#include <linux/if_ether.h>
#include <linux/if_arp.h>
+#include <net/arp.h>
#include "main.h"
+#include "hash.h"
#include "distributed-arp-table.h"
#include "hard-interface.h"
#include "originator.h"
#include "send.h"
#include "types.h"
+#include "translation-table.h"
#include "unicast.h"
static void batadv_dat_purge(struct work_struct *work);
}
/**
+ * batadv_arp_hw_src - extract the hw_src field from an ARP packet
+ * @skb: ARP packet
+ * @hdr_size: size of the possible header before the ARP packet
+ *
+ * Returns the value of the hw_src field in the ARP packet
+ */
+static uint8_t *batadv_arp_hw_src(struct sk_buff *skb, int hdr_size)
+{
+ uint8_t *addr;
+
+ addr = (uint8_t *)(skb->data + hdr_size);
+ addr += ETH_HLEN + sizeof(struct arphdr);
+
+ return addr;
+}
+
+/**
+ * batadv_arp_ip_src - extract the ip_src field from an ARP packet
+ * @skb: ARP packet
+ * @hdr_size: size of the possible header before the ARP packet
+ *
+ * Returns the value of the ip_src field in the ARP packet
+ */
+static __be32 batadv_arp_ip_src(struct sk_buff *skb, int hdr_size)
+{
+ return *(__be32 *)(batadv_arp_hw_src(skb, hdr_size) + ETH_ALEN);
+}
+
+/**
+ * batadv_arp_hw_dst - extract the hw_dst field from an ARP packet
+ * @skb: ARP packet
+ * @hdr_size: size of the possible header before the ARP packet
+ *
+ * Returns the value of the hw_dst field in the ARP packet
+ */
+static uint8_t *batadv_arp_hw_dst(struct sk_buff *skb, int hdr_size)
+{
+ return batadv_arp_hw_src(skb, hdr_size) + ETH_ALEN + 4;
+}
+
+/**
+ * batadv_arp_ip_dst - extract the ip_dst field from an ARP packet
+ * @skb: ARP packet
+ * @hdr_size: size of the possible header before the ARP packet
+ *
+ * Returns the value of the ip_dst field in the ARP packet
+ */
+static __be32 batadv_arp_ip_dst(struct sk_buff *skb, int hdr_size)
+{
+ return *(__be32 *)(batadv_arp_hw_src(skb, hdr_size) + ETH_ALEN * 2 + 4);
+}
+
+/**
* batadv_hash_dat - compute the hash value for an IP address
* @data: data to hash
* @size: size of the hash table
batadv_dat_entry_free_ref(dat_entry);
}
+#ifdef CONFIG_BATMAN_ADV_DEBUG
+
+/**
+ * batadv_dbg_arp - print a debug message containing all the ARP packet details
+ * @bat_priv: the bat priv with all the soft interface information
+ * @skb: ARP packet
+ * @type: ARP type
+ * @hdr_size: size of the possible header before the ARP packet
+ * @msg: message to print together with the debugging information
+ */
+static void batadv_dbg_arp(struct batadv_priv *bat_priv, struct sk_buff *skb,
+ uint16_t type, int hdr_size, char *msg)
+{
+ struct batadv_unicast_4addr_packet *unicast_4addr_packet;
+ struct batadv_bcast_packet *bcast_pkt;
+ uint8_t *orig_addr;
+ __be32 ip_src, ip_dst;
+
+ if (msg)
+ batadv_dbg(BATADV_DBG_DAT, bat_priv, "%s\n", msg);
+
+ ip_src = batadv_arp_ip_src(skb, hdr_size);
+ ip_dst = batadv_arp_ip_dst(skb, hdr_size);
+ batadv_dbg(BATADV_DBG_DAT, bat_priv,
+ "ARP MSG = [src: %pM-%pI4 dst: %pM-%pI4]\n",
+ batadv_arp_hw_src(skb, hdr_size), &ip_src,
