inet.c

来自「操作系统SunOS 4.1.3版本的源码」· C语言 代码 · 共 590 行

/*
 * inet.c
 *
 * @(#)inet.c	1.1
 * Copyright (c) 1986 by Sun Microsystems, Inc.
 */

/*
 * Standalone IP send and receive - specific to Ethernet
 * Includes ARP and Reverse ARP
 */
#include <stand/saio.h>
#include <sys/socket.h>
#include <net/if.h>
#include <net/if_arp.h>
#include <netinet/in.h>
#include <netinet/if_ether.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <stand/sainet.h>
#include <mon/sunromvec.h>
#include <mon/idprom.h>
#define	INADDR1_ANY	0x000000ff

#ifdef OPENPROMS
#define	millitime()	prom_gettime()
#else
#define	millitime()	(*romp->v_nmiclock)
#endif !OPENPROMS

struct ether_addr etherbroadcastaddr = {
	0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
};

struct	in_addr	my_in_addr;
struct	in_addr	null_in_addr;

struct arp_packet {
	struct ether_header	arp_eh;
	struct ether_arp	arp_ea;
#define	used_size (sizeof (struct ether_header)+sizeof (struct ether_arp))
	char	filler[ETHERMIN - sizeof (struct ether_arp)];
};

#define	WAITCNT	2	/* 4 seconds before bitching about arp/revarp */

extern	int	verbosemode;

/*
 * XXX: Fetch our Ethernet address from the ID prom
 */
myetheraddr(ea)
	struct ether_addr *ea;
{
#ifdef TRACE
	extern int trace;
#endif TRACE

	struct idprom id;

#ifdef TRACE
	if (trace >= 10) printf("myetheraddr\n");
#endif TRACE
	if (idprom(IDFORM_1, &id) != IDFORM_1) {
		printf("ERROR: Missing or invalid ID PROM.\n");
		return;
	}
	*ea = *(struct ether_addr *)id.id_ether;
}

/*
 * Initialize IP state.  Find out our Ethernet address and call Reverse ARP
 * to find out our Internet address.  Set the ARP cache to the broadcast host.
 */
inet_init(sip, sain, tmpbuf)
	register struct saioreq *sip;
	register struct sainet  *sain;
	char *tmpbuf;
{
#ifdef TRACE
	extern int trace;
#endif TRACE

#ifdef TRACE
	if (trace >= 10) printf("inet_init\n");
#endif TRACE
	/* get MAC address */
#ifdef OPENPROMS
	(*sip->si_sif->sif_macaddr)(sip->si_devdata, &sain->sain_myether);
#else
	(*sip->si_sif->sif_macaddr)(&sain->sain_myether);
#endif
	bzero((caddr_t)&sain->sain_myaddr, sizeof (struct in_addr));
	bzero((caddr_t)&sain->sain_hisaddr, sizeof (struct in_addr));
	sain->sain_hisether = etherbroadcastaddr;
	revarp(sip, sain, tmpbuf); /* Get Internet address. */
}


/*
 * Output an IP packet
 * Cause ARP to be invoked if necessary
 */
ip_output(sip, buf, len, sain, tmpbuf)
	register struct saioreq *sip;
	caddr_t buf, tmpbuf;
	short len;
	register struct sainet *sain;
{
#ifdef TRACE
	extern int trace;
#endif TRACE
	extern   unsigned short ipcksum();

	register struct ether_header *eh;
	register struct ip *ip;

#ifdef TRACE
	if (trace >= 10) printf("ip_output\n");
#endif TRACE
	eh = (struct ether_header *)buf;
	ip = (struct ip *)(buf + sizeof (struct ether_header));
	if (bcmp((caddr_t)&ip->ip_dst,
		(caddr_t)&sain->sain_hisaddr,
		sizeof (struct in_addr)) != 0) {
			bcopy((caddr_t)&ip->ip_dst,
				(caddr_t)&sain->sain_hisaddr,
				sizeof (struct in_addr));
			arp(sip, sain, tmpbuf);
	}
	eh->ether_type = ETHERTYPE_IP;
	eh->ether_shost = sain->sain_myether;
	eh->ether_dhost = sain->sain_hisether;
	/*
	 * Checksum the packet.
	 */
	ip->ip_sum = 0;
	ip->ip_sum = ipcksum((caddr_t)ip, sizeof (struct ip));
	if (len < ETHERMIN + sizeof (struct ether_header)) {
		len = ETHERMIN + sizeof (struct ether_header);
	}
	return (*sip->si_sif->sif_xmit)(sip->si_devdata, buf, len);
}


