xref: /386bsd/usr/src/kernel/kern/net/ethersubr.c (revision a2142627)
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, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *	This product includes software developed by the University of
16  *	California, Berkeley and its contributors.
17  * 4. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  *
33  * $Id: ethersubr.c,v 1.1 94/10/20 00:01:31 bill Exp $
34  */
35 
36 #include "sys/param.h"
37 #include "sys/socket.h"
38 #include "sys/ioctl.h"
39 #include "sys/syslog.h"
40 #include "sys/errno.h"
41 #include "systm.h"
42 #include "kernel.h"
43 #include "malloc.h"
44 #include "mbuf.h"
45 #include "protosw.h"
46 
47 #include "machine/cpu.h"
48 
49 #include "if.h"
50 #include "netisr.h"
51 #include "route.h"
52 #include "if_llc.h"
53 #include "if_dl.h"
54 
55 #include "in.h"		/* XXX: for if_ether */
56 #ifdef INET
57 #include "in_var.h"
58 #endif
59 #include "if_ether.h"
60 
61 #ifdef NS
62 #include "ns.h"
63 #include "ns_if.h"
64 #endif
65 
66 #ifdef ISO
67 #include "argo_debug.h"
68 #include "iso.h"
69 #include "iso_var.h"
70 #include "iso_snpac.h"
71 #endif
72 
73 u_char	etherbroadcastaddr[6] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
74 /*extern	struct ifnet loif;*/
75 
76 /*
77  * Ethernet output routine.
78  * Encapsulate a packet of type family for the local net.
79  * Use trailer local net encapsulation if enough data in first
80  * packet leaves a multiple of 512 bytes of data in remainder.
81  * Assumes that ifp is actually pointer to arpcom structure.
82  */
83 int
84 ether_output(struct ifnet *ifp, struct mbuf *m0, struct sockaddr *dst,
85 	struct rtentry *rt)
86 {
87 	short type;
88 	int s, error = 0;
89  	u_char edst[6];
90 	struct in_addr idst;
91 	register struct mbuf *m = m0;
92 	struct mbuf *mcopy = (struct mbuf *)0;
93 	register struct ether_header *eh;
94 	int usetrailers, off, len = m->m_pkthdr.len;
95 #define	ac ((struct arpcom *)ifp)
96 
97 	if ((ifp->if_flags & (IFF_UP|IFF_RUNNING)) != (IFF_UP|IFF_RUNNING)) {
98 		error = ENETDOWN;
99 		goto bad;
100 	}
101 	ifp->if_lastchange = time;
102 	switch (dst->sa_family) {
103 
104 #ifdef INET
105 	case AF_INET:
106 		idst = ((struct sockaddr_in *)dst)->sin_addr;
107  		if (!arpresolve(ac, m, &idst, edst, &usetrailers))
108 			return (0);	/* if not yet resolved */
109 		if ((ifp->if_flags & IFF_SIMPLEX) && (*edst & 1))
110 			mcopy = m_copy(m, 0, (int)M_COPYALL);
111 		off = m->m_pkthdr.len - m->m_len;
112 		if (usetrailers && off > 0 && (off & 0x1ff) == 0 &&
113 		    (m->m_flags & M_EXT) == 0 &&
114 		    m->m_data >= m->m_pktdat + 2 * sizeof (u_short)) {
115 			type = ETHERTYPE_TRAIL + (off>>9);
116 			m->m_data -= 2 * sizeof (u_short);
117 			m->m_len += 2 * sizeof (u_short);
118 			len += 2 * sizeof (u_short);
119 			*mtod(m, u_short *) = htons((u_short)ETHERTYPE_IP);
120 			*(mtod(m, u_short *) + 1) = htons((u_short)m->m_len);
121 			goto gottrailertype;
122 		}
123 		type = ETHERTYPE_IP;
124 		goto gottype;
125 #endif
126 #ifdef NS
127 	case AF_NS:
128 		type = ETHERTYPE_NS;
129  		memcpy((caddr_t)edst,
130 		    (caddr_t)&(((struct sockaddr_ns *)dst)->sns_addr.x_host),
131 		    sizeof (edst));
132 		if (!memcmp((caddr_t)edst, (caddr_t)&ns_thishost, sizeof(edst)))
133 			return ((*route_looutput)(ifp, m, dst, rt));
134 		if ((ifp->if_flags & IFF_SIMPLEX) && (*edst & 1))
135 			mcopy = m_copy(m, 0, (int)M_COPYALL);
136 		goto gottype;
137 #endif
138 #ifdef	ISO
139 	case AF_ISO: {
140 		int	snpalen;
141 		struct	llc *l;
142 
143 	iso_again:
144 		if (rt && rt->rt_gateway && (rt->rt_flags & RTF_UP)) {
145 			if (rt->rt_flags & RTF_GATEWAY) {
146 				if (rt->rt_llinfo) {
