include/net/gso.h

8 /* Keeps track of mac header offset relative to skb->head.
10  * For non-tunnel skb it points to skb_mac_header() and for
11  * tunnel skb it points to outer mac header.
24 #define SKB_GSO_CB(skb) ((struct skb_gso_cb *)((skb)->cb + SKB_GSO_CB_OFFSET))
32 static inline int gso_pskb_expand_head(struct sk_buff *skb, int extra)
37 	headroom = skb_headroom(skb);
38 	ret = pskb_expand_head(skb, extra, 0, GFP_ATOMIC);
42 	new_headroom = skb_headroom(skb);
43 	SKB_GSO_CB(skb)->mac_offset += (new_headroom - headroom);
47 static inline void gso_reset_checksum(struct sk_buff *skb, __wsum res)
50 	if (skb->remcsum_offload)
53 	SKB_GSO_CB(skb)->csum = res;
54 	SKB_GSO_CB(skb)->csum_start = skb_checksum_start(skb) - skb->head;
58  * from the start of transport header to SKB_GSO_CB(skb)->csum_start, and
59  * then add in skb->csum (checksum from csum_start to end of packet).
60  * skb->csum and csum_start are then updated to reflect the checksum of the
65 static inline __sum16 gso_make_checksum(struct sk_buff *skb, __wsum res)
67 	unsigned char *csum_start = skb_transport_header(skb);
68 	int plen = (skb->head + SKB_GSO_CB(skb)->csum_start) - csum_start;
69 	__wsum partial = SKB_GSO_CB(skb)->csum;
71 	SKB_GSO_CB(skb)->csum = res;
72 	SKB_GSO_CB(skb)->csum_start = csum_start - skb->head;
77 struct sk_buff *__skb_gso_segment(struct sk_buff *skb,
80 static inline struct sk_buff *skb_gso_segment(struct sk_buff *skb,
83 	return __skb_gso_segment(skb, features, true);
86 struct sk_buff *skb_eth_gso_segment(struct sk_buff *skb,
89 struct sk_buff *skb_mac_gso_segment(struct sk_buff *skb,
92 bool skb_gso_validate_network_len(const struct sk_buff *skb, unsigned int mtu);
94 bool skb_gso_validate_mac_len(const struct sk_buff *skb, unsigned int len);
96 static inline void skb_gso_error_unwind(struct sk_buff *skb, __be16 protocol,
100 	skb->protocol = protocol;
101 	skb->encapsulation = 1;
102 	skb_push(skb, pulled_hlen);
103 	skb_reset_transport_header(skb);
104 	skb->mac_header = mac_offset;
105 	skb->network_header = skb->mac_header + mac_len;
106 	skb->mac_len = mac_len;