1d2912cb1SThomas Gleixner // SPDX-License-Identifier: GPL-2.0-only 220dcb110STom Parkin /* L2TP core. 3fd558d18SJames Chapman * 4fd558d18SJames Chapman * Copyright (c) 2008,2009,2010 Katalix Systems Ltd 5fd558d18SJames Chapman * 6fd558d18SJames Chapman * This file contains some code of the original L2TPv2 pppol2tp 7fd558d18SJames Chapman * driver, which has the following copyright: 8fd558d18SJames Chapman * 9fd558d18SJames Chapman * Authors: Martijn van Oosterhout <kleptog@svana.org> 10fd558d18SJames Chapman * James Chapman (jchapman@katalix.com) 11fd558d18SJames Chapman * Contributors: 12fd558d18SJames Chapman * Michal Ostrowski <mostrows@speakeasy.net> 13fd558d18SJames Chapman * Arnaldo Carvalho de Melo <acme@xconectiva.com.br> 14fd558d18SJames Chapman * David S. Miller (davem@redhat.com) 15fd558d18SJames Chapman */ 16fd558d18SJames Chapman 17a4ca44faSJoe Perches #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 18a4ca44faSJoe Perches 19fd558d18SJames Chapman #include <linux/module.h> 20fd558d18SJames Chapman #include <linux/string.h> 21fd558d18SJames Chapman #include <linux/list.h> 22e02d494dSJames Chapman #include <linux/rculist.h> 23fd558d18SJames Chapman #include <linux/uaccess.h> 24fd558d18SJames Chapman 25fd558d18SJames Chapman #include <linux/kernel.h> 26fd558d18SJames Chapman #include <linux/spinlock.h> 27fd558d18SJames Chapman #include <linux/kthread.h> 28fd558d18SJames Chapman #include <linux/sched.h> 29fd558d18SJames Chapman #include <linux/slab.h> 30fd558d18SJames Chapman #include <linux/errno.h> 31fd558d18SJames Chapman #include <linux/jiffies.h> 32fd558d18SJames Chapman 33fd558d18SJames Chapman #include <linux/netdevice.h> 34fd558d18SJames Chapman #include <linux/net.h> 35fd558d18SJames Chapman #include <linux/inetdevice.h> 36fd558d18SJames Chapman #include <linux/skbuff.h> 37fd558d18SJames Chapman #include <linux/init.h> 380d76751fSJames Chapman #include <linux/in.h> 39fd558d18SJames Chapman #include <linux/ip.h> 40fd558d18SJames Chapman #include <linux/udp.h> 410d76751fSJames Chapman #include <linux/l2tp.h> 42fd558d18SJames Chapman #include <linux/hash.h> 43fd558d18SJames Chapman #include <linux/sort.h> 44fd558d18SJames Chapman #include <linux/file.h> 45fd558d18SJames Chapman #include <linux/nsproxy.h> 46fd558d18SJames Chapman #include <net/net_namespace.h> 47fd558d18SJames Chapman #include <net/netns/generic.h> 48fd558d18SJames Chapman #include <net/dst.h> 49fd558d18SJames Chapman #include <net/ip.h> 50fd558d18SJames Chapman #include <net/udp.h> 5185644b4dSTom Herbert #include <net/udp_tunnel.h> 52309795f4SJames Chapman #include <net/inet_common.h> 53fd558d18SJames Chapman #include <net/xfrm.h> 540d76751fSJames Chapman #include <net/protocol.h> 55d2cf3361SBenjamin LaHaise #include <net/inet6_connection_sock.h> 56d2cf3361SBenjamin LaHaise #include <net/inet_ecn.h> 57d2cf3361SBenjamin LaHaise #include <net/ip6_route.h> 58d499bd2eSDavid S. Miller #include <net/ip6_checksum.h> 59fd558d18SJames Chapman 60fd558d18SJames Chapman #include <asm/byteorder.h> 6160063497SArun Sharma #include <linux/atomic.h> 62fd558d18SJames Chapman 63fd558d18SJames Chapman #include "l2tp_core.h" 646b7bdcd7STom Parkin #include "trace.h" 65fd558d18SJames Chapman 663f117d6fSTom Parkin #define CREATE_TRACE_POINTS 673f117d6fSTom Parkin #include "trace.h" 683f117d6fSTom Parkin 69fd558d18SJames Chapman #define L2TP_DRV_VERSION "V2.0" 70fd558d18SJames Chapman 71fd558d18SJames Chapman /* L2TP header constants */ 72fd558d18SJames Chapman #define L2TP_HDRFLAG_T 0x8000 73fd558d18SJames Chapman #define L2TP_HDRFLAG_L 0x4000 74fd558d18SJames Chapman #define L2TP_HDRFLAG_S 0x0800 75fd558d18SJames Chapman #define L2TP_HDRFLAG_O 0x0200 76fd558d18SJames Chapman #define L2TP_HDRFLAG_P 0x0100 77fd558d18SJames Chapman 78fd558d18SJames Chapman #define L2TP_HDR_VER_MASK 0x000F 79fd558d18SJames Chapman #define L2TP_HDR_VER_2 0x0002 80f7faffa3SJames Chapman #define L2TP_HDR_VER_3 0x0003 81fd558d18SJames Chapman 82fd558d18SJames Chapman /* L2TPv3 default L2-specific sublayer */ 83fd558d18SJames Chapman #define L2TP_SLFLAG_S 0x40000000 84fd558d18SJames Chapman #define L2TP_SL_SEQ_MASK 0x00ffffff 85fd558d18SJames Chapman 8691c52470SJacob Wen #define L2TP_HDR_SIZE_MAX 14 87fd558d18SJames Chapman 88fd558d18SJames Chapman /* Default trace flags */ 89fd558d18SJames Chapman #define L2TP_DEFAULT_DEBUG_FLAGS 0 90fd558d18SJames Chapman 91fd558d18SJames Chapman /* Private data stored for received packets in the skb. 92fd558d18SJames Chapman */ 93fd558d18SJames Chapman struct l2tp_skb_cb { 94f7faffa3SJames Chapman u32 ns; 95fd558d18SJames Chapman u16 has_seq; 96fd558d18SJames Chapman u16 length; 97fd558d18SJames Chapman unsigned long expires; 98fd558d18SJames Chapman }; 99fd558d18SJames Chapman 100efcd8c85STom Parkin #define L2TP_SKB_CB(skb) ((struct l2tp_skb_cb *)&(skb)->cb[sizeof(struct inet_skb_parm)]) 101fd558d18SJames Chapman 102f8ccac0eSTom Parkin static struct workqueue_struct *l2tp_wq; 103fd558d18SJames Chapman 104fd558d18SJames Chapman /* per-net private data for this module */ 105fd558d18SJames Chapman static unsigned int l2tp_net_id; 106fd558d18SJames Chapman struct l2tp_net { 107fd558d18SJames Chapman struct list_head l2tp_tunnel_list; 10820dcb110STom Parkin /* Lock for write access to l2tp_tunnel_list */ 109e02d494dSJames Chapman spinlock_t l2tp_tunnel_list_lock; 110f7faffa3SJames Chapman struct hlist_head l2tp_session_hlist[L2TP_HASH_SIZE_2]; 11120dcb110STom Parkin /* Lock for write access to l2tp_session_hlist */ 112e02d494dSJames Chapman spinlock_t l2tp_session_hlist_lock; 113fd558d18SJames Chapman }; 114fd558d18SJames Chapman 115b954f940SPaolo Abeni #if IS_ENABLED(CONFIG_IPV6) 116b954f940SPaolo Abeni static bool l2tp_sk_is_v6(struct sock *sk) 117b954f940SPaolo Abeni { 118b954f940SPaolo Abeni return sk->sk_family == PF_INET6 && 119b954f940SPaolo Abeni !ipv6_addr_v4mapped(&sk->sk_v6_daddr); 120b954f940SPaolo Abeni } 121b954f940SPaolo Abeni #endif 122fc130840Sstephen hemminger 1238d8a51e2SDavid S. Miller static inline struct l2tp_tunnel *l2tp_tunnel(struct sock *sk) 1248d8a51e2SDavid S. Miller { 1258d8a51e2SDavid S. Miller return sk->sk_user_data; 1268d8a51e2SDavid S. Miller } 1278d8a51e2SDavid S. Miller 1289aaef50cSGuillaume Nault static inline struct l2tp_net *l2tp_pernet(const struct net *net) 129fd558d18SJames Chapman { 130fd558d18SJames Chapman return net_generic(net, l2tp_net_id); 131fd558d18SJames Chapman } 132fd558d18SJames Chapman 133f7faffa3SJames Chapman /* Session hash global list for L2TPv3. 134f7faffa3SJames Chapman * The session_id SHOULD be random according to RFC3931, but several 135f7faffa3SJames Chapman * L2TP implementations use incrementing session_ids. So we do a real 136f7faffa3SJames Chapman * hash on the session_id, rather than a simple bitmask. 137f7faffa3SJames Chapman */ 138f7faffa3SJames Chapman static inline struct hlist_head * 139f7faffa3SJames Chapman l2tp_session_id_hash_2(struct l2tp_net *pn, u32 session_id) 140f7faffa3SJames Chapman { 141f7faffa3SJames Chapman return &pn->l2tp_session_hlist[hash_32(session_id, L2TP_HASH_BITS_2)]; 142f7faffa3SJames Chapman } 143f7faffa3SJames Chapman 144fd558d18SJames Chapman /* Session hash list. 145fd558d18SJames Chapman * The session_id SHOULD be random according to RFC2661, but several 146fd558d18SJames Chapman * L2TP implementations (Cisco and Microsoft) use incrementing 147fd558d18SJames Chapman * session_ids. So we do a real hash on the session_id, rather than a 148fd558d18SJames Chapman * simple bitmask. 149fd558d18SJames Chapman */ 150fd558d18SJames Chapman static inline struct hlist_head * 151fd558d18SJames Chapman l2tp_session_id_hash(struct l2tp_tunnel *tunnel, u32 session_id) 152fd558d18SJames Chapman { 153fd558d18SJames Chapman return &tunnel->session_hlist[hash_32(session_id, L2TP_HASH_BITS)]; 154fd558d18SJames Chapman } 155fd558d18SJames Chapman 15652016e25STom Parkin static void l2tp_tunnel_free(struct l2tp_tunnel *tunnel) 157d00fa9adSJames Chapman { 1586b7bdcd7STom Parkin trace_free_tunnel(tunnel); 159d00fa9adSJames Chapman sock_put(tunnel->sock); 160d00fa9adSJames Chapman /* the tunnel is freed in the socket destructor */ 161d00fa9adSJames Chapman } 16252016e25STom Parkin 16352016e25STom Parkin static void l2tp_session_free(struct l2tp_session *session) 16452016e25STom Parkin { 16552016e25STom Parkin struct l2tp_tunnel *tunnel = session->tunnel; 16652016e25STom Parkin 1676b7bdcd7STom Parkin trace_free_session(session); 1686b7bdcd7STom Parkin 16952016e25STom Parkin if (tunnel) { 17052016e25STom Parkin if (WARN_ON(tunnel->magic != L2TP_TUNNEL_MAGIC)) 17152016e25STom Parkin goto out; 17252016e25STom Parkin l2tp_tunnel_dec_refcount(tunnel); 17352016e25STom Parkin } 17452016e25STom Parkin 17552016e25STom Parkin out: 17652016e25STom Parkin kfree(session); 17752016e25STom Parkin } 17852016e25STom Parkin 17952016e25STom Parkin void l2tp_tunnel_inc_refcount(struct l2tp_tunnel *tunnel) 18052016e25STom Parkin { 18152016e25STom Parkin refcount_inc(&tunnel->ref_count); 18252016e25STom Parkin } 18352016e25STom Parkin EXPORT_SYMBOL_GPL(l2tp_tunnel_inc_refcount); 18452016e25STom Parkin 18552016e25STom Parkin void l2tp_tunnel_dec_refcount(struct l2tp_tunnel *tunnel) 18652016e25STom Parkin { 18752016e25STom Parkin if (refcount_dec_and_test(&tunnel->ref_count)) 18852016e25STom Parkin l2tp_tunnel_free(tunnel); 18952016e25STom Parkin } 19052016e25STom Parkin EXPORT_SYMBOL_GPL(l2tp_tunnel_dec_refcount); 19152016e25STom Parkin 19252016e25STom Parkin void l2tp_session_inc_refcount(struct l2tp_session *session) 19352016e25STom Parkin { 19452016e25STom Parkin refcount_inc(&session->ref_count); 19552016e25STom Parkin } 19652016e25STom Parkin EXPORT_SYMBOL_GPL(l2tp_session_inc_refcount); 19752016e25STom Parkin 19852016e25STom Parkin void l2tp_session_dec_refcount(struct l2tp_session *session) 19952016e25STom Parkin { 20052016e25STom Parkin if (refcount_dec_and_test(&session->ref_count)) 20152016e25STom Parkin l2tp_session_free(session); 20252016e25STom Parkin } 20352016e25STom Parkin EXPORT_SYMBOL_GPL(l2tp_session_dec_refcount); 204d00fa9adSJames Chapman 20554652eb1SGuillaume Nault /* Lookup a tunnel. A new reference is held on the returned tunnel. */ 20654652eb1SGuillaume Nault struct l2tp_tunnel *l2tp_tunnel_get(const struct net *net, u32 tunnel_id) 20754652eb1SGuillaume Nault { 20854652eb1SGuillaume Nault const struct l2tp_net *pn = l2tp_pernet(net); 20954652eb1SGuillaume Nault struct l2tp_tunnel *tunnel; 21054652eb1SGuillaume Nault 21154652eb1SGuillaume Nault rcu_read_lock_bh(); 21254652eb1SGuillaume Nault list_for_each_entry_rcu(tunnel, &pn->l2tp_tunnel_list, list) { 213a622b400SEric Dumazet if (tunnel->tunnel_id == tunnel_id && 214a622b400SEric Dumazet refcount_inc_not_zero(&tunnel->ref_count)) { 21554652eb1SGuillaume Nault rcu_read_unlock_bh(); 21654652eb1SGuillaume Nault 21754652eb1SGuillaume Nault return tunnel; 21854652eb1SGuillaume Nault } 21954652eb1SGuillaume Nault } 