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> |
David S. Miller | d499bd2 | 2012-04-30 13:21:28 -0400 | [diff] [blame^] | 59 | #include <net/ip6_checksum.h> |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 60 | |
| 61 | #include <asm/byteorder.h> |
Arun Sharma | 60063497 | 2011-07-26 16:09:06 -0700 | [diff] [blame] | 62 | #include <linux/atomic.h> |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 63 | |
| 64 | #include "l2tp_core.h" |
| 65 | |
| 66 | #define L2TP_DRV_VERSION "V2.0" |
| 67 | |
| 68 | /* L2TP header constants */ |
| 69 | #define L2TP_HDRFLAG_T 0x8000 |
| 70 | #define L2TP_HDRFLAG_L 0x4000 |
| 71 | #define L2TP_HDRFLAG_S 0x0800 |
| 72 | #define L2TP_HDRFLAG_O 0x0200 |
| 73 | #define L2TP_HDRFLAG_P 0x0100 |
| 74 | |
| 75 | #define L2TP_HDR_VER_MASK 0x000F |
| 76 | #define L2TP_HDR_VER_2 0x0002 |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 77 | #define L2TP_HDR_VER_3 0x0003 |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 78 | |
| 79 | /* L2TPv3 default L2-specific sublayer */ |
| 80 | #define L2TP_SLFLAG_S 0x40000000 |
| 81 | #define L2TP_SL_SEQ_MASK 0x00ffffff |
| 82 | |
| 83 | #define L2TP_HDR_SIZE_SEQ 10 |
| 84 | #define L2TP_HDR_SIZE_NOSEQ 6 |
| 85 | |
| 86 | /* Default trace flags */ |
| 87 | #define L2TP_DEFAULT_DEBUG_FLAGS 0 |
| 88 | |
| 89 | #define PRINTK(_mask, _type, _lvl, _fmt, args...) \ |
| 90 | do { \ |
| 91 | if ((_mask) & (_type)) \ |
| 92 | printk(_lvl "L2TP: " _fmt, ##args); \ |
| 93 | } while (0) |
| 94 | |
| 95 | /* Private data stored for received packets in the skb. |
| 96 | */ |
| 97 | struct l2tp_skb_cb { |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 98 | u32 ns; |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 99 | u16 has_seq; |
| 100 | u16 length; |
| 101 | unsigned long expires; |
| 102 | }; |
| 103 | |
| 104 | #define L2TP_SKB_CB(skb) ((struct l2tp_skb_cb *) &skb->cb[sizeof(struct inet_skb_parm)]) |
| 105 | |
| 106 | static atomic_t l2tp_tunnel_count; |
| 107 | static atomic_t l2tp_session_count; |
| 108 | |
| 109 | /* per-net private data for this module */ |
| 110 | static unsigned int l2tp_net_id; |
| 111 | struct l2tp_net { |
| 112 | struct list_head l2tp_tunnel_list; |
James Chapman | e02d494 | 2010-04-02 06:19:16 +0000 | [diff] [blame] | 113 | spinlock_t l2tp_tunnel_list_lock; |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 114 | struct hlist_head l2tp_session_hlist[L2TP_HASH_SIZE_2]; |
James Chapman | e02d494 | 2010-04-02 06:19:16 +0000 | [diff] [blame] | 115 | spinlock_t l2tp_session_hlist_lock; |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 116 | }; |
| 117 | |
stephen hemminger | fc13084 | 2010-10-21 07:50:46 +0000 | [diff] [blame] | 118 | static void l2tp_session_set_header_len(struct l2tp_session *session, int version); |
| 119 | static void l2tp_tunnel_free(struct l2tp_tunnel *tunnel); |
| 120 | static void l2tp_tunnel_closeall(struct l2tp_tunnel *tunnel); |
| 121 | |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 122 | static inline struct l2tp_net *l2tp_pernet(struct net *net) |
| 123 | { |
| 124 | BUG_ON(!net); |
| 125 | |
| 126 | return net_generic(net, l2tp_net_id); |
| 127 | } |
| 128 | |
stephen hemminger | fc13084 | 2010-10-21 07:50:46 +0000 | [diff] [blame] | 129 | |
| 130 | /* Tunnel reference counts. Incremented per session that is added to |
| 131 | * the tunnel. |
| 132 | */ |
| 133 | static inline void l2tp_tunnel_inc_refcount_1(struct l2tp_tunnel *tunnel) |
| 134 | { |
| 135 | atomic_inc(&tunnel->ref_count); |
| 136 | } |
| 137 | |
| 138 | static inline void l2tp_tunnel_dec_refcount_1(struct l2tp_tunnel *tunnel) |
| 139 | { |
| 140 | if (atomic_dec_and_test(&tunnel->ref_count)) |
| 141 | l2tp_tunnel_free(tunnel); |
| 142 | } |
| 143 | #ifdef L2TP_REFCNT_DEBUG |
| 144 | #define l2tp_tunnel_inc_refcount(_t) do { \ |
| 145 | printk(KERN_DEBUG "l2tp_tunnel_inc_refcount: %s:%d %s: cnt=%d\n", __func__, __LINE__, (_t)->name, atomic_read(&_t->ref_count)); \ |
| 146 | l2tp_tunnel_inc_refcount_1(_t); \ |
| 147 | } while (0) |
| 148 | #define l2tp_tunnel_dec_refcount(_t) do { \ |
| 149 | printk(KERN_DEBUG "l2tp_tunnel_dec_refcount: %s:%d %s: cnt=%d\n", __func__, __LINE__, (_t)->name, atomic_read(&_t->ref_count)); \ |
| 150 | l2tp_tunnel_dec_refcount_1(_t); \ |
| 151 | } while (0) |
| 152 | #else |
| 153 | #define l2tp_tunnel_inc_refcount(t) l2tp_tunnel_inc_refcount_1(t) |
| 154 | #define l2tp_tunnel_dec_refcount(t) l2tp_tunnel_dec_refcount_1(t) |
| 155 | #endif |
| 156 | |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 157 | /* Session hash global list for L2TPv3. |
| 158 | * The session_id SHOULD be random according to RFC3931, but several |
| 159 | * L2TP implementations use incrementing session_ids. So we do a real |
| 160 | * hash on the session_id, rather than a simple bitmask. |
| 161 | */ |
| 162 | static inline struct hlist_head * |
| 163 | l2tp_session_id_hash_2(struct l2tp_net *pn, u32 session_id) |
| 164 | { |
| 165 | return &pn->l2tp_session_hlist[hash_32(session_id, L2TP_HASH_BITS_2)]; |
| 166 | |
| 167 | } |
| 168 | |
| 169 | /* Lookup a session by id in the global session list |
| 170 | */ |
| 171 | static struct l2tp_session *l2tp_session_find_2(struct net *net, u32 session_id) |
| 172 | { |
