diff options
| author | Michal Sekletar <msekleta@redhat.com> | 2015-03-24 14:48:41 +0100 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2015-03-24 15:25:15 -0400 |
| commit | 27cd5452476978283decb19e429e81fc6c71e74b (patch) | |
| tree | a147d4576190e18580589e6faaf08e1b7050ef2d /net/core | |
| parent | f6bb76cd4d8552bada1e454c291419f893e1af7b (diff) | |
filter: introduce SKF_AD_VLAN_TPID BPF extension
If vlan offloading takes place then vlan header is removed from frame
and its contents, both vlan_tci and vlan_proto, is available to user
space via TPACKET interface. However, only vlan_tci can be used in BPF
filters.
This commit introduces a new BPF extension. It makes possible to load
the value of vlan_proto (vlan TPID) to register A. Support for classic
BPF and eBPF is being added, analogous to skb->protocol.
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Jiri Pirko <jpirko@redhat.com>
Signed-off-by: Michal Sekletar <msekleta@redhat.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Reviewed-by: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/core')
| -rw-r--r-- | net/core/filter.c | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/net/core/filter.c b/net/core/filter.c index 084eacc4d1d4..32f43c59908c 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -272,6 +272,16 @@ static bool convert_bpf_extensions(struct sock_filter *fp, insn += cnt - 1; break; + case SKF_AD_OFF + SKF_AD_VLAN_TPID: + BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, vlan_proto) != 2); + + /* A = *(u16 *) (CTX + offsetof(vlan_proto)) */ + *insn++ = BPF_LDX_MEM(BPF_H, BPF_REG_A, BPF_REG_CTX, + offsetof(struct sk_buff, vlan_proto)); + /* A = ntohs(A) [emitting a nop or swap16] */ + *insn = BPF_ENDIAN(BPF_FROM_BE, BPF_REG_A, 16); + break; + case SKF_AD_OFF + SKF_AD_PAY_OFFSET: case SKF_AD_OFF + SKF_AD_NLATTR: case SKF_AD_OFF + SKF_AD_NLATTR_NEST: @@ -1226,6 +1236,13 @@ static u32 sk_filter_convert_ctx_access(int dst_reg, int src_reg, int ctx_off, offsetof(struct sk_buff, protocol)); break; + case offsetof(struct __sk_buff, vlan_proto): + BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, vlan_proto) != 2); + + *insn++ = BPF_LDX_MEM(BPF_H, dst_reg, src_reg, + offsetof(struct sk_buff, vlan_proto)); + break; + case offsetof(struct __sk_buff, mark): return convert_skb_access(SKF_AD_MARK, dst_reg, src_reg, insn); |