xref: /netbsd-src/sys/net/if_ethersubr.c (revision 61f282557f0bc41c0b762c629a2f4c14be8b7591)
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  *	@(#)if_ethersubr.c	7.13 (Berkeley) 4/20/91
34  */
35 
36 #include "param.h"
37 #include "systm.h"
38 #include "kernel.h"
39 #include "malloc.h"
40 #include "mbuf.h"
41 #include "protosw.h"
42 #include "socket.h"
43 #include "ioctl.h"
44 #include "errno.h"
45 #include "syslog.h"
46 
47 #include "if.h"
48 #include "netisr.h"
49 #include "route.h"
50 #include "if_llc.h"
51 #include "if_dl.h"
52 
53 #include "machine/mtpr.h"
54 
55 #ifdef INET
56 #include "../netinet/in.h"
57 #include "../netinet/in_var.h"
58 #endif
59 #include "../netinet/if_ether.h"
60 
61 #ifdef NS
62 #include "../netns/ns.h"
63 #include "../netns/ns_if.h"
64 #endif
65 
66 #ifdef ISO
67 #include "../netiso/argo_debug.h"
68 #include "../netiso/iso.h"
69 #include "../netiso/iso_var.h"
70 #include "../netiso/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 ether_output(ifp, m0, dst, rt)
84 	register struct ifnet *ifp;
85 	struct mbuf *m0;
86 	struct sockaddr *dst;
87 	struct rtentry *rt;
88 {
89 	short type;
90 	int s, error = 0;
91  	u_char edst[6];
92 	struct in_addr idst;
93 	register struct mbuf *m = m0;
94 	struct mbuf *mcopy = (struct mbuf *)0;
95 	register struct ether_header *eh;
96 	int usetrailers, off, len = m->m_pkthdr.len;
97 #define	ac ((struct arpcom *)ifp)
98 
99 	if ((ifp->if_flags & (IFF_UP|IFF_RUNNING)) != (IFF_UP|IFF_RUNNING)) {
100 		error = ENETDOWN;
101 		goto bad;
102 	}
103 	ifp->if_lastchange = time;
104 	switch (dst->sa_family) {
105 
106 #ifdef INET
107 	case AF_INET:
108 		idst = ((struct sockaddr_in *)dst)->sin_addr;
109  		if (!arpresolve(ac, m, &idst, edst, &usetrailers))
110 			return (0);	/* if not yet resolved */
111 		if ((ifp->if_flags & IFF_SIMPLEX) && (*edst & 1))
112 			mcopy = m_copy(m, 0, (int)M_COPYALL);
113 		off = m->m_pkthdr.len - m->m_len;
114 		if (usetrailers && off > 0 && (off & 0x1ff) == 0 &&
115 		    (m->m_flags & M_EXT) == 0 &&
116 		    m->m_data >= m->m_pktdat + 2 * sizeof (u_short)) {
117 			type = ETHERTYPE_TRAIL + (off>>9);
118 			m->m_data -= 2 * sizeof (u_short);
119 			m->m_len += 2 * sizeof (u_short);
120 			len += 2 * sizeof (u_short);
121 			*mtod(m, u_short *) = htons((u_short)ETHERTYPE_IP);
122 			*(mtod(m, u_short *) + 1) = htons((u_short)m->m_len);
123 			goto gottrailertype;
124 		}
125 		type = ETHERTYPE_IP;
126 		goto gottype;
127 #endif
128 #ifdef NS
129 	case AF_NS:
130 		type = ETHERTYPE_NS;
131  		bcopy((caddr_t)&(((struct sockaddr_ns *)dst)->sns_addr.x_host),
132 		    (caddr_t)edst, sizeof (edst));
133 		if (!bcmp((caddr_t)edst, (caddr_t)&ns_thishost, sizeof(edst)))
134 			return (looutput(ifp, m, dst, rt));
135 		if ((ifp->if_flags & IFF_SIMPLEX) && (*edst & 1))
136 			mcopy = m_copy(m, 0, (int)M_COPYALL);
137 		goto gottype;
138 #endif
139 #ifdef	ISO
140 	case AF_ISO: {
141 		int	snpalen;
142 		struct	llc *l;
143 
144 	iso_again:
145 		if (rt && rt->rt_gateway && (rt->rt_flags & RTF_UP)) {
146 			if (rt->rt_flags & RTF_GATEWAY) {
147 				if (rt->rt_llinfo) {
148 					rt = (struct rtentry *)rt->rt_llinfo;
149 					goto iso_again;
150 				}
151 			} else {
152 				register struct sockaddr_dl *sdl =
153 					(struct sockaddr_dl *)rt->rt_gateway;
154 				if (sdl && sdl->sdl_family == AF_LINK
155 				    && sdl->sdl_alen > 0) {
