xref: /netbsd-src/sys/net/if_loop.c (revision ce63d6c20fc4ec8ddc95c84bb229e3c4ecf82b69)
1 /*
2  * Copyright (c) 1982, 1986 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  *	from: @(#)if_loop.c	7.13 (Berkeley) 4/26/91
34  *	$Id: if_loop.c,v 1.5 1993/05/20 03:06:02 cgd Exp $
35  */
36 
37 /*
38  * Loopback interface driver for protocol testing and timing.
39  */
40 
41 #include "param.h"
42 #include "systm.h"
43 #include "mbuf.h"
44 #include "socket.h"
45 #include "errno.h"
46 #include "ioctl.h"
47 #include "protosw.h"
48 
49 #include "loop.h"
50 
51 #include "../net/if.h"
52 #include "../net/if_types.h"
53 #include "../net/netisr.h"
54 #include "../net/route.h"
55 
56 #include "machine/mtpr.h"
57 
58 #ifdef	INET
59 #include "../netinet/in.h"
60 #include "../netinet/in_systm.h"
61 #include "../netinet/in_var.h"
62 #include "../netinet/ip.h"
63 #endif
64 
65 #ifdef NS
66 #include "../netns/ns.h"
67 #include "../netns/ns_if.h"
68 #endif
69 
70 #ifdef ISO
71 #include "../netiso/iso.h"
72 #include "../netiso/iso_var.h"
73 #endif
74 
75 #include "bpfilter.h"
76 #if NBPFILTER > 0
77 #include <sys/time.h>
78 #include <net/bpf.h>
79 static caddr_t lo_bpf;
80 #endif
81 
82 #define	LOMTU	(1024+512)
83 
84 struct	ifnet loif[NLOOP];
85 int	looutput(), loioctl();
86 
87 loattach()
88 {
89 	register int i;
90 	register struct ifnet *ifp;
91 
92 	for (i = 0; i < NLOOP; i++)
93 	{
94 		ifp = &loif[i];
95 		ifp->if_unit = i;
96 		ifp->if_name = "lo";
97 		ifp->if_mtu = LOMTU;
98 		ifp->if_flags = IFF_LOOPBACK;
99 		ifp->if_ioctl = loioctl;
100 		ifp->if_output = looutput;
101 		ifp->if_type = IFT_LOOP;
102 		ifp->if_hdrlen = 0;
103 		ifp->if_addrlen = 0;
104 		if_attach(ifp);
105 #if NBPFILTER > 0
106 		bpfattach(&lo_bpf, ifp, DLT_NULL, sizeof(u_int));
107 #endif
108 	}
109 }
110 
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 #if NBPFILTER > 0
123 	if (lo_bpf) {
124 		/*
125 		 * We need to prepend the address family as
126 		 * a four byte field.  Cons up a dummy header
127 		 * to pacify bpf.  This is safe because bpf
128 		 * will only read from the mbuf (i.e., it won't
129 		 * try to free it or keep a pointer to it).
130 		 */
131 		struct mbuf m0;
132 		u_int af = dst->sa_family;
133 
134 		m0.m_next = m;
135 		m0.m_len = 4;
136 		m0.m_data = (char *)&af;
137 
138 		bpf_mtap(lo_bpf, &m0);
139 	}
140 #endif
141 	m->m_pkthdr.rcvif = ifp;
142 
143 	if (rt && rt->rt_flags & RTF_REJECT) {
144 		m_freem(m);
145 		return (rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH);
146 	}
147 	ifp->if_opackets++;
148 	ifp->if_obytes += m->m_pkthdr.len;
149 	switch (dst->sa_family) {
150 
151 #ifdef INET
152 	case AF_INET:
153 		ifq = &ipintrq;
154 		isr = NETISR_IP;
155 		break;
156 #endif
157 #ifdef NS
158 	case AF_NS:
159 		ifq = &nsintrq;
160 		isr = NETISR_NS;
161 		break;
162 #endif
163 #ifdef ISO
164 	case AF_ISO:
165 		ifq = &clnlintrq;
166 		isr = NETISR_ISO;
167 		break;
168 #endif
169 	default:
170 		printf("lo%d: can't handle af%d\n", ifp->if_unit,
171 			dst->sa_family);
172 		m_freem(m);
173 		return (EAFNOSUPPORT);
174 	}
175 	s = splimp();
176 	if (IF_QFULL(ifq)) {
177 		IF_DROP(ifq);
178 		m_freem(m);
179 		splx(s);
180 		return (ENOBUFS);
181 	}
182 	IF_ENQUEUE(ifq, m);
183 	schednetisr(isr);
184 	ifp->if_ipackets++;
185 	ifp->if_ibytes += m->m_pkthdr.len;
186 	splx(s);
187 	return (0);
188 }
189 
190 /* ARGSUSED */
191 lortrequest(cmd, rt, sa)
192 struct rtentry *rt;
193 struct sockaddr *sa;
194 {
195 	if (rt)
196 		rt->rt_rmx.rmx_mtu = LOMTU;
197 }
198 
199 /*
200  * Process an ioctl request.
201  */
202 /* ARGSUSED */
203 loioctl(ifp, cmd, data)
204 	register struct ifnet *ifp;
205 	int cmd;
206 	caddr_t data;
207 {
208 	register struct ifaddr *ifa;
209 	int error = 0;
210 
211 	switch (cmd) {
212 
213 	case SIOCSIFADDR:
214 		ifp->if_flags |= IFF_UP;
215 		ifa = (struct ifaddr *)data;
216 		if (ifa != 0 && ifa->ifa_addr->sa_family == AF_ISO)
217 			ifa->ifa_rtrequest = lortrequest;
218 		/*
219 		 * Everything else is done at a higher level.
220 		 */
221 		break;
222 
223 	default:
224 		error = EINVAL;
225 	}
226 	return (error);
227 }
228