diff options
| -rw-r--r-- | arch/x86/net/bpf_jit_comp.c | 40 |
1 files changed, 39 insertions, 1 deletions
diff --git a/arch/x86/net/bpf_jit_comp.c b/arch/x86/net/bpf_jit_comp.c index d11a47099d33..3cbe45381bbb 100644 --- a/arch/x86/net/bpf_jit_comp.c +++ b/arch/x86/net/bpf_jit_comp.c @@ -1,6 +1,6 @@ /* bpf_jit_comp.c : BPF JIT compiler * - * Copyright (C) 2011 Eric Dumazet (eric.dumazet@gmail.com) + * Copyright (C) 2011-2013 Eric Dumazet (eric.dumazet@gmail.com) * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License @@ -124,6 +124,26 @@ static inline void bpf_flush_icache(void *start, void *end) #define CHOOSE_LOAD_FUNC(K, func) \ ((int)K < 0 ? ((int)K >= SKF_LL_OFF ? func##_negative_offset : func) : func##_positive_offset) +/* Helper to find the offset of pkt_type in sk_buff + * We want to make sure its still a 3bit field starting at a byte boundary. + */ +#define PKT_TYPE_MAX 7 +static int pkt_type_offset(void) +{ + struct sk_buff skb_probe = { + .pkt_type = ~0, + }; + char *ct = (char *)&skb_probe; + unsigned int off; + + for (off = 0; off < sizeof(struct sk_buff); off++) { + if (ct[off] == PKT_TYPE_MAX) + return off; + } + pr_err_once("Please fix pkt_type_offset(), as pkt_type couldn't be found\n"); + return -1; +} + void bpf_jit_compile(struct sk_filter *fp) { u8 temp[64]; @@ -216,6 +236,7 @@ void bpf_jit_compile(struct sk_filter *fp) case BPF_S_ANC_VLAN_TAG: case BPF_S_ANC_VLAN_TAG_PRESENT: case BPF_S_ANC_QUEUE: + case BPF_S_ANC_PKTTYPE: case BPF_S_LD_W_ABS: case BPF_S_LD_H_ABS: case BPF_S_LD_B_ABS: @@ -536,6 +557,23 @@ void bpf_jit_compile(struct sk_filter *fp) EMIT3(0x83, 0xe0, 0x01); /* and $0x1,%eax */ } break; + case BPF_S_ANC_PKTTYPE: + { + int off = pkt_type_offset(); + + if (off < 0) + goto out; + if (is_imm8(off)) { + /* movzbl off8(%rdi),%eax */ + EMIT4(0x0f, 0xb6, 0x47, off); + } else { + /* movbl off32(%rdi),%eax */ + EMIT3(0x0f, 0xb6, 0x87); + EMIT(off, 4); + } + EMIT3(0x83, 0xe0, PKT_TYPE_MAX); /* and $0x7,%eax */ + break; + } case BPF_S_LD_W_ABS: func = CHOOSE_LOAD_FUNC(K, sk_load_word); common_load: seen |= SEEN_DATAREF; |