selftests: xsk: Generate packets from specification

Generate packets from a specification instead of something hard
coded. The idea is that a test generates one or more packet
specifications and provides it/them to both Tx and Rx. The Tx thread
will generate from this specification and Rx will validate that it
receives what is in the specification. The specification can be the
same on both ends, meaning that everything that was sent should be
received, or different which means that Rx will only receive part of
the sent packets.

Currently, the packet specification is the same for both Rx and Tx and
the same for each test. This will change in later work as features
and tests are added.

The data path functions are also renamed to better reflect what
actions they are performing after introducing this feature.

Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210825093722.10219-15-magnus.karlsson@gmail.com

2 files changed, 166 insertions, 121 deletions

diff --git a/tools/testing/selftests/bpf/xdpxceiver.c b/tools/testing/selftests/bpf/xdpxceiver.c
index 433c5c7b1928..5ca853cf27a1 100644
--- a/tools/testing/selftests/bpf/xdpxceiver.c
+++ b/tools/testing/selftests/bpf/xdpxceiver.c
@@ -417,18 +417,59 @@ static void parse_command_line(int argc, char **argv)
 	}
 }
 
-static void pkt_generate(struct ifobject *ifobject, u32 pkt_nb, u64 addr)
+static struct pkt *pkt_stream_get_pkt(struct pkt_stream *pkt_stream, u32 pkt_nb)
 {
-	void *data = xsk_umem__get_data(ifobject->umem->buffer, addr);
-	struct udphdr *udp_hdr =
-		(struct udphdr *)(data + sizeof(struct ethhdr) + sizeof(struct iphdr));
-	struct iphdr *ip_hdr = (struct iphdr *)(data + sizeof(struct ethhdr));
-	struct ethhdr *eth_hdr = (struct ethhdr *)data;
+	if (pkt_nb >= pkt_stream->nb_pkts)
+		return NULL;
+
+	return &pkt_stream->pkts[pkt_nb];
+}
+
+static struct pkt_stream *pkt_stream_generate(u32 nb_pkts, u32 pkt_len)
+{
+	struct pkt_stream *pkt_stream;
+	u32 i;
+
+	pkt_stream = malloc(sizeof(*pkt_stream));
+	if (!pkt_stream)
+		exit_with_error(ENOMEM);
+
+	pkt_stream->pkts = calloc(nb_pkts, sizeof(*pkt_stream->pkts));
+	if (!pkt_stream->pkts)
+		exit_with_error(ENOMEM);
+
+	pkt_stream->nb_pkts = nb_pkts;
+	for (i = 0; i < nb_pkts; i++) {
+		pkt_stream->pkts[i].addr = (i % num_frames) * XSK_UMEM__DEFAULT_FRAME_SIZE;
+		pkt_stream->pkts[i].len = pkt_len;
+		pkt_stream->pkts[i].payload = i;
+	}
+
+	return pkt_stream;
+}
+
+static struct pkt *pkt_generate(struct ifobject *ifobject, u32 pkt_nb)
+{
+	struct pkt *pkt = pkt_stream_get_pkt(ifobject->pkt_stream, pkt_nb);
+	struct udphdr *udp_hdr;
+	struct ethhdr *eth_hdr;
+	struct iphdr *ip_hdr;
+	void *data;
+
+	if (!pkt)
+		return NULL;
+
+	data = xsk_umem__get_data(ifobject->umem->buffer, pkt->addr);
+	udp_hdr = (struct udphdr *)(data + sizeof(struct ethhdr) + sizeof(struct iphdr));
+	ip_hdr = (struct iphdr *)(data + sizeof(struct ethhdr));
+	eth_hdr = (struct ethhdr *)data;
 
 	gen_udp_hdr(pkt_nb, data, ifobject, udp_hdr);
 	gen_ip_hdr(ifobject, ip_hdr);
 	gen_udp_csum(udp_hdr, ip_hdr);
 	gen_eth_hdr(ifobject, eth_hdr);
+
+	return pkt;
 }
 
 static void pkt_dump(void *pkt, u32 len)
@@ -468,33 +509,43 @@ static void pkt_dump(void *pkt, u32 len)
 	fprintf(stdout, "---------------------------------------\n");
 }
 
-static void pkt_validate(void *buffer, u64 addr)
+static bool is_pkt_valid(struct pkt *pkt, void *buffer, const struct xdp_desc *desc)
 {
-	void *data = xsk_umem__get_data(buffer, addr);
+	void *data = xsk_umem__get_data(buffer, desc->addr);
 	struct iphdr *iphdr = (struct iphdr *)(data + sizeof(struct ethhdr));
 
