate mode so packets are processed as they arrive. */
    346   1.1  deraadt 	immediate = 1;
    347   1.1  deraadt 	if (ioctl(fd, BIOCIMMEDIATE, &immediate) < 0) {
    348  1.19    lukem 		rarperr(FATAL, "BIOCIMMEDIATE: %s", strerror(errno));
    349   1.1  deraadt 		/* NOTREACHED */
    350   1.1  deraadt 	}
    351  1.26      mrg 	(void)strncpy(ifr.ifr_name, device, sizeof ifr.ifr_name - 1);
    352  1.26      mrg 	ifr.ifr_name[sizeof ifr.ifr_name - 1] = '\0';
    353   1.1  deraadt 	if (ioctl(fd, BIOCSETIF, (caddr_t) & ifr) < 0) {
    354  1.23     fair 		if (aflag) {	/* for -a skip non-ethernet interfaces */
    355  1.23     fair 			close(fd);
    356  1.23     fair 			return(-1);
    357  1.23     fair 		}
    358  1.19    lukem 		rarperr(FATAL, "BIOCSETIF: %s", strerror(errno));
    359   1.1  deraadt 		/* NOTREACHED */
    360   1.1  deraadt 	}
    361   1.1  deraadt 	/* Check that the data link layer is an Ethernet; this code won't work
    362   1.1  deraadt 	 * with anything else. */
    363   1.1  deraadt 	if (ioctl(fd, BIOCGDLT, (caddr_t) & dlt) < 0) {
    364  1.19    lukem 		rarperr(FATAL, "BIOCGDLT: %s", strerror(errno));
    365   1.1  deraadt 		/* NOTREACHED */
    366   1.1  deraadt 	}
    367   1.1  deraadt 	if (dlt != DLT_EN10MB) {
    368  1.23     fair 		if (aflag) {	/* for -a skip non-ethernet interfaces */
    369  1.23     fair 			close(fd);
    370  1.23     fair 			return(-1);
    371  1.23     fair 		}
    372  1.19    lukem 		rarperr(FATAL, "%s is not an ethernet", device);
    373   1.1  deraadt 		/* NOTREACHED */
    374   1.1  deraadt 	}
    375   1.1  deraadt 	/* Set filter program. */
    376   1.1  deraadt 	if (ioctl(fd, BIOCSETF, (caddr_t) & filter) < 0) {
    377  1.19    lukem 		rarperr(FATAL, "BIOCSETF: %s", strerror(errno));
    378   1.1  deraadt 		/* NOTREACHED */
    379   1.1  deraadt 	}
    380   1.1  deraadt 	return fd;
    381   1.1  deraadt }
    382   1.1  deraadt /*
    383   1.1  deraadt  * Perform various sanity checks on the RARP request packet.  Return
    384   1.1  deraadt  * false on failure and log the reason.
    385   1.1  deraadt  */
    386   1.1  deraadt static int
    387   1.1  deraadt rarp_check(p, len)
    388   1.1  deraadt 	u_char *p;
    389   1.1  deraadt 	int     len;
    390   1.1  deraadt {
    391   1.1  deraadt 	struct ether_header *ep = (struct ether_header *) p;
    392  1.16       is #ifdef __NetBSD__
    393  1.16       is 	struct arphdr *ap = (struct arphdr *) (p + sizeof(*ep));
    394  1.16       is #else
    395   1.1  deraadt 	struct ether_arp *ap = (struct ether_arp *) (p + sizeof(*ep));
    396  1.16       is #endif
    397   1.1  deraadt 
    398  1.18    lukem 	if (dflag)
    399  1.18    lukem 		fprintf(stderr, "got a packet\n");
    400   1.1  deraadt 
    401   1.1  deraadt 	if (len < sizeof(*ep) + sizeof(*ap)) {
    402  1.19    lukem 		rarperr(NONFATAL, "truncated request");
    403   1.1  deraadt 		return 0;
    404   1.1  deraadt 	}
    405  1.16       is #ifdef __NetBSD__
    406  1.16       is 	/* now that we know the fixed part of the ARP hdr is there: */
    407  1.16       is 	if (len < sizeof(*ap) + 2 * ap->ar_hln + 2 * ap->ar_pln) {
    408  1.19    lukem 		rarperr(NONFATAL, "truncated request");
    409  1.16       is 		return 0;
    410  1.16       is 	}
    411  1.16       is #endif
    412   1.1  deraadt 	/* XXX This test might be better off broken out... */
