From 058a8f7f73aae1cc22b53fcefec031b9e391b54d Mon Sep 17 00:00:00 2001 From: Xin Long Date: Sat, 28 Jan 2023 10:58:30 -0500 Subject: 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 Reviewed-by: David Ahern Reviewed-by: Eric Dumazet Signed-off-by: Jakub Kicinski --- include/linux/ip.h | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) (limited to 'include/linux/ip.h') 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 */ -- cgit v1.2.3