From 393d070135ad01f954ca8289c3ee134950e2d0c8 Mon Sep 17 00:00:00 2001 From: Michal Luczaj Date: Thu, 22 May 2025 01:18:25 +0200 Subject: [PATCH] vsock/test: Add test for an unexpectedly lingering close() There was an issue with SO_LINGER: instead of blocking until all queued messages for the socket have been successfully sent (or the linger timeout has been reached), close() would block until packets were handled by the peer. Add a test to alert on close() lingering when it should not. Signed-off-by: Michal Luczaj Reviewed-by: Stefano Garzarella Link: https://patch.msgid.link/20250522-vsock-linger-v6-5-2ad00b0e447e@rbox.co Signed-off-by: Paolo Abeni --- tools/testing/vsock/vsock_test.c | 52 ++++++++++++++++++++++++++++++++ 1 file changed, 52 insertions(+) diff --git a/tools/testing/vsock/vsock_test.c b/tools/testing/vsock/vsock_test.c index b3258d6ba21a..f669baaa0dca 100644 --- a/tools/testing/vsock/vsock_test.c +++ b/tools/testing/vsock/vsock_test.c @@ -1839,6 +1839,53 @@ static void test_stream_linger_server(const struct test_opts *opts) close(fd); } +/* Half of the default to not risk timing out the control channel */ +#define LINGER_TIMEOUT (TIMEOUT / 2) + +static void test_stream_nolinger_client(const struct test_opts *opts) +{ + bool waited; + time_t ns; + int fd; + + fd = vsock_stream_connect(opts->peer_cid, opts->peer_port); + if (fd < 0) { + perror("connect"); + exit(EXIT_FAILURE); + } + + enable_so_linger(fd, LINGER_TIMEOUT); + send_byte(fd, 1, 0); /* Left unread to expose incorrect behaviour. */ + waited = vsock_wait_sent(fd); + + ns = current_nsec(); + close(fd); + ns = current_nsec() - ns; + + if (!waited) { + fprintf(stderr, "Test skipped, SIOCOUTQ not supported.\n"); + } else if (DIV_ROUND_UP(ns, NSEC_PER_SEC) >= LINGER_TIMEOUT) { + fprintf(stderr, "Unexpected lingering\n"); + exit(EXIT_FAILURE); + } + + control_writeln("DONE"); +} + +static void test_stream_nolinger_server(const struct test_opts *opts) +{ + int fd; + + fd = vsock_stream_accept(VMADDR_CID_ANY, opts->peer_port, NULL); + if (fd < 0) { + perror("accept"); + exit(EXIT_FAILURE); + } + + control_expectln("DONE"); + close(fd); +} + static struct test_case test_cases[] = { { .name = "SOCK_STREAM connection reset", @@ -1999,6 +2046,11 @@ static struct test_case test_cases[] = { .run_client = test_stream_linger_client, .run_server = test_stream_linger_server, }, + { + .name = "SOCK_STREAM SO_LINGER close() on unread", + .run_client = test_stream_nolinger_client, + .run_server = test_stream_nolinger_server, + }, {}, }; -- 2.25.1