/**
* batadv_send_skb_packet() - send an already prepared packet
* @skb: the packet to send
* @hard_iface: the interface to use to send the broadcast packet
* @dst_addr: the payload destination
*
* Send out an already prepared packet to the given neighbor or broadcast it
* using the specified interface. Either hard_iface or neigh_node must be not
* NULL.
* If neigh_node is NULL, then the packet is broadcasted using hard_iface,
* otherwise it is sent as unicast to the given neighbor.
*
* Regardless of the return value, the skb is consumed.
*
* Return: A negative errno code is returned on a failure. A success does not
* guarantee the frame will be transmitted as it may be dropped due
* to congestion or traffic shaping.
*/
int batadv_send_skb_packet(struct sk_buff *skb,
struct batadv_hard_iface *hard_iface,
const u8 *dst_addr)
{
struct batadv_priv *bat_priv;
struct ethhdr *ethhdr;
int ret;
bat_priv = netdev_priv(hard_iface->soft_iface);
if (hard_iface->if_status != BATADV_IF_ACTIVE)
goto send_skb_err;
if (unlikely(!hard_iface->net_dev))
goto send_skb_err;
if (!(hard_iface->net_dev->flags & IFF_UP)) {
pr_warn("Interface %s is not up - can't send packet via that interface!\n",
hard_iface->net_dev->name);
goto send_skb_err;
}
/* push to the ethernet header. */
if (batadv_skb_head_push(skb, ETH_HLEN) < 0)
goto send_skb_err;
skb_reset_mac_header(skb);
ethhdr = eth_hdr(skb);
ether_addr_copy(ethhdr->h_source, hard_iface->net_dev->dev_addr);
ether_addr_copy(ethhdr->h_dest, dst_addr);
ethhdr->h_proto = htons(ETH_P_BATMAN);
skb_set_network_header(skb, ETH_HLEN);
skb->protocol = htons(ETH_P_BATMAN);
skb->dev = hard_iface->net_dev;
/* Save a clone of the skb to use when decoding coded packets */
batadv_nc_skb_store_for_decoding(bat_priv, skb);
/* dev_queue_xmit() returns a negative result on error. However on
* congestion and traffic shaping, it drops and returns NET_XMIT_DROP
* (which is > 0). This will not be treated as an error.
*/
ret = dev_queue_xmit(skb);
return net_xmit_eval(ret);
send_skb_err:
kfree_skb(skb);
return NET_XMIT_DROP;
}
/**
* batadv_send_skb_push_fill_unicast() - extend the buffer and initialize the
* common fields for unicast packets
* @skb: the skb carrying the unicast header to initialize
* @hdr_size: amount of bytes to push at the beginning of the skb
* @orig_node: the destination node
*
* Return: false if the buffer extension was not possible or true otherwise.
*/
static bool
batadv_send_skb_push_fill_unicast(struct sk_buff *skb, int hdr_size,
struct batadv_orig_node *orig_node)
{
struct batadv_unicast_packet *unicast_packet;
u8 ttvn = (u8)atomic_read(&orig_node->last_ttvn);
if (batadv_skb_head_push(skb, hdr_size) < 0)
return false;
unicast_packet = (struct batadv_unicast_packet *)skb->data;
unicast_packet->version = BATADV_COMPAT_VERSION;
/* batman packet type: unicast */
unicast_packet->packet_type = BATADV_UNICAST;
/* set unicast ttl */
unicast_packet->ttl = BATADV_TTL;
/* copy the destination for faster routing */
ether_addr_copy(unicast_packet->dest, orig_node->orig);
/* set the destination tt version number */
unicast_packet->ttvn = ttvn;
return true;
}
static int batadv_interface_tx(struct sk_buff *skb,
struct net_device *soft_iface)
{
struct ethhdr *ethhdr = (struct ethhdr *)skb->data;
struct batadv_priv *bat_priv = netdev_priv(soft_iface);
struct batadv_hard_iface *primary_if = NULL;
struct batadv_bcast_packet *bcast_packet;
struct vlan_ethhdr *vhdr;
__be16 ethertype = __constant_htons(ETH_P_BATMAN);
static const uint8_t stp_addr[ETH_ALEN] = {0x01, 0x80, 0xC2, 0x00,
0x00, 0x00};
static const uint8_t ectp_addr[ETH_ALEN] = {0xCF, 0x00, 0x00, 0x00,
0x00, 0x00};
unsigned int header_len = 0;
int data_len = skb->len, ret;
short vid __maybe_unused = -1;
bool do_bcast = false;
uint32_t seqno;
unsigned long brd_delay = 1;
if (atomic_read(&bat_priv->mesh_state) != BATADV_MESH_ACTIVE)
goto dropped;
soft_iface->trans_start = jiffies;
switch (ntohs(ethhdr->h_proto)) {
case ETH_P_8021Q:
vhdr = (struct vlan_ethhdr *)skb->data;
vid = ntohs(vhdr->h_vlan_TCI) & VLAN_VID_MASK;
if (vhdr->h_vlan_encapsulated_proto != ethertype)
break;
/* fall through */
case ETH_P_BATMAN:
goto dropped;
}
if (batadv_bla_tx(bat_priv, skb, vid))
goto dropped;
/* Register the client MAC in the transtable */
if (!is_multicast_ether_addr(ethhdr->h_source))
batadv_tt_local_add(soft_iface, ethhdr->h_source, skb->skb_iif);
/* don't accept stp packets. STP does not help in meshes.
