diff --git a/Documentation/netlink/specs/ovpn.yaml b/Documentation/netlink/specs/ovpn.yaml index b0c782e59a32..ac50d1d7c00a 100644 --- a/Documentation/netlink/specs/ovpn.yaml +++ b/Documentation/netlink/specs/ovpn.yaml @@ -118,12 +118,16 @@ attribute-sets: doc: >- The number of seconds after which a keep alive message is sent to the peer + checks: + max: 86400 - name: keepalive-timeout type: u32 doc: >- The number of seconds from the last activity after which the peer is assumed dead + checks: + max: 86400 - name: del-reason type: u32 diff --git a/drivers/net/ovpn/main.c b/drivers/net/ovpn/main.c index 9993c1dfe471..168cfe9b59a9 100644 --- a/drivers/net/ovpn/main.c +++ b/drivers/net/ovpn/main.c @@ -35,25 +35,11 @@ static void ovpn_priv_free(struct net_device *net) 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 */ @@ -97,9 +83,38 @@ static void ovpn_net_uninit(struct net_device *dev) gro_cells_destroy(&ovpn->gro_cells); } +static int ovpn_net_open(struct net_device *dev) +{ + struct ovpn_priv *ovpn = netdev_priv(dev); + struct in_device *dev_v4; + + /* the IPv4 in_device (and thus its config) is recreated whenever the + * interface is moved to a new netns, so redirects must be disabled on + * every bring-up rather than once at creation time, otherwise the + * setting is silently lost after such a move + */ + 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; + } + } + + return 0; +} + static const struct net_device_ops ovpn_netdev_ops = { .ndo_init = ovpn_net_init, .ndo_uninit = ovpn_net_uninit, + .ndo_open = ovpn_net_open, .ndo_start_xmit = ovpn_net_xmit, }; @@ -183,6 +198,7 @@ static int ovpn_newlink(struct net_device *dev, struct ovpn_priv *ovpn = netdev_priv(dev); struct nlattr **data = params->data; enum ovpn_mode mode = OVPN_MODE_P2P; + int ret; if (data && data[IFLA_OVPN_MODE]) { mode = nla_get_u8(data[IFLA_OVPN_MODE]); @@ -207,7 +223,17 @@ static int ovpn_newlink(struct net_device *dev, else netif_carrier_off(dev); - return register_netdevice(dev); + ret = register_netdevice(dev); + if (ret < 0) + return ret; + + return 0; +} + +static size_t ovpn_get_size(const struct net_device *dev) +{ + /* IFLA_OVPN_MODE */ + return nla_total_size(sizeof(u8)); } static int ovpn_fill_info(struct sk_buff *skb, const struct net_device *dev) @@ -228,13 +254,17 @@ static struct rtnl_link_ops ovpn_link_ops = { .policy = ovpn_policy, .maxtype = IFLA_OVPN_MAX, .newlink = ovpn_newlink, + .get_size = ovpn_get_size, .fill_info = ovpn_fill_info, }; static int __init ovpn_init(void) { - int err = rtnl_link_register(&ovpn_link_ops); + int err; + ovpn_tcp_init(); + + err = rtnl_link_register(&ovpn_link_ops); if (err) { pr_err("ovpn: can't register rtnl link ops: %d\n", err); return err; @@ -246,8 +276,6 @@ static int __init ovpn_init(void) goto unreg_rtnl; } - ovpn_tcp_init(); - return 0; unreg_rtnl: diff --git a/drivers/net/ovpn/netlink-gen.c b/drivers/net/ovpn/netlink-gen.c index 