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@openvpn.net --- drivers/net/ovpn/main.c | 67 +++++++++++++++++- drivers/net/ovpn/ovpnstruct.h | 16 +++++ drivers/net/ovpn/peer.c | 158 ++++++++++++++++++++++++++++++++++++++++-- drivers/net/ovpn/peer.h | 9 +++ 4 files changed, 241 insertions(+), 9 deletions(-)
diff --git a/drivers/net/ovpn/main.c b/drivers/net/ovpn/main.c index 0f291c540f8e05dbfbc15d835d6c71e796114b03..17cdd5a732132de71b854fe0b76c284bd9f3d918 100644 --- a/drivers/net/ovpn/main.c +++ b/drivers/net/ovpn/main.c @@ -24,6 +24,13 @@ #include "proto.h" #include "tcp.h"
+static void ovpn_priv_free(struct net_device *net) +{ + struct ovpn_priv *ovpn = netdev_priv(net); + + kfree(ovpn->peers); +} + static int ovpn_net_init(struct net_device *dev) { struct ovpn_priv *ovpn = netdev_priv(dev); @@ -99,6 +106,8 @@ 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; @@ -120,12 +129,50 @@ static void ovpn_setup(struct net_device *dev) SET_NETDEV_DEVTYPE(dev, &ovpn_type); }
+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_addr[i], i); + INIT_HLIST_NULLS_HEAD(&ovpn->peers->by_transp_addr[i], i); + } + + return 0; +} + static int ovpn_newlink(struct net *src_net, struct net_device *dev, struct nlattr *tb[], struct nlattr *data[], struct netlink_ext_ack *extack) { struct ovpn_priv *ovpn = netdev_priv(dev); enum ovpn_mode mode = OVPN_MODE_P2P; + int err;
if (data && data[IFLA_OVPN_MODE]) { mode = nla_get_u8(data[IFLA_OVPN_MODE]); @@ -136,6 +183,10 @@ static int ovpn_newlink(struct net *src_net, struct net_device *dev, ovpn->mode = mode; spin_lock_init(&ovpn->lock);
+ err = ovpn_mp_alloc(ovpn); + if (err < 0) + return err; + /* turn carrier explicitly off after registration, this way state is * clearly defined */ @@ -195,14 +246,26 @@ 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, OVPN_DEL_PEER_REASON_TEARDOWN); + break; + case OVPN_MODE_MP: + ovpn_peers_free(ovpn, OVPN_DEL_PEER_REASON_TEARDOWN); + break; + } break; case NETDEV_DOWN: - if (ovpn->mode == OVPN_MODE_P2P) + switch (ovpn->mode) { + case OVPN_MODE_P2P: ovpn_peer_release_p2p(ovpn, OVPN_DEL_PEER_REASON_ADMINDOWN); + break; + case OVPN_MODE_MP: + ovpn_peers_free(ovpn, OVPN_DEL_PEER_REASON_ADMINDOWN); + break; + } break; case NETDEV_POST_INIT: case NETDEV_GOING_DOWN: diff --git a/drivers/net/ovpn/ovpnstruct.h b/drivers/net/ovpn/ovpnstruct.h index 7af1f21bb5a76acb34269693bcba5ce8f832137f..bca13e8e4439c2f217ae17896f114347e8aefd06 100644 --- a/drivers/net/ovpn/ovpnstruct.h +++ b/drivers/net/ovpn/ovpnstruct.h @@ -16,6 +16,20 @@ #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_addr: table of peers indexed by VPN IP 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_addr[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 @@ -23,6 +37,7 @@ * @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 */ @@ -32,6 +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 d730aba685101b59e126d2f0bd51debd65fbc037..956104183f40c7c44f4fbbb8f2a4c48748d6b56f 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 "ovpnstruct.h" #include "bind.h" @@ -265,7 +266,15 @@ struct ovpn_peer *ovpn_peer_get_by_id(struct ovpn_priv *ovpn, u32 peer_id) static void ovpn_peer_remove(struct ovpn_peer *peer, enum ovpn_del_peer_reason reason) { + lockdep_assert_held(&peer->ovpn->lock); + switch (peer->ovpn->mode) { + case OVPN_MODE_MP: + 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: RCU_INIT_POINTER(peer->ovpn->peer, NULL); /* in P2P mode the carrier is switched off when the peer is @@ -273,8 +282,6 @@ static void ovpn_peer_remove(struct ovpn_peer *peer, */ netif_carrier_off(peer->ovpn->dev); break; - default: - return; }
peer->delete_reason = reason; @@ -340,6 +347,89 @@ 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_addr, + &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_addr, + &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 @@ -380,11 +470,40 @@ 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) + * + * 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 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); + ret = 0; + } + + if (tmp) + ovpn_peer_put(tmp); + + return ret; }
/** @@ -440,10 +559,35 @@ void ovpn_peer_release_p2p(struct ovpn_priv *ovpn, */ int ovpn_peer_del(struct ovpn_peer *peer, enum ovpn_del_peer_reason reason) { + int ret = -EOPNOTSUPP; + + spin_lock_bh(&peer->ovpn->lock); switch (peer->ovpn->mode) { + case OVPN_MODE_MP: + ret = ovpn_peer_del_mp(peer, reason); + break; case OVPN_MODE_P2P: - return ovpn_peer_del_p2p(peer, reason); - default: - return -EOPNOTSUPP; + ret = ovpn_peer_del_p2p(peer, reason); + break; } + spin_unlock_bh(&peer->ovpn->lock); + return ret; +} + +/** + * ovpn_peers_free - free all peers in the instance + * @ovpn: the instance whose peers should be released + * @reason: the reason for releasing all peers + */ +void ovpn_peers_free(struct ovpn_priv *ovpn, + enum ovpn_del_peer_reason reason) +{ + struct hlist_node *tmp; + struct ovpn_peer *peer; + int bkt; + + spin_lock_bh(&ovpn->lock); + hash_for_each_safe(ovpn->peers->by_id, bkt, tmp, peer, hash_entry_id) + ovpn_peer_remove(peer, reason); + spin_unlock_bh(&ovpn->lock); } diff --git a/drivers/net/ovpn/peer.h b/drivers/net/ovpn/peer.h index 370657baf775e1cf6a88e5a117e4d599196f944d..1aa5be02d17f411484062e07c5c49f88bb9f0c98 100644 --- a/drivers/net/ovpn/peer.h +++ b/drivers/net/ovpn/peer.h @@ -23,6 +23,10 @@ * @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) @@ -55,6 +59,10 @@ 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 *sock;
struct { @@ -116,6 +124,7 @@ 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, enum ovpn_del_peer_reason reason); +void ovpn_peers_free(struct ovpn_priv *ovpn, enum ovpn_del_peer_reason reason);
struct ovpn_peer *ovpn_peer_get_by_transp_addr(struct ovpn_priv *ovpn, struct sk_buff *skb);