diff --git a/drivers/net/ovpn/io.c b/drivers/net/ovpn/io.c index 22c555dd962e..37506e8e1a6b 100644 --- a/drivers/net/ovpn/io.c +++ b/drivers/net/ovpn/io.c @@ -105,6 +105,80 @@ static void ovpn_netdev_write(struct ovpn_peer *peer, struct sk_buff *skb) local_bh_enable(); } +/** + * ovpn_mcast_mld_offset - compute the offset to the MLD payload in an IPv6 packet + * @skb: the packet to inspect + * @offsetp: pointer to store the computed offset + * + * MLD packets may be preceded by a Hop-by-Hop options header containing + * the Router Alert option. Calculate the actual payload offset and + * verify that the next header is ICMPv6. + * + * Caller must ensure that the IPv6 header is linearized. + * + * Return: true if the offset was computed successfully, false otherwise + */ +static bool ovpn_mcast_mld_offset(struct sk_buff *skb, unsigned int *offsetp) +{ + unsigned int offset = sizeof(struct ipv6hdr); + u8 nexthdr = ipv6_hdr(skb)->nexthdr; + + if (nexthdr == IPPROTO_HOPOPTS) { + struct ipv6_opt_hdr *hopopt; + + if (!pskb_may_pull(skb, offset + sizeof(*hopopt))) + return false; + + hopopt = (struct ipv6_opt_hdr *)(skb_network_header(skb) + offset); + nexthdr = hopopt->nexthdr; + offset += ipv6_optlen(hopopt); + } + + if (nexthdr != IPPROTO_ICMPV6) + return false; + + *offsetp = offset; + return true; +} + +/** + * ovpn_mcast_is_control - determine whether an skb is multicast control traffic + * @skb: the packet to inspect + * + * Caller must ensure that IP/IPv6 headers are linearized. + * + * Return: true if the skb contains IGMP or MLD control traffic, + * false otherwise + */ +static bool ovpn_mcast_is_control(struct sk_buff *skb) +{ + unsigned int offset; + struct icmp6hdr *ih; + + if (skb->protocol == htons(ETH_P_IP)) + return ip_hdr(skb)->protocol == IPPROTO_IGMP; + + if (skb->protocol != htons(ETH_P_IPV6)) + return false; + + if (!ovpn_mcast_mld_offset(skb, &offset)) + return false; + + if (!pskb_may_pull(skb, offset + sizeof(*ih))) + return false; + + ih = (struct icmp6hdr *)(skb_network_header(skb) + offset); + switch (ih->icmp6_type) { + case ICMPV6_MGM_QUERY: + case ICMPV6_MGM_REPORT: + case ICMPV6_MGM_REDUCTION: + case ICMPV6_MLD2_REPORT: + return true; + } + + return false; +} + void ovpn_decrypt_post(void *data, int ret) { struct ovpn_crypto_key_slot *ks; @@ -183,8 +257,13 @@ void ovpn_decrypt_post(void *data, int ret) } skb->protocol = proto; - /* perform Reverse Path Filtering (RPF) */ - if (unlikely(!ovpn_peer_check_by_src(peer->ovpn, skb, peer))) { + /* perform Reverse Path Filtering (RPF). + * IGMP/MLD protocols may use source addresses + * that differ from the peer's VPN address + * so we bypass RPF in that case + */ + if (unlikely(!ovpn_mcast_is_control(skb) && + !ovpn_peer_check_by_src(peer->ovpn, skb, peer))) { if (skb->protocol == htons(ETH_P_IPV6)) net_dbg_ratelimited("%s: RPF dropped packet from peer %u, src: %pI6c\n", netdev_name(peer->ovpn->dev), @@ -351,6 +430,70 @@ static void ovpn_send(struct ovpn_priv *ovpn, struct sk_buff *skb, ovpn_peer_put(peer); } +static