Commit 058a8f7f authored by Xin Long's avatar Xin Long Committed by Jakub Kicinski
Browse files

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: default avatarXin Long <lucien.xin@gmail.com>
Reviewed-by: default avatarDavid Ahern <dsahern@kernel.org>
Reviewed-by: default avatarEric Dumazet <edumazet@google.com>
Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent d8673afb

include/linux/ip.h

+21 −0
Original line number Diff line number Diff line
@@ -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 */

include/net/route.h

+0 −3
Original line number Diff line number Diff line
@@ -35,9 +35,6 @@ 
#include <linux/cache.h>

#include <linux/security.h>



/* IPv4 datagram length is stored into 16bit field (tot_len) */

#define IP_MAX_MTU	0xFFFFU



#define RTO_ONLINK	0x01



#define RT_CONN_FLAGS(sk)   (RT_TOS(inet_sk(sk)->tos) | sock_flag(sk, SOCK_LOCALROUTE))