1 /* Copyright (C) 2007-2012 B.A.T.M.A.N. contributors:
2  *
3  * Marek Lindner, Simon Wunderlich
4  *
5  * This program is free software; you can redistribute it and/or
6  * modify it under the terms of version 2 of the GNU General Public
7  * License as published by the Free Software Foundation.
8  *
9  * This program is distributed in the hope that it will be useful, but
10  * WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12  * General Public License for more details.
13  *
14  * You should have received a copy of the GNU General Public License
15  * along with this program; if not, write to the Free Software
16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
17  * 02110-1301, USA
18  */
19 
20 #include "main.h"
21 #include "soft-interface.h"
22 #include "hard-interface.h"
23 #include "routing.h"
24 #include "send.h"
25 #include "debugfs.h"
26 #include "translation-table.h"
27 #include "hash.h"
28 #include "gateway_common.h"
29 #include "gateway_client.h"
30 #include "sysfs.h"
31 #include "originator.h"
32 #include <linux/slab.h>
33 #include <linux/ethtool.h>
34 #include <linux/etherdevice.h>
35 #include <linux/if_vlan.h>
36 #include "unicast.h"
37 #include "bridge_loop_avoidance.h"
38 
39 
40 static int batadv_get_settings(struct net_device *dev, struct ethtool_cmd *cmd);
41 static void batadv_get_drvinfo(struct net_device *dev,
42 			       struct ethtool_drvinfo *info);
43 static u32 batadv_get_msglevel(struct net_device *dev);
44 static void batadv_set_msglevel(struct net_device *dev, u32 value);
45 static u32 batadv_get_link(struct net_device *dev);
46 static void batadv_get_strings(struct net_device *dev, u32 stringset, u8 *data);
47 static void batadv_get_ethtool_stats(struct net_device *dev,
48 				     struct ethtool_stats *stats, u64 *data);
49 static int batadv_get_sset_count(struct net_device *dev, int stringset);
50 
51 static const struct ethtool_ops batadv_ethtool_ops = {
52 	.get_settings = batadv_get_settings,
53 	.get_drvinfo = batadv_get_drvinfo,
54 	.get_msglevel = batadv_get_msglevel,
55 	.set_msglevel = batadv_set_msglevel,
56 	.get_link = batadv_get_link,
57 	.get_strings = batadv_get_strings,
58 	.get_ethtool_stats = batadv_get_ethtool_stats,
59 	.get_sset_count = batadv_get_sset_count,
60 };
61 
62 int batadv_skb_head_push(struct sk_buff *skb, unsigned int len)
63 {
64 	int result;
65 
66 	/* TODO: We must check if we can release all references to non-payload
67 	 * data using skb_header_release in our skbs to allow skb_cow_header to
68 	 * work optimally. This means that those skbs are not allowed to read
69 	 * or write any data which is before the current position of skb->data
70 	 * after that call and thus allow other skbs with the same data buffer
71 	 * to write freely in that area.
72 	 */
73 	result = skb_cow_head(skb, len);
74 	if (result < 0)
75 		return result;
76 
77 	skb_push(skb, len);
78 	return 0;
79 }
80 
81 static int batadv_interface_open(struct net_device *dev)
82 {
83 	netif_start_queue(dev);
84 	return 0;
85 }
86 
87 static int batadv_interface_release(struct net_device *dev)
88 {
89 	netif_stop_queue(dev);
90 	return 0;
91 }
92 
93 static struct net_device_stats *batadv_interface_stats(struct net_device *dev)
94 {
95 	struct batadv_priv *bat_priv = netdev_priv(dev);
96 	return &bat_priv->stats;
97 }
98 
99 static int batadv_interface_set_mac_addr(struct net_device *dev, void *p)
100 {
101 	struct batadv_priv *bat_priv = netdev_priv(dev);
102 	struct sockaddr *addr = p;
103 
104 	if (!is_valid_ether_addr(addr->sa_data))
105 		return -EADDRNOTAVAIL;
106 
107 	/* only modify transtable if it has been initialized before */
108 	if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_ACTIVE) {
109 		batadv_tt_local_remove(bat_priv, dev->dev_addr,
