[PATCH net-next 07/13] selftests: xsk: split xskxceiver main() into setup, run and cleanup

[Maciej Fijalkowski <maciej.fijalkowski@intel.com>]

Prepare xskxceiver for running a single endpoint per process by
untangling main():

- bind_iface() resolves and initializes one interface from its -i
  argument, so the interface list can be assigned to roles after
  parsing; -l lists tests and exits without needing interfaces
- detect_mode_caps() records DRV and zero-copy support and
  detect_ifobj_caps() HW ring support as XSK_CAP flags, and
  mode_supported() tells from them whether a mode can run
- run_pkt_test() returns the result, and main() counts failures from
  it rather than from test->fail, which not every failing path sets
- cleanup_iface() restores rings, detaches and unloads per interface
  and is safe on partially initialized objects, as is
  pkt_stream_delete(NULL), so main() has a single exit path

Call ksft_print_header() before ksft_set_plan(): xskxceiver never did,
and that is where kselftest.h switches stdout to line buffering, so a
launcher reading through a pipe only saw the output at exit.

While at it, exit with 0 for -l instead of KSFT_XPASS: listing the
tests is not a test result, so scripts should be able to run it like
any other command.

Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
---
 .../testing/selftests/net/lib/xsk/test_xsk.c  |  10 +
 .../testing/selftests/net/lib/xsk/test_xsk.h  |   2 +
 .../selftests/net/lib/xsk/xskxceiver.c        | 184 +++++++++---------
 3 files changed, 107 insertions(+), 89 deletions(-)

diff --git a/tools/testing/selftests/net/lib/xsk/test_xsk.c b/tools/testing/selftests/net/lib/xsk/test_xsk.c
index a26f4d8378c4..eb91d74a9f94 100644
--- a/tools/testing/selftests/net/lib/xsk/test_xsk.c
+++ b/tools/testing/selftests/net/lib/xsk/test_xsk.c
@@ -369,6 +369,9 @@ static struct pkt *pkt_stream_get_next_rx_pkt(struct pkt_stream *pkt_stream, u32
 
 void pkt_stream_delete(struct pkt_stream *pkt_stream)
 {
+	if (!pkt_stream)
+		return;
+
 	free(pkt_stream->pkts);
 	free(pkt_stream);
 }
@@ -2331,6 +2334,13 @@ static int detect_ifobj_caps(struct ifobject *ifobj)
 		}
 	}
 
+	if (!get_hw_ring_size(ifobj->ifname, &ifobj->ring)) {
+		ifobj_set_cap(ifobj, XSK_CAP_HW_RING);
+		ifobj->caps.tx_max_pending = ifobj->ring.tx_max_pending;
+		ifobj->set_ring.default_tx = ifobj->ring.tx_pending;
+		ifobj->set_ring.default_rx = ifobj->ring.rx_pending;
+	}
+
 	return 0;
 }
 
diff --git a/tools/testing/selftests/net/lib/xsk/test_xsk.h b/tools/testing/selftests/net/lib/xsk/test_xsk.h
index 1d17e214db91..861a2ee3b8e1 100644
--- a/tools/testing/selftests/net/lib/xsk/test_xsk.h
+++ b/tools/testing/selftests/net/lib/xsk/test_xsk.h
@@ -123,6 +123,8 @@ int hw_ring_size_reset(struct ifobject *ifobj);
 #define XSK_CAP_MBUF             (1U << 1)
 #define XSK_CAP_MBUF_ZC          (1U << 2)
 #define XSK_CAP_HW_RING          (1U << 3)
+#define XSK_CAP_DRV              (1U << 4)
+#define XSK_CAP_ZC               (1U << 5)
 
 struct xsk_caps {
 	u32 flags;
diff --git a/tools/testing/selftests/net/lib/xsk/xskxceiver.c b/tools/testing/selftests/net/lib/xsk/xskxceiver.c
index 8b3e4d18e982..afd6b242aa0d 100644
--- a/tools/testing/selftests/net/lib/xsk/xskxceiver.c
+++ b/tools/testing/selftests/net/lib/xsk/xskxceiver.c
@@ -81,7 +81,6 @@
 #include <linux/netdev.h>
 #include <linux/ethtool.h>
 #include <linux/align.h>
-#include <linux/kernel.h>
 #include <arpa/inet.h>
 #include <net/if.h>
 #include <locale.h>
@@ -101,7 +100,6 @@
 #include "kselftest.h"
 #include "xsk_xdp_common.h"
 
