xref: /original-bsd/sys/net/if_ethersubr.c (revision 549425d7)
1 /*
2  * Copyright (c) 1982, 1986, 1988 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	7.3 (Berkeley) 04/25/89
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 
35 #include "machine/mtpr.h"
36 
37 #ifdef INET
38 #include "../netinet/in.h"
39 #include "../netinet/in_var.h"
40 #include "../netinet/if_ether.h"
41 #endif
42 
43 #ifdef NS
44 #include "../netns/ns.h"
45 #include "../netns/ns_if.h"
46 #endif
47 
48 #ifdef ISO
49 #include "../netiso/argo_debug.h"
50 #include "../netiso/iso.h"
51 #include "../netiso/iso_var.h"
52 #endif
53 
54 u_char	etherbroadcastaddr[6] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
55 extern	struct ifnet loif;
56 
57 /*
58  * Ethernet output routine.
59  * Encapsulate a packet of type family for the local net.
60  * Use trailer local net encapsulation if enough data in first
61  * packet leaves a multiple of 512 bytes of data in remainder.
62  * Assumes that ifp is actually pointer to arpcom structure.
63  */
64 ether_output(ifp, m0, dst)
65 	register struct ifnet *ifp;
66 	struct mbuf *m0;
67 	struct sockaddr *dst;
68 {
69 	short type;
70 	int s, error = 0;
71  	u_char edst[6];
72 	struct in_addr idst;
73 	register struct mbuf *m = m0;
74 	struct mbuf *mcopy = (struct mbuf *)0;
75 	register struct ether_header *eh;
76 	int usetrailers, off;
77 #define	ac ((struct arpcom *)ifp)
78 
79 	if ((ifp->if_flags & (IFF_UP|IFF_RUNNING)) != (IFF_UP|IFF_RUNNING)) {
80 		error = ENETDOWN;
81 		goto bad;
82 	}
83 	if (ifp->if_flags & IFF_SIMPLEX && dst->sa_family != AF_UNSPEC &&
84 	    !bcmp((caddr_t)edst, (caddr_t)etherbroadcastaddr, sizeof (edst)))
85 		mcopy = m_copy(m, 0, (int)M_COPYALL);
86 	switch (dst->sa_family) {
87 
88 #ifdef INET
89 	case AF_INET:
90 		idst = ((struct sockaddr_in *)dst)->sin_addr;
91  		if (!arpresolve(ac, m, &idst, edst, &usetrailers))
92 			return (0);	/* if not yet resolved */
93 		if ((ifp->if_flags & IFF_SIMPLEX) && (*edst & 1))
94 		    mcopy = m_copy(m, 0, (int)M_COPYALL);
95 		off = m->m_pkthdr.len - m->m_len;
96 		if (usetrailers && off > 0 && (off & 0x1ff) == 0 &&
97 		    (m->m_flags & M_EXT) == 0 &&
98 		    m->m_data >= m->m_pktdat + 2 * sizeof (u_short)) {
99 			type = ETHERTYPE_TRAIL + (off>>9);
100 			m->m_data -= 2 * sizeof (u_short);
101 			m->m_len += 2 * sizeof (u_short);
102 			*mtod(m, u_short *) = htons((u_short)ETHERTYPE_IP);
103 			*(mtod(m, u_short *) + 1) = htons((u_short)m->m_len);
104 			goto gottrailertype;
105 		}
106 		type = ETHERTYPE_IP;
107 		goto gottype;
108 #endif
109 #ifdef NS
110 	case AF_NS:
111 		type = ETHERTYPE_NS;
112 		if (!bcmp((caddr_t)edst, (caddr_t)&ns_thishost, sizeof(edst)))
113 			return(looutput(&loif, m, dst));
114  		bcopy((caddr_t)&(((struct sockaddr_ns *)dst)->sns_addr.x_host),
115 		    (caddr_t)edst, sizeof (edst));
