With this change an ovpn instance will be able to stay connected to
multiple remote endpoints.
This functionality is strictly required when running ovpn on an
OpenVPN server.
Signed-off-by: Antonio Quartulli <antonio@xxxxxxxxxxx>
---
drivers/net/ovpn/main.c | 68 ++++++++++++++++-
drivers/net/ovpn/ovpnpriv.h | 19 +++++
drivers/net/ovpn/peer.c | 176 +++++++++++++++++++++++++++++++++++++++++++-
drivers/net/ovpn/peer.h | 10 +++
drivers/net/ovpn/udp.c | 9 ++-
5 files changed, 275 insertions(+), 7 deletions(-)
diff --git a/drivers/net/ovpn/main.c b/drivers/net/ovpn/main.c
index 3498c0dafb1ee64b974a77dae882447e317352fd..bcbbc2200edd2e65190f5a7de07161321e16bb34 100644
--- a/drivers/net/ovpn/main.c
+++ b/drivers/net/ovpn/main.c
@@ -25,11 +25,66 @@
#include "tcp.h"
#include "udp.h"
+static void ovpn_priv_free(struct net_device *net)
+{
+ struct ovpn_priv *ovpn = netdev_priv(net);
+
+ kfree(ovpn->peers);
+}
+
+static int ovpn_mp_alloc(struct ovpn_priv *ovpn)
+{
+ struct in_device *dev_v4;
+ int i;
+
+ if (ovpn->mode != OVPN_MODE_MP)
+ return 0;
+
+ dev_v4 = __in_dev_get_rtnl(ovpn->dev);
+ if (dev_v4) {
+ /* disable redirects as Linux gets confused by ovpn
+ * handling same-LAN routing.
+ * This happens because a multipeer interface is used as
+ * relay point between hosts in the same subnet, while
+ * in a classic LAN this would not be needed because the
+ * two hosts would be able to talk directly.
+ */
+ IN_DEV_CONF_SET(dev_v4, SEND_REDIRECTS, false);
+ IPV4_DEVCONF_ALL(dev_net(ovpn->dev), SEND_REDIRECTS) = false;
+ }
+
+ /* the peer container is fairly large, therefore we allocate it only in
+ * MP mode
+ */
+ ovpn->peers = kzalloc(sizeof(*ovpn->peers), GFP_KERNEL);
+ if (!ovpn->peers)
+ return -ENOMEM;
+
+ for (i = 0; i < ARRAY_SIZE(ovpn->peers->by_id); i++) {
+ INIT_HLIST_HEAD(&ovpn->peers->by_id[i]);
+ INIT_HLIST_NULLS_HEAD(&ovpn->peers->by_vpn_addr4[i], i);
+ INIT_HLIST_NULLS_HEAD(&ovpn->peers->by_vpn_addr6[i], i);
+ INIT_HLIST_NULLS_HEAD(&ovpn->peers->by_transp_addr[i], i);
+ }
+
+ return 0;
+}
+
static int ovpn_net_init(struct net_device *dev)
{
struct ovpn_priv *ovpn = netdev_priv(dev);
+ int err = gro_cells_init(&ovpn->gro_cells, dev);
+
+ if (err < 0)
+ return err;
- return gro_cells_init(&ovpn->gro_cells, dev);
+ err = ovpn_mp_alloc(ovpn);
+ if (err < 0) {
+ gro_cells_destroy(&ovpn->gro_cells);
+ return err;
+ }
+
+ return 0;
}
static void ovpn_net_uninit(struct net_device *dev)
@@ -100,6 +155,8 @@ static void ovpn_setup(struct net_device *dev)
dev->netdev_ops = &ovpn_netdev_ops;
+ dev->priv_destructor = ovpn_priv_free;
+
dev->hard_header_len = 0;
dev->addr_len = 0;
dev->mtu = ETH_DATA_LEN - OVPN_HEAD_ROOM;
@@ -197,9 +254,16 @@ static int ovpn_netdev_notifier_call(struct notifier_block *nb,
netif_carrier_off(dev);
ovpn->registered = false;
- if (ovpn->mode == OVPN_MODE_P2P)
+ switch (ovpn->mode) {
+ case OVPN_MODE_P2P:
ovpn_peer_release_p2p(ovpn, NULL,
OVPN_DEL_PEER_REASON_TEARDOWN);
+ break;
+ case OVPN_MODE_MP:
+ ovpn_peers_free(ovpn, NULL,
+ OVPN_DEL_PEER_REASON_TEARDOWN);
+ break;
+ }
break;
case NETDEV_POST_INIT:
case NETDEV_GOING_DOWN:
diff --git a/drivers/net/ovpn/ovpnpriv.h b/drivers/net/ovpn/ovpnpriv.h
index 2e3f4baf305f0b37b474d7b7d94751aa4af8a2ea..b26ad97215a3d42242ba349b348c2749f570797c 100644
--- a/drivers/net/ovpn/ovpnpriv.h
