diff options
Diffstat (limited to '')
| -rw-r--r-- | net/l2tp/Kconfig | 110 | ||||
| -rw-r--r-- | net/l2tp/Makefile | 18 | ||||
| -rw-r--r-- | net/l2tp/l2tp_core.c | 1723 | ||||
| -rw-r--r-- | net/l2tp/l2tp_core.h | 346 | ||||
| -rw-r--r-- | net/l2tp/l2tp_debugfs.c | 348 | ||||
| -rw-r--r-- | net/l2tp/l2tp_eth.c | 370 | ||||
| -rw-r--r-- | net/l2tp/l2tp_ip.c | 684 | ||||
| -rw-r--r-- | net/l2tp/l2tp_ip6.c | 813 | ||||
| -rw-r--r-- | net/l2tp/l2tp_netlink.c | 1048 | ||||
| -rw-r--r-- | net/l2tp/l2tp_ppp.c | 1743 | ||||
| -rw-r--r-- | net/l2tp/trace.h | 211 |
11 files changed, 7414 insertions, 0 deletions
diff --git a/net/l2tp/Kconfig b/net/l2tp/Kconfig new file mode 100644 index 000000000..b7856748e --- /dev/null +++ b/net/l2tp/Kconfig @@ -0,0 +1,110 @@ +# SPDX-License-Identifier: GPL-2.0-only +# +# Layer Two Tunneling Protocol (L2TP) +# + +menuconfig L2TP + tristate "Layer Two Tunneling Protocol (L2TP)" + depends on (IPV6 || IPV6=n) + depends on INET + select NET_UDP_TUNNEL + help + Layer Two Tunneling Protocol + + From RFC 2661 <http://www.ietf.org/rfc/rfc2661.txt>. + + L2TP facilitates the tunneling of packets across an + intervening network in a way that is as transparent as + possible to both end-users and applications. + + L2TP is often used to tunnel PPP traffic over IP + tunnels. One IP tunnel may carry thousands of individual PPP + connections. L2TP is also used as a VPN protocol, popular + with home workers to connect to their offices. + + L2TPv3 allows other protocols as well as PPP to be carried + over L2TP tunnels. L2TPv3 is defined in RFC 3931 + <http://www.ietf.org/rfc/rfc3931.txt>. + + The kernel component handles only L2TP data packets: a + userland daemon handles L2TP the control protocol (tunnel + and session setup). One such daemon is OpenL2TP + (http://openl2tp.org/). + + If you don't need L2TP, say N. To compile all L2TP code as + modules, choose M here. + +config L2TP_DEBUGFS + tristate "L2TP debugfs support" + depends on L2TP && DEBUG_FS + help + Support for l2tp directory in debugfs filesystem. This may be + used to dump internal state of the l2tp drivers for problem + analysis. + + If unsure, say 'Y'. + + To compile this driver as a module, choose M here. The module + will be called l2tp_debugfs. + +config L2TP_V3 + bool "L2TPv3 support" + depends on L2TP + help + Layer Two Tunneling Protocol Version 3 + + From RFC 3931 <http://www.ietf.org/rfc/rfc3931.txt>. + + The Layer Two Tunneling Protocol (L2TP) provides a dynamic + mechanism for tunneling Layer 2 (L2) "circuits" across a + packet-oriented data network (e.g., over IP). L2TP, as + originally defined in RFC 2661, is a standard method for + tunneling Point-to-Point Protocol (PPP) [RFC1661] sessions. + L2TP has since been adopted for tunneling a number of other + L2 protocols, including ATM, Frame Relay, HDLC and even raw + ethernet frames. + + If you are connecting to L2TPv3 equipment, or you want to + tunnel raw ethernet frames using L2TP, say Y here. If + unsure, say N. + +config L2TP_IP + tristate "L2TP IP encapsulation for L2TPv3" + depends on L2TP_V3 + help + Support for L2TP-over-IP socket family. + + The L2TPv3 protocol defines two possible encapsulations for + L2TP frames, namely UDP and plain IP (without UDP). This + driver provides a new L2TPIP socket family with which + userspace L2TPv3 daemons may create L2TP/IP tunnel sockets + when UDP encapsulation is not required. When L2TP is carried + in IP packets, it used IP protocol number 115, so this port + must be enabled in firewalls. + + To compile this driver as a module, choose M here. The module + will be called l2tp_ip. + +config L2TP_ETH + tristate "L2TP ethernet pseudowire support for L2TPv3" + depends on L2TP_V3 + help + Support for carrying raw ethernet frames over L2TPv3. + + From RFC 4719 <http://www.ietf.org/rfc/rfc4719.txt>. + + The Layer 2 Tunneling Protocol, Version 3 (L2TPv3) can be + used as a control protocol and for data encapsulation to set + up Pseudowires for transporting layer 2 Packet Data Units + across an IP network [RFC3931]. + + This driver provides an ethernet virtual interface for each + L2TP ethernet pseudowire instance. Standard Linux tools may + be used to assign an IP address to the local virtual + interface, or add the interface to a bridge. + + If you are using L2TPv3, you will almost certainly want to + enable this option. + + To compile this driver as a module, choose M here. The module + will be called l2tp_eth. diff --git a/net/l2tp/Makefile b/net/l2tp/Makefile new file mode 100644 index 000000000..cf8f27071 --- /dev/null +++ b/net/l2tp/Makefile @@ -0,0 +1,18 @@ +# SPDX-License-Identifier: GPL-2.0 +# +# Makefile for the L2TP. +# + +obj-$(CONFIG_L2TP) += l2tp_core.o + +CFLAGS_l2tp_core.o += -I$(src) + +# Build l2tp as modules if L2TP is M +obj-$(subst y,$(CONFIG_L2TP),$(CONFIG_PPPOL2TP)) += l2tp_ppp.o +obj-$(subst y,$(CONFIG_L2TP),$(CONFIG_L2TP_IP)) += l2tp_ip.o +obj-$(subst y,$(CONFIG_L2TP),$(CONFIG_L2TP_V3)) += l2tp_netlink.o +obj-$(subst y,$(CONFIG_L2TP),$(CONFIG_L2TP_ETH)) += l2tp_eth.o +obj-$(subst y,$(CONFIG_L2TP),$(CONFIG_L2TP_DEBUGFS)) += l2tp_debugfs.o +ifneq ($(CONFIG_IPV6),) +obj-$(subst y,$(CONFIG_L2TP),$(CONFIG_L2TP_IP)) += l2tp_ip6.o +endif diff --git a/net/l2tp/l2tp_core.c b/net/l2tp/l2tp_core.c new file mode 100644 index 000000000..8d21ff25f --- /dev/null +++ b/net/l2tp/l2tp_core.c @@ -0,0 +1,1723 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* L2TP core. + * + * Copyright (c) 2008,2009,2010 Katalix Systems Ltd + * + * This file contains some code of the original L2TPv2 pppol2tp + * driver, which has the following copyright: + * + * Authors: Martijn van Oosterhout <kleptog@svana.org> + * James Chapman (jchapman@katalix.com) + * Contributors: + * Michal Ostrowski <mostrows@speakeasy.net> + * Arnaldo Carvalho de Melo <acme@xconectiva.com.br> + * David S. Miller (davem@redhat.com) + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/module.h> +#include <linux/string.h> +#include <linux/list.h> +#include <linux/rculist.h> +#include <linux/uaccess.h> + +#include <linux/kernel.h> +#include <linux/spinlock.h> +#include <linux/kthread.h> +#include <linux/sched.h> +#include <linux/slab.h> +#include <linux/errno.h> +#include <linux/jiffies.h> + +#include <linux/netdevice.h> +#include <linux/net.h> +#include <linux/inetdevice.h> +#include <linux/skbuff.h> +#include <linux/init.h> +#include <linux/in.h> +#include <linux/ip.h> +#include <linux/udp.h> +#include <linux/l2tp.h> +#include <linux/hash.h> +#include <linux/sort.h> +#include <linux/file.h> +#include <linux/nsproxy.h> +#include <net/net_namespace.h> +#include <net/netns/generic.h> +#include <net/dst.h> +#include <net/ip.h> +#include <net/udp.h> +#include <net/udp_tunnel.h> +#include <net/inet_common.h> +#include <net/xfrm.h> +#include <net/protocol.h> +#include <net/inet6_connection_sock.h> +#include <net/inet_ecn.h> +#include <net/ip6_route.h> +#include <net/ip6_checksum.h> + +#include <asm/byteorder.h> +#include <linux/atomic.h> + +#include "l2tp_core.h" +#include "trace.h" + +#define CREATE_TRACE_POINTS +#include "trace.h" + +#define L2TP_DRV_VERSION "V2.0" + +/* L2TP header constants */ +#define L2TP_HDRFLAG_T 0x8000 +#define L2TP_HDRFLAG_L 0x4000 +#define L2TP_HDRFLAG_S 0x0800 +#define L2TP_HDRFLAG_O 0x0200 +#define L2TP_HDRFLAG_P 0x0100 + +#define L2TP_HDR_VER_MASK 0x000F +#define L2TP_HDR_VER_2 0x0002 +#define L2TP_HDR_VER_3 0x0003 + +/* L2TPv3 default L2-specific sublayer */ +#define L2TP_SLFLAG_S 0x40000000 +#define L2TP_SL_SEQ_MASK 0x00ffffff + +#define L2TP_HDR_SIZE_MAX 14 + +/* Default trace flags */ +#define L2TP_DEFAULT_DEBUG_FLAGS 0 + +/* Private data stored for received packets in the skb. + */ +struct l2tp_skb_cb { + u32 ns; + u16 has_seq; + u16 length; + unsigned long expires; +}; + +#define L2TP_SKB_CB(skb) ((struct l2tp_skb_cb *)&(skb)->cb[sizeof(struct inet_skb_parm)]) + +static struct workqueue_struct *l2tp_wq; + +/* per-net private data for this module */ +static unsigned int l2tp_net_id; +struct l2tp_net { + /* Lock for write access to l2tp_tunnel_idr */ + spinlock_t l2tp_tunnel_idr_lock; + struct idr l2tp_tunnel_idr; + struct hlist_head l2tp_session_hlist[L2TP_HASH_SIZE_2]; + /* Lock for write access to l2tp_session_hlist */ + spinlock_t l2tp_session_hlist_lock; +}; + +#if IS_ENABLED(CONFIG_IPV6) +static bool l2tp_sk_is_v6(struct sock *sk) +{ + return sk->sk_family == PF_INET6 && + !ipv6_addr_v4mapped(&sk->sk_v6_daddr); +} +#endif + +static inline struct l2tp_net *l2tp_pernet(const struct net *net) +{ + return net_generic(net, l2tp_net_id); +} + +/* Session hash global list for L2TPv3. + * The session_id SHOULD be random according to RFC3931, but several + * L2TP implementations use incrementing session_ids. So we do a real + * hash on the session_id, rather than a simple bitmask. + */ +static inline struct hlist_head * +l2tp_session_id_hash_2(struct l2tp_net *pn, u32 session_id) +{ + return &pn->l2tp_session_hlist[hash_32(session_id, L2TP_HASH_BITS_2)]; +} + +/* Session hash list. + * The session_id SHOULD be random according to RFC2661, but several + * L2TP implementations (Cisco and Microsoft) use incrementing + * session_ids. So we do a real hash on the session_id, rather than a + * simple bitmask. + */ +static inline struct hlist_head * +l2tp_session_id_hash(struct l2tp_tunnel *tunnel, u32 session_id) +{ + return &tunnel->session_hlist[hash_32(session_id, L2TP_HASH_BITS)]; +} + +static void l2tp_tunnel_free(struct l2tp_tunnel *tunnel) +{ + trace_free_tunnel(tunnel); + sock_put(tunnel->sock); + /* the tunnel is freed in the socket destructor */ +} + +static void l2tp_session_free(struct l2tp_session *session) +{ + trace_free_session(session); + if (session->tunnel) + l2tp_tunnel_dec_refcount(session->tunnel); + kfree(session); +} + +struct l2tp_tunnel *l2tp_sk_to_tunnel(struct sock *sk) +{ + struct l2tp_tunnel *tunnel = sk->sk_user_data; + + if (tunnel) + if (WARN_ON(tunnel->magic != L2TP_TUNNEL_MAGIC)) + return NULL; + + return tunnel; +} +EXPORT_SYMBOL_GPL(l2tp_sk_to_tunnel); + +void l2tp_tunnel_inc_refcount(struct l2tp_tunnel *tunnel) +{ + refcount_inc(&tunnel->ref_count); +} +EXPORT_SYMBOL_GPL(l2tp_tunnel_inc_refcount); + +void l2tp_tunnel_dec_refcount(struct l2tp_tunnel *tunnel) +{ + if (refcount_dec_and_test(&tunnel->ref_count)) + l2tp_tunnel_free(tunnel); +} +EXPORT_SYMBOL_GPL(l2tp_tunnel_dec_refcount); + +void l2tp_session_inc_refcount(struct l2tp_session *session) +{ + refcount_inc(&session->ref_count); +} +EXPORT_SYMBOL_GPL(l2tp_session_inc_refcount); + +void l2tp_session_dec_refcount(struct l2tp_session *session) +{ + if (refcount_dec_and_test(&session->ref_count)) + l2tp_session_free(session); +} +EXPORT_SYMBOL_GPL(l2tp_session_dec_refcount); + +/* Lookup a tunnel. A new reference is held on the returned tunnel. */ +struct l2tp_tunnel *l2tp_tunnel_get(const struct net *net, u32 tunnel_id) +{ + const struct l2tp_net *pn = l2tp_pernet(net); + struct l2tp_tunnel *tunnel; + + rcu_read_lock_bh(); + tunnel = idr_find(&pn->l2tp_tunnel_idr, tunnel_id); + if (tunnel && refcount_inc_not_zero(&tunnel->ref_count)) { + rcu_read_unlock_bh(); + return tunnel; + } + rcu_read_unlock_bh(); + + return NULL; +} +EXPORT_SYMBOL_GPL(l2tp_tunnel_get); + +struct l2tp_tunnel *l2tp_tunnel_get_nth(const struct net *net, int nth) +{ + struct l2tp_net *pn = l2tp_pernet(net); + unsigned long tunnel_id, tmp; + struct l2tp_tunnel *tunnel; + int count = 0; + + rcu_read_lock_bh(); + idr_for_each_entry_ul(&pn->l2tp_tunnel_idr, tunnel, tmp, tunnel_id) { + if (tunnel && ++count > nth && + refcount_inc_not_zero(&tunnel->ref_count)) { + rcu_read_unlock_bh(); + return tunnel; + } + } + rcu_read_unlock_bh(); + + return NULL; +} +EXPORT_SYMBOL_GPL(l2tp_tunnel_get_nth); + +struct l2tp_session *l2tp_tunnel_get_session(struct l2tp_tunnel *tunnel, + u32 session_id) +{ + struct hlist_head *session_list; + struct l2tp_session *session; + + session_list = l2tp_session_id_hash(tunnel, session_id); + + rcu_read_lock_bh(); + hlist_for_each_entry_rcu(session, session_list, hlist) + if (session->session_id == session_id) { + l2tp_session_inc_refcount(session); + rcu_read_unlock_bh(); + + return session; + } + rcu_read_unlock_bh(); + + return NULL; +} +EXPORT_SYMBOL_GPL(l2tp_tunnel_get_session); + +struct l2tp_session *l2tp_session_get(const struct net *net, u32 session_id) +{ + struct hlist_head *session_list; + struct l2tp_session *session; + + session_list = l2tp_session_id_hash_2(l2tp_pernet(net), session_id); + + rcu_read_lock_bh(); + hlist_for_each_entry_rcu(session, session_list, global_hlist) + if (session->session_id == session_id) { + l2tp_session_inc_refcount(session); + rcu_read_unlock_bh(); + + return session; + } + rcu_read_unlock_bh(); + + return NULL; +} +EXPORT_SYMBOL_GPL(l2tp_session_get); + +struct l2tp_session *l2tp_session_get_nth(struct l2tp_tunnel *tunnel, int nth) +{ + int hash; + struct l2tp_session *session; + int count = 0; + + rcu_read_lock_bh(); + for (hash = 0; hash < L2TP_HASH_SIZE; hash++) { + hlist_for_each_entry_rcu(session, &tunnel->session_hlist[hash], hlist) { + if (++count > nth) { + l2tp_session_inc_refcount(session); + rcu_read_unlock_bh(); + return session; + } + } + } + + rcu_read_unlock_bh(); + + return NULL; +} +EXPORT_SYMBOL_GPL(l2tp_session_get_nth); + +/* Lookup a session by interface name. + * This is very inefficient but is only used by management interfaces. + */ +struct l2tp_session *l2tp_session_get_by_ifname(const struct net *net, + const char *ifname) +{ + struct l2tp_net *pn = l2tp_pernet(net); + int hash; + struct l2tp_session *session; + + rcu_read_lock_bh(); + for (hash = 0; hash < L2TP_HASH_SIZE_2; hash++) { + hlist_for_each_entry_rcu(session, &pn->l2tp_session_hlist[hash], global_hlist) { + if (!strcmp(session->ifname, ifname)) { + l2tp_session_inc_refcount(session); + rcu_read_unlock_bh(); + + return session; + } + } + } + + rcu_read_unlock_bh(); + + return NULL; +} +EXPORT_SYMBOL_GPL(l2tp_session_get_by_ifname); + +int l2tp_session_register(struct l2tp_session *session, + struct l2tp_tunnel *tunnel) +{ + struct l2tp_session *session_walk; + struct hlist_head *g_head; + struct hlist_head *head; + struct l2tp_net *pn; + int err; + + head = l2tp_session_id_hash(tunnel, session->session_id); + + spin_lock_bh(&tunnel->hlist_lock); + if (!tunnel->acpt_newsess) { + err = -ENODEV; + goto err_tlock; + } + + hlist_for_each_entry(session_walk, head, hlist) + if (session_walk->session_id == session->session_id) { + err = -EEXIST; + goto err_tlock; + } + + if (tunnel->version == L2TP_HDR_VER_3) { + pn = l2tp_pernet(tunnel->l2tp_net); + g_head = l2tp_session_id_hash_2(pn, session->session_id); + + spin_lock_bh(&pn->l2tp_session_hlist_lock); + + /* IP encap expects session IDs to be globally unique, while + * UDP encap doesn't. + */ + hlist_for_each_entry(session_walk, g_head, global_hlist) + if (session_walk->session_id == session->session_id && + (session_walk->tunnel->encap == L2TP_ENCAPTYPE_IP || + tunnel->encap == L2TP_ENCAPTYPE_IP)) { + err = -EEXIST; + goto err_tlock_pnlock; + } + + l2tp_tunnel_inc_refcount(tunnel); + hlist_add_head_rcu(&session->global_hlist, g_head); + + spin_unlock_bh(&pn->l2tp_session_hlist_lock); + } else { + l2tp_tunnel_inc_refcount(tunnel); + } + + hlist_add_head_rcu(&session->hlist, head); + spin_unlock_bh(&tunnel->hlist_lock); + + trace_register_session(session); + + return 0; + +err_tlock_pnlock: + spin_unlock_bh(&pn->l2tp_session_hlist_lock); +err_tlock: + spin_unlock_bh(&tunnel->hlist_lock); + + return err; +} +EXPORT_SYMBOL_GPL(l2tp_session_register); + +/***************************************************************************** + * Receive data handling + *****************************************************************************/ + +/* Queue a skb in order. We come here only if the skb has an L2TP sequence + * number. + */ +static void l2tp_recv_queue_skb(struct l2tp_session *session, struct sk_buff *skb) +{ + struct sk_buff *skbp; + struct sk_buff *tmp; + u32 ns = L2TP_SKB_CB(skb)->ns; + + spin_lock_bh(&session->reorder_q.lock); + skb_queue_walk_safe(&session->reorder_q, skbp, tmp) { + if (L2TP_SKB_CB(skbp)->ns > ns) { + __skb_queue_before(&session->reorder_q, skbp, skb); + atomic_long_inc(&session->stats.rx_oos_packets); + goto out; + } + } + + __skb_queue_tail(&session->reorder_q, skb); + +out: + spin_unlock_bh(&session->reorder_q.lock); +} + +/* Dequeue a single skb. + */ +static void l2tp_recv_dequeue_skb(struct l2tp_session *session, struct sk_buff *skb) +{ + struct l2tp_tunnel *tunnel = session->tunnel; + int length = L2TP_SKB_CB(skb)->length; + + /* We're about to requeue the skb, so return resources + * to its current owner (a socket receive buffer). + */ + skb_orphan(skb); + + atomic_long_inc(&tunnel->stats.rx_packets); + atomic_long_add(length, &tunnel->stats.rx_bytes); + atomic_long_inc(&session->stats.rx_packets); + atomic_long_add(length, &session->stats.rx_bytes); + + if (L2TP_SKB_CB(skb)->has_seq) { + /* Bump our Nr */ + session->nr++; + session->nr &= session->nr_max; + trace_session_seqnum_update(session); + } + + /* call private receive handler */ + if (session->recv_skb) + (*session->recv_skb)(session, skb, L2TP_SKB_CB(skb)->length); + else + kfree_skb(skb); +} + +/* Dequeue skbs from the session's reorder_q, subject to packet order. + * Skbs that have been in the queue for too long are simply discarded. + */ +static void l2tp_recv_dequeue(struct l2tp_session *session) +{ + struct sk_buff *skb; + struct sk_buff *tmp; + + /* If the pkt at the head of the queue has the nr that we + * expect to send up next, dequeue it and any other + * in-sequence packets behind it. + */ +start: + spin_lock_bh(&session->reorder_q.lock); + skb_queue_walk_safe(&session->reorder_q, skb, tmp) { + struct l2tp_skb_cb *cb = L2TP_SKB_CB(skb); + + /* If the packet has been pending on the queue for too long, discard it */ + if (time_after(jiffies, cb->expires)) { + atomic_long_inc(&session->stats.rx_seq_discards); + atomic_long_inc(&session->stats.rx_errors); + trace_session_pkt_expired(session, cb->ns); + session->reorder_skip = 1; + __skb_unlink(skb, &session->reorder_q); + kfree_skb(skb); + continue; + } + + if (cb->has_seq) { + if (session->reorder_skip) { + session->reorder_skip = 0; + session->nr = cb->ns; + trace_session_seqnum_reset(session); + } + if (cb->ns != session->nr) + goto out; + } + __skb_unlink(skb, &session->reorder_q); + + /* Process the skb. We release the queue lock while we + * do so to let other contexts process the queue. + */ + spin_unlock_bh(&session->reorder_q.lock); + l2tp_recv_dequeue_skb(session, skb); + goto start; + } + +out: + spin_unlock_bh(&session->reorder_q.lock); +} + +static int l2tp_seq_check_rx_window(struct l2tp_session *session, u32 nr) +{ + u32 nws; + + if (nr >= session->nr) + nws = nr - session->nr; + else + nws = (session->nr_max + 1) - (session->nr - nr); + + return nws < session->nr_window_size; +} + +/* If packet has sequence numbers, queue it if acceptable. Returns 0 if + * acceptable, else non-zero. + */ +static int l2tp_recv_data_seq(struct l2tp_session *session, struct sk_buff *skb) +{ + struct l2tp_skb_cb *cb = L2TP_SKB_CB(skb); + + if (!l2tp_seq_check_rx_window(session, cb->ns)) { + /* Packet sequence number is outside allowed window. + * Discard it. + */ + trace_session_pkt_outside_rx_window(session, cb->ns); + goto discard; + } + + if (session->reorder_timeout != 0) { + /* Packet reordering enabled. Add skb to session's + * reorder queue, in order of ns. + */ + l2tp_recv_queue_skb(session, skb); + goto out; + } + + /* Packet reordering disabled. Discard out-of-sequence packets, while + * tracking the number if in-sequence packets after the first OOS packet + * is seen. After nr_oos_count_max in-sequence packets, reset the + * sequence number to re-enable packet reception. + */ + if (cb->ns == session->nr) { + skb_queue_tail(&session->reorder_q, skb); + } else { + u32 nr_oos = cb->ns; + u32 nr_next = (session->nr_oos + 1) & session->nr_max; + + if (nr_oos == nr_next) + session->nr_oos_count++; + else + session->nr_oos_count = 0; + + session->nr_oos = nr_oos; + if (session->nr_oos_count > session->nr_oos_count_max) { + session->reorder_skip = 1; + } + if (!session->reorder_skip) { + atomic_long_inc(&session->stats.rx_seq_discards); + trace_session_pkt_oos(session, cb->ns); + goto discard; + } + skb_queue_tail(&session->reorder_q, skb); + } + +out: + return 0; + +discard: + return 1; +} + +/* Do receive processing of L2TP data frames. We handle both L2TPv2 + * and L2TPv3 data frames here. + * + * L2TPv2 Data Message Header + * + * 0 1 2 3 + * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * |T|L|x|x|S|x|O|P|x|x|x|x| Ver | Length (opt) | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | Tunnel ID | Session ID | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | Ns (opt) | Nr (opt) | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | Offset Size (opt) | Offset pad... (opt) + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * + * Data frames are marked by T=0. All other fields are the same as + * those in L2TP control frames. + * + * L2TPv3 Data Message Header + * + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | L2TP Session Header | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | L2-Specific Sublayer | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | Tunnel Payload ... + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * + * L2TPv3 Session Header Over IP + * + * 0 1 2 3 + * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | Session ID | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | Cookie (optional, maximum 64 bits)... + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * + * L2TPv3 L2-Specific Sublayer Format + * + * 0 1 2 3 + * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * |x|S|x|x|x|x|x|x| Sequence Number | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * + * Cookie value and sublayer format are negotiated with the peer when + * the session is set up. Unlike L2TPv2, we do not need to parse the + * packet header to determine if optional fields are present. + * + * Caller must already have parsed the frame and determined that it is + * a data (not control) frame before coming here. Fields up to the + * session-id have already been parsed and ptr points to the data + * after the session-id. + */ +void l2tp_recv_common(struct l2tp_session *session, struct sk_buff *skb, + unsigned char *ptr, unsigned char *optr, u16 hdrflags, + int length) +{ + struct l2tp_tunnel *tunnel = session->tunnel; + int offset; + + /* Parse and check optional cookie */ + if (session->peer_cookie_len > 0) { + if (memcmp(ptr, &session->peer_cookie[0], session->peer_cookie_len)) { + pr_debug_ratelimited("%s: cookie mismatch (%u/%u). Discarding.\n", + tunnel->name, tunnel->tunnel_id, + session->session_id); + atomic_long_inc(&session->stats.rx_cookie_discards); + goto discard; + } + ptr += session->peer_cookie_len; + } + + /* Handle the optional sequence numbers. Sequence numbers are + * in different places for L2TPv2 and L2TPv3. + * + * If we are the LAC, enable/disable sequence numbers under + * the control of the LNS. If no sequence numbers present but + * we were expecting them, discard frame. + */ + L2TP_SKB_CB(skb)->has_seq = 0; + if (tunnel->version == L2TP_HDR_VER_2) { + if (hdrflags & L2TP_HDRFLAG_S) { + /* Store L2TP info in the skb */ + L2TP_SKB_CB(skb)->ns = ntohs(*(__be16 *)ptr); + L2TP_SKB_CB(skb)->has_seq = 1; + ptr += 2; + /* Skip past nr in the header */ + ptr += 2; + + } + } else if (session->l2specific_type == L2TP_L2SPECTYPE_DEFAULT) { + u32 l2h = ntohl(*(__be32 *)ptr); + + if (l2h & 0x40000000) { + /* Store L2TP info in the skb */ + L2TP_SKB_CB(skb)->ns = l2h & 0x00ffffff; + L2TP_SKB_CB(skb)->has_seq = 1; + } + ptr += 4; + } + + if (L2TP_SKB_CB(skb)->has_seq) { + /* Received a packet with sequence numbers. If we're the LAC, + * check if we sre sending sequence numbers and if not, + * configure it so. + */ + if (!session->lns_mode && !session->send_seq) { + trace_session_seqnum_lns_enable(session); + session->send_seq = 1; + l2tp_session_set_header_len(session, tunnel->version); + } + } else { + /* No sequence numbers. + * If user has configured mandatory sequence numbers, discard. + */ + if (session->recv_seq) { + pr_debug_ratelimited("%s: recv data has no seq numbers when required. Discarding.