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_session_set_header_len(struct l2tp_session *session, int version); 116fc130840Sstephen hemminger static void l2tp_tunnel_free(struct l2tp_tunnel *tunnel); 117fc130840Sstephen hemminger 118fd558d18SJames Chapman static inline struct l2tp_net *l2tp_pernet(struct net *net) 119fd558d18SJames Chapman { 120fd558d18SJames Chapman BUG_ON(!net); 121fd558d18SJames Chapman 122fd558d18SJames Chapman return net_generic(net, l2tp_net_id); 123fd558d18SJames Chapman } 124fd558d18SJames Chapman 125fc130840Sstephen hemminger /* Tunnel reference counts. Incremented per session that is added to 126fc130840Sstephen hemminger * the tunnel. 127fc130840Sstephen hemminger */ 128fc130840Sstephen hemminger static inline void l2tp_tunnel_inc_refcount_1(struct l2tp_tunnel *tunnel) 129fc130840Sstephen hemminger { 130fc130840Sstephen hemminger atomic_inc(&tunnel->ref_count); 131fc130840Sstephen hemminger } 132fc130840Sstephen hemminger 133fc130840Sstephen hemminger static inline void l2tp_tunnel_dec_refcount_1(struct l2tp_tunnel *tunnel) 134fc130840Sstephen hemminger { 135fc130840Sstephen hemminger if (atomic_dec_and_test(&tunnel->ref_count)) 136fc130840Sstephen hemminger l2tp_tunnel_free(tunnel); 137fc130840Sstephen hemminger } 138fc130840Sstephen hemminger #ifdef L2TP_REFCNT_DEBUG 139a4ca44faSJoe Perches #define l2tp_tunnel_inc_refcount(_t) \ 140a4ca44faSJoe Perches do { \ 141a4ca44faSJoe Perches pr_debug("l2tp_tunnel_inc_refcount: %s:%d %s: cnt=%d\n", \ 142a4ca44faSJoe Perches __func__, __LINE__, (_t)->name, \ 143a4ca44faSJoe Perches atomic_read(&_t->ref_count)); \ 144fc130840Sstephen hemminger l2tp_tunnel_inc_refcount_1(_t); \ 145fc130840Sstephen hemminger } while (0) 146a4ca44faSJoe Perches #define l2tp_tunnel_dec_refcount(_t) 147a4ca44faSJoe Perches do { \ 148a4ca44faSJoe Perches pr_debug("l2tp_tunnel_dec_refcount: %s:%d %s: cnt=%d\n", \ 149a4ca44faSJoe Perches __func__, __LINE__, (_t)->name, \ 150a4ca44faSJoe Perches atomic_read(&_t->ref_count)); \ 151fc130840Sstephen hemminger l2tp_tunnel_dec_refcount_1(_t); \ 152fc130840Sstephen hemminger } while (0) 153fc130840Sstephen hemminger #else 154fc130840Sstephen hemminger #define l2tp_tunnel_inc_refcount(t) l2tp_tunnel_inc_refcount_1(t) 155fc130840Sstephen hemminger #define l2tp_tunnel_dec_refcount(t) l2tp_tunnel_dec_refcount_1(t) 156fc130840Sstephen hemminger #endif 157fc130840Sstephen hemminger 158f7faffa3SJames Chapman /* Session hash global list for L2TPv3. 159f7faffa3SJames Chapman * The session_id SHOULD be random according to RFC3931, but several 160f7faffa3SJames Chapman * L2TP implementations use incrementing session_ids. So we do a real 161f7faffa3SJames Chapman * hash on the session_id, rather than a simple bitmask. 162f7faffa3SJames Chapman */ 163f7faffa3SJames Chapman static inline struct hlist_head * 164f7faffa3SJames Chapman l2tp_session_id_hash_2(struct l2tp_net *pn, u32 session_id) 165f7faffa3SJames Chapman { 166f7faffa3SJames Chapman return &pn->l2tp_session_hlist[hash_32(session_id, L2TP_HASH_BITS_2)]; 167f7faffa3SJames Chapman 168f7faffa3SJames Chapman } 169f7faffa3SJames Chapman 17080d84ef3STom Parkin /* Lookup the tunnel socket, possibly involving the fs code if the socket is 17180d84ef3STom Parkin * owned by userspace. A struct sock returned from this function must be 17280d84ef3STom Parkin * released using l2tp_tunnel_sock_put once you're done with it. 17380d84ef3STom Parkin */ 17480d84ef3STom Parkin struct sock *l2tp_tunnel_sock_lookup(struct l2tp_tunnel *tunnel) 17580d84ef3STom Parkin { 17680d84ef3STom Parkin int err = 0; 17780d84ef3STom Parkin struct socket *sock = NULL; 17880d84ef3STom Parkin struct sock *sk = NULL; 17980d84ef3STom Parkin 18080d84ef3STom Parkin if (!tunnel) 18180d84ef3STom Parkin goto out; 18280d84ef3STom Parkin 18380d84ef3STom Parkin if (tunnel->fd >= 0) { 18480d84ef3STom Parkin /* Socket is owned by userspace, who might be in the process 18580d84ef3STom Parkin * of closing it. Look the socket up using the fd to ensure 18680d84ef3STom Parkin * consistency. 18780d84ef3STom Parkin */ 18880d84ef3STom Parkin sock = sockfd_lookup(tunnel->fd, &err); 18980d84ef3STom Parkin if (sock) 19080d84ef3STom Parkin sk = sock->sk; 19180d84ef3STom Parkin } else { 19280d84ef3STom Parkin /* Socket is owned by kernelspace */ 19380d84ef3STom Parkin sk = tunnel->sock; 1948abbbe8fSTom Parkin sock_hold(sk); 19580d84ef3STom Parkin } 19680d84ef3STom Parkin 19780d84ef3STom Parkin out: 19880d84ef3STom Parkin return sk; 19980d84ef3STom Parkin } 20080d84ef3STom Parkin EXPORT_SYMBOL_GPL(l2tp_tunnel_sock_lookup); 20180d84ef3STom Parkin 20280d84ef3STom Parkin /* Drop a reference to a tunnel socket obtained via. l2tp_tunnel_sock_put */ 20380d84ef3STom Parkin void l2tp_tunnel_sock_put(struct sock *sk) 20480d84ef3STom Parkin { 20580d84ef3STom Parkin struct l2tp_tunnel *tunnel = l2tp_sock_to_tunnel(sk); 20680d84ef3STom Parkin if (tunnel) { 20780d84ef3STom Parkin if (tunnel->fd >= 0) { 20880d84ef3STom Parkin /* Socket is owned by userspace */ 20980d84ef3STom Parkin sockfd_put(sk->sk_socket); 21080d84ef3STom Parkin } 21180d84ef3STom Parkin sock_put(sk); 21280d84ef3STom Parkin } 2138abbbe8fSTom Parkin sock_put(sk); 21480d84ef3STom Parkin } 21580d84ef3STom Parkin EXPORT_SYMBOL_GPL(l2tp_tunnel_sock_put); 21680d84ef3STom Parkin 217f7faffa3SJames Chapman /* Lookup a session by id in the global session list 218f7faffa3SJames Chapman */ 219f7faffa3SJames Chapman static struct l2tp_session *l2tp_session_find_2(struct net *net, u32 session_id) 220f7faffa3SJames Chapman { 221f7faffa3SJames Chapman struct l2tp_net *pn = l2tp_pernet(net); 222f7faffa3SJames Chapman struct hlist_head *session_list = 223f7faffa3SJames Chapman l2tp_session_id_hash_2(pn, session_id); 224f7faffa3SJames Chapman struct l2tp_session *session; 225f7faffa3SJames Chapman 226e02d494dSJames Chapman rcu_read_lock_bh(); 227b67bfe0dSSasha Levin hlist_for_each_entry_rcu(session, session_list, global_hlist) { 228f7faffa3SJames Chapman if (session->session_id == session_id) { 229e02d494dSJames Chapman rcu_read_unlock_bh(); 230f7faffa3SJames Chapman return session; 231f7faffa3SJames Chapman } 232f7faffa3SJames Chapman } 233e02d494dSJames Chapman rcu_read_unlock_bh(); 234f7faffa3SJames Chapman 235f7faffa3SJames Chapman return NULL; 236f7faffa3SJames Chapman } 237f7faffa3SJames Chapman 238fd558d18SJames Chapman /* Session hash list. 239fd558d18SJames Chapman * The session_id SHOULD be random according to RFC2661, but several 240fd558d18SJames Chapman * L2TP implementations (Cisco and Microsoft) use incrementing 241fd558d18SJames Chapman * session_ids. So we do a real hash on the session_id, rather than a 242fd558d18SJames Chapman * simple bitmask. 243fd558d18SJames Chapman */ 244fd558d18SJames Chapman static inline struct hlist_head * 245fd558d18SJames Chapman l2tp_session_id_hash(struct l2tp_tunnel *tunnel, u32 session_id) 246fd558d18SJames Chapman { 247fd558d18SJames Chapman return &tunnel->session_hlist[hash_32(session_id, L2TP_HASH_BITS)]; 248fd558d18SJames Chapman } 249fd558d18SJames Chapman 250fd558d18SJames Chapman /* Lookup a session by id 251fd558d18SJames Chapman */ 252f7faffa3SJames Chapman struct l2tp_session *l2tp_session_find(struct net *net, struct l2tp_tunnel *tunnel, u32 session_id) 253fd558d18SJames Chapman { 254f7faffa3SJames Chapman struct hlist_head *session_list; 255fd558d18SJames Chapman struct l2tp_session *session; 256fd558d18SJames Chapman 257f7faffa3SJames Chapman /* In L2TPv3, session_ids are unique over all tunnels and we 258f7faffa3SJames Chapman * sometimes need to look them up before we know the 259f7faffa3SJames Chapman * tunnel. 260f7faffa3SJames Chapman */ 261f7faffa3SJames Chapman if (tunnel == NULL) 262f7faffa3SJames Chapman return l2tp_session_find_2(net, session_id); 263f7faffa3SJames Chapman 264f7faffa3SJames Chapman session_list = l2tp_session_id_hash(tunnel, session_id); 265fd558d18SJames Chapman read_lock_bh(&tunnel->hlist_lock); 266b67bfe0dSSasha Levin hlist_for_each_entry(session, session_list, hlist) { 267fd558d18SJames Chapman if (session->session_id == session_id) { 268fd558d18SJames Chapman read_unlock_bh(&tunnel->hlist_lock); 269fd558d18SJames Chapman return session; 270fd558d18SJames Chapman } 271fd558d18SJames Chapman } 272fd558d18SJames Chapman read_unlock_bh(&tunnel->hlist_lock); 273fd558d18SJames Chapman 274fd558d18SJames Chapman return NULL; 275fd558d18SJames Chapman } 276fd558d18SJames Chapman EXPORT_SYMBOL_GPL(l2tp_session_find); 277fd558d18SJames Chapman 278fd558d18SJames Chapman struct l2tp_session *l2tp_session_find_nth(struct l2tp_tunnel *tunnel, int nth) 279fd558d18SJames Chapman { 280fd558d18SJames Chapman int hash; 281fd558d18SJames Chapman struct l2tp_session *session; 282fd558d18SJames Chapman int count = 0; 283fd558d18SJames Chapman 284fd558d18SJames Chapman read_lock_bh(&tunnel->hlist_lock); 285fd558d18SJames Chapman for (hash = 0; hash < L2TP_HASH_SIZE; hash++) { 286b67bfe0dSSasha Levin hlist_for_each_entry(session, &tunnel->session_hlist[hash], hlist) { 287fd558d18SJames Chapman if (++count > nth) { 288fd558d18SJames Chapman read_unlock_bh(&tunnel->hlist_lock); 289fd558d18SJames Chapman return session; 290fd558d18SJames Chapman } 291fd558d18SJames Chapman } 292fd558d18SJames Chapman } 293fd558d18SJames Chapman 294fd558d18SJames Chapman read_unlock_bh(&tunnel->hlist_lock); 295fd558d18SJames Chapman 296fd558d18SJames Chapman return NULL; 297fd558d18SJames Chapman } 298fd558d18SJames Chapman EXPORT_SYMBOL_GPL(l2tp_session_find_nth); 299fd558d18SJames Chapman 300309795f4SJames Chapman /* Lookup a session by interface name. 301309795f4SJames Chapman * This is very inefficient but is only used by management interfaces. 302309795f4SJames Chapman */ 303309795f4SJames Chapman struct l2tp_session *l2tp_session_find_by_ifname(struct net *net, char *ifname) 304309795f4SJames Chapman { 305309795f4SJames Chapman struct l2tp_net *pn = l2tp_pernet(net); 306309795f4SJames Chapman int hash; 307309795f4SJames Chapman struct l2tp_session *session; 308309795f4SJames Chapman 309e02d494dSJames Chapman rcu_read_lock_bh(); 310309795f4SJames Chapman for (hash = 0; hash < L2TP_HASH_SIZE_2; hash++) { 311b67bfe0dSSasha Levin hlist_for_each_entry_rcu(session, &pn->l2tp_session_hlist[hash], global_hlist) { 312309795f4SJames Chapman if (!strcmp(session->ifname, ifname)) { 313e02d494dSJames Chapman rcu_read_unlock_bh(); 314309795f4SJames Chapman return session; 315309795f4SJames Chapman } 316309795f4SJames Chapman } 317309795f4SJames Chapman } 318309795f4SJames Chapman 319e02d494dSJames Chapman rcu_read_unlock_bh(); 320309795f4SJames Chapman 321309795f4SJames Chapman return NULL; 322309795f4SJames Chapman } 323309795f4SJames Chapman EXPORT_SYMBOL_GPL(l2tp_session_find_by_ifname); 324309795f4SJames Chapman 325fd558d18SJames Chapman /* Lookup a tunnel by id 326fd558d18SJames Chapman */ 327fd558d18SJames Chapman struct l2tp_tunnel *l2tp_tunnel_find(struct net *net, u32 tunnel_id) 328fd558d18SJames Chapman { 329fd558d18SJames Chapman struct l2tp_tunnel *tunnel; 330fd558d18SJames Chapman struct l2tp_net *pn = l2tp_pernet(net); 331fd558d18SJames Chapman 332e02d494dSJames Chapman rcu_read_lock_bh(); 333e02d494dSJames Chapman list_for_each_entry_rcu(tunnel, &pn->l2tp_tunnel_list, list) { 334fd558d18SJames Chapman if (tunnel->tunnel_id == tunnel_id) { 335e02d494dSJames Chapman rcu_read_unlock_bh(); 336fd558d18SJames Chapman return tunnel; 337fd558d18SJames Chapman } 338fd558d18SJames Chapman } 339e02d494dSJames Chapman rcu_read_unlock_bh(); 340fd558d18SJames Chapman 341fd558d18SJames Chapman return NULL; 342fd558d18SJames Chapman } 343fd558d18SJames Chapman EXPORT_SYMBOL_GPL(l2tp_tunnel_find); 344fd558d18SJames Chapman 345fd558d18SJames Chapman struct l2tp_tunnel *l2tp_tunnel_find_nth(struct net *net, int nth) 346fd558d18SJames Chapman { 347fd558d18SJames Chapman struct l2tp_net *pn = l2tp_pernet(net); 348fd558d18SJames Chapman struct l2tp_tunnel *tunnel; 349fd558d18SJames Chapman int count = 0; 350fd558d18SJames Chapman 351e02d494dSJames Chapman rcu_read_lock_bh(); 352e02d494dSJames Chapman list_for_each_entry_rcu(tunnel, &pn->l2tp_tunnel_list, list) { 353fd558d18SJames Chapman if (++count > nth) { 354e02d494dSJames Chapman rcu_read_unlock_bh(); 355fd558d18SJames Chapman return tunnel; 356fd558d18SJames Chapman } 357fd558d18SJames Chapman } 358fd558d18SJames Chapman 359e02d494dSJames Chapman rcu_read_unlock_bh(); 360fd558d18SJames Chapman 361fd558d18SJames Chapman return NULL; 362fd558d18SJames Chapman } 363fd558d18SJames Chapman EXPORT_SYMBOL_GPL(l2tp_tunnel_find_nth); 364fd558d18SJames Chapman 365fd558d18SJames Chapman /***************************************************************************** 366fd558d18SJames Chapman * Receive data handling 367fd558d18SJames Chapman *****************************************************************************/ 368fd558d18SJames Chapman 369fd558d18SJames Chapman /* Queue a skb in order. We come here only if the skb has an L2TP sequence 370fd558d18SJames Chapman * number. 