| 173 | struct l2tp_net *pn = l2tp_pernet(net); |
| 174 | struct hlist_head *session_list = |
| 175 | l2tp_session_id_hash_2(pn, session_id); |
| 176 | struct l2tp_session *session; |
| 177 | struct hlist_node *walk; |
| 178 | |
James Chapman | e02d494 | 2010-04-02 06:19:16 +0000 | [diff] [blame] | 179 | rcu_read_lock_bh(); |
| 180 | hlist_for_each_entry_rcu(session, walk, session_list, global_hlist) { |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 181 | if (session->session_id == session_id) { |
James Chapman | e02d494 | 2010-04-02 06:19:16 +0000 | [diff] [blame] | 182 | rcu_read_unlock_bh(); |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 183 | return session; |
| 184 | } |
| 185 | } |
James Chapman | e02d494 | 2010-04-02 06:19:16 +0000 | [diff] [blame] | 186 | rcu_read_unlock_bh(); |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 187 | |
| 188 | return NULL; |
| 189 | } |
| 190 | |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 191 | /* Session hash list. |
| 192 | * The session_id SHOULD be random according to RFC2661, but several |
| 193 | * L2TP implementations (Cisco and Microsoft) use incrementing |
| 194 | * session_ids. So we do a real hash on the session_id, rather than a |
| 195 | * simple bitmask. |
| 196 | */ |
| 197 | static inline struct hlist_head * |
| 198 | l2tp_session_id_hash(struct l2tp_tunnel *tunnel, u32 session_id) |
| 199 | { |
| 200 | return &tunnel->session_hlist[hash_32(session_id, L2TP_HASH_BITS)]; |
| 201 | } |
| 202 | |
| 203 | /* Lookup a session by id |
| 204 | */ |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 205 | 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] | 206 | { |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 207 | struct hlist_head *session_list; |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 208 | struct l2tp_session *session; |
| 209 | struct hlist_node *walk; |
| 210 | |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 211 | /* In L2TPv3, session_ids are unique over all tunnels and we |
| 212 | * sometimes need to look them up before we know the |
| 213 | * tunnel. |
| 214 | */ |
| 215 | if (tunnel == NULL) |
| 216 | return l2tp_session_find_2(net, session_id); |
| 217 | |
| 218 | session_list = l2tp_session_id_hash(tunnel, session_id); |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 219 | read_lock_bh(&tunnel->hlist_lock); |
| 220 | hlist_for_each_entry(session, walk, session_list, hlist) { |
| 221 | if (session->session_id == session_id) { |
| 222 | read_unlock_bh(&tunnel->hlist_lock); |
| 223 | return session; |
| 224 | } |
| 225 | } |
| 226 | read_unlock_bh(&tunnel->hlist_lock); |
| 227 | |
| 228 | return NULL; |
| 229 | } |
| 230 | EXPORT_SYMBOL_GPL(l2tp_session_find); |
| 231 | |
| 232 | struct l2tp_session *l2tp_session_find_nth(struct l2tp_tunnel *tunnel, int nth) |
| 233 | { |
| 234 | int hash; |
| 235 | struct hlist_node *walk; |
| 236 | struct l2tp_session *session; |
| 237 | int count = 0; |
| 238 | |
| 239 | read_lock_bh(&tunnel->hlist_lock); |
| 240 | for (hash = 0; hash < L2TP_HASH_SIZE; hash++) { |
| 241 | hlist_for_each_entry(session, walk, &tunnel->session_hlist[hash], hlist) { |
| 242 | if (++count > nth) { |
| 243 | read_unlock_bh(&tunnel->hlist_lock); |
| 244 | return session; |
| 245 | } |
| 246 | } |
| 247 | } |
| 248 | |
| 249 | read_unlock_bh(&tunnel->hlist_lock); |
| 250 | |
| 251 | return NULL; |
| 252 | } |
| 253 | EXPORT_SYMBOL_GPL(l2tp_session_find_nth); |
| 254 | |
James Chapman | 309795f | 2010-04-02 06:19:10 +0000 | [diff] [blame] | 255 | /* Lookup a session by interface name. |
| 256 | * This is very inefficient but is only used by management interfaces. |
| 257 | */ |
| 258 | struct l2tp_session *l2tp_session_find_by_ifname(struct net *net, char *ifname) |
| 259 | { |
| 260 | struct l2tp_net *pn = l2tp_pernet(net); |
| 261 | int hash; |
| 262 | struct hlist_node *walk; |
| 263 | struct l2tp_session *session; |
| 264 | |
James Chapman | e02d494 | 2010-04-02 06:19:16 +0000 | [diff] [blame] | 265 | rcu_read_lock_bh(); |
James Chapman | 309795f | 2010-04-02 06:19:10 +0000 | [diff] [blame] | 266 | for (hash = 0; hash < L2TP_HASH_SIZE_2; hash++) { |
James Chapman | e02d494 | 2010-04-02 06:19:16 +0000 | [diff] [blame] | 267 | 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] | 268 | if (!strcmp(session->ifname, ifname)) { |
James Chapman | e02d494 | 2010-04-02 06:19:16 +0000 | [diff] [blame] | 269 | rcu_read_unlock_bh(); |
James Chapman | 309795f | 2010-04-02 06:19:10 +0000 | [diff] [blame] | 270 | return session; |
| 271 | } |
| 272 | } |
| 273 | } |
| 274 | |
James Chapman | e02d494 | 2010-04-02 06:19:16 +0000 | [diff] [blame] | 275 | rcu_read_unlock_bh(); |
James Chapman | 309795f | 2010-04-02 06:19:10 +0000 | [diff] [blame] | 276 | |
| 277 | return NULL; |
| 278 | } |
| 279 | EXPORT_SYMBOL_GPL(l2tp_session_find_by_ifname); |
| 280 | |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 281 | /* Lookup a tunnel by id |
| 282 | */ |
| 283 | struct l2tp_tunnel *l2tp_tunnel_find(struct net *net, u32 tunnel_id) |
| 284 | { |
| 285 | struct l2tp_tunnel *tunnel; |
| 286 | struct l2tp_net *pn = l2tp_pernet(net); |
| 287 | |
James Chapman | e02d494 | 2010-04-02 06:19:16 +0000 | [diff] [blame] | 288 | rcu_read_lock_bh(); |