22054652eb1SGuillaume Nault rcu_read_unlock_bh(); 22154652eb1SGuillaume Nault 22254652eb1SGuillaume Nault return NULL; 22354652eb1SGuillaume Nault } 22454652eb1SGuillaume Nault EXPORT_SYMBOL_GPL(l2tp_tunnel_get); 22554652eb1SGuillaume Nault 2265846c131SGuillaume Nault struct l2tp_tunnel *l2tp_tunnel_get_nth(const struct net *net, int nth) 2275846c131SGuillaume Nault { 2285846c131SGuillaume Nault const struct l2tp_net *pn = l2tp_pernet(net); 2295846c131SGuillaume Nault struct l2tp_tunnel *tunnel; 2305846c131SGuillaume Nault int count = 0; 2315846c131SGuillaume Nault 2325846c131SGuillaume Nault rcu_read_lock_bh(); 2335846c131SGuillaume Nault list_for_each_entry_rcu(tunnel, &pn->l2tp_tunnel_list, list) { 234a622b400SEric Dumazet if (++count > nth && 235a622b400SEric Dumazet refcount_inc_not_zero(&tunnel->ref_count)) { 2365846c131SGuillaume Nault rcu_read_unlock_bh(); 2375846c131SGuillaume Nault return tunnel; 2385846c131SGuillaume Nault } 2395846c131SGuillaume Nault } 2405846c131SGuillaume Nault rcu_read_unlock_bh(); 2415846c131SGuillaume Nault 2425846c131SGuillaume Nault return NULL; 2435846c131SGuillaume Nault } 2445846c131SGuillaume Nault EXPORT_SYMBOL_GPL(l2tp_tunnel_get_nth); 2455846c131SGuillaume Nault 24601e28b92SGuillaume Nault struct l2tp_session *l2tp_tunnel_get_session(struct l2tp_tunnel *tunnel, 247a4346210SGuillaume Nault u32 session_id) 24861b9a047SGuillaume Nault { 24961b9a047SGuillaume Nault struct hlist_head *session_list; 25061b9a047SGuillaume Nault struct l2tp_session *session; 25161b9a047SGuillaume Nault 25201e28b92SGuillaume Nault session_list = l2tp_session_id_hash(tunnel, session_id); 25361b9a047SGuillaume Nault 25401e28b92SGuillaume Nault read_lock_bh(&tunnel->hlist_lock); 25501e28b92SGuillaume Nault hlist_for_each_entry(session, session_list, hlist) 25661b9a047SGuillaume Nault if (session->session_id == session_id) { 25761b9a047SGuillaume Nault l2tp_session_inc_refcount(session); 25801e28b92SGuillaume Nault read_unlock_bh(&tunnel->hlist_lock); 25961b9a047SGuillaume Nault 26061b9a047SGuillaume Nault return session; 26161b9a047SGuillaume Nault } 26201e28b92SGuillaume Nault read_unlock_bh(&tunnel->hlist_lock); 26361b9a047SGuillaume Nault 26461b9a047SGuillaume Nault return NULL; 26561b9a047SGuillaume Nault } 26601e28b92SGuillaume Nault EXPORT_SYMBOL_GPL(l2tp_tunnel_get_session); 26761b9a047SGuillaume Nault 26801e28b92SGuillaume Nault struct l2tp_session *l2tp_session_get(const struct net *net, u32 session_id) 26901e28b92SGuillaume Nault { 27001e28b92SGuillaume Nault struct hlist_head *session_list; 27101e28b92SGuillaume Nault struct l2tp_session *session; 27201e28b92SGuillaume Nault 27301e28b92SGuillaume Nault session_list = l2tp_session_id_hash_2(l2tp_pernet(net), session_id); 27401e28b92SGuillaume Nault 27501e28b92SGuillaume Nault rcu_read_lock_bh(); 27601e28b92SGuillaume Nault hlist_for_each_entry_rcu(session, session_list, global_hlist) 27761b9a047SGuillaume Nault if (session->session_id == session_id) { 27861b9a047SGuillaume Nault l2tp_session_inc_refcount(session); 27901e28b92SGuillaume Nault rcu_read_unlock_bh(); 28061b9a047SGuillaume Nault 28161b9a047SGuillaume Nault return session; 28261b9a047SGuillaume Nault } 28301e28b92SGuillaume Nault rcu_read_unlock_bh(); 28461b9a047SGuillaume Nault 28561b9a047SGuillaume Nault return NULL; 28661b9a047SGuillaume Nault } 28761b9a047SGuillaume Nault EXPORT_SYMBOL_GPL(l2tp_session_get); 28861b9a047SGuillaume Nault 289a4346210SGuillaume Nault struct l2tp_session *l2tp_session_get_nth(struct l2tp_tunnel *tunnel, int nth) 290fd558d18SJames Chapman { 291fd558d18SJames Chapman int hash; 292fd558d18SJames Chapman struct l2tp_session *session; 293fd558d18SJames Chapman int count = 0; 294fd558d18SJames Chapman 295fd558d18SJames Chapman read_lock_bh(&tunnel->hlist_lock); 296fd558d18SJames Chapman for (hash = 0; hash < L2TP_HASH_SIZE; hash++) { 297b67bfe0dSSasha Levin hlist_for_each_entry(session, &tunnel->session_hlist[hash], hlist) { 298fd558d18SJames Chapman if (++count > nth) { 299e08293a4SGuillaume Nault l2tp_session_inc_refcount(session); 300fd558d18SJames Chapman read_unlock_bh(&tunnel->hlist_lock); 301fd558d18SJames Chapman return session; 302fd558d18SJames Chapman } 303fd558d18SJames Chapman } 304fd558d18SJames Chapman } 305fd558d18SJames Chapman 306fd558d18SJames Chapman read_unlock_bh(&tunnel->hlist_lock); 307fd558d18SJames Chapman 308fd558d18SJames Chapman return NULL; 309fd558d18SJames Chapman } 310e08293a4SGuillaume Nault EXPORT_SYMBOL_GPL(l2tp_session_get_nth); 311fd558d18SJames Chapman 312309795f4SJames Chapman /* Lookup a session by interface name. 313309795f4SJames Chapman * This is very inefficient but is only used by management interfaces. 314309795f4SJames Chapman */ 3159aaef50cSGuillaume Nault struct l2tp_session *l2tp_session_get_by_ifname(const struct net *net, 316a4346210SGuillaume Nault const char *ifname) 317309795f4SJames Chapman { 318309795f4SJames Chapman struct l2tp_net *pn = l2tp_pernet(net); 319309795f4SJames Chapman int hash; 320309795f4SJames Chapman struct l2tp_session *session; 321309795f4SJames Chapman 322e02d494dSJames Chapman rcu_read_lock_bh(); 323309795f4SJames Chapman for (hash = 0; hash < L2TP_HASH_SIZE_2; hash++) { 324b67bfe0dSSasha Levin hlist_for_each_entry_rcu(session, &pn->l2tp_session_hlist[hash], global_hlist) { 325309795f4SJames Chapman if (!strcmp(session->ifname, ifname)) { 3262777e2abSGuillaume Nault l2tp_session_inc_refcount(session); 327e02d494dSJames Chapman rcu_read_unlock_bh(); 3282777e2abSGuillaume Nault 329309795f4SJames Chapman return session; 330309795f4SJames Chapman } 331309795f4SJames Chapman } 332309795f4SJames Chapman } 333309795f4SJames Chapman 334e02d494dSJames Chapman rcu_read_unlock_bh(); 335309795f4SJames Chapman 336309795f4SJames Chapman return NULL; 337309795f4SJames Chapman } 3382777e2abSGuillaume Nault EXPORT_SYMBOL_GPL(l2tp_session_get_by_ifname); 339309795f4SJames Chapman 3403953ae7bSGuillaume Nault int l2tp_session_register(struct l2tp_session *session, 3413953ae7bSGuillaume Nault struct l2tp_tunnel *tunnel) 342dbdbc73bSGuillaume Nault { 343dbdbc73bSGuillaume Nault struct l2tp_session *session_walk; 344dbdbc73bSGuillaume Nault struct hlist_head *g_head; 345dbdbc73bSGuillaume Nault struct hlist_head *head; 346dbdbc73bSGuillaume Nault struct l2tp_net *pn; 347f3c66d4eSGuillaume Nault int err; 348dbdbc73bSGuillaume Nault 349dbdbc73bSGuillaume Nault head = l2tp_session_id_hash(tunnel, session->session_id); 350dbdbc73bSGuillaume Nault 351dbdbc73bSGuillaume Nault write_lock_bh(&tunnel->hlist_lock); 352f3c66d4eSGuillaume Nault if (!tunnel->acpt_newsess) { 353f3c66d4eSGuillaume Nault err = -ENODEV; 354f3c66d4eSGuillaume Nault goto err_tlock; 355f3c66d4eSGuillaume Nault } 356f3c66d4eSGuillaume Nault 357dbdbc73bSGuillaume Nault hlist_for_each_entry(session_walk, head, hlist) 358f3c66d4eSGuillaume Nault if (session_walk->session_id == session->session_id) { 359f3c66d4eSGuillaume Nault err = -EEXIST; 360f3c66d4eSGuillaume Nault goto err_tlock; 361f3c66d4eSGuillaume Nault } 362dbdbc73bSGuillaume Nault 363dbdbc73bSGuillaume Nault if (tunnel->version == L2TP_HDR_VER_3) { 364dbdbc73bSGuillaume Nault pn = l2tp_pernet(tunnel->l2tp_net); 365363a341dSGuillaume Nault g_head = l2tp_session_id_hash_2(pn, session->session_id); 366dbdbc73bSGuillaume Nault 367dbdbc73bSGuillaume Nault spin_lock_bh(&pn->l2tp_session_hlist_lock); 368dbdbc73bSGuillaume Nault 3690d0d9a38SRidge Kennedy /* IP encap expects session IDs to be globally unique, while 3700d0d9a38SRidge Kennedy * UDP encap doesn't. 3710d0d9a38SRidge Kennedy */ 372f3c66d4eSGuillaume Nault hlist_for_each_entry(session_walk, g_head, global_hlist) 3730d0d9a38SRidge Kennedy if (session_walk->session_id == session->session_id && 3740d0d9a38SRidge Kennedy (session_walk->tunnel->encap == L2TP_ENCAPTYPE_IP || 3750d0d9a38SRidge Kennedy tunnel->encap == L2TP_ENCAPTYPE_IP)) { 376f3c66d4eSGuillaume Nault err = -EEXIST; 377f3c66d4eSGuillaume Nault goto err_tlock_pnlock; 378f3c66d4eSGuillaume Nault } 379f3c66d4eSGuillaume Nault 380f3c66d4eSGuillaume Nault l2tp_tunnel_inc_refcount(tunnel); 381dbdbc73bSGuillaume Nault hlist_add_head_rcu(&session->global_hlist, g_head); 382f3c66d4eSGuillaume Nault 383dbdbc73bSGuillaume Nault spin_unlock_bh(&pn->l2tp_session_hlist_lock); 384f3c66d4eSGuillaume Nault } else { 385f3c66d4eSGuillaume Nault l2tp_tunnel_inc_refcount(tunnel); 386dbdbc73bSGuillaume Nault } 387dbdbc73bSGuillaume Nault 388dbdbc73bSGuillaume Nault hlist_add_head(&session->hlist, head); 389dbdbc73bSGuillaume Nault write_unlock_bh(&tunnel->hlist_lock); 390dbdbc73bSGuillaume Nault 3916b7bdcd7STom Parkin trace_register_session(session); 3926b7bdcd7STom Parkin 393dbdbc73bSGuillaume Nault return 0; 394dbdbc73bSGuillaume Nault 395f3c66d4eSGuillaume Nault err_tlock_pnlock: 396dbdbc73bSGuillaume Nault spin_unlock_bh(&pn->l2tp_session_hlist_lock); 397f3c66d4eSGuillaume Nault err_tlock: 398dbdbc73bSGuillaume Nault write_unlock_bh(&tunnel->hlist_lock); 399dbdbc73bSGuillaume Nault 400f3c66d4eSGuillaume Nault return err; 401dbdbc73bSGuillaume Nault } 4023953ae7bSGuillaume Nault EXPORT_SYMBOL_GPL(l2tp_session_register); 403dbdbc73bSGuillaume Nault 404fd558d18SJames Chapman /***************************************************************************** 405fd558d18SJames Chapman * Receive data handling 406fd558d18SJames Chapman *****************************************************************************/ 407fd558d18SJames Chapman 408fd558d18SJames Chapman /* Queue a skb in order. We come here only if the skb has an L2TP sequence 409fd558d18SJames Chapman * number. 410fd558d18SJames Chapman */ 411fd558d18SJames Chapman static void l2tp_recv_queue_skb(struct l2tp_session *session, struct sk_buff *skb) 412fd558d18SJames Chapman { 413fd558d18SJames Chapman struct sk_buff *skbp; 414fd558d18SJames Chapman struct sk_buff *tmp; 415f7faffa3SJames Chapman u32 ns = L2TP_SKB_CB(skb)->ns; 416fd558d18SJames Chapman 417fd558d18SJames Chapman spin_lock_bh(&session->reorder_q.lock); 418fd558d18SJames Chapman skb_queue_walk_safe(&session->reorder_q, skbp, tmp) { 419fd558d18SJames Chapman if (L2TP_SKB_CB(skbp)->ns > ns) { 420fd558d18SJames Chapman __skb_queue_before(&session->reorder_q, skbp, skb); 4217b7c0719STom Parkin atomic_long_inc(&session->stats.rx_oos_packets); 422fd558d18SJames Chapman goto out; 423fd558d18SJames Chapman } 424fd558d18SJames Chapman } 425fd558d18SJames Chapman 426fd558d18SJames Chapman __skb_queue_tail(&session->reorder_q, skb); 427fd558d18SJames Chapman 428fd558d18SJames Chapman out: 429fd558d18SJames Chapman spin_unlock_bh(&session->reorder_q.lock); 430fd558d18SJames Chapman } 431fd558d18SJames Chapman 432fd558d18SJames Chapman /* Dequeue a single skb. 433fd558d18SJames Chapman */ 434fd558d18SJames Chapman static void l2tp_recv_dequeue_skb(struct l2tp_session *session, struct sk_buff *skb) 435fd558d18SJames Chapman { 436fd558d18SJames Chapman struct l2tp_tunnel *tunnel = session->tunnel; 437fd558d18SJames Chapman int length = L2TP_SKB_CB(skb)->length; 438fd558d18SJames Chapman 439fd558d18SJames Chapman /* We're about to requeue the skb, so return resources 440fd558d18SJames Chapman * to its current owner (a socket receive buffer). 