Commit 989a4a7d authored by Stanislav Fomichev's avatar Stanislav Fomichev Committed by Martin KaFai Lau
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selftests/bpf: Update EFAULT {g,s}etsockopt selftests 



Instead of assuming EFAULT, let's assume the BPF program's
output is ignored.

Remove "getsockopt: deny arbitrary ctx->retval" because it
was actually testing optlen. We have separate set of tests
for retval.

Signed-off-by: default avatarStanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/r/20230511170456.1759459-3-sdf@google.com


Signed-off-by: default avatarMartin KaFai Lau <martin.lau@kernel.org>
parent 29ebbba7

tools/testing/selftests/bpf/prog_tests/sockopt.c

+90 −6
Original line number Diff line number Diff line
@@ -5,10 +5,15 @@ 
static char bpf_log_buf[4096];

static bool verbose;



#ifndef PAGE_SIZE

#define PAGE_SIZE 4096

#endif



enum sockopt_test_error {

	OK = 0,

	DENY_LOAD,

	DENY_ATTACH,

	EOPNOTSUPP_GETSOCKOPT,

	EPERM_GETSOCKOPT,

	EFAULT_GETSOCKOPT,

	EPERM_SETSOCKOPT,
@@ -273,10 +278,31 @@ static struct sockopt_test { 
		.error = EFAULT_GETSOCKOPT,

	},

	{

		.descr = "getsockopt: deny arbitrary ctx->retval",

		.descr = "getsockopt: ignore >PAGE_SIZE optlen",

		.insns = {

			/* ctx->retval = 123 */

			BPF_MOV64_IMM(BPF_REG_0, 123),

			/* write 0xFF to the first optval byte */



			/* 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, 0xFF),

			/* } */



			/* retval changes are ignored */

			/* ctx->retval = 5 */

			BPF_MOV64_IMM(BPF_REG_0, 5),

			BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_0,

				    offsetof(struct bpf_sockopt, retval)),
@@ -287,9 +313,11 @@ static struct sockopt_test { 
		.attach_type = BPF_CGROUP_GETSOCKOPT,

		.expected_attach_type = BPF_CGROUP_GETSOCKOPT,



		.get_optlen = 64,



		.error = EFAULT_GETSOCKOPT,

		.get_level = 1234,

		.get_optname = 5678,

		.get_optval = {}, /* the changes are ignored */

		.get_optlen = PAGE_SIZE + 1,

		.error = EOPNOTSUPP_GETSOCKOPT,

	},

	{

		.descr = "getsockopt: support smaller ctx->optlen",
@@ -648,6 +676,45 @@ static struct sockopt_test { 


		.error = EFAULT_SETSOCKOPT,

	},

	{

		.descr = "setsockopt: ignore >PAGE_SIZE optlen",

		.insns = {

			/* write 0xFF to the first optval byte */



			/* 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),

			/* } */



			BPF_MOV64_IMM(BPF_REG_0, 1),

			BPF_EXIT_INSN(),

		},

		.attach_type = BPF_CGROUP_SETSOCKOPT,

		.expected_attach_type = BPF_CGROUP_SETSOCKOPT,



		.set_level = SOL_IP,

		.set_optname = IP_TOS,

		.set_optval = {},

		.set_optlen = PAGE_SIZE + 1,



		.get_level = SOL_IP,

		.get_optname = IP_TOS,

		.get_optval = {}, /* the changes are ignored */

		.get_optlen = 4,

	},

	{

		.descr = "setsockopt: allow changing ctx->optlen within bounds",

		.insns = {
@@ -906,6 +973,13 @@ static int run_test(int cgroup_fd, struct sockopt_test *test) 
	}



	if (test->set_optlen) {

		if (test->set_optlen >= PAGE_SIZE) {

			int num_pages = test->set_optlen / PAGE_SIZE;

			int remainder = test->set_optlen % PAGE_SIZE;



			test->set_optlen = num_pages * sysconf(_SC_PAGESIZE) + remainder;

		}



		err = setsockopt(sock_fd, test->set_level, test->set_optname,

				 test->set_optval, test->set_optlen);

		if (err) {
@@ -921,7 +995,15 @@ static int run_test(int cgroup_fd, struct sockopt_test *test) 
	}



	if (test->get_optlen) {

		if (test->get_optlen >= PAGE_SIZE) {

			int num_pages = test->get_optlen / PAGE_SIZE;

			int remainder = test->get_optlen % PAGE_SIZE;



			test->get_optlen = num_pages * sysconf(_SC_PAGESIZE) + remainder;

		}



		optval = malloc(test->get_optlen);

		memset(optval, 0, test->get_optlen);

		socklen_t optlen = test->get_optlen;

		socklen_t expected_get_optlen = test->get_optlen_ret ?:

			test->get_optlen;
@@ -929,6 +1011,8 @@ static int run_test(int cgroup_fd, struct sockopt_test *test) 
		err = getsockopt(sock_fd, test->get_level, test->get_optname,

				 optval, &optlen);

		if (err) {

			if (errno == EOPNOTSUPP && test->error == EOPNOTSUPP_GETSOCKOPT)

				goto free_optval;

			if (errno == EPERM && test->error == EPERM_GETSOCKOPT)

				goto free_optval;

			if (errno == EFAULT && test->error == EFAULT_GETSOCKOPT)