| 289 | list_for_each_entry_rcu(tunnel, &pn->l2tp_tunnel_list, list) { |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 290 | if (tunnel->tunnel_id == tunnel_id) { |
James Chapman | e02d494 | 2010-04-02 06:19:16 +0000 | [diff] [blame] | 291 | rcu_read_unlock_bh(); |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 292 | return tunnel; |
| 293 | } |
| 294 | } |
James Chapman | e02d494 | 2010-04-02 06:19:16 +0000 | [diff] [blame] | 295 | rcu_read_unlock_bh(); |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 296 | |
| 297 | return NULL; |
| 298 | } |
| 299 | EXPORT_SYMBOL_GPL(l2tp_tunnel_find); |
| 300 | |
| 301 | struct l2tp_tunnel *l2tp_tunnel_find_nth(struct net *net, int nth) |
| 302 | { |
| 303 | struct l2tp_net *pn = l2tp_pernet(net); |
| 304 | struct l2tp_tunnel *tunnel; |
| 305 | int count = 0; |
| 306 | |
James Chapman | e02d494 | 2010-04-02 06:19:16 +0000 | [diff] [blame] | 307 | rcu_read_lock_bh(); |
| 308 | list_for_each_entry_rcu(tunnel, &pn->l2tp_tunnel_list, list) { |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 309 | if (++count > nth) { |
James Chapman | e02d494 | 2010-04-02 06:19:16 +0000 | [diff] [blame] | 310 | rcu_read_unlock_bh(); |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 311 | return tunnel; |
| 312 | } |
| 313 | } |
| 314 | |
James Chapman | e02d494 | 2010-04-02 06:19:16 +0000 | [diff] [blame] | 315 | rcu_read_unlock_bh(); |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 316 | |
| 317 | return NULL; |
| 318 | } |
| 319 | EXPORT_SYMBOL_GPL(l2tp_tunnel_find_nth); |
| 320 | |
| 321 | /***************************************************************************** |
| 322 | * Receive data handling |
| 323 | *****************************************************************************/ |
| 324 | |
| 325 | /* Queue a skb in order. We come here only if the skb has an L2TP sequence |
| 326 | * number. |
| 327 | */ |
| 328 | static void l2tp_recv_queue_skb(struct l2tp_session *session, struct sk_buff *skb) |
| 329 | { |
| 330 | struct sk_buff *skbp; |
| 331 | struct sk_buff *tmp; |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 332 | u32 ns = L2TP_SKB_CB(skb)->ns; |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 333 | |
| 334 | spin_lock_bh(&session->reorder_q.lock); |
| 335 | skb_queue_walk_safe(&session->reorder_q, skbp, tmp) { |
| 336 | if (L2TP_SKB_CB(skbp)->ns > ns) { |
| 337 | __skb_queue_before(&session->reorder_q, skbp, skb); |
| 338 | PRINTK(session->debug, L2TP_MSG_SEQ, KERN_DEBUG, |
| 339 | "%s: pkt %hu, inserted before %hu, reorder_q len=%d\n", |
| 340 | session->name, ns, L2TP_SKB_CB(skbp)->ns, |
| 341 | skb_queue_len(&session->reorder_q)); |
| 342 | session->stats.rx_oos_packets++; |
| 343 | goto out; |
| 344 | } |
| 345 | } |
| 346 | |
| 347 | __skb_queue_tail(&session->reorder_q, skb); |
| 348 | |
| 349 | out: |
| 350 | spin_unlock_bh(&session->reorder_q.lock); |
| 351 | } |
| 352 | |
| 353 | /* Dequeue a single skb. |
| 354 | */ |
| 355 | static void l2tp_recv_dequeue_skb(struct l2tp_session *session, struct sk_buff *skb) |
| 356 | { |
| 357 | struct l2tp_tunnel *tunnel = session->tunnel; |
| 358 | int length = L2TP_SKB_CB(skb)->length; |
| 359 | |
| 360 | /* We're about to requeue the skb, so return resources |
| 361 | * to its current owner (a socket receive buffer). |
| 362 | */ |
| 363 | skb_orphan(skb); |
| 364 | |
| 365 | tunnel->stats.rx_packets++; |
| 366 | tunnel->stats.rx_bytes += length; |
| 367 | session->stats.rx_packets++; |
| 368 | session->stats.rx_bytes += length; |
| 369 | |
| 370 | if (L2TP_SKB_CB(skb)->has_seq) { |
| 371 | /* Bump our Nr */ |
| 372 | session->nr++; |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 373 | if (tunnel->version == L2TP_HDR_VER_2) |
| 374 | session->nr &= 0xffff; |
| 375 | else |
| 376 | session->nr &= 0xffffff; |
| 377 | |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 378 | PRINTK(session->debug, L2TP_MSG_SEQ, KERN_DEBUG, |
| 379 | "%s: updated nr to %hu\n", session->name, session->nr); |
| 380 | } |
| 381 | |
| 382 | /* call private receive handler */ |
| 383 | if (session->recv_skb != NULL) |
| 384 | (*session->recv_skb)(session, skb, L2TP_SKB_CB(skb)->length); |
| 385 | else |
| 386 | kfree_skb(skb); |
| 387 | |
| 388 | if (session->deref) |
| 389 | (*session->deref)(session); |
| 390 | } |
| 391 | |
| 392 | /* Dequeue skbs from the session's reorder_q, subject to packet order. |
| 393 | * Skbs that have been in the queue for too long are simply discarded. |
| 394 | */ |
| 395 | static void l2tp_recv_dequeue(struct l2tp_session *session) |
| 396 | { |
| 397 | struct sk_buff *skb; |
| 398 | struct sk_buff *tmp; |
| 399 | |
| 400 | /* If the pkt at the head of the queue has the nr that we |
| 401 | * expect to send up next, dequeue it and any other |
| 402 | * in-sequence packets behind it. |
| 403 | */ |
Eric Dumazet | e2e210c | 2011-11-02 22:47:44 +0000 | [diff] [blame] | 404 | start: |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 405 | spin_lock_bh(&session->reorder_q.lock); |
| 406 | skb_queue_walk_safe(&session->reorder_q, skb, tmp) { |
| 407 | if (time_after(jiffies, L2TP_SKB_CB(skb)->expires)) { |
| 408 | session->stats.rx_seq_discards++; |
| 409 | session->stats.rx_errors++; |
