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From: dmh@goanna.cs.rmit.oz.au (Darren Hosking)
Newsgroups: comp.sys.encore
Subject: SIOCSARP doesn't seem to work
Message-ID: <5184@goanna.cs.rmit.oz.au>
Date: 10 Apr 91 06:25:48 GMT
Organization: Comp Sci, RMIT, Melbourne, Australia
Lines: 67

I can't get the set arp cache ioctl (SIOCSARP) to work under UMAXV 2.4. The
code that requires this ioctl is bootpd which previously compiled and
ran correctly (under UMAXV 2.2m). However, under UMAXV 2.4 the ioctl always
produces SIOCSARP: Invalid argument. I have tried different flags etc but
to no avail.

I wrote a small test program that creates an arp cache entry that runs
correctly under BSD 4.3 (on a VAX) but not under UMAXV 2.4.

/*
 * Program to test the SIOCSARP ioctl.
 *
 * Creates a meaningless arp table entry.
 */

#include <sys/types.h>
#include <sys/ioctl.h>
#include <sys/socket.h>
#ifdef UMAXV
#include <sys/net/if.h>
#include <sys/net/if_arp.h>
#include <sys/netinet/in.h>
#else
#include <net/if.h>
#include <netinet/in.h>
#endif

struct	arpreq arpreq;
char	ha[] = {255, 255, 255, 1, 2, 3};
int	len = 6;

main()
{
	int	s;
	struct sockaddr_in *sin;

	if ((s = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
		perror("socket: ");
		exit(1);
        }
        bzero((caddr_t)&arpreq, sizeof(arpreq));

	sin = (struct sockaddr_in *)&arpreq.arp_pa;
        sin->sin_family = AF_INET;
        sin->sin_addr.s_addr = inet_addr("131.170.24.123");

        arpreq.arp_pa.sa_family = AF_INET;
        arpreq.arp_ha.sa_family = AF_UNSPEC;

        arpreq.arp_flags = ATF_INUSE | ATF_COM;
        bcopy(ha, arpreq.arp_ha.sa_data, len);

        if (ioctl(s, SIOCSARP, (caddr_t)&arpreq) < 0) {
		perror("SIOCSARP");
            	exit(1);
	}
}

What am I (and bootpd) doing wrong?

	Thanks, dmh

Darren Hosking			ACSnet: dmh@goanna.cs.rmit.oz	 
Department Of Computer Science	ARPA:   dmh%goanna.cs.rmit.oz.au@uunet.uu.net
RMIT				CSNET:  dmh%goanna.cs.rmit.oz.au@australia
GPO Box 2476V			UUCP:   ...!uunet!goanna.cs.rmit.oz.au!dmh
Melbourne Vic., Australia 3001	PH: +61 3 660 3299 FAX: +61 3 662 1617