371fd558d18SJames Chapman */ 372fd558d18SJames Chapman static void l2tp_recv_queue_skb(struct l2tp_session *session, struct sk_buff *skb) 373fd558d18SJames Chapman { 374fd558d18SJames Chapman struct sk_buff *skbp; 375fd558d18SJames Chapman struct sk_buff *tmp; 376f7faffa3SJames Chapman u32 ns = L2TP_SKB_CB(skb)->ns; 377fd558d18SJames Chapman 378fd558d18SJames Chapman spin_lock_bh(&session->reorder_q.lock); 379fd558d18SJames Chapman skb_queue_walk_safe(&session->reorder_q, skbp, tmp) { 380fd558d18SJames Chapman if (L2TP_SKB_CB(skbp)->ns > ns) { 381fd558d18SJames Chapman __skb_queue_before(&session->reorder_q, skbp, skb); 382a4ca44faSJoe Perches l2tp_dbg(session, L2TP_MSG_SEQ, 383fd558d18SJames Chapman "%s: pkt %hu, inserted before %hu, reorder_q len=%d\n", 384fd558d18SJames Chapman session->name, ns, L2TP_SKB_CB(skbp)->ns, 385fd558d18SJames Chapman skb_queue_len(&session->reorder_q)); 3867b7c0719STom Parkin atomic_long_inc(&session->stats.rx_oos_packets); 387fd558d18SJames Chapman goto out; 388fd558d18SJames Chapman } 389fd558d18SJames Chapman } 390fd558d18SJames Chapman 391fd558d18SJames Chapman __skb_queue_tail(&session->reorder_q, skb); 392fd558d18SJames Chapman 393fd558d18SJames Chapman out: 394fd558d18SJames Chapman spin_unlock_bh(&session->reorder_q.lock); 395fd558d18SJames Chapman } 396fd558d18SJames Chapman 397fd558d18SJames Chapman /* Dequeue a single skb. 398fd558d18SJames Chapman */ 399fd558d18SJames Chapman static void l2tp_recv_dequeue_skb(struct l2tp_session *session, struct sk_buff *skb) 400fd558d18SJames Chapman { 401fd558d18SJames Chapman struct l2tp_tunnel *tunnel = session->tunnel; 402fd558d18SJames Chapman int length = L2TP_SKB_CB(skb)->length; 403fd558d18SJames Chapman 404fd558d18SJames Chapman /* We're about to requeue the skb, so return resources 405fd558d18SJames Chapman * to its current owner (a socket receive buffer). 406fd558d18SJames Chapman */ 407fd558d18SJames Chapman skb_orphan(skb); 408fd558d18SJames Chapman 4097b7c0719STom Parkin atomic_long_inc(&tunnel->stats.rx_packets); 4107b7c0719STom Parkin atomic_long_add(length, &tunnel->stats.rx_bytes); 4117b7c0719STom Parkin atomic_long_inc(&session->stats.rx_packets); 4127b7c0719STom Parkin atomic_long_add(length, &session->stats.rx_bytes); 413fd558d18SJames Chapman 414fd558d18SJames Chapman if (L2TP_SKB_CB(skb)->has_seq) { 415fd558d18SJames Chapman /* Bump our Nr */ 416fd558d18SJames Chapman session->nr++; 4178a1631d5SJames Chapman session->nr &= session->nr_max; 418f7faffa3SJames Chapman 419a4ca44faSJoe Perches l2tp_dbg(session, L2TP_MSG_SEQ, "%s: updated nr to %hu\n", 420a4ca44faSJoe Perches session->name, session->nr); 421fd558d18SJames Chapman } 422fd558d18SJames Chapman 423fd558d18SJames Chapman /* call private receive handler */ 424fd558d18SJames Chapman if (session->recv_skb != NULL) 425fd558d18SJames Chapman (*session->recv_skb)(session, skb, L2TP_SKB_CB(skb)->length); 426fd558d18SJames Chapman else 427fd558d18SJames Chapman kfree_skb(skb); 428fd558d18SJames Chapman 429fd558d18SJames Chapman if (session->deref) 430fd558d18SJames Chapman (*session->deref)(session); 431fd558d18SJames Chapman } 432fd558d18SJames Chapman 433fd558d18SJames Chapman /* Dequeue skbs from the session's reorder_q, subject to packet order. 434fd558d18SJames Chapman * Skbs that have been in the queue for too long are simply discarded. 435fd558d18SJames Chapman */ 436fd558d18SJames Chapman static void l2tp_recv_dequeue(struct l2tp_session *session) 437fd558d18SJames Chapman { 438fd558d18SJames Chapman struct sk_buff *skb; 439fd558d18SJames Chapman struct sk_buff *tmp; 440fd558d18SJames Chapman 441fd558d18SJames Chapman /* If the pkt at the head of the queue has the nr that we 442fd558d18SJames Chapman * expect to send up next, dequeue it and any other 443fd558d18SJames Chapman * in-sequence packets behind it. 444fd558d18SJames Chapman */ 445e2e210c0SEric Dumazet start: 446fd558d18SJames Chapman spin_lock_bh(&session->reorder_q.lock); 447fd558d18SJames Chapman skb_queue_walk_safe(&session->reorder_q, skb, tmp) { 448fd558d18SJames Chapman if (time_after(jiffies, L2TP_SKB_CB(skb)->expires)) { 4497b7c0719STom Parkin atomic_long_inc(&session->stats.rx_seq_discards); 4507b7c0719STom Parkin atomic_long_inc(&session->stats.rx_errors); 451a4ca44faSJoe Perches l2tp_dbg(session, L2TP_MSG_SEQ, 452a4ca44faSJoe Perches "%s: oos pkt %u len %d discarded (too old), waiting for %u, reorder_q_len=%d\n", 453fd558d18SJames Chapman session->name, L2TP_SKB_CB(skb)->ns, 454fd558d18SJames Chapman L2TP_SKB_CB(skb)->length, session->nr, 455fd558d18SJames Chapman skb_queue_len(&session->reorder_q)); 45638d40b3fSJames Chapman session->reorder_skip = 1; 457fd558d18SJames Chapman __skb_unlink(skb, &session->reorder_q); 458fd558d18SJames Chapman kfree_skb(skb); 459fd558d18SJames Chapman if (session->deref) 460fd558d18SJames Chapman (*session->deref)(session); 461fd558d18SJames Chapman continue; 462fd558d18SJames Chapman } 463fd558d18SJames Chapman 464fd558d18SJames Chapman if (L2TP_SKB_CB(skb)->has_seq) { 46538d40b3fSJames Chapman if (session->reorder_skip) { 466a4ca44faSJoe Perches l2tp_dbg(session, L2TP_MSG_SEQ, 46738d40b3fSJames Chapman "%s: advancing nr to next pkt: %u -> %u", 46838d40b3fSJames Chapman session->name, session->nr, 46938d40b3fSJames Chapman L2TP_SKB_CB(skb)->ns); 47038d40b3fSJames Chapman session->reorder_skip = 0; 47138d40b3fSJames Chapman session->nr = L2TP_SKB_CB(skb)->ns; 47238d40b3fSJames Chapman } 473fd558d18SJames Chapman if (L2TP_SKB_CB(skb)->ns != session->nr) { 474a4ca44faSJoe Perches l2tp_dbg(session, L2TP_MSG_SEQ, 475a4ca44faSJoe Perches "%s: holding oos pkt %u len %d, waiting for %u, reorder_q_len=%d\n", 476fd558d18SJames Chapman session->name, L2TP_SKB_CB(skb)->ns, 477fd558d18SJames Chapman L2TP_SKB_CB(skb)->length, session->nr, 478fd558d18SJames Chapman skb_queue_len(&session->reorder_q)); 479fd558d18SJames Chapman goto out; 480fd558d18SJames Chapman } 481fd558d18SJames Chapman } 482fd558d18SJames Chapman __skb_unlink(skb, &session->reorder_q); 483fd558d18SJames Chapman 484fd558d18SJames Chapman /* Process the skb. We release the queue lock while we 485fd558d18SJames Chapman * do so to let other contexts process the queue. 486fd558d18SJames Chapman */ 487fd558d18SJames Chapman spin_unlock_bh(&session->reorder_q.lock); 488fd558d18SJames Chapman l2tp_recv_dequeue_skb(session, skb); 489e2e210c0SEric Dumazet goto start; 490fd558d18SJames Chapman } 491fd558d18SJames Chapman 492fd558d18SJames Chapman out: 493fd558d18SJames Chapman spin_unlock_bh(&session->reorder_q.lock); 494fd558d18SJames Chapman } 495fd558d18SJames Chapman 496fd558d18SJames Chapman static inline int l2tp_verify_udp_checksum(struct sock *sk, 497fd558d18SJames Chapman struct sk_buff *skb) 498fd558d18SJames Chapman { 499*e18503f4SFrançois Cachereul struct l2tp_tunnel *tunnel = (struct l2tp_tunnel *)sk->sk_user_data; 500fd558d18SJames Chapman struct udphdr *uh = udp_hdr(skb); 501fd558d18SJames Chapman u16 ulen = ntohs(uh->len); 502fd558d18SJames Chapman __wsum psum; 503fd558d18SJames Chapman 504d2cf3361SBenjamin LaHaise if (sk->sk_no_check || skb_csum_unnecessary(skb)) 505fd558d18SJames Chapman return 0; 506fd558d18SJames Chapman 507d2cf3361SBenjamin LaHaise #if IS_ENABLED(CONFIG_IPV6) 508*e18503f4SFrançois Cachereul if (sk->sk_family == PF_INET6 && !tunnel->v4mapped) { 509d2cf3361SBenjamin LaHaise if (!uh->check) { 510d2cf3361SBenjamin LaHaise LIMIT_NETDEBUG(KERN_INFO "L2TP: IPv6: checksum is 0\n"); 511d2cf3361SBenjamin LaHaise return 1; 512d2cf3361SBenjamin LaHaise } 513d2cf3361SBenjamin LaHaise if ((skb->ip_summed == CHECKSUM_COMPLETE) && 514d2cf3361SBenjamin LaHaise !csum_ipv6_magic(&ipv6_hdr(skb)->saddr, 515d2cf3361SBenjamin LaHaise &ipv6_hdr(skb)->daddr, ulen, 516d2cf3361SBenjamin LaHaise IPPROTO_UDP, skb->csum)) { 517d2cf3361SBenjamin LaHaise skb->ip_summed = CHECKSUM_UNNECESSARY; 518d2cf3361SBenjamin LaHaise return 0; 519d2cf3361SBenjamin LaHaise } 520d2cf3361SBenjamin LaHaise skb->csum = ~csum_unfold(csum_ipv6_magic(&ipv6_hdr(skb)->saddr, 521d2cf3361SBenjamin LaHaise &ipv6_hdr(skb)->daddr, 522d2cf3361SBenjamin LaHaise skb->len, IPPROTO_UDP, 523d2cf3361SBenjamin LaHaise 0)); 524d2cf3361SBenjamin LaHaise } else 525d2cf3361SBenjamin LaHaise #endif 526d2cf3361SBenjamin LaHaise { 527d2cf3361SBenjamin LaHaise struct inet_sock *inet; 528d2cf3361SBenjamin LaHaise if (!uh->check) 529d2cf3361SBenjamin LaHaise return 0; 530fd558d18SJames Chapman inet = inet_sk(sk); 531d2cf3361SBenjamin LaHaise psum = csum_tcpudp_nofold(inet->inet_saddr, inet->inet_daddr, 532d2cf3361SBenjamin LaHaise ulen, IPPROTO_UDP, 0); 533fd558d18SJames Chapman 534fd558d18SJames Chapman if ((skb->ip_summed == CHECKSUM_COMPLETE) && 535fd558d18SJames Chapman !csum_fold(csum_add(psum, skb->csum))) 536fd558d18SJames Chapman return 0; 537fd558d18SJames Chapman skb->csum = psum; 538d2cf3361SBenjamin LaHaise } 539fd558d18SJames Chapman 540fd558d18SJames Chapman return __skb_checksum_complete(skb); 541fd558d18SJames Chapman } 542fd558d18SJames Chapman 5438a1631d5SJames Chapman static int l2tp_seq_check_rx_window(struct l2tp_session *session, u32 nr) 5448a1631d5SJames Chapman { 5458a1631d5SJames Chapman u32 nws; 5468a1631d5SJames Chapman 5478a1631d5SJames Chapman if (nr >= session->nr) 5488a1631d5SJames Chapman nws = nr - session->nr; 5498a1631d5SJames Chapman else 5508a1631d5SJames Chapman nws = (session->nr_max + 1) - (session->nr - nr); 5518a1631d5SJames Chapman 5528a1631d5SJames Chapman return nws < session->nr_window_size; 5538a1631d5SJames Chapman } 5548a1631d5SJames Chapman 555b6dc01a4SJames Chapman /* If packet has sequence numbers, queue it if acceptable. Returns 0 if 556b6dc01a4SJames Chapman * acceptable, else non-zero. 557b6dc01a4SJames Chapman */ 558b6dc01a4SJames Chapman static int l2tp_recv_data_seq(struct l2tp_session *session, struct sk_buff *skb) 559b6dc01a4SJames Chapman { 5608a1631d5SJames Chapman if (!l2tp_seq_check_rx_window(session, L2TP_SKB_CB(skb)->ns)) { 5618a1631d5SJames Chapman /* Packet sequence number is outside allowed window. 5628a1631d5SJames Chapman * Discard it. 5638a1631d5SJames Chapman */ 5648a1631d5SJames Chapman l2tp_dbg(session, L2TP_MSG_SEQ, 5658a1631d5SJames Chapman "%s: pkt %u len %d discarded, outside window, nr=%u\n", 5668a1631d5SJames Chapman session->name, L2TP_SKB_CB(skb)->ns, 5678a1631d5SJames Chapman L2TP_SKB_CB(skb)->length, session->nr); 5688a1631d5SJames Chapman goto discard; 5698a1631d5SJames Chapman } 5708a1631d5SJames Chapman 571b6dc01a4SJames Chapman if (session->reorder_timeout != 0) { 572b6dc01a4SJames Chapman /* Packet reordering enabled. Add skb to session's 573b6dc01a4SJames Chapman * reorder queue, in order of ns. 574b6dc01a4SJames Chapman */ 575b6dc01a4SJames Chapman l2tp_recv_queue_skb(session, skb); 576a0dbd822SJames Chapman goto out; 577a0dbd822SJames Chapman } 578a0dbd822SJames Chapman 579a0dbd822SJames Chapman /* Packet reordering disabled. Discard out-of-sequence packets, while 580a0dbd822SJames Chapman * tracking the number if in-sequence packets after the first OOS packet 581a0dbd822SJames Chapman * is seen. After nr_oos_count_max in-sequence packets, reset the 582a0dbd822SJames Chapman * sequence number to re-enable packet reception. 