/*
 * Check incoming packets for IP packets addressed to us.
 * Also, respond to ARP packets that wish to know about us.
 * Returns a length for any IP packet addressed to us, 0 otherwise.
 */
ip_input(sip, buf, sain)
	register struct saioreq *sip;
	caddr_t			buf;
	register struct sainet  *sain;
{
#ifdef TRACE
	extern int trace;
#endif TRACE

	register short			len;
	register struct ether_header	*eh;
	register struct ip		*ip;
	register struct ether_arp	*ea;

#ifdef TRACE
	if (trace >= 10) printf("ip_input\n");
#endif TRACE
	len = (*sip->si_sif->sif_poll)(sip->si_devdata, buf);
	eh = (struct ether_header *)buf;
	if (eh->ether_type == ETHERTYPE_IP &&
	    len >= sizeof (struct ether_header)+sizeof (struct ip)) {
		ip = (struct ip *)(buf + sizeof (struct ether_header));
#ifdef NOREVARP
		if ((sain->sain_hisaddr.s_addr & 0xFF000000) == 0 &&
		    bcmp((caddr_t)&etherbroadcastaddr,
			(caddr_t)&eh->ether_dhost,
			sizeof (struct ether_addr)) != 0 &&
		    (in_broadaddr(sain->sain_hisaddr) ||
		    in_lnaof(ip->ip_src) == in_lnaof(sain->sain_hisaddr))) {
			sain->sain_myaddr = ip->ip_dst;
			sain->sain_hisaddr = ip->ip_src;
			sain->sain_hisether = eh->ether_shost;
		}
#endif
		if (bcmp((caddr_t)&ip->ip_dst,
		    (caddr_t)&sain->sain_myaddr,
		    sizeof (struct in_addr)) != 0)
			return (0);
		return (len);
	}
	if (eh->ether_type == ETHERTYPE_ARP &&
	    len >= sizeof (struct ether_header) + sizeof (struct ether_arp)) {
		ea = (struct ether_arp *)(buf + sizeof (struct ether_header));
		if (ea->arp_pro != ETHERTYPE_IP)
			return (0);
		if (bcmp((caddr_t)ea->arp_spa,
			(caddr_t)&sain->sain_hisaddr,
			sizeof (struct in_addr)) == 0)
			sain->sain_hisether = ea->arp_sha;
		if (ea->arp_op == ARPOP_REQUEST &&
		    (bcmp((caddr_t)ea->arp_tpa,
		    (caddr_t)&sain->sain_myaddr,
		    sizeof (struct in_addr)) == 0)) {
			ea->arp_op = ARPOP_REPLY;
			eh->ether_dhost = ea->arp_sha;
			eh->ether_shost = sain->sain_myether;
			ea->arp_tha = ea->arp_sha;
			bcopy((caddr_t)ea->arp_spa,
			    (caddr_t)ea->arp_tpa,
			    sizeof (ea->arp_tpa));
			ea->arp_sha = sain->sain_myether;
			bcopy((caddr_t)&sain->sain_myaddr,
			    (caddr_t)ea->arp_spa,
			    sizeof (ea->arp_spa));
			(*sip->si_sif->sif_xmit)(sip->si_devdata, buf,
						sizeof (struct arp_packet));
		}
		return (0);
	}
	return (0);
}


/*
 * arp
 * Broadcasts to determine Ethernet address given IP address
 * See RFC 826
 */
arp(sip, sain, tmpbuf)
	register struct saioreq *sip;
	register struct sainet  *sain;
	char			*tmpbuf;
{
#ifdef TRACE
	extern int trace;
#endif TRACE

	struct arp_packet	out;

