On 6/28/24 6:20 PM, Geliang Tang wrote:
From: Geliang Tang <tanggeliang@xxxxxxxxxx>
Some callers expect __start_server() helper to pass their own "backlog"
value to listen() instead of the default of 1. So this patch adds struct
member "backlog" for network_helper_opts to allow callers to set "backlog"
value via start_server_str() helper.
Signed-off-by: Geliang Tang <tanggeliang@xxxxxxxxxx>
---
tools/testing/selftests/bpf/network_helpers.c | 2 +-
tools/testing/selftests/bpf/network_helpers.h | 1 +
2 files changed, 2 insertions(+), 1 deletion(-)
diff --git a/tools/testing/selftests/bpf/network_helpers.c b/tools/testing/selftests/bpf/network_helpers.c
index 44c2c8fa542a..16cbb3fdcabf 100644
--- a/tools/testing/selftests/bpf/network_helpers.c
+++ b/tools/testing/selftests/bpf/network_helpers.c
@@ -106,7 +106,7 @@ static int __start_server(int type, const struct sockaddr *addr, socklen_t addrl
}
if (type == SOCK_STREAM) {
- if (listen(fd, 1) < 0) {
+ if (listen(fd, opts->backlog ? : 1) < 0) {
iirc, listen(fd, 0 /* backlog */) can be used to enforce syncookie. Meaning
backlog 0 is a legit value.
Using 0 as a default and changing it to 1 here is fine. It makes the test
program easier to write for the common case. Enforcing syncookie mode by using
backlog 0 is a niche use case but it should at least have a way for the caller
to do that.
May be using -ve backlog to do that, like
if (listen(fd, opts->backlog ? max(opts->backlog, 0): 1) < 0)
log_err("Failed to listed on socket");
goto error_close;
}
diff --git a/tools/testing/selftests/bpf/network_helpers.h b/tools/testing/selftests/bpf/network_helpers.h
index 9ea36524b9db..8339c4e4b075 100644
--- a/tools/testing/selftests/bpf/network_helpers.h
+++ b/tools/testing/selftests/bpf/network_helpers.h
@@ -25,6 +25,7 @@ struct network_helper_opts {
int timeout_ms;
bool must_fail;
int proto;
+ int backlog;
and add a comment here to explain the meaning of the -ve backlog.
int (*post_socket_cb)(int fd, void *opts);
void *cb_opts;
};
