@@ -572,7 +572,8 @@ struct sk_buff {
*/
__u8 encapsulation:1;
__u8 encap_hdr_csum:1;
- /* 5/7 bit hole (depending on ndisc_nodetype presence) */
+ __u8 csum_valid:1;
+ /* 4/6 bit hole (depending on ndisc_nodetype presence) */
kmemcheck_bitfield_end(flags2);
#if defined CONFIG_NET_DMA || defined CONFIG_NET_RX_BUSY_POLL
@@ -2721,7 +2722,7 @@ __sum16 __skb_checksum_complete(struct sk_buff *skb);
static inline int skb_csum_unnecessary(const struct sk_buff *skb)
{
- return skb->ip_summed & CHECKSUM_UNNECESSARY;
+ return ((skb->ip_summed & CHECKSUM_UNNECESSARY) || skb->csum_valid);
}
/**
@@ -2755,10 +2756,8 @@ 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;
+ if (skb_csum_unnecessary(skb) || (zero_okay && !check)) {
+ skb->csum_valid = 1;
return false;
}
@@ -2785,15 +2784,20 @@ static inline __sum16 __skb_checksum_validate_complete(struct sk_buff *skb,
{
if (skb->ip_summed == CHECKSUM_COMPLETE) {
if (!csum_fold(csum_add(psum, skb->csum))) {
- skb->ip_summed = CHECKSUM_UNNECESSARY;
+ skb->csum_valid = 1;
return 0;
}
}
skb->csum = psum;
- if (complete || skb->len <= CHECKSUM_BREAK)
- return __skb_checksum_complete(skb);
+ if (complete || skb->len <= CHECKSUM_BREAK) {
+ __sum16 csum;
+
+ csum = __skb_checksum_complete(skb);
+ skb->csum_valid = !csum;
+ return csum;
+ }
return 0;
}
@@ -2817,6 +2821,7 @@ static inline __wsum null_compute_pseudo(struct sk_buff *skb, int proto)
zero_okay, check, compute_pseudo) \
({ \
__sum16 __ret = 0; \
+ skb->csum_valid = 0; \
if (__skb_checksum_validate_needed(skb, zero_okay, check)) \
__ret = __skb_checksum_validate_complete(skb, \
complete, compute_pseudo(skb, proto)); \
Currently when the first checksum in a packet is validated using CHECKSUM_COMPLETE, ip_summed is overwritten to be CHECKSUM_UNNECESSARY so that any subsequent checksums in the packet are not correctly validated. This patch adds csum_valid flag in sk_buff and uses that to indicate validated checksum instead of setting CHECKSUM_UNNECESSARY. The bit is set accordingly in the skb_checksum_validate_* functions. The flag is checked in skb_checksum_complete, so that validation is communicated between checksum_init and checksum_complete sequence in TCP and UDP. Signed-off-by: Tom Herbert <therbert@google.com> --- include/linux/skbuff.h | 23 ++++++++++++++--------- 1 file changed, 14 insertions(+), 9 deletions(-)