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| author | Eric Dumazet <edumazet@google.com> | 2022-06-20 02:30:17 -0700 |
|---|---|---|
| committer | Paolo Abeni <pabeni@redhat.com> | 2022-06-21 11:21:57 +0200 |
| commit | f9aefd6b2aa38b9787d2705f0f1161dfd23cdb8f (patch) | |
| tree | ed4ae23ea4d26b4a7a7d9f93b4fa74f933d29db5 /include/linux/skbuff.h | |
| parent | 4336487e30c37a2e82a1fed2370d3134cc5b6505 (diff) | |
| download | lwn-f9aefd6b2aa38b9787d2705f0f1161dfd23cdb8f.tar.gz lwn-f9aefd6b2aa38b9787d2705f0f1161dfd23cdb8f.zip | |
net: warn if mac header was not set
Make sure skb_mac_header(), skb_mac_offset() and skb_mac_header_len() uses
are not fooled if the mac header has not been set.
These checks are enabled if CONFIG_DEBUG_NET=y
This commit will likely expose existing bugs in linux networking stacks.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20220620093017.3366713-1-eric.dumazet@gmail.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Diffstat (limited to 'include/linux/skbuff.h')
| -rw-r--r-- | include/linux/skbuff.h | 12 |
1 files changed, 7 insertions, 5 deletions
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 82edf0359ab3..cd4a8268894a 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -2763,8 +2763,14 @@ static inline void skb_set_network_header(struct sk_buff *skb, const int offset) skb->network_header += offset; } +static inline int skb_mac_header_was_set(const struct sk_buff *skb) +{ + return skb->mac_header != (typeof(skb->mac_header))~0U; +} + static inline unsigned char *skb_mac_header(const struct sk_buff *skb) { + DEBUG_NET_WARN_ON_ONCE(!skb_mac_header_was_set(skb)); return skb->head + skb->mac_header; } @@ -2775,14 +2781,10 @@ static inline int skb_mac_offset(const struct sk_buff *skb) static inline u32 skb_mac_header_len(const struct sk_buff *skb) { + DEBUG_NET_WARN_ON_ONCE(!skb_mac_header_was_set(skb)); return skb->network_header - skb->mac_header; } -static inline int skb_mac_header_was_set(const struct sk_buff *skb) -{ - return skb->mac_header != (typeof(skb->mac_header))~0U; -} - static inline void skb_unset_mac_header(struct sk_buff *skb) { skb->mac_header = (typeof(skb->mac_header))~0U; |