[linux-2.6-block.git] / net / batman-adv / unicast.c

/* Copyright (C) 2010-2012 B.A.T.M.A.N. contributors:
 *
 * Andreas Langer
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of version 2 of the GNU General Public
 * License as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
 * 02110-1301, USA
 */

#include "main.h"
#include "unicast.h"
#include "send.h"
#include "soft-interface.h"
#include "gateway_client.h"
#include "originator.h"
#include "hash.h"
#include "translation-table.h"
#include "routing.h"
#include "hard-interface.h"


static struct sk_buff *frag_merge_packet(struct list_head *head,
					 struct frag_packet_list_entry *tfp,
					 struct sk_buff *skb)
{
	struct unicast_frag_packet *up =
		(struct unicast_frag_packet *)skb->data;
	struct sk_buff *tmp_skb;
	struct unicast_packet *unicast_packet;
	int hdr_len = sizeof(*unicast_packet);
	int uni_diff = sizeof(*up) - hdr_len;

	/* set skb to the first part and tmp_skb to the second part */
	if (up->flags & UNI_FRAG_HEAD) {
		tmp_skb = tfp->skb;
	} else {
		tmp_skb = skb;
		skb = tfp->skb;
	}

	if (skb_linearize(skb) < 0 || skb_linearize(tmp_skb) < 0)
		goto err;

	skb_pull(tmp_skb, sizeof(*up));
	if (pskb_expand_head(skb, 0, tmp_skb->len, GFP_ATOMIC) < 0)
		goto err;

	/* move free entry to end */
	tfp->skb = NULL;
	tfp->seqno = 0;
	list_move_tail(&tfp->list, head);

	memcpy(skb_put(skb, tmp_skb->len), tmp_skb->data, tmp_skb->len);
	kfree_skb(tmp_skb);

	memmove(skb->data + uni_diff, skb->data, hdr_len);
	unicast_packet = (struct unicast_packet *)skb_pull(skb, uni_diff);
	unicast_packet->header.packet_type = BAT_UNICAST;

	return skb;

err:
	/* free buffered skb, skb will be freed later */
	kfree_skb(tfp->skb);
	return NULL;
}

static void frag_create_entry(struct list_head *head, struct sk_buff *skb)
{
	struct frag_packet_list_entry *tfp;
	struct unicast_frag_packet *up =
		(struct unicast_frag_packet *)skb->data;

	/* free and oldest packets stand at the end */
	tfp = list_entry((head)->prev, typeof(*tfp), list);
	kfree_skb(tfp->skb);

	tfp->seqno = ntohs(up->seqno);
	tfp->skb = skb;
	list_move(&tfp->list, head);
	return;
}

static int frag_create_buffer(struct list_head *head)
{
	int i;
	struct frag_packet_list_entry *tfp;

	for (i = 0; i < FRAG_BUFFER_SIZE; i++) {
		tfp = kmalloc(sizeof(*tfp), GFP_ATOMIC);
		if (!tfp) {
			batadv_frag_list_free(head);
			return -ENOMEM;
		}
		tfp->skb = NULL;
		tfp->seqno = 0;
		INIT_LIST_HEAD(&tfp->list);
		list_add(&tfp->list, head);
	}

	return 0;
}

static struct frag_packet_list_entry *frag_search_packet(struct list_head *head,
					   const struct unicast_frag_packet *up)
{
	struct frag_packet_list_entry *tfp;
	struct unicast_frag_packet *tmp_up = NULL;
	uint16_t search_seqno;

	if (up->flags & UNI_FRAG_HEAD)
		search_seqno = ntohs(up->seqno)+1;
	else
		search_seqno = ntohs(up->seqno)-1;

	list_for_each_entry(tfp, head, list) {

		if (!tfp->skb)
			continue;

		if (tfp->seqno == ntohs(up->seqno))
			goto mov_tail;

		tmp_up = (struct unicast_frag_packet *)tfp->skb->data;

		if (tfp->seqno == search_seqno) {

			if ((tmp_up->flags & UNI_FRAG_HEAD) !=
			    (up->flags & UNI_FRAG_HEAD))
				return tfp;
			else
				goto mov_tail;
		}
	}
	return NULL;

mov_tail:
	list_move_tail(&tfp->list, head);
	return NULL;
}

void batadv_frag_list_free(struct list_head *head)
{
	struct frag_packet_list_entry *pf, *tmp_pf;

	if (!list_empty(head)) {

		list_for_each_entry_safe(pf, tmp_pf, head, list) {
			kfree_skb(pf->skb);
			list_del(&pf->list);
			kfree(pf);
		}
	}
	return;
}