+++ b/drivers/net/ovpn/ovpnpriv.h
@@ -15,12 +15,30 @@
#include <uapi/linux/if_link.h>
#include <uapi/linux/ovpn.h>
+/**
+ * struct ovpn_peer_collection - container of peers for MultiPeer mode
+ * @by_id: table of peers index by ID
+ * @by_vpn_addr4: table of peers indexed by VPN IPv4 address (items can be
+ * rehashed on the fly due to peer IP change)
+ * @by_vpn_addr6: table of peers indexed by VPN IPv6 address (items can be
+ * rehashed on the fly due to peer IP change)
+ * @by_transp_addr: table of peers indexed by transport address (items can be
+ * rehashed on the fly due to peer IP change)
+ */
+struct ovpn_peer_collection {
+ DECLARE_HASHTABLE(by_id, 12);
+ struct hlist_nulls_head by_vpn_addr4[1 << 12];
+ struct hlist_nulls_head by_vpn_addr6[1 << 12];
+ struct hlist_nulls_head by_transp_addr[1 << 12];
+};
+
/**
* struct ovpn_priv - per ovpn interface state
* @dev: the actual netdev representing the tunnel
* @registered: whether dev is still registered with netdev or not
* @mode: device operation mode (i.e. p2p, mp, ..)
* @lock: protect this object
+ * @peers: data structures holding multi-peer references
* @peer: in P2P mode, this is the only remote peer
* @gro_cells: pointer to the Generic Receive Offload cell
*/
@@ -29,6 +47,7 @@ struct ovpn_priv {
bool registered;
enum ovpn_mode mode;
spinlock_t lock; /* protect writing to the ovpn_priv object */
+ struct ovpn_peer_collection *peers;
struct ovpn_peer __rcu *peer;
struct gro_cells gro_cells;
};
diff --git a/drivers/net/ovpn/peer.c b/drivers/net/ovpn/peer.c
index 1f4148475c8b93aabc72694da5af97ae00a3a59d..b21ef6f10a7138e9f10c01b809df2cb0adf0abad 100644
--- a/drivers/net/ovpn/peer.c
+++ b/drivers/net/ovpn/peer.c
@@ -9,6 +9,7 @@
#include <linux/skbuff.h>
#include <linux/list.h>
+#include <linux/hashtable.h>
#include "ovpnpriv.h"
#include "bind.h"
@@ -280,7 +281,19 @@ static void ovpn_peer_remove(struct ovpn_peer *peer,
enum ovpn_del_peer_reason reason,
struct llist_head *release_list)
{
+ lockdep_assert_held(&peer->ovpn->lock);
+
switch (peer->ovpn->mode) {
+ case OVPN_MODE_MP:
+ /* prevent double remove */
+ if (hlist_unhashed(&peer->hash_entry_id))
+ return;
+
+ hlist_del_init_rcu(&peer->hash_entry_id);
+ hlist_nulls_del_init_rcu(&peer->hash_entry_addr4);
+ hlist_nulls_del_init_rcu(&peer->hash_entry_addr6);
+ hlist_nulls_del_init_rcu(&peer->hash_entry_transp_addr);
+ break;
case OVPN_MODE_P2P:
/* prevent double remove */
if (peer != rcu_access_pointer(peer->ovpn->peer))
@@ -292,8 +305,6 @@ static void ovpn_peer_remove(struct ovpn_peer *peer,
*/
netif_carrier_off(peer->ovpn->dev);
break;
- default:
- return;
}
peer->delete_reason = reason;
@@ -357,6 +368,89 @@ bool ovpn_peer_check_by_src(struct ovpn_priv *ovpn, struct sk_buff *skb,
return match;
}
+#define ovpn_get_hash_head(_tbl, _key, _key_len) ({ \
+ typeof(_tbl) *__tbl = &(_tbl); \
+ (&(*__tbl)[jhash(_key, _key_len, 0) % HASH_SIZE(*__tbl)]); }) \
+
+/**
+ * ovpn_peer_add_mp - add peer to related tables in a MP instance
+ * @ovpn: the instance to add the peer to
+ * @peer: the peer to add
+ *
+ * Return: 0 on success or a negative error code otherwise
+ */
+static int ovpn_peer_add_mp(struct ovpn_priv *ovpn, struct ovpn_peer *peer)
+{
+ struct sockaddr_storage sa = { 0 };
+ struct hlist_nulls_head *nhead;
