1/*	$OpenBSD: if_pair.c,v 1.17 2021/01/13 01:57:31 kn Exp $	*/
2
3/*
4 * Copyright (c) 2015 Reyk Floeter <reyk@openbsd.org>
5 * Copyright (c) 2009 Theo de Raadt <deraadt@openbsd.org>
6 *
7 * Permission to use, copy, modify, and distribute this software for any
8 * purpose with or without fee is hereby granted, provided that the above
9 * copyright notice and this permission notice appear in all copies.
10 *
11 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
12 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
13 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
14 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
15 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
16 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
17 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
18 */
19
20#include <sys/param.h>
21#include <sys/systm.h>
22#include <sys/mbuf.h>
23#include <sys/socket.h>
24#include <sys/sockio.h>
25#include <sys/ioctl.h>
26
27#include <net/if.h>
28#include <net/if_media.h>
29
30#include <netinet/in.h>
31#include <netinet/if_ether.h>
32
33#include "bpfilter.h"
34#if NBPFILTER > 0
35#include <net/bpf.h>
36#endif
37
38void	pairattach(int);
39int	pairioctl(struct ifnet *, u_long, caddr_t);
40void	pairstart(struct ifqueue *);
41int	pair_clone_create(struct if_clone *, int);
42int	pair_clone_destroy(struct ifnet *);
43int	pair_media_change(struct ifnet *);
44void	pair_media_status(struct ifnet *, struct ifmediareq *);
45void	pair_link_state(struct ifnet *);
46
47struct pair_softc {
48	struct arpcom		sc_ac;
49	struct ifmedia		sc_media;
50	unsigned int		sc_pairedif;
51};
52
53struct if_clone	pair_cloner =
54    IF_CLONE_INITIALIZER("pair", pair_clone_create, pair_clone_destroy);
55
56int
57pair_media_change(struct ifnet *ifp)
58{
59	return (0);
60}
61
62void
63pair_media_status(struct ifnet *ifp, struct ifmediareq *imr)
64{
65	struct pair_softc	*sc = ifp->if_softc;
66	struct ifnet		*pairedifp;
67
68	imr->ifm_active = IFM_ETHER | IFM_AUTO;
69
70	if ((pairedifp = if_get(sc->sc_pairedif)) == NULL) {
71		imr->ifm_status = 0;
72		return;
73	}
74	if_put(pairedifp);
75
76	imr->ifm_status = IFM_AVALID | IFM_ACTIVE;
77}
78
79void
80pair_link_state(struct ifnet *ifp)
81{
82	struct pair_softc	*sc = ifp->if_softc;
83	struct ifnet		*pairedifp;
84	unsigned int		 link_state;
85
86	/* The pair state is determined by the paired interface */
87	if ((pairedifp = if_get(sc->sc_pairedif)) != NULL) {
88		link_state = LINK_STATE_UP;
89		if_put(pairedifp);
90	} else
91		link_state = LINK_STATE_DOWN;
92
93	if (ifp->if_link_state != link_state) {
94		ifp->if_link_state = link_state;
95		if_link_state_change(ifp);
96	}
97}
98
99void
100pairattach(int npair)
101{
102	if_clone_attach(&pair_cloner);
103}
104
105int
106pair_clone_create(struct if_clone *ifc, int unit)
107{
108	struct ifnet		*ifp;
109	struct pair_softc	*sc;
110
111	sc = malloc(sizeof(*sc), M_DEVBUF, M_WAITOK|M_ZERO);
112	ifp = &sc->sc_ac.ac_if;
113	snprintf(ifp->if_xname, sizeof ifp->if_xname, "pair%d", unit);
114	ifp->if_flags = IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST;
115	ether_fakeaddr(ifp);
116
117	ifp->if_softc = sc;
118	ifp->if_ioctl = pairioctl;
119	ifp->if_qstart = pairstart;
120	ifp->if_xflags = IFXF_CLONED | IFXF_MPSAFE;
121
122	ifp->if_hardmtu = ETHER_MAX_HARDMTU_LEN;
123	ifp->if_capabilities = IFCAP_VLAN_MTU;
124
125	ifmedia_init(&sc->sc_media, 0, pair_media_change,
126	    pair_media_status);
127	ifmedia_add(&sc->sc_media, IFM_ETHER | IFM_AUTO, 0, NULL);
