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 | 55 +++++++++++++- drivers/net/ovpn/ovpnstruct.h | 19 +++++ drivers/net/ovpn/peer.c | 166 ++++++++++++++++++++++++++++++++++++++++-- drivers/net/ovpn/peer.h | 9 +++ 4 files changed, 243 insertions(+), 6 deletions(-)
diff --git a/drivers/net/ovpn/main.c b/drivers/net/ovpn/main.c index 0488e395eb27d3dba1efc8ff39c023e0ac4a38dd..c7453127ab640d7268c1ce919a87cc5419fac9ee 100644 --- a/drivers/net/ovpn/main.c +++ b/drivers/net/ovpn/main.c @@ -30,6 +30,9 @@
static void ovpn_struct_free(struct net_device *net) { + struct ovpn_struct *ovpn = netdev_priv(net); + + kfree(ovpn->peers); }
static int ovpn_net_init(struct net_device *dev) @@ -133,12 +136,52 @@ static void ovpn_setup(struct net_device *dev) SET_NETDEV_DEVTYPE(dev, &ovpn_type); }
+static int ovpn_mp_alloc(struct ovpn_struct *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; + + 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_newlink(struct net *src_net, struct net_device *dev, struct nlattr *tb[], struct nlattr *data[], struct netlink_ext_ack *extack) { struct ovpn_struct *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]); @@ -149,6 +192,10 @@ 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 */ @@ -197,8 +244,14 @@ 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); + break; + case OVPN_MODE_MP: + ovpn_peers_free(ovpn); + 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 4a48fc048890ab1cda78bc104fe3034b4a49d226..12ed5e22c2108c9f143d1984048eb40c887cac63 100644 --- a/drivers/net/ovpn/ovpnstruct.h +++ b/drivers/net/ovpn/ovpnstruct.h @@ -15,6 +15,23 @@ #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) + * @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 @@ -22,6 +39,7 @@ * @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 @@ -32,6 +50,7 @@ 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 5025bfb759d6a5f31e3f2ec094fe561fbdb9f451..73ef509faab9701192a45ffe78a46dbbbeab01c2 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" @@ -64,17 +65,16 @@ struct ovpn_peer *ovpn_peer_new(struct ovpn_struct *ovpn, u32 id) return peer; }
-/** - * ovpn_peer_release - release peer private members - * @peer: the peer to release - */ static void ovpn_peer_release(struct ovpn_peer *peer) { if (peer->sock) ovpn_socket_put(peer->sock);
ovpn_crypto_state_release(&peer->crypto); + spin_lock_bh(&peer->lock); ovpn_bind_reset(peer, NULL); + spin_unlock_bh(&peer->lock); + dst_cache_destroy(&peer->dst_cache); netdev_put(peer->ovpn->dev, &peer->ovpn->dev_tracker); kfree_rcu(peer, rcu); @@ -309,6 +309,89 @@ 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 +432,8 @@ 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 +441,51 @@ 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 +541,36 @@ 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 2b7fa9510e362ef3646157bb0d361bab19ddaa99..942b90c84a0fb9e6fbb96f6df7f7842a9f738caf 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;
/* state of the TCP reading. Needed to keep track of how much of a @@ -119,6 +127,7 @@ 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);