James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1 | /* |
| 2 | * L2TP core. |
| 3 | * |
| 4 | * Copyright (c) 2008,2009,2010 Katalix Systems Ltd |
| 5 | * |
| 6 | * This file contains some code of the original L2TPv2 pppol2tp |
| 7 | * driver, which has the following copyright: |
| 8 | * |
| 9 | * Authors: Martijn van Oosterhout <kleptog@svana.org> |
| 10 | * James Chapman (jchapman@katalix.com) |
| 11 | * Contributors: |
| 12 | * Michal Ostrowski <mostrows@speakeasy.net> |
| 13 | * Arnaldo Carvalho de Melo <acme@xconectiva.com.br> |
| 14 | * David S. Miller (davem@redhat.com) |
| 15 | * |
| 16 | * This program is free software; you can redistribute it and/or modify |
| 17 | * it under the terms of the GNU General Public License version 2 as |
| 18 | * published by the Free Software Foundation. |
| 19 | */ |
| 20 | |
| 21 | #include <linux/module.h> |
| 22 | #include <linux/string.h> |
| 23 | #include <linux/list.h> |
James Chapman | e02d494 | 2010-04-02 06:19:16 +0000 | [diff] [blame] | 24 | #include <linux/rculist.h> |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 25 | #include <linux/uaccess.h> |
| 26 | |
| 27 | #include <linux/kernel.h> |
| 28 | #include <linux/spinlock.h> |
| 29 | #include <linux/kthread.h> |
| 30 | #include <linux/sched.h> |
| 31 | #include <linux/slab.h> |
| 32 | #include <linux/errno.h> |
| 33 | #include <linux/jiffies.h> |
| 34 | |
| 35 | #include <linux/netdevice.h> |
| 36 | #include <linux/net.h> |
| 37 | #include <linux/inetdevice.h> |
| 38 | #include <linux/skbuff.h> |
| 39 | #include <linux/init.h> |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 40 | #include <linux/in.h> |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 41 | #include <linux/ip.h> |
| 42 | #include <linux/udp.h> |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 43 | #include <linux/l2tp.h> |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 44 | #include <linux/hash.h> |
| 45 | #include <linux/sort.h> |
| 46 | #include <linux/file.h> |
| 47 | #include <linux/nsproxy.h> |
| 48 | #include <net/net_namespace.h> |
| 49 | #include <net/netns/generic.h> |
| 50 | #include <net/dst.h> |
| 51 | #include <net/ip.h> |
| 52 | #include <net/udp.h> |
James Chapman | 309795f | 2010-04-02 06:19:10 +0000 | [diff] [blame] | 53 | #include <net/inet_common.h> |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 54 | #include <net/xfrm.h> |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 55 | #include <net/protocol.h> |
Benjamin LaHaise | d2cf336 | 2012-04-27 08:24:18 +0000 | [diff] [blame^] | 56 | #include <net/inet6_connection_sock.h> |
| 57 | #include <net/inet_ecn.h> |
| 58 | #include <net/ip6_route.h> |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 59 | |
| 60 | #include <asm/byteorder.h> |
Arun Sharma | 60063497 | 2011-07-26 16:09:06 -0700 | [diff] [blame] | 61 | #include <linux/atomic.h> |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 62 | |
| 63 | #include "l2tp_core.h" |
| 64 | |
| 65 | #define L2TP_DRV_VERSION "V2.0" |
| 66 | |
| 67 | /* L2TP header constants */ |
| 68 | #define L2TP_HDRFLAG_T 0x8000 |
| 69 | #define L2TP_HDRFLAG_L 0x4000 |
| 70 | #define L2TP_HDRFLAG_S 0x0800 |
| 71 | #define L2TP_HDRFLAG_O 0x0200 |
| 72 | #define L2TP_HDRFLAG_P 0x0100 |
| 73 | |
| 74 | #define L2TP_HDR_VER_MASK 0x000F |
| 75 | #define L2TP_HDR_VER_2 0x0002 |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 76 | #define L2TP_HDR_VER_3 0x0003 |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 77 | |
| 78 | /* L2TPv3 default L2-specific sublayer */ |
| 79 | #define L2TP_SLFLAG_S 0x40000000 |
| 80 | #define L2TP_SL_SEQ_MASK 0x00ffffff |
| 81 | |
| 82 | #define L2TP_HDR_SIZE_SEQ 10 |
| 83 | #define L2TP_HDR_SIZE_NOSEQ 6 |
| 84 | |
| 85 | /* Default trace flags */ |
| 86 | #define L2TP_DEFAULT_DEBUG_FLAGS 0 |
| 87 | |
| 88 | #define PRINTK(_mask, _type, _lvl, _fmt, args...) \ |
| 89 | do { \ |
| 90 | if ((_mask) & (_type)) \ |
| 91 | printk(_lvl "L2TP: " _fmt, ##args); \ |
| 92 | } while (0) |
| 93 | |
| 94 | /* Private data stored for received packets in the skb. |
| 95 | */ |
| 96 | struct l2tp_skb_cb { |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 97 | u32 ns; |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 98 | u16 has_seq; |
| 99 | u16 length; |
| 100 | unsigned long expires; |
| 101 | }; |
| 102 | |
| 103 | #define L2TP_SKB_CB(skb) ((struct l2tp_skb_cb *) &skb->cb[sizeof(struct inet_skb_parm)]) |
| 104 | |
| 105 | static atomic_t l2tp_tunnel_count; |
| 106 | static atomic_t l2tp_session_count; |
| 107 | |
| 108 | /* per-net private data for this module */ |
| 109 | static unsigned int l2tp_net_id; |
| 110 | struct l2tp_net { |
| 111 | struct list_head l2tp_tunnel_list; |
James Chapman | e02d494 | 2010-04-02 06:19:16 +0000 | [diff] [blame] | 112 | spinlock_t l2tp_tunnel_list_lock; |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 113 | struct hlist_head l2tp_session_hlist[L2TP_HASH_SIZE_2]; |
James Chapman | e02d494 | 2010-04-02 06:19:16 +0000 | [diff] [blame] | 114 | spinlock_t l2tp_session_hlist_lock; |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 115 | }; |
| 116 | |
stephen hemminger | fc13084 | 2010-10-21 07:50:46 +0000 | [diff] [blame] | 117 | static void l2tp_session_set_header_len(struct l2tp_session *session, int version); |
| 118 | static void l2tp_tunnel_free(struct l2tp_tunnel *tunnel); |
| 119 | static void l2tp_tunnel_closeall(struct l2tp_tunnel *tunnel); |
| 120 | |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 121 | static inline struct l2tp_net *l2tp_pernet(struct net *net) |
| 122 | { |
| 123 | BUG_ON(!net); |
| 124 | |
| 125 | return net_generic(net, l2tp_net_id); |
| 126 | } |
| 127 | |
stephen hemminger | fc13084 | 2010-10-21 07:50:46 +0000 | [diff] [blame] | 128 | |
| 129 | /* Tunnel reference counts. Incremented per session that is added to |
| 130 | * the tunnel. |
| 131 | */ |
| 132 | static inline void l2tp_tunnel_inc_refcount_1(struct l2tp_tunnel *tunnel) |
| 133 | { |
| 134 | atomic_inc(&tunnel->ref_count); |
| 135 | } |
| 136 | |
| 137 | static inline void l2tp_tunnel_dec_refcount_1(struct l2tp_tunnel *tunnel) |
| 138 | { |
| 139 | if (atomic_dec_and_test(&tunnel->ref_count)) |
| 140 | l2tp_tunnel_free(tunnel); |
| 141 | } |
| 142 | #ifdef L2TP_REFCNT_DEBUG |
| 143 | #define l2tp_tunnel_inc_refcount(_t) do { \ |
| 144 | printk(KERN_DEBUG "l2tp_tunnel_inc_refcount: %s:%d %s: cnt=%d\n", __func__, __LINE__, (_t)->name, atomic_read(&_t->ref_count)); \ |
| 145 | l2tp_tunnel_inc_refcount_1(_t); \ |
| 146 | } while (0) |
| 147 | #define l2tp_tunnel_dec_refcount(_t) do { \ |
| 148 | printk(KERN_DEBUG "l2tp_tunnel_dec_refcount: %s:%d %s: cnt=%d\n", __func__, __LINE__, (_t)->name, atomic_read(&_t->ref_count)); \ |
| 149 | l2tp_tunnel_dec_refcount_1(_t); \ |
| 150 | } while (0) |
| 151 | #else |
| 152 | #define l2tp_tunnel_inc_refcount(t) l2tp_tunnel_inc_refcount_1(t) |
| 153 | #define l2tp_tunnel_dec_refcount(t) l2tp_tunnel_dec_refcount_1(t) |
| 154 | #endif |
| 155 | |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 156 | /* Session hash global list for L2TPv3. |
| 157 | * The session_id SHOULD be random according to RFC3931, but several |
| 158 | * L2TP implementations use incrementing session_ids. So we do a real |
| 159 | * hash on the session_id, rather than a simple bitmask. |
| 160 | */ |
| 161 | static inline struct hlist_head * |
| 162 | l2tp_session_id_hash_2(struct l2tp_net *pn, u32 session_id) |
| 163 | { |
| 164 | return &pn->l2tp_session_hlist[hash_32(session_id, L2TP_HASH_BITS_2)]; |
| 165 | |
| 166 | } |
| 167 | |
| 168 | /* Lookup a session by id in the global session list |
| 169 | */ |
| 170 | static struct l2tp_session *l2tp_session_find_2(struct net *net, u32 session_id) |
| 171 | { |
| 172 | struct l2tp_net *pn = l2tp_pernet(net); |
| 173 | struct hlist_head *session_list = |
| 174 | l2tp_session_id_hash_2(pn, session_id); |
| 175 | struct l2tp_session *session; |
| 176 | struct hlist_node *walk; |
| 177 | |
James Chapman | e02d494 | 2010-04-02 06:19:16 +0000 | [diff] [blame] | 178 | rcu_read_lock_bh(); |
| 179 | hlist_for_each_entry_rcu(session, walk, session_list, global_hlist) { |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 180 | if (session->session_id == session_id) { |
James Chapman | e02d494 | 2010-04-02 06:19:16 +0000 | [diff] [blame] | 181 | rcu_read_unlock_bh(); |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 182 | return session; |
| 183 | } |
| 184 | } |
James Chapman | e02d494 | 2010-04-02 06:19:16 +0000 | [diff] [blame] | 185 | rcu_read_unlock_bh(); |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 186 | |
| 187 | return NULL; |
| 188 | } |
| 189 | |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 190 | /* Session hash list. |
| 191 | * The session_id SHOULD be random according to RFC2661, but several |
| 192 | * L2TP implementations (Cisco and Microsoft) use incrementing |
| 193 | * session_ids. So we do a real hash on the session_id, rather than a |
| 194 | * simple bitmask. |
| 195 | */ |
| 196 | static inline struct hlist_head * |
| 197 | l2tp_session_id_hash(struct l2tp_tunnel *tunnel, u32 session_id) |
| 198 | { |
| 199 | return &tunnel->session_hlist[hash_32(session_id, L2TP_HASH_BITS)]; |
| 200 | } |
| 201 | |
| 202 | /* Lookup a session by id |
| 203 | */ |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 204 | struct l2tp_session *l2tp_session_find(struct net *net, struct l2tp_tunnel *tunnel, u32 session_id) |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 205 | { |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 206 | struct hlist_head *session_list; |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 207 | struct l2tp_session *session; |
| 208 | struct hlist_node *walk; |
| 209 | |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 210 | /* In L2TPv3, session_ids are unique over all tunnels and we |
