xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

netfilter: helper: add build-time asserts for helper data size

Browse Source 
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>
This commit is contained in:
Florian Westphal
2017-04-16 01:29:15 +02:00
committed by Pablo Neira Ayuso
parent 906535b046
commit dcf67740f2
9 changed files with 20 additions and 1 deletions
Download Patch File Download Diff File Expand all files Collapse all files

5
include/net/netfilter/nf_conntrack_helper.h
View File

@@ -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);