128	ifmedia_set(&sc->sc_media, IFM_ETHER | IFM_AUTO);
129
130	if_attach(ifp);
131	ether_ifattach(ifp);
132
133	pair_link_state(ifp);
134
135	return (0);
136}
137
138int
139pair_clone_destroy(struct ifnet *ifp)
140{
141	struct pair_softc	*sc = ifp->if_softc;
142	struct ifnet		*pairedifp;
143	struct pair_softc	*dstsc = ifp->if_softc;
144
145	if ((pairedifp = if_get(sc->sc_pairedif)) != NULL) {
146		dstsc = pairedifp->if_softc;
147		dstsc->sc_pairedif = 0;
148		pair_link_state(pairedifp);
149		if_put(pairedifp);
150	}
151
152	ifmedia_delete_instance(&sc->sc_media, IFM_INST_ANY);
153	ether_ifdetach(ifp);
154	if_detach(ifp);
155	free(sc, M_DEVBUF, sizeof(*sc));
156
157	return (0);
158}
159
160void
161pairstart(struct ifqueue *ifq)
162{
163	struct ifnet		*ifp = ifq->ifq_if;
164	struct pair_softc	*sc = (struct pair_softc *)ifp->if_softc;
165	struct mbuf_list	 ml = MBUF_LIST_INITIALIZER();
166	struct ifnet		*pairedifp;
167	struct mbuf		*m;
168
169	pairedifp = if_get(sc->sc_pairedif);
170
171	while ((m = ifq_dequeue(ifq)) != NULL) {
172#if NBPFILTER > 0
173		if (ifp->if_bpf)
174			bpf_mtap(ifp->if_bpf, m, BPF_DIRECTION_OUT);
175#endif /* NBPFILTER > 0 */
176
177		if (pairedifp != NULL) {
178			if (m->m_flags & M_PKTHDR)
179				m_resethdr(m);
180			ml_enqueue(&ml, m);
181		} else
182			m_freem(m);
183	}
184
185	if (pairedifp != NULL) {
186		if_input(pairedifp, &ml);
187		if_put(pairedifp);
188	}
189}
190
191int
192pairioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
193{
194	struct pair_softc	*sc = (struct pair_softc *)ifp->if_softc;
195	struct ifreq		*ifr = (struct ifreq *)data;
196	struct if_clone		*ifc;
197	struct pair_softc	*pairedsc = ifp->if_softc;
198	struct ifnet		*oldifp = NULL, *newifp = NULL;
199	int			 error = 0, unit;
200
201	switch (cmd) {
202	case SIOCSIFADDR:
203		ifp->if_flags |= IFF_UP;
204		/* FALLTHROUGH */
205
206	case SIOCSIFFLAGS:
207		if (ifp->if_flags & IFF_UP)
208			ifp->if_flags |= IFF_RUNNING;
209		else
210			ifp->if_flags &= ~IFF_RUNNING;
211		break;
212
213	case SIOCADDMULTI:
214	case SIOCDELMULTI:
215		break;
216
217	case SIOCGIFMEDIA:
218	case SIOCSIFMEDIA:
219		error = ifmedia_ioctl(ifp, ifr, &sc->sc_media, cmd);
220		break;
221
222	case SIOCSIFPAIR:
223		if (sc->sc_pairedif == ifr->ifr_index)
224			break;
225
226		/* Cannot link to myself */
227		if (ifr->ifr_index == ifp->if_index) {
228			error = EINVAL;
229			break;
230		}
231
232		oldifp = if_get(sc->sc_pairedif);
233		newifp = if_get(ifr->ifr_index);
234
235		if (newifp != NULL) {
236			pairedsc = newifp->if_softc;
237
238			if (pairedsc->sc_pairedif != 0) {
239				error = EBUSY;
240				break;
241			}
242
243			/* Only allow pair(4) interfaces for the pair */
244			if ((ifc = if_clone_lookup(newifp->if_xname,
245			    &unit)) == NULL || strcmp("pair",
246			    ifc->ifc_name) != 0) {
247				error = ENODEV;
248				break;
249			}
250
251			pairedsc->sc_pairedif = ifp->if_index;
252			sc->sc_pairedif = ifr->ifr_index;
253		} else
254			sc->sc_pairedif = 0;
255
256		if (oldifp != NULL) {
257			pairedsc = oldifp->if_softc;
258			pairedsc->sc_pairedif = 0;
259		}
260		break;
261
262	case SIOCGIFPAIR:
263		ifr->ifr_index = sc->sc_pairedif;
264		break;
265
266	default:
267		error = ether_ioctl(ifp, &sc->sc_ac, cmd, data);
268	}
269
270	if (newifp != NULL || oldifp != NULL)
271		pair_link_state(ifp);
272	if (oldifp != NULL) {
273		pair_link_state(oldifp);
274		if_put(oldifp);
275	}
276	if (newifp != NULL) {
277		pair_link_state(newifp);
278		if_put(newifp);
279	}
280
281	return (error);
282}
283