tp_inet.c

早期freebsd实现

 *
 * CALLED FROM:  tp_emit()
 *
 * FUNCTION and ARGUMENTS:
 *  Take a packet(m0) from tp and package it so that ip will accept it.
 *  This means prepending space for the ip header and filling in a few
 *  of the fields.
 *  inp is the inpcb structure; datalen is the length of the data in the
 *  mbuf string m0.
 * RETURNS:			
 *  whatever (E*) is returned form the net layer output routine.
 *
 * SIDE EFFECTS:	
 *
 * NOTES:			
 */

int
tpip_output(inp, m0, datalen, nochksum)
	struct inpcb		*inp;
	struct mbuf 		*m0;
	int 				datalen;
	int					nochksum;
{
	return tpip_output_dg( &inp->inp_laddr, &inp->inp_faddr, m0, datalen,
		&inp->inp_route, nochksum);
}

/*
 * NAME:	tpip_output_dg()
 *
 * CALLED FROM:  tp_error_emit()
 *
 * FUNCTION and ARGUMENTS:
 *  This is a copy of tpip_output that takes the addresses
 *  instead of a pcb.  It's used by the tp_error_emit, when we
 *  don't have an in_pcb with which to call the normal output rtn.
 *
 * RETURNS:	 ENOBUFS or  whatever (E*) is 
 *	returned form the net layer output routine.
 *
 * SIDE EFFECTS:	
 *
 * NOTES:			
 */

/*ARGSUSED*/
int
tpip_output_dg(laddr, faddr, m0, datalen, ro, nochksum)
	struct in_addr		*laddr, *faddr;
	struct mbuf 		*m0;
	int 				datalen;
	struct route 		*ro;
	int					nochksum;
{
	register struct mbuf 	*m;
	register struct ip *ip;
	int 					error;

	IFDEBUG(D_EMIT)
		printf("tpip_output_dg  datalen 0x%x m0 0x%x\n", datalen, m0);
	ENDDEBUG


	MGETHDR(m, M_DONTWAIT, TPMT_IPHDR);
	if (m == 0) {
		error = ENOBUFS;
		goto bad;
	}
	m->m_next = m0;
	MH_ALIGN(m, sizeof(struct ip));
	m->m_len = sizeof(struct ip);

	ip = mtod(m, struct ip *);
	bzero((caddr_t)ip, sizeof *ip);

	ip->ip_p = IPPROTO_TP;
	m->m_pkthdr.len = ip->ip_len = sizeof(struct ip) + datalen;
	ip->ip_ttl = MAXTTL;	
		/* don't know why you need to set ttl;
		 * overlay doesn't even make this available
		 */

	ip->ip_src = *laddr;
	ip->ip_dst = *faddr;

	IncStat(ts_tpdu_sent);
	IFDEBUG(D_EMIT)
		dump_mbuf(m, "tpip_output_dg before ip_output\n");
	ENDDEBUG

	error = ip_output(m, (struct mbuf *)0, ro, IP_ALLOWBROADCAST, NULL);

	IFDEBUG(D_EMIT)
		printf("tpip_output_dg after ip_output\n");
	ENDDEBUG

	return error;

bad:
	m_freem(m);
	IncStat(ts_send_drop);
	return error;
}

/*
 * NAME:  tpip_input()
 *
 * CALLED FROM:
 * 	ip's input routine, indirectly through the protosw.
 *
 * FUNCTION and ARGUMENTS:
 * Take a packet (m) from ip, strip off the ip header and give it to tp
 *
 * RETURNS:  No return value.  
 * 
 * SIDE EFFECTS:
 *
 * NOTES:
 */
ProtoHook
tpip_input(m, iplen)
	struct mbuf *m;
	int iplen;
{
	struct sockaddr_in 	src, dst;
	register struct ip 		*ip;
	int						s = splnet(), hdrlen;

	IncStat(ts_pkt_rcvd);

	/*
	 * IP layer has already pulled up the IP header,
	 * but the first byte after the IP header may not be there,
	 * e.g. if you came in via loopback, so you have to do an
	 * m_pullup to before you can even look to see how much you
	 * really need.  The good news is that m_pullup will round
	 * up to almost the next mbuf's worth.
	 */


	if((m = m_pullup(m, iplen + 1)) == MNULL)
		goto discard;
	CHANGE_MTYPE(m, TPMT_DATA);
	
	/*
	 * Now pull up the whole tp header:
	 * Unfortunately, there may be IP options to skip past so we
	 * just fetch it as an unsigned char.
	 */
	hdrlen = iplen + 1 + mtod(m, u_char *)[iplen];

	if( m->m_len < hdrlen ) {
		if((m = m_pullup(m, hdrlen)) == MNULL){
			IFDEBUG(D_TPINPUT)
				printf("tp_input, pullup 2!\n");
			ENDDEBUG
			goto discard;
		}
	}
	/* 
	 * cannot use tp_inputprep() here 'cause you don't 
	 * have quite the same situation
	 */

	IFDEBUG(D_TPINPUT)
		dump_mbuf(m, "after tpip_input both pullups");
	ENDDEBUG
	/* 
	 * m_pullup may have returned a different mbuf
	 */
	ip = mtod(m, struct ip *);

