xref: /csrg-svn/sys/net/if_ethersubr.c (revision 39187)
1 /*
2  * Copyright (c) 1982, 1989 Regents of the University of California.
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms are permitted
6  * provided that the above copyright notice and this paragraph are
7  * duplicated in all such forms and that any documentation,
8  * advertising materials, and other materials related to such
9  * distribution and use acknowledge that the software was developed
10  * by the University of California, Berkeley.  The name of the
11  * University may not be used to endorse or promote products derived
12  * from this software without specific prior written permission.
13  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
14  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
15  * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
16  *
17  *	@(#)if_ethersubr.c	7.5 (Berkeley) 09/20/89
18  */
19 
20 #include "param.h"
21 #include "systm.h"
22 #include "malloc.h"
23 #include "mbuf.h"
24 #include "protosw.h"
25 #include "socket.h"
26 #include "ioctl.h"
27 #include "errno.h"
28 #include "syslog.h"
29 
30 #include "if.h"
31 #include "netisr.h"
32 #include "route.h"
33 #include "if_llc.h"
34 
35 #include "machine/mtpr.h"
36 
37 #ifdef INET
38 #include "../netinet/in.h"
39 #include "../netinet/in_var.h"
40 #include "../netinet/if_ether.h"
41 #endif
42 
43 #ifdef NS
44 #include "../netns/ns.h"
45 #include "../netns/ns_if.h"
46 #endif
47 
48 #ifdef ISO
49 #include "../netiso/argo_debug.h"
50 #include "../netiso/iso.h"
51 #include "../netiso/iso_var.h"
52 #endif
53 
54 u_char	etherbroadcastaddr[6] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
55 extern	struct ifnet loif;
56 
57 /*
58  * Ethernet output routine.
59  * Encapsulate a packet of type family for the local net.
60  * Use trailer local net encapsulation if enough data in first
61  * packet leaves a multiple of 512 bytes of data in remainder.
62  * Assumes that ifp is actually pointer to arpcom structure.
63  */
64 ether_output(ifp, m0, dst)
65 	register struct ifnet *ifp;
66 	struct mbuf *m0;
67 	struct sockaddr *dst;
68 {
69 	short type;
70 	int s, error = 0;
71  	u_char edst[6];
72 	struct in_addr idst;
73 	register struct mbuf *m = m0;
74 	struct mbuf *mcopy = (struct mbuf *)0;
75 	register struct ether_header *eh;
76 	int usetrailers, off, len = m->m_pkthdr.len;
77 	extern struct timeval time;
78 #define	ac ((struct arpcom *)ifp)
79 
80 	if ((ifp->if_flags & (IFF_UP|IFF_RUNNING)) != (IFF_UP|IFF_RUNNING)) {
81 		error = ENETDOWN;
82 		goto bad;
83 	}
84 	ifp->if_lastchange = time;
85 	switch (dst->sa_family) {
86 
87 #ifdef INET
88 	case AF_INET:
89 		idst = ((struct sockaddr_in *)dst)->sin_addr;
90  		if (!arpresolve(ac, m, &idst, edst, &usetrailers))
91 			return (0);	/* if not yet resolved */
92 		if ((ifp->if_flags & IFF_SIMPLEX) && (*edst & 1))
93 		    mcopy = m_copy(m, 0, (int)M_COPYALL);
94 		off = m->m_pkthdr.len - m->m_len;
95 		if (usetrailers && off > 0 && (off & 0x1ff) == 0 &&
96 		    (m->m_flags & M_EXT) == 0 &&
97 		    m->m_data >= m->m_pktdat + 2 * sizeof (u_short)) {
98 			type = ETHERTYPE_TRAIL + (off>>9);
99 			m->m_data -= 2 * sizeof (u_short);
100 			m->m_len += 2 * sizeof (u_short);
101 			len += 2 * sizeof (u_short);
102 			*mtod(m, u_short *) = htons((u_short)ETHERTYPE_IP);