    413  1.11  mycroft #ifdef __FreeBSD__
    414  1.11  mycroft 	/* BPF (incorrectly) returns this in host order. */
    415  1.11  mycroft 	if (ep->ether_type != ETHERTYPE_REVARP ||
    416  1.11  mycroft #else
    417   1.1  deraadt 	if (ntohs (ep->ether_type) != ETHERTYPE_REVARP ||
    418  1.11  mycroft #endif
    419  1.16       is #ifdef __NetBSD__
    420  1.16       is 	    ntohs (ap->ar_hrd) != ARPHRD_ETHER ||
    421  1.16       is 	    ntohs (ap->ar_op) != ARPOP_REVREQUEST ||
    422  1.16       is 	    ntohs (ap->ar_pro) != ETHERTYPE_IP ||
    423  1.16       is 	    ap->ar_hln != 6 || ap->ar_pln != 4) {
    424  1.16       is #else
    425   1.1  deraadt 	    ntohs (ap->arp_hrd) != ARPHRD_ETHER ||
    426   1.6      cgd 	    ntohs (ap->arp_op) != ARPOP_REVREQUEST ||
    427   1.1  deraadt 	    ntohs (ap->arp_pro) != ETHERTYPE_IP ||
    428   1.1  deraadt 	    ap->arp_hln != 6 || ap->arp_pln != 4) {
    429  1.16       is #endif
    430  1.19    lukem 		rarperr(NONFATAL, "request fails sanity check");
    431   1.1  deraadt 		return 0;
    432   1.1  deraadt 	}
    433  1.16       is #ifdef __NetBSD__
    434  1.21    lukem 	if (memcmp((char *) &ep->ether_shost, ar_sha(ap), 6) != 0) {
    435  1.16       is #else
    436  1.21    lukem 	if (memcmp((char *) &ep->ether_shost, ap->arp_sha, 6) != 0) {
    437  1.16       is #endif
    438  1.19    lukem 		rarperr(NONFATAL, "ether/arp sender address mismatch");
    439   1.1  deraadt 		return 0;
    440   1.1  deraadt 	}
    441  1.16       is #ifdef __NetBSD__
    442  1.21    lukem 	if (memcmp(ar_sha(ap), ar_tha(ap), 6) != 0) {
    443  1.16       is #else
    444  1.21    lukem 	if (memcmp((char *) &ap->arp_sha, (char *) &ap->arp_tha, 6) != 0) {
    445  1.16       is #endif
    446  1.19    lukem 		rarperr(NONFATAL, "ether/arp target address mismatch");
    447   1.1  deraadt 		return 0;
    448   1.1  deraadt 	}
    449   1.1  deraadt 	return 1;
    450   1.1  deraadt }
    451   1.1  deraadt 
    452   1.1  deraadt /*
    453   1.1  deraadt  * Loop indefinitely listening for RARP requests on the
    454   1.1  deraadt  * interfaces in 'iflist'.
    455   1.1  deraadt  */
    456   1.1  deraadt void
    457   1.1  deraadt rarp_loop()
    458   1.1  deraadt {
    459   1.1  deraadt 	u_char *buf, *bp, *ep;
    460   1.1  deraadt 	int     cc, fd;
    461   1.1  deraadt 	fd_set  fds, listeners;
    462   1.1  deraadt 	int     bufsize, maxfd = 0;
    463   1.1  deraadt 	struct if_info *ii;
    464   1.1  deraadt 
    465   1.1  deraadt 	if (iflist == 0) {
    466  1.19    lukem 		rarperr(FATAL, "no interfaces");
    467   1.1  deraadt 		/* NOTREACHED */
    468   1.1  deraadt 	}
    469   1.1  deraadt 	if (ioctl(iflist->ii_fd, BIOCGBLEN, (caddr_t) & bufsize) < 0) {
    470  1.19    lukem 		rarperr(FATAL, "BIOCGBLEN: %s", strerror(errno));
    471   1.1  deraadt 		/* NOTREACHED */
    472   1.1  deraadt 	}
    473   1.1  deraadt 	buf = (u_char *) malloc((unsigned) bufsize);
    474   1.1  deraadt 	if (buf == 0) {
    475  1.19    lukem 		rarperr(FATAL, "malloc: %s", strerror(errno));
    476   1.1  deraadt 		/* NOTREACHED */
    477   1.1  deraadt 	}
    478   1.1  deraadt 	/*
    479   1.1  deraadt          * Find the highest numbered file descriptor for select().
    480   1.1  deraadt          * Initialize the set of descriptors to listen to.