| 211 | * sometimes need to look them up before we know the |
| 212 | * tunnel. |
| 213 | */ |
| 214 | if (tunnel == NULL) |
| 215 | return l2tp_session_find_2(net, session_id); |
| 216 | |
| 217 | session_list = l2tp_session_id_hash(tunnel, session_id); |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 218 | read_lock_bh(&tunnel->hlist_lock); |
| 219 | hlist_for_each_entry(session, walk, session_list, hlist) { |
| 220 | if (session->session_id == session_id) { |
| 221 | read_unlock_bh(&tunnel->hlist_lock); |
| 222 | return session; |
| 223 | } |
| 224 | } |
| 225 | read_unlock_bh(&tunnel->hlist_lock); |
| 226 | |
| 227 | return NULL; |
| 228 | } |
| 229 | EXPORT_SYMBOL_GPL(l2tp_session_find); |
| 230 | |
| 231 | struct l2tp_session *l2tp_session_find_nth(struct l2tp_tunnel *tunnel, int nth) |
| 232 | { |
| 233 | int hash; |
| 234 | struct hlist_node *walk; |
| 235 | struct l2tp_session *session; |
| 236 | int count = 0; |
| 237 | |
| 238 | read_lock_bh(&tunnel->hlist_lock); |
| 239 | for (hash = 0; hash < L2TP_HASH_SIZE; hash++) { |
| 240 | hlist_for_each_entry(session, walk, &tunnel->session_hlist[hash], hlist) { |
| 241 | if (++count > nth) { |
| 242 | read_unlock_bh(&tunnel->hlist_lock); |
| 243 | return session; |
| 244 | } |
| 245 | } |
| 246 | } |
| 247 | |
| 248 | read_unlock_bh(&tunnel->hlist_lock); |
| 249 | |
| 250 | return NULL; |
| 251 | } |
| 252 | EXPORT_SYMBOL_GPL(l2tp_session_find_nth); |
| 253 | |
James Chapman | 309795f | 2010-04-02 06:19:10 +0000 | [diff] [blame] | 254 | /* Lookup a session by interface name. |
| 255 | * This is very inefficient but is only used by management interfaces. |
| 256 | */ |
| 257 | struct l2tp_session *l2tp_session_find_by_ifname(struct net *net, char *ifname) |
| 258 | { |
| 259 | struct l2tp_net *pn = l2tp_pernet(net); |
| 260 | int hash; |
| 261 | struct hlist_node *walk; |
| 262 | struct l2tp_session *session; |
| 263 | |
James Chapman | e02d494 | 2010-04-02 06:19:16 +0000 | [diff] [blame] | 264 | rcu_read_lock_bh(); |
James Chapman | 309795f | 2010-04-02 06:19:10 +0000 | [diff] [blame] | 265 | for (hash = 0; hash < L2TP_HASH_SIZE_2; hash++) { |
James Chapman | e02d494 | 2010-04-02 06:19:16 +0000 | [diff] [blame] | 266 | hlist_for_each_entry_rcu(session, walk, &pn->l2tp_session_hlist[hash], global_hlist) { |
James Chapman | 309795f | 2010-04-02 06:19:10 +0000 | [diff] [blame] | 267 | if (!strcmp(session->ifname, ifname)) { |
James Chapman | e02d494 | 2010-04-02 06:19:16 +0000 | [diff] [blame] | 268 | rcu_read_unlock_bh(); |
James Chapman | 309795f | 2010-04-02 06:19:10 +0000 | [diff] [blame] | 269 | return session; |
| 270 | } |
| 271 | } |
| 272 | } |
| 273 | |
James Chapman | e02d494 | 2010-04-02 06:19:16 +0000 | [diff] [blame] | 274 | rcu_read_unlock_bh(); |
James Chapman | 309795f | 2010-04-02 06:19:10 +0000 | [diff] [blame] | 275 | |
| 276 | return NULL; |
| 277 | } |
| 278 | EXPORT_SYMBOL_GPL(l2tp_session_find_by_ifname); |
| 279 | |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 280 | /* Lookup a tunnel by id |
| 281 | */ |
| 282 | struct l2tp_tunnel *l2tp_tunnel_find(struct net *net, u32 tunnel_id) |
| 283 | { |
| 284 | struct l2tp_tunnel *tunnel; |
| 285 | struct l2tp_net *pn = l2tp_pernet(net); |
| 286 | |
James Chapman | e02d494 | 2010-04-02 06:19:16 +0000 | [diff] [blame] | 287 | rcu_read_lock_bh(); |
| 288 | list_for_each_entry_rcu(tunnel, &pn->l2tp_tunnel_list, list) { |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 289 | if (tunnel->tunnel_id == tunnel_id) { |
James Chapman | e02d494 | 2010-04-02 06:19:16 +0000 | [diff] [blame] | 290 | rcu_read_unlock_bh(); |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 291 | return tunnel; |
| 292 | } |
| 293 | } |
James Chapman | e02d494 | 2010-04-02 06:19:16 +0000 | [diff] [blame] | 294 | rcu_read_unlock_bh(); |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 295 | |
| 296 | return NULL; |
| 297 | } |
| 298 | EXPORT_SYMBOL_GPL(l2tp_tunnel_find); |
| 299 | |
| 300 | struct l2tp_tunnel *l2tp_tunnel_find_nth(struct net *net, int nth) |
| 301 | { |
| 302 | struct l2tp_net *pn = l2tp_pernet(net); |
| 303 | struct l2tp_tunnel *tunnel; |
| 304 | int count = 0; |
| 305 | |
James Chapman | e02d494 | 2010-04-02 06:19:16 +0000 | [diff] [blame] | 306 | rcu_read_lock_bh(); |
| 307 | list_for_each_entry_rcu(tunnel, &pn->l2tp_tunnel_list, list) { |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 308 | if (++count > nth) { |
James Chapman | e02d494 | 2010-04-02 06:19:16 +0000 | [diff] [blame] | 309 | rcu_read_unlock_bh(); |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 310 | return tunnel; |
| 311 | } |
| 312 | } |
| 313 | |
James Chapman | e02d494 | 2010-04-02 06:19:16 +0000 | [diff] [blame] | 314 | rcu_read_unlock_bh(); |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 315 | |
| 316 | return NULL; |
| 317 | } |
| 318 | EXPORT_SYMBOL_GPL(l2tp_tunnel_find_nth); |
| 319 | |
| 320 | /***************************************************************************** |
| 321 | * Receive data handling |
| 322 | *****************************************************************************/ |
| 323 | |
| 324 | /* Queue a skb in order. We come here only if the skb has an L2TP sequence |
| 325 | * number. |
| 326 | */ |
| 327 | static void l2tp_recv_queue_skb(struct l2tp_session *session, struct sk_buff *skb) |
| 328 | { |
| 329 | struct sk_buff *skbp; |
| 330 | struct sk_buff *tmp; |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 331 | u32 ns = L2TP_SKB_CB(skb)->ns; |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 332 | |
| 333 | spin_lock_bh(&session->reorder_q.lock); |
| 334 | skb_queue_walk_safe(&session->reorder_q, skbp, tmp) { |
| 335 | if (L2TP_SKB_CB(skbp)->ns > ns) { |
| 336 | __skb_queue_before(&session->reorder_q, skbp, skb); |
| 337 | PRINTK(session->debug, L2TP_MSG_SEQ, KERN_DEBUG, |
| 338 | "%s: pkt %hu, inserted before %hu, reorder_q len=%d\n", |
| 339 | session->name, ns, L2TP_SKB_CB(skbp)->ns, |
| 340 | skb_queue_len(&session->reorder_q)); |
| 341 | session->stats.rx_oos_packets++; |
| 342 | goto out; |
| 343 | } |
| 344 | } |
| 345 | |
| 346 | __skb_queue_tail(&session->reorder_q, skb); |
| 347 | |
| 348 | out: |
| 349 | spin_unlock_bh(&session->reorder_q.lock); |
| 350 | } |
| 351 | |
| 352 | /* Dequeue a single skb. |
| 353 | */ |
| 354 | static void l2tp_recv_dequeue_skb(struct l2tp_session *session, struct sk_buff *skb) |
| 355 | { |
| 356 | struct l2tp_tunnel *tunnel = session->tunnel; |
| 357 | int length = L2TP_SKB_CB(skb)->length; |
| 358 | |
| 359 | /* We're about to requeue the skb, so return resources |
| 360 | * to its current owner (a socket receive buffer). |
| 361 | */ |
| 362 | skb_orphan(skb); |
| 363 | |
| 364 | tunnel->stats.rx_packets++; |
| 365 | tunnel->stats.rx_bytes += length; |
| 366 | session->stats.rx_packets++; |
| 367 | session->stats.rx_bytes += length; |
| 368 | |
| 369 | if (L2TP_SKB_CB(skb)->has_seq) { |
| 370 | /* Bump our Nr */ |
| 371 | session->nr++; |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 372 | if (tunnel->version == L2TP_HDR_VER_2) |
| 373 | session->nr &= 0xffff; |
| 374 | else |
| 375 | session->nr &= 0xffffff; |
| 376 | |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 377 | PRINTK(session->debug, L2TP_MSG_SEQ, KERN_DEBUG, |
| 378 | "%s: updated nr to %hu\n", session->name, session->nr); |
| 379 | } |
| 380 | |
| 381 | /* call private receive handler */ |
| 382 | if (session->recv_skb != NULL) |
| 383 | (*session->recv_skb)(session, skb, L2TP_SKB_CB(skb)->length); |
| 384 | else |
| 385 | kfree_skb(skb); |
| 386 | |
| 387 | if (session->deref) |
| 388 | (*session->deref)(session); |
| 389 | } |
| 390 | |
| 391 | /* Dequeue skbs from the session's reorder_q, subject to packet order. |
| 392 | * Skbs that have been in the queue for too long are simply discarded. |
| 393 | */ |
| 394 | static void l2tp_recv_dequeue(struct l2tp_session *session) |
| 395 | { |
| 396 | struct sk_buff *skb; |
| 397 | struct sk_buff *tmp; |
| 398 | |
| 399 | /* If the pkt at the head of the queue has the nr that we |
| 400 | * expect to send up next, dequeue it and any other |
| 401 | * in-sequence packets behind it. |
| 402 | */ |
Eric Dumazet | e2e210c | 2011-11-02 22:47:44 +0000 | [diff] [blame] | 403 | start: |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 404 | spin_lock_bh(&session->reorder_q.lock); |
| 405 | skb_queue_walk_safe(&session->reorder_q, skb, tmp) { |
| 406 | if (time_after(jiffies, L2TP_SKB_CB(skb)->expires)) { |
| 407 | session->stats.rx_seq_discards++; |
| 408 | session->stats.rx_errors++; |
| 409 | PRINTK(session->debug, L2TP_MSG_SEQ, KERN_DEBUG, |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 410 | "%s: oos pkt %u len %d discarded (too old), " |
| 411 | "waiting for %u, reorder_q_len=%d\n", |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 412 | session->name, L2TP_SKB_CB(skb)->ns, |
| 413 | L2TP_SKB_CB(skb)->length, session->nr, |
| 414 | skb_queue_len(&session->reorder_q)); |
| 415 | __skb_unlink(skb, &session->reorder_q); |
| 416 | kfree_skb(skb); |
| 417 | if (session->deref) |
| 418 | (*session->deref)(session); |
| 419 | continue; |
| 420 | } |
| 421 | |
| 422 | if (L2TP_SKB_CB(skb)->has_seq) { |
| 423 | if (L2TP_SKB_CB(skb)->ns != session->nr) { |
| 424 | PRINTK(session->debug, L2TP_MSG_SEQ, KERN_DEBUG, |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 425 | "%s: holding oos pkt %u len %d, " |
| 426 | "waiting for %u, reorder_q_len=%d\n", |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 427 | session->name, L2TP_SKB_CB(skb)->ns, |
| 428 | L2TP_SKB_CB(skb)->length, session->nr, |
| 429 | skb_queue_len(&session->reorder_q)); |
| 430 | goto out; |
| 431 | } |
| 432 | } |
| 433 | __skb_unlink(skb, &session->reorder_q); |
| 434 | |
| 435 | /* Process the skb. We release the queue lock while we |