+	if (!pkt) {
+		ksft_test_result_fail("ERROR: [%s] too many packets received\n", __func__);
+		return false;
+	}
+
 	if (iphdr->version == IP_PKT_VER && iphdr->tos == IP_PKT_TOS) {
 		u32 seqnum = ntohl(*((u32 *)(data + PKT_HDR_SIZE)));
-		u32 expected_seqnum = pkt_counter % num_frames;
 
 		if (debug_pkt_dump && test_type != TEST_TYPE_STATS)
 			pkt_dump(data, PKT_SIZE);
 
-		if (expected_seqnum != seqnum) {
+		if (pkt->len != desc->len) {
 			ksft_test_result_fail
-				("ERROR: [%s] expected seqnum [%d], got seqnum [%d]\n",
-					__func__, expected_seqnum, seqnum);
-			sigvar = 1;
+				("ERROR: [%s] expected length [%d], got length [%d]\n",
+					__func__, pkt->len, desc->len);
+			return false;
 		}
 
-		if (++pkt_counter == opt_pkt_count)
-			sigvar = 1;
+		if (pkt->payload != seqnum) {
+			ksft_test_result_fail
+				("ERROR: [%s] expected seqnum [%d], got seqnum [%d]\n",
+					__func__, pkt->payload, seqnum);
+			return false;
+		}
 	} else {
 		ksft_print_msg("Invalid frame received: ");
 		ksft_print_msg("[IP_PKT_VER: %02X], [IP_PKT_TOS: %02X]\n", iphdr->version,
 			       iphdr->tos);
-		sigvar = 1;
+		return false;
 	}
+
+	return true;
 }
 
 static void kick_tx(struct xsk_socket_info *xsk)
@@ -507,7 +558,7 @@ static void kick_tx(struct xsk_socket_info *xsk)
 	exit_with_error(errno);
 }
 
-static void complete_tx_only(struct xsk_socket_info *xsk, int batch_size)
+static void complete_pkts(struct xsk_socket_info *xsk, int batch_size)
 {
 	unsigned int rcvd;
 	u32 idx;
@@ -525,116 +576,105 @@ static void complete_tx_only(struct xsk_socket_info *xsk, int batch_size)
 	}
 }
 
-static void rx_pkt(struct xsk_socket_info *xsk, struct pollfd *fds)
+static void receive_pkts(struct pkt_stream *pkt_stream, struct xsk_socket_info *xsk,
+			 struct pollfd *fds)
 {
-	unsigned int rcvd, i;
-	u32 idx_rx = 0, idx_fq = 0;
+	u32 idx_rx = 0, idx_fq = 0, rcvd, i, pkt_count = 0;
+	struct pkt *pkt;
 	int ret;
 
-	rcvd = xsk_ring_cons__peek(&xsk->rx, BATCH_SIZE, &idx_rx);
-	if (!rcvd) {
-		if (xsk_ring_prod__needs_wakeup(&xsk->umem->fq)) {
-			ret = poll(fds, 1, POLL_TMOUT);
-			if (ret < 0)
-				exit_with_error(-ret);
+	pkt = pkt_stream_get_pkt(pkt_stream, pkt_count++);
+	while (pkt) {
+		rcvd = xsk_ring_cons__peek(&xsk->rx, BATCH_SIZE, &idx_rx);
+		if (!rcvd) {
+			if (xsk_ring_prod__needs_wakeup(&xsk->umem->fq)) {
+				ret = poll(fds, 1, POLL_TMOUT);
+				if (ret < 0)
+					exit_with_error(-ret);
+			}
+			continue;
 		}
-		return;
-	}
 
-	ret = xsk_ring_prod__reserve(&xsk->umem->fq, rcvd, &idx_fq);
-	while (ret != rcvd) {
-		if (ret < 0)
-			exit_with_error(-ret);
-		if (xsk_ring_prod__needs_wakeup(&xsk->umem->fq)) {
-			ret = poll(fds, 1, POLL_TMOUT);
+		ret = xsk_ring_prod__reserve(&xsk->umem->fq, rcvd, &idx_fq);
+		while (ret != rcvd) {
 			if (ret < 0)
 				exit_with_error(-ret);
+			if (xsk_ring_prod__needs_wakeup(&xsk->umem->fq)) {
+				ret = poll(fds, 1, POLL_TMOUT);
+				if (ret < 0)
+					exit_with_error(-ret);
+			}
+			ret = xsk_ring_prod__reserve(&xsk->umem->fq, rcvd, &idx_fq);
 		}
-		ret = xsk_ring_prod__reserve(&xsk->umem->fq, rcvd, &idx_fq);
-	}
 
