Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 2ca71441 authored by Jakub Kicinski's avatar Jakub Kicinski Committed by David S. Miller
Browse files

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: default avatarJakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: default avatarSimon Horman <simon.horman@netronome.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 0a793977

drivers/net/ethernet/netronome/nfp/bpf/jit.c

+81 −4
Original line number Diff line number Diff line
@@ -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_ldx4(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)

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, 4);

			return mem_ldx_xdp(nfp_prog, meta, size);

		else

		return mem_ldx_skb(nfp_prog, meta, 4);

			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)

{

	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,

drivers/net/ethernet/netronome/nfp/bpf/main.h

+3 −0
Original line number Diff line number Diff line
@@ -36,6 +36,7 @@ 


#include <linux/bitfield.h>

#include <linux/bpf.h>

#include <linux/bpf_verifier.h>

#include <linux/list.h>

#include <linux/types.h>
@@ -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;

drivers/net/ethernet/netronome/nfp/bpf/verifier.c

+14 −7
Original line number Diff line number Diff line
@@ -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,

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;

}
@@ -145,10 +152,10 @@ 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,

		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,

		return nfp_bpf_check_ptr(priv->prog, meta, env,

					 meta->insn.dst_reg);



	return 0;

drivers/net/ethernet/netronome/nfp/nfp_asm.c

+3 −0
Original line number Diff line number Diff line
@@ -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 },

};

drivers/net/ethernet/netronome/nfp/nfp_asm.h

+4 −0
Original line number Diff line number Diff line
@@ -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,