116 		if ((ifp->if_flags & IFF_SIMPLEX) && (*edst & 1))
117 		    mcopy = m_copy(m, 0, (int)M_COPYALL);
118 		goto gottype;
119 #endif
120 #ifdef	ISO
121 	case AF_ISO: {
122 		int	len;
123 		int	ret;
124 		struct	llc *l;
125 
126 		if ((ret = iso_tryloopback(m, (struct sockaddr_iso *)dst)) >= 0)
127 			return (ret);
128 		ret = iso_snparesolve(ifp, (struct sockaddr_iso *)dst,
129 					(char *)edst, &len);
130 		if (ret > 0) {
131 			m_freem(m); /* Not Resolved */
132 			return(ret);
133 		}
134 		M_PREPEND(m, 3, M_DONTWAIT);
135 		if (m == NULL)
136 			return(0);
137 		type = m->m_pkthdr.len;
138 		l = mtod(m, struct llc *);
139 		l->llc_dsap = l->llc_ssap = LLC_ISO_LSAP;
140 		l->llc_control = LLC_UI;
141 		IFDEBUG(D_ETHER)
142 			int i;
143 			printf("unoutput: sending pkt to: ");
144 			for (i=0; i<6; i++)
145 				printf("%x ", edst[i] & 0xff);
146 			printf("\n");
147 		ENDDEBUG
148 		} goto gottype;
149 #endif	ISO
150 	case AF_UNSPEC:
151 		eh = (struct ether_header *)dst->sa_data;
152  		bcopy((caddr_t)eh->ether_dhost, (caddr_t)edst, sizeof (edst));
153 		type = eh->ether_type;
154 		goto gottype;
155 
156 	default:
157 		printf("%s%d: can't handle af%d\n", ifp->if_name, ifp->if_unit,
158 			dst->sa_family);
159 		error = EAFNOSUPPORT;
160 		goto bad;
161 	}
162 
163 gottrailertype:
164 	/*
165 	 * Packet to be sent as trailer: move first packet
166 	 * (control information) to end of chain.
167 	 */
168 	while (m->m_next)
169 		m = m->m_next;
170 	m->m_next = m0;
171 	m = m0->m_next;
172 	m0->m_next = 0;
173 
174 gottype:
175 	/*
176 	 * Add local net header.  If no space in first mbuf,
177 	 * allocate another.
178 	 */
179 	M_PREPEND(m, sizeof (struct ether_header), M_DONTWAIT);
180 	if (m == 0) {
181 		error = ENOBUFS;
182 		goto bad;
183 	}
184 	eh = mtod(m, struct ether_header *);
185 	type = htons((u_short)type);
186 	bcopy((caddr_t)&type,(caddr_t)&eh->ether_type,
187 		sizeof(eh->ether_type));
188  	bcopy((caddr_t)edst, (caddr_t)eh->ether_dhost, sizeof (edst));
189  	bcopy((caddr_t)ac->ac_enaddr, (caddr_t)eh->ether_shost,
190 	    sizeof(eh->ether_shost));
191 	/*
192 	 * Queue message on interface, and start output if interface
193 	 * not yet active.
194 	 */
195 	s = splimp();
196 	if (IF_QFULL(&ifp->if_snd)) {
197 		IF_DROP(&ifp->if_snd);
198 		splx(s);
199 		error = ENOBUFS;
200 		goto bad;
201 	}
202 	IF_ENQUEUE(&ifp->if_snd, m);
203 	if ((ifp->if_flags & IFF_OACTIVE) == 0)
204 		error = (*ifp->if_start)(ifp);
205 	splx(s);
206 	if (mcopy)
207 		(void) looutput(&loif, mcopy, dst);
208 	return (error);
209 
210 bad:
211 	if (mcopy)
212 		m_freem(mcopy);
213 	if (m)
214 		m_freem(m);
215 	return (error);
216 }
217 
218 /*
219  * Pull packet off interface.  Off is nonzero if packet
220  * has trailing header; we still have to drop
221  * the type and length which are at the front of any trailer data.
