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| author | Florian Westphal <fw@strlen.de> | 2017-04-16 01:29:15 +0200 |
|---|---|---|
| committer | Pablo Neira Ayuso <pablo@netfilter.org> | 2017-04-19 17:55:16 +0200 |
| commit | dcf67740f22d31be685d7172f05b289c8243ea12 (patch) | |
| tree | e7f9efc1a8a7a1115b15ce1a1576ffa4f58a0c9c /include/net/netfilter | |
| parent | 906535b04671c84ec8731030d4968570d8d2a16c (diff) | |
| download | linux-dcf67740f22d31be685d7172f05b289c8243ea12.tar.gz linux-dcf67740f22d31be685d7172f05b289c8243ea12.tar.bz2 linux-dcf67740f22d31be685d7172f05b289c8243ea12.zip | |
netfilter: helper: add build-time asserts for helper data size
add a 32 byte scratch area in the helper struct instead of relying
on variable sized helpers plus compile-time asserts to let us know
if 32 bytes aren't enough anymore.
Not having variable sized helpers will later allow to add BUILD_BUG_ON
for the total size of conntrack extensions -- the helper extension is
the only one that doesn't have a fixed size.
The (useless!) NF_CT_HELPER_BUILD_BUG_ON(0); are added so that in case
someone adds a new helper and copy-pastes from one that doesn't store
private data at least some indication that this macro should be used
somehow is there...
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Diffstat (limited to 'include/net/netfilter')
| -rw-r--r-- | include/net/netfilter/nf_conntrack_helper.h | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/include/net/netfilter/nf_conntrack_helper.h b/include/net/netfilter/nf_conntrack_helper.h index 15d746558665..29539ed1008f 100644 --- a/include/net/netfilter/nf_conntrack_helper.h +++ b/include/net/netfilter/nf_conntrack_helper.h @@ -66,9 +66,12 @@ struct nf_conn_help { u8 expecting[NF_CT_MAX_EXPECT_CLASSES]; /* private helper information. */ - char data[]; + char data[32] __aligned(8); }; +#define NF_CT_HELPER_BUILD_BUG_ON(structsize) \ + BUILD_BUG_ON((structsize) > FIELD_SIZEOF(struct nf_conn_help, data)) + struct nf_conntrack_helper *__nf_conntrack_helper_find(const char *name, u16 l3num, u8 protonum); |