[PATCH v4 10/10] selftests/bpf/sockopt: Add io_uring support

Breno Leitao
2023-09-04T16:26:31Z

Expand the sockopt test to use also check for io_uring {g,s}etsockopt
commands operations.

This patch starts by marking each test if they support io_uring support
or not.

Right now, io_uring cmd getsockopt() has a limitation of only
accepting level == SOL_SOCKET, otherwise it returns -EOPNOTSUPP. Since
there aren't any test exercising getsockopt(level == SOL_SOCKET), this
patch changes two tests to use level == SOL_SOCKET, they are
"getsockopt: support smaller ctx->optlen" and "getsockopt: read
ctx->optlen".
There is no limitation for the setsockopt() part.

Later, each test runs using regular {g,s}etsockopt systemcalls, and, if
liburing is supported, execute the same test (again), but calling
liburing {g,s}setsockopt commands.

This patch also changes the level of two tests to use SOL_SOCKET for the
following two tests. This is going to help to exercise the io_uring
subsystem:
* getsockopt: read ctx->optlen
* getsockopt: support smaller ctx->optlen

Signed-off-by: Breno Leitao <leitao@debian.org>
---
.../selftests/bpf/prog_tests/sockopt.c | 113 +++++++++++++++++-
1 file changed, 107 insertions(+), 6 deletions(-)

diff --git a/tools/testing/selftests/bpf/prog_tests/sockopt.c b/tools/testing/selftests/bpf/prog_tests/sockopt.c
index 9e6a5e3ed4de..9b1f7f0b1f7e 100644
--- a/tools/testing/selftests/bpf/prog_tests/sockopt.c
+++ b/tools/testing/selftests/bpf/prog_tests/sockopt.c
@@ -1,5 +1,6 @@
// SPDX-License-Identifier: GPL-2.0
#include <test_progs.h>
+#include <io_uring/mini_liburing.h>
#include "cgroup_helpers.h"

static char bpf_log_buf[4096];
@@ -38,6 +39,7 @@ static struct sockopt_test {
socklen_t get_optlen_ret;

enum sockopt_test_error error;
+ bool io_uring_support;
} tests[] = {

/* ==================== getsockopt ==================== */
@@ -251,7 +253,9 @@ static struct sockopt_test {
.attach_type = BPF_CGROUP_GETSOCKOPT,
.expected_attach_type = BPF_CGROUP_GETSOCKOPT,

+ .get_level = SOL_SOCKET,
.get_optlen = 64,
+ .io_uring_support = true,
},
{
.descr = "getsockopt: deny bigger ctx->optlen",
@@ -276,6 +280,7 @@ static struct sockopt_test {
.get_optlen = 64,

.error = EFAULT_GETSOCKOPT,
+ .io_uring_support = true,
},
{
.descr = "getsockopt: ignore >PAGE_SIZE optlen",
@@ -318,6 +323,7 @@ static struct sockopt_test {
.get_optval = {}, /* the changes are ignored */
.get_optlen = PAGE_SIZE + 1,
.error = EOPNOTSUPP_GETSOCKOPT,
+ .io_uring_support = true,
},
{
.descr = "getsockopt: support smaller ctx->optlen",
@@ -337,8 +343,10 @@ static struct sockopt_test {
.attach_type = BPF_CGROUP_GETSOCKOPT,
.expected_attach_type = BPF_CGROUP_GETSOCKOPT,

+ .get_level = SOL_SOCKET,
.get_optlen = 64,
.get_optlen_ret = 32,
+ .io_uring_support = true,
},
{
.descr = "getsockopt: deny writing to ctx->optval",
@@ -518,6 +526,7 @@ static struct sockopt_test {
.set_level = 123,

.set_optlen = 1,
+ .io_uring_support = true,
},
{
.descr = "setsockopt: allow changing ctx->level",
@@ -572,6 +581,7 @@ static struct sockopt_test {
.set_optname = 123,

.set_optlen = 1,
+ .io_uring_support = true,
},
{
.descr = "setsockopt: allow changing ctx->optname",
@@ -624,6 +634,7 @@ static struct sockopt_test {
.expected_attach_type = BPF_CGROUP_SETSOCKOPT,

.set_optlen = 64,
+ .io_uring_support = true,
},
{
.descr = "setsockopt: ctx->optlen == -1 is ok",
@@ -640,6 +651,7 @@ static struct sockopt_test {
.expected_attach_type = BPF_CGROUP_SETSOCKOPT,

.set_optlen = 64,
+ .io_uring_support = true,
},
{
.descr = "setsockopt: deny ctx->optlen < 0 (except -1)",
@@ -658,6 +670,7 @@ static struct sockopt_test {
.set_optlen = 4,

