1fd558d18SJames Chapman /* 2fd558d18SJames Chapman * 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 * This program is free software; you can redistribute it and/or modify 17fd558d18SJames Chapman * it under the terms of the GNU General Public License version 2 as 18fd558d18SJames Chapman * published by the Free Software Foundation. 19fd558d18SJames Chapman */ 20fd558d18SJames Chapman 21a4ca44faSJoe Perches #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 22a4ca44faSJoe Perches 23fd558d18SJames Chapman #include <linux/module.h> 24fd558d18SJames Chapman #include <linux/string.h> 25fd558d18SJames Chapman #include <linux/list.h> 26e02d494dSJames Chapman #include <linux/rculist.h> 27fd558d18SJames Chapman #include <linux/uaccess.h> 28fd558d18SJames Chapman 29fd558d18SJames Chapman #include <linux/kernel.h> 30fd558d18SJames Chapman #include <linux/spinlock.h> 31fd558d18SJames Chapman #include <linux/kthread.h> 32fd558d18SJames Chapman #include <linux/sched.h> 33fd558d18SJames Chapman #include <linux/slab.h> 34fd558d18SJames Chapman #include <linux/errno.h> 35fd558d18SJames Chapman #include <linux/jiffies.h> 36fd558d18SJames Chapman 37fd558d18SJames Chapman #include <linux/netdevice.h> 38fd558d18SJames Chapman #include <linux/net.h> 39fd558d18SJames Chapman #include <linux/inetdevice.h> 40fd558d18SJames Chapman #include <linux/skbuff.h> 41fd558d18SJames Chapman #include <linux/init.h> 420d76751fSJames Chapman #include <linux/in.h> 43fd558d18SJames Chapman #include <linux/ip.h> 44fd558d18SJames Chapman #include <linux/udp.h> 450d76751fSJames Chapman #include <linux/l2tp.h> 46fd558d18SJames Chapman #include <linux/hash.h> 47fd558d18SJames Chapman #include <linux/sort.h> 48fd558d18SJames Chapman #include <linux/file.h> 49fd558d18SJames Chapman #include <linux/nsproxy.h> 50fd558d18SJames Chapman #include <net/net_namespace.h> 51fd558d18SJames Chapman #include <net/netns/generic.h> 52fd558d18SJames Chapman #include <net/dst.h> 53fd558d18SJames Chapman #include <net/ip.h> 54fd558d18SJames Chapman #include <net/udp.h> 55309795f4SJames Chapman #include <net/inet_common.h> 56fd558d18SJames Chapman #include <net/xfrm.h> 570d76751fSJames Chapman #include <net/protocol.h> 58d2cf3361SBenjamin LaHaise #include <net/inet6_connection_sock.h> 59d2cf3361SBenjamin LaHaise #include <net/inet_ecn.h> 60d2cf3361SBenjamin LaHaise #include <net/ip6_route.h> 61d499bd2eSDavid S. Miller #include <net/ip6_checksum.h> 62fd558d18SJames Chapman 63fd558d18SJames Chapman #include <asm/byteorder.h> 6460063497SArun Sharma #include <linux/atomic.h> 65fd558d18SJames Chapman 66fd558d18SJames Chapman #include "l2tp_core.h" 67fd558d18SJames Chapman 68fd558d18SJames Chapman #define L2TP_DRV_VERSION "V2.0" 69fd558d18SJames Chapman 70fd558d18SJames Chapman /* L2TP header constants */ 71fd558d18SJames Chapman #define L2TP_HDRFLAG_T 0x8000 72fd558d18SJames Chapman #define L2TP_HDRFLAG_L 0x4000 73fd558d18SJames Chapman #define L2TP_HDRFLAG_S 0x0800 74fd558d18SJames Chapman #define L2TP_HDRFLAG_O 0x0200 75fd558d18SJames Chapman #define L2TP_HDRFLAG_P 0x0100 76fd558d18SJames Chapman 77fd558d18SJames Chapman #define L2TP_HDR_VER_MASK 0x000F 78fd558d18SJames Chapman #define L2TP_HDR_VER_2 0x0002 79f7faffa3SJames Chapman #define L2TP_HDR_VER_3 0x0003 80fd558d18SJames Chapman 81fd558d18SJames Chapman /* L2TPv3 default L2-specific sublayer */ 82fd558d18SJames Chapman #define L2TP_SLFLAG_S 0x40000000 83fd558d18SJames Chapman #define L2TP_SL_SEQ_MASK 0x00ffffff 84fd558d18SJames Chapman 85fd558d18SJames Chapman #define L2TP_HDR_SIZE_SEQ 10 86fd558d18SJames Chapman #define L2TP_HDR_SIZE_NOSEQ 6 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 100fd558d18SJames Chapman #define L2TP_SKB_CB(skb) ((struct l2tp_skb_cb *) &skb->cb[sizeof(struct inet_skb_parm)]) 101fd558d18SJames Chapman 102fd558d18SJames Chapman static atomic_t l2tp_tunnel_count; 103fd558d18SJames Chapman static atomic_t l2tp_session_count; 104f8ccac0eSTom Parkin static struct workqueue_struct *l2tp_wq; 105fd558d18SJames Chapman 106fd558d18SJames Chapman /* per-net private data for this module */ 107fd558d18SJames Chapman static unsigned int l2tp_net_id; 108fd558d18SJames Chapman struct l2tp_net { 109fd558d18SJames Chapman struct list_head l2tp_tunnel_list; 110e02d494dSJames Chapman spinlock_t l2tp_tunnel_list_lock; 111f7faffa3SJames Chapman struct hlist_head l2tp_session_hlist[L2TP_HASH_SIZE_2]; 112e02d494dSJames Chapman spinlock_t l2tp_session_hlist_lock; 113fd558d18SJames Chapman }; 114fd558d18SJames Chapman 115fc130840Sstephen hemminger static void l2tp_tunnel_free(struct l2tp_tunnel *tunnel); 116fc130840Sstephen hemminger 1178d8a51e2SDavid S. Miller static inline struct l2tp_tunnel *l2tp_tunnel(struct sock *sk) 1188d8a51e2SDavid S. Miller { 1198d8a51e2SDavid S. Miller return sk->sk_user_data; 1208d8a51e2SDavid S. Miller } 1218d8a51e2SDavid S. Miller 122fd558d18SJames Chapman static inline struct l2tp_net *l2tp_pernet(struct net *net) 123fd558d18SJames Chapman { 124fd558d18SJames Chapman BUG_ON(!net); 125fd558d18SJames Chapman 126fd558d18SJames Chapman return net_generic(net, l2tp_net_id); 127fd558d18SJames Chapman } 128fd558d18SJames Chapman 129fc130840Sstephen hemminger /* Tunnel reference counts. Incremented per session that is added to 130fc130840Sstephen hemminger * the tunnel. 131fc130840Sstephen hemminger */ 132fc130840Sstephen hemminger static inline void l2tp_tunnel_inc_refcount_1(struct l2tp_tunnel *tunnel) 133fc130840Sstephen hemminger { 134fc130840Sstephen hemminger atomic_inc(&tunnel->ref_count); 135fc130840Sstephen hemminger } 136fc130840Sstephen hemminger 137fc130840Sstephen hemminger static inline void l2tp_tunnel_dec_refcount_1(struct l2tp_tunnel *tunnel) 138fc130840Sstephen hemminger { 139fc130840Sstephen hemminger if (atomic_dec_and_test(&tunnel->ref_count)) 140fc130840Sstephen hemminger l2tp_tunnel_free(tunnel); 141fc130840Sstephen hemminger } 142fc130840Sstephen hemminger #ifdef L2TP_REFCNT_DEBUG 143a4ca44faSJoe Perches #define l2tp_tunnel_inc_refcount(_t) \ 144a4ca44faSJoe Perches do { \ 145a4ca44faSJoe Perches pr_debug("l2tp_tunnel_inc_refcount: %s:%d %s: cnt=%d\n", \ 146a4ca44faSJoe Perches __func__, __LINE__, (_t)->name, \ 147a4ca44faSJoe Perches atomic_read(&_t->ref_count)); \ 148fc130840Sstephen hemminger l2tp_tunnel_inc_refcount_1(_t); \ 149fc130840Sstephen hemminger } while (0) 150a4ca44faSJoe Perches #define l2tp_tunnel_dec_refcount(_t) 151a4ca44faSJoe Perches do { \ 152a4ca44faSJoe Perches pr_debug("l2tp_tunnel_dec_refcount: %s:%d %s: cnt=%d\n", \ 153a4ca44faSJoe Perches __func__, __LINE__, (_t)->name, \ 154a4ca44faSJoe Perches atomic_read(&_t->ref_count)); \ 155fc130840Sstephen hemminger l2tp_tunnel_dec_refcount_1(_t); \ 156fc130840Sstephen hemminger } while (0) 157fc130840Sstephen hemminger #else 158fc130840Sstephen hemminger #define l2tp_tunnel_inc_refcount(t) l2tp_tunnel_inc_refcount_1(t) 159fc130840Sstephen hemminger #define l2tp_tunnel_dec_refcount(t) l2tp_tunnel_dec_refcount_1(t) 160fc130840Sstephen hemminger #endif 161fc130840Sstephen hemminger 162f7faffa3SJames Chapman /* Session hash global list for L2TPv3. 163f7faffa3SJames Chapman * The session_id SHOULD be random according to RFC3931, but several 164f7faffa3SJames Chapman * L2TP implementations use incrementing session_ids. So we do a real 165f7faffa3SJames Chapman * hash on the session_id, rather than a simple bitmask. 166f7faffa3SJames Chapman */ 167f7faffa3SJames Chapman static inline struct hlist_head * 168f7faffa3SJames Chapman l2tp_session_id_hash_2(struct l2tp_net *pn, u32 session_id) 169f7faffa3SJames Chapman { 170f7faffa3SJames Chapman return &pn->l2tp_session_hlist[hash_32(session_id, L2TP_HASH_BITS_2)]; 171f7faffa3SJames Chapman 172f7faffa3SJames Chapman } 173f7faffa3SJames Chapman 17480d84ef3STom Parkin /* Lookup the tunnel socket, possibly involving the fs code if the socket is 17580d84ef3STom Parkin * owned by userspace. A struct sock returned from this function must be 17680d84ef3STom Parkin * released using l2tp_tunnel_sock_put once you're done with it. 17780d84ef3STom Parkin */ 178b5d2b285Sstephen hemminger static struct sock *l2tp_tunnel_sock_lookup(struct l2tp_tunnel *tunnel) 17980d84ef3STom Parkin { 18080d84ef3STom Parkin int err = 0; 18180d84ef3STom Parkin struct socket *sock = NULL; 18280d84ef3STom Parkin struct sock *sk = NULL; 18380d84ef3STom Parkin 18480d84ef3STom Parkin if (!tunnel) 18580d84ef3STom Parkin goto out; 18680d84ef3STom Parkin 18780d84ef3STom Parkin if (tunnel->fd >= 0) { 18880d84ef3STom Parkin /* Socket is owned by userspace, who might be in the process 18980d84ef3STom Parkin * of closing it. Look the socket up using the fd to ensure 19080d84ef3STom Parkin * consistency. 19180d84ef3STom Parkin */ 19280d84ef3STom Parkin sock = sockfd_lookup(tunnel->fd, &err); 19380d84ef3STom Parkin if (sock) 19480d84ef3STom Parkin sk = sock->sk; 19580d84ef3STom Parkin } else { 19680d84ef3STom Parkin /* Socket is owned by kernelspace */ 19780d84ef3STom Parkin sk = tunnel->sock; 1988abbbe8fSTom Parkin sock_hold(sk); 19980d84ef3STom Parkin } 20080d84ef3STom Parkin 20180d84ef3STom Parkin out: 20280d84ef3STom Parkin return sk; 20380d84ef3STom Parkin } 20480d84ef3STom Parkin 20580d84ef3STom Parkin /* Drop a reference to a tunnel socket obtained via. l2tp_tunnel_sock_put */ 206b5d2b285Sstephen hemminger static void l2tp_tunnel_sock_put(struct sock *sk) 20780d84ef3STom Parkin { 20880d84ef3STom Parkin struct l2tp_tunnel *tunnel = l2tp_sock_to_tunnel(sk); 20980d84ef3STom Parkin if (tunnel) { 21080d84ef3STom Parkin if (tunnel->fd >= 0) { 21180d84ef3STom Parkin /* Socket is owned by userspace */ 21280d84ef3STom Parkin sockfd_put(sk->sk_socket); 21380d84ef3STom Parkin } 21480d84ef3STom Parkin sock_put(sk); 21580d84ef3STom Parkin } 2168abbbe8fSTom Parkin sock_put(sk); 21780d84ef3STom Parkin } 21880d84ef3STom Parkin 219f7faffa3SJames Chapman /* Lookup a session by id in the global session list 220f7faffa3SJames Chapman */ 221f7faffa3SJames Chapman static struct l2tp_session *l2tp_session_find_2(struct net *net, u32 session_id) 222f7faffa3SJames Chapman { 223f7faffa3SJames Chapman struct l2tp_net *pn = l2tp_pernet(net); 224f7faffa3SJames Chapman struct hlist_head *session_list = 225f7faffa3SJames Chapman l2tp_session_id_hash_2(pn, session_id); 226f7faffa3SJames Chapman struct l2tp_session *session; 227f7faffa3SJames Chapman 228e02d494dSJames Chapman rcu_read_lock_bh(); 229b67bfe0dSSasha Levin hlist_for_each_entry_rcu(session, session_list, global_hlist) { 230f7faffa3SJames Chapman if (session->session_id == session_id) { 231e02d494dSJames Chapman rcu_read_unlock_bh(); 232f7faffa3SJames Chapman return session; 233f7faffa3SJames Chapman } 234f7faffa3SJames Chapman } 235e02d494dSJames Chapman rcu_read_unlock_bh(); 236f7faffa3SJames Chapman 237f7faffa3SJames Chapman return NULL; 238f7faffa3SJames Chapman } 239f7faffa3SJames Chapman 240fd558d18SJames Chapman /* Session hash list. 241fd558d18SJames Chapman * The session_id SHOULD be random according to RFC2661, but several 242fd558d18SJames Chapman * L2TP implementations (Cisco and Microsoft) use incrementing 243fd558d18SJames Chapman * session_ids. So we do a real hash on the session_id, rather than a 244fd558d18SJames Chapman * simple bitmask. 245fd558d18SJames Chapman */ 246fd558d18SJames Chapman static inline struct hlist_head * 247fd558d18SJames Chapman l2tp_session_id_hash(struct l2tp_tunnel *tunnel, u32 session_id) 248fd558d18SJames Chapman { 249fd558d18SJames Chapman return &tunnel->session_hlist[hash_32(session_id, L2TP_HASH_BITS)]; 250fd558d18SJames Chapman } 251fd558d18SJames Chapman 252fd558d18SJames Chapman /* Lookup a session by id 253fd558d18SJames Chapman */ 254f7faffa3SJames Chapman struct l2tp_session *l2tp_session_find(struct net *net, struct l2tp_tunnel *tunnel, u32 session_id) 255fd558d18SJames Chapman { 256f7faffa3SJames Chapman struct hlist_head *session_list; 257fd558d18SJames Chapman struct l2tp_session *session; 258fd558d18SJames Chapman 259f7faffa3SJames Chapman /* In L2TPv3, session_ids are unique over all tunnels and we 260f7faffa3SJames Chapman * sometimes need to look them up before we know the 261f7faffa3SJames Chapman * tunnel. 