147 					rt = (struct rtentry *)rt->rt_llinfo;
148 					goto iso_again;
149 				}
150 			} else {
151 				register struct sockaddr_dl *sdl =
152 					(struct sockaddr_dl *)rt->rt_gateway;
153 				if (sdl && sdl->sdl_family == AF_LINK
154 				    && sdl->sdl_alen > 0) {
155 					memcpy((char *)edst, LLADDR(sdl),
156 								sizeof(edst));
157 					goto iso_resolved;
158 				}
159 			}
160 		}
161 		if ((error = iso_snparesolve(ifp, (struct sockaddr_iso *)dst,
162 					(char *)edst, &snpalen)) > 0)
163 			goto bad; /* Not Resolved */
164 	iso_resolved:
165 		if ((ifp->if_flags & IFF_SIMPLEX) && (*edst & 1) &&
166 		    (mcopy = m_copy(m, 0, (int)M_COPYALL))) {
167 			M_PREPEND(mcopy, sizeof (*eh), M_DONTWAIT);
168 			if (mcopy) {
169 				eh = mtod(mcopy, struct ether_header *);
170 				memcpy((caddr_t)eh->ether_dhost, (caddr_t)edst,
171 					sizeof (edst));
172 				memcpy((caddr_t)eh->ether_shost,
173 				      (caddr_t)ac->ac_enaddr, sizeof (edst));
174 			}
175 		}
176 		M_PREPEND(m, 3, M_DONTWAIT);
177 		if (m == NULL)
178 			return (0);
179 		type = m->m_pkthdr.len;
180 		l = mtod(m, struct llc *);
181 		l->llc_dsap = l->llc_ssap = LLC_ISO_LSAP;
182 		l->llc_control = LLC_UI;
183 		len += 3;
184 		IFDEBUG(D_ETHER)
185 			int i;
186 			printf("unoutput: sending pkt to: ");
187 			for (i=0; i<6; i++)
188 				printf("%x ", edst[i] & 0xff);
189 			printf("\n");
190 		ENDDEBUG
191 		} goto gottype;
192 #endif	ISO
193 #ifdef RMP
194 	case AF_RMP:
195 		/*
196 		 *  This is IEEE 802.3 -- the Ethernet `type' field is
197 		 *  really a `length' field.
198 		 */
199 		type = m->m_len;
200  		memcpy((caddr_t)edst, (caddr_t)dst->sa_data, sizeof(edst));
201 		break;
202 #endif
203 
204 	case AF_UNSPEC:
205 		eh = (struct ether_header *)dst->sa_data;
206  		memcpy((caddr_t)edst, (caddr_t)eh->ether_dhost, sizeof (edst));
207 		type = eh->ether_type;
208 		goto gottype;
209 
210 	default:
211 		printf("%s%d: can't handle af%d\n", ifp->if_name, ifp->if_unit,
212 			dst->sa_family);
213 		error = EAFNOSUPPORT;
214 		goto bad;
215 	}
216 
217 gottrailertype:
218 	/*
219 	 * Packet to be sent as trailer: move first packet
220 	 * (control information) to end of chain.
221 	 */
222 	while (m->m_next)
223 		m = m->m_next;
224 	m->m_next = m0;
225 	m = m0->m_next;
226 	m0->m_next = 0;
227 
228 gottype:
229 	if (mcopy)
230 		(void) (*route_looutput)(ifp, mcopy, dst, rt);
231 	/*
232 	 * Add local net header.  If no space in first mbuf,
233 	 * allocate another.
234 	 */
235 	M_PREPEND(m, sizeof (struct ether_header), M_DONTWAIT);
236 	if (m == 0) {
237 		error = ENOBUFS;
238 		goto bad;
239 	}
240 	eh = mtod(m, struct ether_header *);
241 	type = htons((u_short)type);
242 	memcpy((caddr_t)&eh->ether_type, (caddr_t)&type,
243 		sizeof(eh->ether_type));
244  	memcpy((caddr_t)eh->ether_dhost, (caddr_t)edst, sizeof (edst));
245  	memcpy((caddr_t)eh->ether_shost, (caddr_t)ac->ac_enaddr,
246 	    sizeof(eh->ether_shost));
247 	s = splimp();
248 	/*
249 	 * Queue message on interface, and start output if interface
250 	 * not yet active.
251 	 */
252 	if (IF_QFULL(&ifp->if_snd)) {
253 		IF_DROP(&ifp->if_snd);
254 		splx(s);
255 		error = ENOBUFS;
256 		goto bad;
257 	}
258 	IF_ENQUEUE(&ifp->if_snd, m);
259 	if ((ifp->if_flags & IFF_OACTIVE) == 0)
260 		(*ifp->if_start)(ifp);
261 	splx(s);
262 	ifp->if_obytes += len + sizeof (struct ether_header);
263 	if (edst[0] & 1)
264 		ifp->if_omcasts++;
265 	return (error);
266 
267 bad:
268 	if (m)
269 		m_freem(m);
270 	return (error);
271 }
272 
273 /*
274  * Process a received Ethernet packet;
275  * the packet is in the mbuf chain m without
276  * the ether header, which is provided separately.