441fd558d18SJames Chapman */ 442fd558d18SJames Chapman skb_orphan(skb); 443fd558d18SJames Chapman 4447b7c0719STom Parkin atomic_long_inc(&tunnel->stats.rx_packets); 4457b7c0719STom Parkin atomic_long_add(length, &tunnel->stats.rx_bytes); 4467b7c0719STom Parkin atomic_long_inc(&session->stats.rx_packets); 4477b7c0719STom Parkin atomic_long_add(length, &session->stats.rx_bytes); 448fd558d18SJames Chapman 449fd558d18SJames Chapman if (L2TP_SKB_CB(skb)->has_seq) { 450fd558d18SJames Chapman /* Bump our Nr */ 451fd558d18SJames Chapman session->nr++; 4528a1631d5SJames Chapman session->nr &= session->nr_max; 4536b7bdcd7STom Parkin trace_session_seqnum_update(session); 454fd558d18SJames Chapman } 455fd558d18SJames Chapman 456fd558d18SJames Chapman /* call private receive handler */ 4570febc7b3STom Parkin if (session->recv_skb) 458fd558d18SJames Chapman (*session->recv_skb)(session, skb, L2TP_SKB_CB(skb)->length); 459fd558d18SJames Chapman else 460fd558d18SJames Chapman kfree_skb(skb); 461fd558d18SJames Chapman } 462fd558d18SJames Chapman 463fd558d18SJames Chapman /* Dequeue skbs from the session's reorder_q, subject to packet order. 464fd558d18SJames Chapman * Skbs that have been in the queue for too long are simply discarded. 465fd558d18SJames Chapman */ 466fd558d18SJames Chapman static void l2tp_recv_dequeue(struct l2tp_session *session) 467fd558d18SJames Chapman { 468fd558d18SJames Chapman struct sk_buff *skb; 469fd558d18SJames Chapman struct sk_buff *tmp; 470fd558d18SJames Chapman 471fd558d18SJames Chapman /* If the pkt at the head of the queue has the nr that we 472fd558d18SJames Chapman * expect to send up next, dequeue it and any other 473fd558d18SJames Chapman * in-sequence packets behind it. 474fd558d18SJames Chapman */ 475e2e210c0SEric Dumazet start: 476fd558d18SJames Chapman spin_lock_bh(&session->reorder_q.lock); 477fd558d18SJames Chapman skb_queue_walk_safe(&session->reorder_q, skb, tmp) { 4786b7bdcd7STom Parkin struct l2tp_skb_cb *cb = L2TP_SKB_CB(skb); 4796b7bdcd7STom Parkin 4806b7bdcd7STom Parkin /* If the packet has been pending on the queue for too long, discard it */ 4816b7bdcd7STom Parkin if (time_after(jiffies, cb->expires)) { 4827b7c0719STom Parkin atomic_long_inc(&session->stats.rx_seq_discards); 4837b7c0719STom Parkin atomic_long_inc(&session->stats.rx_errors); 4846b7bdcd7STom Parkin trace_session_pkt_expired(session, cb->ns); 48538d40b3fSJames Chapman session->reorder_skip = 1; 486fd558d18SJames Chapman __skb_unlink(skb, &session->reorder_q); 487fd558d18SJames Chapman kfree_skb(skb); 488fd558d18SJames Chapman continue; 489fd558d18SJames Chapman } 490fd558d18SJames Chapman 4916b7bdcd7STom Parkin if (cb->has_seq) { 49238d40b3fSJames Chapman if (session->reorder_skip) { 49338d40b3fSJames Chapman session->reorder_skip = 0; 4946b7bdcd7STom Parkin session->nr = cb->ns; 4956b7bdcd7STom Parkin trace_session_seqnum_reset(session); 49638d40b3fSJames Chapman } 4976b7bdcd7STom Parkin if (cb->ns != session->nr) 498fd558d18SJames Chapman goto out; 499fd558d18SJames Chapman } 500fd558d18SJames Chapman __skb_unlink(skb, &session->reorder_q); 501fd558d18SJames Chapman 502fd558d18SJames Chapman /* Process the skb. We release the queue lock while we 503fd558d18SJames Chapman * do so to let other contexts process the queue. 504fd558d18SJames Chapman */ 505fd558d18SJames Chapman spin_unlock_bh(&session->reorder_q.lock); 506fd558d18SJames Chapman l2tp_recv_dequeue_skb(session, skb); 507e2e210c0SEric Dumazet goto start; 508fd558d18SJames Chapman } 509fd558d18SJames Chapman 510fd558d18SJames Chapman out: 511fd558d18SJames Chapman spin_unlock_bh(&session->reorder_q.lock); 512fd558d18SJames Chapman } 513fd558d18SJames Chapman 5148a1631d5SJames Chapman static int l2tp_seq_check_rx_window(struct l2tp_session *session, u32 nr) 5158a1631d5SJames Chapman { 5168a1631d5SJames Chapman u32 nws; 5178a1631d5SJames Chapman 5188a1631d5SJames Chapman if (nr >= session->nr) 5198a1631d5SJames Chapman nws = nr - session->nr; 5208a1631d5SJames Chapman else 5218a1631d5SJames Chapman nws = (session->nr_max + 1) - (session->nr - nr); 5228a1631d5SJames Chapman 5238a1631d5SJames Chapman return nws < session->nr_window_size; 5248a1631d5SJames Chapman } 5258a1631d5SJames Chapman 526b6dc01a4SJames Chapman /* If packet has sequence numbers, queue it if acceptable. Returns 0 if 527b6dc01a4SJames Chapman * acceptable, else non-zero. 528b6dc01a4SJames Chapman */ 529b6dc01a4SJames Chapman static int l2tp_recv_data_seq(struct l2tp_session *session, struct sk_buff *skb) 530b6dc01a4SJames Chapman { 5316b7bdcd7STom Parkin struct l2tp_skb_cb *cb = L2TP_SKB_CB(skb); 5326b7bdcd7STom Parkin 5336b7bdcd7STom Parkin if (!l2tp_seq_check_rx_window(session, cb->ns)) { 5348a1631d5SJames Chapman /* Packet sequence number is outside allowed window. 5358a1631d5SJames Chapman * Discard it. 5368a1631d5SJames Chapman */ 5376b7bdcd7STom Parkin trace_session_pkt_outside_rx_window(session, cb->ns); 5388a1631d5SJames Chapman goto discard; 5398a1631d5SJames Chapman } 5408a1631d5SJames Chapman 541b6dc01a4SJames Chapman if (session->reorder_timeout != 0) { 542b6dc01a4SJames Chapman /* Packet reordering enabled. Add skb to session's 543b6dc01a4SJames Chapman * reorder queue, in order of ns. 544b6dc01a4SJames Chapman */ 545b6dc01a4SJames Chapman l2tp_recv_queue_skb(session, skb); 546a0dbd822SJames Chapman goto out; 547a0dbd822SJames Chapman } 548a0dbd822SJames Chapman 549a0dbd822SJames Chapman /* Packet reordering disabled. Discard out-of-sequence packets, while 550a0dbd822SJames Chapman * tracking the number if in-sequence packets after the first OOS packet 551a0dbd822SJames Chapman * is seen. After nr_oos_count_max in-sequence packets, reset the 552a0dbd822SJames Chapman * sequence number to re-enable packet reception. 553b6dc01a4SJames Chapman */ 5546b7bdcd7STom Parkin if (cb->ns == session->nr) { 555a0dbd822SJames Chapman skb_queue_tail(&session->reorder_q, skb); 556a0dbd822SJames Chapman } else { 5576b7bdcd7STom Parkin u32 nr_oos = cb->ns; 558a0dbd822SJames Chapman u32 nr_next = (session->nr_oos + 1) & session->nr_max; 559a0dbd822SJames Chapman 560a0dbd822SJames Chapman if (nr_oos == nr_next) 561a0dbd822SJames Chapman session->nr_oos_count++; 562a0dbd822SJames Chapman else 563a0dbd822SJames Chapman session->nr_oos_count = 0; 564a0dbd822SJames Chapman 565a0dbd822SJames Chapman session->nr_oos = nr_oos; 566a0dbd822SJames Chapman if (session->nr_oos_count > session->nr_oos_count_max) { 567a0dbd822SJames Chapman session->reorder_skip = 1; 568a0dbd822SJames Chapman } 569a0dbd822SJames Chapman if (!session->reorder_skip) { 570b6dc01a4SJames Chapman atomic_long_inc(&session->stats.rx_seq_discards); 5716b7bdcd7STom Parkin trace_session_pkt_oos(session, cb->ns); 572b6dc01a4SJames Chapman goto discard; 573b6dc01a4SJames Chapman } 574b6dc01a4SJames Chapman skb_queue_tail(&session->reorder_q, skb); 575b6dc01a4SJames Chapman } 576b6dc01a4SJames Chapman 577a0dbd822SJames Chapman out: 578b6dc01a4SJames Chapman return 0; 579b6dc01a4SJames Chapman 580b6dc01a4SJames Chapman discard: 581b6dc01a4SJames Chapman return 1; 582b6dc01a4SJames Chapman } 583b6dc01a4SJames Chapman 584f7faffa3SJames Chapman /* Do receive processing of L2TP data frames. We handle both L2TPv2 585f7faffa3SJames Chapman * and L2TPv3 data frames here. 586f7faffa3SJames Chapman * 587f7faffa3SJames Chapman * L2TPv2 Data Message Header 588f7faffa3SJames Chapman * 589f7faffa3SJames Chapman * 0 1 2 3 590f7faffa3SJames Chapman * 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 591f7faffa3SJames Chapman * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 592f7faffa3SJames Chapman * |T|L|x|x|S|x|O|P|x|x|x|x| Ver | Length (opt) | 593f7faffa3SJames Chapman * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 594f7faffa3SJames Chapman * | Tunnel ID | Session ID | 595f7faffa3SJames Chapman * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 596f7faffa3SJames Chapman * | Ns (opt) | Nr (opt) | 597f7faffa3SJames Chapman * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 598f7faffa3SJames Chapman * | Offset Size (opt) | Offset pad... (opt) 599f7faffa3SJames Chapman * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 600f7faffa3SJames Chapman * 601f7faffa3SJames Chapman * Data frames are marked by T=0. All other fields are the same as 602f7faffa3SJames Chapman * those in L2TP control frames. 603f7faffa3SJames Chapman * 604f7faffa3SJames Chapman * L2TPv3 Data Message Header 605f7faffa3SJames Chapman * 606f7faffa3SJames Chapman * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 607f7faffa3SJames Chapman * | L2TP Session Header | 608f7faffa3SJames Chapman * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 609f7faffa3SJames Chapman * | L2-Specific Sublayer | 610f7faffa3SJames Chapman * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 611f7faffa3SJames Chapman * | Tunnel Payload ... 612f7faffa3SJames Chapman * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 613f7faffa3SJames Chapman * 614f7faffa3SJames Chapman * L2TPv3 Session Header Over IP 615f7faffa3SJames Chapman * 616f7faffa3SJames Chapman * 0 1 2 3 617f7faffa3SJames Chapman * 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 618f7faffa3SJames Chapman * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 619f7faffa3SJames Chapman * | Session ID | 620f7faffa3SJames Chapman * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 621f7faffa3SJames Chapman * | Cookie (optional, maximum 64 bits)... 622f7faffa3SJames Chapman * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 623f7faffa3SJames Chapman * | 624f7faffa3SJames Chapman * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 625f7faffa3SJames Chapman * 626f7faffa3SJames Chapman * L2TPv3 L2-Specific Sublayer Format 627f7faffa3SJames Chapman * 628f7faffa3SJames Chapman * 0 1 2 3 629f7faffa3SJames Chapman * 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 630f7faffa3SJames Chapman * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 631f7faffa3SJames Chapman * |x|S|x|x|x|x|x|x| Sequence Number | 632f7faffa3SJames Chapman * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 633f7faffa3SJames Chapman * 63423fe846fSGuillaume Nault * Cookie value and sublayer format are negotiated with the peer when 63523fe846fSGuillaume Nault * the session is set up. Unlike L2TPv2, we do not need to parse the 63623fe846fSGuillaume Nault * packet header to determine if optional fields are present. 