Commit d97dac54 authored by Sowmini Varadhan's avatar Sowmini Varadhan Committed by David S. Miller
Browse files

net/rds: Add setsockopt support for SO_RDS_TRANSPORT 



An application may deterministically attach the underlying transport for
a PF_RDS socket by invoking setsockopt(2) with the SO_RDS_TRANSPORT
option at the SOL_RDS level. The integer argument to setsockopt must be
one of the RDS_TRANS_* transport types, e.g., RDS_TRANS_TCP. The option
must be specified before invoking bind(2) on the socket, and may only
be used once on the socket. An attempt to set the option on a bound
socket, or to invoke the option after a successful SO_RDS_TRANSPORT
attachment, will return EOPNOTSUPP.

Signed-off-by: default avatarSowmini Varadhan <sowmini.varadhan@oracle.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent a28c257c

net/rds/af_rds.c

+27 −0
Original line number Diff line number Diff line
@@ -270,6 +270,28 @@ static int rds_cong_monitor(struct rds_sock *rs, char __user *optval, 
	return ret;

}



static int rds_set_transport(struct rds_sock *rs, char __user *optval,

			     int optlen)

{

	int t_type;



	if (rs->rs_transport)

		return -EOPNOTSUPP; /* previously attached to transport */



	if (optlen != sizeof(int))

		return -EINVAL;



	if (copy_from_user(&t_type, (int __user *)optval, sizeof(t_type)))

		return -EFAULT;



	if (t_type < 0 || t_type >= RDS_TRANS_COUNT)

		return -EINVAL;



	rs->rs_transport = rds_trans_get(t_type);



	return rs->rs_transport ? 0 : -ENOPROTOOPT;

}



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

			  char __user *optval, unsigned int optlen)

{
@@ -300,6 +322,11 @@ static int rds_setsockopt(struct socket *sock, int level, int optname, 
	case RDS_CONG_MONITOR:

		ret = rds_cong_monitor(rs, optval, optlen);

		break;

	case SO_RDS_TRANSPORT:

		lock_sock(sock->sk);

		ret = rds_set_transport(rs, optval, optlen);

		release_sock(sock->sk);

		break;

	default:

		ret = -ENOPROTOOPT;

	}

net/rds/bind.c

+4 −0
Original line number Diff line number Diff line
@@ -181,6 +181,10 @@ int rds_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len) 
	if (ret)

		goto out;



	if (rs->rs_transport) { /* previously bound */

		ret = 0;

		goto out;

	}

	trans = rds_trans_get_preferred(sin->sin_addr.s_addr);

	if (!trans) {

		ret = -EADDRNOTAVAIL;

net/rds/rds.h

+1 −0
Original line number Diff line number Diff line
@@ -798,6 +798,7 @@ struct rds_transport *rds_trans_get_preferred(__be32 addr); 
void rds_trans_put(struct rds_transport *trans);

unsigned int rds_trans_stats_info_copy(struct rds_info_iterator *iter,

				       unsigned int avail);

struct rds_transport *rds_trans_get(int t_type);

int rds_trans_init(void);

void rds_trans_exit(void);

net/rds/transport.c

+21 −0
Original line number Diff line number Diff line
@@ -101,6 +101,27 @@ struct rds_transport *rds_trans_get_preferred(__be32 addr) 
	return ret;

}



struct rds_transport *rds_trans_get(int t_type)

{

	struct rds_transport *ret = NULL;

	struct rds_transport *trans;

	unsigned int i;



	down_read(&rds_trans_sem);

	for (i = 0; i < RDS_TRANS_COUNT; i++) {

		trans = transports[i];



		if (trans && trans->t_type == t_type &&

		    (!trans->t_owner || try_module_get(trans->t_owner))) {

			ret = trans;

			break;

		}

	}

	up_read(&rds_trans_sem);



	return ret;

}



/*

 * This returns the number of stats entries in the snapshot and only

 * copies them using the iter if there is enough space for them.  The

CRA Git | Maintained and supported by SUSTech CRA and CCSE