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Commit be7af5cf authored by Marek Lindner's avatar Marek Lindner Committed by Sven Eckelmann
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batman-adv: refactoring gateway handling code 



Signed-off-by: default avatarMarek Lindner <lindner_marek@yahoo.de>
Acked-by: default avatarAntonio Quartulli <ordex@autistici.org>
Signed-off-by: default avatarSven Eckelmann <sven@narfation.org>
parent 25a92b13

net/batman-adv/gateway_client.c

+94 −59
Original line number Diff line number Diff line
@@ -25,6 +25,7 @@ 
#include "gateway_common.h"

#include "hard-interface.h"

#include "originator.h"

#include "translation-table.h"

#include "routing.h"

#include <linux/ip.h>

#include <linux/ipv6.h>
@@ -572,108 +573,142 @@ static bool is_type_dhcprequest(struct sk_buff *skb, int header_len) 
	return ret;

}



int gw_is_target(struct bat_priv *bat_priv, struct sk_buff *skb,

		 struct orig_node *old_gw)

bool gw_is_dhcp_target(struct sk_buff *skb, unsigned int *header_len)

{

	struct ethhdr *ethhdr;

	struct iphdr *iphdr;

	struct ipv6hdr *ipv6hdr;

	struct udphdr *udphdr;

	struct gw_node *curr_gw;

	struct neigh_node *neigh_curr = NULL, *neigh_old = NULL;

	unsigned int header_len = 0;

	int ret = 1;



	if (atomic_read(&bat_priv->gw_mode) == GW_MODE_OFF)

		return 0;



	/* check for ethernet header */

	if (!pskb_may_pull(skb, header_len + ETH_HLEN))

		return 0;

	if (!pskb_may_pull(skb, *header_len + ETH_HLEN))

		return false;

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

	header_len += ETH_HLEN;

	*header_len += ETH_HLEN;



	/* check for initial vlan header */

	if (ntohs(ethhdr->h_proto) == ETH_P_8021Q) {

		if (!pskb_may_pull(skb, header_len + VLAN_HLEN))

			return 0;

		if (!pskb_may_pull(skb, *header_len + VLAN_HLEN))

			return false;

		ethhdr = (struct ethhdr *)(skb->data + VLAN_HLEN);

		header_len += VLAN_HLEN;

		*header_len += VLAN_HLEN;

	}



	/* check for ip header */

	switch (ntohs(ethhdr->h_proto)) {

	case ETH_P_IP:

		if (!pskb_may_pull(skb, header_len + sizeof(*iphdr)))

			return 0;

		iphdr = (struct iphdr *)(skb->data + header_len);

		header_len += iphdr->ihl * 4;

		if (!pskb_may_pull(skb, *header_len + sizeof(*iphdr)))

			return false;

		iphdr = (struct iphdr *)(skb->data + *header_len);

		*header_len += iphdr->ihl * 4;



		/* check for udp header */

		if (iphdr->protocol != IPPROTO_UDP)

			return 0;

			return false;



		break;

	case ETH_P_IPV6:

		if (!pskb_may_pull(skb, header_len + sizeof(*ipv6hdr)))

			return 0;

		ipv6hdr = (struct ipv6hdr *)(skb->data + header_len);

		header_len += sizeof(*ipv6hdr);

		if (!pskb_may_pull(skb, *header_len + sizeof(*ipv6hdr)))

			return false;

		ipv6hdr = (struct ipv6hdr *)(skb->data + *header_len);

		*header_len += sizeof(*ipv6hdr);



		/* check for udp header */

		if (ipv6hdr->nexthdr != IPPROTO_UDP)

			return 0;

			return false;



		break;

	default:

		return 0;

		return false;

	}



	if (!pskb_may_pull(skb, header_len + sizeof(*udphdr)))

		return 0;

	udphdr = (struct udphdr *)(skb->data + header_len);

	header_len += sizeof(*udphdr);

	if (!pskb_may_pull(skb, *header_len + sizeof(*udphdr)))

		return false;

	udphdr = (struct udphdr *)(skb->data + *header_len);

	*header_len += sizeof(*udphdr);



	/* check for bootp port */

	if ((ntohs(ethhdr->h_proto) == ETH_P_IP) &&

	     (ntohs(udphdr->dest) != 67))

		return 0;

		return false;



	if ((ntohs(ethhdr->h_proto) == ETH_P_IPV6) &&

	    (ntohs(udphdr->dest) != 547))

		return 0;

		return false;



	return true;

}



	if (atomic_read(&bat_priv->gw_mode) == GW_MODE_SERVER)

		return -1;

bool gw_out_of_range(struct bat_priv *bat_priv,

		     struct sk_buff *skb, struct ethhdr *ethhdr)

{

	struct neigh_node *neigh_curr = NULL, *neigh_old = NULL;

	struct orig_node *orig_dst_node = NULL;

	struct gw_node *curr_gw = NULL;

	bool ret, out_of_range = false;

	unsigned int header_len = 0;

	uint8_t curr_tq_avg;



	ret = gw_is_dhcp_target(skb, &header_len);

	if (!ret)

		goto out;



	orig_dst_node = transtable_search(bat_priv, ethhdr->h_source,

					  ethhdr->h_dest);

	if (!orig_dst_node)

		goto out;



	if (!orig_dst_node->gw_flags)

		goto out;



	ret = is_type_dhcprequest(skb, header_len);

	if (!ret)

		goto out;



	switch (atomic_read(&bat_priv->gw_mode)) {

	case GW_MODE_SERVER:

		/* If we are a GW then we are our best GW. We can artificially

		 * set the tq towards ourself as the maximum value */

		curr_tq_avg = TQ_MAX_VALUE;

		break;

	case GW_MODE_CLIENT:

		curr_gw = gw_get_selected_gw_node(bat_priv);

		if (!curr_gw)

		return 0;

			goto out;



		/* packet is going to our gateway */

		if (curr_gw->orig_node == orig_dst_node)

			goto out;



	/* If old_gw != NULL then this packet is unicast.