#ifdef TRACE
	if (trace >= 10) printf("arp\n");
#endif TRACE
	if (in_lnaof(sain->sain_hisaddr) == INADDR_ANY ||
	    (in_lnaof(sain->sain_hisaddr) & INADDR1_ANY) == INADDR1_ANY) {
		sain->sain_hisether = etherbroadcastaddr;
		return;
	}
	out.arp_eh.ether_type = ETHERTYPE_ARP;
	out.arp_ea.arp_op = ARPOP_REQUEST;
	out.arp_ea.arp_tha = etherbroadcastaddr;	/* What we want. */
	bcopy((caddr_t)&sain->sain_hisaddr,
	    (caddr_t)out.arp_ea.arp_tpa,
	    sizeof (out.arp_ea.arp_tpa));
	comarp(sip, sain, &out, tmpbuf);
}


/*
 * Reverse ARP client side.  Determine our Internet address given our Ethernet
 * address.  See RFC 903.
 */
revarp(sip, sain, tmpbuf)
	register struct saioreq *sip;
	register struct sainet  *sain;
	char			*tmpbuf;
{
#ifdef TRACE
	extern int trace;
#endif TRACE

	struct arp_packet	out;

#ifdef TRACE
	if (trace >= 10) printf("revarp\n");
#endif TRACE
	bzero(&out, sizeof (struct arp_packet));

#ifdef NOREVARP
	bzero((caddr_t)&sain->sain_myaddr, sizeof (struct in_addr));
	bcopy((caddr_t)&sain->sain_myether.ether_addr_octet[3],
		(caddr_t)(&sain->sain_myaddr)+1, 3);
#else
	out.arp_eh.ether_type = ETHERTYPE_REVARP;
	out.arp_ea.arp_op = REVARP_REQUEST;
	out.arp_ea.arp_tha = sain->sain_myether;
	/* What we want to find out... */
	bzero(out.arp_ea.arp_tpa, sizeof (struct in_addr));
	comarp(sip, sain, &out, tmpbuf);
#endif
	bcopy(&sain->sain_myaddr, &my_in_addr, sizeof (struct in_addr));
	return;
}

/*
 * Common ARP code.  Broadcast the packet and wait for the right response.
 * Fills in structure 'sain' with the results.
 */

static char *pktprint = "packet ignored:  %s\n";

comarp(sip, sain, out, tmpbuf)
	register struct saioreq		*sip;
	register struct sainet		*sain;
	register struct arp_packet	*out;
	char				*tmpbuf;
{
#ifdef TRACE
	extern int trace;
#endif TRACE

	register struct arp_packet *in=((struct arp_packet *) tmpbuf);
	register int			count = 0;
	register int			time = 0;
	register int			len = 0;
	register int			delay = 2;
	struct in_addr			isaddr; /* Required for Sparc */
	struct in_addr			isaddr2; /* alignment restrictions. */
	int				timebomb;
	struct in_addr			tmp_ia;
	int				e;

#ifdef TRACE
	if (trace >= 10) printf("comarp\n");
#endif TRACE
	out->arp_eh.ether_dhost = etherbroadcastaddr;
	out->arp_eh.ether_shost = sain->sain_myether;
	out->arp_ea.arp_hrd = ARPHRD_ETHER;
	out->arp_ea.arp_pro = ETHERTYPE_IP;
	out->arp_ea.arp_hln = sizeof (struct ether_addr);
	out->arp_ea.arp_pln = sizeof (struct in_addr);
	out->arp_ea.arp_sha = sain->sain_myether;
	bcopy((caddr_t)&sain->sain_myaddr,
	    (caddr_t)out->arp_ea.arp_spa,
	    sizeof (out->arp_ea.arp_spa));

