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linux_dsm_epyc7002/tools/testing/selftests/bpf/test_sockopt.c

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selftests/bpf: add sockopt test Add sockopt selftests: * require proper expected_attach_type * enforce context field read/write access * test bpf_sockopt_handled handler * test EPERM * test limiting optlen from getsockopt * test out-of-bounds access v9: * add tests for setsockopt argument mangling v7: * remove return 2; test retval=0 and optlen=-1 v3: * use DW for optval{,_end} loads v2: * use return code 2 for kernel bypass Cc: Andrii Nakryiko <andriin@fb.com> Cc: Martin Lau <kafai@fb.com> Signed-off-by: Stanislav Fomichev <sdf@google.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-06-28 03:38:51 +07:00
// SPDX-License-Identifier: GPL-2.0
#include <errno.h>
#include <stdio.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <linux/filter.h>
#include <bpf/bpf.h>
#include <bpf/libbpf.h>
#include "bpf_rlimit.h"
#include "bpf_util.h"
#include "cgroup_helpers.h"
#define CG_PATH "/sockopt"
static char bpf_log_buf[4096];
static bool verbose;
enum sockopt_test_error {
OK = 0,
DENY_LOAD,
DENY_ATTACH,
EPERM_GETSOCKOPT,
EFAULT_GETSOCKOPT,
EPERM_SETSOCKOPT,
EFAULT_SETSOCKOPT,
};
static struct sockopt_test {
const char *descr;
const struct bpf_insn insns[64];
enum bpf_attach_type attach_type;
enum bpf_attach_type expected_attach_type;
int set_optname;
int set_level;
const char set_optval[64];
socklen_t set_optlen;
int get_optname;
int get_level;
const char get_optval[64];
socklen_t get_optlen;
socklen_t get_optlen_ret;
enum sockopt_test_error error;
} tests[] = {
/* ==================== getsockopt ==================== */
{
.descr = "getsockopt: no expected_attach_type",
.insns = {
/* return 1 */
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_EXIT_INSN(),
},
.attach_type = BPF_CGROUP_GETSOCKOPT,
.expected_attach_type = 0,
.error = DENY_LOAD,
},
{
.descr = "getsockopt: wrong expected_attach_type",
.insns = {
/* return 1 */
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_EXIT_INSN(),
},
.attach_type = BPF_CGROUP_GETSOCKOPT,
.expected_attach_type = BPF_CGROUP_SETSOCKOPT,
.error = DENY_ATTACH,
},
{
.descr = "getsockopt: bypass bpf hook",
.insns = {
/* return 1 */
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_EXIT_INSN(),
},
.attach_type = BPF_CGROUP_GETSOCKOPT,
.expected_attach_type = BPF_CGROUP_GETSOCKOPT,
.get_level = SOL_IP,
.set_level = SOL_IP,
.get_optname = IP_TOS,
.set_optname = IP_TOS,
.set_optval = { 1 << 3 },
.set_optlen = 1,
.get_optval = { 1 << 3 },
.get_optlen = 1,
},
{
.descr = "getsockopt: return EPERM from bpf hook",
.insns = {
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_EXIT_INSN(),
},
.attach_type = BPF_CGROUP_GETSOCKOPT,
.expected_attach_type = BPF_CGROUP_GETSOCKOPT,
.get_level = SOL_IP,
.get_optname = IP_TOS,
.get_optlen = 1,
.error = EPERM_GETSOCKOPT,
},
{
