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-rw-r--r--net/l2tp/l2tp_core.c62
-rw-r--r--net/l2tp/l2tp_core.h12
-rw-r--r--net/l2tp/l2tp_eth.c55
-rw-r--r--net/l2tp/l2tp_netlink.c5
4 files changed, 63 insertions, 71 deletions
diff --git a/net/l2tp/l2tp_core.c b/net/l2tp/l2tp_core.c
index e37d9554da7b..fa0342574b89 100644
--- a/net/l2tp/l2tp_core.c
+++ b/net/l2tp/l2tp_core.c
@@ -120,7 +120,7 @@ static inline struct l2tp_tunnel *l2tp_tunnel(struct sock *sk)
return sk->sk_user_data;
}
-static inline struct l2tp_net *l2tp_pernet(struct net *net)
+static inline struct l2tp_net *l2tp_pernet(const struct net *net)
{
BUG_ON(!net);
@@ -217,27 +217,6 @@ static void l2tp_tunnel_sock_put(struct sock *sk)
sock_put(sk);
}
-/* Lookup a session by id in the global session list
- */
-static struct l2tp_session *l2tp_session_find_2(struct net *net, u32 session_id)
-{
- struct l2tp_net *pn = l2tp_pernet(net);
- struct hlist_head *session_list =
- l2tp_session_id_hash_2(pn, session_id);
- struct l2tp_session *session;
-
- rcu_read_lock_bh();
- hlist_for_each_entry_rcu(session, session_list, global_hlist) {
- if (session->session_id == session_id) {
- rcu_read_unlock_bh();
- return session;
- }
- }
- rcu_read_unlock_bh();
-
- return NULL;
-}
-
/* Session hash list.
* The session_id SHOULD be random according to RFC2661, but several
* L2TP implementations (Cisco and Microsoft) use incrementing
@@ -250,38 +229,10 @@ l2tp_session_id_hash(struct l2tp_tunnel *tunnel, u32 session_id)
return &tunnel->session_hlist[hash_32(session_id, L2TP_HASH_BITS)];
}
-/* Lookup a session by id
- */
-struct l2tp_session *l2tp_session_find(struct net *net, struct l2tp_tunnel *tunnel, u32 session_id)
-{
- struct hlist_head *session_list;
- struct l2tp_session *session;
-
- /* In L2TPv3, session_ids are unique over all tunnels and we
- * sometimes need to look them up before we know the
- * tunnel.
- */
- if (tunnel == NULL)
- return l2tp_session_find_2(net, session_id);
-
- session_list = l2tp_session_id_hash(tunnel, session_id);
- read_lock_bh(&tunnel->hlist_lock);
- hlist_for_each_entry(session, session_list, hlist) {
- if (session->session_id == session_id) {
- read_unlock_bh(&tunnel->hlist_lock);
- return session;
- }
- }
- read_unlock_bh(&tunnel->hlist_lock);
-
- return NULL;
-}
-EXPORT_SYMBOL_GPL(l2tp_session_find);
-
-/* Like l2tp_session_find() but takes a reference on the returned session.
+/* Lookup a session. A new reference is held on the returned session.
* Optionally calls session->ref() too if do_ref is true.
*/
-struct l2tp_session *l2tp_session_get(struct net *net,
+struct l2tp_session *l2tp_session_get(const struct net *net,
struct l2tp_tunnel *tunnel,
u32 session_id, bool do_ref)
{
@@ -356,7 +307,8 @@ EXPORT_SYMBOL_GPL(l2tp_session_get_nth);
/* Lookup a session by interface name.
* This is very inefficient but is only used by management interfaces.
*/
-struct l2tp_session *l2tp_session_get_by_ifname(struct net *net, char *ifname,
+struct l2tp_session *l2tp_session_get_by_ifname(const struct net *net,
+ const char *ifname,
bool do_ref)
{
struct l2tp_net *pn = l2tp_pernet(net);
@@ -427,7 +379,7 @@ exist:
/* Lookup a tunnel by id
*/
-struct l2tp_tunnel *l2tp_tunnel_find(struct net *net, u32 tunnel_id)
+struct l2tp_tunnel *l2tp_tunnel_find(const struct net *net, u32 tunnel_id)
{
struct l2tp_tunnel *tunnel;
struct l2tp_net *pn = l2tp_pernet(net);
@@ -445,7 +397,7 @@ struct l2tp_tunnel *l2tp_tunnel_find(struct net *net, u32 tunnel_id)
}
EXPORT_SYMBOL_GPL(l2tp_tunnel_find);
-struct l2tp_tunnel *l2tp_tunnel_find_nth(struct net *net, int nth)
+struct l2tp_tunnel *l2tp_tunnel_find_nth(const struct net *net, int nth)
{
struct l2tp_net *pn = l2tp_pernet(net);
struct l2tp_tunnel *tunnel;
diff --git a/net/l2tp/l2tp_core.h b/net/l2tp/l2tp_core.h
index 8ce7818c7a9d..eec5ad2ebb93 100644
--- a/net/l2tp/l2tp_core.h
+++ b/net/l2tp/l2tp_core.h
