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      1 /*	$NetBSD: if_vether.c,v 1.4 2024/09/26 09:59:55 roy Exp $	*/
      2 /* $OpenBSD: if_vether.c,v 1.27 2016/04/13 11:41:15 mpi Exp $ */
      3 
      4 /*
      5  * Copyright (c) 2009 Theo de Raadt
      6  * Copyright (c) 2020 Roy Marples
      7  *
      8  * Permission to use, copy, modify, and distribute this software for any
      9  * purpose with or without fee is hereby granted, provided that the above
     10  * copyright notice and this permission notice appear in all copies.
     11  *
     12  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
     13  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
     14  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
     15  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
     16  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
     17  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
     18  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
     19  */
     20 
     21 #include <sys/cdefs.h>
     22 __KERNEL_RCSID(0, "$NetBSD: if_vether.c,v 1.4 2024/09/26 09:59:55 roy Exp $");
     23 
     24 #include <sys/cprng.h>
     25 #include <sys/kmem.h>
     26 #include <sys/mbuf.h>
     27 
     28 #include <net/if.h>
     29 #include <net/if_ether.h>
     30 #include <net/if_media.h>
     31 #include <net/bpf.h>
     32 
     33 void		vetherattach(int);
     34 static int	vether_ioctl(struct ifnet *, u_long, void *);
     35 static int	vether_mediachange(struct ifnet *);
     36 static void	vether_mediastatus(struct ifnet *, struct ifmediareq *);
     37 static void	vether_start(struct ifnet *);
     38 static int	vether_clone_create(struct if_clone *, int);
     39 static int	vether_clone_destroy(struct ifnet *);
     40 
     41 static void	vether_stop(struct ifnet *, int);
     42 static int	vether_init(struct ifnet *);
     43 
     44 struct vether_softc {
     45 	struct ethercom		sc_ec;
     46 	struct ifmedia		sc_im;
     47 };
     48 
     49 struct if_clone	vether_cloner =
     50     IF_CLONE_INITIALIZER("vether", vether_clone_create, vether_clone_destroy);
     51 
     52 void
     53 vetherattach(int nvether)
     54 {
     55 
     56 	if_clone_attach(&vether_cloner);
     57 }
     58 
     59 static int
     60 vether_clone_create(struct if_clone *ifc, int unit)
     61 {
     62 	struct ifnet *ifp;
     63 	struct vether_softc *sc;
     64 	uint8_t enaddr[ETHER_ADDR_LEN] =
     65 	    { 0xf2, 0x0b, 0xa4, 0xff, 0xff, 0xff };
     66 
     67 	sc = kmem_zalloc(sizeof(*sc), KM_SLEEP);
     68 
     69 	sc->sc_ec.ec_ifmedia = &sc->sc_im;
     70 	ifmedia_init(&sc->sc_im, 0, vether_mediachange, vether_mediastatus);
     71 	ifmedia_add(&sc->sc_im, IFM_ETHER|IFM_AUTO, 0, NULL);
     72 	ifmedia_add(&sc->sc_im, IFM_ETHER|IFM_NONE, 0, NULL);
     73 	ifmedia_set(&sc->sc_im, IFM_ETHER|IFM_AUTO);
     74 
     75 	ifp = &sc->sc_ec.ec_if;
     76 	if_initname(ifp, ifc->ifc_name, unit);
     77 	ifp->if_softc = sc;
     78 	ifp->if_flags = IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST;
     79 #ifdef NET_MPSAFE
     80 	ifp->if_extflags = IFEF_MPSAFE;
     81 #endif
     82 	ifp->if_ioctl = vether_ioctl;
     83 	ifp->if_start = vether_start;
     84 	ifp->if_stop  = vether_stop;
     85 	ifp->if_init  = vether_init;
     86 	IFQ_SET_MAXLEN(&ifp->if_snd, IFQ_MAXLEN);
     87 	IFQ_SET_READY(&ifp->if_snd);
     88 
     89 	sc->sc_ec.ec_capabilities = ETHERCAP_VLAN_MTU | ETHERCAP_JUMBO_MTU;
     90 
     91 	/*
     92 	 * In order to obtain unique initial Ethernet address on a host,
     93 	 * do some randomisation.  It's not meant for anything but avoiding
     94 	 * hard-coding an address.
     95 	 */
     96 	cprng_fast(&enaddr[3], 3);
     97 
     98 	/* Those steps are mandatory for an Ethernet driver. */
     99 	if_initialize(ifp);
    100 	ether_ifattach(ifp, enaddr);
    101 	if_register(ifp);
    102 
    103 	/* Notify our link state */
    104 	vether_mediachange(ifp);
    105 
    106 	return 0;
    107 }
    108 
    109 static int
    110 vether_clone_destroy(struct ifnet *ifp)
    111 {
    112 	struct vether_softc *sc = ifp->if_softc;
    113 
    114 	ether_ifdetach(ifp);
    115 	if_detach(ifp);
    116 	kmem_free(sc, sizeof(*sc));
    117 	return 0;
    118 }
    119 
    120 static int
    121 vether_init(struct ifnet *ifp)
    122 {
    123 
    124 	ifp->if_flags |= IFF_RUNNING;
    125 	vether_start(ifp);
    126 	return 0;
    127 }
    128 
    129 static int
    130 vether_mediachange(struct ifnet *ifp)
    131 {
    132 	struct vether_softc *sc = ifp->if_softc;
    133 	int link_state;
    134 
    135 	if (IFM_SUBTYPE(sc->sc_im.ifm_cur->ifm_media) == IFM_NONE)
    136 		link_state = LINK_STATE_DOWN;
    137 	else
    138 		link_state = LINK_STATE_UP;
    139 
    140 	if_link_state_change(ifp, link_state);
    141 	return 0;
    142 }
    143 
    144 static void
    145 vether_mediastatus(struct ifnet *ifp, struct ifmediareq *imr)
    146 {
    147 	struct vether_softc *sc = ifp->if_softc;
    148 
    149 	imr->ifm_active = sc->sc_im.ifm_cur->ifm_media;
    150 
    151 	imr->ifm_status = IFM_AVALID;
    152 	if (IFM_SUBTYPE(imr->ifm_active) != IFM_NONE)
    153 		imr->ifm_status |= IFM_ACTIVE;
    154 }
    155 
    156 /*
    157  * The bridge has magically already done all the work for us,
    158  * and we only need to discard the packets.
    159  */
    160 static void
    161 vether_start(struct ifnet *ifp)
    162 {
    163 	struct mbuf *m;
    164 
    165 	for (;;) {
    166 		IFQ_DEQUEUE(&ifp->if_snd, m);
    167 		if (m == NULL)
    168 			break;
    169 		bpf_mtap(ifp, m, BPF_D_OUT);
    170 		m_freem(m);
    171 		if_statinc(ifp, if_opackets);
    172 	}
    173 }
    174 
    175 static void
    176 vether_stop(struct ifnet *ifp, __unused int disable)
    177 {
    178 
    179 	ifp->if_flags &= ~IFF_RUNNING;
    180 }
    181 
    182 static int
    183 vether_ioctl(struct ifnet *ifp, unsigned long cmd, void *data)
    184 {
    185 	int error = 0;
    186 
    187 	switch (cmd) {
    188 	case SIOCADDMULTI:
    189 	case SIOCDELMULTI:
    190 		break;
    191 
    192 	default:
    193 		error = ether_ioctl(ifp, cmd, data);
    194 	}
    195 	return error;
    196 }
    197