\n", + session->name); + atomic_long_inc(&session->stats.rx_seq_discards); + goto discard; + } + + /* If we're the LAC and we're sending sequence numbers, the + * LNS has requested that we no longer send sequence numbers. + * If we're the LNS and we're sending sequence numbers, the + * LAC is broken. Discard the frame. + */ + if (!session->lns_mode && session->send_seq) { + trace_session_seqnum_lns_disable(session); + session->send_seq = 0; + l2tp_session_set_header_len(session, tunnel->version); + } else if (session->send_seq) { + pr_debug_ratelimited("%s: recv data has no seq numbers when required. Discarding.\n", + session->name); + atomic_long_inc(&session->stats.rx_seq_discards); + goto discard; + } + } + + /* Session data offset is defined only for L2TPv2 and is + * indicated by an optional 16-bit value in the header. + */ + if (tunnel->version == L2TP_HDR_VER_2) { + /* If offset bit set, skip it. */ + if (hdrflags & L2TP_HDRFLAG_O) { + offset = ntohs(*(__be16 *)ptr); + ptr += 2 + offset; + } + } + + offset = ptr - optr; + if (!pskb_may_pull(skb, offset)) + goto discard; + + __skb_pull(skb, offset); + + /* Prepare skb for adding to the session's reorder_q. Hold + * packets for max reorder_timeout or 1 second if not + * reordering. + */ + L2TP_SKB_CB(skb)->length = length; + L2TP_SKB_CB(skb)->expires = jiffies + + (session->reorder_timeout ? session->reorder_timeout : HZ); + + /* Add packet to the session's receive queue. Reordering is done here, if + * enabled. Saved L2TP protocol info is stored in skb->sb[]. + */ + if (L2TP_SKB_CB(skb)->has_seq) { + if (l2tp_recv_data_seq(session, skb)) + goto discard; + } else { + /* No sequence numbers. Add the skb to the tail of the + * reorder queue. This ensures that it will be + * delivered after all previous sequenced skbs. + */ + skb_queue_tail(&session->reorder_q, skb); + } + + /* Try to dequeue as many skbs from reorder_q as we can. */ + l2tp_recv_dequeue(session); + + return; + +discard: + atomic_long_inc(&session->stats.rx_errors); + kfree_skb(skb); +} +EXPORT_SYMBOL_GPL(l2tp_recv_common); + +/* Drop skbs from the session's reorder_q + */ +static void l2tp_session_queue_purge(struct l2tp_session *session) +{ + struct sk_buff *skb = NULL; + + while ((skb = skb_dequeue(&session->reorder_q))) { + atomic_long_inc(&session->stats.rx_errors); + kfree_skb(skb); + } +} + +/* Internal UDP receive frame. Do the real work of receiving an L2TP data frame + * here. The skb is not on a list when we get here. + * Returns 0 if the packet was a data packet and was successfully passed on. + * Returns 1 if the packet was not a good data packet and could not be + * forwarded. All such packets are passed up to userspace to deal with. + */ +static int l2tp_udp_recv_core(struct l2tp_tunnel *tunnel, struct sk_buff *skb) +{ + struct l2tp_session *session = NULL; + unsigned char *ptr, *optr; + u16 hdrflags; + u32 tunnel_id, session_id; + u16 version; + int length; + + /* UDP has verified checksum */ + + /* UDP always verifies the packet length. */ + __skb_pull(skb, sizeof(struct udphdr)); + + /* Short packet? */ + if (!pskb_may_pull(skb, L2TP_HDR_SIZE_MAX)) { + pr_debug_ratelimited("%s: recv short packet (len=%d)\n", + tunnel->name, skb->len); + goto invalid; + } + + /* Point to L2TP header */ + optr = skb->data; + ptr = skb->data; + + /* Get L2TP header flags */ + hdrflags = ntohs(*(__be16 *)ptr); + + /* Check protocol version */ + version = hdrflags & L2TP_HDR_VER_MASK; + if (version != tunnel->version) { + pr_debug_ratelimited("%s: recv protocol version mismatch: got %d expected %d\n", + tunnel->name, version, tunnel->version); + goto invalid; + } + + /* Get length of L2TP packet */ + length = skb->len; + + /* If type is control packet, it is handled by userspace. */ + if (hdrflags & L2TP_HDRFLAG_T) + goto pass; + + /* Skip flags */ + ptr += 2; + + if (tunnel->version == L2TP_HDR_VER_2) { + /* If length is present, skip it */ + if (hdrflags & L2TP_HDRFLAG_L) + ptr += 2; + + /* Extract tunnel and session ID */ + tunnel_id = ntohs(*(__be16 *)ptr); + ptr += 2; + session_id = ntohs(*(__be16 *)ptr); + ptr += 2; + } else { + ptr += 2; /* skip reserved bits */ + tunnel_id = tunnel->tunnel_id; + session_id = ntohl(*(__be32 *)ptr); + ptr += 4; + } + + /* Find the session context */ + session = l2tp_tunnel_get_session(tunnel, session_id); + if (!session || !session->recv_skb) { + if (session) + l2tp_session_dec_refcount(session); + + /* Not found? Pass to userspace to deal with */ + pr_debug_ratelimited("%s: no session found (%u/%u). Passing up.\n", + tunnel->name, tunnel_id, session_id); + goto pass; + } + + if (tunnel->version == L2TP_HDR_VER_3 && + l2tp_v3_ensure_opt_in_linear(session, skb, &ptr, &optr)) { + l2tp_session_dec_refcount(session); + goto invalid; + } + + l2tp_recv_common(session, skb, ptr, optr, hdrflags, length); + l2tp_session_dec_refcount(session); + + return 0; + +invalid: + atomic_long_inc(&tunnel->stats.rx_invalid); + +pass: + /* Put UDP header back */ + __skb_push(skb, sizeof(struct udphdr)); + + return 1; +} + +/* UDP encapsulation receive handler. See net/ipv4/udp.c. + * Return codes: + * 0 : success. + * <0: error + * >0: skb should be passed up to userspace as UDP. + */ +int l2tp_udp_encap_recv(struct sock *sk, struct sk_buff *skb) +{ + struct l2tp_tunnel *tunnel; + + /* Note that this is called from the encap_rcv hook inside an + * RCU-protected region, but without the socket being locked. + * Hence we use rcu_dereference_sk_user_data to access the + * tunnel data structure rather the usual l2tp_sk_to_tunnel + * accessor function. + */ + tunnel = rcu_dereference_sk_user_data(sk); + if (!tunnel) + goto pass_up; + if (WARN_ON(tunnel->magic != L2TP_TUNNEL_MAGIC)) + goto pass_up; + + if (l2tp_udp_recv_core(tunnel, skb)) + goto pass_up; + + return 0; + +pass_up: + return 1; +} +EXPORT_SYMBOL_GPL(l2tp_udp_encap_recv); + +/************************************************************************ + * Transmit handling + ***********************************************************************/ + +/* Build an L2TP header for the session into the buffer provided. + */ +static int l2tp_build_l2tpv2_header(struct l2tp_session *session, void *buf) +{ + struct l2tp_tunnel *tunnel = session->tunnel; + __be16 *bufp = buf; + __be16 *optr = buf; + u16 flags = L2TP_HDR_VER_2; + u32 tunnel_id = tunnel->peer_tunnel_id; + u32 session_id = session->peer_session_id; + + if (session->send_seq) + flags |= L2TP_HDRFLAG_S; + + /* Setup L2TP header. */ + *bufp++ = htons(flags); + *bufp++ = htons(tunnel_id); + *bufp++ = htons(session_id); + if (session->send_seq) { + *bufp++ = htons(session->ns); + *bufp++ = 0; + session->ns++; + session->ns &= 0xffff; + trace_session_seqnum_update(session); + } + + return bufp - optr; +} + +static int l2tp_build_l2tpv3_header(struct l2tp_session *session, void *buf) +{ + struct l2tp_tunnel *tunnel = session->tunnel; + char *bufp = buf; + char *optr = bufp; + + /* Setup L2TP header. The header differs slightly for UDP and + * IP encapsulations. For UDP, there is 4 bytes of flags. + */ + if (tunnel->encap == L2TP_ENCAPTYPE_UDP) { + u16 flags = L2TP_HDR_VER_3; + *((__be16 *)bufp) = htons(flags); + bufp += 2; + *((__be16 *)bufp) = 0; + bufp += 2; + } + + *((__be32 *)bufp) = htonl(session->peer_session_id); + bufp += 4; + if (session->cookie_len) { + memcpy(bufp, &session->cookie[0], session->cookie_len); + bufp += session->cookie_len; + } + if (session->l2specific_type == L2TP_L2SPECTYPE_DEFAULT) { + u32 l2h = 0; + + if (session->send_seq) { + l2h = 0x40000000 | session->ns; + session->ns++; + session->ns &= 0xffffff; + trace_session_seqnum_update(session); + } + + *((__be32 *)bufp) = htonl(l2h); + bufp += 4; + } + + return bufp - optr; +} + +/* Queue the packet to IP for output: tunnel socket lock must be held */ +static int l2tp_xmit_queue(struct l2tp_tunnel *tunnel, struct sk_buff *skb, struct flowi *fl) +{ + int err; + + skb->ignore_df = 1; + skb_dst_drop(skb); +#if IS_ENABLED(CONFIG_IPV6) + if (l2tp_sk_is_v6(tunnel->sock)) + err = inet6_csk_xmit(tunnel->sock, skb, NULL); + else +#endif + err = ip_queue_xmit(tunnel->sock, skb, fl); + + return err >= 0 ? NET_XMIT_SUCCESS : NET_XMIT_DROP; +} + +static int l2tp_xmit_core(struct l2tp_session *session, struct sk_buff *skb, unsigned int *len) +{ + struct l2tp_tunnel *tunnel = session->tunnel; + unsigned int data_len = skb->len; + struct sock *sk = tunnel->sock; + int headroom, uhlen, udp_len; + int ret = NET_XMIT_SUCCESS; + struct inet_sock *inet; + struct udphdr *uh; + + /* Check that there's enough headroom in the skb to insert IP, + * UDP and L2TP headers. If not enough, expand it to + * make room. Adjust truesize. + */ + uhlen = (tunnel->encap == L2TP_ENCAPTYPE_UDP) ? sizeof(*uh) : 0; + headroom = NET_SKB_PAD + sizeof(struct iphdr) + uhlen + session->hdr_len; + if (skb_cow_head(skb, headroom)) { + kfree_skb(skb); + return NET_XMIT_DROP; + } + + /* Setup L2TP header */ + if (tunnel->version == L2TP_HDR_VER_2) + l2tp_build_l2tpv2_header(session, __skb_push(skb, session->hdr_len)); + else + l2tp_build_l2tpv3_header(session, __skb_push(skb, session->hdr_len)); + + /* Reset skb netfilter state */ + memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt)); + IPCB(skb)->flags &= ~(IPSKB_XFRM_TUNNEL_SIZE | IPSKB_XFRM_TRANSFORMED | IPSKB_REROUTED); + nf_reset_ct(skb); + + bh_lock_sock_nested(sk); + if (sock_owned_by_user(sk)) { + kfree_skb(skb); + ret = NET_XMIT_DROP; + goto out_unlock; + } + + /* The user-space may change the connection status for the user-space + * provided socket at run time: we must check it under the socket lock + */ + if (tunnel->fd >= 0 && sk->sk_state != TCP_ESTABLISHED) { + kfree_skb(skb); + ret = NET_XMIT_DROP; + goto out_unlock; + } + + /* Report transmitted length before we add encap header, which keeps + * statistics consistent for both UDP and IP encap tx/rx paths. + */ + *len = skb->len; + + inet = inet_sk(sk); + switch (tunnel->encap) { + case L2TP_ENCAPTYPE_UDP: + /* Setup UDP header */ + __skb_push(skb, sizeof(*uh)); + skb_reset_transport_header(skb); + uh = udp_hdr(skb); + uh->source = inet->inet_sport; + uh->dest = inet->inet_dport; + udp_len = uhlen + session->hdr_len + data_len; + uh->len = htons(udp_len); + + /* Calculate UDP checksum if configured to do so */ +#if IS_ENABLED(CONFIG_IPV6) + if (l2tp_sk_is_v6(sk)) + udp6_set_csum(udp_get_no_check6_tx(sk), + skb, &inet6_sk(sk)->saddr, + &sk->sk_v6_daddr, udp_len); + else +#endif + udp_set_csum(sk->sk_no_check_tx, skb, inet->inet_saddr, + inet->inet_daddr, udp_len); + break; + + case L2TP_ENCAPTYPE_IP: + break; + } + + ret = l2tp_xmit_queue(tunnel, skb, &inet->cork.fl); + +out_unlock: + bh_unlock_sock(sk); + + return ret; +} + +/* If caller requires the skb to have a ppp header, the header must be + * inserted in the skb data before calling this function. + */ +int l2tp_xmit_skb(struct l2tp_session *session, struct sk_buff *skb) +{ + unsigned int len = 0; + int ret; + + ret = l2tp_xmit_core(session, skb, &len); + if (ret == NET_XMIT_SUCCESS) { + atomic_long_inc(&session->tunnel->stats.tx_packets); + atomic_long_add(len, &session->tunnel->stats.tx_bytes); + atomic_long_inc(&session->stats.tx_packets); + atomic_long_add(len, &session->stats.tx_bytes); + } else { + atomic_long_inc(&session->tunnel->stats.tx_errors); + atomic_long_inc(&session->stats.tx_errors); + } + return ret; +} +EXPORT_SYMBOL_GPL(l2tp_xmit_skb); + +/***************************************************************************** + * Tinnel and session create/destroy. + *****************************************************************************/ + +/* Tunnel socket destruct hook. + * The tunnel context is deleted only when all session sockets have been + * closed. + */ +static void l2tp_tunnel_destruct(struct sock *sk) +{ + struct l2tp_tunnel *tunnel = l2tp_sk_to_tunnel(sk); + + if (!tunnel) + goto end; + + /* Disable udp encapsulation */ + switch (tunnel->encap) { + case L2TP_ENCAPTYPE_UDP: + /* No longer an encapsulation socket. See net/ipv4/udp.c */ + WRITE_ONCE(udp_sk(sk)->encap_type, 0); + udp_sk(sk)->encap_rcv = NULL; + udp_sk(sk)->encap_destroy = NULL; + break; + case L2TP_ENCAPTYPE_IP: + break; + } + + /* Remove hooks into tunnel socket */ + write_lock_bh(&sk->sk_callback_lock); + sk->sk_destruct = tunnel->old_sk_destruct; + sk->sk_user_data = NULL; + write_unlock_bh(&sk->sk_callback_lock); + + /* Call the original destructor */ + if (sk->sk_destruct) + (*sk->sk_destruct)(sk); + + kfree_rcu(tunnel, rcu); +end: + return; +} + +/* Remove an l2tp session from l2tp_core's hash lists. */ +static void l2tp_session_unhash(struct l2tp_session *session) +{ + struct l2tp_tunnel *tunnel = session->tunnel; + + /* Remove the session from core hashes */ + if (tunnel) { + /* Remove from the per-tunnel hash */ + spin_lock_bh(&tunnel->hlist_lock); + hlist_del_init_rcu(&session->hlist); + spin_unlock_bh(&tunnel->hlist_lock); + + /* For L2TPv3 we have a per-net hash: remove from there, too */ + if (tunnel->version != L2TP_HDR_VER_2) { + struct l2tp_net *pn = l2tp_pernet(tunnel->l2tp_net); + + spin_lock_bh(&pn->l2tp_session_hlist_lock); + hlist_del_init_rcu(&session->global_hlist); + spin_unlock_bh(&pn->l2tp_session_hlist_lock); + } + + synchronize_rcu(); + } +} + +/* When the tunnel is closed, all the attached sessions need to go too. + */ +static void l2tp_tunnel_closeall(struct l2tp_tunnel *tunnel) +{ + struct l2tp_session *session; + int hash; + + spin_lock_bh(&tunnel->hlist_lock); + tunnel->acpt_newsess = false; + for (hash = 0; hash < L2TP_HASH_SIZE; hash++) { +again: + hlist_for_each_entry_rcu(session, &tunnel->session_hlist[hash], hlist) { + hlist_del_init_rcu(&session->hlist); + + spin_unlock_bh(&tunnel->hlist_lock); + l2tp_session_delete(session); + spin_lock_bh(&tunnel->hlist_lock); + + /* Now restart from the beginning of this hash + * chain. We always remove a session from the + * list so we are guaranteed to make forward + * progress. + */ + goto again; + } + } + spin_unlock_bh(&tunnel->hlist_lock); +} + +/* Tunnel socket destroy hook for UDP encapsulation */ +static void l2tp_udp_encap_destroy(struct sock *sk) +{ + struct l2tp_tunnel *tunnel = l2tp_sk_to_tunnel(sk); + + if (tunnel) + l2tp_tunnel_delete(tunnel); +} + +static void l2tp_tunnel_remove(struct net *net, struct l2tp_tunnel *tunnel) +{ + struct l2tp_net *pn = l2tp_pernet(net); + + spin_lock_bh(&pn->l2tp_tunnel_idr_lock); + idr_remove(&pn->l2tp_tunnel_idr, tunnel->tunnel_id); + spin_unlock_bh(&pn->l2tp_tunnel_idr_lock); +} + +/* Workqueue tunnel deletion function */ +static void l2tp_tunnel_del_work(struct work_struct *work) +{ + struct l2tp_tunnel *tunnel = container_of(work, struct l2tp_tunnel, + del_work); + struct sock *sk = tunnel->sock; + struct socket *sock = sk->sk_socket; + + l2tp_tunnel_closeall(tunnel); + + /* If the tunnel socket was created within the kernel, use + * the sk API to release it here. + */ + if (tunnel->fd < 0) { + if (sock) { + kernel_sock_shutdown(sock, SHUT_RDWR); + sock_release(sock); + } + } + + l2tp_tunnel_remove(tunnel->l2tp_net, tunnel); + /* drop initial ref */ + l2tp_tunnel_dec_refcount(tunnel); + + /* drop workqueue ref */ + l2tp_tunnel_dec_refcount(tunnel); +} + +/* Create a socket for the tunnel, if one isn't set up by + * userspace. This is used for static tunnels where there is no + * managing L2TP daemon. + * + * Since we don't want these sockets to keep a namespace alive by + * themselves, we drop the socket's namespace refcount after creation. + * These sockets are freed when the namespace exits using the pernet + * exit hook. + */ +static int l2tp_tunnel_sock_create(struct net *net, + u32 tunnel_id, + u32 peer_tunnel_id, + struct l2tp_tunnel_cfg *cfg, + struct socket **sockp) +{ + int err = -EINVAL; + struct socket *sock = NULL; + struct udp_port_cfg udp_conf; + + switch (cfg->encap) { + case L2TP_ENCAPTYPE_UDP: + memset(&udp_conf, 0, sizeof(udp_conf)); + +#if IS_ENABLED(CONFIG_IPV6) + if (cfg->local_ip6 && cfg->peer_ip6) { + udp_conf.family = AF_INET6; + memcpy(&udp_conf.local_ip6, cfg->local_ip6, + sizeof(udp_conf.local_ip6)); + memcpy(&udp_conf.peer_ip6, cfg->peer_ip6, + sizeof(udp_conf.peer_ip6)); + udp_conf.use_udp6_tx_checksums = + !cfg->udp6_zero_tx_checksums; + udp_conf.use_udp6_rx_checksums = + !cfg->udp6_zero_rx_checksums; + } else +#endif + { + udp_conf.family = AF_INET; + udp_conf.local_ip = cfg->local_ip; + udp_conf.peer_ip = cfg->peer_ip; + udp_conf.use_udp_checksums = cfg->use_udp_checksums; + } + + udp_conf.local_udp_port = htons(cfg->local_udp_port); + udp_conf.peer_udp_port = htons(cfg->peer_udp_port); + + err = udp_sock_create(net, &udp_conf, &sock); + if (err < 0) + goto out; + + break; + + case L2TP_ENCAPTYPE_IP: +#if IS_ENABLED(CONFIG_IPV6) + if (cfg->local_ip6 && cfg->peer_ip6) { + struct sockaddr_l2tpip6 ip6_addr = {0}; + + err = sock_create_kern(net, AF_INET6, SOCK_DGRAM, + IPPROTO_L2TP, &sock); + if (err < 0) + goto out; + + ip6_addr.l2tp_family = AF_INET6; + memcpy(&ip6_addr.l2tp_addr, cfg->local_ip6, + sizeof(ip6_addr.l2tp_addr)); + ip6_addr.l2tp_conn_id = tunnel_id; + err = kernel_bind(sock, (struct sockaddr *)&ip6_addr, + sizeof(ip6_addr)); + if (err < 0) + goto out; + + ip6_addr.l2tp_family = AF_INET6; + memcpy(&ip6_addr.l2tp_addr, cfg->peer_ip6, + sizeof(ip6_addr.l2tp_addr)); + ip6_addr.l2tp_conn_id = peer_tunnel_id; + err = kernel_connect(sock, + (struct sockaddr *)&ip6_addr, + sizeof(ip6_addr), 0); + if (err < 0) + goto out; + } else +#endif + { + struct sockaddr_l2tpip ip_addr = {0}; + + err = sock_create_kern(net, AF_INET, SOCK_DGRAM, + IPPROTO_L2TP, &sock); + if (err < 0) + goto out; + + ip_addr.l2tp_family = AF_INET; + ip_addr.l2tp_addr = cfg->local_ip; + ip_addr.l2tp_conn_id = tunnel_id; + err = kernel_bind(sock, (struct sockaddr *)&ip_addr, + sizeof(ip_addr)); + if (err < 0) + goto out; + + ip_addr.l2tp_family = AF_INET; + ip_addr.l2tp_addr = cfg->peer_ip; + ip_addr.l2tp_conn_id = peer_tunnel_id; + err = kernel_connect(sock, (struct sockaddr *)&ip_addr, + sizeof(ip_addr), 0); + if (err < 0) + goto out; + } + break; + + default: + goto out; + } + +out: + *sockp = sock; + if (err < 0 && sock) { + kernel_sock_shutdown(sock, SHUT_RDWR); + sock_release(sock); + *sockp = NULL; + } + + return err; +} + +int l2tp_tunnel_create(int fd, int version, u32 tunnel_id, u32 peer_tunnel_id, + struct l2tp_tunnel_cfg *cfg, struct l2tp_tunnel **tunnelp) +{ + struct l2tp_tunnel *tunnel = NULL; + int err; + enum l2tp_encap_type encap = L2TP_ENCAPTYPE_UDP; + + if (cfg) + encap = cfg->encap; + + tunnel = kzalloc(sizeof(*tunnel), GFP_KERNEL); + if (!tunnel) { + err = -ENOMEM; + goto err; + } + + tunnel->version = version; + tunnel->tunnel_id = tunnel_id; + tunnel->peer_tunnel_id = peer_tunnel_id; + + tunnel->magic = L2TP_TUNNEL_MAGIC; + sprintf(&tunnel->name[0], "tunl %u", tunnel_id); + spin_lock_init(&tunnel->hlist_lock); + tunnel->acpt_newsess = true; + + tunnel->encap = encap; + + refcount_set(&tunnel->ref_count, 1); + tunnel->fd = fd; + + /* Init delete workqueue struct */ + INIT_WORK(&tunnel->del_work, l2tp_tunnel_del_work); + + INIT_LIST_HEAD(&tunnel->list); + + err = 0; +err: + if (tunnelp) + *tunnelp = tunnel; + + return err; +} +EXPORT_SYMBOL_GPL(l2tp_tunnel_create); + +static int l2tp_validate_socket(const struct sock *sk, const struct net *net, + enum l2tp_encap_type encap) +{ + if (!net_eq(sock_net(sk), net)) + return -EINVAL; + + if (sk->sk_type != SOCK_DGRAM) + return -EPROTONOSUPPORT; + + if (sk->sk_family != PF_INET && sk->sk_family != PF_INET6) + return -EPROTONOSUPPORT; + + if ((encap == L2TP_ENCAPTYPE_UDP && sk->sk_protocol != IPPROTO_UDP) || + (encap == L2TP_ENCAPTYPE_IP && sk->sk_protocol != IPPROTO_L2TP)) + return -EPROTONOSUPPORT; + + if (sk->sk_user_data) + return -EBUSY; + + return 0; +} + +int l2tp_tunnel_register(struct l2tp_tunnel *tunnel, struct net *net, + struct l2tp_tunnel_cfg *cfg) +{ + struct l2tp_net *pn = l2tp_pernet(net); + u32 tunnel_id = tunnel->tunnel_id; + struct socket *sock; + struct sock *sk; + int ret; + + spin_lock_bh(&pn->l2tp_tunnel_idr_lock); + ret = idr_alloc_u32(&pn->l2tp_tunnel_idr, NULL, &tunnel_id, tunnel_id, + GFP_ATOMIC); + spin_unlock_bh(&pn->l2tp_tunnel_idr_lock); + if (ret) + return ret == -ENOSPC ? -EEXIST : ret; + + if (tunnel->fd < 0) { + ret = l2tp_tunnel_sock_create(net, tunnel->tunnel_id, + tunnel->peer_tunnel_id, cfg, + &sock); + if (ret < 0) + goto err; + } else { + sock = sockfd_lookup(tunnel->fd, &ret); + if (!sock) + goto err; + } + + sk = sock->sk; + lock_sock(sk); + write_lock_bh(&sk->sk_callback_lock); + ret = l2tp_validate_socket(sk, net, tunnel->encap); + if (ret < 0) + goto err_inval_sock; + rcu_assign_sk_user_data(sk, tunnel); + write_unlock_bh(&sk->sk_callback_lock); + + if (tunnel->encap == L2TP_ENCAPTYPE_UDP) { + struct udp_tunnel_sock_cfg udp_cfg = { + .sk_user_data = tunnel, + .encap_type = UDP_ENCAP_L2TPINUDP, + .encap_rcv = l2tp_udp_encap_recv, + .encap_destroy = l2tp_udp_encap_destroy, + }; + + setup_udp_tunnel_sock(net, sock, &udp_cfg); + } + + tunnel->old_sk_destruct = sk->sk_destruct; + sk->sk_destruct = &l2tp_tunnel_destruct; + sk->sk_allocation = GFP_ATOMIC; + release_sock(sk); + + sock_hold(sk); + tunnel->sock = sk; + tunnel->l2tp_net = net; + + spin_lock_bh(&pn->l2tp_tunnel_idr_lock); + idr_replace(&pn->l2tp_tunnel_idr, tunnel, tunnel->tunnel_id); + spin_unlock_bh(&pn->l2tp_tunnel_idr_lock); + + trace_register_tunnel(tunnel); + + if (tunnel->fd >= 0) + sockfd_put(sock); + + return 0; + +err_inval_sock: + write_unlock_bh(&sk->sk_callback_lock); + release_sock(sk); + + if (tunnel->fd < 0) + sock_release(sock); + else + sockfd_put(sock); +err: + l2tp_tunnel_remove(net, tunnel); + return ret; +} +EXPORT_SYMBOL_GPL(l2tp_tunnel_register); + +/* This function is used by the netlink TUNNEL_DELETE command. + */ +void l2tp_tunnel_delete(struct l2tp_tunnel *tunnel) +{ + if (!test_and_set_bit(0, &tunnel->dead)) { + trace_delete_tunnel(tunnel); + l2tp_tunnel_inc_refcount(tunnel); + queue_work(l2tp_wq, &tunnel->del_work); + } +} +EXPORT_SYMBOL_GPL(l2tp_tunnel_delete); + +void l2tp_session_delete(struct l2tp_session *session) +{ + if (test_and_set_bit(0, &session->dead)) + return; + + trace_delete_session(session); + l2tp_session_unhash(session); + l2tp_session_queue_purge(session); + if (session->session_close) + (*session->session_close)(session); + + l2tp_session_dec_refcount(session); +} +EXPORT_SYMBOL_GPL(l2tp_session_delete); + +/* We come here whenever a session's send_seq, cookie_len or + * l2specific_type parameters are set. + */ +void l2tp_session_set_header_len(struct l2tp_session *session, int version) +{ + if (version == L2TP_HDR_VER_2) { + session->hdr_len = 6; + if (session->send_seq) + session->hdr_len += 4; + } else { + session->hdr_len = 4 + session->cookie_len; + session->hdr_len += l2tp_get_l2specific_len(session); + if (session->tunnel->encap == L2TP_ENCAPTYPE_UDP) + session->hdr_len += 4; + } +} +EXPORT_SYMBOL_GPL(l2tp_session_set_header_len); + +struct l2tp_session *l2tp_session_create(int priv_size, struct l2tp_tunnel *tunnel, u32 session_id, + u32 peer_session_id, struct l2tp_session_cfg *cfg) +{ + struct l2tp_session *session; + + session = kzalloc(sizeof(*session) + priv_size, GFP_KERNEL); + if (session) { + session->magic = L2TP_SESSION_MAGIC; + session->tunnel = tunnel; + + session->session_id = session_id; + session->peer_session_id = peer_session_id; + session->nr = 0; + if (tunnel->version == L2TP_HDR_VER_2) + session->nr_max = 0xffff; + else + session->nr_max = 0xffffff; + session->nr_window_size = session->nr_max / 2; + session->nr_oos_count_max = 4; + + /* Use NR of first received packet */ + session->reorder_skip = 1; + + sprintf(&session->name[0], "sess %u/%u", + tunnel->tunnel_id, session->session_id); + + skb_queue_head_init(&session->reorder_q); + + INIT_HLIST_NODE(&session->hlist); + INIT_HLIST_NODE(&session->global_hlist); + + if (cfg) { + session->pwtype = cfg->pw_type; + session->send_seq = cfg->send_seq; + session->recv_seq = cfg->recv_seq; + session->lns_mode = cfg->lns_mode; + session->reorder_timeout = cfg->reorder_timeout; + session->l2specific_type = cfg->l2specific_type; + session->cookie_len = cfg->cookie_len; + memcpy(&session->cookie[0], &cfg->cookie[0], cfg->cookie_len); + session->peer_cookie_len = cfg->peer_cookie_len; + memcpy(&session->peer_cookie[0], &cfg->peer_cookie[0], cfg->peer_cookie_len); + } + + l2tp_session_set_header_len(session, tunnel->version); + + refcount_set(&session->ref_count, 1); + + return session; + } + + return ERR_PTR(-ENOMEM); +} +EXPORT_SYMBOL_GPL(l2tp_session_create); + +/***************************************************************************** + * Init and cleanup + *****************************************************************************/ + +static __net_init int l2tp_init_net(struct net *net) +{ + struct l2tp_net *pn = net_generic(net, l2tp_net_id); + int hash; + + idr_init(&pn->l2tp_tunnel_idr); + spin_lock_init(&pn->l2tp_tunnel_idr_lock); + + for (hash = 0; hash < L2TP_HASH_SIZE_2; hash++) + INIT_HLIST_HEAD(&pn->l2tp_session_hlist[hash]); + + spin_lock_init(&pn->l2tp_session_hlist_lock); + + return 0; +} + +static __net_exit void l2tp_exit_net(struct net *net) +{ + struct l2tp_net *pn = l2tp_pernet(net); + struct l2tp_tunnel *tunnel = NULL; + unsigned long tunnel_id, tmp; + int hash; + + rcu_read_lock_bh(); + idr_for_each_entry_ul(&pn->l2tp_tunnel_idr, tunnel, tmp, tunnel_id) { + if (tunnel) + l2tp_tunnel_delete(tunnel); + } + rcu_read_unlock_bh(); + + if (l2tp_wq) + flush_workqueue(l2tp_wq); + rcu_barrier(); + + for (hash = 0; hash < L2TP_HASH_SIZE_2; hash++) + WARN_ON_ONCE(!hlist_empty(&pn->l2tp_session_hlist[hash])); + idr_destroy(&pn->l2tp_tunnel_idr); +} + +static struct pernet_operations l2tp_net_ops = { + .init = l2tp_init_net, + .exit = l2tp_exit_net, + .id = &l2tp_net_id, + .size = sizeof(struct l2tp_net), +}; + +static int __init l2tp_init(void) +{ + int rc = 0; + + rc = register_pernet_device(&l2tp_net_ops); + if (rc) + goto out; + + l2tp_wq = alloc_workqueue("l2tp", WQ_UNBOUND, 0); + if (!l2tp_wq) { + pr_err("alloc_workqueue failed\n"); + unregister_pernet_device(&l2tp_net_ops); + rc = -ENOMEM; + goto out; + } + + pr_info("L2TP core driver, %s\n", L2TP_DRV_VERSION); + +out: + return rc; +} + +static void __exit l2tp_exit(void) +{ + unregister_pernet_device(&l2tp_net_ops); + if (l2tp_wq) { + destroy_workqueue(l2tp_wq); + l2tp_wq = NULL; + } +} + +module_init(l2tp_init); +module_exit(l2tp_exit); + +MODULE_AUTHOR("James Chapman <jchapman@katalix.com>"); +MODULE_DESCRIPTION("L2TP core"); +MODULE_LICENSE("GPL"); +MODULE_VERSION(L2TP_DRV_VERSION); diff --git a/net/l2tp/l2tp_core.h b/net/l2tp/l2tp_core.h new file mode 100644 index 000000000..a88e070b4 --- /dev/null +++ b/net/l2tp/l2tp_core.h @@ -0,0 +1,346 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* L2TP internal definitions. + * + * Copyright (c) 2008,2009 Katalix Systems Ltd + */ +#include <linux/refcount.h> + +#ifndef _L2TP_CORE_H_ +#define _L2TP_CORE_H_ + +#include <net/dst.h> +#include <net/sock.h> + +#ifdef CONFIG_XFRM +#include <net/xfrm.h> +#endif + +/* Random numbers used for internal consistency checks of tunnel and session structures */ +#define L2TP_TUNNEL_MAGIC 0x42114DDA +#define L2TP_SESSION_MAGIC 0x0C04EB7D + +/* Per tunnel session hash table size */ +#define L2TP_HASH_BITS 4 +#define L2TP_HASH_SIZE BIT(L2TP_HASH_BITS) + +/* System-wide session hash table size */ +#define L2TP_HASH_BITS_2 8 +#define L2TP_HASH_SIZE_2 BIT(L2TP_HASH_BITS_2) + +struct sk_buff; + +struct l2tp_stats { + atomic_long_t tx_packets; + atomic_long_t tx_bytes; + atomic_long_t tx_errors; + atomic_long_t rx_packets; + atomic_long_t rx_bytes; + atomic_long_t rx_seq_discards; + atomic_long_t rx_oos_packets; + atomic_long_t rx_errors; + atomic_long_t rx_cookie_discards; + atomic_long_t rx_invalid; +}; + +struct l2tp_tunnel; + +/* L2TP session configuration */ +struct l2tp_session_cfg { + enum l2tp_pwtype pw_type; + unsigned int recv_seq:1; /* expect receive packets with sequence numbers? */ + unsigned int send_seq:1; /* send packets with sequence numbers? */ + unsigned int lns_mode:1; /* behave as LNS? + * LAC enables sequence numbers under LNS control. + */ + u16 l2specific_type; /* Layer 2 specific type */ + u8 cookie[8]; /* optional cookie */ + int cookie_len; /* 0, 4 or 8 bytes */ + u8 peer_cookie[8]; /* peer's cookie */ + int peer_cookie_len; /* 0, 4 or 8 bytes */ + int reorder_timeout; /* configured reorder timeout (in jiffies) */ + char *ifname; +}; + +/* Represents a session (pseudowire) instance. + * Tracks runtime state including cookies, dataplane packet sequencing, and IO statistics. + * Is linked into a per-tunnel session hashlist; and in the case of an L2TPv3 session into + * an additional per-net ("global") hashlist. + */ +#define L2TP_SESSION_NAME_MAX 32 +struct l2tp_session { + int magic; /* should be L2TP_SESSION_MAGIC */ + long dead; + + struct l2tp_tunnel *tunnel; /* back pointer to tunnel context */ + u32 session_id; + u32 peer_session_id; + u8 cookie[8]; + int cookie_len; + u8 peer_cookie[8]; + int peer_cookie_len; + u16 l2specific_type; + u16 hdr_len; + u32 nr; /* session NR state (receive) */ + u32 ns; /* session NR state (send) */ + struct sk_buff_head reorder_q; /* receive reorder queue */ + u32 nr_max; /* max NR. Depends on tunnel */ + u32 nr_window_size; /* NR window size */ + u32 nr_oos; /* NR of last OOS packet */ + int nr_oos_count; /* for OOS recovery */ + int nr_oos_count_max; + struct hlist_node hlist; /* hash list node */ + refcount_t ref_count; + + char name[L2TP_SESSION_NAME_MAX]; /* for logging */ + char ifname[IFNAMSIZ]; + unsigned int recv_seq:1; /* expect receive packets with sequence numbers? */ + unsigned int send_seq:1; /* send packets with sequence numbers? */ + unsigned int lns_mode:1; /* behave as LNS? + * LAC enables sequence numbers under LNS control. + */ + int reorder_timeout; /* configured reorder timeout (in jiffies) */ + int reorder_skip; /* set if skip to next nr */ + enum l2tp_pwtype pwtype; + struct l2tp_stats stats; + struct hlist_node global_hlist; /* global hash list node */ + + /* Session receive handler for data packets. + * Each pseudowire implementation should implement this callback in order to + * handle incoming packets. Packets are passed to the pseudowire handler after + * reordering, if data sequence numbers are enabled for the session. + */ + void (*recv_skb)(struct l2tp_session *session, struct sk_buff *skb, int data_len); + + /* Session close handler. + * Each pseudowire implementation may implement this callback in order to carry + * out pseudowire-specific shutdown actions. + * The callback is called by core after unhashing the session and purging its + * reorder queue. + */ + void (*session_close)(struct l2tp_session *session); + + /* Session show handler. + * Pseudowire-specific implementation of debugfs session rendering. + * The callback is called by l2tp_debugfs.c after rendering core session + * information. + */ + void (*show)(struct seq_file *m, void *priv); + + u8 priv[]; /* private data */ +}; + +/* L2TP tunnel configuration */ +struct l2tp_tunnel_cfg { + enum l2tp_encap_type encap; + + /* Used only for kernel-created sockets */ + struct in_addr local_ip; + struct in_addr peer_ip; +#if IS_ENABLED(CONFIG_IPV6) + struct in6_addr *local_ip6; + struct in6_addr *peer_ip6; +#endif + u16 local_udp_port; + u16 peer_udp_port; + unsigned int use_udp_checksums:1, + udp6_zero_tx_checksums:1, + udp6_zero_rx_checksums:1; +}; + +/* Represents a tunnel instance. + * Tracks runtime state including IO statistics. + * Holds the tunnel socket (either passed from userspace or directly created by the kernel). + * Maintains a hashlist of sessions belonging to the tunnel instance. + * Is linked into a per-net list of tunnels. + */ +#define L2TP_TUNNEL_NAME_MAX 20 +struct l2tp_tunnel { + int magic; /* Should be L2TP_TUNNEL_MAGIC */ + + unsigned long dead; + + struct rcu_head rcu; + spinlock_t hlist_lock; /* write-protection for session_hlist */ + bool acpt_newsess; /* indicates whether this tunnel accepts + * new sessions. Protected by hlist_lock. + */ + struct hlist_head session_hlist[L2TP_HASH_SIZE]; + /* hashed list of sessions, hashed by id */ + u32 tunnel_id; + u32 peer_tunnel_id; + int version; /* 2=>L2TPv2, 3=>L2TPv3 */ + + char name[L2TP_TUNNEL_NAME_MAX]; /* for logging */ + enum l2tp_encap_type encap; + struct l2tp_stats stats; + + struct list_head list; /* list node on per-namespace list of tunnels */ + struct net *l2tp_net; /* the net we belong to */ + + refcount_t ref_count; + void (*old_sk_destruct)(struct sock *sk); + struct sock *sock; /* parent socket */ + int fd; /* parent fd, if tunnel socket was created + * by userspace + */ + + struct work_struct del_work; +}; + +/* Pseudowire ops callbacks for use with the l2tp genetlink interface */ +struct l2tp_nl_cmd_ops { + /* The pseudowire session create callback is responsible for creating a session + * instance for a specific pseudowire type. + * It must call l2tp_session_create and l2tp_session_register to register the + * session instance, as well as carry out any pseudowire-specific initialisation. + * It must return >= 0 on success, or an appropriate negative errno value on failure. + */ + int (*session_create)(struct net *net, struct l2tp_tunnel *tunnel, + u32 session_id, u32 peer_session_id, + struct l2tp_session_cfg *cfg); + + /* The pseudowire session delete callback is responsible for initiating the deletion + * of a session instance. + * It must call l2tp_session_delete, as well as carry out any pseudowire-specific + * teardown actions. + */ + void (*session_delete)(struct l2tp_session *session); +}; + +static inline void *l2tp_session_priv(struct l2tp_session *session) +{ + return &session->priv[0]; +} + +/* Tunnel and session refcounts */ +void l2tp_tunnel_inc_refcount(struct l2tp_tunnel *tunnel); +void l2tp_tunnel_dec_refcount(struct l2tp_tunnel *tunnel); +void l2tp_session_inc_refcount(struct l2tp_session *session); +void l2tp_session_dec_refcount(struct l2tp_session *session); + +/* Tunnel and session lookup. + * These functions take a reference on the instances they return, so + * the caller must ensure that the reference is dropped appropriately. + */ +struct l2tp_tunnel *l2tp_tunnel_get(const struct net *net, u32 tunnel_id); +struct l2tp_tunnel *l2tp_tunnel_get_nth(const struct net *net, int nth); +struct l2tp_session *l2tp_tunnel_get_session(struct l2tp_tunnel *tunnel, + u32 session_id); + +struct l2tp_session *l2tp_session_get(const struct net *net, u32 session_id); +struct l2tp_session *l2tp_session_get_nth(struct l2tp_tunnel *tunnel, int nth); +struct l2tp_session *l2tp_session_get_by_ifname(const struct net *net, + const char *ifname); + +/* Tunnel and session lifetime management. + * Creation of a new instance is a two-step process: create, then register. + * Destruction is triggered using the *_delete functions, and completes asynchronously. + */ +int l2tp_tunnel_create(int fd, int version, u32 tunnel_id, + u32 peer_tunnel_id, struct l2tp_tunnel_cfg *cfg, + struct l2tp_tunnel **tunnelp); +int l2tp_tunnel_register(struct l2tp_tunnel *tunnel, struct net *net, + struct l2tp_tunnel_cfg *cfg); +void l2tp_tunnel_delete(struct l2tp_tunnel *tunnel); + +struct l2tp_session *l2tp_session_create(int priv_size, + struct l2tp_tunnel *tunnel, + u32 session_id, u32 peer_session_id, + struct l2tp_session_cfg *cfg); +int l2tp_session_register(struct l2tp_session *session, + struct l2tp_tunnel *tunnel); +void l2tp_session_delete(struct l2tp_session *session); + +/* Receive path helpers. If data sequencing is enabled for the session these + * functions handle queuing and reordering prior to passing packets to the + * pseudowire code to be passed to userspace. + */ +void l2tp_recv_common(struct l2tp_session *session, struct sk_buff *skb, + unsigned char *ptr, unsigned char *optr, u16 hdrflags, + int length); +int l2tp_udp_encap_recv(struct sock *sk, struct sk_buff *skb); + +/* Transmit path helpers for sending packets over the tunnel socket. */ +void l2tp_session_set_header_len(struct l2tp_session *session, int version); +int l2tp_xmit_skb(struct l2tp_session *session, struct sk_buff *skb); + +/* Pseudowire management. + * Pseudowires should register with l2tp core on module init, and unregister + * on module exit. + */ +int l2tp_nl_register_ops(enum l2tp_pwtype pw_type, const struct l2tp_nl_cmd_ops *ops); +void l2tp_nl_unregister_ops(enum l2tp_pwtype pw_type); + +/* IOCTL helper for IP encap modules. */ +int l2tp_ioctl(struct sock *sk, int cmd, unsigned long arg); + +/* Extract the tunnel structure from a socket's sk_user_data pointer, + * validating the tunnel magic feather. + */ +struct l2tp_tunnel *l2tp_sk_to_tunnel(struct sock *sk); + +static inline int l2tp_get_l2specific_len(struct l2tp_session *session) +{ + switch (session->l2specific_type) { + case L2TP_L2SPECTYPE_DEFAULT: + return 4; + case L2TP_L2SPECTYPE_NONE: + default: + return 0; + } +} + +static inline u32 l2tp_tunnel_dst_mtu(const struct l2tp_tunnel *tunnel) +{ + struct dst_entry *dst; + u32 mtu; + + dst = sk_dst_get(tunnel->sock); + if (!dst) + return 0; + + mtu = dst_mtu(dst); + dst_release(dst); + + return mtu; +} + +#ifdef CONFIG_XFRM +static inline bool l2tp_tunnel_uses_xfrm(const struct l2tp_tunnel *tunnel) +{ + struct sock *sk = tunnel->sock; + + return sk && (rcu_access_pointer(sk->sk_policy[0]) || + rcu_access_pointer(sk->sk_policy[1])); +} +#else +static inline bool l2tp_tunnel_uses_xfrm(const struct l2tp_tunnel *tunnel) +{ + return false; +} +#endif + +static inline int l2tp_v3_ensure_opt_in_linear(struct l2tp_session *session, struct sk_buff *skb, + unsigned char **ptr, unsigned char **optr) +{ + int opt_len = session->peer_cookie_len + l2tp_get_l2specific_len(session); + + if (opt_len > 0) { + int off = *ptr - *optr; + + if (!pskb_may_pull(skb, off + opt_len)) + return -1; + + if (skb->data != *optr) { + *optr = skb->data; + *ptr = skb->data + off; + } + } + + return 0; +} + +#define MODULE_ALIAS_L2TP_PWTYPE(type) \ + MODULE_ALIAS("net-l2tp-type-" __stringify(type)) + +#endif /* _L2TP_CORE_H_ */ diff --git a/net/l2tp/l2tp_debugfs.c b/net/l2tp/l2tp_debugfs.c new file mode 100644 index 000000000..4595b56d1 --- /dev/null +++ b/net/l2tp/l2tp_debugfs.c @@ -0,0 +1,348 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* L2TP subsystem debugfs + * + * Copyright (c) 2010 Katalix Systems Ltd + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/module.h> +#include <linux/skbuff.h> +#include <linux/socket.h> +#include <linux/hash.h> +#include <linux/l2tp.h> +#include <linux/in.h> +#include <linux/etherdevice.h> +#include <linux/spinlock.h> +#include <linux/debugfs.h> +#include <net/sock.h> +#include <net/ip.h> +#include <net/icmp.h> +#include <net/udp.h> +#include <net/inet_common.h> +#include <net/inet_hashtables.h> +#include <net/tcp_states.h> +#include <net/protocol.h> +#include <net/xfrm.h> +#include <net/net_namespace.h> +#include <net/netns/generic.h> + +#include "l2tp_core.h" + +static struct dentry *rootdir; + +struct l2tp_dfs_seq_data { + struct net *net; + netns_tracker ns_tracker; + int tunnel_idx; /* current tunnel */ + int session_idx; /* index of session within current tunnel */ + struct l2tp_tunnel *tunnel; + struct l2tp_session *session; /* NULL means get next tunnel */ +}; + +static void l2tp_dfs_next_tunnel(struct l2tp_dfs_seq_data *pd) +{ + /* Drop reference taken during previous invocation */ + if (pd->tunnel) + l2tp_tunnel_dec_refcount(pd->tunnel); + + pd->tunnel = l2tp_tunnel_get_nth(pd->net, pd->tunnel_idx); + pd->tunnel_idx++; +} + +static void l2tp_dfs_next_session(struct l2tp_dfs_seq_data *pd) +{ + /* Drop reference taken during previous invocation */ + if (pd->session) + l2tp_session_dec_refcount(pd->session); + + pd->session = l2tp_session_get_nth(pd->tunnel, pd->session_idx); + pd->session_idx++; + + if (!pd->session) { + pd->session_idx = 0; + l2tp_dfs_next_tunnel(pd); + } +} + +static void *l2tp_dfs_seq_start(struct seq_file *m, loff_t *offs) +{ + struct l2tp_dfs_seq_data *pd = SEQ_START_TOKEN; + loff_t pos = *offs; + + if (!pos) + goto out; + + if (WARN_ON(!m->private)) { + pd = NULL; + goto out; + } + pd = m->private; + + if (!pd->tunnel) + l2tp_dfs_next_tunnel(pd); + else + l2tp_dfs_next_session(pd); + + /* NULL tunnel and session indicates end of list */ + if (!pd->tunnel && !pd->session) + pd = NULL; + +out: + return pd; +} + +static void *l2tp_dfs_seq_next(struct seq_file *m, void *v, loff_t *pos) +{ + (*pos)++; + return NULL; +} + +static void l2tp_dfs_seq_stop(struct seq_file *p, void *v) +{ + struct l2tp_dfs_seq_data *pd = v; + + if (!pd || pd == SEQ_START_TOKEN) + return; + + /* Drop reference taken by last invocation of l2tp_dfs_next_session() + * or l2tp_dfs_next_tunnel(). + */ + if (pd->session) { + l2tp_session_dec_refcount(pd->session); + pd->session = NULL; + } + if (pd->tunnel) { + l2tp_tunnel_dec_refcount(pd->tunnel); + pd->tunnel = NULL; + } +} + +static void l2tp_dfs_seq_tunnel_show(struct seq_file *m, void *v) +{ + struct l2tp_tunnel *tunnel = v; + struct l2tp_session *session; + int session_count = 0; + int hash; + + rcu_read_lock_bh(); + for (hash = 0; hash < L2TP_HASH_SIZE; hash++) { + hlist_for_each_entry_rcu(session, &tunnel->session_hlist[hash], hlist) { + /* Session ID of zero is a dummy/reserved value used by pppol2tp */ + if (session->session_id == 0) + continue; + + session_count++; + } + } + rcu_read_unlock_bh(); + + seq_printf(m, "\nTUNNEL %u peer %u", tunnel->tunnel_id, tunnel->peer_tunnel_id); + if (tunnel->sock) { + struct inet_sock *inet = inet_sk(tunnel->sock); + +#if IS_ENABLED(CONFIG_IPV6) + if (tunnel->sock->sk_family == AF_INET6) { + const struct ipv6_pinfo *np = inet6_sk(tunnel->sock); + + seq_printf(m, " from %pI6c to %pI6c\n", + &np->saddr, &tunnel->sock->sk_v6_daddr); + } +#endif + if (tunnel->sock->sk_family == AF_INET) + seq_printf(m, " from %pI4 to %pI4\n", + &inet->inet_saddr, &inet->inet_daddr); + + if (tunnel->encap == L2TP_ENCAPTYPE_UDP) + seq_printf(m, " source port %hu, dest port %hu\n", + ntohs(inet->inet_sport), ntohs(inet->inet_dport)); + } + seq_printf(m, " L2TPv%d, %s\n", tunnel->version, + tunnel->encap == L2TP_ENCAPTYPE_UDP ? "UDP" : + tunnel->encap == L2TP_ENCAPTYPE_IP ? "IP" : + ""); + seq_printf(m, " %d sessions, refcnt %d/%d\n", session_count, + tunnel->sock ? refcount_read(&tunnel->sock->sk_refcnt) : 0, + refcount_read(&tunnel->ref_count)); + seq_printf(m, " %08x rx %ld/%ld/%ld rx %ld/%ld/%ld\n", + 0, + atomic_long_read(&tunnel->stats.tx_packets), + atomic_long_read(&tunnel->stats.tx_bytes), + atomic_long_read(&tunnel->stats.tx_errors), + atomic_long_read(&tunnel->stats.rx_packets), + atomic_long_read(&tunnel->stats.rx_bytes), + atomic_long_read(&tunnel->stats.rx_errors)); +} + +static void l2tp_dfs_seq_session_show(struct seq_file *m, void *v) +{ + struct l2tp_session *session = v; + + seq_printf(m, " SESSION %u, peer %u, %s\n", session->session_id, + session->peer_session_id, + session->pwtype == L2TP_PWTYPE_ETH ? "ETH" : + session->pwtype == L2TP_PWTYPE_PPP ? "PPP" : + ""); + if (session->send_seq || session->recv_seq) + seq_printf(m, " nr %u, ns %u\n", session->nr, session->ns); + seq_printf(m, " refcnt %d\n", refcount_read(&session->ref_count)); + seq_printf(m, " config 0/0/%c/%c/-/%s %08x %u\n", + session->recv_seq ? 'R' : '-', + session->send_seq ? 'S' : '-', + session->lns_mode ? "LNS" : "LAC", + 0, + jiffies_to_msecs(session->reorder_timeout)); + seq_printf(m, " offset 0 l2specific %hu/%d\n", + session->l2specific_type, l2tp_get_l2specific_len(session)); + if (session->cookie_len) { + seq_printf(m, " cookie %02x%02x%02x%02x", + session->cookie[0], session->cookie[1], + session->cookie[2], session->cookie[3]); + if (session->cookie_len == 8) + seq_printf(m, "%02x%02x%02x%02x", + session->cookie[4], session->cookie[5], + session->cookie[6], session->cookie[7]); + seq_puts(m, "\n"); + } + if (session->peer_cookie_len) { + seq_printf(m, " peer cookie %02x%02x%02x%02x", + session->peer_cookie[0], session->peer_cookie[1], + session->peer_cookie[2], session->peer_cookie[3]); + if (session->peer_cookie_len == 8) + seq_printf(m, "%02x%02x%02x%02x", + session->peer_cookie[4], session->peer_cookie[5], + session->peer_cookie[6], session->peer_cookie[7]); + seq_puts(m, "\n"); + } + + seq_printf(m, " %u/%u tx %ld/%ld/%ld rx %ld/%ld/%ld\n", + session->nr, session->ns, + atomic_long_read(&session->stats.tx_packets), + atomic_long_read(&session->stats.tx_bytes), + atomic_long_read(&session->stats.tx_errors), + atomic_long_read(&session->stats.rx_packets), + atomic_long_read(&session->stats.rx_bytes), + atomic_long_read(&session->stats.rx_errors)); + + if (session->show) + session->show(m, session); +} + +static int l2tp_dfs_seq_show(struct seq_file *m, void *v) +{ + struct l2tp_dfs_seq_data *pd = v; + + /* display header on line 1 */ + if (v == SEQ_START_TOKEN) { + seq_puts(m, "TUNNEL ID, peer ID from IP to IP\n"); + seq_puts(m, " L2TPv2/L2TPv3, UDP/IP\n"); + seq_puts(m, " sessions session-count, refcnt refcnt/sk->refcnt\n"); + seq_puts(m, " debug tx-pkts/bytes/errs rx-pkts/bytes/errs\n"); + seq_puts(m, " SESSION ID, peer ID, PWTYPE\n"); + seq_puts(m, " refcnt cnt\n"); + seq_puts(m, " offset OFFSET l2specific TYPE/LEN\n"); + seq_puts(m, " [ cookie ]\n"); + seq_puts(m, " [ peer cookie ]\n"); + seq_puts(m, " config mtu/mru/rcvseq/sendseq/dataseq/lns debug reorderto\n"); + seq_puts(m, " nr/ns tx-pkts/bytes/errs rx-pkts/bytes/errs\n"); + goto out; + } + + if (!pd->session) + l2tp_dfs_seq_tunnel_show(m, pd->tunnel); + else + l2tp_dfs_seq_session_show(m, pd->session); + +out: + return 0; +} + +static const struct seq_operations l2tp_dfs_seq_ops = { + .start = l2tp_dfs_seq_start, + .next = l2tp_dfs_seq_next, + .stop = l2tp_dfs_seq_stop, + .show = l2tp_dfs_seq_show, +}; + +static int l2tp_dfs_seq_open(struct inode *inode, struct file *file) +{ + struct l2tp_dfs_seq_data *pd; + struct seq_file *seq; + int rc = -ENOMEM; + + pd = kzalloc(sizeof(*pd), GFP_KERNEL); + if (!pd) + goto out; + + /* Derive the network namespace from the pid opening the + * file. + */ + pd->net = get_net_ns_by_pid(current->pid); + if (IS_ERR(pd->net)) { + rc = PTR_ERR(pd->net); + goto err_free_pd; + } + netns_tracker_alloc(pd->net, &pd->ns_tracker, GFP_KERNEL); + rc = seq_open(file, &l2tp_dfs_seq_ops); + if (rc) + goto err_free_net; + + seq = file->private_data; + seq->private = pd; + +out: + return rc; + +err_free_net: + put_net_track(pd->net, &pd->ns_tracker); +err_free_pd: + kfree(pd); + goto out; +} + +static int l2tp_dfs_seq_release(struct inode *inode, struct file *file) +{ + struct l2tp_dfs_seq_data *pd; + struct seq_file *seq; + + seq = file->private_data; + pd = seq->private; + if (pd->net) + put_net_track(pd->net, &pd->ns_tracker); + kfree(pd); + seq_release(inode, file); + + return 0; +} + +static const struct file_operations l2tp_dfs_fops = { + .owner = THIS_MODULE, + .open = l2tp_dfs_seq_open, + .read = seq_read, + .llseek = seq_lseek, + .release = l2tp_dfs_seq_release, +}; + +static int __init l2tp_debugfs_init(void) +{ + rootdir = debugfs_create_dir("l2tp", NULL); + + debugfs_create_file("tunnels", 0600, rootdir, NULL, &l2tp_dfs_fops); + + pr_info("L2TP debugfs support\n"); + + return 0; +} + +static void __exit l2tp_debugfs_exit(void) +{ + debugfs_remove_recursive(rootdir); +} + +module_init(l2tp_debugfs_init); +module_exit(l2tp_debugfs_exit); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("James Chapman <jchapman@katalix.com>"); +MODULE_DESCRIPTION("L2TP debugfs driver"); +MODULE_VERSION("1.0"); diff --git a/net/l2tp/l2tp_eth.c b/net/l2tp/l2tp_eth.c new file mode 100644 index 000000000..f2ae03c40 --- /dev/null +++ b/net/l2tp/l2tp_eth.c @@ -0,0 +1,370 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* L2TPv3 ethernet pseudowire driver + * + * Copyright (c) 2008,2009,2010 Katalix Systems Ltd + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/module.h> +#include <linux/skbuff.h> +#include <linux/socket.h> +#include <linux/hash.h> +#include <linux/l2tp.h> +#include <linux/in.h> +#include <linux/etherdevice.h> +#include <linux/spinlock.h> +#include <net/sock.h> +#include <net/ip.h> +#include <net/icmp.h> +#include <net/udp.h> +#include <net/inet_common.h> +#include <net/inet_hashtables.h> +#include <net/tcp_states.h> +#include <net/protocol.h> +#include <net/xfrm.h> +#include <net/net_namespace.h> +#include <net/netns/generic.h> +#include <linux/ip.h> +#include <linux/ipv6.h> +#include <linux/udp.h> + +#include "l2tp_core.h" + +/* Default device name. May be overridden by name specified by user */ +#define L2TP_ETH_DEV_NAME "l2tpeth%d" + +/* via netdev_priv() */ +struct l2tp_eth { + struct l2tp_session *session; + atomic_long_t tx_bytes; + atomic_long_t tx_packets; + atomic_long_t tx_dropped; + atomic_long_t rx_bytes; + atomic_long_t rx_packets; + atomic_long_t rx_errors; +}; + +/* via l2tp_session_priv() */ +struct l2tp_eth_sess { + struct net_device __rcu *dev; +}; + +static int l2tp_eth_dev_init(struct net_device *dev) +{ + eth_hw_addr_random(dev); + eth_broadcast_addr(dev->broadcast); + netdev_lockdep_set_classes(dev); + + return 0; +} + +static void l2tp_eth_dev_uninit(struct net_device *dev) +{ + struct l2tp_eth *priv = netdev_priv(dev); + struct l2tp_eth_sess *spriv; + + spriv = l2tp_session_priv(priv->session); + RCU_INIT_POINTER(spriv->dev, NULL); + /* No need for synchronize_net() here. We're called by + * unregister_netdev*(), which does the synchronisation for us. + */ +} + +static netdev_tx_t l2tp_eth_dev_xmit(struct sk_buff *skb, struct net_device *dev) +{ + struct l2tp_eth *priv = netdev_priv(dev); + struct l2tp_session *session = priv->session; + unsigned int len = skb->len; + int ret = l2tp_xmit_skb(session, skb); + + if (likely(ret == NET_XMIT_SUCCESS)) { + atomic_long_add(len, &priv->tx_bytes); + atomic_long_inc(&priv->tx_packets); + } else { + atomic_long_inc(&priv->tx_dropped); + } + return NETDEV_TX_OK; +} + +static void l2tp_eth_get_stats64(struct net_device *dev, + struct rtnl_link_stats64 *stats) +{ + struct l2tp_eth *priv = netdev_priv(dev); + + stats->tx_bytes = (unsigned long)atomic_long_read(&priv->tx_bytes); + stats->tx_packets = (unsigned long)atomic_long_read(&priv->tx_packets); + stats->tx_dropped = (unsigned long)atomic_long_read(&priv->tx_dropped); + stats->rx_bytes = (unsigned long)atomic_long_read(&priv->rx_bytes); + stats->rx_packets = (unsigned long)atomic_long_read(&priv->rx_packets); + stats->rx_errors = (unsigned long)atomic_long_read(&priv->rx_errors); +} + +static const struct net_device_ops l2tp_eth_netdev_ops = { + .ndo_init = l2tp_eth_dev_init, + .ndo_uninit = l2tp_eth_dev_uninit, + .ndo_start_xmit = l2tp_eth_dev_xmit, + .ndo_get_stats64 = l2tp_eth_get_stats64, + .ndo_set_mac_address = eth_mac_addr, +}; + +static struct device_type l2tpeth_type = { + .name = "l2tpeth", +}; + +static void l2tp_eth_dev_setup(struct net_device *dev) +{ + SET_NETDEV_DEVTYPE(dev, &l2tpeth_type); + ether_setup(dev); + dev->priv_flags &= ~IFF_TX_SKB_SHARING; + dev->features |= NETIF_F_LLTX; + dev->netdev_ops = &l2tp_eth_netdev_ops; + dev->needs_free_netdev = true; +} + +static void l2tp_eth_dev_recv(struct l2tp_session *session, struct sk_buff *skb, int data_len) +{ + struct l2tp_eth_sess *spriv = l2tp_session_priv(session); + struct net_device *dev; + struct l2tp_eth *priv; + + if (!pskb_may_pull(skb, ETH_HLEN)) + goto error; + + secpath_reset(skb); + + /* checksums verified by L2TP */ + skb->ip_summed = CHECKSUM_NONE; + + skb_dst_drop(skb); + nf_reset_ct(skb); + + rcu_read_lock(); + dev = rcu_dereference(spriv->dev); + if (!dev) + goto error_rcu; + + priv = netdev_priv(dev); + if (dev_forward_skb(dev, skb) == NET_RX_SUCCESS) { + atomic_long_inc(&priv->rx_packets); + atomic_long_add(data_len, &priv->rx_bytes); + } else { + atomic_long_inc(&priv->rx_errors); + } + rcu_read_unlock(); + + return; + +error_rcu: + rcu_read_unlock(); +error: + kfree_skb(skb); +} + +static void l2tp_eth_delete(struct l2tp_session *session) +{ + struct l2tp_eth_sess *spriv; + struct net_device *dev; + + if (session) { + spriv = l2tp_session_priv(session); + + rtnl_lock(); + dev = rtnl_dereference(spriv->dev); + if (dev) { + unregister_netdevice(dev); + rtnl_unlock(); + module_put(THIS_MODULE); + } else { + rtnl_unlock(); + } + } +} + +static void l2tp_eth_show(struct seq_file *m, void *arg) +{ + struct l2tp_session *session = arg; + struct l2tp_eth_sess *spriv = l2tp_session_priv(session); + struct net_device *dev; + + rcu_read_lock(); + dev = rcu_dereference(spriv->dev); + if (!dev) { + rcu_read_unlock(); + return; + } + dev_hold(dev); + rcu_read_unlock(); + + seq_printf(m, " interface %s\n", dev->name); + + dev_put(dev); +} + +static void l2tp_eth_adjust_mtu(struct l2tp_tunnel *tunnel, + struct l2tp_session *session, + struct net_device *dev) +{ + unsigned int overhead = 0; + u32 l3_overhead = 0; + u32 mtu; + + /* if the encap is UDP, account for UDP header size */ + if (tunnel->encap == L2TP_ENCAPTYPE_UDP) { + overhead += sizeof(struct udphdr); + dev->needed_headroom += sizeof(struct udphdr); + } + + lock_sock(tunnel->sock); + l3_overhead = kernel_sock_ip_overhead(tunnel->sock); + release_sock(tunnel->sock); + + if (l3_overhead == 0) { + /* L3 Overhead couldn't be identified, this could be + * because tunnel->sock was NULL or the socket's + * address family was not IPv4 or IPv6, + * dev mtu stays at 1500. + */ + return; + } + /* Adjust MTU, factor overhead - underlay L3, overlay L2 hdr + * UDP overhead, if any, was already factored in above. + */ + overhead += session->hdr_len + ETH_HLEN + l3_overhead; + + mtu = l2tp_tunnel_dst_mtu(tunnel) - overhead; + if (mtu < dev->min_mtu || mtu > dev->max_mtu) + dev->mtu = ETH_DATA_LEN - overhead; + else + dev->mtu = mtu; + + dev->needed_headroom += session->hdr_len; +} + +static int l2tp_eth_create(struct net *net, struct l2tp_tunnel *tunnel, + u32 session_id, u32 peer_session_id, + struct l2tp_session_cfg *cfg) +{ + unsigned char name_assign_type; + struct net_device *dev; + char name[IFNAMSIZ]; + struct l2tp_session *session; + struct l2tp_eth *priv; + struct l2tp_eth_sess *spriv; + int rc; + + if (cfg->ifname) { + strscpy(name, cfg->ifname, IFNAMSIZ); + name_assign_type = NET_NAME_USER; + } else { + strcpy(name, L2TP_ETH_DEV_NAME); + name_assign_type = NET_NAME_ENUM; + } + + session = l2tp_session_create(sizeof(*spriv), tunnel, session_id, + peer_session_id, cfg); + if (IS_ERR(session)) { + rc = PTR_ERR(session); + goto err; + } + + dev = alloc_netdev(sizeof(*priv), name, name_assign_type, + l2tp_eth_dev_setup); + if (!dev) { + rc = -ENOMEM; + goto err_sess; + } + + dev_net_set(dev, net); + dev->min_mtu = 0; + dev->max_mtu = ETH_MAX_MTU; + l2tp_eth_adjust_mtu(tunnel, session, dev); + + priv = netdev_priv(dev); + priv->session = session; + + session->recv_skb = l2tp_eth_dev_recv; + session->session_close = l2tp_eth_delete; + if (IS_ENABLED(CONFIG_L2TP_DEBUGFS)) + session->show = l2tp_eth_show; + + spriv = l2tp_session_priv(session); + + l2tp_session_inc_refcount(session); + + rtnl_lock(); + + /* Register both device and session while holding the rtnl lock. This + * ensures that l2tp_eth_delete() will see that there's a device to + * unregister, even if it happened to run before we assign spriv->dev. + */ + rc = l2tp_session_register(session, tunnel); + if (rc < 0) { + rtnl_unlock(); + goto err_sess_dev; + } + + rc = register_netdevice(dev); + if (rc < 0) { + rtnl_unlock(); + l2tp_session_delete(session); + l2tp_session_dec_refcount(session); + free_netdev(dev); + + return rc; + } + + strscpy(session->ifname, dev->name, IFNAMSIZ); + rcu_assign_pointer(spriv->dev, dev); + + rtnl_unlock(); + + l2tp_session_dec_refcount(session); + + __module_get(THIS_MODULE); + + return 0; + +err_sess_dev: + l2tp_session_dec_refcount(session); + free_netdev(dev); +err_sess: + kfree(session); +err: + return rc; +} + +static const struct l2tp_nl_cmd_ops l2tp_eth_nl_cmd_ops = { + .session_create = l2tp_eth_create, + .session_delete = l2tp_session_delete, +}; + +static int __init l2tp_eth_init(void) +{ + int err = 0; + + err = l2tp_nl_register_ops(L2TP_PWTYPE_ETH, &l2tp_eth_nl_cmd_ops); + if (err) + goto err; + + pr_info("L2TP ethernet pseudowire support (L2TPv3)\n"); + + return 0; + +err: + return err; +} + +static void __exit l2tp_eth_exit(void) +{ + l2tp_nl_unregister_ops(L2TP_PWTYPE_ETH); +} + +module_init(l2tp_eth_init); +module_exit(l2tp_eth_exit); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("James Chapman <jchapman@katalix.com>"); +MODULE_DESCRIPTION("L2TP ethernet pseudowire driver"); +MODULE_VERSION("1.0"); +MODULE_ALIAS_L2TP_PWTYPE(5); diff --git a/net/l2tp/l2tp_ip.c b/net/l2tp/l2tp_ip.c new file mode 100644 index 000000000..41a74fc84 --- /dev/null +++ b/net/l2tp/l2tp_ip.c @@ -0,0 +1,684 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* L2TPv3 IP encapsulation support + * + * Copyright (c) 2008,2009,2010 Katalix Systems Ltd + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <asm/ioctls.h> +#include <linux/icmp.h> +#include <linux/module.h> +#include <linux/skbuff.h> +#include <linux/random.h> +#include <linux/socket.h> +#include <linux/l2tp.h> +#include <linux/in.h> +#include <net/sock.h> +#include <net/ip.h> +#include <net/icmp.h> +#include <net/udp.h> +#include <net/inet_common.h> +#include <net/tcp_states.h> +#include <net/protocol.h> +#include <net/xfrm.h> + +#include "l2tp_core.h" + +struct l2tp_ip_sock { + /* inet_sock has to be the first member of l2tp_ip_sock */ + struct inet_sock inet; + + u32 conn_id; + u32 peer_conn_id; +}; + +static DEFINE_RWLOCK(l2tp_ip_lock); +static struct hlist_head l2tp_ip_table; +static struct hlist_head l2tp_ip_bind_table; + +static inline struct l2tp_ip_sock *l2tp_ip_sk(const struct sock *sk) +{ + return (struct l2tp_ip_sock *)sk; +} + +static struct sock *__l2tp_ip_bind_lookup(const struct net *net, __be32 laddr, + __be32 raddr, int dif, u32 tunnel_id) +{ + struct sock *sk; + + sk_for_each_bound(sk, &l2tp_ip_bind_table) { + const struct l2tp_ip_sock *l2tp = l2tp_ip_sk(sk); + const struct inet_sock *inet = inet_sk(sk); + int bound_dev_if; + + if (!net_eq(sock_net(sk), net)) + continue; + + bound_dev_if = READ_ONCE(sk->sk_bound_dev_if); + if (bound_dev_if && dif && bound_dev_if != dif) + continue; + + if (inet->inet_rcv_saddr && laddr && + inet->inet_rcv_saddr != laddr) + continue; + + if (inet->inet_daddr && raddr && inet->inet_daddr != raddr) + continue; + + if (l2tp->conn_id != tunnel_id) + continue; + + goto found; + } + + sk = NULL; +found: + return sk; +} + +/* When processing receive frames, there are two cases to + * consider. Data frames consist of a non-zero session-id and an + * optional cookie. Control frames consist of a regular L2TP header + * preceded by 32-bits of zeros. + * + * L2TPv3 Session Header Over IP + * + * 0 1 2 3 + * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | Session ID | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | Cookie (optional, maximum 64 bits)... + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * + * L2TPv3 Control Message Header Over IP + * + * 0 1 2 3 + * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | (32 bits of zeros) | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * |T|L|x|x|S|x|x|x|x|x|x|x| Ver | Length | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | Control Connection ID | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | Ns | Nr | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * + * All control frames are passed to userspace. + */ +static int l2tp_ip_recv(struct sk_buff *skb) +{ + struct net *net = dev_net(skb->dev); + struct sock *sk; + u32 session_id; + u32 tunnel_id; + unsigned char *ptr, *optr; + struct l2tp_session *session; + struct l2tp_tunnel *tunnel = NULL; + struct iphdr *iph; + + if (!pskb_may_pull(skb, 4)) + goto discard; + + /* Point to L2TP header */ + optr = skb->data; + ptr = skb->data; + session_id = ntohl(*((__be32 *)ptr)); + ptr += 4; + + /* RFC3931: L2TP/IP packets have the first 4 bytes containing + * the session_id. If it is 0, the packet is a L2TP control + * frame and the session_id value can be discarded. + */ + if (session_id == 0) { + __skb_pull(skb, 4); + goto pass_up; + } + + /* Ok, this is a data packet. Lookup the session. */ + session = l2tp_session_get(net, session_id); + if (!session) + goto discard; + + tunnel = session->tunnel; + if (!tunnel) + goto discard_sess; + + if (l2tp_v3_ensure_opt_in_linear(session, skb, &ptr, &optr)) + goto discard_sess; + + l2tp_recv_common(session, skb, ptr, optr, 0, skb->len); + l2tp_session_dec_refcount(session); + + return 0; + +pass_up: + /* Get the tunnel_id from the L2TP header */ + if (!pskb_may_pull(skb, 12)) + goto discard; + + if ((skb->data[0] & 0xc0) != 0xc0) + goto discard; + + tunnel_id = ntohl(*(__be32 *)&skb->data[4]); + iph = (struct iphdr *)skb_network_header(skb); + + read_lock_bh(&l2tp_ip_lock); + sk = __l2tp_ip_bind_lookup(net, iph->daddr, iph->saddr, inet_iif(skb), + tunnel_id); + if (!sk) { + read_unlock_bh(&l2tp_ip_lock); + goto discard; + } + sock_hold(sk); + read_unlock_bh(&l2tp_ip_lock); + + if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb)) + goto discard_put; + + nf_reset_ct(skb); + + return sk_receive_skb(sk, skb, 1); + +discard_sess: + l2tp_session_dec_refcount(session); + goto discard; + +discard_put: + sock_put(sk); + +discard: + kfree_skb(skb); + return 0; +} + +static int l2tp_ip_hash(struct sock *sk) +{ + if (sk_unhashed(sk)) { + write_lock_bh(&l2tp_ip_lock); + sk_add_node(sk, &l2tp_ip_table); + write_unlock_bh(&l2tp_ip_lock); + } + return 0; +} + +static void l2tp_ip_unhash(struct sock *sk) +{ + if (sk_unhashed(sk)) + return; + write_lock_bh(&l2tp_ip_lock); + sk_del_node_init(sk); + write_unlock_bh(&l2tp_ip_lock); +} + +static int l2tp_ip_open(struct sock *sk) +{ + /* Prevent autobind. We don't have ports. */ + inet_sk(sk)->inet_num = IPPROTO_L2TP; + + l2tp_ip_hash(sk); + return 0; +} + +static void l2tp_ip_close(struct sock *sk, long timeout) +{ + write_lock_bh(&l2tp_ip_lock); + hlist_del_init(&sk->sk_bind_node); + sk_del_node_init(sk); + write_unlock_bh(&l2tp_ip_lock); + sk_common_release(sk); +} + +static void l2tp_ip_destroy_sock(struct sock *sk) +{ + struct l2tp_tunnel *tunnel = l2tp_sk_to_tunnel(sk); + struct sk_buff *skb; + + while ((skb = __skb_dequeue_tail(&sk->sk_write_queue)) != NULL) + kfree_skb(skb); + + if (tunnel) + l2tp_tunnel_delete(tunnel); +} + +static int l2tp_ip_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len) +{ + struct inet_sock *inet = inet_sk(sk); + struct sockaddr_l2tpip *addr = (struct sockaddr_l2tpip *)uaddr; + struct net *net = sock_net(sk); + int ret; + int chk_addr_ret; + + if (addr_len < sizeof(struct sockaddr_l2tpip)) + return -EINVAL; + if (addr->l2tp_family != AF_INET) + return -EINVAL; + + lock_sock(sk); + + ret = -EINVAL; + if (!sock_flag(sk, SOCK_ZAPPED)) + goto out; + + if (sk->sk_state != TCP_CLOSE) + goto out; + + chk_addr_ret = inet_addr_type(net, addr->l2tp_addr.s_addr); + ret = -EADDRNOTAVAIL; + if (addr->l2tp_addr.s_addr && chk_addr_ret != RTN_LOCAL && + chk_addr_ret != RTN_MULTICAST && chk_addr_ret != RTN_BROADCAST) + goto out; + + if (addr->l2tp_addr.s_addr) { + inet->inet_rcv_saddr = addr->l2tp_addr.s_addr; + inet->inet_saddr = addr->l2tp_addr.s_addr; + } + if (chk_addr_ret == RTN_MULTICAST || chk_addr_ret == RTN_BROADCAST) + inet->inet_saddr = 0; /* Use device */ + + write_lock_bh(&l2tp_ip_lock); + if (__l2tp_ip_bind_lookup(net, addr->l2tp_addr.s_addr, 0, + sk->sk_bound_dev_if, addr->l2tp_conn_id)) { + write_unlock_bh(&l2tp_ip_lock); + ret = -EADDRINUSE; + goto out; + } + + sk_dst_reset(sk); + l2tp_ip_sk(sk)->conn_id = addr->l2tp_conn_id; + + sk_add_bind_node(sk, &l2tp_ip_bind_table); + sk_del_node_init(sk); + write_unlock_bh(&l2tp_ip_lock); + + ret = 0; + sock_reset_flag(sk, SOCK_ZAPPED); + +out: + release_sock(sk); + + return ret; +} + +static int l2tp_ip_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len) +{ + struct sockaddr_l2tpip *lsa = (struct sockaddr_l2tpip *)uaddr; + int rc; + + if (addr_len < sizeof(*lsa)) + return -EINVAL; + + if (ipv4_is_multicast(lsa->l2tp_addr.s_addr)) + return -EINVAL; + + lock_sock(sk); + + /* Must bind first - autobinding does not work */ + if (sock_flag(sk, SOCK_ZAPPED)) { + rc = -EINVAL; + goto out_sk; + } + + rc = __ip4_datagram_connect(sk, uaddr, addr_len); + if (rc < 0) + goto out_sk; + + l2tp_ip_sk(sk)->peer_conn_id = lsa->l2tp_conn_id; + + write_lock_bh(&l2tp_ip_lock); + hlist_del_init(&sk->sk_bind_node); + sk_add_bind_node(sk, &l2tp_ip_bind_table); + write_unlock_bh(&l2tp_ip_lock); + +out_sk: + release_sock(sk); + + return rc; +} + +static int l2tp_ip_disconnect(struct sock *sk, int flags) +{ + if (sock_flag(sk, SOCK_ZAPPED)) + return 0; + + return __udp_disconnect(sk, flags); +} + +static int l2tp_ip_getname(struct socket *sock, struct sockaddr *uaddr, + int peer) +{ + struct sock *sk = sock->sk; + struct inet_sock *inet = inet_sk(sk); + struct l2tp_ip_sock *lsk = l2tp_ip_sk(sk); + struct sockaddr_l2tpip *lsa = (struct sockaddr_l2tpip *)uaddr; + + memset(lsa, 0, sizeof(*lsa)); + lsa->l2tp_family = AF_INET; + if (peer) { + if (!inet->inet_dport) + return -ENOTCONN; + lsa->l2tp_conn_id = lsk->peer_conn_id; + lsa->l2tp_addr.s_addr = inet->inet_daddr; + } else { + __be32 addr = inet->inet_rcv_saddr; + + if (!addr) + addr = inet->inet_saddr; + lsa->l2tp_conn_id = lsk->conn_id; + lsa->l2tp_addr.s_addr = addr; + } + return sizeof(*lsa); +} + +static int l2tp_ip_backlog_recv(struct sock *sk, struct sk_buff *skb) +{ + int rc; + + /* Charge it to the socket, dropping if the queue is full. */ + rc = sock_queue_rcv_skb(sk, skb); + if (rc < 0) + goto drop; + + return 0; + +drop: + IP_INC_STATS(sock_net(sk), IPSTATS_MIB_INDISCARDS); + kfree_skb(skb); + return 0; +} + +/* Userspace will call sendmsg() on the tunnel socket to send L2TP + * control frames. + */ +static int l2tp_ip_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) +{ + struct sk_buff *skb; + int rc; + struct inet_sock *inet = inet_sk(sk); + struct rtable *rt = NULL; + struct flowi4 *fl4; + int connected = 0; + __be32 daddr; + + lock_sock(sk); + + rc = -ENOTCONN; + if (sock_flag(sk, SOCK_DEAD)) + goto out; + + /* Get and verify the address. */ + if (msg->msg_name) { + DECLARE_SOCKADDR(struct sockaddr_l2tpip *, lip, msg->msg_name); + + rc = -EINVAL; + if (msg->msg_namelen < sizeof(*lip)) + goto out; + + if (lip->l2tp_family != AF_INET) { + rc = -EAFNOSUPPORT; + if (lip->l2tp_family != AF_UNSPEC) + goto out; + } + + daddr = lip->l2tp_addr.s_addr; + } else { + rc = -EDESTADDRREQ; + if (sk->sk_state != TCP_ESTABLISHED) + goto out; + + daddr = inet->inet_daddr; + connected = 1; + } + + /* Allocate a socket buffer */ + rc = -ENOMEM; + skb = sock_wmalloc(sk, 2 + NET_SKB_PAD + sizeof(struct iphdr) + + 4 + len, 0, GFP_KERNEL); + if (!skb) + goto error; + + /* Reserve space for headers, putting IP header on 4-byte boundary. */ + skb_reserve(skb, 2 + NET_SKB_PAD); + skb_reset_network_header(skb); + skb_reserve(skb, sizeof(struct iphdr)); + skb_reset_transport_header(skb); + + /* Insert 0 session_id */ + *((__be32 *)skb_put(skb, 4)) = 0; + + /* Copy user data into skb */ + rc = memcpy_from_msg(skb_put(skb, len), msg, len); + if (rc < 0) { + kfree_skb(skb); + goto error; + } + + fl4 = &inet->cork.fl.u.ip4; + if (connected) + rt = (struct rtable *)__sk_dst_check(sk, 0); + + rcu_read_lock(); + if (!rt) { + const struct ip_options_rcu *inet_opt; + + inet_opt = rcu_dereference(inet->inet_opt); + + /* Use correct destination address if we have options. */ + if (inet_opt && inet_opt->opt.srr) + daddr = inet_opt->opt.faddr; + + /* If this fails, retransmit mechanism of transport layer will + * keep trying until route appears or the connection times + * itself out. + */ + rt = ip_route_output_ports(sock_net(sk), fl4, sk, + daddr, inet->inet_saddr, + inet->inet_dport, inet->inet_sport, + sk->sk_protocol, RT_CONN_FLAGS(sk), + sk->sk_bound_dev_if); + if (IS_ERR(rt)) + goto no_route; + if (connected) { + sk_setup_caps(sk, &rt->dst); + } else { + skb_dst_set(skb, &rt->dst); + goto xmit; + } + } + + /* We don't need to clone dst here, it is guaranteed to not disappear. + * __dev_xmit_skb() might force a refcount if needed. + */ + skb_dst_set_noref(skb, &rt->dst); + +xmit: + /* Queue the packet to IP for output */ + rc = ip_queue_xmit(sk, skb, &inet->cork.fl); + rcu_read_unlock(); + +error: + if (rc >= 0) + rc = len; + +out: + release_sock(sk); + return rc; + +no_route: + rcu_read_unlock(); + IP_INC_STATS(sock_net(sk), IPSTATS_MIB_OUTNOROUTES); + kfree_skb(skb); + rc = -EHOSTUNREACH; + goto out; +} + +static int l2tp_ip_recvmsg(struct sock *sk, struct msghdr *msg, + size_t len, int flags, int *addr_len) +{ + struct inet_sock *inet = inet_sk(sk); + size_t copied = 0; + int err = -EOPNOTSUPP; + DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name); + struct sk_buff *skb; + + if (flags & MSG_OOB) + goto out; + + skb = skb_recv_datagram(sk, flags, &err); + if (!skb) + goto out; + + copied = skb->len; + if (len < copied) { + msg->msg_flags |= MSG_TRUNC; + copied = len; + } + + err = skb_copy_datagram_msg(skb, 0, msg, copied); + if (err) + goto done; + + sock_recv_timestamp(msg, sk, skb); + + /* Copy the address. */ + if (sin) { + sin->sin_family = AF_INET; + sin->sin_addr.s_addr = ip_hdr(skb)->saddr; + sin->sin_port = 0; + memset(&sin->sin_zero, 0, sizeof(sin->sin_zero)); + *addr_len = sizeof(*sin); + } + if (inet->cmsg_flags) + ip_cmsg_recv(msg, skb); + if (flags & MSG_TRUNC) + copied = skb->len; +done: + skb_free_datagram(sk, skb); +out: + return err ? err : copied; +} + +int l2tp_ioctl(struct sock *sk, int cmd, unsigned long arg) +{ + struct sk_buff *skb; + int amount; + + switch (cmd) { + case SIOCOUTQ: + amount = sk_wmem_alloc_get(sk); + break; + case SIOCINQ: + spin_lock_bh(&sk->sk_receive_queue.lock); + skb = skb_peek(&sk->sk_receive_queue); + amount = skb ? skb->len : 0; + spin_unlock_bh(&sk->sk_receive_queue.lock); + break; + + default: + return -ENOIOCTLCMD; + } + + return put_user(amount, (int __user *)arg); +} +EXPORT_SYMBOL_GPL(l2tp_ioctl); + +static struct proto l2tp_ip_prot = { + .name = "L2TP/IP", + .owner = THIS_MODULE, + .init = l2tp_ip_open, + .close = l2tp_ip_close, + .bind = l2tp_ip_bind, + .connect = l2tp_ip_connect, + .disconnect = l2tp_ip_disconnect, + .ioctl = l2tp_ioctl, + .destroy = l2tp_ip_destroy_sock, + .setsockopt = ip_setsockopt, + .getsockopt = ip_getsockopt, + .sendmsg = l2tp_ip_sendmsg, + .recvmsg = l2tp_ip_recvmsg, + .backlog_rcv = l2tp_ip_backlog_recv, + .hash = l2tp_ip_hash, + .unhash = l2tp_ip_unhash, + .obj_size = sizeof(struct l2tp_ip_sock), +}; + +static const struct proto_ops l2tp_ip_ops = { + .family = PF_INET, + .owner = THIS_MODULE, + .release = inet_release, + .bind = inet_bind, + .connect = inet_dgram_connect, + .socketpair = sock_no_socketpair, + .accept = sock_no_accept, + .getname = l2tp_ip_getname, + .poll = datagram_poll, + .ioctl = inet_ioctl, + .gettstamp = sock_gettstamp, + .listen = sock_no_listen, + .shutdown = inet_shutdown, + .setsockopt = sock_common_setsockopt, + .getsockopt = sock_common_getsockopt, + .sendmsg = inet_sendmsg, + .recvmsg = sock_common_recvmsg, + .mmap = sock_no_mmap, + .sendpage = sock_no_sendpage, +}; + +static struct inet_protosw l2tp_ip_protosw = { + .type = SOCK_DGRAM, + .protocol = IPPROTO_L2TP, + .prot = &l2tp_ip_prot, + .ops = &l2tp_ip_ops, +}; + +static struct net_protocol l2tp_ip_protocol __read_mostly = { + .handler = l2tp_ip_recv, +}; + +static int __init l2tp_ip_init(void) +{ + int err; + + pr_info("L2TP IP encapsulation support (L2TPv3)\n"); + + err = proto_register(&l2tp_ip_prot, 1); + if (err != 0) + goto out; + + err = inet_add_protocol(&l2tp_ip_protocol, IPPROTO_L2TP); + if (err) + goto out1; + + inet_register_protosw(&l2tp_ip_protosw); + return 0; + +out1: + proto_unregister(&l2tp_ip_prot); +out: + return err; +} + +static void __exit l2tp_ip_exit(void) +{ + inet_unregister_protosw(&l2tp_ip_protosw); + inet_del_protocol(&l2tp_ip_protocol, IPPROTO_L2TP); + proto_unregister(&l2tp_ip_prot); +} + +module_init(l2tp_ip_init); +module_exit(l2tp_ip_exit); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("James Chapman <jchapman@katalix.com>"); +MODULE_DESCRIPTION("L2TP over IP"); +MODULE_VERSION("1.0"); + +/* Use the values of SOCK_DGRAM (2) as type and IPPROTO_L2TP (115) as protocol, + * because __stringify doesn't like enums + */ +MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET, 115, 2); +MODULE_ALIAS_NET_PF_PROTO(PF_INET, 115); diff --git a/net/l2tp/l2tp_ip6.c b/net/l2tp/l2tp_ip6.c new file mode 100644 index 000000000..314ec3a51 --- /dev/null +++ b/net/l2tp/l2tp_ip6.c @@ -0,0 +1,813 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* L2TPv3 IP encapsulation support for IPv6 + * + * Copyright (c) 