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29 * @(#)if_loop.c 8.2 (Berkeley) 1/9/95
34 * Loopback interface driver for protocol testing and timing.
37 #include "opt_atalk.h"
39 #include "opt_inet6.h"
42 #include <sys/param.h>
43 #include <sys/systm.h>
44 #include <sys/kernel.h>
46 #include <sys/module.h>
47 #include <machine/bus.h>
49 #include <sys/socket.h>
50 #include <sys/sockio.h>
51 #include <sys/sysctl.h>
54 #include <net/if_clone.h>
55 #include <net/if_types.h>
56 #include <net/netisr.h>
57 #include <net/route.h>
62 #include <netinet/in.h>
63 #include <netinet/in_var.h>
67 #include <netipx/ipx.h>
68 #include <netipx/ipx_if.h>
73 #include <netinet/in.h>
75 #include <netinet6/in6_var.h>
76 #include <netinet/ip6.h>
80 #include <netatalk/at.h>
81 #include <netatalk/at_var.h>
84 #include <security/mac/mac_framework.h>
87 #define LOMTU (1024+512)
88 #elif defined(LARGE_LOMTU)
94 #define LO_CSUM_FEATURES (CSUM_IP | CSUM_TCP | CSUM_UDP | CSUM_SCTP)
95 #define LO_CSUM_FEATURES6 (CSUM_TCP_IPV6 | CSUM_UDP_IPV6 | CSUM_SCTP_IPV6)
96 #define LO_CSUM_SET (CSUM_DATA_VALID | CSUM_DATA_VALID_IPV6 | \
98 CSUM_IP_CHECKED | CSUM_IP_VALID | \
101 int loioctl(struct ifnet *, u_long, caddr_t);
102 static void lortrequest(int, struct rtentry *, struct rt_addrinfo *);
103 int looutput(struct ifnet *ifp, struct mbuf *m,
104 const struct sockaddr *dst, struct route *ro);
105 static int lo_clone_create(struct if_clone *, int, caddr_t);
106 static void lo_clone_destroy(struct ifnet *);
108 VNET_DEFINE(struct ifnet *, loif); /* Used externally */
111 static VNET_DEFINE(struct if_clone *, lo_cloner);
112 #define V_lo_cloner VNET(lo_cloner)
115 static struct if_clone *lo_cloner;
116 static const char loname[] = "lo";
119 lo_clone_destroy(struct ifnet *ifp)
123 /* XXX: destroying lo0 will lead to panics. */
124 KASSERT(V_loif != ifp, ("%s: destroying lo0", __func__));
133 lo_clone_create(struct if_clone *ifc, int unit, caddr_t params)
137 ifp = if_alloc(IFT_LOOP);
141 if_initname(ifp, loname, unit);
143 ifp->if_flags = IFF_LOOPBACK | IFF_MULTICAST;
144 ifp->if_ioctl = loioctl;
145 ifp->if_output = looutput;
146 ifp->if_snd.ifq_maxlen = ifqmaxlen;
147 ifp->if_capabilities = ifp->if_capenable =
148 IFCAP_HWCSUM | IFCAP_HWCSUM_IPV6;
149 ifp->if_hwassist = LO_CSUM_FEATURES | LO_CSUM_FEATURES6;
151 bpfattach(ifp, DLT_NULL, sizeof(u_int32_t));
159 vnet_loif_init(const void *unused __unused)
163 lo_cloner = if_clone_simple(loname, lo_clone_create, lo_clone_destroy,
165 V_lo_cloner = lo_cloner;
167 lo_cloner = if_clone_simple(loname, lo_clone_create, lo_clone_destroy,
171 VNET_SYSINIT(vnet_loif_init, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY,
172 vnet_loif_init, NULL);
176 vnet_loif_uninit(const void *unused __unused)
179 if_clone_detach(V_lo_cloner);
182 VNET_SYSUNINIT(vnet_loif_uninit, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY,
183 vnet_loif_uninit, NULL);
187 loop_modevent(module_t mod, int type, void *data)
195 printf("loop module unload - not possible for this module type\n");
204 static moduledata_t loop_mod = {
210 DECLARE_MODULE(if_lo, loop_mod, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY);
213 looutput(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst,
217 struct rtentry *rt = NULL;
222 M_ASSERTPKTHDR(m); /* check if we have the packet header */
227 error = mac_ifnet_check_transmit(ifp, m);
234 if (rt && rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) {
236 return (rt->rt_flags & RTF_BLACKHOLE ? 0 :
237 rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH);
241 ifp->if_obytes += m->m_pkthdr.len;
243 /* BPF writes need to be handled specially. */
244 if (dst->sa_family == AF_UNSPEC || dst->sa_family == pseudo_AF_HDRCMPLT)
245 bcopy(dst->sa_data, &af, sizeof(af));
252 if (ifp->if_capenable & IFCAP_RXCSUM) {
253 m->m_pkthdr.csum_data = 0xffff;
254 m->m_pkthdr.csum_flags = LO_CSUM_SET;
256 m->m_pkthdr.csum_flags &= ~LO_CSUM_FEATURES;
261 * XXX-BZ for now always claim the checksum is good despite
262 * any interface flags. This is a workaround for 9.1-R and
263 * a proper solution ought to be sought later.
