From 571ec995fe035557d4166ae310f627bdf307714b Mon Sep 17 00:00:00 2001 From: Lennart Poettering Date: Fri, 5 Mar 2021 18:46:31 +0100 Subject: [PATCH] socket-util: cache result of socket_ipv6_is_supported() And while we are at it, log about unexpected errors. --- src/basic/socket-util.c | 19 ++++++++++++++++--- 1 file changed, 16 insertions(+), 3 deletions(-) diff --git a/src/basic/socket-util.c b/src/basic/socket-util.c index 8267988ad9..315a99c3fa 100644 --- a/src/basic/socket-util.c +++ b/src/basic/socket-util.c @@ -277,10 +277,23 @@ const char* socket_address_get_path(const SocketAddress *a) { } bool socket_ipv6_is_supported(void) { - if (access("/proc/net/if_inet6", F_OK) != 0) - return false; + static int cached = -1; - return true; + if (cached < 0) { + + if (access("/proc/net/if_inet6", F_OK) < 0) { + + if (errno != ENOENT) { + log_debug_errno(errno, "Unexpected error when checking whether /proc/net/if_inet6 exists: %m"); + return false; + } + + cached = false; + } else + cached = true; + } + + return cached; } bool socket_address_matches_fd(const SocketAddress *a, int fd) {