diff options
| author | Tom Herbert <therbert@google.com> | 2014-08-31 15:12:41 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2014-09-01 21:36:27 -0700 |
| commit | 5a21232983aa7acfe7fd26170832a9e0a4a7b4ae (patch) | |
| tree | 460b541ed810999e911bf64b51443fb1b4f04c30 /include | |
| parent | 52aec126c42819899793b9ffbd3f2e25705ba096 (diff) | |
net: Support for csum_bad in skbuff
This flag indicates that an invalid checksum was detected in the
packet. __skb_mark_checksum_bad helper function was added to set this.
Checksums can be marked bad from a driver or the GRO path (the latter
is implemented in this patch). csum_bad is checked in
__skb_checksum_validate_complete (i.e. calling that when ip_summed ==
CHECKSUM_NONE).
csum_bad works in conjunction with ip_summed value. In the case that
ip_summed is CHECKSUM_NONE and csum_bad is set, this implies that the
first (or next) checksum encountered in the packet is bad. When
ip_summed is CHECKSUM_UNNECESSARY, the first checksum after the last
one validated is bad. For example, if ip_summed == CHECKSUM_UNNECESSARY,
csum_level == 1, and csum_bad is set-- then the third checksum in the
packet is bad. In the normal path, the packet will be dropped when
processing the protocol layer of the bad checksum:
__skb_decr_checksum_unnecessary called twice for the good checksums
changing ip_summed to CHECKSUM_NONE so that
__skb_checksum_validate_complete is called to validate the third
checksum and that will fail since csum_bad is set.
Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/netdevice.h | 4 | ||||
| -rw-r--r-- | include/linux/skbuff.h | 21 |
2 files changed, 23 insertions, 2 deletions
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 202c25a9aadf..a0ab6d9d400a 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -2216,7 +2216,9 @@ static inline void skb_gro_incr_csum_unnecessary(struct sk_buff *skb) if (__skb_gro_checksum_validate_needed(skb, zero_okay, check)) \ __ret = __skb_gro_checksum_validate_complete(skb, \ compute_pseudo(skb, proto)); \ - if (!__ret) \ + if (__ret) \ + __skb_mark_checksum_bad(skb); \ + else \ skb_gro_incr_csum_unnecessary(skb); \ __ret; \ }) diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index c93b5859a772..23710a243439 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -617,7 +617,8 @@ struct sk_buff { kmemcheck_bitfield_begin(flags3); __u8 csum_level:2; - /* 14 bit hole */ + __u8 csum_bad:1; + /* 13 bit hole */ kmemcheck_bitfield_end(flags3); __be16 inner_protocol; @@ -2825,6 +2826,21 @@ static inline void __skb_incr_checksum_unnecessary(struct sk_buff *skb) } } +static inline void __skb_mark_checksum_bad(struct sk_buff *skb) +{ + /* Mark current checksum as bad (typically called from GRO + * path). In the case that ip_summed is CHECKSUM_NONE + * this must be the first checksum encountered in the packet. + * When ip_summed is CHECKSUM_UNNECESSARY, this is the first + * checksum after the last one validated. For UDP, a zero + * checksum can not be marked as bad. + */ + + if (skb->ip_summed == CHECKSUM_NONE || + skb->ip_summed == CHECKSUM_UNNECESSARY) + skb->csum_bad = 1; +} + /* Check if we need to perform checksum complete validation. * * Returns true if checksum complete is needed, false otherwise @@ -2866,6 +2882,9 @@ static inline __sum16 __skb_checksum_validate_complete(struct sk_buff *skb, skb->csum_valid = 1; return 0; } + } else if (skb->csum_bad) { + /* ip_summed == CHECKSUM_NONE in this case */ + return 1; } skb->csum = psum; |