From 83e230739cb578049f62c626946e04a79b46c85b Mon Sep 17 00:00:00 2001 From: Kevin Mihelich Date: Mon, 29 Sep 2014 12:14:00 -0600 Subject: [PATCH] Backport BFP XOR operation Squashed commit of the following: commit 210b6dd797945571a92ae1f502be6b885cdeae23 Author: Daniel Borkmann Date: Mon Sep 24 02:23:59 2012 +0000 filter: add XOR instruction for use with X/K SKF_AD_ALU_XOR_X has been added a while ago, but as an 'ancillary' operation that is invoked through a negative offset in K within BPF load operations. Since BPF_MOD has recently been added, BPF_XOR should also be part of the common ALU operations. Removing SKF_AD_ALU_XOR_X might not be an option since this is exposed to user space. Signed-off-by: Daniel Borkmann Acked-by: Eric Dumazet Signed-off-by: David S. Miller commit 11acc6e3fc94f8b18483af729760b9025d708409 Author: Eric Dumazet Date: Fri Sep 7 22:03:35 2012 +0000 filter: add MOD operation Add a new ALU opcode, to compute a modulus. Commit ffe06c17afbbb used an ancillary to implement XOR_X, but here we reserve one of the available ALU opcode to implement both MOD_X and MOD_K Signed-off-by: Eric Dumazet Suggested-by: George Bakos Cc: Jay Schulist Cc: Jiri Pirko Cc: Andi Kleen Signed-off-by: David S. Miller commit 3026fca84f0230d96693ba6d3e6089343874ca09 Author: Daniel Borkmann Date: Mon Sep 24 07:34:51 2012 +0000 x86: bpf_jit_comp: add XOR instruction for BPF JIT This patch is a follow-up for patch "filter: add XOR instruction for use with X/K" that implements BPF x86 JIT parts for the BPF XOR operation. Signed-off-by: Daniel Borkmann Acked-by: Eric Dumazet Signed-off-by: David S. Miller commit cf2f055d4abff198aaa0128aa06e458a6ff767d7 Author: Eric Dumazet Date: Mon Jun 4 21:26:30 2012 +0000 x86 bpf_jit: support BPF_S_ANC_ALU_XOR_X instruction commit ffe06c17afbb (filter: add XOR operation) added generic support for XOR operation. This patch implements the XOR instruction in x86 jit. Signed-off-by: Eric Dumazet Cc: Jiri Pirko Signed-off-by: David S. Miller commit e0d7a646c8684dac88c6ebbeb155313ad7fc624d Author: Jiri Pirko Date: Sat Mar 31 11:01:20 2012 +0000 filter: add XOR operation Add XOR instruction fo BPF machine. Needed for computing packet hashes. Signed-off-by: Jiri Pirko Signed-off-by: David S. Miller --- arch/x86/net/bpf_jit_comp.c | 13 +++++++++++++ include/linux/filter.h | 11 ++++++++++- net/core/filter.c | 25 +++++++++++++++++++++++++ 3 files changed, 48 insertions(+), 1 deletion(-) diff --git a/arch/x86/net/bpf_jit_comp.c b/arch/x86/net/bpf_jit_comp.c index 0597f95..db99f9a 100644 --- a/arch/x86/net/bpf_jit_comp.c +++ b/arch/x86/net/bpf_jit_comp.c @@ -309,6 +309,19 @@ void bpf_jit_compile(struct sk_filter *fp) else EMIT1_off32(0x0d, K); /* or imm32,%eax */ break; + case BPF_S_ANC_ALU_XOR_X: /* A ^= X; */ + case BPF_S_ALU_XOR_X: + seen |= SEEN_XREG; + EMIT2(0x31, 0xd8); /* xor %ebx,%eax */ + break; + case BPF_S_ALU_XOR_K: /* A ^= K; */ + if (K == 0) + break; + if (is_imm8(K)) + EMIT3(0x83, 0xf0, K); /* xor imm8,%eax */ + else + EMIT1_off32(0x35, K); /* xor imm32,%eax */ + break; case BPF_S_ALU_LSH_X: /* A <<= X; */ seen |= SEEN_XREG; EMIT4(0x89, 0xd9, 0xd3, 0xe0); /* mov %ebx,%ecx; shl %cl,%eax */ diff --git a/include/linux/filter.h b/include/linux/filter.h index 8eeb205..0031feb 100644 --- a/include/linux/filter.h +++ b/include/linux/filter.h @@ -73,6 +73,9 @@ struct sock_fprog { /* Required for SO_ATTACH_FILTER. */ #define BPF_LSH 0x60 #define BPF_RSH 0x70 #define BPF_NEG 0x80 +#define BPF_MOD 0x90 +#define BPF_XOR 0xa0 + #define BPF_JA 0x00 #define BPF_JEQ 0x10 #define BPF_JGT 0x20 @@ -126,7 +129,8 @@ struct sock_fprog { /* Required for SO_ATTACH_FILTER. */ #define SKF_AD_HATYPE 28 #define SKF_AD_RXHASH 32 #define SKF_AD_CPU 36 -#define SKF_AD_MAX 40 +#define SKF_AD_ALU_XOR_X 40 +#define SKF_AD_MAX 44 #define SKF_NET_OFF (-0x100000) #define SKF_LL_OFF (-0x200000) @@ -181,10 +185,14 @@ enum { BPF_S_ALU_MUL_K, BPF_S_ALU_MUL_X, BPF_S_ALU_DIV_X, + BPF_S_ALU_MOD_K, + BPF_S_ALU_MOD_X, BPF_S_ALU_AND_K, BPF_S_ALU_AND_X, BPF_S_ALU_OR_K, BPF_S_ALU_OR_X, + BPF_S_ALU_XOR_K, + BPF_S_ALU_XOR_X, BPF_S_ALU_LSH_K, BPF_S_ALU_LSH_X, BPF_S_ALU_RSH_K, @@ -228,6 +236,7 @@ enum { BPF_S_ANC_HATYPE, BPF_S_ANC_RXHASH, BPF_S_ANC_CPU, + BPF_S_ANC_ALU_XOR_X, }; #endif /* __KERNEL__ */ diff --git a/net/core/filter.c b/net/core/filter.c index 3b7398a..26c7bbe 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -158,6 +158,14 @@ unsigned int sk_run_filter(const struct sk_buff *skb, case BPF_S_ALU_DIV_K: A = reciprocal_divide(A, K); continue; + case BPF_S_ALU_MOD_X: + if (X == 0) + return 0; + A %= X; + continue; + case BPF_S_ALU_MOD_K: + A %= K; + continue; case BPF_S_ALU_AND_X: A &= X; continue; @@ -170,6 +178,13 @@ unsigned int sk_run_filter(const struct sk_buff *skb, case BPF_S_ALU_OR_K: A |= K; continue; + case BPF_S_ANC_ALU_XOR_X: + case BPF_S_ALU_XOR_X: + A ^= X; + continue; + case BPF_S_ALU_XOR_K: + A ^= K; + continue; case BPF_S_ALU_LSH_X: A <<= X; continue; @@ -456,10 +471,14 @@ int sk_chk_filter(struct sock_filter *filter, unsigned int flen) [BPF_ALU|BPF_MUL|BPF_K] = BPF_S_ALU_MUL_K, [BPF_ALU|BPF_MUL|BPF_X] = BPF_S_ALU_MUL_X, [BPF_ALU|BPF_DIV|BPF_X] = BPF_S_ALU_DIV_X, + [BPF_ALU|BPF_MOD|BPF_K] = BPF_S_ALU_MOD_K, + [BPF_ALU|BPF_MOD|BPF_X] = BPF_S_ALU_MOD_X, [BPF_ALU|BPF_AND|BPF_K] = BPF_S_ALU_AND_K, [BPF_ALU|BPF_AND|BPF_X] = BPF_S_ALU_AND_X, [BPF_ALU|BPF_OR|BPF_K] = BPF_S_ALU_OR_K, [BPF_ALU|BPF_OR|BPF_X] = BPF_S_ALU_OR_X, + [BPF_ALU|BPF_XOR|BPF_K] = BPF_S_ALU_XOR_K, + [BPF_ALU|BPF_XOR|BPF_X] = BPF_S_ALU_XOR_X, [BPF_ALU|BPF_LSH|BPF_K] = BPF_S_ALU_LSH_K, [BPF_ALU|BPF_LSH|BPF_X] = BPF_S_ALU_LSH_X, [BPF_ALU|BPF_RSH|BPF_K] = BPF_S_ALU_RSH_K, @@ -518,6 +537,11 @@ int sk_chk_filter(struct sock_filter *filter, unsigned int flen) return -EINVAL; ftest->k = reciprocal_value(ftest->k); break; + case BPF_S_ALU_MOD_K: + /* check for division by zero */ + if (ftest->k == 0) + return -EINVAL; + break; case BPF_S_LD_MEM: case BPF_S_LDX_MEM: case BPF_S_ST: @@ -565,6 +589,7 @@ int sk_chk_filter(struct sock_filter *filter, unsigned int flen) ANCILLARY(HATYPE); ANCILLARY(RXHASH); ANCILLARY(CPU); + ANCILLARY(ALU_XOR_X); } } ftest->code = code; -- 2.1.1