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Commit 3f731d89 authored by Thomas Graf's avatar Thomas Graf Committed by David S. Miller
Browse files

bpf: add additional verifier tests for BPF_PROG_TYPE_LWT_* 



- direct packet read is allowed for LWT_*
 - direct packet write for LWT_IN/LWT_OUT is prohibited
 - direct packet write for LWT_XMIT is allowed
 - access to skb->tc_classid is prohibited for LWT_*

Signed-off-by: default avatarThomas Graf <tgraf@suug.ch>
Acked-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Acked-by: default avatarAlexei Starovoitov <ast@kernel.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent fd7aabb0

tools/testing/selftests/bpf/test_verifier.c

+134 −0
Original line number Diff line number Diff line
@@ -2743,6 +2743,140 @@ static struct bpf_test tests[] = { 
		.result = REJECT,

		.prog_type = BPF_PROG_TYPE_TRACEPOINT,

	},

	{

		"invalid direct packet write for LWT_IN",

		.insns = {

			BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1,

				    offsetof(struct __sk_buff, data)),

			BPF_LDX_MEM(BPF_W, BPF_REG_3, BPF_REG_1,

				    offsetof(struct __sk_buff, data_end)),

			BPF_MOV64_REG(BPF_REG_0, BPF_REG_2),

			BPF_ALU64_IMM(BPF_ADD, BPF_REG_0, 8),

			BPF_JMP_REG(BPF_JGT, BPF_REG_0, BPF_REG_3, 1),

			BPF_STX_MEM(BPF_B, BPF_REG_2, BPF_REG_2, 0),

			BPF_MOV64_IMM(BPF_REG_0, 0),

			BPF_EXIT_INSN(),

		},

		.errstr = "cannot write into packet",

		.result = REJECT,

		.prog_type = BPF_PROG_TYPE_LWT_IN,

	},

	{

		"invalid direct packet write for LWT_OUT",

		.insns = {

			BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1,

				    offsetof(struct __sk_buff, data)),

			BPF_LDX_MEM(BPF_W, BPF_REG_3, BPF_REG_1,

				    offsetof(struct __sk_buff, data_end)),

			BPF_MOV64_REG(BPF_REG_0, BPF_REG_2),

			BPF_ALU64_IMM(BPF_ADD, BPF_REG_0, 8),

			BPF_JMP_REG(BPF_JGT, BPF_REG_0, BPF_REG_3, 1),

			BPF_STX_MEM(BPF_B, BPF_REG_2, BPF_REG_2, 0),

			BPF_MOV64_IMM(BPF_REG_0, 0),

			BPF_EXIT_INSN(),

		},

		.errstr = "cannot write into packet",

		.result = REJECT,

		.prog_type = BPF_PROG_TYPE_LWT_OUT,

	},

	{

		"direct packet write for LWT_XMIT",

		.insns = {

			BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1,

				    offsetof(struct __sk_buff, data)),

			BPF_LDX_MEM(BPF_W, BPF_REG_3, BPF_REG_1,

				    offsetof(struct __sk_buff, data_end)),

			BPF_MOV64_REG(BPF_REG_0, BPF_REG_2),

			BPF_ALU64_IMM(BPF_ADD, BPF_REG_0, 8),

			BPF_JMP_REG(BPF_JGT, BPF_REG_0, BPF_REG_3, 1),

			BPF_STX_MEM(BPF_B, BPF_REG_2, BPF_REG_2, 0),

			BPF_MOV64_IMM(BPF_REG_0, 0),

			BPF_EXIT_INSN(),

		},

		.result = ACCEPT,

		.prog_type = BPF_PROG_TYPE_LWT_XMIT,

	},

	{

		"direct packet read for LWT_IN",

		.insns = {

			BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1,

				    offsetof(struct __sk_buff, data)),

			BPF_LDX_MEM(BPF_W, BPF_REG_3, BPF_REG_1,

				    offsetof(struct __sk_buff, data_end)),

			BPF_MOV64_REG(BPF_REG_0, BPF_REG_2),

			BPF_ALU64_IMM(BPF_ADD, BPF_REG_0, 8),

			BPF_JMP_REG(BPF_JGT, BPF_REG_0, BPF_REG_3, 1),

			BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_2, 0),

			BPF_MOV64_IMM(BPF_REG_0, 0),

			BPF_EXIT_INSN(),

		},

		.result = ACCEPT,

		.prog_type = BPF_PROG_TYPE_LWT_IN,

	},

	{

		"direct packet read for LWT_OUT",

		.insns = {

			BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1,

				    offsetof(struct __sk_buff, data)),

			BPF_LDX_MEM(BPF_W, BPF_REG_3, BPF_REG_1,

				    offsetof(struct __sk_buff, data_end)),

			BPF_MOV64_REG(BPF_REG_0, BPF_REG_2),

			BPF_ALU64_IMM(BPF_ADD, BPF_REG_0, 8),

			BPF_JMP_REG(BPF_JGT, BPF_REG_0, BPF_REG_3, 1),

			BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_2, 0),

			BPF_MOV64_IMM(BPF_REG_0, 0),

			BPF_EXIT_INSN(),

		},

		.result = ACCEPT,

		.prog_type = BPF_PROG_TYPE_LWT_OUT,

	},

	{

		"direct packet read for LWT_XMIT",

		.insns = {

			BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1,

				    offsetof(struct __sk_buff, data)),

			BPF_LDX_MEM(BPF_W, BPF_REG_3, BPF_REG_1,

				    offsetof(struct __sk_buff, data_end)),

			BPF_MOV64_REG(BPF_REG_0, BPF_REG_2),

			BPF_ALU64_IMM(BPF_ADD, BPF_REG_0, 8),

			BPF_JMP_REG(BPF_JGT, BPF_REG_0, BPF_REG_3, 1),

			BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_2, 0),

			BPF_MOV64_IMM(BPF_REG_0, 0),

			BPF_EXIT_INSN(),

		},

		.result = ACCEPT,

		.prog_type = BPF_PROG_TYPE_LWT_XMIT,

	},

	{

		"invalid access of tc_classid for LWT_IN",

		.insns = {

			BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_1,

				    offsetof(struct __sk_buff, tc_classid)),

			BPF_EXIT_INSN(),

		},

		.result = REJECT,

		.errstr = "invalid bpf_context access",

	},

	{

		"invalid access of tc_classid for LWT_OUT",

		.insns = {

			BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_1,

				    offsetof(struct __sk_buff, tc_classid)),

			BPF_EXIT_INSN(),

		},

		.result = REJECT,

		.errstr = "invalid bpf_context access",

	},

	{

		"invalid access of tc_classid for LWT_XMIT",

		.insns = {

			BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_1,

				    offsetof(struct __sk_buff, tc_classid)),

			BPF_EXIT_INSN(),

		},

		.result = REJECT,

		.errstr = "invalid bpf_context access",

	},

};



static int probe_filter_length(const struct bpf_insn *fp)