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 * 4. Neither the name of the University nor the names of its contributors
14 * may be used to endorse or promote products derived from this software
15 * without specific prior written permission.
17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * @(#)if_loop.c 8.2 (Berkeley) 1/9/95
34 * Loopback interface driver for protocol testing and timing.
38 #include "opt_inet6.h"
40 #include <sys/param.h>
41 #include <sys/systm.h>
42 #include <sys/kernel.h>
44 #include <sys/module.h>
45 #include <machine/bus.h>
47 #include <sys/socket.h>
48 #include <sys/sockio.h>
49 #include <sys/sysctl.h>
52 #include <net/if_var.h>
53 #include <net/if_clone.h>
54 #include <net/if_types.h>
55 #include <net/netisr.h>
56 #include <net/route.h>
61 #include <netinet/in.h>
62 #include <netinet/in_var.h>
67 #include <netinet/in.h>
69 #include <netinet6/in6_var.h>
70 #include <netinet/ip6.h>
73 #include <security/mac/mac_framework.h>
76 #define LOMTU (1024+512)
77 #elif defined(LARGE_LOMTU)
83 #define LO_CSUM_FEATURES (CSUM_IP | CSUM_TCP | CSUM_UDP | CSUM_SCTP)
84 #define LO_CSUM_FEATURES6 (CSUM_TCP_IPV6 | CSUM_UDP_IPV6 | CSUM_SCTP_IPV6)
85 #define LO_CSUM_SET (CSUM_DATA_VALID | CSUM_DATA_VALID_IPV6 | \
87 CSUM_IP_CHECKED | CSUM_IP_VALID | \
90 int loioctl(struct ifnet *, u_long, caddr_t);
91 static void lortrequest(int, struct rtentry *, struct rt_addrinfo *);
92 int looutput(struct ifnet *ifp, struct mbuf *m,
93 const struct sockaddr *dst, struct route *ro);
94 static int lo_clone_create(struct if_clone *, int, caddr_t);
95 static void lo_clone_destroy(struct ifnet *);
97 VNET_DEFINE(struct ifnet *, loif); /* Used externally */
100 static VNET_DEFINE(struct if_clone *, lo_cloner);
101 #define V_lo_cloner VNET(lo_cloner)
104 static struct if_clone *lo_cloner;
105 static const char loname[] = "lo";
108 lo_clone_destroy(struct ifnet *ifp)
112 /* XXX: destroying lo0 will lead to panics. */
113 KASSERT(V_loif != ifp, ("%s: destroying lo0", __func__));
122 lo_clone_create(struct if_clone *ifc, int unit, caddr_t params)
126 ifp = if_alloc(IFT_LOOP);
130 if_initname(ifp, loname, unit);
132 ifp->if_flags = IFF_LOOPBACK | IFF_MULTICAST;
133 ifp->if_ioctl = loioctl;
134 ifp->if_output = looutput;
135 ifp->if_snd.ifq_maxlen = ifqmaxlen;
136 ifp->if_capabilities = ifp->if_capenable =
137 IFCAP_HWCSUM | IFCAP_HWCSUM_IPV6;
138 ifp->if_hwassist = LO_CSUM_FEATURES | LO_CSUM_FEATURES6;
140 bpfattach(ifp, DLT_NULL, sizeof(u_int32_t));
148 vnet_loif_init(const void *unused __unused)
152 lo_cloner = if_clone_simple(loname, lo_clone_create, lo_clone_destroy,
154 V_lo_cloner = lo_cloner;
156 lo_cloner = if_clone_simple(loname, lo_clone_create, lo_clone_destroy,
160 VNET_SYSINIT(vnet_loif_init, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY,
161 vnet_loif_init, NULL);
165 vnet_loif_uninit(const void *unused __unused)
168 if_clone_detach(V_lo_cloner);
171 VNET_SYSUNINIT(vnet_loif_uninit, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY,
172 vnet_loif_uninit, NULL);
176 loop_modevent(module_t mod, int type, void *data)
184 printf("loop module unload - not possible for this module type\n");
193 static moduledata_t loop_mod = {
199 DECLARE_MODULE(if_lo, loop_mod, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY);
202 looutput(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst,
206 struct rtentry *rt = NULL;
211 M_ASSERTPKTHDR(m); /* check if we have the packet header */
216 error = mac_ifnet_check_transmit(ifp, m);
223 if (rt && rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) {
225 return (rt->rt_flags & RTF_BLACKHOLE ? 0 :
226 rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH);
230 ifp->if_obytes += m->m_pkthdr.len;
232 /* BPF writes need to be handled specially. */
233 if (dst->sa_family == AF_UNSPEC)
234 bcopy(dst->sa_data, &af, sizeof(af));
241 if (ifp->if_capenable & IFCAP_RXCSUM) {
242 m->m_pkthdr.csum_data = 0xffff;
243 m->m_pkthdr.csum_flags = LO_CSUM_SET;
245 m->m_pkthdr.csum_flags &= ~LO_CSUM_FEATURES;
250 * XXX-BZ for now always claim the checksum is good despite
251 * any interface flags. This is a workaround for 9.1-R and
252 * a proper solution ought to be sought later.
