From 2ca71441f524b0a0cc01d8e51c875b00fbe31275 Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Thu, 12 Oct 2017 10:34:16 -0700 Subject: [PATCH] nfp: bpf: add support for direct packet access - read In direct packet access bound checks are already done, we can simply dereference the packet pointer. Verifier/parser logic needs to record pointer type. Note that although verifier does protect us from CTX vs other pointer changes we will also want to differentiate between PACKET vs MAP_VALUE or STACK, so we can add the check already. Signed-off-by: Jakub Kicinski Reviewed-by: Simon Horman Signed-off-by: David S. Miller --- drivers/net/ethernet/netronome/nfp/bpf/jit.c | 85 ++++++++++++++++++- drivers/net/ethernet/netronome/nfp/bpf/main.h | 3 + .../net/ethernet/netronome/nfp/bpf/verifier.c | 21 +++-- drivers/net/ethernet/netronome/nfp/nfp_asm.c | 3 + drivers/net/ethernet/netronome/nfp/nfp_asm.h | 4 + 5 files changed, 105 insertions(+), 11 deletions(-) diff --git a/drivers/net/ethernet/netronome/nfp/bpf/jit.c b/drivers/net/ethernet/netronome/nfp/bpf/jit.c index 3e173da16428..975d63fbc1d5 100644 --- a/drivers/net/ethernet/netronome/nfp/bpf/jit.c +++ b/drivers/net/ethernet/netronome/nfp/bpf/jit.c @@ -543,6 +543,36 @@ data_ld(struct nfp_prog *nfp_prog, swreg offset, u8 dst_gpr, int size) return 0; } +static int +data_ld_host_order(struct nfp_prog *nfp_prog, u8 src_gpr, swreg offset, + u8 dst_gpr, int size) +{ + unsigned int i; + u8 mask, sz; + + /* We load the value from the address indicated in @offset and then + * mask out the data we don't need. Note: this is little endian! + */ + sz = max(size, 4); + mask = size < 4 ? GENMASK(size - 1, 0) : 0; + + emit_cmd(nfp_prog, CMD_TGT_READ32_SWAP, CMD_MODE_32b, 0, + reg_a(src_gpr), offset, sz / 4 - 1, true); + + i = 0; + if (mask) + emit_ld_field_any(nfp_prog, reg_both(dst_gpr), mask, + reg_xfer(0), SHF_SC_NONE, 0, true); + else + for (; i * 4 < size; i++) + wrp_mov(nfp_prog, reg_both(dst_gpr + i), reg_xfer(i)); + + if (i < 2) + wrp_immed(nfp_prog, reg_both(dst_gpr + 1), 0); + + return 0; +} + static int construct_data_ind_ld(struct nfp_prog *nfp_prog, u16 offset, u16 src, u8 size) { @@ -1117,12 +1147,53 @@ static int mem_ldx_xdp(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta, return 0; } +static int +mem_ldx_data(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta, + unsigned int size) +{ + swreg tmp_reg; + + tmp_reg = re_load_imm_any(nfp_prog, meta->insn.off, imm_b(nfp_prog)); + + return data_ld_host_order(nfp_prog, meta->insn.src_reg * 2, tmp_reg, + meta->insn.dst_reg * 2, size); +} + +static int +mem_ldx(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta, + unsigned int size) +{ + if (meta->ptr.type == PTR_TO_CTX) { + if (nfp_prog->act == NN_ACT_XDP) + return mem_ldx_xdp(nfp_prog, meta, size); + else + return mem_ldx_skb(nfp_prog, meta, size); + } + + if (meta->ptr.type == PTR_TO_PACKET) + return mem_ldx_data(nfp_prog, meta, size); + + return -EOPNOTSUPP; +} + +static int mem_ldx1(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta) +{ + return mem_ldx(nfp_prog, meta, 1); +} + +static int mem_ldx2(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta) +{ + return mem_ldx(nfp_prog, meta, 2); +} + static int mem_ldx4(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta) { - if (nfp_prog->act == NN_ACT_XDP) - return mem_ldx_xdp(nfp_prog, meta, 4); - else - return mem_ldx_skb(nfp_prog, meta, 4); + return mem_ldx(nfp_prog, meta, 4); +} + +static int mem_ldx8(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta) +{ + return mem_ldx(nfp_prog, meta, 8); } static int mem_stx4_skb(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta) @@ -1137,6 +1208,9 @@ static int mem_stx4_xdp(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta) static int mem_stx4(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta) { + if (meta->ptr.type == PTR_TO_PACKET) + return -EOPNOTSUPP; + if (nfp_prog->act == NN_ACT_XDP) return mem_stx4_xdp(nfp_prog, meta); return mem_stx4_skb(nfp_prog, meta); @@ -1354,7 +1428,10 @@ static const instr_cb_t instr_cb[256] = { [BPF_LD | BPF_IND | BPF_B] = data_ind_ld1, [BPF_LD | BPF_IND | BPF_H] = data_ind_ld2, [BPF_LD | BPF_IND | BPF_W] = data_ind_ld4, + [BPF_LDX | BPF_MEM | BPF_B] = mem_ldx1, + [BPF_LDX | BPF_MEM | BPF_H] = mem_ldx2, [BPF_LDX | BPF_MEM | BPF_W] = mem_ldx4, + [BPF_LDX | BPF_MEM | BPF_DW] = mem_ldx8, [BPF_STX | BPF_MEM | BPF_W] = mem_stx4, [BPF_JMP | BPF_JA | BPF_K] = jump, [BPF_JMP | BPF_JEQ | BPF_K] = jeq_imm, diff --git a/drivers/net/ethernet/netronome/nfp/bpf/main.h b/drivers/net/ethernet/netronome/nfp/bpf/main.h index b7a112acbdb7..d77e88a45409 100644 --- a/drivers/net/ethernet/netronome/nfp/bpf/main.h +++ b/drivers/net/ethernet/netronome/nfp/bpf/main.h @@ -36,6 +36,7 @@ #include #include +#include #include #include @@ -96,6 +97,7 @@ typedef int (*instr_cb_t)(struct nfp_prog *, struct nfp_insn_meta *); /** * struct nfp_insn_meta - BPF instruction wrapper * @insn: BPF instruction + * @ptr: pointer type for memory operations * @off: index of first generated machine instruction (in nfp_prog.prog) * @n: eBPF instruction number * @skip: skip this instruction (optimized out) @@ -104,6 +106,7 @@ typedef int (*instr_cb_t)(struct nfp_prog *, struct nfp_insn_meta *); */ struct nfp_insn_meta { struct bpf_insn insn; + struct bpf_reg_state ptr; unsigned int off; unsigned short n; bool skip; diff --git a/drivers/net/ethernet/netronome/nfp/bpf/verifier.c b/drivers/net/ethernet/netronome/nfp/bpf/verifier.c index 5b783a91b115..e361c0e3b788 100644 --- a/drivers/net/ethernet/netronome/nfp/bpf/verifier.c +++ b/drivers/net/ethernet/netronome/nfp/bpf/verifier.c @@ -112,12 +112,19 @@ nfp_bpf_check_exit(struct nfp_prog *nfp_prog, } static int -nfp_bpf_check_ctx_ptr(struct nfp_prog *nfp_prog, - const struct bpf_verifier_env *env, u8 reg) +nfp_bpf_check_ptr(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta, + const struct bpf_verifier_env *env, u8 reg) { - if (env->cur_state.regs[reg].type != PTR_TO_CTX) + if (env->cur_state.regs[reg].type != PTR_TO_CTX && + env->cur_state.regs[reg].type != PTR_TO_PACKET) return -EINVAL; + if (meta->ptr.type != NOT_INIT && + meta->ptr.type != env->cur_state.regs[reg].type) + return -EINVAL; + + meta->ptr = env->cur_state.regs[reg]; + return 0; } @@ -145,11 +152,11 @@ nfp_verify_insn(struct bpf_verifier_env *env, int insn_idx, int prev_insn_idx) return nfp_bpf_check_exit(priv->prog, env); if ((meta->insn.code & ~BPF_SIZE_MASK) == (BPF_LDX | BPF_MEM)) - return nfp_bpf_check_ctx_ptr(priv->prog, env, - meta->insn.src_reg); + return nfp_bpf_check_ptr(priv->prog, meta, env, + meta->insn.src_reg); if ((meta->insn.code & ~BPF_SIZE_MASK) == (BPF_STX | BPF_MEM)) - return nfp_bpf_check_ctx_ptr(priv->prog, env, - meta->insn.dst_reg); + return nfp_bpf_check_ptr(priv->prog, meta, env, + meta->insn.dst_reg); return 0; } diff --git a/drivers/net/ethernet/netronome/nfp/nfp_asm.c b/drivers/net/ethernet/netronome/nfp/nfp_asm.c index de76e7444fc2..7cae99b3e00a 100644 --- a/drivers/net/ethernet/netronome/nfp/nfp_asm.c +++ b/drivers/net/ethernet/netronome/nfp/nfp_asm.c @@ -42,6 +42,9 @@ const struct cmd_tgt_act cmd_tgt_act[__CMD_TGT_MAP_SIZE] = { [CMD_TGT_WRITE8] = { 0x00, 0x42 }, [CMD_TGT_READ8] = { 0x01, 0x43 }, + [CMD_TGT_READ32] = { 0x00, 0x5c }, + [CMD_TGT_READ32_LE] = { 0x01, 0x5c }, + [CMD_TGT_READ32_SWAP] = { 0x02, 0x5c }, [CMD_TGT_READ_LE] = { 0x01, 0x40 }, [CMD_TGT_READ_SWAP_LE] = { 0x03, 0x40 }, }; diff --git a/drivers/net/ethernet/netronome/nfp/nfp_asm.h b/drivers/net/ethernet/netronome/nfp/nfp_asm.h index c4c18dd5630a..e3df7a26724f 100644 --- a/drivers/net/ethernet/netronome/nfp/nfp_asm.h +++ b/drivers/net/ethernet/netronome/nfp/nfp_asm.h @@ -153,6 +153,7 @@ enum shf_op { enum shf_sc { SHF_SC_R_ROT = 0, + SHF_SC_NONE = SHF_SC_R_ROT, SHF_SC_R_SHF = 1, SHF_SC_L_SHF = 2, SHF_SC_R_DSHF = 3, @@ -217,6 +218,9 @@ struct cmd_tgt_act { enum cmd_tgt_map { CMD_TGT_READ8, CMD_TGT_WRITE8, + CMD_TGT_READ32, + CMD_TGT_READ32_LE, + CMD_TGT_READ32_SWAP, CMD_TGT_READ_LE, CMD_TGT_READ_SWAP_LE, __CMD_TGT_MAP_SIZE,