110 				       "mac address changed", false);
111 		batadv_tt_local_add(dev, addr->sa_data, BATADV_NULL_IFINDEX);
112 	}
113 
114 	memcpy(dev->dev_addr, addr->sa_data, ETH_ALEN);
115 	dev->addr_assign_type &= ~NET_ADDR_RANDOM;
116 	return 0;
117 }
118 
119 static int batadv_interface_change_mtu(struct net_device *dev, int new_mtu)
120 {
121 	/* check ranges */
122 	if ((new_mtu < 68) || (new_mtu > batadv_hardif_min_mtu(dev)))
123 		return -EINVAL;
124 
125 	dev->mtu = new_mtu;
126 
127 	return 0;
128 }
129 
130 static int batadv_interface_tx(struct sk_buff *skb,
131 			       struct net_device *soft_iface)
132 {
133 	struct ethhdr *ethhdr = (struct ethhdr *)skb->data;
134 	struct batadv_priv *bat_priv = netdev_priv(soft_iface);
135 	struct batadv_hard_iface *primary_if = NULL;
136 	struct batadv_bcast_packet *bcast_packet;
137 	struct vlan_ethhdr *vhdr;
138 	__be16 ethertype = __constant_htons(BATADV_ETH_P_BATMAN);
139 	static const uint8_t stp_addr[ETH_ALEN] = {0x01, 0x80, 0xC2, 0x00, 0x00,
140 						   0x00};
141 	unsigned int header_len = 0;
142 	int data_len = skb->len, ret;
143 	short vid __maybe_unused = -1;
144 	bool do_bcast = false;
145 
146 	if (atomic_read(&bat_priv->mesh_state) != BATADV_MESH_ACTIVE)
147 		goto dropped;
148 
149 	soft_iface->trans_start = jiffies;
150 
151 	switch (ntohs(ethhdr->h_proto)) {
152 	case ETH_P_8021Q:
153 		vhdr = (struct vlan_ethhdr *)skb->data;
154 		vid = ntohs(vhdr->h_vlan_TCI) & VLAN_VID_MASK;
155 
156 		if (vhdr->h_vlan_encapsulated_proto != ethertype)
157 			break;
158 
159 		/* fall through */
160 	case BATADV_ETH_P_BATMAN:
161 		goto dropped;
162 	}
163 
164 	if (batadv_bla_tx(bat_priv, skb, vid))
165 		goto dropped;
166 
167 	/* Register the client MAC in the transtable */
168 	batadv_tt_local_add(soft_iface, ethhdr->h_source, skb->skb_iif);
169 
170 	/* don't accept stp packets. STP does not help in meshes.
171 	 * better use the bridge loop avoidance ...
172 	 */
173 	if (batadv_compare_eth(ethhdr->h_dest, stp_addr))
174 		goto dropped;
175 
176 	if (is_multicast_ether_addr(ethhdr->h_dest)) {
177 		do_bcast = true;
178 
179 		switch (atomic_read(&bat_priv->gw_mode)) {
180 		case BATADV_GW_MODE_SERVER:
181 			/* gateway servers should not send dhcp
182 			 * requests into the mesh
183 			 */
184 			ret = batadv_gw_is_dhcp_target(skb, &header_len);
185 			if (ret)
186 				goto dropped;
187 			break;
188 		case BATADV_GW_MODE_CLIENT:
189 			/* gateway clients should send dhcp requests
190 			 * via unicast to their gateway
191 			 */
192 			ret = batadv_gw_is_dhcp_target(skb, &header_len);
193 			if (ret)
194 				do_bcast = false;
195 			break;
196 		case BATADV_GW_MODE_OFF:
197 		default:
198 			break;
199 		}
200 	}
201 
202 	/* ethernet packet should be broadcasted */
203 	if (do_bcast) {
204 		primary_if = batadv_primary_if_get_selected(bat_priv);
205 		if (!primary_if)
206 			goto dropped;
207 
208 		if (batadv_skb_head_push(skb, sizeof(*bcast_packet)) < 0)
209 			goto dropped;
210 
211 		bcast_packet = (struct batadv_bcast_packet *)skb->data;
212 		bcast_packet->header.version = BATADV_COMPAT_VERSION;
213 		bcast_packet->header.ttl = BATADV_TTL;
214 
215 		/* batman packet type: broadcast */
216 		bcast_packet->header.packet_type = BATADV_BCAST;
217 		bcast_packet->reserved = 0;
218 
219 		/* hw address of first interface is the orig mac because only
220 		 * this mac is known throughout the mesh
221 		 */
222 		memcpy(bcast_packet->orig,
223 		       primary_if->net_dev->dev_addr, ETH_ALEN);
224 
225 		/* set broadcast sequence number */
226 		bcast_packet->seqno =
227 			htonl(atomic_inc_return(&bat_priv->bcast_seqno));
228 
229 		batadv_add_bcast_packet_to_list(bat_priv, skb, 1);
230 
231 		/* a copy is stored in the bcast list, therefore removing
232 		 * the original skb.