/* frag_reassemble_skb():
 * returns NET_RX_DROP if the operation failed - skb is left intact
 * returns NET_RX_SUCCESS if the fragment was buffered (skb_new will be NULL)
 * or the skb could be reassembled (skb_new will point to the new packet and
 * skb was freed)
 */
int batadv_frag_reassemble_skb(struct sk_buff *skb, struct bat_priv *bat_priv,
			       struct sk_buff **new_skb)
{
	struct orig_node *orig_node;
	struct frag_packet_list_entry *tmp_frag_entry;
	int ret = NET_RX_DROP;
	struct unicast_frag_packet *unicast_packet =
		(struct unicast_frag_packet *)skb->data;

	*new_skb = NULL;

	orig_node = orig_hash_find(bat_priv, unicast_packet->orig);
	if (!orig_node)
		goto out;

	orig_node->last_frag_packet = jiffies;

	if (list_empty(&orig_node->frag_list) &&
	    frag_create_buffer(&orig_node->frag_list)) {
		pr_debug("couldn't create frag buffer\n");
		goto out;
	}

	tmp_frag_entry = frag_search_packet(&orig_node->frag_list,
					    unicast_packet);

	if (!tmp_frag_entry) {
		frag_create_entry(&orig_node->frag_list, skb);
		ret = NET_RX_SUCCESS;
		goto out;
	}

	*new_skb = frag_merge_packet(&orig_node->frag_list, tmp_frag_entry,
				     skb);
	/* if not, merge failed */
	if (*new_skb)
		ret = NET_RX_SUCCESS;

out:
	if (orig_node)
		batadv_orig_node_free_ref(orig_node);
	return ret;
}

int batadv_frag_send_skb(struct sk_buff *skb, struct bat_priv *bat_priv,
			 struct hard_iface *hard_iface, const uint8_t dstaddr[])
{
	struct unicast_packet tmp_uc, *unicast_packet;
	struct hard_iface *primary_if;
	struct sk_buff *frag_skb;
	struct unicast_frag_packet *frag1, *frag2;
	int uc_hdr_len = sizeof(*unicast_packet);
	int ucf_hdr_len = sizeof(*frag1);
	int data_len = skb->len - uc_hdr_len;
	int large_tail = 0, ret = NET_RX_DROP;
	uint16_t seqno;

	primary_if = primary_if_get_selected(bat_priv);
	if (!primary_if)
		goto dropped;

	frag_skb = dev_alloc_skb(data_len - (data_len / 2) + ucf_hdr_len);
	if (!frag_skb)
		goto dropped;
	skb_reserve(frag_skb, ucf_hdr_len);

	unicast_packet = (struct unicast_packet *)skb->data;
	memcpy(&tmp_uc, unicast_packet, uc_hdr_len);
	skb_split(skb, frag_skb, data_len / 2 + uc_hdr_len);

	if (batadv_skb_head_push(skb, ucf_hdr_len - uc_hdr_len) < 0 ||
	    batadv_skb_head_push(frag_skb, ucf_hdr_len) < 0)
		goto drop_frag;

	frag1 = (struct unicast_frag_packet *)skb->data;
	frag2 = (struct unicast_frag_packet *)frag_skb->data;

	memcpy(frag1, &tmp_uc, sizeof(tmp_uc));

	frag1->header.ttl--;
	frag1->header.version = COMPAT_VERSION;
	frag1->header.packet_type = BAT_UNICAST_FRAG;

