xref: /csrg-svn/sys/net/if_ethersubr.c (revision 43073)
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	7.8 (Berkeley) 06/09/90
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 		if (rt && rt->rt_gateway && (rt->rt_flags & RTF_UP)) {
130 			if (rt->rt_flags & RTF_GATEWAY) {
131 				register struct llinfo_llc *lc =
132 					(struct llinfo_llc *)rt->rt_llinfo;
133 				if (lc && lc->lc_rtgate) {
134 					rt = lc->lc_rtgate;
135 					goto iso_again;
136 				}
137 			} else {
138 				register struct sockaddr_dl *sdl =
139 					(struct sockaddr_dl *)rt->rt_gateway;
140 				if (sdl && sdl->sdl_family == AF_LINK
141 				    && sdl->sdl_alen > 0) {
142 					bcopy(LLADDR(sdl), (char *)edst,
143 								sizeof(edst));
144 					goto iso_resolved;
145 				}
146 			}
147 		}
148 		if ((error = iso_snparesolve(ifp, (struct sockaddr_iso *)dst,
149 					(char *)edst, &snpalen)) > 0)
150 			goto bad; /* Not Resolved */
151 	iso_resolved:
152 		M_PREPEND(m, 3, M_DONTWAIT);
153 		if (m == NULL)
154 			return (0);
155 		type = m->m_pkthdr.len;
156 		l = mtod(m, struct llc *);
157 		l->llc_dsap = l->llc_ssap = LLC_ISO_LSAP;
158 		l->llc_control = LLC_UI;
159 		len += 3;
160 		IFDEBUG(D_ETHER)
161 			int i;
162 			printf("unoutput: sending pkt to: ");
163 			for (i=0; i<6; i++)
164 				printf("%x ", edst[i] & 0xff);
165 			printf("\n");
166 		ENDDEBUG
167 		} goto gottype;
168 #endif	ISO
169 #ifdef RMP
170 	case AF_RMP:
171 		/*
172 		 *  This is IEEE 802.3 -- the Ethernet `type' field is
173 		 *  really a `length' field.
174 		 */
175 		type = m->m_len;
176  		bcopy((caddr_t)dst->sa_data, (caddr_t)edst, sizeof(edst));
177 		break;
178 #endif
179 
180 	case AF_UNSPEC:
181 		eh = (struct ether_header *)dst->sa_data;
182  		bcopy((caddr_t)eh->ether_dhost, (caddr_t)edst, sizeof (edst));
183 		type = eh->ether_type;
184 		goto gottype;
185 
186 	default:
187 		printf("%s%d: can't handle af%d\n", ifp->if_name, ifp->if_unit,
188 			dst->sa_family);
189 		error = EAFNOSUPPORT;
190 		goto bad;
191 	}
192 
193 gottrailertype:
194 	/*
195 	 * Packet to be sent as trailer: move first packet
196 	 * (control information) to end of chain.
197 	 */
198 	while (m->m_next)
199 		m = m->m_next;
200 	m->m_next = m0;
201 	m = m0->m_next;
202 	m0->m_next = 0;
203 
204 gottype:
205 	/*
206 	 * Add local net header.  If no space in first mbuf,
207 	 * allocate another.
208 	 */
209 	M_PREPEND(m, sizeof (struct ether_header), M_DONTWAIT);
210 	if (m == 0) {
211 		error = ENOBUFS;
212 		goto bad;
213 	}
214 	eh = mtod(m, struct ether_header *);
215 	type = htons((u_short)type);
216 	bcopy((caddr_t)&type,(caddr_t)&eh->ether_type,
217 		sizeof(eh->ether_type));
218  	bcopy((caddr_t)edst, (caddr_t)eh->ether_dhost, sizeof (edst));
219  	bcopy((caddr_t)ac->ac_enaddr, (caddr_t)eh->ether_shost,
220 	    sizeof(eh->ether_shost));
221 	/*
222 	 * Queue message on interface, and start output if interface
223 	 * not yet active.
224 	 */
225 	s = splimp();
226 	if (IF_QFULL(&ifp->if_snd)) {
227 		IF_DROP(&ifp->if_snd);
228 		splx(s);
229 		error = ENOBUFS;
230 		goto bad;
231 	}
232 	IF_ENQUEUE(&ifp->if_snd, m);
233 	if ((ifp->if_flags & IFF_OACTIVE) == 0)
234 		(*ifp->if_start)(ifp);
235 	splx(s);
236 	if (mcopy)
237 		(void) looutput(&loif, mcopy, dst);
238 	ifp->if_obytes += len + sizeof (struct ether_header);
239 	if (edst[0] & 1)
240 		ifp->if_omcasts++;
241 	return (error);
242 
243 bad:
244 	if (mcopy)
245 		m_freem(mcopy);
246 	if (m)
247 		m_freem(m);
248 	return (error);
249 }
250 
251 /*
252  * Process a received Ethernet packet;
253  * the packet is in the mbuf chain m without
254  * the ether header, which is provided separately.