262f7faffa3SJames Chapman */ 263f7faffa3SJames Chapman if (tunnel == NULL) 264f7faffa3SJames Chapman return l2tp_session_find_2(net, session_id); 265f7faffa3SJames Chapman 266f7faffa3SJames Chapman session_list = l2tp_session_id_hash(tunnel, session_id); 267fd558d18SJames Chapman read_lock_bh(&tunnel->hlist_lock); 268b67bfe0dSSasha Levin hlist_for_each_entry(session, session_list, hlist) { 269fd558d18SJames Chapman if (session->session_id == session_id) { 270fd558d18SJames Chapman read_unlock_bh(&tunnel->hlist_lock); 271fd558d18SJames Chapman return session; 272fd558d18SJames Chapman } 273fd558d18SJames Chapman } 274fd558d18SJames Chapman read_unlock_bh(&tunnel->hlist_lock); 275fd558d18SJames Chapman 276fd558d18SJames Chapman return NULL; 277fd558d18SJames Chapman } 278fd558d18SJames Chapman EXPORT_SYMBOL_GPL(l2tp_session_find); 279fd558d18SJames Chapman 280fd558d18SJames Chapman struct l2tp_session *l2tp_session_find_nth(struct l2tp_tunnel *tunnel, int nth) 281fd558d18SJames Chapman { 282fd558d18SJames Chapman int hash; 283fd558d18SJames Chapman struct l2tp_session *session; 284fd558d18SJames Chapman int count = 0; 285fd558d18SJames Chapman 286fd558d18SJames Chapman read_lock_bh(&tunnel->hlist_lock); 287fd558d18SJames Chapman for (hash = 0; hash < L2TP_HASH_SIZE; hash++) { 288b67bfe0dSSasha Levin hlist_for_each_entry(session, &tunnel->session_hlist[hash], hlist) { 289fd558d18SJames Chapman if (++count > nth) { 290fd558d18SJames Chapman read_unlock_bh(&tunnel->hlist_lock); 291fd558d18SJames Chapman return session; 292fd558d18SJames Chapman } 293fd558d18SJames Chapman } 294fd558d18SJames Chapman } 295fd558d18SJames Chapman 296fd558d18SJames Chapman read_unlock_bh(&tunnel->hlist_lock); 297fd558d18SJames Chapman 298fd558d18SJames Chapman return NULL; 299fd558d18SJames Chapman } 300fd558d18SJames Chapman EXPORT_SYMBOL_GPL(l2tp_session_find_nth); 301fd558d18SJames Chapman 302309795f4SJames Chapman /* Lookup a session by interface name. 303309795f4SJames Chapman * This is very inefficient but is only used by management interfaces. 304309795f4SJames Chapman */ 305309795f4SJames Chapman struct l2tp_session *l2tp_session_find_by_ifname(struct net *net, char *ifname) 306309795f4SJames Chapman { 307309795f4SJames Chapman struct l2tp_net *pn = l2tp_pernet(net); 308309795f4SJames Chapman int hash; 309309795f4SJames Chapman struct l2tp_session *session; 310309795f4SJames Chapman 311e02d494dSJames Chapman rcu_read_lock_bh(); 312309795f4SJames Chapman for (hash = 0; hash < L2TP_HASH_SIZE_2; hash++) { 313b67bfe0dSSasha Levin hlist_for_each_entry_rcu(session, &pn->l2tp_session_hlist[hash], global_hlist) { 314309795f4SJames Chapman if (!strcmp(session->ifname, ifname)) { 315e02d494dSJames Chapman rcu_read_unlock_bh(); 316309795f4SJames Chapman return session; 317309795f4SJames Chapman } 318309795f4SJames Chapman } 319309795f4SJames Chapman } 320309795f4SJames Chapman 321e02d494dSJames Chapman rcu_read_unlock_bh(); 322309795f4SJames Chapman 323309795f4SJames Chapman return NULL; 324309795f4SJames Chapman } 325309795f4SJames Chapman EXPORT_SYMBOL_GPL(l2tp_session_find_by_ifname); 326309795f4SJames Chapman 327fd558d18SJames Chapman /* Lookup a tunnel by id 328fd558d18SJames Chapman */ 329fd558d18SJames Chapman struct l2tp_tunnel *l2tp_tunnel_find(struct net *net, u32 tunnel_id) 330fd558d18SJames Chapman { 331fd558d18SJames Chapman struct l2tp_tunnel *tunnel; 332fd558d18SJames Chapman struct l2tp_net *pn = l2tp_pernet(net); 333fd558d18SJames Chapman 334e02d494dSJames Chapman rcu_read_lock_bh(); 335e02d494dSJames Chapman list_for_each_entry_rcu(tunnel, &pn->l2tp_tunnel_list, list) { 336fd558d18SJames Chapman if (tunnel->tunnel_id == tunnel_id) { 337e02d494dSJames Chapman rcu_read_unlock_bh(); 338fd558d18SJames Chapman return tunnel; 339fd558d18SJames Chapman } 340fd558d18SJames Chapman } 341e02d494dSJames Chapman rcu_read_unlock_bh(); 342fd558d18SJames Chapman 343fd558d18SJames Chapman return NULL; 344fd558d18SJames Chapman } 345fd558d18SJames Chapman EXPORT_SYMBOL_GPL(l2tp_tunnel_find); 346fd558d18SJames Chapman 347fd558d18SJames Chapman struct l2tp_tunnel *l2tp_tunnel_find_nth(struct net *net, int nth) 348fd558d18SJames Chapman { 349fd558d18SJames Chapman struct l2tp_net *pn = l2tp_pernet(net); 350fd558d18SJames Chapman struct l2tp_tunnel *tunnel; 351fd558d18SJames Chapman int count = 0; 352fd558d18SJames Chapman 353e02d494dSJames Chapman rcu_read_lock_bh(); 354e02d494dSJames Chapman list_for_each_entry_rcu(tunnel, &pn->l2tp_tunnel_list, list) { 355fd558d18SJames Chapman if (++count > nth) { 356e02d494dSJames Chapman rcu_read_unlock_bh(); 357fd558d18SJames Chapman return tunnel; 358fd558d18SJames Chapman } 359fd558d18SJames Chapman } 360fd558d18SJames Chapman 361e02d494dSJames Chapman rcu_read_unlock_bh(); 362fd558d18SJames Chapman 363fd558d18SJames Chapman return NULL; 364fd558d18SJames Chapman } 365fd558d18SJames Chapman EXPORT_SYMBOL_GPL(l2tp_tunnel_find_nth); 366fd558d18SJames Chapman 367fd558d18SJames Chapman /***************************************************************************** 368fd558d18SJames Chapman * Receive data handling 369fd558d18SJames Chapman *****************************************************************************/ 370fd558d18SJames Chapman 371fd558d18SJames Chapman /* Queue a skb in order. We come here only if the skb has an L2TP sequence 372fd558d18SJames Chapman * number. 373fd558d18SJames Chapman */ 374fd558d18SJames Chapman static void l2tp_recv_queue_skb(struct l2tp_session *session, struct sk_buff *skb) 375fd558d18SJames Chapman { 376fd558d18SJames Chapman struct sk_buff *skbp; 377fd558d18SJames Chapman struct sk_buff *tmp; 378f7faffa3SJames Chapman u32 ns = L2TP_SKB_CB(skb)->ns; 379fd558d18SJames Chapman 380fd558d18SJames Chapman spin_lock_bh(&session->reorder_q.lock); 381fd558d18SJames Chapman skb_queue_walk_safe(&session->reorder_q, skbp, tmp) { 382fd558d18SJames Chapman if (L2TP_SKB_CB(skbp)->ns > ns) { 383fd558d18SJames Chapman __skb_queue_before(&session->reorder_q, skbp, skb); 384a4ca44faSJoe Perches l2tp_dbg(session, L2TP_MSG_SEQ, 385fd558d18SJames Chapman "%s: pkt %hu, inserted before %hu, reorder_q len=%d\n", 386fd558d18SJames Chapman session->name, ns, L2TP_SKB_CB(skbp)->ns, 387fd558d18SJames Chapman skb_queue_len(&session->reorder_q)); 3887b7c0719STom Parkin atomic_long_inc(&session->stats.rx_oos_packets); 389fd558d18SJames Chapman goto out; 390fd558d18SJames Chapman } 391fd558d18SJames Chapman } 392fd558d18SJames Chapman 393fd558d18SJames Chapman __skb_queue_tail(&session->reorder_q, skb); 394fd558d18SJames Chapman 395fd558d18SJames Chapman out: 396fd558d18SJames Chapman spin_unlock_bh(&session->reorder_q.lock); 397fd558d18SJames Chapman } 398fd558d18SJames Chapman 399fd558d18SJames Chapman /* Dequeue a single skb. 400fd558d18SJames Chapman */ 401fd558d18SJames Chapman static void l2tp_recv_dequeue_skb(struct l2tp_session *session, struct sk_buff *skb) 402fd558d18SJames Chapman { 403fd558d18SJames Chapman struct l2tp_tunnel *tunnel = session->tunnel; 404fd558d18SJames Chapman int length = L2TP_SKB_CB(skb)->length; 405fd558d18SJames Chapman 406fd558d18SJames Chapman /* We're about to requeue the skb, so return resources 407fd558d18SJames Chapman * to its current owner (a socket receive buffer). 408fd558d18SJames Chapman */ 409fd558d18SJames Chapman skb_orphan(skb); 410fd558d18SJames Chapman 4117b7c0719STom Parkin atomic_long_inc(&tunnel->stats.rx_packets); 4127b7c0719STom Parkin atomic_long_add(length, &tunnel->stats.rx_bytes); 4137b7c0719STom Parkin atomic_long_inc(&session->stats.rx_packets); 4147b7c0719STom Parkin atomic_long_add(length, &session->stats.rx_bytes); 415fd558d18SJames Chapman 416fd558d18SJames Chapman if (L2TP_SKB_CB(skb)->has_seq) { 417fd558d18SJames Chapman /* Bump our Nr */ 418fd558d18SJames Chapman session->nr++; 4198a1631d5SJames Chapman session->nr &= session->nr_max; 420f7faffa3SJames Chapman 421a4ca44faSJoe Perches l2tp_dbg(session, L2TP_MSG_SEQ, "%s: updated nr to %hu\n", 422a4ca44faSJoe Perches session->name, session->nr); 423fd558d18SJames Chapman } 424fd558d18SJames Chapman 425fd558d18SJames Chapman /* call private receive handler */ 426fd558d18SJames Chapman if (session->recv_skb != NULL) 427fd558d18SJames Chapman (*session->recv_skb)(session, skb, L2TP_SKB_CB(skb)->length); 428fd558d18SJames Chapman else 429fd558d18SJames Chapman kfree_skb(skb); 430fd558d18SJames Chapman 431fd558d18SJames Chapman if (session->deref) 432fd558d18SJames Chapman (*session->deref)(session); 433fd558d18SJames Chapman } 434fd558d18SJames Chapman 435fd558d18SJames Chapman /* Dequeue skbs from the session's reorder_q, subject to packet order. 436fd558d18SJames Chapman * Skbs that have been in the queue for too long are simply discarded. 437fd558d18SJames Chapman */ 438fd558d18SJames Chapman static void l2tp_recv_dequeue(struct l2tp_session *session) 439fd558d18SJames Chapman { 440fd558d18SJames Chapman struct sk_buff *skb; 441fd558d18SJames Chapman struct sk_buff *tmp; 442fd558d18SJames Chapman 443fd558d18SJames Chapman /* If the pkt at the head of the queue has the nr that we 444fd558d18SJames Chapman * expect to send up next, dequeue it and any other 445fd558d18SJames Chapman * in-sequence packets behind it. 446fd558d18SJames Chapman */ 447e2e210c0SEric Dumazet start: 448fd558d18SJames Chapman spin_lock_bh(&session->reorder_q.lock); 449fd558d18SJames Chapman skb_queue_walk_safe(&session->reorder_q, skb, tmp) { 450fd558d18SJames Chapman if (time_after(jiffies, L2TP_SKB_CB(skb)->expires)) { 4517b7c0719STom Parkin atomic_long_inc(&session->stats.rx_seq_discards); 4527b7c0719STom Parkin atomic_long_inc(&session->stats.rx_errors); 453a4ca44faSJoe Perches l2tp_dbg(session, L2TP_MSG_SEQ, 454a4ca44faSJoe Perches "%s: oos pkt %u len %d discarded (too old), waiting for %u, reorder_q_len=%d\n", 455fd558d18SJames Chapman session->name, L2TP_SKB_CB(skb)->ns, 456fd558d18SJames Chapman L2TP_SKB_CB(skb)->length, session->nr, 457fd558d18SJames Chapman skb_queue_len(&session->reorder_q)); 45838d40b3fSJames Chapman session->reorder_skip = 1; 459fd558d18SJames Chapman __skb_unlink(skb, &session->reorder_q); 460fd558d18SJames Chapman kfree_skb(skb); 461fd558d18SJames Chapman if (session->deref) 462fd558d18SJames Chapman (*session->deref)(session); 463fd558d18SJames Chapman continue; 464fd558d18SJames Chapman } 465fd558d18SJames Chapman 466fd558d18SJames Chapman if (L2TP_SKB_CB(skb)->has_seq) { 46738d40b3fSJames Chapman if (session->reorder_skip) { 468a4ca44faSJoe Perches l2tp_dbg(session, L2TP_MSG_SEQ, 46938d40b3fSJames Chapman "%s: advancing nr to next pkt: %u -> %u", 47038d40b3fSJames Chapman session->name, session->nr, 47138d40b3fSJames Chapman L2TP_SKB_CB(skb)->ns); 47238d40b3fSJames Chapman session->reorder_skip = 0; 47338d40b3fSJames Chapman session->nr = L2TP_SKB_CB(skb)->ns; 47438d40b3fSJames Chapman } 475fd558d18SJames Chapman if (L2TP_SKB_CB(skb)->ns != session->nr) { 476a4ca44faSJoe Perches l2tp_dbg(session, L2TP_MSG_SEQ, 477a4ca44faSJoe Perches "%s: holding oos pkt %u len %d, waiting for %u, reorder_q_len=%d\n", 478fd558d18SJames Chapman session->name, L2TP_SKB_CB(skb)->ns, 479fd558d18SJames Chapman L2TP_SKB_CB(skb)->length, session->nr, 480fd558d18SJames Chapman skb_queue_len(&session->reorder_q)); 481fd558d18SJames Chapman goto out; 482fd558d18SJames Chapman } 483fd558d18SJames Chapman } 484fd558d18SJames Chapman __skb_unlink(skb, &session->reorder_q); 485fd558d18SJames Chapman 486fd558d18SJames Chapman /* Process the skb. We release the queue lock while we 487fd558d18SJames Chapman * do so to let other contexts process the queue. 488fd558d18SJames Chapman */ 489fd558d18SJames Chapman spin_unlock_bh(&session->reorder_q.lock); 490fd558d18SJames Chapman l2tp_recv_dequeue_skb(session, skb); 491e2e210c0SEric Dumazet goto start; 492fd558d18SJames Chapman } 493fd558d18SJames Chapman 494fd558d18SJames Chapman out: 495fd558d18SJames Chapman spin_unlock_bh(&session->reorder_q.lock); 496fd558d18SJames Chapman } 497fd558d18SJames Chapman 498fd558d18SJames Chapman static inline int l2tp_verify_udp_checksum(struct sock *sk, 499fd558d18SJames Chapman struct sk_buff *skb) 500fd558d18SJames Chapman { 501fd558d18SJames Chapman struct udphdr *uh = udp_hdr(skb); 502fd558d18SJames Chapman u16 ulen = ntohs(uh->len); 503fd558d18SJames Chapman __wsum psum; 504fd558d18SJames Chapman 505d2cf3361SBenjamin LaHaise if (sk->sk_no_check || skb_csum_unnecessary(skb)) 506fd558d18SJames Chapman return 0; 507fd558d18SJames Chapman 508d2cf3361SBenjamin LaHaise #if IS_ENABLED(CONFIG_IPV6) 5098d8a51e2SDavid S. Miller if (sk->sk_family == PF_INET6 && !l2tp_tunnel(sk)->v4mapped) { 510d2cf3361SBenjamin LaHaise if (!uh->check) { 511d2cf3361SBenjamin LaHaise LIMIT_NETDEBUG(KERN_INFO "L2TP: IPv6: checksum is 0\n"); 512d2cf3361SBenjamin LaHaise return 1; 513d2cf3361SBenjamin LaHaise } 514d2cf3361SBenjamin LaHaise if ((skb->ip_summed == CHECKSUM_COMPLETE) && 515d2cf3361SBenjamin LaHaise !csum_ipv6_magic(&ipv6_hdr(skb)->saddr, 516d2cf3361SBenjamin LaHaise &ipv6_hdr(skb)->daddr, ulen, 517d2cf3361SBenjamin LaHaise IPPROTO_UDP, skb->csum)) { 518d2cf3361SBenjamin LaHaise skb->ip_summed = CHECKSUM_UNNECESSARY; 519d2cf3361SBenjamin LaHaise return 0; 520d2cf3361SBenjamin LaHaise } 521d2cf3361SBenjamin LaHaise skb->csum = ~csum_unfold(csum_ipv6_magic(&ipv6_hdr(skb)->saddr, 522d2cf3361SBenjamin LaHaise &ipv6_hdr(skb)->daddr, 523d2cf3361SBenjamin LaHaise skb->len, IPPROTO_UDP, 524d2cf3361SBenjamin LaHaise 0)); 525d2cf3361SBenjamin LaHaise } else 526d2cf3361SBenjamin LaHaise #endif 527d2cf3361SBenjamin LaHaise { 528d2cf3361SBenjamin LaHaise struct inet_sock *inet; 529d2cf3361SBenjamin LaHaise if (!uh->check) 530d2cf3361SBenjamin LaHaise return 0; 531fd558d18SJames Chapman inet = inet_sk(sk); 532d2cf3361SBenjamin LaHaise psum = csum_tcpudp_nofold(inet->inet_saddr, inet->inet_daddr, 533d2cf3361SBenjamin LaHaise ulen, IPPROTO_UDP, 0); 534fd558d18SJames Chapman 535fd558d18SJames Chapman if ((skb->ip_summed == CHECKSUM_COMPLETE) && 536fd558d18SJames Chapman !csum_fold(csum_add(psum, skb->csum))) 537fd558d18SJames Chapman return 0; 538fd558d18SJames Chapman skb->csum = psum; 539d2cf3361SBenjamin LaHaise } 540fd558d18SJames Chapman 541fd558d18SJames Chapman return __skb_checksum_complete(skb); 542fd558d18SJames Chapman } 543fd558d18SJames Chapman 5448a1631d5SJames Chapman static int l2tp_seq_check_rx_window(struct l2tp_session *session, u32 nr) 5458a1631d5SJames Chapman { 5468a1631d5SJames Chapman u32 nws; 5478a1631d5SJames Chapman 5488a1631d5SJames Chapman if (nr >= session->nr) 5498a1631d5SJames Chapman nws = nr - session->nr; 5508a1631d5SJames Chapman else 5518a1631d5SJames Chapman nws = (session->nr_max + 1) - (session->nr - nr); 5528a1631d5SJames Chapman 5538a1631d5SJames Chapman return nws < session->nr_window_size; 5548a1631d5SJames Chapman } 5558a1631d5SJames Chapman 556b6dc01a4SJames Chapman /* If packet has sequence numbers, queue it if acceptable. Returns 0 if 557b6dc01a4SJames Chapman * acceptable, else non-zero. 558b6dc01a4SJames Chapman */ 559b6dc01a4SJames Chapman static int l2tp_recv_data_seq(struct l2tp_session *session, struct sk_buff *skb) 560b6dc01a4SJames Chapman { 5618a1631d5SJames Chapman if (!l2tp_seq_check_rx_window(session, L2TP_SKB_CB(skb)->ns)) { 5628a1631d5SJames Chapman /* Packet sequence number is outside allowed window. 