xref: /freebsd/sys/compat/linsysfs/linsysfs_net.c (revision 88362a00863a1c8369fab1cf63ad0e673403f7d0)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2023 Dmitry Chagin <dchagin@FreeBSD.org>
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25  * SUCH DAMAGE.
26  */
27 
28 #include <sys/param.h>
29 #include <sys/eventhandler.h>
30 #include <sys/kernel.h>
31 #include <sys/lock.h>
32 #include <sys/malloc.h>
33 #include <sys/mutex.h>
34 #include <sys/sbuf.h>
35 #include <sys/socket.h>
36 
37 #include <net/if.h>
38 #include <net/if_var.h>
39 #include <net/vnet.h>
40 
41 #include <compat/linux/linux.h>
42 #include <compat/linux/linux_common.h>
43 #include <fs/pseudofs/pseudofs.h>
44 
45 #include <compat/linsysfs/linsysfs.h>
46 
47 struct pfs_node *net;
48 static eventhandler_tag if_arrival_tag, if_departure_tag;
49 
50 static uint32_t net_latch_count = 0;
51 static struct mtx net_latch_mtx;
52 MTX_SYSINIT(net_latch_mtx, &net_latch_mtx, "lsfnet", MTX_DEF);
53 
54 struct ifp_nodes_queue {
55 	TAILQ_ENTRY(ifp_nodes_queue) ifp_nodes_next;
56 	if_t ifp;
57 	struct vnet *vnet;
58 	struct pfs_node *pn;
59 };
60 TAILQ_HEAD(,ifp_nodes_queue) ifp_nodes_q;
61 
62 static void
linsysfs_net_latch_hold(void)63 linsysfs_net_latch_hold(void)
64 {
65 
66 	mtx_lock(&net_latch_mtx);
67 	if (net_latch_count++ > 0)
68 		mtx_sleep(&net_latch_count, &net_latch_mtx, PDROP, "lsfnet", 0);
69 	else
70 		mtx_unlock(&net_latch_mtx);
71 }
72 
73 static void
linsysfs_net_latch_rele(void)74 linsysfs_net_latch_rele(void)
75 {
76 
77 	mtx_lock(&net_latch_mtx);
78 	if (--net_latch_count > 0)
79 		wakeup_one(&net_latch_count);
80 	mtx_unlock(&net_latch_mtx);
81 }
82 
83 static int
linsysfs_if_addr(PFS_FILL_ARGS)84 linsysfs_if_addr(PFS_FILL_ARGS)
85 {
86 	struct epoch_tracker et;
87 	struct l_sockaddr lsa;
88 	if_t ifp;
89 	int error;
90 
91 	CURVNET_SET(TD_TO_VNET(td));
92 	NET_EPOCH_ENTER(et);
93 	ifp = ifname_linux_to_ifp(td, pn->pn_parent->pn_name);
94 	if (ifp != NULL && (error = linux_ifhwaddr(ifp, &lsa)) == 0)
95 		error = sbuf_printf(sb, "%02hhx:%02hhx:%02hhx:%02hhx:%02hhx:%02hhx\n",
96 		    lsa.sa_data[0], lsa.sa_data[1], lsa.sa_data[2],
97 		    lsa.sa_data[3], lsa.sa_data[4], lsa.sa_data[5]);
98 	else
99 		error = ENOENT;
100 	NET_EPOCH_EXIT(et);
101 	CURVNET_RESTORE();
102 	return (error == -1 ? ERANGE : error);
103 }
104 
105 static int
linsysfs_if_addrlen(PFS_FILL_ARGS)106 linsysfs_if_addrlen(PFS_FILL_ARGS)
107 {
108 
109 	sbuf_printf(sb, "%d\n", LINUX_IFHWADDRLEN);
110 	return (0);
111 }
112 
113 static int
linsysfs_if_flags(PFS_FILL_ARGS)114 linsysfs_if_flags(PFS_FILL_ARGS)
115 {
116 	struct epoch_tracker et;
117 	if_t ifp;
118 	int error;
119 
120 	CURVNET_SET(TD_TO_VNET(td));
121 	NET_EPOCH_ENTER(et);
122 	ifp = ifname_linux_to_ifp(td, pn->pn_parent->pn_name);
123 	if (ifp != NULL)
124 		error = sbuf_printf(sb, "0x%x\n", linux_ifflags(ifp));
125 	else
126 		error = ENOENT;
127 	NET_EPOCH_EXIT(et);
128 	CURVNET_RESTORE();
129 	return (error == -1 ? ERANGE : error);
130 }
131 
132 static int
linsysfs_if_ifindex(PFS_FILL_ARGS)133 linsysfs_if_ifindex(PFS_FILL_ARGS)
134 {
135 	struct epoch_tracker et;
136 	if_t ifp;
137 	int error;
138 
139 	CURVNET_SET(TD_TO_VNET(td));
140 	NET_EPOCH_ENTER(et);
141 	ifp = ifname_linux_to_ifp(td, pn->pn_parent->pn_name);
142 	if (ifp != NULL)
143 		error = sbuf_printf(sb, "%u\n", if_getindex(ifp));
144 	else