| 436 | * do so to let other contexts process the queue. |
| 437 | */ |
| 438 | spin_unlock_bh(&session->reorder_q.lock); |
| 439 | l2tp_recv_dequeue_skb(session, skb); |
Eric Dumazet | e2e210c | 2011-11-02 22:47:44 +0000 | [diff] [blame] | 440 | goto start; |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 441 | } |
| 442 | |
| 443 | out: |
| 444 | spin_unlock_bh(&session->reorder_q.lock); |
| 445 | } |
| 446 | |
| 447 | static inline int l2tp_verify_udp_checksum(struct sock *sk, |
| 448 | struct sk_buff *skb) |
| 449 | { |
| 450 | struct udphdr *uh = udp_hdr(skb); |
| 451 | u16 ulen = ntohs(uh->len); |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 452 | __wsum psum; |
| 453 | |
Benjamin LaHaise | d2cf336 | 2012-04-27 08:24:18 +0000 | [diff] [blame^] | 454 | if (sk->sk_no_check || skb_csum_unnecessary(skb)) |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 455 | return 0; |
| 456 | |
Benjamin LaHaise | d2cf336 | 2012-04-27 08:24:18 +0000 | [diff] [blame^] | 457 | #if IS_ENABLED(CONFIG_IPV6) |
| 458 | if (sk->sk_family == PF_INET6) { |
| 459 | if (!uh->check) { |
| 460 | LIMIT_NETDEBUG(KERN_INFO "L2TP: IPv6: checksum is 0\n"); |
| 461 | return 1; |
| 462 | } |
| 463 | if ((skb->ip_summed == CHECKSUM_COMPLETE) && |
| 464 | !csum_ipv6_magic(&ipv6_hdr(skb)->saddr, |
| 465 | &ipv6_hdr(skb)->daddr, ulen, |
| 466 | IPPROTO_UDP, skb->csum)) { |
| 467 | skb->ip_summed = CHECKSUM_UNNECESSARY; |
| 468 | return 0; |
| 469 | } |
| 470 | skb->csum = ~csum_unfold(csum_ipv6_magic(&ipv6_hdr(skb)->saddr, |
| 471 | &ipv6_hdr(skb)->daddr, |
| 472 | skb->len, IPPROTO_UDP, |
| 473 | 0)); |
| 474 | } else |
| 475 | #endif |
| 476 | { |
| 477 | struct inet_sock *inet; |
| 478 | if (!uh->check) |
| 479 | return 0; |
| 480 | inet = inet_sk(sk); |
| 481 | psum = csum_tcpudp_nofold(inet->inet_saddr, inet->inet_daddr, |
| 482 | ulen, IPPROTO_UDP, 0); |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 483 | |
Benjamin LaHaise | d2cf336 | 2012-04-27 08:24:18 +0000 | [diff] [blame^] | 484 | if ((skb->ip_summed == CHECKSUM_COMPLETE) && |
| 485 | !csum_fold(csum_add(psum, skb->csum))) |
| 486 | return 0; |
| 487 | skb->csum = psum; |
| 488 | } |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 489 | |
| 490 | return __skb_checksum_complete(skb); |
| 491 | } |
| 492 | |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 493 | /* Do receive processing of L2TP data frames. We handle both L2TPv2 |
| 494 | * and L2TPv3 data frames here. |
| 495 | * |
| 496 | * L2TPv2 Data Message Header |
| 497 | * |
| 498 | * 0 1 2 3 |
| 499 | * 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 |
| 500 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| 501 | * |T|L|x|x|S|x|O|P|x|x|x|x| Ver | Length (opt) | |
| 502 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| 503 | * | Tunnel ID | Session ID | |
| 504 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| 505 | * | Ns (opt) | Nr (opt) | |
| 506 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| 507 | * | Offset Size (opt) | Offset pad... (opt) |
| 508 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| 509 | * |
| 510 | * Data frames are marked by T=0. All other fields are the same as |
| 511 | * those in L2TP control frames. |
| 512 | * |
| 513 | * L2TPv3 Data Message Header |
| 514 | * |
| 515 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| 516 | * | L2TP Session Header | |
| 517 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| 518 | * | L2-Specific Sublayer | |
| 519 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| 520 | * | Tunnel Payload ... |
| 521 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| 522 | * |
| 523 | * L2TPv3 Session Header Over IP |
| 524 | * |
| 525 | * 0 1 2 3 |
| 526 | * 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 |
| 527 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| 528 | * | Session ID | |
| 529 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| 530 | * | Cookie (optional, maximum 64 bits)... |
| 531 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| 532 | * | |
| 533 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| 534 | * |
| 535 | * L2TPv3 L2-Specific Sublayer Format |
| 536 | * |
| 537 | * 0 1 2 3 |
| 538 | * 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 |
| 539 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| 540 | * |x|S|x|x|x|x|x|x| Sequence Number | |
| 541 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| 542 | * |
| 543 | * Cookie value, sublayer format and offset (pad) are negotiated with |
| 544 | * the peer when the session is set up. Unlike L2TPv2, we do not need |
| 545 | * to parse the packet header to determine if optional fields are |
| 546 | * present. |
| 547 | * |
| 548 | * Caller must already have parsed the frame and determined that it is |
| 549 | * a data (not control) frame before coming here. Fields up to the |
| 550 | * session-id have already been parsed and ptr points to the data |
| 551 | * after the session-id. |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 552 | */ |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 553 | void l2tp_recv_common(struct l2tp_session *session, struct sk_buff *skb, |
| 554 | unsigned char *ptr, unsigned char *optr, u16 hdrflags, |
| 555 | int length, int (*payload_hook)(struct sk_buff *skb)) |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 556 | { |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 557 | struct l2tp_tunnel *tunnel = session->tunnel; |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 558 | int offset; |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 559 | u32 ns, nr; |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 560 | |
| 561 | /* The ref count is increased since we now hold a pointer to |
| 562 | * the session. Take care to decrement the refcnt when exiting |
| 563 | * this function from now on... |
| 564 | */ |
| 565 | l2tp_session_inc_refcount(session); |
| 566 | if (session->ref) |
| 567 | (*session->ref)(session); |
| 568 | |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 569 | /* Parse and check optional cookie */ |
| 570 | if (session->peer_cookie_len > 0) { |
| 571 | if (memcmp(ptr, &session->peer_cookie[0], session->peer_cookie_len)) { |
| 572 | PRINTK(tunnel->debug, L2TP_MSG_DATA, KERN_INFO, |
| 573 | "%s: cookie mismatch (%u/%u). Discarding.\n", |
| 574 | tunnel->name, tunnel->tunnel_id, session->session_id); |
| 575 | session->stats.rx_cookie_discards++; |
| 576 | goto discard; |
| 577 | } |
| 578 | ptr += session->peer_cookie_len; |
| 579 | } |
| 580 | |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 581 | /* Handle the optional sequence numbers. Sequence numbers are |
| 582 | * in different places for L2TPv2 and L2TPv3. |
| 583 | * |
| 584 | * If we are the LAC, enable/disable sequence numbers under |
| 585 | * the control of the LNS. If no sequence numbers present but |
| 586 | * we were expecting them, discard frame. |
| 587 | */ |
| 588 | ns = nr = 0; |
| 589 | L2TP_SKB_CB(skb)->has_seq = 0; |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 590 | if (tunnel->version == L2TP_HDR_VER_2) { |
| 591 | if (hdrflags & L2TP_HDRFLAG_S) { |
| 592 | ns = ntohs(*(__be16 *) ptr); |
| 593 | ptr += 2; |
| 594 | nr = ntohs(*(__be16 *) ptr); |
| 595 | ptr += 2; |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 596 | |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 597 | /* Store L2TP info in the skb */ |
| 598 | L2TP_SKB_CB(skb)->ns = ns; |
| 599 | L2TP_SKB_CB(skb)->has_seq = 1; |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 600 | |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 601 | PRINTK(session->debug, L2TP_MSG_SEQ, KERN_DEBUG, |
| 602 | "%s: recv data ns=%u, nr=%u, session nr=%u\n", |
| 603 | session->name, ns, nr, session->nr); |
| 604 | } |
| 605 | } else if (session->l2specific_type == L2TP_L2SPECTYPE_DEFAULT) { |
| 606 | u32 l2h = ntohl(*(__be32 *) ptr); |
| 607 | |
| 608 | if (l2h & 0x40000000) { |
| 609 | ns = l2h & 0x00ffffff; |
| 610 | |
| 611 | /* Store L2TP info in the skb */ |
| 612 | L2TP_SKB_CB(skb)->ns = ns; |
| 613 | L2TP_SKB_CB(skb)->has_seq = 1; |
| 614 | |
| 615 | PRINTK(session->debug, L2TP_MSG_SEQ, KERN_DEBUG, |
| 616 | "%s: recv data ns=%u, session nr=%u\n", |
| 617 | session->name, ns, session->nr); |
| 618 | } |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 619 | } |
| 620 | |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 621 | /* Advance past L2-specific header, if present */ |
| 622 | ptr += session->l2specific_len; |
| 623 | |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 624 | if (L2TP_SKB_CB(skb)->has_seq) { |
| 625 | /* Received a packet with sequence numbers. If we're the LNS, |
| 626 | * check if we sre sending sequence numbers and if not, |
| 627 | * configure it so. |
| 628 | */ |
| 629 | if ((!session->lns_mode) && (!session->send_seq)) { |
| 630 | PRINTK(session->debug, L2TP_MSG_SEQ, KERN_INFO, |
| 631 | "%s: requested to enable seq numbers by LNS\n", |
| 632 | session->name); |
| 633 | session->send_seq = -1; |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 634 | l2tp_session_set_header_len(session, tunnel->version); |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 635 | } |
| 636 | } else { |
| 637 | /* No sequence numbers. |
| 638 | * If user has configured mandatory sequence numbers, discard. |
| 639 | */ |
| 640 | if (session->recv_seq) { |
| 641 | PRINTK(session->debug, L2TP_MSG_SEQ, KERN_WARNING, |
| 642 | "%s: recv data has no seq numbers when required. " |
| 643 | "Discarding\n", session->name); |
| 644 | session->stats.rx_seq_discards++; |
| 645 | goto discard; |
| 646 | } |
| 647 | |
| 648 | /* If we're the LAC and we're sending sequence numbers, the |
| 649 | * LNS has requested that we no longer send sequence numbers. |
| 650 | * If we're the LNS and we're sending sequence numbers, the |
