From 18f3d6be6be124316d3abfee667c5e8b88dec100 Mon Sep 17 00:00:00 2001 From: Yonghong Song Date: Tue, 13 Jun 2017 15:52:14 -0700 Subject: [PATCH] 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: Daniel Borkmann Signed-off-by: Yonghong Song Signed-off-by: David S. Miller --- tools/testing/selftests/bpf/Makefile | 3 +- .../selftests/bpf/test_pkt_md_access.c | 35 ++++ tools/testing/selftests/bpf/test_progs.c | 21 +++ tools/testing/selftests/bpf/test_verifier.c | 176 ++++++++++++++++++ 4 files changed, 234 insertions(+), 1 deletion(-) create mode 100644 tools/testing/selftests/bpf/test_pkt_md_access.c diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile index 9f0e07ba5334..2ca51a8a588c 100644 --- a/tools/testing/selftests/bpf/Makefile +++ b/tools/testing/selftests/bpf/Makefile @@ -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 diff --git a/tools/testing/selftests/bpf/test_pkt_md_access.c b/tools/testing/selftests/bpf/test_pkt_md_access.c new file mode 100644 index 000000000000..71729d47eb85 --- /dev/null +++ b/tools/testing/selftests/bpf/test_pkt_md_access.c @@ -0,0 +1,35 @@ +/* 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 +#include +#include +#include +#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; +} diff --git a/tools/testing/selftests/bpf/test_progs.c b/tools/testing/selftests/bpf/test_progs.c index f10493d4c37c..5855cd3d3d45 100644 --- a/tools/testing/selftests/bpf/test_progs.c +++ b/tools/testing/selftests/bpf/test_progs.c @@ -484,6 +484,26 @@ done: 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; diff --git a/tools/testing/selftests/bpf/test_verifier.c b/tools/testing/selftests/bpf/test_verifier.c index 13341700930c..c0af0195432f 100644 --- a/tools/testing/selftests/bpf/test_verifier.c +++ b/tools/testing/selftests/bpf/test_verifier.c @@ -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) -- 2.20.1