2 * Copyright (c) 1982, 1986, 1993
3 * The Regents of the University of California. All rights reserved.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
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.
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
33 * @(#)if_loop.c 8.1 (Berkeley) 6/10/93
34 * $FreeBSD: src/sys/net/if_loop.c,v 1.47.2.8 2003/06/01 01:46:11 silby Exp $
35 * $DragonFly: src/sys/net/if_loop.c,v 1.20 2006/12/22 23:44:54 swildner Exp $
39 * Loopback interface driver for protocol testing and timing.
43 #include "opt_atalk.h"
45 #include "opt_inet6.h"
48 #include <sys/param.h>
49 #include <sys/systm.h>
50 #include <sys/kernel.h>
52 #include <sys/socket.h>
53 #include <sys/sockio.h>
56 #include <net/if_types.h>
57 #include <net/ifq_var.h>
58 #include <net/netisr.h>
59 #include <net/route.h>
61 #include <net/bpfdesc.h>
64 #include <netinet/in.h>
65 #include <netinet/in_var.h>
69 #include <netproto/ipx/ipx.h>
70 #include <netproto/ipx/ipx_if.h>
75 #include <netinet/in.h>
77 #include <netinet6/in6_var.h>
78 #include <netinet/ip6.h>
83 #include <netns/ns_if.h>
87 #include <netproto/atalk/at.h>
88 #include <netproto/atalk/at_var.h>
91 int loioctl (struct ifnet *, u_long, caddr_t, struct ucred *);
92 static void lortrequest (int, struct rtentry *, struct rt_addrinfo *);
94 static void loopattach (void *);
96 static void lo_altqstart(struct ifnet *);
98 PSEUDO_SET(loopattach, if_loop);
100 int looutput (struct ifnet *ifp,
101 struct mbuf *m, struct sockaddr *dst, struct rtentry *rt);
104 #define LOMTU (1024+512)
105 #elif defined(LARGE_LOMTU)
111 struct ifnet loif[NLOOP];
115 loopattach(void *dummy)
120 for (i = 0, ifp = loif; i < NLOOP; i++, ifp++) {
121 if_initname(ifp, "lo", i);
123 ifp->if_flags = IFF_LOOPBACK | IFF_MULTICAST;
124 ifp->if_ioctl = loioctl;
125 ifp->if_output = looutput;
126 ifp->if_type = IFT_LOOP;
127 ifq_set_maxlen(&ifp->if_snd, ifqmaxlen);
128 ifq_set_ready(&ifp->if_snd);
130 ifp->if_start = lo_altqstart;
132 if_attach(ifp, NULL);
133 bpfattach(ifp, DLT_NULL, sizeof(u_int));
141 struct sockaddr *dst,
146 if ((m->m_flags & M_PKTHDR) == 0)
147 panic("looutput no HDR");
149 if (rt && rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) {
151 return (rt->rt_flags & RTF_BLACKHOLE ? 0 :
152 rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH);
155 * KAME requires that the packet to be contiguous on the
156 * mbuf. We need to make that sure.
157 * this kind of code should be avoided.
159 * XXX: KAME may no longer need contiguous packets. Once
160 * that has been verified, the following code _should_ be
163 if (m && m->m_next != NULL) {
165 n = m_defrag(m, MB_DONTWAIT);
176 ifp->if_obytes += m->m_pkthdr.len;
178 switch (dst->sa_family) {
186 kprintf("looutput: af=%d unexpected\n", dst->sa_family);
188 return (EAFNOSUPPORT);
191 return (if_simloop(ifp, m, dst->sa_family, 0));
197 * This function is to support software emulation of hardware loopback,
198 * i.e., for interfaces with the IFF_SIMPLEX attribute. Since they can't
199 * hear their own broadcasts, we create a copy of the packet that we
200 * would normally receive via a hardware loopback.
202 * This function expects the packet to include the media header of length hlen.
205 if_simloop(struct ifnet *ifp, struct mbuf *m, int af, int hlen)
209 KASSERT((m->m_flags & M_PKTHDR) != 0, ("if_simloop: no HDR"));
210 m->m_pkthdr.rcvif = ifp;
212 /* BPF write needs to be handled specially */
213 if (af == AF_UNSPEC) {
214 KASSERT(m->m_len >= sizeof(int), ("if_simloop: m_len"));
215 af = *(mtod(m, int *));
216 m->m_len -= sizeof(int);
217 m->m_pkthdr.len -= sizeof(int);
218 m->m_data += sizeof(int);
222 if (ifp->if_bpf->bif_dlt == DLT_NULL) {
223 uint32_t bpf_af = (uint32_t)af;
224 bpf_ptap(ifp->if_bpf, m, &bpf_af, 4);
227 bpf_mtap(ifp->if_bpf, m);
231 /* Strip away media header */
237 * altq for loop is just for debugging.
238 * only used when called for loop interface (not for
239 * a simplex interface).
241 if (ifq_is_enabled(&ifp->if_snd) && ifp->if_start == lo_altqstart) {
242 struct altq_pktattr pktattr;
247 * if the queueing discipline needs packet classification,
248 * do it before prepending link headers.
250 ifq_classify(&ifp->if_snd, m, af, &pktattr);
252 M_PREPEND(m, sizeof(int32_t), MB_DONTWAIT);
255 afp = mtod(m, int32_t *);
259 * A critical section is needed for subsystems protected by
260 * the MP lock, and the serializer is assumed to already
261 * be held for MPSAFE subsystems.
264 error = ifq_enqueue(&ifp->if_snd, m, &pktattr);
265 (*ifp->if_start)(ifp);
271 /* Deliver to upper layer protocol */
280 m->m_flags |= M_LOOP;
300 kprintf("if_simloop: can't handle af=%d\n", af);
302 return (EAFNOSUPPORT);
306 ifp->if_ibytes += m->m_pkthdr.len;
307 netisr_queue(isr, m);
313 lo_altqstart(struct ifnet *ifp)
321 m = ifq_dequeue(&ifp->if_snd, NULL);
326 afp = mtod(m, int32_t *);
328 m_adj(m, sizeof(int32_t));
338 m->m_flags |= M_LOOP;
363 kprintf("lo_altqstart: can't handle af%d\n", af);
369 ifp->if_ibytes += m->m_pkthdr.len;
370 netisr_queue(isr, m);
377 lortrequest(int cmd, struct rtentry *rt, struct rt_addrinfo *info)
380 rt->rt_rmx.rmx_mtu = rt->rt_ifp->if_mtu; /* for ISO */
382 * For optimal performance, the send and receive buffers
383 * should be at least twice the MTU plus a little more for
386 rt->rt_rmx.rmx_recvpipe = rt->rt_rmx.rmx_sendpipe = 3 * LOMTU;
391 * Process an ioctl request.
395 loioctl(struct ifnet *ifp, u_long cmd, caddr_t data, struct ucred *cr)
398 struct ifreq *ifr = (struct ifreq *)data;
404 ifp->if_flags |= IFF_UP | IFF_RUNNING;
405 ifa = (struct ifaddr *)data;
406 ifa->ifa_rtrequest = lortrequest;
408 * Everything else is done at a higher level.
415 error = EAFNOSUPPORT; /* XXX */
418 switch (ifr->ifr_addr.sa_family) {
430 error = EAFNOSUPPORT;
436 ifp->if_mtu = ifr->ifr_mtu;