xref: /csrg-svn/sys/net/if_ethersubr.c (revision 44464)
1 /*
2  * Copyright (c) 1982, 1989 Regents of the University of California.
3  * All rights reserved.
4  *
5  * %sccs.include.redist.c%
6  *
7  *	@(#)if_ethersubr.c	7.10 (Berkeley) 06/28/90
8  */
9 
10 #include "param.h"
11 #include "systm.h"
12 #include "malloc.h"
13 #include "mbuf.h"
14 #include "protosw.h"
15 #include "socket.h"
16 #include "ioctl.h"
17 #include "errno.h"
18 #include "syslog.h"
19 
20 #include "if.h"
21 #include "netisr.h"
22 #include "route.h"
23 #include "if_llc.h"
24 #include "if_dl.h"
25 
26 #include "machine/mtpr.h"
27 
28 #ifdef INET
29 #include "../netinet/in.h"
30 #include "../netinet/in_var.h"
31 #include "../netinet/if_ether.h"
32 #endif
33 
34 #ifdef NS
35 #include "../netns/ns.h"
36 #include "../netns/ns_if.h"
37 #endif
38 
39 #ifdef ISO
40 #include "../netiso/argo_debug.h"
41 #include "../netiso/iso.h"
42 #include "../netiso/iso_var.h"
43 #include "../netiso/iso_snpac.h"
44 #endif
45 
46 u_char	etherbroadcastaddr[6] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
47 extern	struct ifnet loif;
48 
49 /*
50  * Ethernet output routine.
51  * Encapsulate a packet of type family for the local net.
52  * Use trailer local net encapsulation if enough data in first
53  * packet leaves a multiple of 512 bytes of data in remainder.
54  * Assumes that ifp is actually pointer to arpcom structure.
55  */
56 ether_output(ifp, m0, dst, rt)
57 	register struct ifnet *ifp;
58 	struct mbuf *m0;
59 	struct sockaddr *dst;
60 	struct rtentry *rt;
61 {
62 	short type;
63 	int s, error = 0;
64  	u_char edst[6];
65 	struct in_addr idst;
66 	register struct mbuf *m = m0;
67 	struct mbuf *mcopy = (struct mbuf *)0;
68 	register struct ether_header *eh;
69 	int usetrailers, off, len = m->m_pkthdr.len;
70 	extern struct timeval time;
71 #define	ac ((struct arpcom *)ifp)
72 
73 	if ((ifp->if_flags & (IFF_UP|IFF_RUNNING)) != (IFF_UP|IFF_RUNNING)) {
74 		error = ENETDOWN;
75 		goto bad;
76 	}
77 	ifp->if_lastchange = time;
78 	switch (dst->sa_family) {
79 
80 #ifdef INET
81 	case AF_INET:
82 		idst = ((struct sockaddr_in *)dst)->sin_addr;
83  		if (!arpresolve(ac, m, &idst, edst, &usetrailers))
84 			return (0);	/* if not yet resolved */
85 		if ((ifp->if_flags & IFF_SIMPLEX) && (*edst & 1))
86 			mcopy = m_copy(m, 0, (int)M_COPYALL);
87 		off = m->m_pkthdr.len - m->m_len;
88 		if (usetrailers && off > 0 && (off & 0x1ff) == 0 &&
89 		    (m->m_flags & M_EXT) == 0 &&
90 		    m->m_data >= m->m_pktdat + 2 * sizeof (u_short)) {
91 			type = ETHERTYPE_TRAIL + (off>>9);
92 			m->m_data -= 2 * sizeof (u_short);
93 			m->m_len += 2 * sizeof (u_short);
94 			len += 2 * sizeof (u_short);
95 			*mtod(m, u_short *) = htons((u_short)ETHERTYPE_IP);
96 			*(mtod(m, u_short *) + 1) = htons((u_short)m->m_len);
97 			goto gottrailertype;
98 		}
99 		type = ETHERTYPE_IP;
100 		goto gottype;
101 #endif
102 #ifdef NS
103 	case AF_NS:
104 		type = ETHERTYPE_NS;
105  		bcopy((caddr_t)&(((struct sockaddr_ns *)dst)->sns_addr.x_host),
106 		    (caddr_t)edst, sizeof (edst));
107 		if (!bcmp((caddr_t)edst, (caddr_t)&ns_thishost, sizeof(edst)))
108 			return (looutput(&loif, m, dst));
109 		if ((ifp->if_flags & IFF_SIMPLEX) && (*edst & 1))
110 			mcopy = m_copy(m, 0, (int)M_COPYALL);
111 		goto gottype;
112 #endif
113 #ifdef	ISO
114 	case AF_ISO: {
115 		int	snpalen;
116 		struct	llc *l;
117 
118 	iso_again:
119 		iso_etherout();