-	for (i = 0; i < rcvd; i++) {
-		u64 addr, orig;
+		for (i = 0; i < rcvd; i++) {
+			const struct xdp_desc *desc = xsk_ring_cons__rx_desc(&xsk->rx, idx_rx++);
+			u64 addr = desc->addr, orig;
 
-		addr = xsk_ring_cons__rx_desc(&xsk->rx, idx_rx)->addr;
-		xsk_ring_cons__rx_desc(&xsk->rx, idx_rx++);
-		orig = xsk_umem__extract_addr(addr);
+			orig = xsk_umem__extract_addr(addr);
+			addr = xsk_umem__add_offset_to_addr(addr);
+			if (!is_pkt_valid(pkt, xsk->umem->buffer, desc))
+				return;
 
-		addr = xsk_umem__add_offset_to_addr(addr);
-		pkt_validate(xsk->umem->buffer, addr);
+			*xsk_ring_prod__fill_addr(&xsk->umem->fq, idx_fq++) = orig;
+			pkt = pkt_stream_get_pkt(pkt_stream, pkt_count++);
+		}
 
-		*xsk_ring_prod__fill_addr(&xsk->umem->fq, idx_fq++) = orig;
+		xsk_ring_prod__submit(&xsk->umem->fq, rcvd);
+		xsk_ring_cons__release(&xsk->rx, rcvd);
 	}
-
-	xsk_ring_prod__submit(&xsk->umem->fq, rcvd);
-	xsk_ring_cons__release(&xsk->rx, rcvd);
 }
 
-static void tx_only(struct ifobject *ifobject, u32 *frameptr, int batch_size)
+static u32 __send_pkts(struct ifobject *ifobject, u32 pkt_nb)
 {
 	struct xsk_socket_info *xsk = ifobject->xsk;
-	u32 idx = 0;
-	unsigned int i;
-	bool tx_invalid_test = stat_test_type == STAT_TEST_TX_INVALID;
-	u32 len = tx_invalid_test ? XSK_UMEM__DEFAULT_FRAME_SIZE + 1 : PKT_SIZE;
+	u32 i, idx;
 
-	while (xsk_ring_prod__reserve(&xsk->tx, batch_size, &idx) < batch_size)
-		complete_tx_only(xsk, batch_size);
+	while (xsk_ring_prod__reserve(&xsk->tx, BATCH_SIZE, &idx) < BATCH_SIZE)
+		complete_pkts(xsk, BATCH_SIZE);
 
-	for (i = 0; i < batch_size; i++) {
+	for (i = 0; i < BATCH_SIZE; i++) {
 		struct xdp_desc *tx_desc = xsk_ring_prod__tx_desc(&xsk->tx, idx + i);
+		struct pkt *pkt = pkt_generate(ifobject, pkt_nb);
 
-		tx_desc->addr = (*frameptr + i) << XSK_UMEM__DEFAULT_FRAME_SHIFT;
-		tx_desc->len = len;
-		pkt_generate(ifobject, *frameptr + i, tx_desc->addr);
-	}
+		if (!pkt)
+			break;
 
-	xsk_ring_prod__submit(&xsk->tx, batch_size);
-	if (!tx_invalid_test) {
-		xsk->outstanding_tx += batch_size;
-	} else if (xsk_ring_prod__needs_wakeup(&xsk->tx)) {
-		kick_tx(xsk);
+		tx_desc->addr = pkt->addr;
+		tx_desc->len = pkt->len;
+		pkt_nb++;
 	}
-	*frameptr += batch_size;
-	*frameptr %= num_frames;
-	complete_tx_only(xsk, batch_size);
-}
 
-static int get_batch_size(int pkt_cnt)
-{
-	if (pkt_cnt + BATCH_SIZE <= opt_pkt_count)
-		return BATCH_SIZE;
+	xsk_ring_prod__submit(&xsk->tx, i);
+	if (stat_test_type != STAT_TEST_TX_INVALID)
+		xsk->outstanding_tx += i;
+	else if (xsk_ring_prod__needs_wakeup(&xsk->tx))
+		kick_tx(xsk);
+	complete_pkts(xsk, i);
 
-	return opt_pkt_count - pkt_cnt;
+	return i;
 }
 
-static void complete_tx_only_all(struct ifobject *ifobject)
+static void wait_for_tx_completion(struct xsk_socket_info *xsk)
 {
-	bool pending;
-
-	do {
-		pending = false;
-		if (ifobject->xsk->outstanding_tx) {
-			complete_tx_only(ifobject->xsk, BATCH_SIZE);
-			pending = !!ifobject->xsk->outstanding_tx;
-		}
-	} while (pending);
+	while (xsk->outstanding_tx)
+		complete_pkts(xsk, BATCH_SIZE);
 }
 
