From a8fc92778080c845eaadc369a0ecf5699a03bef0 Mon Sep 17 00:00:00 2001 From: Pavel Emelyanov Date: Thu, 1 Nov 2012 02:01:48 +0000 Subject: sk-filter: Add ability to get socket filter program (v2) The SO_ATTACH_FILTER option is set only. I propose to add the get ability by using SO_ATTACH_FILTER in getsockopt. To be less irritating to eyes the SO_GET_FILTER alias to it is declared. This ability is required by checkpoint-restore project to be able to save full state of a socket. There are two issues with getting filter back. First, kernel modifies the sock_filter->code on filter load, thus in order to return the filter element back to user we have to decode it into user-visible constants. Fortunately the modification in question is interconvertible. Second, the BPF_S_ALU_DIV_K code modifies the command argument k to speed up the run-time division by doing kernel_k = reciprocal(user_k). Bad news is that different user_k may result in same kernel_k, so we can't get the original user_k back. Good news is that we don't have to do it. What we need to is calculate a user2_k so, that reciprocal(user2_k) == reciprocal(user_k) == kernel_k i.e. if it's re-loaded back the compiled again value will be exactly the same as it was. That said, the user2_k can be calculated like this user2_k = reciprocal(kernel_k) with an exception, that if kernel_k == 0, then user2_k == 1. The optlen argument is treated like this -- when zero, kernel returns the amount of sock_fprog elements in filter, otherwise it should be large enough for the sock_fprog array. changes since v1: * Declared SO_GET_FILTER in all arch headers * Added decode of vlan-tag codes Signed-off-by: Pavel Emelyanov Signed-off-by: David S. Miller --- arch/sparc/include/uapi/asm/socket.h | 1 + 1 file changed, 1 insertion(+) (limited to 'arch/sparc') diff --git a/arch/sparc/include/uapi/asm/socket.h b/arch/sparc/include/uapi/asm/socket.h index bea1568..c83a937 100644 --- a/arch/sparc/include/uapi/asm/socket.h +++ b/arch/sparc/include/uapi/asm/socket.h @@ -41,6 +41,7 @@ #define SO_ATTACH_FILTER 0x001a #define SO_DETACH_FILTER 0x001b +#define SO_GET_FILTER SO_ATTACH_FILTER #define SO_PEERNAME 0x001c #define SO_TIMESTAMP 0x001d -- cgit v1.1 From 54e7e2df3e2f854ae33015cec25da5190e6a18ac Mon Sep 17 00:00:00 2001 From: Daniel Borkmann Date: Sun, 4 Nov 2012 16:59:30 +0000 Subject: sparc: bpf_jit_comp: add VLAN instructions for BPF JIT This patch is a follow-up for patch "net: filter: add vlan tag access" to support the new VLAN_TAG/VLAN_TAG_PRESENT accessors in BPF JIT. Signed-off-by: Daniel Borkmann Signed-off-by: David S. Miller --- arch/sparc/net/bpf_jit_comp.c | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) (limited to 'arch/sparc') diff --git a/arch/sparc/net/bpf_jit_comp.c b/arch/sparc/net/bpf_jit_comp.c index 2836870..3109ca6 100644 --- a/arch/sparc/net/bpf_jit_comp.c +++ b/arch/sparc/net/bpf_jit_comp.c @@ -3,6 +3,7 @@ #include #include #include +#include #include #include @@ -312,6 +313,12 @@ do { *prog++ = BR_OPC | WDISP22(OFF); \ #define emit_addi(R1, IMM, R3) \ *prog++ = (ADD | IMMED | RS1(R1) | S13(IMM) | RD(R3)) +#define emit_and(R1, R2, R3) \ + *prog++ = (AND | RS1(R1) | RS2(R2) | RD(R3)) + +#define emit_andi(R1, IMM, R3) \ + *prog++ = (AND | IMMED | RS1(R1) | S13(IMM) | RD(R3)) + #define emit_alloc_stack(SZ) \ *prog++ = (SUB | IMMED | RS1(SP) | S13(SZ) | RD(SP)) @@ -415,6 +422,8 @@ void bpf_jit_compile(struct sk_filter *fp) case BPF_S_ANC_IFINDEX: case BPF_S_ANC_MARK: case BPF_S_ANC_RXHASH: + case BPF_S_ANC_VLAN_TAG: + case BPF_S_ANC_VLAN_TAG_PRESENT: case BPF_S_ANC_CPU: case BPF_S_ANC_QUEUE: case BPF_S_LD_W_ABS: @@ -600,6 +609,16 @@ void bpf_jit_compile(struct sk_filter *fp) case BPF_S_ANC_RXHASH: emit_skb_load32(rxhash, r_A); break; + case BPF_S_ANC_VLAN_TAG: + case BPF_S_ANC_VLAN_TAG_PRESENT: + emit_skb_load16(vlan_tci, r_A); + if (filter[i].code == BPF_S_ANC_VLAN_TAG) { + emit_andi(r_A, VLAN_VID_MASK, r_A); + } else { + emit_loadimm(VLAN_TAG_PRESENT, r_TMP); + emit_and(r_A, r_TMP, r_A); + } + break; case BPF_S_LD_IMM: emit_loadimm(K, r_A); -- cgit v1.1