| 651 | * LAC is broken. Discard the frame. |
| 652 | */ |
| 653 | if ((!session->lns_mode) && (session->send_seq)) { |
| 654 | PRINTK(session->debug, L2TP_MSG_SEQ, KERN_INFO, |
| 655 | "%s: requested to disable seq numbers by LNS\n", |
| 656 | session->name); |
| 657 | session->send_seq = 0; |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 658 | l2tp_session_set_header_len(session, tunnel->version); |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 659 | } else if (session->send_seq) { |
| 660 | PRINTK(session->debug, L2TP_MSG_SEQ, KERN_WARNING, |
| 661 | "%s: recv data has no seq numbers when required. " |
| 662 | "Discarding\n", session->name); |
| 663 | session->stats.rx_seq_discards++; |
| 664 | goto discard; |
| 665 | } |
| 666 | } |
| 667 | |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 668 | /* Session data offset is handled differently for L2TPv2 and |
| 669 | * L2TPv3. For L2TPv2, there is an optional 16-bit value in |
| 670 | * the header. For L2TPv3, the offset is negotiated using AVPs |
| 671 | * in the session setup control protocol. |
| 672 | */ |
| 673 | if (tunnel->version == L2TP_HDR_VER_2) { |
| 674 | /* If offset bit set, skip it. */ |
| 675 | if (hdrflags & L2TP_HDRFLAG_O) { |
| 676 | offset = ntohs(*(__be16 *)ptr); |
| 677 | ptr += 2 + offset; |
| 678 | } |
| 679 | } else |
| 680 | ptr += session->offset; |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 681 | |
| 682 | offset = ptr - optr; |
| 683 | if (!pskb_may_pull(skb, offset)) |
| 684 | goto discard; |
| 685 | |
| 686 | __skb_pull(skb, offset); |
| 687 | |
| 688 | /* If caller wants to process the payload before we queue the |
| 689 | * packet, do so now. |
| 690 | */ |
| 691 | if (payload_hook) |
| 692 | if ((*payload_hook)(skb)) |
| 693 | goto discard; |
| 694 | |
| 695 | /* Prepare skb for adding to the session's reorder_q. Hold |
| 696 | * packets for max reorder_timeout or 1 second if not |
| 697 | * reordering. |
| 698 | */ |
| 699 | L2TP_SKB_CB(skb)->length = length; |
| 700 | L2TP_SKB_CB(skb)->expires = jiffies + |
| 701 | (session->reorder_timeout ? session->reorder_timeout : HZ); |
| 702 | |
| 703 | /* Add packet to the session's receive queue. Reordering is done here, if |
| 704 | * enabled. Saved L2TP protocol info is stored in skb->sb[]. |
| 705 | */ |
| 706 | if (L2TP_SKB_CB(skb)->has_seq) { |
| 707 | if (session->reorder_timeout != 0) { |
| 708 | /* Packet reordering enabled. Add skb to session's |
| 709 | * reorder queue, in order of ns. |
| 710 | */ |
| 711 | l2tp_recv_queue_skb(session, skb); |
| 712 | } else { |
| 713 | /* Packet reordering disabled. Discard out-of-sequence |
| 714 | * packets |
| 715 | */ |
| 716 | if (L2TP_SKB_CB(skb)->ns != session->nr) { |
| 717 | session->stats.rx_seq_discards++; |
| 718 | PRINTK(session->debug, L2TP_MSG_SEQ, KERN_DEBUG, |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 719 | "%s: oos pkt %u len %d discarded, " |
| 720 | "waiting for %u, reorder_q_len=%d\n", |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 721 | session->name, L2TP_SKB_CB(skb)->ns, |
| 722 | L2TP_SKB_CB(skb)->length, session->nr, |
| 723 | skb_queue_len(&session->reorder_q)); |
| 724 | goto discard; |
| 725 | } |
| 726 | skb_queue_tail(&session->reorder_q, skb); |
| 727 | } |
| 728 | } else { |
| 729 | /* No sequence numbers. Add the skb to the tail of the |
| 730 | * reorder queue. This ensures that it will be |
| 731 | * delivered after all previous sequenced skbs. |
| 732 | */ |
| 733 | skb_queue_tail(&session->reorder_q, skb); |
| 734 | } |
| 735 | |
| 736 | /* Try to dequeue as many skbs from reorder_q as we can. */ |
| 737 | l2tp_recv_dequeue(session); |
| 738 | |
| 739 | l2tp_session_dec_refcount(session); |
| 740 | |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 741 | return; |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 742 | |
| 743 | discard: |
| 744 | session->stats.rx_errors++; |
| 745 | kfree_skb(skb); |
| 746 | |
| 747 | if (session->deref) |
| 748 | (*session->deref)(session); |
| 749 | |
| 750 | l2tp_session_dec_refcount(session); |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 751 | } |
| 752 | EXPORT_SYMBOL(l2tp_recv_common); |
| 753 | |
| 754 | /* Internal UDP receive frame. Do the real work of receiving an L2TP data frame |
| 755 | * here. The skb is not on a list when we get here. |
| 756 | * Returns 0 if the packet was a data packet and was successfully passed on. |
| 757 | * Returns 1 if the packet was not a good data packet and could not be |
| 758 | * forwarded. All such packets are passed up to userspace to deal with. |
| 759 | */ |
stephen hemminger | fc13084 | 2010-10-21 07:50:46 +0000 | [diff] [blame] | 760 | static int l2tp_udp_recv_core(struct l2tp_tunnel *tunnel, struct sk_buff *skb, |
| 761 | int (*payload_hook)(struct sk_buff *skb)) |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 762 | { |
| 763 | struct l2tp_session *session = NULL; |
| 764 | unsigned char *ptr, *optr; |
| 765 | u16 hdrflags; |
| 766 | u32 tunnel_id, session_id; |
| 767 | int offset; |
| 768 | u16 version; |
| 769 | int length; |
| 770 | |
| 771 | if (tunnel->sock && l2tp_verify_udp_checksum(tunnel->sock, skb)) |
| 772 | goto discard_bad_csum; |
| 773 | |
| 774 | /* UDP always verifies the packet length. */ |
| 775 | __skb_pull(skb, sizeof(struct udphdr)); |
| 776 | |
| 777 | /* Short packet? */ |
| 778 | if (!pskb_may_pull(skb, L2TP_HDR_SIZE_SEQ)) { |
| 779 | PRINTK(tunnel->debug, L2TP_MSG_DATA, KERN_INFO, |
| 780 | "%s: recv short packet (len=%d)\n", tunnel->name, skb->len); |
| 781 | goto error; |
| 782 | } |
| 783 | |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 784 | /* Trace packet contents, if enabled */ |
| 785 | if (tunnel->debug & L2TP_MSG_DATA) { |
| 786 | length = min(32u, skb->len); |
| 787 | if (!pskb_may_pull(skb, length)) |
| 788 | goto error; |
| 789 | |
| 790 | printk(KERN_DEBUG "%s: recv: ", tunnel->name); |
| 791 | |
| 792 | offset = 0; |
| 793 | do { |
Eric Dumazet | e50e705 | 2011-11-08 13:59:44 -0500 | [diff] [blame] | 794 | printk(" %02X", skb->data[offset]); |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 795 | } while (++offset < length); |
| 796 | |
| 797 | printk("\n"); |
| 798 | } |
| 799 | |
Eric Dumazet | e50e705 | 2011-11-08 13:59:44 -0500 | [diff] [blame] | 800 | /* Point to L2TP header */ |
| 801 | optr = ptr = skb->data; |
| 802 | |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 803 | /* Get L2TP header flags */ |
| 804 | hdrflags = ntohs(*(__be16 *) ptr); |
| 805 | |
| 806 | /* Check protocol version */ |
| 807 | version = hdrflags & L2TP_HDR_VER_MASK; |
| 808 | if (version != tunnel->version) { |
| 809 | PRINTK(tunnel->debug, L2TP_MSG_DATA, KERN_INFO, |
| 810 | "%s: recv protocol version mismatch: got %d expected %d\n", |
| 811 | tunnel->name, version, tunnel->version); |
| 812 | goto error; |
| 813 | } |
| 814 | |
| 815 | /* Get length of L2TP packet */ |
| 816 | length = skb->len; |
| 817 | |
| 818 | /* If type is control packet, it is handled by userspace. */ |
| 819 | if (hdrflags & L2TP_HDRFLAG_T) { |
| 820 | PRINTK(tunnel->debug, L2TP_MSG_DATA, KERN_DEBUG, |
| 821 | "%s: recv control packet, len=%d\n", tunnel->name, length); |
| 822 | goto error; |
| 823 | } |
| 824 | |
| 825 | /* Skip flags */ |
| 826 | ptr += 2; |
| 827 | |
| 828 | if (tunnel->version == L2TP_HDR_VER_2) { |
| 829 | /* If length is present, skip it */ |
| 830 | if (hdrflags & L2TP_HDRFLAG_L) |
| 831 | ptr += 2; |
| 832 | |
| 833 | /* Extract tunnel and session ID */ |
| 834 | tunnel_id = ntohs(*(__be16 *) ptr); |
| 835 | ptr += 2; |
| 836 | session_id = ntohs(*(__be16 *) ptr); |
| 837 | ptr += 2; |
| 838 | } else { |
| 839 | ptr += 2; /* skip reserved bits */ |
| 840 | tunnel_id = tunnel->tunnel_id; |
| 841 | session_id = ntohl(*(__be32 *) ptr); |
| 842 | ptr += 4; |
| 843 | } |
| 844 | |
| 845 | /* Find the session context */ |
| 846 | session = l2tp_session_find(tunnel->l2tp_net, tunnel, session_id); |
James Chapman | 309795f | 2010-04-02 06:19:10 +0000 | [diff] [blame] | 847 | if (!session || !session->recv_skb) { |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 848 | /* Not found? Pass to userspace to deal with */ |
| 849 | PRINTK(tunnel->debug, L2TP_MSG_DATA, KERN_INFO, |
| 850 | "%s: no session found (%u/%u). Passing up.\n", |
| 851 | tunnel->name, tunnel_id, session_id); |
| 852 | goto error; |
| 853 | } |
| 854 | |
| 855 | l2tp_recv_common(session, skb, ptr, optr, hdrflags, length, payload_hook); |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 856 | |
| 857 | return 0; |
| 858 | |
| 859 | discard_bad_csum: |
| 860 | LIMIT_NETDEBUG("%s: UDP: bad checksum\n", tunnel->name); |
| 861 | UDP_INC_STATS_USER(tunnel->l2tp_net, UDP_MIB_INERRORS, 0); |
| 862 | tunnel->stats.rx_errors++; |
| 863 | kfree_skb(skb); |
| 864 | |
| 865 | return 0; |
| 866 | |
| 867 | error: |
| 868 | /* Put UDP header back */ |
| 869 | __skb_push(skb, sizeof(struct udphdr)); |
| 870 | |
| 871 | return 1; |
| 872 | } |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 873 | |
| 874 | /* UDP encapsulation receive handler. See net/ipv4/udp.c. |
| 875 | * Return codes: |
| 876 | * 0 : success. |
| 877 | * <0: error |
| 878 | * >0: skb should be passed up to userspace as UDP. |
| 879 | */ |
| 880 | int l2tp_udp_encap_recv(struct sock *sk, struct sk_buff *skb) |
| 881 | { |
| 882 | struct l2tp_tunnel *tunnel; |
| 883 | |
| 884 | tunnel = l2tp_sock_to_tunnel(sk); |
| 885 | if (tunnel == NULL) |
| 886 | goto pass_up; |
| 887 | |
| 888 | PRINTK(tunnel->debug, L2TP_MSG_DATA, KERN_DEBUG, |
| 889 | "%s: received %d bytes\n", tunnel->name, skb->len); |
| 890 | |
| 891 | if (l2tp_udp_recv_core(tunnel, skb, tunnel->recv_payload_hook)) |
| 892 | goto pass_up_put; |
| 893 | |
| 894 | sock_put(sk); |
| 895 | return 0; |
| 896 | |
| 897 | pass_up_put: |
| 898 | sock_put(sk); |
| 899 | pass_up: |