@@ -230,18 +230,16 @@ out:
return tunnel;
}
-struct l2tp_session *l2tp_session_get(struct net *net,
+struct l2tp_session *l2tp_session_get(const struct net *net,
struct l2tp_tunnel *tunnel,
u32 session_id, bool do_ref);
-struct l2tp_session *l2tp_session_find(struct net *net,
- struct l2tp_tunnel *tunnel,
- u32 session_id);
struct l2tp_session *l2tp_session_get_nth(struct l2tp_tunnel *tunnel, int nth,
bool do_ref);
-struct l2tp_session *l2tp_session_get_by_ifname(struct net *net, char *ifname,
+struct l2tp_session *l2tp_session_get_by_ifname(const struct net *net,
+ const char *ifname,
bool do_ref);
-struct l2tp_tunnel *l2tp_tunnel_find(struct net *net, u32 tunnel_id);
-struct l2tp_tunnel *l2tp_tunnel_find_nth(struct net *net, int nth);
+struct l2tp_tunnel *l2tp_tunnel_find(const struct net *net, u32 tunnel_id);
+struct l2tp_tunnel *l2tp_tunnel_find_nth(const struct net *net, int nth);
int l2tp_tunnel_create(struct net *net, int fd, int version, u32 tunnel_id,
u32 peer_tunnel_id, struct l2tp_tunnel_cfg *cfg,
diff --git a/net/l2tp/l2tp_eth.c b/net/l2tp/l2tp_eth.c
index 6fd41d7afe1e..138566a63123 100644
--- a/net/l2tp/l2tp_eth.c
+++ b/net/l2tp/l2tp_eth.c
@@ -30,6 +30,9 @@
#include <net/xfrm.h>
#include <net/net_namespace.h>
#include <net/netns/generic.h>
+#include <linux/ip.h>
+#include <linux/ipv6.h>
+#include <linux/udp.h>
#include "l2tp_core.h"
@@ -204,6 +207,53 @@ static void l2tp_eth_show(struct seq_file *m, void *arg)
}
#endif
+static void l2tp_eth_adjust_mtu(struct l2tp_tunnel *tunnel,
+ struct l2tp_session *session,
+ struct net_device *dev)
+{
+ unsigned int overhead = 0;
+ struct dst_entry *dst;
+ u32 l3_overhead = 0;
+
+ /* if the encap is UDP, account for UDP header size */
+ if (tunnel->encap == L2TP_ENCAPTYPE_UDP) {
+ overhead += sizeof(struct udphdr);
+ dev->needed_headroom += sizeof(struct udphdr);
+ }
+ if (session->mtu != 0) {
+ dev->mtu = session->mtu;
+ dev->needed_headroom += session->hdr_len;
+ return;
+ }
+ l3_overhead = kernel_sock_ip_overhead(tunnel->sock);
+ if (l3_overhead == 0) {
+ /* L3 Overhead couldn't be identified, this could be
+ * because tunnel->sock was NULL or the socket's
+ * address family was not IPv4 or IPv6,
+ * dev mtu stays at 1500.
+ */
+ return;
+ }
+ /* Adjust MTU, factor overhead - underlay L3, overlay L2 hdr
+ * UDP overhead, if any, was already factored in above.
+ */
+ overhead += session->hdr_len + ETH_HLEN + l3_overhead;
+
+ /* If PMTU discovery was enabled, use discovered MTU on L2TP device */
+ dst = sk_dst_get(tunnel->sock);
+ if (dst) {
+ /* dst_mtu will use PMTU if found, else fallback to intf MTU */
+ u32 pmtu = dst_mtu(dst);
+
+ if (pmtu != 0)
+ dev->mtu = pmtu;
+ dst_release(dst);
+ }
+ session->mtu = dev->mtu - overhead;
+ dev->mtu = session->mtu;
+ dev->needed_headroom += session->hdr_len;
+}
+
static int l2tp_eth_create(struct net *net, u32 tunnel_id, u32 session_id, u32 peer_session_id, struct l2tp_session_cfg *cfg)
{
struct net_device *dev;
@@ -247,12 +297,9 @@ static int l2tp_eth_create(struct net *net, u32 tunnel_id, u32 session_id, u32 p
}
dev_net_set(dev, net);
- if (session->mtu == 0)
- session->mtu = dev->mtu - session->hdr_len;
- dev->mtu = session->mtu;
- dev->needed_headroom += session->hdr_len;
dev->min_mtu = 0;
dev->max_mtu = ETH_MAX_MTU;
+ l2tp_eth_adjust_mtu(tunnel, session, dev);
priv = netdev_priv(dev);
priv->dev = dev;
diff --git a/net/l2tp/l2tp_netlink.c b/net/l2tp/l2tp_netlink.c
index 7e3e669baac4..12cfcd0ca807 100644
--- a/net/l2tp/l2tp_netlink.c
+++ b/net/l2tp/l2tp_netlink.c
@@ -521,11 +521,6 @@ static int l2tp_nl_cmd_session_create(struct sk_buff *skb, struct genl_info *inf
goto out;
}
session_id = nla_get_u32(info->attrs[L2TP_ATTR_SESSION_ID]);
- session = l2tp_session_find(net, tunnel, session_id);
- if (session) {
- ret = -EEXIST;
- goto out;
- }
if (!info->attrs[L2TP_ATTR_PEER_SESSION_ID]) {
ret = -EINVAL;