145 		error = ENOENT;
146 	NET_EPOCH_EXIT(et);
147 	CURVNET_RESTORE();
148 	return (error == -1 ? ERANGE : error);
149 }
150 
151 static int
linsysfs_if_mtu(PFS_FILL_ARGS)152 linsysfs_if_mtu(PFS_FILL_ARGS)
153 {
154 	struct epoch_tracker et;
155 	if_t ifp;
156 	int error;
157 
158 	CURVNET_SET(TD_TO_VNET(td));
159 	NET_EPOCH_ENTER(et);
160 	ifp = ifname_linux_to_ifp(td, pn->pn_parent->pn_name);
161 	if (ifp != NULL)
162 		error = sbuf_printf(sb, "%u\n", if_getmtu(ifp));
163 	else
164 		error = ENOENT;
165 	NET_EPOCH_EXIT(et);
166 	CURVNET_RESTORE();
167 	return (error == -1 ? ERANGE : error);
168 }
169 
170 static int
linsysfs_if_txq_len(PFS_FILL_ARGS)171 linsysfs_if_txq_len(PFS_FILL_ARGS)
172 {
173 
174 	/* XXX */
175 	sbuf_printf(sb, "1000\n");
176 	return (0);
177 }
178 
179 static int
linsysfs_if_type(PFS_FILL_ARGS)180 linsysfs_if_type(PFS_FILL_ARGS)
181 {
182 	struct epoch_tracker et;
183 	struct l_sockaddr lsa;
184 	if_t ifp;
185 	int error;
186 
187 	CURVNET_SET(TD_TO_VNET(td));
188 	NET_EPOCH_ENTER(et);
189 	ifp = ifname_linux_to_ifp(td, pn->pn_parent->pn_name);
190 	if (ifp != NULL && (error = linux_ifhwaddr(ifp, &lsa)) == 0)
191 		error = sbuf_printf(sb, "%d\n", lsa.sa_family);
192 	else
193 		error = ENOENT;
194 	NET_EPOCH_EXIT(et);
195 	CURVNET_RESTORE();
196 	return (error == -1 ? ERANGE : error);
197 }
198 
199 static int
linsysfs_if_visible(PFS_VIS_ARGS)200 linsysfs_if_visible(PFS_VIS_ARGS)
201 {
202 	struct ifp_nodes_queue *nq, *nq_tmp;
203 	struct epoch_tracker et;
204 	if_t ifp;
205 	int visible;
206 
207 	visible = 0;
208 	CURVNET_SET(TD_TO_VNET(td));
209 	NET_EPOCH_ENTER(et);
210 	ifp = ifname_linux_to_ifp(td, pn->pn_name);
211 	if (ifp != NULL) {
212 		TAILQ_FOREACH_SAFE(nq, &ifp_nodes_q, ifp_nodes_next, nq_tmp) {
213 			if (nq->ifp == ifp && nq->vnet == curvnet) {
214 				visible = 1;
215 				break;
216 			}
217 		}
218 	}
219 	NET_EPOCH_EXIT(et);
220 	CURVNET_RESTORE();
221 	return (visible);
222 }
223 
224 static int
linsysfs_net_addif(if_t ifp,void * arg)225 linsysfs_net_addif(if_t ifp, void *arg)
226 {
227 	struct ifp_nodes_queue *nq, *nq_tmp;
228 	struct pfs_node *nic, *dir = arg;
229 	char ifname[LINUX_IFNAMSIZ];
230 	struct epoch_tracker et;
231 	int ret __diagused;
232 
233 	NET_EPOCH_ENTER(et);
234 	ret = ifname_bsd_to_linux_ifp(ifp, ifname, sizeof(ifname));
235 	NET_EPOCH_EXIT(et);
236 	KASSERT(ret > 0, ("Interface (%s) is not converted", if_name(ifp)));
237 
238 	nic = pfs_find_node(dir, ifname);
239 	if (nic == NULL) {
240 		nic = pfs_create_dir(dir, ifname, NULL, linsysfs_if_visible,
241 		    NULL, 0);
242 		pfs_create_file(nic, "address", &linsysfs_if_addr,
243 		    NULL, NULL, NULL, PFS_RD);
244 		pfs_create_file(nic, "addr_len", &linsysfs_if_addrlen,
245 		    NULL, NULL, NULL, PFS_RD);
246 		pfs_create_file(nic, "flags", &linsysfs_if_flags,
247 		    NULL, NULL, NULL, PFS_RD);
248 		pfs_create_file(nic, "ifindex", &linsysfs_if_ifindex,
249 		    NULL, NULL, NULL, PFS_RD);
250 		pfs_create_file(nic, "mtu", &linsysfs_if_mtu,
251 		    NULL, NULL, NULL, PFS_RD);
252 		pfs_create_file(nic, "tx_queue_len", &linsysfs_if_txq_len,
253 		    NULL, NULL, NULL, PFS_RD);
254 		pfs_create_file(nic, "type", &linsysfs_if_type,
255 		NULL, NULL, NULL, PFS_RD);
256 	}
257 	/*
258 	 * There is a small window between registering the if_arrival
259 	 * eventhandler and creating a list of interfaces.