583b6dc01a4SJames Chapman */ 584a0dbd822SJames Chapman if (L2TP_SKB_CB(skb)->ns == session->nr) { 585a0dbd822SJames Chapman skb_queue_tail(&session->reorder_q, skb); 586a0dbd822SJames Chapman } else { 587a0dbd822SJames Chapman u32 nr_oos = L2TP_SKB_CB(skb)->ns; 588a0dbd822SJames Chapman u32 nr_next = (session->nr_oos + 1) & session->nr_max; 589a0dbd822SJames Chapman 590a0dbd822SJames Chapman if (nr_oos == nr_next) 591a0dbd822SJames Chapman session->nr_oos_count++; 592a0dbd822SJames Chapman else 593a0dbd822SJames Chapman session->nr_oos_count = 0; 594a0dbd822SJames Chapman 595a0dbd822SJames Chapman session->nr_oos = nr_oos; 596a0dbd822SJames Chapman if (session->nr_oos_count > session->nr_oos_count_max) { 597a0dbd822SJames Chapman session->reorder_skip = 1; 598a0dbd822SJames Chapman l2tp_dbg(session, L2TP_MSG_SEQ, 599a0dbd822SJames Chapman "%s: %d oos packets received. Resetting sequence numbers\n", 600a0dbd822SJames Chapman session->name, session->nr_oos_count); 601a0dbd822SJames Chapman } 602a0dbd822SJames Chapman if (!session->reorder_skip) { 603b6dc01a4SJames Chapman atomic_long_inc(&session->stats.rx_seq_discards); 604b6dc01a4SJames Chapman l2tp_dbg(session, L2TP_MSG_SEQ, 605b6dc01a4SJames Chapman "%s: oos pkt %u len %d discarded, waiting for %u, reorder_q_len=%d\n", 606b6dc01a4SJames Chapman session->name, L2TP_SKB_CB(skb)->ns, 607b6dc01a4SJames Chapman L2TP_SKB_CB(skb)->length, session->nr, 608b6dc01a4SJames Chapman skb_queue_len(&session->reorder_q)); 609b6dc01a4SJames Chapman goto discard; 610b6dc01a4SJames Chapman } 611b6dc01a4SJames Chapman skb_queue_tail(&session->reorder_q, skb); 612b6dc01a4SJames Chapman } 613b6dc01a4SJames Chapman 614a0dbd822SJames Chapman out: 615b6dc01a4SJames Chapman return 0; 616b6dc01a4SJames Chapman 617b6dc01a4SJames Chapman discard: 618b6dc01a4SJames Chapman return 1; 619b6dc01a4SJames Chapman } 620b6dc01a4SJames Chapman 621f7faffa3SJames Chapman /* Do receive processing of L2TP data frames. We handle both L2TPv2 622f7faffa3SJames Chapman * and L2TPv3 data frames here. 623f7faffa3SJames Chapman * 624f7faffa3SJames Chapman * L2TPv2 Data Message Header 625f7faffa3SJames Chapman * 626f7faffa3SJames Chapman * 0 1 2 3 627f7faffa3SJames 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 628f7faffa3SJames Chapman * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 629f7faffa3SJames Chapman * |T|L|x|x|S|x|O|P|x|x|x|x| Ver | Length (opt) | 630f7faffa3SJames Chapman * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 631f7faffa3SJames Chapman * | Tunnel ID | Session ID | 632f7faffa3SJames Chapman * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 633f7faffa3SJames Chapman * | Ns (opt) | Nr (opt) | 634f7faffa3SJames Chapman * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 635f7faffa3SJames Chapman * | Offset Size (opt) | Offset pad... (opt) 636f7faffa3SJames Chapman * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 637f7faffa3SJames Chapman * 638f7faffa3SJames Chapman * Data frames are marked by T=0. All other fields are the same as 639f7faffa3SJames Chapman * those in L2TP control frames. 640f7faffa3SJames Chapman * 641f7faffa3SJames Chapman * L2TPv3 Data Message Header 642f7faffa3SJames Chapman * 643f7faffa3SJames Chapman * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 644f7faffa3SJames Chapman * | L2TP Session Header | 645f7faffa3SJames Chapman * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 646f7faffa3SJames Chapman * | L2-Specific Sublayer | 647f7faffa3SJames Chapman * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 648f7faffa3SJames Chapman * | Tunnel Payload ... 649f7faffa3SJames Chapman * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 650f7faffa3SJames Chapman * 651f7faffa3SJames Chapman * L2TPv3 Session Header Over IP 652f7faffa3SJames Chapman * 653f7faffa3SJames Chapman * 0 1 2 3 654f7faffa3SJames 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 655f7faffa3SJames Chapman * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 656f7faffa3SJames Chapman * | Session ID | 657f7faffa3SJames Chapman * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 658f7faffa3SJames Chapman * | Cookie (optional, maximum 64 bits)... 659f7faffa3SJames Chapman * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 660f7faffa3SJames Chapman * | 661f7faffa3SJames Chapman * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 662f7faffa3SJames Chapman * 663f7faffa3SJames Chapman * L2TPv3 L2-Specific Sublayer Format 664f7faffa3SJames Chapman * 665f7faffa3SJames Chapman * 0 1 2 3 666f7faffa3SJames 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 667f7faffa3SJames Chapman * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 668f7faffa3SJames Chapman * |x|S|x|x|x|x|x|x| Sequence Number | 669f7faffa3SJames Chapman * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 670f7faffa3SJames Chapman * 671f7faffa3SJames Chapman * Cookie value, sublayer format and offset (pad) are negotiated with 672f7faffa3SJames Chapman * the peer when the session is set up. Unlike L2TPv2, we do not need 673f7faffa3SJames Chapman * to parse the packet header to determine if optional fields are 674f7faffa3SJames Chapman * present. 675f7faffa3SJames Chapman * 676f7faffa3SJames Chapman * Caller must already have parsed the frame and determined that it is 677f7faffa3SJames Chapman * a data (not control) frame before coming here. Fields up to the 678f7faffa3SJames Chapman * session-id have already been parsed and ptr points to the data 679f7faffa3SJames Chapman * after the session-id. 680f7faffa3SJames Chapman */ 681f7faffa3SJames Chapman void l2tp_recv_common(struct l2tp_session *session, struct sk_buff *skb, 682f7faffa3SJames Chapman unsigned char *ptr, unsigned char *optr, u16 hdrflags, 683f7faffa3SJames Chapman int length, int (*payload_hook)(struct sk_buff *skb)) 684f7faffa3SJames Chapman { 685f7faffa3SJames Chapman struct l2tp_tunnel *tunnel = session->tunnel; 686f7faffa3SJames Chapman int offset; 687f7faffa3SJames Chapman u32 ns, nr; 688f7faffa3SJames Chapman 689f7faffa3SJames Chapman /* The ref count is increased since we now hold a pointer to 690f7faffa3SJames Chapman * the session. Take care to decrement the refcnt when exiting 691f7faffa3SJames Chapman * this function from now on... 692f7faffa3SJames Chapman */ 693f7faffa3SJames Chapman l2tp_session_inc_refcount(session); 694f7faffa3SJames Chapman if (session->ref) 695f7faffa3SJames Chapman (*session->ref)(session); 696f7faffa3SJames Chapman 697f7faffa3SJames Chapman /* Parse and check optional cookie */ 698f7faffa3SJames Chapman if (session->peer_cookie_len > 0) { 699f7faffa3SJames Chapman if (memcmp(ptr, &session->peer_cookie[0], session->peer_cookie_len)) { 700a4ca44faSJoe Perches l2tp_info(tunnel, L2TP_MSG_DATA, 701f7faffa3SJames Chapman "%s: cookie mismatch (%u/%u). Discarding.\n", 702a4ca44faSJoe Perches tunnel->name, tunnel->tunnel_id, 703a4ca44faSJoe Perches session->session_id); 7047b7c0719STom Parkin atomic_long_inc(&session->stats.rx_cookie_discards); 705f7faffa3SJames Chapman goto discard; 706f7faffa3SJames Chapman } 707f7faffa3SJames Chapman ptr += session->peer_cookie_len; 708f7faffa3SJames Chapman } 709f7faffa3SJames Chapman 710f7faffa3SJames Chapman /* Handle the optional sequence numbers. Sequence numbers are 711f7faffa3SJames Chapman * in different places for L2TPv2 and L2TPv3. 712f7faffa3SJames Chapman * 713f7faffa3SJames Chapman * If we are the LAC, enable/disable sequence numbers under 714f7faffa3SJames Chapman * the control of the LNS. If no sequence numbers present but 715f7faffa3SJames Chapman * we were expecting them, discard frame. 716f7faffa3SJames Chapman */ 717f7faffa3SJames Chapman ns = nr = 0; 718f7faffa3SJames Chapman L2TP_SKB_CB(skb)->has_seq = 0; 719f7faffa3SJames Chapman if (tunnel->version == L2TP_HDR_VER_2) { 720f7faffa3SJames Chapman if (hdrflags & L2TP_HDRFLAG_S) { 721f7faffa3SJames Chapman ns = ntohs(*(__be16 *) ptr); 722f7faffa3SJames Chapman ptr += 2; 723f7faffa3SJames Chapman nr = ntohs(*(__be16 *) ptr); 724f7faffa3SJames Chapman ptr += 2; 725f7faffa3SJames Chapman 726f7faffa3SJames Chapman /* Store L2TP info in the skb */ 727f7faffa3SJames Chapman L2TP_SKB_CB(skb)->ns = ns; 728f7faffa3SJames Chapman L2TP_SKB_CB(skb)->has_seq = 1; 729f7faffa3SJames Chapman 730a4ca44faSJoe Perches l2tp_dbg(session, L2TP_MSG_SEQ, 731f7faffa3SJames Chapman "%s: recv data ns=%u, nr=%u, session nr=%u\n", 732f7faffa3SJames Chapman session->name, ns, nr, session->nr); 733f7faffa3SJames Chapman } 734f7faffa3SJames Chapman } else if (session->l2specific_type == L2TP_L2SPECTYPE_DEFAULT) { 735f7faffa3SJames Chapman u32 l2h = ntohl(*(__be32 *) ptr); 736f7faffa3SJames Chapman 737f7faffa3SJames Chapman if (l2h & 0x40000000) { 738f7faffa3SJames Chapman ns = l2h & 0x00ffffff; 739f7faffa3SJames Chapman 740f7faffa3SJames Chapman /* Store L2TP info in the skb */ 741f7faffa3SJames Chapman L2TP_SKB_CB(skb)->ns = ns; 742f7faffa3SJames Chapman L2TP_SKB_CB(skb)->has_seq = 1; 743f7faffa3SJames Chapman 744a4ca44faSJoe Perches l2tp_dbg(session, L2TP_MSG_SEQ, 745f7faffa3SJames Chapman "%s: recv data ns=%u, session nr=%u\n", 746f7faffa3SJames Chapman session->name, ns, session->nr); 747f7faffa3SJames Chapman } 748f7faffa3SJames Chapman } 749f7faffa3SJames Chapman 750f7faffa3SJames Chapman /* Advance past L2-specific header, if present */ 751f7faffa3SJames Chapman ptr += session->l2specific_len; 752f7faffa3SJames Chapman 753f7faffa3SJames Chapman if (L2TP_SKB_CB(skb)->has_seq) { 754f7faffa3SJames Chapman /* Received a packet with sequence numbers. If we're the LNS, 755f7faffa3SJames Chapman * check if we sre sending sequence numbers and if not, 756f7faffa3SJames Chapman * configure it so. 757f7faffa3SJames Chapman */ 758f7faffa3SJames Chapman if ((!session->lns_mode) && (!session->send_seq)) { 759a4ca44faSJoe Perches l2tp_info(session, L2TP_MSG_SEQ, 760f7faffa3SJames Chapman "%s: requested to enable seq numbers by LNS\n", 761f7faffa3SJames Chapman session->name); 762f7faffa3SJames Chapman session->send_seq = -1; 763f7faffa3SJames Chapman l2tp_session_set_header_len(session, tunnel->version); 764f7faffa3SJames Chapman } 765f7faffa3SJames Chapman } else { 766f7faffa3SJames Chapman /* No sequence numbers. 767f7faffa3SJames Chapman * If user has configured mandatory sequence numbers, discard. 768f7faffa3SJames Chapman */ 769f7faffa3SJames Chapman if (session->recv_seq) { 770a4ca44faSJoe Perches l2tp_warn(session, L2TP_MSG_SEQ, 771a4ca44faSJoe Perches "%s: recv data has no seq numbers when required. Discarding.\n", 772a4ca44faSJoe Perches session->name); 7737b7c0719STom Parkin atomic_long_inc(&session->stats.rx_seq_discards); 774f7faffa3SJames Chapman goto discard; 775f7faffa3SJames Chapman } 776f7faffa3SJames Chapman 777f7faffa3SJames Chapman /* If we're the LAC and we're sending sequence numbers, the 778f7faffa3SJames Chapman * LNS has requested that we no longer send sequence numbers. 779f7faffa3SJames Chapman * If we're the LNS and we're sending sequence numbers, the 780f7faffa3SJames Chapman * LAC is broken. Discard the frame. 781f7faffa3SJames Chapman */ 782f7faffa3SJames Chapman if ((!session->lns_mode) && (session->send_seq)) { 783a4ca44faSJoe Perches l2tp_info(session, L2TP_MSG_SEQ, 784f7faffa3SJames Chapman "%s: requested to disable seq numbers by LNS\n", 785f7faffa3SJames Chapman session->name); 786f7faffa3SJames Chapman session->send_seq = 0; 787f7faffa3SJames Chapman l2tp_session_set_header_len(session, tunnel->version); 788f7faffa3SJames Chapman } else if (session->send_seq) { 789a4ca44faSJoe Perches l2tp_warn(session, L2TP_MSG_SEQ, 790a4ca44faSJoe Perches "%s: recv data has no seq numbers when required. Discarding.\n", 791a4ca44faSJoe Perches session->name); 7927b7c0719STom Parkin atomic_long_inc(&session->stats.rx_seq_discards); 793f7faffa3SJames Chapman goto discard; 794f7faffa3SJames Chapman } 795f7faffa3SJames Chapman } 796f7faffa3SJames Chapman 797f7faffa3SJames Chapman /* Session data offset is handled differently for L2TPv2 and 798f7faffa3SJames Chapman * L2TPv3. For L2TPv2, there is an optional 16-bit value in 799f7faffa3SJames Chapman * the header. For L2TPv3, the offset is negotiated using AVPs 800f7faffa3SJames Chapman * in the session setup control protocol. 801f7faffa3SJames Chapman */ 802f7faffa3SJames Chapman if (tunnel->version == L2TP_HDR_VER_2) { 803f7faffa3SJames Chapman /* If offset bit set, skip it. */ 804f7faffa3SJames Chapman if (hdrflags & L2TP_HDRFLAG_O) { 805f7faffa3SJames Chapman offset = ntohs(*(__be16 *)ptr); 806f7faffa3SJames Chapman ptr += 2 + offset; 807f7faffa3SJames Chapman } 808f7faffa3SJames Chapman } else 809f7faffa3SJames Chapman ptr += session->offset; 810f7faffa3SJames Chapman 811f7faffa3SJames Chapman offset = ptr - optr; 812f7faffa3SJames Chapman if (!pskb_may_pull(skb, offset)) 813f7faffa3SJames Chapman goto discard; 814f7faffa3SJames Chapman 815f7faffa3SJames Chapman __skb_pull(skb, offset); 816f7faffa3SJames Chapman 817f7faffa3SJames Chapman /* If caller wants to process the payload before we queue the 818f7faffa3SJames Chapman * packet, do so now. 819f7faffa3SJames Chapman */ 820f7faffa3SJames Chapman if (payload_hook) 821f7faffa3SJames Chapman if ((*payload_hook)(skb)) 822f7faffa3SJames Chapman goto discard; 823f7faffa3SJames Chapman 824f7faffa3SJames Chapman /* Prepare skb for adding to the session's reorder_q. Hold 825f7faffa3SJames Chapman * packets for max reorder_timeout or 1 second if not 826f7faffa3SJames Chapman * reordering. 