Commit 8def0be8 authored by Sven Eckelmann's avatar Sven Eckelmann Committed by Simon Wunderlich
Browse files

batman-adv: Consume skb in batadv_frag_send_packet 



Sending functions in Linux consume the supplied skbuff. Doing the same in
batadv_frag_send_packet avoids the hack of returning -1 (-EPERM) to signal
the caller that he is responsible for cleaning up the skb.

Signed-off-by: default avatarSven Eckelmann <sven@narfation.org>
Signed-off-by: default avatarSimon Wunderlich <sw@simonwunderlich.de>
parent eaac2c87

net/batman-adv/fragmentation.c

+29 −21
Original line number Original line Diff line number Diff line
@@ -20,6 +20,7 @@ 




#include <linux/atomic.h>

#include <linux/atomic.h>

#include <linux/byteorder/generic.h>

#include <linux/byteorder/generic.h>

#include <linux/errno.h>

#include <linux/etherdevice.h>

#include <linux/etherdevice.h>

#include <linux/fs.h>

#include <linux/fs.h>

#include <linux/if_ether.h>

#include <linux/if_ether.h>
@@ -441,8 +442,7 @@ static struct sk_buff *batadv_frag_create(struct sk_buff *skb, 
 * @orig_node: final destination of the created fragments

 * @orig_node: final destination of the created fragments

 * @neigh_node: next-hop of the created fragments

 * @neigh_node: next-hop of the created fragments

 *

 *

 * Return: the netdev tx status or -1 in case of error.

 * Return: the netdev tx status or a negative errno code on a failure

 * When -1 is returned the skb is not consumed.

 */

 */

int batadv_frag_send_packet(struct sk_buff *skb,

int batadv_frag_send_packet(struct sk_buff *skb,

			    struct batadv_orig_node *orig_node,

			    struct batadv_orig_node *orig_node,
@@ -455,7 +455,7 @@ int batadv_frag_send_packet(struct sk_buff *skb, 
	unsigned int mtu = neigh_node->if_incoming->net_dev->mtu;

	unsigned int mtu = neigh_node->if_incoming->net_dev->mtu;

	unsigned int header_size = sizeof(frag_header);

	unsigned int header_size = sizeof(frag_header);

	unsigned int max_fragment_size, max_packet_size;

	unsigned int max_fragment_size, max_packet_size;

	int ret = -1;

	int ret;





	/* To avoid merge and refragmentation at next-hops we never send

	/* To avoid merge and refragmentation at next-hops we never send

	 * fragments larger than BATADV_FRAG_MAX_FRAG_SIZE

	 * fragments larger than BATADV_FRAG_MAX_FRAG_SIZE
@@ -465,13 +465,17 @@ int batadv_frag_send_packet(struct sk_buff *skb, 
	max_packet_size = max_fragment_size * BATADV_FRAG_MAX_FRAGMENTS;

	max_packet_size = max_fragment_size * BATADV_FRAG_MAX_FRAGMENTS;





	/* Don't even try to fragment, if we need more than 16 fragments */

	/* Don't even try to fragment, if we need more than 16 fragments */

	if (skb->len > max_packet_size)

	if (skb->len > max_packet_size) {

		goto out;

		ret = -EAGAIN;

		goto free_skb;

	}





	bat_priv = orig_node->bat_priv;

	bat_priv = orig_node->bat_priv;

	primary_if = batadv_primary_if_get_selected(bat_priv);

	primary_if = batadv_primary_if_get_selected(bat_priv);

	if (!primary_if)

	if (!primary_if) {

		goto out;

		ret = -EINVAL;

		goto put_primary_if;

	}





	/* Create one header to be copied to all fragments */

	/* Create one header to be copied to all fragments */

	frag_header.packet_type = BATADV_UNICAST_FRAG;

	frag_header.packet_type = BATADV_UNICAST_FRAG;
@@ -496,34 +500,35 @@ int batadv_frag_send_packet(struct sk_buff *skb, 
	/* Eat and send fragments from the tail of skb */

	/* Eat and send fragments from the tail of skb */

	while (skb->len > max_fragment_size) {

	while (skb->len > max_fragment_size) {

		skb_fragment = batadv_frag_create(skb, &frag_header, mtu);

		skb_fragment = batadv_frag_create(skb, &frag_header, mtu);

		if (!skb_fragment)

		if (!skb_fragment) {

			goto out;

			ret = -ENOMEM;

			goto free_skb;

		}





		batadv_inc_counter(bat_priv, BATADV_CNT_FRAG_TX);

		batadv_inc_counter(bat_priv, BATADV_CNT_FRAG_TX);

		batadv_add_counter(bat_priv, BATADV_CNT_FRAG_TX_BYTES,

		batadv_add_counter(bat_priv, BATADV_CNT_FRAG_TX_BYTES,

				   skb_fragment->len + ETH_HLEN);

				   skb_fragment->len + ETH_HLEN);

		ret = batadv_send_unicast_skb(skb_fragment, neigh_node);

		ret = batadv_send_unicast_skb(skb_fragment, neigh_node);

		if (ret != NET_XMIT_SUCCESS) {

		if (ret != NET_XMIT_SUCCESS) {

			/* return -1 so that the caller can free the original

			ret = NET_XMIT_DROP;

			 * skb

			goto free_skb;

			 */

			ret = -1;

			goto out;

		}

		}





		frag_header.no++;

		frag_header.no++;





		/* The initial check in this function should cover this case */

		/* The initial check in this function should cover this case */

		if (frag_header.no == BATADV_FRAG_MAX_FRAGMENTS - 1) {

		if (frag_header.no == BATADV_FRAG_MAX_FRAGMENTS - 1) {

			ret = -1;

			ret = -EINVAL;

			goto out;

			goto free_skb;

		}

		}

	}

	}





	/* Make room for the fragment header. */

	/* Make room for the fragment header. */

	if (batadv_skb_head_push(skb, header_size) < 0 ||

	if (batadv_skb_head_push(skb, header_size) < 0 ||

	    pskb_expand_head(skb, header_size + ETH_HLEN, 0, GFP_ATOMIC) < 0)

	    pskb_expand_head(skb, header_size + ETH_HLEN, 0, GFP_ATOMIC) < 0) {

		goto out;

		ret = -ENOMEM;

		goto free_skb;

	}





	memcpy(skb->data, &frag_header, header_size);

	memcpy(skb->data, &frag_header, header_size);
@@ -532,10 +537,13 @@ int batadv_frag_send_packet(struct sk_buff *skb, 
	batadv_add_counter(bat_priv, BATADV_CNT_FRAG_TX_BYTES,

	batadv_add_counter(bat_priv, BATADV_CNT_FRAG_TX_BYTES,

			   skb->len + ETH_HLEN);

			   skb->len + ETH_HLEN);

	ret = batadv_send_unicast_skb(skb, neigh_node);

	ret = batadv_send_unicast_skb(skb, neigh_node);

	/* skb was consumed */

	skb = NULL;





out:

put_primary_if:

	if (primary_if)

	batadv_hardif_put(primary_if);

	batadv_hardif_put(primary_if);

free_skb:

	kfree_skb(skb);





	return ret;

	return ret;

}
 
}