2147cec7c2c5..92d2fdc17c2e 100644 --- a/drivers/net/ovpn/netlink-gen.c +++ b/drivers/net/ovpn/netlink-gen.c @@ -16,6 +16,14 @@ static const struct netlink_range_validation ovpn_a_peer_id_range = { .max = 16777215ULL, }; +static const struct netlink_range_validation ovpn_a_peer_keepalive_interval_range = { + .max = 86400ULL, +}; + +static const struct netlink_range_validation ovpn_a_peer_keepalive_timeout_range = { + .max = 86400ULL, +}; + static const struct netlink_range_validation ovpn_a_peer_tx_id_range = { .max = 16777215ULL, }; @@ -68,8 +76,8 @@ const struct nla_policy ovpn_peer_nl_policy[OVPN_A_PEER_TX_ID + 1] = { [OVPN_A_PEER_LOCAL_IPV4] = { .type = NLA_BE32, }, [OVPN_A_PEER_LOCAL_IPV6] = NLA_POLICY_EXACT_LEN(16), [OVPN_A_PEER_LOCAL_PORT] = NLA_POLICY_MIN(NLA_BE16, 1), - [OVPN_A_PEER_KEEPALIVE_INTERVAL] = { .type = NLA_U32, }, - [OVPN_A_PEER_KEEPALIVE_TIMEOUT] = { .type = NLA_U32, }, + [OVPN_A_PEER_KEEPALIVE_INTERVAL] = NLA_POLICY_FULL_RANGE(NLA_U32, &ovpn_a_peer_keepalive_interval_range), + [OVPN_A_PEER_KEEPALIVE_TIMEOUT] = NLA_POLICY_FULL_RANGE(NLA_U32, &ovpn_a_peer_keepalive_timeout_range), [OVPN_A_PEER_DEL_REASON] = NLA_POLICY_MAX(NLA_U32, 4), [OVPN_A_PEER_VPN_RX_BYTES] = { .type = NLA_UINT, }, [OVPN_A_PEER_VPN_TX_BYTES] = { .type = NLA_UINT, }, @@ -97,8 +105,8 @@ const struct nla_policy ovpn_peer_new_input_nl_policy[OVPN_A_PEER_TX_ID + 1] = { [OVPN_A_PEER_VPN_IPV6] = NLA_POLICY_EXACT_LEN(16), [OVPN_A_PEER_LOCAL_IPV4] = { .type = NLA_BE32, }, [OVPN_A_PEER_LOCAL_IPV6] = NLA_POLICY_EXACT_LEN(16), - [OVPN_A_PEER_KEEPALIVE_INTERVAL] = { .type = NLA_U32, }, - [OVPN_A_PEER_KEEPALIVE_TIMEOUT] = { .type = NLA_U32, }, + [OVPN_A_PEER_KEEPALIVE_INTERVAL] = NLA_POLICY_FULL_RANGE(NLA_U32, &ovpn_a_peer_keepalive_interval_range), + [OVPN_A_PEER_KEEPALIVE_TIMEOUT] = NLA_POLICY_FULL_RANGE(NLA_U32, &ovpn_a_peer_keepalive_timeout_range), [OVPN_A_PEER_TX_ID] = NLA_POLICY_FULL_RANGE(NLA_U32, &ovpn_a_peer_tx_id_range), }; @@ -112,8 +120,8 @@ const struct nla_policy ovpn_peer_set_input_nl_policy[OVPN_A_PEER_TX_ID + 1] = { [OVPN_A_PEER_VPN_IPV6] = NLA_POLICY_EXACT_LEN(16), [OVPN_A_PEER_LOCAL_IPV4] = { .type = NLA_BE32, }, [OVPN_A_PEER_LOCAL_IPV6] = NLA_POLICY_EXACT_LEN(16), - [OVPN_A_PEER_KEEPALIVE_INTERVAL] = { .type = NLA_U32, }, - [OVPN_A_PEER_KEEPALIVE_TIMEOUT] = { .type = NLA_U32, }, + [OVPN_A_PEER_KEEPALIVE_INTERVAL] = NLA_POLICY_FULL_RANGE(NLA_U32, &ovpn_a_peer_keepalive_interval_range), + [OVPN_A_PEER_KEEPALIVE_TIMEOUT] = NLA_POLICY_FULL_RANGE(NLA_U32, &ovpn_a_peer_keepalive_timeout_range), [OVPN_A_PEER_TX_ID] = NLA_POLICY_FULL_RANGE(NLA_U32, &ovpn_a_peer_tx_id_range), }; diff --git a/drivers/net/ovpn/netlink.c b/drivers/net/ovpn/netlink.c index 4c66c1ec497e..4dad85294198 100644 --- a/drivers/net/ovpn/netlink.c +++ b/drivers/net/ovpn/netlink.c @@ -534,6 +534,12 @@ int ovpn_nl_peer_set_doit(struct sk_buff *skb, struct genl_info *info) */ if (ret > 0) ovpn_peer_hash_vpn_ip(peer); + /* if