| 410 | PRINTK(session->debug, L2TP_MSG_SEQ, KERN_DEBUG, |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 411 | "%s: oos pkt %u len %d discarded (too old), " |
| 412 | "waiting for %u, reorder_q_len=%d\n", |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 413 | session->name, L2TP_SKB_CB(skb)->ns, |
| 414 | L2TP_SKB_CB(skb)->length, session->nr, |
| 415 | skb_queue_len(&session->reorder_q)); |
| 416 | __skb_unlink(skb, &session->reorder_q); |
| 417 | kfree_skb(skb); |
| 418 | if (session->deref) |
| 419 | (*session->deref)(session); |
| 420 | continue; |
| 421 | } |
| 422 | |
| 423 | if (L2TP_SKB_CB(skb)->has_seq) { |
| 424 | if (L2TP_SKB_CB(skb)->ns != session->nr) { |
| 425 | PRINTK(session->debug, L2TP_MSG_SEQ, KERN_DEBUG, |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 426 | "%s: holding oos pkt %u len %d, " |
| 427 | "waiting for %u, reorder_q_len=%d\n", |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 428 | session->name, L2TP_SKB_CB(skb)->ns, |
| 429 | L2TP_SKB_CB(skb)->length, session->nr, |
| 430 | skb_queue_len(&session->reorder_q)); |
| 431 | goto out; |
| 432 | } |
| 433 | } |
| 434 | __skb_unlink(skb, &session->reorder_q); |
| 435 | |
| 436 | /* Process the skb. We release the queue lock while we |
| 437 | * do so to let other contexts process the queue. |
| 438 | */ |
| 439 | spin_unlock_bh(&session->reorder_q.lock); |
| 440 | l2tp_recv_dequeue_skb(session, skb); |
Eric Dumazet | e2e210c | 2011-11-02 22:47:44 +0000 | [diff] [blame] | 441 | goto start; |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 442 | } |
| 443 | |
| 444 | out: |
| 445 | spin_unlock_bh(&session->reorder_q.lock); |
| 446 | } |
| 447 | |
| 448 | static inline int l2tp_verify_udp_checksum(struct sock *sk, |
| 449 | struct sk_buff *skb) |
| 450 | { |
| 451 | struct udphdr *uh = udp_hdr(skb); |
| 452 | u16 ulen = ntohs(uh->len); |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 453 | __wsum psum; |
| 454 | |
Benjamin LaHaise | d2cf336 | 2012-04-27 08:24:18 +0000 | [diff] [blame] | 455 | if (sk->sk_no_check || skb_csum_unnecessary(skb)) |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 456 | return 0; |
| 457 | |
Benjamin LaHaise | d2cf336 | 2012-04-27 08:24:18 +0000 | [diff] [blame] | 458 | #if IS_ENABLED(CONFIG_IPV6) |
| 459 | if (sk->sk_family == PF_INET6) { |
| 460 | if (!uh->check) { |
| 461 | LIMIT_NETDEBUG(KERN_INFO "L2TP: IPv6: checksum is 0\n"); |
| 462 | return 1; |
| 463 | } |
| 464 | if ((skb->ip_summed == CHECKSUM_COMPLETE) && |
| 465 | !csum_ipv6_magic(&ipv6_hdr(skb)->saddr, |
| 466 | &ipv6_hdr(skb)->daddr, ulen, |
| 467 | IPPROTO_UDP, skb->csum)) { |
| 468 | skb->ip_summed = CHECKSUM_UNNECESSARY; |
| 469 | return 0; |
| 470 | } |
| 471 | skb->csum = ~csum_unfold(csum_ipv6_magic(&ipv6_hdr(skb)->saddr, |
| 472 | &ipv6_hdr(skb)->daddr, |
| 473 | skb->len, IPPROTO_UDP, |
| 474 | 0)); |
| 475 | } else |
| 476 | #endif |
| 477 | { |
| 478 | struct inet_sock *inet; |
| 479 | if (!uh->check) |
| 480 | return 0; |
| 481 | inet = inet_sk(sk); |
| 482 | psum = csum_tcpudp_nofold(inet->inet_saddr, inet->inet_daddr, |
| 483 | ulen, IPPROTO_UDP, 0); |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 484 | |
Benjamin LaHaise | d2cf336 | 2012-04-27 08:24:18 +0000 | [diff] [blame] | 485 | if ((skb->ip_summed == CHECKSUM_COMPLETE) && |
| 486 | !csum_fold(csum_add(psum, skb->csum))) |
| 487 | return 0; |
| 488 | skb->csum = psum; |
| 489 | } |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 490 | |
| 491 | return __skb_checksum_complete(skb); |
| 492 | } |
| 493 | |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 494 | /* Do receive processing of L2TP data frames. We handle both L2TPv2 |
| 495 | * and L2TPv3 data frames here. |
| 496 | * |
| 497 | * L2TPv2 Data Message Header |
| 498 | * |
| 499 | * 0 1 2 3 |
| 500 | * 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 |
| 501 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| 502 | * |T|L|x|x|S|x|O|P|x|x|x|x| Ver | Length (opt) | |
| 503 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| 504 | * | Tunnel ID | Session ID | |
| 505 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| 506 | * | Ns (opt) | Nr (opt) | |
| 507 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| 508 | * | Offset Size (opt) | Offset pad... (opt) |
| 509 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| 510 | * |
| 511 | * Data frames are marked by T=0. All other fields are the same as |
| 512 | * those in L2TP control frames. |
| 513 | * |
| 514 | * L2TPv3 Data Message Header |
| 515 | * |
| 516 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| 517 | * | L2TP Session Header | |
| 518 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| 519 | * | L2-Specific Sublayer | |
| 520 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| 521 | * | Tunnel Payload ... |
| 522 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| 523 | * |
| 524 | * L2TPv3 Session Header Over IP |
| 525 | * |
| 526 | * 0 1 2 3 |
| 527 | * 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 |
| 528 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| 529 | * | Session ID | |
| 530 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| 531 | * | Cookie (optional, maximum 64 bits)... |
| 532 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| 533 | * | |
| 534 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| 535 | * |
| 536 | * L2TPv3 L2-Specific Sublayer Format |
| 537 | * |
| 538 | * 0 1 2 3 |
| 539 | * 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 |
| 540 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| 541 | * |x|S|x|x|x|x|x|x| Sequence Number | |
| 542 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| 543 | * |
| 544 | * Cookie value, sublayer format and offset (pad) are negotiated with |
| 545 | * the peer when the session is set up. Unlike L2TPv2, we do not need |
| 546 | * to parse the packet header to determine if optional fields are |
| 547 | * present. |
| 548 | * |
| 549 | * Caller must already have parsed the frame and determined that it is |
| 550 | * a data (not control) frame before coming here. Fields up to the |
| 551 | * session-id have already been parsed and ptr points to the data |
| 552 | * after the session-id. |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 553 | */ |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 554 | void l2tp_recv_common(struct l2tp_session *session, struct sk_buff *skb, |
| 555 | unsigned char *ptr, unsigned char *optr, u16 hdrflags, |
| 556 | int length, int (*payload_hook)(struct sk_buff *skb)) |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 557 | { |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 558 | struct l2tp_tunnel *tunnel = session->tunnel; |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 559 | int offset; |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 560 | u32 ns, nr; |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 561 | |
| 562 | /* The ref count is increased since we now hold a pointer to |
| 563 | * the session. Take care to decrement the refcnt when exiting |
| 564 | * this function from now on... |
| 565 | */ |
| 566 | l2tp_session_inc_refcount(session); |
| 567 | if (session->ref) |
| 568 | (*session->ref)(session); |
| 569 | |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 570 | /* Parse and check optional cookie */ |
| 571 | if (session->peer_cookie_len > 0) { |
| 572 | if (memcmp(ptr, &session->peer_cookie[0], session->peer_cookie_len)) { |
| 573 | PRINTK(tunnel->debug, L2TP_MSG_DATA, KERN_INFO, |
| 574 | "%s: cookie mismatch (%u/%u). Discarding.\n", |
| 575 | tunnel->name, tunnel->tunnel_id, session->session_id); |
| 576 | session->stats.rx_cookie_discards++; |
| 577 | goto discard; |
| 578 | } |
| 579 | ptr += session->peer_cookie_len; |
| 580 | } |
| 581 | |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 582 | /* Handle the optional sequence numbers. Sequence numbers are |
| 583 | * in different places for L2TPv2 and L2TPv3. |
| 584 | * |
| 585 | * If we are the LAC, enable/disable sequence numbers under |
| 586 | * the control of the LNS. If no sequence numbers present but |
| 587 | * we were expecting them, discard frame. |
| 588 | */ |
| 589 | ns = nr = 0; |
| 590 | L2TP_SKB_CB(skb)->has_seq = 0; |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 591 | if (tunnel->version == L2TP_HDR_VER_2) { |
| 592 | if (hdrflags & L2TP_HDRFLAG_S) { |
| 593 | ns = ntohs(*(__be16 *) ptr); |
| 594 | ptr += 2; |
| 595 | nr = ntohs(*(__be16 *) ptr); |
| 596 | ptr += 2; |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 597 | |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 598 | /* Store L2TP info in the skb */ |
| 599 | L2TP_SKB_CB(skb)->ns = ns; |
| 600 | L2TP_SKB_CB(skb)->has_seq = 1; |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 601 | |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 602 | PRINTK(session->debug, L2TP_MSG_SEQ, KERN_DEBUG, |
| 603 | "%s: recv data ns=%u, nr=%u, session nr=%u\n", |
| 604 | session->name, ns, nr, session->nr); |
| 605 | } |
| 606 | } else if (session->l2specific_type == L2TP_L2SPECTYPE_DEFAULT) { |
| 607 | u32 l2h = ntohl(*(__be32 *) ptr); |
| 608 | |
| 609 | if (l2h & 0x40000000) { |
| 610 | ns = l2h & 0x00ffffff; |
| 611 | |
| 612 | /* Store L2TP info in the skb */ |
| 613 | L2TP_SKB_CB(skb)->ns = ns; |
| 614 | L2TP_SKB_CB(skb)->has_seq = 1; |
| 615 | |
| 616 | PRINTK(session->debug, L2TP_MSG_SEQ, KERN_DEBUG, |
| 617 | "%s: recv data ns=%u, session nr=%u\n", |
| 618 | session->name, ns, session->nr); |
| 619 | } |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 620 | } |
| 621 | |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 622 | /* Advance past L2-specific header, if present */ |
| 623 | ptr += session->l2specific_len; |
| 624 | |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 625 | if (L2TP_SKB_CB(skb)->has_seq) { |
| 626 | /* Received a packet with sequence numbers. If we're the LNS, |
| 627 | * check if we sre sending sequence numbers and if not, |
| 628 | * configure it so. |
| 629 | */ |
| 630 | if ((!session->lns_mode) && (!session->send_seq)) { |
| 631 | PRINTK(session->debug, L2TP_MSG_SEQ, KERN_INFO, |
| 632 | "%s: requested to enable seq numbers by LNS\n", |
| 633 | session->name); |
| 634 | session->send_seq = -1; |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 635 | l2tp_session_set_header_len(session, tunnel->version); |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 636 | } |
| 637 | } else { |
| 638 | /* No sequence numbers. |