	memcpy(frag1->orig, primary_if->net_dev->dev_addr, ETH_ALEN);
	memcpy(frag2, frag1, sizeof(*frag2));

	if (data_len & 1)
		large_tail = UNI_FRAG_LARGETAIL;

	frag1->flags = UNI_FRAG_HEAD | large_tail;
	frag2->flags = large_tail;

	seqno = atomic_add_return(2, &hard_iface->frag_seqno);
	frag1->seqno = htons(seqno - 1);
	frag2->seqno = htons(seqno);

	batadv_send_skb_packet(skb, hard_iface, dstaddr);
	batadv_send_skb_packet(frag_skb, hard_iface, dstaddr);
	ret = NET_RX_SUCCESS;
	goto out;

drop_frag:
	kfree_skb(frag_skb);
dropped:
	kfree_skb(skb);
out:
	if (primary_if)
		hardif_free_ref(primary_if);
	return ret;
}

int batadv_unicast_send_skb(struct sk_buff *skb, struct bat_priv *bat_priv)
{
	struct ethhdr *ethhdr = (struct ethhdr *)skb->data;
	struct unicast_packet *unicast_packet;
	struct orig_node *orig_node;
	struct neigh_node *neigh_node;
	int data_len = skb->len;
	int ret = 1;

	/* get routing information */
	if (is_multicast_ether_addr(ethhdr->h_dest)) {
		orig_node = batadv_gw_get_selected_orig(bat_priv);
		if (orig_node)
			goto find_router;
	}

	/* check for tt host - increases orig_node refcount.
	 * returns NULL in case of AP isolation
	 */
	orig_node = batadv_transtable_search(bat_priv, ethhdr->h_source,
					     ethhdr->h_dest);
find_router:
	/* find_router():
	 *  - if orig_node is NULL it returns NULL
	 *  - increases neigh_nodes refcount if found.
	 */
	neigh_node = batadv_find_router(bat_priv, orig_node, NULL);
	if (!neigh_node)
		goto out;

	if (batadv_skb_head_push(skb, sizeof(*unicast_packet)) < 0)
		goto out;

	unicast_packet = (struct unicast_packet *)skb->data;

	unicast_packet->header.version = COMPAT_VERSION;
	/* batman packet type: unicast */
	unicast_packet->header.packet_type = BAT_UNICAST;
	/* set unicast ttl */
	unicast_packet->header.ttl = TTL;
	/* copy the destination for faster routing */
	memcpy(unicast_packet->dest, orig_node->orig, ETH_ALEN);
	/* set the destination tt version number */
	unicast_packet->ttvn =
		(uint8_t)atomic_read(&orig_node->last_ttvn);

	/* inform the destination node that we are still missing a correct route
	 * for this client. The destination will receive this packet and will
	 * try to reroute it because the ttvn contained in the header is less
	 * than the current one
	 */
	if (batadv_tt_global_client_is_roaming(bat_priv, ethhdr->h_dest))
		unicast_packet->ttvn = unicast_packet->ttvn - 1;

	if (atomic_read(&bat_priv->fragmentation) &&
	    data_len + sizeof(*unicast_packet) >
				neigh_node->if_incoming->net_dev->mtu) {
		/* send frag skb decreases ttl */
		unicast_packet->header.ttl++;
		ret = batadv_frag_send_skb(skb, bat_priv,
					   neigh_node->if_incoming,
					   neigh_node->addr);
		goto out;
	}

	batadv_send_skb_packet(skb, neigh_node->if_incoming, neigh_node->addr);
	ret = 0;
	goto out;