2012 Katalix Systems Ltd + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/icmp.h> +#include <linux/module.h> +#include <linux/skbuff.h> +#include <linux/random.h> +#include <linux/socket.h> +#include <linux/l2tp.h> +#include <linux/in.h> +#include <linux/in6.h> +#include <net/sock.h> +#include <net/ip.h> +#include <net/icmp.h> +#include <net/udp.h> +#include <net/inet_common.h> +#include <net/tcp_states.h> +#include <net/protocol.h> +#include <net/xfrm.h> + +#include <net/transp_v6.h> +#include <net/addrconf.h> +#include <net/ip6_route.h> + +#include "l2tp_core.h" + +struct l2tp_ip6_sock { + /* inet_sock has to be the first member of l2tp_ip6_sock */ + struct inet_sock inet; + + u32 conn_id; + u32 peer_conn_id; + + /* ipv6_pinfo has to be the last member of l2tp_ip6_sock, see + * inet6_sk_generic + */ + struct ipv6_pinfo inet6; +}; + +static DEFINE_RWLOCK(l2tp_ip6_lock); +static struct hlist_head l2tp_ip6_table; +static struct hlist_head l2tp_ip6_bind_table; + +static inline struct l2tp_ip6_sock *l2tp_ip6_sk(const struct sock *sk) +{ + return (struct l2tp_ip6_sock *)sk; +} + +static struct sock *__l2tp_ip6_bind_lookup(const struct net *net, + const struct in6_addr *laddr, + const struct in6_addr *raddr, + int dif, u32 tunnel_id) +{ + struct sock *sk; + + sk_for_each_bound(sk, &l2tp_ip6_bind_table) { + const struct in6_addr *sk_laddr = inet6_rcv_saddr(sk); + const struct in6_addr *sk_raddr = &sk->sk_v6_daddr; + const struct l2tp_ip6_sock *l2tp = l2tp_ip6_sk(sk); + int bound_dev_if; + + if (!net_eq(sock_net(sk), net)) + continue; + + bound_dev_if = READ_ONCE(sk->sk_bound_dev_if); + if (bound_dev_if && dif && bound_dev_if != dif) + continue; + + if (sk_laddr && !ipv6_addr_any(sk_laddr) && + !ipv6_addr_any(laddr) && !ipv6_addr_equal(sk_laddr, laddr)) + continue; + + if (!ipv6_addr_any(sk_raddr) && raddr && + !ipv6_addr_any(raddr) && !ipv6_addr_equal(sk_raddr, raddr)) + continue; + + if (l2tp->conn_id != tunnel_id) + continue; + + goto found; + } + + sk = NULL; +found: + return sk; +} + +/* When processing receive frames, there are two cases to + * consider. Data frames consist of a non-zero session-id and an + * optional cookie. Control frames consist of a regular L2TP header + * preceded by 32-bits of zeros. + * + * L2TPv3 Session Header Over IP + * + * 0 1 2 3 + * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | Session ID | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | Cookie (optional, maximum 64 bits)... + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * + * L2TPv3 Control Message Header Over IP + * + * 0 1 2 3 + * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | (32 bits of zeros) | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * |T|L|x|x|S|x|x|x|x|x|x|x| Ver | Length | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | Control Connection ID | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | Ns | Nr | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * + * All control frames are passed to userspace. + */ +static int l2tp_ip6_recv(struct sk_buff *skb) +{ + struct net *net = dev_net(skb->dev); + struct sock *sk; + u32 session_id; + u32 tunnel_id; + unsigned char *ptr, *optr; + struct l2tp_session *session; + struct l2tp_tunnel *tunnel = NULL; + struct ipv6hdr *iph; + + if (!pskb_may_pull(skb, 4)) + goto discard; + + /* Point to L2TP header */ + optr = skb->data; + ptr = skb->data; + session_id = ntohl(*((__be32 *)ptr)); + ptr += 4; + + /* RFC3931: L2TP/IP packets have the first 4 bytes containing + * the session_id. If it is 0, the packet is a L2TP control + * frame and the session_id value can be discarded. + */ + if (session_id == 0) { + __skb_pull(skb, 4); + goto pass_up; + } + + /* Ok, this is a data packet. Lookup the session. */ + session = l2tp_session_get(net, session_id); + if (!session) + goto discard; + + tunnel = session->tunnel; + if (!tunnel) + goto discard_sess; + + if (l2tp_v3_ensure_opt_in_linear(session, skb, &ptr, &optr)) + goto discard_sess; + + l2tp_recv_common(session, skb, ptr, optr, 0, skb->len); + l2tp_session_dec_refcount(session); + + return 0; + +pass_up: + /* Get the tunnel_id from the L2TP header */ + if (!pskb_may_pull(skb, 12)) + goto discard; + + if ((skb->data[0] & 0xc0) != 0xc0) + goto discard; + + tunnel_id = ntohl(*(__be32 *)&skb->data[4]); + iph = ipv6_hdr(skb); + + read_lock_bh(&l2tp_ip6_lock); + sk = __l2tp_ip6_bind_lookup(net, &iph->daddr, &iph->saddr, + inet6_iif(skb), tunnel_id); + if (!sk) { + read_unlock_bh(&l2tp_ip6_lock); + goto discard; + } + sock_hold(sk); + read_unlock_bh(&l2tp_ip6_lock); + + if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb)) + goto discard_put; + + nf_reset_ct(skb); + + return sk_receive_skb(sk, skb, 1); + +discard_sess: + l2tp_session_dec_refcount(session); + goto discard; + +discard_put: + sock_put(sk); + +discard: + kfree_skb(skb); + return 0; +} + +static int l2tp_ip6_hash(struct sock *sk) +{ + if (sk_unhashed(sk)) { + write_lock_bh(&l2tp_ip6_lock); + sk_add_node(sk, &l2tp_ip6_table); + write_unlock_bh(&l2tp_ip6_lock); + } + return 0; +} + +static void l2tp_ip6_unhash(struct sock *sk) +{ + if (sk_unhashed(sk)) + return; + write_lock_bh(&l2tp_ip6_lock); + sk_del_node_init(sk); + write_unlock_bh(&l2tp_ip6_lock); +} + +static int l2tp_ip6_open(struct sock *sk) +{ + /* Prevent autobind. We don't have ports. */ + inet_sk(sk)->inet_num = IPPROTO_L2TP; + + l2tp_ip6_hash(sk); + return 0; +} + +static void l2tp_ip6_close(struct sock *sk, long timeout) +{ + write_lock_bh(&l2tp_ip6_lock); + hlist_del_init(&sk->sk_bind_node); + sk_del_node_init(sk); + write_unlock_bh(&l2tp_ip6_lock); + + sk_common_release(sk); +} + +static void l2tp_ip6_destroy_sock(struct sock *sk) +{ + struct l2tp_tunnel *tunnel = l2tp_sk_to_tunnel(sk); + + lock_sock(sk); + ip6_flush_pending_frames(sk); + release_sock(sk); + + if (tunnel) + l2tp_tunnel_delete(tunnel); +} + +static int l2tp_ip6_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len) +{ + struct inet_sock *inet = inet_sk(sk); + struct ipv6_pinfo *np = inet6_sk(sk); + struct sockaddr_l2tpip6 *addr = (struct sockaddr_l2tpip6 *)uaddr; + struct net *net = sock_net(sk); + __be32 v4addr = 0; + int bound_dev_if; + int addr_type; + int err; + + if (addr->l2tp_family != AF_INET6) + return -EINVAL; + if (addr_len < sizeof(*addr)) + return -EINVAL; + + addr_type = ipv6_addr_type(&addr->l2tp_addr); + + /* l2tp_ip6 sockets are IPv6 only */ + if (addr_type == IPV6_ADDR_MAPPED) + return -EADDRNOTAVAIL; + + /* L2TP is point-point, not multicast */ + if (addr_type & IPV6_ADDR_MULTICAST) + return -EADDRNOTAVAIL; + + lock_sock(sk); + + err = -EINVAL; + if (!sock_flag(sk, SOCK_ZAPPED)) + goto out_unlock; + + if (sk->sk_state != TCP_CLOSE) + goto out_unlock; + + bound_dev_if = sk->sk_bound_dev_if; + + /* Check if the address belongs to the host. */ + rcu_read_lock(); + if (addr_type != IPV6_ADDR_ANY) { + struct net_device *dev = NULL; + + if (addr_type & IPV6_ADDR_LINKLOCAL) { + if (addr->l2tp_scope_id) + bound_dev_if = addr->l2tp_scope_id; + + /* Binding to link-local address requires an + * interface. + */ + if (!bound_dev_if) + goto out_unlock_rcu; + + err = -ENODEV; + dev = dev_get_by_index_rcu(sock_net(sk), bound_dev_if); + if (!dev) + goto out_unlock_rcu; + } + + /* ipv4 addr of the socket is invalid. Only the + * unspecified and mapped address have a v4 equivalent. + */ + v4addr = LOOPBACK4_IPV6; + err = -EADDRNOTAVAIL; + if (!ipv6_chk_addr(sock_net(sk), &addr->l2tp_addr, dev, 0)) + goto out_unlock_rcu; + } + rcu_read_unlock(); + + write_lock_bh(&l2tp_ip6_lock); + if (__l2tp_ip6_bind_lookup(net, &addr->l2tp_addr, NULL, bound_dev_if, + addr->l2tp_conn_id)) { + write_unlock_bh(&l2tp_ip6_lock); + err = -EADDRINUSE; + goto out_unlock; + } + + inet->inet_saddr = v4addr; + inet->inet_rcv_saddr = v4addr; + sk->sk_bound_dev_if = bound_dev_if; + sk->sk_v6_rcv_saddr = addr->l2tp_addr; + np->saddr = addr->l2tp_addr; + + l2tp_ip6_sk(sk)->conn_id = addr->l2tp_conn_id; + + sk_add_bind_node(sk, &l2tp_ip6_bind_table); + sk_del_node_init(sk); + write_unlock_bh(&l2tp_ip6_lock); + + sock_reset_flag(sk, SOCK_ZAPPED); + release_sock(sk); + return 0; + +out_unlock_rcu: + rcu_read_unlock(); +out_unlock: + release_sock(sk); + + return err; +} + +static int l2tp_ip6_connect(struct sock *sk, struct sockaddr *uaddr, + int addr_len) +{ + struct sockaddr_l2tpip6 *lsa = (struct sockaddr_l2tpip6 *)uaddr; + struct sockaddr_in6 *usin = (struct sockaddr_in6 *)uaddr; + struct in6_addr *daddr; + int addr_type; + int rc; + + if (addr_len < sizeof(*lsa)) + return -EINVAL; + + if (usin->sin6_family != AF_INET6) + return -EINVAL; + + addr_type = ipv6_addr_type(&usin->sin6_addr); + if (addr_type & IPV6_ADDR_MULTICAST) + return -EINVAL; + + if (addr_type & IPV6_ADDR_MAPPED) { + daddr = &usin->sin6_addr; + if (ipv4_is_multicast(daddr->s6_addr32[3])) + return -EINVAL; + } + + lock_sock(sk); + + /* Must bind first - autobinding does not work */ + if (sock_flag(sk, SOCK_ZAPPED)) { + rc = -EINVAL; + goto out_sk; + } + + rc = __ip6_datagram_connect(sk, uaddr, addr_len); + if (rc < 0) + goto out_sk; + + l2tp_ip6_sk(sk)->peer_conn_id = lsa->l2tp_conn_id; + + write_lock_bh(&l2tp_ip6_lock); + hlist_del_init(&sk->sk_bind_node); + sk_add_bind_node(sk, &l2tp_ip6_bind_table); + write_unlock_bh(&l2tp_ip6_lock); + +out_sk: + release_sock(sk); + + return rc; +} + +static int l2tp_ip6_disconnect(struct sock *sk, int flags) +{ + if (sock_flag(sk, SOCK_ZAPPED)) + return 0; + + return __udp_disconnect(sk, flags); +} + +static int l2tp_ip6_getname(struct socket *sock, struct sockaddr *uaddr, + int peer) +{ + struct sockaddr_l2tpip6 *lsa = (struct sockaddr_l2tpip6 *)uaddr; + struct sock *sk = sock->sk; + struct ipv6_pinfo *np = inet6_sk(sk); + struct l2tp_ip6_sock *lsk = l2tp_ip6_sk(sk); + + lsa->l2tp_family = AF_INET6; + lsa->l2tp_flowinfo = 0; + lsa->l2tp_scope_id = 0; + lsa->l2tp_unused = 0; + if (peer) { + if (!lsk->peer_conn_id) + return -ENOTCONN; + lsa->l2tp_conn_id = lsk->peer_conn_id; + lsa->l2tp_addr = sk->sk_v6_daddr; + if (np->sndflow) + lsa->l2tp_flowinfo = np->flow_label; + } else { + if (ipv6_addr_any(&sk->sk_v6_rcv_saddr)) + lsa->l2tp_addr = np->saddr; + else + lsa->l2tp_addr = sk->sk_v6_rcv_saddr; + + lsa->l2tp_conn_id = lsk->conn_id; + } + if (ipv6_addr_type(&lsa->l2tp_addr) & IPV6_ADDR_LINKLOCAL) + lsa->l2tp_scope_id = READ_ONCE(sk->sk_bound_dev_if); + return sizeof(*lsa); +} + +static int l2tp_ip6_backlog_recv(struct sock *sk, struct sk_buff *skb) +{ + int rc; + + /* Charge it to the socket, dropping if the queue is full. */ + rc = sock_queue_rcv_skb(sk, skb); + if (rc < 0) + goto drop; + + return 0; + +drop: + IP_INC_STATS(sock_net(sk), IPSTATS_MIB_INDISCARDS); + kfree_skb(skb); + return -1; +} + +static int l2tp_ip6_push_pending_frames(struct sock *sk) +{ + struct sk_buff *skb; + __be32 *transhdr = NULL; + int err = 0; + + skb = skb_peek(&sk->sk_write_queue); + if (!skb) + goto out; + + transhdr = (__be32 *)skb_transport_header(skb); + *transhdr = 0; + + err = ip6_push_pending_frames(sk); + +out: + return err; +} + +/* Userspace will call sendmsg() on the tunnel socket to send L2TP + * control frames. + */ +static int l2tp_ip6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) +{ + struct ipv6_txoptions opt_space; + DECLARE_SOCKADDR(struct sockaddr_l2tpip6 *, lsa, msg->msg_name); + struct in6_addr *daddr, *final_p, final; + struct ipv6_pinfo *np = inet6_sk(sk); + struct ipv6_txoptions *opt_to_free = NULL; + struct ipv6_txoptions *opt = NULL; + struct ip6_flowlabel *flowlabel = NULL; + struct dst_entry *dst = NULL; + struct flowi6 fl6; + struct ipcm6_cookie ipc6; + int addr_len = msg->msg_namelen; + int transhdrlen = 4; /* zero session-id */ + int ulen; + int err; + + /* Rough check on arithmetic overflow, + * better check is made in ip6_append_data(). + */ + if (len > INT_MAX - transhdrlen) + return -EMSGSIZE; + + /* Mirror BSD error message compatibility */ + if (msg->msg_flags & MSG_OOB) + return -EOPNOTSUPP; + + /* Get and verify the address */ + memset(&fl6, 0, sizeof(fl6)); + + fl6.flowi6_mark = READ_ONCE(sk->sk_mark); + fl6.flowi6_uid = sk->sk_uid; + + ipcm6_init(&ipc6); + + if (lsa) { + if (addr_len < SIN6_LEN_RFC2133) + return -EINVAL; + + if (lsa->l2tp_family && lsa->l2tp_family != AF_INET6) + return -EAFNOSUPPORT; + + daddr = &lsa->l2tp_addr; + if (np->sndflow) { + fl6.flowlabel = lsa->l2tp_flowinfo & IPV6_FLOWINFO_MASK; + if (fl6.flowlabel & IPV6_FLOWLABEL_MASK) { + flowlabel = fl6_sock_lookup(sk, fl6.flowlabel); + if (IS_ERR(flowlabel)) + return -EINVAL; + } + } + + /* Otherwise it will be difficult to maintain + * sk->sk_dst_cache. + */ + if (sk->sk_state == TCP_ESTABLISHED && + ipv6_addr_equal(daddr, &sk->sk_v6_daddr)) + daddr = &sk->sk_v6_daddr; + + if (addr_len >= sizeof(struct sockaddr_in6) && + lsa->l2tp_scope_id && + ipv6_addr_type(daddr) & IPV6_ADDR_LINKLOCAL) + fl6.flowi6_oif = lsa->l2tp_scope_id; + } else { + if (sk->sk_state != TCP_ESTABLISHED) + return -EDESTADDRREQ; + + daddr = &sk->sk_v6_daddr; + fl6.flowlabel = np->flow_label; + } + + if (fl6.flowi6_oif == 0) + fl6.flowi6_oif = READ_ONCE(sk->sk_bound_dev_if); + + if (msg->msg_controllen) { + opt = &opt_space; + memset(opt, 0, sizeof(struct ipv6_txoptions)); + opt->tot_len = sizeof(struct ipv6_txoptions); + ipc6.opt = opt; + + err = ip6_datagram_send_ctl(sock_net(sk), sk, msg, &fl6, &ipc6); + if (err < 0) { + fl6_sock_release(flowlabel); + return err; + } + if ((fl6.flowlabel & IPV6_FLOWLABEL_MASK) && !flowlabel) { + flowlabel = fl6_sock_lookup(sk, fl6.flowlabel); + if (IS_ERR(flowlabel)) + return -EINVAL; + } + if (!(opt->opt_nflen | opt->opt_flen)) + opt = NULL; + } + + if (!opt) { + opt = txopt_get(np); + opt_to_free = opt; + } + if (flowlabel) + opt = fl6_merge_options(&opt_space, flowlabel, opt); + opt = ipv6_fixup_options(&opt_space, opt); + ipc6.opt = opt; + + fl6.flowi6_proto = sk->sk_protocol; + if (!ipv6_addr_any(daddr)) + fl6.daddr = *daddr; + else + fl6.daddr.s6_addr[15] = 0x1; /* :: means loopback (BSD'ism) */ + if (ipv6_addr_any(&fl6.saddr) && !ipv6_addr_any(&np->saddr)) + fl6.saddr = np->saddr; + + final_p = fl6_update_dst(&fl6, opt, &final); + + if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr)) + fl6.flowi6_oif = np->mcast_oif; + else if (!fl6.flowi6_oif) + fl6.flowi6_oif = np->ucast_oif; + + security_sk_classify_flow(sk, flowi6_to_flowi_common(&fl6)); + + if (ipc6.tclass < 0) + ipc6.tclass = np->tclass; + + fl6.flowlabel = ip6_make_flowinfo(ipc6.tclass, fl6.flowlabel); + + dst = ip6_dst_lookup_flow(sock_net(sk), sk, &fl6, final_p); + if (IS_ERR(dst)) { + err = PTR_ERR(dst); + goto out; + } + + if (ipc6.hlimit < 0) + ipc6.hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst); + + if (ipc6.dontfrag < 0) + ipc6.dontfrag = np->dontfrag; + + if (msg->msg_flags & MSG_CONFIRM) + goto do_confirm; + +back_from_confirm: + lock_sock(sk); + ulen = len + skb_queue_empty(&sk->sk_write_queue) ? transhdrlen : 0; + err = ip6_append_data(sk, ip_generic_getfrag, msg, + ulen, transhdrlen, &ipc6, + &fl6, (struct rt6_info *)dst, + msg->msg_flags); + if (err) + ip6_flush_pending_frames(sk); + else if (!(msg->msg_flags & MSG_MORE)) + err = l2tp_ip6_push_pending_frames(sk); + release_sock(sk); +done: + dst_release(dst); +out: + fl6_sock_release(flowlabel); + txopt_put(opt_to_free); + + return err < 0 ? err : len; + +do_confirm: + if (msg->msg_flags & MSG_PROBE) + dst_confirm_neigh(dst, &fl6.daddr); + if (!(msg->msg_flags & MSG_PROBE) || len) + goto back_from_confirm; + err = 0; + goto done; +} + +static int l2tp_ip6_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, + int flags, int *addr_len) +{ + struct ipv6_pinfo *np = inet6_sk(sk); + DECLARE_SOCKADDR(struct sockaddr_l2tpip6 *, lsa, msg->msg_name); + size_t copied = 0; + int err = -EOPNOTSUPP; + struct sk_buff *skb; + + if (flags & MSG_OOB) + goto out; + + if (flags & MSG_ERRQUEUE) + return ipv6_recv_error(sk, msg, len, addr_len); + + skb = skb_recv_datagram(sk, flags, &err); + if (!skb) + goto out; + + copied = skb->len; + if (len < copied) { + msg->msg_flags |= MSG_TRUNC; + copied = len; + } + + err = skb_copy_datagram_msg(skb, 0, msg, copied); + if (err) + goto done; + + sock_recv_timestamp(msg, sk, skb); + + /* Copy the address. */ + if (lsa) { + lsa->l2tp_family = AF_INET6; + lsa->l2tp_unused = 0; + lsa->l2tp_addr = ipv6_hdr(skb)->saddr; + lsa->l2tp_flowinfo = 0; + lsa->l2tp_scope_id = 0; + lsa->l2tp_conn_id = 0; + if (ipv6_addr_type(&lsa->l2tp_addr) & IPV6_ADDR_LINKLOCAL) + lsa->l2tp_scope_id = inet6_iif(skb); + *addr_len = sizeof(*lsa); + } + + if (np->rxopt.all) + ip6_datagram_recv_ctl(sk, msg, skb); + + if (flags & MSG_TRUNC) + copied = skb->len; +done: + skb_free_datagram(sk, skb); +out: + return err ? err : copied; +} + +static struct proto l2tp_ip6_prot = { + .name = "L2TP/IPv6", + .owner = THIS_MODULE, + .init = l2tp_ip6_open, + .close = l2tp_ip6_close, + .bind = l2tp_ip6_bind, + .connect = l2tp_ip6_connect, + .disconnect = l2tp_ip6_disconnect, + .ioctl = l2tp_ioctl, + .destroy = l2tp_ip6_destroy_sock, + .setsockopt = ipv6_setsockopt, + .getsockopt = ipv6_getsockopt, + .sendmsg = l2tp_ip6_sendmsg, + .recvmsg = l2tp_ip6_recvmsg, + .backlog_rcv = l2tp_ip6_backlog_recv, + .hash = l2tp_ip6_hash, + .unhash = l2tp_ip6_unhash, + .obj_size = sizeof(struct l2tp_ip6_sock), +}; + +static const struct proto_ops l2tp_ip6_ops = { + .family = PF_INET6, + .owner = THIS_MODULE, + .release = inet6_release, + .bind = inet6_bind, + .connect = inet_dgram_connect, + .socketpair = sock_no_socketpair, + .accept = sock_no_accept, + .getname = l2tp_ip6_getname, + .poll = datagram_poll, + .ioctl = inet6_ioctl, + .gettstamp = sock_gettstamp, + .listen = sock_no_listen, + .shutdown = inet_shutdown, + .setsockopt = sock_common_setsockopt, + .getsockopt = sock_common_getsockopt, + .sendmsg = inet_sendmsg, + .recvmsg = sock_common_recvmsg, + .mmap = sock_no_mmap, + .sendpage = sock_no_sendpage, +#ifdef CONFIG_COMPAT + .compat_ioctl = inet6_compat_ioctl, +#endif +}; + +static struct inet_protosw l2tp_ip6_protosw = { + .type = SOCK_DGRAM, + .protocol = IPPROTO_L2TP, + .prot = &l2tp_ip6_prot, + .ops = &l2tp_ip6_ops, +}; + +static struct inet6_protocol l2tp_ip6_protocol __read_mostly = { + .handler = l2tp_ip6_recv, +}; + +static int __init l2tp_ip6_init(void) +{ + int err; + + pr_info("L2TP IP encapsulation support for IPv6 (L2TPv3)\n"); + + err = proto_register(&l2tp_ip6_prot, 1); + if (err != 0) + goto out; + + err = inet6_add_protocol(&l2tp_ip6_protocol, IPPROTO_L2TP); + if (err) + goto out1; + + inet6_register_protosw(&l2tp_ip6_protosw); + return 0; + +out1: + proto_unregister(&l2tp_ip6_prot); +out: + return err; +} + +static void __exit l2tp_ip6_exit(void) +{ + inet6_unregister_protosw(&l2tp_ip6_protosw); + inet6_del_protocol(&l2tp_ip6_protocol, IPPROTO_L2TP); + proto_unregister(&l2tp_ip6_prot); +} + +module_init(l2tp_ip6_init); +module_exit(l2tp_ip6_exit); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Chris Elston <celston@katalix.com>"); +MODULE_DESCRIPTION("L2TP IP encapsulation for IPv6"); +MODULE_VERSION("1.0"); + +/* Use the values of SOCK_DGRAM (2) as type and IPPROTO_L2TP (115) as protocol, + * because __stringify doesn't like enums + */ +MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET6, 115, 2); +MODULE_ALIAS_NET_PF_PROTO(PF_INET6, 115); diff --git a/net/l2tp/l2tp_netlink.c b/net/l2tp/l2tp_netlink.c new file mode 100644 index 000000000..a901fd14f --- /dev/null +++ b/net/l2tp/l2tp_netlink.c @@ -0,0 +1,1048 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* L2TP netlink layer, for management + * + * Copyright (c) 2008,2009,2010 Katalix Systems Ltd + * + * Partly based on the IrDA nelink implementation + * (see net/irda/irnetlink.c) which is: + * Copyright (c) 2007 Samuel Ortiz <samuel@sortiz.org> + * which is in turn partly based on the wireless netlink code: + * Copyright 2006 Johannes Berg <johannes@sipsolutions.net> + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <net/sock.h> +#include <net/genetlink.h> +#include <net/udp.h> +#include <linux/in.h> +#include <linux/udp.h> +#include <linux/socket.h> +#include <linux/module.h> +#include <linux/list.h> +#include <net/net_namespace.h> + +#include <linux/l2tp.h> + +#include "l2tp_core.h" + +static struct genl_family l2tp_nl_family; + +static const struct genl_multicast_group l2tp_multicast_group[] = { + { + .name = L2TP_GENL_MCGROUP, + }, +}; + +static int l2tp_nl_tunnel_send(struct sk_buff *skb, u32 portid, u32 seq, + int flags, struct l2tp_tunnel *tunnel, u8 cmd); +static int l2tp_nl_session_send(struct sk_buff *skb, u32 portid, u32 seq, + int flags, struct l2tp_session *session, + u8 cmd); + +/* Accessed under genl lock */ +static const struct l2tp_nl_cmd_ops *l2tp_nl_cmd_ops[__L2TP_PWTYPE_MAX]; + +static struct l2tp_session *l2tp_nl_session_get(struct genl_info *info) +{ + u32 tunnel_id; + u32 session_id; + char *ifname; + struct l2tp_tunnel *tunnel; + struct l2tp_session *session = NULL; + struct net *net = genl_info_net(info); + + if (info->attrs[L2TP_ATTR_IFNAME]) { + ifname = nla_data(info->attrs[L2TP_ATTR_IFNAME]); + session = l2tp_session_get_by_ifname(net, ifname); + } else if ((info->attrs[L2TP_ATTR_SESSION_ID]) && + (info->attrs[L2TP_ATTR_CONN_ID])) { + tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]); + session_id = nla_get_u32(info->attrs[L2TP_ATTR_SESSION_ID]); + tunnel = l2tp_tunnel_get(net, tunnel_id); + if (tunnel) { + session = l2tp_tunnel_get_session(tunnel, session_id); + l2tp_tunnel_dec_refcount(tunnel); + } + } + + return session; +} + +static int l2tp_nl_cmd_noop(struct sk_buff *skb, struct genl_info *info) +{ + struct sk_buff *msg; + void *hdr; + int ret = -ENOBUFS; + + msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL); + if (!msg) { + ret = -ENOMEM; + goto out; + } + + hdr = genlmsg_put(msg, info->snd_portid, info->snd_seq, + &l2tp_nl_family, 0, L2TP_CMD_NOOP); + if (!hdr) { + ret = -EMSGSIZE; + goto err_out; + } + + genlmsg_end(msg, hdr); + + return genlmsg_unicast(genl_info_net(info), msg, info->snd_portid); + +err_out: + nlmsg_free(msg); + +out: + return ret; +} + +static int l2tp_tunnel_notify(struct genl_family *family, + struct genl_info *info, + struct l2tp_tunnel *tunnel, + u8 cmd) +{ + struct sk_buff *msg; + int ret; + + msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL); + if (!msg) + return -ENOMEM; + + ret = l2tp_nl_tunnel_send(msg, info->snd_portid, info->snd_seq, + NLM_F_ACK, tunnel, cmd); + + if (ret >= 0) { + ret = genlmsg_multicast_allns(family, msg, 0, 0, GFP_ATOMIC); + /* We don't care if no one is listening */ + if (ret == -ESRCH) + ret = 0; + return ret; + } + + nlmsg_free(msg); + + return ret; +} + +static int l2tp_session_notify(struct genl_family *family, + struct genl_info *info, + struct l2tp_session *session, + u8 cmd) +{ + struct sk_buff *msg; + int ret; + + msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL); + if (!msg) + return -ENOMEM; + + ret = l2tp_nl_session_send(msg, info->snd_portid, info->snd_seq, + NLM_F_ACK, session, cmd); + + if (ret >= 0) { + ret = genlmsg_multicast_allns(family, msg, 0, 0, GFP_ATOMIC); + /* We don't care if no one is listening */ + if (ret == -ESRCH) + ret = 0; + return ret; + } + + nlmsg_free(msg); + + return ret; +} + +static int l2tp_nl_cmd_tunnel_create_get_addr(struct nlattr **attrs, struct l2tp_tunnel_cfg *cfg) +{ + if (attrs[L2TP_ATTR_UDP_SPORT]) + cfg->local_udp_port = nla_get_u16(attrs[L2TP_ATTR_UDP_SPORT]); + if (attrs[L2TP_ATTR_UDP_DPORT]) + cfg->peer_udp_port = nla_get_u16(attrs[L2TP_ATTR_UDP_DPORT]); + cfg->use_udp_checksums = nla_get_flag(attrs[L2TP_ATTR_UDP_CSUM]); + + /* Must have either AF_INET or AF_INET6 address for source and destination */ +#if IS_ENABLED(CONFIG_IPV6) + if (attrs[L2TP_ATTR_IP6_SADDR] && attrs[L2TP_ATTR_IP6_DADDR]) { + cfg->local_ip6 = nla_data(attrs[L2TP_ATTR_IP6_SADDR]); + cfg->peer_ip6 = nla_data(attrs[L2TP_ATTR_IP6_DADDR]); + cfg->udp6_zero_tx_checksums = nla_get_flag(attrs[L2TP_ATTR_UDP_ZERO_CSUM6_TX]); + cfg->udp6_zero_rx_checksums = nla_get_flag(attrs[L2TP_ATTR_UDP_ZERO_CSUM6_RX]); + return 0; + } +#endif + if (attrs[L2TP_ATTR_IP_SADDR] && attrs[L2TP_ATTR_IP_DADDR]) { + cfg->local_ip.s_addr = nla_get_in_addr(attrs[L2TP_ATTR_IP_SADDR]); + cfg->peer_ip.s_addr = nla_get_in_addr(attrs[L2TP_ATTR_IP_DADDR]); + return 0; + } + return -EINVAL; +} + +static int l2tp_nl_cmd_tunnel_create(struct