/sys/net/if_loop.c
C | 487 lines | 351 code | 57 blank | 79 comment | 41 complexity | 4191ea884dc7867fc1cf04fecde8cc9f MD5 | raw file
Possible License(s): MPL-2.0-no-copyleft-exception, BSD-3-Clause, LGPL-2.0, LGPL-2.1, BSD-2-Clause, 0BSD, JSON, AGPL-1.0, GPL-2.0
- /*-
- * Copyright (c) 1982, 1986, 1993
- * The Regents of the University of California. All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- * 1. Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- * 2. Redistributions in binary form must reproduce the above copyright
- * notice, this list of conditions and the following disclaimer in the
- * documentation and/or other materials provided with the distribution.
- * 4. Neither the name of the University nor the names of its contributors
- * may be used to endorse or promote products derived from this software
- * without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
- * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
- * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
- * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
- * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
- * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
- * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
- * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
- * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
- * SUCH DAMAGE.
- *
- * @(#)if_loop.c 8.2 (Berkeley) 1/9/95
- * $FreeBSD$
- */
- /*
- * Loopback interface driver for protocol testing and timing.
- */
- #include "opt_atalk.h"
- #include "opt_inet.h"
- #include "opt_inet6.h"
- #include "opt_ipx.h"
- #include <sys/param.h>
- #include <sys/systm.h>
- #include <sys/kernel.h>
- #include <sys/mbuf.h>
- #include <sys/module.h>
- #include <machine/bus.h>
- #include <sys/rman.h>
- #include <sys/socket.h>
- #include <sys/sockio.h>
- #include <sys/sysctl.h>
- #include <net/if.h>
- #include <net/if_clone.h>
- #include <net/if_types.h>
- #include <net/netisr.h>
- #include <net/route.h>
- #include <net/bpf.h>
- #include <net/vnet.h>
- #ifdef INET
- #include <netinet/in.h>
- #include <netinet/in_var.h>
- #endif
- #ifdef IPX
- #include <netipx/ipx.h>
- #include <netipx/ipx_if.h>
- #endif
- #ifdef INET6
- #ifndef INET
- #include <netinet/in.h>
- #endif
- #include <netinet6/in6_var.h>
- #include <netinet/ip6.h>
- #endif
- #ifdef NETATALK
- #include <netatalk/at.h>
- #include <netatalk/at_var.h>
- #endif
- #include <security/mac/mac_framework.h>
- #ifdef TINY_LOMTU
- #define LOMTU (1024+512)
- #elif defined(LARGE_LOMTU)
- #define LOMTU 131072
- #else
- #define LOMTU 16384
- #endif
- #define LO_CSUM_FEATURES (CSUM_IP | CSUM_TCP | CSUM_UDP | CSUM_SCTP)
- #define LO_CSUM_FEATURES6 (CSUM_TCP_IPV6 | CSUM_UDP_IPV6 | CSUM_SCTP_IPV6)
- #define LO_CSUM_SET (CSUM_DATA_VALID | CSUM_DATA_VALID_IPV6 | \
- CSUM_PSEUDO_HDR | \
- CSUM_IP_CHECKED | CSUM_IP_VALID | \
- CSUM_SCTP_VALID)
- int loioctl(struct ifnet *, u_long, caddr_t);
- static void lortrequest(int, struct rtentry *, struct rt_addrinfo *);
- int looutput(struct ifnet *ifp, struct mbuf *m,
- struct sockaddr *dst, struct route *ro);
- static int lo_clone_create(struct if_clone *, int, caddr_t);
- static void lo_clone_destroy(struct ifnet *);
- VNET_DEFINE(struct ifnet *, loif); /* Used externally */
- #ifdef VIMAGE
- static VNET_DEFINE(struct if_clone *, lo_cloner);
- #define V_lo_cloner VNET(lo_cloner)
- #endif
- static struct if_clone *lo_cloner;
- static const char loname[] = "lo";
- static void
- lo_clone_destroy(struct ifnet *ifp)
- {
- #ifndef VIMAGE
- /* XXX: destroying lo0 will lead to panics. */
- KASSERT(V_loif != ifp, ("%s: destroying lo0", __func__));
- #endif
- bpfdetach(ifp);
- if_detach(ifp);
- if_free(ifp);
- }
- static int
- lo_clone_create(struct if_clone *ifc, int unit, caddr_t params)
- {
- struct ifnet *ifp;
- ifp = if_alloc(IFT_LOOP);
- if (ifp == NULL)
- return (ENOSPC);
- if_initname(ifp, loname, unit);
- ifp->if_mtu = LOMTU;
- ifp->if_flags = IFF_LOOPBACK | IFF_MULTICAST;
- ifp->if_ioctl = loioctl;
- ifp->if_output = looutput;
- ifp->if_snd.ifq_maxlen = ifqmaxlen;
- ifp->if_capabilities = ifp->if_capenable =
- IFCAP_HWCSUM | IFCAP_HWCSUM_IPV6;
- ifp->if_hwassist = LO_CSUM_FEATURES | LO_CSUM_FEATURES6;
- if_attach(ifp);