out:
	if (neigh_node)
		batadv_neigh_node_free_ref(neigh_node);
	if (orig_node)
		batadv_orig_node_free_ref(orig_node);
	if (ret == 1)
		kfree_skb(skb);
	return ret;
}
Commit	Line	Data
9cfc7bd6	1	/* Copyright (C) 2010-2012 B.A.T.M.A.N. contributors:
c6c8fea2 SE	2	*
	3	* Andreas Langer
	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
c6c8fea2 SE	18	*/
	19
	20	#include "main.h"
	21	#include "unicast.h"
	22	#include "send.h"
	23	#include "soft-interface.h"
	24	#include "gateway_client.h"
	25	#include "originator.h"
	26	#include "hash.h"
	27	#include "translation-table.h"
	28	#include "routing.h"
	29	#include "hard-interface.h"
	30
	31
	32	static struct sk_buff frag_merge_packet(struct list_head head,
	33	struct frag_packet_list_entry *tfp,
	34	struct sk_buff *skb)
	35	{
	36	struct unicast_frag_packet *up =
	37	(struct unicast_frag_packet *)skb->data;
	38	struct sk_buff *tmp_skb;
	39	struct unicast_packet *unicast_packet;
704509b8 SE	40	int hdr_len = sizeof(*unicast_packet);
704509b8 SE	41	int uni_diff = sizeof(*up) - hdr_len;
c6c8fea2 SE	42
	43	/* set skb to the first part and tmp_skb to the second part */
	44	if (up->flags & UNI_FRAG_HEAD) {
	45	tmp_skb = tfp->skb;
	46	} else {
	47	tmp_skb = skb;
	48	skb = tfp->skb;
	49	}
	50
531c9da8 SE	51	if (skb_linearize(skb) < 0 \|\| skb_linearize(tmp_skb) < 0)
	52	goto err;
	53
704509b8	54	skb_pull(tmp_skb, sizeof(*up));
531c9da8 SE	55	if (pskb_expand_head(skb, 0, tmp_skb->len, GFP_ATOMIC) < 0)
531c9da8 SE	56	goto err;
c6c8fea2 SE	57
	58	/* move free entry to end */
	59	tfp->skb = NULL;
	60	tfp->seqno = 0;
	61	list_move_tail(&tfp->list, head);
	62
	63	memcpy(skb_put(skb, tmp_skb->len), tmp_skb->data, tmp_skb->len);
	64	kfree_skb(tmp_skb);
	65
	66	memmove(skb->data + uni_diff, skb->data, hdr_len);
40e0c4f5	67	unicast_packet = (struct unicast_packet *)skb_pull(skb, uni_diff);
76543d14	68	unicast_packet->header.packet_type = BAT_UNICAST;
c6c8fea2 SE	69
c6c8fea2 SE	70	return skb;
531c9da8 SE	71
	72	err:
	73	/* free buffered skb, skb will be freed later */
	74	kfree_skb(tfp->skb);
	75	return NULL;
c6c8fea2 SE	76	}
	77
	78	static void frag_create_entry(struct list_head head, struct sk_buff skb)
	79	{
	80	struct frag_packet_list_entry *tfp;
	81	struct unicast_frag_packet *up =
	82	(struct unicast_frag_packet *)skb->data;
	83
	84	/* free and oldest packets stand at the end */
	85	tfp = list_entry((head)->prev, typeof(*tfp), list);
	86	kfree_skb(tfp->skb);
	87
	88	tfp->seqno = ntohs(up->seqno);
	89	tfp->skb = skb;
	90	list_move(&tfp->list, head);
	91	return;
	92	}
	93
	94	static int frag_create_buffer(struct list_head *head)
	95	{
	96	int i;
	97	struct frag_packet_list_entry *tfp;
	98
	99	for (i = 0; i < FRAG_BUFFER_SIZE; i++) {
704509b8	100	tfp = kmalloc(sizeof(*tfp), GFP_ATOMIC);
c6c8fea2	101	if (!tfp) {
88ed1e77	102	batadv_frag_list_free(head);
c6c8fea2 SE	103	return -ENOMEM;
	104	}
	105	tfp->skb = NULL;
	106	tfp->seqno = 0;