637f7faffa3SJames Chapman * 638f7faffa3SJames Chapman * Caller must already have parsed the frame and determined that it is 639f7faffa3SJames Chapman * a data (not control) frame before coming here. Fields up to the 640f7faffa3SJames Chapman * session-id have already been parsed and ptr points to the data 641f7faffa3SJames Chapman * after the session-id. 642f7faffa3SJames Chapman */ 643f7faffa3SJames Chapman void l2tp_recv_common(struct l2tp_session *session, struct sk_buff *skb, 644f7faffa3SJames Chapman unsigned char *ptr, unsigned char *optr, u16 hdrflags, 6452b139e6bSGuillaume Nault int length) 646f7faffa3SJames Chapman { 647f7faffa3SJames Chapman struct l2tp_tunnel *tunnel = session->tunnel; 648f7faffa3SJames Chapman int offset; 649f7faffa3SJames Chapman 650f7faffa3SJames Chapman /* Parse and check optional cookie */ 651f7faffa3SJames Chapman if (session->peer_cookie_len > 0) { 652f7faffa3SJames Chapman if (memcmp(ptr, &session->peer_cookie[0], session->peer_cookie_len)) { 6535ee759cdSTom Parkin pr_warn_ratelimited("%s: cookie mismatch (%u/%u). Discarding.\n", 654a4ca44faSJoe Perches tunnel->name, tunnel->tunnel_id, 655a4ca44faSJoe Perches session->session_id); 6567b7c0719STom Parkin atomic_long_inc(&session->stats.rx_cookie_discards); 657f7faffa3SJames Chapman goto discard; 658f7faffa3SJames Chapman } 659f7faffa3SJames Chapman ptr += session->peer_cookie_len; 660f7faffa3SJames Chapman } 661f7faffa3SJames Chapman 662f7faffa3SJames Chapman /* Handle the optional sequence numbers. Sequence numbers are 663f7faffa3SJames Chapman * in different places for L2TPv2 and L2TPv3. 664f7faffa3SJames Chapman * 665f7faffa3SJames Chapman * If we are the LAC, enable/disable sequence numbers under 666f7faffa3SJames Chapman * the control of the LNS. If no sequence numbers present but 667f7faffa3SJames Chapman * we were expecting them, discard frame. 668f7faffa3SJames Chapman */ 669f7faffa3SJames Chapman L2TP_SKB_CB(skb)->has_seq = 0; 670f7faffa3SJames Chapman if (tunnel->version == L2TP_HDR_VER_2) { 671f7faffa3SJames Chapman if (hdrflags & L2TP_HDRFLAG_S) { 672f7faffa3SJames Chapman /* Store L2TP info in the skb */ 67312923365STom Parkin L2TP_SKB_CB(skb)->ns = ntohs(*(__be16 *)ptr); 674f7faffa3SJames Chapman L2TP_SKB_CB(skb)->has_seq = 1; 67512923365STom Parkin ptr += 2; 67612923365STom Parkin /* Skip past nr in the header */ 67712923365STom Parkin ptr += 2; 678f7faffa3SJames Chapman 679f7faffa3SJames Chapman } 680f7faffa3SJames Chapman } else if (session->l2specific_type == L2TP_L2SPECTYPE_DEFAULT) { 681f7faffa3SJames Chapman u32 l2h = ntohl(*(__be32 *)ptr); 682f7faffa3SJames Chapman 683f7faffa3SJames Chapman if (l2h & 0x40000000) { 684f7faffa3SJames Chapman /* Store L2TP info in the skb */ 68512923365STom Parkin L2TP_SKB_CB(skb)->ns = l2h & 0x00ffffff; 686f7faffa3SJames Chapman L2TP_SKB_CB(skb)->has_seq = 1; 687f7faffa3SJames Chapman } 68862e7b6a5SLorenzo Bianconi ptr += 4; 689f7faffa3SJames Chapman } 690f7faffa3SJames Chapman 691f7faffa3SJames Chapman if (L2TP_SKB_CB(skb)->has_seq) { 69220dcb110STom Parkin /* Received a packet with sequence numbers. If we're the LAC, 693f7faffa3SJames Chapman * check if we sre sending sequence numbers and if not, 694f7faffa3SJames Chapman * configure it so. 695f7faffa3SJames Chapman */ 6966c0ec37bSTom Parkin if (!session->lns_mode && !session->send_seq) { 6976b7bdcd7STom Parkin trace_session_seqnum_lns_enable(session); 6983f9b9770SAsbjørn Sloth Tønnesen session->send_seq = 1; 699f7faffa3SJames Chapman l2tp_session_set_header_len(session, tunnel->version); 700f7faffa3SJames Chapman } 701f7faffa3SJames Chapman } else { 702f7faffa3SJames Chapman /* No sequence numbers. 703f7faffa3SJames Chapman * If user has configured mandatory sequence numbers, discard. 704f7faffa3SJames Chapman */ 705f7faffa3SJames Chapman if (session->recv_seq) { 7065ee759cdSTom Parkin pr_warn_ratelimited("%s: recv data has no seq numbers when required. Discarding.\n", 707a4ca44faSJoe Perches session->name); 7087b7c0719STom Parkin atomic_long_inc(&session->stats.rx_seq_discards); 709f7faffa3SJames Chapman goto discard; 710f7faffa3SJames Chapman } 711f7faffa3SJames Chapman 712f7faffa3SJames Chapman /* If we're the LAC and we're sending sequence numbers, the 713f7faffa3SJames Chapman * LNS has requested that we no longer send sequence numbers. 714f7faffa3SJames Chapman * If we're the LNS and we're sending sequence numbers, the 715f7faffa3SJames Chapman * LAC is broken. Discard the frame. 716f7faffa3SJames Chapman */ 7176c0ec37bSTom Parkin if (!session->lns_mode && session->send_seq) { 7186b7bdcd7STom Parkin trace_session_seqnum_lns_disable(session); 719f7faffa3SJames Chapman session->send_seq = 0; 720f7faffa3SJames Chapman l2tp_session_set_header_len(session, tunnel->version); 721f7faffa3SJames Chapman } else if (session->send_seq) { 7225ee759cdSTom Parkin pr_warn_ratelimited("%s: recv data has no seq numbers when required. Discarding.\n", 723a4ca44faSJoe Perches session->name); 7247b7c0719STom Parkin atomic_long_inc(&session->stats.rx_seq_discards); 725f7faffa3SJames Chapman goto discard; 726f7faffa3SJames Chapman } 727f7faffa3SJames Chapman } 728f7faffa3SJames Chapman 729900631eeSJames Chapman /* Session data offset is defined only for L2TPv2 and is 730900631eeSJames Chapman * indicated by an optional 16-bit value in the header. 731f7faffa3SJames Chapman */ 732f7faffa3SJames Chapman if (tunnel->version == L2TP_HDR_VER_2) { 733f7faffa3SJames Chapman /* If offset bit set, skip it. */ 734f7faffa3SJames Chapman if (hdrflags & L2TP_HDRFLAG_O) { 735f7faffa3SJames Chapman offset = ntohs(*(__be16 *)ptr); 736f7faffa3SJames Chapman ptr += 2 + offset; 737f7faffa3SJames Chapman } 738900631eeSJames Chapman } 739f7faffa3SJames Chapman 740f7faffa3SJames Chapman offset = ptr - optr; 741f7faffa3SJames Chapman if (!pskb_may_pull(skb, offset)) 742f7faffa3SJames Chapman goto discard; 743f7faffa3SJames Chapman 744f7faffa3SJames Chapman __skb_pull(skb, offset); 745f7faffa3SJames Chapman 746f7faffa3SJames Chapman /* Prepare skb for adding to the session's reorder_q. Hold 747f7faffa3SJames Chapman * packets for max reorder_timeout or 1 second if not 748f7faffa3SJames Chapman * reordering. 749f7faffa3SJames Chapman */ 750f7faffa3SJames Chapman L2TP_SKB_CB(skb)->length = length; 751f7faffa3SJames Chapman L2TP_SKB_CB(skb)->expires = jiffies + 752f7faffa3SJames Chapman (session->reorder_timeout ? session->reorder_timeout : HZ); 753f7faffa3SJames Chapman 754f7faffa3SJames Chapman /* Add packet to the session's receive queue. Reordering is done here, if 755f7faffa3SJames Chapman * enabled. Saved L2TP protocol info is stored in skb->sb[]. 756f7faffa3SJames Chapman */ 757f7faffa3SJames Chapman if (L2TP_SKB_CB(skb)->has_seq) { 758b6dc01a4SJames Chapman if (l2tp_recv_data_seq(session, skb)) 759f7faffa3SJames Chapman goto discard; 760f7faffa3SJames Chapman } else { 761f7faffa3SJames Chapman /* No sequence numbers. Add the skb to the tail of the 762f7faffa3SJames Chapman * reorder queue. This ensures that it will be 763f7faffa3SJames Chapman * delivered after all previous sequenced skbs. 764f7faffa3SJames Chapman */ 765f7faffa3SJames Chapman skb_queue_tail(&session->reorder_q, skb); 766f7faffa3SJames Chapman } 767f7faffa3SJames Chapman 768f7faffa3SJames Chapman /* Try to dequeue as many skbs from reorder_q as we can. */ 769f7faffa3SJames Chapman l2tp_recv_dequeue(session); 770f7faffa3SJames Chapman 771f7faffa3SJames Chapman return; 772f7faffa3SJames Chapman 773f7faffa3SJames Chapman discard: 7747b7c0719STom Parkin atomic_long_inc(&session->stats.rx_errors); 775f7faffa3SJames Chapman kfree_skb(skb); 776f7faffa3SJames Chapman } 777ca7885dbSTom Parkin EXPORT_SYMBOL_GPL(l2tp_recv_common); 778f7faffa3SJames Chapman 77948f72f92STom Parkin /* Drop skbs from the session's reorder_q 78048f72f92STom Parkin */ 781493048f5STom Parkin static void l2tp_session_queue_purge(struct l2tp_session *session) 78248f72f92STom Parkin { 78348f72f92STom Parkin struct sk_buff *skb = NULL; 784b71a61ccSTom Parkin 785493048f5STom Parkin if (WARN_ON(session->magic != L2TP_SESSION_MAGIC)) 786493048f5STom Parkin return; 787493048f5STom Parkin 78848f72f92STom Parkin while ((skb = skb_dequeue(&session->reorder_q))) { 78948f72f92STom Parkin atomic_long_inc(&session->stats.rx_errors); 79048f72f92STom Parkin kfree_skb(skb); 79148f72f92STom Parkin } 79248f72f92STom Parkin } 79348f72f92STom Parkin 794fd558d18SJames Chapman /* Internal UDP receive frame. Do the real work of receiving an L2TP data frame 795fd558d18SJames Chapman * here. The skb is not on a list when we get here. 796fd558d18SJames Chapman * Returns 0 if the packet was a data packet and was successfully passed on. 797fd558d18SJames Chapman * Returns 1 if the packet was not a good data packet and could not be 798fd558d18SJames Chapman * forwarded. All such packets are passed up to userspace to deal with. 799fd558d18SJames Chapman */ 8002b139e6bSGuillaume Nault static int l2tp_udp_recv_core(struct l2tp_tunnel *tunnel, struct sk_buff *skb) 801fd558d18SJames Chapman { 802fd558d18SJames Chapman struct l2tp_session *session = NULL; 803fd558d18SJames Chapman unsigned char *ptr, *optr; 804fd558d18SJames Chapman u16 hdrflags; 805fd558d18SJames Chapman u32 tunnel_id, session_id; 806fd558d18SJames Chapman u16 version; 807f7faffa3SJames Chapman int length; 808fd558d18SJames Chapman 80958d6085cSTom Herbert /* UDP has verifed checksum */ 810fd558d18SJames Chapman 811fd558d18SJames Chapman /* UDP always verifies the packet length. */ 812fd558d18SJames Chapman __skb_pull(skb, sizeof(struct udphdr)); 813fd558d18SJames Chapman 814fd558d18SJames Chapman /* Short packet? */ 81591c52470SJacob Wen if (!pskb_may_pull(skb, L2TP_HDR_SIZE_MAX)) { 8165ee759cdSTom Parkin pr_warn_ratelimited("%s: recv short packet (len=%d)\n", 817a4ca44faSJoe Perches tunnel->name, skb->len); 818fd558d18SJames Chapman goto error; 819fd558d18SJames Chapman } 820fd558d18SJames Chapman 821e50e705cSEric Dumazet /* Point to L2TP header */ 82295075150STom Parkin optr = skb->data; 82395075150STom Parkin ptr = skb->data; 824e50e705cSEric Dumazet 825fd558d18SJames Chapman /* Get L2TP header flags */ 826fd558d18SJames Chapman hdrflags = ntohs(*(__be16 *)ptr); 827fd558d18SJames Chapman 828fd558d18SJames Chapman /* Check protocol version */ 829fd558d18SJames Chapman version = hdrflags & L2TP_HDR_VER_MASK; 830fd558d18SJames Chapman if (version != tunnel->version) { 8315ee759cdSTom Parkin pr_warn_ratelimited("%s: recv protocol version mismatch: got %d expected %d\n", 832fd558d18SJames Chapman tunnel->name, version, tunnel->version); 833fd558d18SJames Chapman goto error; 834fd558d18SJames Chapman } 835fd558d18SJames Chapman 836fd558d18SJames Chapman /* Get length of L2TP packet */ 837fd558d18SJames Chapman length = skb->len; 838fd558d18SJames Chapman 839fd558d18SJames Chapman /* If type is control packet, it is handled by userspace. */ 84012923365STom Parkin if (hdrflags & L2TP_HDRFLAG_T) 841fd558d18SJames Chapman goto error; 842fd558d18SJames Chapman 843fd558d18SJames Chapman /* Skip flags */ 844fd558d18SJames Chapman ptr += 2; 845fd558d18SJames Chapman 846f7faffa3SJames Chapman if (tunnel->version == L2TP_HDR_VER_2) { 847fd558d18SJames Chapman /* If length is present, skip it */ 848fd558d18SJames Chapman if (hdrflags & L2TP_HDRFLAG_L) 849fd558d18SJames Chapman ptr += 2; 850fd558d18SJames Chapman 851fd558d18SJames Chapman /* Extract tunnel and session ID */ 852fd558d18SJames Chapman tunnel_id = ntohs(*(__be16 *)ptr); 853fd558d18SJames Chapman ptr += 2; 854fd558d18SJames Chapman session_id = ntohs(*(__be16 *)ptr); 855fd558d18SJames Chapman ptr += 2; 856f7faffa3SJames Chapman } else { 857f7faffa3SJames Chapman ptr += 2; /* skip reserved bits */ 858f7faffa3SJames Chapman tunnel_id = tunnel->tunnel_id; 859f7faffa3SJames Chapman session_id = ntohl(*(__be32 *)ptr); 860f7faffa3SJames Chapman ptr += 4; 861f7faffa3SJames Chapman } 862fd558d18SJames Chapman 863fd558d18SJames Chapman /* Find the session context */ 86401e28b92SGuillaume Nault session = l2tp_tunnel_get_session(tunnel, session_id); 865309795f4SJames Chapman if (!session || !session->recv_skb) { 866a4346210SGuillaume Nault if (session) 86761b9a047SGuillaume Nault l2tp_session_dec_refcount(session); 86861b9a047SGuillaume Nault 869fd558d18SJames Chapman /* Not found? Pass to userspace to deal with */ 8705ee759cdSTom Parkin pr_warn_ratelimited("%s: no session found (%u/%u). Passing up.