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; 3775de7aee5SJames Chapman struct l2tp_stats *sstats; 378fd558d18SJames Chapman 379fd558d18SJames Chapman spin_lock_bh(&session->reorder_q.lock); 3805de7aee5SJames Chapman sstats = &session->stats; 381fd558d18SJames Chapman skb_queue_walk_safe(&session->reorder_q, skbp, tmp) { 382fd558d18SJames Chapman if (L2TP_SKB_CB(skbp)->ns > ns) { 383fd558d18SJames Chapman __skb_queue_before(&session->reorder_q, skbp, skb); 384a4ca44faSJoe Perches l2tp_dbg(session, L2TP_MSG_SEQ, 385fd558d18SJames Chapman "%s: pkt %hu, inserted before %hu, reorder_q len=%d\n", 386fd558d18SJames Chapman session->name, ns, L2TP_SKB_CB(skbp)->ns, 387fd558d18SJames Chapman skb_queue_len(&session->reorder_q)); 3885de7aee5SJames Chapman u64_stats_update_begin(&sstats->syncp); 3895de7aee5SJames Chapman sstats->rx_oos_packets++; 3905de7aee5SJames Chapman u64_stats_update_end(&sstats->syncp); 391fd558d18SJames Chapman goto out; 392fd558d18SJames Chapman } 393fd558d18SJames Chapman } 394fd558d18SJames Chapman 395fd558d18SJames Chapman __skb_queue_tail(&session->reorder_q, skb); 396fd558d18SJames Chapman 397fd558d18SJames Chapman out: 398fd558d18SJames Chapman spin_unlock_bh(&session->reorder_q.lock); 399fd558d18SJames Chapman } 400fd558d18SJames Chapman 401fd558d18SJames Chapman /* Dequeue a single skb. 402fd558d18SJames Chapman */ 403fd558d18SJames Chapman static void l2tp_recv_dequeue_skb(struct l2tp_session *session, struct sk_buff *skb) 404fd558d18SJames Chapman { 405fd558d18SJames Chapman struct l2tp_tunnel *tunnel = session->tunnel; 406fd558d18SJames Chapman int length = L2TP_SKB_CB(skb)->length; 4075de7aee5SJames Chapman struct l2tp_stats *tstats, *sstats; 408fd558d18SJames Chapman 409fd558d18SJames Chapman /* We're about to requeue the skb, so return resources 410fd558d18SJames Chapman * to its current owner (a socket receive buffer). 411fd558d18SJames Chapman */ 412fd558d18SJames Chapman skb_orphan(skb); 413fd558d18SJames Chapman 4145de7aee5SJames Chapman tstats = &tunnel->stats; 4155de7aee5SJames Chapman u64_stats_update_begin(&tstats->syncp); 4165de7aee5SJames Chapman sstats = &session->stats; 4175de7aee5SJames Chapman u64_stats_update_begin(&sstats->syncp); 4185de7aee5SJames Chapman tstats->rx_packets++; 4195de7aee5SJames Chapman tstats->rx_bytes += length; 4205de7aee5SJames Chapman sstats->rx_packets++; 4215de7aee5SJames Chapman sstats->rx_bytes += length; 4225de7aee5SJames Chapman u64_stats_update_end(&tstats->syncp); 4235de7aee5SJames Chapman u64_stats_update_end(&sstats->syncp); 424fd558d18SJames Chapman 425fd558d18SJames Chapman if (L2TP_SKB_CB(skb)->has_seq) { 426fd558d18SJames Chapman /* Bump our Nr */ 427fd558d18SJames Chapman session->nr++; 428f7faffa3SJames Chapman if (tunnel->version == L2TP_HDR_VER_2) 429f7faffa3SJames Chapman session->nr &= 0xffff; 430f7faffa3SJames Chapman else 431f7faffa3SJames Chapman session->nr &= 0xffffff; 432f7faffa3SJames Chapman 433a4ca44faSJoe Perches l2tp_dbg(session, L2TP_MSG_SEQ, "%s: updated nr to %hu\n", 434a4ca44faSJoe Perches session->name, session->nr); 435fd558d18SJames Chapman } 436fd558d18SJames Chapman 437fd558d18SJames Chapman /* call private receive handler */ 438fd558d18SJames Chapman if (session->recv_skb != NULL) 439fd558d18SJames Chapman (*session->recv_skb)(session, skb, L2TP_SKB_CB(skb)->length); 440fd558d18SJames Chapman else 441fd558d18SJames Chapman kfree_skb(skb); 442fd558d18SJames Chapman 443fd558d18SJames Chapman if (session->deref) 444fd558d18SJames Chapman (*session->deref)(session); 445fd558d18SJames Chapman } 446fd558d18SJames Chapman 447fd558d18SJames Chapman /* Dequeue skbs from the session's reorder_q, subject to packet order. 448fd558d18SJames Chapman * Skbs that have been in the queue for too long are simply discarded. 449fd558d18SJames Chapman */ 450fd558d18SJames Chapman static void l2tp_recv_dequeue(struct l2tp_session *session) 451fd558d18SJames Chapman { 452fd558d18SJames Chapman struct sk_buff *skb; 453fd558d18SJames Chapman struct sk_buff *tmp; 4545de7aee5SJames Chapman struct l2tp_stats *sstats; 455fd558d18SJames Chapman 456fd558d18SJames Chapman /* If the pkt at the head of the queue has the nr that we 457fd558d18SJames Chapman * expect to send up next, dequeue it and any other 458fd558d18SJames Chapman * in-sequence packets behind it. 459fd558d18SJames Chapman */ 460e2e210c0SEric Dumazet start: 461fd558d18SJames Chapman spin_lock_bh(&session->reorder_q.lock); 4625de7aee5SJames Chapman sstats = &session->stats; 463fd558d18SJames Chapman skb_queue_walk_safe(&session->reorder_q, skb, tmp) { 464fd558d18SJames Chapman if (time_after(jiffies, L2TP_SKB_CB(skb)->expires)) { 4655de7aee5SJames Chapman u64_stats_update_begin(&sstats->syncp); 4665de7aee5SJames Chapman sstats->rx_seq_discards++; 4675de7aee5SJames Chapman sstats->rx_errors++; 4685de7aee5SJames Chapman u64_stats_update_end(&sstats->syncp); 469a4ca44faSJoe Perches l2tp_dbg(session, L2TP_MSG_SEQ, 470a4ca44faSJoe Perches "%s: oos pkt %u len %d discarded (too old), waiting for %u, reorder_q_len=%d\n", 471fd558d18SJames Chapman session->name, L2TP_SKB_CB(skb)->ns, 472fd558d18SJames Chapman L2TP_SKB_CB(skb)->length, session->nr, 473fd558d18SJames Chapman skb_queue_len(&session->reorder_q)); 47438d40b3fSJames Chapman session->reorder_skip = 1; 475fd558d18SJames Chapman __skb_unlink(skb, &session->reorder_q); 476fd558d18SJames Chapman kfree_skb(skb); 477fd558d18SJames Chapman if (session->deref) 478fd558d18SJames Chapman (*session->deref)(session); 479fd558d18SJames Chapman continue; 480fd558d18SJames Chapman } 481fd558d18SJames Chapman 482fd558d18SJames Chapman if (L2TP_SKB_CB(skb)->has_seq) { 48338d40b3fSJames Chapman if (session->reorder_skip) { 484a4ca44faSJoe Perches l2tp_dbg(session, L2TP_MSG_SEQ, 48538d40b3fSJames Chapman "%s: advancing nr to next pkt: %u -> %u", 48638d40b3fSJames Chapman session->name, session->nr, 48738d40b3fSJames Chapman L2TP_SKB_CB(skb)->ns); 48838d40b3fSJames Chapman session->reorder_skip = 0; 48938d40b3fSJames Chapman session->nr = L2TP_SKB_CB(skb)->ns; 49038d40b3fSJames Chapman } 491fd558d18SJames Chapman if (L2TP_SKB_CB(skb)->ns != session->nr) { 492a4ca44faSJoe Perches l2tp_dbg(session, L2TP_MSG_SEQ, 493a4ca44faSJoe Perches "%s: holding oos pkt %u len %d, waiting for %u, reorder_q_len=%d\n", 494fd558d18SJames Chapman session->name, L2TP_SKB_CB(skb)->ns, 495fd558d18SJames Chapman L2TP_SKB_CB(skb)->length, session->nr, 496fd558d18SJames Chapman skb_queue_len(&session->reorder_q)); 497fd558d18SJames Chapman goto out; 498fd558d18SJames Chapman } 499fd558d18SJames Chapman } 500fd558d18SJames Chapman __skb_unlink(skb, &session->reorder_q); 501fd558d18SJames Chapman 502fd558d18SJames Chapman /* Process the skb. We release the queue lock while we 503fd558d18SJames Chapman * do so to let other contexts process the queue. 504fd558d18SJames Chapman */ 505fd558d18SJames Chapman spin_unlock_bh(&session->reorder_q.lock); 506fd558d18SJames Chapman l2tp_recv_dequeue_skb(session, skb); 507e2e210c0SEric Dumazet goto start; 508fd558d18SJames Chapman } 509fd558d18SJames Chapman 510fd558d18SJames Chapman out: 511fd558d18SJames Chapman spin_unlock_bh(&session->reorder_q.lock); 512fd558d18SJames Chapman } 513fd558d18SJames Chapman 514fd558d18SJames Chapman static inline int l2tp_verify_udp_checksum(struct sock *sk, 515fd558d18SJames Chapman struct sk_buff *skb) 516fd558d18SJames Chapman { 517fd558d18SJames Chapman struct udphdr *uh = udp_hdr(skb); 518fd558d18SJames Chapman u16 ulen = ntohs(uh->len); 519fd558d18SJames Chapman __wsum psum; 520fd558d18SJames Chapman 521d2cf3361SBenjamin LaHaise if (sk->sk_no_check || skb_csum_unnecessary(skb)) 522fd558d18SJames Chapman return 0; 523fd558d18SJames Chapman 524d2cf3361SBenjamin LaHaise #if IS_ENABLED(CONFIG_IPV6) 525d2cf3361SBenjamin LaHaise if (sk->sk_family == PF_INET6) { 526d2cf3361SBenjamin LaHaise if (!uh->check) { 527d2cf3361SBenjamin LaHaise LIMIT_NETDEBUG(KERN_INFO "L2TP: IPv6: checksum is 0\n"); 528d2cf3361SBenjamin LaHaise return 1; 529d2cf3361SBenjamin LaHaise } 530d2cf3361SBenjamin LaHaise if ((skb->ip_summed == CHECKSUM_COMPLETE) && 531d2cf3361SBenjamin LaHaise !csum_ipv6_magic(&ipv6_hdr(skb)->saddr, 532d2cf3361SBenjamin LaHaise &ipv6_hdr(skb)->daddr, ulen, 533d2cf3361SBenjamin LaHaise IPPROTO_UDP, skb->csum)) { 534d2cf3361SBenjamin LaHaise skb->ip_summed = CHECKSUM_UNNECESSARY; 535d2cf3361SBenjamin LaHaise return 0; 536d2cf3361SBenjamin LaHaise } 537d2cf3361SBenjamin LaHaise skb->csum = ~csum_unfold(csum_ipv6_magic(&ipv6_hdr(skb)->saddr, 538d2cf3361SBenjamin LaHaise &ipv6_hdr(skb)->daddr, 539d2cf3361SBenjamin LaHaise skb->len, IPPROTO_UDP, 540d2cf3361SBenjamin LaHaise 0)); 541d2cf3361SBenjamin LaHaise } else 542d2cf3361SBenjamin LaHaise #endif 543d2cf3361SBenjamin LaHaise { 544d2cf3361SBenjamin LaHaise struct inet_sock *inet; 545d2cf3361SBenjamin LaHaise if (!uh->check) 546d2cf3361SBenjamin LaHaise return 0; 547fd558d18SJames Chapman inet = inet_sk(sk); 548d2cf3361SBenjamin LaHaise psum = csum_tcpudp_nofold(inet->inet_saddr, inet->inet_daddr, 549d2cf3361SBenjamin LaHaise ulen, IPPROTO_UDP, 0); 550fd558d18SJames Chapman 551fd558d18SJames Chapman if ((skb->ip_summed == CHECKSUM_COMPLETE) && 552fd558d18SJames Chapman !csum_fold(csum_add(psum, skb->csum))) 553fd558d18SJames Chapman return 0; 554fd558d18SJames Chapman skb->csum = psum; 555d2cf3361SBenjamin LaHaise } 556fd558d18SJames Chapman 557fd558d18SJames Chapman return __skb_checksum_complete(skb); 558fd558d18SJames Chapman } 559fd558d18SJames Chapman 560f7faffa3SJames Chapman /* Do receive processing of L2TP data frames. We handle both L2TPv2 561f7faffa3SJames Chapman * and L2TPv3 data frames here. 562f7faffa3SJames Chapman * 563f7faffa3SJames Chapman * L2TPv2 Data Message Header 564f7faffa3SJames Chapman * 565f7faffa3SJames Chapman * 0 1 2 3 566f7faffa3SJames 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 567f7faffa3SJames Chapman * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 568f7faffa3SJames Chapman * |T|L|x|x|S|x|O|P|x|x|x|x| Ver | Length (opt) | 569f7faffa3SJames Chapman * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 570f7faffa3SJames Chapman * | Tunnel ID | Session ID | 571f7faffa3SJames Chapman * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 572f7faffa3SJames Chapman * | Ns (opt) | Nr (opt) | 573f7faffa3SJames Chapman * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 574f7faffa3SJames Chapman * | Offset Size (opt) | Offset pad... (opt) 575f7faffa3SJames Chapman * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 576f7faffa3SJames Chapman * 577f7faffa3SJames Chapman * Data frames are marked by T=0. All other fields are the same as 578f7faffa3SJames Chapman * those in L2TP control frames. 