.error = EFAULT_SETSOCKOPT,
+ .io_uring_support = true,
},
{
.descr = "setsockopt: deny ctx->optlen > input optlen",
@@ -675,6 +688,7 @@ static struct sockopt_test {
.set_optlen = 64,

.error = EFAULT_SETSOCKOPT,
+ .io_uring_support = true,
},
{
.descr = "setsockopt: ignore >PAGE_SIZE optlen",
@@ -940,7 +954,89 @@ static int load_prog(const struct bpf_insn *insns,
return fd;
}

-static int run_test(int cgroup_fd, struct sockopt_test *test)
+/* Core function that handles io_uring ring initialization,
+ * sending SQE with sockopt command and waiting for the CQE.
+ */
+static int uring_sockopt(int op, int fd, int level, int optname,
+ const void *optval, socklen_t optlen)
+{
+ struct io_uring_cqe *cqe;
+ struct io_uring_sqe *sqe;
+ struct io_uring ring;
+ int err;
+
+ err = io_uring_queue_init(1, &ring, 0);
+ if (!ASSERT_OK(err, "Failed to initialize io_uring ring"))
+ return err;
+
+ sqe = io_uring_get_sqe(&ring);
+ if (!ASSERT_NEQ(sqe, NULL, "Failed to get an SQE")) {
+ err = -1;
+ goto fail;
+ }
+
+ io_uring_prep_cmd(sqe, op, fd, level, optname, optval, optlen);
+
+ err = io_uring_submit(&ring);
+ if (!ASSERT_EQ(err, 1, "Failed to submit SQE"))
+ goto fail;
+
+ err = io_uring_wait_cqe(&ring, &cqe);
+ if (!ASSERT_OK(err, "Failed to wait for CQE"))
+ goto fail;
+
+ err = cqe->res;
+
+fail:
+ io_uring_queue_exit(&ring);
+
+ return err;
+}
+
+static int uring_setsockopt(int fd, int level, int optname, const void *optval,
+ socklen_t optlen)
+{
+ return uring_sockopt(SOCKET_URING_OP_SETSOCKOPT, fd, level, optname,
+ optval, optlen);
+}
+
+static int uring_getsockopt(int fd, int level, int optname, void *optval,
+ socklen_t *optlen)
+{
+ int ret = uring_sockopt(SOCKET_URING_OP_GETSOCKOPT, fd, level, optname,
+ optval, *optlen);
+ if (ret < 0)
+ return ret;
+
+ /* Populate optlen back to be compatible with systemcall interface,
+ * and simplify the test.
+ */
+ *optlen = ret;
+
+ return 0;
+}
+
+/* Execute the setsocktopt operation */
+static int call_setsockopt(bool use_io_uring, int fd, int level, int optname,
+ const void *optval, socklen_t optlen)
+{
+ if (use_io_uring)
+ return uring_setsockopt(fd, level, optname, optval, optlen);
+
+ return setsockopt(fd, level, optname, optval, optlen);
+}
+
+/* Execute the getsocktopt operation */
+static int call_getsockopt(bool use_io_uring, int fd, int level, int optname,
+ void *optval, socklen_t *optlen)
+{
+ if (use_io_uring)
+ return uring_getsockopt(fd, level, optname, optval, optlen);
+
+ return getsockopt(fd, level, optname, optval, optlen);
+}
+
+static int run_test(int cgroup_fd, struct sockopt_test *test, bool use_io_uring)
{
int sock_fd, err, prog_fd;
void *optval = NULL;
@@ -980,8 +1076,9 @@ static int run_test(int cgroup_fd, struct sockopt_test *test)
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);
+ err = call_setsockopt(use_io_uring, 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;
@@ -1008,8 +1105,8 @@ static int run_test(int cgroup_fd, struct sockopt_test *test)
socklen_t expected_get_optlen = test->get_optlen_ret ?:
test->get_optlen;

- err = getsockopt(sock_fd, test->get_level, test->get_optname,
- optval, &optlen);
+ err = call_getsockopt(use_io_uring, sock_fd, test->get_level,
+ test->get_optname, optval, &optlen);
if (err) {
if (errno == EOPNOTSUPP && test->error == EOPNOTSUPP_GETSOCKOPT)
goto free_optval;
@@ -1063,7 +1160,11 @@ void test_sockopt(void)
if (!test__start_subtest(tests[i].descr))
continue;

- ASSERT_OK(run_test(cgroup_fd, &tests[i]), tests[i].descr);
+ ASSERT_OK(run_test(cgroup_fd, &tests[i], false),
+ tests[i].descr);
+ if (tests[i].io_uring_support)
+ ASSERT_OK(run_test(cgroup_fd, &tests[i], true),
+ tests[i].descr);
}

close(cgroup_fd);
--
2.34.1