selftests/bpf: Xsk selftests - Bi-directional Sockets - SKB, DRV

Adds following tests:

1. AF_XDP SKB mode
   d. Bi-directional Sockets
      Configure sockets as bi-directional tx/rx sockets, sets up fill
      and completion rings on each socket, tx/rx in both directions.
      Only nopoll mode is used

2. AF_XDP DRV/Native mode
   d. Bi-directional Sockets
   * Only copy mode is supported because veth does not currently support
     zero-copy mode
Signed-off-by: Weqaar Janjua <weqaar.a.janjua@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Tested-by: Yonghong Song <yhs@fb.com>
Acked-by: Björn Töpel <bjorn.topel@intel.com>
Link: https://lore.kernel.org/bpf/20201207215333.11586-6-weqaar.a.janjua@intel.com

tools/testing/selftests/bpf/test_xsk.sh

@@ -221,6 +221,30 @@ retval=$?
 test_status $retval "${TEST_NAME}"
 statusList+=($retval)
 
+### TEST 8
+TEST_NAME="SKB BIDIRECTIONAL SOCKETS"
+
+vethXDPgeneric ${VETH0} ${VETH1} ${NS1}
+
+params=("-S" "-B")
+execxdpxceiver params
+
+retval=$?
+test_status $retval "${TEST_NAME}"
+statusList+=($retval)
+
+### TEST 9
+TEST_NAME="DRV BIDIRECTIONAL SOCKETS"
+
+vethXDPnative ${VETH0} ${VETH1} ${NS1}
+
+params=("-N" "-B")
+execxdpxceiver params
+
+retval=$?
+test_status $retval "${TEST_NAME}"
+statusList+=($retval)
+
 ## END TESTS
 
 cleanup_exit ${VETH0} ${VETH1} ${NS1}

tools/testing/selftests/bpf/xdpxceiver.c

@@ -29,6 +29,10 @@
  *    c. Socket Teardown
  *       Create a Tx and a Rx socket, Tx from one socket, Rx on another. Destroy
  *       both sockets, then repeat multiple times. Only nopoll mode is used
+ *    d. Bi-directional sockets
+ *       Configure sockets as bi-directional tx/rx sockets, sets up fill and
+ *       completion rings on each socket, tx/rx in both directions. Only nopoll
+ *       mode is used
  *
  * 2. AF_XDP DRV/Native mode
  *    Works on any netdevice with XDP_REDIRECT support, driver dependent. Processes
@@ -37,10 +41,11 @@
  *    a. nopoll
  *    b. poll
  *    c. Socket Teardown
+ *    d. Bi-directional sockets
  *    - Only copy mode is supported because veth does not currently support
  *      zero-copy mode
  *
- * Total tests: 6
+ * Total tests: 8
  *
  * Flow:
  * -----
@@ -101,8 +106,9 @@ static void __exit_with_error(int error, const char *file, const char *func, int
 #define exit_with_error(error) __exit_with_error(error, __FILE__, __func__, __LINE__)
 
 #define print_ksft_result(void)\
-	(ksft_test_result_pass("PASS: %s %s %s\n", uut ? "DRV" : "SKB", opt_poll ? "POLL" :\
-			       "NOPOLL", opt_teardown ? "Socket Teardown" : ""))
+	(ksft_test_result_pass("PASS: %s %s %s%s\n", uut ? "DRV" : "SKB", opt_poll ? "POLL" :\
+			       "NOPOLL", opt_teardown ? "Socket Teardown" : "",\
+			       opt_bidi ? "Bi-directional Sockets" : ""))
 
 static void pthread_init_mutex(void)
 {
@@ -308,8 +314,13 @@ static int xsk_configure_socket(struct ifobject *ifobject)
 	cfg.xdp_flags = opt_xdp_flags;
 	cfg.bind_flags = opt_xdp_bind_flags;
 
