From: zhenwei pi pizhenwei@bytedance.com
mptcp_connect.c is a startup tutorial of MPTCP programming, however there is a lack of ai_protocol(IPPROTO_MPTCP) usage. Add comment for getaddrinfo MPTCP support.
This patch first uses IPPROTO_MPTCP to get addrinfo, and if glibc version is too old, it falls back to using IPPROTO_TCP.
Co-developed-by: Geliang Tang geliang@kernel.org Signed-off-by: Geliang Tang geliang@kernel.org Signed-off-by: zhenwei pi pizhenwei@bytedance.com Reviewed-by: Matthieu Baerts (NGI0) matttbe@kernel.org Signed-off-by: Matthieu Baerts (NGI0) matttbe@kernel.org --- Notes: - a previous version has already been sent to Netdev. ChangeLog: - show how to use IPPROTO_MPTCP with getaddrinfo, not only a comment. - Link to this version: https://lore.kernel.org/20250407085122.1203489-1-pizhenwei@bytedance.com --- tools/testing/selftests/net/mptcp/mptcp_connect.c | 21 +++++++++++++++++---- 1 file changed, 17 insertions(+), 4 deletions(-)
diff --git a/tools/testing/selftests/net/mptcp/mptcp_connect.c b/tools/testing/selftests/net/mptcp/mptcp_connect.c index c83a8b47bbdfa5fcf1462e2b2949b41fd32c9b14..ac1349c4b9e5404c95935eb38b08a15d774eb1d9 100644 --- a/tools/testing/selftests/net/mptcp/mptcp_connect.c +++ b/tools/testing/selftests/net/mptcp/mptcp_connect.c @@ -180,13 +180,26 @@ static void xgetnameinfo(const struct sockaddr *addr, socklen_t addrlen, }
static void xgetaddrinfo(const char *node, const char *service, - const struct addrinfo *hints, + struct addrinfo *hints, struct addrinfo **res) { +again: int err = getaddrinfo(node, service, hints, res);
if (err) { - const char *errstr = getxinfo_strerr(err); + const char *errstr; + + /* glibc starts to support MPTCP since v2.42. + * For older versions, use IPPROTO_TCP to resolve, + * and use TCP/MPTCP to create socket. + * Link: https://sourceware.org/git/?p=glibc.git%3Ba=commit%3Bh=a8e9022e0f82 + */ + if (err == EAI_SOCKTYPE) { + hints->ai_protocol = IPPROTO_TCP; + goto again; + } + + errstr = getxinfo_strerr(err);
fprintf(stderr, "Fatal: getaddrinfo(%s:%s): %s\n", node ? node : "", service ? service : "", errstr); @@ -292,7 +305,7 @@ static int sock_listen_mptcp(const char * const listenaddr, { int sock = -1; struct addrinfo hints = { - .ai_protocol = IPPROTO_TCP, + .ai_protocol = IPPROTO_MPTCP, .ai_socktype = SOCK_STREAM, .ai_flags = AI_PASSIVE | AI_NUMERICHOST }; @@ -356,7 +369,7 @@ static int sock_connect_mptcp(const char * const remoteaddr, int infd, struct wstate *winfo) { struct addrinfo hints = { - .ai_protocol = IPPROTO_TCP, + .ai_protocol = IPPROTO_MPTCP, .ai_socktype = SOCK_STREAM, }; struct addrinfo *a, *addr;