void ovpn_bcast_work(struct work_struct *work) +{ + struct ovpn_priv *ovpn = container_of_const(work, struct ovpn_priv, bcast.work); + struct sk_buff *skb, *to_send; + struct llist_head peer_list; + struct llist_node *node, *n; + struct ovpn_peer *peer; + int bkt; + + while ((skb = skb_dequeue(&ovpn->bcast.queue))) { + skb_mark_not_on_list(skb); + init_llist_head(&peer_list); + + rcu_read_lock(); + hash_for_each_rcu(ovpn->peers->by_id, bkt, peer, hash_entry_id) { + if (likely(ovpn_peer_hold(peer))) + llist_add(&peer->bcast_entry, &peer_list); + } + rcu_read_unlock(); + + if (unlikely(llist_empty(&peer_list))) { + dev_dstats_tx_dropped(ovpn->dev); + skb_tx_error(skb); + kfree_skb(skb); + continue; + } + + llist_for_each_safe(node, n, peer_list.first) { + peer = llist_entry(node, struct ovpn_peer, bcast_entry); + + if (likely(n)) + to_send = skb_clone(skb, GFP_KERNEL); + else + to_send = skb; + + if (likely(to_send)) { + ovpn_peer_stats_increment_tx(&peer->vpn_stats, skb->len); + ovpn_send(ovpn, to_send, peer); + continue; + } + dev_dstats_tx_dropped(ovpn->dev); + ovpn_peer_put(peer); + } + } +} + +int ovpn_bcast_init(struct ovpn_priv *ovpn) +{ + skb_queue_head_init(&ovpn->bcast.queue); + INIT_WORK(&ovpn->bcast.work, ovpn_bcast_work); + ovpn->bcast.wq = alloc_ordered_workqueue("ovpn-bcast-%s", WQ_MEM_RECLAIM, + netdev_name(ovpn->dev)); + if (!ovpn->bcast.wq) + return -ENOMEM; + + return 0; +} + +void ovpn_bcast_exit(struct ovpn_priv *ovpn) +{ + cancel_work_sync(&ovpn->bcast.work); + skb_queue_purge(&ovpn->bcast.queue); +} + /* Send user data to the network */ netdev_tx_t ovpn_net_xmit(struct sk_buff *skb, struct net_device *dev) @@ -362,6 +505,7 @@ netdev_tx_t ovpn_net_xmit(struct sk_buff *skb, struct net_device *dev) struct ovpn_peer *peer; __be16 proto; int ret; + bool bcast = false; /* reset netfilter state */ nf_reset_ct(skb); @@ -372,8 +516,8 @@ netdev_tx_t ovpn_net_xmit(struct sk_buff *skb, struct net_device *dev) goto drop_no_peer; /* retrieve peer serving the destination IP of this packet */ - peer = ovpn_peer_get_by_dst(ovpn, skb); - if (unlikely(!peer)) { + peer = ovpn_peer_get_by_dst(ovpn, skb, &bcast); + if (unlikely(!peer && !bcast)) { switch (skb->protocol) { case htons(ETH_P_IP): net_dbg_ratelimited("%s: no peer to send data to dst=%pI4\n", @@ -418,11 +562,31 @@ netdev_tx_t ovpn_net_xmit(struct sk_buff *skb, struct net_device *dev) continue; } + if (unlikely(bcast)) { + spin_lock_bh(&ovpn->bcast.queue.lock); + if (unlikely(skb_queue_len(&ovpn->bcast.queue) >= OVPN_BCAST_MAX_QLEN)) { + spin_unlock_bh(&ovpn->bcast.queue.lock); + dev_dstats_tx_dropped(ovpn->dev); + skb_tx_error(curr); + kfree_skb(curr); + continue; + } + __skb_queue_tail(&ovpn->bcast.queue, curr); + spin_unlock_bh(&ovpn->bcast.queue.lock); + continue; + } + /* only count what we actually send */ tx_bytes += curr->len; __skb_queue_tail(&skb_list, curr); } + if (unlikely(bcast)) { + if (!skb_queue_empty(&ovpn->bcast.queue)) + queue_work(ovpn->bcast.wq, &ovpn->bcast.work); + return NETDEV_TX_OK; + } + /* no