579f7faffa3SJames Chapman * 580f7faffa3SJames Chapman * L2TPv3 Data Message Header 581f7faffa3SJames Chapman * 582f7faffa3SJames Chapman * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 583f7faffa3SJames Chapman * | L2TP Session Header | 584f7faffa3SJames Chapman * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 585f7faffa3SJames Chapman * | L2-Specific Sublayer | 586f7faffa3SJames Chapman * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 587f7faffa3SJames Chapman * | Tunnel Payload ... 588f7faffa3SJames Chapman * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 589f7faffa3SJames Chapman * 590f7faffa3SJames Chapman * L2TPv3 Session Header Over IP 591f7faffa3SJames Chapman * 592f7faffa3SJames Chapman * 0 1 2 3 593f7faffa3SJames 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 594f7faffa3SJames Chapman * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 595f7faffa3SJames Chapman * | Session ID | 596f7faffa3SJames Chapman * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 597f7faffa3SJames Chapman * | Cookie (optional, maximum 64 bits)... 598f7faffa3SJames Chapman * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 599f7faffa3SJames Chapman * | 600f7faffa3SJames Chapman * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 601f7faffa3SJames Chapman * 602f7faffa3SJames Chapman * L2TPv3 L2-Specific Sublayer Format 603f7faffa3SJames Chapman * 604f7faffa3SJames Chapman * 0 1 2 3 605f7faffa3SJames 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 606f7faffa3SJames Chapman * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 607f7faffa3SJames Chapman * |x|S|x|x|x|x|x|x| Sequence Number | 608f7faffa3SJames Chapman * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 609f7faffa3SJames Chapman * 610f7faffa3SJames Chapman * Cookie value, sublayer format and offset (pad) are negotiated with 611f7faffa3SJames Chapman * the peer when the session is set up. Unlike L2TPv2, we do not need 612f7faffa3SJames Chapman * to parse the packet header to determine if optional fields are 613f7faffa3SJames Chapman * present. 614f7faffa3SJames Chapman * 615f7faffa3SJames Chapman * Caller must already have parsed the frame and determined that it is 616f7faffa3SJames Chapman * a data (not control) frame before coming here. Fields up to the 617f7faffa3SJames Chapman * session-id have already been parsed and ptr points to the data 618f7faffa3SJames Chapman * after the session-id. 619f7faffa3SJames Chapman */ 620f7faffa3SJames Chapman void l2tp_recv_common(struct l2tp_session *session, struct sk_buff *skb, 621f7faffa3SJames Chapman unsigned char *ptr, unsigned char *optr, u16 hdrflags, 622f7faffa3SJames Chapman int length, int (*payload_hook)(struct sk_buff *skb)) 623f7faffa3SJames Chapman { 624f7faffa3SJames Chapman struct l2tp_tunnel *tunnel = session->tunnel; 625f7faffa3SJames Chapman int offset; 626f7faffa3SJames Chapman u32 ns, nr; 6275de7aee5SJames Chapman struct l2tp_stats *sstats = &session->stats; 628f7faffa3SJames Chapman 629f7faffa3SJames Chapman /* The ref count is increased since we now hold a pointer to 630f7faffa3SJames Chapman * the session. Take care to decrement the refcnt when exiting 631f7faffa3SJames Chapman * this function from now on... 632f7faffa3SJames Chapman */ 633f7faffa3SJames Chapman l2tp_session_inc_refcount(session); 634f7faffa3SJames Chapman if (session->ref) 635f7faffa3SJames Chapman (*session->ref)(session); 636f7faffa3SJames Chapman 637f7faffa3SJames Chapman /* Parse and check optional cookie */ 638f7faffa3SJames Chapman if (session->peer_cookie_len > 0) { 639f7faffa3SJames Chapman if (memcmp(ptr, &session->peer_cookie[0], session->peer_cookie_len)) { 640a4ca44faSJoe Perches l2tp_info(tunnel, L2TP_MSG_DATA, 641f7faffa3SJames Chapman "%s: cookie mismatch (%u/%u). Discarding.\n", 642a4ca44faSJoe Perches tunnel->name, tunnel->tunnel_id, 643a4ca44faSJoe Perches session->session_id); 6445de7aee5SJames Chapman u64_stats_update_begin(&sstats->syncp); 6455de7aee5SJames Chapman sstats->rx_cookie_discards++; 6465de7aee5SJames Chapman u64_stats_update_end(&sstats->syncp); 647f7faffa3SJames Chapman goto discard; 648f7faffa3SJames Chapman } 649f7faffa3SJames Chapman ptr += session->peer_cookie_len; 650f7faffa3SJames Chapman } 651f7faffa3SJames Chapman 652f7faffa3SJames Chapman /* Handle the optional sequence numbers. Sequence numbers are 653f7faffa3SJames Chapman * in different places for L2TPv2 and L2TPv3. 654f7faffa3SJames Chapman * 655f7faffa3SJames Chapman * If we are the LAC, enable/disable sequence numbers under 656f7faffa3SJames Chapman * the control of the LNS. If no sequence numbers present but 657f7faffa3SJames Chapman * we were expecting them, discard frame. 658f7faffa3SJames Chapman */ 659f7faffa3SJames Chapman ns = nr = 0; 660f7faffa3SJames Chapman L2TP_SKB_CB(skb)->has_seq = 0; 661f7faffa3SJames Chapman if (tunnel->version == L2TP_HDR_VER_2) { 662f7faffa3SJames Chapman if (hdrflags & L2TP_HDRFLAG_S) { 663f7faffa3SJames Chapman ns = ntohs(*(__be16 *) ptr); 664f7faffa3SJames Chapman ptr += 2; 665f7faffa3SJames Chapman nr = ntohs(*(__be16 *) ptr); 666f7faffa3SJames Chapman ptr += 2; 667f7faffa3SJames Chapman 668f7faffa3SJames Chapman /* Store L2TP info in the skb */ 669f7faffa3SJames Chapman L2TP_SKB_CB(skb)->ns = ns; 670f7faffa3SJames Chapman L2TP_SKB_CB(skb)->has_seq = 1; 671f7faffa3SJames Chapman 672a4ca44faSJoe Perches l2tp_dbg(session, L2TP_MSG_SEQ, 673f7faffa3SJames Chapman "%s: recv data ns=%u, nr=%u, session nr=%u\n", 674f7faffa3SJames Chapman session->name, ns, nr, session->nr); 675f7faffa3SJames Chapman } 676f7faffa3SJames Chapman } else if (session->l2specific_type == L2TP_L2SPECTYPE_DEFAULT) { 677f7faffa3SJames Chapman u32 l2h = ntohl(*(__be32 *) ptr); 678f7faffa3SJames Chapman 679f7faffa3SJames Chapman if (l2h & 0x40000000) { 680f7faffa3SJames Chapman ns = l2h & 0x00ffffff; 681f7faffa3SJames Chapman 682f7faffa3SJames Chapman /* Store L2TP info in the skb */ 683f7faffa3SJames Chapman L2TP_SKB_CB(skb)->ns = ns; 684f7faffa3SJames Chapman L2TP_SKB_CB(skb)->has_seq = 1; 685f7faffa3SJames Chapman 686a4ca44faSJoe Perches l2tp_dbg(session, L2TP_MSG_SEQ, 687f7faffa3SJames Chapman "%s: recv data ns=%u, session nr=%u\n", 688f7faffa3SJames Chapman session->name, ns, session->nr); 689f7faffa3SJames Chapman } 690f7faffa3SJames Chapman } 691f7faffa3SJames Chapman 692f7faffa3SJames Chapman /* Advance past L2-specific header, if present */ 693f7faffa3SJames Chapman ptr += session->l2specific_len; 694f7faffa3SJames Chapman 695f7faffa3SJames Chapman if (L2TP_SKB_CB(skb)->has_seq) { 696f7faffa3SJames Chapman /* Received a packet with sequence numbers. If we're the LNS, 697f7faffa3SJames Chapman * check if we sre sending sequence numbers and if not, 698f7faffa3SJames Chapman * configure it so. 699f7faffa3SJames Chapman */ 700f7faffa3SJames Chapman if ((!session->lns_mode) && (!session->send_seq)) { 701a4ca44faSJoe Perches l2tp_info(session, L2TP_MSG_SEQ, 702f7faffa3SJames Chapman "%s: requested to enable seq numbers by LNS\n", 703f7faffa3SJames Chapman session->name); 704f7faffa3SJames Chapman session->send_seq = -1; 705f7faffa3SJames Chapman l2tp_session_set_header_len(session, tunnel->version); 706f7faffa3SJames Chapman } 707f7faffa3SJames Chapman } else { 708f7faffa3SJames Chapman /* No sequence numbers. 709f7faffa3SJames Chapman * If user has configured mandatory sequence numbers, discard. 710f7faffa3SJames Chapman */ 711f7faffa3SJames Chapman if (session->recv_seq) { 712a4ca44faSJoe Perches l2tp_warn(session, L2TP_MSG_SEQ, 713a4ca44faSJoe Perches "%s: recv data has no seq numbers when required. Discarding.\n", 714a4ca44faSJoe Perches session->name); 7155de7aee5SJames Chapman u64_stats_update_begin(&sstats->syncp); 7165de7aee5SJames Chapman sstats->rx_seq_discards++; 7175de7aee5SJames Chapman u64_stats_update_end(&sstats->syncp); 718f7faffa3SJames Chapman goto discard; 719f7faffa3SJames Chapman } 720f7faffa3SJames Chapman 721f7faffa3SJames Chapman /* If we're the LAC and we're sending sequence numbers, the 722f7faffa3SJames Chapman * LNS has requested that we no longer send sequence numbers. 723f7faffa3SJames Chapman * If we're the LNS and we're sending sequence numbers, the 724f7faffa3SJames Chapman * LAC is broken. Discard the frame. 725f7faffa3SJames Chapman */ 726f7faffa3SJames Chapman if ((!session->lns_mode) && (session->send_seq)) { 727a4ca44faSJoe Perches l2tp_info(session, L2TP_MSG_SEQ, 728f7faffa3SJames Chapman "%s: requested to disable seq numbers by LNS\n", 729f7faffa3SJames Chapman session->name); 730f7faffa3SJames Chapman session->send_seq = 0; 731f7faffa3SJames Chapman l2tp_session_set_header_len(session, tunnel->version); 732f7faffa3SJames Chapman } else if (session->send_seq) { 733a4ca44faSJoe Perches l2tp_warn(session, L2TP_MSG_SEQ, 734a4ca44faSJoe Perches "%s: recv data has no seq numbers when required. Discarding.\n", 735a4ca44faSJoe Perches session->name); 7365de7aee5SJames Chapman u64_stats_update_begin(&sstats->syncp); 7375de7aee5SJames Chapman sstats->rx_seq_discards++; 7385de7aee5SJames Chapman u64_stats_update_end(&sstats->syncp); 739f7faffa3SJames Chapman goto discard; 740f7faffa3SJames Chapman } 741f7faffa3SJames Chapman } 742f7faffa3SJames Chapman 743f7faffa3SJames Chapman /* Session data offset is handled differently for L2TPv2 and 744f7faffa3SJames Chapman * L2TPv3. For L2TPv2, there is an optional 16-bit value in 745f7faffa3SJames Chapman * the header. For L2TPv3, the offset is negotiated using AVPs 746f7faffa3SJames Chapman * in the session setup control protocol. 747f7faffa3SJames Chapman */ 748f7faffa3SJames Chapman if (tunnel->version == L2TP_HDR_VER_2) { 749f7faffa3SJames Chapman /* If offset bit set, skip it. */ 750f7faffa3SJames Chapman if (hdrflags & L2TP_HDRFLAG_O) { 751f7faffa3SJames Chapman offset = ntohs(*(__be16 *)ptr); 752f7faffa3SJames Chapman ptr += 2 + offset; 753f7faffa3SJames Chapman } 754f7faffa3SJames Chapman } else 755f7faffa3SJames Chapman ptr += session->offset; 756f7faffa3SJames Chapman 757f7faffa3SJames Chapman offset = ptr - optr; 758f7faffa3SJames Chapman if (!pskb_may_pull(skb, offset)) 759f7faffa3SJames Chapman goto discard; 760f7faffa3SJames Chapman 761f7faffa3SJames Chapman __skb_pull(skb, offset); 762f7faffa3SJames Chapman 763f7faffa3SJames Chapman /* If caller wants to process the payload before we queue the 764f7faffa3SJames Chapman * packet, do so now. 765f7faffa3SJames Chapman */ 766f7faffa3SJames Chapman if (payload_hook) 767f7faffa3SJames Chapman if ((*payload_hook)(skb)) 768f7faffa3SJames Chapman goto discard; 769f7faffa3SJames Chapman 770f7faffa3SJames Chapman /* Prepare skb for adding to the session's reorder_q. Hold 771f7faffa3SJames Chapman * packets for max reorder_timeout or 1 second if not 772f7faffa3SJames Chapman * reordering. 