+ batadv_arp_hw_dst(skb, hdr_size), &ip_dst);
+
+ if (hdr_size == 0)
+ return;
+
+ /* if the ARP packet is encapsulated in a batman packet, let's print
+ * some debug messages
+ */
+ unicast_4addr_packet = (struct batadv_unicast_4addr_packet *)skb->data;
+
+ switch (unicast_4addr_packet->u.header.packet_type) {
+ case BATADV_UNICAST:
+ batadv_dbg(BATADV_DBG_DAT, bat_priv,
+ "* encapsulated within a UNICAST packet\n");
+ break;
+ case BATADV_UNICAST_4ADDR:
+ batadv_dbg(BATADV_DBG_DAT, bat_priv,
+ "* encapsulated within a UNICAST_4ADDR packet (src: %pM)\n",
+ unicast_4addr_packet->src);
+ switch (unicast_4addr_packet->subtype) {
+ case BATADV_P_DAT_DHT_PUT:
+ batadv_dbg(BATADV_DBG_DAT, bat_priv, "* type: DAT_DHT_PUT\n");
+ break;
+ case BATADV_P_DAT_DHT_GET:
+ batadv_dbg(BATADV_DBG_DAT, bat_priv, "* type: DAT_DHT_GET\n");
+ break;
+ case BATADV_P_DAT_CACHE_REPLY:
+ batadv_dbg(BATADV_DBG_DAT, bat_priv,
+ "* type: DAT_CACHE_REPLY\n");
+ break;
+ case BATADV_P_DATA:
+ batadv_dbg(BATADV_DBG_DAT, bat_priv, "* type: DATA\n");
+ break;
+ default:
+ batadv_dbg(BATADV_DBG_DAT, bat_priv, "* type: Unknown (%u)!\n",
+ unicast_4addr_packet->u.header.packet_type);
+ }
+ break;
+ case BATADV_BCAST:
+ bcast_pkt = (struct batadv_bcast_packet *)unicast_4addr_packet;
+ orig_addr = bcast_pkt->orig;
+ batadv_dbg(BATADV_DBG_DAT, bat_priv,
+ "* encapsulated within a BCAST packet (src: %pM)\n",
+ orig_addr);
+ break;
+ default:
+ batadv_dbg(BATADV_DBG_DAT, bat_priv,
+ "* encapsulated within an unknown packet type (0x%x)\n",
+ unicast_4addr_packet->u.header.packet_type);
+ }
+}
+
+#else
+
+static void batadv_dbg_arp(struct batadv_priv *bat_priv, struct sk_buff *skb,
+ uint16_t type, int hdr_size, char *msg)
+{
+}
+
+#endif /* CONFIG_BATMAN_ADV_DEBUG */
+
/**
* batadv_is_orig_node_eligible - check whether a node can be a DHT candidate
* @res: the array with the already selected candidates
*/
static void batadv_dat_hash_free(struct batadv_priv *bat_priv)
{
+ if (!bat_priv->dat.hash)
+ return;
+
__batadv_dat_purge(bat_priv, NULL);
batadv_hash_destroy(bat_priv->dat.hash);
batadv_hardif_free_ref(primary_if);
return 0;
}
+
+/**
+ * batadv_arp_get_type - parse an ARP packet and gets the type
+ * @bat_priv: the bat priv with all the soft interface information
+ * @skb: packet to analyse
+ * @hdr_size: size of the possible header before the ARP packet in the skb
+ *
+ * Returns the ARP type if the skb contains a valid ARP packet, 0 otherwise
+ */
+static uint16_t batadv_arp_get_type(struct batadv_priv *bat_priv,
+ struct sk_buff *skb, int hdr_size)
+{
+ struct arphdr *arphdr;
+ struct ethhdr *ethhdr;
+ __be32 ip_src, ip_dst;
+ uint16_t type = 0;
+
+ /* pull the ethernet header */
+ if (unlikely(!pskb_may_pull(skb, hdr_size + ETH_HLEN)))
+ goto out;
+
+ ethhdr = (struct ethhdr *)(skb->data + hdr_size);
+
+ if (ethhdr->h_proto != htons(ETH_P_ARP))
+ goto out;
+
+ /* pull the ARP payload */
+ if (unlikely(!pskb_may_pull(skb, hdr_size + ETH_HLEN +
