xref: /csrg-svn/sys/net/if_ethersubr.c (revision 40790)
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	7.6 (Berkeley) 04/05/90
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 #endif
54 
55 u_char	etherbroadcastaddr[6] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
56 extern	struct ifnet loif;
57 
58 /*
59  * Ethernet output routine.
60  * Encapsulate a packet of type family for the local net.
61  * Use trailer local net encapsulation if enough data in first
62  * packet leaves a multiple of 512 bytes of data in remainder.
63  * Assumes that ifp is actually pointer to arpcom structure.
64  */
65 ether_output(ifp, m0, dst, rt)
66 	register struct ifnet *ifp;
67 	struct mbuf *m0;
68 	struct sockaddr *dst;
69 	struct rtentry *rt;
70 {
71 	short type;
72 	int s, error = 0;
73  	u_char edst[6];
74 	struct in_addr idst;
75 	register struct mbuf *m = m0;
76 	struct mbuf *mcopy = (struct mbuf *)0;
77 	register struct ether_header *eh;
78 	int usetrailers, off, len = m->m_pkthdr.len;
79 	extern struct timeval time;
80 #define	ac ((struct arpcom *)ifp)
81 
82 	if ((ifp->if_flags & (IFF_UP|IFF_RUNNING)) != (IFF_UP|IFF_RUNNING)) {
83 		error = ENETDOWN;
84 		goto bad;
85 	}
86 	ifp->if_lastchange = time;
87 	switch (dst->sa_family) {
88 
89 #ifdef INET
90 	case AF_INET:
91 		idst = ((struct sockaddr_in *)dst)->sin_addr;
92  		if (!arpresolve(ac, m, &idst, edst, &usetrailers))
93 			return (0);	/* if not yet resolved */
94 		if ((ifp->if_flags & IFF_SIMPLEX) && (*edst & 1))
95 		    mcopy = m_copy(m, 0, (int)M_COPYALL);
96 		off = m->m_pkthdr.len - m->m_len;
97 		if (usetrailers && off > 0 && (off & 0x1ff) == 0 &&
98 		    (m->m_flags & M_EXT) == 0 &&
99 		    m->m_data >= m->m_pktdat + 2 * sizeof (u_short)) {
100 			type = ETHERTYPE_TRAIL + (off>>9);
101 			m->m_data -= 2 * sizeof (u_short);
102 			m->m_len += 2 * sizeof (u_short);
103 			len += 2 * sizeof (u_short);
104 			*mtod(m, u_short *) = htons((u_short)ETHERTYPE_IP);
105 			*(mtod(m, u_short *) + 1) = htons((u_short)m->m_len);
106 			goto gottrailertype;
107 		}
108 		type = ETHERTYPE_IP;
109 		goto gottype;
110 #endif
111 #ifdef NS
112 	case AF_NS:
113 		type = ETHERTYPE_NS;
114  		bcopy((caddr_t)&(((struct sockaddr_ns *)dst)->sns_addr.x_host),
115 		    (caddr_t)edst, sizeof (edst));
116 		if (!bcmp((caddr_t)edst, (caddr_t)&ns_thishost, sizeof(edst)))
117 			return(looutput(&loif, m, dst));
118 		if ((ifp->if_flags & IFF_SIMPLEX) && (*edst & 1))
119 		    mcopy = m_copy(m, 0, (int)M_COPYALL);
120 		goto gottype;
121 #endif
122 #ifdef	ISO
123 	case AF_ISO: {
124 		int	len;
125 		int	ret;
126 		struct	llc *l;
127 
128 		if (rt && rt->rt_gateway &&
129 		    rt->rt_gateway->sa_family == AF_LINK) {
130 			register struct sockaddr_dl *sdl;
131 			sdl = (struct sockaddr_dl *)rt->rt_gateway;
132 			if (len = sdl->sdl_nlen) {