827f7faffa3SJames Chapman */ 828f7faffa3SJames Chapman L2TP_SKB_CB(skb)->length = length; 829f7faffa3SJames Chapman L2TP_SKB_CB(skb)->expires = jiffies + 830f7faffa3SJames Chapman (session->reorder_timeout ? session->reorder_timeout : HZ); 831f7faffa3SJames Chapman 832f7faffa3SJames Chapman /* Add packet to the session's receive queue. Reordering is done here, if 833f7faffa3SJames Chapman * enabled. Saved L2TP protocol info is stored in skb->sb[]. 834f7faffa3SJames Chapman */ 835f7faffa3SJames Chapman if (L2TP_SKB_CB(skb)->has_seq) { 836b6dc01a4SJames Chapman if (l2tp_recv_data_seq(session, skb)) 837f7faffa3SJames Chapman goto discard; 838f7faffa3SJames Chapman } else { 839f7faffa3SJames Chapman /* No sequence numbers. Add the skb to the tail of the 840f7faffa3SJames Chapman * reorder queue. This ensures that it will be 841f7faffa3SJames Chapman * delivered after all previous sequenced skbs. 842f7faffa3SJames Chapman */ 843f7faffa3SJames Chapman skb_queue_tail(&session->reorder_q, skb); 844f7faffa3SJames Chapman } 845f7faffa3SJames Chapman 846f7faffa3SJames Chapman /* Try to dequeue as many skbs from reorder_q as we can. */ 847f7faffa3SJames Chapman l2tp_recv_dequeue(session); 848f7faffa3SJames Chapman 849f7faffa3SJames Chapman l2tp_session_dec_refcount(session); 850f7faffa3SJames Chapman 851f7faffa3SJames Chapman return; 852f7faffa3SJames Chapman 853f7faffa3SJames Chapman discard: 8547b7c0719STom Parkin atomic_long_inc(&session->stats.rx_errors); 855f7faffa3SJames Chapman kfree_skb(skb); 856f7faffa3SJames Chapman 857f7faffa3SJames Chapman if (session->deref) 858f7faffa3SJames Chapman (*session->deref)(session); 859f7faffa3SJames Chapman 860f7faffa3SJames Chapman l2tp_session_dec_refcount(session); 861f7faffa3SJames Chapman } 862f7faffa3SJames Chapman EXPORT_SYMBOL(l2tp_recv_common); 863f7faffa3SJames Chapman 86448f72f92STom Parkin /* Drop skbs from the session's reorder_q 86548f72f92STom Parkin */ 86648f72f92STom Parkin int l2tp_session_queue_purge(struct l2tp_session *session) 86748f72f92STom Parkin { 86848f72f92STom Parkin struct sk_buff *skb = NULL; 86948f72f92STom Parkin BUG_ON(!session); 87048f72f92STom Parkin BUG_ON(session->magic != L2TP_SESSION_MAGIC); 87148f72f92STom Parkin while ((skb = skb_dequeue(&session->reorder_q))) { 87248f72f92STom Parkin atomic_long_inc(&session->stats.rx_errors); 87348f72f92STom Parkin kfree_skb(skb); 87448f72f92STom Parkin if (session->deref) 87548f72f92STom Parkin (*session->deref)(session); 87648f72f92STom Parkin } 87748f72f92STom Parkin return 0; 87848f72f92STom Parkin } 87948f72f92STom Parkin EXPORT_SYMBOL_GPL(l2tp_session_queue_purge); 88048f72f92STom Parkin 881fd558d18SJames Chapman /* Internal UDP receive frame. Do the real work of receiving an L2TP data frame 882fd558d18SJames Chapman * here. The skb is not on a list when we get here. 883fd558d18SJames Chapman * Returns 0 if the packet was a data packet and was successfully passed on. 884fd558d18SJames Chapman * Returns 1 if the packet was not a good data packet and could not be 885fd558d18SJames Chapman * forwarded. All such packets are passed up to userspace to deal with. 886fd558d18SJames Chapman */ 887fc130840Sstephen hemminger static int l2tp_udp_recv_core(struct l2tp_tunnel *tunnel, struct sk_buff *skb, 888fd558d18SJames Chapman int (*payload_hook)(struct sk_buff *skb)) 889fd558d18SJames Chapman { 890fd558d18SJames Chapman struct l2tp_session *session = NULL; 891fd558d18SJames Chapman unsigned char *ptr, *optr; 892fd558d18SJames Chapman u16 hdrflags; 893fd558d18SJames Chapman u32 tunnel_id, session_id; 894fd558d18SJames Chapman u16 version; 895f7faffa3SJames Chapman int length; 896fd558d18SJames Chapman 897fd558d18SJames Chapman if (tunnel->sock && l2tp_verify_udp_checksum(tunnel->sock, skb)) 898fd558d18SJames Chapman goto discard_bad_csum; 899fd558d18SJames Chapman 900fd558d18SJames Chapman /* UDP always verifies the packet length. */ 901fd558d18SJames Chapman __skb_pull(skb, sizeof(struct udphdr)); 902fd558d18SJames Chapman 903fd558d18SJames Chapman /* Short packet? */ 904fd558d18SJames Chapman if (!pskb_may_pull(skb, L2TP_HDR_SIZE_SEQ)) { 905a4ca44faSJoe Perches l2tp_info(tunnel, L2TP_MSG_DATA, 906a4ca44faSJoe Perches "%s: recv short packet (len=%d)\n", 907a4ca44faSJoe Perches tunnel->name, skb->len); 908fd558d18SJames Chapman goto error; 909fd558d18SJames Chapman } 910fd558d18SJames Chapman 911fd558d18SJames Chapman /* Trace packet contents, if enabled */ 912fd558d18SJames Chapman if (tunnel->debug & L2TP_MSG_DATA) { 913fd558d18SJames Chapman length = min(32u, skb->len); 914fd558d18SJames Chapman if (!pskb_may_pull(skb, length)) 915fd558d18SJames Chapman goto error; 916fd558d18SJames Chapman 917a4ca44faSJoe Perches pr_debug("%s: recv\n", tunnel->name); 918a4ca44faSJoe Perches print_hex_dump_bytes("", DUMP_PREFIX_OFFSET, skb->data, length); 919fd558d18SJames Chapman } 920fd558d18SJames Chapman 921e50e705cSEric Dumazet /* Point to L2TP header */ 922e50e705cSEric Dumazet optr = ptr = skb->data; 923e50e705cSEric Dumazet 924fd558d18SJames Chapman /* Get L2TP header flags */ 925fd558d18SJames Chapman hdrflags = ntohs(*(__be16 *) ptr); 926fd558d18SJames Chapman 927fd558d18SJames Chapman /* Check protocol version */ 928fd558d18SJames Chapman version = hdrflags & L2TP_HDR_VER_MASK; 929fd558d18SJames Chapman if (version != tunnel->version) { 930a4ca44faSJoe Perches l2tp_info(tunnel, L2TP_MSG_DATA, 931fd558d18SJames Chapman "%s: recv protocol version mismatch: got %d expected %d\n", 932fd558d18SJames Chapman tunnel->name, version, tunnel->version); 933fd558d18SJames Chapman goto error; 934fd558d18SJames Chapman } 935fd558d18SJames Chapman 936fd558d18SJames Chapman /* Get length of L2TP packet */ 937fd558d18SJames Chapman length = skb->len; 938fd558d18SJames Chapman 939fd558d18SJames Chapman /* If type is control packet, it is handled by userspace. */ 940fd558d18SJames Chapman if (hdrflags & L2TP_HDRFLAG_T) { 941a4ca44faSJoe Perches l2tp_dbg(tunnel, L2TP_MSG_DATA, 942a4ca44faSJoe Perches "%s: recv control packet, len=%d\n", 943a4ca44faSJoe Perches tunnel->name, length); 944fd558d18SJames Chapman goto error; 945fd558d18SJames Chapman } 946fd558d18SJames Chapman 947fd558d18SJames Chapman /* Skip flags */ 948fd558d18SJames Chapman ptr += 2; 949fd558d18SJames Chapman 950f7faffa3SJames Chapman if (tunnel->version == L2TP_HDR_VER_2) { 951fd558d18SJames Chapman /* If length is present, skip it */ 952fd558d18SJames Chapman if (hdrflags & L2TP_HDRFLAG_L) 953fd558d18SJames Chapman ptr += 2; 954fd558d18SJames Chapman 955fd558d18SJames Chapman /* Extract tunnel and session ID */ 956fd558d18SJames Chapman tunnel_id = ntohs(*(__be16 *) ptr); 957fd558d18SJames Chapman ptr += 2; 958fd558d18SJames Chapman session_id = ntohs(*(__be16 *) ptr); 959fd558d18SJames Chapman ptr += 2; 960f7faffa3SJames Chapman } else { 961f7faffa3SJames Chapman ptr += 2; /* skip reserved bits */ 962f7faffa3SJames Chapman tunnel_id = tunnel->tunnel_id; 963f7faffa3SJames Chapman session_id = ntohl(*(__be32 *) ptr); 964f7faffa3SJames Chapman ptr += 4; 965f7faffa3SJames Chapman } 966fd558d18SJames Chapman 967fd558d18SJames Chapman /* Find the session context */ 968f7faffa3SJames Chapman session = l2tp_session_find(tunnel->l2tp_net, tunnel, session_id); 969309795f4SJames Chapman if (!session || !session->recv_skb) { 970fd558d18SJames Chapman /* Not found? Pass to userspace to deal with */ 971a4ca44faSJoe Perches l2tp_info(tunnel, L2TP_MSG_DATA, 972f7faffa3SJames Chapman "%s: no session found (%u/%u). Passing up.\n", 973fd558d18SJames Chapman tunnel->name, tunnel_id, session_id); 974fd558d18SJames Chapman goto error; 975fd558d18SJames Chapman } 976fd558d18SJames Chapman 977f7faffa3SJames Chapman l2tp_recv_common(session, skb, ptr, optr, hdrflags, length, payload_hook); 978fd558d18SJames Chapman 979fd558d18SJames Chapman return 0; 980fd558d18SJames Chapman 981fd558d18SJames Chapman discard_bad_csum: 982fd558d18SJames Chapman LIMIT_NETDEBUG("%s: UDP: bad checksum\n", tunnel->name); 983fd558d18SJames Chapman UDP_INC_STATS_USER(tunnel->l2tp_net, UDP_MIB_INERRORS, 0); 9847b7c0719STom Parkin atomic_long_inc(&tunnel->stats.rx_errors); 985fd558d18SJames Chapman kfree_skb(skb); 986fd558d18SJames Chapman 987fd558d18SJames Chapman return 0; 988fd558d18SJames Chapman 989fd558d18SJames Chapman error: 990fd558d18SJames Chapman /* Put UDP header back */ 991fd558d18SJames Chapman __skb_push(skb, sizeof(struct udphdr)); 992fd558d18SJames Chapman 993fd558d18SJames Chapman return 1; 994fd558d18SJames Chapman } 995fd558d18SJames Chapman 996fd558d18SJames Chapman /* UDP encapsulation receive handler. See net/ipv4/udp.c. 997fd558d18SJames Chapman * Return codes: 998fd558d18SJames Chapman * 0 : success. 999fd558d18SJames Chapman * <0: error 1000fd558d18SJames Chapman * >0: skb should be passed up to userspace as UDP. 1001fd558d18SJames Chapman */ 1002fd558d18SJames Chapman int l2tp_udp_encap_recv(struct sock *sk, struct sk_buff *skb) 1003fd558d18SJames Chapman { 1004fd558d18SJames Chapman struct l2tp_tunnel *tunnel; 1005fd558d18SJames Chapman 1006fd558d18SJames Chapman tunnel = l2tp_sock_to_tunnel(sk); 1007fd558d18SJames Chapman if (tunnel == NULL) 1008fd558d18SJames Chapman goto pass_up; 1009fd558d18SJames Chapman 1010a4ca44faSJoe Perches l2tp_dbg(tunnel, L2TP_MSG_DATA, "%s: received %d bytes\n", 1011a4ca44faSJoe Perches tunnel->name, skb->len); 1012fd558d18SJames Chapman 1013fd558d18SJames Chapman if (l2tp_udp_recv_core(tunnel, skb, tunnel->recv_payload_hook)) 1014fd558d18SJames Chapman goto pass_up_put; 1015fd558d18SJames Chapman 1016fd558d18SJames Chapman sock_put(sk); 1017fd558d18SJames Chapman return 0; 1018fd558d18SJames Chapman 1019fd558d18SJames Chapman pass_up_put: 1020fd558d18SJames Chapman sock_put(sk); 1021fd558d18SJames Chapman pass_up: 1022fd558d18SJames Chapman return 1; 1023fd558d18SJames Chapman } 1024fd558d18SJames Chapman EXPORT_SYMBOL_GPL(l2tp_udp_encap_recv); 1025fd558d18SJames Chapman 1026fd558d18SJames Chapman /************************************************************************ 1027fd558d18SJames Chapman * Transmit handling 1028fd558d18SJames Chapman ***********************************************************************/ 1029fd558d18SJames Chapman 1030fd558d18SJames Chapman /* Build an L2TP header for the session into the buffer provided. 1031fd558d18SJames Chapman */ 1032f7faffa3SJames Chapman static int l2tp_build_l2tpv2_header(struct l2tp_session *session, void *buf) 1033fd558d18SJames Chapman { 1034f7faffa3SJames Chapman struct l2tp_tunnel *tunnel = session->tunnel; 1035fd558d18SJames Chapman __be16 *bufp = buf; 1036f7faffa3SJames Chapman __be16 *optr = buf; 1037fd558d18SJames Chapman u16 flags = L2TP_HDR_VER_2; 1038fd558d18SJames Chapman u32 tunnel_id = tunnel->peer_tunnel_id; 1039fd558d18SJames Chapman u32 session_id = session->peer_session_id; 1040fd558d18SJames Chapman 1041fd558d18SJames Chapman if (session->send_seq) 1042fd558d18SJames Chapman flags |= L2TP_HDRFLAG_S; 1043fd558d18SJames Chapman 1044fd558d18SJames Chapman /* Setup L2TP header. */ 1045fd558d18SJames Chapman *bufp++ = htons(flags); 1046fd558d18SJames Chapman *bufp++ = htons(tunnel_id); 1047fd558d18SJames Chapman *bufp++ = htons(session_id); 1048fd558d18SJames Chapman if (session->send_seq) { 1049fd558d18SJames Chapman *bufp++ = htons(session->ns); 1050fd558d18SJames Chapman *bufp++ = 0; 1051fd558d18SJames Chapman session->ns++; 1052f7faffa3SJames Chapman session->ns &= 0xffff; 1053a4ca44faSJoe Perches l2tp_dbg(session, L2TP_MSG_SEQ, "%s: updated ns to %u\n", 1054a4ca44faSJoe Perches session->name, session->ns); 1055fd558d18SJames Chapman } 1056fd558d18SJames Chapman 1057f7faffa3SJames Chapman return bufp - optr; 1058f7faffa3SJames Chapman } 1059f7faffa3SJames Chapman 1060f7faffa3SJames Chapman static int l2tp_build_l2tpv3_header(struct l2tp_session *session, void *buf) 1061fd558d18SJames Chapman { 10620d76751fSJames Chapman struct l2tp_tunnel *tunnel = session->tunnel; 1063f7faffa3SJames Chapman char *bufp = buf; 1064f7faffa3SJames Chapman char *optr = bufp; 1065fd558d18SJames Chapman 10660d76751fSJames Chapman /* Setup L2TP header. The header differs slightly for UDP and 10670d76751fSJames Chapman * IP encapsulations. For UDP, there is 4 bytes of flags. 