* better use the bridge loop avoidance ...
*
* The same goes for ECTP sent at least by some Cisco Switches,
* it might confuse the mesh when used with bridge loop avoidance.
*/
if (batadv_compare_eth(ethhdr->h_dest, stp_addr))
goto dropped;
if (batadv_compare_eth(ethhdr->h_dest, ectp_addr))
goto dropped;
if (is_multicast_ether_addr(ethhdr->h_dest)) {
do_bcast = true;
switch (atomic_read(&bat_priv->gw_mode)) {
case BATADV_GW_MODE_SERVER:
/* gateway servers should not send dhcp
* requests into the mesh
*/
ret = batadv_gw_is_dhcp_target(skb, &header_len);
if (ret)
goto dropped;
break;
case BATADV_GW_MODE_CLIENT:
/* gateway clients should send dhcp requests
* via unicast to their gateway
*/
ret = batadv_gw_is_dhcp_target(skb, &header_len);
if (ret)
do_bcast = false;
break;
case BATADV_GW_MODE_OFF:
default:
break;
}
}
/* ethernet packet should be broadcasted */
if (do_bcast) {
primary_if = batadv_primary_if_get_selected(bat_priv);
if (!primary_if)
goto dropped;
/* in case of ARP request, we do not immediately broadcasti the
* packet, instead we first wait for DAT to try to retrieve the
* correct ARP entry
*/
if (batadv_dat_snoop_outgoing_arp_request(bat_priv, skb))
brd_delay = msecs_to_jiffies(ARP_REQ_DELAY);
if (batadv_skb_head_push(skb, sizeof(*bcast_packet)) < 0)
goto dropped;
bcast_packet = (struct batadv_bcast_packet *)skb->data;
bcast_packet->header.version = BATADV_COMPAT_VERSION;
bcast_packet->header.ttl = BATADV_TTL;
/* batman packet type: broadcast */
bcast_packet->header.packet_type = BATADV_BCAST;
bcast_packet->reserved = 0;
/* hw address of first interface is the orig mac because only
* this mac is known throughout the mesh
*/
memcpy(bcast_packet->orig,
primary_if->net_dev->dev_addr, ETH_ALEN);
/* set broadcast sequence number */
seqno = atomic_inc_return(&bat_priv->bcast_seqno);
bcast_packet->seqno = htonl(seqno);
batadv_add_bcast_packet_to_list(bat_priv, skb, brd_delay);
/* a copy is stored in the bcast list, therefore removing
* the original skb.
*/
kfree_skb(skb);
/* unicast packet */
} else {
if (atomic_read(&bat_priv->gw_mode) != BATADV_GW_MODE_OFF) {
ret = batadv_gw_out_of_range(bat_priv, skb, ethhdr);
if (ret)
goto dropped;
}
if (batadv_dat_snoop_outgoing_arp_request(bat_priv, skb))
goto dropped;
batadv_dat_snoop_outgoing_arp_reply(bat_priv, skb);
ret = batadv_unicast_send_skb(bat_priv, skb);
if (ret != 0)
goto dropped_freed;
}
batadv_inc_counter(bat_priv, BATADV_CNT_TX);
batadv_add_counter(bat_priv, BATADV_CNT_TX_BYTES, data_len);
goto end;
dropped:
kfree_skb(skb);
dropped_freed:
batadv_inc_counter(bat_priv, BATADV_CNT_TX_DROPPED);
end:
if (primary_if)
batadv_hardif_free_ref(primary_if);
return NETDEV_TX_OK;
}