773f7faffa3SJames Chapman */ 774f7faffa3SJames Chapman L2TP_SKB_CB(skb)->length = length; 775f7faffa3SJames Chapman L2TP_SKB_CB(skb)->expires = jiffies + 776f7faffa3SJames Chapman (session->reorder_timeout ? session->reorder_timeout : HZ); 777f7faffa3SJames Chapman 778f7faffa3SJames Chapman /* Add packet to the session's receive queue. Reordering is done here, if 779f7faffa3SJames Chapman * enabled. Saved L2TP protocol info is stored in skb->sb[]. 780f7faffa3SJames Chapman */ 781f7faffa3SJames Chapman if (L2TP_SKB_CB(skb)->has_seq) { 782f7faffa3SJames Chapman if (session->reorder_timeout != 0) { 783f7faffa3SJames Chapman /* Packet reordering enabled. Add skb to session's 784f7faffa3SJames Chapman * reorder queue, in order of ns. 785f7faffa3SJames Chapman */ 786f7faffa3SJames Chapman l2tp_recv_queue_skb(session, skb); 787f7faffa3SJames Chapman } else { 788f7faffa3SJames Chapman /* Packet reordering disabled. Discard out-of-sequence 789f7faffa3SJames Chapman * packets 790f7faffa3SJames Chapman */ 791f7faffa3SJames Chapman if (L2TP_SKB_CB(skb)->ns != session->nr) { 7925de7aee5SJames Chapman u64_stats_update_begin(&sstats->syncp); 7935de7aee5SJames Chapman sstats->rx_seq_discards++; 7945de7aee5SJames Chapman u64_stats_update_end(&sstats->syncp); 795a4ca44faSJoe Perches l2tp_dbg(session, L2TP_MSG_SEQ, 796a4ca44faSJoe Perches "%s: oos pkt %u len %d discarded, waiting for %u, reorder_q_len=%d\n", 797f7faffa3SJames Chapman session->name, L2TP_SKB_CB(skb)->ns, 798f7faffa3SJames Chapman L2TP_SKB_CB(skb)->length, session->nr, 799f7faffa3SJames Chapman skb_queue_len(&session->reorder_q)); 800f7faffa3SJames Chapman goto discard; 801f7faffa3SJames Chapman } 802f7faffa3SJames Chapman skb_queue_tail(&session->reorder_q, skb); 803f7faffa3SJames Chapman } 804f7faffa3SJames Chapman } else { 805f7faffa3SJames Chapman /* No sequence numbers. Add the skb to the tail of the 806f7faffa3SJames Chapman * reorder queue. This ensures that it will be 807f7faffa3SJames Chapman * delivered after all previous sequenced skbs. 808f7faffa3SJames Chapman */ 809f7faffa3SJames Chapman skb_queue_tail(&session->reorder_q, skb); 810f7faffa3SJames Chapman } 811f7faffa3SJames Chapman 812f7faffa3SJames Chapman /* Try to dequeue as many skbs from reorder_q as we can. */ 813f7faffa3SJames Chapman l2tp_recv_dequeue(session); 814f7faffa3SJames Chapman 815f7faffa3SJames Chapman l2tp_session_dec_refcount(session); 816f7faffa3SJames Chapman 817f7faffa3SJames Chapman return; 818f7faffa3SJames Chapman 819f7faffa3SJames Chapman discard: 8205de7aee5SJames Chapman u64_stats_update_begin(&sstats->syncp); 8215de7aee5SJames Chapman sstats->rx_errors++; 8225de7aee5SJames Chapman u64_stats_update_end(&sstats->syncp); 823f7faffa3SJames Chapman kfree_skb(skb); 824f7faffa3SJames Chapman 825f7faffa3SJames Chapman if (session->deref) 826f7faffa3SJames Chapman (*session->deref)(session); 827f7faffa3SJames Chapman 828f7faffa3SJames Chapman l2tp_session_dec_refcount(session); 829f7faffa3SJames Chapman } 830f7faffa3SJames Chapman EXPORT_SYMBOL(l2tp_recv_common); 831f7faffa3SJames Chapman 83248f72f92STom Parkin /* Drop skbs from the session's reorder_q 83348f72f92STom Parkin */ 83448f72f92STom Parkin int l2tp_session_queue_purge(struct l2tp_session *session) 83548f72f92STom Parkin { 83648f72f92STom Parkin struct sk_buff *skb = NULL; 83748f72f92STom Parkin BUG_ON(!session); 83848f72f92STom Parkin BUG_ON(session->magic != L2TP_SESSION_MAGIC); 83948f72f92STom Parkin while ((skb = skb_dequeue(&session->reorder_q))) { 84048f72f92STom Parkin atomic_long_inc(&session->stats.rx_errors); 84148f72f92STom Parkin kfree_skb(skb); 84248f72f92STom Parkin if (session->deref) 84348f72f92STom Parkin (*session->deref)(session); 84448f72f92STom Parkin } 84548f72f92STom Parkin return 0; 84648f72f92STom Parkin } 84748f72f92STom Parkin EXPORT_SYMBOL_GPL(l2tp_session_queue_purge); 84848f72f92STom Parkin 849fd558d18SJames Chapman /* Internal UDP receive frame. Do the real work of receiving an L2TP data frame 850fd558d18SJames Chapman * here. The skb is not on a list when we get here. 851fd558d18SJames Chapman * Returns 0 if the packet was a data packet and was successfully passed on. 852fd558d18SJames Chapman * Returns 1 if the packet was not a good data packet and could not be 853fd558d18SJames Chapman * forwarded. All such packets are passed up to userspace to deal with. 854fd558d18SJames Chapman */ 855fc130840Sstephen hemminger static int l2tp_udp_recv_core(struct l2tp_tunnel *tunnel, struct sk_buff *skb, 856fd558d18SJames Chapman int (*payload_hook)(struct sk_buff *skb)) 857fd558d18SJames Chapman { 858fd558d18SJames Chapman struct l2tp_session *session = NULL; 859fd558d18SJames Chapman unsigned char *ptr, *optr; 860fd558d18SJames Chapman u16 hdrflags; 861fd558d18SJames Chapman u32 tunnel_id, session_id; 862fd558d18SJames Chapman u16 version; 863f7faffa3SJames Chapman int length; 8645de7aee5SJames Chapman struct l2tp_stats *tstats; 865fd558d18SJames Chapman 866fd558d18SJames Chapman if (tunnel->sock && l2tp_verify_udp_checksum(tunnel->sock, skb)) 867fd558d18SJames Chapman goto discard_bad_csum; 868fd558d18SJames Chapman 869fd558d18SJames Chapman /* UDP always verifies the packet length. */ 870fd558d18SJames Chapman __skb_pull(skb, sizeof(struct udphdr)); 871fd558d18SJames Chapman 872fd558d18SJames Chapman /* Short packet? */ 873fd558d18SJames Chapman if (!pskb_may_pull(skb, L2TP_HDR_SIZE_SEQ)) { 874a4ca44faSJoe Perches l2tp_info(tunnel, L2TP_MSG_DATA, 875a4ca44faSJoe Perches "%s: recv short packet (len=%d)\n", 876a4ca44faSJoe Perches tunnel->name, skb->len); 877fd558d18SJames Chapman goto error; 878fd558d18SJames Chapman } 879fd558d18SJames Chapman 880fd558d18SJames Chapman /* Trace packet contents, if enabled */ 881fd558d18SJames Chapman if (tunnel->debug & L2TP_MSG_DATA) { 882fd558d18SJames Chapman length = min(32u, skb->len); 883fd558d18SJames Chapman if (!pskb_may_pull(skb, length)) 884fd558d18SJames Chapman goto error; 885fd558d18SJames Chapman 886a4ca44faSJoe Perches pr_debug("%s: recv\n", tunnel->name); 887a4ca44faSJoe Perches print_hex_dump_bytes("", DUMP_PREFIX_OFFSET, skb->data, length); 888fd558d18SJames Chapman } 889fd558d18SJames Chapman 890e50e705cSEric Dumazet /* Point to L2TP header */ 891e50e705cSEric Dumazet optr = ptr = skb->data; 892e50e705cSEric Dumazet 893fd558d18SJames Chapman /* Get L2TP header flags */ 894fd558d18SJames Chapman hdrflags = ntohs(*(__be16 *) ptr); 895fd558d18SJames Chapman 896fd558d18SJames Chapman /* Check protocol version */ 897fd558d18SJames Chapman version = hdrflags & L2TP_HDR_VER_MASK; 898fd558d18SJames Chapman if (version != tunnel->version) { 899a4ca44faSJoe Perches l2tp_info(tunnel, L2TP_MSG_DATA, 900fd558d18SJames Chapman "%s: recv protocol version mismatch: got %d expected %d\n", 901fd558d18SJames Chapman tunnel->name, version, tunnel->version); 902fd558d18SJames Chapman goto error; 903fd558d18SJames Chapman } 904fd558d18SJames Chapman 905fd558d18SJames Chapman /* Get length of L2TP packet */ 906fd558d18SJames Chapman length = skb->len; 907fd558d18SJames Chapman 908fd558d18SJames Chapman /* If type is control packet, it is handled by userspace. */ 909fd558d18SJames Chapman if (hdrflags & L2TP_HDRFLAG_T) { 910a4ca44faSJoe Perches l2tp_dbg(tunnel, L2TP_MSG_DATA, 911a4ca44faSJoe Perches "%s: recv control packet, len=%d\n", 912a4ca44faSJoe Perches tunnel->name, length); 913fd558d18SJames Chapman goto error; 914fd558d18SJames Chapman } 915fd558d18SJames Chapman 916fd558d18SJames Chapman /* Skip flags */ 917fd558d18SJames Chapman ptr += 2; 918fd558d18SJames Chapman 919f7faffa3SJames Chapman if (tunnel->version == L2TP_HDR_VER_2) { 920fd558d18SJames Chapman /* If length is present, skip it */ 921fd558d18SJames Chapman if (hdrflags & L2TP_HDRFLAG_L) 922fd558d18SJames Chapman ptr += 2; 923fd558d18SJames Chapman 924fd558d18SJames Chapman /* Extract tunnel and session ID */ 925fd558d18SJames Chapman tunnel_id = ntohs(*(__be16 *) ptr); 926fd558d18SJames Chapman ptr += 2; 927fd558d18SJames Chapman session_id = ntohs(*(__be16 *) ptr); 928fd558d18SJames Chapman ptr += 2; 929f7faffa3SJames Chapman } else { 930f7faffa3SJames Chapman ptr += 2; /* skip reserved bits */ 931f7faffa3SJames Chapman tunnel_id = tunnel->tunnel_id; 932f7faffa3SJames Chapman session_id = ntohl(*(__be32 *) ptr); 933f7faffa3SJames Chapman ptr += 4; 934f7faffa3SJames Chapman } 935fd558d18SJames Chapman 936fd558d18SJames Chapman /* Find the session context */ 937f7faffa3SJames Chapman session = l2tp_session_find(tunnel->l2tp_net, tunnel, session_id); 938309795f4SJames Chapman if (!session || !session->recv_skb) { 939fd558d18SJames Chapman /* Not found? Pass to userspace to deal with */ 940a4ca44faSJoe Perches l2tp_info(tunnel, L2TP_MSG_DATA, 941f7faffa3SJames Chapman "%s: no session found (%u/%u). Passing up.\n", 942fd558d18SJames Chapman tunnel->name, tunnel_id, session_id); 943fd558d18SJames Chapman goto error; 944fd558d18SJames Chapman } 945fd558d18SJames Chapman 946f7faffa3SJames Chapman l2tp_recv_common(session, skb, ptr, optr, hdrflags, length, payload_hook); 947fd558d18SJames Chapman 948fd558d18SJames Chapman return 0; 949fd558d18SJames Chapman 950fd558d18SJames Chapman discard_bad_csum: 951fd558d18SJames Chapman LIMIT_NETDEBUG("%s: UDP: bad checksum\n", tunnel->name); 952fd558d18SJames Chapman UDP_INC_STATS_USER(tunnel->l2tp_net, UDP_MIB_INERRORS, 0); 9535de7aee5SJames Chapman tstats = &tunnel->stats; 9545de7aee5SJames Chapman u64_stats_update_begin(&tstats->syncp); 9555de7aee5SJames Chapman tstats->rx_errors++; 9565de7aee5SJames Chapman u64_stats_update_end(&tstats->syncp); 957fd558d18SJames Chapman kfree_skb(skb); 958fd558d18SJames Chapman 959fd558d18SJames Chapman return 0; 960fd558d18SJames Chapman 961fd558d18SJames Chapman error: 962fd558d18SJames Chapman /* Put UDP header back */ 963fd558d18SJames Chapman __skb_push(skb, sizeof(struct udphdr)); 964fd558d18SJames Chapman 965fd558d18SJames Chapman return 1; 966fd558d18SJames Chapman } 967fd558d18SJames Chapman 968fd558d18SJames Chapman /* UDP encapsulation receive handler. See net/ipv4/udp.c. 969fd558d18SJames Chapman * Return codes: 970fd558d18SJames Chapman * 0 : success. 