5638a1631d5SJames Chapman * Discard it. 5648a1631d5SJames Chapman */ 5658a1631d5SJames Chapman l2tp_dbg(session, L2TP_MSG_SEQ, 5668a1631d5SJames Chapman "%s: pkt %u len %d discarded, outside window, nr=%u\n", 5678a1631d5SJames Chapman session->name, L2TP_SKB_CB(skb)->ns, 5688a1631d5SJames Chapman L2TP_SKB_CB(skb)->length, session->nr); 5698a1631d5SJames Chapman goto discard; 5708a1631d5SJames Chapman } 5718a1631d5SJames Chapman 572b6dc01a4SJames Chapman if (session->reorder_timeout != 0) { 573b6dc01a4SJames Chapman /* Packet reordering enabled. Add skb to session's 574b6dc01a4SJames Chapman * reorder queue, in order of ns. 575b6dc01a4SJames Chapman */ 576b6dc01a4SJames Chapman l2tp_recv_queue_skb(session, skb); 577a0dbd822SJames Chapman goto out; 578a0dbd822SJames Chapman } 579a0dbd822SJames Chapman 580a0dbd822SJames Chapman /* Packet reordering disabled. Discard out-of-sequence packets, while 581a0dbd822SJames Chapman * tracking the number if in-sequence packets after the first OOS packet 582a0dbd822SJames Chapman * is seen. After nr_oos_count_max in-sequence packets, reset the 583a0dbd822SJames Chapman * sequence number to re-enable packet reception. 584b6dc01a4SJames Chapman */ 585a0dbd822SJames Chapman if (L2TP_SKB_CB(skb)->ns == session->nr) { 586a0dbd822SJames Chapman skb_queue_tail(&session->reorder_q, skb); 587a0dbd822SJames Chapman } else { 588a0dbd822SJames Chapman u32 nr_oos = L2TP_SKB_CB(skb)->ns; 589a0dbd822SJames Chapman u32 nr_next = (session->nr_oos + 1) & session->nr_max; 590a0dbd822SJames Chapman 591a0dbd822SJames Chapman if (nr_oos == nr_next) 592a0dbd822SJames Chapman session->nr_oos_count++; 593a0dbd822SJames Chapman else 594a0dbd822SJames Chapman session->nr_oos_count = 0; 595a0dbd822SJames Chapman 596a0dbd822SJames Chapman session->nr_oos = nr_oos; 597a0dbd822SJames Chapman if (session->nr_oos_count > session->nr_oos_count_max) { 598a0dbd822SJames Chapman session->reorder_skip = 1; 599a0dbd822SJames Chapman l2tp_dbg(session, L2TP_MSG_SEQ, 600a0dbd822SJames Chapman "%s: %d oos packets received. Resetting sequence numbers\n", 601a0dbd822SJames Chapman session->name, session->nr_oos_count); 602a0dbd822SJames Chapman } 603a0dbd822SJames Chapman if (!session->reorder_skip) { 604b6dc01a4SJames Chapman atomic_long_inc(&session->stats.rx_seq_discards); 605b6dc01a4SJames Chapman l2tp_dbg(session, L2TP_MSG_SEQ, 606b6dc01a4SJames Chapman "%s: oos pkt %u len %d discarded, waiting for %u, reorder_q_len=%d\n", 607b6dc01a4SJames Chapman session->name, L2TP_SKB_CB(skb)->ns, 608b6dc01a4SJames Chapman L2TP_SKB_CB(skb)->length, session->nr, 609b6dc01a4SJames Chapman skb_queue_len(&session->reorder_q)); 610b6dc01a4SJames Chapman goto discard; 611b6dc01a4SJames Chapman } 612b6dc01a4SJames Chapman skb_queue_tail(&session->reorder_q, skb); 613b6dc01a4SJames Chapman } 614b6dc01a4SJames Chapman 615a0dbd822SJames Chapman out: 616b6dc01a4SJames Chapman return 0; 617b6dc01a4SJames Chapman 618b6dc01a4SJames Chapman discard: 619b6dc01a4SJames Chapman return 1; 620b6dc01a4SJames Chapman } 621b6dc01a4SJames Chapman 622f7faffa3SJames Chapman /* Do receive processing of L2TP data frames. We handle both L2TPv2 623f7faffa3SJames Chapman * and L2TPv3 data frames here. 624f7faffa3SJames Chapman * 625f7faffa3SJames Chapman * L2TPv2 Data Message Header 626f7faffa3SJames Chapman * 627f7faffa3SJames Chapman * 0 1 2 3 628f7faffa3SJames 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 629f7faffa3SJames Chapman * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 630f7faffa3SJames Chapman * |T|L|x|x|S|x|O|P|x|x|x|x| Ver | Length (opt) | 631f7faffa3SJames Chapman * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 632f7faffa3SJames Chapman * | Tunnel ID | Session ID | 633f7faffa3SJames Chapman * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 634f7faffa3SJames Chapman * | Ns (opt) | Nr (opt) | 635f7faffa3SJames Chapman * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 636f7faffa3SJames Chapman * | Offset Size (opt) | Offset pad... (opt) 637f7faffa3SJames Chapman * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 638f7faffa3SJames Chapman * 639f7faffa3SJames Chapman * Data frames are marked by T=0. All other fields are the same as 640f7faffa3SJames Chapman * those in L2TP control frames. 641f7faffa3SJames Chapman * 642f7faffa3SJames Chapman * L2TPv3 Data Message Header 643f7faffa3SJames Chapman * 644f7faffa3SJames Chapman * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 645f7faffa3SJames Chapman * | L2TP Session Header | 646f7faffa3SJames Chapman * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 647f7faffa3SJames Chapman * | L2-Specific Sublayer | 648f7faffa3SJames Chapman * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 649f7faffa3SJames Chapman * | Tunnel Payload ... 650f7faffa3SJames Chapman * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 651f7faffa3SJames Chapman * 652f7faffa3SJames Chapman * L2TPv3 Session Header Over IP 653f7faffa3SJames Chapman * 654f7faffa3SJames Chapman * 0 1 2 3 655f7faffa3SJames 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 656f7faffa3SJames Chapman * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 657f7faffa3SJames Chapman * | Session ID | 658f7faffa3SJames Chapman * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 659f7faffa3SJames Chapman * | Cookie (optional, maximum 64 bits)... 660f7faffa3SJames Chapman * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 661f7faffa3SJames Chapman * | 662f7faffa3SJames Chapman * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 663f7faffa3SJames Chapman * 664f7faffa3SJames Chapman * L2TPv3 L2-Specific Sublayer Format 665f7faffa3SJames Chapman * 666f7faffa3SJames Chapman * 0 1 2 3 667f7faffa3SJames 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 668f7faffa3SJames Chapman * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 669f7faffa3SJames Chapman * |x|S|x|x|x|x|x|x| Sequence Number | 670f7faffa3SJames Chapman * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 671f7faffa3SJames Chapman * 672f7faffa3SJames Chapman * Cookie value, sublayer format and offset (pad) are negotiated with 673f7faffa3SJames Chapman * the peer when the session is set up. Unlike L2TPv2, we do not need 674f7faffa3SJames Chapman * to parse the packet header to determine if optional fields are 675f7faffa3SJames Chapman * present. 676f7faffa3SJames Chapman * 677f7faffa3SJames Chapman * Caller must already have parsed the frame and determined that it is 678f7faffa3SJames Chapman * a data (not control) frame before coming here. Fields up to the 679f7faffa3SJames Chapman * session-id have already been parsed and ptr points to the data 680f7faffa3SJames Chapman * after the session-id. 681f7faffa3SJames Chapman */ 682f7faffa3SJames Chapman void l2tp_recv_common(struct l2tp_session *session, struct sk_buff *skb, 683f7faffa3SJames Chapman unsigned char *ptr, unsigned char *optr, u16 hdrflags, 684f7faffa3SJames Chapman int length, int (*payload_hook)(struct sk_buff *skb)) 685f7faffa3SJames Chapman { 686f7faffa3SJames Chapman struct l2tp_tunnel *tunnel = session->tunnel; 687f7faffa3SJames Chapman int offset; 688f7faffa3SJames Chapman u32 ns, nr; 689f7faffa3SJames Chapman 690f7faffa3SJames Chapman /* The ref count is increased since we now hold a pointer to 691f7faffa3SJames Chapman * the session. Take care to decrement the refcnt when exiting 692f7faffa3SJames Chapman * this function from now on... 693f7faffa3SJames Chapman */ 694f7faffa3SJames Chapman l2tp_session_inc_refcount(session); 695f7faffa3SJames Chapman if (session->ref) 696f7faffa3SJames Chapman (*session->ref)(session); 697f7faffa3SJames Chapman 698f7faffa3SJames Chapman /* Parse and check optional cookie */ 699f7faffa3SJames Chapman if (session->peer_cookie_len > 0) { 700f7faffa3SJames Chapman if (memcmp(ptr, &session->peer_cookie[0], session->peer_cookie_len)) { 701a4ca44faSJoe Perches l2tp_info(tunnel, L2TP_MSG_DATA, 702f7faffa3SJames Chapman "%s: cookie mismatch (%u/%u). Discarding.\n", 703a4ca44faSJoe Perches tunnel->name, tunnel->tunnel_id, 704a4ca44faSJoe Perches session->session_id); 7057b7c0719STom Parkin atomic_long_inc(&session->stats.rx_cookie_discards); 706f7faffa3SJames Chapman goto discard; 707f7faffa3SJames Chapman } 708f7faffa3SJames Chapman ptr += session->peer_cookie_len; 709f7faffa3SJames Chapman } 710f7faffa3SJames Chapman 711f7faffa3SJames Chapman /* Handle the optional sequence numbers. Sequence numbers are 712f7faffa3SJames Chapman * in different places for L2TPv2 and L2TPv3. 713f7faffa3SJames Chapman * 714f7faffa3SJames Chapman * If we are the LAC, enable/disable sequence numbers under 715f7faffa3SJames Chapman * the control of the LNS. If no sequence numbers present but 716f7faffa3SJames Chapman * we were expecting them, discard frame. 717f7faffa3SJames Chapman */ 718f7faffa3SJames Chapman ns = nr = 0; 719f7faffa3SJames Chapman L2TP_SKB_CB(skb)->has_seq = 0; 720f7faffa3SJames Chapman if (tunnel->version == L2TP_HDR_VER_2) { 721f7faffa3SJames Chapman if (hdrflags & L2TP_HDRFLAG_S) { 722f7faffa3SJames Chapman ns = ntohs(*(__be16 *) ptr); 723f7faffa3SJames Chapman ptr += 2; 724f7faffa3SJames Chapman nr = ntohs(*(__be16 *) ptr); 725f7faffa3SJames Chapman ptr += 2; 726f7faffa3SJames Chapman 727f7faffa3SJames Chapman /* Store L2TP info in the skb */ 728f7faffa3SJames Chapman L2TP_SKB_CB(skb)->ns = ns; 729f7faffa3SJames Chapman L2TP_SKB_CB(skb)->has_seq = 1; 730f7faffa3SJames Chapman 731a4ca44faSJoe Perches l2tp_dbg(session, L2TP_MSG_SEQ, 732f7faffa3SJames Chapman "%s: recv data ns=%u, nr=%u, session nr=%u\n", 733f7faffa3SJames Chapman session->name, ns, nr, session->nr); 734f7faffa3SJames Chapman } 735f7faffa3SJames Chapman } else if (session->l2specific_type == L2TP_L2SPECTYPE_DEFAULT) { 736f7faffa3SJames Chapman u32 l2h = ntohl(*(__be32 *) ptr); 737f7faffa3SJames Chapman 738f7faffa3SJames Chapman if (l2h & 0x40000000) { 739f7faffa3SJames Chapman ns = l2h & 0x00ffffff; 740f7faffa3SJames Chapman 741f7faffa3SJames Chapman /* Store L2TP info in the skb */ 742f7faffa3SJames Chapman L2TP_SKB_CB(skb)->ns = ns; 743f7faffa3SJames Chapman L2TP_SKB_CB(skb)->has_seq = 1; 744f7faffa3SJames Chapman 745a4ca44faSJoe Perches l2tp_dbg(session, L2TP_MSG_SEQ, 746f7faffa3SJames Chapman "%s: recv data ns=%u, session nr=%u\n", 747f7faffa3SJames Chapman session->name, ns, session->nr); 748f7faffa3SJames Chapman } 749f7faffa3SJames Chapman } 750f7faffa3SJames Chapman 751f7faffa3SJames Chapman /* Advance past L2-specific header, if present */ 752f7faffa3SJames Chapman ptr += session->l2specific_len; 753f7faffa3SJames Chapman 754f7faffa3SJames Chapman if (L2TP_SKB_CB(skb)->has_seq) { 755f7faffa3SJames Chapman /* Received a packet with sequence numbers. If we're the LNS, 756f7faffa3SJames Chapman * check if we sre sending sequence numbers and if not, 757f7faffa3SJames Chapman * configure it so. 758f7faffa3SJames Chapman */ 759f7faffa3SJames Chapman if ((!session->lns_mode) && (!session->send_seq)) { 760a4ca44faSJoe Perches l2tp_info(session, L2TP_MSG_SEQ, 761f7faffa3SJames Chapman "%s: requested to enable seq numbers by LNS\n", 762f7faffa3SJames Chapman session->name); 763f7faffa3SJames Chapman session->send_seq = -1; 764f7faffa3SJames Chapman l2tp_session_set_header_len(session, tunnel->version); 765f7faffa3SJames Chapman } 766f7faffa3SJames Chapman } else { 767f7faffa3SJames Chapman /* No sequence numbers. 