10680d76751fSJames Chapman */ 10690d76751fSJames Chapman if (tunnel->encap == L2TP_ENCAPTYPE_UDP) { 10700d76751fSJames Chapman u16 flags = L2TP_HDR_VER_3; 1071f7faffa3SJames Chapman *((__be16 *) bufp) = htons(flags); 1072f7faffa3SJames Chapman bufp += 2; 1073f7faffa3SJames Chapman *((__be16 *) bufp) = 0; 1074f7faffa3SJames Chapman bufp += 2; 10750d76751fSJames Chapman } 10760d76751fSJames Chapman 1077f7faffa3SJames Chapman *((__be32 *) bufp) = htonl(session->peer_session_id); 1078f7faffa3SJames Chapman bufp += 4; 1079f7faffa3SJames Chapman if (session->cookie_len) { 1080f7faffa3SJames Chapman memcpy(bufp, &session->cookie[0], session->cookie_len); 1081f7faffa3SJames Chapman bufp += session->cookie_len; 1082fd558d18SJames Chapman } 1083f7faffa3SJames Chapman if (session->l2specific_len) { 1084f7faffa3SJames Chapman if (session->l2specific_type == L2TP_L2SPECTYPE_DEFAULT) { 1085f7faffa3SJames Chapman u32 l2h = 0; 1086f7faffa3SJames Chapman if (session->send_seq) { 1087f7faffa3SJames Chapman l2h = 0x40000000 | session->ns; 1088f7faffa3SJames Chapman session->ns++; 1089f7faffa3SJames Chapman session->ns &= 0xffffff; 1090a4ca44faSJoe Perches l2tp_dbg(session, L2TP_MSG_SEQ, 1091a4ca44faSJoe Perches "%s: updated ns to %u\n", 1092a4ca44faSJoe Perches session->name, session->ns); 1093f7faffa3SJames Chapman } 1094f7faffa3SJames Chapman 1095f7faffa3SJames Chapman *((__be32 *) bufp) = htonl(l2h); 1096f7faffa3SJames Chapman } 1097f7faffa3SJames Chapman bufp += session->l2specific_len; 1098f7faffa3SJames Chapman } 1099f7faffa3SJames Chapman if (session->offset) 1100f7faffa3SJames Chapman bufp += session->offset; 1101f7faffa3SJames Chapman 1102f7faffa3SJames Chapman return bufp - optr; 1103f7faffa3SJames Chapman } 1104fd558d18SJames Chapman 1105fc130840Sstephen hemminger static int l2tp_xmit_core(struct l2tp_session *session, struct sk_buff *skb, 1106d9d8da80SDavid S. Miller struct flowi *fl, size_t data_len) 1107fd558d18SJames Chapman { 1108fd558d18SJames Chapman struct l2tp_tunnel *tunnel = session->tunnel; 1109fd558d18SJames Chapman unsigned int len = skb->len; 1110fd558d18SJames Chapman int error; 1111fd558d18SJames Chapman 1112fd558d18SJames Chapman /* Debug */ 1113fd558d18SJames Chapman if (session->send_seq) 1114a4ca44faSJoe Perches l2tp_dbg(session, L2TP_MSG_DATA, "%s: send %Zd bytes, ns=%u\n", 1115a4ca44faSJoe Perches session->name, data_len, session->ns - 1); 1116fd558d18SJames Chapman else 1117a4ca44faSJoe Perches l2tp_dbg(session, L2TP_MSG_DATA, "%s: send %Zd bytes\n", 1118a4ca44faSJoe Perches session->name, data_len); 1119fd558d18SJames Chapman 1120fd558d18SJames Chapman if (session->debug & L2TP_MSG_DATA) { 11210d76751fSJames Chapman int uhlen = (tunnel->encap == L2TP_ENCAPTYPE_UDP) ? sizeof(struct udphdr) : 0; 11220d76751fSJames Chapman unsigned char *datap = skb->data + uhlen; 1123fd558d18SJames Chapman 1124a4ca44faSJoe Perches pr_debug("%s: xmit\n", session->name); 1125a4ca44faSJoe Perches print_hex_dump_bytes("", DUMP_PREFIX_OFFSET, 1126a4ca44faSJoe Perches datap, min_t(size_t, 32, len - uhlen)); 1127fd558d18SJames Chapman } 1128fd558d18SJames Chapman 1129fd558d18SJames Chapman /* Queue the packet to IP for output */ 11304e15ed4dSShan Wei skb->local_df = 1; 1131d2cf3361SBenjamin LaHaise #if IS_ENABLED(CONFIG_IPV6) 1132*e18503f4SFrançois Cachereul if (skb->sk->sk_family == PF_INET6 && !tunnel->v4mapped) 1133d2cf3361SBenjamin LaHaise error = inet6_csk_xmit(skb, NULL); 1134d2cf3361SBenjamin LaHaise else 1135d2cf3361SBenjamin LaHaise #endif 1136d9d8da80SDavid S. Miller error = ip_queue_xmit(skb, fl); 1137fd558d18SJames Chapman 1138fd558d18SJames Chapman /* Update stats */ 1139fd558d18SJames Chapman if (error >= 0) { 11407b7c0719STom Parkin atomic_long_inc(&tunnel->stats.tx_packets); 11417b7c0719STom Parkin atomic_long_add(len, &tunnel->stats.tx_bytes); 11427b7c0719STom Parkin atomic_long_inc(&session->stats.tx_packets); 11437b7c0719STom Parkin atomic_long_add(len, &session->stats.tx_bytes); 1144fd558d18SJames Chapman } else { 11457b7c0719STom Parkin atomic_long_inc(&tunnel->stats.tx_errors); 11467b7c0719STom Parkin atomic_long_inc(&session->stats.tx_errors); 1147fd558d18SJames Chapman } 1148fd558d18SJames Chapman 1149fd558d18SJames Chapman return 0; 1150fd558d18SJames Chapman } 1151fd558d18SJames Chapman 1152fd558d18SJames Chapman /* Automatically called when the skb is freed. 1153fd558d18SJames Chapman */ 1154fd558d18SJames Chapman static void l2tp_sock_wfree(struct sk_buff *skb) 1155fd558d18SJames Chapman { 1156fd558d18SJames Chapman sock_put(skb->sk); 1157fd558d18SJames Chapman } 1158fd558d18SJames Chapman 1159fd558d18SJames Chapman /* For data skbs that we transmit, we associate with the tunnel socket 1160fd558d18SJames Chapman * but don't do accounting. 1161fd558d18SJames Chapman */ 1162fd558d18SJames Chapman static inline void l2tp_skb_set_owner_w(struct sk_buff *skb, struct sock *sk) 1163fd558d18SJames Chapman { 1164fd558d18SJames Chapman sock_hold(sk); 1165fd558d18SJames Chapman skb->sk = sk; 1166fd558d18SJames Chapman skb->destructor = l2tp_sock_wfree; 1167fd558d18SJames Chapman } 1168fd558d18SJames Chapman 1169d2cf3361SBenjamin LaHaise #if IS_ENABLED(CONFIG_IPV6) 1170d2cf3361SBenjamin LaHaise static void l2tp_xmit_ipv6_csum(struct sock *sk, struct sk_buff *skb, 1171d2cf3361SBenjamin LaHaise int udp_len) 1172d2cf3361SBenjamin LaHaise { 1173d2cf3361SBenjamin LaHaise struct ipv6_pinfo *np = inet6_sk(sk); 1174d2cf3361SBenjamin LaHaise struct udphdr *uh = udp_hdr(skb); 1175d2cf3361SBenjamin LaHaise 1176d2cf3361SBenjamin LaHaise if (!skb_dst(skb) || !skb_dst(skb)->dev || 1177d2cf3361SBenjamin LaHaise !(skb_dst(skb)->dev->features & NETIF_F_IPV6_CSUM)) { 1178d2cf3361SBenjamin LaHaise __wsum csum = skb_checksum(skb, 0, udp_len, 0); 1179d2cf3361SBenjamin LaHaise skb->ip_summed = CHECKSUM_UNNECESSARY; 1180d2cf3361SBenjamin LaHaise uh->check = csum_ipv6_magic(&np->saddr, &np->daddr, udp_len, 1181d2cf3361SBenjamin LaHaise IPPROTO_UDP, csum); 1182d2cf3361SBenjamin LaHaise if (uh->check == 0) 1183d2cf3361SBenjamin LaHaise uh->check = CSUM_MANGLED_0; 1184d2cf3361SBenjamin LaHaise } else { 1185d2cf3361SBenjamin LaHaise skb->ip_summed = CHECKSUM_PARTIAL; 1186d2cf3361SBenjamin LaHaise skb->csum_start = skb_transport_header(skb) - skb->head; 1187d2cf3361SBenjamin LaHaise skb->csum_offset = offsetof(struct udphdr, check); 1188d2cf3361SBenjamin LaHaise uh->check = ~csum_ipv6_magic(&np->saddr, &np->daddr, 1189d2cf3361SBenjamin LaHaise udp_len, IPPROTO_UDP, 0); 1190d2cf3361SBenjamin LaHaise } 1191d2cf3361SBenjamin LaHaise } 1192d2cf3361SBenjamin LaHaise #endif 1193d2cf3361SBenjamin LaHaise 1194fd558d18SJames Chapman /* If caller requires the skb to have a ppp header, the header must be 1195fd558d18SJames Chapman * inserted in the skb data before calling this function. 1196fd558d18SJames Chapman */ 1197fd558d18SJames Chapman int l2tp_xmit_skb(struct l2tp_session *session, struct sk_buff *skb, int hdr_len) 1198fd558d18SJames Chapman { 1199fd558d18SJames Chapman int data_len = skb->len; 12000d76751fSJames Chapman struct l2tp_tunnel *tunnel = session->tunnel; 12010d76751fSJames Chapman struct sock *sk = tunnel->sock; 1202d9d8da80SDavid S. Miller struct flowi *fl; 1203fd558d18SJames Chapman struct udphdr *uh; 1204fd558d18SJames Chapman struct inet_sock *inet; 1205fd558d18SJames Chapman __wsum csum; 1206fd558d18SJames Chapman int headroom; 12070d76751fSJames Chapman int uhlen = (tunnel->encap == L2TP_ENCAPTYPE_UDP) ? sizeof(struct udphdr) : 0; 12080d76751fSJames Chapman int udp_len; 1209b8c84307SEric Dumazet int ret = NET_XMIT_SUCCESS; 1210fd558d18SJames Chapman 1211fd558d18SJames Chapman /* Check that there's enough headroom in the skb to insert IP, 1212fd558d18SJames Chapman * UDP and L2TP headers. If not enough, expand it to 1213fd558d18SJames Chapman * make room. Adjust truesize. 1214fd558d18SJames Chapman */ 1215fd558d18SJames Chapman headroom = NET_SKB_PAD + sizeof(struct iphdr) + 12160d76751fSJames Chapman uhlen + hdr_len; 1217835acf5dSEric Dumazet if (skb_cow_head(skb, headroom)) { 1218b8c84307SEric Dumazet kfree_skb(skb); 1219b8c84307SEric Dumazet return NET_XMIT_DROP; 1220835acf5dSEric Dumazet } 1221fd558d18SJames Chapman 1222fd558d18SJames Chapman skb_orphan(skb); 1223fd558d18SJames Chapman /* Setup L2TP header */ 1224f7faffa3SJames Chapman session->build_header(session, __skb_push(skb, hdr_len)); 1225fd558d18SJames Chapman 12260d76751fSJames Chapman /* Reset skb netfilter state */ 1227fd558d18SJames Chapman memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt)); 1228fd558d18SJames Chapman IPCB(skb)->flags &= ~(IPSKB_XFRM_TUNNEL_SIZE | IPSKB_XFRM_TRANSFORMED | 1229fd558d18SJames Chapman IPSKB_REROUTED); 1230fd558d18SJames Chapman nf_reset(skb); 1231fd558d18SJames Chapman 12326af88da1SDavid S. Miller bh_lock_sock(sk); 12336af88da1SDavid S. Miller if (sock_owned_by_user(sk)) { 1234b8c84307SEric Dumazet kfree_skb(skb); 1235b8c84307SEric Dumazet ret = NET_XMIT_DROP; 12366af88da1SDavid S. Miller goto out_unlock; 12376af88da1SDavid S. Miller } 12386af88da1SDavid S. Miller 1239fd558d18SJames Chapman /* Get routing info from the tunnel socket */ 1240fd558d18SJames Chapman skb_dst_drop(skb); 124171b1391aSFlorian Westphal skb_dst_set(skb, dst_clone(__sk_dst_check(sk, 0))); 12420d76751fSJames Chapman 1243d9d8da80SDavid S. Miller inet = inet_sk(sk); 1244d9d8da80SDavid S. Miller fl = &inet->cork.fl; 12450d76751fSJames Chapman switch (tunnel->encap) { 12460d76751fSJames Chapman case L2TP_ENCAPTYPE_UDP: 12470d76751fSJames Chapman /* Setup UDP header */ 12480d76751fSJames Chapman __skb_push(skb, sizeof(*uh)); 12490d76751fSJames Chapman skb_reset_transport_header(skb); 12500d76751fSJames Chapman uh = udp_hdr(skb); 12510d76751fSJames Chapman uh->source = inet->inet_sport; 12520d76751fSJames Chapman uh->dest = inet->inet_dport; 12530d76751fSJames Chapman udp_len = uhlen + hdr_len + data_len; 12540d76751fSJames Chapman uh->len = htons(udp_len); 12550d76751fSJames Chapman uh->check = 0; 1256fd558d18SJames Chapman 1257fd558d18SJames Chapman /* Calculate UDP checksum if configured to do so */ 1258d2cf3361SBenjamin LaHaise #if IS_ENABLED(CONFIG_IPV6) 1259*e18503f4SFrançois Cachereul if (sk->sk_family == PF_INET6 && !tunnel->v4mapped) 1260d2cf3361SBenjamin LaHaise l2tp_xmit_ipv6_csum(sk, skb, udp_len); 1261d2cf3361SBenjamin LaHaise else 1262d2cf3361SBenjamin LaHaise #endif 1263fd558d18SJames Chapman if (sk->sk_no_check == UDP_CSUM_NOXMIT) 1264fd558d18SJames Chapman skb->ip_summed = CHECKSUM_NONE; 1265fd558d18SJames Chapman else if ((skb_dst(skb) && skb_dst(skb)->dev) && 1266fd558d18SJames Chapman (!(skb_dst(skb)->dev->features & NETIF_F_V4_CSUM))) { 1267fd558d18SJames Chapman skb->ip_summed = CHECKSUM_COMPLETE; 1268fd558d18SJames Chapman csum = skb_checksum(skb, 0, udp_len, 0); 1269fd558d18SJames Chapman uh->check = csum_tcpudp_magic(inet->inet_saddr, 1270fd558d18SJames Chapman inet->inet_daddr, 1271fd558d18SJames Chapman udp_len, IPPROTO_UDP, csum); 1272fd558d18SJames Chapman if (uh->check == 0) 1273fd558d18SJames Chapman uh->check = CSUM_MANGLED_0; 1274fd558d18SJames Chapman } else { 1275fd558d18SJames Chapman skb->ip_summed = CHECKSUM_PARTIAL; 1276fd558d18SJames Chapman skb->csum_start = skb_transport_header(skb) - skb->head; 1277fd558d18SJames Chapman skb->csum_offset = offsetof(struct udphdr, check); 1278fd558d18SJames Chapman uh->check = ~csum_tcpudp_magic(inet->inet_saddr, 1279fd558d18SJames Chapman inet->inet_daddr, 1280fd558d18SJames Chapman udp_len, IPPROTO_UDP, 0); 1281fd558d18SJames Chapman } 12820d76751fSJames Chapman break; 12830d76751fSJames Chapman 12840d76751fSJames Chapman case L2TP_ENCAPTYPE_IP: 12850d76751fSJames Chapman break; 12860d76751fSJames Chapman } 12870d76751fSJames Chapman 12880d76751fSJames Chapman l2tp_skb_set_owner_w(skb, sk); 1289fd558d18SJames Chapman 1290d9d8da80SDavid S. Miller l2tp_xmit_core(session, skb, fl, data_len); 12916af88da1SDavid S. Miller out_unlock: 12926af88da1SDavid S. Miller bh_unlock_sock(sk); 1293fd558d18SJames Chapman 1294b8c84307SEric Dumazet return ret; 1295fd558d18SJames Chapman } 1296fd558d18SJames Chapman EXPORT_SYMBOL_GPL(l2tp_xmit_skb); 1297fd558d18SJames Chapman 1298fd558d18SJames Chapman /***************************************************************************** 1299fd558d18SJames Chapman * Tinnel and session create/destroy. 1300fd558d18SJames Chapman *****************************************************************************/ 1301fd558d18SJames Chapman 1302fd558d18SJames Chapman /* Tunnel socket destruct hook. 1303fd558d18SJames Chapman * The tunnel context is deleted only when all session sockets have been 1304fd558d18SJames Chapman * closed. 