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Commit 18f3d6be authored by Yonghong Song's avatar Yonghong Song Committed by David S. Miller
Browse files

selftests/bpf: Add test cases to test narrower ctx field loads 



Add test cases in test_verifier and test_progs.
Negative tests are added in test_verifier as well.
The test in test_progs will compare the value of narrower ctx field
load result vs. the masked value of normal full-field load result,
and will fail if they are not the same.

Acked-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Signed-off-by: default avatarYonghong Song <yhs@fb.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 31fd8581

tools/testing/selftests/bpf/Makefile

+2 −1
Original line number Diff line number Diff line
@@ -14,7 +14,8 @@ LDLIBS += -lcap -lelf 
TEST_GEN_PROGS = test_verifier test_tag test_maps test_lru_map test_lpm_map test_progs \

	test_align



TEST_GEN_FILES = test_pkt_access.o test_xdp.o test_l4lb.o test_tcp_estats.o test_obj_id.o

TEST_GEN_FILES = test_pkt_access.o test_xdp.o test_l4lb.o test_tcp_estats.o test_obj_id.o \

	test_pkt_md_access.o



TEST_PROGS := test_kmod.sh

tools/testing/selftests/bpf/test_pkt_md_access.c

0 → 100644
+35 −0
Original line number Diff line number Diff line 
/* Copyright (c) 2017 Facebook

 *

 * This program is free software; you can redistribute it and/or

 * modify it under the terms of version 2 of the GNU General Public

 * License as published by the Free Software Foundation.

 */

#include <stddef.h>

#include <string.h>

#include <linux/bpf.h>

#include <linux/pkt_cls.h>

#include "bpf_helpers.h"



int _version SEC("version") = 1;



#define TEST_FIELD(TYPE, FIELD, MASK)					\

	{								\

		TYPE tmp = *(volatile TYPE *)&skb->FIELD;		\

		if (tmp != ((*(volatile __u32 *)&skb->FIELD) & MASK))	\

			return TC_ACT_SHOT;				\

	}



SEC("test1")

int process(struct __sk_buff *skb)

{

	TEST_FIELD(__u8,  len, 0xFF);

	TEST_FIELD(__u16, len, 0xFFFF);

	TEST_FIELD(__u32, len, 0xFFFFFFFF);

	TEST_FIELD(__u16, protocol, 0xFFFF);

	TEST_FIELD(__u32, protocol, 0xFFFFFFFF);

	TEST_FIELD(__u8,  hash, 0xFF);

	TEST_FIELD(__u16, hash, 0xFFFF);

	TEST_FIELD(__u32, hash, 0xFFFFFFFF);



	return TC_ACT_OK;

}

tools/testing/selftests/bpf/test_progs.c

+21 −0
Original line number Diff line number Diff line
@@ -484,6 +484,26 @@ static void test_bpf_obj_id(void) 
		bpf_object__close(objs[i]);

}



static void test_pkt_md_access(void)

{

	const char *file = "./test_pkt_md_access.o";

	struct bpf_object *obj;

	__u32 duration, retval;

	int err, prog_fd;



	err = bpf_prog_load(file, BPF_PROG_TYPE_SCHED_CLS, &obj, &prog_fd);

	if (err)

		return;



	err = bpf_prog_test_run(prog_fd, 10, &pkt_v4, sizeof(pkt_v4),

				NULL, NULL, &retval, &duration);

	CHECK(err || retval, "",

	      "err %d errno %d retval %d duration %d\n",

	      err, errno, retval, duration);



	bpf_object__close(obj);

}



int main(void)

{

	struct rlimit rinf = { RLIM_INFINITY, RLIM_INFINITY };
@@ -495,6 +515,7 @@ int main(void) 
	test_l4lb();

	test_tcp_estats();

	test_bpf_obj_id();

	test_pkt_md_access();



	printf("Summary: %d PASSED, %d FAILED\n", pass_cnt, error_cnt);

	return error_cnt ? EXIT_FAILURE : EXIT_SUCCESS;

tools/testing/selftests/bpf/test_verifier.c

+176 −0
Original line number Diff line number Diff line
@@ -1094,6 +1094,59 @@ static struct bpf_test tests[] = { 
		.errstr = "invalid bpf_context access",

		.result = REJECT,

	},

	{

		"check skb->hash byte load permitted",

		.insns = {

			BPF_MOV64_IMM(BPF_REG_0, 0),

#ifdef __LITTLE_ENDIAN

			BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_1,

				    offsetof(struct __sk_buff, hash)),

#else

			BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_1,

				    offsetof(struct __sk_buff, hash) + 3),

#endif

			BPF_EXIT_INSN(),

		},

		.result = ACCEPT,

	},

	{

		"check skb->hash byte load not permitted 1",

		.insns = {

			BPF_MOV64_IMM(BPF_REG_0, 0),

			BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_1,

				    offsetof(struct __sk_buff, hash) + 1),

			BPF_EXIT_INSN(),

		},

		.errstr = "invalid bpf_context access",

		.result = REJECT,

	},

	{

		"check skb->hash byte load not permitted 2",

		.insns = {

			BPF_MOV64_IMM(BPF_REG_0, 0),

			BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_1,

				    offsetof(struct __sk_buff, hash) + 2),

			BPF_EXIT_INSN(),

		},

		.errstr = "invalid bpf_context access",

		.result = REJECT,

	},

	{

		"check skb->hash byte load not permitted 3",

		.insns = {

			BPF_MOV64_IMM(BPF_REG_0, 0),

#ifdef __LITTLE_ENDIAN

			BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_1,

				    offsetof(struct __sk_buff, hash) + 3),

#else

			BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_1,

				    offsetof(struct __sk_buff, hash)),

#endif

			BPF_EXIT_INSN(),

		},

		.errstr = "invalid bpf_context access",

		.result = REJECT,

	},

	{

		"check cb access: byte, wrong type",

		.insns = {
@@ -1187,6 +1240,37 @@ static struct bpf_test tests[] = { 
		.errstr = "invalid bpf_context access",