sk_buff *skb, struct genl_info *info) +{ + u32 tunnel_id; + u32 peer_tunnel_id; + int proto_version; + int fd = -1; + int ret = 0; + struct l2tp_tunnel_cfg cfg = { 0, }; + struct l2tp_tunnel *tunnel; + struct net *net = genl_info_net(info); + struct nlattr **attrs = info->attrs; + + if (!attrs[L2TP_ATTR_CONN_ID]) { + ret = -EINVAL; + goto out; + } + tunnel_id = nla_get_u32(attrs[L2TP_ATTR_CONN_ID]); + + if (!attrs[L2TP_ATTR_PEER_CONN_ID]) { + ret = -EINVAL; + goto out; + } + peer_tunnel_id = nla_get_u32(attrs[L2TP_ATTR_PEER_CONN_ID]); + + if (!attrs[L2TP_ATTR_PROTO_VERSION]) { + ret = -EINVAL; + goto out; + } + proto_version = nla_get_u8(attrs[L2TP_ATTR_PROTO_VERSION]); + + if (!attrs[L2TP_ATTR_ENCAP_TYPE]) { + ret = -EINVAL; + goto out; + } + cfg.encap = nla_get_u16(attrs[L2TP_ATTR_ENCAP_TYPE]); + + /* Managed tunnels take the tunnel socket from userspace. + * Unmanaged tunnels must call out the source and destination addresses + * for the kernel to create the tunnel socket itself. + */ + if (attrs[L2TP_ATTR_FD]) { + fd = nla_get_u32(attrs[L2TP_ATTR_FD]); + } else { + ret = l2tp_nl_cmd_tunnel_create_get_addr(attrs, &cfg); + if (ret < 0) + goto out; + } + + ret = -EINVAL; + switch (cfg.encap) { + case L2TP_ENCAPTYPE_UDP: + case L2TP_ENCAPTYPE_IP: + ret = l2tp_tunnel_create(fd, proto_version, tunnel_id, + peer_tunnel_id, &cfg, &tunnel); + break; + } + + if (ret < 0) + goto out; + + l2tp_tunnel_inc_refcount(tunnel); + ret = l2tp_tunnel_register(tunnel, net, &cfg); + if (ret < 0) { + kfree(tunnel); + goto out; + } + ret = l2tp_tunnel_notify(&l2tp_nl_family, info, tunnel, + L2TP_CMD_TUNNEL_CREATE); + l2tp_tunnel_dec_refcount(tunnel); + +out: + return ret; +} + +static int l2tp_nl_cmd_tunnel_delete(struct sk_buff *skb, struct genl_info *info) +{ + struct l2tp_tunnel *tunnel; + u32 tunnel_id; + int ret = 0; + struct net *net = genl_info_net(info); + + if (!info->attrs[L2TP_ATTR_CONN_ID]) { + ret = -EINVAL; + goto out; + } + tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]); + + tunnel = l2tp_tunnel_get(net, tunnel_id); + if (!tunnel) { + ret = -ENODEV; + goto out; + } + + l2tp_tunnel_notify(&l2tp_nl_family, info, + tunnel, L2TP_CMD_TUNNEL_DELETE); + + l2tp_tunnel_delete(tunnel); + + l2tp_tunnel_dec_refcount(tunnel); + +out: + return ret; +} + +static int l2tp_nl_cmd_tunnel_modify(struct sk_buff *skb, struct genl_info *info) +{ + struct l2tp_tunnel *tunnel; + u32 tunnel_id; + int ret = 0; + struct net *net = genl_info_net(info); + + if (!info->attrs[L2TP_ATTR_CONN_ID]) { + ret = -EINVAL; + goto out; + } + tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]); + + tunnel = l2tp_tunnel_get(net, tunnel_id); + if (!tunnel) { + ret = -ENODEV; + goto out; + } + + ret = l2tp_tunnel_notify(&l2tp_nl_family, info, + tunnel, L2TP_CMD_TUNNEL_MODIFY); + + l2tp_tunnel_dec_refcount(tunnel); + +out: + return ret; +} + +#if IS_ENABLED(CONFIG_IPV6) +static int l2tp_nl_tunnel_send_addr6(struct sk_buff *skb, struct sock *sk, + enum l2tp_encap_type encap) +{ + struct inet_sock *inet = inet_sk(sk); + struct ipv6_pinfo *np = inet6_sk(sk); + + switch (encap) { + case L2TP_ENCAPTYPE_UDP: + if (udp_get_no_check6_tx(sk) && + nla_put_flag(skb, L2TP_ATTR_UDP_ZERO_CSUM6_TX)) + return -1; + if (udp_get_no_check6_rx(sk) && + nla_put_flag(skb, L2TP_ATTR_UDP_ZERO_CSUM6_RX)) + return -1; + if (nla_put_u16(skb, L2TP_ATTR_UDP_SPORT, ntohs(inet->inet_sport)) || + nla_put_u16(skb, L2TP_ATTR_UDP_DPORT, ntohs(inet->inet_dport))) + return -1; + fallthrough; + case L2TP_ENCAPTYPE_IP: + if (nla_put_in6_addr(skb, L2TP_ATTR_IP6_SADDR, &np->saddr) || + nla_put_in6_addr(skb, L2TP_ATTR_IP6_DADDR, &sk->sk_v6_daddr)) + return -1; + break; + } + return 0; +} +#endif + +static int l2tp_nl_tunnel_send_addr4(struct sk_buff *skb, struct sock *sk, + enum l2tp_encap_type encap) +{ + struct inet_sock *inet = inet_sk(sk); + + switch (encap) { + case L2TP_ENCAPTYPE_UDP: + if (nla_put_u8(skb, L2TP_ATTR_UDP_CSUM, !sk->sk_no_check_tx) || + nla_put_u16(skb, L2TP_ATTR_UDP_SPORT, ntohs(inet->inet_sport)) || + nla_put_u16(skb, L2TP_ATTR_UDP_DPORT, ntohs(inet->inet_dport))) + return -1; + fallthrough; + case L2TP_ENCAPTYPE_IP: + if (nla_put_in_addr(skb, L2TP_ATTR_IP_SADDR, inet->inet_saddr) || + nla_put_in_addr(skb, L2TP_ATTR_IP_DADDR, inet->inet_daddr)) + return -1; + break; + } + + return 0; +} + +/* Append attributes for the tunnel address, handling the different attribute types + * used for different tunnel encapsulation and AF_INET v.s. AF_INET6. + */ +static int l2tp_nl_tunnel_send_addr(struct sk_buff *skb, struct l2tp_tunnel *tunnel) +{ + struct sock *sk = tunnel->sock; + + if (!sk) + return 0; + +#if IS_ENABLED(CONFIG_IPV6) + if (sk->sk_family == AF_INET6) + return l2tp_nl_tunnel_send_addr6(skb, sk, tunnel->encap); +#endif + return l2tp_nl_tunnel_send_addr4(skb, sk, tunnel->encap); +} + +static int l2tp_nl_tunnel_send(struct sk_buff *skb, u32 portid, u32 seq, int flags, + struct l2tp_tunnel *tunnel, u8 cmd) +{ + void *hdr; + struct nlattr *nest; + + hdr = genlmsg_put(skb, portid, seq, &l2tp_nl_family, flags, cmd); + if (!hdr) + return -EMSGSIZE; + + if (nla_put_u8(skb, L2TP_ATTR_PROTO_VERSION, tunnel->version) || + nla_put_u32(skb, L2TP_ATTR_CONN_ID, tunnel->tunnel_id) || + nla_put_u32(skb, L2TP_ATTR_PEER_CONN_ID, tunnel->peer_tunnel_id) || + nla_put_u32(skb, L2TP_ATTR_DEBUG, 0) || + nla_put_u16(skb, L2TP_ATTR_ENCAP_TYPE, tunnel->encap)) + goto nla_put_failure; + + nest = nla_nest_start_noflag(skb, L2TP_ATTR_STATS); + if (!nest) + goto nla_put_failure; + + if (nla_put_u64_64bit(skb, L2TP_ATTR_TX_PACKETS, + atomic_long_read(&tunnel->stats.tx_packets), + L2TP_ATTR_STATS_PAD) || + nla_put_u64_64bit(skb, L2TP_ATTR_TX_BYTES, + atomic_long_read(&tunnel->stats.tx_bytes), + L2TP_ATTR_STATS_PAD) || + nla_put_u64_64bit(skb, L2TP_ATTR_TX_ERRORS, + atomic_long_read(&tunnel->stats.tx_errors), + L2TP_ATTR_STATS_PAD) || + nla_put_u64_64bit(skb, L2TP_ATTR_RX_PACKETS, + atomic_long_read(&tunnel->stats.rx_packets), + L2TP_ATTR_STATS_PAD) || + nla_put_u64_64bit(skb, L2TP_ATTR_RX_BYTES, + atomic_long_read(&tunnel->stats.rx_bytes), + L2TP_ATTR_STATS_PAD) || + nla_put_u64_64bit(skb, L2TP_ATTR_RX_SEQ_DISCARDS, + atomic_long_read(&tunnel->stats.rx_seq_discards), + L2TP_ATTR_STATS_PAD) || + nla_put_u64_64bit(skb, L2TP_ATTR_RX_COOKIE_DISCARDS, + atomic_long_read(&tunnel->stats.rx_cookie_discards), + L2TP_ATTR_STATS_PAD) || + nla_put_u64_64bit(skb, L2TP_ATTR_RX_OOS_PACKETS, + atomic_long_read(&tunnel->stats.rx_oos_packets), + L2TP_ATTR_STATS_PAD) || + nla_put_u64_64bit(skb, L2TP_ATTR_RX_ERRORS, + atomic_long_read(&tunnel->stats.rx_errors), + L2TP_ATTR_STATS_PAD) || + nla_put_u64_64bit(skb, L2TP_ATTR_RX_INVALID, + atomic_long_read(&tunnel->stats.rx_invalid), + L2TP_ATTR_STATS_PAD)) + goto nla_put_failure; + nla_nest_end(skb, nest); + + if (l2tp_nl_tunnel_send_addr(skb, tunnel)) + goto nla_put_failure; + + genlmsg_end(skb, hdr); + return 0; + +nla_put_failure: + genlmsg_cancel(skb, hdr); + return -1; +} + +static int l2tp_nl_cmd_tunnel_get(struct sk_buff *skb, struct genl_info *info) +{ + struct l2tp_tunnel *tunnel; + struct sk_buff *msg; + u32 tunnel_id; + int ret = -ENOBUFS; + struct net *net = genl_info_net(info); + + if (!info->attrs[L2TP_ATTR_CONN_ID]) { + ret = -EINVAL; + goto err; + } + + tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]); + + msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL); + if (!msg) { + ret = -ENOMEM; + goto err; + } + + tunnel = l2tp_tunnel_get(net, tunnel_id); + if (!tunnel) { + ret = -ENODEV; + goto err_nlmsg; + } + + ret = l2tp_nl_tunnel_send(msg, info->snd_portid, info->snd_seq, + NLM_F_ACK, tunnel, L2TP_CMD_TUNNEL_GET); + if (ret < 0) + goto err_nlmsg_tunnel; + + l2tp_tunnel_dec_refcount(tunnel); + + return genlmsg_unicast(net, msg, info->snd_portid); + +err_nlmsg_tunnel: + l2tp_tunnel_dec_refcount(tunnel); +err_nlmsg: + nlmsg_free(msg); +err: + return ret; +} + +static int l2tp_nl_cmd_tunnel_dump(struct sk_buff *skb, struct netlink_callback *cb) +{ + int ti = cb->args[0]; + struct l2tp_tunnel *tunnel; + struct net *net = sock_net(skb->sk); + + for (;;) { + tunnel = l2tp_tunnel_get_nth(net, ti); + if (!tunnel) + goto out; + + if (l2tp_nl_tunnel_send(skb, NETLINK_CB(cb->skb).portid, + cb->nlh->nlmsg_seq, NLM_F_MULTI, + tunnel, L2TP_CMD_TUNNEL_GET) < 0) { + l2tp_tunnel_dec_refcount(tunnel); + goto out; + } + l2tp_tunnel_dec_refcount(tunnel); + + ti++; + } + +out: + cb->args[0] = ti; + + return skb->len; +} + +static int l2tp_nl_cmd_session_create(struct sk_buff *skb, struct genl_info *info) +{ + u32 tunnel_id = 0; + u32 session_id; + u32 peer_session_id; + int ret = 0; + struct l2tp_tunnel *tunnel; + struct l2tp_session *session; + struct l2tp_session_cfg cfg = { 0, }; + struct net *net = genl_info_net(info); + + if (!info->attrs[L2TP_ATTR_CONN_ID]) { + ret = -EINVAL; + goto out; + } + + tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]); + tunnel = l2tp_tunnel_get(net, tunnel_id); + if (!tunnel) { + ret = -ENODEV; + goto out; + } + + if (!info->attrs[L2TP_ATTR_SESSION_ID]) { + ret = -EINVAL; + goto out_tunnel; + } + session_id = nla_get_u32(info->attrs[L2TP_ATTR_SESSION_ID]); + + if (!info->attrs[L2TP_ATTR_PEER_SESSION_ID]) { + ret = -EINVAL; + goto out_tunnel; + } + peer_session_id = nla_get_u32(info->attrs[L2TP_ATTR_PEER_SESSION_ID]); + + if (!info->attrs[L2TP_ATTR_PW_TYPE]) { + ret = -EINVAL; + goto out_tunnel; + } + cfg.pw_type = nla_get_u16(info->attrs[L2TP_ATTR_PW_TYPE]); + if (cfg.pw_type >= __L2TP_PWTYPE_MAX) { + ret = -EINVAL; + goto out_tunnel; + } + + /* L2TPv2 only accepts PPP pseudo-wires */ + if (tunnel->version == 2 && cfg.pw_type != L2TP_PWTYPE_PPP) { + ret = -EPROTONOSUPPORT; + goto out_tunnel; + } + + if (tunnel->version > 2) { + if (info->attrs[L2TP_ATTR_L2SPEC_TYPE]) { + cfg.l2specific_type = nla_get_u8(info->attrs[L2TP_ATTR_L2SPEC_TYPE]); + if (cfg.l2specific_type != L2TP_L2SPECTYPE_DEFAULT && + cfg.l2specific_type != L2TP_L2SPECTYPE_NONE) { + ret = -EINVAL; + goto out_tunnel; + } + } else { + cfg.l2specific_type = L2TP_L2SPECTYPE_DEFAULT; + } + + if (info->attrs[L2TP_ATTR_COOKIE]) { + u16 len = nla_len(info->attrs[L2TP_ATTR_COOKIE]); + + if (len > 8) { + ret = -EINVAL; + goto out_tunnel; + } + cfg.cookie_len = len; + memcpy(&cfg.cookie[0], nla_data(info->attrs[L2TP_ATTR_COOKIE]), len); + } + if (info->attrs[L2TP_ATTR_PEER_COOKIE]) { + u16 len = nla_len(info->attrs[L2TP_ATTR_PEER_COOKIE]); + + if (len > 8) { + ret = -EINVAL; + goto out_tunnel; + } + cfg.peer_cookie_len = len; + memcpy(&cfg.peer_cookie[0], nla_data(info->attrs[L2TP_ATTR_PEER_COOKIE]), len); + } + if (info->attrs[L2TP_ATTR_IFNAME]) + cfg.ifname = nla_data(info->attrs[L2TP_ATTR_IFNAME]); + } + + if (info->attrs[L2TP_ATTR_RECV_SEQ]) + cfg.recv_seq = nla_get_u8(info->attrs[L2TP_ATTR_RECV_SEQ]); + + if (info->attrs[L2TP_ATTR_SEND_SEQ]) + cfg.send_seq = nla_get_u8(info->attrs[L2TP_ATTR_SEND_SEQ]); + + if (info->attrs[L2TP_ATTR_LNS_MODE]) + cfg.lns_mode = nla_get_u8(info->attrs[L2TP_ATTR_LNS_MODE]); + + if (info->attrs[L2TP_ATTR_RECV_TIMEOUT]) + cfg.reorder_timeout = nla_get_msecs(info->attrs[L2TP_ATTR_RECV_TIMEOUT]); + +#ifdef CONFIG_MODULES + if (!l2tp_nl_cmd_ops[cfg.pw_type]) { + genl_unlock(); + request_module("net-l2tp-type-%u", cfg.pw_type); + genl_lock(); + } +#endif + if (!l2tp_nl_cmd_ops[cfg.pw_type] || !l2tp_nl_cmd_ops[cfg.pw_type]->session_create) { + ret = -EPROTONOSUPPORT; + goto out_tunnel; + } + + ret = l2tp_nl_cmd_ops[cfg.pw_type]->session_create(net, tunnel, + session_id, + peer_session_id, + &cfg); + + if (ret >= 0) { + session = l2tp_tunnel_get_session(tunnel, session_id); + if (session) { + ret = l2tp_session_notify(&l2tp_nl_family, info, session, + L2TP_CMD_SESSION_CREATE); + l2tp_session_dec_refcount(session); + } + } + +out_tunnel: + l2tp_tunnel_dec_refcount(tunnel); +out: + return ret; +} + +static int l2tp_nl_cmd_session_delete(struct sk_buff *skb, struct genl_info *info) +{ + int ret = 0; + struct l2tp_session *session; + u16 pw_type; + + session = l2tp_nl_session_get(info); + if (!session) { + ret = -ENODEV; + goto out; + } + + l2tp_session_notify(&l2tp_nl_family, info, + session, L2TP_CMD_SESSION_DELETE); + + pw_type = session->pwtype; + if (pw_type < __L2TP_PWTYPE_MAX) + if (l2tp_nl_cmd_ops[pw_type] && l2tp_nl_cmd_ops[pw_type]->session_delete) + l2tp_nl_cmd_ops[pw_type]->session_delete(session); + + l2tp_session_dec_refcount(session); + +out: + return ret; +} + +static int l2tp_nl_cmd_session_modify(struct sk_buff *skb, struct genl_info *info) +{ + int ret = 0; + struct l2tp_session *session; + + session = l2tp_nl_session_get(info); + if (!session) { + ret = -ENODEV; + goto out; + } + + if (info->attrs[L2TP_ATTR_RECV_SEQ]) + session->recv_seq = nla_get_u8(info->attrs[L2TP_ATTR_RECV_SEQ]); + + if (info->attrs[L2TP_ATTR_SEND_SEQ]) { + session->send_seq = nla_get_u8(info->attrs[L2TP_ATTR_SEND_SEQ]); + l2tp_session_set_header_len(session, session->tunnel->version); + } + + if (info->attrs[L2TP_ATTR_LNS_MODE]) + session->lns_mode = nla_get_u8(info->attrs[L2TP_ATTR_LNS_MODE]); + + if (info->attrs[L2TP_ATTR_RECV_TIMEOUT]) + session->reorder_timeout = nla_get_msecs(info->attrs[L2TP_ATTR_RECV_TIMEOUT]); + + ret = l2tp_session_notify(&l2tp_nl_family, info, + session, L2TP_CMD_SESSION_MODIFY); + + l2tp_session_dec_refcount(session); + +out: + return ret; +} + +static int l2tp_nl_session_send(struct sk_buff *skb, u32 portid, u32 seq, int flags, + struct l2tp_session *session, u8 cmd) +{ + void *hdr; + struct nlattr *nest; + struct l2tp_tunnel *tunnel = session->tunnel; + + hdr = genlmsg_put(skb, portid, seq, &l2tp_nl_family, flags, cmd); + if (!hdr) + return -EMSGSIZE; + + if (nla_put_u32(skb, L2TP_ATTR_CONN_ID, tunnel->tunnel_id) || + nla_put_u32(skb, L2TP_ATTR_SESSION_ID, session->session_id) || + nla_put_u32(skb, L2TP_ATTR_PEER_CONN_ID, tunnel->peer_tunnel_id) || + nla_put_u32(skb, L2TP_ATTR_PEER_SESSION_ID, session->peer_session_id) || + nla_put_u32(skb, L2TP_ATTR_DEBUG, 0) || + nla_put_u16(skb, L2TP_ATTR_PW_TYPE, session->pwtype)) + goto nla_put_failure; + + if ((session->ifname[0] && + nla_put_string(skb, L2TP_ATTR_IFNAME, session->ifname)) || + (session->cookie_len && + nla_put(skb, L2TP_ATTR_COOKIE, session->cookie_len, session->cookie)) || + (session->peer_cookie_len && + nla_put(skb, L2TP_ATTR_PEER_COOKIE, session->peer_cookie_len, session->peer_cookie)) || + nla_put_u8(skb, L2TP_ATTR_RECV_SEQ, session->recv_seq) || + nla_put_u8(skb, L2TP_ATTR_SEND_SEQ, session->send_seq) || + nla_put_u8(skb, L2TP_ATTR_LNS_MODE, session->lns_mode) || + (l2tp_tunnel_uses_xfrm(tunnel) && + nla_put_u8(skb, L2TP_ATTR_USING_IPSEC, 1)) || + (session->reorder_timeout && + nla_put_msecs(skb, L2TP_ATTR_RECV_TIMEOUT, + session->reorder_timeout, L2TP_ATTR_PAD))) + goto nla_put_failure; + + nest = nla_nest_start_noflag(skb, L2TP_ATTR_STATS); + if (!nest) + goto nla_put_failure; + + if (nla_put_u64_64bit(skb, L2TP_ATTR_TX_PACKETS, + atomic_long_read(&session->stats.tx_packets), + L2TP_ATTR_STATS_PAD) || + nla_put_u64_64bit(skb, L2TP_ATTR_TX_BYTES, + atomic_long_read(&session->stats.tx_bytes), + L2TP_ATTR_STATS_PAD) || + nla_put_u64_64bit(skb, L2TP_ATTR_TX_ERRORS, + atomic_long_read(&session->stats.tx_errors), + L2TP_ATTR_STATS_PAD) || + nla_put_u64_64bit(skb, L2TP_ATTR_RX_PACKETS, + atomic_long_read(&session->stats.rx_packets), + L2TP_ATTR_STATS_PAD) || + nla_put_u64_64bit(skb, L2TP_ATTR_RX_BYTES, + atomic_long_read(&session->stats.rx_bytes), + L2TP_ATTR_STATS_PAD) || + nla_put_u64_64bit(skb, L2TP_ATTR_RX_SEQ_DISCARDS, + atomic_long_read(&session->stats.rx_seq_discards), + L2TP_ATTR_STATS_PAD) || + nla_put_u64_64bit(skb, L2TP_ATTR_RX_COOKIE_DISCARDS, + atomic_long_read(&session->stats.rx_cookie_discards), + L2TP_ATTR_STATS_PAD) || + nla_put_u64_64bit(skb, L2TP_ATTR_RX_OOS_PACKETS, + atomic_long_read(&session->stats.rx_oos_packets), + L2TP_ATTR_STATS_PAD) || + nla_put_u64_64bit(skb, L2TP_ATTR_RX_ERRORS, + atomic_long_read(&session->stats.rx_errors), + L2TP_ATTR_STATS_PAD) || + nla_put_u64_64bit(skb, L2TP_ATTR_RX_INVALID, + atomic_long_read(&session->stats.rx_invalid), + L2TP_ATTR_STATS_PAD)) + goto nla_put_failure; + nla_nest_end(skb, nest); + + genlmsg_end(skb, hdr); + return 0; + + nla_put_failure: + genlmsg_cancel(skb, hdr); + return -1; +} + +static int l2tp_nl_cmd_session_get(struct sk_buff *skb, struct genl_info *info) +{ + struct l2tp_session *session; + struct sk_buff *msg; + int ret; + + session = l2tp_nl_session_get(info); + if (!session) { + ret = -ENODEV; + goto err; + } + + msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL); + if (!msg) { + ret = -ENOMEM; + goto err_ref; + } + + ret = l2tp_nl_session_send(msg, info->snd_portid, info->snd_seq, + 0, session, L2TP_CMD_SESSION_GET); + if (ret < 0) + goto err_ref_msg; + + ret = genlmsg_unicast(genl_info_net(info), msg, info->snd_portid); + + l2tp_session_dec_refcount(session); + + return ret; + +err_ref_msg: + nlmsg_free(msg); +err_ref: + l2tp_session_dec_refcount(session); +err: + return ret; +} + +static int l2tp_nl_cmd_session_dump(struct sk_buff *skb, struct netlink_callback *cb) +{ + struct net *net = sock_net(skb->sk); + struct l2tp_session *session; + struct l2tp_tunnel *tunnel = NULL; + int ti = cb->args[0]; + int si = cb->args[1]; + + for (;;) { + if (!tunnel) { + tunnel = l2tp_tunnel_get_nth(net, ti); + if (!tunnel) + goto out; + } + + session = l2tp_session_get_nth(tunnel, si); + if (!session) { + ti++; + l2tp_tunnel_dec_refcount(tunnel); + tunnel = NULL; + si = 0; + continue; + } + + if (l2tp_nl_session_send(skb, NETLINK_CB(cb->skb).portid, + cb->nlh->nlmsg_seq, NLM_F_MULTI, + session, L2TP_CMD_SESSION_GET) < 0) { + l2tp_session_dec_refcount(session); + l2tp_tunnel_dec_refcount(tunnel); + break; + } + l2tp_session_dec_refcount(session); + + si++; + } + +out: + cb->args[0] = ti; + cb->args[1] = si; + + return skb->len; +} + +static const struct nla_policy l2tp_nl_policy[L2TP_ATTR_MAX + 1] = { + [L2TP_ATTR_NONE] = { .type = NLA_UNSPEC, }, + [L2TP_ATTR_PW_TYPE] = { .type = NLA_U16, }, + [L2TP_ATTR_ENCAP_TYPE] = { .type = NLA_U16, }, + [L2TP_ATTR_OFFSET] = { .type = NLA_U16, }, + [L2TP_ATTR_DATA_SEQ] = { .type = NLA_U8, }, + [L2TP_ATTR_L2SPEC_TYPE] = { .type = NLA_U8, }, + [L2TP_ATTR_L2SPEC_LEN] = { .type = NLA_U8, }, + [L2TP_ATTR_PROTO_VERSION] = { .type = NLA_U8, }, + [L2TP_ATTR_CONN_ID] = { .type = NLA_U32, }, + [L2TP_ATTR_PEER_CONN_ID] = { .type = NLA_U32, }, + [L2TP_ATTR_SESSION_ID] = { .type = NLA_U32, }, + [L2TP_ATTR_PEER_SESSION_ID] = { .type = NLA_U32, }, + [L2TP_ATTR_UDP_CSUM] = { .type = NLA_U8, }, + [L2TP_ATTR_VLAN_ID] = { .type = NLA_U16, }, + [L2TP_ATTR_DEBUG] = { .type = NLA_U32, }, + [L2TP_ATTR_RECV_SEQ] = { .type = NLA_U8, }, + [L2TP_ATTR_SEND_SEQ] = { .type = NLA_U8, }, + [L2TP_ATTR_LNS_MODE] = { .type = NLA_U8, }, + [L2TP_ATTR_USING_IPSEC] = { .type = NLA_U8, }, + [L2TP_ATTR_RECV_TIMEOUT] = { .type = NLA_MSECS, }, + [L2TP_ATTR_FD] = { .type = NLA_U32, }, + [L2TP_ATTR_IP_SADDR] = { .type = NLA_U32, }, + [L2TP_ATTR_IP_DADDR] = { .type = NLA_U32, }, + [L2TP_ATTR_UDP_SPORT] = { .type = NLA_U16, }, + [L2TP_ATTR_UDP_DPORT] = { .type = NLA_U16, }, + [L2TP_ATTR_MTU] = { .type = NLA_U16, }, + [L2TP_ATTR_MRU] = { .type = NLA_U16, }, + [L2TP_ATTR_STATS] = { .type = NLA_NESTED, }, + [L2TP_ATTR_IP6_SADDR] = { + .type = NLA_BINARY, + .len = sizeof(struct in6_addr), + }, + [L2TP_ATTR_IP6_DADDR] = { + .type = NLA_BINARY, + .len = sizeof(struct in6_addr), + }, + [L2TP_ATTR_IFNAME] = { + .type = NLA_NUL_STRING, + .len = IFNAMSIZ - 1, + }, + [L2TP_ATTR_COOKIE] = { + .type = NLA_BINARY, + .len = 8, + }, + [L2TP_ATTR_PEER_COOKIE] = { + .type = NLA_BINARY, + .len = 8, + }, +}; + +static const struct genl_small_ops l2tp_nl_ops[] = { + { + .cmd = L2TP_CMD_NOOP, + .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP, + .doit = l2tp_nl_cmd_noop, + /* can be retrieved by unprivileged users */ + }, + { + .cmd = L2TP_CMD_TUNNEL_CREATE, + .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP, + .doit = l2tp_nl_cmd_tunnel_create, + .flags = GENL_UNS_ADMIN_PERM, + }, + { + .cmd = L2TP_CMD_TUNNEL_DELETE, + .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP, + .doit = l2tp_nl_cmd_tunnel_delete, + .flags = GENL_UNS_ADMIN_PERM, + }, + { + .cmd = L2TP_CMD_TUNNEL_MODIFY, + .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP, + .doit = l2tp_nl_cmd_tunnel_modify, + .flags = GENL_UNS_ADMIN_PERM, + }, + { + .cmd = L2TP_CMD_TUNNEL_GET, + .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP, + .doit = l2tp_nl_cmd_tunnel_get, + .dumpit = l2tp_nl_cmd_tunnel_dump, + .flags = GENL_UNS_ADMIN_PERM, + }, + { + .cmd = L2TP_CMD_SESSION_CREATE, + .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP, + .doit = l2tp_nl_cmd_session_create, + .flags = GENL_UNS_ADMIN_PERM, + }, + { + .cmd = L2TP_CMD_SESSION_DELETE, + .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP, + .doit = l2tp_nl_cmd_session_delete, + .flags = GENL_UNS_ADMIN_PERM, + }, + { + .cmd = L2TP_CMD_SESSION_MODIFY, + .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP, + .doit = l2tp_nl_cmd_session_modify, + .flags = GENL_UNS_ADMIN_PERM, + }, + { + .cmd = L2TP_CMD_SESSION_GET, + .