1305fd558d18SJames Chapman */ 1306fc130840Sstephen hemminger static void l2tp_tunnel_destruct(struct sock *sk) 1307fd558d18SJames Chapman { 1308fd558d18SJames Chapman struct l2tp_tunnel *tunnel; 1309f8ccac0eSTom Parkin struct l2tp_net *pn; 1310fd558d18SJames Chapman 1311fd558d18SJames Chapman tunnel = sk->sk_user_data; 1312fd558d18SJames Chapman if (tunnel == NULL) 1313fd558d18SJames Chapman goto end; 1314fd558d18SJames Chapman 1315a4ca44faSJoe Perches l2tp_info(tunnel, L2TP_MSG_CONTROL, "%s: closing...\n", tunnel->name); 1316fd558d18SJames Chapman 1317fd558d18SJames Chapman 1318f8ccac0eSTom Parkin /* Disable udp encapsulation */ 13190d76751fSJames Chapman switch (tunnel->encap) { 13200d76751fSJames Chapman case L2TP_ENCAPTYPE_UDP: 1321fd558d18SJames Chapman /* No longer an encapsulation socket. See net/ipv4/udp.c */ 1322fd558d18SJames Chapman (udp_sk(sk))->encap_type = 0; 1323fd558d18SJames Chapman (udp_sk(sk))->encap_rcv = NULL; 13249980d001STom Parkin (udp_sk(sk))->encap_destroy = NULL; 13250d76751fSJames Chapman break; 13260d76751fSJames Chapman case L2TP_ENCAPTYPE_IP: 13270d76751fSJames Chapman break; 13280d76751fSJames Chapman } 1329fd558d18SJames Chapman 1330fd558d18SJames Chapman /* Remove hooks into tunnel socket */ 1331fd558d18SJames Chapman sk->sk_destruct = tunnel->old_sk_destruct; 1332fd558d18SJames Chapman sk->sk_user_data = NULL; 1333f8ccac0eSTom Parkin tunnel->sock = NULL; 1334f8ccac0eSTom Parkin 1335f8ccac0eSTom Parkin /* Remove the tunnel struct from the tunnel list */ 1336f8ccac0eSTom Parkin pn = l2tp_pernet(tunnel->l2tp_net); 1337f8ccac0eSTom Parkin spin_lock_bh(&pn->l2tp_tunnel_list_lock); 1338f8ccac0eSTom Parkin list_del_rcu(&tunnel->list); 1339f8ccac0eSTom Parkin spin_unlock_bh(&pn->l2tp_tunnel_list_lock); 1340f8ccac0eSTom Parkin atomic_dec(&l2tp_tunnel_count); 1341f8ccac0eSTom Parkin 1342f8ccac0eSTom Parkin l2tp_tunnel_closeall(tunnel); 1343f8ccac0eSTom Parkin l2tp_tunnel_dec_refcount(tunnel); 1344fd558d18SJames Chapman 1345fd558d18SJames Chapman /* Call the original destructor */ 1346fd558d18SJames Chapman if (sk->sk_destruct) 1347fd558d18SJames Chapman (*sk->sk_destruct)(sk); 1348fd558d18SJames Chapman end: 1349fd558d18SJames Chapman return; 1350fd558d18SJames Chapman } 1351fd558d18SJames Chapman 1352fd558d18SJames Chapman /* When the tunnel is closed, all the attached sessions need to go too. 1353fd558d18SJames Chapman */ 1354e34f4c70STom Parkin void l2tp_tunnel_closeall(struct l2tp_tunnel *tunnel) 1355fd558d18SJames Chapman { 1356fd558d18SJames Chapman int hash; 1357fd558d18SJames Chapman struct hlist_node *walk; 1358fd558d18SJames Chapman struct hlist_node *tmp; 1359fd558d18SJames Chapman struct l2tp_session *session; 1360fd558d18SJames Chapman 1361fd558d18SJames Chapman BUG_ON(tunnel == NULL); 1362fd558d18SJames Chapman 1363a4ca44faSJoe Perches l2tp_info(tunnel, L2TP_MSG_CONTROL, "%s: closing all sessions...\n", 1364a4ca44faSJoe Perches tunnel->name); 1365fd558d18SJames Chapman 1366fd558d18SJames Chapman write_lock_bh(&tunnel->hlist_lock); 1367fd558d18SJames Chapman for (hash = 0; hash < L2TP_HASH_SIZE; hash++) { 1368fd558d18SJames Chapman again: 1369fd558d18SJames Chapman hlist_for_each_safe(walk, tmp, &tunnel->session_hlist[hash]) { 1370fd558d18SJames Chapman session = hlist_entry(walk, struct l2tp_session, hlist); 1371fd558d18SJames Chapman 1372a4ca44faSJoe Perches l2tp_info(session, L2TP_MSG_CONTROL, 1373fd558d18SJames Chapman "%s: closing session\n", session->name); 1374fd558d18SJames Chapman 1375fd558d18SJames Chapman hlist_del_init(&session->hlist); 1376fd558d18SJames Chapman 1377fd558d18SJames Chapman if (session->ref != NULL) 1378fd558d18SJames Chapman (*session->ref)(session); 1379fd558d18SJames Chapman 1380fd558d18SJames Chapman write_unlock_bh(&tunnel->hlist_lock); 1381fd558d18SJames Chapman 1382f6e16b29STom Parkin __l2tp_session_unhash(session); 13834c6e2fd3STom Parkin l2tp_session_queue_purge(session); 13844c6e2fd3STom Parkin 1385fd558d18SJames Chapman if (session->session_close != NULL) 1386fd558d18SJames Chapman (*session->session_close)(session); 1387fd558d18SJames Chapman 1388fd558d18SJames Chapman if (session->deref != NULL) 1389fd558d18SJames Chapman (*session->deref)(session); 1390fd558d18SJames Chapman 13919980d001STom Parkin l2tp_session_dec_refcount(session); 13929980d001STom Parkin 1393fd558d18SJames Chapman write_lock_bh(&tunnel->hlist_lock); 1394fd558d18SJames Chapman 1395fd558d18SJames Chapman /* Now restart from the beginning of this hash 1396fd558d18SJames Chapman * chain. We always remove a session from the 1397fd558d18SJames Chapman * list so we are guaranteed to make forward 1398fd558d18SJames Chapman * progress. 1399fd558d18SJames Chapman */ 1400fd558d18SJames Chapman goto again; 1401fd558d18SJames Chapman } 1402fd558d18SJames Chapman } 1403fd558d18SJames Chapman write_unlock_bh(&tunnel->hlist_lock); 1404fd558d18SJames Chapman } 1405e34f4c70STom Parkin EXPORT_SYMBOL_GPL(l2tp_tunnel_closeall); 1406fd558d18SJames Chapman 14079980d001STom Parkin /* Tunnel socket destroy hook for UDP encapsulation */ 14089980d001STom Parkin static void l2tp_udp_encap_destroy(struct sock *sk) 14099980d001STom Parkin { 14109980d001STom Parkin struct l2tp_tunnel *tunnel = l2tp_sock_to_tunnel(sk); 14119980d001STom Parkin if (tunnel) { 14129980d001STom Parkin l2tp_tunnel_closeall(tunnel); 14139980d001STom Parkin sock_put(sk); 14149980d001STom Parkin } 14159980d001STom Parkin } 14169980d001STom Parkin 1417fd558d18SJames Chapman /* Really kill the tunnel. 1418fd558d18SJames Chapman * Come here only when all sessions have been cleared from the tunnel. 1419fd558d18SJames Chapman */ 1420fc130840Sstephen hemminger static void l2tp_tunnel_free(struct l2tp_tunnel *tunnel) 1421fd558d18SJames Chapman { 1422fd558d18SJames Chapman BUG_ON(atomic_read(&tunnel->ref_count) != 0); 1423fd558d18SJames Chapman BUG_ON(tunnel->sock != NULL); 1424a4ca44faSJoe Perches l2tp_info(tunnel, L2TP_MSG_CONTROL, "%s: free...\n", tunnel->name); 142599469c32Sxeb@mail.ru kfree_rcu(tunnel, rcu); 1426f8ccac0eSTom Parkin } 1427fd558d18SJames Chapman 1428f8ccac0eSTom Parkin /* Workqueue tunnel deletion function */ 1429f8ccac0eSTom Parkin static void l2tp_tunnel_del_work(struct work_struct *work) 1430f8ccac0eSTom Parkin { 1431f8ccac0eSTom Parkin struct l2tp_tunnel *tunnel = NULL; 1432f8ccac0eSTom Parkin struct socket *sock = NULL; 1433f8ccac0eSTom Parkin struct sock *sk = NULL; 1434f8ccac0eSTom Parkin 1435f8ccac0eSTom Parkin tunnel = container_of(work, struct l2tp_tunnel, del_work); 1436f8ccac0eSTom Parkin sk = l2tp_tunnel_sock_lookup(tunnel); 1437f8ccac0eSTom Parkin if (!sk) 1438f8ccac0eSTom Parkin return; 1439f8ccac0eSTom Parkin 1440f8ccac0eSTom Parkin sock = sk->sk_socket; 1441f8ccac0eSTom Parkin 144202d13ed5STom Parkin /* If the tunnel socket was created by userspace, then go through the 144302d13ed5STom Parkin * inet layer to shut the socket down, and let userspace close it. 144402d13ed5STom Parkin * Otherwise, if we created the socket directly within the kernel, use 144502d13ed5STom Parkin * the sk API to release it here. 1446167eb17eSTom Parkin * In either case the tunnel resources are freed in the socket 1447167eb17eSTom Parkin * destructor when the tunnel socket goes away. 1448f8ccac0eSTom Parkin */ 144902d13ed5STom Parkin if (tunnel->fd >= 0) { 145002d13ed5STom Parkin if (sock) 145102d13ed5STom Parkin inet_shutdown(sock, 2); 145202d13ed5STom Parkin } else { 145302d13ed5STom Parkin if (sock) 1454167eb17eSTom Parkin kernel_sock_shutdown(sock, SHUT_RDWR); 1455167eb17eSTom Parkin sk_release_kernel(sk); 1456167eb17eSTom Parkin } 1457f8ccac0eSTom Parkin 1458f8ccac0eSTom Parkin l2tp_tunnel_sock_put(sk); 1459fd558d18SJames Chapman } 1460fd558d18SJames Chapman 1461789a4a2cSJames Chapman /* Create a socket for the tunnel, if one isn't set up by 1462789a4a2cSJames Chapman * userspace. This is used for static tunnels where there is no 1463789a4a2cSJames Chapman * managing L2TP daemon. 1464167eb17eSTom Parkin * 1465167eb17eSTom Parkin * Since we don't want these sockets to keep a namespace alive by 1466167eb17eSTom Parkin * themselves, we drop the socket's namespace refcount after creation. 1467167eb17eSTom Parkin * These sockets are freed when the namespace exits using the pernet 1468167eb17eSTom Parkin * exit hook. 1469789a4a2cSJames Chapman */ 1470167eb17eSTom Parkin static int l2tp_tunnel_sock_create(struct net *net, 1471167eb17eSTom Parkin u32 tunnel_id, 1472167eb17eSTom Parkin u32 peer_tunnel_id, 1473167eb17eSTom Parkin struct l2tp_tunnel_cfg *cfg, 1474167eb17eSTom Parkin struct socket **sockp) 1475789a4a2cSJames Chapman { 1476789a4a2cSJames Chapman int err = -EINVAL; 14777bddd0dbSEric Dumazet struct socket *sock = NULL; 1478167eb17eSTom Parkin struct sockaddr_in udp_addr = {0}; 1479167eb17eSTom Parkin struct sockaddr_l2tpip ip_addr = {0}; 1480167eb17eSTom Parkin #if IS_ENABLED(CONFIG_IPV6) 1481167eb17eSTom Parkin struct sockaddr_in6 udp6_addr = {0}; 1482167eb17eSTom Parkin struct sockaddr_l2tpip6 ip6_addr = {0}; 1483167eb17eSTom Parkin #endif 1484789a4a2cSJames Chapman 1485789a4a2cSJames Chapman switch (cfg->encap) { 1486789a4a2cSJames Chapman case L2TP_ENCAPTYPE_UDP: 1487f9bac8dfSChris Elston #if IS_ENABLED(CONFIG_IPV6) 1488f9bac8dfSChris Elston if (cfg->local_ip6 && cfg->peer_ip6) { 1489167eb17eSTom Parkin err = sock_create_kern(AF_INET6, SOCK_DGRAM, 0, &sock); 1490f9bac8dfSChris Elston if (err < 0) 1491f9bac8dfSChris Elston goto out; 1492f9bac8dfSChris Elston 1493167eb17eSTom Parkin sk_change_net(sock->sk, net); 1494f9bac8dfSChris Elston 1495f9bac8dfSChris Elston udp6_addr.sin6_family = AF_INET6; 1496f9bac8dfSChris Elston memcpy(&udp6_addr.sin6_addr, cfg->local_ip6, 1497f9bac8dfSChris Elston sizeof(udp6_addr.sin6_addr)); 1498f9bac8dfSChris Elston udp6_addr.sin6_port = htons(cfg->local_udp_port); 1499f9bac8dfSChris Elston err = kernel_bind(sock, (struct sockaddr *) &udp6_addr, 1500f9bac8dfSChris Elston sizeof(udp6_addr)); 1501f9bac8dfSChris Elston if (err < 0) 1502f9bac8dfSChris Elston goto out; 1503f9bac8dfSChris Elston 1504f9bac8dfSChris Elston udp6_addr.sin6_family = AF_INET6; 1505f9bac8dfSChris Elston memcpy(&udp6_addr.sin6_addr, cfg->peer_ip6, 1506f9bac8dfSChris Elston sizeof(udp6_addr.sin6_addr)); 1507f9bac8dfSChris Elston udp6_addr.sin6_port = htons(cfg->peer_udp_port); 1508f9bac8dfSChris Elston err = kernel_connect(sock, 1509f9bac8dfSChris Elston (struct sockaddr *) &udp6_addr, 1510f9bac8dfSChris Elston sizeof(udp6_addr), 0); 1511f9bac8dfSChris Elston if (err < 0) 1512f9bac8dfSChris Elston goto out; 1513f9bac8dfSChris Elston } else 1514f9bac8dfSChris Elston #endif 1515f9bac8dfSChris Elston { 1516167eb17eSTom Parkin err = sock_create_kern(AF_INET, SOCK_DGRAM, 0, &sock); 1517789a4a2cSJames Chapman if (err < 0) 1518789a4a2cSJames Chapman goto out; 1519789a4a2cSJames Chapman 1520167eb17eSTom Parkin sk_change_net(sock->sk, net); 1521789a4a2cSJames Chapman 1522789a4a2cSJames Chapman udp_addr.sin_family = AF_INET; 1523789a4a2cSJames Chapman udp_addr.sin_addr = cfg->local_ip; 1524789a4a2cSJames Chapman udp_addr.sin_port = htons(cfg->local_udp_port); 1525f9bac8dfSChris Elston err = kernel_bind(sock, (struct sockaddr *) &udp_addr, 1526f9bac8dfSChris Elston sizeof(udp_addr)); 1527789a4a2cSJames Chapman if (err < 0) 1528789a4a2cSJames Chapman goto out; 1529789a4a2cSJames Chapman 1530789a4a2cSJames Chapman udp_addr.sin_family = AF_INET; 1531789a4a2cSJames Chapman udp_addr.sin_addr = cfg->peer_ip; 1532789a4a2cSJames Chapman udp_addr.sin_port = htons(cfg->peer_udp_port); 1533f9bac8dfSChris Elston err = kernel_connect(sock, 1534f9bac8dfSChris Elston (struct sockaddr *) &udp_addr, 1535f9bac8dfSChris Elston sizeof(udp_addr), 0); 1536789a4a2cSJames Chapman if (err < 0) 1537789a4a2cSJames Chapman goto out; 1538f9bac8dfSChris Elston } 1539789a4a2cSJames Chapman 1540789a4a2cSJames Chapman if (!cfg->use_udp_checksums) 1541789a4a2cSJames Chapman sock->sk->sk_no_check = UDP_CSUM_NOXMIT; 1542789a4a2cSJames Chapman 1543789a4a2cSJames Chapman break; 1544789a4a2cSJames Chapman 1545789a4a2cSJames Chapman case L2TP_ENCAPTYPE_IP: 1546f9bac8dfSChris Elston #if IS_ENABLED(CONFIG_IPV6) 1547f9bac8dfSChris Elston if (cfg->local_ip6 && cfg->peer_ip6) { 1548167eb17eSTom Parkin err = sock_create_kern(AF_INET6, SOCK_DGRAM, 1549167eb17eSTom Parkin IPPROTO_L2TP, &sock); 15505dac94e1SJames Chapman if (err < 0) 1551f9bac8dfSChris Elston goto out; 15525dac94e1SJames Chapman 1553167eb17eSTom Parkin sk_change_net(sock->sk, net); 15545dac94e1SJames Chapman 15555dac94e1SJames Chapman ip6_addr.l2tp_family = AF_INET6; 