233 		 */
234 		kfree_skb(skb);
235 
236 	/* unicast packet */
237 	} else {
238 		if (atomic_read(&bat_priv->gw_mode) != BATADV_GW_MODE_OFF) {
239 			ret = batadv_gw_out_of_range(bat_priv, skb, ethhdr);
240 			if (ret)
241 				goto dropped;
242 		}
243 
244 		ret = batadv_unicast_send_skb(skb, bat_priv);
245 		if (ret != 0)
246 			goto dropped_freed;
247 	}
248 
249 	bat_priv->stats.tx_packets++;
250 	bat_priv->stats.tx_bytes += data_len;
251 	goto end;
252 
253 dropped:
254 	kfree_skb(skb);
255 dropped_freed:
256 	bat_priv->stats.tx_dropped++;
257 end:
258 	if (primary_if)
259 		batadv_hardif_free_ref(primary_if);
260 	return NETDEV_TX_OK;
261 }
262 
263 void batadv_interface_rx(struct net_device *soft_iface,
264 			 struct sk_buff *skb, struct batadv_hard_iface *recv_if,
265 			 int hdr_size)
266 {
267 	struct batadv_priv *bat_priv = netdev_priv(soft_iface);
268 	struct ethhdr *ethhdr;
269 	struct vlan_ethhdr *vhdr;
270 	struct batadv_header *batadv_header = (struct batadv_header *)skb->data;
271 	short vid __maybe_unused = -1;
272 	__be16 ethertype = __constant_htons(BATADV_ETH_P_BATMAN);
273 	bool is_bcast;
274 
275 	is_bcast = (batadv_header->packet_type == BATADV_BCAST);
276 
277 	/* check if enough space is available for pulling, and pull */
278 	if (!pskb_may_pull(skb, hdr_size))
279 		goto dropped;
280 
281 	skb_pull_rcsum(skb, hdr_size);
282 	skb_reset_mac_header(skb);
283 
284 	ethhdr = (struct ethhdr *)skb_mac_header(skb);
285 
286 	switch (ntohs(ethhdr->h_proto)) {
287 	case ETH_P_8021Q:
288 		vhdr = (struct vlan_ethhdr *)skb->data;
289 		vid = ntohs(vhdr->h_vlan_TCI) & VLAN_VID_MASK;
290 
291 		if (vhdr->h_vlan_encapsulated_proto != ethertype)
292 			break;
293 
294 		/* fall through */
295 	case BATADV_ETH_P_BATMAN:
296 		goto dropped;
297 	}
298 
299 	/* skb->dev & skb->pkt_type are set here */
300 	if (unlikely(!pskb_may_pull(skb, ETH_HLEN)))
301 		goto dropped;
302 	skb->protocol = eth_type_trans(skb, soft_iface);
303 
304 	/* should not be necessary anymore as we use skb_pull_rcsum()
305 	 * TODO: please verify this and remove this TODO
306 	 * -- Dec 21st 2009, Simon Wunderlich
307 	 */
308 
309 	/* skb->ip_summed = CHECKSUM_UNNECESSARY; */
310 
311 	bat_priv->stats.rx_packets++;
312 	bat_priv->stats.rx_bytes += skb->len + ETH_HLEN;
313 
314 	soft_iface->last_rx = jiffies;
315 
316 	if (batadv_is_ap_isolated(bat_priv, ethhdr->h_source, ethhdr->h_dest))
317 		goto dropped;
318 
319 	/* Let the bridge loop avoidance check the packet. If will
320 	 * not handle it, we can safely push it up.