103 			*(mtod(m, u_short *) + 1) = htons((u_short)m->m_len);
104 			goto gottrailertype;
105 		}
106 		type = ETHERTYPE_IP;
107 		goto gottype;
108 #endif
109 #ifdef NS
110 	case AF_NS:
111 		type = ETHERTYPE_NS;
112  		bcopy((caddr_t)&(((struct sockaddr_ns *)dst)->sns_addr.x_host),
113 		    (caddr_t)edst, sizeof (edst));
114 		if (!bcmp((caddr_t)edst, (caddr_t)&ns_thishost, sizeof(edst)))
115 			return(looutput(&loif, m, dst));
116 		if ((ifp->if_flags & IFF_SIMPLEX) && (*edst & 1))
117 		    mcopy = m_copy(m, 0, (int)M_COPYALL);
118 		goto gottype;
119 #endif
120 #ifdef	ISO
121 	case AF_ISO: {
122 		int	len;
123 		int	ret;
124 		struct	llc *l;
125 
126 		if ((ret = iso_tryloopback(m, (struct sockaddr_iso *)dst)) >= 0)
127 			return (ret);
128 		ret = iso_snparesolve(ifp, (struct sockaddr_iso *)dst,
129 					(char *)edst, &len);
130 		if (ret > 0) {
131 			m_freem(m); /* Not Resolved */
132 			return(ret);
133 		}
134 		M_PREPEND(m, 3, M_DONTWAIT);
135 		if (m == NULL)
136 			return(0);
137 		type = m->m_pkthdr.len;
138 		l = mtod(m, struct llc *);
139 		l->llc_dsap = l->llc_ssap = LLC_ISO_LSAP;
140 		l->llc_control = LLC_UI;
141 		len += 3;
142 		IFDEBUG(D_ETHER)
143 			int i;
144 			printf("unoutput: sending pkt to: ");
145 			for (i=0; i<6; i++)
146 				printf("%x ", edst[i] & 0xff);
147 			printf("\n");
148 		ENDDEBUG
149 		} goto gottype;
150 #endif	ISO
151 	case AF_UNSPEC:
152 		eh = (struct ether_header *)dst->sa_data;
153  		bcopy((caddr_t)eh->ether_dhost, (caddr_t)edst, sizeof (edst));
154 		type = eh->ether_type;
155 		goto gottype;
156 
157 	default:
158 		printf("%s%d: can't handle af%d\n", ifp->if_name, ifp->if_unit,
159 			dst->sa_family);
160 		error = EAFNOSUPPORT;
161 		goto bad;
162 	}
163 
164 gottrailertype:
165 	/*
166 	 * Packet to be sent as trailer: move first packet
167 	 * (control information) to end of chain.
168 	 */
169 	while (m->m_next)
170 		m = m->m_next;
171 	m->m_next = m0;
172 	m = m0->m_next;
173 	m0->m_next = 0;
174 
175 gottype:
176 	/*
177 	 * Add local net header.  If no space in first mbuf,
178 	 * allocate another.
179 	 */
180 	M_PREPEND(m, sizeof (struct ether_header), M_DONTWAIT);
181 	if (m == 0) {
182 		error = ENOBUFS;
183 		goto bad;
184 	}
185 	eh = mtod(m, struct ether_header *);
186 	type = htons((u_short)type);
187 	bcopy((caddr_t)&type,(caddr_t)&eh->ether_type,
188 		sizeof(eh->ether_type));
189  	bcopy((caddr_t)edst, (caddr_t)eh->ether_dhost, sizeof (edst));
190  	bcopy((caddr_t)ac->ac_enaddr, (caddr_t)eh->ether_shost,
191 	    sizeof(eh->ether_shost));
192 	/*
193 	 * Queue message on interface, and start output if interface
194 	 * not yet active.
195 	 */
196 	s = splimp();
197 	if (IF_QFULL(&ifp->if_snd)) {
198 		IF_DROP(&ifp->if_snd);
199 		splx(s);
200 		error = ENOBUFS;
201 		goto bad;
202 	}
203 	IF_ENQUEUE(&ifp->if_snd, m);
204 	if ((ifp->if_flags & IFF_OACTIVE) == 0)
205 		(*ifp->if_start)(ifp);
206 	splx(s);
207 	if (mcopy)
208 		(void) looutput(&loif, mcopy, dst);
209 	ifp->if_obytes += len + sizeof (struct ether_header);
210 	if (edst[0] & 1)
211 		ifp->if_omcasts++;
212 	return (error);
213 
214 bad:
215 	if (mcopy)
216 		m_freem(mcopy);
217 	if (m)
218 		m_freem(m);
219 	return (error);
220 }
221 
222 /*
223  * Process a received Ethernet packet;
224  * the packet is in the mbuf chain m without
225  * the ether header, which is provided separately.
