PPC: bpf_jit_comp: add SKF_AD_HATYPE instruction

Add BPF extension SKF_AD_HATYPE to ppc JIT to check
the hw type of the interface

Before:
[   57.723666] test_bpf: #20 LD_HATYPE
[   57.723675] BPF filter opcode 0020 (@0) unsupported
[   57.724168] 48 48 PASS

After:
[  103.053184] test_bpf: #20 LD_HATYPE 7 6 PASS

CC: Alexei Starovoitov<alexei.starovoitov@gmail.com>
CC: Daniel Borkmann<dborkman@redhat.com>
CC: Philippe Bergheaud<felix@linux.vnet.ibm.com>
Signed-off-by: Denis Kirjanov <kda@linux-powerpc.org>

v2: address Alexei's comments
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 13 insertions, 4 deletions

diff --git a/arch/powerpc/net/bpf_jit_comp.c b/arch/powerpc/net/bpf_jit_comp.c
index d110e288d7ac..d3fa80d04e6b 100644
--- a/arch/powerpc/net/bpf_jit_comp.c
+++ b/arch/powerpc/net/bpf_jit_comp.c
@@ -361,6 +361,11 @@ static int bpf_jit_build_body(struct bpf_prog *fp, u32 *image,
                                                             protocol));
                         break;
                 case BPF_ANC | SKF_AD_IFINDEX:
+                case BPF_ANC | SKF_AD_HATYPE:
+                        BUILD_BUG_ON(FIELD_SIZEOF(struct net_device,
+                                                ifindex) != 4);
+                        BUILD_BUG_ON(FIELD_SIZEOF(struct net_device,
+                                                type) != 2);
                         PPC_LD_OFFS(r_scratch1, r_skb, offsetof(struct sk_buff,
                                                                 dev));
                         PPC_CMPDI(r_scratch1, 0);
@@ -368,14 +373,18 @@ static int bpf_jit_build_body(struct bpf_prog *fp, u32 *image,
                                 PPC_BCC(COND_EQ, addrs[ctx->pc_ret0]);
                         } else {
                                 /* Exit, returning 0; first pass hits here. */
-                                PPC_BCC_SHORT(COND_NE, (ctx->idx*4)+12);
+                                PPC_BCC_SHORT(COND_NE, ctx->idx * 4 + 12);
                                 PPC_LI(r_ret, 0);
                                 PPC_JMP(exit_addr);
                         }
-                        BUILD_BUG_ON(FIELD_SIZEOF(struct net_device,
-                                                  ifindex) != 4);
-                        PPC_LWZ_OFFS(r_A, r_scratch1,
+                        if (code == (BPF_ANC | SKF_AD_IFINDEX)) {
+                                PPC_LWZ_OFFS(r_A, r_scratch1,
                                      offsetof(struct net_device, ifindex));
+                        } else {
+                                PPC_LHZ_OFFS(r_A, r_scratch1,
+                                     offsetof(struct net_device, type));
+                        }
+
                         break;
                 case BPF_ANC | SKF_AD_MARK:
                         BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, mark) != 4);