+ struct sockaddr_in6 *sa6;
+ struct sockaddr_in *sa4;
+ struct ovpn_bind *bind;
+ struct ovpn_peer *tmp;
+ size_t salen;
+ int ret = 0;
+
+ spin_lock_bh(&ovpn->lock);
+ /* do not add duplicates */
+ tmp = ovpn_peer_get_by_id(ovpn, peer->id);
+ if (tmp) {
+ ovpn_peer_put(tmp);
+ ret = -EEXIST;
+ goto out;
+ }
+
+ bind = rcu_dereference_protected(peer->bind, true);
+ /* peers connected via TCP have bind == NULL */
+ if (bind) {
+ switch (bind->remote.in4.sin_family) {
+ case AF_INET:
+ sa4 = (struct sockaddr_in *)&sa;
+
+ sa4->sin_family = AF_INET;
+ sa4->sin_addr.s_addr = bind->remote.in4.sin_addr.s_addr;
+ sa4->sin_port = bind->remote.in4.sin_port;
+ salen = sizeof(*sa4);
+ break;
+ case AF_INET6:
+ sa6 = (struct sockaddr_in6 *)&sa;
+
+ sa6->sin6_family = AF_INET6;
+ sa6->sin6_addr = bind->remote.in6.sin6_addr;
+ sa6->sin6_port = bind->remote.in6.sin6_port;
+ salen = sizeof(*sa6);
+ break;
+ default:
+ ret = -EPROTONOSUPPORT;
+ goto out;
+ }
+
+ nhead = ovpn_get_hash_head(ovpn->peers->by_transp_addr, &sa,
+ salen);
+ hlist_nulls_add_head_rcu(&peer->hash_entry_transp_addr, nhead);
+ }
+
+ hlist_add_head_rcu(&peer->hash_entry_id,
+ ovpn_get_hash_head(ovpn->peers->by_id, &peer->id,
+ sizeof(peer->id)));
+
+ if (peer->vpn_addrs.ipv4.s_addr != htonl(INADDR_ANY)) {
+ nhead = ovpn_get_hash_head(ovpn->peers->by_vpn_addr4,
+ &peer->vpn_addrs.ipv4,
+ sizeof(peer->vpn_addrs.ipv4));
+ hlist_nulls_add_head_rcu(&peer->hash_entry_addr4, nhead);
+ }
+
+ if (!ipv6_addr_any(&peer->vpn_addrs.ipv6)) {
+ nhead = ovpn_get_hash_head(ovpn->peers->by_vpn_addr6,
+ &peer->vpn_addrs.ipv6,
+ sizeof(peer->vpn_addrs.ipv6));
+ hlist_nulls_add_head_rcu(&peer->hash_entry_addr6, nhead);
+ }
+out:
+ spin_unlock_bh(&ovpn->lock);
+ return ret;
+}
+
/**
* ovpn_peer_add_p2p - add peer to related tables in a P2P instance
* @ovpn: the instance to add the peer to
@@ -399,11 +493,42 @@ static int ovpn_peer_add_p2p(struct ovpn_priv *ovpn, struct ovpn_peer *peer)
int ovpn_peer_add(struct ovpn_priv *ovpn, struct ovpn_peer *peer)
{
switch (ovpn->mode) {
+ case OVPN_MODE_MP:
+ return ovpn_peer_add_mp(ovpn, peer);
case OVPN_MODE_P2P:
return ovpn_peer_add_p2p(ovpn, peer);
- default:
- return -EOPNOTSUPP;
}
+
+ return -EOPNOTSUPP;
+}
+
+/**
+ * ovpn_peer_del_mp - delete peer from related tables in a MP instance
+ * @peer: the peer to delete
+ * @reason: reason why the peer was deleted (sent to userspace)
+ * @release_list: list where delete peer should be appended
+ *
+ * Return: 0 on success or a negative error code otherwise
+ */
+static int ovpn_peer_del_mp(struct ovpn_peer *peer,
+ enum ovpn_del_peer_reason reason,
+ struct llist_head *release_list)
+{
+ struct ovpn_peer *tmp;
+ int ret = -ENOENT;
+
+ lockdep_assert_held(&peer->ovpn->lock);
+
+ tmp = ovpn_peer_get_by_id(peer->ovpn, peer->id);
+ if (tmp == peer) {
+ ovpn_peer_remove(peer, reason, release_list);
+ ret = 0;
+ }
+
+ if (tmp)
+ ovpn_peer_put(tmp);
+
+ return ret;
}
/**
@@ -480,6 +605,9 @@ int ovpn_peer_del(struct ovpn_peer *peer, enum ovpn_del_peer_reason reason)
spin_lock_bh(&peer->ovpn->lock);
switch (peer->ovpn->mode) {
+ case OVPN_MODE_MP:
+ ret = ovpn_peer_del_mp(peer, reason, &release_list);
+ break;
case OVPN_MODE_P2P:
ret = ovpn_peer_del_p2p(peer, reason, &release_list);
break;