768f7faffa3SJames Chapman * If user has configured mandatory sequence numbers, discard. 769f7faffa3SJames Chapman */ 770f7faffa3SJames Chapman if (session->recv_seq) { 771a4ca44faSJoe Perches l2tp_warn(session, L2TP_MSG_SEQ, 772a4ca44faSJoe Perches "%s: recv data has no seq numbers when required. Discarding.\n", 773a4ca44faSJoe Perches session->name); 7747b7c0719STom Parkin atomic_long_inc(&session->stats.rx_seq_discards); 775f7faffa3SJames Chapman goto discard; 776f7faffa3SJames Chapman } 777f7faffa3SJames Chapman 778f7faffa3SJames Chapman /* If we're the LAC and we're sending sequence numbers, the 779f7faffa3SJames Chapman * LNS has requested that we no longer send sequence numbers. 780f7faffa3SJames Chapman * If we're the LNS and we're sending sequence numbers, the 781f7faffa3SJames Chapman * LAC is broken. Discard the frame. 782f7faffa3SJames Chapman */ 783f7faffa3SJames Chapman if ((!session->lns_mode) && (session->send_seq)) { 784a4ca44faSJoe Perches l2tp_info(session, L2TP_MSG_SEQ, 785f7faffa3SJames Chapman "%s: requested to disable seq numbers by LNS\n", 786f7faffa3SJames Chapman session->name); 787f7faffa3SJames Chapman session->send_seq = 0; 788f7faffa3SJames Chapman l2tp_session_set_header_len(session, tunnel->version); 789f7faffa3SJames Chapman } else if (session->send_seq) { 790a4ca44faSJoe Perches l2tp_warn(session, L2TP_MSG_SEQ, 791a4ca44faSJoe Perches "%s: recv data has no seq numbers when required. Discarding.\n", 792a4ca44faSJoe Perches session->name); 7937b7c0719STom Parkin atomic_long_inc(&session->stats.rx_seq_discards); 794f7faffa3SJames Chapman goto discard; 795f7faffa3SJames Chapman } 796f7faffa3SJames Chapman } 797f7faffa3SJames Chapman 798f7faffa3SJames Chapman /* Session data offset is handled differently for L2TPv2 and 799f7faffa3SJames Chapman * L2TPv3. For L2TPv2, there is an optional 16-bit value in 800f7faffa3SJames Chapman * the header. For L2TPv3, the offset is negotiated using AVPs 801f7faffa3SJames Chapman * in the session setup control protocol. 802f7faffa3SJames Chapman */ 803f7faffa3SJames Chapman if (tunnel->version == L2TP_HDR_VER_2) { 804f7faffa3SJames Chapman /* If offset bit set, skip it. */ 805f7faffa3SJames Chapman if (hdrflags & L2TP_HDRFLAG_O) { 806f7faffa3SJames Chapman offset = ntohs(*(__be16 *)ptr); 807f7faffa3SJames Chapman ptr += 2 + offset; 808f7faffa3SJames Chapman } 809f7faffa3SJames Chapman } else 810f7faffa3SJames Chapman ptr += session->offset; 811f7faffa3SJames Chapman 812f7faffa3SJames Chapman offset = ptr - optr; 813f7faffa3SJames Chapman if (!pskb_may_pull(skb, offset)) 814f7faffa3SJames Chapman goto discard; 815f7faffa3SJames Chapman 816f7faffa3SJames Chapman __skb_pull(skb, offset); 817f7faffa3SJames Chapman 818f7faffa3SJames Chapman /* If caller wants to process the payload before we queue the 819f7faffa3SJames Chapman * packet, do so now. 820f7faffa3SJames Chapman */ 821f7faffa3SJames Chapman if (payload_hook) 822f7faffa3SJames Chapman if ((*payload_hook)(skb)) 823f7faffa3SJames Chapman goto discard; 824f7faffa3SJames Chapman 825f7faffa3SJames Chapman /* Prepare skb for adding to the session's reorder_q. Hold 826f7faffa3SJames Chapman * packets for max reorder_timeout or 1 second if not 827f7faffa3SJames Chapman * reordering. 828f7faffa3SJames Chapman */ 829f7faffa3SJames Chapman L2TP_SKB_CB(skb)->length = length; 830f7faffa3SJames Chapman L2TP_SKB_CB(skb)->expires = jiffies + 831f7faffa3SJames Chapman (session->reorder_timeout ? session->reorder_timeout : HZ); 832f7faffa3SJames Chapman 833f7faffa3SJames Chapman /* Add packet to the session's receive queue. Reordering is done here, if 834f7faffa3SJames Chapman * enabled. Saved L2TP protocol info is stored in skb->sb[]. 835f7faffa3SJames Chapman */ 836f7faffa3SJames Chapman if (L2TP_SKB_CB(skb)->has_seq) { 837b6dc01a4SJames Chapman if (l2tp_recv_data_seq(session, skb)) 838f7faffa3SJames Chapman goto discard; 839f7faffa3SJames Chapman } else { 840f7faffa3SJames Chapman /* No sequence numbers. Add the skb to the tail of the 841f7faffa3SJames Chapman * reorder queue. This ensures that it will be 842f7faffa3SJames Chapman * delivered after all previous sequenced skbs. 843f7faffa3SJames Chapman */ 844f7faffa3SJames Chapman skb_queue_tail(&session->reorder_q, skb); 845f7faffa3SJames Chapman } 846f7faffa3SJames Chapman 847f7faffa3SJames Chapman /* Try to dequeue as many skbs from reorder_q as we can. */ 848f7faffa3SJames Chapman l2tp_recv_dequeue(session); 849f7faffa3SJames Chapman 850f7faffa3SJames Chapman l2tp_session_dec_refcount(session); 851f7faffa3SJames Chapman 852f7faffa3SJames Chapman return; 853f7faffa3SJames Chapman 854f7faffa3SJames Chapman discard: 8557b7c0719STom Parkin atomic_long_inc(&session->stats.rx_errors); 856f7faffa3SJames Chapman kfree_skb(skb); 857f7faffa3SJames Chapman 858f7faffa3SJames Chapman if (session->deref) 859f7faffa3SJames Chapman (*session->deref)(session); 860f7faffa3SJames Chapman 861f7faffa3SJames Chapman l2tp_session_dec_refcount(session); 862f7faffa3SJames Chapman } 863f7faffa3SJames Chapman EXPORT_SYMBOL(l2tp_recv_common); 864f7faffa3SJames Chapman 86548f72f92STom Parkin /* Drop skbs from the session's reorder_q 86648f72f92STom Parkin */ 86748f72f92STom Parkin int l2tp_session_queue_purge(struct l2tp_session *session) 86848f72f92STom Parkin { 86948f72f92STom Parkin struct sk_buff *skb = NULL; 87048f72f92STom Parkin BUG_ON(!session); 87148f72f92STom Parkin BUG_ON(session->magic != L2TP_SESSION_MAGIC); 87248f72f92STom Parkin while ((skb = skb_dequeue(&session->reorder_q))) { 87348f72f92STom Parkin atomic_long_inc(&session->stats.rx_errors); 87448f72f92STom Parkin kfree_skb(skb); 87548f72f92STom Parkin if (session->deref) 87648f72f92STom Parkin (*session->deref)(session); 87748f72f92STom Parkin } 87848f72f92STom Parkin return 0; 87948f72f92STom Parkin } 88048f72f92STom Parkin EXPORT_SYMBOL_GPL(l2tp_session_queue_purge); 88148f72f92STom Parkin 882fd558d18SJames Chapman /* Internal UDP receive frame. Do the real work of receiving an L2TP data frame 883fd558d18SJames Chapman * here. The skb is not on a list when we get here. 884fd558d18SJames Chapman * Returns 0 if the packet was a data packet and was successfully passed on. 885fd558d18SJames Chapman * Returns 1 if the packet was not a good data packet and could not be 886fd558d18SJames Chapman * forwarded. All such packets are passed up to userspace to deal with. 887fd558d18SJames Chapman */ 888fc130840Sstephen hemminger static int l2tp_udp_recv_core(struct l2tp_tunnel *tunnel, struct sk_buff *skb, 889fd558d18SJames Chapman int (*payload_hook)(struct sk_buff *skb)) 890fd558d18SJames Chapman { 891fd558d18SJames Chapman struct l2tp_session *session = NULL; 892fd558d18SJames Chapman unsigned char *ptr, *optr; 893fd558d18SJames Chapman u16 hdrflags; 894fd558d18SJames Chapman u32 tunnel_id, session_id; 895fd558d18SJames Chapman u16 version; 896f7faffa3SJames Chapman int length; 897fd558d18SJames Chapman 898fd558d18SJames Chapman if (tunnel->sock && l2tp_verify_udp_checksum(tunnel->sock, skb)) 899fd558d18SJames Chapman goto discard_bad_csum; 900fd558d18SJames Chapman 901fd558d18SJames Chapman /* UDP always verifies the packet length. */ 902fd558d18SJames Chapman __skb_pull(skb, sizeof(struct udphdr)); 903fd558d18SJames Chapman 904fd558d18SJames Chapman /* Short packet? */ 905fd558d18SJames Chapman if (!pskb_may_pull(skb, L2TP_HDR_SIZE_SEQ)) { 906a4ca44faSJoe Perches l2tp_info(tunnel, L2TP_MSG_DATA, 907a4ca44faSJoe Perches "%s: recv short packet (len=%d)\n", 908a4ca44faSJoe Perches tunnel->name, skb->len); 909fd558d18SJames Chapman goto error; 910fd558d18SJames Chapman } 911fd558d18SJames Chapman 912fd558d18SJames Chapman /* Trace packet contents, if enabled */ 913fd558d18SJames Chapman if (tunnel->debug & L2TP_MSG_DATA) { 914fd558d18SJames Chapman length = min(32u, skb->len); 915fd558d18SJames Chapman if (!pskb_may_pull(skb, length)) 916fd558d18SJames Chapman goto error; 917fd558d18SJames Chapman 918a4ca44faSJoe Perches pr_debug("%s: recv\n", tunnel->name); 919a4ca44faSJoe Perches print_hex_dump_bytes("", DUMP_PREFIX_OFFSET, skb->data, length); 920fd558d18SJames Chapman } 921fd558d18SJames Chapman 922e50e705cSEric Dumazet /* Point to L2TP header */ 923e50e705cSEric Dumazet optr = ptr = skb->data; 924e50e705cSEric Dumazet 925fd558d18SJames Chapman /* Get L2TP header flags */ 926fd558d18SJames Chapman hdrflags = ntohs(*(__be16 *) ptr); 927fd558d18SJames Chapman 928fd558d18SJames Chapman /* Check protocol version */ 929fd558d18SJames Chapman version = hdrflags & L2TP_HDR_VER_MASK; 930fd558d18SJames Chapman if (version != tunnel->version) { 931a4ca44faSJoe Perches l2tp_info(tunnel, L2TP_MSG_DATA, 932fd558d18SJames Chapman "%s: recv protocol version mismatch: got %d expected %d\n", 933fd558d18SJames Chapman tunnel->name, version, tunnel->version); 934fd558d18SJames Chapman goto error; 935fd558d18SJames Chapman } 936fd558d18SJames Chapman 937fd558d18SJames Chapman /* Get length of L2TP packet */ 938fd558d18SJames Chapman length = skb->len; 939fd558d18SJames Chapman 940fd558d18SJames Chapman /* If type is control packet, it is handled by userspace. */ 941fd558d18SJames Chapman if (hdrflags & L2TP_HDRFLAG_T) { 942a4ca44faSJoe Perches l2tp_dbg(tunnel, L2TP_MSG_DATA, 943a4ca44faSJoe Perches "%s: recv control packet, len=%d\n", 944a4ca44faSJoe Perches tunnel->name, length); 945fd558d18SJames Chapman goto error; 946fd558d18SJames Chapman } 947fd558d18SJames Chapman 948fd558d18SJames Chapman /* Skip flags */ 949fd558d18SJames Chapman ptr += 2; 950fd558d18SJames Chapman 951f7faffa3SJames Chapman if (tunnel->version == L2TP_HDR_VER_2) { 952fd558d18SJames Chapman /* If length is present, skip it */ 953fd558d18SJames Chapman if (hdrflags & L2TP_HDRFLAG_L) 954fd558d18SJames Chapman ptr += 2; 955fd558d18SJames Chapman 956fd558d18SJames Chapman /* Extract tunnel and session ID */ 957fd558d18SJames Chapman tunnel_id = ntohs(*(__be16 *) ptr); 958fd558d18SJames Chapman ptr += 2; 959fd558d18SJames Chapman session_id = ntohs(*(__be16 *) ptr); 960fd558d18SJames Chapman ptr += 2; 961f7faffa3SJames Chapman } else { 962f7faffa3SJames Chapman ptr += 2; /* skip reserved bits */ 963f7faffa3SJames Chapman tunnel_id = tunnel->tunnel_id; 964f7faffa3SJames Chapman session_id = ntohl(*(__be32 *) ptr); 965f7faffa3SJames Chapman ptr += 4; 966f7faffa3SJames Chapman } 967fd558d18SJames Chapman 968fd558d18SJames Chapman /* Find the session context */ 969f7faffa3SJames Chapman session = l2tp_session_find(tunnel->l2tp_net, tunnel, session_id); 970309795f4SJames Chapman if (!session || !session->recv_skb) { 971fd558d18SJames Chapman /* Not found? Pass to userspace to deal with */ 972a4ca44faSJoe Perches l2tp_info(tunnel, L2TP_MSG_DATA, 973f7faffa3SJames Chapman "%s: no session found (%u/%u). Passing up.\n", 974fd558d18SJames Chapman tunnel->name, tunnel_id, session_id); 975fd558d18SJames Chapman goto error; 976fd558d18SJames Chapman } 977fd558d18SJames Chapman 978f7faffa3SJames Chapman l2tp_recv_common(session, skb, ptr, optr, hdrflags, length, payload_hook); 979fd558d18SJames Chapman 980fd558d18SJames Chapman return 0; 981fd558d18SJames Chapman 982fd558d18SJames Chapman discard_bad_csum: 983fd558d18SJames Chapman LIMIT_NETDEBUG("%s: UDP: bad checksum\n", tunnel->name); 984fd558d18SJames Chapman UDP_INC_STATS_USER(tunnel->l2tp_net, UDP_MIB_INERRORS, 0); 9857b7c0719STom Parkin atomic_long_inc(&tunnel->stats.rx_errors); 986fd558d18SJames Chapman kfree_skb(skb); 987fd558d18SJames Chapman 988fd558d18SJames Chapman return 0; 989fd558d18SJames Chapman 990fd558d18SJames Chapman error: 991fd558d18SJames Chapman /* Put UDP header back */ 992fd558d18SJames Chapman __skb_push(skb, sizeof(struct udphdr)); 993fd558d18SJames Chapman 994fd558d18SJames Chapman return 1; 995fd558d18SJames Chapman } 996fd558d18SJames Chapman 997fd558d18SJames Chapman /* UDP encapsulation receive handler. See net/ipv4/udp.c. 998fd558d18SJames Chapman * Return codes: 999fd558d18SJames Chapman * 0 : success. 1000fd558d18SJames Chapman * <0: error 1001fd558d18SJames Chapman * >0: skb should be passed up to userspace as UDP. 1002fd558d18SJames Chapman */ 1003fd558d18SJames Chapman int l2tp_udp_encap_recv(struct sock *sk, struct sk_buff *skb) 1004fd558d18SJames Chapman { 1005fd558d18SJames Chapman struct l2tp_tunnel *tunnel; 1006fd558d18SJames Chapman 1007fd558d18SJames Chapman tunnel = l2tp_sock_to_tunnel(sk); 1008fd558d18SJames Chapman if (tunnel == NULL) 1009fd558d18SJames Chapman goto pass_up; 1010fd558d18SJames Chapman 1011a4ca44faSJoe Perches l2tp_dbg(tunnel, L2TP_MSG_DATA, "%s: received %d bytes\n", 1012a4ca44faSJoe Perches tunnel->name, skb->len); 1013fd558d18SJames Chapman 1014fd558d18SJames Chapman if (l2tp_udp_recv_core(tunnel, skb, tunnel->recv_payload_hook)) 1015fd558d18SJames Chapman goto pass_up_put; 1016fd558d18SJames Chapman 1017fd558d18SJames Chapman sock_put(sk); 1018fd558d18SJames Chapman return 0; 1019fd558d18SJames Chapman 1020fd558d18SJames Chapman pass_up_put: 1021fd558d18SJames Chapman sock_put(sk); 1022fd558d18SJames Chapman pass_up: 1023fd558d18SJames Chapman return 1; 1024fd558d18SJames Chapman } 1025fd558d18SJames Chapman EXPORT_SYMBOL_GPL(l2tp_udp_encap_recv); 1026fd558d18SJames Chapman 1027fd558d18SJames Chapman /************************************************************************ 1028fd558d18SJames Chapman * Transmit handling 1029fd558d18SJames Chapman ***********************************************************************/ 1030fd558d18SJames Chapman 1031fd558d18SJames Chapman /* Build an L2TP header for the session into the buffer provided. 