	/*
	 * drop the ip header from the front of the mbuf
	 * this is necessary for the tp checksum
	 */
	m->m_len -= iplen;
	m->m_data += iplen;

	src.sin_addr = *(struct in_addr *)&(ip->ip_src);
	src.sin_family  = AF_INET;
	src.sin_len  = sizeof(src);
	dst.sin_addr = *(struct in_addr *)&(ip->ip_dst);
	dst.sin_family  = AF_INET; 
	dst.sin_len  = sizeof(dst);

	(void) tp_input(m, (struct sockaddr *)&src, (struct sockaddr *)&dst,
				0, tpip_output_dg, 0);
	return 0;

discard:
	IFDEBUG(D_TPINPUT)
		printf("tpip_input DISCARD\n");
	ENDDEBUG
	IFTRACE(D_TPINPUT)
		tptrace(TPPTmisc, "tpip_input DISCARD m",  m,0,0,0);
	ENDTRACE
	m_freem(m);
	IncStat(ts_recv_drop);
	splx(s);
	return 0;
}


#include <sys/protosw.h>
#include <netinet/ip_icmp.h>

extern void tp_quench();
/*
 * NAME:	tpin_quench()
 *
 * CALLED FROM: tpip_ctlinput()
 *
 * FUNCTION and ARGUMENTS:  find the tpcb pointer and pass it to tp_quench
 *
 * RETURNS:	Nada
 *
 * SIDE EFFECTS:	
 *
 * NOTES:			
 */

void
tpin_quench(inp)
	struct inpcb *inp;
{
	tp_quench((struct tp_pcb *)inp->inp_socket->so_pcb, PRC_QUENCH);
}

/*
 * NAME:	tpip_ctlinput()
 *
 * CALLED FROM:
 *  The network layer through the protosw table.
 *
 * FUNCTION and ARGUMENTS:
 *	When clnp gets an ICMP msg this gets called.
 *	It either returns an error status to the user or
 *	causes all connections on this address to be aborted
 *	by calling the appropriate xx_notify() routine.
 *	(cmd) is the type of ICMP error.   
 * 	(sa) the address of the sender
 *
 * RETURNS:	 Nothing
 *
 * SIDE EFFECTS:	
 *
 * NOTES:			
 */
ProtoHook
tpip_ctlinput(cmd, sin)
	int cmd;
	struct sockaddr_in *sin;
{
	extern u_char inetctlerrmap[];
	extern struct in_addr zeroin_addr;
	void tp_quench __P((struct inpcb *,int));
	void tpin_abort __P((struct inpcb *,int));

	if (sin->sin_family != AF_INET && sin->sin_family != AF_IMPLINK)
		return 0;
	if (sin->sin_addr.s_addr == INADDR_ANY)
		return 0;
	if (cmd < 0 || cmd > PRC_NCMDS)
		return 0;
	switch (cmd) {

		case	PRC_QUENCH:
			in_pcbnotify(&tp_inpcb, (struct sockaddr *)sin, 0,
				zeroin_addr, 0, cmd, tp_quench);
			break;

		case	PRC_ROUTEDEAD:
		case	PRC_HOSTUNREACH:
		case	PRC_UNREACH_NET:
		case	PRC_IFDOWN:
		case	PRC_HOSTDEAD:
			in_pcbnotify(&tp_inpcb, (struct sockaddr *)sin, 0,
				zeroin_addr, 0, cmd, in_rtchange);
			break;

		default:
		/*
		case	PRC_MSGSIZE:
		case	PRC_UNREACH_HOST:
		case	PRC_UNREACH_PROTOCOL:
		case	PRC_UNREACH_PORT:
		case	PRC_UNREACH_NEEDFRAG:
		case	PRC_UNREACH_SRCFAIL:
		case	PRC_REDIRECT_NET:
		case	PRC_REDIRECT_HOST:
		case	PRC_REDIRECT_TOSNET:
		case	PRC_REDIRECT_TOSHOST:
		case	PRC_TIMXCEED_INTRANS:
		case	PRC_TIMXCEED_REASS:
		case	PRC_PARAMPROB:
		*/
		in_pcbnotify(&tp_inpcb, (struct sockaddr *)sin, 0,
			zeroin_addr, 0, cmd, tpin_abort);
	}
	return 0;
}

/*
 * NAME:	tpin_abort()
 *
 * CALLED FROM:
 *	xxx_notify() from tp_ctlinput() when
 *  net level gets some ICMP-equiv. type event.
 *
 * FUNCTION and ARGUMENTS:
 *  Cause the connection to be aborted with some sort of error
 *  reason indicating that the network layer caused the abort.
 *  Fakes an ER TPDU so we can go through the driver.
 *
 * RETURNS:	 Nothing
 *
 * SIDE EFFECTS:	
 *
 * NOTES:			
 */

ProtoHook
tpin_abort(inp)
	struct inpcb *inp;
{
	struct tp_event e;

	e.ev_number = ER_TPDU;
	e.ATTR(ER_TPDU).e_reason = ENETRESET;
	(void) tp_driver((struct tp_pcb *)inp->inp_ppcb, &e);
	return 0;
}

#ifdef ARGO_DEBUG
dump_inaddr(addr)
	register struct sockaddr_in *addr;
{
	printf("INET: port 0x%x; addr 0x%x\n", addr->sin_port, addr->sin_addr);
}
#endif /* ARGO_DEBUG */
#endif /* INET */