segments survived: don't jump to 'drop' because we already * incremented the counter for each failure in the loop */ @@ -438,7 +602,8 @@ netdev_tx_t ovpn_net_xmit(struct sk_buff *skb, struct net_device *dev) return NETDEV_TX_OK; drop: - ovpn_peer_put(peer); + if (peer) + ovpn_peer_put(peer); drop_no_peer: dev_dstats_tx_dropped(ovpn->dev); skb_tx_error(skb); diff --git a/drivers/net/ovpn/io.h b/drivers/net/ovpn/io.h index db9e10f9077c..9519b9a08030 100644 --- a/drivers/net/ovpn/io.h +++ b/drivers/net/ovpn/io.h @@ -31,4 +31,7 @@ void ovpn_xmit_special(struct ovpn_peer *peer, const void *data, void ovpn_encrypt_post(void *data, int ret); void ovpn_decrypt_post(void *data, int ret); +int ovpn_bcast_init(struct ovpn_priv *ovpn); +void ovpn_bcast_exit(struct ovpn_priv *ovpn); + #endif /* _NET_OVPN_OVPN_H_ */ diff --git a/drivers/net/ovpn/main.c b/drivers/net/ovpn/main.c index 2e0420febda0..0537b3d22cf6 100644 --- a/drivers/net/ovpn/main.c +++ b/drivers/net/ovpn/main.c @@ -30,6 +30,8 @@ static void ovpn_priv_free(struct net_device *net) { struct ovpn_priv *ovpn = netdev_priv(net); + if (ovpn->bcast.wq) + destroy_workqueue(ovpn->bcast.wq); kfree(ovpn->peers); } @@ -155,7 +157,7 @@ static void ovpn_setup(struct net_device *dev) dev->max_mtu = IP_MAX_MTU - OVPN_HEAD_ROOM; dev->type = ARPHRD_NONE; - dev->flags = IFF_POINTOPOINT | IFF_NOARP; + dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST | IFF_BROADCAST; dev->priv_flags |= IFF_NO_QUEUE; /* when routing packets to a LAN behind a client, we rely on the * route entry that originally brought the packet into ovpn, so @@ -192,6 +194,9 @@ static int ovpn_newlink(struct net_device *dev, spin_lock_init(&ovpn->lock); INIT_DELAYED_WORK(&ovpn->keepalive_work, ovpn_peer_keepalive_work); + if (ovpn_bcast_init(ovpn)) + return -ENOMEM; + /* Set carrier explicitly after registration, this way state is * clearly defined. * @@ -212,6 +217,7 @@ static void ovpn_dellink(struct net_device *dev, struct list_head *head) { struct ovpn_priv *ovpn = netdev_priv(dev); + ovpn_bcast_exit(ovpn); cancel_delayed_work_sync(&ovpn->keepalive_work); ovpn_peers_free(ovpn, NULL, OVPN_DEL_PEER_REASON_TEARDOWN); unregister_netdevice_queue(dev, head); diff --git a/drivers/net/ovpn/ovpnpriv.h b/drivers/net/ovpn/ovpnpriv.h index 5898f6adada7..5c86b239527b 100644 --- a/drivers/net/ovpn/ovpnpriv.h +++ b/drivers/net/ovpn/ovpnpriv.h @@ -32,6 +32,14 @@ struct ovpn_peer_collection { struct hlist_nulls_head by_transp_addr[1 << 12]; }; +#define OVPN_BCAST_MAX_QLEN 1000 + +struct ovpn_bcast { + struct sk_buff_head queue; + struct work_struct work; + struct workqueue_struct *wq; +}; + /** * struct ovpn_priv - per ovpn interface state * @dev: the actual netdev representing the tunnel @@ -41,6 +49,7 @@ struct ovpn_peer_collection { * @peer: in P2P mode, this is the only remote peer * @gro_cells: pointer to the Generic Receive Offload cell * @keepalive_work: struct used to schedule keepalive periodic job + * @bcast: struct used to queue and transmit broadcast messages */ struct