971fd558d18SJames Chapman * <0: error 972fd558d18SJames Chapman * >0: skb should be passed up to userspace as UDP. 973fd558d18SJames Chapman */ 974fd558d18SJames Chapman int l2tp_udp_encap_recv(struct sock *sk, struct sk_buff *skb) 975fd558d18SJames Chapman { 976fd558d18SJames Chapman struct l2tp_tunnel *tunnel; 977fd558d18SJames Chapman 978fd558d18SJames Chapman tunnel = l2tp_sock_to_tunnel(sk); 979fd558d18SJames Chapman if (tunnel == NULL) 980fd558d18SJames Chapman goto pass_up; 981fd558d18SJames Chapman 982a4ca44faSJoe Perches l2tp_dbg(tunnel, L2TP_MSG_DATA, "%s: received %d bytes\n", 983a4ca44faSJoe Perches tunnel->name, skb->len); 984fd558d18SJames Chapman 985fd558d18SJames Chapman if (l2tp_udp_recv_core(tunnel, skb, tunnel->recv_payload_hook)) 986fd558d18SJames Chapman goto pass_up_put; 987fd558d18SJames Chapman 988fd558d18SJames Chapman sock_put(sk); 989fd558d18SJames Chapman return 0; 990fd558d18SJames Chapman 991fd558d18SJames Chapman pass_up_put: 992fd558d18SJames Chapman sock_put(sk); 993fd558d18SJames Chapman pass_up: 994fd558d18SJames Chapman return 1; 995fd558d18SJames Chapman } 996fd558d18SJames Chapman EXPORT_SYMBOL_GPL(l2tp_udp_encap_recv); 997fd558d18SJames Chapman 998fd558d18SJames Chapman /************************************************************************ 999fd558d18SJames Chapman * Transmit handling 1000fd558d18SJames Chapman ***********************************************************************/ 1001fd558d18SJames Chapman 1002fd558d18SJames Chapman /* Build an L2TP header for the session into the buffer provided. 1003fd558d18SJames Chapman */ 1004f7faffa3SJames Chapman static int l2tp_build_l2tpv2_header(struct l2tp_session *session, void *buf) 1005fd558d18SJames Chapman { 1006f7faffa3SJames Chapman struct l2tp_tunnel *tunnel = session->tunnel; 1007fd558d18SJames Chapman __be16 *bufp = buf; 1008f7faffa3SJames Chapman __be16 *optr = buf; 1009fd558d18SJames Chapman u16 flags = L2TP_HDR_VER_2; 1010fd558d18SJames Chapman u32 tunnel_id = tunnel->peer_tunnel_id; 1011fd558d18SJames Chapman u32 session_id = session->peer_session_id; 1012fd558d18SJames Chapman 1013fd558d18SJames Chapman if (session->send_seq) 1014fd558d18SJames Chapman flags |= L2TP_HDRFLAG_S; 1015fd558d18SJames Chapman 1016fd558d18SJames Chapman /* Setup L2TP header. */ 1017fd558d18SJames Chapman *bufp++ = htons(flags); 1018fd558d18SJames Chapman *bufp++ = htons(tunnel_id); 1019fd558d18SJames Chapman *bufp++ = htons(session_id); 1020fd558d18SJames Chapman if (session->send_seq) { 1021fd558d18SJames Chapman *bufp++ = htons(session->ns); 1022fd558d18SJames Chapman *bufp++ = 0; 1023fd558d18SJames Chapman session->ns++; 1024f7faffa3SJames Chapman session->ns &= 0xffff; 1025a4ca44faSJoe Perches l2tp_dbg(session, L2TP_MSG_SEQ, "%s: updated ns to %u\n", 1026a4ca44faSJoe Perches session->name, session->ns); 1027fd558d18SJames Chapman } 1028fd558d18SJames Chapman 1029f7faffa3SJames Chapman return bufp - optr; 1030f7faffa3SJames Chapman } 1031f7faffa3SJames Chapman 1032f7faffa3SJames Chapman static int l2tp_build_l2tpv3_header(struct l2tp_session *session, void *buf) 1033fd558d18SJames Chapman { 10340d76751fSJames Chapman struct l2tp_tunnel *tunnel = session->tunnel; 1035f7faffa3SJames Chapman char *bufp = buf; 1036f7faffa3SJames Chapman char *optr = bufp; 1037fd558d18SJames Chapman 10380d76751fSJames Chapman /* Setup L2TP header. The header differs slightly for UDP and 10390d76751fSJames Chapman * IP encapsulations. For UDP, there is 4 bytes of flags. 10400d76751fSJames Chapman */ 10410d76751fSJames Chapman if (tunnel->encap == L2TP_ENCAPTYPE_UDP) { 10420d76751fSJames Chapman u16 flags = L2TP_HDR_VER_3; 1043f7faffa3SJames Chapman *((__be16 *) bufp) = htons(flags); 1044f7faffa3SJames Chapman bufp += 2; 1045f7faffa3SJames Chapman *((__be16 *) bufp) = 0; 1046f7faffa3SJames Chapman bufp += 2; 10470d76751fSJames Chapman } 10480d76751fSJames Chapman 1049f7faffa3SJames Chapman *((__be32 *) bufp) = htonl(session->peer_session_id); 1050f7faffa3SJames Chapman bufp += 4; 1051f7faffa3SJames Chapman if (session->cookie_len) { 1052f7faffa3SJames Chapman memcpy(bufp, &session->cookie[0], session->cookie_len); 1053f7faffa3SJames Chapman bufp += session->cookie_len; 1054fd558d18SJames Chapman } 1055f7faffa3SJames Chapman if (session->l2specific_len) { 1056f7faffa3SJames Chapman if (session->l2specific_type == L2TP_L2SPECTYPE_DEFAULT) { 1057f7faffa3SJames Chapman u32 l2h = 0; 1058f7faffa3SJames Chapman if (session->send_seq) { 1059f7faffa3SJames Chapman l2h = 0x40000000 | session->ns; 1060f7faffa3SJames Chapman session->ns++; 1061f7faffa3SJames Chapman session->ns &= 0xffffff; 1062a4ca44faSJoe Perches l2tp_dbg(session, L2TP_MSG_SEQ, 1063a4ca44faSJoe Perches "%s: updated ns to %u\n", 1064a4ca44faSJoe Perches session->name, session->ns); 1065f7faffa3SJames Chapman } 1066f7faffa3SJames Chapman 1067f7faffa3SJames Chapman *((__be32 *) bufp) = htonl(l2h); 1068f7faffa3SJames Chapman } 1069f7faffa3SJames Chapman bufp += session->l2specific_len; 1070f7faffa3SJames Chapman } 1071f7faffa3SJames Chapman if (session->offset) 1072f7faffa3SJames Chapman bufp += session->offset; 1073f7faffa3SJames Chapman 1074f7faffa3SJames Chapman return bufp - optr; 1075f7faffa3SJames Chapman } 1076fd558d18SJames Chapman 1077fc130840Sstephen hemminger static int l2tp_xmit_core(struct l2tp_session *session, struct sk_buff *skb, 1078d9d8da80SDavid S. Miller struct flowi *fl, size_t data_len) 1079fd558d18SJames Chapman { 1080fd558d18SJames Chapman struct l2tp_tunnel *tunnel = session->tunnel; 1081fd558d18SJames Chapman unsigned int len = skb->len; 1082fd558d18SJames Chapman int error; 10835de7aee5SJames Chapman struct l2tp_stats *tstats, *sstats; 1084fd558d18SJames Chapman 1085fd558d18SJames Chapman /* Debug */ 1086fd558d18SJames Chapman if (session->send_seq) 1087a4ca44faSJoe Perches l2tp_dbg(session, L2TP_MSG_DATA, "%s: send %Zd bytes, ns=%u\n", 1088a4ca44faSJoe Perches session->name, data_len, session->ns - 1); 1089fd558d18SJames Chapman else 1090a4ca44faSJoe Perches l2tp_dbg(session, L2TP_MSG_DATA, "%s: send %Zd bytes\n", 1091a4ca44faSJoe Perches session->name, data_len); 1092fd558d18SJames Chapman 1093fd558d18SJames Chapman if (session->debug & L2TP_MSG_DATA) { 10940d76751fSJames Chapman int uhlen = (tunnel->encap == L2TP_ENCAPTYPE_UDP) ? sizeof(struct udphdr) : 0; 10950d76751fSJames Chapman unsigned char *datap = skb->data + uhlen; 1096fd558d18SJames Chapman 1097a4ca44faSJoe Perches pr_debug("%s: xmit\n", session->name); 1098a4ca44faSJoe Perches print_hex_dump_bytes("", DUMP_PREFIX_OFFSET, 1099a4ca44faSJoe Perches datap, min_t(size_t, 32, len - uhlen)); 1100fd558d18SJames Chapman } 1101fd558d18SJames Chapman 1102fd558d18SJames Chapman /* Queue the packet to IP for output */ 11034e15ed4dSShan Wei skb->local_df = 1; 1104d2cf3361SBenjamin LaHaise #if IS_ENABLED(CONFIG_IPV6) 1105d2cf3361SBenjamin LaHaise if (skb->sk->sk_family == PF_INET6) 1106d2cf3361SBenjamin LaHaise error = inet6_csk_xmit(skb, NULL); 1107d2cf3361SBenjamin LaHaise else 1108d2cf3361SBenjamin LaHaise #endif 1109d9d8da80SDavid S. Miller error = ip_queue_xmit(skb, fl); 1110fd558d18SJames Chapman 1111fd558d18SJames Chapman /* Update stats */ 11125de7aee5SJames Chapman tstats = &tunnel->stats; 11135de7aee5SJames Chapman u64_stats_update_begin(&tstats->syncp); 11145de7aee5SJames Chapman sstats = &session->stats; 11155de7aee5SJames Chapman u64_stats_update_begin(&sstats->syncp); 1116fd558d18SJames Chapman if (error >= 0) { 11175de7aee5SJames Chapman tstats->tx_packets++; 11185de7aee5SJames Chapman tstats->tx_bytes += len; 11195de7aee5SJames Chapman sstats->tx_packets++; 11205de7aee5SJames Chapman sstats->tx_bytes += len; 1121fd558d18SJames Chapman } else { 11225de7aee5SJames Chapman tstats->tx_errors++; 11235de7aee5SJames Chapman sstats->tx_errors++; 1124fd558d18SJames Chapman } 11255de7aee5SJames Chapman u64_stats_update_end(&tstats->syncp); 11265de7aee5SJames Chapman u64_stats_update_end(&sstats->syncp); 1127fd558d18SJames Chapman 1128fd558d18SJames Chapman return 0; 1129fd558d18SJames Chapman } 1130fd558d18SJames Chapman 1131fd558d18SJames Chapman /* Automatically called when the skb is freed. 1132fd558d18SJames Chapman */ 1133fd558d18SJames Chapman static void l2tp_sock_wfree(struct sk_buff *skb) 1134fd558d18SJames Chapman { 1135fd558d18SJames Chapman sock_put(skb->sk); 1136fd558d18SJames Chapman } 1137fd558d18SJames Chapman 1138fd558d18SJames Chapman /* For data skbs that we transmit, we associate with the tunnel socket 1139fd558d18SJames Chapman * but don't do accounting. 1140fd558d18SJames Chapman */ 1141fd558d18SJames Chapman static inline void l2tp_skb_set_owner_w(struct sk_buff *skb, struct sock *sk) 1142fd558d18SJames Chapman { 1143fd558d18SJames Chapman sock_hold(sk); 1144fd558d18SJames Chapman skb->sk = sk; 1145fd558d18SJames Chapman skb->destructor = l2tp_sock_wfree; 1146fd558d18SJames Chapman } 1147fd558d18SJames Chapman 1148d2cf3361SBenjamin LaHaise #if IS_ENABLED(CONFIG_IPV6) 1149d2cf3361SBenjamin LaHaise static void l2tp_xmit_ipv6_csum(struct sock *sk, struct sk_buff *skb, 1150d2cf3361SBenjamin LaHaise int udp_len) 1151d2cf3361SBenjamin LaHaise { 1152d2cf3361SBenjamin LaHaise struct ipv6_pinfo *np = inet6_sk(sk); 1153d2cf3361SBenjamin LaHaise struct udphdr *uh = udp_hdr(skb); 1154d2cf3361SBenjamin LaHaise 1155d2cf3361SBenjamin LaHaise if (!skb_dst(skb) || !skb_dst(skb)->dev || 1156d2cf3361SBenjamin LaHaise !(skb_dst(skb)->dev->features & NETIF_F_IPV6_CSUM)) { 1157d2cf3361SBenjamin LaHaise __wsum csum = skb_checksum(skb, 0, udp_len, 0); 1158d2cf3361SBenjamin LaHaise skb->ip_summed = CHECKSUM_UNNECESSARY; 1159d2cf3361SBenjamin LaHaise uh->check = csum_ipv6_magic(&np->saddr, &np->daddr, udp_len, 1160d2cf3361SBenjamin LaHaise IPPROTO_UDP, csum); 1161d2cf3361SBenjamin LaHaise if (uh->check == 0) 1162d2cf3361SBenjamin LaHaise uh->check = CSUM_MANGLED_0; 1163d2cf3361SBenjamin LaHaise } else { 1164d2cf3361SBenjamin LaHaise skb->ip_summed = CHECKSUM_PARTIAL; 1165d2cf3361SBenjamin LaHaise skb->csum_start = skb_transport_header(skb) - skb->head; 1166d2cf3361SBenjamin LaHaise skb->csum_offset = offsetof(struct udphdr, check); 1167d2cf3361SBenjamin LaHaise uh->check = ~csum_ipv6_magic(&np->saddr, &np->daddr, 1168d2cf3361SBenjamin LaHaise udp_len, IPPROTO_UDP, 0); 1169d2cf3361SBenjamin LaHaise } 1170d2cf3361SBenjamin LaHaise } 1171d2cf3361SBenjamin LaHaise #endif 1172d2cf3361SBenjamin LaHaise 1173fd558d18SJames Chapman /* If caller requires the skb to have a ppp header, the header must be 1174fd558d18SJames Chapman * inserted in the skb data before calling this function. 