| 900 | return 1; |
| 901 | } |
| 902 | EXPORT_SYMBOL_GPL(l2tp_udp_encap_recv); |
| 903 | |
| 904 | /************************************************************************ |
| 905 | * Transmit handling |
| 906 | ***********************************************************************/ |
| 907 | |
| 908 | /* Build an L2TP header for the session into the buffer provided. |
| 909 | */ |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 910 | static int l2tp_build_l2tpv2_header(struct l2tp_session *session, void *buf) |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 911 | { |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 912 | struct l2tp_tunnel *tunnel = session->tunnel; |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 913 | __be16 *bufp = buf; |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 914 | __be16 *optr = buf; |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 915 | u16 flags = L2TP_HDR_VER_2; |
| 916 | u32 tunnel_id = tunnel->peer_tunnel_id; |
| 917 | u32 session_id = session->peer_session_id; |
| 918 | |
| 919 | if (session->send_seq) |
| 920 | flags |= L2TP_HDRFLAG_S; |
| 921 | |
| 922 | /* Setup L2TP header. */ |
| 923 | *bufp++ = htons(flags); |
| 924 | *bufp++ = htons(tunnel_id); |
| 925 | *bufp++ = htons(session_id); |
| 926 | if (session->send_seq) { |
| 927 | *bufp++ = htons(session->ns); |
| 928 | *bufp++ = 0; |
| 929 | session->ns++; |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 930 | session->ns &= 0xffff; |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 931 | PRINTK(session->debug, L2TP_MSG_SEQ, KERN_DEBUG, |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 932 | "%s: updated ns to %u\n", session->name, session->ns); |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 933 | } |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 934 | |
| 935 | return bufp - optr; |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 936 | } |
| 937 | |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 938 | static int l2tp_build_l2tpv3_header(struct l2tp_session *session, void *buf) |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 939 | { |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 940 | struct l2tp_tunnel *tunnel = session->tunnel; |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 941 | char *bufp = buf; |
| 942 | char *optr = bufp; |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 943 | |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 944 | /* Setup L2TP header. The header differs slightly for UDP and |
| 945 | * IP encapsulations. For UDP, there is 4 bytes of flags. |
| 946 | */ |
| 947 | if (tunnel->encap == L2TP_ENCAPTYPE_UDP) { |
| 948 | u16 flags = L2TP_HDR_VER_3; |
| 949 | *((__be16 *) bufp) = htons(flags); |
| 950 | bufp += 2; |
| 951 | *((__be16 *) bufp) = 0; |
| 952 | bufp += 2; |
| 953 | } |
| 954 | |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 955 | *((__be32 *) bufp) = htonl(session->peer_session_id); |
| 956 | bufp += 4; |
| 957 | if (session->cookie_len) { |
| 958 | memcpy(bufp, &session->cookie[0], session->cookie_len); |
| 959 | bufp += session->cookie_len; |
| 960 | } |
| 961 | if (session->l2specific_len) { |
| 962 | if (session->l2specific_type == L2TP_L2SPECTYPE_DEFAULT) { |
| 963 | u32 l2h = 0; |
| 964 | if (session->send_seq) { |
| 965 | l2h = 0x40000000 | session->ns; |
| 966 | session->ns++; |
| 967 | session->ns &= 0xffffff; |
| 968 | PRINTK(session->debug, L2TP_MSG_SEQ, KERN_DEBUG, |
| 969 | "%s: updated ns to %u\n", session->name, session->ns); |
| 970 | } |
| 971 | |
| 972 | *((__be32 *) bufp) = htonl(l2h); |
| 973 | } |
| 974 | bufp += session->l2specific_len; |
| 975 | } |
| 976 | if (session->offset) |
| 977 | bufp += session->offset; |
| 978 | |
| 979 | return bufp - optr; |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 980 | } |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 981 | |
stephen hemminger | fc13084 | 2010-10-21 07:50:46 +0000 | [diff] [blame] | 982 | static int l2tp_xmit_core(struct l2tp_session *session, struct sk_buff *skb, |
David S. Miller | d9d8da8 | 2011-05-06 22:23:20 -0700 | [diff] [blame] | 983 | struct flowi *fl, size_t data_len) |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 984 | { |
| 985 | struct l2tp_tunnel *tunnel = session->tunnel; |
| 986 | unsigned int len = skb->len; |
| 987 | int error; |
| 988 | |
| 989 | /* Debug */ |
| 990 | if (session->send_seq) |
| 991 | PRINTK(session->debug, L2TP_MSG_DATA, KERN_DEBUG, |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 992 | "%s: send %Zd bytes, ns=%u\n", session->name, |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 993 | data_len, session->ns - 1); |
| 994 | else |
| 995 | PRINTK(session->debug, L2TP_MSG_DATA, KERN_DEBUG, |
| 996 | "%s: send %Zd bytes\n", session->name, data_len); |
| 997 | |
| 998 | if (session->debug & L2TP_MSG_DATA) { |
| 999 | int i; |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 1000 | int uhlen = (tunnel->encap == L2TP_ENCAPTYPE_UDP) ? sizeof(struct udphdr) : 0; |
| 1001 | unsigned char *datap = skb->data + uhlen; |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1002 | |
| 1003 | printk(KERN_DEBUG "%s: xmit:", session->name); |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 1004 | for (i = 0; i < (len - uhlen); i++) { |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1005 | printk(" %02X", *datap++); |
| 1006 | if (i == 31) { |
| 1007 | printk(" ..."); |
| 1008 | break; |
| 1009 | } |
| 1010 | } |
| 1011 | printk("\n"); |
| 1012 | } |
| 1013 | |
| 1014 | /* Queue the packet to IP for output */ |
Shan Wei | 4e15ed4 | 2010-04-15 16:43:08 +0000 | [diff] [blame] | 1015 | skb->local_df = 1; |
Benjamin LaHaise | d2cf336 | 2012-04-27 08:24:18 +0000 | [diff] [blame^] | 1016 | #if IS_ENABLED(CONFIG_IPV6) |
| 1017 | if (skb->sk->sk_family == PF_INET6) |
| 1018 | error = inet6_csk_xmit(skb, NULL); |
| 1019 | else |
| 1020 | #endif |
| 1021 | error = ip_queue_xmit(skb, fl); |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1022 | |
| 1023 | /* Update stats */ |
| 1024 | if (error >= 0) { |
| 1025 | tunnel->stats.tx_packets++; |
| 1026 | tunnel->stats.tx_bytes += len; |
| 1027 | session->stats.tx_packets++; |
| 1028 | session->stats.tx_bytes += len; |
| 1029 | } else { |
| 1030 | tunnel->stats.tx_errors++; |
| 1031 | session->stats.tx_errors++; |
| 1032 | } |
| 1033 | |
| 1034 | return 0; |
| 1035 | } |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1036 | |
| 1037 | /* Automatically called when the skb is freed. |
| 1038 | */ |
| 1039 | static void l2tp_sock_wfree(struct sk_buff *skb) |
| 1040 | { |
| 1041 | sock_put(skb->sk); |
| 1042 | } |
| 1043 | |
| 1044 | /* For data skbs that we transmit, we associate with the tunnel socket |
| 1045 | * but don't do accounting. |
| 1046 | */ |
| 1047 | static inline void l2tp_skb_set_owner_w(struct sk_buff *skb, struct sock *sk) |
| 1048 | { |
| 1049 | sock_hold(sk); |
| 1050 | skb->sk = sk; |
| 1051 | skb->destructor = l2tp_sock_wfree; |
| 1052 | } |
| 1053 | |
Benjamin LaHaise | d2cf336 | 2012-04-27 08:24:18 +0000 | [diff] [blame^] | 1054 | #if IS_ENABLED(CONFIG_IPV6) |
| 1055 | static void l2tp_xmit_ipv6_csum(struct sock *sk, struct sk_buff *skb, |
| 1056 | int udp_len) |
| 1057 | { |
| 1058 | struct ipv6_pinfo *np = inet6_sk(sk); |
| 1059 | struct udphdr *uh = udp_hdr(skb); |
| 1060 | |
| 1061 | if (!skb_dst(skb) || !skb_dst(skb)->dev || |
| 1062 | !(skb_dst(skb)->dev->features & NETIF_F_IPV6_CSUM)) { |
| 1063 | __wsum csum = skb_checksum(skb, 0, udp_len, 0); |
| 1064 | skb->ip_summed = CHECKSUM_UNNECESSARY; |
| 1065 | uh->check = csum_ipv6_magic(&np->saddr, &np->daddr, udp_len, |
| 1066 | IPPROTO_UDP, csum); |
| 1067 | if (uh->check == 0) |
| 1068 | uh->check = CSUM_MANGLED_0; |
| 1069 | } else { |
| 1070 | skb->ip_summed = CHECKSUM_PARTIAL; |
| 1071 | skb->csum_start = skb_transport_header(skb) - skb->head; |
| 1072 | skb->csum_offset = offsetof(struct udphdr, check); |
| 1073 | uh->check = ~csum_ipv6_magic(&np->saddr, &np->daddr, |
| 1074 | udp_len, IPPROTO_UDP, 0); |
| 1075 | } |
| 1076 | } |
| 1077 | #endif |
| 1078 | |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1079 | /* If caller requires the skb to have a ppp header, the header must be |
| 1080 | * inserted in the skb data before calling this function. |
| 1081 | */ |
| 1082 | int l2tp_xmit_skb(struct l2tp_session *session, struct sk_buff *skb, int hdr_len) |
| 1083 | { |
| 1084 | int data_len = skb->len; |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 1085 | struct l2tp_tunnel *tunnel = session->tunnel; |
| 1086 | struct sock *sk = tunnel->sock; |
David S. Miller | d9d8da8 | 2011-05-06 22:23:20 -0700 | [diff] [blame] | 1087 | struct flowi *fl; |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1088 | struct udphdr *uh; |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1089 | struct inet_sock *inet; |
| 1090 | __wsum csum; |
| 1091 | int old_headroom; |
| 1092 | int new_headroom; |
| 1093 | int headroom; |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 1094 | int uhlen = (tunnel->encap == L2TP_ENCAPTYPE_UDP) ? sizeof(struct udphdr) : 0; |
| 1095 | int udp_len; |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1096 | |
| 1097 | /* Check that there's enough headroom in the skb to insert IP, |
| 1098 | * UDP and L2TP headers. If not enough, expand it to |
| 1099 | * make room. Adjust truesize. |
| 1100 | */ |
| 1101 | headroom = NET_SKB_PAD + sizeof(struct iphdr) + |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 1102 | uhlen + hdr_len; |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1103 | old_headroom = skb_headroom(skb); |
Eric Dumazet | 835acf5 | 2011-10-07 05:35:46 +0000 | [diff] [blame] | 1104 | if (skb_cow_head(skb, headroom)) { |
| 1105 | dev_kfree_skb(skb); |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1106 | goto abort; |