265 if (ifp->if_capenable & IFCAP_RXCSUM_IPV6) {
266 m->m_pkthdr.csum_data = 0xffff;
267 m->m_pkthdr.csum_flags = LO_CSUM_SET;
270 m->m_pkthdr.csum_data = 0xffff;
271 m->m_pkthdr.csum_flags = LO_CSUM_SET;
273 m->m_pkthdr.csum_flags &= ~LO_CSUM_FEATURES6;
279 printf("looutput: af=%d unexpected\n", af);
281 return (EAFNOSUPPORT);
284 return (if_simloop(ifp, m, af, 0));
290 * This function is to support software emulation of hardware loopback,
291 * i.e., for interfaces with the IFF_SIMPLEX attribute. Since they can't
292 * hear their own broadcasts, we create a copy of the packet that we
293 * would normally receive via a hardware loopback.
295 * This function expects the packet to include the media header of length hlen.
298 if_simloop(struct ifnet *ifp, struct mbuf *m, int af, int hlen)
303 m_tag_delete_nonpersistent(m);
304 m->m_pkthdr.rcvif = ifp;
307 mac_ifnet_create_mbuf(ifp, m);
311 * Let BPF see incoming packet in the following manner:
312 * - Emulated packet loopback for a simplex interface
313 * (net/if_ethersubr.c)
314 * -> passes it to ifp's BPF
315 * - IPv4/v6 multicast packet loopback (netinet(6)/ip(6)_output.c)
316 * -> not passes it to any BPF
317 * - Normal packet loopback from myself to myself (net/if_loop.c)
318 * -> passes to lo0's BPF (even in case of IPv6, where ifp!=lo0)
321 if (bpf_peers_present(ifp->if_bpf)) {
322 bpf_mtap(ifp->if_bpf, m);
325 if (bpf_peers_present(V_loif->if_bpf)) {
326 if ((m->m_flags & M_MCAST) == 0 || V_loif == ifp) {
327 /* XXX beware sizeof(af) != 4 */
331 * We need to prepend the address family.
333 bpf_mtap2(V_loif->if_bpf, &af1, sizeof(af1), m);
338 /* Strip away media header */
341 #ifndef __NO_STRICT_ALIGNMENT
343 * Some archs do not like unaligned data, so
344 * we move data down in the first mbuf.
346 if (mtod(m, vm_offset_t) & 3) {
347 KASSERT(hlen >= 3, ("if_simloop: hlen too small"));
349 (char *)(mtod(m, vm_offset_t)
350 - (mtod(m, vm_offset_t) & 3)),
352 m->m_data -= (mtod(m,vm_offset_t) & 3);
357 /* Deliver to upper layer protocol */
366 m->m_flags |= M_LOOP;
381 printf("if_simloop: can't handle af=%d\n", af);
383 return (EAFNOSUPPORT);
386 ifp->if_ibytes += m->m_pkthdr.len;
387 netisr_queue(isr, m); /* mbuf is free'd on failure. */
393 lortrequest(int cmd, struct rtentry *rt, struct rt_addrinfo *info)
397 rt->rt_mtu = rt->rt_ifp->if_mtu;
401 * Process an ioctl request.
405 loioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
408 struct ifreq *ifr = (struct ifreq *)data;
413 ifp->if_flags |= IFF_UP;
414 ifp->if_drv_flags |= IFF_DRV_RUNNING;
415 ifa = (struct ifaddr *)data;
416 ifa->ifa_rtrequest = lortrequest;
418 * Everything else is done at a higher level.
425 error = EAFNOSUPPORT; /* XXX */
428 switch (ifr->ifr_addr.sa_family) {
440 error = EAFNOSUPPORT;
446 ifp->if_mtu = ifr->ifr_mtu;
453 mask = ifp->if_capenable ^ ifr->ifr_reqcap;
454 if ((mask & IFCAP_RXCSUM) != 0)
455 ifp->if_capenable ^= IFCAP_RXCSUM;
456 if ((mask & IFCAP_TXCSUM) != 0)
457 ifp->if_capenable ^= IFCAP_TXCSUM;
458 if ((mask & IFCAP_RXCSUM_IPV6) != 0) {
460 ifp->if_capenable ^= IFCAP_RXCSUM_IPV6;
466 if ((mask & IFCAP_TXCSUM_IPV6) != 0) {
468 ifp->if_capenable ^= IFCAP_TXCSUM_IPV6;
474 ifp->if_hwassist = 0;
475 if (ifp->if_capenable & IFCAP_TXCSUM)
476 ifp->if_hwassist = LO_CSUM_FEATURES;
478 if (ifp->if_capenable & IFCAP_TXCSUM_IPV6)
479 ifp->if_hwassist |= LO_CSUM_FEATURES6;