Commit 36bb1d71 authored by Antonio Quartulli's avatar Antonio Quartulli Committed by Paolo Abeni
Browse files

ovpn: add support for MSG_NOSIGNAL in tcp_sendmsg 



Userspace may want to pass the MSG_NOSIGNAL flag to
tcp_sendmsg() in order to avoid generating a SIGPIPE.

To pass this flag down the TCP stack a new skb sending API
accepting a flags argument is introduced.

Cc: Eric Dumazet <edumazet@google.com>
Cc: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: default avatarAntonio Quartulli <antonio@openvpn.net>
Link: https://patch.msgid.link/20250415-b4-ovpn-v26-13-577f6097b964@openvpn.net


Reviewed-by: default avatarSabrina Dubroca <sd@queasysnail.net>
Tested-by: default avatarOleksandr Natalenko <oleksandr@natalenko.name>
Signed-off-by: default avatarPaolo Abeni <pabeni@redhat.com>
parent 17240749

drivers/net/ovpn/skb.h

+1 −0
Original line number Diff line number Diff line
@@ -25,6 +25,7 @@ struct ovpn_cb { 
	struct scatterlist *sg;

	u8 *iv;

	unsigned int payload_offset;

	bool nosignal;

};



static inline struct ovpn_cb *ovpn_skb_cb(struct sk_buff *skb)

drivers/net/ovpn/tcp.c

+8 −4
Original line number Diff line number Diff line
@@ -220,6 +220,7 @@ void ovpn_tcp_socket_wait_finish(struct ovpn_socket *sock) 
static void ovpn_tcp_send_sock(struct ovpn_peer *peer, struct sock *sk)

{

	struct sk_buff *skb = peer->tcp.out_msg.skb;

	int ret, flags;



	if (!skb)

		return;
@@ -230,9 +231,11 @@ static void ovpn_tcp_send_sock(struct ovpn_peer *peer, struct sock *sk) 
	peer->tcp.tx_in_progress = true;



	do {

		int ret = skb_send_sock_locked(sk, skb,

		flags = ovpn_skb_cb(skb)->nosignal ? MSG_NOSIGNAL : 0;

		ret = skb_send_sock_locked_with_flags(sk, skb,

						      peer->tcp.out_msg.offset,

					       peer->tcp.out_msg.len);

						      peer->tcp.out_msg.len,

						      flags);

		if (unlikely(ret < 0)) {

			if (ret == -EAGAIN)

				goto out;
@@ -380,7 +383,7 @@ static int ovpn_tcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t size) 
	rcu_read_unlock();

	peer = sock->peer;



	if (msg->msg_flags & ~MSG_DONTWAIT) {

	if (msg->msg_flags & ~(MSG_DONTWAIT | MSG_NOSIGNAL)) {

		ret = -EOPNOTSUPP;

		goto peer_free;

	}
@@ -413,6 +416,7 @@ static int ovpn_tcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t size) 
		goto peer_free;

	}



	ovpn_skb_cb(skb)->nosignal = msg->msg_flags & MSG_NOSIGNAL;

	ovpn_tcp_send_sock_skb(peer, sk, skb);

	ret = size;

peer_free: