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 <anto...@openvpn.net> --- drivers/net/ovpn/main.c | 50 +++++++++++- drivers/net/ovpn/ovpnstruct.h | 19 +++++ drivers/net/ovpn/peer.c | 173 ++++++++++++++++++++++++++++++++++++++++-- drivers/net/ovpn/peer.h | 9 +++ 4 files changed, 241 insertions(+), 10 deletions(-) diff --git a/drivers/net/ovpn/main.c b/drivers/net/ovpn/main.c index cb5cc3d4b5620f5a1e401e06e52e67c32e57aa78..7604f0970d3c283f8680f6800a125427999bb174 100644 --- a/drivers/net/ovpn/main.c +++ b/drivers/net/ovpn/main.c @@ -50,13 +50,53 @@ static void ovpn_struct_free(struct net_device *net) struct ovpn_struct *ovpn = netdev_priv(net); gro_cells_destroy(&ovpn->gro_cells); + kfree(ovpn->peers); } static int ovpn_net_init(struct net_device *dev) { struct ovpn_struct *ovpn = netdev_priv(dev); + struct in_device *dev_v4; + int i, err; - return gro_cells_init(&ovpn->gro_cells, dev); + err = gro_cells_init(&ovpn->gro_cells, dev); + if (err) + return err; + + if (ovpn->mode == OVPN_MODE_MP) { + dev_v4 = __in_dev_get_rtnl(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(dev), SEND_REDIRECTS) = false; + } + + /* the peer container is fairly large, therefore we dynamically + * allocate it only when needed + */ + ovpn->peers = kzalloc(sizeof(*ovpn->peers), GFP_KERNEL); + if (!ovpn->peers) { + gro_cells_destroy(&ovpn->gro_cells); + return -ENOMEM; + } + + spin_lock_init(&ovpn->peers->lock); + + 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_net_open(struct net_device *dev) @@ -201,8 +241,14 @@ void ovpn_iface_destruct(struct ovpn_struct *ovpn) ovpn->registered = false; - if (ovpn->mode == OVPN_MODE_P2P) + switch (ovpn->mode) { + case OVPN_MODE_P2P: ovpn_peer_release_p2p(ovpn); + break; + default: + ovpn_peers_free(ovpn); + break; + } } static int ovpn_netdev_notifier_call(struct notifier_block *nb, diff --git a/drivers/net/ovpn/ovpnstruct.h b/drivers/net/ovpn/ovpnstruct.h index 65497ce115aa4be719ed03f89135a80b73f9ef9b..4373d1bbc4874dc2f1d1f1697e7b847ec2f486c9 100644 --- a/drivers/net/ovpn/ovpnstruct.h +++ b/drivers/net/ovpn/ovpnstruct.h @@ -14,6 +14,23 @@ #include <net/net_trackers.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) + * @lock: protects writes to peer tables + */ +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]; + + spinlock_t lock; /* protects writes to peer tables */ +}; + /** * struct ovpn_struct - per ovpn interface state * @dev: the actual netdev representing the tunnel @@ -21,6 +38,7 @@ * @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 * @dev_list: entry for the module wide device list * @gro_cells: pointer to the Generic Receive Offload cell @@ -31,6 +49,7 @@ struct ovpn_struct { bool registered; enum ovpn_mode mode; spinlock_t lock; /* protect writing to the ovpn_struct object */ + struct ovpn_peer_collection *peers; struct ovpn_peer __rcu *peer; struct list_head dev_list; struct gro_cells gro_cells; diff --git a/drivers/net/ovpn/peer.c b/drivers/net/ovpn/peer.c index 6d34c56a4a51ce407b20b6175e6140aafc4b4e33..3c6fbf99f696c18d8a2dbe169c7f6f5933fb71ac 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" @@ -65,13 +66,12 @@ struct ovpn_peer *ovpn_peer_new(struct ovpn_struct *ovpn, u32 id) } /** - * ovpn_peer_release - release peer private members - * @peer: the peer to release + * ovpn_peer_release_rcu - release peer private members + * @head: RCU head belonging to peer being released */ -static void ovpn_peer_release(struct ovpn_peer *peer) +static void ovpn_peer_release_rcu(struct rcu_head *head) { - if (peer->sock) - ovpn_socket_put(peer->sock); + struct ovpn_peer *peer = container_of(head, struct ovpn_peer, rcu); ovpn_crypto_state_release(&peer->crypto); ovpn_bind_reset(peer, NULL); @@ -86,9 +86,10 @@ void ovpn_peer_release_kref(struct kref *kref) { struct ovpn_peer *peer = container_of(kref, struct ovpn_peer, refcount); - ovpn_peer_release(peer); + if (peer->sock) + ovpn_socket_put(peer->sock); netdev_put(peer->ovpn->dev, &peer->ovpn->dev_tracker); - kfree_rcu(peer, rcu); + call_rcu(&peer->rcu, ovpn_peer_release_rcu); } /** @@ -309,6 +310,89 @@ bool ovpn_peer_check_by_src(struct ovpn_struct *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_struct *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->peers->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->peers->lock); + return ret; +} + /** * ovpn_peer_add_p2p - add peer to related tables in a P2P instance * @ovpn: the instance to add the peer to @@ -349,6 +433,8 @@ static int ovpn_peer_add_p2p(struct ovpn_struct *ovpn, struct ovpn_peer *peer) int ovpn_peer_add(struct ovpn_struct *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: @@ -356,6 +442,51 @@ int ovpn_peer_add(struct ovpn_struct *ovpn, struct ovpn_peer *peer) } } +/** + * ovpn_peer_unhash - remove peer reference from all hashtables + * @peer: the peer to remove + * @reason: the delete reason to attach to the peer + */ +static void ovpn_peer_unhash(struct ovpn_peer *peer, + enum ovpn_del_peer_reason reason) + __must_hold(&ovpn->peers->lock) +{ + 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); + + ovpn_peer_put(peer); + peer->delete_reason = reason; +} + +/** + * 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) + __must_hold(&peer->ovpn->peers->lock) +{ + struct ovpn_peer *tmp; + int ret = -ENOENT; + + tmp = ovpn_peer_get_by_id(peer->ovpn, peer->id); + if (tmp == peer) { + ovpn_peer_unhash(peer, reason); + ret = 0; + } + + if (tmp) + ovpn_peer_put(tmp); + + return ret; +} + /** * ovpn_peer_del_p2p - delete peer from related tables in a P2P instance * @peer: the peer to delete @@ -411,10 +542,36 @@ void ovpn_peer_release_p2p(struct ovpn_struct *ovpn) */ int ovpn_peer_del(struct ovpn_peer *peer, enum ovpn_del_peer_reason reason) { + int ret; + switch (peer->ovpn->mode) { + case OVPN_MODE_MP: + spin_lock_bh(&peer->ovpn->peers->lock); + ret = ovpn_peer_del_mp(peer, reason); + spin_unlock_bh(&peer->ovpn->peers->lock); + return ret; case OVPN_MODE_P2P: - return ovpn_peer_del_p2p(peer, reason); + spin_lock_bh(&peer->ovpn->lock); + ret = ovpn_peer_del_p2p(peer, reason); + spin_unlock_bh(&peer->ovpn->lock); + return ret; default: return -EOPNOTSUPP; } } + +/** + * ovpn_peers_free - free all peers in the instance + * @ovpn: the instance whose peers should be released + */ +void ovpn_peers_free(struct ovpn_struct *ovpn) +{ + struct hlist_node *tmp; + struct ovpn_peer *peer; + int bkt; + + spin_lock_bh(&ovpn->peers->lock); + hash_for_each_safe(ovpn->peers->by_id, bkt, tmp, peer, hash_entry_id) + ovpn_peer_unhash(peer, OVPN_DEL_PEER_REASON_TEARDOWN); + spin_unlock_bh(&ovpn->peers->lock); +} diff --git a/drivers/net/ovpn/peer.h b/drivers/net/ovpn/peer.h index 86d4696b1529c45025b63d2973fc48ca81ca8f63..9481eb41742ca2a6c88ee0262dd448fd947614fd 100644 --- a/drivers/net/ovpn/peer.h +++ b/drivers/net/ovpn/peer.h @@ -30,6 +30,10 @@ * @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) @@ -62,6 +66,10 @@ 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; /* state of the TCP reading. Needed to keep track of how much of a @@ -126,6 +134,7 @@ struct ovpn_peer *ovpn_peer_new(struct ovpn_struct *ovpn, u32 id); int ovpn_peer_add(struct ovpn_struct *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_struct *ovpn); +void ovpn_peers_free(struct ovpn_struct *ovpn); struct ovpn_peer *ovpn_peer_get_by_transp_addr(struct ovpn_struct *ovpn, struct sk_buff *skb); -- 2.45.2