1032fd558d18SJames Chapman */ 1033f7faffa3SJames Chapman static int l2tp_build_l2tpv2_header(struct l2tp_session *session, void *buf) 1034fd558d18SJames Chapman { 1035f7faffa3SJames Chapman struct l2tp_tunnel *tunnel = session->tunnel; 1036fd558d18SJames Chapman __be16 *bufp = buf; 1037f7faffa3SJames Chapman __be16 *optr = buf; 1038fd558d18SJames Chapman u16 flags = L2TP_HDR_VER_2; 1039fd558d18SJames Chapman u32 tunnel_id = tunnel->peer_tunnel_id; 1040fd558d18SJames Chapman u32 session_id = session->peer_session_id; 1041fd558d18SJames Chapman 1042fd558d18SJames Chapman if (session->send_seq) 1043fd558d18SJames Chapman flags |= L2TP_HDRFLAG_S; 1044fd558d18SJames Chapman 1045fd558d18SJames Chapman /* Setup L2TP header. */ 1046fd558d18SJames Chapman *bufp++ = htons(flags); 1047fd558d18SJames Chapman *bufp++ = htons(tunnel_id); 1048fd558d18SJames Chapman *bufp++ = htons(session_id); 1049fd558d18SJames Chapman if (session->send_seq) { 1050fd558d18SJames Chapman *bufp++ = htons(session->ns); 1051fd558d18SJames Chapman *bufp++ = 0; 1052fd558d18SJames Chapman session->ns++; 1053f7faffa3SJames Chapman session->ns &= 0xffff; 1054a4ca44faSJoe Perches l2tp_dbg(session, L2TP_MSG_SEQ, "%s: updated ns to %u\n", 1055a4ca44faSJoe Perches session->name, session->ns); 1056fd558d18SJames Chapman } 1057fd558d18SJames Chapman 1058f7faffa3SJames Chapman return bufp - optr; 1059f7faffa3SJames Chapman } 1060f7faffa3SJames Chapman 1061f7faffa3SJames Chapman static int l2tp_build_l2tpv3_header(struct l2tp_session *session, void *buf) 1062fd558d18SJames Chapman { 10630d76751fSJames Chapman struct l2tp_tunnel *tunnel = session->tunnel; 1064f7faffa3SJames Chapman char *bufp = buf; 1065f7faffa3SJames Chapman char *optr = bufp; 1066fd558d18SJames Chapman 10670d76751fSJames Chapman /* Setup L2TP header. The header differs slightly for UDP and 10680d76751fSJames Chapman * IP encapsulations. For UDP, there is 4 bytes of flags. 10690d76751fSJames Chapman */ 10700d76751fSJames Chapman if (tunnel->encap == L2TP_ENCAPTYPE_UDP) { 10710d76751fSJames Chapman u16 flags = L2TP_HDR_VER_3; 1072f7faffa3SJames Chapman *((__be16 *) bufp) = htons(flags); 1073f7faffa3SJames Chapman bufp += 2; 1074f7faffa3SJames Chapman *((__be16 *) bufp) = 0; 1075f7faffa3SJames Chapman bufp += 2; 10760d76751fSJames Chapman } 10770d76751fSJames Chapman 1078f7faffa3SJames Chapman *((__be32 *) bufp) = htonl(session->peer_session_id); 1079f7faffa3SJames Chapman bufp += 4; 1080f7faffa3SJames Chapman if (session->cookie_len) { 1081f7faffa3SJames Chapman memcpy(bufp, &session->cookie[0], session->cookie_len); 1082f7faffa3SJames Chapman bufp += session->cookie_len; 1083fd558d18SJames Chapman } 1084f7faffa3SJames Chapman if (session->l2specific_len) { 1085f7faffa3SJames Chapman if (session->l2specific_type == L2TP_L2SPECTYPE_DEFAULT) { 1086f7faffa3SJames Chapman u32 l2h = 0; 1087f7faffa3SJames Chapman if (session->send_seq) { 1088f7faffa3SJames Chapman l2h = 0x40000000 | session->ns; 1089f7faffa3SJames Chapman session->ns++; 1090f7faffa3SJames Chapman session->ns &= 0xffffff; 1091a4ca44faSJoe Perches l2tp_dbg(session, L2TP_MSG_SEQ, 1092a4ca44faSJoe Perches "%s: updated ns to %u\n", 1093a4ca44faSJoe Perches session->name, session->ns); 1094f7faffa3SJames Chapman } 1095f7faffa3SJames Chapman 1096f7faffa3SJames Chapman *((__be32 *) bufp) = htonl(l2h); 1097f7faffa3SJames Chapman } 1098f7faffa3SJames Chapman bufp += session->l2specific_len; 1099f7faffa3SJames Chapman } 1100f7faffa3SJames Chapman if (session->offset) 1101f7faffa3SJames Chapman bufp += session->offset; 1102f7faffa3SJames Chapman 1103f7faffa3SJames Chapman return bufp - optr; 1104f7faffa3SJames Chapman } 1105fd558d18SJames Chapman 1106fc130840Sstephen hemminger static int l2tp_xmit_core(struct l2tp_session *session, struct sk_buff *skb, 1107d9d8da80SDavid S. Miller struct flowi *fl, size_t data_len) 1108fd558d18SJames Chapman { 1109fd558d18SJames Chapman struct l2tp_tunnel *tunnel = session->tunnel; 1110fd558d18SJames Chapman unsigned int len = skb->len; 1111fd558d18SJames Chapman int error; 1112fd558d18SJames Chapman 1113fd558d18SJames Chapman /* Debug */ 1114fd558d18SJames Chapman if (session->send_seq) 1115a4ca44faSJoe Perches l2tp_dbg(session, L2TP_MSG_DATA, "%s: send %Zd bytes, ns=%u\n", 1116a4ca44faSJoe Perches session->name, data_len, session->ns - 1); 1117fd558d18SJames Chapman else 1118a4ca44faSJoe Perches l2tp_dbg(session, L2TP_MSG_DATA, "%s: send %Zd bytes\n", 1119a4ca44faSJoe Perches session->name, data_len); 1120fd558d18SJames Chapman 1121fd558d18SJames Chapman if (session->debug & L2TP_MSG_DATA) { 11220d76751fSJames Chapman int uhlen = (tunnel->encap == L2TP_ENCAPTYPE_UDP) ? sizeof(struct udphdr) : 0; 11230d76751fSJames Chapman unsigned char *datap = skb->data + uhlen; 1124fd558d18SJames Chapman 1125a4ca44faSJoe Perches pr_debug("%s: xmit\n", session->name); 1126a4ca44faSJoe Perches print_hex_dump_bytes("", DUMP_PREFIX_OFFSET, 1127a4ca44faSJoe Perches datap, min_t(size_t, 32, len - uhlen)); 1128fd558d18SJames Chapman } 1129fd558d18SJames Chapman 1130fd558d18SJames Chapman /* Queue the packet to IP for output */ 11314e15ed4dSShan Wei skb->local_df = 1; 1132d2cf3361SBenjamin LaHaise #if IS_ENABLED(CONFIG_IPV6) 1133746e3499SEric Dumazet if (tunnel->sock->sk_family == PF_INET6 && !tunnel->v4mapped) 1134b0270e91SEric Dumazet error = inet6_csk_xmit(tunnel->sock, skb, NULL); 1135d2cf3361SBenjamin LaHaise else 1136d2cf3361SBenjamin LaHaise #endif 1137b0270e91SEric Dumazet error = ip_queue_xmit(tunnel->sock, skb, fl); 1138fd558d18SJames Chapman 1139fd558d18SJames Chapman /* Update stats */ 1140fd558d18SJames Chapman if (error >= 0) { 11417b7c0719STom Parkin atomic_long_inc(&tunnel->stats.tx_packets); 11427b7c0719STom Parkin atomic_long_add(len, &tunnel->stats.tx_bytes); 11437b7c0719STom Parkin atomic_long_inc(&session->stats.tx_packets); 11447b7c0719STom Parkin atomic_long_add(len, &session->stats.tx_bytes); 1145fd558d18SJames Chapman } else { 11467b7c0719STom Parkin atomic_long_inc(&tunnel->stats.tx_errors); 11477b7c0719STom Parkin atomic_long_inc(&session->stats.tx_errors); 1148fd558d18SJames Chapman } 1149fd558d18SJames Chapman 1150fd558d18SJames Chapman return 0; 1151fd558d18SJames Chapman } 1152fd558d18SJames Chapman 1153d2cf3361SBenjamin LaHaise #if IS_ENABLED(CONFIG_IPV6) 1154d2cf3361SBenjamin LaHaise static void l2tp_xmit_ipv6_csum(struct sock *sk, struct sk_buff *skb, 1155d2cf3361SBenjamin LaHaise int udp_len) 1156d2cf3361SBenjamin LaHaise { 1157d2cf3361SBenjamin LaHaise struct ipv6_pinfo *np = inet6_sk(sk); 1158d2cf3361SBenjamin LaHaise struct udphdr *uh = udp_hdr(skb); 1159d2cf3361SBenjamin LaHaise 1160d2cf3361SBenjamin LaHaise if (!skb_dst(skb) || !skb_dst(skb)->dev || 1161d2cf3361SBenjamin LaHaise !(skb_dst(skb)->dev->features & NETIF_F_IPV6_CSUM)) { 1162d2cf3361SBenjamin LaHaise __wsum csum = skb_checksum(skb, 0, udp_len, 0); 1163d2cf3361SBenjamin LaHaise skb->ip_summed = CHECKSUM_UNNECESSARY; 1164efe4208fSEric Dumazet uh->check = csum_ipv6_magic(&np->saddr, &sk->sk_v6_daddr, udp_len, 1165d2cf3361SBenjamin LaHaise IPPROTO_UDP, csum); 1166d2cf3361SBenjamin LaHaise if (uh->check == 0) 1167d2cf3361SBenjamin LaHaise uh->check = CSUM_MANGLED_0; 1168d2cf3361SBenjamin LaHaise } else { 1169d2cf3361SBenjamin LaHaise skb->ip_summed = CHECKSUM_PARTIAL; 1170d2cf3361SBenjamin LaHaise skb->csum_start = skb_transport_header(skb) - skb->head; 1171d2cf3361SBenjamin LaHaise skb->csum_offset = offsetof(struct udphdr, check); 1172efe4208fSEric Dumazet uh->check = ~csum_ipv6_magic(&np->saddr, &sk->sk_v6_daddr, 1173d2cf3361SBenjamin LaHaise udp_len, IPPROTO_UDP, 0); 1174d2cf3361SBenjamin LaHaise } 1175d2cf3361SBenjamin LaHaise } 1176d2cf3361SBenjamin LaHaise #endif 1177d2cf3361SBenjamin LaHaise 1178fd558d18SJames Chapman /* If caller requires the skb to have a ppp header, the header must be 1179fd558d18SJames Chapman * inserted in the skb data before calling this function. 1180fd558d18SJames Chapman */ 1181fd558d18SJames Chapman int l2tp_xmit_skb(struct l2tp_session *session, struct sk_buff *skb, int hdr_len) 1182fd558d18SJames Chapman { 1183fd558d18SJames Chapman int data_len = skb->len; 11840d76751fSJames Chapman struct l2tp_tunnel *tunnel = session->tunnel; 11850d76751fSJames Chapman struct sock *sk = tunnel->sock; 1186d9d8da80SDavid S. Miller struct flowi *fl; 1187fd558d18SJames Chapman struct udphdr *uh; 1188fd558d18SJames Chapman struct inet_sock *inet; 1189fd558d18SJames Chapman __wsum csum; 1190fd558d18SJames Chapman int headroom; 11910d76751fSJames Chapman int uhlen = (tunnel->encap == L2TP_ENCAPTYPE_UDP) ? sizeof(struct udphdr) : 0; 11920d76751fSJames Chapman int udp_len; 1193b8c84307SEric Dumazet int ret = NET_XMIT_SUCCESS; 1194fd558d18SJames Chapman 1195fd558d18SJames Chapman /* Check that there's enough headroom in the skb to insert IP, 1196fd558d18SJames Chapman * UDP and L2TP headers. If not enough, expand it to 1197fd558d18SJames Chapman * make room. Adjust truesize. 1198fd558d18SJames Chapman */ 1199fd558d18SJames Chapman headroom = NET_SKB_PAD + sizeof(struct iphdr) + 12000d76751fSJames Chapman uhlen + hdr_len; 1201835acf5dSEric Dumazet if (skb_cow_head(skb, headroom)) { 1202b8c84307SEric Dumazet kfree_skb(skb); 1203b8c84307SEric Dumazet return NET_XMIT_DROP; 1204835acf5dSEric Dumazet } 1205fd558d18SJames Chapman 1206fd558d18SJames Chapman /* Setup L2TP header */ 1207f7faffa3SJames Chapman session->build_header(session, __skb_push(skb, hdr_len)); 1208fd558d18SJames Chapman 12090d76751fSJames Chapman /* Reset skb netfilter state */ 1210fd558d18SJames Chapman memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt)); 1211fd558d18SJames Chapman IPCB(skb)->flags &= ~(IPSKB_XFRM_TUNNEL_SIZE | IPSKB_XFRM_TRANSFORMED | 1212fd558d18SJames Chapman IPSKB_REROUTED); 1213fd558d18SJames Chapman nf_reset(skb); 1214fd558d18SJames Chapman 12156af88da1SDavid S. Miller bh_lock_sock(sk); 12166af88da1SDavid S. Miller if (sock_owned_by_user(sk)) { 1217b8c84307SEric Dumazet kfree_skb(skb); 1218b8c84307SEric Dumazet ret = NET_XMIT_DROP; 12196af88da1SDavid S. Miller goto out_unlock; 12206af88da1SDavid S. Miller } 12216af88da1SDavid S. Miller 1222fd558d18SJames Chapman /* Get routing info from the tunnel socket */ 1223fd558d18SJames Chapman skb_dst_drop(skb); 122471b1391aSFlorian Westphal skb_dst_set(skb, dst_clone(__sk_dst_check(sk, 0))); 12250d76751fSJames Chapman 1226d9d8da80SDavid S. Miller inet = inet_sk(sk); 1227d9d8da80SDavid S. Miller fl = &inet->cork.fl; 12280d76751fSJames Chapman switch (tunnel->encap) { 12290d76751fSJames Chapman case L2TP_ENCAPTYPE_UDP: 12300d76751fSJames Chapman /* Setup UDP header */ 12310d76751fSJames Chapman __skb_push(skb, sizeof(*uh)); 12320d76751fSJames Chapman skb_reset_transport_header(skb); 12330d76751fSJames Chapman uh = udp_hdr(skb); 12340d76751fSJames Chapman uh->source = inet->inet_sport; 12350d76751fSJames Chapman uh->dest = inet->inet_dport; 12360d76751fSJames Chapman udp_len = uhlen + hdr_len + data_len; 12370d76751fSJames Chapman uh->len = htons(udp_len); 12380d76751fSJames Chapman uh->check = 0; 1239fd558d18SJames Chapman 1240fd558d18SJames Chapman /* Calculate UDP checksum if configured to do so */ 1241d2cf3361SBenjamin LaHaise #if IS_ENABLED(CONFIG_IPV6) 1242e18503f4SFrançois Cachereul if (sk->sk_family == PF_INET6 && !tunnel->v4mapped) 1243d2cf3361SBenjamin LaHaise l2tp_xmit_ipv6_csum(sk, skb, udp_len); 1244d2cf3361SBenjamin LaHaise else 1245d2cf3361SBenjamin LaHaise #endif 1246fd558d18SJames Chapman if (sk->sk_no_check == UDP_CSUM_NOXMIT) 1247fd558d18SJames Chapman skb->ip_summed = CHECKSUM_NONE; 1248fd558d18SJames Chapman else if ((skb_dst(skb) && skb_dst(skb)->dev) && 1249fd558d18SJames Chapman (!