    481   1.1  deraadt          */
    482   1.1  deraadt 	FD_ZERO(&fds);
    483   1.1  deraadt 	for (ii = iflist; ii; ii = ii->ii_next) {
    484   1.1  deraadt 		FD_SET(ii->ii_fd, &fds);
    485   1.1  deraadt 		if (ii->ii_fd > maxfd)
    486   1.1  deraadt 			maxfd = ii->ii_fd;
    487   1.1  deraadt 	}
    488   1.1  deraadt 	while (1) {
    489   1.1  deraadt 		listeners = fds;
    490   1.1  deraadt 		if (select(maxfd + 1, &listeners, (struct fd_set *) 0,
    491   1.1  deraadt 			(struct fd_set *) 0, (struct timeval *) 0) < 0) {
    492  1.19    lukem 			rarperr(FATAL, "select: %s", strerror(errno));
    493   1.1  deraadt 			/* NOTREACHED */
    494   1.1  deraadt 		}
    495   1.1  deraadt 		for (ii = iflist; ii; ii = ii->ii_next) {
    496   1.1  deraadt 			fd = ii->ii_fd;
    497   1.1  deraadt 			if (!FD_ISSET(fd, &listeners))
    498   1.1  deraadt 				continue;
    499  1.24      mrg 		again:
    500   1.1  deraadt 			cc = read(fd, (char *) buf, bufsize);
    501   1.1  deraadt 			/* Don't choke when we get ptraced */
    502   1.1  deraadt 			if (cc < 0 && errno == EINTR)
    503   1.1  deraadt 				goto again;
    504   1.1  deraadt 			/* Due to a SunOS bug, after 2^31 bytes, the file
    505   1.1  deraadt 			 * offset overflows and read fails with EINVAL.  The
    506   1.1  deraadt 			 * lseek() to 0 will fix things. */
    507   1.1  deraadt 			if (cc < 0) {
    508   1.1  deraadt 				if (errno == EINVAL &&
    509   1.5      cgd 				    (lseek(fd, 0, SEEK_CUR) + bufsize) < 0) {
    510  1.26      mrg 					(void)lseek(fd, 0, 0);
    511   1.1  deraadt 					goto again;
    512   1.1  deraadt 				}
    513  1.19    lukem 				rarperr(FATAL, "read: %s", strerror(errno));
    514   1.1  deraadt 				/* NOTREACHED */
    515   1.1  deraadt 			}
    516   1.1  deraadt 			/* Loop through the packet(s) */
    517   1.1  deraadt #define bhp ((struct bpf_hdr *)bp)
    518   1.1  deraadt 			bp = buf;
    519   1.1  deraadt 			ep = bp + cc;
    520   1.1  deraadt 			while (bp < ep) {
    521   1.1  deraadt 				register int caplen, hdrlen;
    522   1.1  deraadt 
    523   1.1  deraadt 				caplen = bhp->bh_caplen;
    524   1.1  deraadt 				hdrlen = bhp->bh_hdrlen;
    525   1.1  deraadt 				if (rarp_check(bp + hdrlen, caplen))
    526   1.1  deraadt 					rarp_process(ii, bp + hdrlen);
    527   1.1  deraadt 				bp += BPF_WORDALIGN(hdrlen + caplen);
    528   1.1  deraadt 			}
    529   1.1  deraadt 		}
    530   1.1  deraadt 	}
    531   1.1  deraadt }
    532   1.8  thorpej 
    533   1.8  thorpej #ifdef REQUIRE_TFTPBOOT
    534   1.8  thorpej 
    535   1.1  deraadt #ifndef TFTP_DIR
    536   1.1  deraadt #define TFTP_DIR "/tftpboot"
    537   1.1  deraadt #endif
    538   1.1  deraadt 
    539   1.1  deraadt /*
    540   1.1  deraadt  * True if this server can boot the host whose IP address is 'addr'.
    541   1.1  deraadt  * This check is made by looking in the tftp directory for the
    542   1.1  deraadt  * configuration file.
    543   1.1  deraadt  */
    544   1.1  deraadt int
    545   1.1  deraadt rarp_bootable(addr)
    546   1.1  deraadt 	u_long  addr;
    547   1.1  deraadt {
    548   1.1  deraadt 	register struct dirent *dent;
    549   1.1  deraadt 	register DIR *d;
    550   1.1  deraadt 	char    ipname[9];
    551   1.1  deraadt 	static DIR *dd = 0;
    552   1.1  deraadt 
    553  1.26      mrg 	(void)sprintf(ipname, "%08X", addr);
    554   1.1  deraadt 	/* If directory is already open, rewind it.  Otherwise, open it. */
    555   1.1  deraadt 	if (d = dd)
    556   1.1  deraadt 		rewinddir(d);
    557   1.1  deraadt 	else {
    558   1.1  deraadt 		if (chdir(TFTP_DIR) == -1) {
    559  1.19    lukem 			rarperr(FATAL, "chdir: %s", strerror(errno));
    560   1.1  deraadt 			/* NOTREACHED */
    561   1.1  deraadt 		}
    562   1.1  deraadt 		d = opendir(".");
    563   1.1  deraadt 		if (d == 0) {
    564  1.19    lukem 			rarperr(FATAL, "opendir: %s", strerror(errno));
    565   1.1  deraadt 			/* NOTREACHED */
    566   1.1  deraadt 		}
    567   1.1  deraadt 		dd = d;
    568   1.1  deraadt 	}
    569   1.1  deraadt 	while (dent = readdir(d))
    570   1.1  deraadt 		if (strncmp(dent->d_name, ipname, 8) == 0)
    571   1.1  deraadt 			return 1;
    572   1.1  deraadt 	return 0;
    573   1.1  deraadt }
    574   1.8  thorpej #endif /* REQUIRE_TFTPBOOT */
    575   1.8  thorpej 
    576   1.1  deraadt /*
    577   1.1  deraadt  * Given a list of IP addresses, 'alist', return the first address that
    578   1.1  deraadt  * is on network 'net'; 'netmask' is a mask indicating the network portion
    579   1.1  deraadt  * of the address.