-static bool opt_print_tests;
 static enum test_mode opt_mode = TEST_MODE_ALL;
 static u32 opt_run_test = RUN_ALL_TESTS;
 
@@ -185,17 +183,40 @@ static void print_usage(char **argv)
 	ksft_exit_xfail();
 }
 
-static bool validate_interface(struct ifobject *ifobj)
+static void bind_iface(struct ifobject *ifobj, const char *ifname, thread_func_t func,
+		       char **argv)
 {
-	if (!strcmp(ifobj->ifname, ""))
-		return false;
-	return true;
+	size_t len = ifname ? strlen(ifname) : 0;
+
+	if (!len || len >= sizeof(ifobj->ifname))
+		print_usage(argv);
+
+	memcpy(ifobj->ifname, ifname, len + 1);
+	ifobj->ifindex = if_nametoindex(ifobj->ifname);
+	if (!ifobj->ifindex) {
+		ksft_print_msg("Error: cannot resolve interface %s\n", ifobj->ifname);
+		ksft_exit_fail();
+	}
+
+	if (init_iface(ifobj, func)) {
+		ksft_print_msg("Error: cannot initialize interface %s\n", ifobj->ifname);
+		ksft_exit_fail();
+	}
+}
+
+static void print_tests(void)
+{
+	u32 i;
+
+	printf("Tests:\n");
+	for (i = 0; i < ARRAY_SIZE(tests); i++)
+		printf("%u: %s\n", i, tests[i].name);
 }
 
 static void parse_command_line(struct ifobject *ifobj_tx, struct ifobject *ifobj_rx, int argc,
 			       char **argv)
 {
-	struct ifobject *ifobj;
+	const char *ifname[2] = {};
 	u32 interface_nb = 0;
 	int option_index, c;
 
@@ -208,21 +229,10 @@ static void parse_command_line(struct ifobject *ifobj_tx, struct ifobject *ifobj
 
 		switch (c) {
 		case 'i':
-			if (interface_nb == 0)
-				ifobj = ifobj_tx;
-			else if (interface_nb == 1)
-				ifobj = ifobj_rx;
-			else
+			if (interface_nb >= ARRAY_SIZE(ifname))
 				break;
 
-			memcpy(ifobj->ifname, optarg,
-			       min_t(size_t, MAX_INTERFACE_NAME_CHARS, strlen(optarg)));
-
-			ifobj->ifindex = if_nametoindex(ifobj->ifname);
-			if (!ifobj->ifindex)
-				exit_with_error(errno);
-
-			interface_nb++;
+			ifname[interface_nb++] = optarg;
 			break;
 		case 'v':
 			opt_verbose = true;
@@ -242,7 +252,8 @@ static void parse_command_line(struct ifobject *ifobj_tx, struct ifobject *ifobj
 				print_usage(argv);
 			break;
 		case 'l':
-			opt_print_tests = true;
+			print_tests();
+			ksft_exit_pass();
 			break;
 		case 't':
 			errno = 0;
@@ -255,6 +266,9 @@ static void parse_command_line(struct ifobject *ifobj_tx, struct ifobject *ifobj
 			print_usage(argv);
 		}
 	}
+
+	bind_iface(ifobj_tx, ifname[0], worker_testapp_validate_tx, argv);
+	bind_iface(ifobj_rx, ifname[1], worker_testapp_validate_rx, argv);
 }
 
 static void xsk_unload_xdp_programs(struct ifobject *ifobj)
@@ -262,7 +276,7 @@ static void xsk_unload_xdp_programs(struct ifobject *ifobj)
 	xsk_xdp_progs__destroy(ifobj->xdp_progs);
 }
 
-static void run_pkt_test(struct test_spec *test)
+static int run_pkt_test(struct test_spec *test)
 {
 	int ret;
 