the remote endpoint was updated, the by_transp_addr hash bucket + * also needs to be refreshed, otherwise incoming packets from the new + * remote address would fail the lockless lookup + */ + if (attrs[OVPN_A_PEER_REMOTE_IPV4] || attrs[OVPN_A_PEER_REMOTE_IPV6]) + ovpn_peer_hash_transp_addr(peer); spin_unlock_bh(&ovpn->lock); ovpn_peer_put(peer); diff --git a/drivers/net/ovpn/peer.c b/drivers/net/ovpn/peer.c index a21d02ac715e..b0519f9840d8 100644 --- a/drivers/net/ovpn/peer.c +++ b/drivers/net/ovpn/peer.c @@ -189,6 +189,9 @@ int ovpn_peer_reset_sockaddr(struct ovpn_peer *peer, &(*__tbl1)[ovpn_get_hash_slot(*__tbl1, _key, _key_len)];\ }) +static void __ovpn_peer_hash_transp_addr(struct ovpn_peer *peer, + const struct ovpn_bind *bind); + /** * ovpn_peer_endpoints_update - update remote or local endpoint for peer * @peer: peer to update the remote endpoint for @@ -196,7 +199,6 @@ int ovpn_peer_reset_sockaddr(struct ovpn_peer *peer, */ void ovpn_peer_endpoints_update(struct ovpn_peer *peer, struct sk_buff *skb) { - struct hlist_nulls_head *nhead; struct sockaddr_storage ss; struct sockaddr_in6 *sa6; bool reset_cache = false; @@ -220,9 +222,16 @@ void ovpn_peer_endpoints_update(struct ovpn_peer *peer, struct sk_buff *skb) */ local_ip = &ip_hdr(skb)->daddr; sa = (struct sockaddr_in *)&ss; - sa->sin_family = AF_INET; - sa->sin_addr.s_addr = ip_hdr(skb)->saddr; - sa->sin_port = udp_hdr(skb)->source; + /* use a designated initializer so the sin_zero padding + * is zeroed (it ends up in the by_transp_addr hash key) + * without memset-ing the whole sockaddr_storage on the + * RX fast path + */ + *sa = (struct sockaddr_in) { + .sin_family = AF_INET, + .sin_addr.s_addr = ip_hdr(skb)->saddr, + .sin_port = udp_hdr(skb)->source, + }; salen = sizeof(*sa); reset_cache = true; break; @@ -248,11 +257,19 @@ void ovpn_peer_endpoints_update(struct ovpn_peer *peer, struct sk_buff *skb) */ local_ip = &ipv6_hdr(skb)->daddr; sa6 = (struct sockaddr_in6 *)&ss; - sa6->sin6_family = AF_INET6; - sa6->sin6_addr = ipv6_hdr(skb)->saddr; - sa6->sin6_port = udp_hdr(skb)->source; - sa6->sin6_scope_id = ipv6_iface_scope_id(&ipv6_hdr(skb)->saddr, - skb->skb_iif); + /* use a designated initializer so the sin6_flowinfo + * padding is zeroed (it ends up in the by_transp_addr + * hash key) without memset-ing the whole + * sockaddr_storage on the RX fast path + */ + *sa6 = (struct sockaddr_in6) { + .sin6_family = AF_INET6, + .sin6_addr = ipv6_hdr(skb)->saddr, + .sin6_port = udp_hdr(skb)->source, + .sin6_scope_id = + ipv6_iface_scope_id(&ipv6_hdr(skb)->saddr, + skb->skb_iif), + }; salen = sizeof(*sa6); reset_cache = true; break; @@ -295,42 +312,25 @@ void ovpn_peer_endpoints_update(struct ovpn_peer *peer, struct sk_buff *skb) ovpn_nl_peer_float_notify(peer, &ss); /* rehashing is required only in MP mode as P2P has one peer - * only and thus there is no hashtable + * only and thus there is no hashtable. + * + * This