/**
* batadv_bla_process_claim
* @bat_priv: the bat priv with all the soft interface information
* @primary_if: the primary hard interface of this batman soft interface
* @skb: the frame to be checked
*
* Check if this is a claim frame, and process it accordingly.
*
* returns 1 if it was a claim frame, otherwise return 0 to
* tell the callee that it can use the frame on its own.
*/
static int batadv_bla_process_claim(struct batadv_priv *bat_priv,
struct batadv_hard_iface *primary_if,
struct sk_buff *skb)
{
struct batadv_bla_claim_dst *bla_dst, *bla_dst_own;
uint8_t *hw_src, *hw_dst;
struct vlan_hdr *vhdr, vhdr_buf;
struct ethhdr *ethhdr;
struct arphdr *arphdr;
unsigned short vid;
int vlan_depth = 0;
__be16 proto;
int headlen;
int ret;
vid = batadv_get_vid(skb, 0);
ethhdr = eth_hdr(skb);
proto = ethhdr->h_proto;
headlen = ETH_HLEN;
if (vid & BATADV_VLAN_HAS_TAG) {
/* Traverse the VLAN/Ethertypes.
*
* At this point it is known that the first protocol is a VLAN
* header, so start checking at the encapsulated protocol.
*
* The depth of the VLAN headers is recorded to drop BLA claim
* frames encapsulated into multiple VLAN headers (QinQ).
*/
do {
vhdr = skb_header_pointer(skb, headlen, VLAN_HLEN,
&vhdr_buf);
if (!vhdr)
return 0;
proto = vhdr->h_vlan_encapsulated_proto;
headlen += VLAN_HLEN;
vlan_depth++;
} while (proto == htons(ETH_P_8021Q));
}
if (proto != htons(ETH_P_ARP))
return 0; /* not a claim frame */
/* this must be a ARP frame. check if it is a claim. */
if (unlikely(!pskb_may_pull(skb, headlen + arp_hdr_len(skb->dev))))
return 0;
/* pskb_may_pull() may have modified the pointers, get ethhdr again */
ethhdr = eth_hdr(skb);
arphdr = (struct arphdr *)((uint8_t *)ethhdr + headlen);
/* Check whether the ARP frame carries a valid
* IP information
*/
if (arphdr->ar_hrd != htons(ARPHRD_ETHER))
return 0;
if (arphdr->ar_pro != htons(ETH_P_IP))
return 0;
if (arphdr->ar_hln != ETH_ALEN)
return 0;
if (arphdr->ar_pln != 4)
return 0;
hw_src = (uint8_t *)arphdr + sizeof(struct arphdr);
hw_dst = hw_src + ETH_ALEN + 4;
bla_dst = (struct batadv_bla_claim_dst *)hw_dst;
bla_dst_own = &bat_priv->bla.claim_dest;
/* check if it is a claim frame in general */
if (memcmp(bla_dst->magic, bla_dst_own->magic,
sizeof(bla_dst->magic)) != 0)
return 0;
/* check if there is a claim frame encapsulated deeper in (QinQ) and
* drop that, as this is not supported by BLA but should also not be
* sent via the mesh.
*/
if (vlan_depth > 1)
return 1;
/* check if it is a claim frame. */
ret = batadv_check_claim_group(bat_priv, primary_if, hw_src, hw_dst,
ethhdr);
if (ret == 1)
batadv_dbg(BATADV_DBG_BLA, bat_priv,
"bla_process_claim(): received a claim frame from another group. From: %pM on vid %d ...(hw_src %pM, hw_dst %pM)\n",
ethhdr->h_source, BATADV_PRINT_VID(vid), hw_src,
hw_dst);
if (ret < 2)
return ret;
/* become a backbone gw ourselves on this vlan if not happened yet */
batadv_bla_update_own_backbone_gw(bat_priv, primary_if, vid);
/* check for the different types of claim frames ... */
switch (bla_dst->type) {
case BATADV_CLAIM_TYPE_CLAIM:
if (batadv_handle_claim(bat_priv, primary_if, hw_src,
ethhdr->h_source, vid))
return 1;
break;
case BATADV_CLAIM_TYPE_UNCLAIM:
if (batadv_handle_unclaim(bat_priv, primary_if,
ethhdr->h_source, hw_src, vid))
return 1;
break;
case BATADV_CLAIM_TYPE_ANNOUNCE:
if (batadv_handle_announce(bat_priv, hw_src, ethhdr->h_source,
vid))
return 1;
break;
case BATADV_CLAIM_TYPE_REQUEST:
if (batadv_handle_request(bat_priv, primary_if, hw_src, ethhdr,
vid))
return 1;
break;
}
batadv_dbg(BATADV_DBG_BLA, bat_priv,
"bla_process_claim(): ERROR - this looks like a claim frame, but is useless. eth src %pM on vid %d ...(hw_src %pM, hw_dst %pM)\n",
ethhdr->h_source, BATADV_PRINT_VID(vid), hw_src, hw_dst);
return 1;
}
/* @bat_priv: the bat priv with all the soft interface information
* @skb: the frame to be checked
*
* Check if this is a claim frame, and process it accordingly.