- bpfattach(ifp, DLT_NULL, sizeof(u_int32_t));
- if (V_loif == NULL)
- V_loif = ifp;
- return (0);
- }
- static void
- vnet_loif_init(const void *unused __unused)
- {
- #ifdef VIMAGE
- lo_cloner = if_clone_simple(loname, lo_clone_create, lo_clone_destroy,
- 1);
- V_lo_cloner = lo_cloner;
- #else
- lo_cloner = if_clone_simple(loname, lo_clone_create, lo_clone_destroy,
- 1);
- #endif
- }
- VNET_SYSINIT(vnet_loif_init, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY,
- vnet_loif_init, NULL);
- #ifdef VIMAGE
- static void
- vnet_loif_uninit(const void *unused __unused)
- {
- if_clone_detach(V_lo_cloner);
- V_loif = NULL;
- }
- VNET_SYSUNINIT(vnet_loif_uninit, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY,
- vnet_loif_uninit, NULL);
- #endif
- static int
- loop_modevent(module_t mod, int type, void *data)
- {
- switch (type) {
- case MOD_LOAD:
- break;
- case MOD_UNLOAD:
- printf("loop module unload - not possible for this module type\n");
- return (EINVAL);
- default:
- return (EOPNOTSUPP);
- }
- return (0);
- }
- static moduledata_t loop_mod = {
- "if_lo",
- loop_modevent,
- 0
- };
- DECLARE_MODULE(if_lo, loop_mod, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY);
- int
- looutput(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst,
- struct route *ro)
- {
- u_int32_t af;
- struct rtentry *rt = NULL;
- #ifdef MAC
- int error;
- #endif
- M_ASSERTPKTHDR(m); /* check if we have the packet header */
- if (ro != NULL)
- rt = ro->ro_rt;
- #ifdef MAC
- error = mac_ifnet_check_transmit(ifp, m);
- if (error) {
- m_freem(m);
- return (error);
- }
- #endif
- if (rt && rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) {
- m_freem(m);
- return (rt->rt_flags & RTF_BLACKHOLE ? 0 :
- rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH);
- }
- ifp->if_opackets++;
- ifp->if_obytes += m->m_pkthdr.len;
- /* BPF writes need to be handled specially. */
- if (dst->sa_family == AF_UNSPEC) {
- bcopy(dst->sa_data, &af, sizeof(af));
- dst->sa_family = af;
- }
- #if 1 /* XXX */
- switch (dst->sa_family) {
- case AF_INET:
- if (ifp->if_capenable & IFCAP_RXCSUM) {
- m->m_pkthdr.csum_data = 0xffff;
- m->m_pkthdr.csum_flags = LO_CSUM_SET;
- }
- m->m_pkthdr.csum_flags &= ~LO_CSUM_FEATURES;
- break;
- case AF_INET6:
- #if 0
- /*
- * XXX-BZ for now always claim the checksum is good despite
- * any interface flags. This is a workaround for 9.1-R and
- * a proper solution ought to be sought later.
- */
- if (ifp->if_capenable & IFCAP_RXCSUM_IPV6) {
- m->m_pkthdr.csum_data = 0xffff;
- m->m_pkthdr.csum_flags = LO_CSUM_SET;
- }
- #else
- m->m_pkthdr.csum_data = 0xffff;
- m->m_pkthdr.csum_flags = LO_CSUM_SET;
- #endif
- m->m_pkthdr.csum_flags &= ~LO_CSUM_FEATURES6;
- break;
- case AF_IPX:
- case AF_APPLETALK:
- break;
- default:
- printf("looutput: af=%d unexpected\n", dst->sa_family);
- m_freem(m);
- return (EAFNOSUPPORT);
- }
- #endif
- return (if_simloop(ifp, m, dst->sa_family, 0));
- }
- /*
- * if_simloop()
- *
- * This function is to support software emulation of hardware loopback,
- * i.e., for interfaces with the IFF_SIMPLEX attribute. Since they can't
- * hear their own broadcasts, we create a copy of the packet that we
- * would normally receive via a hardware loopback.
- *
- * This function expects the packet to include the media header of length hlen.
- */
- int
- if_simloop(struct ifnet *ifp, struct mbuf *m, int af, int hlen)
- {
- int isr;
- M_ASSERTPKTHDR(m);
- m_tag_delete_nonpersistent(m);
- m->m_pkthdr.rcvif = ifp;
- #ifdef MAC
- mac_ifnet_create_mbuf(ifp, m);
- #endif
- /*
- * Let BPF see incoming packet in the following manner:
- * - Emulated packet loopback for a simplex interface
- * (net/if_ethersubr.c)
- * -> passes it to ifp's BPF
- * - IPv4/v6 multicast packet loopback (netinet(6)/ip(6)_output.c)
- * -> not passes it to any BPF
- * - Normal packet loopback from myself to myself (net/if_loop.c)
- * -> passes to lo0's BPF (even in case of IPv6, where ifp!=lo0)
- */
- if (hlen > 0) {
- if (bpf_peers_present(ifp->if_bpf)) {
- bpf_mtap(ifp->if_bpf, m);
- }
- } else {
- if (bpf_peers_present(V_loif->if_bpf)) {
- if ((m->m_flags & M_MCAST) == 0 || V_loif == ifp) {
- /* XXX beware sizeof(af) != 4 */
- u_int32_t af1 = af;
- /*
- * We need to prepend the address family.