		.result = REJECT,

	},

	{

		"check skb->hash half load permitted",

		.insns = {

			BPF_MOV64_IMM(BPF_REG_0, 0),

#ifdef __LITTLE_ENDIAN

			BPF_LDX_MEM(BPF_H, BPF_REG_0, BPF_REG_1,

				    offsetof(struct __sk_buff, hash)),

#else

			BPF_LDX_MEM(BPF_H, BPF_REG_0, BPF_REG_1,

				    offsetof(struct __sk_buff, hash) + 2),

#endif

			BPF_EXIT_INSN(),

		},

		.result = ACCEPT,

	},

	{

		"check skb->hash half load not permitted",

		.insns = {

			BPF_MOV64_IMM(BPF_REG_0, 0),

#ifdef __LITTLE_ENDIAN

			BPF_LDX_MEM(BPF_H, BPF_REG_0, BPF_REG_1,

				    offsetof(struct __sk_buff, hash) + 2),

#else

			BPF_LDX_MEM(BPF_H, BPF_REG_0, BPF_REG_1,

				    offsetof(struct __sk_buff, hash)),

#endif

			BPF_EXIT_INSN(),

		},

		.errstr = "invalid bpf_context access",

		.result = REJECT,

	},

	{

		"check cb access: half, wrong type",

		.insns = {
@@ -5103,6 +5187,98 @@ static struct bpf_test tests[] = { 
		},

		.result = ACCEPT,

	},

	{

		"check bpf_perf_event_data->sample_period byte load permitted",

		.insns = {

			BPF_MOV64_IMM(BPF_REG_0, 0),

#ifdef __LITTLE_ENDIAN

			BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_1,

				    offsetof(struct bpf_perf_event_data, sample_period)),

#else

			BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_1,

				    offsetof(struct bpf_perf_event_data, sample_period) + 7),

#endif

			BPF_EXIT_INSN(),

		},

		.result = ACCEPT,

		.prog_type = BPF_PROG_TYPE_PERF_EVENT,

	},

	{

		"check bpf_perf_event_data->sample_period half load permitted",

		.insns = {

			BPF_MOV64_IMM(BPF_REG_0, 0),

#ifdef __LITTLE_ENDIAN

			BPF_LDX_MEM(BPF_H, BPF_REG_0, BPF_REG_1,

				    offsetof(struct bpf_perf_event_data, sample_period)),

#else

			BPF_LDX_MEM(BPF_H, BPF_REG_0, BPF_REG_1,

				    offsetof(struct bpf_perf_event_data, sample_period) + 6),

#endif

			BPF_EXIT_INSN(),

		},

		.result = ACCEPT,

		.prog_type = BPF_PROG_TYPE_PERF_EVENT,

	},

	{

		"check bpf_perf_event_data->sample_period word load permitted",

		.insns = {

			BPF_MOV64_IMM(BPF_REG_0, 0),

#ifdef __LITTLE_ENDIAN

			BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_1,

				    offsetof(struct bpf_perf_event_data, sample_period)),

#else

			BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_1,

				    offsetof(struct bpf_perf_event_data, sample_period) + 4),

#endif

			BPF_EXIT_INSN(),

		},

		.result = ACCEPT,

		.prog_type = BPF_PROG_TYPE_PERF_EVENT,

	},

	{

		"check bpf_perf_event_data->sample_period dword load permitted",

		.insns = {

			BPF_MOV64_IMM(BPF_REG_0, 0),

			BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_1,

				    offsetof(struct bpf_perf_event_data, sample_period)),

			BPF_EXIT_INSN(),

		},

		.result = ACCEPT,

		.prog_type = BPF_PROG_TYPE_PERF_EVENT,

	},

	{

		"check skb->data half load not permitted",

		.insns = {

			BPF_MOV64_IMM(BPF_REG_0, 0),

#ifdef __LITTLE_ENDIAN

			BPF_LDX_MEM(BPF_H, BPF_REG_0, BPF_REG_1,

				    offsetof(struct __sk_buff, data)),

#else

			BPF_LDX_MEM(BPF_H, BPF_REG_0, BPF_REG_1,

				    offsetof(struct __sk_buff, data) + 2),

#endif

			BPF_EXIT_INSN(),

		},

		.result = REJECT,

		.errstr = "invalid bpf_context access",

	},

	{

		"check skb->tc_classid half load not permitted for lwt prog",

		.insns = {

			BPF_MOV64_IMM(BPF_REG_0, 0),

#ifdef __LITTLE_ENDIAN

			BPF_LDX_MEM(BPF_H, BPF_REG_0, BPF_REG_1,

				    offsetof(struct __sk_buff, tc_classid)),

#else

			BPF_LDX_MEM(BPF_H, BPF_REG_0, BPF_REG_1,

				    offsetof(struct __sk_buff, tc_classid) + 2),

#endif

			BPF_EXIT_INSN(),

		},

		.result = REJECT,

		.errstr = "invalid bpf_context access",

		.prog_type = BPF_PROG_TYPE_LWT_IN,

	},

};



static int probe_filter_length(const struct bpf_insn *fp)