Merge branch 'export send_recv_data'

Geliang Tang says:

====================
v5:
 - address Martin's comments for v4 (thanks).
 - update patch 2, use 'return err' instead of 'return -1/0'.
 - drop patch 3 in v4.

v4:
 - fix a bug in v3, it should be 'if (err)', not 'if (!err)'.
 - move "selftests/bpf: Use log_err in network_helpers" out of this
   series.

v3:
 - add two more patches.
 - use log_err instead of ASSERT in v3.
 - let send_recv_data return int as Martin suggested.

v2:

Address Martin's comments for v1 (thanks.)
 - drop patch 1, "export send_byte helper".
 - drop "WRITE_ONCE(arg.stop, 0)".
 - rebased.

send_recv_data will be re-used in MPTCP bpf tests, but not included
in this set because it depends on other patches that have not been
in the bpf-next yet. It will be sent as another set soon.
====================
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>

tools/testing/selftests/bpf/network_helpers.c

@@ -545,3 +545,105 @@ int set_hw_ring_size(char *ifname, struct ethtool_ringparam *ring_param)
 	close(sockfd);
 	return 0;
 }
+
+struct send_recv_arg {
+	int		fd;
+	uint32_t	bytes;
+	int		stop;
+};
+
+static void *send_recv_server(void *arg)
+{
+	struct send_recv_arg *a = (struct send_recv_arg *)arg;
+	ssize_t nr_sent = 0, bytes = 0;
+	char batch[1500];
+	int err = 0, fd;
+
+	fd = accept(a->fd, NULL, NULL);
+	while (fd == -1) {
+		if (errno == EINTR)
+			continue;
+		err = -errno;
+		goto done;
+	}
+
+	if (settimeo(fd, 0)) {
+		err = -errno;
+		goto done;
+	}
+
+	while (bytes < a->bytes && !READ_ONCE(a->stop)) {
+		nr_sent = send(fd, &batch,
+			       MIN(a->bytes - bytes, sizeof(batch)), 0);
+		if (nr_sent == -1 && errno == EINTR)
+			continue;
+		if (nr_sent == -1) {
+			err = -errno;
+			break;
+		}
+		bytes += nr_sent;
+	}
+
+	if (bytes != a->bytes) {
+		log_err("send %zd expected %u", bytes, a->bytes);
+		if (!err)
+			err = bytes > a->bytes ? -E2BIG : -EINTR;
+	}
+
+done:
+	if (fd >= 0)
+		close(fd);
+	if (err) {
+		WRITE_ONCE(a->stop, 1);
+		return ERR_PTR(err);
+	}
+	return NULL;
+}
+
+int send_recv_data(int lfd, int fd, uint32_t total_bytes)
+{
+	ssize_t nr_recv = 0, bytes = 0;
+	struct send_recv_arg arg = {
+		.fd	= lfd,
+		.bytes	= total_bytes,
+		.stop	= 0,
+	};
+	pthread_t srv_thread;
+	void *thread_ret;
+	char batch[1500];
+	int err = 0;
+
+	err = pthread_create(&srv_thread, NULL, send_recv_server, (void *)&arg);
+	if (err) {
+		log_err("Failed to pthread_create");
+		return err;
+	}
+
+	/* recv total_bytes */
+	while (bytes < total_bytes && !READ_ONCE(arg.stop)) {
+		nr_recv = recv(fd, &batch,
+			       MIN(total_bytes - bytes, sizeof(batch)), 0);
+		if (nr_recv == -1 && errno == EINTR)
+			continue;
+		if (nr_recv == -1) {
+			err = -errno;
+			break;
+		}
+		bytes += nr_recv;
+	}
+
+	if (bytes != total_bytes) {
+		log_err("recv %zd expected %u", bytes, total_bytes);
+		if (!err)
+			err = bytes > total_bytes ? -E2BIG : -EINTR;
+	}
+
+	WRITE_ONCE(arg.stop, 1);
+	pthread_join(srv_thread, &thread_ret);
+	if (IS_ERR(thread_ret)) {
+		log_err("Failed in thread_ret %ld", PTR_ERR(thread_ret));
+		err = err ? : PTR_ERR(thread_ret);
+	}
+
+	return err;
+}