255  */
256 ether_input(ifp, eh, m)
257 	struct ifnet *ifp;
258 	register struct ether_header *eh;
259 	struct mbuf *m;
260 {
261 	register struct ifqueue *inq;
262 	register struct llc *l;
263 	int s;
264 
265 	ifp->if_lastchange = time;
266 	ifp->if_ibytes += m->m_pkthdr.len + sizeof (*eh);
267 	if (bcmp((caddr_t)etherbroadcastaddr, (caddr_t)eh->ether_dhost,
268 	    sizeof(etherbroadcastaddr)) == 0)
269 		m->m_flags |= M_BCAST;
270 	else if (eh->ether_dhost[0] & 1)
271 		m->m_flags |= M_MCAST;
272 	if (m->m_flags & (M_BCAST|M_MCAST))
273 		ifp->if_imcasts++;
274 
275 	switch (eh->ether_type) {
276 #ifdef INET
277 	case ETHERTYPE_IP:
278 		schednetisr(NETISR_IP);
279 		inq = &ipintrq;
280 		break;
281 
282 	case ETHERTYPE_ARP:
283 		arpinput((struct arpcom *)ifp, m);
284 		return;
285 #endif
286 #ifdef NS
287 	case ETHERTYPE_NS:
288 		schednetisr(NETISR_NS);
289 		inq = &nsintrq;
290 		break;
291 
292 #endif
293 	default:
294 #ifdef	ISO
295 		if (eh->ether_type > ETHERMTU)
296 			goto dropanyway;
297 		l = mtod(m, struct llc *);
298 		switch (l->llc_control) {
299 		case LLC_UI:
300 		/* LLC_UI_P forbidden in class 1 service */
301 		    if ((l->llc_dsap == LLC_ISO_LSAP) &&
302 			(l->llc_ssap == LLC_ISO_LSAP)) {
303 				/* LSAP for ISO */
304 			m->m_data += 3;		/* XXX */
305 			m->m_len -= 3;		/* XXX */
306 			m->m_pkthdr.len -= 3;	/* XXX */
307 			M_PREPEND(m, sizeof *eh, M_DONTWAIT);
308 			if (m == 0)
309 				return;
310 			*mtod(m, struct ether_header *) = *eh;
311 			IFDEBUG(D_ETHER)
312 			    printf("clnp packet");
313 			ENDDEBUG
314 			schednetisr(NETISR_ISO);
315 			inq = &clnlintrq;
316 			break;
317 		    }
318 		    goto dropanyway;
319 
320 		case LLC_XID:
321 		case LLC_XID_P:
322 		    if(m->m_len < 6)
323 			goto dropanyway;
324 		    l->llc_window = 0;
325 		    l->llc_fid = 9;
326 		    l->llc_class = 1;
327 		    l->llc_dsap = l->llc_ssap = 0;
328 		    /* Fall through to */
329 		case LLC_TEST:
330 		case LLC_TEST_P:
331 		{
332 		    struct sockaddr sa;
333 		    register struct ether_header *eh2;
334 		    int i;
335 		    u_char c = l->llc_dsap;
336 		    l->llc_dsap = l->llc_ssap;
337 		    l->llc_ssap = c;
338 		    if (m->m_flags & (M_BCAST | M_MCAST))
339 			bcopy((caddr_t)ac->ac_enaddr,
340 			      (caddr_t)eh->ether_dhost, 6);
341 		    sa.sa_family = AF_UNSPEC;
342 		    sa.sa_len = sizeof(sa);
343 		    eh2 = (struct ether_header *)sa.sa_data;
344 		    for (i = 0; i < 6; i++) {
345 			eh2->ether_shost[i] = c = eh->ether_dhost[i];
346 			eh2->ether_dhost[i] =
347 				eh->ether_dhost[i] = eh->ether_shost[i];
348 			eh->ether_shost[i] = c;
349 		    }
350 		    ifp->if_output(ifp, m, &sa);
351 		    return;
352 		}
353 		dropanyway:
354 		default:
355 		    m_freem(m);
356 		    return;
357 	    }
358 #else
359 	    m_freem(m);
360 	    return;
361 #endif	ISO
362 	}
363 
364 	s = splimp();
365 	if (IF_QFULL(inq)) {
366 		IF_DROP(inq);
367 		m_freem(m);
368 	} else
369 		IF_ENQUEUE(inq, m);
370 	splx(s);
371 }
372 
373 /*
374  * Convert Ethernet address to printable (loggable) representation.
375  */
376 static char digits[] = "0123456789abcdef";
377 char *
378 ether_sprintf(ap)
379 	register u_char *ap;
380 {
381 	register i;
382 	static char etherbuf[18];
383 	register char *cp = etherbuf;
384 
385 	for (i = 0; i < 6; i++) {
386 		*cp++ = digits[*ap >> 4];
387 		*cp++ = digits[*ap++ & 0xf];
388 		*cp++ = ':';
389 	}
390 	*--cp = 0;
391 	return (etherbuf);
392 }
393