diff options
Diffstat (limited to 'include/linux/skbuff.h')
| -rw-r--r-- | include/linux/skbuff.h | 93 |
1 files changed, 93 insertions, 0 deletions
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 08074a810164..3ca0dda5a42e 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -2741,6 +2741,99 @@ static inline __sum16 skb_checksum_complete(struct sk_buff *skb) 0 : __skb_checksum_complete(skb); } +/* Check if we need to perform checksum complete validation. + * + * Returns true if checksum complete is needed, false otherwise + * (either checksum is unnecessary or zero checksum is allowed). + */ +static inline bool __skb_checksum_validate_needed(struct sk_buff *skb, + bool zero_okay, + __sum16 check) +{ + if (skb_csum_unnecessary(skb)) { + return false; + } else if (zero_okay && !check) { + skb->ip_summed = CHECKSUM_UNNECESSARY; + return false; + } + + return true; +} + +/* For small packets <= CHECKSUM_BREAK peform checksum complete directly + * in checksum_init. + */ +#define CHECKSUM_BREAK 76 + +/* Validate (init) checksum based on checksum complete. + * + * Return values: + * 0: checksum is validated or try to in skb_checksum_complete. In the latter + * case the ip_summed will not be CHECKSUM_UNNECESSARY and the pseudo + * checksum is stored in skb->csum for use in __skb_checksum_complete + * non-zero: value of invalid checksum + * + */ +static inline __sum16 __skb_checksum_validate_complete(struct sk_buff *skb, + bool complete, + __wsum psum) +{ + if (skb->ip_summed == CHECKSUM_COMPLETE) { + if (!csum_fold(csum_add(psum, skb->csum))) { + skb->ip_summed = CHECKSUM_UNNECESSARY; + return 0; + } + } + + skb->csum = psum; + + if (complete || skb->len <= CHECKSUM_BREAK) + return __skb_checksum_complete(skb); + + return 0; +} + +static inline __wsum null_compute_pseudo(struct sk_buff *skb, int proto) +{ + return 0; +} + +/* Perform checksum validate (init). Note that this is a macro since we only + * want to calculate the pseudo header which is an input function if necessary. + * First we try to validate without any computation (checksum unnecessary) and + * then calculate based on checksum complete calling the function to compute + * pseudo header. + * + * Return values: + * 0: checksum is validated or try to in skb_checksum_complete + * non-zero: value of invalid checksum + */ +#define __skb_checksum_validate(skb, proto, complete, \ + zero_okay, check, compute_pseudo) \ +({ \ + __sum16 __ret = 0; \ + if (__skb_checksum_validate_needed(skb, zero_okay, check)) \ + __ret = __skb_checksum_validate_complete(skb, \ + complete, compute_pseudo(skb, proto)); \ + __ret; \ +}) + +#define skb_checksum_init(skb, proto, compute_pseudo) \ + __skb_checksum_validate(skb, proto, false, false, 0, compute_pseudo) + +#define skb_checksum_init_zero_check(skb, proto, check, compute_pseudo) \ + __skb_checksum_validate(skb, proto, false, true, check, compute_pseudo) + +#define skb_checksum_validate(skb, proto, compute_pseudo) \ + __skb_checksum_validate(skb, proto, true, false, 0, compute_pseudo) + +#define skb_checksum_validate_zero_check(skb, proto, check, \ + compute_pseudo) \ + __skb_checksum_validate_(skb, proto, true, true, check, compute_pseudo) + +#define skb_checksum_simple_validate(skb) \ + __skb_checksum_validate(skb, 0, true, false, 0, null_compute_pseudo) + #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) void nf_conntrack_destroy(struct nf_conntrack *nfct); static inline void nf_conntrack_put(struct nf_conntrack *nfct) |