321 	 */
322 	if (batadv_bla_rx(bat_priv, skb, vid, is_bcast))
323 		goto out;
324 
325 	netif_rx(skb);
326 	goto out;
327 
328 dropped:
329 	kfree_skb(skb);
330 out:
331 	return;
332 }
333 
334 static const struct net_device_ops batadv_netdev_ops = {
335 	.ndo_open = batadv_interface_open,
336 	.ndo_stop = batadv_interface_release,
337 	.ndo_get_stats = batadv_interface_stats,
338 	.ndo_set_mac_address = batadv_interface_set_mac_addr,
339 	.ndo_change_mtu = batadv_interface_change_mtu,
340 	.ndo_start_xmit = batadv_interface_tx,
341 	.ndo_validate_addr = eth_validate_addr
342 };
343 
344 static void batadv_interface_setup(struct net_device *dev)
345 {
346 	struct batadv_priv *priv = netdev_priv(dev);
347 
348 	ether_setup(dev);
349 
350 	dev->netdev_ops = &batadv_netdev_ops;
351 	dev->destructor = free_netdev;
352 	dev->tx_queue_len = 0;
353 
354 	/* can't call min_mtu, because the needed variables
355 	 * have not been initialized yet
356 	 */
357 	dev->mtu = ETH_DATA_LEN;
358 	/* reserve more space in the skbuff for our header */
359 	dev->hard_header_len = BATADV_HEADER_LEN;
360 
361 	/* generate random address */
362 	eth_hw_addr_random(dev);
363 
364 	SET_ETHTOOL_OPS(dev, &batadv_ethtool_ops);
365 
366 	memset(priv, 0, sizeof(*priv));
367 }
368 
369 struct net_device *batadv_softif_create(const char *name)
370 {
371 	struct net_device *soft_iface;
372 	struct batadv_priv *bat_priv;
373 	int ret;
374 	size_t cnt_len = sizeof(uint64_t) * BATADV_CNT_NUM;
375 
376 	soft_iface = alloc_netdev(sizeof(*bat_priv), name,
377 				  batadv_interface_setup);
378 
379 	if (!soft_iface)
380 		goto out;
381 
382 	ret = register_netdevice(soft_iface);
383 	if (ret < 0) {
384 		pr_err("Unable to register the batman interface '%s': %i\n",
385 		       name, ret);
386 		goto free_soft_iface;
387 	}
388 
389 	bat_priv = netdev_priv(soft_iface);
390 
391 	atomic_set(&bat_priv->aggregated_ogms, 1);
392 	atomic_set(&bat_priv->bonding, 0);
393 	atomic_set(&bat_priv->bridge_loop_avoidance, 0);
394 	atomic_set(&bat_priv->ap_isolation, 0);
395 	atomic_set(&bat_priv->vis_mode, BATADV_VIS_TYPE_CLIENT_UPDATE);
396 	atomic_set(&bat_priv->gw_mode, BATADV_GW_MODE_OFF);
397 	atomic_set(&bat_priv->gw_sel_class, 20);
398 	atomic_set(&bat_priv->gw_bandwidth, 41);
399 	atomic_set(&bat_priv->orig_interval, 1000);
400 	atomic_set(&bat_priv->hop_penalty, 30);
401 	atomic_set(&bat_priv->log_level, 0);
402 	atomic_set(&bat_priv->fragmentation, 1);
403 	atomic_set(&bat_priv->bcast_queue_left, BATADV_BCAST_QUEUE_LEN);
404 	atomic_set(&bat_priv->batman_queue_left, BATADV_BATMAN_QUEUE_LEN);
405 
406 	atomic_set(&bat_priv->mesh_state, BATADV_MESH_INACTIVE);
407 	atomic_set(&bat_priv->bcast_seqno, 1);
408 	atomic_set(&bat_priv->ttvn, 0);
409 	atomic_set(&bat_priv->tt_local_changes, 0);
410 	atomic_set(&bat_priv->tt_ogm_append_cnt, 0);
411 	atomic_set(&bat_priv->bla_num_requests, 0);
412 
413 	bat_priv->tt_buff = NULL;
414 	bat_priv->tt_buff_len = 0;
415 	bat_priv->tt_poss_change = false;
416 
417 	bat_priv->primary_if = NULL;
418 	bat_priv->num_ifaces = 0;
419 
420 	bat_priv->bat_counters = __alloc_percpu(cnt_len, __alignof__(uint64_t));
421 	if (!bat_priv->bat_counters)
422 		goto unreg_soft_iface;
423 
424 	ret = batadv_algo_select(bat_priv, batadv_routing_algo);
425 	if (ret < 0)
426 		goto free_bat_counters;
427 
428 	ret = batadv_sysfs_add_meshif(soft_iface);
429 	if (ret < 0)
430 		goto free_bat_counters;