    580   1.1  deraadt  */
    581  1.17      cgd u_int32_t
    582   1.1  deraadt choose_ipaddr(alist, net, netmask)
    583  1.17      cgd 	u_int32_t **alist;
    584  1.17      cgd 	u_int32_t net;
    585  1.17      cgd 	u_int32_t netmask;
    586   1.1  deraadt {
    587  1.26      mrg 
    588   1.1  deraadt 	for (; *alist; ++alist) {
    589   1.1  deraadt 		if ((**alist & netmask) == net)
    590   1.1  deraadt 			return **alist;
    591   1.1  deraadt 	}
    592   1.1  deraadt 	return 0;
    593   1.1  deraadt }
    594   1.1  deraadt /*
    595   1.1  deraadt  * Answer the RARP request in 'pkt', on the interface 'ii'.  'pkt' has
    596   1.1  deraadt  * already been checked for validity.  The reply is overlaid on the request.
    597   1.1  deraadt  */
    598   1.1  deraadt void
    599   1.1  deraadt rarp_process(ii, pkt)
    600   1.1  deraadt 	struct if_info *ii;
    601   1.1  deraadt 	u_char *pkt;
    602   1.1  deraadt {
    603   1.1  deraadt 	struct ether_header *ep;
    604   1.1  deraadt 	struct hostent *hp;
    605   1.1  deraadt 	u_long  target_ipaddr;
    606  1.18    lukem 	char    ename[MAXHOSTNAMELEN + 1];
    607   1.2  deraadt 	struct	in_addr in;
    608   1.1  deraadt 
    609   1.1  deraadt 	ep = (struct ether_header *) pkt;
    610   1.1  deraadt 
    611  1.18    lukem 	if (ether_ntohost(ename, (struct ether_addr *)&ep->ether_shost) != 0) {
    612  1.18    lukem 		debug("no IP address for %s",
    613  1.18    lukem 		    ether_ntoa((struct ether_addr *)&ep->ether_shost));
    614   1.1  deraadt 		return;
    615  1.18    lukem 	}
    616  1.18    lukem 	ename[sizeof(ename)-1] = '\0';
    617  1.18    lukem 
    618  1.18    lukem 	if ((hp = gethostbyname(ename)) == 0) {
    619  1.18    lukem 		debug("gethostbyname(%s) failed: %s", ename,
    620  1.18    lukem 		    hstrerror(h_errno));
    621  1.18    lukem 		return;
    622  1.18    lukem 	}
    623   1.1  deraadt 
    624   1.1  deraadt 	/* Choose correct address from list. */
    625   1.1  deraadt 	if (hp->h_addrtype != AF_INET) {
    626  1.19    lukem 		rarperr(FATAL, "cannot handle non IP addresses");
    627   1.1  deraadt 		/* NOTREACHED */
    628   1.1  deraadt 	}
    629  1.17      cgd 	target_ipaddr = choose_ipaddr((u_int32_t **) hp->h_addr_list,
    630   1.2  deraadt 	    ii->ii_ipaddr & ii->ii_netmask, ii->ii_netmask);
    631   1.1  deraadt 
    632   1.1  deraadt 	if (target_ipaddr == 0) {
    633   1.2  deraadt 		in.s_addr = ii->ii_ipaddr & ii->ii_netmask;
    634  1.19    lukem 		rarperr(NONFATAL, "cannot find %s on net %s\n",
    635   1.2  deraadt 		    ename, inet_ntoa(in));
    636   1.1  deraadt 		return;
    637   1.1  deraadt 	}
    638   1.8  thorpej #ifdef REQUIRE_TFTPBOOT
    639   1.1  deraadt 	if (rarp_bootable(htonl(target_ipaddr)))
    640   1.8  thorpej #endif
    641  1.24      mrg 		rarp_reply(ii, ep, target_ipaddr, hp);
    642  1.18    lukem #ifdef REQUIRE_TFTPBOOT
    643  1.18    lukem 	else
    644  1.18    lukem 		debug("%08X not bootable", htonl(target_ipaddr));
    645  1.18    lukem #endif
    646   1.1  deraadt }
    647   1.1  deraadt /*
    648   1.1  deraadt  * Lookup the ethernet address of the interface attached to the BPF
    649   1.1  deraadt  * file descriptor 'fd'; return it in 'eaddr'.