.descr = "getsockopt: no optval bounds check, deny loading",
.insns = {
/* r6 = ctx->optval */
BPF_LDX_MEM(BPF_DW, BPF_REG_6, BPF_REG_1,
offsetof(struct bpf_sockopt, optval)),
/* ctx->optval[0] = 0x80 */
BPF_MOV64_IMM(BPF_REG_0, 0x80),
BPF_STX_MEM(BPF_W, BPF_REG_6, BPF_REG_0, 0),
/* return 1 */
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_EXIT_INSN(),
},
.attach_type = BPF_CGROUP_GETSOCKOPT,
.expected_attach_type = BPF_CGROUP_GETSOCKOPT,
.error = DENY_LOAD,
},
{
.descr = "getsockopt: read ctx->level",
.insns = {
/* r6 = ctx->level */
BPF_LDX_MEM(BPF_W, BPF_REG_6, BPF_REG_1,
offsetof(struct bpf_sockopt, level)),
/* if (ctx->level == 123) { */
BPF_JMP_IMM(BPF_JNE, BPF_REG_6, 123, 4),
/* ctx->retval = 0 */
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_0,
offsetof(struct bpf_sockopt, retval)),
/* return 1 */
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_JMP_A(1),
/* } else { */
/* return 0 */
BPF_MOV64_IMM(BPF_REG_0, 0),
/* } */
BPF_EXIT_INSN(),
},
.attach_type = BPF_CGROUP_GETSOCKOPT,
.expected_attach_type = BPF_CGROUP_GETSOCKOPT,
.get_level = 123,
.get_optlen = 1,
},
{
.descr = "getsockopt: deny writing to ctx->level",
.insns = {
/* ctx->level = 1 */
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_0,
offsetof(struct bpf_sockopt, level)),
BPF_EXIT_INSN(),
},
.attach_type = BPF_CGROUP_GETSOCKOPT,
.expected_attach_type = BPF_CGROUP_GETSOCKOPT,
.error = DENY_LOAD,
},
{
.descr = "getsockopt: read ctx->optname",
.insns = {
/* r6 = ctx->optname */
BPF_LDX_MEM(BPF_W, BPF_REG_6, BPF_REG_1,
offsetof(struct bpf_sockopt, optname)),
/* if (ctx->optname == 123) { */
BPF_JMP_IMM(BPF_JNE, BPF_REG_6, 123, 4),
/* ctx->retval = 0 */
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_0,
offsetof(struct bpf_sockopt, retval)),
/* return 1 */
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_JMP_A(1),
/* } else { */
/* return 0 */
BPF_MOV64_IMM(BPF_REG_0, 0),
/* } */
BPF_EXIT_INSN(),
},
.attach_type = BPF_CGROUP_GETSOCKOPT,
.expected_attach_type = BPF_CGROUP_GETSOCKOPT,
.get_optname = 123,
.get_optlen = 1,
},
{
.descr = "getsockopt: read ctx->retval",
.insns = {
/* r6 = ctx->retval */
BPF_LDX_MEM(BPF_W, BPF_REG_6, BPF_REG_1,
offsetof(struct bpf_sockopt, retval)),
/* return 1 */
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_EXIT_INSN(),
},
.attach_type = BPF_CGROUP_GETSOCKOPT,
.expected_attach_type = BPF_CGROUP_GETSOCKOPT,
.get_level = SOL_IP,
.get_optname = IP_TOS,
.get_optlen = 1,
},
{
.descr = "getsockopt: deny writing to ctx->optname",
.insns = {
/* ctx->optname = 1 */
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_0,
offsetof(struct bpf_sockopt, optname)),
BPF_EXIT_INSN(),
},
.attach_type = BPF_CGROUP_GETSOCKOPT,
.expected_attach_type = BPF_CGROUP_GETSOCKOPT,
.error = DENY_LOAD,
},
{
.descr = "getsockopt: read ctx->optlen",
.insns = {
/* r6 = ctx->optlen */
BPF_LDX_MEM(BPF_W, BPF_REG_6, BPF_REG_1,
offsetof(struct bpf_sockopt, optlen)),
/* if (ctx->optlen == 64) { */
