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| author | Hannes Frederic Sowa <hannes@stressinduktion.org> | 2014-09-12 14:04:43 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2014-09-13 23:07:21 +0200 |
| commit | 233577a22089facf5271ab5e845b2262047c971f (patch) | |
| tree | c93ec43dbf3adb316b3af67a3d315984b3cc5f10 /net/core | |
| parent | net: dsa: change tag_protocol to an enum (diff) | |
| download | linux-233577a22089facf5271ab5e845b2262047c971f.tar.xz linux-233577a22089facf5271ab5e845b2262047c971f.zip | |
net: filter: constify detection of pkt_type_offset
Currently we have 2 pkt_type_offset functions doing the same thing and
spread across the architecture files. Remove those and replace them
with a PKT_TYPE_OFFSET macro helper which gets the constant value from a
zero sized sk_buff member right in front of the bitfield with offsetof.
This new offset marker does not change size of struct sk_buff.
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Markos Chandras <markos.chandras@imgtec.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Daniel Borkmann <dborkman@redhat.com>
Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Signed-off-by: Denis Kirjanov <kda@linux-powerpc.org>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Acked-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/core')
| -rw-r--r-- | net/core/filter.c | 31 |
1 files changed, 2 insertions, 29 deletions
diff --git a/net/core/filter.c b/net/core/filter.c index dfc716ffa44b..601f28de7311 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -87,30 +87,6 @@ int sk_filter(struct sock *sk, struct sk_buff *skb) } EXPORT_SYMBOL(sk_filter); -/* Helper to find the offset of pkt_type in sk_buff structure. We want - * to make sure its still a 3bit field starting at a byte boundary; - * taken from arch/x86/net/bpf_jit_comp.c. - */ -#ifdef __BIG_ENDIAN_BITFIELD -#define PKT_TYPE_MAX (7 << 5) -#else -#define PKT_TYPE_MAX 7 -#endif -static unsigned int pkt_type_offset(void) -{ - struct sk_buff skb_probe = { .pkt_type = ~0, }; - u8 *ct = (u8 *) &skb_probe; - unsigned int off; - - for (off = 0; off < sizeof(struct sk_buff); off++) { - if (ct[off] == PKT_TYPE_MAX) - return off; - } - - pr_err_once("Please fix %s, as pkt_type couldn't be found!\n", __func__); - return -1; -} - static u64 __skb_get_pay_offset(u64 ctx, u64 a, u64 x, u64 r4, u64 r5) { return skb_get_poff((struct sk_buff *)(unsigned long) ctx); @@ -190,11 +166,8 @@ static bool convert_bpf_extensions(struct sock_filter *fp, break; case SKF_AD_OFF + SKF_AD_PKTTYPE: - *insn = BPF_LDX_MEM(BPF_B, BPF_REG_A, BPF_REG_CTX, - pkt_type_offset()); - if (insn->off < 0) - return false; - insn++; + *insn++ = BPF_LDX_MEM(BPF_B, BPF_REG_A, BPF_REG_CTX, + PKT_TYPE_OFFSET()); *insn = BPF_ALU32_IMM(BPF_AND, BPF_REG_A, PKT_TYPE_MAX); #ifdef __BIG_ENDIAN_BITFIELD insn++; |