	107	INIT_LIST_HEAD(&tfp->list);
	108	list_add(&tfp->list, head);
	109	}
	110
	111	return 0;
	112	}
	113
	114	static struct frag_packet_list_entry frag_search_packet(struct list_head head,
747e4221	115	const struct unicast_frag_packet *up)
c6c8fea2 SE	116	{
	117	struct frag_packet_list_entry *tfp;
	118	struct unicast_frag_packet *tmp_up = NULL;
	119	uint16_t search_seqno;
	120
	121	if (up->flags & UNI_FRAG_HEAD)
	122	search_seqno = ntohs(up->seqno)+1;
	123	else
	124	search_seqno = ntohs(up->seqno)-1;
	125
	126	list_for_each_entry(tfp, head, list) {
	127
	128	if (!tfp->skb)
	129	continue;
	130
	131	if (tfp->seqno == ntohs(up->seqno))
	132	goto mov_tail;
	133
	134	tmp_up = (struct unicast_frag_packet *)tfp->skb->data;
	135
	136	if (tfp->seqno == search_seqno) {
	137
	138	if ((tmp_up->flags & UNI_FRAG_HEAD) !=
	139	(up->flags & UNI_FRAG_HEAD))
	140	return tfp;
	141	else
	142	goto mov_tail;
	143	}
	144	}
	145	return NULL;
	146
	147	mov_tail:
	148	list_move_tail(&tfp->list, head);
	149	return NULL;
	150	}
	151
88ed1e77	152	void batadv_frag_list_free(struct list_head *head)
c6c8fea2 SE	153	{
	154	struct frag_packet_list_entry pf, tmp_pf;
	155
	156	if (!list_empty(head)) {
	157
	158	list_for_each_entry_safe(pf, tmp_pf, head, list) {
	159	kfree_skb(pf->skb);
	160	list_del(&pf->list);
	161	kfree(pf);
	162	}
	163	}
	164	return;
	165	}
	166
	167	/* frag_reassemble_skb():
	168	* returns NET_RX_DROP if the operation failed - skb is left intact
	169	* returns NET_RX_SUCCESS if the fragment was buffered (skb_new will be NULL)
	170	* or the skb could be reassembled (skb_new will point to the new packet and
	171	* skb was freed)
	172	*/
88ed1e77 SE	173	int batadv_frag_reassemble_skb(struct sk_buff skb, struct bat_priv bat_priv,
88ed1e77 SE	174	struct sk_buff **new_skb)
c6c8fea2 SE	175	{
	176	struct orig_node *orig_node;
	177	struct frag_packet_list_entry *tmp_frag_entry;
	178	int ret = NET_RX_DROP;
	179	struct unicast_frag_packet *unicast_packet =
	180	(struct unicast_frag_packet *)skb->data;
	181
	182	*new_skb = NULL;
c6c8fea2	183
7aadf889 ML	184	orig_node = orig_hash_find(bat_priv, unicast_packet->orig);
7aadf889 ML	185	if (!orig_node)
c6c8fea2	186	goto out;
c6c8fea2 SE	187
	188	orig_node->last_frag_packet = jiffies;
	189
	190	if (list_empty(&orig_node->frag_list) &&
	191	frag_create_buffer(&orig_node->frag_list)) {
	192	pr_debug("couldn't create frag buffer\n");
	193	goto out;
	194	}
	195
	196	tmp_frag_entry = frag_search_packet(&orig_node->frag_list,
	197	unicast_packet);
	198
	199	if (!tmp_frag_entry) {
	200	frag_create_entry(&orig_node->frag_list, skb);
	201	ret = NET_RX_SUCCESS;
	202	goto out;
	203	}
	204
	205	*new_skb = frag_merge_packet(&orig_node->frag_list, tmp_frag_entry,
	206	skb);
	207	/* if not, merge failed */
	208	if (*new_skb)
	209	ret = NET_RX_SUCCESS;
c6c8fea2	210
7aadf889 ML	211	out:
7aadf889 ML	212	if (orig_node)
7d211efc	213	batadv_orig_node_free_ref(orig_node);