BPF_JMP_IMM(BPF_JNE, BPF_REG_6, 64, 4),
/* ctx->retval = 0 */
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_0,
offsetof(struct bpf_sockopt, retval)),
/* return 1 */
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_JMP_A(1),
/* } else { */
/* return 0 */
BPF_MOV64_IMM(BPF_REG_0, 0),
/* } */
BPF_EXIT_INSN(),
},
.attach_type = BPF_CGROUP_GETSOCKOPT,
.expected_attach_type = BPF_CGROUP_GETSOCKOPT,
.get_optlen = 64,
},
{
.descr = "getsockopt: deny bigger ctx->optlen",
.insns = {
/* ctx->optlen = 65 */
BPF_MOV64_IMM(BPF_REG_0, 65),
BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_0,
offsetof(struct bpf_sockopt, optlen)),
/* ctx->retval = 0 */
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_0,
offsetof(struct bpf_sockopt, retval)),
/* return 1 */
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_EXIT_INSN(),
},
.attach_type = BPF_CGROUP_GETSOCKOPT,
.expected_attach_type = BPF_CGROUP_GETSOCKOPT,
.get_optlen = 64,
.error = EFAULT_GETSOCKOPT,
},
{
.descr = "getsockopt: deny arbitrary ctx->retval",
.insns = {
/* ctx->retval = 123 */
BPF_MOV64_IMM(BPF_REG_0, 123),
BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_0,
offsetof(struct bpf_sockopt, retval)),
/* return 1 */
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_EXIT_INSN(),
},
.attach_type = BPF_CGROUP_GETSOCKOPT,
.expected_attach_type = BPF_CGROUP_GETSOCKOPT,
.get_optlen = 64,
.error = EFAULT_GETSOCKOPT,
},
{
.descr = "getsockopt: support smaller ctx->optlen",
.insns = {
/* ctx->optlen = 32 */
BPF_MOV64_IMM(BPF_REG_0, 32),
BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_0,
offsetof(struct bpf_sockopt, optlen)),
/* ctx->retval = 0 */
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_0,
offsetof(struct bpf_sockopt, retval)),
/* return 1 */
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_EXIT_INSN(),
},
.attach_type = BPF_CGROUP_GETSOCKOPT,
.expected_attach_type = BPF_CGROUP_GETSOCKOPT,
.get_optlen = 64,
.get_optlen_ret = 32,
},
{
.descr = "getsockopt: deny writing to ctx->optval",
.insns = {
/* ctx->optval = 1 */
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_STX_MEM(BPF_DW, BPF_REG_1, BPF_REG_0,
offsetof(struct bpf_sockopt, optval)),
BPF_EXIT_INSN(),
},
.attach_type = BPF_CGROUP_GETSOCKOPT,
.expected_attach_type = BPF_CGROUP_GETSOCKOPT,
.error = DENY_LOAD,
},
{
.descr = "getsockopt: deny writing to ctx->optval_end",
.insns = {
/* ctx->optval_end = 1 */
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_STX_MEM(BPF_DW, BPF_REG_1, BPF_REG_0,
offsetof(struct bpf_sockopt, optval_end)),
BPF_EXIT_INSN(),
},
.attach_type = BPF_CGROUP_GETSOCKOPT,
.expected_attach_type = BPF_CGROUP_GETSOCKOPT,
.error = DENY_LOAD,
},
{
.descr = "getsockopt: rewrite value",
.insns = {
/* r6 = ctx->optval */
BPF_LDX_MEM(BPF_DW, BPF_REG_6, BPF_REG_1,
offsetof(struct bpf_sockopt, optval)),
/* r2 = ctx->optval */
BPF_MOV64_REG(BPF_REG_2, BPF_REG_6),
/* r6 = ctx->optval + 1 */
BPF_ALU64_IMM(BPF_ADD, BPF_REG_6, 1),
