[PATCH net-next 5/6] selftests: mptcp: add splice io mode
From: "Matthieu Baerts (NGI0)" <matttbe@kernel.org>
Date: 2026-01-29 19:24:05
Also in:
linux-kselftest, lkml, mptcp
Subsystem:
kernel selftest framework, networking [general], networking [mptcp], the rest · Maintainers:
Shuah Khan, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Matthieu Baerts, Mat Martineau, Linus Torvalds
From: Geliang Tang <redacted> This patch adds a new 'splice' io mode for mptcp_connect to test the newly added read_sock() and splice_read() functions of MPTCP. do_splice() efficiently transfers data directly between two file descriptors (infd and outfd) without copying to userspace, using Linux's splice() system call. Usage: ./mptcp_connect.sh -m splice Signed-off-by: Geliang Tang <redacted> Reviewed-by: Mat Martineau <martineau@kernel.org> Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> --- tools/testing/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 10f6f99cfd4e..1c4fe60089a2 100644
--- a/tools/testing/selftests/net/mptcp/mptcp_connect.c
+++ b/tools/testing/selftests/net/mptcp/mptcp_connect.c@@ -52,6 +52,7 @@ enum cfg_mode { CFG_MODE_POLL, CFG_MODE_MMAP, CFG_MODE_SENDFILE, + CFG_MODE_SPLICE, }; enum cfg_peek {
@@ -124,7 +125,7 @@ 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");
@@ -935,6 +936,55 @@ 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;
@@ -967,6 +1017,14 @@ 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);
@@ -1380,12 +1438,15 @@ 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();
--
2.51.0