@@ -188,22 +188,21 @@ static u32 convert_skb_access(int skb_field, int dst_reg, int src_reg,
break;
case SKF_AD_VLAN_TAG:
- case SKF_AD_VLAN_TAG_PRESENT:
BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, vlan_tci) != 2);
- BUILD_BUG_ON(VLAN_TAG_PRESENT != 0x1000);
/* dst_reg = *(u16 *) (src_reg + offsetof(vlan_tci)) */
*insn++ = BPF_LDX_MEM(BPF_H, dst_reg, src_reg,
offsetof(struct sk_buff, vlan_tci));
- if (skb_field == SKF_AD_VLAN_TAG) {
- *insn++ = BPF_ALU32_IMM(BPF_AND, dst_reg,
- ~VLAN_TAG_PRESENT);
- } else {
- /* dst_reg >>= 12 */
- *insn++ = BPF_ALU32_IMM(BPF_RSH, dst_reg, 12);
- /* dst_reg &= 1 */
+#ifdef VLAN_TAG_PRESENT
+ *insn++ = BPF_ALU32_IMM(BPF_AND, dst_reg, ~VLAN_TAG_PRESENT);
+#endif
+ break;
+ case SKF_AD_VLAN_TAG_PRESENT:
+ *insn++ = BPF_LDX_MEM(BPF_B, dst_reg, src_reg, PKT_VLAN_PRESENT_OFFSET());
+ if (PKT_VLAN_PRESENT_BIT)
+ *insn++ = BPF_ALU32_IMM(BPF_RSH, dst_reg, PKT_VLAN_PRESENT_BIT);
+ if (PKT_VLAN_PRESENT_BIT < 7)
*insn++ = BPF_ALU32_IMM(BPF_AND, dst_reg, 1);
- }
break;
}
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl> --- v2: save an insn on big-endiands net/core/filter.c | 19 +++++++++---------- 1 file changed, 9 insertions(+), 10 deletions(-)