From: Geliang Tang <tanggeliang@kylinos.cn>

This patch adds a new 'splice' io mode for mptcp_connect to test
the newly added read_sock() and splice() functions of MPTCP.

	./mptcp_connect.sh -m splice

v2:
 - only use 'splice' mode for MPTCP fallback tests too.

Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
---
 .../selftests/net/mptcp/mptcp_connect.c       | 63 ++++++++++++++++++-
 1 file changed, 62 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/net/mptcp/mptcp_connect.c b/tools/testing/selftests/net/mptcp/mptcp_connect.c
index ac1349c4b9e5..4c219d620398 100644
--- a/tools/testing/selftests/net/mptcp/mptcp_connect.c
+++ b/tools/testing/selftests/net/mptcp/mptcp_connect.c
@@ -51,6 +51,7 @@ enum cfg_mode {
 	CFG_MODE_POLL,
 	CFG_MODE_MMAP,
 	CFG_MODE_SENDFILE,
+	CFG_MODE_SPLICE,
 };
 
 enum cfg_peek {
@@ -123,7 +124,7 @@ static void die_usage(void)
 	fprintf(stderr, "\t-j     -- add additional sleep at connection start and tear down "
 		"-- for MPJ tests\n");
 	fprintf(stderr, "\t-l     -- listens mode, accepts incoming connection\n");
-	fprintf(stderr, "\t-m [poll|mmap|sendfile] -- use poll(default)/mmap+write/sendfile\n");
+	fprintf(stderr, "\t-m [poll|mmap|sendfile|splice] -- use poll(default)/mmap+write/sendfile/splice\n");
 	fprintf(stderr, "\t-M mark -- set socket packet mark\n");
 	fprintf(stderr, "\t-o option -- test sockopt <option>\n");
 	fprintf(stderr, "\t-p num -- use port num\n");
@@ -925,6 +926,55 @@ static int copyfd_io_sendfile(int infd, int peerfd, int outfd,
 	return err;
 }
 
+static int do_splice(const int infd, const int outfd, const size_t len,
+		     struct wstate *winfo)
+{
+	int pipefd[2];
+	ssize_t bytes;
+	int err;
+
+	err = pipe(pipefd);
+	if (err)
+		return err;
+
+	while ((bytes = splice(infd, NULL, pipefd[1], NULL,
+			       len - winfo->total_len,
+			       SPLICE_F_MOVE | SPLICE_F_MORE)) > 0) {
+		splice(pipefd[0], NULL, outfd, NULL, bytes,
+		       SPLICE_F_MOVE | SPLICE_F_MORE);
+	}
+
+	close(pipefd[0]);
+	close(pipefd[1]);
+
+	return 0;
+}
+
+static int copyfd_io_splice(int infd, int peerfd, int outfd, unsigned int size,
+			    bool *in_closed_after_out, struct wstate *winfo)
+{
+	int err;
+
+	if (listen_mode) {
+		err = do_splice(peerfd, outfd, size, winfo);
+		if (err)
+			return err;
+
+		err = do_splice(infd, peerfd, size, winfo);
+	} else {
+		err = do_splice(infd, peerfd, size, winfo);
+		if (err)
+			return err;
+
+		shut_wr(peerfd);
+
+		err = do_splice(peerfd, outfd, size, winfo);
+		*in_closed_after_out = true;
+	}
+
+	return err;
+}
+
 static int copyfd_io(int infd, int peerfd, int outfd, bool close_peerfd, struct wstate *winfo)
 {
 	bool in_closed_after_out = false;
@@ -957,6 +1007,14 @@ static int copyfd_io(int infd, int peerfd, int outfd, bool close_peerfd, struct
 					 &in_closed_after_out, winfo);
 		break;
 
+	case CFG_MODE_SPLICE:
+		file_size = get_infd_size(infd);
+		if (file_size < 0)
+			return file_size;
+		ret = copyfd_io_splice(infd, peerfd, outfd, file_size,
+				       &in_closed_after_out, winfo);
+		break;
+
 	default:
 		fprintf(stderr, "Invalid mode %d\n", cfg_mode);
 
@@ -1361,12 +1419,15 @@ int parse_mode(const char *mode)
 		return CFG_MODE_MMAP;
 	if (!strcasecmp(mode, "sendfile"))
 		return CFG_MODE_SENDFILE;
+	if (!strcasecmp(mode, "splice"))
+		return CFG_MODE_SPLICE;
 
 	fprintf(stderr, "Unknown test mode: %s\n", mode);
 	fprintf(stderr, "Supported modes are:\n");
 	fprintf(stderr, "\t\t\"poll\" - interleaved read/write using poll()\n");
 	fprintf(stderr, "\t\t\"mmap\" - send entire input file (mmap+write), then read response (-l will read input first)\n");
 	fprintf(stderr, "\t\t\"sendfile\" - send entire input file (sendfile), then read response (-l will read input first)\n");
+	fprintf(stderr, "\t\t\"splice\" - send entire input file (splice), then read response (-l will read input first)\n");
 
 	die_usage();
 
-- 
2.48.1

Hi Geliang,

On 07/07/2025 11:34, Geliang Tang wrote:
> From: Geliang Tang <tanggeliang@kylinos.cn>
> 
> This patch adds a new 'splice' io mode for mptcp_connect to test
> the newly added read_sock() and splice() functions of MPTCP.
> 
> 	./mptcp_connect.sh -m splice

That's good, but CI will not check them by default. For our CI, we can
easily modify it to run extra tests, but CI check stable versions will not.

What about adding new .sh files call mptcp_connect.sh with -m <mode>?

  mptcp_connect_mmap.sh
  mptcp_connect_sendfile.sh
  mptcp_connect_splice.sh

I will quickly check if that can work, and maybe propose patches for the
two others that we could backport to improve the code coverage on stable
releases too. If it works, feel free to do the same for splice.sh. I
will then modify the CI to remove the specific case checking mmap on the
side.

Cheers,
Matt
-- 
Sponsored by the NGI0 Core fund.