0 7!li~ *j"TrN\h bѿ 0ai~ *j"TrN\h bѿ # dN #/* SPDX-License-Identifier: GPL-2.0-or-later */ #ifndef _NET_GSO_H #define _NET_GSO_H #include /* Keeps track of mac header offset relative to skb->head. * It is useful for TSO of Tunneling protocol. e.g. GRE. * For non-tunnel skb it points to skb_mac_header() and for * tunnel skb it points to outer mac header. * Keeps track of level of encapsulation of network headers. */ struct skb_gso_cb { union { int mac_offset; int data_offset; }; int encap_level; __wsum csum; __u16 csum_start; }; #define SKB_GSO_CB_OFFSET 32 #define SKB_GSO_CB(skb) ((struct skb_gso_cb *)((skb)->cb + SKB_GSO_CB_OFFSET)) static inline int skb_tnl_header_len(const struct sk_buff *inner_skb) { return (skb_mac_header(inner_skb) - inner_skb->head) - SKB_GSO_CB(inner_skb)->mac_offset; } static inline int gso_pskb_expand_head(struct sk_buff *skb, int extra) { int new_headroom, headroom; int ret; headroom = skb_headroom(skb); ret = pskb_expand_head(skb, extra, 0, GFP_ATOMIC); if (ret) return ret; new_headroom = skb_headroom(skb); SKB_GSO_CB(skb)->mac_offset += (new_headroom - headroom); return 0; } static inline void gso_reset_checksum(struct sk_buff *skb, __wsum res) { /* Do not update partial checksums if remote checksum is enabled. */ if (skb->remcsum_offload) return; SKB_GSO_CB(skb)->csum = res; SKB_GSO_CB(skb)->csum_start = skb_checksum_start(skb) - skb->head; } /* Compute the checksum for a gso segment. First compute the checksum value * from the start of transport header to SKB_GSO_CB(skb)->csum_start, and * then add in skb->csum (checksum from csum_start to end of packet). * skb->csum and csum_start are then updated to reflect the checksum of the * resultant packet starting from the transport header-- the resultant checksum * is in the res argument (i.e. normally zero or ~ of checksum of a pseudo * header. */ static inline __sum16 gso_make_checksum(struct sk_buff *skb, __wsum res) { unsigned char *csum_start = skb_transport_header(skb); int plen = (skb->head + SKB_GSO_CB(skb)->csum_start) - csum_start; __wsum partial = SKB_GSO_CB(skb)->csum; SKB_GSO_CB(skb)->csum = res; SKB_GSO_CB(skb)->csum_start = csum_start - skb->head; return csum_fold(csum_partial(csum_start, plen, partial)); } struct sk_buff *__skb_gso_segment(struct sk_buff *skb, netdev_features_t features, bool tx_path); static inline struct sk_buff *skb_gso_segment(struct sk_buff *skb, netdev_features_t features) { return __skb_gso_segment(skb, features, true); } struct sk_buff *skb_eth_gso_segment(struct sk_buff *skb, netdev_features_t features, __be16 type); struct sk_buff *skb_mac_gso_segment(struct sk_buff *skb, netdev_features_t features); bool skb_gso_validate_network_len(const struct sk_buff *skb, unsigned int mtu); bool skb_gso_validate_mac_len(const struct sk_buff *skb, unsigned int len); static inline void skb_gso_error_unwind(struct sk_buff *skb, __be16 protocol, int pulled_hlen, u16 mac_offset, int mac_len) { skb->protocol = protocol; skb->encapsulation = 1; skb_push(skb, pulled_hlen); skb_reset_transport_header(skb); skb->mac_header = mac_offset; skb->network_header = skb->mac_header + mac_len; skb->mac_len = mac_len; } #endif /* _NET_GSO_H */ +%li~ҁvpF m9_I|M% Index of new symbols in 2.2.0: HarfBuzz Manual