    650   1.1  deraadt  */
    651   1.1  deraadt void
    652   1.1  deraadt lookup_eaddr(ifname, eaddr)
    653   1.1  deraadt 	char *ifname;
    654   1.1  deraadt 	u_char *eaddr;
    655   1.1  deraadt {
    656  1.26      mrg 	char inbuf[8192*2];
    657   1.1  deraadt 	struct ifconf ifc;
    658   1.1  deraadt 	struct ifreq *ifr;
    659   1.7  mycroft 	struct sockaddr_dl *sdl;
    660   1.1  deraadt 	int fd;
    661   1.1  deraadt 	int i, len;
    662   1.1  deraadt 
    663   1.1  deraadt 	/* We cannot use SIOCGIFADDR on the BPF descriptor.
    664   1.1  deraadt 	   We must instead get all the interfaces with SIOCGIFCONF
    665   1.1  deraadt 	   and find the right one.  */
    666   1.1  deraadt 
    667   1.1  deraadt 	/* Use datagram socket to get Ethernet address. */
    668   1.1  deraadt 	if ((fd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
    669  1.19    lukem 		rarperr(FATAL, "socket: %s", strerror(errno));
    670   1.1  deraadt 		/* NOTREACHED */
    671   1.1  deraadt 	}
    672   1.1  deraadt 
    673   1.7  mycroft 	ifc.ifc_len = sizeof(inbuf);
    674   1.1  deraadt 	ifc.ifc_buf = inbuf;
    675   1.7  mycroft 	if (ioctl(fd, SIOCGIFCONF, (caddr_t)&ifc) < 0 ||
    676   1.7  mycroft 	    ifc.ifc_len < sizeof(struct ifreq)) {
    677  1.19    lukem 		rarperr(FATAL, "lookup_eaddr: SIOGIFCONF: %s", strerror(errno));
    678   1.1  deraadt 		/* NOTREACHED */
    679   1.1  deraadt 	}
    680   1.1  deraadt 	ifr = ifc.ifc_req;
    681   1.7  mycroft 	for (i = 0; i < ifc.ifc_len;
    682   1.7  mycroft 	     i += len, ifr = (struct ifreq *)((caddr_t)ifr + len)) {
    683   1.7  mycroft 		len = sizeof(ifr->ifr_name) + ifr->ifr_addr.sa_len;
    684   1.7  mycroft 		sdl = (struct sockaddr_dl *)&ifr->ifr_addr;
    685   1.7  mycroft 		if (sdl->sdl_family != AF_LINK || sdl->sdl_type != IFT_ETHER ||
    686   1.7  mycroft 		    sdl->sdl_alen != 6)
    687   1.7  mycroft 			continue;
    688   1.7  mycroft 		if (!strncmp(ifr->ifr_name, ifname, sizeof(ifr->ifr_name))) {
    689  1.21    lukem 			memmove((caddr_t)eaddr, (caddr_t)LLADDR(sdl), 6);
    690  1.18    lukem 			debug("%s: %x:%x:%x:%x:%x:%x",
    691  1.18    lukem 			    ifr->ifr_name, eaddr[0], eaddr[1],
    692  1.18    lukem 			    eaddr[2], eaddr[3], eaddr[4], eaddr[5]);
    693   1.1  deraadt 			return;
    694   1.1  deraadt 		}
    695   1.1  deraadt 	}
    696   1.1  deraadt 
    697  1.19    lukem 	rarperr(FATAL, "lookup_eaddr: Never saw interface `%s'!", ifname);
    698   1.1  deraadt }
    699   1.1  deraadt /*
    700   1.1  deraadt  * Lookup the IP address and network mask of the interface named 'ifname'.
    701   1.1  deraadt  */
    702   1.1  deraadt void
    703   1.1  deraadt lookup_ipaddr(ifname, addrp, netmaskp)
    704   1.1  deraadt 	char   *ifname;
    705   1.1  deraadt 	u_long *addrp;
    706   1.1  deraadt 	u_long *netmaskp;
    707   1.1  deraadt {
    708   1.1  deraadt 	int     fd;
    709   1.1  deraadt 	struct ifreq ifr;
    710   1.1  deraadt 
    711   1.1  deraadt 	/* Use datagram socket to get IP address. */
    712   1.1  deraadt 	if ((fd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
    713  1.19    lukem 		rarperr(FATAL, "socket: %s", strerror(errno));
    714   1.1  deraadt 		/* NOTREACHED */
    715   1.1  deraadt 	}
    716  1.26      mrg 	(void)strncpy(ifr.ifr_name, ifname, sizeof ifr.ifr_name);
    717   1.1  deraadt 	if (ioctl(fd, SIOCGIFADDR, (char *) &ifr) < 0) {
    718  1.19    lukem 		rarperr(FATAL, "SIOCGIFADDR: %s", strerror(errno));
    719   1.1  deraadt 		/* NOTREACHED */
    720   1.1  deraadt 	}
    721   1.1  deraadt 	*addrp = ((struct sockaddr_in *) & ifr.ifr_addr)->sin_addr.s_addr;
    722   1.1  deraadt 	if (ioctl(fd, SIOCGIFNETMASK, (char *) &ifr) < 0) {
    723   1.1  deraadt 		perror("SIOCGIFNETMASK");
    724  1.25      mrg 		unlink(_PATH_RARPDPID);
    725   1.1  deraadt 		exit(1);
    726   1.1  deraadt 	}
    727   1.1  deraadt 	*netmaskp = ((struct sockaddr_in *) & ifr.ifr_addr)->sin_addr.s_addr;
    728   1.1  deraadt 	/* If SIOCGIFNETMASK didn't work, figure out a mask from the IP
    729   1.1  deraadt 	 * address class. */
    730   1.1  deraadt 	if (*netmaskp == 0)
    731   1.1  deraadt 		*netmaskp = ipaddrtonetmask(*addrp);
    732   1.1  deraadt 
    733  1.26      mrg 	(void)close(fd);
    734   1.1  deraadt }
    735   1.1  deraadt /*
    736   1.1  deraadt  * Poke the kernel arp tables with the ethernet/ip address combinataion
    737   1.1  deraadt  * given.  When processing a reply, we must do this so that the booting
    738   1.1  deraadt  * host (i.e. the guy running rarpd), won't try to ARP for the hardware
    739   1.1  deraadt  * address of the guy being booted (he cannot answer the ARP).