tools/testing/selftests/bpf/network_helpers.h

@@ -76,6 +76,7 @@ struct nstoken;
  */
 struct nstoken *open_netns(const char *name);
 void close_netns(struct nstoken *token);
+int send_recv_data(int lfd, int fd, uint32_t total_bytes);
 
 static __u16 csum_fold(__u32 csum)
 {

tools/testing/selftests/bpf/prog_tests/bpf_tcp_ca.c

@@ -21,7 +21,6 @@
 
 static const unsigned int total_bytes = 10 * 1024 * 1024;
 static int expected_stg = 0xeB9F;
-static int stop;
 
 static int settcpca(int fd, const char *tcp_ca)
 {
@@ -34,60 +33,11 @@ static int settcpca(int fd, const char *tcp_ca)
 	return 0;
 }
 
-static void *server(void *arg)
-{
-	int lfd = (int)(long)arg, err = 0, fd;
-	ssize_t nr_sent = 0, bytes = 0;
-	char batch[1500];
-
-	fd = accept(lfd, NULL, NULL);
-	while (fd == -1) {
-		if (errno == EINTR)
-			continue;
-		err = -errno;
-		goto done;
-	}
-
-	if (settimeo(fd, 0)) {
-		err = -errno;
-		goto done;
-	}
-
-	while (bytes < total_bytes && !READ_ONCE(stop)) {
-		nr_sent = send(fd, &batch,
-			       MIN(total_bytes - bytes, sizeof(batch)), 0);
-		if (nr_sent == -1 && errno == EINTR)
-			continue;
-		if (nr_sent == -1) {
-			err = -errno;
-			break;
-		}
-		bytes += nr_sent;
-	}
-
-	ASSERT_EQ(bytes, total_bytes, "send");
-
-done:
-	if (fd >= 0)
-		close(fd);
-	if (err) {
-		WRITE_ONCE(stop, 1);
-		return ERR_PTR(err);
-	}
-	return NULL;
-}
-
 static void do_test(const char *tcp_ca, const struct bpf_map *sk_stg_map)
 {
-	ssize_t nr_recv = 0, bytes = 0;
 	int lfd = -1, fd = -1;
-	pthread_t srv_thread;
-	void *thread_ret;
-	char batch[1500];
 	int err;
 
-	WRITE_ONCE(stop, 0);
-
 	lfd = start_server(AF_INET6, SOCK_STREAM, NULL, 0, 0);
 	if (!ASSERT_NEQ(lfd, -1, "socket"))
 		return;
@@ -123,26 +73,7 @@ static void do_test(const char *tcp_ca, const struct bpf_map *sk_stg_map)
 			goto done;
 	}
 
-	err = pthread_create(&srv_thread, NULL, server, (void *)(long)lfd);
-	if (!ASSERT_OK(err, "pthread_create"))
-		goto done;
-
-	/* recv total_bytes */
-	while (bytes < total_bytes && !READ_ONCE(stop)) {
-		nr_recv = recv(fd, &batch,
-			       MIN(total_bytes - bytes, sizeof(batch)), 0);
-		if (nr_recv == -1 && errno == EINTR)
-			continue;
-		if (nr_recv == -1)
-			break;
-		bytes += nr_recv;
-	}
-
-	ASSERT_EQ(bytes, total_bytes, "recv");
-
-	WRITE_ONCE(stop, 1);
-	pthread_join(srv_thread, &thread_ret);
-	ASSERT_OK(IS_ERR(thread_ret), "thread_ret");
+	ASSERT_OK(send_recv_data(lfd, fd, total_bytes), "send_recv_data");
 
 done:
 	close(lfd);