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 | 64 +++++++++++++-- drivers/net/ovpn/ovpnpriv.h | 19 +++++ drivers/net/ovpn/peer.c | 189 ++++++++++++++++++++++++++++++++++++++++++-- drivers/net/ovpn/peer.h | 12 ++- drivers/net/ovpn/udp.c | 4 +- 5 files changed, 272 insertions(+), 16 deletions(-)
diff --git a/drivers/net/ovpn/main.c b/drivers/net/ovpn/main.c index 948c36129914ca45fb7118b821c7c60359e600f6..1b3d5b6c839999202743a15f38029251bf102f45 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);
- return gro_cells_init(&ovpn->gro_cells, dev); + if (err < 0) + return err; + + 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) @@ -91,6 +146,8 @@ 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; @@ -187,10 +244,7 @@ static int ovpn_netdev_notifier_call(struct notifier_block *nb,
netif_carrier_off(dev); ovpn->registered = false; - - if (ovpn->mode == OVPN_MODE_P2P) - ovpn_peer_release_p2p(ovpn, NULL, - OVPN_DEL_PEER_REASON_TEARDOWN); + ovpn_peers_free(ovpn, NULL, OVPN_DEL_PEER_REASON_TEARDOWN); 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 0fe5333c6b8104913526dacc4d7d2260b97f62aa..bed2e591c000c4efecdcd92db484e590f97f9f7f 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; }
/** @@ -446,6 +571,9 @@ 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; @@ -463,8 +591,8 @@ int ovpn_peer_del(struct ovpn_peer *peer, enum ovpn_del_peer_reason reason) * @sk: if not NULL, release peer only if it's using this specific socket * @reason: the reason for releasing the peer */ -void ovpn_peer_release_p2p(struct ovpn_priv *ovpn, struct sock *sk, - enum ovpn_del_peer_reason reason) +static void ovpn_peer_release_p2p(struct ovpn_priv *ovpn, struct sock *sk, + enum ovpn_del_peer_reason reason) { struct ovpn_socket *ovpn_sock; LLIST_HEAD(release_list); @@ -490,3 +618,52 @@ void ovpn_peer_release_p2p(struct ovpn_priv *ovpn, struct sock *sk, ovpn_peer_remove(peer, reason, &release_list); unlock_ovpn(ovpn, &release_list); } + +static void ovpn_peers_release_mp(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; + int bkt; + + spin_lock_bh(&ovpn->lock); + hash_for_each_safe(ovpn->peers->by_id, bkt, tmp, peer, hash_entry_id) { + bool remove = true; + + /* if a socket was passed as argument, skip all peers except + * those using it + */ + if (sk) { + rcu_read_lock(); + ovpn_sock = rcu_dereference(peer->sock); + remove = ovpn_sock && ovpn_sock->sock->sk == sk; + rcu_read_unlock(); + } + + if (remove) + ovpn_peer_remove(peer, reason, &release_list); + } + unlock_ovpn(ovpn, &release_list); +} + +/** + * 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) +{ + switch (ovpn->mode) { + case OVPN_MODE_P2P: + ovpn_peer_release_p2p(ovpn, sk, reason); + break; + case OVPN_MODE_MP: + ovpn_peers_release_mp(ovpn, sk, reason); + break; + } +} diff --git a/drivers/net/ovpn/peer.h b/drivers/net/ovpn/peer.h index 5ef00ba6523d7bf6608adb86fa7c7029f559ce2a..2a3b1031f58dd73925a9ed74aed7ac4cb7b8c4c5 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 { @@ -117,8 +125,8 @@ static inline void ovpn_peer_put(struct ovpn_peer *peer) struct ovpn_peer *ovpn_peer_new(struct ovpn_priv *ovpn, u32 id); 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 6f4b51089033a8d806eede0a63f62b239197af0b..3367feb5cf725e41d01e140e838072e93f7fd4ef 100644 --- a/drivers/net/ovpn/udp.c +++ b/drivers/net/ovpn/udp.c @@ -370,9 +370,7 @@ static void ovpn_udp_encap_destroy(struct sock *sk) ovpn = sock->ovpn; rcu_read_unlock();
- if (ovpn->mode == OVPN_MODE_P2P) - ovpn_peer_release_p2p(ovpn, sk, - OVPN_DEL_PEER_REASON_TRANSPORT_DISCONNECT); + ovpn_peers_free(ovpn, sk, OVPN_DEL_PEER_REASON_TRANSPORT_DISCONNECT); }
/**