156 					bcopy(LLADDR(sdl), (char *)edst,
157 								sizeof(edst));
158 					goto iso_resolved;
159 				}
160 			}
161 		}
162 		if ((error = iso_snparesolve(ifp, (struct sockaddr_iso *)dst,
163 					(char *)edst, &snpalen)) > 0)
164 			goto bad; /* Not Resolved */
165 	iso_resolved:
166 		if ((ifp->if_flags & IFF_SIMPLEX) && (*edst & 1) &&
167 		    (mcopy = m_copy(m, 0, (int)M_COPYALL))) {
168 			M_PREPEND(mcopy, sizeof (*eh), M_DONTWAIT);
169 			if (mcopy) {
170 				eh = mtod(mcopy, struct ether_header *);
171 				bcopy((caddr_t)edst,
172 				      (caddr_t)eh->ether_dhost, sizeof (edst));
173 				bcopy((caddr_t)ac->ac_enaddr,
174 				      (caddr_t)eh->ether_shost, sizeof (edst));
175 			}
176 		}
177 		M_PREPEND(m, 3, M_DONTWAIT);
178 		if (m == NULL)
179 			return (0);
180 		type = m->m_pkthdr.len;
181 		l = mtod(m, struct llc *);
182 		l->llc_dsap = l->llc_ssap = LLC_ISO_LSAP;
183 		l->llc_control = LLC_UI;
184 		len += 3;
185 		IFDEBUG(D_ETHER)
186 			int i;
187 			printf("unoutput: sending pkt to: ");
188 			for (i=0; i<6; i++)
189 				printf("%x ", edst[i] & 0xff);
190 			printf("\n");
191 		ENDDEBUG
192 		} goto gottype;
193 #endif	ISO
194 #ifdef RMP
195 	case AF_RMP:
196 		/*
197 		 *  This is IEEE 802.3 -- the Ethernet `type' field is
198 		 *  really a `length' field.
199 		 */
200 		type = m->m_len;
201  		bcopy((caddr_t)dst->sa_data, (caddr_t)edst, sizeof(edst));
202 		break;
203 #endif
204 
205 	case AF_UNSPEC:
206 		eh = (struct ether_header *)dst->sa_data;
207  		bcopy((caddr_t)eh->ether_dhost, (caddr_t)edst, sizeof (edst));
208 		type = eh->ether_type;
209 		goto gottype;
210 
211 	default:
212 		printf("%s%d: can't handle af%d\n", ifp->if_name, ifp->if_unit,
213 			dst->sa_family);
214 		error = EAFNOSUPPORT;
215 		goto bad;
216 	}
217 
218 gottrailertype:
219 	/*
220 	 * Packet to be sent as trailer: move first packet
221 	 * (control information) to end of chain.
222 	 */
223 	while (m->m_next)
224 		m = m->m_next;
225 	m->m_next = m0;
226 	m = m0->m_next;
227 	m0->m_next = 0;
228 
229 gottype:
230 	if (mcopy)
231 		(void) looutput(ifp, mcopy, dst, rt);
232 	/*
233 	 * Add local net header.  If no space in first mbuf,
234 	 * allocate another.
235 	 */
236 	M_PREPEND(m, sizeof (struct ether_header), M_DONTWAIT);
237 	if (m == 0) {
238 		error = ENOBUFS;
239 		goto bad;
240 	}
241 	eh = mtod(m, struct ether_header *);
242 	type = htons((u_short)type);
243 	bcopy((caddr_t)&type,(caddr_t)&eh->ether_type,
244 		sizeof(eh->ether_type));
245  	bcopy((caddr_t)edst, (caddr_t)eh->ether_dhost, sizeof (edst));
246  	bcopy((caddr_t)ac->ac_enaddr, (caddr_t)eh->ether_shost,
247 	    sizeof(eh->ether_shost));
248 	s = splimp();
249 	/*
250 	 * Queue message on interface, and start output if interface
251 	 * not yet active.
252 	 */
253 	if (IF_QFULL(&ifp->if_snd)) {
254 		IF_DROP(&ifp->if_snd);
255 		splx(s);
256 		error = ENOBUFS;
257 		goto bad;
258 	}
259 	IF_ENQUEUE(&ifp->if_snd, m);
260 	if ((ifp->if_flags & IFF_OACTIVE) == 0)
261 		(*ifp->if_start)(ifp);
262 	splx(s);
263 	ifp->if_obytes += len + sizeof (struct ether_header);
264 	if (edst[0] & 1)
265 		ifp->if_omcasts++;
266 	return (error);
267 
268 bad:
269 	if (m)
270 		m_freem(m);
271 	return (error);
272 }
273 
274 /*
275  * Process a received Ethernet packet;
276  * the packet is in the mbuf chain m without
277  * the ether header, which is provided separately.
