[RFC net-next 15/17] mptcp: implement ulp getsockopt for tls support
From: Geliang Tang <geliang@kernel.org>
Date: 2026-06-22 10:45:41
Also in:
mptcp
Subsystem:
networking [general], networking [mptcp], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Matthieu Baerts, Mat Martineau, Linus Torvalds
From: Geliang Tang <redacted> Add mptcp_getsockopt_tcp_ulp() to handle TCP_ULP getsockopt on MPTCP sockets. The helper reads the user length once, checks for negative value, takes the socket lock, caps the length to TCP_ULP_NAME_MAX, and copies the ULP name (or sets the length to zero if no ULP is attached) to userspace. The lock ensures safe access to icsk->icsk_ulp_ops. Co-developed-by: Gang Yan <redacted> Signed-off-by: Gang Yan <redacted> Co-developed-by: Zqiang <qiang.zhang@linux.dev> Signed-off-by: Zqiang <qiang.zhang@linux.dev> Signed-off-by: Geliang Tang <redacted> --- net/mptcp/sockopt.c | 34 ++++++++++++++++++++++++++++++++++ 1 file changed, 34 insertions(+)
diff --git a/net/mptcp/sockopt.c b/net/mptcp/sockopt.c
index fcf6feb2a9eb..cc45491cd3b2 100644
--- a/net/mptcp/sockopt.c
+++ b/net/mptcp/sockopt.c@@ -1408,6 +1408,39 @@ static int mptcp_put_int_option(struct mptcp_sock *msk, char __user *optval, return 0; } +static int mptcp_getsockopt_tcp_ulp(struct sock *sk, + char __user *optval, + int __user *optlen) +{ + struct inet_connection_sock *icsk = inet_csk(sk); + int ret = 0, len; + + if (copy_from_sockptr(&len, USER_SOCKPTR(optlen), sizeof(int))) + return -EFAULT; + + if (len < 0) + return -EINVAL; + + lock_sock(sk); + len = min_t(unsigned int, len, TCP_ULP_NAME_MAX); + if (!icsk->icsk_ulp_ops) { + len = 0; + if (copy_to_sockptr(USER_SOCKPTR(optlen), &len, sizeof(int))) + ret = -EFAULT; + goto out; + } + if (copy_to_sockptr(USER_SOCKPTR(optlen), &len, sizeof(int))) { + ret = -EFAULT; + goto out; + } + if (copy_to_sockptr(USER_SOCKPTR(optval), icsk->icsk_ulp_ops->name, + len)) + ret = -EFAULT; +out: + release_sock(sk); + return ret; +} + static int mptcp_getsockopt_sol_tcp(struct mptcp_sock *msk, int optname, char __user *optval, int __user *optlen) {
@@ -1415,6 +1448,7 @@ static int mptcp_getsockopt_sol_tcp(struct mptcp_sock *msk, int optname, switch (optname) { case TCP_ULP: + return mptcp_getsockopt_tcp_ulp(sk, optval, optlen); case TCP_CONGESTION: case TCP_INFO: case TCP_CC_INFO:
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2.53.0