| 639 | * If user has configured mandatory sequence numbers, discard. |
| 640 | */ |
| 641 | if (session->recv_seq) { |
| 642 | PRINTK(session->debug, L2TP_MSG_SEQ, KERN_WARNING, |
| 643 | "%s: recv data has no seq numbers when required. " |
| 644 | "Discarding\n", session->name); |
| 645 | session->stats.rx_seq_discards++; |
| 646 | goto discard; |
| 647 | } |
| 648 | |
| 649 | /* If we're the LAC and we're sending sequence numbers, the |
| 650 | * LNS has requested that we no longer send sequence numbers. |
| 651 | * If we're the LNS and we're sending sequence numbers, the |
| 652 | * LAC is broken. Discard the frame. |
| 653 | */ |
| 654 | if ((!session->lns_mode) && (session->send_seq)) { |
| 655 | PRINTK(session->debug, L2TP_MSG_SEQ, KERN_INFO, |
| 656 | "%s: requested to disable seq numbers by LNS\n", |
| 657 | session->name); |
| 658 | session->send_seq = 0; |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 659 | l2tp_session_set_header_len(session, tunnel->version); |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 660 | } else if (session->send_seq) { |
| 661 | PRINTK(session->debug, L2TP_MSG_SEQ, KERN_WARNING, |
| 662 | "%s: recv data has no seq numbers when required. " |
| 663 | "Discarding\n", session->name); |
| 664 | session->stats.rx_seq_discards++; |
| 665 | goto discard; |
| 666 | } |
| 667 | } |
| 668 | |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 669 | /* Session data offset is handled differently for L2TPv2 and |
| 670 | * L2TPv3. For L2TPv2, there is an optional 16-bit value in |
| 671 | * the header. For L2TPv3, the offset is negotiated using AVPs |
| 672 | * in the session setup control protocol. |
| 673 | */ |
| 674 | if (tunnel->version == L2TP_HDR_VER_2) { |
| 675 | /* If offset bit set, skip it. */ |
| 676 | if (hdrflags & L2TP_HDRFLAG_O) { |
| 677 | offset = ntohs(*(__be16 *)ptr); |
| 678 | ptr += 2 + offset; |
| 679 | } |
| 680 | } else |
| 681 | ptr += session->offset; |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 682 | |
| 683 | offset = ptr - optr; |
| 684 | if (!pskb_may_pull(skb, offset)) |
| 685 | goto discard; |
| 686 | |
| 687 | __skb_pull(skb, offset); |
| 688 | |
| 689 | /* If caller wants to process the payload before we queue the |
| 690 | * packet, do so now. |
| 691 | */ |
| 692 | if (payload_hook) |
| 693 | if ((*payload_hook)(skb)) |
| 694 | goto discard; |
| 695 | |
| 696 | /* Prepare skb for adding to the session's reorder_q. Hold |
| 697 | * packets for max reorder_timeout or 1 second if not |
| 698 | * reordering. |
| 699 | */ |
| 700 | L2TP_SKB_CB(skb)->length = length; |
| 701 | L2TP_SKB_CB(skb)->expires = jiffies + |
| 702 | (session->reorder_timeout ? session->reorder_timeout : HZ); |
| 703 | |
| 704 | /* Add packet to the session's receive queue. Reordering is done here, if |
| 705 | * enabled. Saved L2TP protocol info is stored in skb->sb[]. |
| 706 | */ |
| 707 | if (L2TP_SKB_CB(skb)->has_seq) { |
| 708 | if (session->reorder_timeout != 0) { |
| 709 | /* Packet reordering enabled. Add skb to session's |
| 710 | * reorder queue, in order of ns. |
| 711 | */ |
| 712 | l2tp_recv_queue_skb(session, skb); |
| 713 | } else { |
| 714 | /* Packet reordering disabled. Discard out-of-sequence |
| 715 | * packets |
| 716 | */ |
| 717 | if (L2TP_SKB_CB(skb)->ns != session->nr) { |
| 718 | session->stats.rx_seq_discards++; |
| 719 | PRINTK(session->debug, L2TP_MSG_SEQ, KERN_DEBUG, |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 720 | "%s: oos pkt %u len %d discarded, " |
| 721 | "waiting for %u, reorder_q_len=%d\n", |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 722 | session->name, L2TP_SKB_CB(skb)->ns, |
| 723 | L2TP_SKB_CB(skb)->length, session->nr, |
| 724 | skb_queue_len(&session->reorder_q)); |
| 725 | goto discard; |
| 726 | } |
| 727 | skb_queue_tail(&session->reorder_q, skb); |
| 728 | } |
| 729 | } else { |
| 730 | /* No sequence numbers. Add the skb to the tail of the |
| 731 | * reorder queue. This ensures that it will be |
| 732 | * delivered after all previous sequenced skbs. |
| 733 | */ |
| 734 | skb_queue_tail(&session->reorder_q, skb); |
| 735 | } |
| 736 | |
| 737 | /* Try to dequeue as many skbs from reorder_q as we can. */ |
| 738 | l2tp_recv_dequeue(session); |
| 739 | |
| 740 | l2tp_session_dec_refcount(session); |
| 741 | |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 742 | return; |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 743 | |
| 744 | discard: |
| 745 | session->stats.rx_errors++; |
| 746 | kfree_skb(skb); |
| 747 | |
| 748 | if (session->deref) |
| 749 | (*session->deref)(session); |
| 750 | |
| 751 | l2tp_session_dec_refcount(session); |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 752 | } |
| 753 | EXPORT_SYMBOL(l2tp_recv_common); |
| 754 | |
| 755 | /* Internal UDP receive frame. Do the real work of receiving an L2TP data frame |
| 756 | * here. The skb is not on a list when we get here. |
| 757 | * Returns 0 if the packet was a data packet and was successfully passed on. |
| 758 | * Returns 1 if the packet was not a good data packet and could not be |
| 759 | * forwarded. All such packets are passed up to userspace to deal with. |
| 760 | */ |
stephen hemminger | fc13084 | 2010-10-21 07:50:46 +0000 | [diff] [blame] | 761 | static int l2tp_udp_recv_core(struct l2tp_tunnel *tunnel, struct sk_buff *skb, |
