Repository : ssh://git@open-mesh.org/batman-adv

On branch : master

commit 8b4132b1447a4afececa894ac618510e9de4f3e8 Author: Sven Eckelmann sven@narfation.org Date: Sun Jul 17 21:04:02 2016 +0200

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: Sven Eckelmann sven@narfation.org Signed-off-by: Simon Wunderlich sw@simonwunderlich.de

8b4132b1447a4afececa894ac618510e9de4f3e8 net/batman-adv/fragmentation.c | 50 ++++++++++++++++++++++++------------------ 1 file changed, 29 insertions(+), 21 deletions(-)

diff --git a/net/batman-adv/fragmentation.c b/net/batman-adv/fragmentation.c index a2e28a1..9c561e6 100644 --- a/net/batman-adv/fragmentation.c +++ b/net/batman-adv/fragmentation.c @@ -20,6 +20,7 @@

#include <linux/atomic.h> #include <linux/byteorder/generic.h> +#include <linux/errno.h> #include <linux/etherdevice.h> #include <linux/fs.h> #include <linux/if_ether.h> @@ -441,8 +442,7 @@ err: * @orig_node: final destination of the created fragments * @neigh_node: next-hop of the created fragments * - * Return: the netdev tx status or -1 in case of error. - * When -1 is returned the skb is not consumed. + * Return: the netdev tx status or a negative errno code on a failure */ int batadv_frag_send_packet(struct sk_buff *skb, 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 header_size = sizeof(frag_header); unsigned int max_fragment_size, max_packet_size; - int ret = -1; + int ret;

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

/* Don't even try to fragment, if we need more than 16 fragments */ - if (skb->len > max_packet_size) - goto out; + if (skb->len > max_packet_size) { + ret = -EAGAIN; + goto free_skb; + }

bat_priv = orig_node->bat_priv; primary_if = batadv_primary_if_get_selected(bat_priv); - if (!primary_if) - goto out; + if (!primary_if) { + ret = -EINVAL; + goto put_primary_if; + }

/* Create one header to be copied to all fragments */ 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 */ while (skb->len > max_fragment_size) { skb_fragment = batadv_frag_create(skb, &frag_header, mtu); - if (!skb_fragment) - goto out; + if (!skb_fragment) { + ret = -ENOMEM; + goto free_skb; + }

batadv_inc_counter(bat_priv, BATADV_CNT_FRAG_TX); batadv_add_counter(bat_priv, BATADV_CNT_FRAG_TX_BYTES, skb_fragment->len + ETH_HLEN); ret = batadv_send_unicast_skb(skb_fragment, neigh_node); if (ret != NET_XMIT_SUCCESS) { - /* return -1 so that the caller can free the original - * skb - */ - ret = -1; - goto out; + ret = NET_XMIT_DROP; + goto free_skb; }

frag_header.no++;

/* The initial check in this function should cover this case */ if (frag_header.no == BATADV_FRAG_MAX_FRAGMENTS - 1) { - ret = -1; - goto out; + ret = -EINVAL; + goto free_skb; } }

/* Make room for the fragment header. */ if (batadv_skb_head_push(skb, header_size) < 0 || - pskb_expand_head(skb, header_size + ETH_HLEN, 0, GFP_ATOMIC) < 0) - goto out; + pskb_expand_head(skb, header_size + ETH_HLEN, 0, GFP_ATOMIC) < 0) { + ret = -ENOMEM; + goto free_skb; + }

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, skb->len + ETH_HLEN); ret = batadv_send_unicast_skb(skb, neigh_node); + /* skb was consumed */ + skb = NULL;

-out: - if (primary_if) - batadv_hardif_put(primary_if); +put_primary_if: + batadv_hardif_put(primary_if); +free_skb: + kfree_skb(skb);

return ret; }