    740   1.1  deraadt  */
    741  1.22       is #ifndef __NetBSD__
    742   1.1  deraadt void
    743   1.1  deraadt update_arptab(ep, ipaddr)
    744   1.1  deraadt 	u_char *ep;
    745   1.1  deraadt 	u_long  ipaddr;
    746   1.1  deraadt {
    747   1.1  deraadt 	struct arpreq request;
    748   1.1  deraadt 	struct sockaddr_in *sin;
    749   1.1  deraadt 
    750   1.1  deraadt 	request.arp_flags = 0;
    751   1.1  deraadt 	sin = (struct sockaddr_in *) & request.arp_pa;
    752   1.1  deraadt 	sin->sin_family = AF_INET;
    753   1.1  deraadt 	sin->sin_addr.s_addr = ipaddr;
    754   1.1  deraadt 	request.arp_ha.sa_family = AF_UNSPEC;
    755   1.1  deraadt 	/* This is needed #if defined(COMPAT_43) && BYTE_ORDER != BIG_ENDIAN,
    756   1.1  deraadt 	   because AF_UNSPEC is zero and the kernel assumes that a zero
    757   1.1  deraadt 	   sa_family means that the real sa_family value is in sa_len.  */
    758   1.1  deraadt 	request.arp_ha.sa_len = 16; /* XXX */
    759  1.21    lukem 	memmove((char *) request.arp_ha.sa_data, (char *)ep, 6);
    760   1.1  deraadt 
    761   1.7  mycroft #if 0
    762   1.1  deraadt 	s = socket(AF_INET, SOCK_DGRAM, 0);
    763   1.1  deraadt 	if (ioctl(s, SIOCSARP, (caddr_t) & request) < 0) {
    764  1.19    lukem 		rarperr(NONFATAL, "SIOCSARP: %s", strerror(errno));
    765   1.1  deraadt 	}
    766  1.26      mrg 	(void)close(s);
    767   1.7  mycroft #endif
    768   1.1  deraadt }
    769  1.22       is #endif
    770  1.22       is 
    771   1.1  deraadt /*
    772   1.1  deraadt  * Build a reverse ARP packet and sent it out on the interface.
    773   1.6      cgd  * 'ep' points to a valid ARPOP_REVREQUEST.  The ARPOP_REVREPLY is built
    774   1.1  deraadt  * on top of the request, then written to the network.
    775   1.1  deraadt  *
    776   1.1  deraadt  * RFC 903 defines the ether_arp fields as follows.  The following comments
    777   1.1  deraadt  * are taken (more or less) straight from this document.
    778   1.1  deraadt  *
    779   1.6      cgd  * ARPOP_REVREQUEST
    780   1.1  deraadt  *
    781   1.1  deraadt  * arp_sha is the hardware address of the sender of the packet.
    782   1.1  deraadt  * arp_spa is undefined.
    783   1.1  deraadt  * arp_tha is the 'target' hardware address.
    784   1.1  deraadt  *   In the case where the sender wishes to determine his own
    785   1.1  deraadt  *   protocol address, this, like arp_sha, will be the hardware
    786   1.1  deraadt  *   address of the sender.
    787   1.1  deraadt  * arp_tpa is undefined.
    788   1.1  deraadt  *
    789   1.6      cgd  * ARPOP_REVREPLY
    790   1.1  deraadt  *
    791   1.1  deraadt  * arp_sha is the hardware address of the responder (the sender of the
    792   1.1  deraadt  *   reply packet).
    793   1.1  deraadt  * arp_spa is the protocol address of the responder (see the note below).
