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net: skb_gro_checksum_* functions 

Add skb_gro_checksum_validate, skb_gro_checksum_validate_zero_check,
and skb_gro_checksum_simple_validate, and __skb_gro_checksum_complete.
These are the cognates of the normal checksum functions but are used
in the gro_receive path and operate on GRO related fields in sk_buffs.

Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
wifi-calibration
Tom Herbert 2014-08-22 13:33:47 -07:00 committed by David S. Miller
parent 8fc54f6891
commit 573e8fca25
2 changed files with 107 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

76
include/linux/netdevice.h
View File

@ -1883,7 +1883,13 @@ struct napi_gro_cb {
u16 proto;
/* Used in udp_gro_receive */
u16 udp_mark;
u8 udp_mark:1;
/* GRO checksum is valid */
u8 csum_valid:1;
/* Number encapsulation layers crossed */
u8 encapsulation;
/* used to support CHECKSUM_COMPLETE for tunneling protocols */
__wsum csum;
@ -2154,11 +2160,77 @@ static inline void *skb_gro_network_header(struct sk_buff *skb)
static inline void skb_gro_postpull_rcsum(struct sk_buff *skb,
const void *start, unsigned int len)
{
if (skb->ip_summed == CHECKSUM_COMPLETE)
if (NAPI_GRO_CB(skb)->csum_valid)
NAPI_GRO_CB(skb)->csum = csum_sub(NAPI_GRO_CB(skb)->csum,
csum_partial(start, len, 0));
}
/* GRO checksum functions. These are logical equivalents of the normal
* checksum functions (in skbuff.h) except that they operate on the GRO
* offsets and fields in sk_buff.
*/
__sum16 __skb_gro_checksum_complete(struct sk_buff *skb);
static inline bool __skb_gro_checksum_validate_needed(struct sk_buff *skb,
bool zero_okay,
__sum16 check)
{
return (skb->ip_summed != CHECKSUM_PARTIAL &&
(skb->ip_summed != CHECKSUM_UNNECESSARY ||
(NAPI_GRO_CB(skb)->encapsulation > skb->encapsulation)) &&
(!zero_okay || check));
}
static inline __sum16 __skb_gro_checksum_validate_complete(struct sk_buff *skb,
__wsum psum)
{
if (NAPI_GRO_CB(skb)->csum_valid &&
!csum_fold(csum_add(psum, NAPI_GRO_CB(skb)->csum)))
return 0;
NAPI_GRO_CB(skb)->csum = psum;
return __skb_gro_checksum_complete(skb);
}
/* Update skb for CHECKSUM_UNNECESSARY when we verified a top level
* checksum or an encapsulated one during GRO. This saves work
* if we fallback to normal path with the packet.
*/
static inline void skb_gro_incr_csum_unnecessary(struct sk_buff *skb)
{
if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
if (NAPI_GRO_CB(skb)->encapsulation)
skb->encapsulation = 1;
} else if (skb->ip_summed != CHECKSUM_PARTIAL) {
skb->ip_summed = CHECKSUM_UNNECESSARY;
skb->encapsulation = 0;
}
}
#define __skb_gro_checksum_validate(skb, proto, zero_okay, check, \
compute_pseudo) \
({ \
__sum16 __ret = 0; \
if (__skb_gro_checksum_validate_needed(skb, zero_okay, check)) \
__ret = __skb_gro_checksum_validate_complete(skb, \
compute_pseudo(skb, proto)); \
if (!__ret) \
skb_gro_incr_csum_unnecessary(skb); \
__ret; \
})
#define skb_gro_checksum_validate(skb, proto, compute_pseudo) \
__skb_gro_checksum_validate(skb, proto, false, 0, compute_pseudo)
#define skb_gro_checksum_validate_zero_check(skb, proto, check, \
compute_pseudo) \
__skb_gro_checksum_validate(skb, proto, true, check, compute_pseudo)
#define skb_gro_checksum_simple_validate(skb) \
__skb_gro_checksum_validate(skb, 0, false, 0, null_compute_pseudo)
static inline int dev_hard_header(struct sk_buff *skb, struct net_device *dev,
unsigned short type,
const void *daddr, const void *saddr,

34
net/core/dev.c
View File

@ -3962,7 +3962,13 @@ static enum gro_result dev_gro_receive(struct napi_struct *napi, struct sk_buff
goto normal;
gro_list_prepare(napi, skb);
NAPI_GRO_CB(skb)->csum = skb->csum; /* Needed for CHECKSUM_COMPLETE */
if (skb->ip_summed == CHECKSUM_COMPLETE) {
NAPI_GRO_CB(skb)->csum = skb->csum;
NAPI_GRO_CB(skb)->csum_valid = 1;
} else {
NAPI_GRO_CB(skb)->csum_valid = 0;
}
rcu_read_lock();
list_for_each_entry_rcu(ptype, head, list) {
@ -3975,6 +3981,7 @@ static enum gro_result dev_gro_receive(struct napi_struct *napi, struct sk_buff
NAPI_GRO_CB(skb)->flush = 0;
NAPI_GRO_CB(skb)->free = 0;
NAPI_GRO_CB(skb)->udp_mark = 0;
NAPI_GRO_CB(skb)->encapsulation = 0;
pp = ptype->callbacks.gro_receive(&napi->gro_list, skb);
break;
@ -4205,6 +4212,31 @@ gro_result_t napi_gro_frags(struct napi_struct *napi)
}
EXPORT_SYMBOL(napi_gro_frags);
/* Compute the checksum from gro_offset and return the folded value
* after adding in any pseudo checksum.
*/
__sum16 __skb_gro_checksum_complete(struct sk_buff *skb)
{
__wsum wsum;
__sum16 sum;
wsum = skb_checksum(skb, skb_gro_offset(skb), skb_gro_len(skb), 0);
/* NAPI_GRO_CB(skb)->csum holds pseudo checksum */
sum = csum_fold(csum_add(NAPI_GRO_CB(skb)->csum, wsum));
if (likely(!sum)) {
if (unlikely(skb->ip_summed == CHECKSUM_COMPLETE) &&
!skb->csum_complete_sw)
netdev_rx_csum_fault(skb->dev);
}
NAPI_GRO_CB(skb)->csum = wsum;
NAPI_GRO_CB(skb)->csum_valid = 1;
return sum;
}
EXPORT_SYMBOL(__skb_gro_checksum_complete);
/*
* net_rps_action_and_irq_enable sends any pending IPI's for rps.
* Note: called with local irq disabled, but exits with local irq enabled.