raw_ip.c

<B>Digital的Unix操作系统VAX 4.2源码</B>

#ifndef lint
static	char	*sccsid = "@(#)raw_ip.c	4.1	(ULTRIX)	7/2/90";
#endif lint

/************************************************************************
 *									*
 *			Copyright (c) 1985 by				*
 *		Digital Equipment Corporation, Maynard, MA		*
 *			All rights reserved.				*
 *									*
 *   This software is furnished under a license and may be used and	*
 *   copied  only  in accordance with the terms of such license and	*
 *   with the  inclusion  of  the  above  copyright  notice.   This	*
 *   software  or  any  other copies thereof may not be provided or	*
 *   otherwise made available to any other person.  No title to and	*
 *   ownership of the software is hereby transferred.			*
 *									*
 *   This software is  derived  from  software  received  from  the	*
 *   University    of   California,   Berkeley,   and   from   Bell	*
 *   Laboratories.  Use, duplication, or disclosure is  subject  to	*
 *   restrictions  under  license  agreements  with  University  of	*
 *   California and with AT&T.						*
 *									*
 *   The information in this software is subject to change  without	*
 *   notice  and should not be construed as a commitment by Digital	*
 *   Equipment Corporation.						*
 *									*
 *   Digital assumes no responsibility for the use  or  reliability	*
 *   of its software on equipment which is not supplied by Digital.	*
 *									*
 ************************************************************************/

/************************************************************************
 *			Modification History				*
 *									*
 *	Uttam Shikarpur - 10/17/89    					*
 *		Changed the value of MAXTTL from a manifest constant    *
 *		to an variable (an integer.)				*
 *
 *	30-May-89	U. Sinkewicz
 *		Added support for asymmetric network drivers.
 *
 *	15-Jan-88	lp
 *		Merge of final 43BSD changes.
 *
 *	Larry Cohen  -	09/16/85					*
 * 		Add 43bsd alpha tape changes for subnet routing		*
 *									*
 ************************************************************************/

/*
 * Copyright (c) 1982 Regents of the University of California.
 * All rights reserved.  The Berkeley software License Agreement
 * specifies the terms and conditions for redistribution.
 *
 *	raw_ip.c	6.6 (Berkeley) 6/8/85
 */

#include "../h/param.h"
#include "../h/mbuf.h"
#include "../h/socket.h"
#include "../h/protosw.h"
#include "../h/socketvar.h"
#include "../h/errno.h"

#include "../net/net/if.h"
#include "../net/net/route.h"
#include "../net/net/raw_cb.h"

#include "../net/netinet/in.h"
#include "../net/netinet/in_systm.h"
#include "../net/netinet/ip.h"
#include "../net/netinet/ip_var.h"

/*
 * Raw interface to IP protocol.
 */
struct	sockaddr_in ripdst = { AF_INET };
struct	sockaddr_in ripsrc = { AF_INET };
struct	sockproto ripproto = { PF_INET };
/*
 * Setup generic address and protocol structures
 * for raw_input routine, then pass them along with
 * mbuf chain.
 */
rip_input(m)
	struct mbuf *m;
{
	register struct ip *ip = mtod(m, struct ip *);

	ripproto.sp_protocol = ip->ip_p;
	ripdst.sin_addr = ip->ip_dst;
	ripsrc.sin_addr = ip->ip_src;
	raw_input(m, &ripproto, (struct sockaddr *)&ripsrc,
	  (struct sockaddr *)&ripdst);
}

/*
 * Generate IP header and pass packet to ip_output.
 * Tack on options user may have setup with control call.
 */
rip_output(m, so)
	register struct mbuf *m;
	struct socket *so;
{
	register struct ip *ip;
	int error;
	struct rawcb *rp = sotorawcb(so);
	struct sockaddr_in *sin;
	short proto = rp->rcb_proto.sp_protocol;

	if (smp_debug){
		if ( !smp_owner(&so->lk_socket) )
			panic("rip_output: not lock owner\n");
	}

	/*
	 * if the protocol is IPPROTO_RAW, the user handed us a
	 * complete IP packet.  Otherwise, allocate an mbuf for a
	 * header and fill it in as needed.
	 */
	if (proto != IPPROTO_RAW) {
		/*
		 * Calculate data length and get an mbuf
		 * for IP header.
		 */
		int len = 0;
		struct mbuf *m0;

		for (m0 = m; m; m = m->m_next)
			len += m->m_len;

		m = m_get(M_DONTWAIT, MT_HEADER);
		if (m == 0) {
			m = m0;
			error = ENOBUFS;
			goto bad;
		}
	
		/*
		 * Fill in IP header as needed.
		 */
		m->m_off = MMAXOFF - sizeof(struct ip);
		m->m_len = sizeof(struct ip);
		m->m_next = m0;

		ip = mtod(m, struct ip *);
		ip->ip_tos = 0;
		ip->ip_off = 0;
		ip->ip_p = proto;
		ip->ip_len = sizeof(struct ip) + len;
		ip->ip_ttl = maxttl;
	} else
		ip = mtod(m, struct ip *);

	if (rp->rcb_flags & RAW_LADDR) {
		sin = (struct sockaddr_in *)&rp->rcb_laddr;
		if (sin->sin_family != AF_INET) {
			error = EAFNOSUPPORT;
			goto bad;
		}
		ip->ip_src.s_addr = sin->sin_addr.s_addr;
	} else
		ip->ip_src.s_addr = 0;
	ip->ip_dst = ((struct sockaddr_in *)&rp->rcb_faddr)->sin_addr;
	return (ip_output(m, rp->rcb_options, &rp->rcb_route, 
	   (so->so_options & SO_DONTROUTE) | IP_ALLOWBROADCAST, so));
bad:
	m_freem(m);
	return (error);
}


/*
 * Raw IP socket option processing.
 */
rip_ctloutput(op, so, level, optname, m)
	int op;
	struct socket *so;
	int level, optname;
	struct mbuf **m;
{
	int error = 0;
	register struct rawcb *rp = sotorawcb(so);

	if (level != IPPROTO_IP)
		error = EINVAL;
	else switch (op) {

	case PRCO_SETOPT:
		switch (optname) {
		case IP_OPTIONS:
			return (ip_pcbopts(&rp->rcb_options, *m));

		default:
			error = EINVAL;
			break;
		}
		break;

	case PRCO_GETOPT:
		switch (optname) {
		case IP_OPTIONS:
			*m = m_get(M_DONTWAIT, MT_SOOPTS); /* SMP */
			if (*m == NULL){
				error = ENOBUFS;
				break;
			}
			if (rp->rcb_options) {
				(*m)->m_off = rp->rcb_options->m_off;
				(*m)->m_len = rp->rcb_options->m_len;
				bcopy(mtod(rp->rcb_options, caddr_t),
				    mtod(*m, caddr_t), (unsigned)(*m)->m_len);
			} else
				(*m)->m_len = 0;
			break;
		default:
			error = EINVAL;
			break;
		}
		break;
	}
	if (op == PRCO_SETOPT && *m != NULL)
		(void)m_free(*m);
	return (error);
}