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP, + .doit = l2tp_nl_cmd_session_get, + .dumpit = l2tp_nl_cmd_session_dump, + .flags = GENL_UNS_ADMIN_PERM, + }, +}; + +static struct genl_family l2tp_nl_family __ro_after_init = { + .name = L2TP_GENL_NAME, + .version = L2TP_GENL_VERSION, + .hdrsize = 0, + .maxattr = L2TP_ATTR_MAX, + .policy = l2tp_nl_policy, + .netnsok = true, + .module = THIS_MODULE, + .small_ops = l2tp_nl_ops, + .n_small_ops = ARRAY_SIZE(l2tp_nl_ops), + .resv_start_op = L2TP_CMD_SESSION_GET + 1, + .mcgrps = l2tp_multicast_group, + .n_mcgrps = ARRAY_SIZE(l2tp_multicast_group), +}; + +int l2tp_nl_register_ops(enum l2tp_pwtype pw_type, const struct l2tp_nl_cmd_ops *ops) +{ + int ret; + + ret = -EINVAL; + if (pw_type >= __L2TP_PWTYPE_MAX) + goto err; + + genl_lock(); + ret = -EBUSY; + if (l2tp_nl_cmd_ops[pw_type]) + goto out; + + l2tp_nl_cmd_ops[pw_type] = ops; + ret = 0; + +out: + genl_unlock(); +err: + return ret; +} +EXPORT_SYMBOL_GPL(l2tp_nl_register_ops); + +void l2tp_nl_unregister_ops(enum l2tp_pwtype pw_type) +{ + if (pw_type < __L2TP_PWTYPE_MAX) { + genl_lock(); + l2tp_nl_cmd_ops[pw_type] = NULL; + genl_unlock(); + } +} +EXPORT_SYMBOL_GPL(l2tp_nl_unregister_ops); + +static int __init l2tp_nl_init(void) +{ + pr_info("L2TP netlink interface\n"); + return genl_register_family(&l2tp_nl_family); +} + +static void l2tp_nl_cleanup(void) +{ + genl_unregister_family(&l2tp_nl_family); +} + +module_init(l2tp_nl_init); +module_exit(l2tp_nl_cleanup); + +MODULE_AUTHOR("James Chapman <jchapman@katalix.com>"); +MODULE_DESCRIPTION("L2TP netlink"); +MODULE_LICENSE("GPL"); +MODULE_VERSION("1.0"); +MODULE_ALIAS_GENL_FAMILY("l2tp"); diff --git a/net/l2tp/l2tp_ppp.c b/net/l2tp/l2tp_ppp.c new file mode 100644 index 000000000..f011af660 --- /dev/null +++ b/net/l2tp/l2tp_ppp.c @@ -0,0 +1,1743 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/***************************************************************************** + * Linux PPP over L2TP (PPPoX/PPPoL2TP) Sockets + * + * PPPoX --- Generic PPP encapsulation socket family + * PPPoL2TP --- PPP over L2TP (RFC 2661) + * + * Version: 2.0.0 + * + * Authors: James Chapman (jchapman@katalix.com) + * + * Based on original work by Martijn van Oosterhout <kleptog@svana.org> + * + * License: + */ + +/* This driver handles only L2TP data frames; control frames are handled by a + * userspace application. + * + * To send data in an L2TP session, userspace opens a PPPoL2TP socket and + * attaches it to a bound UDP socket with local tunnel_id / session_id and + * peer tunnel_id / session_id set. Data can then be sent or received using + * regular socket sendmsg() / recvmsg() calls. Kernel parameters of the socket + * can be read or modified using ioctl() or [gs]etsockopt() calls. + * + * When a PPPoL2TP socket is connected with local and peer session_id values + * zero, the socket is treated as a special tunnel management socket. + * + * Here's example userspace code to create a socket for sending/receiving data + * over an L2TP session:- + * + * struct sockaddr_pppol2tp sax; + * int fd; + * int session_fd; + * + * fd = socket(AF_PPPOX, SOCK_DGRAM, PX_PROTO_OL2TP); + * + * sax.sa_family = AF_PPPOX; + * sax.sa_protocol = PX_PROTO_OL2TP; + * sax.pppol2tp.fd = tunnel_fd; // bound UDP socket + * sax.pppol2tp.addr.sin_addr.s_addr = addr->sin_addr.s_addr; + * sax.pppol2tp.addr.sin_port = addr->sin_port; + * sax.pppol2tp.addr.sin_family = AF_INET; + * sax.pppol2tp.s_tunnel = tunnel_id; + * sax.pppol2tp.s_session = session_id; + * sax.pppol2tp.d_tunnel = peer_tunnel_id; + * sax.pppol2tp.d_session = peer_session_id; + * + * session_fd = connect(fd, (struct sockaddr *)&sax, sizeof(sax)); + * + * A pppd plugin that allows PPP traffic to be carried over L2TP using + * this driver is available from the OpenL2TP project at + * http://openl2tp.sourceforge.net. + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/module.h> +#include <linux/string.h> +#include <linux/list.h> +#include <linux/uaccess.h> + +#include <linux/kernel.h> +#include <linux/spinlock.h> +#include <linux/kthread.h> +#include <linux/sched.h> +#include <linux/slab.h> +#include <linux/errno.h> +#include <linux/jiffies.h> + +#include <linux/netdevice.h> +#include <linux/net.h> +#include <linux/inetdevice.h> +#include <linux/skbuff.h> +#include <linux/init.h> +#include <linux/ip.h> +#include <linux/udp.h> +#include <linux/if_pppox.h> +#include <linux/if_pppol2tp.h> +#include <net/sock.h> +#include <linux/ppp_channel.h> +#include <linux/ppp_defs.h> +#include <linux/ppp-ioctl.h> +#include <linux/file.h> +#include <linux/hash.h> +#include <linux/sort.h> +#include <linux/proc_fs.h> +#include <linux/l2tp.h> +#include <linux/nsproxy.h> +#include <net/net_namespace.h> +#include <net/netns/generic.h> +#include <net/ip.h> +#include <net/udp.h> +#include <net/inet_common.h> + +#include <asm/byteorder.h> +#include <linux/atomic.h> + +#include "l2tp_core.h" + +#define PPPOL2TP_DRV_VERSION "V2.0" + +/* Space for UDP, L2TP and PPP headers */ +#define PPPOL2TP_HEADER_OVERHEAD 40 + +/* Number of bytes to build transmit L2TP headers. + * Unfortunately the size is different depending on whether sequence numbers + * are enabled. + */ +#define PPPOL2TP_L2TP_HDR_SIZE_SEQ 10 +#define PPPOL2TP_L2TP_HDR_SIZE_NOSEQ 6 + +/* Private data of each session. This data lives at the end of struct + * l2tp_session, referenced via session->priv[]. + */ +struct pppol2tp_session { + int owner; /* pid that opened the socket */ + + struct mutex sk_lock; /* Protects .sk */ + struct sock __rcu *sk; /* Pointer to the session PPPoX socket */ + struct sock *__sk; /* Copy of .sk, for cleanup */ + struct rcu_head rcu; /* For asynchronous release */ +}; + +static int pppol2tp_xmit(struct ppp_channel *chan, struct sk_buff *skb); + +static const struct ppp_channel_ops pppol2tp_chan_ops = { + .start_xmit = pppol2tp_xmit, +}; + +static const struct proto_ops pppol2tp_ops; + +/* Retrieves the pppol2tp socket associated to a session. + * A reference is held on the returned socket, so this function must be paired + * with sock_put(). + */ +static struct sock *pppol2tp_session_get_sock(struct l2tp_session *session) +{ + struct pppol2tp_session *ps = l2tp_session_priv(session); + struct sock *sk; + + rcu_read_lock(); + sk = rcu_dereference(ps->sk); + if (sk) + sock_hold(sk); + rcu_read_unlock(); + + return sk; +} + +/* Helpers to obtain tunnel/session contexts from sockets. + */ +static inline struct l2tp_session *pppol2tp_sock_to_session(struct sock *sk) +{ + struct l2tp_session *session; + + if (!sk) + return NULL; + + sock_hold(sk); + session = (struct l2tp_session *)(sk->sk_user_data); + if (!session) { + sock_put(sk); + goto out; + } + if (WARN_ON(session->magic != L2TP_SESSION_MAGIC)) { + session = NULL; + sock_put(sk); + goto out; + } + +out: + return session; +} + +/***************************************************************************** + * Receive data handling + *****************************************************************************/ + +/* Receive message. This is the recvmsg for the PPPoL2TP socket. + */ +static int pppol2tp_recvmsg(struct socket *sock, struct msghdr *msg, + size_t len, int flags) +{ + int err; + struct sk_buff *skb; + struct sock *sk = sock->sk; + + err = -EIO; + if (sk->sk_state & PPPOX_BOUND) + goto end; + + err = 0; + skb = skb_recv_datagram(sk, flags, &err); + if (!skb) + goto end; + + if (len > skb->len) + len = skb->len; + else if (len < skb->len) + msg->msg_flags |= MSG_TRUNC; + + err = skb_copy_datagram_msg(skb, 0, msg, len); + if (likely(err == 0)) + err = len; + + kfree_skb(skb); +end: + return err; +} + +static void pppol2tp_recv(struct l2tp_session *session, struct sk_buff *skb, int data_len) +{ + struct pppol2tp_session *ps = l2tp_session_priv(session); + struct sock *sk = NULL; + + /* If the socket is bound, send it in to PPP's input queue. Otherwise + * queue it on the session socket. + */ + rcu_read_lock(); + sk = rcu_dereference(ps->sk); + if (!sk) + goto no_sock; + + /* If the first two bytes are 0xFF03, consider that it is the PPP's + * Address and Control fields and skip them. The L2TP module has always + * worked this way, although, in theory, the use of these fields should + * be negotiated and handled at the PPP layer. These fields are + * constant: 0xFF is the All-Stations Address and 0x03 the Unnumbered + * Information command with Poll/Final bit set to zero (RFC 1662). + */ + if (pskb_may_pull(skb, 2) && skb->data[0] == PPP_ALLSTATIONS && + skb->data[1] == PPP_UI) + skb_pull(skb, 2); + + if (sk->sk_state & PPPOX_BOUND) { + struct pppox_sock *po; + + po = pppox_sk(sk); + ppp_input(&po->chan, skb); + } else { + if (sock_queue_rcv_skb(sk, skb) < 0) { + atomic_long_inc(&session->stats.rx_errors); + kfree_skb(skb); + } + } + rcu_read_unlock(); + + return; + +no_sock: + rcu_read_unlock(); + pr_warn_ratelimited("%s: no socket in recv\n", session->name); + kfree_skb(skb); +} + +/************************************************************************ + * Transmit handling + ***********************************************************************/ + +/* This is the sendmsg for the PPPoL2TP pppol2tp_session socket. We come here + * when a user application does a sendmsg() on the session socket. L2TP and + * PPP headers must be inserted into the user's data. + */ +static int pppol2tp_sendmsg(struct socket *sock, struct msghdr *m, + size_t total_len) +{ + struct sock *sk = sock->sk; + struct sk_buff *skb; + int error; + struct l2tp_session *session; + struct l2tp_tunnel *tunnel; + int uhlen; + + error = -ENOTCONN; + if (sock_flag(sk, SOCK_DEAD) || !(sk->sk_state & PPPOX_CONNECTED)) + goto error; + + /* Get session and tunnel contexts */ + error = -EBADF; + session = pppol2tp_sock_to_session(sk); + if (!session) + goto error; + + tunnel = session->tunnel; + + uhlen = (tunnel->encap == L2TP_ENCAPTYPE_UDP) ? sizeof(struct udphdr) : 0; + + /* Allocate a socket buffer */ + error = -ENOMEM; + skb = sock_wmalloc(sk, NET_SKB_PAD + sizeof(struct iphdr) + + uhlen + session->hdr_len + + 2 + total_len, /* 2 bytes for PPP_ALLSTATIONS & PPP_UI */ + 0, GFP_KERNEL); + if (!skb) + goto error_put_sess; + + /* Reserve space for headers. */ + skb_reserve(skb, NET_SKB_PAD); + skb_reset_network_header(skb); + skb_reserve(skb, sizeof(struct iphdr)); + skb_reset_transport_header(skb); + skb_reserve(skb, uhlen); + + /* Add PPP header */ + skb->data[0] = PPP_ALLSTATIONS; + skb->data[1] = PPP_UI; + skb_put(skb, 2); + + /* Copy user data into skb */ + error = memcpy_from_msg(skb_put(skb, total_len), m, total_len); + if (error < 0) { + kfree_skb(skb); + goto error_put_sess; + } + + local_bh_disable(); + l2tp_xmit_skb(session, skb); + local_bh_enable(); + + sock_put(sk); + + return total_len; + +error_put_sess: + sock_put(sk); +error: + return error; +} + +/* Transmit function called by generic PPP driver. Sends PPP frame + * over PPPoL2TP socket. + * + * This is almost the same as pppol2tp_sendmsg(), but rather than + * being called with a msghdr from userspace, it is called with a skb + * from the kernel. + * + * The supplied skb from ppp doesn't have enough headroom for the + * insertion of L2TP, UDP and IP headers so we need to allocate more + * headroom in the skb. This will create a cloned skb. But we must be + * careful in the error case because the caller will expect to free + * the skb it supplied, not our cloned skb. So we take care to always + * leave the original skb unfreed if we return an error. + */ +static int pppol2tp_xmit(struct ppp_channel *chan, struct sk_buff *skb) +{ + struct sock *sk = (struct sock *)chan->private; + struct l2tp_session *session; + struct l2tp_tunnel *tunnel; + int uhlen, headroom; + + if (sock_flag(sk, SOCK_DEAD) || !(sk->sk_state & PPPOX_CONNECTED)) + goto abort; + + /* Get session and tunnel contexts from the socket */ + session = pppol2tp_sock_to_session(sk); + if (!session) + goto abort; + + tunnel = session->tunnel; + + uhlen = (tunnel->encap == L2TP_ENCAPTYPE_UDP) ? sizeof(struct udphdr) : 0; + headroom = NET_SKB_PAD + + sizeof(struct iphdr) + /* IP header */ + uhlen + /* UDP header (if L2TP_ENCAPTYPE_UDP) */ + session->hdr_len + /* L2TP header */ + 2; /* 2 bytes for PPP_ALLSTATIONS & PPP_UI */ + if (skb_cow_head(skb, headroom)) + goto abort_put_sess; + + /* Setup PPP header */ + __skb_push(skb, 2); + skb->data[0] = PPP_ALLSTATIONS; + skb->data[1] = PPP_UI; + + local_bh_disable(); + l2tp_xmit_skb(session, skb); + local_bh_enable(); + + sock_put(sk); + + return 1; + +abort_put_sess: + sock_put(sk); +abort: + /* Free the original skb */ + kfree_skb(skb); + return 1; +} + +/***************************************************************************** + * Session (and tunnel control) socket create/destroy. + *****************************************************************************/ + +static void pppol2tp_put_sk(struct rcu_head *head) +{ + struct pppol2tp_session *ps; + + ps = container_of(head, typeof(*ps), rcu); + sock_put(ps->__sk); +} + +/* Really kill the session socket. (Called from sock_put() if + * refcnt == 0.) + */ +static void pppol2tp_session_destruct(struct sock *sk) +{ + struct l2tp_session *session = sk->sk_user_data; + + skb_queue_purge(&sk->sk_receive_queue); + skb_queue_purge(&sk->sk_write_queue); + + if (session) { + sk->sk_user_data = NULL; + if (WARN_ON(session->magic != L2TP_SESSION_MAGIC)) + return; + l2tp_session_dec_refcount(session); + } +} + +/* Called when the PPPoX socket (session) is closed. + */ +static int pppol2tp_release(struct socket *sock) +{ + struct sock *sk = sock->sk; + struct l2tp_session *session; + int error; + + if (!sk) + return 0; + + error = -EBADF; + lock_sock(sk); + if (sock_flag(sk, SOCK_DEAD) != 0) + goto error; + + pppox_unbind_sock(sk); + + /* Signal the death of the socket. */ + sk->sk_state = PPPOX_DEAD; + sock_orphan(sk); + sock->sk = NULL; + + session = pppol2tp_sock_to_session(sk); + if (session) { + struct pppol2tp_session *ps; + + l2tp_session_delete(session); + + ps = l2tp_session_priv(session); + mutex_lock(&ps->sk_lock); + ps->__sk = rcu_dereference_protected(ps->sk, + lockdep_is_held(&ps->sk_lock)); + RCU_INIT_POINTER(ps->sk, NULL); + mutex_unlock(&ps->sk_lock); + call_rcu(&ps->rcu, pppol2tp_put_sk); + + /* Rely on the sock_put() call at the end of the function for + * dropping the reference held by pppol2tp_sock_to_session(). + * The last reference will be dropped by pppol2tp_put_sk(). + */ + } + + release_sock(sk); + + /* This will delete the session context via + * pppol2tp_session_destruct() if the socket's refcnt drops to + * zero. + */ + sock_put(sk); + + return 0; + +error: + release_sock(sk); + return error; +} + +static struct proto pppol2tp_sk_proto = { + .name = "PPPOL2TP", + .owner = THIS_MODULE, + .obj_size = sizeof(struct pppox_sock), +}; + +static int pppol2tp_backlog_recv(struct sock *sk, struct sk_buff *skb) +{ + int rc; + + rc = l2tp_udp_encap_recv(sk, skb); + if (rc) + kfree_skb(skb); + + return NET_RX_SUCCESS; +} + +/* socket() handler. Initialize a new struct sock. + */ +static int pppol2tp_create(struct net *net, struct socket *sock, int kern) +{ + int error = -ENOMEM; + struct sock *sk; + + sk = sk_alloc(net, PF_PPPOX, GFP_KERNEL, &pppol2tp_sk_proto, kern); + if (!sk) + goto out; + + sock_init_data(sock, sk); + + sock->state = SS_UNCONNECTED; + sock->ops = &pppol2tp_ops; + + sk->sk_backlog_rcv = pppol2tp_backlog_recv; + sk->sk_protocol = PX_PROTO_OL2TP; + sk->sk_family = PF_PPPOX; + sk->sk_state = PPPOX_NONE; + sk->sk_type = SOCK_STREAM; + sk->sk_destruct = pppol2tp_session_destruct; + + error = 0; + +out: + return error; +} + +static void pppol2tp_show(struct seq_file *m, void *arg) +{ + struct l2tp_session *session = arg; + struct sock *sk; + + sk = pppol2tp_session_get_sock(session); + if (sk) { + struct pppox_sock *po = pppox_sk(sk); + + seq_printf(m, " interface %s\n", ppp_dev_name(&po->chan)); + sock_put(sk); + } +} + +static void pppol2tp_session_init(struct l2tp_session *session) +{ + struct pppol2tp_session *ps; + + session->recv_skb = pppol2tp_recv; + if (IS_ENABLED(CONFIG_L2TP_DEBUGFS)) + session->show = pppol2tp_show; + + ps = l2tp_session_priv(session); + mutex_init(&ps->sk_lock); + ps->owner = current->pid; +} + +struct l2tp_connect_info { + u8 version; + int fd; + u32 tunnel_id; + u32 peer_tunnel_id; + u32 session_id; + u32 peer_session_id; +}; + +static int pppol2tp_sockaddr_get_info(const void *sa, int sa_len, + struct l2tp_connect_info *info) +{ + switch (sa_len) { + case sizeof(struct sockaddr_pppol2tp): + { + const struct sockaddr_pppol2tp *sa_v2in4 = sa; + + if (sa_v2in4->sa_protocol != PX_PROTO_OL2TP) + return -EINVAL; + + info->version = 2; + info->fd = sa_v2in4->pppol2tp.fd; + info->tunnel_id = sa_v2in4->pppol2tp.s_tunnel; + info->peer_tunnel_id = sa_v2in4->pppol2tp.d_tunnel; + info->session_id = sa_v2in4->pppol2tp.s_session; + info->peer_session_id = sa_v2in4->pppol2tp.d_session; + + break; + } + case sizeof(struct sockaddr_pppol2tpv3): + { + const struct sockaddr_pppol2tpv3 *sa_v3in4 = sa; + + if (sa_v3in4->sa_protocol != PX_PROTO_OL2TP) + return -EINVAL; + + info->version = 3; + info->fd = sa_v3in4->pppol2tp.fd; + info->tunnel_id = sa_v3in4->pppol2tp.s_tunnel; + info->peer_tunnel_id = sa_v3in4->pppol2tp.d_tunnel; + info->session_id = sa_v3in4->pppol2tp.s_session; + info->peer_session_id = sa_v3in4->pppol2tp.d_session; + + break; + } + case sizeof(struct sockaddr_pppol2tpin6): + { + const struct sockaddr_pppol2tpin6 *sa_v2in6 = sa; + + if (sa_v2in6->sa_protocol != PX_PROTO_OL2TP) + return -EINVAL; + + info->version = 2; + info->fd = sa_v2in6->pppol2tp.fd; + info->tunnel_id = sa_v2in6->pppol2tp.s_tunnel; + info->peer_tunnel_id = sa_v2in6->pppol2tp.d_tunnel; + info->session_id = sa_v2in6->pppol2tp.s_session; + info->peer_session_id = sa_v2in6->pppol2tp.d_session; + + break; + } + case sizeof(struct sockaddr_pppol2tpv3in6): + { + const struct sockaddr_pppol2tpv3in6 *sa_v3in6 = sa; + + if (sa_v3in6->sa_protocol != PX_PROTO_OL2TP) + return -EINVAL; + + info->version = 3; + info->fd = sa_v3in6->pppol2tp.fd; + info->tunnel_id = sa_v3in6->pppol2tp.s_tunnel; + info->peer_tunnel_id = sa_v3in6->pppol2tp.d_tunnel; + info->session_id = sa_v3in6->pppol2tp.s_session; + info->peer_session_id = sa_v3in6->pppol2tp.d_session; + + break; + } + default: + return -EINVAL; + } + + return 0; +} + +/* Rough estimation of the maximum payload size a tunnel can transmit without + * fragmenting at the lower IP layer. Assumes L2TPv2 with sequence + * numbers and no IP option. Not quite accurate, but the result is mostly + * unused anyway. + */ +static int pppol2tp_tunnel_mtu(const struct l2tp_tunnel *tunnel) +{ + int mtu; + + mtu = l2tp_tunnel_dst_mtu(tunnel); + if (mtu <= PPPOL2TP_HEADER_OVERHEAD) + return 1500 - PPPOL2TP_HEADER_OVERHEAD; + + return mtu - PPPOL2TP_HEADER_OVERHEAD; +} + +static struct l2tp_tunnel *pppol2tp_tunnel_get(struct net *net, + const struct l2tp_connect_info *info, + bool *new_tunnel) +{ + struct l2tp_tunnel *tunnel; + int error; + + *new_tunnel = false; + + tunnel = l2tp_tunnel_get(net, info->tunnel_id); + + /* Special case: create tunnel context if session_id and + * peer_session_id is 0. Otherwise look up tunnel using supplied + * tunnel id. + */ + if (!info->session_id && !info->peer_session_id) { + if (!tunnel) { + struct l2tp_tunnel_cfg tcfg = { + .encap = L2TP_ENCAPTYPE_UDP, + }; + + /* Prevent l2tp_tunnel_register() from trying to set up + * a kernel socket. + */ + if (info->fd < 0) + return ERR_PTR(-EBADF); + + error = l2tp_tunnel_create(info->fd, + info->version, + info->tunnel_id, + info->peer_tunnel_id, &tcfg, + &tunnel); + if (error < 0) + return ERR_PTR(error); + + l2tp_tunnel_inc_refcount(tunnel); + error = l2tp_tunnel_register(tunnel, net, &tcfg); + if (error < 0) { + kfree(tunnel); + return ERR_PTR(error); + } + + *new_tunnel = true; + } + } else { + /* Error if we can't find the tunnel */ + if (!tunnel) + return ERR_PTR(-ENOENT); + + /* Error if socket is not prepped */ + if (!tunnel->sock) { + l2tp_tunnel_dec_refcount(tunnel); + return ERR_PTR(-ENOENT); + } + } + + return tunnel; +} + +/* connect() handler. Attach a PPPoX socket to a tunnel UDP socket + */ +static int pppol2tp_connect(struct socket *sock, struct sockaddr *uservaddr, + int sockaddr_len, int flags) +{ + struct sock *sk = sock->sk; + struct pppox_sock *po = pppox_sk(sk); + struct l2tp_session *session = NULL; + struct l2tp_connect_info info; + struct l2tp_tunnel *tunnel; + struct pppol2tp_session *ps; + struct l2tp_session_cfg cfg = { 0, }; + bool drop_refcnt = false; + bool new_session = false; + bool new_tunnel = false; + int error; + + error = pppol2tp_sockaddr_get_info(uservaddr, sockaddr_len, &info); + if (error < 0) + return error; + + /* Don't bind if tunnel_id is 0 */ + if (!info.tunnel_id) + return -EINVAL; + + tunnel = pppol2tp_tunnel_get(sock_net(sk), &info, &new_tunnel); + if (IS_ERR(tunnel)) + return PTR_ERR(tunnel); + + lock_sock(sk); + + /* Check for already bound sockets */ + error = -EBUSY; + if (sk->sk_state & PPPOX_CONNECTED) + goto end; + + /* We don't supporting rebinding anyway */ + error = -EALREADY; + if (sk->sk_user_data) + goto end; /* socket is already attached */ + + if (tunnel->peer_tunnel_id == 0) + tunnel->peer_tunnel_id = info.peer_tunnel_id; + + session = l2tp_tunnel_get_session(tunnel, info.session_id); + if (session) { + drop_refcnt = true; + + if (session->pwtype != L2TP_PWTYPE_PPP) { + error = -EPROTOTYPE; + goto end; + } + + ps = l2tp_session_priv(session); + + /* Using a pre-existing session is fine as long as it hasn't + * been connected yet. + */ + mutex_lock(&ps->sk_lock); + if (rcu_dereference_protected(ps->sk, + lockdep_is_held(&ps->sk_lock)) || + ps->__sk) { + mutex_unlock(&ps->sk_lock); + error = -EEXIST; + goto end; + } + } else { + cfg.pw_type = L2TP_PWTYPE_PPP; + + session = l2tp_session_create(sizeof(struct pppol2tp_session), + tunnel, info.session_id, + info.peer_session_id, &cfg); + if (IS_ERR(session)) { + error = PTR_ERR(session); + goto end; + } + + pppol2tp_session_init(session); + ps = l2tp_session_priv(session); + l2tp_session_inc_refcount(session); + + mutex_lock(&ps->sk_lock); + error = l2tp_session_register(session, tunnel); + if (error < 0) { + mutex_unlock(&ps->sk_lock); + kfree(session); + goto end; + } + drop_refcnt = true; + new_session = true; + } + + /* Special case: if source & dest session_id == 0x0000, this + * socket is being created to manage the tunnel. Just set up + * the internal context for use by ioctl() and sockopt() + * handlers. + */ + if (session->session_id == 0 && session->peer_session_id == 0) { + error = 0; + goto out_no_ppp; + } + + /* The only header we need to worry about is the L2TP + * header. This size is different depending on whether + * sequence numbers are enabled for the data channel. + */ + po->chan.hdrlen = PPPOL2TP_L2TP_HDR_SIZE_NOSEQ; + + po->chan.private = sk; + po->chan.ops = &pppol2tp_chan_ops; + po->chan.mtu = pppol2tp_tunnel_mtu(tunnel); + + error = ppp_register_net_channel(sock_net(sk), &po->chan); + if (error) { + mutex_unlock(&ps->sk_lock); + goto end; + } + +out_no_ppp: + /* This is how we get the session context from the socket. */ + sk->sk_user_data = session; + rcu_assign_pointer(ps->sk, sk); + mutex_unlock(&ps->sk_lock); + + /* Keep the reference we've grabbed on the session: sk doesn't expect + * the session to disappear. pppol2tp_session_destruct() is responsible + * for dropping it. + */ + drop_refcnt = false; + + sk->sk_state = PPPOX_CONNECTED; + +end: + if (error) { + if (new_session) + l2tp_session_delete(session); + if (new_tunnel) + l2tp_tunnel_delete(tunnel); + } + if (drop_refcnt) + l2tp_session_dec_refcount(session); + l2tp_tunnel_dec_refcount(tunnel); + release_sock(sk); + + return error; +} + +#ifdef CONFIG_L2TP_V3 + +/* Called when creating sessions via the netlink interface. */ +static int pppol2tp_session_create(struct net *net, struct l2tp_tunnel *tunnel, + u32 session_id, u32 peer_session_id, + struct l2tp_session_cfg *cfg) +{ + int error; + struct l2tp_session *session; + + /* Error if tunnel socket is not prepped */ + if (!tunnel->sock) { + error = -ENOENT; + goto err; + } + + /* Allocate and initialize a new session context. */ + session = l2tp_session_create(sizeof(struct pppol2tp_session), + tunnel, session_id, + peer_session_id, cfg); + if (IS_ERR(session)) { + error = PTR_ERR(session); + goto err; + } + + pppol2tp_session_init(session); + + error = l2tp_session_register(session, tunnel); + if (error < 0) + goto err_sess; + + return 0; + +err_sess: + kfree(session); +err: + return error; +} + +#endif /* CONFIG_L2TP_V3 */ + +/* getname() support. + */ +static int pppol2tp_getname(struct socket *sock, struct sockaddr *uaddr, + int peer) +{ + int len = 0; + int error = 0; + struct l2tp_session *session; + struct l2tp_tunnel *tunnel; + struct sock *sk = sock->sk; + struct inet_sock *inet; + struct pppol2tp_session *pls; + + error = -ENOTCONN; + if (!sk) + goto end; + if (!