120 		if (rt && rt->rt_gateway && (rt->rt_flags & RTF_UP)) {
121 			if (rt->rt_flags & RTF_GATEWAY) {
122 				if (rt->rt_llinfo) {
123 					rt = (struct rtentry *)rt->rt_llinfo;
124 					goto iso_again;
125 				}
126 			} else {
127 				register struct sockaddr_dl *sdl =
128 					(struct sockaddr_dl *)rt->rt_gateway;
129 				if (sdl && sdl->sdl_family == AF_LINK
130 				    && sdl->sdl_alen > 0) {
131 					bcopy(LLADDR(sdl), (char *)edst,
132 								sizeof(edst));
133 					goto iso_resolved;
134 				}
135 			}
136 		}
137 		if ((error = iso_snparesolve(ifp, (struct sockaddr_iso *)dst,
138 					(char *)edst, &snpalen)) > 0)
139 			goto bad; /* Not Resolved */
140 	iso_resolved:
141 		M_PREPEND(m, 3, M_DONTWAIT);
142 		if (m == NULL)
143 			return (0);
144 		type = m->m_pkthdr.len;
145 		l = mtod(m, struct llc *);
146 		l->llc_dsap = l->llc_ssap = LLC_ISO_LSAP;
147 		l->llc_control = LLC_UI;
148 		len += 3;
149 		IFDEBUG(D_ETHER)
150 			int i;
151 			printf("unoutput: sending pkt to: ");
152 			for (i=0; i<6; i++)
153 				printf("%x ", edst[i] & 0xff);
154 			printf("\n");
155 		ENDDEBUG
156 		} goto gottype;
157 #endif	ISO
158 #ifdef RMP
159 	case AF_RMP:
160 		/*
161 		 *  This is IEEE 802.3 -- the Ethernet `type' field is
162 		 *  really a `length' field.
163 		 */
164 		type = m->m_len;
165  		bcopy((caddr_t)dst->sa_data, (caddr_t)edst, sizeof(edst));
166 		break;
167 #endif
168 
169 	case AF_UNSPEC:
170 		eh = (struct ether_header *)dst->sa_data;
171  		bcopy((caddr_t)eh->ether_dhost, (caddr_t)edst, sizeof (edst));
172 		type = eh->ether_type;
173 		goto gottype;
174 
175 	default:
176 		printf("%s%d: can't handle af%d\n", ifp->if_name, ifp->if_unit,
177 			dst->sa_family);
178 		error = EAFNOSUPPORT;
179 		goto bad;
180 	}
181 
182 gottrailertype:
183 	/*
184 	 * Packet to be sent as trailer: move first packet
185 	 * (control information) to end of chain.
186 	 */
187 	while (m->m_next)
188 		m = m->m_next;
189 	m->m_next = m0;
190 	m = m0->m_next;
191 	m0->m_next = 0;
192 
193 gottype:
194 	/*
195 	 * Add local net header.  If no space in first mbuf,
196 	 * allocate another.
197 	 */
198 	M_PREPEND(m, sizeof (struct ether_header), M_DONTWAIT);
199 	if (m == 0) {
200 		error = ENOBUFS;
201 		goto bad;
202 	}
203 	eh = mtod(m, struct ether_header *);
204 	type = htons((u_short)type);
205 	bcopy((caddr_t)&type,(caddr_t)&eh->ether_type,
206 		sizeof(eh->ether_type));
207  	bcopy((caddr_t)edst, (caddr_t)eh->ether_dhost, sizeof (edst));
208  	bcopy((caddr_t)ac->ac_enaddr, (caddr_t)eh->ether_shost,
209 	    sizeof(eh->ether_shost));
210 	/*
211 	 * Queue message on interface, and start output if interface
212 	 * not yet active.
213 	 */
214 	s = splimp();
215 	if (IF_QFULL(&ifp->if_snd)) {
216 		IF_DROP(&ifp->if_snd);
217 		splx(s);
218 		error = ENOBUFS;
219 		goto bad;
220 	}
221 	IF_ENQUEUE(&ifp->if_snd, m);
222 	if ((ifp->if_flags & IFF_OACTIVE) == 0)
223 		(*ifp->if_start)(ifp);
224 	splx(s);
225 	if (mcopy)
226 		(void) looutput(&loif, mcopy, dst);
227 	ifp->if_obytes += len + sizeof (struct ether_header);
228 	if (edst[0] & 1)
229 		ifp->if_omcasts++;
230 	return (error);
231 
232 bad:
233 	if (mcopy)
234 		m_freem(mcopy);
235 	if (m)
236 		m_freem(m);
237 	return (error);
238 }
239 
240 /*
241  * Process a received Ethernet packet;
242  * the packet is in the mbuf chain m without
243  * the ether header, which is provided separately.