(skb_dst(skb)->dev->features & NETIF_F_V4_CSUM))) { 1250fd558d18SJames Chapman skb->ip_summed = CHECKSUM_COMPLETE; 1251fd558d18SJames Chapman csum = skb_checksum(skb, 0, udp_len, 0); 1252fd558d18SJames Chapman uh->check = csum_tcpudp_magic(inet->inet_saddr, 1253fd558d18SJames Chapman inet->inet_daddr, 1254fd558d18SJames Chapman udp_len, IPPROTO_UDP, csum); 1255fd558d18SJames Chapman if (uh->check == 0) 1256fd558d18SJames Chapman uh->check = CSUM_MANGLED_0; 1257fd558d18SJames Chapman } else { 1258fd558d18SJames Chapman skb->ip_summed = CHECKSUM_PARTIAL; 1259fd558d18SJames Chapman skb->csum_start = skb_transport_header(skb) - skb->head; 1260fd558d18SJames Chapman skb->csum_offset = offsetof(struct udphdr, check); 1261fd558d18SJames Chapman uh->check = ~csum_tcpudp_magic(inet->inet_saddr, 1262fd558d18SJames Chapman inet->inet_daddr, 1263fd558d18SJames Chapman udp_len, IPPROTO_UDP, 0); 1264fd558d18SJames Chapman } 12650d76751fSJames Chapman break; 12660d76751fSJames Chapman 12670d76751fSJames Chapman case L2TP_ENCAPTYPE_IP: 12680d76751fSJames Chapman break; 12690d76751fSJames Chapman } 12700d76751fSJames Chapman 1271d9d8da80SDavid S. Miller l2tp_xmit_core(session, skb, fl, data_len); 12726af88da1SDavid S. Miller out_unlock: 12736af88da1SDavid S. Miller bh_unlock_sock(sk); 1274fd558d18SJames Chapman 1275b8c84307SEric Dumazet return ret; 1276fd558d18SJames Chapman } 1277fd558d18SJames Chapman EXPORT_SYMBOL_GPL(l2tp_xmit_skb); 1278fd558d18SJames Chapman 1279fd558d18SJames Chapman /***************************************************************************** 1280fd558d18SJames Chapman * Tinnel and session create/destroy. 1281fd558d18SJames Chapman *****************************************************************************/ 1282fd558d18SJames Chapman 1283fd558d18SJames Chapman /* Tunnel socket destruct hook. 1284fd558d18SJames Chapman * The tunnel context is deleted only when all session sockets have been 1285fd558d18SJames Chapman * closed. 1286fd558d18SJames Chapman */ 1287fc130840Sstephen hemminger static void l2tp_tunnel_destruct(struct sock *sk) 1288fd558d18SJames Chapman { 12898d8a51e2SDavid S. Miller struct l2tp_tunnel *tunnel = l2tp_tunnel(sk); 1290f8ccac0eSTom Parkin struct l2tp_net *pn; 1291fd558d18SJames Chapman 1292fd558d18SJames Chapman if (tunnel == NULL) 1293fd558d18SJames Chapman goto end; 1294fd558d18SJames Chapman 1295a4ca44faSJoe Perches l2tp_info(tunnel, L2TP_MSG_CONTROL, "%s: closing...\n", tunnel->name); 1296fd558d18SJames Chapman 1297fd558d18SJames Chapman 1298f8ccac0eSTom Parkin /* Disable udp encapsulation */ 12990d76751fSJames Chapman switch (tunnel->encap) { 13000d76751fSJames Chapman case L2TP_ENCAPTYPE_UDP: 1301fd558d18SJames Chapman /* No longer an encapsulation socket. See net/ipv4/udp.c */ 1302fd558d18SJames Chapman (udp_sk(sk))->encap_type = 0; 1303fd558d18SJames Chapman (udp_sk(sk))->encap_rcv = NULL; 13049980d001STom Parkin (udp_sk(sk))->encap_destroy = NULL; 13050d76751fSJames Chapman break; 13060d76751fSJames Chapman case L2TP_ENCAPTYPE_IP: 13070d76751fSJames Chapman break; 13080d76751fSJames Chapman } 1309fd558d18SJames Chapman 1310fd558d18SJames Chapman /* Remove hooks into tunnel socket */ 1311fd558d18SJames Chapman sk->sk_destruct = tunnel->old_sk_destruct; 1312fd558d18SJames Chapman sk->sk_user_data = NULL; 1313f8ccac0eSTom Parkin tunnel->sock = NULL; 1314f8ccac0eSTom Parkin 1315f8ccac0eSTom Parkin /* Remove the tunnel struct from the tunnel list */ 1316f8ccac0eSTom Parkin pn = l2tp_pernet(tunnel->l2tp_net); 1317f8ccac0eSTom Parkin spin_lock_bh(&pn->l2tp_tunnel_list_lock); 1318f8ccac0eSTom Parkin list_del_rcu(&tunnel->list); 1319f8ccac0eSTom Parkin spin_unlock_bh(&pn->l2tp_tunnel_list_lock); 1320f8ccac0eSTom Parkin atomic_dec(&l2tp_tunnel_count); 1321f8ccac0eSTom Parkin 1322f8ccac0eSTom Parkin l2tp_tunnel_closeall(tunnel); 1323f8ccac0eSTom Parkin l2tp_tunnel_dec_refcount(tunnel); 1324fd558d18SJames Chapman 1325fd558d18SJames Chapman /* Call the original destructor */ 1326fd558d18SJames Chapman if (sk->sk_destruct) 1327fd558d18SJames Chapman (*sk->sk_destruct)(sk); 1328fd558d18SJames Chapman end: 1329fd558d18SJames Chapman return; 1330fd558d18SJames Chapman } 1331fd558d18SJames Chapman 1332fd558d18SJames Chapman /* When the tunnel is closed, all the attached sessions need to go too. 1333fd558d18SJames Chapman */ 1334e34f4c70STom Parkin void l2tp_tunnel_closeall(struct l2tp_tunnel *tunnel) 1335fd558d18SJames Chapman { 1336fd558d18SJames Chapman int hash; 1337fd558d18SJames Chapman struct hlist_node *walk; 1338fd558d18SJames Chapman struct hlist_node *tmp; 1339fd558d18SJames Chapman struct l2tp_session *session; 1340fd558d18SJames Chapman 1341fd558d18SJames Chapman BUG_ON(tunnel == NULL); 1342fd558d18SJames Chapman 1343a4ca44faSJoe Perches l2tp_info(tunnel, L2TP_MSG_CONTROL, "%s: closing all sessions...\n", 1344a4ca44faSJoe Perches tunnel->name); 1345fd558d18SJames Chapman 1346fd558d18SJames Chapman write_lock_bh(&tunnel->hlist_lock); 1347fd558d18SJames Chapman for (hash = 0; hash < L2TP_HASH_SIZE; hash++) { 1348fd558d18SJames Chapman again: 1349fd558d18SJames Chapman hlist_for_each_safe(walk, tmp, &tunnel->session_hlist[hash]) { 1350fd558d18SJames Chapman session = hlist_entry(walk, struct l2tp_session, hlist); 1351fd558d18SJames Chapman 1352a4ca44faSJoe Perches l2tp_info(session, L2TP_MSG_CONTROL, 1353fd558d18SJames Chapman "%s: closing session\n", session->name); 1354fd558d18SJames Chapman 1355fd558d18SJames Chapman hlist_del_init(&session->hlist); 1356fd558d18SJames Chapman 1357fd558d18SJames Chapman if (session->ref != NULL) 1358fd558d18SJames Chapman (*session->ref)(session); 1359fd558d18SJames Chapman 1360fd558d18SJames Chapman write_unlock_bh(&tunnel->hlist_lock); 1361fd558d18SJames Chapman 1362f6e16b29STom Parkin __l2tp_session_unhash(session); 13634c6e2fd3STom Parkin l2tp_session_queue_purge(session); 13644c6e2fd3STom Parkin 1365fd558d18SJames Chapman if (session->session_close != NULL) 1366fd558d18SJames Chapman (*session->session_close)(session); 1367fd558d18SJames Chapman 1368fd558d18SJames Chapman if (session->deref != NULL) 1369fd558d18SJames Chapman (*session->deref)(session); 1370fd558d18SJames Chapman 13719980d001STom Parkin l2tp_session_dec_refcount(session); 13729980d001STom Parkin 1373fd558d18SJames Chapman write_lock_bh(&tunnel->hlist_lock); 1374fd558d18SJames Chapman 1375fd558d18SJames Chapman /* Now restart from the beginning of this hash 1376fd558d18SJames Chapman * chain. We always remove a session from the 1377fd558d18SJames Chapman * list so we are guaranteed to make forward 1378fd558d18SJames Chapman * progress. 1379fd558d18SJames Chapman */ 1380fd558d18SJames Chapman goto again; 1381fd558d18SJames Chapman } 1382fd558d18SJames Chapman } 1383fd558d18SJames Chapman write_unlock_bh(&tunnel->hlist_lock); 1384fd558d18SJames Chapman } 1385e34f4c70STom Parkin EXPORT_SYMBOL_GPL(l2tp_tunnel_closeall); 1386fd558d18SJames Chapman 13879980d001STom Parkin /* Tunnel socket destroy hook for UDP encapsulation */ 13889980d001STom Parkin static void l2tp_udp_encap_destroy(struct sock *sk) 13899980d001STom Parkin { 13909980d001STom Parkin struct l2tp_tunnel *tunnel = l2tp_sock_to_tunnel(sk); 13919980d001STom Parkin if (tunnel) { 13929980d001STom Parkin l2tp_tunnel_closeall(tunnel); 13939980d001STom Parkin sock_put(sk); 13949980d001STom Parkin } 13959980d001STom Parkin } 13969980d001STom Parkin 1397fd558d18SJames Chapman /* Really kill the tunnel. 1398fd558d18SJames Chapman * Come here only when all sessions have been cleared from the tunnel. 1399fd558d18SJames Chapman */ 1400fc130840Sstephen hemminger static void l2tp_tunnel_free(struct l2tp_tunnel *tunnel) 1401fd558d18SJames Chapman { 1402fd558d18SJames Chapman BUG_ON(atomic_read(&tunnel->ref_count) != 0); 1403fd558d18SJames Chapman BUG_ON(tunnel->sock != NULL); 1404a4ca44faSJoe Perches l2tp_info(tunnel, L2TP_MSG_CONTROL, "%s: free...\n", tunnel->name); 140599469c32Sxeb@mail.ru kfree_rcu(tunnel, rcu); 1406f8ccac0eSTom Parkin } 1407fd558d18SJames Chapman 1408f8ccac0eSTom Parkin /* Workqueue tunnel deletion function */ 1409f8ccac0eSTom Parkin static void l2tp_tunnel_del_work(struct work_struct *work) 1410f8ccac0eSTom Parkin { 1411f8ccac0eSTom Parkin struct l2tp_tunnel *tunnel = NULL; 1412f8ccac0eSTom Parkin struct socket *sock = NULL; 1413f8ccac0eSTom Parkin struct sock *sk = NULL; 1414f8ccac0eSTom Parkin 1415f8ccac0eSTom Parkin tunnel = container_of(work, struct l2tp_tunnel, del_work); 1416f8ccac0eSTom Parkin sk = l2tp_tunnel_sock_lookup(tunnel); 1417f8ccac0eSTom Parkin if (!sk) 1418f8ccac0eSTom Parkin return; 1419f8ccac0eSTom Parkin 1420f8ccac0eSTom Parkin sock = sk->sk_socket; 1421f8ccac0eSTom Parkin 142202d13ed5STom Parkin /* If the tunnel socket was created by userspace, then go through the 142302d13ed5STom Parkin * inet layer to shut the socket down, and let userspace close it. 142402d13ed5STom Parkin * Otherwise, if we created the socket directly within the kernel, use 142502d13ed5STom Parkin * the sk API to release it here. 1426167eb17eSTom Parkin * In either case the tunnel resources are freed in the socket 1427167eb17eSTom Parkin * destructor when the tunnel socket goes away. 1428f8ccac0eSTom Parkin */ 142902d13ed5STom Parkin if (tunnel->fd >= 0) { 143002d13ed5STom Parkin if (sock) 143102d13ed5STom Parkin inet_shutdown(sock, 2); 143202d13ed5STom Parkin } else { 143302d13ed5STom Parkin if (sock) 1434167eb17eSTom Parkin kernel_sock_shutdown(sock, SHUT_RDWR); 1435167eb17eSTom Parkin sk_release_kernel(sk); 1436167eb17eSTom Parkin } 1437f8ccac0eSTom Parkin 1438f8ccac0eSTom Parkin l2tp_tunnel_sock_put(sk); 1439fd558d18SJames Chapman } 1440fd558d18SJames Chapman 1441789a4a2cSJames Chapman /* Create a socket for the tunnel, if one isn't set up by 1442789a4a2cSJames Chapman * userspace. This is used for static tunnels where there is no 1443789a4a2cSJames Chapman * managing L2TP daemon. 1444167eb17eSTom Parkin * 1445167eb17eSTom Parkin * Since we don't want these sockets to keep a namespace alive by 1446167eb17eSTom Parkin * themselves, we drop the socket's namespace refcount after creation. 1447167eb17eSTom Parkin * These sockets are freed when the namespace exits using the pernet 1448167eb17eSTom Parkin * exit hook. 1449789a4a2cSJames Chapman */ 1450167eb17eSTom Parkin static int l2tp_tunnel_sock_create(struct net *net, 1451167eb17eSTom Parkin u32 tunnel_id, 1452167eb17eSTom Parkin u32 peer_tunnel_id, 1453167eb17eSTom Parkin struct l2tp_tunnel_cfg *cfg, 1454167eb17eSTom Parkin struct socket **sockp) 1455789a4a2cSJames Chapman { 1456789a4a2cSJames Chapman int err = -EINVAL; 14577bddd0dbSEric Dumazet struct socket *sock = NULL; 1458167eb17eSTom Parkin struct sockaddr_in udp_addr = {0}; 1459167eb17eSTom Parkin struct sockaddr_l2tpip ip_addr = {0}; 1460167eb17eSTom Parkin #if IS_ENABLED(CONFIG_IPV6) 1461167eb17eSTom Parkin struct sockaddr_in6 udp6_addr = {0}; 1462167eb17eSTom Parkin struct sockaddr_l2tpip6 ip6_addr = {0}; 1463167eb17eSTom Parkin #endif 1464789a4a2cSJames Chapman 1465789a4a2cSJames Chapman switch (cfg->encap) { 1466789a4a2cSJames Chapman case L2TP_ENCAPTYPE_UDP: 1467f9bac8dfSChris Elston #if IS_ENABLED(CONFIG_IPV6) 1468f9bac8dfSChris Elston if (cfg->local_ip6 && cfg->peer_ip6) { 1469167eb17eSTom Parkin err = sock_create_kern(AF_INET6, SOCK_DGRAM, 0, &sock); 1470f9bac8dfSChris Elston if (err < 0) 1471f9bac8dfSChris Elston goto out; 1472f9bac8dfSChris Elston 1473167eb17eSTom Parkin sk_change_net(sock->sk, net); 1474f9bac8dfSChris Elston 1475f9bac8dfSChris Elston udp6_addr.sin6_family = AF_INET6; 1476f9bac8dfSChris Elston memcpy(&udp6_addr.sin6_addr, cfg->local_ip6, 1477f9bac8dfSChris Elston sizeof(udp6_addr.sin6_addr)); 1478f9bac8dfSChris Elston udp6_addr.sin6_port = htons(cfg->local_udp_port); 1479f9bac8dfSChris Elston err = kernel_bind(sock, (struct sockaddr *) &udp6_addr, 1480f9bac8dfSChris Elston sizeof(udp6_addr)); 1481f9bac8dfSChris Elston if (err < 0) 1482f9bac8dfSChris Elston goto out; 1483f9bac8dfSChris Elston 1484f9bac8dfSChris Elston udp6_addr.sin6_family = AF_INET6; 1485f9bac8dfSChris Elston memcpy(&udp6_addr.sin6_addr, cfg->peer_ip6, 1486f9bac8dfSChris Elston sizeof(udp6_addr.sin6_addr)); 1487f9bac8dfSChris Elston udp6_addr.sin6_port = htons(cfg->peer_udp_port); 1488f9bac8dfSChris Elston err = kernel_connect(sock, 1489f9bac8dfSChris Elston (struct sockaddr *) &udp6_addr, 1490f9bac8dfSChris Elston sizeof(udp6_addr), 0); 1491f9bac8dfSChris Elston if (err < 0) 1492f9bac8dfSChris Elston goto out; 1493f9bac8dfSChris Elston } else 1494f9bac8dfSChris Elston #endif 1495f9bac8dfSChris Elston { 1496167eb17eSTom Parkin err = sock_create_kern(AF_INET, SOCK_DGRAM, 0, &sock); 1497789a4a2cSJames Chapman if (err < 0) 1498789a4a2cSJames Chapman goto out; 1499789a4a2cSJames Chapman 1500167eb17eSTom Parkin sk_change_net(sock->sk, net); 1501789a4a2cSJames Chapman 1502789a4a2cSJames Chapman udp_addr.sin_family = AF_INET; 1503789a4a2cSJames Chapman udp_addr.sin_addr = cfg->local_ip; 1504789a4a2cSJames Chapman udp_addr.sin_port = htons(cfg->local_udp_port); 1505f9bac8dfSChris Elston err = kernel_bind(sock, (struct sockaddr *) &udp_addr, 1506f9bac8dfSChris Elston sizeof(udp_addr)); 1507789a4a2cSJames Chapman if (err < 0) 1508789a4a2cSJames Chapman goto out; 1509789a4a2cSJames Chapman 1510789a4a2cSJames Chapman udp_addr.sin_family = AF_INET; 1511789a4a2cSJames Chapman udp_addr.sin_addr = cfg->peer_ip; 1512789a4a2cSJames Chapman udp_addr.sin_port = htons(cfg->peer_udp_port); 1513f9bac8dfSChris Elston err = kernel_connect(sock, 1514f9bac8dfSChris Elston (struct sockaddr *) &udp_addr, 1515f9bac8dfSChris Elston sizeof(udp_addr), 0); 1516789a4a2cSJames Chapman if (err < 0) 1517789a4a2cSJames