| 762 | int (*payload_hook)(struct sk_buff *skb)) |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 763 | { |
| 764 | struct l2tp_session *session = NULL; |
| 765 | unsigned char *ptr, *optr; |
| 766 | u16 hdrflags; |
| 767 | u32 tunnel_id, session_id; |
| 768 | int offset; |
| 769 | u16 version; |
| 770 | int length; |
| 771 | |
| 772 | if (tunnel->sock && l2tp_verify_udp_checksum(tunnel->sock, skb)) |
| 773 | goto discard_bad_csum; |
| 774 | |
| 775 | /* UDP always verifies the packet length. */ |
| 776 | __skb_pull(skb, sizeof(struct udphdr)); |
| 777 | |
| 778 | /* Short packet? */ |
| 779 | if (!pskb_may_pull(skb, L2TP_HDR_SIZE_SEQ)) { |
| 780 | PRINTK(tunnel->debug, L2TP_MSG_DATA, KERN_INFO, |
| 781 | "%s: recv short packet (len=%d)\n", tunnel->name, skb->len); |
| 782 | goto error; |
| 783 | } |
| 784 | |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 785 | /* Trace packet contents, if enabled */ |
| 786 | if (tunnel->debug & L2TP_MSG_DATA) { |
| 787 | length = min(32u, skb->len); |
| 788 | if (!pskb_may_pull(skb, length)) |
| 789 | goto error; |
| 790 | |
| 791 | printk(KERN_DEBUG "%s: recv: ", tunnel->name); |
| 792 | |
| 793 | offset = 0; |
| 794 | do { |
Eric Dumazet | e50e705 | 2011-11-08 13:59:44 -0500 | [diff] [blame] | 795 | printk(" %02X", skb->data[offset]); |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 796 | } while (++offset < length); |
| 797 | |
| 798 | printk("\n"); |
| 799 | } |
| 800 | |
Eric Dumazet | e50e705 | 2011-11-08 13:59:44 -0500 | [diff] [blame] | 801 | /* Point to L2TP header */ |
| 802 | optr = ptr = skb->data; |
| 803 | |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 804 | /* Get L2TP header flags */ |
| 805 | hdrflags = ntohs(*(__be16 *) ptr); |
| 806 | |
| 807 | /* Check protocol version */ |
| 808 | version = hdrflags & L2TP_HDR_VER_MASK; |
| 809 | if (version != tunnel->version) { |
| 810 | PRINTK(tunnel->debug, L2TP_MSG_DATA, KERN_INFO, |
| 811 | "%s: recv protocol version mismatch: got %d expected %d\n", |
| 812 | tunnel->name, version, tunnel->version); |
| 813 | goto error; |
| 814 | } |
| 815 | |
| 816 | /* Get length of L2TP packet */ |
| 817 | length = skb->len; |
| 818 | |
| 819 | /* If type is control packet, it is handled by userspace. */ |
| 820 | if (hdrflags & L2TP_HDRFLAG_T) { |
| 821 | PRINTK(tunnel->debug, L2TP_MSG_DATA, KERN_DEBUG, |
| 822 | "%s: recv control packet, len=%d\n", tunnel->name, length); |
| 823 | goto error; |
| 824 | } |
| 825 | |
| 826 | /* Skip flags */ |
| 827 | ptr += 2; |
| 828 | |
| 829 | if (tunnel->version == L2TP_HDR_VER_2) { |
| 830 | /* If length is present, skip it */ |
| 831 | if (hdrflags & L2TP_HDRFLAG_L) |
| 832 | ptr += 2; |
| 833 | |
| 834 | /* Extract tunnel and session ID */ |
| 835 | tunnel_id = ntohs(*(__be16 *) ptr); |
| 836 | ptr += 2; |
| 837 | session_id = ntohs(*(__be16 *) ptr); |
| 838 | ptr += 2; |
| 839 | } else { |
| 840 | ptr += 2; /* skip reserved bits */ |
| 841 | tunnel_id = tunnel->tunnel_id; |
| 842 | session_id = ntohl(*(__be32 *) ptr); |
| 843 | ptr += 4; |
| 844 | } |
| 845 | |
| 846 | /* Find the session context */ |
| 847 | session = l2tp_session_find(tunnel->l2tp_net, tunnel, session_id); |
James Chapman | 309795f | 2010-04-02 06:19:10 +0000 | [diff] [blame] | 848 | if (!session || !session->recv_skb) { |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 849 | /* Not found? Pass to userspace to deal with */ |
| 850 | PRINTK(tunnel->debug, L2TP_MSG_DATA, KERN_INFO, |
| 851 | "%s: no session found (%u/%u). Passing up.\n", |
| 852 | tunnel->name, tunnel_id, session_id); |
| 853 | goto error; |
| 854 | } |
| 855 | |
| 856 | l2tp_recv_common(session, skb, ptr, optr, hdrflags, length, payload_hook); |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 857 | |
| 858 | return 0; |
| 859 | |
| 860 | discard_bad_csum: |
| 861 | LIMIT_NETDEBUG("%s: UDP: bad checksum\n", tunnel->name); |
| 862 | UDP_INC_STATS_USER(tunnel->l2tp_net, UDP_MIB_INERRORS, 0); |
| 863 | tunnel->stats.rx_errors++; |
| 864 | kfree_skb(skb); |
| 865 | |
| 866 | return 0; |
| 867 | |
| 868 | error: |
| 869 | /* Put UDP header back */ |
| 870 | __skb_push(skb, sizeof(struct udphdr)); |
| 871 | |
| 872 | return 1; |
| 873 | } |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 874 | |
| 875 | /* UDP encapsulation receive handler. See net/ipv4/udp.c. |
| 876 | * Return codes: |
| 877 | * 0 : success. |
| 878 | * <0: error |
| 879 | * >0: skb should be passed up to userspace as UDP. |
| 880 | */ |
| 881 | int l2tp_udp_encap_recv(struct sock *sk, struct sk_buff *skb) |
| 882 | { |
| 883 | struct l2tp_tunnel *tunnel; |
| 884 | |
| 885 | tunnel = l2tp_sock_to_tunnel(sk); |
| 886 | if (tunnel == NULL) |
| 887 | goto pass_up; |
| 888 | |
| 889 | PRINTK(tunnel->debug, L2TP_MSG_DATA, KERN_DEBUG, |
| 890 | "%s: received %d bytes\n", tunnel->name, skb->len); |
| 891 | |
| 892 | if (l2tp_udp_recv_core(tunnel, skb, tunnel->recv_payload_hook)) |
| 893 | goto pass_up_put; |
| 894 | |
| 895 | sock_put(sk); |
| 896 | return 0; |
| 897 | |
| 898 | pass_up_put: |
| 899 | sock_put(sk); |
| 900 | pass_up: |
| 901 | return 1; |
| 902 | } |
| 903 | EXPORT_SYMBOL_GPL(l2tp_udp_encap_recv); |
| 904 | |
