xref: /netbsd-src/sys/net/if_loop.c (revision 448e711c7835101c94f75b7ebddf58046df58290)
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 1.7 1993/11/23 08:16:55 deraadt 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 void
88 loopattach()
89 {
90 	register int i;
91 	register struct ifnet *ifp;
92 
93 	for (i = 0; i < NLOOP; i++)
94 	{
95 		ifp = &loif[i];
96 		ifp->if_unit = i;
97 		ifp->if_name = "lo";
98 		ifp->if_mtu = LOMTU;
99 		ifp->if_flags = IFF_LOOPBACK;
100 		ifp->if_ioctl = loioctl;
101 		ifp->if_output = looutput;
102 		ifp->if_type = IFT_LOOP;
103 		ifp->if_hdrlen = 0;
104 		ifp->if_addrlen = 0;
105 		if_attach(ifp);
106 #if NBPFILTER > 0
107 		bpfattach(&lo_bpf, ifp, DLT_NULL, sizeof(u_int));
108 #endif
109 	}
110 }
111 
112 looutput(ifp, m, dst, rt)
113 	struct ifnet *ifp;
114 	register struct mbuf *m;
115 	struct sockaddr *dst;
116 	register struct rtentry *rt;
117 {
118 	int s, isr;
119 	register struct ifqueue *ifq = 0;
120 
121 	if ((m->m_flags & M_PKTHDR) == 0)
122 		panic("looutput no HDR");
123 #if NBPFILTER > 0
124 	if (lo_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(lo_bpf, &m0);
140 	}
141 #endif
142 	m->m_pkthdr.rcvif = ifp;
143 
144 	if (rt && rt->rt_flags & RTF_REJECT) {
145 		m_freem(m);
146 		return (rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH);
147 	}
148 	ifp->if_opackets++;
149 	ifp->if_obytes += m->m_pkthdr.len;
150 	switch (dst->sa_family) {
151 
152 #ifdef INET
153 	case AF_INET:
154 		ifq = &ipintrq;
155 		isr = NETISR_IP;
156 		break;
157 #endif
158 #ifdef NS
159 	case AF_NS:
160 		ifq = &nsintrq;
161 		isr = NETISR_NS;
162 		break;
163 #endif
164 #ifdef ISO
165 	case AF_ISO:
166 		ifq = &clnlintrq;
167 		isr = NETISR_ISO;
168 		break;
169 #endif
170 	default:
171 		printf("lo%d: can't handle af%d\n", ifp->if_unit,
172 			dst->sa_family);
173 		m_freem(m);
174 		return (EAFNOSUPPORT);
175 	}
176 	s = splimp();
177 	if (IF_QFULL(ifq)) {
178 		IF_DROP(ifq);
179 		m_freem(m);
180 		splx(s);
181 		return (ENOBUFS);
182 	}
183 	IF_ENQUEUE(ifq, m);
184 	schednetisr(isr);
185 	ifp->if_ipackets++;
186 	ifp->if_ibytes += m->m_pkthdr.len;
187 	splx(s);
188 	return (0);
189 }
190 
191 /* ARGSUSED */
192 lortrequest(cmd, rt, sa)
193 struct rtentry *rt;
194 struct sockaddr *sa;
195 {
196 	if (rt)
197 		rt->rt_rmx.rmx_mtu = LOMTU;
198 }
199 
200 /*
201  * Process an ioctl request.
202  */
203 /* ARGSUSED */
204 loioctl(ifp, cmd, data)
205 	register struct ifnet *ifp;
206 	int cmd;
207 	caddr_t data;
208 {
209 	register struct ifaddr *ifa;
210 	int error = 0;
211 
212 	switch (cmd) {
213 
214 	case SIOCSIFADDR:
215 		ifp->if_flags |= IFF_UP;
216 		ifa = (struct ifaddr *)data;
217 		if (ifa != 0 && ifa->ifa_addr->sa_family == AF_ISO)
218 			ifa->ifa_rtrequest = lortrequest;
219 		/*
220 		 * Everything else is done at a higher level.
221 		 */
222 		break;
223 
224 	default:
225 		error = EINVAL;
226 	}
227 	return (error);
228 }
229