1175fd558d18SJames Chapman */ 1176fd558d18SJames Chapman int l2tp_xmit_skb(struct l2tp_session *session, struct sk_buff *skb, int hdr_len) 1177fd558d18SJames Chapman { 1178fd558d18SJames Chapman int data_len = skb->len; 11790d76751fSJames Chapman struct l2tp_tunnel *tunnel = session->tunnel; 11800d76751fSJames Chapman struct sock *sk = tunnel->sock; 1181d9d8da80SDavid S. Miller struct flowi *fl; 1182fd558d18SJames Chapman struct udphdr *uh; 1183fd558d18SJames Chapman struct inet_sock *inet; 1184fd558d18SJames Chapman __wsum csum; 1185fd558d18SJames Chapman int headroom; 11860d76751fSJames Chapman int uhlen = (tunnel->encap == L2TP_ENCAPTYPE_UDP) ? sizeof(struct udphdr) : 0; 11870d76751fSJames Chapman int udp_len; 1188b8c84307SEric Dumazet int ret = NET_XMIT_SUCCESS; 1189fd558d18SJames Chapman 1190fd558d18SJames Chapman /* Check that there's enough headroom in the skb to insert IP, 1191fd558d18SJames Chapman * UDP and L2TP headers. If not enough, expand it to 1192fd558d18SJames Chapman * make room. Adjust truesize. 1193fd558d18SJames Chapman */ 1194fd558d18SJames Chapman headroom = NET_SKB_PAD + sizeof(struct iphdr) + 11950d76751fSJames Chapman uhlen + hdr_len; 1196835acf5dSEric Dumazet if (skb_cow_head(skb, headroom)) { 1197b8c84307SEric Dumazet kfree_skb(skb); 1198b8c84307SEric Dumazet return NET_XMIT_DROP; 1199835acf5dSEric Dumazet } 1200fd558d18SJames Chapman 1201fd558d18SJames Chapman skb_orphan(skb); 1202fd558d18SJames Chapman /* Setup L2TP header */ 1203f7faffa3SJames Chapman session->build_header(session, __skb_push(skb, hdr_len)); 1204fd558d18SJames Chapman 12050d76751fSJames Chapman /* Reset skb netfilter state */ 1206fd558d18SJames Chapman memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt)); 1207fd558d18SJames Chapman IPCB(skb)->flags &= ~(IPSKB_XFRM_TUNNEL_SIZE | IPSKB_XFRM_TRANSFORMED | 1208fd558d18SJames Chapman IPSKB_REROUTED); 1209fd558d18SJames Chapman nf_reset(skb); 1210fd558d18SJames Chapman 12116af88da1SDavid S. Miller bh_lock_sock(sk); 12126af88da1SDavid S. Miller if (sock_owned_by_user(sk)) { 1213b8c84307SEric Dumazet kfree_skb(skb); 1214b8c84307SEric Dumazet ret = NET_XMIT_DROP; 12156af88da1SDavid S. Miller goto out_unlock; 12166af88da1SDavid S. Miller } 12176af88da1SDavid S. Miller 1218fd558d18SJames Chapman /* Get routing info from the tunnel socket */ 1219fd558d18SJames Chapman skb_dst_drop(skb); 122071b1391aSFlorian Westphal skb_dst_set(skb, dst_clone(__sk_dst_check(sk, 0))); 12210d76751fSJames Chapman 1222d9d8da80SDavid S. Miller inet = inet_sk(sk); 1223d9d8da80SDavid S. Miller fl = &inet->cork.fl; 12240d76751fSJames Chapman switch (tunnel->encap) { 12250d76751fSJames Chapman case L2TP_ENCAPTYPE_UDP: 12260d76751fSJames Chapman /* Setup UDP header */ 12270d76751fSJames Chapman __skb_push(skb, sizeof(*uh)); 12280d76751fSJames Chapman skb_reset_transport_header(skb); 12290d76751fSJames Chapman uh = udp_hdr(skb); 12300d76751fSJames Chapman uh->source = inet->inet_sport; 12310d76751fSJames Chapman uh->dest = inet->inet_dport; 12320d76751fSJames Chapman udp_len = uhlen + hdr_len + data_len; 12330d76751fSJames Chapman uh->len = htons(udp_len); 12340d76751fSJames Chapman uh->check = 0; 1235fd558d18SJames Chapman 1236fd558d18SJames Chapman /* Calculate UDP checksum if configured to do so */ 1237d2cf3361SBenjamin LaHaise #if IS_ENABLED(CONFIG_IPV6) 1238d2cf3361SBenjamin LaHaise if (sk->sk_family == PF_INET6) 1239d2cf3361SBenjamin LaHaise l2tp_xmit_ipv6_csum(sk, skb, udp_len); 1240d2cf3361SBenjamin LaHaise else 1241d2cf3361SBenjamin LaHaise #endif 1242fd558d18SJames Chapman if (sk->sk_no_check == UDP_CSUM_NOXMIT) 1243fd558d18SJames Chapman skb->ip_summed = CHECKSUM_NONE; 1244fd558d18SJames Chapman else if ((skb_dst(skb) && skb_dst(skb)->dev) && 1245fd558d18SJames Chapman (!(skb_dst(skb)->dev->features & NETIF_F_V4_CSUM))) { 1246fd558d18SJames Chapman skb->ip_summed = CHECKSUM_COMPLETE; 1247fd558d18SJames Chapman csum = skb_checksum(skb, 0, udp_len, 0); 1248fd558d18SJames Chapman uh->check = csum_tcpudp_magic(inet->inet_saddr, 1249fd558d18SJames Chapman inet->inet_daddr, 1250fd558d18SJames Chapman udp_len, IPPROTO_UDP, csum); 1251fd558d18SJames Chapman if (uh->check == 0) 1252fd558d18SJames Chapman uh->check = CSUM_MANGLED_0; 1253fd558d18SJames Chapman } else { 1254fd558d18SJames Chapman skb->ip_summed = CHECKSUM_PARTIAL; 1255fd558d18SJames Chapman skb->csum_start = skb_transport_header(skb) - skb->head; 1256fd558d18SJames Chapman skb->csum_offset = offsetof(struct udphdr, check); 1257fd558d18SJames Chapman uh->check = ~csum_tcpudp_magic(inet->inet_saddr, 1258fd558d18SJames Chapman inet->inet_daddr, 1259fd558d18SJames Chapman udp_len, IPPROTO_UDP, 0); 1260fd558d18SJames Chapman } 12610d76751fSJames Chapman break; 12620d76751fSJames Chapman 12630d76751fSJames Chapman case L2TP_ENCAPTYPE_IP: 12640d76751fSJames Chapman break; 12650d76751fSJames Chapman } 12660d76751fSJames Chapman 12670d76751fSJames Chapman l2tp_skb_set_owner_w(skb, sk); 1268fd558d18SJames Chapman 1269d9d8da80SDavid S. Miller l2tp_xmit_core(session, skb, fl, data_len); 12706af88da1SDavid S. Miller out_unlock: 12716af88da1SDavid S. Miller bh_unlock_sock(sk); 1272fd558d18SJames Chapman 1273b8c84307SEric Dumazet return ret; 1274fd558d18SJames Chapman } 1275fd558d18SJames Chapman EXPORT_SYMBOL_GPL(l2tp_xmit_skb); 1276fd558d18SJames Chapman 1277fd558d18SJames Chapman /***************************************************************************** 1278fd558d18SJames Chapman * Tinnel and session create/destroy. 1279fd558d18SJames Chapman *****************************************************************************/ 1280fd558d18SJames Chapman 1281fd558d18SJames Chapman /* Tunnel socket destruct hook. 1282fd558d18SJames Chapman * The tunnel context is deleted only when all session sockets have been 1283fd558d18SJames Chapman * closed. 1284fd558d18SJames Chapman */ 1285fc130840Sstephen hemminger static void l2tp_tunnel_destruct(struct sock *sk) 1286fd558d18SJames Chapman { 1287fd558d18SJames Chapman struct l2tp_tunnel *tunnel; 1288f8ccac0eSTom Parkin struct l2tp_net *pn; 1289fd558d18SJames Chapman 1290fd558d18SJames Chapman tunnel = sk->sk_user_data; 1291fd558d18SJames Chapman if (tunnel == NULL) 1292fd558d18SJames Chapman goto end; 1293fd558d18SJames Chapman 1294a4ca44faSJoe Perches l2tp_info(tunnel, L2TP_MSG_CONTROL, "%s: closing...\n", tunnel->name); 1295fd558d18SJames Chapman 1296fd558d18SJames Chapman 1297f8ccac0eSTom Parkin /* Disable udp encapsulation */ 12980d76751fSJames Chapman switch (tunnel->encap) { 12990d76751fSJames Chapman case L2TP_ENCAPTYPE_UDP: 1300fd558d18SJames Chapman /* No longer an encapsulation socket. See net/ipv4/udp.c */ 1301fd558d18SJames Chapman (udp_sk(sk))->encap_type = 0; 1302fd558d18SJames Chapman (udp_sk(sk))->encap_rcv = NULL; 13039980d001STom Parkin (udp_sk(sk))->encap_destroy = NULL; 13040d76751fSJames Chapman break; 13050d76751fSJames Chapman case L2TP_ENCAPTYPE_IP: 13060d76751fSJames Chapman break; 13070d76751fSJames Chapman } 1308fd558d18SJames Chapman 1309fd558d18SJames Chapman /* Remove hooks into tunnel socket */ 1310fd558d18SJames Chapman sk->sk_destruct = tunnel->old_sk_destruct; 1311fd558d18SJames Chapman sk->sk_user_data = NULL; 1312f8ccac0eSTom Parkin tunnel->sock = NULL; 1313f8ccac0eSTom Parkin 1314f8ccac0eSTom Parkin /* Remove the tunnel struct from the tunnel list */ 1315f8ccac0eSTom Parkin pn = l2tp_pernet(tunnel->l2tp_net); 1316f8ccac0eSTom Parkin spin_lock_bh(&pn->l2tp_tunnel_list_lock); 1317f8ccac0eSTom Parkin list_del_rcu(&tunnel->list); 1318f8ccac0eSTom Parkin spin_unlock_bh(&pn->l2tp_tunnel_list_lock); 1319f8ccac0eSTom Parkin atomic_dec(&l2tp_tunnel_count); 1320f8ccac0eSTom Parkin 1321f8ccac0eSTom Parkin l2tp_tunnel_closeall(tunnel); 1322f8ccac0eSTom Parkin l2tp_tunnel_dec_refcount(tunnel); 1323fd558d18SJames Chapman 1324fd558d18SJames Chapman /* Call the original destructor */ 1325fd558d18SJames Chapman if (sk->sk_destruct) 1326fd558d18SJames Chapman (*sk->sk_destruct)(sk); 1327fd558d18SJames Chapman end: 1328fd558d18SJames Chapman return; 1329fd558d18SJames Chapman } 1330fd558d18SJames Chapman 1331fd558d18SJames Chapman /* When the tunnel is closed, all the attached sessions need to go too. 1332fd558d18SJames Chapman */ 1333e34f4c70STom Parkin void l2tp_tunnel_closeall(struct l2tp_tunnel *tunnel) 1334fd558d18SJames Chapman { 1335fd558d18SJames Chapman int hash; 1336fd558d18SJames Chapman struct hlist_node *walk; 1337fd558d18SJames Chapman struct hlist_node *tmp; 1338fd558d18SJames Chapman struct l2tp_session *session; 1339fd558d18SJames Chapman 1340fd558d18SJames Chapman BUG_ON(tunnel == NULL); 1341fd558d18SJames Chapman 1342a4ca44faSJoe Perches l2tp_info(tunnel, L2TP_MSG_CONTROL, "%s: closing all sessions...\n", 1343a4ca44faSJoe Perches tunnel->name); 1344fd558d18SJames Chapman 1345fd558d18SJames Chapman write_lock_bh(&tunnel->hlist_lock); 1346fd558d18SJames Chapman for (hash = 0; hash < L2TP_HASH_SIZE; hash++) { 1347fd558d18SJames Chapman again: 1348fd558d18SJames Chapman hlist_for_each_safe(walk, tmp, &tunnel->session_hlist[hash]) { 1349fd558d18SJames Chapman session = hlist_entry(walk, struct l2tp_session, hlist); 1350fd558d18SJames Chapman 1351a4ca44faSJoe Perches l2tp_info(session, L2TP_MSG_CONTROL, 1352fd558d18SJames Chapman "%s: closing session\n", session->name); 1353fd558d18SJames Chapman 1354fd558d18SJames Chapman hlist_del_init(&session->hlist); 1355fd558d18SJames Chapman 1356fd558d18SJames Chapman /* Since we should hold the sock lock while 1357fd558d18SJames Chapman * doing any unbinding, we need to release the 1358fd558d18SJames Chapman * lock we're holding before taking that lock. 1359fd558d18SJames Chapman * Hold a reference to the sock so it doesn't 1360fd558d18SJames Chapman * disappear as we're jumping between locks. 