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authorLinus Lüssing <linus.luessing@c0d3.blue>2019-01-21 07:26:25 +0100
committerDavid S. Miller <davem@davemloft.net>2019-01-22 17:18:08 -0800
commitba5ea614622dca6d675b4cc8a97270569ae13a23 (patch)
tree9bcc70bdcaa5cb0b19a1c625c470e70571327d0e /include/linux/ip.h
parent6679cf099b81994884246612538bd4c7fb935b30 (diff)
bridge: simplify ip_mc_check_igmp() and ipv6_mc_check_mld() calls
This patch refactors ip_mc_check_igmp(), ipv6_mc_check_mld() and their callers (more precisely, the Linux bridge) to not rely on the skb_trimmed parameter anymore. An skb with its tail trimmed to the IP packet length was initially introduced for the following three reasons: 1) To be able to verify the ICMPv6 checksum. 2) To be able to distinguish the version of an IGMP or MLD query. They are distinguishable only by their size. 3) To avoid parsing data for an IGMPv3 or MLDv2 report that is beyond the IP packet but still within the skb. The first case still uses a cloned and potentially trimmed skb to verfiy. However, there is no need to propagate it to the caller. For the second and third case explicit IP packet length checks were added. This hopefully makes ip_mc_check_igmp() and ipv6_mc_check_mld() easier to read and verfiy, as well as easier to use. Signed-off-by: Linus Lüssing <linus.luessing@c0d3.blue> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include/linux/ip.h')
-rw-r--r--include/linux/ip.h5
1 files changed, 5 insertions, 0 deletions
diff --git a/include/linux/ip.h b/include/linux/ip.h
index 492bc6513533..482b7b7c9f30 100644
--- a/include/linux/ip.h
+++ b/include/linux/ip.h
@@ -34,4 +34,9 @@ static inline struct iphdr *ipip_hdr(const struct sk_buff *skb)
{
return (struct iphdr *)skb_transport_header(skb);
}
+
+static inline unsigned int ip_transport_len(const struct sk_buff *skb)
+{
+ return ntohs(ip_hdr(skb)->tot_len) - skb_network_header_len(skb);
+}
#endif /* _LINUX_IP_H */