xref: /netbsd-src/sys/net/if_loop.c (revision d9158b13b5dfe46201430699a3f7a235ecf28df3)
1 /*
2  * Copyright (c) 1982, 1986, 1993
3  *	The Regents of the University of California.  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  *	from: @(#)if_loop.c	8.1 (Berkeley) 6/10/93
34  *	$Id: if_loop.c,v 1.11 1994/05/13 06:02:44 mycroft Exp $
35  */
36 
37 /*
38  * Loopback interface driver for protocol testing and timing.
39  */
40 
41 #include "bpfilter.h"
42 #include "loop.h"
43 
44 #include <sys/param.h>
45 #include <sys/systm.h>
46 #include <sys/kernel.h>
47 #include <sys/mbuf.h>
48 #include <sys/socket.h>
49 #include <sys/errno.h>
50 #include <sys/ioctl.h>
51 #include <sys/time.h>
52 
53 #include <machine/cpu.h>
54 
55 #include <net/if.h>
56 #include <net/if_types.h>
57 #include <net/netisr.h>
58 #include <net/route.h>
59 
60 #ifdef	INET
61 #include <netinet/in.h>
62 #include <netinet/in_systm.h>
63 #include <netinet/in_var.h>
64 #include <netinet/ip.h>
65 #endif
66 
67 #ifdef NS
68 #include <netns/ns.h>
69 #include <netns/ns_if.h>
70 #endif
71 
72 #ifdef ISO
73 #include <netiso/iso.h>
74 #include <netiso/iso_var.h>
75 #endif
76 
77 #if NBPFILTER > 0
78 #include <net/bpf.h>
79 #endif
80 
81 #define	LOMTU	(32768)
82 
83 struct	ifnet loif[NLOOP];
84 
85 void
86 loopattach(n)
87 	int n;
88 {
89 	register int i;
90 	register struct ifnet *ifp;
91 
92 	for (i = 0; i < NLOOP; i++) {
93 		ifp = &loif[i];
94 		ifp->if_unit = i;
95 		ifp->if_name = "lo";
96 		ifp->if_mtu = LOMTU;
97 		ifp->if_flags = IFF_LOOPBACK | IFF_MULTICAST;
98 		ifp->if_ioctl = loioctl;
99 		ifp->if_output = looutput;
100 		ifp->if_type = IFT_LOOP;
101 		ifp->if_hdrlen = 0;
102 		ifp->if_addrlen = 0;
103 		if_attach(ifp);
104 #if NBPFILTER > 0
105 		bpfattach(&ifp->if_bpf, ifp, DLT_NULL, sizeof(u_int));
106 #endif
107 	}
108 }
109 
110 int
111 looutput(ifp, m, dst, rt)
112 	struct ifnet *ifp;
113 	register struct mbuf *m;
114 	struct sockaddr *dst;
115 	register struct rtentry *rt;
116 {
117 	int s, isr;
118 	register struct ifqueue *ifq = 0;
119 
120 	if ((m->m_flags & M_PKTHDR) == 0)
121 		panic("looutput no HDR");
122 	ifp->if_lastchange = time;
123 #if NBPFILTER > 0
124 	if (ifp->if_bpf) {
125 		/*
126 		 * We need to prepend the address family as
127 		 * a four byte field.  Cons up a dummy header
128 		 * to pacify bpf.  This is safe because bpf
129 		 * will only read from the mbuf (i.e., it won't
130 		 * try to free it or keep a pointer to it).
131 		 */
132 		struct mbuf m0;
133 		u_int af = dst->sa_family;
134 
135 		m0.m_next = m;
136 		m0.m_len = 4;
137 		m0.m_data = (char *)&af;
138 
139 		bpf_mtap(ifp->if_bpf, &m0);
140 	}
141 #endif
142 	m->m_pkthdr.rcvif = ifp;
143 
144 	if (rt && rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) {
145 		m_freem(m);
146 		return (rt->rt_flags & RTF_BLACKHOLE ? 0 :
147 			rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH);
148 	}
149 	ifp->if_opackets++;
150 	ifp->if_obytes += m->m_pkthdr.len;
151 	switch (dst->sa_family) {
152 
153 #ifdef INET
154 	case AF_INET:
155 		ifq = &ipintrq;
156 		isr = NETISR_IP;
157 		break;
158 #endif
159 #ifdef NS
160 	case AF_NS:
161 		ifq = &nsintrq;
162 		isr = NETISR_NS;
163 		break;
164 #endif
165 #ifdef ISO
166 	case AF_ISO:
167 		ifq = &clnlintrq;
168 		isr = NETISR_ISO;
169 		break;
170 #endif
171 	default:
172 		printf("lo%d: can't handle af%d\n", ifp->if_unit,
173 			dst->sa_family);
174 		m_freem(m);
175 		return (EAFNOSUPPORT);
176 	}
177 	s = splimp();
178 	if (IF_QFULL(ifq)) {
179 		IF_DROP(ifq);
180 		m_freem(m);
181 		splx(s);
182 		return (ENOBUFS);
183 	}
184 	IF_ENQUEUE(ifq, m);
185 	schednetisr(isr);
186 	ifp->if_ipackets++;
187 	ifp->if_ibytes += m->m_pkthdr.len;
188 	splx(s);
189 	return (0);
190 }
191 
192 /* ARGSUSED */
193 void
194 lortrequest(cmd, rt, sa)
195 	int cmd;
196 	struct rtentry *rt;
197 	struct sockaddr *sa;
198 {
199 
200 	if (rt)
201 		rt->rt_rmx.rmx_mtu = LOMTU;
202 }
203 
204 /*
205  * Process an ioctl request.
206  */
207 /* ARGSUSED */
208 int
209 loioctl(ifp, cmd, data)
210 	register struct ifnet *ifp;
211 	int cmd;
212 	caddr_t data;
213 {
214 	register struct ifaddr *ifa;
215 	register struct ifreq *ifr;
216 	register int error = 0;
217 
218 	switch (cmd) {
219 
220 	case SIOCSIFADDR:
221 		ifp->if_flags |= IFF_UP;
222 		ifa = (struct ifaddr *)data;
223 		if (ifa != 0 && ifa->ifa_addr->sa_family == AF_ISO)
224 			ifa->ifa_rtrequest = lortrequest;
225 		/*
226 		 * Everything else is done at a higher level.
227 		 */
228 		break;
229 
230 	case SIOCADDMULTI:
231 	case SIOCDELMULTI:
232 		ifr = (struct ifreq *)data;
233 		if (ifr == 0) {
234 			error = EAFNOSUPPORT;		/* XXX */
235 			break;
236 		}
237 		switch (ifr->ifr_addr.sa_family) {
238 
239 #ifdef INET
240 		case AF_INET:
241 			break;
242 #endif
243 
244 		default:
245 			error = EAFNOSUPPORT;
246 			break;
247 		}
248 		break;
249 
250 	default:
251 		error = EINVAL;
252 	}
253 	return (error);
254 }
255