@@ -287,6 +301,7 @@ static void run_pkt_test(struct test_spec *test)
 	}
 
 	pkt_stream_restore_default(test);
+	return ret;
 }
 
 static bool is_xdp_supported(int ifindex)
@@ -317,26 +332,46 @@ static bool is_xdp_supported(int ifindex)
 	return true;
 }
 
-static void print_tests(void)
+static u32 detect_mode_caps(struct ifobject *ifobj)
 {
-	u32 i;
+	if (is_xdp_supported(ifobj->ifindex)) {
+		ifobj_set_cap(ifobj, XSK_CAP_DRV);
+		if (ifobj_zc_avail(ifobj))
+			ifobj_set_cap(ifobj, XSK_CAP_ZC);
+	}
 
-	printf("Tests:\n");
-	for (i = 0; i < ARRAY_SIZE(tests); i++)
-		printf("%u: %s\n", i, tests[i].name);
+	return ifobj->caps.flags;
+}
+
+static bool mode_supported(enum test_mode mode, u32 caps)
+{
+	if (mode == TEST_MODE_SKB)
+		return true;
+	if (mode == TEST_MODE_DRV)
+		return caps & XSK_CAP_DRV;
+	return caps & XSK_CAP_ZC;
+}
+
+static void cleanup_iface(struct ifobject *ifobj)
+{
+	if (ifobj_has_cap(ifobj, XSK_CAP_HW_RING))
+		hw_ring_size_reset(ifobj);
+	if (ifobj->xdp_prog)
+		xsk_detach_xdp_program(ifobj->ifindex,
+				       ifobj->mode == TEST_MODE_SKB ?
+				       XDP_FLAGS_SKB_MODE : XDP_FLAGS_DRV_MODE);
+	xsk_unload_xdp_programs(ifobj);
 }
 
 int main(int argc, char **argv)
 {
 	u32 cache_line_size, max_frags, umem_tailroom;
 	const size_t total_tests = ARRAY_SIZE(tests);
-	struct pkt_stream *rx_pkt_stream_default;
-	struct pkt_stream *tx_pkt_stream_default;
 	struct ifobject *ifobj_tx, *ifobj_rx;
 	u32 i, j, failed_tests = 0, nb_tests;
-	int modes = TEST_MODE_SKB + 1;
-	struct test_spec test;
-	int ret;
+	struct test_spec test = {};
+	int ret = TEST_FAILURE;
+	u32 caps, modes = 0;
 
 	/* Use libbpf 1.0 API mode */
 	libbpf_set_strict_mode(LIBBPF_STRICT_ALL);
@@ -373,93 +408,64 @@ int main(int argc, char **argv)
 
 	parse_command_line(ifobj_tx, ifobj_rx, argc, argv);
 
-	if (opt_print_tests) {
-		print_tests();
-		ksft_exit_xpass();
-	}
 	if (opt_run_test != RUN_ALL_TESTS && opt_run_test >= total_tests) {
 		ksft_print_msg("Error: test %u does not exist.\n", opt_run_test);
 		ksft_exit_xfail();
 	}
 
-	if (!validate_interface(ifobj_tx) || !validate_interface(ifobj_rx))
-		print_usage(argv);
-
-	if (is_xdp_supported(ifobj_tx->ifindex)) {
-		modes++;
-		if (ifobj_zc_avail(ifobj_tx))
-			modes++;
-	}
+	test.tx_pkt_stream_default = pkt_stream_generate(DEFAULT_PKT_CNT, MIN_PKT_SIZE);
+	test.rx_pkt_stream_default = pkt_stream_generate(DEFAULT_PKT_CNT, MIN_PKT_SIZE);
+	if (!test.tx_pkt_stream_default || !test.rx_pkt_stream_default)
+		goto out;
 
-	ret = get_hw_ring_size(ifobj_tx->ifname, &ifobj_tx->ring);
-	if (!ret) {
-		ifobj_set_cap(ifobj_tx, XSK_CAP_HW_RING);
-		ifobj_tx->caps.tx_max_pending = ifobj_tx->ring.tx_max_pending;
-		ifobj_tx->set_ring.default_tx = ifobj_tx->ring.tx_pending;
-		ifobj_tx->set_ring.default_rx = ifobj_tx->ring.rx_pending;
-	}
+	caps = detect_mode_caps(ifobj_tx);
 
