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if_vether.c revision 1.3 
      1 /*	$NetBSD: if_vether.c,v 1.3 2024/09/24 15:23:53 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 1.3 2024/09/24 15:23:53 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/bpf.h>
     31 
     32 void		vetherattach(int);
     33 static int	vether_ioctl(struct ifnet *, u_long, void *);
     34 static void	vether_start(struct ifnet *);
     35 static int	vether_clone_create(struct if_clone *, int);
     36 static int	vether_clone_destroy(struct ifnet *);
     37 
     38 static void	vether_stop(struct ifnet *, int);
     39 static int	vether_init(struct ifnet *);
     40 
     41 struct vether_softc {
     42 	struct ethercom		sc_ec;
     43 };
     44 
     45 struct if_clone	vether_cloner =
     46     IF_CLONE_INITIALIZER("vether", vether_clone_create, vether_clone_destroy);
     47 
     48 void
     49 vetherattach(int nvether)
     50 {
     51 
     52 	if_clone_attach(&vether_cloner);
     53 }
     54 
     55 static int
     56 vether_clone_create(struct if_clone *ifc, int unit)
     57 {
     58 	struct ifnet *ifp;
     59 	struct vether_softc *sc;
     60 	uint8_t enaddr[ETHER_ADDR_LEN] =
     61 	    { 0xf2, 0x0b, 0xa4, 0xff, 0xff, 0xff };
     62 
     63 	sc = kmem_zalloc(sizeof(*sc), KM_SLEEP);
     64 	ifp = &sc->sc_ec.ec_if;
     65 	if_initname(ifp, ifc->ifc_name, unit);
     66 	ifp->if_softc = sc;
     67 	ifp->if_flags = IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST | IFF_LINK0;
     68 #ifdef NET_MPSAFE
     69 	ifp->if_extflags = IFEF_MPSAFE;
     70 #endif
     71 	ifp->if_ioctl = vether_ioctl;
     72 	ifp->if_start = vether_start;
     73 	ifp->if_stop  = vether_stop;
     74 	ifp->if_init  = vether_init;
     75 	IFQ_SET_MAXLEN(&ifp->if_snd, IFQ_MAXLEN);
     76 	IFQ_SET_READY(&ifp->if_snd);
     77 
     78 	sc->sc_ec.ec_capabilities = ETHERCAP_VLAN_MTU | ETHERCAP_JUMBO_MTU;
     79 
     80 	/*
     81 	 * In order to obtain unique initial Ethernet address on a host,
     82 	 * do some randomisation.  It's not meant for anything but avoiding
     83 	 * hard-coding an address.
     84 	 */
     85 	cprng_fast(&enaddr[3], 3);
     86 
     87 	/* Those steps are mandatory for an Ethernet driver. */
     88 	if_initialize(ifp);
     89 	ether_ifattach(ifp, enaddr);
     90 	if_register(ifp);
     91 
     92 	if_link_state_change(ifp, LINK_STATE_UP);
     93 
     94 	return 0;
     95 }
     96 
     97 static int
     98 vether_clone_destroy(struct ifnet *ifp)
     99 {
    100 	struct vether_softc *sc = ifp->if_softc;
    101 
    102 	ether_ifdetach(ifp);
    103 	if_detach(ifp);
    104 	kmem_free(sc, sizeof(*sc));
    105 	return 0;
    106 }
    107 
    108 static int
    109 vether_init(struct ifnet *ifp)
    110 {
    111 
    112 	ifp->if_flags |= IFF_RUNNING;
    113 	vether_start(ifp);
    114 	return 0;
    115 }
    116 
    117 /*
    118  * The bridge has magically already done all the work for us,
    119  * and we only need to discard the packets.
    120  */
    121 static void
    122 vether_start(struct ifnet *ifp)
    123 {
    124 	struct mbuf *m;
    125 
    126 	for (;;) {
    127 		IFQ_DEQUEUE(&ifp->if_snd, m);
    128 		if (m == NULL)
    129 			break;
    130 		bpf_mtap(ifp, m, BPF_D_OUT);
    131 		m_freem(m);
    132 		if_statinc(ifp, if_opackets);
    133 	}
    134 }
    135 
    136 static void
    137 vether_stop(struct ifnet *ifp, __unused int disable)
    138 {
    139 
    140 	ifp->if_flags &= ~IFF_RUNNING;
    141 }
    142 
    143 static int
    144 vether_ioctl(struct ifnet *ifp, unsigned long cmd, void *data)
    145 {
    146 	int error = 0;
    147 
    148 	switch (cmd) {
    149 	case SIOCADDMULTI:
    150 	case SIOCDELMULTI:
    151 		break;
    152 
    153         case SIOCSIFFLAGS:
    154                 if ((error = ifioctl_common(ifp, cmd, data)) != 0)
    155 			break;
    156 		if_link_state_change(ifp, ifp->if_flags & IFF_LINK0 ?
    157 		    LINK_STATE_UP : LINK_STATE_DOWN);
    158 		break;
    159 
    160 	default:
    161 		error = ether_ioctl(ifp, cmd, data);
    162 	}
    163 	return error;
    164 }
    165