1361fd558d18SJames Chapman */ 1362fd558d18SJames Chapman if (session->ref != NULL) 1363fd558d18SJames Chapman (*session->ref)(session); 1364fd558d18SJames Chapman 1365fd558d18SJames Chapman write_unlock_bh(&tunnel->hlist_lock); 1366fd558d18SJames Chapman 1367f7faffa3SJames Chapman if (tunnel->version != L2TP_HDR_VER_2) { 1368f7faffa3SJames Chapman struct l2tp_net *pn = l2tp_pernet(tunnel->l2tp_net); 1369f7faffa3SJames Chapman 1370e02d494dSJames Chapman spin_lock_bh(&pn->l2tp_session_hlist_lock); 1371e02d494dSJames Chapman hlist_del_init_rcu(&session->global_hlist); 1372e02d494dSJames Chapman spin_unlock_bh(&pn->l2tp_session_hlist_lock); 1373e02d494dSJames Chapman synchronize_rcu(); 1374f7faffa3SJames Chapman } 1375f7faffa3SJames Chapman 13764c6e2fd3STom Parkin l2tp_session_queue_purge(session); 13774c6e2fd3STom Parkin 1378fd558d18SJames Chapman if (session->session_close != NULL) 1379fd558d18SJames Chapman (*session->session_close)(session); 1380fd558d18SJames Chapman 1381fd558d18SJames Chapman if (session->deref != NULL) 1382fd558d18SJames Chapman (*session->deref)(session); 1383fd558d18SJames Chapman 13849980d001STom Parkin l2tp_session_dec_refcount(session); 13859980d001STom Parkin 1386fd558d18SJames Chapman write_lock_bh(&tunnel->hlist_lock); 1387fd558d18SJames Chapman 1388fd558d18SJames Chapman /* Now restart from the beginning of this hash 1389fd558d18SJames Chapman * chain. We always remove a session from the 1390fd558d18SJames Chapman * list so we are guaranteed to make forward 1391fd558d18SJames Chapman * progress. 1392fd558d18SJames Chapman */ 1393fd558d18SJames Chapman goto again; 1394fd558d18SJames Chapman } 1395fd558d18SJames Chapman } 1396fd558d18SJames Chapman write_unlock_bh(&tunnel->hlist_lock); 1397fd558d18SJames Chapman } 1398e34f4c70STom Parkin EXPORT_SYMBOL_GPL(l2tp_tunnel_closeall); 1399fd558d18SJames Chapman 14009980d001STom Parkin /* Tunnel socket destroy hook for UDP encapsulation */ 14019980d001STom Parkin static void l2tp_udp_encap_destroy(struct sock *sk) 14029980d001STom Parkin { 14039980d001STom Parkin struct l2tp_tunnel *tunnel = l2tp_sock_to_tunnel(sk); 14049980d001STom Parkin if (tunnel) { 14059980d001STom Parkin l2tp_tunnel_closeall(tunnel); 14069980d001STom Parkin sock_put(sk); 14079980d001STom Parkin } 14089980d001STom Parkin } 14099980d001STom Parkin 1410fd558d18SJames Chapman /* Really kill the tunnel. 1411fd558d18SJames Chapman * Come here only when all sessions have been cleared from the tunnel. 1412fd558d18SJames Chapman */ 1413fc130840Sstephen hemminger static void l2tp_tunnel_free(struct l2tp_tunnel *tunnel) 1414fd558d18SJames Chapman { 1415fd558d18SJames Chapman BUG_ON(atomic_read(&tunnel->ref_count) != 0); 1416fd558d18SJames Chapman BUG_ON(tunnel->sock != NULL); 1417a4ca44faSJoe Perches l2tp_info(tunnel, L2TP_MSG_CONTROL, "%s: free...\n", tunnel->name); 141899469c32Sxeb@mail.ru kfree_rcu(tunnel, rcu); 1419f8ccac0eSTom Parkin } 1420fd558d18SJames Chapman 1421f8ccac0eSTom Parkin /* Workqueue tunnel deletion function */ 1422f8ccac0eSTom Parkin static void l2tp_tunnel_del_work(struct work_struct *work) 1423f8ccac0eSTom Parkin { 1424f8ccac0eSTom Parkin struct l2tp_tunnel *tunnel = NULL; 1425f8ccac0eSTom Parkin struct socket *sock = NULL; 1426f8ccac0eSTom Parkin struct sock *sk = NULL; 1427f8ccac0eSTom Parkin 1428f8ccac0eSTom Parkin tunnel = container_of(work, struct l2tp_tunnel, del_work); 1429f8ccac0eSTom Parkin sk = l2tp_tunnel_sock_lookup(tunnel); 1430f8ccac0eSTom Parkin if (!sk) 1431f8ccac0eSTom Parkin return; 1432f8ccac0eSTom Parkin 1433f8ccac0eSTom Parkin sock = sk->sk_socket; 1434f8ccac0eSTom Parkin 143502d13ed5STom Parkin /* If the tunnel socket was created by userspace, then go through the 143602d13ed5STom Parkin * inet layer to shut the socket down, and let userspace close it. 143702d13ed5STom Parkin * Otherwise, if we created the socket directly within the kernel, use 143802d13ed5STom Parkin * the sk API to release it here. 1439167eb17eSTom Parkin * In either case the tunnel resources are freed in the socket 1440167eb17eSTom Parkin * destructor when the tunnel socket goes away. 1441f8ccac0eSTom Parkin */ 144202d13ed5STom Parkin if (tunnel->fd >= 0) { 144302d13ed5STom Parkin if (sock) 144402d13ed5STom Parkin inet_shutdown(sock, 2); 144502d13ed5STom Parkin } else { 144602d13ed5STom Parkin if (sock) 1447167eb17eSTom Parkin kernel_sock_shutdown(sock, SHUT_RDWR); 1448167eb17eSTom Parkin sk_release_kernel(sk); 1449167eb17eSTom Parkin } 1450f8ccac0eSTom Parkin 1451f8ccac0eSTom Parkin l2tp_tunnel_sock_put(sk); 1452fd558d18SJames Chapman } 1453fd558d18SJames Chapman 1454789a4a2cSJames Chapman /* Create a socket for the tunnel, if one isn't set up by 1455789a4a2cSJames Chapman * userspace. This is used for static tunnels where there is no 1456789a4a2cSJames Chapman * managing L2TP daemon. 1457167eb17eSTom Parkin * 1458167eb17eSTom Parkin * Since we don't want these sockets to keep a namespace alive by 1459167eb17eSTom Parkin * themselves, we drop the socket's namespace refcount after creation. 1460167eb17eSTom Parkin * These sockets are freed when the namespace exits using the pernet 1461167eb17eSTom Parkin * exit hook. 1462789a4a2cSJames Chapman */ 1463167eb17eSTom Parkin static int l2tp_tunnel_sock_create(struct net *net, 1464167eb17eSTom Parkin u32 tunnel_id, 1465167eb17eSTom Parkin u32 peer_tunnel_id, 1466167eb17eSTom Parkin struct l2tp_tunnel_cfg *cfg, 1467167eb17eSTom Parkin struct socket **sockp) 1468789a4a2cSJames Chapman { 1469789a4a2cSJames Chapman int err = -EINVAL; 14707bddd0dbSEric Dumazet struct socket *sock = NULL; 1471167eb17eSTom Parkin struct sockaddr_in udp_addr = {0}; 1472167eb17eSTom Parkin struct sockaddr_l2tpip ip_addr = {0}; 1473167eb17eSTom Parkin #if IS_ENABLED(CONFIG_IPV6) 1474167eb17eSTom Parkin struct sockaddr_in6 udp6_addr = {0}; 1475167eb17eSTom Parkin struct sockaddr_l2tpip6 ip6_addr = {0}; 1476167eb17eSTom Parkin #endif 1477789a4a2cSJames Chapman 1478789a4a2cSJames Chapman switch (cfg->encap) { 1479789a4a2cSJames Chapman case L2TP_ENCAPTYPE_UDP: 1480f9bac8dfSChris Elston #if IS_ENABLED(CONFIG_IPV6) 1481f9bac8dfSChris Elston if (cfg->local_ip6 && cfg->peer_ip6) { 1482167eb17eSTom Parkin err = sock_create_kern(AF_INET6, SOCK_DGRAM, 0, &sock); 1483f9bac8dfSChris Elston if (err < 0) 1484f9bac8dfSChris Elston goto out; 1485f9bac8dfSChris Elston 1486167eb17eSTom Parkin sk_change_net(sock->sk, net); 1487f9bac8dfSChris Elston 1488f9bac8dfSChris Elston udp6_addr.sin6_family = AF_INET6; 1489f9bac8dfSChris Elston memcpy(&udp6_addr.sin6_addr, cfg->local_ip6, 1490f9bac8dfSChris Elston sizeof(udp6_addr.sin6_addr)); 1491f9bac8dfSChris Elston udp6_addr.sin6_port = htons(cfg->local_udp_port); 1492f9bac8dfSChris Elston err = kernel_bind(sock, (struct sockaddr *) &udp6_addr, 1493f9bac8dfSChris Elston sizeof(udp6_addr)); 1494f9bac8dfSChris Elston if (err < 0) 1495f9bac8dfSChris Elston goto out; 1496f9bac8dfSChris Elston 1497f9bac8dfSChris Elston udp6_addr.sin6_family = AF_INET6; 1498f9bac8dfSChris Elston memcpy(&udp6_addr.sin6_addr, cfg->peer_ip6, 1499f9bac8dfSChris Elston sizeof(udp6_addr.sin6_addr)); 1500f9bac8dfSChris Elston udp6_addr.sin6_port = htons(cfg->peer_udp_port); 1501f9bac8dfSChris Elston err = kernel_connect(sock, 1502f9bac8dfSChris Elston (struct sockaddr *) &udp6_addr, 1503f9bac8dfSChris Elston sizeof(udp6_addr), 0); 1504f9bac8dfSChris Elston if (err < 0) 1505f9bac8dfSChris Elston goto out; 1506f9bac8dfSChris Elston } else 1507f9bac8dfSChris Elston #endif 1508f9bac8dfSChris Elston { 1509167eb17eSTom Parkin err = sock_create_kern(AF_INET, SOCK_DGRAM, 0, &sock); 1510789a4a2cSJames Chapman if (err < 0) 1511789a4a2cSJames Chapman goto out; 1512789a4a2cSJames Chapman 1513167eb17eSTom Parkin sk_change_net(sock->sk, net); 1514789a4a2cSJames Chapman 1515789a4a2cSJames Chapman udp_addr.sin_family = AF_INET; 1516789a4a2cSJames Chapman udp_addr.sin_addr = cfg->local_ip; 1517789a4a2cSJames Chapman udp_addr.sin_port = htons(cfg->local_udp_port); 1518f9bac8dfSChris Elston err = kernel_bind(sock, (struct sockaddr *) &udp_addr, 1519f9bac8dfSChris Elston sizeof(udp_addr)); 1520789a4a2cSJames Chapman if (err < 0) 1521789a4a2cSJames Chapman goto out; 1522789a4a2cSJames Chapman 1523789a4a2cSJames Chapman udp_addr.sin_family = AF_INET; 1524789a4a2cSJames Chapman udp_addr.sin_addr = cfg->peer_ip; 1525789a4a2cSJames Chapman udp_addr.sin_port = htons(cfg->peer_udp_port); 1526f9bac8dfSChris Elston err = kernel_connect(sock, 1527f9bac8dfSChris Elston (struct sockaddr *) &udp_addr, 1528f9bac8dfSChris Elston sizeof(udp_addr), 0); 1529789a4a2cSJames Chapman if (err < 0) 1530789a4a2cSJames Chapman goto out; 1531f9bac8dfSChris Elston } 1532789a4a2cSJames Chapman 1533789a4a2cSJames Chapman if (!cfg->use_udp_checksums) 1534789a4a2cSJames Chapman sock->sk->sk_no_check = UDP_CSUM_NOXMIT; 1535789a4a2cSJames Chapman 1536789a4a2cSJames Chapman break; 1537789a4a2cSJames Chapman 1538789a4a2cSJames Chapman case L2TP_ENCAPTYPE_IP: 1539f9bac8dfSChris Elston #if IS_ENABLED(CONFIG_IPV6) 1540f9bac8dfSChris Elston if (cfg->local_ip6 && cfg->peer_ip6) { 1541167eb17eSTom Parkin err = sock_create_kern(AF_INET6, SOCK_DGRAM, 1542167eb17eSTom Parkin IPPROTO_L2TP, &sock); 15435dac94e1SJames Chapman if (err < 0) 1544f9bac8dfSChris Elston goto out; 15455dac94e1SJames Chapman 1546167eb17eSTom Parkin sk_change_net(sock->sk, net); 15475dac94e1SJames Chapman 15485dac94e1SJames Chapman ip6_addr.l2tp_family = AF_INET6; 15495dac94e1SJames Chapman memcpy(&ip6_addr.l2tp_addr, cfg->local_ip6, 15505dac94e1SJames Chapman sizeof(ip6_addr.l2tp_addr)); 15515dac94e1SJames Chapman ip6_addr.l2tp_conn_id = tunnel_id; 15525dac94e1SJames Chapman err = kernel_bind(sock, (struct sockaddr *) &ip6_addr, 15535dac94e1SJames Chapman sizeof(ip6_addr)); 15545dac94e1SJames Chapman if (err < 0) 15555dac94e1SJames Chapman goto out; 15565dac94e1SJames Chapman 15575dac94e1SJames Chapman ip6_addr.l2tp_family = AF_INET6; 15585dac94e1SJames Chapman memcpy(&ip6_addr.l2tp_addr, cfg->peer_ip6, 15595dac94e1SJames Chapman sizeof(ip6_addr.l2tp_addr)); 15605dac94e1SJames Chapman ip6_addr.l2tp_conn_id = peer_tunnel_id; 15615dac94e1SJames Chapman err = kernel_connect(sock, 15625dac94e1SJames Chapman (struct sockaddr *) &ip6_addr, 15635dac94e1SJames Chapman sizeof(ip6_addr), 0); 15645dac94e1SJames Chapman if (err < 0) 15655dac94e1SJames Chapman goto out; 15665dac94e1SJames Chapman } else 1567f9bac8dfSChris Elston #endif 15685dac94e1SJames Chapman { 1569167eb17eSTom Parkin err = sock_create_kern(AF_INET, SOCK_DGRAM, 1570167eb17eSTom Parkin IPPROTO_L2TP, &sock); 1571789a4a2cSJames Chapman if (err < 0) 1572789a4a2cSJames Chapman goto out; 1573789a4a2cSJames Chapman 1574167eb17eSTom Parkin sk_change_net(sock->sk, net); 1575789a4a2cSJames Chapman 1576789a4a2cSJames Chapman ip_addr.l2tp_family = AF_INET; 1577789a4a2cSJames Chapman ip_addr.l2tp_addr = cfg->local_ip; 1578789a4a2cSJames Chapman ip_addr.l2tp_conn_id = tunnel_id; 15795dac94e1SJames Chapman err = kernel_bind(sock, (struct sockaddr *) &ip_addr, 15805dac94e1SJames Chapman sizeof(ip_addr)); 1581789a4a2cSJames Chapman if (err < 0) 1582789a4a2cSJames Chapman goto out; 1583789a4a2cSJames Chapman 1584789a4a2cSJames Chapman ip_addr.l2tp_family = AF_INET; 1585789a4a2cSJames Chapman ip_addr.l2tp_addr = cfg->peer_ip; 1586789a4a2cSJames Chapman