+ arp_hdr_len(skb->dev))))
+ goto out;
+
+ arphdr = (struct arphdr *)(skb->data + hdr_size + ETH_HLEN);
+
+ /* Check whether the ARP packet carries a valid
+ * IP information
+ */
+ if (arphdr->ar_hrd != htons(ARPHRD_ETHER))
+ goto out;
+
+ if (arphdr->ar_pro != htons(ETH_P_IP))
+ goto out;
+
+ if (arphdr->ar_hln != ETH_ALEN)
+ goto out;
+
+ if (arphdr->ar_pln != 4)
+ goto out;
+
+ /* Check for bad reply/request. If the ARP message is not sane, DAT
+ * will simply ignore it
+ */
+ ip_src = batadv_arp_ip_src(skb, hdr_size);
+ ip_dst = batadv_arp_ip_dst(skb, hdr_size);
+ if (ipv4_is_loopback(ip_src) || ipv4_is_multicast(ip_src) ||
+ ipv4_is_loopback(ip_dst) || ipv4_is_multicast(ip_dst))
+ goto out;
+
+ type = ntohs(arphdr->ar_op);
+out:
+ return type;
+}
+
+/**
+ * batadv_dat_snoop_outgoing_arp_request - snoop the ARP request and try to
+ * answer using DAT
+ * @bat_priv: the bat priv with all the soft interface information
+ * @skb: packet to check
+ *
+ * Returns true if the message has been sent to the dht candidates, false
+ * otherwise. In case of true the message has to be enqueued to permit the
+ * fallback
+ */
+bool batadv_dat_snoop_outgoing_arp_request(struct batadv_priv *bat_priv,
+ struct sk_buff *skb)
+{
+ uint16_t type = 0;
+ __be32 ip_dst, ip_src;
+ uint8_t *hw_src;
+ bool ret = false;
+ struct batadv_dat_entry *dat_entry = NULL;
+ struct sk_buff *skb_new;
+ struct batadv_hard_iface *primary_if = NULL;
+
+ if (!atomic_read(&bat_priv->distributed_arp_table))
+ goto out;
+
+ type = batadv_arp_get_type(bat_priv, skb, 0);
+ /* If the node gets an ARP_REQUEST it has to send a DHT_GET unicast
+ * message to the selected DHT candidates
+ */
+ if (type != ARPOP_REQUEST)
+ goto out;
+
+ batadv_dbg_arp(bat_priv, skb, type, 0, "Parsing outgoing ARP REQUEST");
+
+ ip_src = batadv_arp_ip_src(skb, 0);
+ hw_src = batadv_arp_hw_src(skb, 0);
+ ip_dst = batadv_arp_ip_dst(skb, 0);
+
+ batadv_dat_entry_add(bat_priv, ip_src, hw_src);
+
+ dat_entry = batadv_dat_entry_hash_find(bat_priv, ip_dst);
+ if (dat_entry) {
+ primary_if = batadv_primary_if_get_selected(bat_priv);
+ if (!primary_if)
+ goto out;
+
+ skb_new = arp_create(ARPOP_REPLY, ETH_P_ARP, ip_src,
+ primary_if->soft_iface, ip_dst, hw_src,
+ dat_entry->mac_addr, hw_src);
+ if (!skb_new)
+ goto out;
+
+ skb_reset_mac_header(skb_new);
+ skb_new->protocol = eth_type_trans(skb_new,
+ primary_if->soft_iface);
+ bat_priv->stats.rx_packets++;
+ bat_priv->stats.rx_bytes += skb->len + ETH_HLEN;
+ primary_if->soft_iface->last_rx = jiffies;
+
+ netif_rx(skb_new);
+ batadv_dbg(BATADV_DBG_DAT, bat_priv, "ARP request replied locally\n");
+ ret = true;
+ } else {
+ /* Send the request on the DHT */
+ ret = batadv_dat_send_data(bat_priv, skb, ip_dst,
+ BATADV_P_DAT_DHT_GET);
+ }
+out:
+ if (dat_entry)
+ batadv_dat_entry_free_ref(dat_entry);
+ if (primary_if)
+ batadv_hardif_free_ref(primary_if);
+ return ret;
+}
+
+/**
+ * batadv_dat_snoop_incoming_arp_request - snoop the ARP request and try to