Eric Dumazet | 835acf5 | 2011-10-07 05:35:46 +0000 | [diff] [blame] | 1107 | } |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1108 | |
| 1109 | new_headroom = skb_headroom(skb); |
| 1110 | skb_orphan(skb); |
| 1111 | skb->truesize += new_headroom - old_headroom; |
| 1112 | |
| 1113 | /* Setup L2TP header */ |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 1114 | session->build_header(session, __skb_push(skb, hdr_len)); |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1115 | |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 1116 | /* Reset skb netfilter state */ |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1117 | memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt)); |
| 1118 | IPCB(skb)->flags &= ~(IPSKB_XFRM_TUNNEL_SIZE | IPSKB_XFRM_TRANSFORMED | |
| 1119 | IPSKB_REROUTED); |
| 1120 | nf_reset(skb); |
| 1121 | |
David S. Miller | 6af88da | 2011-05-08 13:45:20 -0700 | [diff] [blame] | 1122 | bh_lock_sock(sk); |
| 1123 | if (sock_owned_by_user(sk)) { |
| 1124 | dev_kfree_skb(skb); |
| 1125 | goto out_unlock; |
| 1126 | } |
| 1127 | |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1128 | /* Get routing info from the tunnel socket */ |
| 1129 | skb_dst_drop(skb); |
Florian Westphal | 71b1391 | 2011-11-25 06:47:16 +0000 | [diff] [blame] | 1130 | skb_dst_set(skb, dst_clone(__sk_dst_check(sk, 0))); |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1131 | |
David S. Miller | d9d8da8 | 2011-05-06 22:23:20 -0700 | [diff] [blame] | 1132 | inet = inet_sk(sk); |
| 1133 | fl = &inet->cork.fl; |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 1134 | switch (tunnel->encap) { |
| 1135 | case L2TP_ENCAPTYPE_UDP: |
| 1136 | /* Setup UDP header */ |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 1137 | __skb_push(skb, sizeof(*uh)); |
| 1138 | skb_reset_transport_header(skb); |
| 1139 | uh = udp_hdr(skb); |
| 1140 | uh->source = inet->inet_sport; |
| 1141 | uh->dest = inet->inet_dport; |
| 1142 | udp_len = uhlen + hdr_len + data_len; |
| 1143 | uh->len = htons(udp_len); |
| 1144 | uh->check = 0; |
| 1145 | |
| 1146 | /* Calculate UDP checksum if configured to do so */ |
Benjamin LaHaise | d2cf336 | 2012-04-27 08:24:18 +0000 | [diff] [blame^] | 1147 | #if IS_ENABLED(CONFIG_IPV6) |
| 1148 | if (sk->sk_family == PF_INET6) |
| 1149 | l2tp_xmit_ipv6_csum(sk, skb, udp_len); |
| 1150 | else |
| 1151 | #endif |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 1152 | if (sk->sk_no_check == UDP_CSUM_NOXMIT) |
| 1153 | skb->ip_summed = CHECKSUM_NONE; |
| 1154 | else if ((skb_dst(skb) && skb_dst(skb)->dev) && |
| 1155 | (!(skb_dst(skb)->dev->features & NETIF_F_V4_CSUM))) { |
| 1156 | skb->ip_summed = CHECKSUM_COMPLETE; |
| 1157 | csum = skb_checksum(skb, 0, udp_len, 0); |
| 1158 | uh->check = csum_tcpudp_magic(inet->inet_saddr, |
| 1159 | inet->inet_daddr, |
| 1160 | udp_len, IPPROTO_UDP, csum); |
| 1161 | if (uh->check == 0) |
| 1162 | uh->check = CSUM_MANGLED_0; |
| 1163 | } else { |
| 1164 | skb->ip_summed = CHECKSUM_PARTIAL; |
| 1165 | skb->csum_start = skb_transport_header(skb) - skb->head; |
| 1166 | skb->csum_offset = offsetof(struct udphdr, check); |
| 1167 | uh->check = ~csum_tcpudp_magic(inet->inet_saddr, |
| 1168 | inet->inet_daddr, |
| 1169 | udp_len, IPPROTO_UDP, 0); |
| 1170 | } |
| 1171 | break; |
| 1172 | |
| 1173 | case L2TP_ENCAPTYPE_IP: |
| 1174 | break; |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1175 | } |
| 1176 | |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 1177 | l2tp_skb_set_owner_w(skb, sk); |
| 1178 | |
David S. Miller | d9d8da8 | 2011-05-06 22:23:20 -0700 | [diff] [blame] | 1179 | l2tp_xmit_core(session, skb, fl, data_len); |
David S. Miller | 6af88da | 2011-05-08 13:45:20 -0700 | [diff] [blame] | 1180 | out_unlock: |
| 1181 | bh_unlock_sock(sk); |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1182 | |
| 1183 | abort: |
| 1184 | return 0; |
| 1185 | } |
| 1186 | EXPORT_SYMBOL_GPL(l2tp_xmit_skb); |
| 1187 | |
| 1188 | /***************************************************************************** |
| 1189 | * Tinnel and session create/destroy. |
| 1190 | *****************************************************************************/ |
| 1191 | |
| 1192 | /* Tunnel socket destruct hook. |
| 1193 | * The tunnel context is deleted only when all session sockets have been |
| 1194 | * closed. |
| 1195 | */ |
stephen hemminger | fc13084 | 2010-10-21 07:50:46 +0000 | [diff] [blame] | 1196 | static void l2tp_tunnel_destruct(struct sock *sk) |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1197 | { |
| 1198 | struct l2tp_tunnel *tunnel; |
| 1199 | |
| 1200 | tunnel = sk->sk_user_data; |
| 1201 | if (tunnel == NULL) |
| 1202 | goto end; |
| 1203 | |
| 1204 | PRINTK(tunnel->debug, L2TP_MSG_CONTROL, KERN_INFO, |
| 1205 | "%s: closing...\n", tunnel->name); |
| 1206 | |
| 1207 | /* Close all sessions */ |
| 1208 | l2tp_tunnel_closeall(tunnel); |
| 1209 | |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 1210 | switch (tunnel->encap) { |
| 1211 | case L2TP_ENCAPTYPE_UDP: |
| 1212 | /* No longer an encapsulation socket. See net/ipv4/udp.c */ |
| 1213 | (udp_sk(sk))->encap_type = 0; |
| 1214 | (udp_sk(sk))->encap_rcv = NULL; |
| 1215 | break; |
| 1216 | case L2TP_ENCAPTYPE_IP: |
| 1217 | break; |
| 1218 | } |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1219 | |
| 1220 | /* Remove hooks into tunnel socket */ |
| 1221 | tunnel->sock = NULL; |
| 1222 | sk->sk_destruct = tunnel->old_sk_destruct; |
| 1223 | sk->sk_user_data = NULL; |
| 1224 | |
| 1225 | /* Call the original destructor */ |
| 1226 | if (sk->sk_destruct) |
| 1227 | (*sk->sk_destruct)(sk); |
| 1228 | |
| 1229 | /* We're finished with the socket */ |
| 1230 | l2tp_tunnel_dec_refcount(tunnel); |
| 1231 | |
| 1232 | end: |
| 1233 | return; |
| 1234 | } |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1235 | |
| 1236 | /* When the tunnel is closed, all the attached sessions need to go too. |
| 1237 | */ |
stephen hemminger | fc13084 | 2010-10-21 07:50:46 +0000 | [diff] [blame] | 1238 | static void l2tp_tunnel_closeall(struct l2tp_tunnel *tunnel) |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1239 | { |
| 1240 | int hash; |
| 1241 | struct hlist_node *walk; |
| 1242 | struct hlist_node *tmp; |
| 1243 | struct l2tp_session *session; |
| 1244 | |
| 1245 | BUG_ON(tunnel == NULL); |
| 1246 | |
| 1247 | PRINTK(tunnel->debug, L2TP_MSG_CONTROL, KERN_INFO, |
| 1248 | "%s: closing all sessions...\n", tunnel->name); |
| 1249 | |
| 1250 | write_lock_bh(&tunnel->hlist_lock); |
| 1251 | for (hash = 0; hash < L2TP_HASH_SIZE; hash++) { |
| 1252 | again: |
| 1253 | hlist_for_each_safe(walk, tmp, &tunnel->session_hlist[hash]) { |
| 1254 | session = hlist_entry(walk, struct l2tp_session, hlist); |
| 1255 | |
| 1256 | PRINTK(session->debug, L2TP_MSG_CONTROL, KERN_INFO, |
| 1257 | "%s: closing session\n", session->name); |
| 1258 | |
| 1259 | hlist_del_init(&session->hlist); |
| 1260 | |
| 1261 | /* Since we should hold the sock lock while |
| 1262 | * doing any unbinding, we need to release the |
| 1263 | * lock we're holding before taking that lock. |
| 1264 | * Hold a reference to the sock so it doesn't |
| 1265 | * disappear as we're jumping between locks. |
| 1266 | */ |
| 1267 | if (session->ref != NULL) |
| 1268 | (*session->ref)(session); |
| 1269 | |
| 1270 | write_unlock_bh(&tunnel->hlist_lock); |
| 1271 | |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 1272 | if (tunnel->version != L2TP_HDR_VER_2) { |
| 1273 | struct l2tp_net *pn = l2tp_pernet(tunnel->l2tp_net); |
| 1274 | |
James Chapman | e02d494 | 2010-04-02 06:19:16 +0000 | [diff] [blame] | 1275 | spin_lock_bh(&pn->l2tp_session_hlist_lock); |
| 1276 | hlist_del_init_rcu(&session->global_hlist); |
| 1277 | spin_unlock_bh(&pn->l2tp_session_hlist_lock); |
| 1278 | synchronize_rcu(); |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 1279 | } |
| 1280 | |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1281 | if (session->session_close != NULL) |
| 1282 | (*session->session_close)(session); |
| 1283 | |
| 1284 | if (session->deref != NULL) |
| 1285 | (*session->deref)(session); |
| 1286 | |
| 1287 | write_lock_bh(&tunnel->hlist_lock); |
| 1288 | |
| 1289 | /* Now restart from the beginning of this hash |
| 1290 | * chain. We always remove a session from the |
| 1291 | * list so we are guaranteed to make forward |
| 1292 | * progress. |
| 1293 | */ |
| 1294 | goto again; |
| 1295 | } |
| 1296 | } |
| 1297 | write_unlock_bh(&tunnel->hlist_lock); |
| 1298 | } |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1299 | |
| 1300 | /* Really kill the tunnel. |
| 1301 | * Come here only when all sessions have been cleared from the tunnel. |
| 1302 | */ |
stephen hemminger | fc13084 | 2010-10-21 07:50:46 +0000 | [diff] [blame] | 1303 | static void l2tp_tunnel_free(struct l2tp_tunnel *tunnel) |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1304 | { |
| 1305 | struct l2tp_net *pn = l2tp_pernet(tunnel->l2tp_net); |
| 1306 | |
| 1307 | BUG_ON(atomic_read(&tunnel->ref_count) != 0); |
| 1308 | BUG_ON(tunnel->sock != NULL); |
| 1309 | |
| 1310 | PRINTK(tunnel->debug, L2TP_MSG_CONTROL, KERN_INFO, |
| 1311 | "%s: free...\n", tunnel->name); |
| 1312 | |
| 1313 | /* Remove from tunnel list */ |
James Chapman | e02d494 | 2010-04-02 06:19:16 +0000 | [diff] [blame] | 1314 | spin_lock_bh(&pn->l2tp_tunnel_list_lock); |
| 1315 | list_del_rcu(&tunnel->list); |
| 1316 | spin_unlock_bh(&pn->l2tp_tunnel_list_lock); |
| 1317 | synchronize_rcu(); |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1318 | |
| 1319 | atomic_dec(&l2tp_tunnel_count); |
| 1320 | kfree(tunnel); |
| 1321 | } |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1322 | |
James Chapman | 789a4a2 | 2010-04-02 06:19:40 +0000 | [diff] [blame] | 1323 | /* Create a socket for the tunnel, if one isn't set up by |