133 				bcopy(LLADDR(sdl), (char *)edst, len);
134 				goto iso_resolved;
135 			}
136 		}
137 		if ((ret = iso_tryloopback(m, (struct sockaddr_iso *)dst)) >= 0)
138 			return (ret);
139 		ret = iso_snparesolve(ifp, (struct sockaddr_iso *)dst,
140 					(char *)edst, &len);
141 		if (ret > 0) {
142 			m_freem(m); /* Not Resolved */
143 			return(ret);
144 		}
145 	iso_resolved:
146 		M_PREPEND(m, 3, M_DONTWAIT);
147 		if (m == NULL)
148 			return(0);
149 		type = m->m_pkthdr.len;
150 		l = mtod(m, struct llc *);
151 		l->llc_dsap = l->llc_ssap = LLC_ISO_LSAP;
152 		l->llc_control = LLC_UI;
153 		len += 3;
154 		IFDEBUG(D_ETHER)
155 			int i;
156 			printf("unoutput: sending pkt to: ");
157 			for (i=0; i<6; i++)
158 				printf("%x ", edst[i] & 0xff);
159 			printf("\n");
160 		ENDDEBUG
161 		} goto gottype;
162 #endif	ISO
163 	case AF_UNSPEC:
164 		eh = (struct ether_header *)dst->sa_data;
165  		bcopy((caddr_t)eh->ether_dhost, (caddr_t)edst, sizeof (edst));
166 		type = eh->ether_type;
167 		goto gottype;
168 
169 	default:
170 		printf("%s%d: can't handle af%d\n", ifp->if_name, ifp->if_unit,
171 			dst->sa_family);
172 		error = EAFNOSUPPORT;
173 		goto bad;
174 	}
175 
176 gottrailertype:
177 	/*
178 	 * Packet to be sent as trailer: move first packet
179 	 * (control information) to end of chain.
180 	 */
181 	while (m->m_next)
182 		m = m->m_next;
183 	m->m_next = m0;
184 	m = m0->m_next;
185 	m0->m_next = 0;
186 
187 gottype:
188 	/*
189 	 * Add local net header.  If no space in first mbuf,
190 	 * allocate another.
191 	 */
192 	M_PREPEND(m, sizeof (struct ether_header), M_DONTWAIT);
193 	if (m == 0) {
194 		error = ENOBUFS;
195 		goto bad;
196 	}
197 	eh = mtod(m, struct ether_header *);
198 	type = htons((u_short)type);
199 	bcopy((caddr_t)&type,(caddr_t)&eh->ether_type,
200 		sizeof(eh->ether_type));
201  	bcopy((caddr_t)edst, (caddr_t)eh->ether_dhost, sizeof (edst));
202  	bcopy((caddr_t)ac->ac_enaddr, (caddr_t)eh->ether_shost,
203 	    sizeof(eh->ether_shost));
204 	/*
205 	 * Queue message on interface, and start output if interface
206 	 * not yet active.
207 	 */
208 	s = splimp();
209 	if (IF_QFULL(&ifp->if_snd)) {
210 		IF_DROP(&ifp->if_snd);
211 		splx(s);
212 		error = ENOBUFS;
213 		goto bad;
214 	}
215 	IF_ENQUEUE(&ifp->if_snd, m);
216 	if ((ifp->if_flags & IFF_OACTIVE) == 0)
217 		(*ifp->if_start)(ifp);
218 	splx(s);
219 	if (mcopy)
220 		(void) looutput(&loif, mcopy, dst);
221 	ifp->if_obytes += len + sizeof (struct ether_header);
222 	if (edst[0] & 1)
223 		ifp->if_omcasts++;
224 	return (error);
225 
226 bad:
227 	if (mcopy)
228 		m_freem(mcopy);
229 	if (m)
230 		m_freem(m);
231 	return (error);
232 }
233 
234 /*
235  * Process a received Ethernet packet;
236  * the packet is in the mbuf chain m without
237  * the ether header, which is provided separately.