+ * answer using the local DAT storage
+ * @bat_priv: the bat priv with all the soft interface information
+ * @skb: packet to check
+ * @hdr_size: size of the encapsulation header
+ *
+ * Returns true if the request has been answered, false otherwise
+ */
+bool batadv_dat_snoop_incoming_arp_request(struct batadv_priv *bat_priv,
+ struct sk_buff *skb, int hdr_size)
+{
+ uint16_t type;
+ __be32 ip_src, ip_dst;
+ uint8_t *hw_src;
+ struct sk_buff *skb_new;
+ struct batadv_hard_iface *primary_if = NULL;
+ struct batadv_dat_entry *dat_entry = NULL;
+ bool ret = false;
+ int err;
+
+ if (!atomic_read(&bat_priv->distributed_arp_table))
+ goto out;
+
+ type = batadv_arp_get_type(bat_priv, skb, hdr_size);
+ if (type != ARPOP_REQUEST)
+ goto out;
+
+ hw_src = batadv_arp_hw_src(skb, hdr_size);
+ ip_src = batadv_arp_ip_src(skb, hdr_size);
+ ip_dst = batadv_arp_ip_dst(skb, hdr_size);
+
+ batadv_dbg_arp(bat_priv, skb, type, hdr_size,
+ "Parsing incoming ARP REQUEST");
+
+ batadv_dat_entry_add(bat_priv, ip_src, hw_src);
+
+ dat_entry = batadv_dat_entry_hash_find(bat_priv, ip_dst);
+ if (!dat_entry)
+ goto out;
+
+ primary_if = batadv_primary_if_get_selected(bat_priv);
+ if (!primary_if)
+ goto out;
+
+ skb_new = arp_create(ARPOP_REPLY, ETH_P_ARP, ip_src,
+ primary_if->soft_iface, ip_dst, hw_src,
+ dat_entry->mac_addr, hw_src);
+
+ if (!skb_new)
+ goto out;
+
+ /* to preserve backwards compatibility, here the node has to answer
+ * using the same packet type it received for the request. This is due
+ * to that if a node is not using the 4addr packet format it may not
+ * support it.
+ */
+ if (hdr_size == sizeof(struct batadv_unicast_4addr_packet))
+ err = batadv_unicast_4addr_send_skb(bat_priv, skb_new,
+ BATADV_P_DAT_CACHE_REPLY);
+ else
+ err = batadv_unicast_send_skb(bat_priv, skb_new);
+
+ if (!err)
+ ret = true;
+out:
+ if (dat_entry)
+ batadv_dat_entry_free_ref(dat_entry);
+ if (primary_if)
+ batadv_hardif_free_ref(primary_if);
+ if (ret)
+ kfree_skb(skb);
+ return ret;
+}
+
+/**
+ * batadv_dat_snoop_outgoing_arp_reply - snoop the ARP reply and fill the DHT
+ * @bat_priv: the bat priv with all the soft interface information
+ * @skb: packet to check
+ */
+void batadv_dat_snoop_outgoing_arp_reply(struct batadv_priv *bat_priv,
+ struct sk_buff *skb)
+{
+ uint16_t type;
+ __be32 ip_src, ip_dst;
+ uint8_t *hw_src, *hw_dst;
+
+ if (!atomic_read(&bat_priv->distributed_arp_table))
+ return;
+
+ type = batadv_arp_get_type(bat_priv, skb, 0);
+ if (type != ARPOP_REPLY)
+ return;
+
+ batadv_dbg_arp(bat_priv, skb, type, 0, "Parsing outgoing ARP REPLY");
+
+ hw_src = batadv_arp_hw_src(skb, 0);
+ ip_src = batadv_arp_ip_src(skb, 0);
+ hw_dst = batadv_arp_hw_dst(skb, 0);
+ ip_dst = batadv_arp_ip_dst(skb, 0);
+
+ batadv_dat_entry_add(bat_priv, ip_src, hw_src);
+ batadv_dat_entry_add(bat_priv, ip_dst, hw_dst);
+
+ /* Send the ARP reply to the candidates for both the IP addresses that
+ * the node got within the ARP reply
