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Commit ee9dfbef authored by Ursula Braun's avatar Ursula Braun Committed by David S. Miller
Browse files

net/smc: handle sockopts forcing fallback 



Several TCP sockopts do not work for SMC. One example are the
TCP_FASTOPEN sockopts, since SMC-connection setup is based on the TCP
three-way-handshake.
If the SMC socket is still in state SMC_INIT, such sockopts trigger
fallback to TCP. Otherwise an error is returned.

Signed-off-by: default avatarUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 33825761

net/smc/af_smc.c

+50 −4
Original line number Diff line number Diff line
@@ -391,6 +391,9 @@ static int smc_connect_rdma(struct smc_sock *smc) 


	sock_hold(&smc->sk); /* sock put in passive closing */



	if (smc->use_fallback)

		goto out_connected;



	if (!tcp_sk(smc->clcsock->sk)->syn_smc) {

		/* peer has not signalled SMC-capability */

		smc->use_fallback = true;
@@ -790,6 +793,9 @@ static void smc_listen_work(struct work_struct *work) 
	int rc = 0;

	u8 ibport;



	if (new_smc->use_fallback)

		goto out_connected;



	/* check if peer is smc capable */

	if (!tcp_sk(newclcsock->sk)->syn_smc) {

		new_smc->use_fallback = true;
@@ -968,7 +974,7 @@ static void smc_tcp_listen_work(struct work_struct *work) 
			continue;



		new_smc->listen_smc = lsmc;

		new_smc->use_fallback = false; /* assume rdma capability first*/

		new_smc->use_fallback = lsmc->use_fallback;

		sock_hold(lsk); /* sock_put in smc_listen_work */

		INIT_WORK(&new_smc->smc_listen_work, smc_listen_work);

		smc_copy_sock_settings_to_smc(new_smc);
@@ -1004,6 +1010,7 @@ static int smc_listen(struct socket *sock, int backlog) 
	 * them to the clc socket -- copy smc socket options to clc socket

	 */

	smc_copy_sock_settings_to_clc(smc);

	if (!smc->use_fallback)

		tcp_sk(smc->clcsock->sk)->syn_smc = 1;



	rc = kernel_listen(smc->clcsock, backlog);
@@ -1097,6 +1104,16 @@ static int smc_sendmsg(struct socket *sock, struct msghdr *msg, size_t len) 
	    (sk->sk_state != SMC_APPCLOSEWAIT1) &&

	    (sk->sk_state != SMC_INIT))

		goto out;



	if (msg->msg_flags & MSG_FASTOPEN) {

		if (sk->sk_state == SMC_INIT) {

			smc->use_fallback = true;

		} else {

			rc = -EINVAL;

			goto out;

		}

	}



	if (smc->use_fallback)

		rc = smc->clcsock->ops->sendmsg(smc->clcsock, msg, len);

	else
@@ -1274,14 +1291,43 @@ static int smc_setsockopt(struct socket *sock, int level, int optname, 
{

	struct sock *sk = sock->sk;

	struct smc_sock *smc;

	int rc;



	smc = smc_sk(sk);



	/* generic setsockopts reaching us here always apply to the

	 * CLC socket

	 */

	return smc->clcsock->ops->setsockopt(smc->clcsock, level, optname,

	rc = smc->clcsock->ops->setsockopt(smc->clcsock, level, optname,

					   optval, optlen);

	if (smc->clcsock->sk->sk_err) {

		sk->sk_err = smc->clcsock->sk->sk_err;

		sk->sk_error_report(sk);

	}

	if (rc)

		return rc;



	lock_sock(sk);

	switch (optname) {

	case TCP_ULP:

	case TCP_FASTOPEN:

	case TCP_FASTOPEN_CONNECT:

	case TCP_FASTOPEN_KEY:

	case TCP_FASTOPEN_NO_COOKIE:

		/* option not supported by SMC */

		if (sk->sk_state == SMC_INIT) {

			smc->use_fallback = true;

		} else {

			if (!smc->use_fallback)

				rc = -EINVAL;

		}

		break;

	default:

		break;

	}

	release_sock(sk);



	return rc;

}



static int smc_getsockopt(struct socket *sock, int level, int optname,