15565dac94e1SJames Chapman memcpy(&ip6_addr.l2tp_addr, cfg->local_ip6, 15575dac94e1SJames Chapman sizeof(ip6_addr.l2tp_addr)); 15585dac94e1SJames Chapman ip6_addr.l2tp_conn_id = tunnel_id; 15595dac94e1SJames Chapman err = kernel_bind(sock, (struct sockaddr *) &ip6_addr, 15605dac94e1SJames Chapman sizeof(ip6_addr)); 15615dac94e1SJames Chapman if (err < 0) 15625dac94e1SJames Chapman goto out; 15635dac94e1SJames Chapman 15645dac94e1SJames Chapman ip6_addr.l2tp_family = AF_INET6; 15655dac94e1SJames Chapman memcpy(&ip6_addr.l2tp_addr, cfg->peer_ip6, 15665dac94e1SJames Chapman sizeof(ip6_addr.l2tp_addr)); 15675dac94e1SJames Chapman ip6_addr.l2tp_conn_id = peer_tunnel_id; 15685dac94e1SJames Chapman err = kernel_connect(sock, 15695dac94e1SJames Chapman (struct sockaddr *) &ip6_addr, 15705dac94e1SJames Chapman sizeof(ip6_addr), 0); 15715dac94e1SJames Chapman if (err < 0) 15725dac94e1SJames Chapman goto out; 15735dac94e1SJames Chapman } else 1574f9bac8dfSChris Elston #endif 15755dac94e1SJames Chapman { 1576167eb17eSTom Parkin err = sock_create_kern(AF_INET, SOCK_DGRAM, 1577167eb17eSTom Parkin IPPROTO_L2TP, &sock); 1578789a4a2cSJames Chapman if (err < 0) 1579789a4a2cSJames Chapman goto out; 1580789a4a2cSJames Chapman 1581167eb17eSTom Parkin sk_change_net(sock->sk, net); 1582789a4a2cSJames Chapman 1583789a4a2cSJames Chapman ip_addr.l2tp_family = AF_INET; 1584789a4a2cSJames Chapman ip_addr.l2tp_addr = cfg->local_ip; 1585789a4a2cSJames Chapman ip_addr.l2tp_conn_id = tunnel_id; 15865dac94e1SJames Chapman err = kernel_bind(sock, (struct sockaddr *) &ip_addr, 15875dac94e1SJames Chapman sizeof(ip_addr)); 1588789a4a2cSJames Chapman if (err < 0) 1589789a4a2cSJames Chapman goto out; 1590789a4a2cSJames Chapman 1591789a4a2cSJames Chapman ip_addr.l2tp_family = AF_INET; 1592789a4a2cSJames Chapman ip_addr.l2tp_addr = cfg->peer_ip; 1593789a4a2cSJames Chapman ip_addr.l2tp_conn_id = peer_tunnel_id; 15945dac94e1SJames Chapman err = kernel_connect(sock, (struct sockaddr *) &ip_addr, 15955dac94e1SJames Chapman sizeof(ip_addr), 0); 1596789a4a2cSJames Chapman if (err < 0) 1597789a4a2cSJames Chapman goto out; 15985dac94e1SJames Chapman } 1599789a4a2cSJames Chapman break; 1600789a4a2cSJames Chapman 1601789a4a2cSJames Chapman default: 1602789a4a2cSJames Chapman goto out; 1603789a4a2cSJames Chapman } 1604789a4a2cSJames Chapman 1605789a4a2cSJames Chapman out: 1606167eb17eSTom Parkin *sockp = sock; 1607789a4a2cSJames Chapman if ((err < 0) && sock) { 1608167eb17eSTom Parkin kernel_sock_shutdown(sock, SHUT_RDWR); 1609167eb17eSTom Parkin sk_release_kernel(sock->sk); 1610789a4a2cSJames Chapman *sockp = NULL; 1611789a4a2cSJames Chapman } 1612789a4a2cSJames Chapman 1613789a4a2cSJames Chapman return err; 1614789a4a2cSJames Chapman } 1615789a4a2cSJames Chapman 161637159ef2SEric Dumazet static struct lock_class_key l2tp_socket_class; 161737159ef2SEric Dumazet 1618fd558d18SJames 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) 1619fd558d18SJames Chapman { 1620fd558d18SJames Chapman struct l2tp_tunnel *tunnel = NULL; 1621fd558d18SJames Chapman int err; 1622fd558d18SJames Chapman struct socket *sock = NULL; 1623fd558d18SJames Chapman struct sock *sk = NULL; 1624fd558d18SJames Chapman struct l2tp_net *pn; 16250d76751fSJames Chapman enum l2tp_encap_type encap = L2TP_ENCAPTYPE_UDP; 1626fd558d18SJames Chapman 1627fd558d18SJames Chapman /* Get the tunnel socket from the fd, which was opened by 1628789a4a2cSJames Chapman * the userspace L2TP daemon. If not specified, create a 1629789a4a2cSJames Chapman * kernel socket. 1630fd558d18SJames Chapman */ 1631789a4a2cSJames Chapman if (fd < 0) { 1632167eb17eSTom Parkin err = l2tp_tunnel_sock_create(net, tunnel_id, peer_tunnel_id, 1633167eb17eSTom Parkin cfg, &sock); 1634789a4a2cSJames Chapman if (err < 0) 1635789a4a2cSJames Chapman goto err; 1636789a4a2cSJames Chapman } else { 1637fd558d18SJames Chapman sock = sockfd_lookup(fd, &err); 1638fd558d18SJames Chapman if (!sock) { 1639cbb95e0cSTom Parkin pr_err("tunl %u: sockfd_lookup(fd=%d) returned %d\n", 1640fd558d18SJames Chapman tunnel_id, fd, err); 1641cbb95e0cSTom Parkin err = -EBADF; 1642cbb95e0cSTom Parkin goto err; 1643cbb95e0cSTom Parkin } 1644cbb95e0cSTom Parkin 1645cbb95e0cSTom Parkin /* Reject namespace mismatches */ 1646cbb95e0cSTom Parkin if (!net_eq(sock_net(sock->sk), net)) { 1647cbb95e0cSTom Parkin pr_err("tunl %u: netns mismatch\n", tunnel_id); 1648cbb95e0cSTom Parkin err = -EINVAL; 1649fd558d18SJames Chapman goto err; 1650fd558d18SJames Chapman } 1651789a4a2cSJames Chapman } 1652fd558d18SJames Chapman 1653fd558d18SJames Chapman sk = sock->sk; 1654fd558d18SJames Chapman 16550d76751fSJames Chapman if (cfg != NULL) 16560d76751fSJames Chapman encap = cfg->encap; 16570d76751fSJames Chapman 1658fd558d18SJames Chapman /* Quick sanity checks */ 16590d76751fSJames Chapman switch (encap) { 16600d76751fSJames Chapman case L2TP_ENCAPTYPE_UDP: 1661fd558d18SJames Chapman err = -EPROTONOSUPPORT; 1662fd558d18SJames Chapman if (sk->sk_protocol != IPPROTO_UDP) { 1663a4ca44faSJoe Perches pr_err("tunl %hu: fd %d wrong protocol, got %d, expected %d\n", 1664fd558d18SJames Chapman tunnel_id, fd, sk->sk_protocol, IPPROTO_UDP); 1665fd558d18SJames Chapman goto err; 1666fd558d18SJames Chapman } 16670d76751fSJames Chapman break; 16680d76751fSJames Chapman case L2TP_ENCAPTYPE_IP: 16690d76751fSJames Chapman err = -EPROTONOSUPPORT; 16700d76751fSJames Chapman if (sk->sk_protocol != IPPROTO_L2TP) { 1671a4ca44faSJoe Perches pr_err("tunl %hu: fd %d wrong protocol, got %d, expected %d\n", 16720d76751fSJames Chapman tunnel_id, fd, sk->sk_protocol, IPPROTO_L2TP); 1673fd558d18SJames Chapman goto err; 1674fd558d18SJames Chapman } 16750d76751fSJames Chapman break; 16760d76751fSJames Chapman } 1677fd558d18SJames Chapman 1678fd558d18SJames Chapman /* Check if this socket has already been prepped */ 1679fd558d18SJames Chapman tunnel = (struct l2tp_tunnel *)sk->sk_user_data; 1680fd558d18SJames Chapman if (tunnel != NULL) { 1681fd558d18SJames Chapman /* This socket has already been prepped */ 1682fd558d18SJames Chapman err = -EBUSY; 1683fd558d18SJames Chapman goto err; 1684fd558d18SJames Chapman } 1685fd558d18SJames Chapman 1686fd558d18SJames Chapman tunnel = kzalloc(sizeof(struct l2tp_tunnel), GFP_KERNEL); 1687fd558d18SJames Chapman if (tunnel == NULL) { 1688fd558d18SJames Chapman err = -ENOMEM; 1689fd558d18SJames Chapman goto err; 1690fd558d18SJames Chapman } 1691fd558d18SJames Chapman 1692fd558d18SJames Chapman tunnel->version = version; 1693fd558d18SJames Chapman tunnel->tunnel_id = tunnel_id; 1694fd558d18SJames Chapman tunnel->peer_tunnel_id = peer_tunnel_id; 1695fd558d18SJames Chapman tunnel->debug = L2TP_DEFAULT_DEBUG_FLAGS; 1696fd558d18SJames Chapman 1697fd558d18SJames Chapman tunnel->magic = L2TP_TUNNEL_MAGIC; 1698fd558d18SJames Chapman sprintf(&tunnel->name[0], "tunl %u", tunnel_id); 1699fd558d18SJames Chapman rwlock_init(&tunnel->hlist_lock); 1700fd558d18SJames Chapman 1701fd558d18SJames Chapman /* The net we belong to */ 1702fd558d18SJames Chapman tunnel->l2tp_net = net; 1703fd558d18SJames Chapman pn = l2tp_pernet(net); 1704fd558d18SJames Chapman 17050d76751fSJames Chapman if (cfg != NULL) 1706fd558d18SJames Chapman tunnel->debug = cfg->debug; 1707fd558d18SJames Chapman 1708*e18503f4SFrançois Cachereul #if IS_ENABLED(CONFIG_IPV6) 1709*e18503f4SFrançois Cachereul if (sk->sk_family == PF_INET6) { 1710*e18503f4SFrançois Cachereul struct ipv6_pinfo *np = inet6_sk(sk); 1711*e18503f4SFrançois Cachereul 1712*e18503f4SFrançois Cachereul if (ipv6_addr_v4mapped(&np->saddr) && 1713*e18503f4SFrançois Cachereul ipv6_addr_v4mapped(&np->daddr)) { 1714*e18503f4SFrançois Cachereul struct inet_sock *inet = inet_sk(sk); 1715*e18503f4SFrançois Cachereul 1716*e18503f4SFrançois Cachereul tunnel->v4mapped = true; 1717*e18503f4SFrançois Cachereul inet->inet_saddr = np->saddr.s6_addr32[3]; 1718*e18503f4SFrançois Cachereul inet->inet_rcv_saddr = np->rcv_saddr.s6_addr32[3]; 1719*e18503f4SFrançois Cachereul inet->inet_daddr = np->daddr.s6_addr32[3]; 1720*e18503f4SFrançois Cachereul } else { 1721*e18503f4SFrançois Cachereul tunnel->v4mapped = false; 1722*e18503f4SFrançois Cachereul } 1723*e18503f4SFrançois Cachereul } 1724*e18503f4SFrançois Cachereul #endif 1725*e18503f4SFrançois Cachereul 1726fd558d18SJames Chapman /* Mark socket as an encapsulation socket. See net/ipv4/udp.c */ 17270d76751fSJames Chapman tunnel->encap = encap; 17280d76751fSJames Chapman if (encap == L2TP_ENCAPTYPE_UDP) { 17290d76751fSJames Chapman /* Mark socket as an encapsulation socket. See net/ipv4/udp.c */ 1730fd558d18SJames Chapman udp_sk(sk)->encap_type = UDP_ENCAP_L2TPINUDP; 1731fd558d18SJames Chapman udp_sk(sk)->encap_rcv = l2tp_udp_encap_recv; 17329980d001STom Parkin udp_sk(sk)->encap_destroy = l2tp_udp_encap_destroy; 1733d2cf3361SBenjamin LaHaise #if IS_ENABLED(CONFIG_IPV6) 1734*e18503f4SFrançois Cachereul if (sk->sk_family == PF_INET6 && !tunnel->v4mapped) 1735d2cf3361SBenjamin LaHaise udpv6_encap_enable(); 1736d2cf3361SBenjamin LaHaise else 1737d2cf3361SBenjamin LaHaise #endif 1738447167bfSEric Dumazet udp_encap_enable(); 17390d76751fSJames Chapman } 1740fd558d18SJames Chapman 1741fd558d18SJames Chapman sk->sk_user_data = tunnel; 1742fd558d18SJames Chapman 1743fd558d18SJames Chapman /* Hook on the tunnel socket destructor so that we can cleanup 1744fd558d18SJames Chapman * if the tunnel socket goes away. 1745fd558d18SJames Chapman */ 1746fd558d18SJames Chapman tunnel->old_sk_destruct = sk->sk_destruct; 1747fd558d18SJames Chapman sk->sk_destruct = &l2tp_tunnel_destruct; 1748fd558d18SJames Chapman tunnel->sock = sk; 174980d84ef3STom Parkin tunnel->fd = fd; 175037159ef2SEric Dumazet lockdep_set_class_and_name(&sk->sk_lock.slock, &l2tp_socket_class, "l2tp_sock"); 175137159ef2SEric Dumazet 1752fd558d18SJames Chapman sk->sk_allocation = GFP_ATOMIC; 1753fd558d18SJames Chapman 1754f8ccac0eSTom Parkin /* Init delete workqueue struct */ 1755f8ccac0eSTom Parkin INIT_WORK(&tunnel->del_work, l2tp_tunnel_del_work); 1756f8ccac0eSTom Parkin 1757fd558d18SJames Chapman /* Add tunnel to our list */ 1758fd558d18SJames Chapman INIT_LIST_HEAD(&tunnel->list); 1759fd558d18SJames Chapman atomic_inc(&l2tp_tunnel_count); 1760fd558d18SJames Chapman 1761fd558d18SJames Chapman /* Bump the reference count. The tunnel context is deleted 17621769192aSEric Dumazet * only when this drops to zero. Must be done before list insertion 1763fd558d18SJames Chapman */ 1764fd558d18SJames Chapman l2tp_tunnel_inc_refcount(tunnel); 17651769192aSEric Dumazet spin_lock_bh(&pn->l2tp_tunnel_list_lock); 17661769192aSEric Dumazet list_add_rcu(&tunnel->list, &pn->l2tp_tunnel_list); 17671769192aSEric Dumazet spin_unlock_bh(&pn->l2tp_tunnel_list_lock); 1768fd558d18SJames Chapman 1769fd558d18SJames Chapman err = 0; 1770fd558d18SJames Chapman err: 1771fd558d18SJames Chapman if (tunnelp) 1772fd558d18SJames Chapman *tunnelp = tunnel; 1773fd558d18SJames Chapman 1774789a4a2cSJames Chapman /* If tunnel's socket was created by the kernel, it doesn't 1775789a4a2cSJames Chapman * have a file. 1776789a4a2cSJames Chapman */ 1777789a4a2cSJames Chapman if (sock && sock->file) 1778fd558d18SJames Chapman sockfd_put(sock); 1779fd558d18SJames Chapman 1780fd558d18SJames Chapman return err; 1781fd558d18SJames Chapman } 1782fd558d18SJames Chapman EXPORT_SYMBOL_GPL(l2tp_tunnel_create); 1783fd558d18SJames Chapman 1784309795f4SJames Chapman /* This function is used by the netlink TUNNEL_DELETE command. 1785309795f4SJames Chapman */ 1786309795f4SJames Chapman int l2tp_tunnel_delete(struct l2tp_tunnel *tunnel) 1787309795f4SJames Chapman { 17882b551c6eSTom Parkin l2tp_tunnel_closeall(tunnel); 1789f8ccac0eSTom Parkin return (false == queue_work(l2tp_wq, &tunnel->del_work)); 1790309795f4SJames Chapman } 1791309795f4SJames Chapman EXPORT_SYMBOL_GPL(l2tp_tunnel_delete); 1792309795f4SJames Chapman 1793fd558d18SJames Chapman /* Really kill the session. 1794fd558d18SJames Chapman */ 1795fd558d18SJames Chapman void l2tp_session_free(struct l2tp_session *session) 1796fd558d18SJames Chapman { 1797f6e16b29STom Parkin struct l2tp_tunnel *tunnel = session->tunnel; 1798fd558d18SJames Chapman 1799fd558d18SJames Chapman BUG_ON(atomic_read(&session->ref_count) != 0); 1800fd558d18SJames Chapman 1801f6e16b29STom Parkin if (tunnel) { 1802fd558d18SJames Chapman BUG_ON(tunnel->magic != L2TP_TUNNEL_MAGIC); 1803fd558d18SJames Chapman if (session->session_id != 0) 1804fd558d18SJames Chapman atomic_dec(&l2tp_session_count); 1805fd558d18SJames Chapman sock_put(tunnel->sock); 1806fd558d18SJames Chapman session->tunnel = NULL; 1807fd558d18SJames Chapman l2tp_tunnel_dec_refcount(tunnel); 1808fd558d18SJames Chapman } 1809fd558d18SJames Chapman 1810fd558d18SJames Chapman kfree(session); 1811fd558d18SJames Chapman 1812fd558d18SJames Chapman return; 1813fd558d18SJames Chapman } 1814fd558d18SJames Chapman EXPORT_SYMBOL_GPL(l2tp_session_free); 1815fd558d18SJames Chapman 1816f6e16b29STom Parkin /* Remove an l2tp session from l2tp_core's hash lists. 