\n", 871fd558d18SJames Chapman tunnel->name, tunnel_id, session_id); 872fd558d18SJames Chapman goto error; 873fd558d18SJames Chapman } 874fd558d18SJames Chapman 8754522a70dSJacob Wen if (tunnel->version == L2TP_HDR_VER_3 && 8764522a70dSJacob Wen l2tp_v3_ensure_opt_in_linear(session, skb, &ptr, &optr)) 8774522a70dSJacob Wen goto error; 8784522a70dSJacob Wen 8792b139e6bSGuillaume Nault l2tp_recv_common(session, skb, ptr, optr, hdrflags, length); 88061b9a047SGuillaume Nault l2tp_session_dec_refcount(session); 881fd558d18SJames Chapman 882fd558d18SJames Chapman return 0; 883fd558d18SJames Chapman 884fd558d18SJames Chapman error: 885fd558d18SJames Chapman /* Put UDP header back */ 886fd558d18SJames Chapman __skb_push(skb, sizeof(struct udphdr)); 887fd558d18SJames Chapman 888fd558d18SJames Chapman return 1; 889fd558d18SJames Chapman } 890fd558d18SJames Chapman 891fd558d18SJames Chapman /* UDP encapsulation receive handler. See net/ipv4/udp.c. 892fd558d18SJames Chapman * Return codes: 893fd558d18SJames Chapman * 0 : success. 894fd558d18SJames Chapman * <0: error 895fd558d18SJames Chapman * >0: skb should be passed up to userspace as UDP. 896fd558d18SJames Chapman */ 897fd558d18SJames Chapman int l2tp_udp_encap_recv(struct sock *sk, struct sk_buff *skb) 898fd558d18SJames Chapman { 899fd558d18SJames Chapman struct l2tp_tunnel *tunnel; 900fd558d18SJames Chapman 901c1c47721SEric Dumazet tunnel = rcu_dereference_sk_user_data(sk); 9020febc7b3STom Parkin if (!tunnel) 903fd558d18SJames Chapman goto pass_up; 904fd558d18SJames Chapman 9052b139e6bSGuillaume Nault if (l2tp_udp_recv_core(tunnel, skb)) 906d00fa9adSJames Chapman goto pass_up; 907fd558d18SJames Chapman 908fd558d18SJames Chapman return 0; 909fd558d18SJames Chapman 910fd558d18SJames Chapman pass_up: 911fd558d18SJames Chapman return 1; 912fd558d18SJames Chapman } 913fd558d18SJames Chapman EXPORT_SYMBOL_GPL(l2tp_udp_encap_recv); 914fd558d18SJames Chapman 915fd558d18SJames Chapman /************************************************************************ 916fd558d18SJames Chapman * Transmit handling 917fd558d18SJames Chapman ***********************************************************************/ 918fd558d18SJames Chapman 919fd558d18SJames Chapman /* Build an L2TP header for the session into the buffer provided. 920fd558d18SJames Chapman */ 921f7faffa3SJames Chapman static int l2tp_build_l2tpv2_header(struct l2tp_session *session, void *buf) 922fd558d18SJames Chapman { 923f7faffa3SJames Chapman struct l2tp_tunnel *tunnel = session->tunnel; 924fd558d18SJames Chapman __be16 *bufp = buf; 925f7faffa3SJames Chapman __be16 *optr = buf; 926fd558d18SJames Chapman u16 flags = L2TP_HDR_VER_2; 927fd558d18SJames Chapman u32 tunnel_id = tunnel->peer_tunnel_id; 928fd558d18SJames Chapman u32 session_id = session->peer_session_id; 929fd558d18SJames Chapman 930fd558d18SJames Chapman if (session->send_seq) 931fd558d18SJames Chapman flags |= L2TP_HDRFLAG_S; 932fd558d18SJames Chapman 933fd558d18SJames Chapman /* Setup L2TP header. */ 934fd558d18SJames Chapman *bufp++ = htons(flags); 935fd558d18SJames Chapman *bufp++ = htons(tunnel_id); 936fd558d18SJames Chapman *bufp++ = htons(session_id); 937fd558d18SJames Chapman if (session->send_seq) { 938fd558d18SJames Chapman *bufp++ = htons(session->ns); 939fd558d18SJames Chapman *bufp++ = 0; 940fd558d18SJames Chapman session->ns++; 941f7faffa3SJames Chapman session->ns &= 0xffff; 9426b7bdcd7STom Parkin trace_session_seqnum_update(session); 943fd558d18SJames Chapman } 944fd558d18SJames Chapman 945f7faffa3SJames Chapman return bufp - optr; 946f7faffa3SJames Chapman } 947f7faffa3SJames Chapman 948f7faffa3SJames Chapman static int l2tp_build_l2tpv3_header(struct l2tp_session *session, void *buf) 949fd558d18SJames Chapman { 9500d76751fSJames Chapman struct l2tp_tunnel *tunnel = session->tunnel; 951f7faffa3SJames Chapman char *bufp = buf; 952f7faffa3SJames Chapman char *optr = bufp; 953fd558d18SJames Chapman 9540d76751fSJames Chapman /* Setup L2TP header. The header differs slightly for UDP and 9550d76751fSJames Chapman * IP encapsulations. For UDP, there is 4 bytes of flags. 9560d76751fSJames Chapman */ 9570d76751fSJames Chapman if (tunnel->encap == L2TP_ENCAPTYPE_UDP) { 9580d76751fSJames Chapman u16 flags = L2TP_HDR_VER_3; 959f7faffa3SJames Chapman *((__be16 *)bufp) = htons(flags); 960f7faffa3SJames Chapman bufp += 2; 961f7faffa3SJames Chapman *((__be16 *)bufp) = 0; 962f7faffa3SJames Chapman bufp += 2; 9630d76751fSJames Chapman } 9640d76751fSJames Chapman 965f7faffa3SJames Chapman *((__be32 *)bufp) = htonl(session->peer_session_id); 966f7faffa3SJames Chapman bufp += 4; 967f7faffa3SJames Chapman if (session->cookie_len) { 968f7faffa3SJames Chapman memcpy(bufp, &session->cookie[0], session->cookie_len); 969f7faffa3SJames Chapman bufp += session->cookie_len; 970fd558d18SJames Chapman } 971f7faffa3SJames Chapman if (session->l2specific_type == L2TP_L2SPECTYPE_DEFAULT) { 972f7faffa3SJames Chapman u32 l2h = 0; 97362e7b6a5SLorenzo Bianconi 974f7faffa3SJames Chapman if (session->send_seq) { 975f7faffa3SJames Chapman l2h = 0x40000000 | session->ns; 976f7faffa3SJames Chapman session->ns++; 977f7faffa3SJames Chapman session->ns &= 0xffffff; 9786b7bdcd7STom Parkin trace_session_seqnum_update(session); 979f7faffa3SJames Chapman } 980f7faffa3SJames Chapman 981f7faffa3SJames Chapman *((__be32 *)bufp) = htonl(l2h); 98262e7b6a5SLorenzo Bianconi bufp += 4; 983f7faffa3SJames Chapman } 984f7faffa3SJames Chapman 985f7faffa3SJames Chapman return bufp - optr; 986f7faffa3SJames Chapman } 987fd558d18SJames Chapman 9882685fbb8SGuillaume Nault static void l2tp_xmit_core(struct l2tp_session *session, struct sk_buff *skb, 989d9d8da80SDavid S. Miller struct flowi *fl, size_t data_len) 990fd558d18SJames Chapman { 991fd558d18SJames Chapman struct l2tp_tunnel *tunnel = session->tunnel; 992fd558d18SJames Chapman unsigned int len = skb->len; 993fd558d18SJames Chapman int error; 994fd558d18SJames Chapman 995fd558d18SJames Chapman /* Queue the packet to IP for output */ 99660ff7467SWANG Cong skb->ignore_df = 1; 99727d53323SXin Long skb_dst_drop(skb); 998d2cf3361SBenjamin LaHaise #if IS_ENABLED(CONFIG_IPV6) 999b954f940SPaolo Abeni if (l2tp_sk_is_v6(tunnel->sock)) 1000b0270e91SEric Dumazet error = inet6_csk_xmit(tunnel->sock, skb, NULL); 1001d2cf3361SBenjamin LaHaise else 1002d2cf3361SBenjamin LaHaise #endif 1003b0270e91SEric Dumazet error = ip_queue_xmit(tunnel->sock, skb, fl); 1004fd558d18SJames Chapman 1005fd558d18SJames Chapman /* Update stats */ 1006fd558d18SJames Chapman if (error >= 0) { 10077b7c0719STom Parkin atomic_long_inc(&tunnel->stats.tx_packets); 10087b7c0719STom Parkin atomic_long_add(len, &tunnel->stats.tx_bytes); 10097b7c0719STom Parkin atomic_long_inc(&session->stats.tx_packets); 10107b7c0719STom Parkin atomic_long_add(len, &session->stats.tx_bytes); 1011fd558d18SJames Chapman } else { 10127b7c0719STom Parkin atomic_long_inc(&tunnel->stats.tx_errors); 10137b7c0719STom Parkin atomic_long_inc(&session->stats.tx_errors); 1014fd558d18SJames Chapman } 1015fd558d18SJames Chapman } 1016fd558d18SJames Chapman 1017fd558d18SJames Chapman /* If caller requires the skb to have a ppp header, the header must be 1018fd558d18SJames Chapman * inserted in the skb data before calling this function. 1019fd558d18SJames Chapman */ 1020fd558d18SJames Chapman int l2tp_xmit_skb(struct l2tp_session *session, struct sk_buff *skb, int hdr_len) 1021fd558d18SJames Chapman { 1022fd558d18SJames Chapman int data_len = skb->len; 10230d76751fSJames Chapman struct l2tp_tunnel *tunnel = session->tunnel; 10240d76751fSJames Chapman struct sock *sk = tunnel->sock; 1025d9d8da80SDavid S. Miller struct flowi *fl; 1026fd558d18SJames Chapman struct udphdr *uh; 1027fd558d18SJames Chapman struct inet_sock *inet; 1028fd558d18SJames Chapman int headroom; 10290d76751fSJames Chapman int uhlen = (tunnel->encap == L2TP_ENCAPTYPE_UDP) ? sizeof(struct udphdr) : 0; 10300d76751fSJames Chapman int udp_len; 1031b8c84307SEric Dumazet int ret = NET_XMIT_SUCCESS; 1032fd558d18SJames Chapman 1033fd558d18SJames Chapman /* Check that there's enough headroom in the skb to insert IP, 1034fd558d18SJames Chapman * UDP and L2TP headers. If not enough, expand it to 1035fd558d18SJames Chapman * make room. Adjust truesize. 