[PATCH net-next] filter: add XOR instruction for use with X/K
From: Daniel Borkmann <hidden>
Date: 2012-09-24 12:24:04
Subsystem:
bpf [core], bpf [general] (safe dynamic programs and tools), bpf [networking] (tcx & tc bpf, sock_addr), networking [general], the rest · Maintainers:
Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
BPF_S_ANC_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 BPF_S_ANC_ALU_XOR_X might not be an option since this is exposed to user space. Signed-off-by: Daniel Borkmann <redacted> --- include/linux/filter.h | 3 +++ net/core/filter.c | 12 +++++++++--- 2 files changed, 12 insertions(+), 3 deletions(-)
diff --git a/include/linux/filter.h b/include/linux/filter.h
index 3cf5fd5..2ded090 100644
--- a/include/linux/filter.h
+++ b/include/linux/filter.h@@ -75,6 +75,7 @@ struct sock_fprog { /* Required for SO_ATTACH_FILTER. */ #define BPF_RSH 0x70 #define BPF_NEG 0x80 #define BPF_MOD 0x90 +#define BPF_XOR 0xa0 #define BPF_JA 0x00 #define BPF_JEQ 0x10
@@ -204,6 +205,8 @@ enum { 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,
diff --git a/net/core/filter.c b/net/core/filter.c
index fbe3a8d..3d92ebb 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c@@ -187,6 +187,13 @@ 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;
@@ -334,9 +341,6 @@ load_b: case BPF_S_ANC_CPU: A = raw_smp_processor_id(); continue; - case BPF_S_ANC_ALU_XOR_X: - A ^= X; - continue; case BPF_S_ANC_NLATTR: { struct nlattr *nla;
@@ -483,6 +487,8 @@ int sk_chk_filter(struct sock_filter *filter, unsigned int flen) [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,