226  */
227 ether_input(ifp, eh, m)
228 	struct ifnet *ifp;
229 	register struct ether_header *eh;
230 	struct mbuf *m;
231 {
232 	register struct ifqueue *inq;
233 	register struct llc *l;
234 	int s;
235 
236 	ifp->if_lastchange = time;
237 	ifp->if_ibytes += m->m_pkthdr.len + sizeof (*eh);
238 	if (bcmp((caddr_t)etherbroadcastaddr, (caddr_t)eh->ether_dhost,
239 	    sizeof(etherbroadcastaddr)) == 0)
240 		m->m_flags |= M_BCAST;
241 	else if (eh->ether_dhost[0] & 1)
242 		m->m_flags |= M_MCAST;
243 	if (m->m_flags & (M_BCAST|M_MCAST))
244 		ifp->if_imcasts++;
245 
246 	switch (eh->ether_type) {
247 #ifdef INET
248 	case ETHERTYPE_IP:
249 		schednetisr(NETISR_IP);
250 		inq = &ipintrq;
251 		break;
252 
253 	case ETHERTYPE_ARP:
254 		arpinput((struct arpcom *)ifp, m);
255 		return;
256 #endif
257 #ifdef NS
258 	case ETHERTYPE_NS:
259 		schednetisr(NETISR_NS);
260 		inq = &nsintrq;
261 		break;
262 
263 #endif
264 	default:
265 #ifdef	ISO
266 		if (eh->ether_type > ETHERMTU)
267 			goto dropanyway;
268 		l = mtod(m, struct llc *);
269 		switch (l->llc_control) {
270 		case LLC_UI:
271 		/* LLC_UI_P forbidden in class 1 service */
272 		    if ((l->llc_dsap == LLC_ISO_LSAP) &&
273 			(l->llc_ssap == LLC_ISO_LSAP)) {
274 				/* LSAP for ISO */
275 			m->m_data += 3;		/* XXX */
276 			m->m_len -= 3;		/* XXX */
277 			m->m_pkthdr.len -= 3;	/* XXX */
278 			M_PREPEND(m, sizeof *eh, M_DONTWAIT);
279 			if (m == 0)
280 				return;
281 			*mtod(m, struct ether_header *) = *eh;
282 			IFDEBUG(D_ETHER)
283 			    printf("clnp packet");
284 			ENDDEBUG
285 			schednetisr(NETISR_ISO);
286 			inq = &clnlintrq;
287 			break;
288 		    }
289 		    goto dropanyway;
290 
291 		case LLC_XID:
292 		case LLC_XID_P:
293 		    if(m->m_len < 6)
294 			goto dropanyway;
295 		    l->llc_window = 0;
296 		    l->llc_fid = 9;
297 		    l->llc_class = 1;
298 		    l->llc_dsap = l->llc_ssap = 0;
299 		    /* Fall through to */
300 		case LLC_TEST:
301 		case LLC_TEST_P:
302 		{
303 		    struct sockaddr sa;
304 		    register struct ether_header *eh2;
305 		    int i;
306 		    u_char c = l->llc_dsap;
307 		    l->llc_dsap = l->llc_ssap;
308 		    l->llc_ssap = c;
309 		    if (m->m_flags & (M_BCAST | M_MCAST))
310 			bcopy((caddr_t)ac->ac_enaddr,
311 			      (caddr_t)eh->ether_dhost, 6);
312 		    sa.sa_family = AF_UNSPEC;
313 		    sa.sa_len = sizeof(sa);
314 		    eh2 = (struct ether_header *)sa.sa_data;
315 		    for (i = 0; i < 6; i++) {
316 			eh2->ether_shost[i] = c = eh->ether_dhost[i];
317 			eh2->ether_dhost[i] =
318 				eh->ether_dhost[i] = eh->ether_shost[i];
319 			eh->ether_shost[i] = c;
320 		    }
321 		    ifp->if_output(ifp, m, &sa);
322 		    return;
323 		}
324 		dropanyway:
325 		default:
326 		    m_freem(m);
327 		    return;
328 	    }
329 #else
330 	    m_freem(m);
331 	    return;
332 #endif	ISO
333 	}
334 
335 	s = splimp();
336 	if (IF_QFULL(inq)) {
337 		IF_DROP(inq);
338 		m_freem(m);
339 	} else
340 		IF_ENQUEUE(inq, m);
341 	splx(s);
342 }
343 
344 /*
345  * Convert Ethernet address to printable (loggable) representation.
346  */
347 static char digits[] = "0123456789abcdef";
348 char *
349 ether_sprintf(ap)
350 	register u_char *ap;
351 {
352 	register i;
353 	static char etherbuf[18];
354 	register char *cp = etherbuf;
355 
356 	for (i = 0; i < 6; i++) {
357 		*cp++ = digits[*ap >> 4];
358 		*cp++ = digits[*ap++ & 0xf];
359 		*cp++ = ':';
360 	}
361 	*--cp = 0;
362 	return (etherbuf);
363 }
364