xref: /csrg-svn/sys/net/if_ethersubr.c (revision 43336)
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	7.9 (Berkeley) 06/20/90
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 #include "if_dl.h"
35 
36 #include "machine/mtpr.h"
37 
38 #ifdef INET
39 #include "../netinet/in.h"
40 #include "../netinet/in_var.h"
41 #include "../netinet/if_ether.h"
42 #endif
43 
44 #ifdef NS
45 #include "../netns/ns.h"
46 #include "../netns/ns_if.h"
47 #endif
48 
49 #ifdef ISO
50 #include "../netiso/argo_debug.h"
51 #include "../netiso/iso.h"
52 #include "../netiso/iso_var.h"
53 #include "../netiso/iso_snpac.h"
54 #endif
55 
56 u_char	etherbroadcastaddr[6] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
57 extern	struct ifnet loif;
58 
59 /*
60  * Ethernet output routine.
61  * Encapsulate a packet of type family for the local net.
62  * Use trailer local net encapsulation if enough data in first
63  * packet leaves a multiple of 512 bytes of data in remainder.
64  * Assumes that ifp is actually pointer to arpcom structure.
65  */
66 ether_output(ifp, m0, dst, rt)
67 	register struct ifnet *ifp;
68 	struct mbuf *m0;
69 	struct sockaddr *dst;
70 	struct rtentry *rt;
71 {
72 	short type;
73 	int s, error = 0;
74  	u_char edst[6];
75 	struct in_addr idst;
76 	register struct mbuf *m = m0;
77 	struct mbuf *mcopy = (struct mbuf *)0;
78 	register struct ether_header *eh;
79 	int usetrailers, off, len = m->m_pkthdr.len;
80 	extern struct timeval time;
81 #define	ac ((struct arpcom *)ifp)
82 
83 	if ((ifp->if_flags & (IFF_UP|IFF_RUNNING)) != (IFF_UP|IFF_RUNNING)) {
84 		error = ENETDOWN;
85 		goto bad;
86 	}
87 	ifp->if_lastchange = time;
88 	switch (dst->sa_family) {
89 
90 #ifdef INET
91 	case AF_INET:
92 		idst = ((struct sockaddr_in *)dst)->sin_addr;
93  		if (!arpresolve(ac, m, &idst, edst, &usetrailers))
94 			return (0);	/* if not yet resolved */
95 		if ((ifp->if_flags & IFF_SIMPLEX) && (*edst & 1))
96 			mcopy = m_copy(m, 0, (int)M_COPYALL);
97 		off = m->m_pkthdr.len - m->m_len;
98 		if (usetrailers && off > 0 && (off & 0x1ff) == 0 &&
99 		    (m->m_flags & M_EXT) == 0 &&
100 		    m->m_data >= m->m_pktdat + 2 * sizeof (u_short)) {
101 			type = ETHERTYPE_TRAIL + (off>>9);
102 			m->m_data -= 2 * sizeof (u_short);
103 			m->m_len += 2 * sizeof (u_short);
104 			len += 2 * sizeof (u_short);
105 			*mtod(m, u_short *) = htons((u_short)ETHERTYPE_IP);
106 			*(mtod(m, u_short *) + 1) = htons((u_short)m->m_len);
107 			goto gottrailertype;
108 		}
109 		type = ETHERTYPE_IP;
110 		goto gottype;
111 #endif
112 #ifdef NS
113 	case AF_NS:
114 		type = ETHERTYPE_NS;
115  		bcopy((caddr_t)&(((struct sockaddr_ns *)dst)->sns_addr.x_host),
116 		    (caddr_t)edst, sizeof (edst));
117 		if (!bcmp((caddr_t)edst, (caddr_t)&ns_thishost, sizeof(edst)))
118 			return (looutput(&loif, m, dst));
119 		if ((ifp->if_flags & IFF_SIMPLEX) && (*edst & 1))
120 			mcopy = m_copy(m, 0, (int)M_COPYALL);
121 		goto gottype;
122 #endif
123 #ifdef	ISO
124 	case AF_ISO: {
125 		int	snpalen;
126 		struct	llc *l;
127 
128 	iso_again:
129 		iso_etherout();
130 		if (rt && rt->rt_gateway && (rt->rt_flags & RTF_UP)) {
131 			if (rt->rt_flags & RTF_GATEWAY) {
132 				if (rt->rt_llinfo) {
133 					rt = (struct rtentry *)rt->rt_llinfo;
134 					goto iso_again;
135 				}
136 			} else {
137 				register struct sockaddr_dl *sdl =
138 					(struct sockaddr_dl *)rt->rt_gateway;
139 				if (sdl && sdl->sdl_family == AF_LINK
140 				    && sdl->sdl_alen > 0) {
141 					bcopy(LLADDR(sdl), (char *)edst,
142 								sizeof(edst));
143 					goto iso_resolved;
144 				}
145 			}
146 		}
147 		if ((error = iso_snparesolve(ifp, (struct sockaddr_iso *)dst,
148 					(char *)edst, &snpalen)) > 0)
149 			goto bad; /* Not Resolved */
150 	iso_resolved:
151 		M_PREPEND(m, 3, M_DONTWAIT);
152 		if (m == NULL)
153 			return (0);
154 		type = m->m_pkthdr.len;
155 		l = mtod(m, struct llc *);
156 		l->llc_dsap = l->llc_ssap = LLC_ISO_LSAP;
157 		l->llc_control = LLC_UI;
158 		len += 3;
159 		IFDEBUG(D_ETHER)
160 			int i;
161 			printf("unoutput: sending pkt to: ");
162 			for (i=0; i<6; i++)
163 				printf("%x ", edst[i] & 0xff);
164 			printf("\n");
165 		ENDDEBUG
166 		} goto gottype;
167 #endif	ISO
168 #ifdef RMP
169 	case AF_RMP:
170 		/*
171 		 *  This is IEEE 802.3 -- the Ethernet `type' field is
172 		 *  really a `length' field.