278  */
279 ether_input(ifp, eh, m)
280 	struct ifnet *ifp;
281 	register struct ether_header *eh;
282 	struct mbuf *m;
283 {
284 	register struct ifqueue *inq;
285 	register struct llc *l;
286 	int s;
287 
288 	ifp->if_lastchange = time;
289 	ifp->if_ibytes += m->m_pkthdr.len + sizeof (*eh);
290 	if (bcmp((caddr_t)etherbroadcastaddr, (caddr_t)eh->ether_dhost,
291 	    sizeof(etherbroadcastaddr)) == 0)
292 		m->m_flags |= M_BCAST;
293 	else if (eh->ether_dhost[0] & 1)
294 		m->m_flags |= M_MCAST;
295 	if (m->m_flags & (M_BCAST|M_MCAST))
296 		ifp->if_imcasts++;
297 
298 	switch (eh->ether_type) {
299 #ifdef INET
300 	case ETHERTYPE_IP:
301 		schednetisr(NETISR_IP);
302 		inq = &ipintrq;
303 		break;
304 
305 	case ETHERTYPE_ARP:
306 		arpinput((struct arpcom *)ifp, m);
307 		return;
308 #endif
309 #ifdef NS
310 	case ETHERTYPE_NS:
311 		schednetisr(NETISR_NS);
312 		inq = &nsintrq;
313 		break;
314 
315 #endif
316 	default:
317 #ifdef	ISO
318 		if (eh->ether_type > ETHERMTU)
319 			goto dropanyway;
320 		l = mtod(m, struct llc *);
321 		switch (l->llc_control) {
322 		case LLC_UI:
323 		/* LLC_UI_P forbidden in class 1 service */
324 		    if ((l->llc_dsap == LLC_ISO_LSAP) &&
325 			(l->llc_ssap == LLC_ISO_LSAP)) {
326 				/* LSAP for ISO */
327 			if (m->m_pkthdr.len > eh->ether_type)
328 				m_adj(m, eh->ether_type - m->m_pkthdr.len);
329 			m->m_data += 3;		/* XXX */
330 			m->m_len -= 3;		/* XXX */
331 			m->m_pkthdr.len -= 3;	/* XXX */
332 			M_PREPEND(m, sizeof *eh, M_DONTWAIT);
333 			if (m == 0)
334 				return;
335 			*mtod(m, struct ether_header *) = *eh;
336 			IFDEBUG(D_ETHER)
337 			    printf("clnp packet");
338 			ENDDEBUG
339 			schednetisr(NETISR_ISO);
340 			inq = &clnlintrq;
341 			break;
342 		    }
343 		    goto dropanyway;
344 
345 		case LLC_XID:
346 		case LLC_XID_P:
347 		    if(m->m_len < 6)
348 			goto dropanyway;
349 		    l->llc_window = 0;
350 		    l->llc_fid = 9;
351 		    l->llc_class = 1;
352 		    l->llc_dsap = l->llc_ssap = 0;
353 		    /* Fall through to */
354 		case LLC_TEST:
355 		case LLC_TEST_P:
356 		{
357 		    struct sockaddr sa;
358 		    register struct ether_header *eh2;
359 		    int i;
360 		    u_char c = l->llc_dsap;
361 		    l->llc_dsap = l->llc_ssap;
362 		    l->llc_ssap = c;
363 		    if (m->m_flags & (M_BCAST | M_MCAST))
364 			bcopy((caddr_t)ac->ac_enaddr,
365 			      (caddr_t)eh->ether_dhost, 6);
366 		    sa.sa_family = AF_UNSPEC;
367 		    sa.sa_len = sizeof(sa);
368 		    eh2 = (struct ether_header *)sa.sa_data;
369 		    for (i = 0; i < 6; i++) {
370 			eh2->ether_shost[i] = c = eh->ether_dhost[i];
371 			eh2->ether_dhost[i] =
372 				eh->ether_dhost[i] = eh->ether_shost[i];
373 			eh->ether_shost[i] = c;
374 		    }
375 		    ifp->if_output(ifp, m, &sa);
376 		    return;
377 		}
378 		dropanyway:
379 		default:
380 		    m_freem(m);
381 		    return;
382 	    }
383 #else
384 	    m_freem(m);
385 	    return;
386 #endif	ISO
387 	}
388 
389 	s = splimp();
390 	if (IF_QFULL(inq)) {
391 		IF_DROP(inq);
392 		m_freem(m);
393 	} else
394 		IF_ENQUEUE(inq, m);
395 	splx(s);
396 }
397 
398 /*
399  * Convert Ethernet address to printable (loggable) representation.
400  */
401 static char digits[] = "0123456789abcdef";
402 char *
403 ether_sprintf(ap)
404 	register u_char *ap;
405 {
406 	register i;
407 	static char etherbuf[18];
408 	register char *cp = etherbuf;
409 
410 	for (i = 0; i < 6; i++) {
411 		*cp++ = digits[*ap >> 4];
412 		*cp++ = digits[*ap++ & 0xf];
413 		*cp++ = ':';
414 	}
415 	*--cp = 0;
416 	return (etherbuf);
417 }
418