-static void tx_only_all(struct ifobject *ifobject)
+static void send_pkts(struct ifobject *ifobject)
 {
 	struct pollfd fds[MAX_SOCKS] = { };
-	u32 frame_nb = 0;
-	int pkt_cnt = 0;
-	int ret;
+	u32 pkt_cnt = 0;
 
 	fds[0].fd = xsk_socket__fd(ifobject->xsk->xsk);
 	fds[0].events = POLLOUT;
 
-	while (pkt_cnt < opt_pkt_count) {
-		int batch_size = get_batch_size(pkt_cnt);
+	while (pkt_cnt < ifobject->pkt_stream->nb_pkts) {
+		u32 sent;
 
 		if (test_type == TEST_TYPE_POLL) {
+			int ret;
+
 			ret = poll(fds, 1, POLL_TMOUT);
 			if (ret <= 0)
 				continue;
@@ -643,17 +683,17 @@ static void tx_only_all(struct ifobject *ifobject)
 				continue;
 		}
 
-		tx_only(ifobject, &frame_nb, batch_size);
-		pkt_cnt += batch_size;
+		sent = __send_pkts(ifobject, pkt_cnt);
+		pkt_cnt += sent;
 		usleep(10);
 	}
 
-	complete_tx_only_all(ifobject);
+	wait_for_tx_completion(ifobject->xsk);
 }
 
 static bool rx_stats_are_valid(struct ifobject *ifobject)
 {
-	u32 xsk_stat = 0, expected_stat = opt_pkt_count;
+	u32 xsk_stat = 0, expected_stat = ifobject->pkt_stream->nb_pkts;
 	struct xsk_socket *xsk = ifobject->xsk->xsk;
 	int fd = xsk_socket__fd(xsk);
 	struct xdp_statistics stats;
@@ -709,11 +749,11 @@ static void tx_stats_validate(struct ifobject *ifobject)
 		return;
 	}
 
-	if (stats.tx_invalid_descs == opt_pkt_count)
+	if (stats.tx_invalid_descs == ifobject->pkt_stream->nb_pkts)
 		return;
 
 	ksft_test_result_fail("ERROR: [%s] tx_invalid_descs incorrect. Got [%u] expected [%u]\n",
-			      __func__, stats.tx_invalid_descs, opt_pkt_count);
+			      __func__, stats.tx_invalid_descs, ifobject->pkt_stream->nb_pkts);
 }
 
 static void thread_common_ops(struct ifobject *ifobject, void *bufs)
@@ -782,8 +822,9 @@ static void *worker_testapp_validate_tx(void *arg)
 	if (!second_step)
 		thread_common_ops(ifobject, bufs);
 
-	print_verbose("Sending %d packets on interface %s\n", opt_pkt_count, ifobject->ifname);
-	tx_only_all(ifobject);
+	print_verbose("Sending %d packets on interface %s\n", ifobject->pkt_stream->nb_pkts,
+		      ifobject->ifname);
+	send_pkts(ifobject);
 
 	if (stat_test_type == STAT_TEST_TX_INVALID)
 		tx_stats_validate(ifobject);
@@ -809,19 +850,11 @@ static void *worker_testapp_validate_rx(void *arg)
 
 	pthread_barrier_wait(&barr);
 
-	while (1) {
-		if (test_type != TEST_TYPE_STATS) {
-			rx_pkt(ifobject->xsk, fds);
-		} else {
-			if (rx_stats_are_valid(ifobject))
-				break;
-		}
-		if (sigvar)
-			break;
-	}
-
-	print_verbose("Received %d packets on interface %s\n",
-		      pkt_counter, ifobject->ifname);
+	if (test_type == TEST_TYPE_STATS)
+		while (!rx_stats_are_valid(ifobject))
+			continue;
+	else
+		receive_pkts(ifobject->pkt_stream, ifobject->xsk, fds);
 
 	if (test_type == TEST_TYPE_TEARDOWN)
 		print_verbose("Destroying socket\n");
@@ -834,10 +867,18 @@ static void testapp_validate(void)
 {
 	bool bidi = test_type == TEST_TYPE_BIDI;
 	bool bpf = test_type == TEST_TYPE_BPF_RES;
+	struct pkt_stream *pkt_stream;
 
 	if (pthread_barrier_init(&barr, NULL, 2))
 		exit_with_error(errno);
 
