From 9c2122559709fe35f493634bc61065b8c0ecb2ad Mon Sep 17 00:00:00 2001 From: =?utf8?q?Micha=C5=82=20Miros=C5=82aw?= Date: Sat, 10 Nov 2018 19:58:35 +0100 Subject: [PATCH] net/bpf: split VLAN_PRESENT bit handling from VLAN_TCI MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Signed-off-by: Michał Mirosław Signed-off-by: David S. Miller --- net/core/filter.c | 40 +++++++++++++++++++++------------------- 1 file changed, 21 insertions(+), 19 deletions(-) diff --git a/net/core/filter.c b/net/core/filter.c index e521c5ebc7d1..c151b906df53 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -296,22 +296,21 @@ 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; } @@ -6140,19 +6139,22 @@ static u32 bpf_convert_ctx_access(enum bpf_access_type type, break; case offsetof(struct __sk_buff, vlan_present): - case offsetof(struct __sk_buff, vlan_tci): - BUILD_BUG_ON(VLAN_TAG_PRESENT != 0x1000); + *target_size = 1; + *insn++ = BPF_LDX_MEM(BPF_B, si->dst_reg, si->src_reg, + PKT_VLAN_PRESENT_OFFSET()); + if (PKT_VLAN_PRESENT_BIT) + *insn++ = BPF_ALU32_IMM(BPF_RSH, si->dst_reg, PKT_VLAN_PRESENT_BIT); + if (PKT_VLAN_PRESENT_BIT < 7) + *insn++ = BPF_ALU32_IMM(BPF_AND, si->dst_reg, 1); + break; + case offsetof(struct __sk_buff, vlan_tci): *insn++ = BPF_LDX_MEM(BPF_H, si->dst_reg, si->src_reg, bpf_target_off(struct sk_buff, vlan_tci, 2, target_size)); - if (si->off == offsetof(struct __sk_buff, vlan_tci)) { - *insn++ = BPF_ALU32_IMM(BPF_AND, si->dst_reg, - ~VLAN_TAG_PRESENT); - } else { - *insn++ = BPF_ALU32_IMM(BPF_RSH, si->dst_reg, 12); - *insn++ = BPF_ALU32_IMM(BPF_AND, si->dst_reg, 1); - } +#ifdef VLAN_TAG_PRESENT + *insn++ = BPF_ALU32_IMM(BPF_AND, si->dst_reg, ~VLAN_TAG_PRESENT); +#endif break; case offsetof(struct __sk_buff, cb[0]) ... -- 2.30.2