173 		 */
174 		type = m->m_len;
175  		bcopy((caddr_t)dst->sa_data, (caddr_t)edst, sizeof(edst));
176 		break;
177 #endif
178 
179 	case AF_UNSPEC:
180 		eh = (struct ether_header *)dst->sa_data;
181  		bcopy((caddr_t)eh->ether_dhost, (caddr_t)edst, sizeof (edst));
182 		type = eh->ether_type;
183 		goto gottype;
184 
185 	default:
186 		printf("%s%d: can't handle af%d\n", ifp->if_name, ifp->if_unit,
187 			dst->sa_family);
188 		error = EAFNOSUPPORT;
189 		goto bad;
190 	}
191 
192 gottrailertype:
193 	/*
194 	 * Packet to be sent as trailer: move first packet
195 	 * (control information) to end of chain.
196 	 */
197 	while (m->m_next)
198 		m = m->m_next;
199 	m->m_next = m0;
200 	m = m0->m_next;
201 	m0->m_next = 0;
202 
203 gottype:
204 	/*
205 	 * Add local net header.  If no space in first mbuf,
206 	 * allocate another.
207 	 */
208 	M_PREPEND(m, sizeof (struct ether_header), M_DONTWAIT);
209 	if (m == 0) {
210 		error = ENOBUFS;
211 		goto bad;
212 	}
213 	eh = mtod(m, struct ether_header *);
214 	type = htons((u_short)type);
215 	bcopy((caddr_t)&type,(caddr_t)&eh->ether_type,
216 		sizeof(eh->ether_type));
217  	bcopy((caddr_t)edst, (caddr_t)eh->ether_dhost, sizeof (edst));
218  	bcopy((caddr_t)ac->ac_enaddr, (caddr_t)eh->ether_shost,
219 	    sizeof(eh->ether_shost));
220 	/*
221 	 * Queue message on interface, and start output if interface
222 	 * not yet active.
223 	 */
224 	s = splimp();
225 	if (IF_QFULL(&ifp->if_snd)) {
226 		IF_DROP(&ifp->if_snd);
227 		splx(s);
228 		error = ENOBUFS;
229 		goto bad;
230 	}
231 	IF_ENQUEUE(&ifp->if_snd, m);
232 	if ((ifp->if_flags & IFF_OACTIVE) == 0)
233 		(*ifp->if_start)(ifp);
234 	splx(s);
235 	if (mcopy)
236 		(void) looutput(&loif, mcopy, dst);
237 	ifp->if_obytes += len + sizeof (struct ether_header);
238 	if (edst[0] & 1)
239 		ifp->if_omcasts++;
240 	return (error);
241 
242 bad:
243 	if (mcopy)
244 		m_freem(mcopy);
245 	if (m)
246 		m_freem(m);
247 	return (error);
248 }
249 
250 /*
251  * Process a received Ethernet packet;
252  * the packet is in the mbuf chain m without
253  * the ether header, which is provided separately.
