l2tp: drop ->mru from struct l2tp_session

This field is not used.

Treat PPPIOC*MRU the same way as PPPIOC*FLAGS: "get" requests return 0,
while "set" requests vadidate the user supplied pointer but discard its
value.
Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/uapi/linux/l2tp.h

@@ -120,7 +120,7 @@ enum {
 	L2TP_ATTR_UDP_SPORT,		/* u16 */
 	L2TP_ATTR_UDP_DPORT,		/* u16 */
 	L2TP_ATTR_MTU,			/* u16 */
-	L2TP_ATTR_MRU,			/* u16 */
+	L2TP_ATTR_MRU,			/* u16 (not used) */
 	L2TP_ATTR_STATS,		/* nested */
 	L2TP_ATTR_IP6_SADDR,		/* struct in6_addr */
 	L2TP_ATTR_IP6_DADDR,		/* struct in6_addr */

net/l2tp/l2tp_core.c

@@ -1675,7 +1675,6 @@ struct l2tp_session *l2tp_session_create(int priv_size, struct l2tp_tunnel *tunn
 			session->pwtype = cfg->pw_type;
 			session->debug = cfg->debug;
 			session->mtu = cfg->mtu;
-			session->mru = cfg->mru;
 			session->send_seq = cfg->send_seq;
 			session->recv_seq = cfg->recv_seq;
 			session->lns_mode = cfg->lns_mode;

net/l2tp/l2tp_core.h

@@ -62,7 +62,6 @@ struct l2tp_session_cfg {
 	int			reorder_timeout; /* configured reorder timeout
 						  * (in jiffies) */
 	int			mtu;
-	int			mru;
 	char			*ifname;
 };
 
@@ -107,7 +106,6 @@ struct l2tp_session {
 						  * (in jiffies) */
 	int			reorder_skip;	/* set if skip to next nr */
 	int			mtu;
-	int			mru;
 	enum l2tp_pwtype	pwtype;
 	struct l2tp_stats	stats;
 	struct hlist_node	global_hlist;	/* Global hash list node */

net/l2tp/l2tp_debugfs.c

@@ -191,8 +191,8 @@ static void l2tp_dfs_seq_session_show(struct seq_file *m, void *v)
 	if (session->send_seq || session->recv_seq)
 		seq_printf(m, "   nr %hu, ns %hu\n", session->nr, session->ns);
 	seq_printf(m, "   refcnt %d\n", refcount_read(&session->ref_count));
-	seq_printf(m, "   config %d/%d/%c/%c/-/%s %08x %u\n",
-		   session->mtu, session->mru,
+	seq_printf(m, "   config %d/0/%c/%c/-/%s %08x %u\n",
+		   session->mtu,
 		   session->recv_seq ? 'R' : '-',
 		   session->send_seq ? 'S' : '-',
 		   session->lns_mode ? "LNS" : "LAC",

net/l2tp/l2tp_netlink.c

@@ -611,9 +611,6 @@ static int l2tp_nl_cmd_session_create(struct sk_buff *skb, struct genl_info *inf
 	if (info->attrs[L2TP_ATTR_MTU])
 		cfg.mtu = nla_get_u16(info->attrs[L2TP_ATTR_MTU]);
 
-	if (info->attrs[L2TP_ATTR_MRU])
-		cfg.mru = nla_get_u16(info->attrs[L2TP_ATTR_MRU]);
-
 #ifdef CONFIG_MODULES
 	if (l2tp_nl_cmd_ops[cfg.pw_type] == NULL) {
 		genl_unlock();
@@ -704,9 +701,6 @@ static int l2tp_nl_cmd_session_modify(struct sk_buff *skb, struct genl_info *inf
 	if (info->attrs[L2TP_ATTR_MTU])
 		session->mtu = nla_get_u16(info->attrs[L2TP_ATTR_MTU]);
 
-	if (info->attrs[L2TP_ATTR_MRU])
-		session->mru = nla_get_u16(info->attrs[L2TP_ATTR_MRU]);
-
 	ret = l2tp_session_notify(&l2tp_nl_family, info,
 				  session, L2TP_CMD_SESSION_MODIFY);
 