	 * So, at this point we have to check the message type: if it is a

	 * DHCPREQUEST we have to decide whether to drop it or not */

	if (old_gw && curr_gw->orig_node != old_gw) {

		if (is_type_dhcprequest(skb, header_len)) {

		/* If the dhcp packet has been sent to a different gw,

		 * we have to evaluate whether the old gw is still

		 * reliable enough */

			neigh_curr = find_router(bat_priv, curr_gw->orig_node,

						 NULL);

			neigh_old = find_router(bat_priv, old_gw, NULL);

			if (!neigh_curr || !neigh_old)

				goto free_neigh;

			if (neigh_curr->tq_avg - neigh_old->tq_avg <

								GW_THRESHOLD)

				ret = -1;

		}

		neigh_curr = find_router(bat_priv, curr_gw->orig_node, NULL);

		if (!neigh_curr)

			goto out;



		curr_tq_avg = neigh_curr->tq_avg;

		break;

	case GW_MODE_OFF:

	default:

		goto out;

	}

free_neigh:



	neigh_old = find_router(bat_priv, orig_dst_node, NULL);

	if (!!neigh_old)

		goto out;



	if (curr_tq_avg - neigh_old->tq_avg > GW_THRESHOLD)

		out_of_range = true;



out:

	if (orig_dst_node)

		orig_node_free_ref(orig_dst_node);

	if (curr_gw)

		gw_node_free_ref(curr_gw);

	if (neigh_old)

		neigh_node_free_ref(neigh_old);

	if (neigh_curr)

		neigh_node_free_ref(neigh_curr);

	if (curr_gw)

		gw_node_free_ref(curr_gw);

	return ret;

	return out_of_range;

}

net/batman-adv/gateway_client.h

+3 −2
Original line number Diff line number Diff line
@@ -31,7 +31,8 @@ void gw_node_update(struct bat_priv *bat_priv, 
void gw_node_delete(struct bat_priv *bat_priv, struct orig_node *orig_node);

void gw_node_purge(struct bat_priv *bat_priv);

int gw_client_seq_print_text(struct seq_file *seq, void *offset);

int gw_is_target(struct bat_priv *bat_priv, struct sk_buff *skb,

		 struct orig_node *old_gw);

bool gw_is_dhcp_target(struct sk_buff *skb, unsigned int *header_len);

bool gw_out_of_range(struct bat_priv *bat_priv,

		     struct sk_buff *skb, struct ethhdr *ethhdr);



#endif /* _NET_BATMAN_ADV_GATEWAY_CLIENT_H_ */

net/batman-adv/soft-interface.c

+29 −14
Original line number Diff line number Diff line
@@ -563,10 +563,10 @@ static int interface_tx(struct sk_buff *skb, struct net_device *soft_iface) 
	struct bcast_packet *bcast_packet;

	struct vlan_ethhdr *vhdr;

	struct softif_neigh *curr_softif_neigh = NULL;

	struct orig_node *orig_node = NULL;

	unsigned int header_len = 0;

	int data_len = skb->len, ret;

	short vid = -1;

	bool do_bcast;

	bool do_bcast = false;



	if (atomic_read(&bat_priv->mesh_state) != MESH_ACTIVE)

		goto dropped;
@@ -598,17 +598,28 @@ static int interface_tx(struct sk_buff *skb, struct net_device *soft_iface) 
	/* Register the client MAC in the transtable */

	tt_local_add(soft_iface, ethhdr->h_source, skb->skb_iif);



	orig_node = transtable_search(bat_priv, ethhdr->h_source,

				      ethhdr->h_dest);

	do_bcast = is_multicast_ether_addr(ethhdr->h_dest);

	if (do_bcast || (orig_node && orig_node->gw_flags)) {

		ret = gw_is_target(bat_priv, skb, orig_node);

	if (is_multicast_ether_addr(ethhdr->h_dest)) {

		do_bcast = true;



		if (ret < 0)

		switch (atomic_read(&bat_priv->gw_mode)) {

		case GW_MODE_SERVER:

			/* gateway servers should not send dhcp

			 * requests into the mesh */

			ret = gw_is_dhcp_target(skb, &header_len);

			if (ret)

				goto dropped;



			break;

		case GW_MODE_CLIENT:

			/* gateway clients should send dhcp requests

			 * via unicast to their gateway */

			ret = gw_is_dhcp_target(skb, &header_len);

			if (ret)

				do_bcast = false;

			break;

		case GW_MODE_OFF:

		default:

			break;

		}

	}



	/* ethernet packet should be broadcasted */
@@ -644,6 +655,12 @@ static int interface_tx(struct sk_buff *skb, struct net_device *soft_iface) 


	/* unicast packet */

	} else {

		if (atomic_read(&bat_priv->gw_mode) != GW_MODE_OFF) {

			ret = gw_out_of_range(bat_priv, skb, ethhdr);

			if (ret)

				goto dropped;

		}



		ret = unicast_send_skb(skb, bat_priv);

		if (ret != 0)

			goto dropped_freed;
@@ -662,8 +679,6 @@ static int interface_tx(struct sk_buff *skb, struct net_device *soft_iface) 
		softif_neigh_free_ref(curr_softif_neigh);

	if (primary_if)

		hardif_free_ref(primary_if);

	if (orig_node)

		orig_node_free_ref(orig_node);

	return NETDEV_TX_OK;

}