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authorXin Long <lucien.xin@gmail.com>2023-01-28 18:58:30 +0300
committerJakub Kicinski <kuba@kernel.org>2023-02-02 07:54:27 +0300
commit058a8f7f73aae1cc22b53fcefec031b9e391b54d (patch)
tree84e3a78af92605ddbc9897dd46432d5c18d1696b /include/linux/ip.h
parentd8673afbf51036ed1d72d9828d0d679035bb0d54 (diff)
downloadlinux-058a8f7f73aae1cc22b53fcefec031b9e391b54d.tar.xz
net: add a couple of helpers for iph tot_len
This patch adds three APIs to replace the iph->tot_len setting and getting in all places where IPv4 BIG TCP packets may reach, they will be used in the following patches. Note that iph_totlen() will be used when iph is not in linear data of the skb. Signed-off-by: Xin Long <lucien.xin@gmail.com> Reviewed-by: David Ahern <dsahern@kernel.org> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'include/linux/ip.h')
-rw-r--r--include/linux/ip.h21
1 files changed, 21 insertions, 0 deletions
diff --git a/include/linux/ip.h b/include/linux/ip.h
index 3d9c6750af62..d11c25f5030a 100644
--- a/include/linux/ip.h
+++ b/include/linux/ip.h
@@ -35,4 +35,25 @@ static inline unsigned int ip_transport_len(const struct sk_buff *skb)
{
return ntohs(ip_hdr(skb)->tot_len) - skb_network_header_len(skb);
}
+
+static inline unsigned int iph_totlen(const struct sk_buff *skb, const struct iphdr *iph)
+{
+ u32 len = ntohs(iph->tot_len);
+
+ return (len || !skb_is_gso(skb) || !skb_is_gso_tcp(skb)) ?
+ len : skb->len - skb_network_offset(skb);
+}
+
+static inline unsigned int skb_ip_totlen(const struct sk_buff *skb)
+{
+ return iph_totlen(skb, ip_hdr(skb));
+}
+
+/* IPv4 datagram length is stored into 16bit field (tot_len) */
+#define IP_MAX_MTU 0xFFFFU
+
+static inline void iph_set_totlen(struct iphdr *iph, unsigned int len)
+{
+ iph->tot_len = len <= IP_MAX_MTU ? htons(len) : 0;
+}
#endif /* _LINUX_IP_H */