    794   1.1  deraadt  * arp_tha is the hardware address of the target, and should be the same as
    795   1.1  deraadt  *   that which was given in the request.
    796   1.1  deraadt  * arp_tpa is the protocol address of the target, that is, the desired address.
    797   1.1  deraadt  *
    798   1.1  deraadt  * Note that the requirement that arp_spa be filled in with the responder's
    799   1.1  deraadt  * protocol is purely for convenience.  For instance, if a system were to use
    800   1.1  deraadt  * both ARP and RARP, then the inclusion of the valid protocol-hardware
    801   1.1  deraadt  * address pair (arp_spa, arp_sha) may eliminate the need for a subsequent
    802   1.1  deraadt  * ARP request.
    803   1.1  deraadt  */
    804   1.1  deraadt void
    805  1.24      mrg rarp_reply(ii, ep, ipaddr, hp)
    806   1.1  deraadt 	struct if_info *ii;
    807   1.1  deraadt 	struct ether_header *ep;
    808   1.1  deraadt 	u_long  ipaddr;
    809  1.24      mrg 	struct hostent *hp;
    810   1.1  deraadt {
    811   1.1  deraadt 	int     n;
    812  1.16       is #ifdef __NetBSD__
    813  1.16       is 	struct arphdr *ap = (struct arphdr *) (ep + 1);
    814  1.16       is #else
    815   1.1  deraadt 	struct ether_arp *ap = (struct ether_arp *) (ep + 1);
    816  1.16       is #endif
    817  1.16       is 
    818   1.1  deraadt 	int     len;
    819   1.1  deraadt 
    820  1.16       is #ifdef __NetBSD__
    821  1.22       is 	(void)mkarp(ar_sha(ap), ipaddr);
    822  1.16       is #else
    823   1.1  deraadt 	update_arptab((u_char *) & ap->arp_sha, ipaddr);
    824  1.16       is #endif
    825   1.1  deraadt 
    826   1.1  deraadt 	/* Build the rarp reply by modifying the rarp request in place. */
    827  1.11  mycroft #ifdef __FreeBSD__
    828  1.11  mycroft 	/* BPF (incorrectly) wants this in host order. */
    829  1.11  mycroft 	ep->ether_type = ETHERTYPE_REVARP;
    830  1.11  mycroft #else
    831   1.3  deraadt 	ep->ether_type = htons(ETHERTYPE_REVARP);
    832  1.11  mycroft #endif
    833  1.16       is #ifdef __NetBSD__
    834  1.16       is 	ap->ar_hrd = htons(ARPHRD_ETHER);
    835  1.16       is 	ap->ar_pro = htons(ETHERTYPE_IP);
    836  1.16       is 	ap->ar_op = htons(ARPOP_REVREPLY);
    837  1.16       is 
    838  1.21    lukem 	memmove((char *) &ep->ether_dhost, ar_sha(ap), 6);
    839  1.21    lukem 	memmove((char *) &ep->ether_shost, (char *) ii->ii_eaddr, 6);
    840  1.21    lukem 	memmove(ar_sha(ap), (char *) ii->ii_eaddr, 6);
    841  1.16       is 
    842  1.21    lukem 	memmove(ar_tpa(ap), (char *) &ipaddr, 4);
    843  1.16       is 	/* Target hardware is unchanged. */
    844  1.21    lukem 	memmove(ar_spa(ap), (char *) &ii->ii_ipaddr, 4);
    845  1.16       is 
    846  1.16       is 	len = sizeof(*ep) + sizeof(*ap) +
    847  1.16       is 	    2 * ap->ar_pln + 2 * ap->ar_hln;
    848  1.16       is #else
    849   1.4      cgd 	ap->ea_hdr.ar_hrd = htons(ARPHRD_ETHER);
    850   1.4      cgd 	ap->ea_hdr.ar_pro = htons(ETHERTYPE_IP);
    851   1.6      cgd 	ap->arp_op = htons(ARPOP_REVREPLY);
    852   1.1  deraadt 
    853  1.21    lukem 	memmove((char *) &ep->ether_dhost, (char *) &ap->arp_sha, 6);
    854  1.21    lukem 	memmove((char *) &ep->ether_shost, (char *) ii->ii_eaddr, 6);
    855  1.21    lukem 	memmove((char *) &ap->arp_sha, (char *) ii->ii_eaddr, 6);
    856   1.1  deraadt 
    857  1.21    lukem 	memmove((char *) ap->arp_tpa, (char *) &ipaddr, 4);
    858   1.1  deraadt 	/* Target hardware is unchanged. */
    859  1.21    lukem 	memmove((char *) ap->arp_spa, (char *) &ii->ii_ipaddr, 4);
    860   1.1  deraadt 
    861   1.1  deraadt 	len = sizeof(*ep) + sizeof(*ap);
    862  1.16       is #endif
    863  1.16       is 
    864  1.24      mrg 	if (lflag)
    865  1.24      mrg 		syslog(LOG_INFO, "%s asked; %s replied", hp->h_name,
    866  1.24      mrg 		    ether_ntoa((struct ether_addr *)ar_tha(ap)));
    867   1.1  deraadt 	n = write(ii->ii_fd, (char *) ep, len);
    868   1.1  deraadt 	if (n != len) {
    869  1.19    lukem 		rarperr(NONFATAL, "write: only %d of %d bytes written", n, len);
    870   1.1  deraadt 	}
    871   1.1  deraadt }
    872   1.1  deraadt /*
    873   1.1  deraadt  * Get the netmask of an IP address.  This routine is used if
    874   1.1  deraadt  * SIOCGIFNETMASK doesn't work.