function may be invoked concurrently, so re-read peer->bind + * under the proper locks and rehash against its current value. */ - if (peer->ovpn->mode == OVPN_MODE_MP) { - spin_lock_bh(&peer->ovpn->lock); - spin_lock_bh(&peer->lock); - bind = rcu_dereference_protected(peer->bind, - lockdep_is_held(&peer->lock)); - if (unlikely(!bind)) { - spin_unlock_bh(&peer->lock); - spin_unlock_bh(&peer->ovpn->lock); - return; - } + if (peer->ovpn->mode != OVPN_MODE_MP) + return; - /* This function may be invoked concurrently, therefore another - * float may have happened in parallel: perform rehashing - * using the peer->bind->remote directly as key - */ - - switch (bind->remote.in4.sin_family) { - case AF_INET: - salen = sizeof(*sa); - break; - case AF_INET6: - salen = sizeof(*sa6); - break; - } - - /* remove old hashing */ - hlist_nulls_del_init_rcu(&peer->hash_entry_transp_addr); - /* re-add with new transport address */ - nhead = ovpn_get_hash_head(peer->ovpn->peers->by_transp_addr, - &bind->remote, salen); - hlist_nulls_add_head_rcu(&peer->hash_entry_transp_addr, nhead); - spin_unlock_bh(&peer->lock); - spin_unlock_bh(&peer->ovpn->lock); - } + /* This function may be invoked concurrently, therefore another + * float may have happened in parallel: re-acquire the locks and + * rehash using the peer->bind->remote directly as key + */ + spin_lock_bh(&peer->ovpn->lock); + spin_lock_bh(&peer->lock); + bind = rcu_dereference_protected(peer->bind, + lockdep_is_held(&peer->lock)); + __ovpn_peer_hash_transp_addr(peer, bind); + spin_unlock_bh(&peer->lock); + spin_unlock_bh(&peer->ovpn->lock); return; unlock: spin_unlock_bh(&peer->lock); @@ -896,6 +896,83 @@ bool ovpn_peer_check_by_src(struct ovpn_priv *ovpn, struct sk_buff *skb, return match; } +/* Move @peer to the by_transp_addr bucket matching its current bind. + * + * Caller must hold both peer->ovpn->lock and peer->lock, and must have + * already dereferenced a valid (non-NULL) peer->bind, passed in as @bind. + */ +static void __ovpn_peer_hash_transp_addr(struct ovpn_peer *peer, + const struct ovpn_bind *bind) +{ + struct sockaddr_storage sa = {}; + struct hlist_nulls_head *nhead; + struct sockaddr_in6 *sa6; + struct sockaddr_in *sa4; + size_t salen; + + lockdep_assert_held(&peer->ovpn->lock); + lockdep_assert_held(&peer->lock); + + if (WARN_ON_ONCE(!bind)) + return; + + /* peer may have been concurrently removed between the caller's + * initial lookup and our acquisition of ovpn->lock; skip the + * rehash so we don't re-insert a removed peer + */ + if (unlikely(hlist_unhashed(&peer->hash_entry_id))) + return; + + /* Build the hash key from the transport identity only + * (family/address/port), matching ovpn_peer_add_mp() and the lookup + * in ovpn_peer_get_by_transp_addr(). Hashing bind->remote directly + * would fold in sin6_scope_id (set on the float path but never by the + * lookup), scattering the peer into a bucket lookups cannot