[PATCH v3 9/9] selftests/bpf/sockopt: Add io_uring support

From: Breno Leitao
Date: Thu Aug 17 2023 - 10:57:36 EST


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

This patch starts by marking marks 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.

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.

For that, leverage the mini liburing to do basic io_uring operations.

Signed-off-by: Breno Leitao <leitao@xxxxxxxxxx>
---
tools/testing/selftests/bpf/Makefile | 1 +
.../selftests/bpf/prog_tests/sockopt.c | 129 +++++++++++++++++-
2 files changed, 124 insertions(+), 6 deletions(-)

diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile
index 538df8fb8c42..4da04242b848 100644
--- a/tools/testing/selftests/bpf/Makefile
+++ b/tools/testing/selftests/bpf/Makefile
@@ -362,6 +362,7 @@ CLANG_CFLAGS = $(CLANG_SYS_INCLUDES) \

$(OUTPUT)/test_l4lb_noinline.o: BPF_CFLAGS += -fno-inline
$(OUTPUT)/test_xdp_noinline.o: BPF_CFLAGS += -fno-inline
+$(OUTPUT)/test_progs.o: CFLAGS += -I../../../include/

$(OUTPUT)/flow_dissector_load.o: flow_dissector_load.h
$(OUTPUT)/cgroup_getset_retval_hooks.o: cgroup_getset_retval_hooks.h
diff --git a/tools/testing/selftests/bpf/prog_tests/sockopt.c b/tools/testing/selftests/bpf/prog_tests/sockopt.c
index 9e6a5e3ed4de..4693ad8bfe8f 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 ==================== */
@@ -53,6 +55,7 @@ static struct sockopt_test {
.attach_type = BPF_CGROUP_GETSOCKOPT,
.expected_attach_type = 0,
.error = DENY_LOAD,
+ .io_uring_support = true,
},
{
.descr = "getsockopt: wrong expected_attach_type",
@@ -65,6 +68,7 @@ static struct sockopt_test {
.attach_type = BPF_CGROUP_GETSOCKOPT,
.expected_attach_type = BPF_CGROUP_SETSOCKOPT,
.error = DENY_ATTACH,
+ .io_uring_support = true,
},
{
.descr = "getsockopt: bypass bpf hook",
@@ -121,6 +125,7 @@ static struct sockopt_test {
.attach_type = BPF_CGROUP_GETSOCKOPT,
.expected_attach_type = BPF_CGROUP_GETSOCKOPT,
.error = DENY_LOAD,
+ .io_uring_support = true,
},
{
.descr = "getsockopt: read ctx->level",
@@ -164,6 +169,7 @@ static struct sockopt_test {
.expected_attach_type = BPF_CGROUP_GETSOCKOPT,

.error = DENY_LOAD,
+ .io_uring_support = true,
},
{
.descr = "getsockopt: read ctx->optname",
@@ -225,6 +231,7 @@ static struct sockopt_test {
.expected_attach_type = BPF_CGROUP_GETSOCKOPT,

.error = DENY_LOAD,
+ .io_uring_support = true,
},
{
.descr = "getsockopt: read ctx->optlen",
@@ -252,6 +259,7 @@ static struct sockopt_test {
.expected_attach_type = BPF_CGROUP_GETSOCKOPT,

.get_optlen = 64,
+ .io_uring_support = true,
},
{
.descr = "getsockopt: deny bigger ctx->optlen",
@@ -276,6 +284,7 @@ static struct sockopt_test {
.get_optlen = 64,

.error = EFAULT_GETSOCKOPT,
+ .io_uring_support = true,
},
{
.descr = "getsockopt: ignore >PAGE_SIZE optlen",
@@ -318,6 +327,7 @@ 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",
@@ -339,6 +349,7 @@ static struct sockopt_test {

.get_optlen = 64,
.get_optlen_ret = 32,
+ .io_uring_support = true,
},
{
.descr = "getsockopt: deny writing to ctx->optval",
@@ -353,6 +364,7 @@ static struct sockopt_test {
.expected_attach_type = BPF_CGROUP_GETSOCKOPT,