254 if (ifp->if_capenable & IFCAP_RXCSUM_IPV6) {
255 m->m_pkthdr.csum_data = 0xffff;
256 m->m_pkthdr.csum_flags = LO_CSUM_SET;
259 m->m_pkthdr.csum_data = 0xffff;
260 m->m_pkthdr.csum_flags = LO_CSUM_SET;
262 m->m_pkthdr.csum_flags &= ~LO_CSUM_FEATURES6;
265 printf("looutput: af=%d unexpected\n", af);
267 return (EAFNOSUPPORT);
270 return (if_simloop(ifp, m, af, 0));
276 * This function is to support software emulation of hardware loopback,
277 * i.e., for interfaces with the IFF_SIMPLEX attribute. Since they can't
278 * hear their own broadcasts, we create a copy of the packet that we
279 * would normally receive via a hardware loopback.
281 * This function expects the packet to include the media header of length hlen.
284 if_simloop(struct ifnet *ifp, struct mbuf *m, int af, int hlen)
289 m_tag_delete_nonpersistent(m);
290 m->m_pkthdr.rcvif = ifp;
293 mac_ifnet_create_mbuf(ifp, m);
297 * Let BPF see incoming packet in the following manner:
298 * - Emulated packet loopback for a simplex interface
299 * (net/if_ethersubr.c)
300 * -> passes it to ifp's BPF
301 * - IPv4/v6 multicast packet loopback (netinet(6)/ip(6)_output.c)
302 * -> not passes it to any BPF
303 * - Normal packet loopback from myself to myself (net/if_loop.c)
304 * -> passes to lo0's BPF (even in case of IPv6, where ifp!=lo0)
307 if (bpf_peers_present(ifp->if_bpf)) {
308 bpf_mtap(ifp->if_bpf, m);
311 if (bpf_peers_present(V_loif->if_bpf)) {
312 if ((m->m_flags & M_MCAST) == 0 || V_loif == ifp) {
313 /* XXX beware sizeof(af) != 4 */
317 * We need to prepend the address family.
319 bpf_mtap2(V_loif->if_bpf, &af1, sizeof(af1), m);
324 /* Strip away media header */
327 #ifndef __NO_STRICT_ALIGNMENT
329 * Some archs do not like unaligned data, so
330 * we move data down in the first mbuf.
332 if (mtod(m, vm_offset_t) & 3) {
333 KASSERT(hlen >= 3, ("if_simloop: hlen too small"));
335 (char *)(mtod(m, vm_offset_t)
336 - (mtod(m, vm_offset_t) & 3)),
338 m->m_data -= (mtod(m,vm_offset_t) & 3);
343 /* Deliver to upper layer protocol */
352 m->m_flags |= M_LOOP;
357 printf("if_simloop: can't handle af=%d\n", af);
359 return (EAFNOSUPPORT);
362 ifp->if_ibytes += m->m_pkthdr.len;
363 netisr_queue(isr, m); /* mbuf is free'd on failure. */
369 lortrequest(int cmd, struct rtentry *rt, struct rt_addrinfo *info)
373 rt->rt_mtu = rt->rt_ifp->if_mtu;
377 * Process an ioctl request.
381 loioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
384 struct ifreq *ifr = (struct ifreq *)data;
389 ifp->if_flags |= IFF_UP;
390 ifp->if_drv_flags |= IFF_DRV_RUNNING;
391 ifa = (struct ifaddr *)data;
392 ifa->ifa_rtrequest = lortrequest;
394 * Everything else is done at a higher level.
401 error = EAFNOSUPPORT; /* XXX */
404 switch (ifr->ifr_addr.sa_family) {
416 error = EAFNOSUPPORT;
422 ifp->if_mtu = ifr->ifr_mtu;
429 mask = ifp->if_capenable ^ ifr->ifr_reqcap;
430 if ((mask & IFCAP_RXCSUM) != 0)
431 ifp->if_capenable ^= IFCAP_RXCSUM;
432 if ((mask & IFCAP_TXCSUM) != 0)
433 ifp->if_capenable ^= IFCAP_TXCSUM;
434 if ((mask & IFCAP_RXCSUM_IPV6) != 0) {
436 ifp->if_capenable ^= IFCAP_RXCSUM_IPV6;
442 if ((mask & IFCAP_TXCSUM_IPV6) != 0) {
444 ifp->if_capenable ^= IFCAP_TXCSUM_IPV6;
450 ifp->if_hwassist = 0;
451 if (ifp->if_capenable & IFCAP_TXCSUM)
452 ifp->if_hwassist = LO_CSUM_FEATURES;
454 if (ifp->if_capenable & IFCAP_TXCSUM_IPV6)
455 ifp->if_hwassist |= LO_CSUM_FEATURES6;