431 
432 	ret = batadv_debugfs_add_meshif(soft_iface);
433 	if (ret < 0)
434 		goto unreg_sysfs;
435 
436 	ret = batadv_mesh_init(soft_iface);
437 	if (ret < 0)
438 		goto unreg_debugfs;
439 
440 	return soft_iface;
441 
442 unreg_debugfs:
443 	batadv_debugfs_del_meshif(soft_iface);
444 unreg_sysfs:
445 	batadv_sysfs_del_meshif(soft_iface);
446 free_bat_counters:
447 	free_percpu(bat_priv->bat_counters);
448 unreg_soft_iface:
449 	unregister_netdevice(soft_iface);
450 	return NULL;
451 
452 free_soft_iface:
453 	free_netdev(soft_iface);
454 out:
455 	return NULL;
456 }
457 
458 void batadv_softif_destroy(struct net_device *soft_iface)
459 {
460 	batadv_debugfs_del_meshif(soft_iface);
461 	batadv_sysfs_del_meshif(soft_iface);
462 	batadv_mesh_free(soft_iface);
463 	unregister_netdevice(soft_iface);
464 }
465 
466 int batadv_softif_is_valid(const struct net_device *net_dev)
467 {
468 	if (net_dev->netdev_ops->ndo_start_xmit == batadv_interface_tx)
469 		return 1;
470 
471 	return 0;
472 }
473 
474 /* ethtool */
475 static int batadv_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
476 {
477 	cmd->supported = 0;
478 	cmd->advertising = 0;
479 	ethtool_cmd_speed_set(cmd, SPEED_10);
480 	cmd->duplex = DUPLEX_FULL;
481 	cmd->port = PORT_TP;
482 	cmd->phy_address = 0;
483 	cmd->transceiver = XCVR_INTERNAL;
484 	cmd->autoneg = AUTONEG_DISABLE;
485 	cmd->maxtxpkt = 0;
486 	cmd->maxrxpkt = 0;
487 
488 	return 0;
489 }
490 
491 static void batadv_get_drvinfo(struct net_device *dev,
492 			       struct ethtool_drvinfo *info)
493 {
494 	strcpy(info->driver, "B.A.T.M.A.N. advanced");
495 	strcpy(info->version, BATADV_SOURCE_VERSION);
496 	strcpy(info->fw_version, "N/A");
497 	strcpy(info->bus_info, "batman");
498 }
499 
500 static u32 batadv_get_msglevel(struct net_device *dev)
501 {
502 	return -EOPNOTSUPP;
503 }
504 
505 static void batadv_set_msglevel(struct net_device *dev, u32 value)
506 {
507 }
508 
509 static u32 batadv_get_link(struct net_device *dev)
510 {
511 	return 1;
512 }
513 
514 /* Inspired by drivers/net/ethernet/dlink/sundance.c:1702
515  * Declare each description string in struct.name[] to get fixed sized buffer
516  * and compile time checking for strings longer than ETH_GSTRING_LEN.
517  */
518 static const struct {
519 	const char name[ETH_GSTRING_LEN];
520 } batadv_counters_strings[] = {
521 	{ "forward" },
522 	{ "forward_bytes" },
523 	{ "mgmt_tx" },
524 	{ "mgmt_tx_bytes" },
525 	{ "mgmt_rx" },
526 	{ "mgmt_rx_bytes" },
527 	{ "tt_request_tx" },
528 	{ "tt_request_rx" },
529 	{ "tt_response_tx" },
530 	{ "tt_response_rx" },
531 	{ "tt_roam_adv_tx" },
532 	{ "tt_roam_adv_rx" },
533 };
534 
535 static void batadv_get_strings(struct net_device *dev, uint32_t stringset,
536 			       uint8_t *data)
537 {
538 	if (stringset == ETH_SS_STATS)
539 		memcpy(data, batadv_counters_strings,
540 		       sizeof(batadv_counters_strings));
541 }
542 
543 static void batadv_get_ethtool_stats(struct net_device *dev,
544 				     struct ethtool_stats *stats,
545 				     uint64_t *data)
546 {
547 	struct batadv_priv *bat_priv = netdev_priv(dev);
548 	int i;
549 
550 	for (i = 0; i < BATADV_CNT_NUM; i++)
551 		data[i] = batadv_sum_counter(bat_priv, i);
552 }
553 
554 static int batadv_get_sset_count(struct net_device *dev, int stringset)
555 {
556 	if (stringset == ETH_SS_STATS)
557 		return BATADV_CNT_NUM;
558 
559 	return -EOPNOTSUPP;
560 }
561