ip_addr.l2tp_conn_id = peer_tunnel_id; 15875dac94e1SJames Chapman err = kernel_connect(sock, (struct sockaddr *) &ip_addr, 15885dac94e1SJames Chapman sizeof(ip_addr), 0); 1589789a4a2cSJames Chapman if (err < 0) 1590789a4a2cSJames Chapman goto out; 15915dac94e1SJames Chapman } 1592789a4a2cSJames Chapman break; 1593789a4a2cSJames Chapman 1594789a4a2cSJames Chapman default: 1595789a4a2cSJames Chapman goto out; 1596789a4a2cSJames Chapman } 1597789a4a2cSJames Chapman 1598789a4a2cSJames Chapman out: 1599167eb17eSTom Parkin *sockp = sock; 1600789a4a2cSJames Chapman if ((err < 0) && sock) { 1601167eb17eSTom Parkin kernel_sock_shutdown(sock, SHUT_RDWR); 1602167eb17eSTom Parkin sk_release_kernel(sock->sk); 1603789a4a2cSJames Chapman *sockp = NULL; 1604789a4a2cSJames Chapman } 1605789a4a2cSJames Chapman 1606789a4a2cSJames Chapman return err; 1607789a4a2cSJames Chapman } 1608789a4a2cSJames Chapman 160937159ef2SEric Dumazet static struct lock_class_key l2tp_socket_class; 161037159ef2SEric Dumazet 1611fd558d18SJames 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) 1612fd558d18SJames Chapman { 1613fd558d18SJames Chapman struct l2tp_tunnel *tunnel = NULL; 1614fd558d18SJames Chapman int err; 1615fd558d18SJames Chapman struct socket *sock = NULL; 1616fd558d18SJames Chapman struct sock *sk = NULL; 1617fd558d18SJames Chapman struct l2tp_net *pn; 16180d76751fSJames Chapman enum l2tp_encap_type encap = L2TP_ENCAPTYPE_UDP; 1619fd558d18SJames Chapman 1620fd558d18SJames Chapman /* Get the tunnel socket from the fd, which was opened by 1621789a4a2cSJames Chapman * the userspace L2TP daemon. If not specified, create a 1622789a4a2cSJames Chapman * kernel socket. 1623fd558d18SJames Chapman */ 1624789a4a2cSJames Chapman if (fd < 0) { 1625167eb17eSTom Parkin err = l2tp_tunnel_sock_create(net, tunnel_id, peer_tunnel_id, 1626167eb17eSTom Parkin cfg, &sock); 1627789a4a2cSJames Chapman if (err < 0) 1628789a4a2cSJames Chapman goto err; 1629789a4a2cSJames Chapman } else { 1630fd558d18SJames Chapman sock = sockfd_lookup(fd, &err); 1631fd558d18SJames Chapman if (!sock) { 1632cbb95e0cSTom Parkin pr_err("tunl %u: sockfd_lookup(fd=%d) returned %d\n", 1633fd558d18SJames Chapman tunnel_id, fd, err); 1634cbb95e0cSTom Parkin err = -EBADF; 1635cbb95e0cSTom Parkin goto err; 1636cbb95e0cSTom Parkin } 1637cbb95e0cSTom Parkin 1638cbb95e0cSTom Parkin /* Reject namespace mismatches */ 1639cbb95e0cSTom Parkin if (!net_eq(sock_net(sock->sk), net)) { 1640cbb95e0cSTom Parkin pr_err("tunl %u: netns mismatch\n", tunnel_id); 1641cbb95e0cSTom Parkin err = -EINVAL; 1642fd558d18SJames Chapman goto err; 1643fd558d18SJames Chapman } 1644789a4a2cSJames Chapman } 1645fd558d18SJames Chapman 1646fd558d18SJames Chapman sk = sock->sk; 1647fd558d18SJames Chapman 16480d76751fSJames Chapman if (cfg != NULL) 16490d76751fSJames Chapman encap = cfg->encap; 16500d76751fSJames Chapman 1651fd558d18SJames Chapman /* Quick sanity checks */ 16520d76751fSJames Chapman switch (encap) { 16530d76751fSJames Chapman case L2TP_ENCAPTYPE_UDP: 1654fd558d18SJames Chapman err = -EPROTONOSUPPORT; 1655fd558d18SJames Chapman if (sk->sk_protocol != IPPROTO_UDP) { 1656a4ca44faSJoe Perches pr_err("tunl %hu: fd %d wrong protocol, got %d, expected %d\n", 1657fd558d18SJames Chapman tunnel_id, fd, sk->sk_protocol, IPPROTO_UDP); 1658fd558d18SJames Chapman goto err; 1659fd558d18SJames Chapman } 16600d76751fSJames Chapman break; 16610d76751fSJames Chapman case L2TP_ENCAPTYPE_IP: 16620d76751fSJames Chapman err = -EPROTONOSUPPORT; 16630d76751fSJames Chapman if (sk->sk_protocol != IPPROTO_L2TP) { 1664a4ca44faSJoe Perches pr_err("tunl %hu: fd %d wrong protocol, got %d, expected %d\n", 16650d76751fSJames Chapman tunnel_id, fd, sk->sk_protocol, IPPROTO_L2TP); 1666fd558d18SJames Chapman goto err; 1667fd558d18SJames Chapman } 16680d76751fSJames Chapman break; 16690d76751fSJames Chapman } 1670fd558d18SJames Chapman 1671fd558d18SJames Chapman /* Check if this socket has already been prepped */ 1672fd558d18SJames Chapman tunnel = (struct l2tp_tunnel *)sk->sk_user_data; 1673fd558d18SJames Chapman if (tunnel != NULL) { 1674fd558d18SJames Chapman /* This socket has already been prepped */ 1675fd558d18SJames Chapman err = -EBUSY; 1676fd558d18SJames Chapman goto err; 1677fd558d18SJames Chapman } 1678fd558d18SJames Chapman 1679fd558d18SJames Chapman tunnel = kzalloc(sizeof(struct l2tp_tunnel), GFP_KERNEL); 1680fd558d18SJames Chapman if (tunnel == NULL) { 1681fd558d18SJames Chapman err = -ENOMEM; 1682fd558d18SJames Chapman goto err; 1683fd558d18SJames Chapman } 1684fd558d18SJames Chapman 1685fd558d18SJames Chapman tunnel->version = version; 1686fd558d18SJames Chapman tunnel->tunnel_id = tunnel_id; 1687fd558d18SJames Chapman tunnel->peer_tunnel_id = peer_tunnel_id; 1688fd558d18SJames Chapman tunnel->debug = L2TP_DEFAULT_DEBUG_FLAGS; 1689fd558d18SJames Chapman 1690fd558d18SJames Chapman tunnel->magic = L2TP_TUNNEL_MAGIC; 1691fd558d18SJames Chapman sprintf(&tunnel->name[0], "tunl %u", tunnel_id); 1692fd558d18SJames Chapman rwlock_init(&tunnel->hlist_lock); 1693fd558d18SJames Chapman 1694fd558d18SJames Chapman /* The net we belong to */ 1695fd558d18SJames Chapman tunnel->l2tp_net = net; 1696fd558d18SJames Chapman pn = l2tp_pernet(net); 1697fd558d18SJames Chapman 16980d76751fSJames Chapman if (cfg != NULL) 1699fd558d18SJames Chapman tunnel->debug = cfg->debug; 1700fd558d18SJames Chapman 1701fd558d18SJames Chapman /* Mark socket as an encapsulation socket. See net/ipv4/udp.c */ 17020d76751fSJames Chapman tunnel->encap = encap; 17030d76751fSJames Chapman if (encap == L2TP_ENCAPTYPE_UDP) { 17040d76751fSJames Chapman /* Mark socket as an encapsulation socket. See net/ipv4/udp.c */ 1705fd558d18SJames Chapman udp_sk(sk)->encap_type = UDP_ENCAP_L2TPINUDP; 1706fd558d18SJames Chapman udp_sk(sk)->encap_rcv = l2tp_udp_encap_recv; 17079980d001STom Parkin udp_sk(sk)->encap_destroy = l2tp_udp_encap_destroy; 1708d2cf3361SBenjamin LaHaise #if IS_ENABLED(CONFIG_IPV6) 1709d2cf3361SBenjamin LaHaise if (sk->sk_family == PF_INET6) 1710d2cf3361SBenjamin LaHaise udpv6_encap_enable(); 1711d2cf3361SBenjamin LaHaise else 1712d2cf3361SBenjamin LaHaise #endif 1713447167bfSEric Dumazet udp_encap_enable(); 17140d76751fSJames Chapman } 1715fd558d18SJames Chapman 1716fd558d18SJames Chapman sk->sk_user_data = tunnel; 1717fd558d18SJames Chapman 1718fd558d18SJames Chapman /* Hook on the tunnel socket destructor so that we can cleanup 1719fd558d18SJames Chapman * if the tunnel socket goes away. 1720fd558d18SJames Chapman */ 1721fd558d18SJames Chapman tunnel->old_sk_destruct = sk->sk_destruct; 1722fd558d18SJames Chapman sk->sk_destruct = &l2tp_tunnel_destruct; 1723fd558d18SJames Chapman tunnel->sock = sk; 172480d84ef3STom Parkin tunnel->fd = fd; 172537159ef2SEric Dumazet lockdep_set_class_and_name(&sk->sk_lock.slock, &l2tp_socket_class, "l2tp_sock"); 172637159ef2SEric Dumazet 1727fd558d18SJames Chapman sk->sk_allocation = GFP_ATOMIC; 1728fd558d18SJames Chapman 1729f8ccac0eSTom Parkin /* Init delete workqueue struct */ 1730f8ccac0eSTom Parkin INIT_WORK(&tunnel->del_work, l2tp_tunnel_del_work); 1731f8ccac0eSTom Parkin 1732fd558d18SJames Chapman /* Add tunnel to our list */ 1733fd558d18SJames Chapman INIT_LIST_HEAD(&tunnel->list); 1734fd558d18SJames Chapman atomic_inc(&l2tp_tunnel_count); 1735fd558d18SJames Chapman 1736fd558d18SJames Chapman /* Bump the reference count. The tunnel context is deleted 17371769192aSEric Dumazet * only when this drops to zero. Must be done before list insertion 1738fd558d18SJames Chapman */ 1739fd558d18SJames Chapman l2tp_tunnel_inc_refcount(tunnel); 17401769192aSEric Dumazet spin_lock_bh(&pn->l2tp_tunnel_list_lock); 17411769192aSEric Dumazet list_add_rcu(&tunnel->list, &pn->l2tp_tunnel_list); 17421769192aSEric Dumazet spin_unlock_bh(&pn->l2tp_tunnel_list_lock); 1743fd558d18SJames Chapman 1744fd558d18SJames Chapman err = 0; 1745fd558d18SJames Chapman err: 1746fd558d18SJames Chapman if (tunnelp) 1747fd558d18SJames Chapman *tunnelp = tunnel; 1748fd558d18SJames Chapman 1749789a4a2cSJames Chapman /* If tunnel's socket was created by the kernel, it doesn't 1750789a4a2cSJames Chapman * have a file. 1751789a4a2cSJames Chapman */ 1752789a4a2cSJames Chapman if (sock && sock->file) 1753fd558d18SJames Chapman sockfd_put(sock); 1754fd558d18SJames Chapman 1755fd558d18SJames Chapman return err; 1756fd558d18SJames Chapman } 1757fd558d18SJames Chapman EXPORT_SYMBOL_GPL(l2tp_tunnel_create); 1758fd558d18SJames Chapman 1759309795f4SJames Chapman /* This function is used by the netlink TUNNEL_DELETE command. 1760309795f4SJames Chapman */ 1761309795f4SJames Chapman int l2tp_tunnel_delete(struct l2tp_tunnel *tunnel) 1762309795f4SJames Chapman { 17632b551c6eSTom Parkin l2tp_tunnel_closeall(tunnel); 1764f8ccac0eSTom Parkin return (false == queue_work(l2tp_wq, &tunnel->del_work)); 1765309795f4SJames Chapman } 1766309795f4SJames Chapman EXPORT_SYMBOL_GPL(l2tp_tunnel_delete); 1767309795f4SJames Chapman 1768fd558d18SJames Chapman /* Really kill the session. 1769fd558d18SJames Chapman */ 1770fd558d18SJames Chapman void l2tp_session_free(struct l2tp_session *session) 1771fd558d18SJames Chapman { 1772fd558d18SJames Chapman struct l2tp_tunnel *tunnel; 1773fd558d18SJames Chapman 1774fd558d18SJames Chapman BUG_ON(atomic_read(&session->ref_count) != 0); 1775fd558d18SJames Chapman 1776fd558d18SJames Chapman tunnel = session->tunnel; 1777fd558d18SJames Chapman if (tunnel != NULL) { 1778fd558d18SJames Chapman BUG_ON(tunnel->magic != L2TP_TUNNEL_MAGIC); 1779fd558d18SJames Chapman 1780fd558d18SJames Chapman /* Delete the session from the hash */ 1781fd558d18SJames Chapman write_lock_bh(&tunnel->hlist_lock); 1782fd558d18SJames Chapman hlist_del_init(&session->hlist); 1783fd558d18SJames Chapman write_unlock_bh(&tunnel->hlist_lock); 1784fd558d18SJames Chapman 1785f7faffa3SJames Chapman /* Unlink from the global hash if not L2TPv2 */ 1786f7faffa3SJames Chapman if (tunnel->version != L2TP_HDR_VER_2) { 1787f7faffa3SJames Chapman struct l2tp_net *pn = l2tp_pernet(tunnel->l2tp_net); 1788f7faffa3SJames Chapman 1789e02d494dSJames Chapman spin_lock_bh(&pn->l2tp_session_hlist_lock); 1790e02d494dSJames Chapman hlist_del_init_rcu(&session->global_hlist); 1791e02d494dSJames Chapman spin_unlock_bh(&pn->l2tp_session_hlist_lock); 1792e02d494dSJames Chapman synchronize_rcu(); 1793f7faffa3SJames Chapman } 1794f7faffa3SJames Chapman 1795fd558d18SJames Chapman if (session->session_id != 0) 1796fd558d18SJames Chapman atomic_dec(&l2tp_session_count); 1797fd558d18SJames Chapman 1798fd558d18SJames Chapman sock_put(tunnel->sock); 1799fd558d18SJames Chapman 1800fd558d18SJames Chapman /* This will delete the tunnel context if this 1801fd558d18SJames Chapman * is the last session on the tunnel. 