1817f6e16b29STom Parkin * Provides a tidyup interface for pseudowire code which can't just route all 1818f6e16b29STom Parkin * shutdown via. l2tp_session_delete and a pseudowire-specific session_close 1819f6e16b29STom Parkin * callback. 1820f6e16b29STom Parkin */ 1821f6e16b29STom Parkin void __l2tp_session_unhash(struct l2tp_session *session) 1822f6e16b29STom Parkin { 1823f6e16b29STom Parkin struct l2tp_tunnel *tunnel = session->tunnel; 1824f6e16b29STom Parkin 1825f6e16b29STom Parkin /* Remove the session from core hashes */ 1826f6e16b29STom Parkin if (tunnel) { 1827f6e16b29STom Parkin /* Remove from the per-tunnel hash */ 1828f6e16b29STom Parkin write_lock_bh(&tunnel->hlist_lock); 1829f6e16b29STom Parkin hlist_del_init(&session->hlist); 1830f6e16b29STom Parkin write_unlock_bh(&tunnel->hlist_lock); 1831f6e16b29STom Parkin 1832f6e16b29STom Parkin /* For L2TPv3 we have a per-net hash: remove from there, too */ 1833f6e16b29STom Parkin if (tunnel->version != L2TP_HDR_VER_2) { 1834f6e16b29STom Parkin struct l2tp_net *pn = l2tp_pernet(tunnel->l2tp_net); 1835f6e16b29STom Parkin spin_lock_bh(&pn->l2tp_session_hlist_lock); 1836f6e16b29STom Parkin hlist_del_init_rcu(&session->global_hlist); 1837f6e16b29STom Parkin spin_unlock_bh(&pn->l2tp_session_hlist_lock); 1838f6e16b29STom Parkin synchronize_rcu(); 1839f6e16b29STom Parkin } 1840f6e16b29STom Parkin } 1841f6e16b29STom Parkin } 1842f6e16b29STom Parkin EXPORT_SYMBOL_GPL(__l2tp_session_unhash); 1843f6e16b29STom Parkin 1844309795f4SJames Chapman /* This function is used by the netlink SESSION_DELETE command and by 1845309795f4SJames Chapman pseudowire modules. 1846309795f4SJames Chapman */ 1847309795f4SJames Chapman int l2tp_session_delete(struct l2tp_session *session) 1848309795f4SJames Chapman { 1849f6e16b29STom Parkin if (session->ref) 1850f6e16b29STom Parkin (*session->ref)(session); 1851f6e16b29STom Parkin __l2tp_session_unhash(session); 18524c6e2fd3STom Parkin l2tp_session_queue_purge(session); 1853309795f4SJames Chapman if (session->session_close != NULL) 1854309795f4SJames Chapman (*session->session_close)(session); 1855f6e16b29STom Parkin if (session->deref) 18561b7c92b9SDan Carpenter (*session->deref)(session); 1857309795f4SJames Chapman l2tp_session_dec_refcount(session); 1858309795f4SJames Chapman return 0; 1859309795f4SJames Chapman } 1860309795f4SJames Chapman EXPORT_SYMBOL_GPL(l2tp_session_delete); 1861309795f4SJames Chapman 1862f7faffa3SJames Chapman /* We come here whenever a session's send_seq, cookie_len or 1863f7faffa3SJames Chapman * l2specific_len parameters are set. 1864f7faffa3SJames Chapman */ 1865fc130840Sstephen hemminger static void l2tp_session_set_header_len(struct l2tp_session *session, int version) 1866f7faffa3SJames Chapman { 1867f7faffa3SJames Chapman if (version == L2TP_HDR_VER_2) { 1868f7faffa3SJames Chapman session->hdr_len = 6; 1869f7faffa3SJames Chapman if (session->send_seq) 1870f7faffa3SJames Chapman session->hdr_len += 4; 1871f7faffa3SJames Chapman } else { 18720d76751fSJames Chapman session->hdr_len = 4 + session->cookie_len + session->l2specific_len + session->offset; 18730d76751fSJames Chapman if (session->tunnel->encap == L2TP_ENCAPTYPE_UDP) 18740d76751fSJames Chapman session->hdr_len += 4; 1875f7faffa3SJames Chapman } 1876f7faffa3SJames Chapman 1877f7faffa3SJames Chapman } 1878f7faffa3SJames Chapman 1879fd558d18SJames 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) 1880fd558d18SJames Chapman { 1881fd558d18SJames Chapman struct l2tp_session *session; 1882fd558d18SJames Chapman 1883fd558d18SJames Chapman session = kzalloc(sizeof(struct l2tp_session) + priv_size, GFP_KERNEL); 1884fd558d18SJames Chapman if (session != NULL) { 1885fd558d18SJames Chapman session->magic = L2TP_SESSION_MAGIC; 1886fd558d18SJames Chapman session->tunnel = tunnel; 1887fd558d18SJames Chapman 1888fd558d18SJames Chapman session->session_id = session_id; 1889fd558d18SJames Chapman session->peer_session_id = peer_session_id; 1890d301e325SJames Chapman session->nr = 0; 18918a1631d5SJames Chapman if (tunnel->version == L2TP_HDR_VER_2) 18928a1631d5SJames Chapman session->nr_max = 0xffff; 18938a1631d5SJames Chapman else 18948a1631d5SJames Chapman session->nr_max = 0xffffff; 18958a1631d5SJames Chapman session->nr_window_size = session->nr_max / 2; 1896a0dbd822SJames Chapman session->nr_oos_count_max = 4; 1897a0dbd822SJames Chapman 1898a0dbd822SJames Chapman /* Use NR of first received packet */ 1899a0dbd822SJames Chapman session->reorder_skip = 1; 1900fd558d18SJames Chapman 1901fd558d18SJames Chapman sprintf(&session->name[0], "sess %u/%u", 1902fd558d18SJames Chapman tunnel->tunnel_id, session->session_id); 1903fd558d18SJames Chapman 1904fd558d18SJames Chapman skb_queue_head_init(&session->reorder_q); 1905fd558d18SJames Chapman 1906fd558d18SJames Chapman INIT_HLIST_NODE(&session->hlist); 1907f7faffa3SJames Chapman INIT_HLIST_NODE(&session->global_hlist); 1908fd558d18SJames Chapman 1909fd558d18SJames Chapman /* Inherit debug options from tunnel */ 1910fd558d18SJames Chapman session->debug = tunnel->debug; 1911fd558d18SJames Chapman 1912fd558d18SJames Chapman if (cfg) { 1913f7faffa3SJames Chapman session->pwtype = cfg->pw_type; 1914fd558d18SJames Chapman session->debug = cfg->debug; 1915fd558d18SJames Chapman session->mtu = cfg->mtu; 1916fd558d18SJames Chapman session->mru = cfg->mru; 1917fd558d18SJames Chapman session->send_seq = cfg->send_seq; 1918fd558d18SJames Chapman session->recv_seq = cfg->recv_seq; 1919fd558d18SJames Chapman session->lns_mode = cfg->lns_mode; 1920f7faffa3SJames Chapman session->reorder_timeout = cfg->reorder_timeout; 1921f7faffa3SJames Chapman session->offset = cfg->offset; 1922f7faffa3SJames Chapman session->l2specific_type = cfg->l2specific_type; 1923f7faffa3SJames Chapman session->l2specific_len = cfg->l2specific_len; 1924f7faffa3SJames Chapman session->cookie_len = cfg->cookie_len; 1925f7faffa3SJames Chapman memcpy(&session->cookie[0], &cfg->cookie[0], cfg->cookie_len); 1926f7faffa3SJames Chapman session->peer_cookie_len = cfg->peer_cookie_len; 1927f7faffa3SJames Chapman memcpy(&session->peer_cookie[0], &cfg->peer_cookie[0], cfg->peer_cookie_len); 1928fd558d18SJames Chapman } 1929fd558d18SJames Chapman 1930f7faffa3SJames Chapman if (tunnel->version == L2TP_HDR_VER_2) 1931f7faffa3SJames Chapman session->build_header = l2tp_build_l2tpv2_header; 1932f7faffa3SJames Chapman else 1933f7faffa3SJames Chapman session->build_header = l2tp_build_l2tpv3_header; 1934f7faffa3SJames Chapman 1935f7faffa3SJames Chapman l2tp_session_set_header_len(session, tunnel->version); 1936f7faffa3SJames Chapman 1937fd558d18SJames Chapman /* Bump the reference count. The session context is deleted 1938fd558d18SJames Chapman * only when this drops to zero. 1939fd558d18SJames Chapman */ 1940fd558d18SJames Chapman l2tp_session_inc_refcount(session); 1941fd558d18SJames Chapman l2tp_tunnel_inc_refcount(tunnel); 1942fd558d18SJames Chapman 1943fd558d18SJames Chapman /* Ensure tunnel socket isn't deleted */ 1944fd558d18SJames Chapman sock_hold(tunnel->sock); 1945fd558d18SJames Chapman 1946fd558d18SJames Chapman /* Add session to the tunnel's hash list */ 1947fd558d18SJames Chapman write_lock_bh(&tunnel->hlist_lock); 1948fd558d18SJames Chapman hlist_add_head(&session->hlist, 1949fd558d18SJames Chapman l2tp_session_id_hash(tunnel, session_id)); 1950fd558d18SJames Chapman write_unlock_bh(&tunnel->hlist_lock); 1951fd558d18SJames Chapman 1952f7faffa3SJames Chapman /* And to the global session list if L2TPv3 */ 1953f7faffa3SJames Chapman if (tunnel->version != L2TP_HDR_VER_2) { 1954f7faffa3SJames Chapman struct l2tp_net *pn = l2tp_pernet(tunnel->l2tp_net); 1955f7faffa3SJames Chapman 1956e02d494dSJames Chapman spin_lock_bh(&pn->l2tp_session_hlist_lock); 1957e02d494dSJames Chapman hlist_add_head_rcu(&session->global_hlist, 1958f7faffa3SJames Chapman l2tp_session_id_hash_2(pn, session_id)); 1959e02d494dSJames Chapman spin_unlock_bh(&pn->l2tp_session_hlist_lock); 1960f7faffa3SJames Chapman } 1961f7faffa3SJames Chapman 1962fd558d18SJames Chapman /* Ignore management session in session count value */ 1963fd558d18SJames Chapman if (session->session_id != 0) 1964fd558d18SJames Chapman atomic_inc(&l2tp_session_count); 1965fd558d18SJames Chapman } 1966fd558d18SJames Chapman 1967fd558d18SJames Chapman return session; 1968fd558d18SJames Chapman } 1969fd558d18SJames Chapman EXPORT_SYMBOL_GPL(l2tp_session_create); 1970fd558d18SJames Chapman 1971fd558d18SJames Chapman /***************************************************************************** 1972fd558d18SJames Chapman * Init and cleanup 1973fd558d18SJames Chapman *****************************************************************************/ 1974fd558d18SJames Chapman 1975fd558d18SJames Chapman static __net_init int l2tp_init_net(struct net *net) 1976fd558d18SJames Chapman { 1977e773aaffSJiri Pirko struct l2tp_net *pn = net_generic(net, l2tp_net_id); 1978f7faffa3SJames Chapman int hash; 1979fd558d18SJames Chapman 1980fd558d18SJames Chapman INIT_LIST_HEAD(&pn->l2tp_tunnel_list); 1981e02d494dSJames Chapman spin_lock_init(&pn->l2tp_tunnel_list_lock); 1982fd558d18SJames Chapman 1983f7faffa3SJames Chapman for (hash = 0; hash < L2TP_HASH_SIZE_2; hash++) 1984f7faffa3SJames Chapman INIT_HLIST_HEAD(&pn->l2tp_session_hlist[hash]); 1985f7faffa3SJames Chapman 1986e02d494dSJames Chapman spin_lock_init(&pn->l2tp_session_hlist_lock); 1987f7faffa3SJames Chapman 1988fd558d18SJames Chapman return 0; 1989fd558d18SJames Chapman } 1990fd558d18SJames Chapman 1991167eb17eSTom Parkin static __net_exit void l2tp_exit_net(struct net *net) 1992167eb17eSTom Parkin { 1993167eb17eSTom Parkin struct l2tp_net *pn = l2tp_pernet(net); 1994167eb17eSTom Parkin struct l2tp_tunnel *tunnel = NULL; 1995167eb17eSTom Parkin 1996167eb17eSTom Parkin rcu_read_lock_bh(); 1997167eb17eSTom Parkin list_for_each_entry_rcu(tunnel, &pn->l2tp_tunnel_list, list) { 1998167eb17eSTom Parkin (void)l2tp_tunnel_delete(tunnel); 1999167eb17eSTom Parkin } 2000167eb17eSTom Parkin rcu_read_unlock_bh(); 2001167eb17eSTom Parkin } 2002167eb17eSTom Parkin 2003fd558d18SJames Chapman static struct pernet_operations l2tp_net_ops = { 2004fd558d18SJames Chapman .init = l2tp_init_net, 2005167eb17eSTom Parkin .exit = l2tp_exit_net, 2006fd558d18SJames Chapman .id = &l2tp_net_id, 2007fd558d18SJames Chapman .size = sizeof(struct l2tp_net), 2008fd558d18SJames Chapman }; 2009fd558d18SJames Chapman 2010fd558d18SJames Chapman static int __init l2tp_init(void) 2011fd558d18SJames Chapman { 2012fd558d18SJames Chapman int rc = 0; 2013fd558d18SJames Chapman 2014fd558d18SJames Chapman rc = register_pernet_device(&l2tp_net_ops); 2015fd558d18SJames Chapman if (rc) 2016fd558d18SJames Chapman goto out; 2017fd558d18SJames Chapman 2018f8ccac0eSTom Parkin l2tp_wq = alloc_workqueue("l2tp", WQ_NON_REENTRANT | WQ_UNBOUND, 0); 2019f8ccac0eSTom Parkin if (!l2tp_wq) { 2020f8ccac0eSTom Parkin pr_err("alloc_workqueue failed\n"); 2021f8ccac0eSTom Parkin rc = -ENOMEM; 2022f8ccac0eSTom Parkin goto out; 2023f8ccac0eSTom Parkin } 2024f8ccac0eSTom Parkin 2025a4ca44faSJoe Perches pr_info("L2TP core driver, %s\n", L2TP_DRV_VERSION); 2026fd558d18SJames Chapman 2027fd558d18SJames Chapman out: 2028fd558d18SJames Chapman return rc; 2029fd558d18SJames Chapman } 2030fd558d18SJames Chapman 2031fd558d18SJames Chapman static void __exit l2tp_exit(void) 2032fd558d18SJames Chapman { 2033fd558d18SJames Chapman unregister_pernet_device(&l2tp_net_ops); 2034f8ccac0eSTom Parkin if (l2tp_wq) { 2035f8ccac0eSTom Parkin destroy_workqueue(l2tp_wq); 2036f8ccac0eSTom Parkin l2tp_wq = NULL; 2037f8ccac0eSTom Parkin } 2038fd558d18SJames Chapman } 2039fd558d18SJames Chapman 2040fd558d18SJames Chapman module_init(l2tp_init); 2041fd558d18SJames Chapman module_exit(l2tp_exit); 2042fd558d18SJames Chapman 2043fd558d18SJames Chapman MODULE_AUTHOR("James Chapman <jchapman@katalix.com>"); 2044fd558d18SJames Chapman MODULE_DESCRIPTION("L2TP core"); 2045fd558d18SJames Chapman MODULE_LICENSE("GPL"); 2046fd558d18SJames Chapman MODULE_VERSION(L2TP_DRV_VERSION); 2047fd558d18SJames Chapman 2048