Re: [PATCH net-next 2/6] net/bpf: split VLAN_PRESENT bit handling from VLAN_TCI
From: Daniel Borkmann <daniel@iogearbox.net>
Date: 2018-11-19 11:29:07
Also in:
linuxppc-dev, netdev, sparclinux
On 11/10/2018 07:58 PM, Michał Mirosław wrote:
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Why you have empty commit messages for non-trivial changes like this in 4 out of 6 of your patches ... How was it tested on the JITs you were changing? Did you test on both, big and little endian machines?
quoted hunk ↗ jump to hunk
--- 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): + *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): - BUILD_BUG_ON(VLAN_TAG_PRESENT != 0x1000); - *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]) ...