+ */
+ batadv_dat_send_data(bat_priv, skb, ip_src, BATADV_P_DAT_DHT_PUT);
+ batadv_dat_send_data(bat_priv, skb, ip_dst, BATADV_P_DAT_DHT_PUT);
+}
+/**
+ * batadv_dat_snoop_incoming_arp_reply - snoop the ARP reply and fill the local
+ * DAT storage only
+ * @bat_priv: the bat priv with all the soft interface information
+ * @skb: packet to check
+ * @hdr_size: siaze of the encapsulation header
+ */
+bool batadv_dat_snoop_incoming_arp_reply(struct batadv_priv *bat_priv,
+ struct sk_buff *skb, int hdr_size)
+{
+ uint16_t type;
+ __be32 ip_src, ip_dst;
+ uint8_t *hw_src, *hw_dst;
+ bool ret = false;
+
+ if (!atomic_read(&bat_priv->distributed_arp_table))
+ goto out;
+
+ type = batadv_arp_get_type(bat_priv, skb, hdr_size);
+ if (type != ARPOP_REPLY)
+ goto out;
+
+ batadv_dbg_arp(bat_priv, skb, type, hdr_size,
+ "Parsing incoming ARP REPLY");
+
+ hw_src = batadv_arp_hw_src(skb, hdr_size);
+ ip_src = batadv_arp_ip_src(skb, hdr_size);
+ hw_dst = batadv_arp_hw_dst(skb, hdr_size);
+ ip_dst = batadv_arp_ip_dst(skb, hdr_size);
+
+ /* Update our internal cache with both the IP addresses the node got
+ * within the ARP reply
+ */
+ batadv_dat_entry_add(bat_priv, ip_src, hw_src);
+ batadv_dat_entry_add(bat_priv, ip_dst, hw_dst);
+
+ /* if this REPLY is directed to a client of mine, let's deliver the
+ * packet to the interface
+ */
+ ret = !batadv_is_my_client(bat_priv, hw_dst);
+out:
+ /* if ret == false -> packet has to be delivered to the interface */
+ return ret;
+}
+
+/**
+ * batadv_dat_drop_broadcast_packet - check if an ARP request has to be dropped
+ * (because the node has already got the reply via DAT) or not
+ * @bat_priv: the bat priv with all the soft interface information
+ * @forw_packet: the broadcast packet
+ *
+ * Returns true if the node can drop the packet, false otherwise
+ */
+bool batadv_dat_drop_broadcast_packet(struct batadv_priv *bat_priv,
+ struct batadv_forw_packet *forw_packet)
+{
+ uint16_t type;
+ __be32 ip_dst;
+ struct batadv_dat_entry *dat_entry = NULL;
+ bool ret = false;
+ const size_t bcast_len = sizeof(struct batadv_bcast_packet);
+
+ if (!atomic_read(&bat_priv->distributed_arp_table))
+ goto out;
+
+ /* If this packet is an ARP_REQUEST and the node already has the
+ * information that it is going to ask, then the packet can be dropped
+ */
+ if (forw_packet->num_packets)
+ goto out;
+
+ type = batadv_arp_get_type(bat_priv, forw_packet->skb, bcast_len);
+ if (type != ARPOP_REQUEST)
+ goto out;
+
+ ip_dst = batadv_arp_ip_dst(forw_packet->skb, bcast_len);
+ dat_entry = batadv_dat_entry_hash_find(bat_priv, ip_dst);
+ /* check if the node already got this entry */
+ if (!dat_entry) {
+ batadv_dbg(BATADV_DBG_DAT, bat_priv,
+ "ARP Request for %pI4: fallback\n", &ip_dst);
+ goto out;
+ }
+
+ batadv_dbg(BATADV_DBG_DAT, bat_priv,
+ "ARP Request for %pI4: fallback prevented\n", &ip_dst);
+ ret = true;
+
+out:
+ if (dat_entry)
+ batadv_dat_entry_free_ref(dat_entry);
+ return ret;
+}