From 8def0be82dd1507bcdc5fd35d12e35ace1e39dff Mon Sep 17 00:00:00 2001 From: Sven Eckelmann Date: Sun, 17 Jul 2016 21:04:02 +0200 Subject: [PATCH] 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 Signed-off-by: Simon Wunderlich --- 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 a2e28a12cca8..9c561e683f4b 100644 --- a/net/batman-adv/fragmentation.c +++ b/net/batman-adv/fragmentation.c @@ -20,6 +20,7 @@ #include #include +#include #include #include #include @@ -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; } -- 2.20.1