From: Vincent Whitchurch <vincent.whitchurch@datadoghq.com>

Add a test which checks that splice(2) is still able to read data from
the socket if it is added to a verdict program which returns SK_PASS.

Signed-off-by: Vincent Whitchurch <vincent.whitchurch@datadoghq.com>
---
 tools/testing/selftests/bpf/test_sockmap.c | 73 ++++++++++++++++++++++++++++++
 1 file changed, 73 insertions(+)

diff --git a/tools/testing/selftests/bpf/test_sockmap.c b/tools/testing/selftests/bpf/test_sockmap.c
index 8be2714dd573..b4102161db62 100644
--- a/tools/testing/selftests/bpf/test_sockmap.c
+++ b/tools/testing/selftests/bpf/test_sockmap.c
@@ -1,5 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0
 // Copyright (c) 2017-2018 Covalent IO, Inc. http://covalent.io
+#define _GNU_SOURCE
 #include <stdio.h>
 #include <stdlib.h>
 #include <sys/socket.h>
@@ -965,6 +966,61 @@ static int sendmsg_test(struct sockmap_options *opt)
 	return err;
 }
 
+static int splice_test(struct sockmap_options *opt)
+{
+	int pipefds[2];
+	char buf[1024] = {0};
+	ssize_t bytes;
+	int ret;
+
+	ret = pipe(pipefds);
+	if (ret < 0) {
+		perror("pipe");
+		return ret;
+	}
+
+	bytes = send(c1, buf, sizeof(buf), 0);
+	if (bytes < 0) {
+		perror("send failed");
+		return bytes;
+	}
+	if (bytes == 0) {
+		fprintf(stderr, "send wrote zero bytes\n");
+		return -1;
+	}
+
+	bytes = write(pipefds[1], buf, sizeof(buf));
+	if (bytes < 0) {
+		perror("pipe write failed");
+		return bytes;
+	}
+
+	bytes = splice(p1, NULL, pipefds[1], NULL, sizeof(buf), 0);
+	if (bytes < 0) {
+		perror("splice failed");
+		return bytes;
+	}
+	if (bytes == 0) {
+		fprintf(stderr, "spliced zero bytes\n");
+		return -1;
+	}
+
+	bytes = read(pipefds[0], buf, sizeof(buf));
+	if (bytes < 0) {
+		perror("pipe read failed");
+		return bytes;
+	}
+	if (bytes == 0) {
+		fprintf(stderr, "EOF from pipe\n");
+		return -1;
+	}
+
+	close(pipefds[1]);
+	close(pipefds[0]);
+
+	return 0;
+}
+
 static int forever_ping_pong(int rate, struct sockmap_options *opt)
 {
 	struct timeval timeout;
@@ -1047,6 +1103,7 @@ enum {
 	BASE,
 	BASE_SENDPAGE,
 	SENDPAGE,
+	SPLICE,
 };
 
 static int run_options(struct sockmap_options *options, int cg_fd,  int test)
@@ -1378,6 +1435,8 @@ static int run_options(struct sockmap_options *options, int cg_fd,  int test)
 		options->base = true;
 		options->sendpage = true;
 		err = sendmsg_test(options);
+	} else if (test == SPLICE) {
+		err = splice_test(options);
 	} else
 		fprintf(stderr, "unknown test\n");
 out:
@@ -1993,6 +2052,17 @@ static int populate_progs(char *bpf_file)
 	return 0;
 }
 
+static void test_txmsg_splice_pass(int cgrp, struct sockmap_options *opt)
+{
+	txmsg_omit_skb_parser = 1;
+	txmsg_pass_skb = 1;
+
+	__test_exec(cgrp, SPLICE, opt);
+
+	txmsg_omit_skb_parser = 0;
+	txmsg_pass_skb = 0;
+}
+
 struct _test test[] = {
 	{"txmsg test passthrough", test_txmsg_pass},
 	{"txmsg test redirect", test_txmsg_redir},
@@ -2009,6 +2079,7 @@ struct _test test[] = {
 	{"txmsg test push/pop data", test_txmsg_push_pop},
 	{"txmsg test ingress parser", test_txmsg_ingress_parser},
 	{"txmsg test ingress parser2", test_txmsg_ingress_parser2},
+	{"txmsg test splice pass", test_txmsg_splice_pass},
 };
 
 static int check_whitelist(struct _test *t, struct sockmap_options *opt)
@@ -2187,6 +2258,8 @@ int main(int argc, char **argv)
 				test = BASE_SENDPAGE;
 			} else if (strcmp(optarg, "sendpage") == 0) {
 				test = SENDPAGE;
+			} else if (strcmp(optarg, "splice") == 0) {
+				test = SPLICE;
 			} else {
 				usage(argv);
 				return -1;

-- 
2.34.1