reach. + */ + 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: + return; + } + + /* remove old hashing (no-op if entry is not currently linked) */ + hlist_nulls_del_init_rcu(&peer->hash_entry_transp_addr); + /* re-add with current transport address */ + nhead = ovpn_get_hash_head(peer->ovpn->peers->by_transp_addr, &sa, + salen); + hlist_nulls_add_head_rcu(&peer->hash_entry_transp_addr, nhead); +} + +void ovpn_peer_hash_transp_addr(struct ovpn_peer *peer) +{ + struct ovpn_bind *bind; + + lockdep_assert_held(&peer->ovpn->lock); + + /* rehashing makes sense only in multipeer mode */ + if (peer->ovpn->mode != OVPN_MODE_MP) + return; + + spin_lock_bh(&peer->lock); + bind = rcu_dereference_protected(peer->bind, + lockdep_is_held(&peer->lock)); + __ovpn_peer_hash_transp_addr(peer, bind); + spin_unlock_bh(&peer->lock); +} + void ovpn_peer_hash_vpn_ip(struct ovpn_peer *peer) { struct hlist_nulls_head *nhead; @@ -906,6 +983,13 @@ void ovpn_peer_hash_vpn_ip(struct ovpn_peer *peer) if (peer->ovpn->mode != OVPN_MODE_MP) return; + /* peer may have been concurrently removed between the caller's + * initial lookup and our acquisition of ovpn->lock; skip the + * rehash so we don't re-insert a removed peer + */ + if (hlist_unhashed(&peer->hash_entry_id)) + return; + if (peer->vpn_addrs.ipv4.s_addr != htonl(INADDR_ANY)) { /* remove potential old hashing */ hlist_nulls_del_init_rcu(&peer->hash_entry_addr4); @@ -1165,7 +1249,7 @@ static void ovpn_peer_release_p2p(struct ovpn_priv *ovpn, struct sock *sk, } if (sk) { - ovpn_sock = rcu_access_pointer(peer->sock); + ovpn_sock = rcu_dereference_bh(peer->sock); if (!ovpn_sock || ovpn_sock->sk != sk) { spin_unlock_bh(&ovpn->lock); return; diff --git a/drivers/net/ovpn/peer.h b/drivers/net/ovpn/peer.h index 86c8cffada6d..dfa5c0037e02 100644 --- a/drivers/net/ovpn/peer.h +++ b/drivers/net/ovpn/peer.h @@ -150,6 +150,7 @@ struct ovpn_peer *ovpn_peer_get_by_id(struct ovpn_priv *ovpn, u32 peer_id); struct ovpn_peer *ovpn_peer_get_by_dst(struct ovpn_priv *ovpn, struct sk_buff *skb); void ovpn_peer_hash_vpn_ip(struct ovpn_peer *peer); +void ovpn_peer_hash_transp_addr(struct ovpn_peer *peer); bool ovpn_peer_check_by_src(struct ovpn_priv *ovpn, struct sk_buff *skb, struct ovpn_peer *peer); diff --git a/drivers/net/ovpn/socket.c b/drivers/net/ovpn/socket.c index 517caa64a4fe..6cbeb2caaeec 100644 --- a/drivers/net/ovpn/socket.c +++ b/drivers/net/ovpn/socket.c @@ -162,6 +162,15 @@ struct ovpn_socket *ovpn_socket_new(struct socket *sock, struct ovpn_peer *peer) rcu_read_lock(); ovpn_sock = rcu_dereference_sk_user_data(sk); if (ovpn_sock) { + /* something else filled the sk_user_data without + * setting the encap_type. Reject the socket. + */ + if (!type) { + ovpn_sock = ERR_PTR(-EBUSY); + rcu_read_unlock(); + goto sock_release; + } + /* socket owned by another ovpn instance, we can't use it */ if (ovpn_sock->ovpn != peer->ovpn) { ovpn_sock = ERR_PTR(-EBUSY);