+	if (!opt_bidi) {
 		rxr = (ifobject->fv.vector == rx) ? &ifobject->xsk->rx : NULL;
 		txr = (ifobject->fv.vector == tx) ? &ifobject->xsk->tx : NULL;
+	} else {
+		rxr = &ifobject->xsk->rx;
+		txr = &ifobject->xsk->tx;
+	}
 
 	ret = xsk_socket__create(&ifobject->xsk->xsk, ifobject->ifname,
 				 opt_queue, ifobject->umem->umem, rxr, txr, &cfg);
@@ -328,6 +339,7 @@ static struct option long_options[] = {
 	{"xdp-native", no_argument, 0, 'N'},
 	{"copy", no_argument, 0, 'c'},
 	{"tear-down", no_argument, 0, 'T'},
+	{"bidi", optional_argument, 0, 'B'},
 	{"debug", optional_argument, 0, 'D'},
 	{"tx-pkt-count", optional_argument, 0, 'C'},
 	{0, 0, 0, 0}
@@ -345,6 +357,7 @@ static void usage(const char *prog)
 	    "  -N, --xdp-native=n   Enforce XDP DRV (native) mode\n"
 	    "  -c, --copy           Force copy mode\n"
 	    "  -T, --tear-down      Tear down sockets by repeatedly recreating them\n"
+	    "  -B, --bidi           Bi-directional sockets test\n"
 	    "  -D, --debug          Debug mode - dump packets L2 - L5\n"
 	    "  -C, --tx-pkt-count=n Number of packets to send\n";
 	ksft_print_msg(str, prog);
@@ -435,7 +448,7 @@ static void parse_command_line(int argc, char **argv)
 	opterr = 0;
 
 	for (;;) {
-		c = getopt_long(argc, argv, "i:q:pSNcTDC:", long_options, &option_index);
+		c = getopt_long(argc, argv, "i:q:pSNcTBDC:", long_options, &option_index);
 
 		if (c == -1)
 			break;
@@ -477,6 +490,9 @@ static void parse_command_line(int argc, char **argv)
 		case 'T':
 			opt_teardown = 1;
 			break;
+		case 'B':
+			opt_bidi = 1;
+			break;
 		case 'D':
 			debug_pkt_dump = 1;
 			break;
@@ -802,10 +818,11 @@ static void *worker_testapp_validate(void *arg)
 	struct generic_data *data = (struct generic_data *)malloc(sizeof(struct generic_data));
 	struct iphdr *ip_hdr = (struct iphdr *)(pkt_data + sizeof(struct ethhdr));
 	struct ethhdr *eth_hdr = (struct ethhdr *)pkt_data;
-	void *bufs;
+	void *bufs = NULL;
 
 	pthread_attr_setstacksize(&attr, THREAD_STACK);
 
+	if (!bidi_pass) {
 		bufs = mmap(NULL, num_frames * XSK_UMEM__DEFAULT_FRAME_SIZE,
 			    PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
 		if (bufs == MAP_FAILED)
@@ -813,10 +830,12 @@ static void *worker_testapp_validate(void *arg)
 
 		if (strcmp(((struct ifobject *)arg)->nsname, ""))
 			switch_namespace(((struct ifobject *)arg)->ifdict_index);
+	}
 
 	if (((struct ifobject *)arg)->fv.vector == tx) {
 		int spinningrxctr = 0;
 
+		if (!bidi_pass)
 			thread_common_ops(arg, bufs, &sync_mutex_tx, &spinning_tx);
 
 		while (atomic_load(&spinning_rx) && spinningrxctr < SOCK_RECONF_CTR) {
@@ -847,6 +866,7 @@ static void *worker_testapp_validate(void *arg)
 		struct pollfd fds[MAX_SOCKS] = { };
 		int ret;
 
+		if (!bidi_pass)
 			thread_common_ops(arg, bufs, &sync_mutex_tx, &spinning_rx);
 
 		ksft_print_msg("Interface [%s] vector [Rx]\n", ((struct ifobject *)arg)->ifname);
@@ -886,8 +906,10 @@ static void *worker_testapp_validate(void *arg)
 			ksft_print_msg("Destroying socket\n");
 	}
 
+	if (!opt_bidi || (opt_bidi && bidi_pass)) {
 		xsk_socket__delete(((struct ifobject *)arg)->xsk->xsk);
 		(void)xsk_umem__delete(((struct ifobject *)arg)->umem->umem);
+	}
 	pthread_exit(NULL);
 }
 
@@ -896,11 +918,26 @@ static void testapp_validate(void)
 	pthread_attr_init(&attr);
 	pthread_attr_setstacksize(&attr, THREAD_STACK);
 