c6c8fea2 SE	214	return ret;
	215	}
	216
88ed1e77 SE	217	int batadv_frag_send_skb(struct sk_buff skb, struct bat_priv bat_priv,
88ed1e77 SE	218	struct hard_iface *hard_iface, const uint8_t dstaddr[])
c6c8fea2 SE	219	{
c6c8fea2 SE	220	struct unicast_packet tmp_uc, *unicast_packet;
32ae9b22	221	struct hard_iface *primary_if;
c6c8fea2 SE	222	struct sk_buff *frag_skb;
c6c8fea2 SE	223	struct unicast_frag_packet frag1, frag2;
704509b8 SE	224	int uc_hdr_len = sizeof(*unicast_packet);
704509b8 SE	225	int ucf_hdr_len = sizeof(*frag1);
5c77d8bb	226	int data_len = skb->len - uc_hdr_len;
32ae9b22	227	int large_tail = 0, ret = NET_RX_DROP;
c2f7f0e7	228	uint16_t seqno;
c6c8fea2	229
32ae9b22 ML	230	primary_if = primary_if_get_selected(bat_priv);
32ae9b22 ML	231	if (!primary_if)
c6c8fea2 SE	232	goto dropped;
c6c8fea2 SE	233
ed7809d9 JJ	234	frag_skb = dev_alloc_skb(data_len - (data_len / 2) + ucf_hdr_len);
	235	if (!frag_skb)
	236	goto dropped;
5c77d8bb	237	skb_reserve(frag_skb, ucf_hdr_len);
c6c8fea2	238
40e0c4f5	239	unicast_packet = (struct unicast_packet *)skb->data;
c6c8fea2	240	memcpy(&tmp_uc, unicast_packet, uc_hdr_len);
5c77d8bb	241	skb_split(skb, frag_skb, data_len / 2 + uc_hdr_len);
c6c8fea2	242
04b482a2 SE	243	if (batadv_skb_head_push(skb, ucf_hdr_len - uc_hdr_len) < 0 \|\|
04b482a2 SE	244	batadv_skb_head_push(frag_skb, ucf_hdr_len) < 0)
c6c8fea2 SE	245	goto drop_frag;
	246
	247	frag1 = (struct unicast_frag_packet *)skb->data;
	248	frag2 = (struct unicast_frag_packet *)frag_skb->data;
	249
704509b8	250	memcpy(frag1, &tmp_uc, sizeof(tmp_uc));
c6c8fea2	251
76543d14 SE	252	frag1->header.ttl--;
	253	frag1->header.version = COMPAT_VERSION;
	254	frag1->header.packet_type = BAT_UNICAST_FRAG;
c6c8fea2	255
32ae9b22	256	memcpy(frag1->orig, primary_if->net_dev->dev_addr, ETH_ALEN);
704509b8	257	memcpy(frag2, frag1, sizeof(*frag2));
c6c8fea2	258
ae361ce1 SE	259	if (data_len & 1)
	260	large_tail = UNI_FRAG_LARGETAIL;
	261
	262	frag1->flags = UNI_FRAG_HEAD \| large_tail;
	263	frag2->flags = large_tail;
c6c8fea2	264
e6c10f43	265	seqno = atomic_add_return(2, &hard_iface->frag_seqno);
c2f7f0e7 SE	266	frag1->seqno = htons(seqno - 1);
c2f7f0e7 SE	267	frag2->seqno = htons(seqno);
c6c8fea2	268
9455e34c SE	269	batadv_send_skb_packet(skb, hard_iface, dstaddr);
9455e34c SE	270	batadv_send_skb_packet(frag_skb, hard_iface, dstaddr);
32ae9b22 ML	271	ret = NET_RX_SUCCESS;
32ae9b22 ML	272	goto out;
c6c8fea2 SE	273
	274	drop_frag:
	275	kfree_skb(frag_skb);
	276	dropped:
	277	kfree_skb(skb);
32ae9b22 ML	278	out:
	279	if (primary_if)
	280	hardif_free_ref(primary_if);
	281	return ret;
c6c8fea2 SE	282	}
c6c8fea2 SE	283
88ed1e77	284	int batadv_unicast_send_skb(struct sk_buff skb, struct bat_priv bat_priv)
c6c8fea2 SE	285	{
	286	struct ethhdr ethhdr = (struct ethhdr )skb->data;
	287	struct unicast_packet *unicast_packet;
7b36e8ee	288	struct orig_node *orig_node;