1036fd558d18SJames Chapman */ 1037fd558d18SJames Chapman headroom = NET_SKB_PAD + sizeof(struct iphdr) + 10380d76751fSJames Chapman uhlen + hdr_len; 1039835acf5dSEric Dumazet if (skb_cow_head(skb, headroom)) { 1040b8c84307SEric Dumazet kfree_skb(skb); 1041b8c84307SEric Dumazet return NET_XMIT_DROP; 1042835acf5dSEric Dumazet } 1043fd558d18SJames Chapman 1044fd558d18SJames Chapman /* Setup L2TP header */ 10452dedab6fSTom Parkin if (tunnel->version == L2TP_HDR_VER_2) 10462dedab6fSTom Parkin l2tp_build_l2tpv2_header(session, __skb_push(skb, hdr_len)); 10472dedab6fSTom Parkin else 10482dedab6fSTom Parkin l2tp_build_l2tpv3_header(session, __skb_push(skb, hdr_len)); 1049fd558d18SJames Chapman 10500d76751fSJames Chapman /* Reset skb netfilter state */ 1051fd558d18SJames Chapman memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt)); 1052fd558d18SJames Chapman IPCB(skb)->flags &= ~(IPSKB_XFRM_TUNNEL_SIZE | IPSKB_XFRM_TRANSFORMED | 1053fd558d18SJames Chapman IPSKB_REROUTED); 1054895b5c9fSFlorian Westphal nf_reset_ct(skb); 1055fd558d18SJames Chapman 10566af88da1SDavid S. Miller bh_lock_sock(sk); 10576af88da1SDavid S. Miller if (sock_owned_by_user(sk)) { 1058b8c84307SEric Dumazet kfree_skb(skb); 1059b8c84307SEric Dumazet ret = NET_XMIT_DROP; 10606af88da1SDavid S. Miller goto out_unlock; 10616af88da1SDavid S. Miller } 10626af88da1SDavid S. Miller 1063b954f940SPaolo Abeni /* The user-space may change the connection status for the user-space 1064b954f940SPaolo Abeni * provided socket at run time: we must check it under the socket lock 1065b954f940SPaolo Abeni */ 1066b954f940SPaolo Abeni if (tunnel->fd >= 0 && sk->sk_state != TCP_ESTABLISHED) { 1067b954f940SPaolo Abeni kfree_skb(skb); 1068b954f940SPaolo Abeni ret = NET_XMIT_DROP; 1069b954f940SPaolo Abeni goto out_unlock; 1070b954f940SPaolo Abeni } 1071b954f940SPaolo Abeni 1072d9d8da80SDavid S. Miller inet = inet_sk(sk); 1073d9d8da80SDavid S. Miller fl = &inet->cork.fl; 10740d76751fSJames Chapman switch (tunnel->encap) { 10750d76751fSJames Chapman case L2TP_ENCAPTYPE_UDP: 10760d76751fSJames Chapman /* Setup UDP header */ 10770d76751fSJames Chapman __skb_push(skb, sizeof(*uh)); 10780d76751fSJames Chapman skb_reset_transport_header(skb); 10790d76751fSJames Chapman uh = udp_hdr(skb); 10800d76751fSJames Chapman uh->source = inet->inet_sport; 10810d76751fSJames Chapman uh->dest = inet->inet_dport; 10820d76751fSJames Chapman udp_len = uhlen + hdr_len + data_len; 10830d76751fSJames Chapman uh->len = htons(udp_len); 1084fd558d18SJames Chapman 1085fd558d18SJames Chapman /* Calculate UDP checksum if configured to do so */ 1086d2cf3361SBenjamin LaHaise #if IS_ENABLED(CONFIG_IPV6) 1087b954f940SPaolo Abeni if (l2tp_sk_is_v6(sk)) 108877157e19STom Herbert udp6_set_csum(udp_get_no_check6_tx(sk), 108977157e19STom Herbert skb, &inet6_sk(sk)->saddr, 109077157e19STom Herbert &sk->sk_v6_daddr, udp_len); 1091d2cf3361SBenjamin LaHaise else 1092d2cf3361SBenjamin LaHaise #endif 109377157e19STom Herbert udp_set_csum(sk->sk_no_check_tx, skb, inet->inet_saddr, 109477157e19STom Herbert inet->inet_daddr, udp_len); 10950d76751fSJames Chapman break; 10960d76751fSJames Chapman 10970d76751fSJames Chapman case L2TP_ENCAPTYPE_IP: 10980d76751fSJames Chapman break; 10990d76751fSJames Chapman } 11000d76751fSJames Chapman 1101d9d8da80SDavid S. Miller l2tp_xmit_core(session, skb, fl, data_len); 11026af88da1SDavid S. Miller out_unlock: 11036af88da1SDavid S. Miller bh_unlock_sock(sk); 1104fd558d18SJames Chapman 1105b8c84307SEric Dumazet return ret; 1106fd558d18SJames Chapman } 1107fd558d18SJames Chapman EXPORT_SYMBOL_GPL(l2tp_xmit_skb); 1108fd558d18SJames Chapman 1109fd558d18SJames Chapman /***************************************************************************** 1110fd558d18SJames Chapman * Tinnel and session create/destroy. 1111fd558d18SJames Chapman *****************************************************************************/ 1112fd558d18SJames Chapman 1113fd558d18SJames Chapman /* Tunnel socket destruct hook. 1114fd558d18SJames Chapman * The tunnel context is deleted only when all session sockets have been 1115fd558d18SJames Chapman * closed. 1116fd558d18SJames Chapman */ 1117fc130840Sstephen hemminger static void l2tp_tunnel_destruct(struct sock *sk) 1118fd558d18SJames Chapman { 11198d8a51e2SDavid S. Miller struct l2tp_tunnel *tunnel = l2tp_tunnel(sk); 1120fd558d18SJames Chapman 11210febc7b3STom Parkin if (!tunnel) 1122fd558d18SJames Chapman goto end; 1123fd558d18SJames Chapman 1124f8ccac0eSTom Parkin /* Disable udp encapsulation */ 11250d76751fSJames Chapman switch (tunnel->encap) { 11260d76751fSJames Chapman case L2TP_ENCAPTYPE_UDP: 1127fd558d18SJames Chapman /* No longer an encapsulation socket. See net/ipv4/udp.c */ 1128fd558d18SJames Chapman (udp_sk(sk))->encap_type = 0; 1129fd558d18SJames Chapman (udp_sk(sk))->encap_rcv = NULL; 11309980d001STom Parkin (udp_sk(sk))->encap_destroy = NULL; 11310d76751fSJames Chapman break; 11320d76751fSJames Chapman case L2TP_ENCAPTYPE_IP: 11330d76751fSJames Chapman break; 11340d76751fSJames Chapman } 1135fd558d18SJames Chapman 1136fd558d18SJames Chapman /* Remove hooks into tunnel socket */ 1137fd558d18SJames Chapman sk->sk_destruct = tunnel->old_sk_destruct; 1138fd558d18SJames Chapman sk->sk_user_data = NULL; 1139f8ccac0eSTom Parkin 1140fd558d18SJames Chapman /* Call the original destructor */ 1141fd558d18SJames Chapman if (sk->sk_destruct) 1142fd558d18SJames Chapman (*sk->sk_destruct)(sk); 1143d00fa9adSJames Chapman 1144d00fa9adSJames Chapman kfree_rcu(tunnel, rcu); 1145fd558d18SJames Chapman end: 1146fd558d18SJames Chapman return; 1147fd558d18SJames Chapman } 1148fd558d18SJames Chapman 1149b2aecfe8STom Parkin /* Remove an l2tp session from l2tp_core's hash lists. */ 1150b2aecfe8STom Parkin static void l2tp_session_unhash(struct l2tp_session *session) 1151b2aecfe8STom Parkin { 1152b2aecfe8STom Parkin struct l2tp_tunnel *tunnel = session->tunnel; 1153b2aecfe8STom Parkin 1154b2aecfe8STom Parkin /* Remove the session from core hashes */ 1155b2aecfe8STom Parkin if (tunnel) { 1156b2aecfe8STom Parkin /* Remove from the per-tunnel hash */ 1157b2aecfe8STom Parkin write_lock_bh(&tunnel->hlist_lock); 1158b2aecfe8STom Parkin hlist_del_init(&session->hlist); 1159b2aecfe8STom Parkin write_unlock_bh(&tunnel->hlist_lock); 1160b2aecfe8STom Parkin 1161b2aecfe8STom Parkin /* For L2TPv3 we have a per-net hash: remove from there, too */ 1162b2aecfe8STom Parkin if (tunnel->version != L2TP_HDR_VER_2) { 1163b2aecfe8STom Parkin struct l2tp_net *pn = l2tp_pernet(tunnel->l2tp_net); 1164b2aecfe8STom Parkin 1165b2aecfe8STom Parkin spin_lock_bh(&pn->l2tp_session_hlist_lock); 1166b2aecfe8STom Parkin hlist_del_init_rcu(&session->global_hlist); 1167b2aecfe8STom Parkin spin_unlock_bh(&pn->l2tp_session_hlist_lock); 1168b2aecfe8STom Parkin synchronize_rcu(); 1169b2aecfe8STom Parkin } 1170b2aecfe8STom Parkin } 1171b2aecfe8STom Parkin } 1172b2aecfe8STom Parkin 1173fd558d18SJames Chapman /* When the tunnel is closed, all the attached sessions need to go too. 1174fd558d18SJames Chapman */ 1175d08532bbSGuillaume Nault static void l2tp_tunnel_closeall(struct l2tp_tunnel *tunnel) 1176fd558d18SJames Chapman { 1177fd558d18SJames Chapman int hash; 1178fd558d18SJames Chapman struct hlist_node *walk; 1179fd558d18SJames Chapman struct hlist_node *tmp; 1180fd558d18SJames Chapman struct l2tp_session *session; 1181fd558d18SJames Chapman 1182fd558d18SJames Chapman write_lock_bh(&tunnel->hlist_lock); 1183f3c66d4eSGuillaume Nault tunnel->acpt_newsess = false; 1184fd558d18SJames Chapman for (hash = 0; hash < L2TP_HASH_SIZE; hash++) { 1185fd558d18SJames Chapman again: 1186fd558d18SJames Chapman hlist_for_each_safe(walk, tmp, &tunnel->session_hlist[hash]) { 1187fd558d18SJames Chapman session = hlist_entry(walk, struct l2tp_session, hlist); 1188fd558d18SJames Chapman 1189fd558d18SJames Chapman hlist_del_init(&session->hlist); 1190fd558d18SJames Chapman 1191b228a940SGuillaume Nault if (test_and_set_bit(0, &session->dead)) 1192b228a940SGuillaume Nault goto again; 1193b228a940SGuillaume Nault 1194fd558d18SJames Chapman write_unlock_bh(&tunnel->hlist_lock); 1195fd558d18SJames Chapman 1196b2aecfe8STom Parkin l2tp_session_unhash(session); 11974c6e2fd3STom Parkin l2tp_session_queue_purge(session); 11984c6e2fd3STom Parkin 11990febc7b3STom Parkin if (session->session_close) 1200fd558d18SJames Chapman (*session->session_close)(session); 1201fd558d18SJames Chapman 12029980d001STom Parkin l2tp_session_dec_refcount(session); 12039980d001STom Parkin 1204fd558d18SJames Chapman write_lock_bh(&tunnel->hlist_lock); 1205fd558d18SJames Chapman 1206fd558d18SJames Chapman /* Now restart from the beginning of this hash 1207fd558d18SJames Chapman * chain. We always remove a session from the 1208fd558d18SJames Chapman * list so we are guaranteed to make forward 1209fd558d18SJames Chapman * progress. 1210fd558d18SJames Chapman */ 1211fd558d18SJames Chapman goto again; 1212fd558d18SJames Chapman } 1213fd558d18SJames Chapman } 1214fd558d18SJames Chapman write_unlock_bh(&tunnel->hlist_lock); 1215fd558d18SJames Chapman } 1216fd558d18SJames Chapman 12179980d001STom Parkin /* Tunnel socket destroy hook for UDP encapsulation */ 12189980d001STom Parkin static void l2tp_udp_encap_destroy(struct sock *sk) 12199980d001STom Parkin { 1220d00fa9adSJames Chapman struct l2tp_tunnel *tunnel = l2tp_tunnel(sk); 1221d00fa9adSJames Chapman 1222d00fa9adSJames Chapman if (tunnel) 1223d00fa9adSJames Chapman l2tp_tunnel_delete(tunnel); 12249980d001STom Parkin } 12259980d001STom Parkin 1226f8ccac0eSTom Parkin /* Workqueue tunnel deletion function */ 1227f8ccac0eSTom Parkin static void l2tp_tunnel_del_work(struct work_struct *work) 1228f8ccac0eSTom Parkin { 1229d00fa9adSJames Chapman struct l2tp_tunnel *tunnel = container_of(work, struct l2tp_tunnel, 1230d00fa9adSJames Chapman del_work); 1231d00fa9adSJames Chapman struct sock *sk = tunnel->sock; 1232d00fa9adSJames Chapman struct socket *sock = sk->sk_socket; 123328f5bfb8SJames Chapman struct l2tp_net *pn; 123412d656afSRidge Kennedy 123512d656afSRidge Kennedy l2tp_tunnel_closeall(tunnel); 123612d656afSRidge Kennedy 123776a6abdbSJames Chapman /* If the tunnel socket was created within the kernel, use 123802d13ed5STom Parkin * the sk API to release it here. 1239f8ccac0eSTom Parkin */ 124076a6abdbSJames Chapman if (tunnel->fd < 0) { 124126abe143SEric W. Biederman if (sock) { 1242167eb17eSTom Parkin kernel_sock_shutdown(sock, SHUT_RDWR); 124326abe143SEric W. Biederman sock_release(sock); 124426abe143SEric W. Biederman } 1245167eb17eSTom Parkin } 1246f8ccac0eSTom Parkin 124728f5bfb8SJames Chapman /* Remove the tunnel struct from the tunnel list */ 124828f5bfb8SJames Chapman pn = l2tp_pernet(tunnel->l2tp_net); 124928f5bfb8SJames Chapman spin_lock_bh(&pn->l2tp_tunnel_list_lock); 125028f5bfb8SJames Chapman list_del_rcu(&tunnel->list); 125128f5bfb8SJames Chapman spin_unlock_bh(&pn->l2tp_tunnel_list_lock); 125228f5bfb8SJames Chapman 1253d00fa9adSJames Chapman /* drop initial ref */ 1254d00fa9adSJames Chapman l2tp_tunnel_dec_refcount(tunnel); 1255d00fa9adSJames Chapman 1256d00fa9adSJames Chapman /* drop workqueue ref */ 125706a15f51SAlexander Couzens l2tp_tunnel_dec_refcount(tunnel); 1258fd558d18SJames Chapman } 1259fd558d18SJames Chapman 1260789a4a2cSJames Chapman /* Create a socket for the tunnel, if one isn't set up by 1261789a4a2cSJames Chapman * userspace. This is used for static tunnels where there is no 1262789a4a2cSJames Chapman * managing L2TP daemon. 1263167eb17eSTom Parkin * 1264167eb17eSTom Parkin * Since we don't want these sockets to keep a namespace alive by 1265167eb17eSTom Parkin * themselves, we drop the socket's namespace refcount after creation. 