260 	 */
261 	TAILQ_FOREACH_SAFE(nq, &ifp_nodes_q, ifp_nodes_next, nq_tmp) {
262 		if (nq->ifp == ifp && nq->vnet == curvnet)
263 			return (0);
264 	}
265 	nq = malloc(sizeof(*nq), M_LINSYSFS, M_WAITOK);
266 	nq->pn = nic;
267 	nq->ifp = ifp;
268 	nq->vnet = curvnet;
269 	TAILQ_INSERT_TAIL(&ifp_nodes_q, nq, ifp_nodes_next);
270 	return (0);
271 }
272 
273 static void
linsysfs_net_delif(if_t ifp)274 linsysfs_net_delif(if_t ifp)
275 {
276 	struct ifp_nodes_queue *nq, *nq_tmp;
277 	struct pfs_node *pn;
278 
279 	pn = NULL;
280 	TAILQ_FOREACH_SAFE(nq, &ifp_nodes_q, ifp_nodes_next, nq_tmp) {
281 		if (nq->ifp == ifp && nq->vnet == curvnet) {
282 			TAILQ_REMOVE(&ifp_nodes_q, nq, ifp_nodes_next);
283 			pn = nq->pn;
284 			free(nq, M_LINSYSFS);
285 			break;
286 		}
287 	}
288 	if (pn == NULL)
289 		return;
290 	TAILQ_FOREACH_SAFE(nq, &ifp_nodes_q, ifp_nodes_next, nq_tmp) {
291 		if (nq->pn == pn)
292 			return;
293 	}
294 	pfs_destroy(pn);
295 }
296 
297 static void
linsysfs_if_arrival(void * arg __unused,if_t ifp)298 linsysfs_if_arrival(void *arg __unused, if_t ifp)
299 {
300 
301 	linsysfs_net_latch_hold();
302 	(void)linsysfs_net_addif(ifp, net);
303 	linsysfs_net_latch_rele();
304 }
305 
306 static void
linsysfs_if_departure(void * arg __unused,if_t ifp)307 linsysfs_if_departure(void *arg __unused, if_t ifp)
308 {
309 
310 	linsysfs_net_latch_hold();
311 	linsysfs_net_delif(ifp);
312 	linsysfs_net_latch_rele();
313 }
314 
315 void
linsysfs_net_init(void)316 linsysfs_net_init(void)
317 {
318 	VNET_ITERATOR_DECL(vnet_iter);
319 
320 	MPASS(net != NULL);
321 	TAILQ_INIT(&ifp_nodes_q);
322 
323 	if_arrival_tag = EVENTHANDLER_REGISTER(ifnet_arrival_event,
324 	    linsysfs_if_arrival, NULL, EVENTHANDLER_PRI_ANY);
325 	if_departure_tag = EVENTHANDLER_REGISTER(ifnet_departure_event,
326 	    linsysfs_if_departure, NULL, EVENTHANDLER_PRI_ANY);
327 
328 	linsysfs_net_latch_hold();
329 	VNET_LIST_RLOCK();
330 	VNET_FOREACH(vnet_iter) {
331 		CURVNET_SET(vnet_iter);
332 		if_foreach_sleep(NULL, NULL, linsysfs_net_addif, net);
333 		CURVNET_RESTORE();
334 	}
335 	VNET_LIST_RUNLOCK();
336 	linsysfs_net_latch_rele();
337 }
338 
339 void
linsysfs_net_uninit(void)340 linsysfs_net_uninit(void)
341 {
342 	struct ifp_nodes_queue *nq, *nq_tmp;
343 
344 	EVENTHANDLER_DEREGISTER(ifnet_arrival_event, if_arrival_tag);
345 	EVENTHANDLER_DEREGISTER(ifnet_departure_event, if_departure_tag);
346 
347 	linsysfs_net_latch_hold();
348 	TAILQ_FOREACH_SAFE(nq, &ifp_nodes_q, ifp_nodes_next, nq_tmp) {
349 		TAILQ_REMOVE(&ifp_nodes_q, nq, ifp_nodes_next);
350 		free(nq, M_LINSYSFS);
351 	}
352 	linsysfs_net_latch_rele();
353 }
354