@@ -490,3 +618,43 @@ int ovpn_peer_del(struct ovpn_peer *peer, enum ovpn_del_peer_reason reason)
return ret;
}
+
+/**
+ * ovpn_peers_free - free all peers in the instance
+ * @ovpn: the instance whose peers should be released
+ * @sk: if not NULL, only peers using this socket are removed and the socket
+ * is released immediately
+ * @reason: the reason for releasing all peers
+ */
+void ovpn_peers_free(struct ovpn_priv *ovpn, struct sock *sk,
+ enum ovpn_del_peer_reason reason)
+{
+ struct ovpn_socket *ovpn_sock;
+ LLIST_HEAD(release_list);
+ struct ovpn_peer *peer;
+ struct hlist_node *tmp;
+ bool skip;
+ int bkt;
+
+ spin_lock_bh(&ovpn->lock);
+ hash_for_each_safe(ovpn->peers->by_id, bkt, tmp, peer, hash_entry_id) {
+ /* if a socket was passed as argument, skip all peers except
+ * those using it
+ */
+ if (sk) {
+ skip = true;
+
+ rcu_read_lock();
+ ovpn_sock = rcu_access_pointer(peer->sock);
+ if (ovpn_sock && ovpn_sock->sock->sk == sk)
+ skip = false;
+ rcu_read_unlock();
+
+ if (skip)
+ continue;
+ }
+
+ ovpn_peer_remove(peer, reason, &release_list);
+ }
+ unlock_ovpn(ovpn, &release_list);
+}
diff --git a/drivers/net/ovpn/peer.h b/drivers/net/ovpn/peer.h
index 777a0b24843ed03e83ae8821837103a979e2c6de..e88f1e695bd7a4cb0827f8d552ee900a2b3f722e 100644
--- a/drivers/net/ovpn/peer.h
+++ b/drivers/net/ovpn/peer.h
@@ -25,6 +25,10 @@
* @vpn_addrs: IP addresses assigned over the tunnel
* @vpn_addrs.ipv4: IPv4 assigned to peer on the tunnel
* @vpn_addrs.ipv6: IPv6 assigned to peer on the tunnel
+ * @hash_entry_id: entry in the peer ID hashtable
+ * @hash_entry_addr4: entry in the peer IPv4 hashtable
+ * @hash_entry_addr6: entry in the peer IPv6 hashtable
+ * @hash_entry_transp_addr: entry in the peer transport address hashtable
* @sock: the socket being used to talk to this peer
* @tcp: keeps track of TCP specific state
* @tcp.strp: stream parser context (TCP only)
@@ -57,6 +61,10 @@ struct ovpn_peer {
struct in_addr ipv4;
struct in6_addr ipv6;
} vpn_addrs;
+ struct hlist_node hash_entry_id;
+ struct hlist_nulls_node hash_entry_addr4;
+ struct hlist_nulls_node hash_entry_addr6;
+ struct hlist_nulls_node hash_entry_transp_addr;
struct ovpn_socket __rcu *sock;
struct {
@@ -117,6 +125,8 @@ int ovpn_peer_add(struct ovpn_priv *ovpn, struct ovpn_peer *peer);
int ovpn_peer_del(struct ovpn_peer *peer, enum ovpn_del_peer_reason reason);
void ovpn_peer_release_p2p(struct ovpn_priv *ovpn, struct sock *sk,
enum ovpn_del_peer_reason reason);
+void ovpn_peers_free(struct ovpn_priv *ovpn, struct sock *sock,
+ enum ovpn_del_peer_reason reason);
struct ovpn_peer *ovpn_peer_get_by_transp_addr(struct ovpn_priv *ovpn,
struct sk_buff *skb);
diff --git a/drivers/net/ovpn/udp.c b/drivers/net/ovpn/udp.c
index 81f0ec332fc885d53e5a357512628f245ef3774f..4201ccf00bfb50a768eaf2d6e28a2fd4470e8644 100644
--- a/drivers/net/ovpn/udp.c
+++ b/drivers/net/ovpn/udp.c
@@ -448,9 +448,16 @@ static void ovpn_udp_close(struct sock *sk, long timeout)
ovpn = sock->ovpn;
rcu_read_unlock();
- if (ovpn->mode == OVPN_MODE_P2P)
+ switch (ovpn->mode) {
+ case OVPN_MODE_MP:
+ ovpn_peers_free(ovpn, sk,
+ OVPN_DEL_PEER_REASON_TRANSPORT_DISCONNECT);
+ break;
+ case OVPN_MODE_P2P:
ovpn_peer_release_p2p(ovpn, sk,
OVPN_DEL_PEER_REASON_TRANSPORT_DISCONNECT);
+ break;
+ }
sock->udp_prot->close(sk, timeout);
}
--
2.45.3