1802fd558d18SJames Chapman */ 1803fd558d18SJames Chapman session->tunnel = NULL; 1804fd558d18SJames Chapman l2tp_tunnel_dec_refcount(tunnel); 1805fd558d18SJames Chapman } 1806fd558d18SJames Chapman 1807fd558d18SJames Chapman kfree(session); 1808fd558d18SJames Chapman 1809fd558d18SJames Chapman return; 1810fd558d18SJames Chapman } 1811fd558d18SJames Chapman EXPORT_SYMBOL_GPL(l2tp_session_free); 1812fd558d18SJames Chapman 1813309795f4SJames Chapman /* This function is used by the netlink SESSION_DELETE command and by 1814309795f4SJames Chapman pseudowire modules. 1815309795f4SJames Chapman */ 1816309795f4SJames Chapman int l2tp_session_delete(struct l2tp_session *session) 1817309795f4SJames Chapman { 18184c6e2fd3STom Parkin l2tp_session_queue_purge(session); 18194c6e2fd3STom Parkin 1820309795f4SJames Chapman if (session->session_close != NULL) 1821309795f4SJames Chapman (*session->session_close)(session); 1822309795f4SJames Chapman 1823309795f4SJames Chapman l2tp_session_dec_refcount(session); 1824309795f4SJames Chapman 1825309795f4SJames Chapman return 0; 1826309795f4SJames Chapman } 1827309795f4SJames Chapman EXPORT_SYMBOL_GPL(l2tp_session_delete); 1828309795f4SJames Chapman 1829309795f4SJames Chapman 1830f7faffa3SJames Chapman /* We come here whenever a session's send_seq, cookie_len or 1831f7faffa3SJames Chapman * l2specific_len parameters are set. 1832f7faffa3SJames Chapman */ 1833fc130840Sstephen hemminger static void l2tp_session_set_header_len(struct l2tp_session *session, int version) 1834f7faffa3SJames Chapman { 1835f7faffa3SJames Chapman if (version == L2TP_HDR_VER_2) { 1836f7faffa3SJames Chapman session->hdr_len = 6; 1837f7faffa3SJames Chapman if (session->send_seq) 1838f7faffa3SJames Chapman session->hdr_len += 4; 1839f7faffa3SJames Chapman } else { 18400d76751fSJames Chapman session->hdr_len = 4 + session->cookie_len + session->l2specific_len + session->offset; 18410d76751fSJames Chapman if (session->tunnel->encap == L2TP_ENCAPTYPE_UDP) 18420d76751fSJames Chapman session->hdr_len += 4; 1843f7faffa3SJames Chapman } 1844f7faffa3SJames Chapman 1845f7faffa3SJames Chapman } 1846f7faffa3SJames Chapman 1847fd558d18SJames 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) 1848fd558d18SJames Chapman { 1849fd558d18SJames Chapman struct l2tp_session *session; 1850fd558d18SJames Chapman 1851fd558d18SJames Chapman session = kzalloc(sizeof(struct l2tp_session) + priv_size, GFP_KERNEL); 1852fd558d18SJames Chapman if (session != NULL) { 1853fd558d18SJames Chapman session->magic = L2TP_SESSION_MAGIC; 1854fd558d18SJames Chapman session->tunnel = tunnel; 1855fd558d18SJames Chapman 1856fd558d18SJames Chapman session->session_id = session_id; 1857fd558d18SJames Chapman session->peer_session_id = peer_session_id; 1858d301e325SJames Chapman session->nr = 0; 1859fd558d18SJames Chapman 1860fd558d18SJames Chapman sprintf(&session->name[0], "sess %u/%u", 1861fd558d18SJames Chapman tunnel->tunnel_id, session->session_id); 1862fd558d18SJames Chapman 1863fd558d18SJames Chapman skb_queue_head_init(&session->reorder_q); 1864fd558d18SJames Chapman 1865fd558d18SJames Chapman INIT_HLIST_NODE(&session->hlist); 1866f7faffa3SJames Chapman INIT_HLIST_NODE(&session->global_hlist); 1867fd558d18SJames Chapman 1868fd558d18SJames Chapman /* Inherit debug options from tunnel */ 1869fd558d18SJames Chapman session->debug = tunnel->debug; 1870fd558d18SJames Chapman 1871fd558d18SJames Chapman if (cfg) { 1872f7faffa3SJames Chapman session->pwtype = cfg->pw_type; 1873fd558d18SJames Chapman session->debug = cfg->debug; 1874fd558d18SJames Chapman session->mtu = cfg->mtu; 1875fd558d18SJames Chapman session->mru = cfg->mru; 1876fd558d18SJames Chapman session->send_seq = cfg->send_seq; 1877fd558d18SJames Chapman session->recv_seq = cfg->recv_seq; 1878fd558d18SJames Chapman session->lns_mode = cfg->lns_mode; 1879f7faffa3SJames Chapman session->reorder_timeout = cfg->reorder_timeout; 1880f7faffa3SJames Chapman session->offset = cfg->offset; 1881f7faffa3SJames Chapman session->l2specific_type = cfg->l2specific_type; 1882f7faffa3SJames Chapman session->l2specific_len = cfg->l2specific_len; 1883f7faffa3SJames Chapman session->cookie_len = cfg->cookie_len; 1884f7faffa3SJames Chapman memcpy(&session->cookie[0], &cfg->cookie[0], cfg->cookie_len); 1885f7faffa3SJames Chapman session->peer_cookie_len = cfg->peer_cookie_len; 1886f7faffa3SJames Chapman memcpy(&session->peer_cookie[0], &cfg->peer_cookie[0], cfg->peer_cookie_len); 1887fd558d18SJames Chapman } 1888fd558d18SJames Chapman 1889f7faffa3SJames Chapman if (tunnel->version == L2TP_HDR_VER_2) 1890f7faffa3SJames Chapman session->build_header = l2tp_build_l2tpv2_header; 1891f7faffa3SJames Chapman else 1892f7faffa3SJames Chapman session->build_header = l2tp_build_l2tpv3_header; 1893f7faffa3SJames Chapman 1894f7faffa3SJames Chapman l2tp_session_set_header_len(session, tunnel->version); 1895f7faffa3SJames Chapman 1896fd558d18SJames Chapman /* Bump the reference count. The session context is deleted 1897fd558d18SJames Chapman * only when this drops to zero. 1898fd558d18SJames Chapman */ 1899fd558d18SJames Chapman l2tp_session_inc_refcount(session); 1900fd558d18SJames Chapman l2tp_tunnel_inc_refcount(tunnel); 1901fd558d18SJames Chapman 1902fd558d18SJames Chapman /* Ensure tunnel socket isn't deleted */ 1903fd558d18SJames Chapman sock_hold(tunnel->sock); 1904fd558d18SJames Chapman 1905fd558d18SJames Chapman /* Add session to the tunnel's hash list */ 1906fd558d18SJames Chapman write_lock_bh(&tunnel->hlist_lock); 1907fd558d18SJames Chapman hlist_add_head(&session->hlist, 1908fd558d18SJames Chapman l2tp_session_id_hash(tunnel, session_id)); 1909fd558d18SJames Chapman write_unlock_bh(&tunnel->hlist_lock); 1910fd558d18SJames Chapman 1911f7faffa3SJames Chapman /* And to the global session list if L2TPv3 */ 1912f7faffa3SJames Chapman if (tunnel->version != L2TP_HDR_VER_2) { 1913f7faffa3SJames Chapman struct l2tp_net *pn = l2tp_pernet(tunnel->l2tp_net); 1914f7faffa3SJames Chapman 1915e02d494dSJames Chapman spin_lock_bh(&pn->l2tp_session_hlist_lock); 1916e02d494dSJames Chapman hlist_add_head_rcu(&session->global_hlist, 1917f7faffa3SJames Chapman l2tp_session_id_hash_2(pn, session_id)); 1918e02d494dSJames Chapman spin_unlock_bh(&pn->l2tp_session_hlist_lock); 1919f7faffa3SJames Chapman } 1920f7faffa3SJames Chapman 1921fd558d18SJames Chapman /* Ignore management session in session count value */ 1922fd558d18SJames Chapman if (session->session_id != 0) 1923fd558d18SJames Chapman atomic_inc(&l2tp_session_count); 1924fd558d18SJames Chapman } 1925fd558d18SJames Chapman 1926fd558d18SJames Chapman return session; 1927fd558d18SJames Chapman } 1928fd558d18SJames Chapman EXPORT_SYMBOL_GPL(l2tp_session_create); 1929fd558d18SJames Chapman 1930fd558d18SJames Chapman /***************************************************************************** 1931fd558d18SJames Chapman * Init and cleanup 1932fd558d18SJames Chapman *****************************************************************************/ 1933fd558d18SJames Chapman 1934fd558d18SJames Chapman static __net_init int l2tp_init_net(struct net *net) 1935fd558d18SJames Chapman { 1936e773aaffSJiri Pirko struct l2tp_net *pn = net_generic(net, l2tp_net_id); 1937f7faffa3SJames Chapman int hash; 1938fd558d18SJames Chapman 1939fd558d18SJames Chapman INIT_LIST_HEAD(&pn->l2tp_tunnel_list); 1940e02d494dSJames Chapman spin_lock_init(&pn->l2tp_tunnel_list_lock); 1941fd558d18SJames Chapman 1942f7faffa3SJames Chapman for (hash = 0; hash < L2TP_HASH_SIZE_2; hash++) 1943f7faffa3SJames Chapman INIT_HLIST_HEAD(&pn->l2tp_session_hlist[hash]); 1944f7faffa3SJames Chapman 1945e02d494dSJames Chapman spin_lock_init(&pn->l2tp_session_hlist_lock); 1946f7faffa3SJames Chapman 1947fd558d18SJames Chapman return 0; 1948fd558d18SJames Chapman } 1949fd558d18SJames Chapman 1950167eb17eSTom Parkin static __net_exit void l2tp_exit_net(struct net *net) 1951167eb17eSTom Parkin { 1952167eb17eSTom Parkin struct l2tp_net *pn = l2tp_pernet(net); 1953167eb17eSTom Parkin struct l2tp_tunnel *tunnel = NULL; 1954167eb17eSTom Parkin 1955167eb17eSTom Parkin rcu_read_lock_bh(); 1956167eb17eSTom Parkin list_for_each_entry_rcu(tunnel, &pn->l2tp_tunnel_list, list) { 1957167eb17eSTom Parkin (void)l2tp_tunnel_delete(tunnel); 1958167eb17eSTom Parkin } 1959167eb17eSTom Parkin rcu_read_unlock_bh(); 1960167eb17eSTom Parkin } 1961167eb17eSTom Parkin 1962fd558d18SJames Chapman static struct pernet_operations l2tp_net_ops = { 1963fd558d18SJames Chapman .init = l2tp_init_net, 1964167eb17eSTom Parkin .exit = l2tp_exit_net, 1965fd558d18SJames Chapman .id = &l2tp_net_id, 1966fd558d18SJames Chapman .size = sizeof(struct l2tp_net), 1967fd558d18SJames Chapman }; 1968fd558d18SJames Chapman 1969fd558d18SJames Chapman static int __init l2tp_init(void) 1970fd558d18SJames Chapman { 1971fd558d18SJames Chapman int rc = 0; 1972fd558d18SJames Chapman 1973fd558d18SJames Chapman rc = register_pernet_device(&l2tp_net_ops); 1974fd558d18SJames Chapman if (rc) 1975fd558d18SJames Chapman goto out; 1976fd558d18SJames Chapman 1977f8ccac0eSTom Parkin l2tp_wq = alloc_workqueue("l2tp", WQ_NON_REENTRANT | WQ_UNBOUND, 0); 1978f8ccac0eSTom Parkin if (!l2tp_wq) { 1979f8ccac0eSTom Parkin pr_err("alloc_workqueue failed\n"); 1980f8ccac0eSTom Parkin rc = -ENOMEM; 1981f8ccac0eSTom Parkin goto out; 1982f8ccac0eSTom Parkin } 1983f8ccac0eSTom Parkin 1984a4ca44faSJoe Perches pr_info("L2TP core driver, %s\n", L2TP_DRV_VERSION); 1985fd558d18SJames Chapman 1986fd558d18SJames Chapman out: 1987fd558d18SJames Chapman return rc; 1988fd558d18SJames Chapman } 1989fd558d18SJames Chapman 1990fd558d18SJames Chapman static void __exit l2tp_exit(void) 1991fd558d18SJames Chapman { 1992fd558d18SJames Chapman unregister_pernet_device(&l2tp_net_ops); 1993f8ccac0eSTom Parkin if (l2tp_wq) { 1994f8ccac0eSTom Parkin destroy_workqueue(l2tp_wq); 1995f8ccac0eSTom Parkin l2tp_wq = NULL; 1996f8ccac0eSTom Parkin } 1997fd558d18SJames Chapman } 1998fd558d18SJames Chapman 1999fd558d18SJames Chapman module_init(l2tp_init); 2000fd558d18SJames Chapman module_exit(l2tp_exit); 2001fd558d18SJames Chapman 2002fd558d18SJames Chapman MODULE_AUTHOR("James Chapman <jchapman@katalix.com>"); 2003fd558d18SJames Chapman MODULE_DESCRIPTION("L2TP core"); 2004fd558d18SJames Chapman MODULE_LICENSE("GPL"); 2005fd558d18SJames Chapman MODULE_VERSION(L2TP_DRV_VERSION); 2006fd558d18SJames Chapman 2007