	for (count=0; /* empty! */; count++) {
		if ((verbosemode) || (count == WAITCNT)) {
			if (out->arp_ea.arp_op == ARPOP_REQUEST) {
				printf("\nRequesting Ethernet address for ");
				bcopy((caddr_t)out->arp_ea.arp_tpa,
				    (caddr_t)&tmp_ia, sizeof (tmp_ia));
				inet_printwhex(tmp_ia);
				printf("\n");
			} else {
				printf("\nRequesting Internet address for ");
				ether_print(&out->arp_ea.arp_tha);
				printf("\n");
			}
		}

		e = (*sip->si_sif->sif_xmit)(sip->si_devdata, (caddr_t)out,
			sizeof (*out));

		if (!verbosemode)	/* show activity */
			if (e)
				printf("X\b");
			else
				feedback();

		time = millitime() + (delay * 1000);	/* broadcast delay */
		while (millitime() <= time) {
			len = (*sip->si_sif->sif_poll)(sip->si_devdata, tmpbuf);
			if (verbosemode)
				if ((len > 0) && (len < used_size))
					printf("got short packet - ignored\n");
			if (len < used_size)
				continue;
			if (verbosemode) {
				printf("got reply from ");
				ether_print(&in->arp_eh.ether_shost);
				printf(" type 0x%x", in->arp_eh.ether_type);
				printf(" arp_pro 0x%x", in->arp_ea.arp_pro);
				printf(" arp_sha ");
				ether_print(&out->arp_ea.arp_sha);
				printf(" arp_spa ");
				inet_print(out->arp_ea.arp_spa);
				printf(" arp_tha ");
				ether_print(&out->arp_ea.arp_tha);
				printf(" arp_tpa ");
				inet_print(out->arp_ea.arp_tpa);
				printf("\n");
			}
			if (in->arp_ea.arp_pro != ETHERTYPE_IP) {
				if (verbosemode)
					printf(pktprint, "wrong arp_pro");
				continue;
			}
			if (out->arp_ea.arp_op == ARPOP_REQUEST) {
				if (in->arp_eh.ether_type != ETHERTYPE_ARP) {
					if (verbosemode)
					    printf(pktprint, "wrong type");
					continue;
				}
				if (in->arp_ea.arp_op != ARPOP_REPLY) {
					if (verbosemode)
					    printf(pktprint, "wrong arp_op");
					continue;
				}
				if (bcmp((caddr_t)in->arp_ea.arp_spa,
				    (caddr_t)out->arp_ea.arp_tpa,
				    sizeof (struct in_addr)) != 0) {
					if (verbosemode)
					    printf(pktprint, "wrong arp_spa");
					continue;
				} else if ((verbosemode) || (count > WAITCNT)) {
					printf("Found at ");
					ether_print(&in->arp_ea.arp_sha);
					printf("\n");
				}
				sain->sain_hisether = in->arp_ea.arp_sha;
				return;
			} else {		/* Reverse ARP */
				if (in->arp_eh.ether_type != ETHERTYPE_REVARP) {
					if (verbosemode)
					    printf(pktprint, "wrong type");
					continue;
				}
				if (in->arp_ea.arp_op != REVARP_REPLY) {
					if (verbosemode)
					    printf(pktprint, "wrong arp_op");
					continue;
				}
				if (bcmp((caddr_t)&in->arp_ea.arp_tha,
				    (caddr_t)&out->arp_ea.arp_tha,
				    sizeof (struct ether_addr)) != 0) {
					if (verbosemode)
					    printf(pktprint, "wrong arp_tha");
					continue;
				}
				printf("Using IP Address ");
				bcopy((caddr_t)in->arp_ea.arp_tpa,
				    (caddr_t)&tmp_ia, sizeof (tmp_ia));
				inet_printwhex(tmp_ia);
				printf("\n");
				bcopy((caddr_t)in->arp_ea.arp_tpa,
				    (caddr_t)&sain->sain_myaddr,
				    sizeof (sain->sain_myaddr));
				/*
				 * Short circuit first ARP.
				 */
				bcopy((caddr_t)in->arp_ea.arp_spa,
				    (caddr_t)&sain->sain_hisaddr,
				    sizeof (sain->sain_hisaddr));
				sain->sain_hisether = in->arp_ea.arp_sha;
				return;
			}
		}

		delay = delay * 2;	/* Double the request delay */
		if (delay > 64)		/* maximum delay is 64 seconds */
			delay = 64;

		if (verbosemode)
			printf("timed out, new delay %d sec\n", delay);