222  */
223 ether_input(ifp, eh, m)
224 	struct ifnet *ifp;
225 	register struct ether_header *eh;
226 	struct mbuf *m;
227 {
228 	register struct ifqueue *inq;
229 	register struct llc *l;
230 	int s;
231 
232 	if (bcmp((caddr_t)etherbroadcastaddr, (caddr_t)eh->ether_dhost,
233 	    sizeof(etherbroadcastaddr)) == 0)
234 		m->m_flags |= M_BCAST;
235 	else if (eh->ether_dhost[0] & 1)
236 		m->m_flags |= M_MCAST;
237 
238 	switch (eh->ether_type) {
239 #ifdef INET
240 	case ETHERTYPE_IP:
241 		schednetisr(NETISR_IP);
242 		inq = &ipintrq;
243 		break;
244 
245 	case ETHERTYPE_ARP:
246 		arpinput((struct arpcom *)ifp, m);
247 		return;
248 #endif
249 #ifdef NS
250 	case ETHERTYPE_NS:
251 		schednetisr(NETISR_NS);
252 		inq = &nsintrq;
253 		break;
254 
255 #endif
256 	default:
257 		if (eh->ether_type > ETHERMTU)
258 			goto dropanyway;
259 		l = mtod(m, struct llc *);
260 		switch (l->llc_control) {
261 		case LLC_UI:
262 		/* LLC_UI_P forbidden in class 1 service */
263 		    if ((l->llc_dsap == LLC_ISO_LSAP) &&
264 			(l->llc_ssap == LLC_ISO_LSAP)) {
265 #ifdef	ISO
266 				/* LSAP for ISO */
267 			M_PREPEND(m, sizeof *eh, M_DONTWAIT);
268 			if (m == 0)
269 				return;
270 			*mtod(m, struct ether_header *) = *eh;
271 			IFDEBUG(D_ETHER)
272 			    printf("clnp packet");
273 			ENDDEBUG
274 			schednetisr(NETISR_ISO);
275 			inq = &clnlintrq;
276 			if (IF_QFULL(inq)){
277 				IFDEBUG(D_ETHER)
278 				    printf(" qfull\n");
279 				ENDDEBUG
280 				IF_DROP(inq);
281 				m_freem(m);
282 			} else {
283 				IF_ENQUEUE(inq, m);
284 				IFDEBUG(D_ETHER)
285 				    printf(" queued\n");
286 				ENDDEBUG
287 			}
288 			return;
289 #endif	ISO
290 		    }
291 		    break;
292 		case LLC_XID:
293 		case LLC_XID_P:
294 		    if(m->m_len < 6)
295 			goto dropanyway;
296 		    l->llc_window = 0;
297 		    l->llc_fid = 9;
298 		    l->llc_class = 1;
299 		    l->llc_dsap = l->llc_ssap = 0;
300 		    /* Fall through to */
301 		case LLC_TEST:
302 		case LLC_TEST_P:
303 		{
304 		    struct sockaddr sa;
305 		    register struct ether_header *eh2;
306 		    int i;
307 		    u_char c = l->llc_dsap;
308 		    l->llc_dsap = l->llc_ssap;
309 		    l->llc_ssap = c;
310 		    if (m->m_flags & (M_BCAST | M_MCAST))
311 			bcopy((caddr_t)ac->ac_enaddr,
312 			      (caddr_t)eh->ether_dhost, 6);
313 		    sa.sa_family = AF_UNSPEC;
314 		    sa.sa_len = sizeof(sa);
315 		    eh2 = (struct ether_header *)sa.sa_data;
316 		    for (i = 0; i < 6; i++) {
317 			eh2->ether_shost[i] = c = eh->ether_dhost[i];
318 			eh2->ether_dhost[i] =
319 				eh->ether_dhost[i] = eh->ether_shost[i];
320 			eh->ether_shost[i] = c;
321 		    }
322 		    ifp->if_output(ifp, m, &sa);
323 		    return;
324 		}
325 		dropanyway:
326 		default:
327 		    m_freem(m);
328 		    return;
329 	    }
330 	}
331 
332 	s = splimp();
333 	if (IF_QFULL(inq)) {
334 		IF_DROP(inq);
335 		m_freem(m);
336 	} else
337 		IF_ENQUEUE(inq, m);
338 	splx(s);
339 }
340 
341 /*
342  * Convert Ethernet address to printable (loggable) representation.
343  */
344 static char digits[] = "0123456789abcdef";
345 char *
346 ether_sprintf(ap)
347 	register u_char *ap;
348 {
349 	register i;
350 	static char etherbuf[18];
351 	register char *cp = etherbuf;
352 
353 	for (i = 0; i < 6; i++) {
354 		*cp++ = digits[*ap >> 4];
355 		*cp++ = digits[*ap++ & 0xf];
356 		*cp++ = ':';
357 	}
358 	*--cp = 0;
359 	return (etherbuf);
360 }
361