| 1324 | * userspace. This is used for static tunnels where there is no |
| 1325 | * managing L2TP daemon. |
| 1326 | */ |
| 1327 | static int l2tp_tunnel_sock_create(u32 tunnel_id, u32 peer_tunnel_id, struct l2tp_tunnel_cfg *cfg, struct socket **sockp) |
| 1328 | { |
| 1329 | int err = -EINVAL; |
| 1330 | struct sockaddr_in udp_addr; |
| 1331 | struct sockaddr_l2tpip ip_addr; |
Eric Dumazet | 7bddd0d | 2010-04-04 01:02:46 -0700 | [diff] [blame] | 1332 | struct socket *sock = NULL; |
James Chapman | 789a4a2 | 2010-04-02 06:19:40 +0000 | [diff] [blame] | 1333 | |
| 1334 | switch (cfg->encap) { |
| 1335 | case L2TP_ENCAPTYPE_UDP: |
| 1336 | err = sock_create(AF_INET, SOCK_DGRAM, 0, sockp); |
| 1337 | if (err < 0) |
| 1338 | goto out; |
| 1339 | |
| 1340 | sock = *sockp; |
| 1341 | |
| 1342 | memset(&udp_addr, 0, sizeof(udp_addr)); |
| 1343 | udp_addr.sin_family = AF_INET; |
| 1344 | udp_addr.sin_addr = cfg->local_ip; |
| 1345 | udp_addr.sin_port = htons(cfg->local_udp_port); |
| 1346 | err = kernel_bind(sock, (struct sockaddr *) &udp_addr, sizeof(udp_addr)); |
| 1347 | if (err < 0) |
| 1348 | goto out; |
| 1349 | |
| 1350 | udp_addr.sin_family = AF_INET; |
| 1351 | udp_addr.sin_addr = cfg->peer_ip; |
| 1352 | udp_addr.sin_port = htons(cfg->peer_udp_port); |
| 1353 | err = kernel_connect(sock, (struct sockaddr *) &udp_addr, sizeof(udp_addr), 0); |
| 1354 | if (err < 0) |
| 1355 | goto out; |
| 1356 | |
| 1357 | if (!cfg->use_udp_checksums) |
| 1358 | sock->sk->sk_no_check = UDP_CSUM_NOXMIT; |
| 1359 | |
| 1360 | break; |
| 1361 | |
| 1362 | case L2TP_ENCAPTYPE_IP: |
| 1363 | err = sock_create(AF_INET, SOCK_DGRAM, IPPROTO_L2TP, sockp); |
| 1364 | if (err < 0) |
| 1365 | goto out; |
| 1366 | |
| 1367 | sock = *sockp; |
| 1368 | |
| 1369 | memset(&ip_addr, 0, sizeof(ip_addr)); |
| 1370 | ip_addr.l2tp_family = AF_INET; |
| 1371 | ip_addr.l2tp_addr = cfg->local_ip; |
| 1372 | ip_addr.l2tp_conn_id = tunnel_id; |
| 1373 | err = kernel_bind(sock, (struct sockaddr *) &ip_addr, sizeof(ip_addr)); |
| 1374 | if (err < 0) |
| 1375 | goto out; |
| 1376 | |
| 1377 | ip_addr.l2tp_family = AF_INET; |
| 1378 | ip_addr.l2tp_addr = cfg->peer_ip; |
| 1379 | ip_addr.l2tp_conn_id = peer_tunnel_id; |
| 1380 | err = kernel_connect(sock, (struct sockaddr *) &ip_addr, sizeof(ip_addr), 0); |
| 1381 | if (err < 0) |
| 1382 | goto out; |
| 1383 | |
| 1384 | break; |
| 1385 | |
| 1386 | default: |
| 1387 | goto out; |
| 1388 | } |
| 1389 | |
| 1390 | out: |
| 1391 | if ((err < 0) && sock) { |
| 1392 | sock_release(sock); |
| 1393 | *sockp = NULL; |
| 1394 | } |
| 1395 | |
| 1396 | return err; |
| 1397 | } |
| 1398 | |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1399 | 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) |
| 1400 | { |
| 1401 | struct l2tp_tunnel *tunnel = NULL; |
| 1402 | int err; |
| 1403 | struct socket *sock = NULL; |
| 1404 | struct sock *sk = NULL; |
| 1405 | struct l2tp_net *pn; |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 1406 | enum l2tp_encap_type encap = L2TP_ENCAPTYPE_UDP; |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1407 | |
| 1408 | /* Get the tunnel socket from the fd, which was opened by |
James Chapman | 789a4a2 | 2010-04-02 06:19:40 +0000 | [diff] [blame] | 1409 | * the userspace L2TP daemon. If not specified, create a |
| 1410 | * kernel socket. |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1411 | */ |
James Chapman | 789a4a2 | 2010-04-02 06:19:40 +0000 | [diff] [blame] | 1412 | if (fd < 0) { |
| 1413 | err = l2tp_tunnel_sock_create(tunnel_id, peer_tunnel_id, cfg, &sock); |
| 1414 | if (err < 0) |
| 1415 | goto err; |
| 1416 | } else { |
| 1417 | err = -EBADF; |
| 1418 | sock = sockfd_lookup(fd, &err); |
| 1419 | if (!sock) { |
| 1420 | printk(KERN_ERR "tunl %hu: sockfd_lookup(fd=%d) returned %d\n", |
| 1421 | tunnel_id, fd, err); |
| 1422 | goto err; |
| 1423 | } |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1424 | } |
| 1425 | |
| 1426 | sk = sock->sk; |
| 1427 | |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 1428 | if (cfg != NULL) |
| 1429 | encap = cfg->encap; |
| 1430 | |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1431 | /* Quick sanity checks */ |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 1432 | switch (encap) { |
| 1433 | case L2TP_ENCAPTYPE_UDP: |
| 1434 | err = -EPROTONOSUPPORT; |
| 1435 | if (sk->sk_protocol != IPPROTO_UDP) { |
| 1436 | printk(KERN_ERR "tunl %hu: fd %d wrong protocol, got %d, expected %d\n", |
| 1437 | tunnel_id, fd, sk->sk_protocol, IPPROTO_UDP); |
| 1438 | goto err; |
| 1439 | } |
| 1440 | break; |
| 1441 | case L2TP_ENCAPTYPE_IP: |
| 1442 | err = -EPROTONOSUPPORT; |
| 1443 | if (sk->sk_protocol != IPPROTO_L2TP) { |
| 1444 | printk(KERN_ERR "tunl %hu: fd %d wrong protocol, got %d, expected %d\n", |
| 1445 | tunnel_id, fd, sk->sk_protocol, IPPROTO_L2TP); |
| 1446 | goto err; |
| 1447 | } |
| 1448 | break; |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1449 | } |
| 1450 | |
| 1451 | /* Check if this socket has already been prepped */ |
| 1452 | tunnel = (struct l2tp_tunnel *)sk->sk_user_data; |
| 1453 | if (tunnel != NULL) { |
| 1454 | /* This socket has already been prepped */ |
| 1455 | err = -EBUSY; |
| 1456 | goto err; |
| 1457 | } |
| 1458 | |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1459 | tunnel = kzalloc(sizeof(struct l2tp_tunnel), GFP_KERNEL); |
| 1460 | if (tunnel == NULL) { |
| 1461 | err = -ENOMEM; |
| 1462 | goto err; |
| 1463 | } |
| 1464 | |
| 1465 | tunnel->version = version; |
| 1466 | tunnel->tunnel_id = tunnel_id; |
| 1467 | tunnel->peer_tunnel_id = peer_tunnel_id; |
| 1468 | tunnel->debug = L2TP_DEFAULT_DEBUG_FLAGS; |
| 1469 | |
| 1470 | tunnel->magic = L2TP_TUNNEL_MAGIC; |
| 1471 | sprintf(&tunnel->name[0], "tunl %u", tunnel_id); |
| 1472 | rwlock_init(&tunnel->hlist_lock); |
| 1473 | |
| 1474 | /* The net we belong to */ |
| 1475 | tunnel->l2tp_net = net; |
| 1476 | pn = l2tp_pernet(net); |
| 1477 | |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 1478 | if (cfg != NULL) |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1479 | tunnel->debug = cfg->debug; |
| 1480 | |
| 1481 | /* Mark socket as an encapsulation socket. See net/ipv4/udp.c */ |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 1482 | tunnel->encap = encap; |
| 1483 | if (encap == L2TP_ENCAPTYPE_UDP) { |
| 1484 | /* Mark socket as an encapsulation socket. See net/ipv4/udp.c */ |
| 1485 | udp_sk(sk)->encap_type = UDP_ENCAP_L2TPINUDP; |
| 1486 | udp_sk(sk)->encap_rcv = l2tp_udp_encap_recv; |
Benjamin LaHaise | d2cf336 | 2012-04-27 08:24:18 +0000 | [diff] [blame^] | 1487 | #if IS_ENABLED(CONFIG_IPV6) |
| 1488 | if (sk->sk_family == PF_INET6) |
| 1489 | udpv6_encap_enable(); |
| 1490 | else |
| 1491 | #endif |
Eric Dumazet | 447167b | 2012-04-11 23:05:28 +0000 | [diff] [blame] | 1492 | udp_encap_enable(); |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 1493 | } |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1494 | |
| 1495 | sk->sk_user_data = tunnel; |
| 1496 | |
| 1497 | /* Hook on the tunnel socket destructor so that we can cleanup |
| 1498 | * if the tunnel socket goes away. |
| 1499 | */ |
| 1500 | tunnel->old_sk_destruct = sk->sk_destruct; |
| 1501 | sk->sk_destruct = &l2tp_tunnel_destruct; |
| 1502 | tunnel->sock = sk; |
| 1503 | sk->sk_allocation = GFP_ATOMIC; |
| 1504 | |
| 1505 | /* Add tunnel to our list */ |
| 1506 | INIT_LIST_HEAD(&tunnel->list); |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1507 | atomic_inc(&l2tp_tunnel_count); |
| 1508 | |
| 1509 | /* Bump the reference count. The tunnel context is deleted |
Eric Dumazet | 1769192 | 2011-05-11 18:22:36 +0000 | [diff] [blame] | 1510 | * only when this drops to zero. Must be done before list insertion |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1511 | */ |
| 1512 | l2tp_tunnel_inc_refcount(tunnel); |
Eric Dumazet | 1769192 | 2011-05-11 18:22:36 +0000 | [diff] [blame] | 1513 | spin_lock_bh(&pn->l2tp_tunnel_list_lock); |
| 1514 | list_add_rcu(&tunnel->list, &pn->l2tp_tunnel_list); |
| 1515 | spin_unlock_bh(&pn->l2tp_tunnel_list_lock); |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1516 | |
| 1517 | err = 0; |
| 1518 | err: |
| 1519 | if (tunnelp) |
| 1520 | *tunnelp = tunnel; |
| 1521 | |
James Chapman | 789a4a2 | 2010-04-02 06:19:40 +0000 | [diff] [blame] | 1522 | /* If tunnel's socket was created by the kernel, it doesn't |
| 1523 | * have a file. |
| 1524 | */ |
| 1525 | if (sock && sock->file) |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1526 | sockfd_put(sock); |
| 1527 | |
| 1528 | return err; |
| 1529 | } |
| 1530 | EXPORT_SYMBOL_GPL(l2tp_tunnel_create); |
| 1531 | |
James Chapman | 309795f | 2010-04-02 06:19:10 +0000 | [diff] [blame] | 1532 | /* This function is used by the netlink TUNNEL_DELETE command. |
| 1533 | */ |
| 1534 | int l2tp_tunnel_delete(struct l2tp_tunnel *tunnel) |
| 1535 | { |
| 1536 | int err = 0; |
James Chapman | 789a4a2 | 2010-04-02 06:19:40 +0000 | [diff] [blame] | 1537 | struct socket *sock = tunnel->sock ? tunnel->sock->sk_socket : NULL; |
James Chapman | 309795f | 2010-04-02 06:19:10 +0000 | [diff] [blame] | 1538 | |
| 1539 | /* Force the tunnel socket to close. This will eventually |
| 1540 | * cause the tunnel to be deleted via the normal socket close |
| 1541 | * mechanisms when userspace closes the tunnel socket. |
| 1542 | */ |
James Chapman | 789a4a2 | 2010-04-02 06:19:40 +0000 | [diff] [blame] | 1543 | if (sock != NULL) { |
| 1544 | err = inet_shutdown(sock, 2); |
| 1545 | |
| 1546 | /* If the tunnel's socket was created by the kernel, |
| 1547 | * close the socket here since the socket was not |
| 1548 | * created by userspace. |
| 1549 | */ |
| 1550 | if (sock->file == NULL) |
| 1551 | err = inet_release(sock); |
| 1552 | } |
James Chapman | 309795f | 2010-04-02 06:19:10 +0000 | [diff] [blame] | 1553 | |