+	if (opt_bidi && bidi_pass) {
+		pthread_init_mutex();
+		if (!switching_notify) {
+			ksft_print_msg("Switching Tx/Rx vectors\n");
+			switching_notify++;
+		}
+	}
+
 	pthread_mutex_lock(&sync_mutex);
 
 	/*Spawn RX thread */
+	if (!opt_bidi || (opt_bidi && !bidi_pass)) {
 		if (pthread_create(&t0, &attr, worker_testapp_validate, (void *)ifdict[1]))
 			exit_with_error(errno);
+	} else if (opt_bidi && bidi_pass) {
+		/*switch Tx/Rx vectors */
+		ifdict[0]->fv.vector = rx;
+		if (pthread_create(&t0, &attr, worker_testapp_validate, (void *)ifdict[0]))
+			exit_with_error(errno);
+	}
 
 	struct timespec max_wait = { 0, 0 };
 
@@ -914,8 +951,15 @@ static void testapp_validate(void)
 	pthread_mutex_unlock(&sync_mutex);
 
 	/*Spawn TX thread */
+	if (!opt_bidi || (opt_bidi && !bidi_pass)) {
 		if (pthread_create(&t1, &attr, worker_testapp_validate, (void *)ifdict[0]))
 			exit_with_error(errno);
+	} else if (opt_bidi && bidi_pass) {
+		/*switch Tx/Rx vectors */
+		ifdict[1]->fv.vector = tx;
+		if (pthread_create(&t1, &attr, worker_testapp_validate, (void *)ifdict[1]))
+			exit_with_error(errno);
+	}
 
 	pthread_join(t1, NULL);
 	pthread_join(t0, NULL);
@@ -929,18 +973,19 @@ static void testapp_validate(void)
 		free(pkt_buf);
 	}
 
-	if (!opt_teardown)
+	if (!opt_teardown && !opt_bidi)
 		print_ksft_result();
 }
 
 static void testapp_sockets(void)
 {
-	for (int i = 0; i < MAX_TEARDOWN_ITER; i++) {
+	for (int i = 0; i < (opt_teardown ? MAX_TEARDOWN_ITER : MAX_BIDI_ITER); i++) {
 		pkt_counter = 0;
 		prev_pkt = -1;
 		sigvar = 0;
 		ksft_print_msg("Creating socket\n");
 		testapp_validate();
+		opt_bidi ? bidi_pass++ : bidi_pass;
 	}
 
 	print_ksft_result();
@@ -1009,7 +1054,14 @@ int main(int argc, char **argv)
 
 	ksft_set_plan(1);
 
-	opt_teardown ? testapp_sockets() : testapp_validate();
+	if (!opt_teardown && !opt_bidi) {
+		testapp_validate();
+	} else if (opt_teardown && opt_bidi) {
+		ksft_test_result_fail("ERROR: parameters -T and -B cannot be used together\n");
+		ksft_exit_xfail();
+	} else {
+		testapp_sockets();
+	}
 
 	for (int i = 0; i < MAX_INTERFACES; i++)
 		free(ifdict[i]);

tools/testing/selftests/bpf/xdpxceiver.h

@@ -22,6 +22,7 @@
 #define MAX_INTERFACES_NAMESPACE_CHARS 10
 #define MAX_SOCKS 1
 #define MAX_TEARDOWN_ITER 10
+#define MAX_BIDI_ITER 2
 #define PKT_HDR_SIZE (sizeof(struct ethhdr) + sizeof(struct iphdr) + \
 			sizeof(struct udphdr))
 #define MIN_PKT_SIZE 64
@@ -53,12 +54,15 @@ enum TESTS {
 u8 uut;
 u8 debug_pkt_dump;
 u32 num_frames;
+u8 switching_notify;
+u8 bidi_pass;
 
 static u32 opt_xdp_flags = XDP_FLAGS_UPDATE_IF_NOEXIST;
 static int opt_queue;
 static int opt_pkt_count;
 static int opt_poll;
 static int opt_teardown;
+static int opt_bidi;
 static u32 opt_xdp_bind_flags = XDP_USE_NEED_WAKEUP;
 static u8 pkt_data[XSK_UMEM__DEFAULT_FRAME_SIZE];
 static u32 pkt_counter;