44524fcd	289	struct neigh_node *neigh_node;
c6c8fea2	290	int data_len = skb->len;
44524fcd	291	int ret = 1;
c6c8fea2 SE	292
c6c8fea2 SE	293	/* get routing information */
43c70ad5	294	if (is_multicast_ether_addr(ethhdr->h_dest)) {
7cf06bc6	295	orig_node = batadv_gw_get_selected_orig(bat_priv);
43c70ad5	296	if (orig_node)
44524fcd ML	297	goto find_router;
44524fcd ML	298	}
c6c8fea2	299
3d393e47	300	/* check for tt host - increases orig_node refcount.
9cfc7bd6 SE	301	* returns NULL in case of AP isolation
9cfc7bd6 SE	302	*/
08c36d3e SE	303	orig_node = batadv_transtable_search(bat_priv, ethhdr->h_source,
08c36d3e SE	304	ethhdr->h_dest);
44524fcd	305	find_router:
9cfc7bd6	306	/* find_router():
d0072609 ML	307	* - if orig_node is NULL it returns NULL
	308	* - increases neigh_nodes refcount if found.
	309	*/
30d3c511	310	neigh_node = batadv_find_router(bat_priv, orig_node, NULL);
44524fcd	311	if (!neigh_node)
d0072609	312	goto out;
c6c8fea2	313
04b482a2	314	if (batadv_skb_head_push(skb, sizeof(*unicast_packet)) < 0)
d0072609	315	goto out;
c6c8fea2 SE	316
	317	unicast_packet = (struct unicast_packet *)skb->data;
	318
76543d14	319	unicast_packet->header.version = COMPAT_VERSION;
c6c8fea2	320	/* batman packet type: unicast */
76543d14	321	unicast_packet->header.packet_type = BAT_UNICAST;
c6c8fea2	322	/* set unicast ttl */
76543d14	323	unicast_packet->header.ttl = TTL;
c6c8fea2 SE	324	/* copy the destination for faster routing */
c6c8fea2 SE	325	memcpy(unicast_packet->dest, orig_node->orig, ETH_ALEN);
a73105b8 AQ	326	/* set the destination tt version number */
	327	unicast_packet->ttvn =
	328	(uint8_t)atomic_read(&orig_node->last_ttvn);
c6c8fea2	329
3275e7cc AQ	330	/* inform the destination node that we are still missing a correct route
	331	* for this client. The destination will receive this packet and will
	332	* try to reroute it because the ttvn contained in the header is less
	333	* than the current one
	334	*/
08c36d3e	335	if (batadv_tt_global_client_is_roaming(bat_priv, ethhdr->h_dest))
3275e7cc AQ	336	unicast_packet->ttvn = unicast_packet->ttvn - 1;
3275e7cc AQ	337
c6c8fea2	338	if (atomic_read(&bat_priv->fragmentation) &&
704509b8	339	data_len + sizeof(*unicast_packet) >
d0072609	340	neigh_node->if_incoming->net_dev->mtu) {
c6c8fea2	341	/* send frag skb decreases ttl */
76543d14	342	unicast_packet->header.ttl++;
88ed1e77 SE	343	ret = batadv_frag_send_skb(skb, bat_priv,
	344	neigh_node->if_incoming,
	345	neigh_node->addr);
44524fcd	346	goto out;
c6c8fea2	347	}
c6c8fea2	348
9455e34c	349	batadv_send_skb_packet(skb, neigh_node->if_incoming, neigh_node->addr);
44524fcd ML	350	ret = 0;
44524fcd ML	351	goto out;
c6c8fea2	352
44524fcd ML	353	out:
44524fcd ML	354	if (neigh_node)
7d211efc	355	batadv_neigh_node_free_ref(neigh_node);
44524fcd	356	if (orig_node)
7d211efc	357	batadv_orig_node_free_ref(orig_node);
44524fcd ML	358	if (ret == 1)
	359	kfree_skb(skb);
	360	return ret;
c6c8fea2	361	}