/* r7 = ctx->optval_end */
BPF_LDX_MEM(BPF_DW, BPF_REG_7, BPF_REG_1,
offsetof(struct bpf_sockopt, optval_end)),
/* if (ctx->optval + 1 <= ctx->optval_end) { */
BPF_JMP_REG(BPF_JGT, BPF_REG_6, BPF_REG_7, 1),
/* ctx->optval[0] = 0xF0 */
BPF_ST_MEM(BPF_B, BPF_REG_2, 0, 0xF0),
/* } */
/* ctx->retval = 0 */
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_0,
offsetof(struct bpf_sockopt, retval)),
/* return 1*/
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_EXIT_INSN(),
},
.attach_type = BPF_CGROUP_GETSOCKOPT,
.expected_attach_type = BPF_CGROUP_GETSOCKOPT,
.get_level = SOL_IP,
.get_optname = IP_TOS,
.get_optval = { 0xF0 },
.get_optlen = 1,
},
/* ==================== setsockopt ==================== */
{
.descr = "setsockopt: no expected_attach_type",
.insns = {
/* return 1 */
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_EXIT_INSN(),
},
.attach_type = BPF_CGROUP_SETSOCKOPT,
.expected_attach_type = 0,
.error = DENY_LOAD,
},
{
.descr = "setsockopt: wrong expected_attach_type",
.insns = {
/* return 1 */
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_EXIT_INSN(),
},
.attach_type = BPF_CGROUP_SETSOCKOPT,
.expected_attach_type = BPF_CGROUP_GETSOCKOPT,
.error = DENY_ATTACH,
},
{
.descr = "setsockopt: bypass bpf hook",
.insns = {
/* return 1 */
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_EXIT_INSN(),
},
.attach_type = BPF_CGROUP_SETSOCKOPT,
.expected_attach_type = BPF_CGROUP_SETSOCKOPT,
.get_level = SOL_IP,
.set_level = SOL_IP,
.get_optname = IP_TOS,
.set_optname = IP_TOS,
.set_optval = { 1 << 3 },
.set_optlen = 1,
.get_optval = { 1 << 3 },
.get_optlen = 1,
},
{
.descr = "setsockopt: return EPERM from bpf hook",
.insns = {
/* return 0 */
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_EXIT_INSN(),
},
.attach_type = BPF_CGROUP_SETSOCKOPT,
.expected_attach_type = BPF_CGROUP_SETSOCKOPT,
.set_level = SOL_IP,
.set_optname = IP_TOS,
.set_optlen = 1,
.error = EPERM_SETSOCKOPT,
},
{
.descr = "setsockopt: no optval bounds check, deny loading",
.insns = {
/* r6 = ctx->optval */
BPF_LDX_MEM(BPF_DW, BPF_REG_6, BPF_REG_1,
offsetof(struct bpf_sockopt, optval)),
/* r0 = ctx->optval[0] */
BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_6, 0),
/* return 1 */
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_EXIT_INSN(),
},
.attach_type = BPF_CGROUP_SETSOCKOPT,
.expected_attach_type = BPF_CGROUP_SETSOCKOPT,
.error = DENY_LOAD,
},
{
.descr = "setsockopt: read ctx->level",
.insns = {
/* r6 = ctx->level */
BPF_LDX_MEM(BPF_W, BPF_REG_6, BPF_REG_1,
offsetof(struct bpf_sockopt, level)),
/* if (ctx->level == 123) { */
BPF_JMP_IMM(BPF_JNE, BPF_REG_6, 123, 4),
/* ctx->optlen = -1 */
BPF_MOV64_IMM(BPF_REG_0, -1),
BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_0,
offsetof(struct bpf_sockopt, optlen)),
/* return 1 */
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_JMP_A(1),
/* } else { */
/* return 0 */
BPF_MOV64_IMM(BPF_REG_0, 0),
/* } */
BPF_EXIT_INSN(),
