xref: /netbsd-src/sys/net/if_vether.c (revision 82d56013d7b633d116a93943de88e08335357a7c)
1 /*	$NetBSD: if_vether.c,v 1.1 2020/09/27 13:31:04 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 1.1 2020/09/27 13:31:04 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;
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 	return 0;
93 }
94 
95 static int
96 vether_clone_destroy(struct ifnet *ifp)
97 {
98 	struct vether_softc *sc = ifp->if_softc;
99 
100 	ether_ifdetach(ifp);
101 	if_detach(ifp);
102 	kmem_free(sc, sizeof(*sc));
103 	return 0;
104 }
105 
106 static int
107 vether_init(struct ifnet *ifp)
108 {
109 
110 	ifp->if_flags |= IFF_RUNNING;
111 	if_link_state_change(ifp, LINK_STATE_UP);
112 	vether_start(ifp);
113 	return 0;
114 }
115 
116 /*
117  * The bridge has magically already done all the work for us,
118  * and we only need to discard the packets.
119  */
120 static void
121 vether_start(struct ifnet *ifp)
122 {
123 	struct mbuf *m;
124 
125 	for (;;) {
126 		IFQ_DEQUEUE(&ifp->if_snd, m);
127 		if (m == NULL)
128 			break;
129 		bpf_mtap(ifp, m, BPF_D_OUT);
130 		m_freem(m);
131 		if_statinc(ifp, if_opackets);
132 	}
133 }
134 
135 static void
136 vether_stop(struct ifnet *ifp, __unused int disable)
137 {
138 
139 	ifp->if_flags &= ~IFF_RUNNING;
140 	if_link_state_change(ifp, LINK_STATE_DOWN);
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 	default:
154 		error = ether_ioctl(ifp, cmd, data);
155 	}
156 	return error;
157 }
158