ovpn_priv { struct net_device *dev; @@ -50,6 +59,7 @@ struct ovpn_priv { struct ovpn_peer __rcu *peer; struct gro_cells gro_cells; struct delayed_work keepalive_work; + struct ovpn_bcast bcast; }; #endif /* _NET_OVPN_OVPNSTRUCT_H_ */ diff --git a/drivers/net/ovpn/peer.c b/drivers/net/ovpn/peer.c index c02dfab51a6e..d1616e04c0ad 100644 --- a/drivers/net/ovpn/peer.c +++ b/drivers/net/ovpn/peer.c @@ -722,6 +722,8 @@ static void ovpn_peer_remove(struct ovpn_peer *peer, * ovpn_peer_get_by_dst - Lookup peer to send skb to * @ovpn: the private data representing the current VPN session * @skb: the skb to extract the destination address from + * @bcast: a pointer to a bool. It's set to true if the packet is a + * broadcast or a multicast. * * This function takes a tunnel packet and looks up the peer to send it to * after encapsulation. The skb is expected to be the in-tunnel packet, without @@ -731,10 +733,11 @@ static void ovpn_peer_remove(struct ovpn_peer *peer, * * Return: the peer if found or NULL otherwise. */ -struct ovpn_peer *ovpn_peer_get_by_dst(struct ovpn_priv *ovpn, - struct sk_buff *skb) +struct ovpn_peer *ovpn_peer_get_by_dst(struct ovpn_priv *ovpn, struct sk_buff *skb, + bool *bcast) { struct ovpn_peer *peer = NULL; + unsigned int addr_type; struct in6_addr addr6; __be32 addr4; @@ -755,11 +758,23 @@ struct ovpn_peer *ovpn_peer_get_by_dst(struct ovpn_priv *ovpn, case htons(ETH_P_IP): addr4 = ovpn_nexthop_from_skb4(skb); peer = ovpn_peer_get_by_vpn_addr4(ovpn, addr4); + + if (peer) + break; + + addr_type = inet_dev_addr_type(dev_net(ovpn->dev), ovpn->dev, addr4); + if (addr_type == RTN_MULTICAST || addr_type == RTN_BROADCAST) + *bcast = true; break; case htons(ETH_P_IPV6): addr6 = ovpn_nexthop_from_skb6(skb); peer = ovpn_peer_get_by_vpn_addr6(ovpn, &addr6); - break; + + if (peer) + break; + + if (ipv6_addr_is_multicast(&addr6)) + *bcast = true; } if (unlikely(peer && !ovpn_peer_hold(peer))) diff --git a/drivers/net/ovpn/peer.h b/drivers/net/ovpn/peer.h index 328401570cba..2b5027d0ad01 100644 --- a/drivers/net/ovpn/peer.h +++ b/drivers/net/ovpn/peer.h @@ -59,6 +59,7 @@ * @refcount: reference counter * @rcu: used to free peer in an RCU safe way * @release_entry: entry for the socket release list + * @bcast_entry: entry for the broadcast peers list * @keepalive_work: used to schedule keepalive sending */ struct ovpn_peer { @@ -113,6 +114,7 @@ struct ovpn_peer { struct kref refcount; struct rcu_head rcu; struct llist_node release_entry; + struct llist_node bcast_entry; struct work_struct keepalive_work; }; @@ -148,8 +150,8 @@ void ovpn_peers_free(struct ovpn_priv *ovpn, struct sock *sock, struct ovpn_peer *ovpn_peer_get_by_transp_addr(struct ovpn_priv *ovpn, struct sk_buff *skb); 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); +struct ovpn_peer *ovpn_peer_get_by_dst(struct ovpn_priv *ovpn, struct sk_buff *skb, + bool *bcast); void ovpn_peer_hash_vpn_ip(struct ovpn_peer *peer); bool ovpn_peer_check_by_src(struct ovpn_priv *ovpn, struct sk_buff *skb, struct ovpn_peer *peer);