.error = DENY_LOAD,
+ .io_uring_support = true,
},
{
.descr = "getsockopt: deny writing to ctx->optval_end",
@@ -367,6 +379,7 @@ static struct sockopt_test {
.expected_attach_type = BPF_CGROUP_GETSOCKOPT,

.error = DENY_LOAD,
+ .io_uring_support = true,
},
{
.descr = "getsockopt: rewrite value",
@@ -421,6 +434,7 @@ static struct sockopt_test {
.attach_type = BPF_CGROUP_SETSOCKOPT,
.expected_attach_type = 0,
.error = DENY_LOAD,
+ .io_uring_support = true,
},
{
.descr = "setsockopt: wrong expected_attach_type",
@@ -433,6 +447,7 @@ static struct sockopt_test {
.attach_type = BPF_CGROUP_SETSOCKOPT,
.expected_attach_type = BPF_CGROUP_GETSOCKOPT,
.error = DENY_ATTACH,
+ .io_uring_support = true,
},
{
.descr = "setsockopt: bypass bpf hook",
@@ -518,6 +533,7 @@ static struct sockopt_test {
.set_level = 123,

.set_optlen = 1,
+ .io_uring_support = true,
},
{
.descr = "setsockopt: allow changing ctx->level",
@@ -572,6 +588,7 @@ static struct sockopt_test {
.set_optname = 123,

.set_optlen = 1,
+ .io_uring_support = true,
},
{
.descr = "setsockopt: allow changing ctx->optname",
@@ -624,6 +641,7 @@ 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 +658,7 @@ 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 +677,7 @@ static struct sockopt_test {
.set_optlen = 4,

.error = EFAULT_SETSOCKOPT,
+ .io_uring_support = true,
},
{
.descr = "setsockopt: deny ctx->optlen > input optlen",
@@ -675,6 +695,7 @@ static struct sockopt_test {
.set_optlen = 64,

.error = EFAULT_SETSOCKOPT,
+ .io_uring_support = true,
},
{
.descr = "setsockopt: ignore >PAGE_SIZE optlen",
@@ -775,6 +796,7 @@ static struct sockopt_test {
.expected_attach_type = BPF_CGROUP_SETSOCKOPT,

.error = DENY_LOAD,
+ .io_uring_support = true,
},
{
.descr = "setsockopt: deny read ctx->retval",
@@ -791,6 +813,7 @@ static struct sockopt_test {
.expected_attach_type = BPF_CGROUP_SETSOCKOPT,

.error = DENY_LOAD,
+ .io_uring_support = true,
},
{
.descr = "setsockopt: deny writing to ctx->optval",
@@ -805,6 +828,7 @@ static struct sockopt_test {
.expected_attach_type = BPF_CGROUP_SETSOCKOPT,

.error = DENY_LOAD,
+ .io_uring_support = true,
},
{
.descr = "setsockopt: deny writing to ctx->optval_end",
@@ -819,6 +843,7 @@ static struct sockopt_test {
.expected_attach_type = BPF_CGROUP_SETSOCKOPT,

.error = DENY_LOAD,
+ .io_uring_support = true,
},
{
.descr = "setsockopt: allow IP_TOS <= 128",
@@ -940,7 +965,94 @@ 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 (err) {
+ log_err("Failed to initialize io_uring ring");
+ return err;
+ }
+
+ sqe = io_uring_get_sqe(&ring);
+ if (!sqe) {
+ log_err("Failed to get an SQE");
+ return -1;
+ }
+
+ io_uring_prep_cmd(sqe, op, fd, level, optname, optval, optlen);
+
+ err = io_uring_submit(&ring);
+ if (err != 1) {
+ log_err("Failed to submit SQE");
+ return err;
+ }
+
+ err = io_uring_wait_cqe(&ring, &cqe);
+ if (err) {
+ log_err("Failed to wait for CQE");
+ return err;
+ }
+
+ err = cqe->res;
+
+ 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 +1092,9 @@ 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 +1121,8 @@ 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 +1176,11 @@ 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