244  */
245 ether_input(ifp, eh, m)
246 	struct ifnet *ifp;
247 	register struct ether_header *eh;
248 	struct mbuf *m;
249 {
250 	register struct ifqueue *inq;
251 	register struct llc *l;
252 	int s;
253 
254 	ifp->if_lastchange = time;
255 	ifp->if_ibytes += m->m_pkthdr.len + sizeof (*eh);
256 	if (bcmp((caddr_t)etherbroadcastaddr, (caddr_t)eh->ether_dhost,
257 	    sizeof(etherbroadcastaddr)) == 0)
258 		m->m_flags |= M_BCAST;
259 	else if (eh->ether_dhost[0] & 1)
260 		m->m_flags |= M_MCAST;
261 	if (m->m_flags & (M_BCAST|M_MCAST))
262 		ifp->if_imcasts++;
263 
264 	switch (eh->ether_type) {
265 #ifdef INET
266 	case ETHERTYPE_IP:
267 		schednetisr(NETISR_IP);
268 		inq = &ipintrq;
269 		break;
270 
271 	case ETHERTYPE_ARP:
272 		arpinput((struct arpcom *)ifp, m);
273 		return;
274 #endif
275 #ifdef NS
276 	case ETHERTYPE_NS:
277 		schednetisr(NETISR_NS);
278 		inq = &nsintrq;
279 		break;
280 
281 #endif
282 	default:
283 #ifdef	ISO
284 		if (eh->ether_type > ETHERMTU)
285 			goto dropanyway;
286 		l = mtod(m, struct llc *);
287 		switch (l->llc_control) {
288 		case LLC_UI:
289 		/* LLC_UI_P forbidden in class 1 service */
290 		    if ((l->llc_dsap == LLC_ISO_LSAP) &&
291 			(l->llc_ssap == LLC_ISO_LSAP)) {
292 				/* LSAP for ISO */
293 			m->m_data += 3;		/* XXX */
294 			m->m_len -= 3;		/* XXX */
295 			m->m_pkthdr.len -= 3;	/* XXX */
296 			M_PREPEND(m, sizeof *eh, M_DONTWAIT);
297 			if (m == 0)
298 				return;
299 			*mtod(m, struct ether_header *) = *eh;
300 			IFDEBUG(D_ETHER)
301 			    printf("clnp packet");
302 			ENDDEBUG
303 			schednetisr(NETISR_ISO);
304 			inq = &clnlintrq;
305 			break;
306 		    }
307 		    goto dropanyway;
308 
309 		case LLC_XID:
310 		case LLC_XID_P:
311 		    if(m->m_len < 6)
312 			goto dropanyway;
313 		    l->llc_window = 0;
314 		    l->llc_fid = 9;
315 		    l->llc_class = 1;
316 		    l->llc_dsap = l->llc_ssap = 0;
317 		    /* Fall through to */
318 		case LLC_TEST:
319 		case LLC_TEST_P:
320 		{
321 		    struct sockaddr sa;
322 		    register struct ether_header *eh2;
323 		    int i;
324 		    u_char c = l->llc_dsap;
325 		    l->llc_dsap = l->llc_ssap;
326 		    l->llc_ssap = c;
327 		    if (m->m_flags & (M_BCAST | M_MCAST))
328 			bcopy((caddr_t)ac->ac_enaddr,
329 			      (caddr_t)eh->ether_dhost, 6);
330 		    sa.sa_family = AF_UNSPEC;
331 		    sa.sa_len = sizeof(sa);
332 		    eh2 = (struct ether_header *)sa.sa_data;
333 		    for (i = 0; i < 6; i++) {
334 			eh2->ether_shost[i] = c = eh->ether_dhost[i];
335 			eh2->ether_dhost[i] =
336 				eh->ether_dhost[i] = eh->ether_shost[i];
337 			eh->ether_shost[i] = c;
338 		    }
339 		    ifp->if_output(ifp, m, &sa);
340 		    return;
341 		}
342 		dropanyway:
343 		default:
344 		    m_freem(m);
345 		    return;
346 	    }
347 #else
348 	    m_freem(m);
349 	    return;
350 #endif	ISO
351 	}
352 
353 	s = splimp();
354 	if (IF_QFULL(inq)) {
355 		IF_DROP(inq);
356 		m_freem(m);
357 	} else
358 		IF_ENQUEUE(inq, m);
359 	splx(s);
360 }
361 
362 /*
363  * Convert Ethernet address to printable (loggable) representation.
364  */
365 static char digits[] = "0123456789abcdef";
366 char *
367 ether_sprintf(ap)
368 	register u_char *ap;
369 {
370 	register i;
371 	static char etherbuf[18];
372 	register char *cp = etherbuf;
373 
374 	for (i = 0; i < 6; i++) {
375 		*cp++ = digits[*ap >> 4];
376 		*cp++ = digits[*ap++ & 0xf];
377 		*cp++ = ':';
378 	}
379 	*--cp = 0;
380 	return (etherbuf);
381 }
382 iso_etherout() {}
383