+	if (stat_test_type == STAT_TEST_TX_INVALID)
+		pkt_stream = pkt_stream_generate(DEFAULT_PKT_CNT, XSK_UMEM__INVALID_FRAME_SIZE);
+	else
+		pkt_stream = pkt_stream_generate(DEFAULT_PKT_CNT, PKT_SIZE);
+	ifdict_tx->pkt_stream = pkt_stream;
+	ifdict_rx->pkt_stream = pkt_stream;
+
 	/*Spawn RX thread */
 	pthread_create(&t0, NULL, ifdict_rx->func_ptr, ifdict_rx);
 
@@ -860,8 +901,6 @@ static void testapp_teardown(void)
 	int i;
 
 	for (i = 0; i < MAX_TEARDOWN_ITER; i++) {
-		pkt_counter = 0;
-		sigvar = 0;
 		print_verbose("Creating socket\n");
 		testapp_validate();
 	}
@@ -887,8 +926,6 @@ static void swap_vectors(struct ifobject *ifobj1, struct ifobject *ifobj2)
 static void testapp_bidi(void)
 {
 	for (int i = 0; i < MAX_BIDI_ITER; i++) {
-		pkt_counter = 0;
-		sigvar = 0;
 		print_verbose("Creating socket\n");
 		testapp_validate();
 		if (!second_step) {
@@ -920,8 +957,6 @@ static void testapp_bpf_res(void)
 	int i;
 
 	for (i = 0; i < MAX_BPF_ITER; i++) {
-		pkt_counter = 0;
-		sigvar = 0;
 		print_verbose("Creating socket\n");
 		testapp_validate();
 		if (!second_step)
@@ -949,6 +984,8 @@ static void testapp_stats(void)
 		case STAT_TEST_RX_FULL:
 			rxqsize = RX_FULL_RXQSIZE;
 			break;
+		case STAT_TEST_TX_INVALID:
+			continue;
 		default:
 			break;
 		}
@@ -994,9 +1031,7 @@ static void run_pkt_test(int mode, int type)
 
 	/* reset defaults after potential previous test */
 	xdp_flags = XDP_FLAGS_UPDATE_IF_NOEXIST;
-	pkt_counter = 0;
 	second_step = 0;
-	sigvar = 0;
 	stat_test_type = -1;
 	rxqsize = XSK_RING_CONS__DEFAULT_NUM_DESCS;
 	frame_headroom = XSK_UMEM__DEFAULT_FRAME_HEADROOM;
diff --git a/tools/testing/selftests/bpf/xdpxceiver.h b/tools/testing/selftests/bpf/xdpxceiver.h
index 7670df7e7746..3e5394295ac1 100644
--- a/tools/testing/selftests/bpf/xdpxceiver.h
+++ b/tools/testing/selftests/bpf/xdpxceiver.h
@@ -40,6 +40,7 @@
 #define POLL_TMOUT 1000
 #define DEFAULT_PKT_CNT (4 * 1024)
 #define RX_FULL_RXQSIZE 32
+#define XSK_UMEM__INVALID_FRAME_SIZE (XSK_UMEM__DEFAULT_FRAME_SIZE + 1)
 
 #define print_verbose(x...) do { if (opt_verbose) ksft_print_msg(x); } while (0)
 
@@ -74,13 +75,10 @@ static u32 num_frames = DEFAULT_PKT_CNT / 4;
 static bool second_step;
 static int test_type;
 
-static u32 opt_pkt_count = DEFAULT_PKT_CNT;
 static u8 opt_verbose;
 
 static u32 xdp_flags = XDP_FLAGS_UPDATE_IF_NOEXIST;
 static u32 xdp_bind_flags = XDP_USE_NEED_WAKEUP | XDP_COPY;
-static u32 pkt_counter;
-static int sigvar;
 static int stat_test_type;
 static u32 rxqsize;
 static u32 frame_headroom;
@@ -107,6 +105,17 @@ struct flow_vector {
 	} vector;
 };
 
+struct pkt {
+	u64 addr;
+	u32 len;
+	u32 payload;
+};
+
+struct pkt_stream {
+	u32 nb_pkts;
+	struct pkt *pkts;
+};
+
 struct ifobject {
 	char ifname[MAX_INTERFACE_NAME_CHARS];
 	char nsname[MAX_INTERFACES_NAMESPACE_CHARS];
@@ -116,6 +125,7 @@ struct ifobject {
 	struct xsk_umem_info *umem;
 	void *(*func_ptr)(void *arg);
 	struct flow_vector fv;
+	struct pkt_stream *pkt_stream;
 	int ns_fd;
 	u32 dst_ip;
 	u32 src_ip;