*
* returns 1 if it was a claim frame, otherwise return 0 to
* tell the callee that it can use the frame on its own.
*/
static int batadv_bla_process_claim(struct batadv_priv *bat_priv,
struct batadv_hard_iface *primary_if,
struct sk_buff *skb)
{
struct ethhdr *ethhdr;
struct vlan_ethhdr *vhdr;
struct arphdr *arphdr;
uint8_t *hw_src, *hw_dst;
struct batadv_bla_claim_dst *bla_dst;
uint16_t proto;
int headlen;
short vid = -1;
int ret;
ethhdr = (struct ethhdr *)skb_mac_header(skb);
if (ntohs(ethhdr->h_proto) == ETH_P_8021Q) {
vhdr = (struct vlan_ethhdr *)ethhdr;
vid = ntohs(vhdr->h_vlan_TCI) & VLAN_VID_MASK;
proto = ntohs(vhdr->h_vlan_encapsulated_proto);
headlen = sizeof(*vhdr);
} else {
proto = ntohs(ethhdr->h_proto);
headlen = ETH_HLEN;
}
if (proto != ETH_P_ARP)
return 0; /* not a claim frame */
/* this must be a ARP frame. check if it is a claim. */
if (unlikely(!pskb_may_pull(skb, headlen + arp_hdr_len(skb->dev))))
return 0;
/* pskb_may_pull() may have modified the pointers, get ethhdr again */
ethhdr = (struct ethhdr *)skb_mac_header(skb);
arphdr = (struct arphdr *)((uint8_t *)ethhdr + headlen);
/* Check whether the ARP frame carries a valid
* IP information
*/
if (arphdr->ar_hrd != htons(ARPHRD_ETHER))
return 0;
if (arphdr->ar_pro != htons(ETH_P_IP))
return 0;
if (arphdr->ar_hln != ETH_ALEN)
return 0;
if (arphdr->ar_pln != 4)
return 0;
hw_src = (uint8_t *)arphdr + sizeof(struct arphdr);
hw_dst = hw_src + ETH_ALEN + 4;
bla_dst = (struct batadv_bla_claim_dst *)hw_dst;
/* check if it is a claim frame. */
ret = batadv_check_claim_group(bat_priv, primary_if, hw_src, hw_dst,
ethhdr);
if (ret == 1)
batadv_dbg(BATADV_DBG_BLA, bat_priv,
"bla_process_claim(): received a claim frame from another group. From: %pM on vid %d ...(hw_src %pM, hw_dst %pM)\n",
ethhdr->h_source, vid, hw_src, hw_dst);
if (ret < 2)
return ret;
/* become a backbone gw ourselves on this vlan if not happened yet */
batadv_bla_update_own_backbone_gw(bat_priv, primary_if, vid);
/* check for the different types of claim frames ... */
switch (bla_dst->type) {
case BATADV_CLAIM_TYPE_CLAIM:
if (batadv_handle_claim(bat_priv, primary_if, hw_src,
ethhdr->h_source, vid))
return 1;
break;
case BATADV_CLAIM_TYPE_UNCLAIM:
if (batadv_handle_unclaim(bat_priv, primary_if,
ethhdr->h_source, hw_src, vid))
return 1;
break;
case BATADV_CLAIM_TYPE_ANNOUNCE:
if (batadv_handle_announce(bat_priv, hw_src, ethhdr->h_source,
vid))
return 1;
break;
case BATADV_CLAIM_TYPE_REQUEST:
if (batadv_handle_request(bat_priv, primary_if, hw_src, ethhdr,
vid))
return 1;
break;
}
batadv_dbg(BATADV_DBG_BLA, bat_priv,
"bla_process_claim(): ERROR - this looks like a claim frame, but is useless. eth src %pM on vid %d ...(hw_src %pM, hw_dst %pM)\n",
ethhdr->h_source, vid, hw_src, hw_dst);
return 1;
}