- */
- bpf_mtap2(V_loif->if_bpf, &af1, sizeof(af1), m);
- }
- }
- }
- /* Strip away media header */
- if (hlen > 0) {
- m_adj(m, hlen);
- #ifndef __NO_STRICT_ALIGNMENT
- /*
- * Some archs do not like unaligned data, so
- * we move data down in the first mbuf.
- */
- if (mtod(m, vm_offset_t) & 3) {
- KASSERT(hlen >= 3, ("if_simloop: hlen too small"));
- bcopy(m->m_data,
- (char *)(mtod(m, vm_offset_t)
- - (mtod(m, vm_offset_t) & 3)),
- m->m_len);
- m->m_data -= (mtod(m,vm_offset_t) & 3);
- }
- #endif
- }
- /* Deliver to upper layer protocol */
- switch (af) {
- #ifdef INET
- case AF_INET:
- isr = NETISR_IP;
- break;
- #endif
- #ifdef INET6
- case AF_INET6:
- m->m_flags |= M_LOOP;
- isr = NETISR_IPV6;
- break;
- #endif
- #ifdef IPX
- case AF_IPX:
- isr = NETISR_IPX;
- break;
- #endif
- #ifdef NETATALK
- case AF_APPLETALK:
- isr = NETISR_ATALK2;
- break;
- #endif
- default:
- printf("if_simloop: can't handle af=%d\n", af);
- m_freem(m);
- return (EAFNOSUPPORT);
- }
- ifp->if_ipackets++;
- ifp->if_ibytes += m->m_pkthdr.len;
- netisr_queue(isr, m); /* mbuf is free'd on failure. */
- return (0);
- }
- /* ARGSUSED */
- static void
- lortrequest(int cmd, struct rtentry *rt, struct rt_addrinfo *info)
- {
- RT_LOCK_ASSERT(rt);
- rt->rt_rmx.rmx_mtu = rt->rt_ifp->if_mtu;
- }
- /*
- * Process an ioctl request.
- */
- /* ARGSUSED */
- int
- loioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
- {
- struct ifaddr *ifa;
- struct ifreq *ifr = (struct ifreq *)data;
- int error = 0, mask;
- switch (cmd) {
- case SIOCSIFADDR:
- ifp->if_flags |= IFF_UP;
- ifp->if_drv_flags |= IFF_DRV_RUNNING;
- ifa = (struct ifaddr *)data;
- ifa->ifa_rtrequest = lortrequest;
- /*
- * Everything else is done at a higher level.
- */
- break;
- case SIOCADDMULTI:
- case SIOCDELMULTI:
- if (ifr == 0) {
- error = EAFNOSUPPORT; /* XXX */
- break;
- }
- switch (ifr->ifr_addr.sa_family) {
- #ifdef INET
- case AF_INET:
- break;
- #endif
- #ifdef INET6
- case AF_INET6:
- break;
- #endif
- default:
- error = EAFNOSUPPORT;
- break;
- }
- break;
- case SIOCSIFMTU:
- ifp->if_mtu = ifr->ifr_mtu;
- break;
- case SIOCSIFFLAGS:
- break;
- case SIOCSIFCAP:
- mask = ifp->if_capenable ^ ifr->ifr_reqcap;
- if ((mask & IFCAP_RXCSUM) != 0)
- ifp->if_capenable ^= IFCAP_RXCSUM;
- if ((mask & IFCAP_TXCSUM) != 0)
- ifp->if_capenable ^= IFCAP_TXCSUM;
- if ((mask & IFCAP_RXCSUM_IPV6) != 0) {
- #if 0
- ifp->if_capenable ^= IFCAP_RXCSUM_IPV6;
- #else
- error = EOPNOTSUPP;
- break;
- #endif
- }
- if ((mask & IFCAP_TXCSUM_IPV6) != 0) {
- #if 0
- ifp->if_capenable ^= IFCAP_TXCSUM_IPV6;
- #else
- error = EOPNOTSUPP;
- break;
- #endif
- }
- ifp->if_hwassist = 0;
- if (ifp->if_capenable & IFCAP_TXCSUM)
- ifp->if_hwassist = LO_CSUM_FEATURES;
- #if 0
- if (ifp->if_capenable & IFCAP_TXCSUM_IPV6)
- ifp->if_hwassist |= LO_CSUM_FEATURES6;
- #endif
- break;
- default:
- error = EINVAL;
- }
- return (error);
- }