| 1554 | return err; |
| 1555 | } |
| 1556 | EXPORT_SYMBOL_GPL(l2tp_tunnel_delete); |
| 1557 | |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1558 | /* Really kill the session. |
| 1559 | */ |
| 1560 | void l2tp_session_free(struct l2tp_session *session) |
| 1561 | { |
| 1562 | struct l2tp_tunnel *tunnel; |
| 1563 | |
| 1564 | BUG_ON(atomic_read(&session->ref_count) != 0); |
| 1565 | |
| 1566 | tunnel = session->tunnel; |
| 1567 | if (tunnel != NULL) { |
| 1568 | BUG_ON(tunnel->magic != L2TP_TUNNEL_MAGIC); |
| 1569 | |
| 1570 | /* Delete the session from the hash */ |
| 1571 | write_lock_bh(&tunnel->hlist_lock); |
| 1572 | hlist_del_init(&session->hlist); |
| 1573 | write_unlock_bh(&tunnel->hlist_lock); |
| 1574 | |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 1575 | /* Unlink from the global hash if not L2TPv2 */ |
| 1576 | if (tunnel->version != L2TP_HDR_VER_2) { |
| 1577 | struct l2tp_net *pn = l2tp_pernet(tunnel->l2tp_net); |
| 1578 | |
James Chapman | e02d494 | 2010-04-02 06:19:16 +0000 | [diff] [blame] | 1579 | spin_lock_bh(&pn->l2tp_session_hlist_lock); |
| 1580 | hlist_del_init_rcu(&session->global_hlist); |
| 1581 | spin_unlock_bh(&pn->l2tp_session_hlist_lock); |
| 1582 | synchronize_rcu(); |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 1583 | } |
| 1584 | |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1585 | if (session->session_id != 0) |
| 1586 | atomic_dec(&l2tp_session_count); |
| 1587 | |
| 1588 | sock_put(tunnel->sock); |
| 1589 | |
| 1590 | /* This will delete the tunnel context if this |
| 1591 | * is the last session on the tunnel. |
| 1592 | */ |
| 1593 | session->tunnel = NULL; |
| 1594 | l2tp_tunnel_dec_refcount(tunnel); |
| 1595 | } |
| 1596 | |
| 1597 | kfree(session); |
| 1598 | |
| 1599 | return; |
| 1600 | } |
| 1601 | EXPORT_SYMBOL_GPL(l2tp_session_free); |
| 1602 | |
James Chapman | 309795f | 2010-04-02 06:19:10 +0000 | [diff] [blame] | 1603 | /* This function is used by the netlink SESSION_DELETE command and by |
| 1604 | pseudowire modules. |
| 1605 | */ |
| 1606 | int l2tp_session_delete(struct l2tp_session *session) |
| 1607 | { |
| 1608 | if (session->session_close != NULL) |
| 1609 | (*session->session_close)(session); |
| 1610 | |
| 1611 | l2tp_session_dec_refcount(session); |
| 1612 | |
| 1613 | return 0; |
| 1614 | } |
| 1615 | EXPORT_SYMBOL_GPL(l2tp_session_delete); |
| 1616 | |
| 1617 | |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 1618 | /* We come here whenever a session's send_seq, cookie_len or |
| 1619 | * l2specific_len parameters are set. |
| 1620 | */ |
stephen hemminger | fc13084 | 2010-10-21 07:50:46 +0000 | [diff] [blame] | 1621 | static void l2tp_session_set_header_len(struct l2tp_session *session, int version) |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 1622 | { |
| 1623 | if (version == L2TP_HDR_VER_2) { |
| 1624 | session->hdr_len = 6; |
| 1625 | if (session->send_seq) |
| 1626 | session->hdr_len += 4; |
| 1627 | } else { |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 1628 | session->hdr_len = 4 + session->cookie_len + session->l2specific_len + session->offset; |
| 1629 | if (session->tunnel->encap == L2TP_ENCAPTYPE_UDP) |
| 1630 | session->hdr_len += 4; |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 1631 | } |
| 1632 | |
| 1633 | } |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 1634 | |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1635 | 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) |
| 1636 | { |
| 1637 | struct l2tp_session *session; |
| 1638 | |
| 1639 | session = kzalloc(sizeof(struct l2tp_session) + priv_size, GFP_KERNEL); |
| 1640 | if (session != NULL) { |
| 1641 | session->magic = L2TP_SESSION_MAGIC; |
| 1642 | session->tunnel = tunnel; |
| 1643 | |
| 1644 | session->session_id = session_id; |
| 1645 | session->peer_session_id = peer_session_id; |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 1646 | session->nr = 1; |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1647 | |
| 1648 | sprintf(&session->name[0], "sess %u/%u", |
| 1649 | tunnel->tunnel_id, session->session_id); |
| 1650 | |
| 1651 | skb_queue_head_init(&session->reorder_q); |
| 1652 | |
| 1653 | INIT_HLIST_NODE(&session->hlist); |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 1654 | INIT_HLIST_NODE(&session->global_hlist); |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1655 | |
| 1656 | /* Inherit debug options from tunnel */ |
| 1657 | session->debug = tunnel->debug; |
| 1658 | |
| 1659 | if (cfg) { |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 1660 | session->pwtype = cfg->pw_type; |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1661 | session->debug = cfg->debug; |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1662 | session->mtu = cfg->mtu; |
| 1663 | session->mru = cfg->mru; |
| 1664 | session->send_seq = cfg->send_seq; |
| 1665 | session->recv_seq = cfg->recv_seq; |
| 1666 | session->lns_mode = cfg->lns_mode; |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 1667 | session->reorder_timeout = cfg->reorder_timeout; |
| 1668 | session->offset = cfg->offset; |
| 1669 | session->l2specific_type = cfg->l2specific_type; |
| 1670 | session->l2specific_len = cfg->l2specific_len; |
| 1671 | session->cookie_len = cfg->cookie_len; |
| 1672 | memcpy(&session->cookie[0], &cfg->cookie[0], cfg->cookie_len); |
| 1673 | session->peer_cookie_len = cfg->peer_cookie_len; |
| 1674 | memcpy(&session->peer_cookie[0], &cfg->peer_cookie[0], cfg->peer_cookie_len); |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1675 | } |
| 1676 | |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 1677 | if (tunnel->version == L2TP_HDR_VER_2) |
| 1678 | session->build_header = l2tp_build_l2tpv2_header; |
| 1679 | else |
| 1680 | session->build_header = l2tp_build_l2tpv3_header; |
| 1681 | |
| 1682 | l2tp_session_set_header_len(session, tunnel->version); |
| 1683 | |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1684 | /* Bump the reference count. The session context is deleted |
| 1685 | * only when this drops to zero. |
| 1686 | */ |
| 1687 | l2tp_session_inc_refcount(session); |
| 1688 | l2tp_tunnel_inc_refcount(tunnel); |
| 1689 | |
| 1690 | /* Ensure tunnel socket isn't deleted */ |
| 1691 | sock_hold(tunnel->sock); |
| 1692 | |
| 1693 | /* Add session to the tunnel's hash list */ |
| 1694 | write_lock_bh(&tunnel->hlist_lock); |
| 1695 | hlist_add_head(&session->hlist, |
| 1696 | l2tp_session_id_hash(tunnel, session_id)); |
| 1697 | write_unlock_bh(&tunnel->hlist_lock); |
| 1698 | |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 1699 | /* And to the global session list if L2TPv3 */ |
| 1700 | if (tunnel->version != L2TP_HDR_VER_2) { |
| 1701 | struct l2tp_net *pn = l2tp_pernet(tunnel->l2tp_net); |
| 1702 | |
James Chapman | e02d494 | 2010-04-02 06:19:16 +0000 | [diff] [blame] | 1703 | spin_lock_bh(&pn->l2tp_session_hlist_lock); |
| 1704 | hlist_add_head_rcu(&session->global_hlist, |
| 1705 | l2tp_session_id_hash_2(pn, session_id)); |
| 1706 | spin_unlock_bh(&pn->l2tp_session_hlist_lock); |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 1707 | } |
| 1708 | |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1709 | /* Ignore management session in session count value */ |
| 1710 | if (session->session_id != 0) |
| 1711 | atomic_inc(&l2tp_session_count); |
| 1712 | } |
| 1713 | |
| 1714 | return session; |
| 1715 | } |
| 1716 | EXPORT_SYMBOL_GPL(l2tp_session_create); |
| 1717 | |
| 1718 | /***************************************************************************** |
| 1719 | * Init and cleanup |
| 1720 | *****************************************************************************/ |
| 1721 | |
| 1722 | static __net_init int l2tp_init_net(struct net *net) |
| 1723 | { |
Jiri Pirko | e773aaf | 2010-04-23 00:53:39 +0000 | [diff] [blame] | 1724 | struct l2tp_net *pn = net_generic(net, l2tp_net_id); |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 1725 | int hash; |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1726 | |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1727 | INIT_LIST_HEAD(&pn->l2tp_tunnel_list); |
James Chapman | e02d494 | 2010-04-02 06:19:16 +0000 | [diff] [blame] | 1728 | spin_lock_init(&pn->l2tp_tunnel_list_lock); |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1729 | |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 1730 | for (hash = 0; hash < L2TP_HASH_SIZE_2; hash++) |
| 1731 | INIT_HLIST_HEAD(&pn->l2tp_session_hlist[hash]); |
| 1732 | |
James Chapman | e02d494 | 2010-04-02 06:19:16 +0000 | [diff] [blame] | 1733 | spin_lock_init(&pn->l2tp_session_hlist_lock); |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 1734 | |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1735 | return 0; |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1736 | } |
| 1737 | |
| 1738 | static struct pernet_operations l2tp_net_ops = { |
| 1739 | .init = l2tp_init_net, |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1740 | .id = &l2tp_net_id, |
| 1741 | .size = sizeof(struct l2tp_net), |
| 1742 | }; |
| 1743 | |
| 1744 | static int __init l2tp_init(void) |
| 1745 | { |
| 1746 | int rc = 0; |
| 1747 | |
| 1748 | rc = register_pernet_device(&l2tp_net_ops); |
| 1749 | if (rc) |
| 1750 | goto out; |
| 1751 | |
| 1752 | printk(KERN_INFO "L2TP core driver, %s\n", L2TP_DRV_VERSION); |
| 1753 | |
| 1754 | out: |
| 1755 | return rc; |
| 1756 | } |
| 1757 | |
| 1758 | static void __exit l2tp_exit(void) |
| 1759 | { |
| 1760 | unregister_pernet_device(&l2tp_net_ops); |
| 1761 | } |
| 1762 | |
| 1763 | module_init(l2tp_init); |
| 1764 | module_exit(l2tp_exit); |
| 1765 | |
| 1766 | MODULE_AUTHOR("James Chapman <jchapman@katalix.com>"); |
| 1767 | MODULE_DESCRIPTION("L2TP core"); |
| 1768 | MODULE_LICENSE("GPL"); |
| 1769 | MODULE_VERSION(L2TP_DRV_VERSION); |
| 1770 | |