254  */
255 ether_input(ifp, eh, m)
256 	struct ifnet *ifp;
257 	register struct ether_header *eh;
258 	struct mbuf *m;
259 {
260 	register struct ifqueue *inq;
261 	register struct llc *l;
262 	int s;
263 
264 	ifp->if_lastchange = time;
265 	ifp->if_ibytes += m->m_pkthdr.len + sizeof (*eh);
266 	if (bcmp((caddr_t)etherbroadcastaddr, (caddr_t)eh->ether_dhost,
267 	    sizeof(etherbroadcastaddr)) == 0)
268 		m->m_flags |= M_BCAST;
269 	else if (eh->ether_dhost[0] & 1)
270 		m->m_flags |= M_MCAST;
271 	if (m->m_flags & (M_BCAST|M_MCAST))
272 		ifp->if_imcasts++;
273 
274 	switch (eh->ether_type) {
275 #ifdef INET
276 	case ETHERTYPE_IP:
277 		schednetisr(NETISR_IP);
278 		inq = &ipintrq;
279 		break;
280 
281 	case ETHERTYPE_ARP:
282 		arpinput((struct arpcom *)ifp, m);
283 		return;
284 #endif
285 #ifdef NS
286 	case ETHERTYPE_NS:
287 		schednetisr(NETISR_NS);
288 		inq = &nsintrq;
289 		break;
290 
291 #endif
292 	default:
293 #ifdef	ISO
294 		if (eh->ether_type > ETHERMTU)
295 			goto dropanyway;
296 		l = mtod(m, struct llc *);
297 		switch (l->llc_control) {
298 		case LLC_UI:
299 		/* LLC_UI_P forbidden in class 1 service */
300 		    if ((l->llc_dsap == LLC_ISO_LSAP) &&
301 			(l->llc_ssap == LLC_ISO_LSAP)) {
302 				/* LSAP for ISO */
303 			m->m_data += 3;		/* XXX */
304 			m->m_len -= 3;		/* XXX */
305 			m->m_pkthdr.len -= 3;	/* XXX */
306 			M_PREPEND(m, sizeof *eh, M_DONTWAIT);
307 			if (m == 0)
308 				return;
309 			*mtod(m, struct ether_header *) = *eh;
310 			IFDEBUG(D_ETHER)
311 			    printf("clnp packet");
312 			ENDDEBUG
313 			schednetisr(NETISR_ISO);
314 			inq = &clnlintrq;
315 			break;
316 		    }
317 		    goto dropanyway;
318 
319 		case LLC_XID:
320 		case LLC_XID_P:
321 		    if(m->m_len < 6)
322 			goto dropanyway;
323 		    l->llc_window = 0;
324 		    l->llc_fid = 9;
325 		    l->llc_class = 1;
326 		    l->llc_dsap = l->llc_ssap = 0;
327 		    /* Fall through to */
328 		case LLC_TEST:
329 		case LLC_TEST_P:
330 		{
331 		    struct sockaddr sa;
332 		    register struct ether_header *eh2;
333 		    int i;
334 		    u_char c = l->llc_dsap;
335 		    l->llc_dsap = l->llc_ssap;
336 		    l->llc_ssap = c;
337 		    if (m->m_flags & (M_BCAST | M_MCAST))
338 			bcopy((caddr_t)ac->ac_enaddr,
339 			      (caddr_t)eh->ether_dhost, 6);
340 		    sa.sa_family = AF_UNSPEC;
341 		    sa.sa_len = sizeof(sa);
342 		    eh2 = (struct ether_header *)sa.sa_data;
343 		    for (i = 0; i < 6; i++) {
344 			eh2->ether_shost[i] = c = eh->ether_dhost[i];
345 			eh2->ether_dhost[i] =
346 				eh->ether_dhost[i] = eh->ether_shost[i];
347 			eh->ether_shost[i] = c;
348 		    }
349 		    ifp->if_output(ifp, m, &sa);
350 		    return;
351 		}
352 		dropanyway:
353 		default:
354 		    m_freem(m);
355 		    return;
356 	    }
357 #else
358 	    m_freem(m);
359 	    return;
360 #endif	ISO
361 	}
362 
363 	s = splimp();
364 	if (IF_QFULL(inq)) {
365 		IF_DROP(inq);
366 		m_freem(m);
367 	} else
368 		IF_ENQUEUE(inq, m);
369 	splx(s);
370 }
371 
372 /*
373  * Convert Ethernet address to printable (loggable) representation.
374  */
375 static char digits[] = "0123456789abcdef";
376 char *
377 ether_sprintf(ap)
378 	register u_char *ap;
379 {
380 	register i;
381 	static char etherbuf[18];
382 	register char *cp = etherbuf;
383 
384 	for (i = 0; i < 6; i++) {
385 		*cp++ = digits[*ap >> 4];
386 		*cp++ = digits[*ap++ & 0xf];
387 		*cp++ = ':';
388 	}
389 	*--cp = 0;
390 	return (etherbuf);
391 }
392 iso_etherout() {}
393