},
.attach_type = BPF_CGROUP_SETSOCKOPT,
.expected_attach_type = BPF_CGROUP_SETSOCKOPT,
.set_level = 123,
.set_optlen = 1,
},
{
.descr = "setsockopt: allow changing ctx->level",
.insns = {
/* ctx->level = SOL_IP */
BPF_MOV64_IMM(BPF_REG_0, SOL_IP),
BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_0,
offsetof(struct bpf_sockopt, level)),
/* return 1 */
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_EXIT_INSN(),
},
.attach_type = BPF_CGROUP_SETSOCKOPT,
.expected_attach_type = BPF_CGROUP_SETSOCKOPT,
.get_level = SOL_IP,
.set_level = 234, /* should be rewritten to SOL_IP */
.get_optname = IP_TOS,
.set_optname = IP_TOS,
.set_optval = { 1 << 3 },
.set_optlen = 1,
.get_optval = { 1 << 3 },
.get_optlen = 1,
},
{
.descr = "setsockopt: read ctx->optname",
.insns = {
/* r6 = ctx->optname */
BPF_LDX_MEM(BPF_W, BPF_REG_6, BPF_REG_1,
offsetof(struct bpf_sockopt, optname)),
/* if (ctx->optname == 123) { */
BPF_JMP_IMM(BPF_JNE, BPF_REG_6, 123, 4),
/* ctx->optlen = -1 */
BPF_MOV64_IMM(BPF_REG_0, -1),
BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_0,
offsetof(struct bpf_sockopt, optlen)),
/* return 1 */
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_JMP_A(1),
/* } else { */
/* return 0 */
BPF_MOV64_IMM(BPF_REG_0, 0),
/* } */
BPF_EXIT_INSN(),
},
.attach_type = BPF_CGROUP_SETSOCKOPT,
.expected_attach_type = BPF_CGROUP_SETSOCKOPT,
.set_optname = 123,
.set_optlen = 1,
},
{
.descr = "setsockopt: allow changing ctx->optname",
.insns = {
/* ctx->optname = IP_TOS */
BPF_MOV64_IMM(BPF_REG_0, IP_TOS),
BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_0,
offsetof(struct bpf_sockopt, optname)),
/* return 1 */
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_EXIT_INSN(),
},
.attach_type = BPF_CGROUP_SETSOCKOPT,
.expected_attach_type = BPF_CGROUP_SETSOCKOPT,
.get_level = SOL_IP,
.set_level = SOL_IP,
.get_optname = IP_TOS,
.set_optname = 456, /* should be rewritten to IP_TOS */
.set_optval = { 1 << 3 },
.set_optlen = 1,
.get_optval = { 1 << 3 },
.get_optlen = 1,
},
{
.descr = "setsockopt: read ctx->optlen",
.insns = {
/* r6 = ctx->optlen */
BPF_LDX_MEM(BPF_W, BPF_REG_6, BPF_REG_1,
offsetof(struct bpf_sockopt, optlen)),
/* if (ctx->optlen == 64) { */
BPF_JMP_IMM(BPF_JNE, BPF_REG_6, 64, 4),
/* ctx->optlen = -1 */
BPF_MOV64_IMM(BPF_REG_0, -1),
BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_0,
offsetof(struct bpf_sockopt, optlen)),
/* return 1 */
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_JMP_A(1),
/* } else { */
/* return 0 */
BPF_MOV64_IMM(BPF_REG_0, 0),
/* } */
BPF_EXIT_INSN(),
},
.attach_type = BPF_CGROUP_SETSOCKOPT,
.expected_attach_type = BPF_CGROUP_SETSOCKOPT,
.set_optlen = 64,
},
{
.descr = "setsockopt: ctx->optlen == -1 is ok",
.insns = {
/* ctx->optlen = -1 */
BPF_MOV64_IMM(BPF_REG_0, -1),
BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_0,
offsetof(struct bpf_sockopt, optlen)),
/* return 1 */
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_EXIT_INSN(),