Chapman goto out; 1518f9bac8dfSChris Elston } 1519789a4a2cSJames Chapman 1520789a4a2cSJames Chapman if (!cfg->use_udp_checksums) 1521789a4a2cSJames Chapman sock->sk->sk_no_check = UDP_CSUM_NOXMIT; 1522789a4a2cSJames Chapman 1523789a4a2cSJames Chapman break; 1524789a4a2cSJames Chapman 1525789a4a2cSJames Chapman case L2TP_ENCAPTYPE_IP: 1526f9bac8dfSChris Elston #if IS_ENABLED(CONFIG_IPV6) 1527f9bac8dfSChris Elston if (cfg->local_ip6 && cfg->peer_ip6) { 1528167eb17eSTom Parkin err = sock_create_kern(AF_INET6, SOCK_DGRAM, 1529167eb17eSTom Parkin IPPROTO_L2TP, &sock); 15305dac94e1SJames Chapman if (err < 0) 1531f9bac8dfSChris Elston goto out; 15325dac94e1SJames Chapman 1533167eb17eSTom Parkin sk_change_net(sock->sk, net); 15345dac94e1SJames Chapman 15355dac94e1SJames Chapman ip6_addr.l2tp_family = AF_INET6; 15365dac94e1SJames Chapman memcpy(&ip6_addr.l2tp_addr, cfg->local_ip6, 15375dac94e1SJames Chapman sizeof(ip6_addr.l2tp_addr)); 15385dac94e1SJames Chapman ip6_addr.l2tp_conn_id = tunnel_id; 15395dac94e1SJames Chapman err = kernel_bind(sock, (struct sockaddr *) &ip6_addr, 15405dac94e1SJames Chapman sizeof(ip6_addr)); 15415dac94e1SJames Chapman if (err < 0) 15425dac94e1SJames Chapman goto out; 15435dac94e1SJames Chapman 15445dac94e1SJames Chapman ip6_addr.l2tp_family = AF_INET6; 15455dac94e1SJames Chapman memcpy(&ip6_addr.l2tp_addr, cfg->peer_ip6, 15465dac94e1SJames Chapman sizeof(ip6_addr.l2tp_addr)); 15475dac94e1SJames Chapman ip6_addr.l2tp_conn_id = peer_tunnel_id; 15485dac94e1SJames Chapman err = kernel_connect(sock, 15495dac94e1SJames Chapman (struct sockaddr *) &ip6_addr, 15505dac94e1SJames Chapman sizeof(ip6_addr), 0); 15515dac94e1SJames Chapman if (err < 0) 15525dac94e1SJames Chapman goto out; 15535dac94e1SJames Chapman } else 1554f9bac8dfSChris Elston #endif 15555dac94e1SJames Chapman { 1556167eb17eSTom Parkin err = sock_create_kern(AF_INET, SOCK_DGRAM, 1557167eb17eSTom Parkin IPPROTO_L2TP, &sock); 1558789a4a2cSJames Chapman if (err < 0) 1559789a4a2cSJames Chapman goto out; 1560789a4a2cSJames Chapman 1561167eb17eSTom Parkin sk_change_net(sock->sk, net); 1562789a4a2cSJames Chapman 1563789a4a2cSJames Chapman ip_addr.l2tp_family = AF_INET; 1564789a4a2cSJames Chapman ip_addr.l2tp_addr = cfg->local_ip; 1565789a4a2cSJames Chapman ip_addr.l2tp_conn_id = tunnel_id; 15665dac94e1SJames Chapman err = kernel_bind(sock, (struct sockaddr *) &ip_addr, 15675dac94e1SJames Chapman sizeof(ip_addr)); 1568789a4a2cSJames Chapman if (err < 0) 1569789a4a2cSJames Chapman goto out; 1570789a4a2cSJames Chapman 1571789a4a2cSJames Chapman ip_addr.l2tp_family = AF_INET; 1572789a4a2cSJames Chapman ip_addr.l2tp_addr = cfg->peer_ip; 1573789a4a2cSJames Chapman ip_addr.l2tp_conn_id = peer_tunnel_id; 15745dac94e1SJames Chapman err = kernel_connect(sock, (struct sockaddr *) &ip_addr, 15755dac94e1SJames Chapman sizeof(ip_addr), 0); 1576789a4a2cSJames Chapman if (err < 0) 1577789a4a2cSJames Chapman goto out; 15785dac94e1SJames Chapman } 1579789a4a2cSJames Chapman break; 1580789a4a2cSJames Chapman 1581789a4a2cSJames Chapman default: 1582789a4a2cSJames Chapman goto out; 1583789a4a2cSJames Chapman } 1584789a4a2cSJames Chapman 1585789a4a2cSJames Chapman out: 1586167eb17eSTom Parkin *sockp = sock; 1587789a4a2cSJames Chapman if ((err < 0) && sock) { 1588167eb17eSTom Parkin kernel_sock_shutdown(sock, SHUT_RDWR); 1589167eb17eSTom Parkin sk_release_kernel(sock->sk); 1590789a4a2cSJames Chapman *sockp = NULL; 1591789a4a2cSJames Chapman } 1592789a4a2cSJames Chapman 1593789a4a2cSJames Chapman return err; 1594789a4a2cSJames Chapman } 1595789a4a2cSJames Chapman 159637159ef2SEric Dumazet static struct lock_class_key l2tp_socket_class; 159737159ef2SEric Dumazet 1598fd558d18SJames Chapman int l2tp_tunnel_create(struct net *net, int fd, int version, u32 tunnel_id, u32 peer_tunnel_id, struct l2tp_tunnel_cfg *cfg, struct l2tp_tunnel **tunnelp) 1599fd558d18SJames Chapman { 1600fd558d18SJames Chapman struct l2tp_tunnel *tunnel = NULL; 1601fd558d18SJames Chapman int err; 1602fd558d18SJames Chapman struct socket *sock = NULL; 1603fd558d18SJames Chapman struct sock *sk = NULL; 1604fd558d18SJames Chapman struct l2tp_net *pn; 16050d76751fSJames Chapman enum l2tp_encap_type encap = L2TP_ENCAPTYPE_UDP; 1606fd558d18SJames Chapman 1607fd558d18SJames Chapman /* Get the tunnel socket from the fd, which was opened by 1608789a4a2cSJames Chapman * the userspace L2TP daemon. If not specified, create a 1609789a4a2cSJames Chapman * kernel socket. 1610fd558d18SJames Chapman */ 1611789a4a2cSJames Chapman if (fd < 0) { 1612167eb17eSTom Parkin err = l2tp_tunnel_sock_create(net, tunnel_id, peer_tunnel_id, 1613167eb17eSTom Parkin cfg, &sock); 1614789a4a2cSJames Chapman if (err < 0) 1615789a4a2cSJames Chapman goto err; 1616789a4a2cSJames Chapman } else { 1617fd558d18SJames Chapman sock = sockfd_lookup(fd, &err); 1618fd558d18SJames Chapman if (!sock) { 1619cbb95e0cSTom Parkin pr_err("tunl %u: sockfd_lookup(fd=%d) returned %d\n", 1620fd558d18SJames Chapman tunnel_id, fd, err); 1621cbb95e0cSTom Parkin err = -EBADF; 1622cbb95e0cSTom Parkin goto err; 1623cbb95e0cSTom Parkin } 1624cbb95e0cSTom Parkin 1625cbb95e0cSTom Parkin /* Reject namespace mismatches */ 1626cbb95e0cSTom Parkin if (!net_eq(sock_net(sock->sk), net)) { 1627cbb95e0cSTom Parkin pr_err("tunl %u: netns mismatch\n", tunnel_id); 1628cbb95e0cSTom Parkin err = -EINVAL; 1629fd558d18SJames Chapman goto err; 1630fd558d18SJames Chapman } 1631789a4a2cSJames Chapman } 1632fd558d18SJames Chapman 1633fd558d18SJames Chapman sk = sock->sk; 1634fd558d18SJames Chapman 16350d76751fSJames Chapman if (cfg != NULL) 16360d76751fSJames Chapman encap = cfg->encap; 16370d76751fSJames Chapman 1638fd558d18SJames Chapman /* Quick sanity checks */ 16390d76751fSJames Chapman switch (encap) { 16400d76751fSJames Chapman case L2TP_ENCAPTYPE_UDP: 1641fd558d18SJames Chapman err = -EPROTONOSUPPORT; 1642fd558d18SJames Chapman if (sk->sk_protocol != IPPROTO_UDP) { 1643a4ca44faSJoe Perches pr_err("tunl %hu: fd %d wrong protocol, got %d, expected %d\n", 1644fd558d18SJames Chapman tunnel_id, fd, sk->sk_protocol, IPPROTO_UDP); 1645fd558d18SJames Chapman goto err; 1646fd558d18SJames Chapman } 16470d76751fSJames Chapman break; 16480d76751fSJames Chapman case L2TP_ENCAPTYPE_IP: 16490d76751fSJames Chapman err = -EPROTONOSUPPORT; 16500d76751fSJames Chapman if (sk->sk_protocol != IPPROTO_L2TP) { 1651a4ca44faSJoe Perches pr_err("tunl %hu: fd %d wrong protocol, got %d, expected %d\n", 16520d76751fSJames Chapman tunnel_id, fd, sk->sk_protocol, IPPROTO_L2TP); 1653fd558d18SJames Chapman goto err; 1654fd558d18SJames Chapman } 16550d76751fSJames Chapman break; 16560d76751fSJames Chapman } 1657fd558d18SJames Chapman 1658fd558d18SJames Chapman /* Check if this socket has already been prepped */ 16598d8a51e2SDavid S. Miller tunnel = l2tp_tunnel(sk); 1660fd558d18SJames Chapman if (tunnel != NULL) { 1661fd558d18SJames Chapman /* This socket has already been prepped */ 1662fd558d18SJames Chapman err = -EBUSY; 1663fd558d18SJames Chapman goto err; 1664fd558d18SJames Chapman } 1665fd558d18SJames Chapman 1666fd558d18SJames Chapman tunnel = kzalloc(sizeof(struct l2tp_tunnel), GFP_KERNEL); 1667fd558d18SJames Chapman if (tunnel == NULL) { 1668fd558d18SJames Chapman err = -ENOMEM; 1669fd558d18SJames Chapman goto err; 1670fd558d18SJames Chapman } 1671fd558d18SJames Chapman 1672fd558d18SJames Chapman tunnel->version = version; 1673fd558d18SJames Chapman tunnel->tunnel_id = tunnel_id; 1674fd558d18SJames Chapman tunnel->peer_tunnel_id = peer_tunnel_id; 1675fd558d18SJames Chapman tunnel->debug = L2TP_DEFAULT_DEBUG_FLAGS; 1676fd558d18SJames Chapman 1677fd558d18SJames Chapman tunnel->magic = L2TP_TUNNEL_MAGIC; 1678fd558d18SJames Chapman sprintf(&tunnel->name[0], "tunl %u", tunnel_id); 1679fd558d18SJames Chapman rwlock_init(&tunnel->hlist_lock); 1680fd558d18SJames Chapman 1681fd558d18SJames Chapman /* The net we belong to */ 1682fd558d18SJames Chapman tunnel->l2tp_net = net; 1683fd558d18SJames Chapman pn = l2tp_pernet(net); 1684fd558d18SJames Chapman 16850d76751fSJames Chapman if (cfg != NULL) 1686fd558d18SJames Chapman tunnel->debug = cfg->debug; 1687fd558d18SJames Chapman 1688e18503f4SFrançois Cachereul #if IS_ENABLED(CONFIG_IPV6) 1689e18503f4SFrançois Cachereul if (sk->sk_family == PF_INET6) { 1690e18503f4SFrançois Cachereul struct ipv6_pinfo *np = inet6_sk(sk); 1691e18503f4SFrançois Cachereul 1692e18503f4SFrançois Cachereul if (ipv6_addr_v4mapped(&np->saddr) && 1693efe4208fSEric Dumazet ipv6_addr_v4mapped(&sk->sk_v6_daddr)) { 1694e18503f4SFrançois Cachereul struct inet_sock *inet = inet_sk(sk); 1695e18503f4SFrançois Cachereul 1696e18503f4SFrançois Cachereul tunnel->v4mapped = true; 1697e18503f4SFrançois Cachereul inet->inet_saddr = np->saddr.s6_addr32[3]; 1698efe4208fSEric Dumazet inet->inet_rcv_saddr = sk->sk_v6_rcv_saddr.s6_addr32[3]; 1699efe4208fSEric Dumazet inet->inet_daddr = sk->sk_v6_daddr.s6_addr32[3]; 1700e18503f4SFrançois Cachereul } else { 1701e18503f4SFrançois Cachereul tunnel->v4mapped = false; 1702e18503f4SFrançois Cachereul } 1703e18503f4SFrançois Cachereul } 1704e18503f4SFrançois Cachereul #endif 1705e18503f4SFrançois Cachereul 1706fd558d18SJames Chapman /* Mark socket as an encapsulation socket. See net/ipv4/udp.c */ 17070d76751fSJames Chapman tunnel->encap = encap; 17080d76751fSJames Chapman if (encap == L2TP_ENCAPTYPE_UDP) { 17090d76751fSJames Chapman /* Mark socket as an encapsulation socket. See net/ipv4/udp.c */ 1710fd558d18SJames Chapman udp_sk(sk)->encap_type = UDP_ENCAP_L2TPINUDP; 1711fd558d18SJames Chapman udp_sk(sk)->encap_rcv = l2tp_udp_encap_recv; 17129980d001STom Parkin udp_sk(sk)->encap_destroy = l2tp_udp_encap_destroy; 1713d2cf3361SBenjamin LaHaise #if IS_ENABLED(CONFIG_IPV6) 1714e18503f4SFrançois Cachereul if (sk->sk_family == PF_INET6 && !tunnel->v4mapped) 1715d2cf3361SBenjamin LaHaise udpv6_encap_enable(); 1716d2cf3361SBenjamin LaHaise else 1717d2cf3361SBenjamin LaHaise #endif 1718447167bfSEric Dumazet udp_encap_enable(); 17190d76751fSJames Chapman } 1720fd558d18SJames Chapman 1721fd558d18SJames Chapman sk->sk_user_data = tunnel; 1722fd558d18SJames Chapman 1723fd558d18SJames Chapman /* Hook on the tunnel socket destructor so that we can cleanup 1724fd558d18SJames Chapman * if the tunnel socket goes away. 1725fd558d18SJames Chapman */ 1726fd558d18SJames Chapman tunnel->old_sk_destruct = sk->sk_destruct; 1727fd558d18SJames Chapman sk->sk_destruct = &l2tp_tunnel_destruct; 1728fd558d18SJames Chapman tunnel->sock = sk; 172980d84ef3STom Parkin tunnel->fd = fd; 173037159ef2SEric Dumazet lockdep_set_class_and_name(&sk->sk_lock.slock, &l2tp_socket_class, "l2tp_sock"); 173137159ef2SEric Dumazet 1732fd558d18SJames Chapman sk->sk_allocation = GFP_ATOMIC; 1733fd558d18SJames Chapman 1734f8ccac0eSTom Parkin /* Init delete workqueue struct */ 1735f8ccac0eSTom Parkin INIT_WORK(&tunnel->del_work, l2tp_tunnel_del_work); 1736f8ccac0eSTom Parkin 1737fd558d18SJames Chapman /* Add tunnel to our list */ 1738fd558d18SJames Chapman INIT_LIST_HEAD(&tunnel->list); 1739fd558d18SJames Chapman atomic_inc(&l2tp_tunnel_count); 1740fd558d18SJames Chapman 1741fd558d18SJames Chapman /* Bump the reference count. The tunnel context is deleted 17421769192aSEric Dumazet * only when this drops to zero. Must be done before list insertion 1743fd558d18SJames Chapman */ 1744fd558d18SJames Chapman l2tp_tunnel_inc_refcount(tunnel); 17451769192aSEric Dumazet spin_lock_bh(&pn->l2tp_tunnel_list_lock); 17461769192aSEric Dumazet list_add_rcu(&tunnel->list, &pn->l2tp_tunnel_list); 17471769192aSEric Dumazet spin_unlock_bh(&pn->l2tp_tunnel_list_lock); 1748fd558d18SJames Chapman 1749fd558d18SJames Chapman err = 0; 1750fd558d18SJames Chapman err: 1751fd558d18SJames Chapman if (tunnelp) 1752fd558d18SJames Chapman *tunnelp = tunnel; 1753fd558d18SJames Chapman 1754789a4a2cSJames Chapman /* If tunnel's socket was created by the kernel, it doesn't 1755789a4a2cSJames Chapman * have a file. 1756789a4a2cSJames Chapman */ 1757789a4a2cSJames Chapman if (sock && sock->file) 1758fd558d18SJames Chapman sockfd_put(sock); 1759fd558d18SJames Chapman 1760fd558d18SJames Chapman return err; 1761fd558d18SJames Chapman } 1762fd558d18SJames Chapman EXPORT_SYMBOL_GPL(l2tp_tunnel_create); 1763fd558d18SJames Chapman 1764309795f4SJames Chapman /* This function is used by the netlink TUNNEL_DELETE command. 1765309795f4SJames Chapman */ 1766309795f4SJames Chapman int l2tp_tunnel_delete(struct l2tp_tunnel *tunnel) 1767309795f4SJames Chapman { 17682b551c6eSTom Parkin l2tp_tunnel_closeall(tunnel); 1769f8ccac0eSTom Parkin return (false == queue_work(l2tp_wq, &tunnel->del_work)); 1770309795f4SJames Chapman } 1771309795f4SJames Chapman EXPORT_SYMBOL_GPL(l2tp_tunnel_delete); 1772309795f4SJames Chapman 1773fd558d18SJames Chapman /* Really kill the session. 