    875   1.1  deraadt  */
    876   1.1  deraadt u_long
    877   1.1  deraadt ipaddrtonetmask(addr)
    878   1.1  deraadt 	u_long  addr;
    879   1.1  deraadt {
    880  1.26      mrg 
    881   1.1  deraadt 	if (IN_CLASSA(addr))
    882   1.1  deraadt 		return IN_CLASSA_NET;
    883   1.1  deraadt 	if (IN_CLASSB(addr))
    884   1.1  deraadt 		return IN_CLASSB_NET;
    885   1.1  deraadt 	if (IN_CLASSC(addr))
    886   1.1  deraadt 		return IN_CLASSC_NET;
    887  1.19    lukem 	rarperr(FATAL, "unknown IP address class: %08X", addr);
    888   1.1  deraadt 	/* NOTREACHED */
    889  1.19    lukem 	return(-1);
    890   1.1  deraadt }
    891   1.1  deraadt 
    892   1.1  deraadt #if __STDC__
    893   1.1  deraadt #include <stdarg.h>
    894   1.1  deraadt #else
    895   1.1  deraadt #include <varargs.h>
    896   1.1  deraadt #endif
    897   1.1  deraadt 
    898   1.1  deraadt void
    899   1.1  deraadt #if __STDC__
    900  1.19    lukem rarperr(int fatal, const char *fmt,...)
    901   1.1  deraadt #else
    902  1.19    lukem rarperr(fmt, va_alist)
    903   1.1  deraadt 	int     fatal;
    904   1.1  deraadt 	char   *fmt;
    905   1.1  deraadt va_dcl
    906   1.1  deraadt #endif
    907   1.1  deraadt {
    908   1.1  deraadt 	va_list ap;
    909  1.26      mrg 
    910   1.1  deraadt #if __STDC__
    911   1.1  deraadt 	va_start(ap, fmt);
    912   1.1  deraadt #else
    913   1.1  deraadt 	va_start(ap);
    914   1.1  deraadt #endif
    915   1.1  deraadt 	if (dflag) {
    916   1.1  deraadt 		if (fatal)
    917  1.26      mrg 			(void)fprintf(stderr, "rarpd: error: ");
    918   1.1  deraadt 		else
    919  1.26      mrg 			(void)fprintf(stderr, "rarpd: warning: ");
    920  1.26      mrg 		(void)vfprintf(stderr, fmt, ap);
    921  1.26      mrg 		(void)fprintf(stderr, "\n");
    922   1.1  deraadt 	}
    923   1.1  deraadt 	vsyslog(LOG_ERR, fmt, ap);
    924   1.1  deraadt 	va_end(ap);
    925  1.25      mrg 	if (fatal) {
    926  1.25      mrg 		unlink(_PATH_RARPDPID);
    927   1.1  deraadt 		exit(1);
    928  1.25      mrg 	}
    929   1.1  deraadt 	/* NOTREACHED */
    930   1.1  deraadt }
    931   1.1  deraadt 
    932   1.1  deraadt void
    933   1.1  deraadt #if __STDC__
    934   1.1  deraadt debug(const char *fmt,...)
    935   1.1  deraadt #else
    936   1.1  deraadt debug(fmt, va_alist)
    937   1.1  deraadt 	char   *fmt;
    938   1.1  deraadt va_dcl
    939   1.1  deraadt #endif
    940   1.1  deraadt {
    941   1.1  deraadt 	va_list ap;
    942   1.1  deraadt 
    943   1.1  deraadt #if __STDC__
    944  1.18    lukem 	va_start(ap, fmt);
    945   1.1  deraadt #else
    946  1.18    lukem 	va_start(ap);
    947   1.1  deraadt #endif
    948  1.18    lukem 	if (dflag) {
    949  1.26      mrg 		(void)fprintf(stderr, "rarpd: ");
    950  1.26      mrg 		(void)vfprintf(stderr, fmt, ap);
    951  1.26      mrg 		(void)fprintf(stderr, "\n");
    952   1.1  deraadt 	}
    953  1.18    lukem 	vsyslog(LOG_WARNING, fmt, ap);
    954  1.18    lukem 	va_end(ap);
    955   1.1  deraadt }
    956