-	if (init_iface(ifobj_rx, worker_testapp_validate_rx) ||
-	    init_iface(ifobj_tx, worker_testapp_validate_tx)) {
-		ksft_print_msg("Error : can't initialize interfaces\n");
+	if (opt_mode != TEST_MODE_ALL && !mode_supported(opt_mode, caps)) {
+		if (opt_mode == TEST_MODE_DRV)
+			ksft_print_msg("Error: XDP_DRV mode not supported.\n");
+		else
+			ksft_print_msg("Error: zero-copy mode not supported.\n");
 		ksft_exit_xfail();
 	}
 
-	test_init(&test, ifobj_tx, ifobj_rx, 0, &tests[0]);
-	tx_pkt_stream_default = pkt_stream_generate(DEFAULT_PKT_CNT, MIN_PKT_SIZE);
-	rx_pkt_stream_default = pkt_stream_generate(DEFAULT_PKT_CNT, MIN_PKT_SIZE);
-	if (!tx_pkt_stream_default || !rx_pkt_stream_default)
-		exit_with_error(ENOMEM);
-	test.tx_pkt_stream_default = tx_pkt_stream_default;
-	test.rx_pkt_stream_default = rx_pkt_stream_default;
-
+	for (i = TEST_MODE_SKB; i <= TEST_MODE_ZC; i++)
+		if ((opt_mode == TEST_MODE_ALL || i == opt_mode) && mode_supported(i, caps))
+			modes++;
 	if (opt_run_test == RUN_ALL_TESTS)
 		nb_tests = total_tests;
 	else
 		nb_tests = 1;
-	if (opt_mode == TEST_MODE_ALL) {
-		ksft_set_plan(modes * nb_tests);
-	} else {
-		if (opt_mode == TEST_MODE_DRV && modes <= TEST_MODE_DRV) {
-			ksft_print_msg("Error: XDP_DRV mode not supported.\n");
-			ksft_exit_xfail();
-		}
-		if (opt_mode == TEST_MODE_ZC && modes <= TEST_MODE_ZC) {
-			ksft_print_msg("Error: zero-copy mode not supported.\n");
-			ksft_exit_xfail();
-		}
-
-		ksft_set_plan(nb_tests);
-	}
+	/* Line-buffer stdout so verdicts reach a capturing launcher live. */
+	ksft_print_header();
+	ksft_set_plan(modes * nb_tests);
 
-	for (i = 0; i < modes; i++) {
+	for (i = TEST_MODE_SKB; i <= TEST_MODE_ZC; i++) {
 		if (opt_mode != TEST_MODE_ALL && i != opt_mode)
 			continue;
+		if (!mode_supported(i, caps))
+			continue;
 
 		for (j = 0; j < total_tests; j++) {
 			if (opt_run_test != RUN_ALL_TESTS && j != opt_run_test)
 				continue;
 
 			test_init(&test, ifobj_tx, ifobj_rx, i, &tests[j]);
-			run_pkt_test(&test);
-			usleep(USLEEP_MAX);
-
-			if (test.fail)
+			if (run_pkt_test(&test) == TEST_FAILURE)
 				failed_tests++;
+			usleep(USLEEP_MAX);
 		}
 	}
+	ret = failed_tests ? TEST_FAILURE : TEST_PASS;
 
-	if (ifobj_has_cap(ifobj_tx, XSK_CAP_HW_RING))
-		hw_ring_size_reset(ifobj_tx);
-
-	pkt_stream_delete(tx_pkt_stream_default);
-	pkt_stream_delete(rx_pkt_stream_default);
-	xsk_unload_xdp_programs(ifobj_tx);
-	xsk_unload_xdp_programs(ifobj_rx);
+out:
+	cleanup_iface(ifobj_tx);
+	cleanup_iface(ifobj_rx);
+	pkt_stream_delete(test.tx_pkt_stream_default);
+	pkt_stream_delete(test.rx_pkt_stream_default);
 	ifobject_delete(ifobj_tx);
 	ifobject_delete(ifobj_rx);
 
-	if (failed_tests)
+	if (ret)
 		ksft_exit_fail();
 	else
 		ksft_exit_pass();
-- 
2.43.0