igmp: avoid two atomic ops in igmp_rcv()
in_dev_get() -> __in_dev_get_rcu() in a rcu protected function. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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66018506e1
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9a57a9d291
1 changed files with 4 additions and 6 deletions
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@ -916,18 +916,19 @@ static void igmp_heard_query(struct in_device *in_dev, struct sk_buff *skb,
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read_unlock(&in_dev->mc_list_lock);
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}
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/* called in rcu_read_lock() section */
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int igmp_rcv(struct sk_buff *skb)
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{
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/* This basically follows the spec line by line -- see RFC1112 */
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struct igmphdr *ih;
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struct in_device *in_dev = in_dev_get(skb->dev);
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struct in_device *in_dev = __in_dev_get_rcu(skb->dev);
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int len = skb->len;
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if (in_dev == NULL)
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goto drop;
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if (!pskb_may_pull(skb, sizeof(struct igmphdr)))
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goto drop_ref;
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goto drop;
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switch (skb->ip_summed) {
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case CHECKSUM_COMPLETE:
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@ -937,7 +938,7 @@ int igmp_rcv(struct sk_buff *skb)
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case CHECKSUM_NONE:
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skb->csum = 0;
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if (__skb_checksum_complete(skb))
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goto drop_ref;
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goto drop;
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}
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ih = igmp_hdr(skb);
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@ -957,7 +958,6 @@ int igmp_rcv(struct sk_buff *skb)
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break;
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case IGMP_PIM:
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#ifdef CONFIG_IP_PIMSM_V1
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in_dev_put(in_dev);
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return pim_rcv_v1(skb);
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#endif
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case IGMPV3_HOST_MEMBERSHIP_REPORT:
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@ -971,8 +971,6 @@ int igmp_rcv(struct sk_buff *skb)
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break;
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}
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drop_ref:
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in_dev_put(in_dev);
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drop:
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kfree_skb(skb);
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return 0;
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