@@ -737,9 +731,7 @@ static int l2tp_nl_session_send(struct sk_buff *skb, u32 portid, u32 seq, int fl
 			session->peer_session_id) ||
 	    nla_put_u32(skb, L2TP_ATTR_DEBUG, session->debug) ||
 	    nla_put_u16(skb, L2TP_ATTR_PW_TYPE, session->pwtype) ||
-	    nla_put_u16(skb, L2TP_ATTR_MTU, session->mtu) ||
-	    (session->mru &&
-	     nla_put_u16(skb, L2TP_ATTR_MRU, session->mru)))
+	    nla_put_u16(skb, L2TP_ATTR_MTU, session->mtu))
 		goto nla_put_failure;
 
 	if ((session->ifname[0] &&

net/l2tp/l2tp_ppp.c

@@ -570,10 +570,9 @@ static void pppol2tp_session_init(struct l2tp_session *session)
 	if (dst) {
 		u32 pmtu = dst_mtu(dst);
 
-		if (pmtu) {
+		if (pmtu)
 			session->mtu = pmtu - PPPOL2TP_HEADER_OVERHEAD;
-			session->mru = pmtu - PPPOL2TP_HEADER_OVERHEAD;
-		}
+
 		dst_release(dst);
 	}
 }
@@ -781,7 +780,6 @@ static int pppol2tp_connect(struct socket *sock, struct sockaddr *uservaddr,
 	} else {
 		/* Default MTU must allow space for UDP/L2TP/PPP headers */
 		cfg.mtu = 1500 - PPPOL2TP_HEADER_OVERHEAD;
-		cfg.mru = cfg.mtu;
 		cfg.pw_type = L2TP_PWTYPE_PPP;
 
 		session = l2tp_session_create(sizeof(struct pppol2tp_session),
@@ -885,8 +883,6 @@ static int pppol2tp_session_create(struct net *net, struct l2tp_tunnel *tunnel,
 	/* Default MTU values. */
 	if (cfg->mtu == 0)
 		cfg->mtu = 1500 - PPPOL2TP_HEADER_OVERHEAD;
-	if (cfg->mru == 0)
-		cfg->mru = cfg->mtu;
 
 	/* Allocate and initialize a new session context. */
 	session = l2tp_session_create(sizeof(struct pppol2tp_session),
@@ -1101,34 +1097,6 @@ static int pppol2tp_session_ioctl(struct l2tp_session *session,
 		break;
 
 	case PPPIOCGMRU:
-		err = -ENXIO;
-		if (!(sk->sk_state & PPPOX_CONNECTED))
-			break;
-
-		err = -EFAULT;
-		if (put_user(session->mru, (int __user *) arg))
-			break;
-
-		l2tp_info(session, L2TP_MSG_CONTROL, "%s: get mru=%d\n",
-			  session->name, session->mru);
-		err = 0;
-		break;
-
-	case PPPIOCSMRU:
-		err = -ENXIO;
-		if (!(sk->sk_state & PPPOX_CONNECTED))
-			break;
-
-		err = -EFAULT;
-		if (get_user(val, (int __user *) arg))
-			break;
-
-		session->mru = val;
-		l2tp_info(session, L2TP_MSG_CONTROL, "%s: set mru=%d\n",
-			  session->name, session->mru);
-		err = 0;
-		break;
-
 	case PPPIOCGFLAGS:
 		err = -EFAULT;
 		if (put_user(0, (int __user *)arg))
@@ -1136,6 +1104,7 @@ static int pppol2tp_session_ioctl(struct l2tp_session *session,
 		err = 0;
 		break;
 
+	case PPPIOCSMRU:
 	case PPPIOCSFLAGS:
 		err = -EFAULT;
 		if (get_user(val, (int __user *)arg))
@@ -1723,8 +1692,8 @@ static void pppol2tp_seq_session_show(struct seq_file *m, void *v)
 		   tunnel->peer_tunnel_id,
 		   session->peer_session_id,
 		   state, user_data_ok);
-	seq_printf(m, "   %d/%d/%c/%c/%s %08x %u\n",
-		   session->mtu, session->mru,
+	seq_printf(m, "   %d/0/%c/%c/%s %08x %u\n",
+		   session->mtu,
 		   session->recv_seq ? 'R' : '-',
 		   session->send_seq ? 'S' : '-',
 		   session->lns_mode ? "LNS" : "LAC",