xref: /netbsd-src/sys/net/if_vether.c (revision cf036a1e8e0b980aa2c597acc9ddf56005d68496)
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