1774fd558d18SJames Chapman */ 1775fd558d18SJames Chapman void l2tp_session_free(struct l2tp_session *session) 1776fd558d18SJames Chapman { 1777f6e16b29STom Parkin struct l2tp_tunnel *tunnel = session->tunnel; 1778fd558d18SJames Chapman 1779fd558d18SJames Chapman BUG_ON(atomic_read(&session->ref_count) != 0); 1780fd558d18SJames Chapman 1781f6e16b29STom Parkin if (tunnel) { 1782fd558d18SJames Chapman BUG_ON(tunnel->magic != L2TP_TUNNEL_MAGIC); 1783fd558d18SJames Chapman if (session->session_id != 0) 1784fd558d18SJames Chapman atomic_dec(&l2tp_session_count); 1785fd558d18SJames Chapman sock_put(tunnel->sock); 1786fd558d18SJames Chapman session->tunnel = NULL; 1787fd558d18SJames Chapman l2tp_tunnel_dec_refcount(tunnel); 1788fd558d18SJames Chapman } 1789fd558d18SJames Chapman 1790fd558d18SJames Chapman kfree(session); 1791fd558d18SJames Chapman } 1792fd558d18SJames Chapman EXPORT_SYMBOL_GPL(l2tp_session_free); 1793fd558d18SJames Chapman 1794f6e16b29STom Parkin /* Remove an l2tp session from l2tp_core's hash lists. 1795f6e16b29STom Parkin * Provides a tidyup interface for pseudowire code which can't just route all 1796f6e16b29STom Parkin * shutdown via. l2tp_session_delete and a pseudowire-specific session_close 1797f6e16b29STom Parkin * callback. 1798f6e16b29STom Parkin */ 1799f6e16b29STom Parkin void __l2tp_session_unhash(struct l2tp_session *session) 1800f6e16b29STom Parkin { 1801f6e16b29STom Parkin struct l2tp_tunnel *tunnel = session->tunnel; 1802f6e16b29STom Parkin 1803f6e16b29STom Parkin /* Remove the session from core hashes */ 1804f6e16b29STom Parkin if (tunnel) { 1805f6e16b29STom Parkin /* Remove from the per-tunnel hash */ 1806f6e16b29STom Parkin write_lock_bh(&tunnel->hlist_lock); 1807f6e16b29STom Parkin hlist_del_init(&session->hlist); 1808f6e16b29STom Parkin write_unlock_bh(&tunnel->hlist_lock); 1809f6e16b29STom Parkin 1810f6e16b29STom Parkin /* For L2TPv3 we have a per-net hash: remove from there, too */ 1811f6e16b29STom Parkin if (tunnel->version != L2TP_HDR_VER_2) { 1812f6e16b29STom Parkin struct l2tp_net *pn = l2tp_pernet(tunnel->l2tp_net); 1813f6e16b29STom Parkin spin_lock_bh(&pn->l2tp_session_hlist_lock); 1814f6e16b29STom Parkin hlist_del_init_rcu(&session->global_hlist); 1815f6e16b29STom Parkin spin_unlock_bh(&pn->l2tp_session_hlist_lock); 1816f6e16b29STom Parkin synchronize_rcu(); 1817f6e16b29STom Parkin } 1818f6e16b29STom Parkin } 1819f6e16b29STom Parkin } 1820f6e16b29STom Parkin EXPORT_SYMBOL_GPL(__l2tp_session_unhash); 1821f6e16b29STom Parkin 1822309795f4SJames Chapman /* This function is used by the netlink SESSION_DELETE command and by 1823309795f4SJames Chapman pseudowire modules. 1824309795f4SJames Chapman */ 1825309795f4SJames Chapman int l2tp_session_delete(struct l2tp_session *session) 1826309795f4SJames Chapman { 1827f6e16b29STom Parkin if (session->ref) 1828f6e16b29STom Parkin (*session->ref)(session); 1829f6e16b29STom Parkin __l2tp_session_unhash(session); 18304c6e2fd3STom Parkin l2tp_session_queue_purge(session); 1831309795f4SJames Chapman if (session->session_close != NULL) 1832309795f4SJames Chapman (*session->session_close)(session); 1833f6e16b29STom Parkin if (session->deref) 18341b7c92b9SDan Carpenter (*session->deref)(session); 1835309795f4SJames Chapman l2tp_session_dec_refcount(session); 1836309795f4SJames Chapman return 0; 1837309795f4SJames Chapman } 1838309795f4SJames Chapman EXPORT_SYMBOL_GPL(l2tp_session_delete); 1839309795f4SJames Chapman 1840f7faffa3SJames Chapman /* We come here whenever a session's send_seq, cookie_len or 1841f7faffa3SJames Chapman * l2specific_len parameters are set. 1842f7faffa3SJames Chapman */ 1843bb5016eaSGuillaume Nault void l2tp_session_set_header_len(struct l2tp_session *session, int version) 1844f7faffa3SJames Chapman { 1845f7faffa3SJames Chapman if (version == L2TP_HDR_VER_2) { 1846f7faffa3SJames Chapman session->hdr_len = 6; 1847f7faffa3SJames Chapman if (session->send_seq) 1848f7faffa3SJames Chapman session->hdr_len += 4; 1849f7faffa3SJames Chapman } else { 18500d76751fSJames Chapman session->hdr_len = 4 + session->cookie_len + session->l2specific_len + session->offset; 18510d76751fSJames Chapman if (session->tunnel->encap == L2TP_ENCAPTYPE_UDP) 18520d76751fSJames Chapman session->hdr_len += 4; 1853f7faffa3SJames Chapman } 1854f7faffa3SJames Chapman 1855f7faffa3SJames Chapman } 1856bb5016eaSGuillaume Nault EXPORT_SYMBOL_GPL(l2tp_session_set_header_len); 1857f7faffa3SJames Chapman 1858fd558d18SJames Chapman 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) 1859fd558d18SJames Chapman { 1860fd558d18SJames Chapman struct l2tp_session *session; 1861fd558d18SJames Chapman 1862fd558d18SJames Chapman session = kzalloc(sizeof(struct l2tp_session) + priv_size, GFP_KERNEL); 1863fd558d18SJames Chapman if (session != NULL) { 1864fd558d18SJames Chapman session->magic = L2TP_SESSION_MAGIC; 1865fd558d18SJames Chapman session->tunnel = tunnel; 1866fd558d18SJames Chapman 1867fd558d18SJames Chapman session->session_id = session_id; 1868fd558d18SJames Chapman session->peer_session_id = peer_session_id; 1869d301e325SJames Chapman session->nr = 0; 18708a1631d5SJames Chapman if (tunnel->version == L2TP_HDR_VER_2) 18718a1631d5SJames Chapman session->nr_max = 0xffff; 18728a1631d5SJames Chapman else 18738a1631d5SJames Chapman session->nr_max = 0xffffff; 18748a1631d5SJames Chapman session->nr_window_size = session->nr_max / 2; 1875a0dbd822SJames Chapman session->nr_oos_count_max = 4; 1876a0dbd822SJames Chapman 1877a0dbd822SJames Chapman /* Use NR of first received packet */ 1878a0dbd822SJames Chapman session->reorder_skip = 1; 1879fd558d18SJames Chapman 1880fd558d18SJames Chapman sprintf(&session->name[0], "sess %u/%u", 1881fd558d18SJames Chapman tunnel->tunnel_id, session->session_id); 1882fd558d18SJames Chapman 1883fd558d18SJames Chapman skb_queue_head_init(&session->reorder_q); 1884fd558d18SJames Chapman 1885fd558d18SJames Chapman INIT_HLIST_NODE(&session->hlist); 1886f7faffa3SJames Chapman INIT_HLIST_NODE(&session->global_hlist); 1887fd558d18SJames Chapman 1888fd558d18SJames Chapman /* Inherit debug options from tunnel */ 1889fd558d18SJames Chapman session->debug = tunnel->debug; 1890fd558d18SJames Chapman 1891fd558d18SJames Chapman if (cfg) { 1892f7faffa3SJames Chapman session->pwtype = cfg->pw_type; 1893fd558d18SJames Chapman session->debug = cfg->debug; 1894fd558d18SJames Chapman session->mtu = cfg->mtu; 1895fd558d18SJames Chapman session->mru = cfg->mru; 1896fd558d18SJames Chapman session->send_seq = cfg->send_seq; 1897fd558d18SJames Chapman session->recv_seq = cfg->recv_seq; 1898fd558d18SJames Chapman session->lns_mode = cfg->lns_mode; 1899f7faffa3SJames Chapman session->reorder_timeout = cfg->reorder_timeout; 1900f7faffa3SJames Chapman session->offset = cfg->offset; 1901f7faffa3SJames Chapman session->l2specific_type = cfg->l2specific_type; 1902f7faffa3SJames Chapman session->l2specific_len = cfg->l2specific_len; 1903f7faffa3SJames Chapman session->cookie_len = cfg->cookie_len; 1904f7faffa3SJames Chapman memcpy(&session->cookie[0], &cfg->cookie[0], cfg->cookie_len); 1905f7faffa3SJames Chapman session->peer_cookie_len = cfg->peer_cookie_len; 1906f7faffa3SJames Chapman memcpy(&session->peer_cookie[0], &cfg->peer_cookie[0], cfg->peer_cookie_len); 1907fd558d18SJames Chapman } 1908fd558d18SJames Chapman 1909f7faffa3SJames Chapman if (tunnel->version == L2TP_HDR_VER_2) 1910f7faffa3SJames Chapman session->build_header = l2tp_build_l2tpv2_header; 1911f7faffa3SJames Chapman else 1912f7faffa3SJames Chapman session->build_header = l2tp_build_l2tpv3_header; 1913f7faffa3SJames Chapman 1914f7faffa3SJames Chapman l2tp_session_set_header_len(session, tunnel->version); 1915f7faffa3SJames Chapman 1916fd558d18SJames Chapman /* Bump the reference count. The session context is deleted 1917fd558d18SJames Chapman * only when this drops to zero. 1918fd558d18SJames Chapman */ 1919fd558d18SJames Chapman l2tp_session_inc_refcount(session); 1920fd558d18SJames Chapman l2tp_tunnel_inc_refcount(tunnel); 1921fd558d18SJames Chapman 1922fd558d18SJames Chapman /* Ensure tunnel socket isn't deleted */ 1923fd558d18SJames Chapman sock_hold(tunnel->sock); 1924fd558d18SJames Chapman 1925fd558d18SJames Chapman /* Add session to the tunnel's hash list */ 1926fd558d18SJames Chapman write_lock_bh(&tunnel->hlist_lock); 1927fd558d18SJames Chapman hlist_add_head(&session->hlist, 1928fd558d18SJames Chapman l2tp_session_id_hash(tunnel, session_id)); 1929fd558d18SJames Chapman write_unlock_bh(&tunnel->hlist_lock); 1930fd558d18SJames Chapman 1931f7faffa3SJames Chapman /* And to the global session list if L2TPv3 */ 1932f7faffa3SJames Chapman if (tunnel->version != L2TP_HDR_VER_2) { 1933f7faffa3SJames Chapman struct l2tp_net *pn = l2tp_pernet(tunnel->l2tp_net); 1934f7faffa3SJames Chapman 1935e02d494dSJames Chapman spin_lock_bh(&pn->l2tp_session_hlist_lock); 1936e02d494dSJames Chapman hlist_add_head_rcu(&session->global_hlist, 1937f7faffa3SJames Chapman l2tp_session_id_hash_2(pn, session_id)); 1938e02d494dSJames Chapman spin_unlock_bh(&pn->l2tp_session_hlist_lock); 1939f7faffa3SJames Chapman } 1940f7faffa3SJames Chapman 1941fd558d18SJames Chapman /* Ignore management session in session count value */ 1942fd558d18SJames Chapman if (session->session_id != 0) 1943fd558d18SJames Chapman atomic_inc(&l2tp_session_count); 1944fd558d18SJames Chapman } 1945fd558d18SJames Chapman 1946fd558d18SJames Chapman return session; 1947fd558d18SJames Chapman } 1948fd558d18SJames Chapman EXPORT_SYMBOL_GPL(l2tp_session_create); 1949fd558d18SJames Chapman 1950fd558d18SJames Chapman /***************************************************************************** 1951fd558d18SJames Chapman * Init and cleanup 1952fd558d18SJames Chapman *****************************************************************************/ 1953fd558d18SJames Chapman 1954fd558d18SJames Chapman static __net_init int l2tp_init_net(struct net *net) 1955fd558d18SJames Chapman { 1956e773aaffSJiri Pirko struct l2tp_net *pn = net_generic(net, l2tp_net_id); 1957f7faffa3SJames Chapman int hash; 1958fd558d18SJames Chapman 1959fd558d18SJames Chapman INIT_LIST_HEAD(&pn->l2tp_tunnel_list); 1960e02d494dSJames Chapman spin_lock_init(&pn->l2tp_tunnel_list_lock); 1961fd558d18SJames Chapman 1962f7faffa3SJames Chapman for (hash = 0; hash < L2TP_HASH_SIZE_2; hash++) 1963f7faffa3SJames Chapman INIT_HLIST_HEAD(&pn->l2tp_session_hlist[hash]); 1964f7faffa3SJames Chapman 1965e02d494dSJames Chapman spin_lock_init(&pn->l2tp_session_hlist_lock); 1966f7faffa3SJames Chapman 1967fd558d18SJames Chapman return 0; 1968fd558d18SJames Chapman } 1969fd558d18SJames Chapman 1970167eb17eSTom Parkin static __net_exit void l2tp_exit_net(struct net *net) 1971167eb17eSTom Parkin { 1972167eb17eSTom Parkin struct l2tp_net *pn = l2tp_pernet(net); 1973167eb17eSTom Parkin struct l2tp_tunnel *tunnel = NULL; 1974167eb17eSTom Parkin 1975167eb17eSTom Parkin rcu_read_lock_bh(); 1976167eb17eSTom Parkin list_for_each_entry_rcu(tunnel, &pn->l2tp_tunnel_list, list) { 1977167eb17eSTom Parkin (void)l2tp_tunnel_delete(tunnel); 1978167eb17eSTom Parkin } 1979167eb17eSTom Parkin rcu_read_unlock_bh(); 1980167eb17eSTom Parkin } 1981167eb17eSTom Parkin 1982fd558d18SJames Chapman static struct pernet_operations l2tp_net_ops = { 1983fd558d18SJames Chapman .init = l2tp_init_net, 1984167eb17eSTom Parkin .exit = l2tp_exit_net, 1985fd558d18SJames Chapman .id = &l2tp_net_id, 1986fd558d18SJames Chapman .size = sizeof(struct l2tp_net), 1987fd558d18SJames Chapman }; 1988fd558d18SJames Chapman 1989fd558d18SJames Chapman static int __init l2tp_init(void) 1990fd558d18SJames Chapman { 1991fd558d18SJames Chapman int rc = 0; 1992fd558d18SJames Chapman 1993fd558d18SJames Chapman rc = register_pernet_device(&l2tp_net_ops); 1994fd558d18SJames Chapman if (rc) 1995fd558d18SJames Chapman goto out; 1996fd558d18SJames Chapman 199759ff3eb6SZhangZhen l2tp_wq = alloc_workqueue("l2tp", WQ_UNBOUND, 0); 1998f8ccac0eSTom Parkin if (!l2tp_wq) { 1999f8ccac0eSTom Parkin pr_err("alloc_workqueue failed\n"); 2000f8ccac0eSTom Parkin rc = -ENOMEM; 2001f8ccac0eSTom Parkin goto out; 2002f8ccac0eSTom Parkin } 2003f8ccac0eSTom Parkin 2004a4ca44faSJoe Perches pr_info("L2TP core driver, %s\n", L2TP_DRV_VERSION); 2005fd558d18SJames Chapman 2006fd558d18SJames Chapman out: 2007fd558d18SJames Chapman return rc; 2008fd558d18SJames Chapman } 2009fd558d18SJames Chapman 2010fd558d18SJames Chapman static void __exit l2tp_exit(void) 2011fd558d18SJames Chapman { 2012fd558d18SJames Chapman unregister_pernet_device(&l2tp_net_ops); 2013f8ccac0eSTom Parkin if (l2tp_wq) { 2014f8ccac0eSTom Parkin destroy_workqueue(l2tp_wq); 2015f8ccac0eSTom Parkin l2tp_wq = NULL; 2016f8ccac0eSTom Parkin } 2017fd558d18SJames Chapman } 2018fd558d18SJames Chapman 2019fd558d18SJames Chapman module_init(l2tp_init); 2020fd558d18SJames Chapman module_exit(l2tp_exit); 2021fd558d18SJames Chapman 2022fd558d18SJames Chapman MODULE_AUTHOR("James Chapman <jchapman@katalix.com>"); 2023fd558d18SJames Chapman MODULE_DESCRIPTION("L2TP core"); 2024fd558d18SJames Chapman MODULE_LICENSE("GPL"); 2025fd558d18SJames Chapman MODULE_VERSION(L2TP_DRV_VERSION); 2026fd558d18SJames Chapman 2027