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batman-adv: Consume skb in batadv_frag_send_packet

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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: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
This commit is contained in:
Sven Eckelmann 2016-07-17 21:04:02 +02:00 committed by Simon Wunderlich
parent eaac2c876e
commit 8def0be82d
1 changed files with 29 additions and 21 deletions
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50
net/batman-adv/fragmentation.c
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@ -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 @@ err:
* @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;
} }