		(*sip->si_sif->sif_reset)(sip->si_devdata);
	}
	/* NOTREACHED */
}

/*
 * Return the host portion of an internet address.
 */
u_long
in_lnaof(in)
	struct in_addr in;
{
	register u_long i = ntohl(in.s_addr);

	if (IN_CLASSA(i))
		return ((i)&IN_CLASSA_HOST);
	else if (IN_CLASSB(i))
		return ((i)&IN_CLASSB_HOST);
	else
		return ((i)&IN_CLASSC_HOST);
}

/*
 * Test for broadcast IP address
 */
in_broadaddr(in)
	struct in_addr in;
{
	register u_long i = ntohl(in.s_addr);

	if (IN_CLASSA(i)) {
		i &= IN_CLASSA_HOST;
		return (i == 0 || i == 0xFFFFFF);
	} else if (IN_CLASSB(i)) {
		i &= IN_CLASSB_HOST;
		return (i == 0 || i == 0xFFFF);
	} else if (IN_CLASSC(i)) {
		i &= IN_CLASSC_HOST;
		return (i == 0 || i == 0xFF);
	} else
		return (0);
	/*NOTREACHED*/
}


/*
 * Compute one's complement checksum for IP packet headers.
 */
unsigned short
ipcksum(cp, count)
	caddr_t cp;
	register int count;
{
#ifdef TRACE
	extern int trace;
#endif TRACE

	register unsigned short	*sp=((unsigned short *) cp);
	register unsigned long	sum=0;
	register unsigned long	oneword=0x00010000;

#ifdef TRACE
	if (trace >= 10) printf("ipcksum\n");
#endif TRACE
	if (count == 0)
		return (0);

	count >>= 1;
	while (count--) {
		sum += *sp++;
		if (sum >= oneword) { /* Wrap carries into low bit. */
			sum -= oneword;
			sum++;
		}
	}
	return (~sum);
}


inet_printwhex(s)
	struct in_addr s;
{
#ifdef TRACE
	extern int trace;
#endif TRACE

	int	len=2;

#ifdef TRACE
	if (trace >= 10) printf("inet_print\n");
#endif TRACE
	printf("%d.%d.%d.%d = ", s.S_un.S_un_b.s_b1, s.S_un.S_un_b.s_b2,
		s.S_un.S_un_b.s_b3, s.S_un.S_un_b.s_b4);
	printhex(s.S_un.S_un_b.s_b1, len);
	printhex(s.S_un.S_un_b.s_b2, len);
	printhex(s.S_un.S_un_b.s_b3, len);
	printhex(s.S_un.S_un_b.s_b4, len);
}

inet_print(s)
	struct in_addr s;
{
	printf("%d.%d.%d.%d", s.S_un.S_un_b.s_b1, s.S_un.S_un_b.s_b2,
		s.S_un.S_un_b.s_b3, s.S_un.S_un_b.s_b4);
}

ether_print(ea)
	struct ether_addr *ea;
{
#ifndef TRACE
	extern int trace;
#endif TRACE

	register u_char *p = (&ea->ether_addr_octet[0]);

#ifdef TRACE
	if (trace >= 10) printf("ether_print\n");
#endif TRACE
	printf("%x:%x:%x:%x:%x:%x", p[0], p[1], p[2], p[3], p[4], p[5]);
}

char chardigs[]="0123456789ABCDEF";

/*
 * printhex() prints rightmost <digs> hex digits of <val>
 */
printhex(val, digs)
	register int val;
	register int digs;
{
	digs = ((digs-1)&7)<<2;		/* digs == 0 => print 8 digits */
	for (; digs >= 0; digs-=4)
		putchar(chardigs[(val>>digs)&0xF]);
}