277  */
278 void
279 ether_input(struct ifnet *ifp, struct ether_header *eh, struct mbuf *m)
280 {
281 	struct ifqueue *inq;
282 	struct llc *l;
283 	int s;
284 
285 	ifp->if_lastchange = time;
286 	ifp->if_ibytes += m->m_pkthdr.len + sizeof (*eh);
287 	if (memcmp((caddr_t)etherbroadcastaddr, (caddr_t)eh->ether_dhost,
288 	    sizeof(etherbroadcastaddr)) == 0)
289 		m->m_flags |= M_BCAST;
290 	else if (eh->ether_dhost[0] & 1)
291 		m->m_flags |= M_MCAST;
292 	if (m->m_flags & (M_BCAST|M_MCAST))
293 		ifp->if_imcasts++;
294 
295 	switch (eh->ether_type) {
296 #ifdef INET
297 	case ETHERTYPE_IP:
298 		schednetisr(NETISR_IP);
299 		inq = &ipintrq;
300 		break;
301 
302 	case ETHERTYPE_ARP:
303 		arpinput((struct arpcom *)ifp, m);
304 		return;
305 #endif
306 #ifdef NS
307 	case ETHERTYPE_NS:
308 		schednetisr(NETISR_NS);
309 		inq = &nsintrq;
310 		break;
311 
312 #endif
313 	default:
314 #ifdef	ISO
315 		if (eh->ether_type > ETHERMTU)
316 			goto dropanyway;
317 		l = mtod(m, struct llc *);
318 		switch (l->llc_control) {
319 		case LLC_UI:
320 		/* LLC_UI_P forbidden in class 1 service */
321 		    if ((l->llc_dsap == LLC_ISO_LSAP) &&
322 			(l->llc_ssap == LLC_ISO_LSAP)) {
323 				/* LSAP for ISO */
324 			if (m->m_pkthdr.len > eh->ether_type)
325 				m_adj(m, eh->ether_type - m->m_pkthdr.len);
326 			m->m_data += 3;		/* XXX */
327 			m->m_len -= 3;		/* XXX */
328 			m->m_pkthdr.len -= 3;	/* XXX */
329 			M_PREPEND(m, sizeof *eh, M_DONTWAIT);
330 			if (m == 0)
331 				return;
332 			*mtod(m, struct ether_header *) = *eh;
333 			IFDEBUG(D_ETHER)
334 			    printf("clnp packet");
335 			ENDDEBUG
336 			schednetisr(NETISR_ISO);
337 			inq = &clnlintrq;
338 			break;
339 		    }
340 		    goto dropanyway;
341 
342 		case LLC_XID:
343 		case LLC_XID_P:
344 		    if(m->m_len < 6)
345 			goto dropanyway;
346 		    l->llc_window = 0;
347 		    l->llc_fid = 9;
348 		    l->llc_class = 1;
349 		    l->llc_dsap = l->llc_ssap = 0;
350 		    /* Fall through to */
351 		case LLC_TEST:
352 		case LLC_TEST_P:
353 		{
354 		    struct sockaddr sa;
355 		    register struct ether_header *eh2;
356 		    int i;
357 		    u_char c = l->llc_dsap;
358 		    l->llc_dsap = l->llc_ssap;
359 		    l->llc_ssap = c;
360 		    if (m->m_flags & (M_BCAST | M_MCAST))
361 			memcpy((caddr_t)eh->ether_dhost,
362 			      (caddr_t)ac->ac_enaddr, 6);
363 		    sa.sa_family = AF_UNSPEC;
364 		    sa.sa_len = sizeof(sa);
365 		    eh2 = (struct ether_header *)sa.sa_data;
366 		    for (i = 0; i < 6; i++) {
367 			eh2->ether_shost[i] = c = eh->ether_dhost[i];
368 			eh2->ether_dhost[i] =
369 				eh->ether_dhost[i] = eh->ether_shost[i];
370 			eh->ether_shost[i] = c;
371 		    }
372 		    ifp->if_output(ifp, m, &sa);
373 		    return;
374 		}
375 		dropanyway:
376 		default:
377 		    m_freem(m);
378 		    return;
379 	    }
380 #else
381 	    m_freem(m);
382 	    return;
383 #endif	ISO
384 	}
385 
386 	s = splimp();
387 	if (IF_QFULL(inq)) {
388 		IF_DROP(inq);
389 		m_freem(m);
390 	} else
391 		IF_ENQUEUE(inq, m);
392 	splx(s);
393 }
394 
395 /*
396  * Convert Ethernet address to printable (loggable) representation.
397  */
398 static char digits[] = "0123456789abcdef";
399 char *
400 ether_sprintf(u_char *ap)
401 {
402 	register i;
403 	static char etherbuf[18];
404 	register char *cp = etherbuf;
405 
406 	for (i = 0; i < 6; i++) {
407 		*cp++ = digits[*ap >> 4];
408 		*cp++ = digits[*ap++ & 0xf];
409 		*cp++ = ':';
410 	}
411 	*--cp = 0;
412 	return (etherbuf);
413 }
414