},
.attach_type = BPF_CGROUP_SETSOCKOPT,
.expected_attach_type = BPF_CGROUP_SETSOCKOPT,
.set_optlen = 64,
},
{
.descr = "setsockopt: deny ctx->optlen < 0 (except -1)",
.insns = {
/* ctx->optlen = -2 */
BPF_MOV64_IMM(BPF_REG_0, -2),
BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_0,
offsetof(struct bpf_sockopt, optlen)),
/* return 1 */
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_EXIT_INSN(),
},
.attach_type = BPF_CGROUP_SETSOCKOPT,
.expected_attach_type = BPF_CGROUP_SETSOCKOPT,
.set_optlen = 4,
.error = EFAULT_SETSOCKOPT,
},
{
.descr = "setsockopt: deny ctx->optlen > input optlen",
.insns = {
/* ctx->optlen = 65 */
BPF_MOV64_IMM(BPF_REG_0, 65),
BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_0,
offsetof(struct bpf_sockopt, optlen)),
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_EXIT_INSN(),
},
.attach_type = BPF_CGROUP_SETSOCKOPT,
.expected_attach_type = BPF_CGROUP_SETSOCKOPT,
.set_optlen = 64,
.error = EFAULT_SETSOCKOPT,
},
{
.descr = "setsockopt: allow changing ctx->optlen within bounds",
.insns = {
/* r6 = ctx->optval */
BPF_LDX_MEM(BPF_DW, BPF_REG_6, BPF_REG_1,
offsetof(struct bpf_sockopt, optval)),
/* r2 = ctx->optval */
BPF_MOV64_REG(BPF_REG_2, BPF_REG_6),
/* r6 = ctx->optval + 1 */
BPF_ALU64_IMM(BPF_ADD, BPF_REG_6, 1),
/* r7 = ctx->optval_end */
BPF_LDX_MEM(BPF_DW, BPF_REG_7, BPF_REG_1,
offsetof(struct bpf_sockopt, optval_end)),
/* if (ctx->optval + 1 <= ctx->optval_end) { */
BPF_JMP_REG(BPF_JGT, BPF_REG_6, BPF_REG_7, 1),
/* ctx->optval[0] = 1 << 3 */
BPF_ST_MEM(BPF_B, BPF_REG_2, 0, 1 << 3),
/* } */
/* ctx->optlen = 1 */
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_0,
offsetof(struct bpf_sockopt, optlen)),
/* return 1*/
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_EXIT_INSN(),
},
.attach_type = BPF_CGROUP_SETSOCKOPT,
.expected_attach_type = BPF_CGROUP_SETSOCKOPT,
.get_level = SOL_IP,
.set_level = SOL_IP,
.get_optname = IP_TOS,
.set_optname = IP_TOS,
.set_optval = { 1, 1, 1, 1 },
.set_optlen = 4,
.get_optval = { 1 << 3 },
.get_optlen = 1,
},
{
.descr = "setsockopt: deny write ctx->retval",
.insns = {
/* ctx->retval = 0 */
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_0,
offsetof(struct bpf_sockopt, retval)),
/* return 1 */
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_EXIT_INSN(),
},
.attach_type = BPF_CGROUP_SETSOCKOPT,
.expected_attach_type = BPF_CGROUP_SETSOCKOPT,
.error = DENY_LOAD,
},
{
.descr = "setsockopt: deny read ctx->retval",
.insns = {
/* r6 = ctx->retval */
BPF_LDX_MEM(BPF_W, BPF_REG_6, BPF_REG_1,
offsetof(struct bpf_sockopt, retval)),
/* return 1 */
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_EXIT_INSN(),
},
.attach_type = BPF_CGROUP_SETSOCKOPT,
.expected_attach_type = BPF_CGROUP_SETSOCKOPT,
.error = DENY_LOAD,
},
{
.descr = "setsockopt: deny writing to ctx->optval",
.insns = {
/* ctx->optval = 1 */
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_STX_MEM(BPF_DW, BPF_REG_1, BPF_REG_0,