(sk->sk_state & PPPOX_CONNECTED)) + goto end; + + error = -EBADF; + session = pppol2tp_sock_to_session(sk); + if (!session) + goto end; + + pls = l2tp_session_priv(session); + tunnel = session->tunnel; + + inet = inet_sk(tunnel->sock); + if (tunnel->version == 2 && tunnel->sock->sk_family == AF_INET) { + struct sockaddr_pppol2tp sp; + + len = sizeof(sp); + memset(&sp, 0, len); + sp.sa_family = AF_PPPOX; + sp.sa_protocol = PX_PROTO_OL2TP; + sp.pppol2tp.fd = tunnel->fd; + sp.pppol2tp.pid = pls->owner; + sp.pppol2tp.s_tunnel = tunnel->tunnel_id; + sp.pppol2tp.d_tunnel = tunnel->peer_tunnel_id; + sp.pppol2tp.s_session = session->session_id; + sp.pppol2tp.d_session = session->peer_session_id; + sp.pppol2tp.addr.sin_family = AF_INET; + sp.pppol2tp.addr.sin_port = inet->inet_dport; + sp.pppol2tp.addr.sin_addr.s_addr = inet->inet_daddr; + memcpy(uaddr, &sp, len); +#if IS_ENABLED(CONFIG_IPV6) + } else if (tunnel->version == 2 && tunnel->sock->sk_family == AF_INET6) { + struct sockaddr_pppol2tpin6 sp; + + len = sizeof(sp); + memset(&sp, 0, len); + sp.sa_family = AF_PPPOX; + sp.sa_protocol = PX_PROTO_OL2TP; + sp.pppol2tp.fd = tunnel->fd; + sp.pppol2tp.pid = pls->owner; + sp.pppol2tp.s_tunnel = tunnel->tunnel_id; + sp.pppol2tp.d_tunnel = tunnel->peer_tunnel_id; + sp.pppol2tp.s_session = session->session_id; + sp.pppol2tp.d_session = session->peer_session_id; + sp.pppol2tp.addr.sin6_family = AF_INET6; + sp.pppol2tp.addr.sin6_port = inet->inet_dport; + memcpy(&sp.pppol2tp.addr.sin6_addr, &tunnel->sock->sk_v6_daddr, + sizeof(tunnel->sock->sk_v6_daddr)); + memcpy(uaddr, &sp, len); + } else if (tunnel->version == 3 && tunnel->sock->sk_family == AF_INET6) { + struct sockaddr_pppol2tpv3in6 sp; + + len = sizeof(sp); + memset(&sp, 0, len); + sp.sa_family = AF_PPPOX; + sp.sa_protocol = PX_PROTO_OL2TP; + sp.pppol2tp.fd = tunnel->fd; + sp.pppol2tp.pid = pls->owner; + sp.pppol2tp.s_tunnel = tunnel->tunnel_id; + sp.pppol2tp.d_tunnel = tunnel->peer_tunnel_id; + sp.pppol2tp.s_session = session->session_id; + sp.pppol2tp.d_session = session->peer_session_id; + sp.pppol2tp.addr.sin6_family = AF_INET6; + sp.pppol2tp.addr.sin6_port = inet->inet_dport; + memcpy(&sp.pppol2tp.addr.sin6_addr, &tunnel->sock->sk_v6_daddr, + sizeof(tunnel->sock->sk_v6_daddr)); + memcpy(uaddr, &sp, len); +#endif + } else if (tunnel->version == 3) { + struct sockaddr_pppol2tpv3 sp; + + len = sizeof(sp); + memset(&sp, 0, len); + sp.sa_family = AF_PPPOX; + sp.sa_protocol = PX_PROTO_OL2TP; + sp.pppol2tp.fd = tunnel->fd; + sp.pppol2tp.pid = pls->owner; + sp.pppol2tp.s_tunnel = tunnel->tunnel_id; + sp.pppol2tp.d_tunnel = tunnel->peer_tunnel_id; + sp.pppol2tp.s_session = session->session_id; + sp.pppol2tp.d_session = session->peer_session_id; + sp.pppol2tp.addr.sin_family = AF_INET; + sp.pppol2tp.addr.sin_port = inet->inet_dport; + sp.pppol2tp.addr.sin_addr.s_addr = inet->inet_daddr; + memcpy(uaddr, &sp, len); + } + + error = len; + + sock_put(sk); +end: + return error; +} + +/**************************************************************************** + * ioctl() handlers. + * + * The PPPoX socket is created for L2TP sessions: tunnels have their own UDP + * sockets. However, in order to control kernel tunnel features, we allow + * userspace to create a special "tunnel" PPPoX socket which is used for + * control only. Tunnel PPPoX sockets have session_id == 0 and simply allow + * the user application to issue L2TP setsockopt(), getsockopt() and ioctl() + * calls. + ****************************************************************************/ + +static void pppol2tp_copy_stats(struct pppol2tp_ioc_stats *dest, + const struct l2tp_stats *stats) +{ + memset(dest, 0, sizeof(*dest)); + + dest->tx_packets = atomic_long_read(&stats->tx_packets); + dest->tx_bytes = atomic_long_read(&stats->tx_bytes); + dest->tx_errors = atomic_long_read(&stats->tx_errors); + dest->rx_packets = atomic_long_read(&stats->rx_packets); + dest->rx_bytes = atomic_long_read(&stats->rx_bytes); + dest->rx_seq_discards = atomic_long_read(&stats->rx_seq_discards); + dest->rx_oos_packets = atomic_long_read(&stats->rx_oos_packets); + dest->rx_errors = atomic_long_read(&stats->rx_errors); +} + +static int pppol2tp_tunnel_copy_stats(struct pppol2tp_ioc_stats *stats, + struct l2tp_tunnel *tunnel) +{ + struct l2tp_session *session; + + if (!stats->session_id) { + pppol2tp_copy_stats(stats, &tunnel->stats); + return 0; + } + + /* If session_id is set, search the corresponding session in the + * context of this tunnel and record the session's statistics. + */ + session = l2tp_tunnel_get_session(tunnel, stats->session_id); + if (!session) + return -EBADR; + + if (session->pwtype != L2TP_PWTYPE_PPP) { + l2tp_session_dec_refcount(session); + return -EBADR; + } + + pppol2tp_copy_stats(stats, &session->stats); + l2tp_session_dec_refcount(session); + + return 0; +} + +static int pppol2tp_ioctl(struct socket *sock, unsigned int cmd, + unsigned long arg) +{ + struct pppol2tp_ioc_stats stats; + struct l2tp_session *session; + + switch (cmd) { + case PPPIOCGMRU: + case PPPIOCGFLAGS: + session = sock->sk->sk_user_data; + if (!session) + return -ENOTCONN; + + if (WARN_ON(session->magic != L2TP_SESSION_MAGIC)) + return -EBADF; + + /* Not defined for tunnels */ + if (!session->session_id && !session->peer_session_id) + return -ENOSYS; + + if (put_user(0, (int __user *)arg)) + return -EFAULT; + break; + + case PPPIOCSMRU: + case PPPIOCSFLAGS: + session = sock->sk->sk_user_data; + if (!session) + return -ENOTCONN; + + if (WARN_ON(session->magic != L2TP_SESSION_MAGIC)) + return -EBADF; + + /* Not defined for tunnels */ + if (!session->session_id && !session->peer_session_id) + return -ENOSYS; + + if (!access_ok((int __user *)arg, sizeof(int))) + return -EFAULT; + break; + + case PPPIOCGL2TPSTATS: + session = sock->sk->sk_user_data; + if (!session) + return -ENOTCONN; + + if (WARN_ON(session->magic != L2TP_SESSION_MAGIC)) + return -EBADF; + + /* Session 0 represents the parent tunnel */ + if (!session->session_id && !session->peer_session_id) { + u32 session_id; + int err; + + if (copy_from_user(&stats, (void __user *)arg, + sizeof(stats))) + return -EFAULT; + + session_id = stats.session_id; + err = pppol2tp_tunnel_copy_stats(&stats, + session->tunnel); + if (err < 0) + return err; + + stats.session_id = session_id; + } else { + pppol2tp_copy_stats(&stats, &session->stats); + stats.session_id = session->session_id; + } + stats.tunnel_id = session->tunnel->tunnel_id; + stats.using_ipsec = l2tp_tunnel_uses_xfrm(session->tunnel); + + if (copy_to_user((void __user *)arg, &stats, sizeof(stats))) + return -EFAULT; + break; + + default: + return -ENOIOCTLCMD; + } + + return 0; +} + +/***************************************************************************** + * setsockopt() / getsockopt() support. + * + * The PPPoX socket is created for L2TP sessions: tunnels have their own UDP + * sockets. In order to control kernel tunnel features, we allow userspace to + * create a special "tunnel" PPPoX socket which is used for control only. + * Tunnel PPPoX sockets have session_id == 0 and simply allow the user + * application to issue L2TP setsockopt(), getsockopt() and ioctl() calls. + *****************************************************************************/ + +/* Tunnel setsockopt() helper. + */ +static int pppol2tp_tunnel_setsockopt(struct sock *sk, + struct l2tp_tunnel *tunnel, + int optname, int val) +{ + int err = 0; + + switch (optname) { + case PPPOL2TP_SO_DEBUG: + /* Tunnel debug flags option is deprecated */ + break; + + default: + err = -ENOPROTOOPT; + break; + } + + return err; +} + +/* Session setsockopt helper. + */ +static int pppol2tp_session_setsockopt(struct sock *sk, + struct l2tp_session *session, + int optname, int val) +{ + int err = 0; + + switch (optname) { + case PPPOL2TP_SO_RECVSEQ: + if (val != 0 && val != 1) { + err = -EINVAL; + break; + } + session->recv_seq = !!val; + break; + + case PPPOL2TP_SO_SENDSEQ: + if (val != 0 && val != 1) { + err = -EINVAL; + break; + } + session->send_seq = !!val; + { + struct pppox_sock *po = pppox_sk(sk); + + po->chan.hdrlen = val ? PPPOL2TP_L2TP_HDR_SIZE_SEQ : + PPPOL2TP_L2TP_HDR_SIZE_NOSEQ; + } + l2tp_session_set_header_len(session, session->tunnel->version); + break; + + case PPPOL2TP_SO_LNSMODE: + if (val != 0 && val != 1) { + err = -EINVAL; + break; + } + session->lns_mode = !!val; + break; + + case PPPOL2TP_SO_DEBUG: + /* Session debug flags option is deprecated */ + break; + + case PPPOL2TP_SO_REORDERTO: + session->reorder_timeout = msecs_to_jiffies(val); + break; + + default: + err = -ENOPROTOOPT; + break; + } + + return err; +} + +/* Main setsockopt() entry point. + * Does API checks, then calls either the tunnel or session setsockopt + * handler, according to whether the PPPoL2TP socket is a for a regular + * session or the special tunnel type. + */ +static int pppol2tp_setsockopt(struct socket *sock, int level, int optname, + sockptr_t optval, unsigned int optlen) +{ + struct sock *sk = sock->sk; + struct l2tp_session *session; + struct l2tp_tunnel *tunnel; + int val; + int err; + + if (level != SOL_PPPOL2TP) + return -EINVAL; + + if (optlen < sizeof(int)) + return -EINVAL; + + if (copy_from_sockptr(&val, optval, sizeof(int))) + return -EFAULT; + + err = -ENOTCONN; + if (!sk->sk_user_data) + goto end; + + /* Get session context from the socket */ + err = -EBADF; + session = pppol2tp_sock_to_session(sk); + if (!session) + goto end; + + /* Special case: if session_id == 0x0000, treat as operation on tunnel + */ + if (session->session_id == 0 && session->peer_session_id == 0) { + tunnel = session->tunnel; + err = pppol2tp_tunnel_setsockopt(sk, tunnel, optname, val); + } else { + err = pppol2tp_session_setsockopt(sk, session, optname, val); + } + + sock_put(sk); +end: + return err; +} + +/* Tunnel getsockopt helper. Called with sock locked. + */ +static int pppol2tp_tunnel_getsockopt(struct sock *sk, + struct l2tp_tunnel *tunnel, + int optname, int *val) +{ + int err = 0; + + switch (optname) { + case PPPOL2TP_SO_DEBUG: + /* Tunnel debug flags option is deprecated */ + *val = 0; + break; + + default: + err = -ENOPROTOOPT; + break; + } + + return err; +} + +/* Session getsockopt helper. Called with sock locked. + */ +static int pppol2tp_session_getsockopt(struct sock *sk, + struct l2tp_session *session, + int optname, int *val) +{ + int err = 0; + + switch (optname) { + case PPPOL2TP_SO_RECVSEQ: + *val = session->recv_seq; + break; + + case PPPOL2TP_SO_SENDSEQ: + *val = session->send_seq; + break; + + case PPPOL2TP_SO_LNSMODE: + *val = session->lns_mode; + break; + + case PPPOL2TP_SO_DEBUG: + /* Session debug flags option is deprecated */ + *val = 0; + break; + + case PPPOL2TP_SO_REORDERTO: + *val = (int)jiffies_to_msecs(session->reorder_timeout); + break; + + default: + err = -ENOPROTOOPT; + } + + return err; +} + +/* Main getsockopt() entry point. + * Does API checks, then calls either the tunnel or session getsockopt + * handler, according to whether the PPPoX socket is a for a regular session + * or the special tunnel type. + */ +static int pppol2tp_getsockopt(struct socket *sock, int level, int optname, + char __user *optval, int __user *optlen) +{ + struct sock *sk = sock->sk; + struct l2tp_session *session; + struct l2tp_tunnel *tunnel; + int val, len; + int err; + + if (level != SOL_PPPOL2TP) + return -EINVAL; + + if (get_user(len, optlen)) + return -EFAULT; + + len = min_t(unsigned int, len, sizeof(int)); + + if (len < 0) + return -EINVAL; + + err = -ENOTCONN; + if (!sk->sk_user_data) + goto end; + + /* Get the session context */ + err = -EBADF; + session = pppol2tp_sock_to_session(sk); + if (!session) + goto end; + + /* Special case: if session_id == 0x0000, treat as operation on tunnel */ + if (session->session_id == 0 && session->peer_session_id == 0) { + tunnel = session->tunnel; + err = pppol2tp_tunnel_getsockopt(sk, tunnel, optname, &val); + if (err) + goto end_put_sess; + } else { + err = pppol2tp_session_getsockopt(sk, session, optname, &val); + if (err) + goto end_put_sess; + } + + err = -EFAULT; + if (put_user(len, optlen)) + goto end_put_sess; + + if (copy_to_user((void __user *)optval, &val, len)) + goto end_put_sess; + + err = 0; + +end_put_sess: + sock_put(sk); +end: + return err; +} + +/***************************************************************************** + * /proc filesystem for debug + * Since the original pppol2tp driver provided /proc/net/pppol2tp for + * L2TPv2, we dump only L2TPv2 tunnels and sessions here. + *****************************************************************************/ + +static unsigned int pppol2tp_net_id; + +#ifdef CONFIG_PROC_FS + +struct pppol2tp_seq_data { + struct seq_net_private p; + int tunnel_idx; /* current tunnel */ + int session_idx; /* index of session within current tunnel */ + struct l2tp_tunnel *tunnel; + struct l2tp_session *session; /* NULL means get next tunnel */ +}; + +static void pppol2tp_next_tunnel(struct net *net, struct pppol2tp_seq_data *pd) +{ + /* Drop reference taken during previous invocation */ + if (pd->tunnel) + l2tp_tunnel_dec_refcount(pd->tunnel); + + for (;;) { + pd->tunnel = l2tp_tunnel_get_nth(net, pd->tunnel_idx); + pd->tunnel_idx++; + + /* Only accept L2TPv2 tunnels */ + if (!pd->tunnel || pd->tunnel->version == 2) + return; + + l2tp_tunnel_dec_refcount(pd->tunnel); + } +} + +static void pppol2tp_next_session(struct net *net, struct pppol2tp_seq_data *pd) +{ + /* Drop reference taken during previous invocation */ + if (pd->session) + l2tp_session_dec_refcount(pd->session); + + pd->session = l2tp_session_get_nth(pd->tunnel, pd->session_idx); + pd->session_idx++; + + if (!pd->session) { + pd->session_idx = 0; + pppol2tp_next_tunnel(net, pd); + } +} + +static void *pppol2tp_seq_start(struct seq_file *m, loff_t *offs) +{ + struct pppol2tp_seq_data *pd = SEQ_START_TOKEN; + loff_t pos = *offs; + struct net *net; + + if (!pos) + goto out; + + if (WARN_ON(!m->private)) { + pd = NULL; + goto out; + } + + pd = m->private; + net = seq_file_net(m); + + if (!pd->tunnel) + pppol2tp_next_tunnel(net, pd); + else + pppol2tp_next_session(net, pd); + + /* NULL tunnel and session indicates end of list */ + if (!pd->tunnel && !pd->session) + pd = NULL; + +out: + return pd; +} + +static void *pppol2tp_seq_next(struct seq_file *m, void *v, loff_t *pos) +{ + (*pos)++; + return NULL; +} + +static void pppol2tp_seq_stop(struct seq_file *p, void *v) +{ + struct pppol2tp_seq_data *pd = v; + + if (!pd || pd == SEQ_START_TOKEN) + return; + + /* Drop reference taken by last invocation of pppol2tp_next_session() + * or pppol2tp_next_tunnel(). + */ + if (pd->session) { + l2tp_session_dec_refcount(pd->session); + pd->session = NULL; + } + if (pd->tunnel) { + l2tp_tunnel_dec_refcount(pd->tunnel); + pd->tunnel = NULL; + } +} + +static void pppol2tp_seq_tunnel_show(struct seq_file *m, void *v) +{ + struct l2tp_tunnel *tunnel = v; + + seq_printf(m, "\nTUNNEL '%s', %c %d\n", + tunnel->name, + (tunnel == tunnel->sock->sk_user_data) ? 'Y' : 'N', + refcount_read(&tunnel->ref_count) - 1); + seq_printf(m, " %08x %ld/%ld/%ld %ld/%ld/%ld\n", + 0, + atomic_long_read(&tunnel->stats.tx_packets), + atomic_long_read(&tunnel->stats.tx_bytes), + atomic_long_read(&tunnel->stats.tx_errors), + atomic_long_read(&tunnel->stats.rx_packets), + atomic_long_read(&tunnel->stats.rx_bytes), + atomic_long_read(&tunnel->stats.rx_errors)); +} + +static void pppol2tp_seq_session_show(struct seq_file *m, void *v) +{ + struct l2tp_session *session = v; + struct l2tp_tunnel *tunnel = session->tunnel; + unsigned char state; + char user_data_ok; + struct sock *sk; + u32 ip = 0; + u16 port = 0; + + if (tunnel->sock) { + struct inet_sock *inet = inet_sk(tunnel->sock); + + ip = ntohl(inet->inet_saddr); + port = ntohs(inet->inet_sport); + } + + sk = pppol2tp_session_get_sock(session); + if (sk) { + state = sk->sk_state; + user_data_ok = (session == sk->sk_user_data) ? 'Y' : 'N'; + } else { + state = 0; + user_data_ok = 'N'; + } + + seq_printf(m, " SESSION '%s' %08X/%d %04X/%04X -> %04X/%04X %d %c\n", + session->name, ip, port, + tunnel->tunnel_id, + session->session_id, + tunnel->peer_tunnel_id, + session->peer_session_id, + state, user_data_ok); + seq_printf(m, " 0/0/%c/%c/%s %08x %u\n", + session->recv_seq ? 'R' : '-', + session->send_seq ? 'S' : '-', + session->lns_mode ? "LNS" : "LAC", + 0, + jiffies_to_msecs(session->reorder_timeout)); + seq_printf(m, " %u/%u %ld/%ld/%ld %ld/%ld/%ld\n", + session->nr, session->ns, + atomic_long_read(&session->stats.tx_packets), + atomic_long_read(&session->stats.tx_bytes), + atomic_long_read(&session->stats.tx_errors), + atomic_long_read(&session->stats.rx_packets), + atomic_long_read(&session->stats.rx_bytes), + atomic_long_read(&session->stats.rx_errors)); + + if (sk) { + struct pppox_sock *po = pppox_sk(sk); + + seq_printf(m, " interface %s\n", ppp_dev_name(&po->chan)); + sock_put(sk); + } +} + +static int pppol2tp_seq_show(struct seq_file *m, void *v) +{ + struct pppol2tp_seq_data *pd = v; + + /* display header on line 1 */ + if (v == SEQ_START_TOKEN) { + seq_puts(m, "PPPoL2TP driver info, " PPPOL2TP_DRV_VERSION "\n"); + seq_puts(m, "TUNNEL name, user-data-ok session-count\n"); + seq_puts(m, " debug tx-pkts/bytes/errs rx-pkts/bytes/errs\n"); + seq_puts(m, " SESSION name, addr/port src-tid/sid dest-tid/sid state user-data-ok\n"); + seq_puts(m, " mtu/mru/rcvseq/sendseq/lns debug reorderto\n"); + seq_puts(m, " nr/ns tx-pkts/bytes/errs rx-pkts/bytes/errs\n"); + goto out; + } + + if (!pd->session) + pppol2tp_seq_tunnel_show(m, pd->tunnel); + else + pppol2tp_seq_session_show(m, pd->session); + +out: + return 0; +} + +static const struct seq_operations pppol2tp_seq_ops = { + .start = pppol2tp_seq_start, + .next = pppol2tp_seq_next, + .stop = pppol2tp_seq_stop, + .show = pppol2tp_seq_show, +}; +#endif /* CONFIG_PROC_FS */ + +/***************************************************************************** + * Network namespace + *****************************************************************************/ + +static __net_init int pppol2tp_init_net(struct net *net) +{ + struct proc_dir_entry *pde; + int err = 0; + + pde = proc_create_net("pppol2tp", 0444, net->proc_net, + &pppol2tp_seq_ops, sizeof(struct pppol2tp_seq_data)); + if (!pde) { + err = -ENOMEM; + goto out; + } + +out: + return err; +} + +static __net_exit void pppol2tp_exit_net(struct net *net) +{ + remove_proc_entry("pppol2tp", net->proc_net); +} + +static struct pernet_operations pppol2tp_net_ops = { + .init = pppol2tp_init_net, + .exit = pppol2tp_exit_net, + .id = &pppol2tp_net_id, +}; + +/***************************************************************************** + * Init and cleanup + *****************************************************************************/ + +static const struct proto_ops pppol2tp_ops = { + .family = AF_PPPOX, + .owner = THIS_MODULE, + .release = pppol2tp_release, + .bind = sock_no_bind, + .connect = pppol2tp_connect, + .socketpair = sock_no_socketpair, + .accept = sock_no_accept, + .getname = pppol2tp_getname, + .poll = datagram_poll, + .listen = sock_no_listen, + .shutdown = sock_no_shutdown, + .setsockopt = pppol2tp_setsockopt, + .getsockopt = pppol2tp_getsockopt, + .sendmsg = pppol2tp_sendmsg, + .recvmsg = pppol2tp_recvmsg, + .mmap = sock_no_mmap, + .ioctl = pppox_ioctl, +#ifdef CONFIG_COMPAT + .compat_ioctl = pppox_compat_ioctl, +#endif +}; + +static const struct pppox_proto pppol2tp_proto = { + .create = pppol2tp_create, + .ioctl = pppol2tp_ioctl, + .owner = THIS_MODULE, +}; + +#ifdef CONFIG_L2TP_V3 + +static const struct l2tp_nl_cmd_ops pppol2tp_nl_cmd_ops = { + .session_create = pppol2tp_session_create, + .session_delete = l2tp_session_delete, +}; + +#endif /* CONFIG_L2TP_V3 */ + +static int __init pppol2tp_init(void) +{ + int err; + + err = register_pernet_device(&pppol2tp_net_ops); + if (err) + goto out; + + err = proto_register(&pppol2tp_sk_proto, 0); + if (err) + goto out_unregister_pppol2tp_pernet; + + err = register_pppox_proto(PX_PROTO_OL2TP, &pppol2tp_proto); + if (err) + goto out_unregister_pppol2tp_proto; + +#ifdef CONFIG_L2TP_V3 + err = l2tp_nl_register_ops(L2TP_PWTYPE_PPP, &pppol2tp_nl_cmd_ops); + if (err) + goto out_unregister_pppox; +#endif + + pr_info("PPPoL2TP kernel driver, %s\n", PPPOL2TP_DRV_VERSION); + +out: + return err; + +#ifdef CONFIG_L2TP_V3 +out_unregister_pppox: + unregister_pppox_proto(PX_PROTO_OL2TP); +#endif +out_unregister_pppol2tp_proto: + proto_unregister(&pppol2tp_sk_proto); +out_unregister_pppol2tp_pernet: + unregister_pernet_device(&pppol2tp_net_ops); + goto out; +} + +static void __exit pppol2tp_exit(void) +{ +#ifdef CONFIG_L2TP_V3 + l2tp_nl_unregister_ops(L2TP_PWTYPE_PPP); +#endif + unregister_pppox_proto(PX_PROTO_OL2TP); + proto_unregister(&pppol2tp_sk_proto); + unregister_pernet_device(&pppol2tp_net_ops); +} + +module_init(pppol2tp_init); +module_exit(pppol2tp_exit); + +MODULE_AUTHOR("James Chapman <jchapman@katalix.com>"); +MODULE_DESCRIPTION("PPP over L2TP over UDP"); +MODULE_LICENSE("GPL"); +MODULE_VERSION(PPPOL2TP_DRV_VERSION); +MODULE_ALIAS_NET_PF_PROTO(PF_PPPOX, PX_PROTO_OL2TP); +MODULE_ALIAS_L2TP_PWTYPE(7); diff --git a/net/l2tp/trace.h b/net/l2tp/trace.h new file mode 100644 index 000000000..8596eaa12 --- /dev/null +++ b/net/l2tp/trace.h @@ -0,0 +1,211 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +#undef TRACE_SYSTEM +#define TRACE_SYSTEM l2tp + +#if !defined(_TRACE_L2TP_H) || defined(TRACE_HEADER_MULTI_READ) +#define _TRACE_L2TP_H + +#include <linux/tracepoint.h> +#include <linux/l2tp.h> +#include "l2tp_core.h" + +#define encap_type_name(e) { L2TP_ENCAPTYPE_##e, #e } +#define show_encap_type_name(val) \ + __print_symbolic(val, \ + encap_type_name(UDP), \ + encap_type_name(IP)) + +#define pw_type_name(p) { L2TP_PWTYPE_##p, #p } +#define show_pw_type_name(val) \ + __print_symbolic(val, \ + pw_type_name(ETH_VLAN), \ + pw_type_name(ETH), \ + pw_type_name(PPP), \ + pw_type_name(PPP_AC), \ + pw_type_name(IP)) + +DECLARE_EVENT_CLASS(tunnel_only_evt, + TP_PROTO(struct l2tp_tunnel *tunnel), + TP_ARGS(tunnel), + TP_STRUCT__entry( + __array(char, name, L2TP_TUNNEL_NAME_MAX) + ), + TP_fast_assign( + memcpy(__entry->name, tunnel->name, L2TP_TUNNEL_NAME_MAX); + ), + TP_printk("%s", __entry->name) +); + +DECLARE_EVENT_CLASS(session_only_evt, + TP_PROTO(struct l2tp_session *session), + TP_ARGS(session), + TP_STRUCT__entry( + __array(char, name, L2TP_SESSION_NAME_MAX) + ), + TP_fast_assign( + memcpy(__entry->name, session->name, L2TP_SESSION_NAME_MAX); + ), + TP_printk("%s", __entry->name) +); + +TRACE_EVENT(register_tunnel, + TP_PROTO(struct l2tp_tunnel *tunnel), + TP_ARGS(tunnel), + TP_STRUCT__entry( + __array(char, name, L2TP_TUNNEL_NAME_MAX) + __field(int, fd) + __field(u32, tid) + __field(u32, ptid) + __field(int, version) + __field(enum l2tp_encap_type, encap) + ), + TP_fast_assign( + memcpy(__entry->name, tunnel->name, L2TP_TUNNEL_NAME_MAX); + __entry->fd = tunnel->fd; + __entry->tid = tunnel->tunnel_id; + __entry->ptid = tunnel->peer_tunnel_id; + __entry->version = tunnel->version; + __entry->encap = tunnel->encap; + ), + TP_printk("%s: type=%s encap=%s version=L2TPv%d tid=%u ptid=%u fd=%d", + __entry->name, + __entry->fd > 0 ? "managed" : "unmanaged", + show_encap_type_name(__entry->encap), + __entry->version, + __entry->tid, + __entry->ptid, + __entry->fd) +); + +DEFINE_EVENT(tunnel_only_evt, delete_tunnel, + TP_PROTO(struct l2tp_tunnel *tunnel), + TP_ARGS(tunnel) +); + +DEFINE_EVENT(tunnel_only_evt, free_tunnel, + TP_PROTO(struct l2tp_tunnel *tunnel), + TP_ARGS(tunnel) +); + +TRACE_EVENT(register_session, + TP_PROTO(struct l2tp_session *session), + TP_ARGS(session), + TP_STRUCT__entry( + __array(char, name, L2TP_SESSION_NAME_MAX) + __field(u32, tid) + __field(u32, ptid) + __field(u32, sid) + __field(u32, psid) + __field(enum l2tp_pwtype, pwtype) + ), + TP_fast_assign( + memcpy(__entry->name, session->name, L2TP_SESSION_NAME_MAX); + __entry->tid = session->tunnel ? session->tunnel->tunnel_id : 0; + __entry->ptid = session->tunnel ? session->tunnel->peer_tunnel_id : 0; + __entry->sid = session->session_id; + __entry->psid = session->peer_session_id; + __entry->pwtype = session->pwtype; + ), + TP_printk("%s: pseudowire=%s sid=%u psid=%u tid=%u ptid=%u", + __entry->name, + show_pw_type_name(__entry->pwtype), + __entry->sid, + __entry->psid, + __entry->sid, + __entry->psid) +); + +DEFINE_EVENT(session_only_evt, delete_session, + TP_PROTO(struct l2tp_session *session), + TP_ARGS(session) +); + +DEFINE_EVENT(session_only_evt, free_session, + TP_PROTO(struct l2tp_session *session), + TP_ARGS(session) +); + +DEFINE_EVENT(session_only_evt, session_seqnum_lns_enable, + TP_PROTO(struct l2tp_session *session), + TP_ARGS(session) +); + +DEFINE_EVENT(session_only_evt, session_seqnum_lns_disable, + TP_PROTO(struct l2tp_session *session), + TP_ARGS(session) +); + +DECLARE_EVENT_CLASS(session_seqnum_evt, + TP_PROTO(struct l2tp_session *session), + TP_ARGS(session), + TP_STRUCT__entry( + __array(char, name, L2TP_SESSION_NAME_MAX) + __field(u32, ns) + __field(u32, nr) + ), + TP_fast_assign( + memcpy(__entry->name, session->name, L2TP_SESSION_NAME_MAX); + __entry->ns = session->ns; + __entry->nr = session->nr; + ), + TP_printk("%s: ns=%u nr=%u", + __entry->name, + __entry->ns, + __entry->nr) +); + +DEFINE_EVENT(session_seqnum_evt, session_seqnum_update, + TP_PROTO(struct l2tp_session *session), + TP_ARGS(session) +); + +DEFINE_EVENT(session_seqnum_evt, session_seqnum_reset, + TP_PROTO(struct l2tp_session *session), + TP_ARGS(session) +); + +DECLARE_EVENT_CLASS(session_pkt_discard_evt, + TP_PROTO(struct l2tp_session *session, u32 pkt_ns), + TP_ARGS(session, pkt_ns), + TP_STRUCT__entry( + __array(char, name, L2TP_SESSION_NAME_MAX) + __field(u32, pkt_ns) + __field(u32, my_nr) + __field(u32, reorder_q_len) + ), + TP_fast_assign( + memcpy(__entry->name, session->name, L2TP_SESSION_NAME_MAX); + __entry->pkt_ns = pkt_ns, + __entry->my_nr = session->nr; + __entry->reorder_q_len = skb_queue_len(&session->reorder_q); + ), + TP_printk("%s: pkt_ns=%u my_nr=%u reorder_q_len=%u", + __entry->name, + __entry->pkt_ns, + __entry->my_nr, + __entry->reorder_q_len) +); + +DEFINE_EVENT(session_pkt_discard_evt, session_pkt_expired, + TP_PROTO(struct l2tp_session *session, u32 pkt_ns), + TP_ARGS(session, pkt_ns) +); + +DEFINE_EVENT(session_pkt_discard_evt, session_pkt_outside_rx_window, + TP_PROTO(struct l2tp_session *session, u32 pkt_ns), + TP_ARGS(session, pkt_ns) +); + +DEFINE_EVENT(session_pkt_discard_evt, session_pkt_oos, + TP_PROTO(struct l2tp_session *session, u32 pkt_ns), + TP_ARGS(session, pkt_ns) +); + +#endif /* _TRACE_L2TP_H */ + +/* This part must be outside protection */ +#undef TRACE_INCLUDE_PATH +#define TRACE_INCLUDE_PATH . +#undef TRACE_INCLUDE_FILE +#define TRACE_INCLUDE_FILE trace +#include <trace/define_trace.h> |