238  */
239 ether_input(ifp, eh, m)
240 	struct ifnet *ifp;
241 	register struct ether_header *eh;
242 	struct mbuf *m;
243 {
244 	register struct ifqueue *inq;
245 	register struct llc *l;
246 	int s;
247 
248 	ifp->if_lastchange = time;
249 	ifp->if_ibytes += m->m_pkthdr.len + sizeof (*eh);
250 	if (bcmp((caddr_t)etherbroadcastaddr, (caddr_t)eh->ether_dhost,
251 	    sizeof(etherbroadcastaddr)) == 0)
252 		m->m_flags |= M_BCAST;
253 	else if (eh->ether_dhost[0] & 1)
254 		m->m_flags |= M_MCAST;
255 	if (m->m_flags & (M_BCAST|M_MCAST))
256 		ifp->if_imcasts++;
257 
258 	switch (eh->ether_type) {
259 #ifdef INET
260 	case ETHERTYPE_IP:
261 		schednetisr(NETISR_IP);
262 		inq = &ipintrq;
263 		break;
264 
265 	case ETHERTYPE_ARP:
266 		arpinput((struct arpcom *)ifp, m);
267 		return;
268 #endif
269 #ifdef NS
270 	case ETHERTYPE_NS:
271 		schednetisr(NETISR_NS);
272 		inq = &nsintrq;
273 		break;
274 
275 #endif
276 	default:
277 #ifdef	ISO
278 		if (eh->ether_type > ETHERMTU)
279 			goto dropanyway;
280 		l = mtod(m, struct llc *);
281 		switch (l->llc_control) {
282 		case LLC_UI:
283 		/* LLC_UI_P forbidden in class 1 service */
284 		    if ((l->llc_dsap == LLC_ISO_LSAP) &&
285 			(l->llc_ssap == LLC_ISO_LSAP)) {
286 				/* LSAP for ISO */
287 			m->m_data += 3;		/* XXX */
288 			m->m_len -= 3;		/* XXX */
289 			m->m_pkthdr.len -= 3;	/* XXX */
290 			M_PREPEND(m, sizeof *eh, M_DONTWAIT);
291 			if (m == 0)
292 				return;
293 			*mtod(m, struct ether_header *) = *eh;
294 			IFDEBUG(D_ETHER)
295 			    printf("clnp packet");
296 			ENDDEBUG
297 			schednetisr(NETISR_ISO);
298 			inq = &clnlintrq;
299 			break;
300 		    }
301 		    goto dropanyway;
302 
303 		case LLC_XID:
304 		case LLC_XID_P:
305 		    if(m->m_len < 6)
306 			goto dropanyway;
307 		    l->llc_window = 0;
308 		    l->llc_fid = 9;
309 		    l->llc_class = 1;
310 		    l->llc_dsap = l->llc_ssap = 0;
311 		    /* Fall through to */
312 		case LLC_TEST:
313 		case LLC_TEST_P:
314 		{
315 		    struct sockaddr sa;
316 		    register struct ether_header *eh2;
317 		    int i;
318 		    u_char c = l->llc_dsap;
319 		    l->llc_dsap = l->llc_ssap;
320 		    l->llc_ssap = c;
321 		    if (m->m_flags & (M_BCAST | M_MCAST))
322 			bcopy((caddr_t)ac->ac_enaddr,
323 			      (caddr_t)eh->ether_dhost, 6);
324 		    sa.sa_family = AF_UNSPEC;
325 		    sa.sa_len = sizeof(sa);
326 		    eh2 = (struct ether_header *)sa.sa_data;
327 		    for (i = 0; i < 6; i++) {
328 			eh2->ether_shost[i] = c = eh->ether_dhost[i];
329 			eh2->ether_dhost[i] =
330 				eh->ether_dhost[i] = eh->ether_shost[i];
331 			eh->ether_shost[i] = c;
332 		    }
333 		    ifp->if_output(ifp, m, &sa);
334 		    return;
335 		}
336 		dropanyway:
337 		default:
338 		    m_freem(m);
339 		    return;
340 	    }
341 #else
342 	    m_freem(m);
343 	    return;
344 #endif	ISO
345 	}
346 
347 	s = splimp();
348 	if (IF_QFULL(inq)) {
349 		IF_DROP(inq);
350 		m_freem(m);
351 	} else
352 		IF_ENQUEUE(inq, m);
353 	splx(s);
354 }
355 
356 /*
357  * Convert Ethernet address to printable (loggable) representation.
358  */
359 static char digits[] = "0123456789abcdef";
360 char *
361 ether_sprintf(ap)
362 	register u_char *ap;
363 {
364 	register i;
365 	static char etherbuf[18];
366 	register char *cp = etherbuf;
367 
368 	for (i = 0; i < 6; i++) {
369 		*cp++ = digits[*ap >> 4];
370 		*cp++ = digits[*ap++ & 0xf];
371 		*cp++ = ':';
372 	}
373 	*--cp = 0;
374 	return (etherbuf);
375 }
376