offsetof(struct bpf_sockopt, optval)),
BPF_EXIT_INSN(),
},
.attach_type = BPF_CGROUP_SETSOCKOPT,
.expected_attach_type = BPF_CGROUP_SETSOCKOPT,
.error = DENY_LOAD,
},
{
.descr = "setsockopt: deny writing to ctx->optval_end",
.insns = {
/* ctx->optval_end = 1 */
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_STX_MEM(BPF_DW, BPF_REG_1, BPF_REG_0,
offsetof(struct bpf_sockopt, optval_end)),
BPF_EXIT_INSN(),
},
.attach_type = BPF_CGROUP_SETSOCKOPT,
.expected_attach_type = BPF_CGROUP_SETSOCKOPT,
.error = DENY_LOAD,
},
{
.descr = "setsockopt: allow IP_TOS <= 128",
.insns = {
/* r6 = ctx->optval */
BPF_LDX_MEM(BPF_DW, BPF_REG_6, BPF_REG_1,
offsetof(struct bpf_sockopt, optval)),
/* r7 = ctx->optval + 1 */
BPF_MOV64_REG(BPF_REG_7, BPF_REG_6),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_7, 1),
/* r8 = ctx->optval_end */
BPF_LDX_MEM(BPF_DW, BPF_REG_8, BPF_REG_1,
offsetof(struct bpf_sockopt, optval_end)),
/* if (ctx->optval + 1 <= ctx->optval_end) { */
BPF_JMP_REG(BPF_JGT, BPF_REG_7, BPF_REG_8, 4),
/* r9 = ctx->optval[0] */
BPF_LDX_MEM(BPF_B, BPF_REG_9, BPF_REG_6, 0),
/* if (ctx->optval[0] < 128) */
BPF_JMP_IMM(BPF_JGT, BPF_REG_9, 128, 2),
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_JMP_A(1),
/* } */
/* } else { */
BPF_MOV64_IMM(BPF_REG_0, 0),
/* } */
BPF_EXIT_INSN(),
},
.attach_type = BPF_CGROUP_SETSOCKOPT,
.expected_attach_type = BPF_CGROUP_SETSOCKOPT,
.get_level = SOL_IP,
.set_level = SOL_IP,
.get_optname = IP_TOS,
.set_optname = IP_TOS,
.set_optval = { 0x80 },
.set_optlen = 1,
.get_optval = { 0x80 },
.get_optlen = 1,
},
{
.descr = "setsockopt: deny IP_TOS > 128",
.insns = {
/* r6 = ctx->optval */
BPF_LDX_MEM(BPF_DW, BPF_REG_6, BPF_REG_1,
offsetof(struct bpf_sockopt, optval)),
/* r7 = ctx->optval + 1 */
BPF_MOV64_REG(BPF_REG_7, BPF_REG_6),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_7, 1),
/* r8 = ctx->optval_end */
BPF_LDX_MEM(BPF_DW, BPF_REG_8, BPF_REG_1,
offsetof(struct bpf_sockopt, optval_end)),
/* if (ctx->optval + 1 <= ctx->optval_end) { */
BPF_JMP_REG(BPF_JGT, BPF_REG_7, BPF_REG_8, 4),
/* r9 = ctx->optval[0] */
BPF_LDX_MEM(BPF_B, BPF_REG_9, BPF_REG_6, 0),
/* if (ctx->optval[0] < 128) */
BPF_JMP_IMM(BPF_JGT, BPF_REG_9, 128, 2),
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_JMP_A(1),
/* } */
/* } else { */
BPF_MOV64_IMM(BPF_REG_0, 0),
/* } */
BPF_EXIT_INSN(),
},
.attach_type = BPF_CGROUP_SETSOCKOPT,
.expected_attach_type = BPF_CGROUP_SETSOCKOPT,
.get_level = SOL_IP,
.set_level = SOL_IP,
.get_optname = IP_TOS,
.set_optname = IP_TOS,
.set_optval = { 0x81 },
.set_optlen = 1,
.get_optval = { 0x00 },
.get_optlen = 1,
.error = EPERM_SETSOCKOPT,
},
};
static int load_prog(const struct bpf_insn *insns,
enum bpf_attach_type expected_attach_type)
{
struct bpf_load_program_attr attr = {
.prog_type = BPF_PROG_TYPE_CGROUP_SOCKOPT,
.expected_attach_type = expected_attach_type,
.insns = insns,
.license = "GPL",
.log_level = 2,
};
int fd;
