From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chema Gonzalez Subject: [PATCH] net: filter: add insn for loading internal transport header offset Date: Wed, 30 Apr 2014 11:29:51 -0700 Message-ID: <1398882591-30422-1-git-send-email-chema@google.com> Cc: Chema Gonzalez , netdev@vger.kernel.org To: "David S. Miller" , Eric Dumazet , Alexei Starovoitov Return-path: Received: from mail-ve0-f201.google.com ([209.85.128.201]:60165 "EHLO mail-ve0-f201.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758931AbaD3S34 (ORCPT ); Wed, 30 Apr 2014 14:29:56 -0400 Received: by mail-ve0-f201.google.com with SMTP id jy13so310168veb.2 for ; Wed, 30 Apr 2014 11:29:55 -0700 (PDT) Sender: netdev-owner@vger.kernel.org List-ID: Patch adds an ANC_TRA_OFFSET insn that loads the internal transport header of a packet ("internal" meaning after decapsulation by the flow dissector). Signed-off-by: Chema Gonzalez --- include/linux/filter.h | 1 + include/uapi/linux/filter.h | 3 ++- net/core/filter.c | 17 +++++++++++++++++ tools/net/bpf_exp.l | 1 + tools/net/bpf_exp.y | 11 ++++++++++- 5 files changed, 31 insertions(+), 2 deletions(-) diff --git a/include/linux/filter.h b/include/linux/filter.h index 759abf7..b76ae2b 100644 --- a/include/linux/filter.h +++ b/include/linux/filter.h @@ -224,6 +224,7 @@ enum { BPF_S_ANC_VLAN_TAG_PRESENT, BPF_S_ANC_PAY_OFFSET, BPF_S_ANC_RANDOM, + BPF_S_ANC_TRA_OFFSET, }; #endif /* __LINUX_FILTER_H__ */ diff --git a/include/uapi/linux/filter.h b/include/uapi/linux/filter.h index 253b4d4..9f1b8f1 100644 --- a/include/uapi/linux/filter.h +++ b/include/uapi/linux/filter.h @@ -131,7 +131,8 @@ struct sock_fprog { /* Required for SO_ATTACH_FILTER. */ #define SKF_AD_VLAN_TAG_PRESENT 48 #define SKF_AD_PAY_OFFSET 52 #define SKF_AD_RANDOM 56 -#define SKF_AD_MAX 60 +#define SKF_AD_TRA_OFFSET 60 +#define SKF_AD_MAX 64 #define SKF_NET_OFF (-0x100000) #define SKF_LL_OFF (-0x200000) diff --git a/net/core/filter.c b/net/core/filter.c index 7c4db3d..e31846a 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -601,6 +601,17 @@ static u64 __skb_get_pay_offset(u64 ctx, u64 A, u64 X, u64 r4, u64 r5) return __skb_get_poff(skb); } +static u64 __skb_get_tra_offset(u64 ctx, u64 A, u64 X, u64 r4, u64 r5) +{ + struct flow_keys keys; + struct sk_buff *skb = (struct sk_buff *)(long) ctx; + + if (!skb_flow_dissect(skb, &keys)) + return 0; + + return keys.thoff; +} + static u64 __skb_get_nlattr(u64 ctx, u64 A, u64 X, u64 r4, u64 r5) { struct sk_buff *skb = (struct sk_buff *)(long) ctx; @@ -788,6 +799,7 @@ static bool convert_bpf_extensions(struct sock_filter *fp, case SKF_AD_OFF + SKF_AD_NLATTR_NEST: case SKF_AD_OFF + SKF_AD_CPU: case SKF_AD_OFF + SKF_AD_RANDOM: + case SKF_AD_OFF + SKF_AD_TRA_OFFSET: /* arg1 = ctx */ insn->code = BPF_ALU64 | BPF_MOV | BPF_X; insn->a_reg = ARG1_REG; @@ -824,6 +836,9 @@ static bool convert_bpf_extensions(struct sock_filter *fp, case SKF_AD_OFF + SKF_AD_RANDOM: insn->imm = __get_random_u32 - __bpf_call_base; break; + case SKF_AD_OFF + SKF_AD_TRA_OFFSET: + insn->imm = __skb_get_tra_offset - __bpf_call_base; + break; } break; @@ -1375,6 +1390,7 @@ int sk_chk_filter(struct sock_filter *filter, unsigned int flen) ANCILLARY(VLAN_TAG_PRESENT); ANCILLARY(PAY_OFFSET); ANCILLARY(RANDOM); + ANCILLARY(TRA_OFFSET); } /* ancillary operation unknown or unsupported */ @@ -1760,6 +1776,7 @@ void sk_decode_filter(struct sock_filter *filt, struct sock_filter *to) [BPF_S_ANC_VLAN_TAG_PRESENT] = BPF_LD|BPF_B|BPF_ABS, [BPF_S_ANC_PAY_OFFSET] = BPF_LD|BPF_B|BPF_ABS, [BPF_S_ANC_RANDOM] = BPF_LD|BPF_B|BPF_ABS, + [BPF_S_ANC_TRA_OFFSET] = BPF_LD|BPF_B|BPF_ABS, [BPF_S_LD_W_LEN] = BPF_LD|BPF_W|BPF_LEN, [BPF_S_LD_W_IND] = BPF_LD|BPF_W|BPF_IND, [BPF_S_LD_H_IND] = BPF_LD|BPF_H|BPF_IND, diff --git a/tools/net/bpf_exp.l b/tools/net/bpf_exp.l index 833a966..4e72934 100644 --- a/tools/net/bpf_exp.l +++ b/tools/net/bpf_exp.l @@ -93,6 +93,7 @@ extern void yyerror(const char *str); "#"?("vlan_tci") { return K_VLANT; } "#"?("vlan_pr") { return K_VLANP; } "#"?("rand") { return K_RAND; } +"#"?("toff") { return K_TOFF; } ":" { return ':'; } "," { return ','; } diff --git a/tools/net/bpf_exp.y b/tools/net/bpf_exp.y index e6306c5..ced6949 100644 --- a/tools/net/bpf_exp.y +++ b/tools/net/bpf_exp.y @@ -56,7 +56,7 @@ static void bpf_set_jmp_label(char *label, enum jmp_type type); %token OP_LDXI %token K_PKT_LEN K_PROTO K_TYPE K_NLATTR K_NLATTR_NEST K_MARK K_QUEUE K_HATYPE -%token K_RXHASH K_CPU K_IFIDX K_VLANT K_VLANP K_POFF K_RAND +%token K_RXHASH K_CPU K_IFIDX K_VLANT K_VLANP K_POFF K_RAND K_TOFF %token ':' ',' '[' ']' '(' ')' 'x' 'a' '+' 'M' '*' '&' '#' '%' @@ -167,6 +167,9 @@ ldb | OP_LDB K_RAND { bpf_set_curr_instr(BPF_LD | BPF_B | BPF_ABS, 0, 0, SKF_AD_OFF + SKF_AD_RANDOM); } + | OP_LDB K_TOFF { + bpf_set_curr_instr(BPF_LD | BPF_B | BPF_ABS, 0, 0, + SKF_AD_OFF + SKF_AD_TRA_OFFSET); } ; ldh @@ -218,6 +221,9 @@ ldh | OP_LDH K_RAND { bpf_set_curr_instr(BPF_LD | BPF_H | BPF_ABS, 0, 0, SKF_AD_OFF + SKF_AD_RANDOM); } + | OP_LDH K_TOFF { + bpf_set_curr_instr(BPF_LD | BPF_H | BPF_ABS, 0, 0, + SKF_AD_OFF + SKF_AD_TRA_OFFSET); } ; ldi @@ -274,6 +280,9 @@ ld | OP_LD K_RAND { bpf_set_curr_instr(BPF_LD | BPF_W | BPF_ABS, 0, 0, SKF_AD_OFF + SKF_AD_RANDOM); } + | OP_LD K_TOFF { + bpf_set_curr_instr(BPF_LD | BPF_W | BPF_ABS, 0, 0, + SKF_AD_OFF + SKF_AD_TRA_OFFSET); } | OP_LD 'M' '[' number ']' { bpf_set_curr_instr(BPF_LD | BPF_MEM, 0, 0, $4); } | OP_LD '[' 'x' '+' number ']' { -- 1.9.1.423.g4596e3a