1266167eb17eSTom Parkin * These sockets are freed when the namespace exits using the pernet 1267167eb17eSTom Parkin * exit hook. 1268789a4a2cSJames Chapman */ 1269167eb17eSTom Parkin static int l2tp_tunnel_sock_create(struct net *net, 1270167eb17eSTom Parkin u32 tunnel_id, 1271167eb17eSTom Parkin u32 peer_tunnel_id, 1272167eb17eSTom Parkin struct l2tp_tunnel_cfg *cfg, 1273167eb17eSTom Parkin struct socket **sockp) 1274789a4a2cSJames Chapman { 1275789a4a2cSJames Chapman int err = -EINVAL; 12767bddd0dbSEric Dumazet struct socket *sock = NULL; 127785644b4dSTom Herbert struct udp_port_cfg udp_conf; 1278789a4a2cSJames Chapman 1279789a4a2cSJames Chapman switch (cfg->encap) { 1280789a4a2cSJames Chapman case L2TP_ENCAPTYPE_UDP: 128185644b4dSTom Herbert memset(&udp_conf, 0, sizeof(udp_conf)); 128285644b4dSTom Herbert 1283f9bac8dfSChris Elston #if IS_ENABLED(CONFIG_IPV6) 1284f9bac8dfSChris Elston if (cfg->local_ip6 && cfg->peer_ip6) { 128585644b4dSTom Herbert udp_conf.family = AF_INET6; 128685644b4dSTom Herbert memcpy(&udp_conf.local_ip6, cfg->local_ip6, 128785644b4dSTom Herbert sizeof(udp_conf.local_ip6)); 128885644b4dSTom Herbert memcpy(&udp_conf.peer_ip6, cfg->peer_ip6, 128985644b4dSTom Herbert sizeof(udp_conf.peer_ip6)); 129085644b4dSTom Herbert udp_conf.use_udp6_tx_checksums = 1291018f8258SWang Shanker !cfg->udp6_zero_tx_checksums; 129285644b4dSTom Herbert udp_conf.use_udp6_rx_checksums = 1293018f8258SWang Shanker !cfg->udp6_zero_rx_checksums; 1294f9bac8dfSChris Elston } else 1295f9bac8dfSChris Elston #endif 1296f9bac8dfSChris Elston { 129785644b4dSTom Herbert udp_conf.family = AF_INET; 129885644b4dSTom Herbert udp_conf.local_ip = cfg->local_ip; 129985644b4dSTom Herbert udp_conf.peer_ip = cfg->peer_ip; 130085644b4dSTom Herbert udp_conf.use_udp_checksums = cfg->use_udp_checksums; 1301f9bac8dfSChris Elston } 1302789a4a2cSJames Chapman 130385644b4dSTom Herbert udp_conf.local_udp_port = htons(cfg->local_udp_port); 130485644b4dSTom Herbert udp_conf.peer_udp_port = htons(cfg->peer_udp_port); 130585644b4dSTom Herbert 130685644b4dSTom Herbert err = udp_sock_create(net, &udp_conf, &sock); 130785644b4dSTom Herbert if (err < 0) 130885644b4dSTom Herbert goto out; 1309789a4a2cSJames Chapman 1310789a4a2cSJames Chapman break; 1311789a4a2cSJames Chapman 1312789a4a2cSJames Chapman case L2TP_ENCAPTYPE_IP: 1313f9bac8dfSChris Elston #if IS_ENABLED(CONFIG_IPV6) 1314f9bac8dfSChris Elston if (cfg->local_ip6 && cfg->peer_ip6) { 131585644b4dSTom Herbert struct sockaddr_l2tpip6 ip6_addr = {0}; 131685644b4dSTom Herbert 131726abe143SEric W. Biederman err = sock_create_kern(net, AF_INET6, SOCK_DGRAM, 1318167eb17eSTom Parkin IPPROTO_L2TP, &sock); 13195dac94e1SJames Chapman if (err < 0) 1320f9bac8dfSChris Elston goto out; 13215dac94e1SJames Chapman 13225dac94e1SJames Chapman ip6_addr.l2tp_family = AF_INET6; 13235dac94e1SJames Chapman memcpy(&ip6_addr.l2tp_addr, cfg->local_ip6, 13245dac94e1SJames Chapman sizeof(ip6_addr.l2tp_addr)); 13255dac94e1SJames Chapman ip6_addr.l2tp_conn_id = tunnel_id; 13265dac94e1SJames Chapman err = kernel_bind(sock, (struct sockaddr *)&ip6_addr, 13275dac94e1SJames Chapman sizeof(ip6_addr)); 13285dac94e1SJames Chapman if (err < 0) 13295dac94e1SJames Chapman goto out; 13305dac94e1SJames Chapman 13315dac94e1SJames Chapman ip6_addr.l2tp_family = AF_INET6; 13325dac94e1SJames Chapman memcpy(&ip6_addr.l2tp_addr, cfg->peer_ip6, 13335dac94e1SJames Chapman sizeof(ip6_addr.l2tp_addr)); 13345dac94e1SJames Chapman ip6_addr.l2tp_conn_id = peer_tunnel_id; 13355dac94e1SJames Chapman err = kernel_connect(sock, 13365dac94e1SJames Chapman (struct sockaddr *)&ip6_addr, 13375dac94e1SJames Chapman sizeof(ip6_addr), 0); 13385dac94e1SJames Chapman if (err < 0) 13395dac94e1SJames Chapman goto out; 13405dac94e1SJames Chapman } else 1341f9bac8dfSChris Elston #endif 13425dac94e1SJames Chapman { 134385644b4dSTom Herbert struct sockaddr_l2tpip ip_addr = {0}; 134485644b4dSTom Herbert 134526abe143SEric W. Biederman err = sock_create_kern(net, AF_INET, SOCK_DGRAM, 1346167eb17eSTom Parkin IPPROTO_L2TP, &sock); 1347789a4a2cSJames Chapman if (err < 0) 1348789a4a2cSJames Chapman goto out; 1349789a4a2cSJames Chapman 1350789a4a2cSJames Chapman ip_addr.l2tp_family = AF_INET; 1351789a4a2cSJames Chapman ip_addr.l2tp_addr = cfg->local_ip; 1352789a4a2cSJames Chapman ip_addr.l2tp_conn_id = tunnel_id; 13535dac94e1SJames Chapman err = kernel_bind(sock, (struct sockaddr *)&ip_addr, 13545dac94e1SJames Chapman sizeof(ip_addr)); 1355789a4a2cSJames Chapman if (err < 0) 1356789a4a2cSJames Chapman goto out; 1357789a4a2cSJames Chapman 1358789a4a2cSJames Chapman ip_addr.l2tp_family = AF_INET; 1359789a4a2cSJames Chapman ip_addr.l2tp_addr = cfg->peer_ip; 1360789a4a2cSJames Chapman ip_addr.l2tp_conn_id = peer_tunnel_id; 13615dac94e1SJames Chapman err = kernel_connect(sock, (struct sockaddr *)&ip_addr, 13625dac94e1SJames Chapman sizeof(ip_addr), 0); 1363789a4a2cSJames Chapman if (err < 0) 1364789a4a2cSJames Chapman goto out; 13655dac94e1SJames Chapman } 1366789a4a2cSJames Chapman break; 1367789a4a2cSJames Chapman 1368789a4a2cSJames Chapman default: 1369789a4a2cSJames Chapman goto out; 1370789a4a2cSJames Chapman } 1371789a4a2cSJames Chapman 1372789a4a2cSJames Chapman out: 1373167eb17eSTom Parkin *sockp = sock; 13746c0ec37bSTom Parkin if (err < 0 && sock) { 1375167eb17eSTom Parkin kernel_sock_shutdown(sock, SHUT_RDWR); 137626abe143SEric W. Biederman sock_release(sock); 1377789a4a2cSJames Chapman *sockp = NULL; 1378789a4a2cSJames Chapman } 1379789a4a2cSJames Chapman 1380789a4a2cSJames Chapman return err; 1381789a4a2cSJames Chapman } 1382789a4a2cSJames Chapman 138337159ef2SEric Dumazet static struct lock_class_key l2tp_socket_class; 138437159ef2SEric Dumazet 1385c0235fb3STom Parkin int l2tp_tunnel_create(struct net *net, int fd, int version, u32 tunnel_id, u32 peer_tunnel_id, 1386c0235fb3STom Parkin struct l2tp_tunnel_cfg *cfg, struct l2tp_tunnel **tunnelp) 1387fd558d18SJames Chapman { 1388fd558d18SJames Chapman struct l2tp_tunnel *tunnel = NULL; 1389fd558d18SJames Chapman int err; 13900d76751fSJames Chapman enum l2tp_encap_type encap = L2TP_ENCAPTYPE_UDP; 1391fd558d18SJames Chapman 13920febc7b3STom Parkin if (cfg) 13930d76751fSJames Chapman encap = cfg->encap; 13940d76751fSJames Chapman 139570c05bfaSTom Parkin tunnel = kzalloc(sizeof(*tunnel), GFP_KERNEL); 13960febc7b3STom Parkin if (!tunnel) { 1397fd558d18SJames Chapman err = -ENOMEM; 1398fd558d18SJames Chapman goto err; 1399fd558d18SJames Chapman } 1400fd558d18SJames Chapman 1401fd558d18SJames Chapman tunnel->version = version; 1402fd558d18SJames Chapman tunnel->tunnel_id = tunnel_id; 1403fd558d18SJames Chapman tunnel->peer_tunnel_id = peer_tunnel_id; 1404fd558d18SJames Chapman tunnel->debug = L2TP_DEFAULT_DEBUG_FLAGS; 1405fd558d18SJames Chapman 1406fd558d18SJames Chapman tunnel->magic = L2TP_TUNNEL_MAGIC; 1407fd558d18SJames Chapman sprintf(&tunnel->name[0], "tunl %u", tunnel_id); 1408fd558d18SJames Chapman rwlock_init(&tunnel->hlist_lock); 1409f3c66d4eSGuillaume Nault tunnel->acpt_newsess = true; 1410fd558d18SJames Chapman 14110febc7b3STom Parkin if (cfg) 1412fd558d18SJames Chapman tunnel->debug = cfg->debug; 1413fd558d18SJames Chapman 14140d76751fSJames Chapman tunnel->encap = encap; 1415fd558d18SJames Chapman 1416d00fa9adSJames Chapman refcount_set(&tunnel->ref_count, 1); 1417d00fa9adSJames Chapman tunnel->fd = fd; 1418d00fa9adSJames Chapman 1419f8ccac0eSTom Parkin /* Init delete workqueue struct */ 1420f8ccac0eSTom Parkin INIT_WORK(&tunnel->del_work, l2tp_tunnel_del_work); 1421f8ccac0eSTom Parkin 1422fd558d18SJames Chapman INIT_LIST_HEAD(&tunnel->list); 1423fd558d18SJames Chapman 1424fd558d18SJames Chapman err = 0; 1425fd558d18SJames Chapman err: 1426fd558d18SJames Chapman if (tunnelp) 1427fd558d18SJames Chapman *tunnelp = tunnel; 1428fd558d18SJames Chapman 1429fd558d18SJames Chapman return err; 1430fd558d18SJames Chapman } 1431fd558d18SJames Chapman EXPORT_SYMBOL_GPL(l2tp_tunnel_create); 1432fd558d18SJames Chapman 14336b9f3423SGuillaume Nault static int l2tp_validate_socket(const struct sock *sk, const struct net *net, 14346b9f3423SGuillaume Nault enum l2tp_encap_type encap) 14356b9f3423SGuillaume Nault { 14366b9f3423SGuillaume Nault if (!net_eq(sock_net(sk), net)) 14376b9f3423SGuillaume Nault return -EINVAL; 14386b9f3423SGuillaume Nault 14396b9f3423SGuillaume Nault if (sk->sk_type != SOCK_DGRAM) 14406b9f3423SGuillaume Nault return -EPROTONOSUPPORT; 14416b9f3423SGuillaume Nault 1442d9a81a22SEric Dumazet if (sk->sk_family != PF_INET && sk->sk_family != PF_INET6) 1443d9a81a22SEric Dumazet return -EPROTONOSUPPORT; 1444d9a81a22SEric Dumazet 14456b9f3423SGuillaume Nault if ((encap == L2TP_ENCAPTYPE_UDP && sk->sk_protocol != IPPROTO_UDP) || 14466b9f3423SGuillaume Nault (encap == L2TP_ENCAPTYPE_IP && sk->sk_protocol != IPPROTO_L2TP)) 14476b9f3423SGuillaume Nault return -EPROTONOSUPPORT; 14486b9f3423SGuillaume Nault 14496b9f3423SGuillaume Nault if (sk->sk_user_data) 14506b9f3423SGuillaume Nault return -EBUSY; 14516b9f3423SGuillaume Nault 14526b9f3423SGuillaume Nault return 0; 14536b9f3423SGuillaume Nault } 14546b9f3423SGuillaume Nault 14556b9f3423SGuillaume Nault int l2tp_tunnel_register(struct l2tp_tunnel *tunnel, struct net *net, 14566b9f3423SGuillaume Nault struct l2tp_tunnel_cfg *cfg) 14576b9f3423SGuillaume Nault { 1458f6cd651bSGuillaume Nault struct l2tp_tunnel *tunnel_walk; 14596b9f3423SGuillaume Nault struct l2tp_net *pn; 14606b9f3423SGuillaume Nault struct socket *sock; 14616b9f3423SGuillaume Nault struct sock *sk; 14626b9f3423SGuillaume Nault int ret; 14636b9f3423SGuillaume Nault 14646b9f3423SGuillaume Nault if (tunnel->fd < 0) { 14656b9f3423SGuillaume Nault ret = l2tp_tunnel_sock_create(net, tunnel->tunnel_id, 14666b9f3423SGuillaume Nault tunnel->peer_tunnel_id, cfg, 14676b9f3423SGuillaume Nault &sock); 14686b9f3423SGuillaume Nault if (ret < 0) 14696b9f3423SGuillaume Nault goto err; 14706b9f3423SGuillaume Nault } else { 14716b9f3423SGuillaume Nault sock = sockfd_lookup(tunnel->fd, &ret); 14726b9f3423SGuillaume Nault if (!sock) 14736b9f3423SGuillaume Nault goto err; 14746b9f3423SGuillaume Nault 14756b9f3423SGuillaume Nault ret = l2tp_validate_socket(sock->sk, net, tunnel->encap); 14766b9f3423SGuillaume Nault if (ret < 0) 14776b9f3423SGuillaume Nault goto err_sock; 14786b9f3423SGuillaume Nault } 14796b9f3423SGuillaume Nault 14806b9f3423SGuillaume Nault tunnel->l2tp_net = net; 14816b9f3423SGuillaume Nault pn = l2tp_pernet(net); 1482f6cd651bSGuillaume Nault 14836b9f3423SGuillaume Nault spin_lock_bh(&pn->l2tp_tunnel_list_lock); 1484f6cd651bSGuillaume Nault list_for_each_entry(tunnel_walk, &pn->l2tp_tunnel_list, list) { 1485f6cd651bSGuillaume Nault if (tunnel_walk->tunnel_id == tunnel->tunnel_id) { 1486f6cd651bSGuillaume Nault spin_unlock_bh(&pn->l2tp_tunnel_list_lock); 1487f6cd651bSGuillaume Nault 1488f6cd651bSGuillaume Nault ret = -EEXIST; 1489f6cd651bSGuillaume Nault goto err_sock; 1490f6cd651bSGuillaume Nault } 1491f6cd651bSGuillaume Nault } 14926b9f3423SGuillaume Nault list_add_rcu(&tunnel->list, &pn->l2tp_tunnel_list); 14936b9f3423SGuillaume Nault spin_unlock_bh(&pn->l2tp_tunnel_list_lock); 14946b9f3423SGuillaume Nault 1495f8504f4cSXin Long sk = sock->sk; 1496f8504f4cSXin Long sock_hold(sk); 1497f8504f4cSXin Long tunnel->sock = sk; 1498f8504f4cSXin Long 14996b9f3423SGuillaume Nault if (tunnel->encap == L2TP_ENCAPTYPE_UDP) { 15006b9f3423SGuillaume Nault struct udp_tunnel_sock_cfg udp_cfg = { 15016b9f3423SGuillaume Nault .sk_user_data = tunnel, 15026b9f3423SGuillaume Nault .encap_type = UDP_ENCAP_L2TPINUDP, 15036b9f3423SGuillaume Nault .encap_rcv = l2tp_udp_encap_recv, 15046b9f3423SGuillaume Nault .encap_destroy = l2tp_udp_encap_destroy, 15056b9f3423SGuillaume Nault }; 15066b9f3423SGuillaume Nault 15076b9f3423SGuillaume Nault setup_udp_tunnel_sock(net, sock, &udp_cfg); 15086b9f3423SGuillaume Nault } else { 15096b9f3423SGuillaume Nault sk->sk_user_data = tunnel; 15106b9f3423SGuillaume Nault } 15116b9f3423SGuillaume Nault 15126b9f3423SGuillaume Nault tunnel->old_sk_destruct = sk->sk_destruct; 15136b9f3423SGuillaume Nault sk->sk_destruct = &l2tp_tunnel_destruct; 15146b9f3423SGuillaume Nault lockdep_set_class_and_name(&sk->sk_lock.slock, &l2tp_socket_class, 15156b9f3423SGuillaume Nault "l2tp_sock"); 15166b9f3423SGuillaume Nault sk->sk_allocation = GFP_ATOMIC; 15176b9f3423SGuillaume Nault 15186b7bdcd7STom Parkin trace_register_tunnel(tunnel); 15196b7bdcd7STom Parkin 15206b9f3423SGuillaume Nault if (tunnel->fd >= 0) 15216b9f3423SGuillaume Nault sockfd_put(sock); 15226b9f3423SGuillaume Nault 15236b9f3423SGuillaume Nault return 0; 15246b9f3423SGuillaume Nault 15256b9f3423SGuillaume Nault err_sock: 1526f6cd651bSGuillaume Nault if (tunnel->fd < 0) 1527f6cd651bSGuillaume Nault sock_release(sock); 1528f6cd651bSGuillaume Nault else 15296b9f3423SGuillaume Nault sockfd_put(sock); 15306b9f3423SGuillaume Nault err: 15316b9f3423SGuillaume Nault return ret; 15326b9f3423SGuillaume Nault } 15336b9f3423SGuillaume Nault EXPORT_SYMBOL_GPL(l2tp_tunnel_register); 15346b9f3423SGuillaume Nault 1535309795f4SJames Chapman /* This function is used by the netlink TUNNEL_DELETE command. 