for (;
insns[attr.insns_cnt].code != (BPF_JMP | BPF_EXIT);
attr.insns_cnt++) {
}
attr.insns_cnt++;
fd = bpf_load_program_xattr(&attr, bpf_log_buf, sizeof(bpf_log_buf));
if (verbose && fd < 0)
fprintf(stderr, "%s\n", bpf_log_buf);
return fd;
}
static int run_test(int cgroup_fd, struct sockopt_test *test)
{
int sock_fd, err, prog_fd;
void *optval = NULL;
int ret = 0;
prog_fd = load_prog(test->insns, test->expected_attach_type);
if (prog_fd < 0) {
if (test->error == DENY_LOAD)
return 0;
log_err("Failed to load BPF program");
return -1;
}
err = bpf_prog_attach(prog_fd, cgroup_fd, test->attach_type, 0);
if (err < 0) {
if (test->error == DENY_ATTACH)
goto close_prog_fd;
log_err("Failed to attach BPF program");
ret = -1;
goto close_prog_fd;
}
sock_fd = socket(AF_INET, SOCK_STREAM, 0);
if (sock_fd < 0) {
log_err("Failed to create AF_INET socket");
ret = -1;
goto detach_prog;
}
if (test->set_optlen) {
err = setsockopt(sock_fd, test->set_level, test->set_optname,
test->set_optval, test->set_optlen);
if (err) {
if (errno == EPERM && test->error == EPERM_SETSOCKOPT)
goto close_sock_fd;
if (errno == EFAULT && test->error == EFAULT_SETSOCKOPT)
goto free_optval;
log_err("Failed to call setsockopt");
ret = -1;
goto close_sock_fd;
}
}
if (test->get_optlen) {
optval = malloc(test->get_optlen);
socklen_t optlen = test->get_optlen;
socklen_t expected_get_optlen = test->get_optlen_ret ?:
test->get_optlen;
err = getsockopt(sock_fd, test->get_level, test->get_optname,
optval, &optlen);
if (err) {
if (errno == EPERM && test->error == EPERM_GETSOCKOPT)
goto free_optval;
if (errno == EFAULT && test->error == EFAULT_GETSOCKOPT)
goto free_optval;
log_err("Failed to call getsockopt");
ret = -1;
goto free_optval;
}
if (optlen != expected_get_optlen) {
errno = 0;
log_err("getsockopt returned unexpected optlen");
ret = -1;
goto free_optval;
}
if (memcmp(optval, test->get_optval, optlen) != 0) {
errno = 0;
log_err("getsockopt returned unexpected optval");
ret = -1;
goto free_optval;
}
}
ret = test->error != OK;
free_optval:
free(optval);
close_sock_fd:
close(sock_fd);
detach_prog:
bpf_prog_detach2(prog_fd, cgroup_fd, test->attach_type);
close_prog_fd:
close(prog_fd);
return ret;
}
int main(int args, char **argv)
{
int err = EXIT_FAILURE, error_cnt = 0;
int cgroup_fd, i;
if (setup_cgroup_environment())
goto cleanup_obj;
cgroup_fd = create_and_get_cgroup(CG_PATH);
if (cgroup_fd < 0)
goto cleanup_cgroup_env;
if (join_cgroup(CG_PATH))
goto cleanup_cgroup;
for (i = 0; i < ARRAY_SIZE(tests); i++) {
int err = run_test(cgroup_fd, &tests[i]);
if (err)
error_cnt++;
printf("#%d %s: %s\n", i, err ? "FAIL" : "PASS",
tests[i].descr);
}
printf("Summary: %ld PASSED, %d FAILED\n",
ARRAY_SIZE(tests) - error_cnt, error_cnt);
err = error_cnt ? EXIT_FAILURE : EXIT_SUCCESS;
cleanup_cgroup:
close(cgroup_fd);
cleanup_cgroup_env:
cleanup_cgroup_environment();
cleanup_obj:
return err;
}
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