1536309795f4SJames Chapman */ 153762b982eeSSabrina Dubroca void l2tp_tunnel_delete(struct l2tp_tunnel *tunnel) 1538309795f4SJames Chapman { 153962b982eeSSabrina Dubroca if (!test_and_set_bit(0, &tunnel->dead)) { 15406b7bdcd7STom Parkin trace_delete_tunnel(tunnel); 154106a15f51SAlexander Couzens l2tp_tunnel_inc_refcount(tunnel); 154262b982eeSSabrina Dubroca queue_work(l2tp_wq, &tunnel->del_work); 154306a15f51SAlexander Couzens } 1544309795f4SJames Chapman } 1545309795f4SJames Chapman EXPORT_SYMBOL_GPL(l2tp_tunnel_delete); 1546309795f4SJames Chapman 1547628703f5STom Parkin void l2tp_session_delete(struct l2tp_session *session) 1548309795f4SJames Chapman { 1549b228a940SGuillaume Nault if (test_and_set_bit(0, &session->dead)) 1550628703f5STom Parkin return; 1551b228a940SGuillaume Nault 15526b7bdcd7STom Parkin trace_delete_session(session); 1553b2aecfe8STom Parkin l2tp_session_unhash(session); 15544c6e2fd3STom Parkin l2tp_session_queue_purge(session); 15550febc7b3STom Parkin if (session->session_close) 1556309795f4SJames Chapman (*session->session_close)(session); 1557a4346210SGuillaume Nault 1558309795f4SJames Chapman l2tp_session_dec_refcount(session); 1559309795f4SJames Chapman } 1560309795f4SJames Chapman EXPORT_SYMBOL_GPL(l2tp_session_delete); 1561309795f4SJames Chapman 1562f7faffa3SJames Chapman /* We come here whenever a session's send_seq, cookie_len or 156362e7b6a5SLorenzo Bianconi * l2specific_type parameters are set. 1564f7faffa3SJames Chapman */ 1565bb5016eaSGuillaume Nault void l2tp_session_set_header_len(struct l2tp_session *session, int version) 1566f7faffa3SJames Chapman { 1567f7faffa3SJames Chapman if (version == L2TP_HDR_VER_2) { 1568f7faffa3SJames Chapman session->hdr_len = 6; 1569f7faffa3SJames Chapman if (session->send_seq) 1570f7faffa3SJames Chapman session->hdr_len += 4; 1571f7faffa3SJames Chapman } else { 157262e7b6a5SLorenzo Bianconi session->hdr_len = 4 + session->cookie_len; 157362e7b6a5SLorenzo Bianconi session->hdr_len += l2tp_get_l2specific_len(session); 15740d76751fSJames Chapman if (session->tunnel->encap == L2TP_ENCAPTYPE_UDP) 15750d76751fSJames Chapman session->hdr_len += 4; 1576f7faffa3SJames Chapman } 1577f7faffa3SJames Chapman } 1578bb5016eaSGuillaume Nault EXPORT_SYMBOL_GPL(l2tp_session_set_header_len); 1579f7faffa3SJames Chapman 1580c0235fb3STom Parkin struct l2tp_session *l2tp_session_create(int priv_size, struct l2tp_tunnel *tunnel, u32 session_id, 1581c0235fb3STom Parkin u32 peer_session_id, struct l2tp_session_cfg *cfg) 1582fd558d18SJames Chapman { 1583fd558d18SJames Chapman struct l2tp_session *session; 1584fd558d18SJames Chapman 158570c05bfaSTom Parkin session = kzalloc(sizeof(*session) + priv_size, GFP_KERNEL); 15860febc7b3STom Parkin if (session) { 1587fd558d18SJames Chapman session->magic = L2TP_SESSION_MAGIC; 1588fd558d18SJames Chapman session->tunnel = tunnel; 1589fd558d18SJames Chapman 1590fd558d18SJames Chapman session->session_id = session_id; 1591fd558d18SJames Chapman session->peer_session_id = peer_session_id; 1592d301e325SJames Chapman session->nr = 0; 15938a1631d5SJames Chapman if (tunnel->version == L2TP_HDR_VER_2) 15948a1631d5SJames Chapman session->nr_max = 0xffff; 15958a1631d5SJames Chapman else 15968a1631d5SJames Chapman session->nr_max = 0xffffff; 15978a1631d5SJames Chapman session->nr_window_size = session->nr_max / 2; 1598a0dbd822SJames Chapman session->nr_oos_count_max = 4; 1599a0dbd822SJames Chapman 1600a0dbd822SJames Chapman /* Use NR of first received packet */ 1601a0dbd822SJames Chapman session->reorder_skip = 1; 1602fd558d18SJames Chapman 1603fd558d18SJames Chapman sprintf(&session->name[0], "sess %u/%u", 1604fd558d18SJames Chapman tunnel->tunnel_id, session->session_id); 1605fd558d18SJames Chapman 1606fd558d18SJames Chapman skb_queue_head_init(&session->reorder_q); 1607fd558d18SJames Chapman 1608fd558d18SJames Chapman INIT_HLIST_NODE(&session->hlist); 1609f7faffa3SJames Chapman INIT_HLIST_NODE(&session->global_hlist); 1610fd558d18SJames Chapman 1611fd558d18SJames Chapman /* Inherit debug options from tunnel */ 1612fd558d18SJames Chapman session->debug = tunnel->debug; 1613fd558d18SJames Chapman 1614fd558d18SJames Chapman if (cfg) { 1615f7faffa3SJames Chapman session->pwtype = cfg->pw_type; 1616fd558d18SJames Chapman session->debug = cfg->debug; 1617fd558d18SJames Chapman session->send_seq = cfg->send_seq; 1618fd558d18SJames Chapman session->recv_seq = cfg->recv_seq; 1619fd558d18SJames Chapman session->lns_mode = cfg->lns_mode; 1620f7faffa3SJames Chapman session->reorder_timeout = cfg->reorder_timeout; 1621f7faffa3SJames Chapman session->l2specific_type = cfg->l2specific_type; 1622f7faffa3SJames Chapman session->cookie_len = cfg->cookie_len; 1623f7faffa3SJames Chapman memcpy(&session->cookie[0], &cfg->cookie[0], cfg->cookie_len); 1624f7faffa3SJames Chapman session->peer_cookie_len = cfg->peer_cookie_len; 1625f7faffa3SJames Chapman memcpy(&session->peer_cookie[0], &cfg->peer_cookie[0], cfg->peer_cookie_len); 1626fd558d18SJames Chapman } 1627fd558d18SJames Chapman 1628f7faffa3SJames Chapman l2tp_session_set_header_len(session, tunnel->version); 1629f7faffa3SJames Chapman 16309ee369a4SGuillaume Nault refcount_set(&session->ref_count, 1); 16319ee369a4SGuillaume Nault 1632fd558d18SJames Chapman return session; 1633fd558d18SJames Chapman } 1634dbdbc73bSGuillaume Nault 1635dbdbc73bSGuillaume Nault return ERR_PTR(-ENOMEM); 1636dbdbc73bSGuillaume Nault } 1637fd558d18SJames Chapman EXPORT_SYMBOL_GPL(l2tp_session_create); 1638fd558d18SJames Chapman 1639fd558d18SJames Chapman /***************************************************************************** 1640fd558d18SJames Chapman * Init and cleanup 1641fd558d18SJames Chapman *****************************************************************************/ 1642fd558d18SJames Chapman 1643fd558d18SJames Chapman static __net_init int l2tp_init_net(struct net *net) 1644fd558d18SJames Chapman { 1645e773aaffSJiri Pirko struct l2tp_net *pn = net_generic(net, l2tp_net_id); 1646f7faffa3SJames Chapman int hash; 1647fd558d18SJames Chapman 1648fd558d18SJames Chapman INIT_LIST_HEAD(&pn->l2tp_tunnel_list); 1649e02d494dSJames Chapman spin_lock_init(&pn->l2tp_tunnel_list_lock); 1650fd558d18SJames Chapman 1651f7faffa3SJames Chapman for (hash = 0; hash < L2TP_HASH_SIZE_2; hash++) 1652f7faffa3SJames Chapman INIT_HLIST_HEAD(&pn->l2tp_session_hlist[hash]); 1653f7faffa3SJames Chapman 1654e02d494dSJames Chapman spin_lock_init(&pn->l2tp_session_hlist_lock); 1655f7faffa3SJames Chapman 1656fd558d18SJames Chapman return 0; 1657fd558d18SJames Chapman } 1658fd558d18SJames Chapman 1659167eb17eSTom Parkin static __net_exit void l2tp_exit_net(struct net *net) 1660167eb17eSTom Parkin { 1661167eb17eSTom Parkin struct l2tp_net *pn = l2tp_pernet(net); 1662167eb17eSTom Parkin struct l2tp_tunnel *tunnel = NULL; 16631e7af3b2SVasily Averin int hash; 1664167eb17eSTom Parkin 1665167eb17eSTom Parkin rcu_read_lock_bh(); 1666167eb17eSTom Parkin list_for_each_entry_rcu(tunnel, &pn->l2tp_tunnel_list, list) { 16674dc12ffeSJiri Slaby l2tp_tunnel_delete(tunnel); 1668167eb17eSTom Parkin } 1669167eb17eSTom Parkin rcu_read_unlock_bh(); 16702f86953eSSabrina Dubroca 1671638a3a1eSYueHaibing if (l2tp_wq) 16722f86953eSSabrina Dubroca flush_workqueue(l2tp_wq); 16732f86953eSSabrina Dubroca rcu_barrier(); 16741e7af3b2SVasily Averin 16751e7af3b2SVasily Averin for (hash = 0; hash < L2TP_HASH_SIZE_2; hash++) 16761e7af3b2SVasily Averin WARN_ON_ONCE(!hlist_empty(&pn->l2tp_session_hlist[hash])); 1677167eb17eSTom Parkin } 1678167eb17eSTom Parkin 1679fd558d18SJames Chapman static struct pernet_operations l2tp_net_ops = { 1680fd558d18SJames Chapman .init = l2tp_init_net, 1681167eb17eSTom Parkin .exit = l2tp_exit_net, 1682fd558d18SJames Chapman .id = &l2tp_net_id, 1683fd558d18SJames Chapman .size = sizeof(struct l2tp_net), 1684fd558d18SJames Chapman }; 1685fd558d18SJames Chapman 1686fd558d18SJames Chapman static int __init l2tp_init(void) 1687fd558d18SJames Chapman { 1688fd558d18SJames Chapman int rc = 0; 1689fd558d18SJames Chapman 1690fd558d18SJames Chapman rc = register_pernet_device(&l2tp_net_ops); 1691fd558d18SJames Chapman if (rc) 1692fd558d18SJames Chapman goto out; 1693fd558d18SJames Chapman 169459ff3eb6SZhangZhen l2tp_wq = alloc_workqueue("l2tp", WQ_UNBOUND, 0); 1695f8ccac0eSTom Parkin if (!l2tp_wq) { 1696f8ccac0eSTom Parkin pr_err("alloc_workqueue failed\n"); 169767e04c29SWANG Cong unregister_pernet_device(&l2tp_net_ops); 1698f8ccac0eSTom Parkin rc = -ENOMEM; 1699f8ccac0eSTom Parkin goto out; 1700f8ccac0eSTom Parkin } 1701f8ccac0eSTom Parkin 1702a4ca44faSJoe Perches pr_info("L2TP core driver, %s\n", L2TP_DRV_VERSION); 1703fd558d18SJames Chapman 1704fd558d18SJames Chapman out: 1705fd558d18SJames Chapman return rc; 1706fd558d18SJames Chapman } 1707fd558d18SJames Chapman 1708fd558d18SJames Chapman static void __exit l2tp_exit(void) 1709fd558d18SJames Chapman { 1710fd558d18SJames Chapman unregister_pernet_device(&l2tp_net_ops); 1711f8ccac0eSTom Parkin if (l2tp_wq) { 1712f8ccac0eSTom Parkin destroy_workqueue(l2tp_wq); 1713f8ccac0eSTom Parkin l2tp_wq = NULL; 1714f8ccac0eSTom Parkin } 1715fd558d18SJames Chapman } 1716fd558d18SJames Chapman 1717fd558d18SJames Chapman module_init(l2tp_init); 1718fd558d18SJames Chapman module_exit(l2tp_exit); 1719fd558d18SJames Chapman 1720fd558d18SJames Chapman MODULE_AUTHOR("James Chapman <jchapman@katalix.com>"); 1721fd558d18SJames Chapman MODULE_DESCRIPTION("L2TP core"); 1722fd558d18SJames Chapman MODULE_LICENSE("GPL"); 1723fd558d18SJames Chapman MODULE_VERSION(L2TP_DRV_VERSION); 1724