| 905 | /************************************************************************ |
| 906 | * Transmit handling |
| 907 | ***********************************************************************/ |
| 908 | |
| 909 | /* Build an L2TP header for the session into the buffer provided. |
| 910 | */ |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 911 | static int l2tp_build_l2tpv2_header(struct l2tp_session *session, void *buf) |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 912 | { |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 913 | struct l2tp_tunnel *tunnel = session->tunnel; |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 914 | __be16 *bufp = buf; |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 915 | __be16 *optr = buf; |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 916 | u16 flags = L2TP_HDR_VER_2; |
| 917 | u32 tunnel_id = tunnel->peer_tunnel_id; |
| 918 | u32 session_id = session->peer_session_id; |
| 919 | |
| 920 | if (session->send_seq) |
| 921 | flags |= L2TP_HDRFLAG_S; |
| 922 | |
| 923 | /* Setup L2TP header. */ |
| 924 | *bufp++ = htons(flags); |
| 925 | *bufp++ = htons(tunnel_id); |
| 926 | *bufp++ = htons(session_id); |
| 927 | if (session->send_seq) { |
| 928 | *bufp++ = htons(session->ns); |
| 929 | *bufp++ = 0; |
| 930 | session->ns++; |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 931 | session->ns &= 0xffff; |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 932 | PRINTK(session->debug, L2TP_MSG_SEQ, KERN_DEBUG, |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 933 | "%s: updated ns to %u\n", session->name, session->ns); |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 934 | } |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 935 | |
| 936 | return bufp - optr; |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 937 | } |
| 938 | |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 939 | static int l2tp_build_l2tpv3_header(struct l2tp_session *session, void *buf) |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 940 | { |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 941 | struct l2tp_tunnel *tunnel = session->tunnel; |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 942 | char *bufp = buf; |
| 943 | char *optr = bufp; |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 944 | |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 945 | /* Setup L2TP header. The header differs slightly for UDP and |
| 946 | * IP encapsulations. For UDP, there is 4 bytes of flags. |
| 947 | */ |
| 948 | if (tunnel->encap == L2TP_ENCAPTYPE_UDP) { |
| 949 | u16 flags = L2TP_HDR_VER_3; |
| 950 | *((__be16 *) bufp) = htons(flags); |
| 951 | bufp += 2; |
| 952 | *((__be16 *) bufp) = 0; |
| 953 | bufp += 2; |
| 954 | } |
| 955 | |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 956 | *((__be32 *) bufp) = htonl(session->peer_session_id); |
| 957 | bufp += 4; |
| 958 | if (session->cookie_len) { |
| 959 | memcpy(bufp, &session->cookie[0], session->cookie_len); |
| 960 | bufp += session->cookie_len; |
| 961 | } |
| 962 | if (session->l2specific_len) { |
| 963 | if (session->l2specific_type == L2TP_L2SPECTYPE_DEFAULT) { |
| 964 | u32 l2h = 0; |
| 965 | if (session->send_seq) { |
| 966 | l2h = 0x40000000 | session->ns; |
| 967 | session->ns++; |
| 968 | session->ns &= 0xffffff; |
| 969 | PRINTK(session->debug, L2TP_MSG_SEQ, KERN_DEBUG, |
| 970 | "%s: updated ns to %u\n", session->name, session->ns); |
| 971 | } |
| 972 | |
| 973 | *((__be32 *) bufp) = htonl(l2h); |
| 974 | } |
| 975 | bufp += session->l2specific_len; |
| 976 | } |
| 977 | if (session->offset) |
| 978 | bufp += session->offset; |
| 979 | |
| 980 | return bufp - optr; |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 981 | } |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 982 | |
stephen hemminger | fc13084 | 2010-10-21 07:50:46 +0000 | [diff] [blame] | 983 | 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] | 984 | struct flowi *fl, size_t data_len) |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 985 | { |
| 986 | struct l2tp_tunnel *tunnel = session->tunnel; |
| 987 | unsigned int len = skb->len; |
| 988 | int error; |
| 989 | |
| 990 | /* Debug */ |
| 991 | if (session->send_seq) |
| 992 | PRINTK(session->debug, L2TP_MSG_DATA, KERN_DEBUG, |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 993 | "%s: send %Zd bytes, ns=%u\n", session->name, |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 994 | data_len, session->ns - 1); |
| 995 | else |
| 996 | PRINTK(session->debug, L2TP_MSG_DATA, KERN_DEBUG, |
| 997 | "%s: send %Zd bytes\n", session->name, data_len); |
| 998 | |
| 999 | if (session->debug & L2TP_MSG_DATA) { |
| 1000 | int i; |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 1001 | int uhlen = (tunnel->encap == L2TP_ENCAPTYPE_UDP) ? sizeof(struct udphdr) : 0; |
| 1002 | unsigned char *datap = skb->data + uhlen; |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1003 | |
| 1004 | printk(KERN_DEBUG "%s: xmit:", session->name); |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 1005 | for (i = 0; i < (len - uhlen); i++) { |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1006 | printk(" %02X", *datap++); |
| 1007 | if (i == 31) { |
| 1008 | printk(" ..."); |
| 1009 | break; |
| 1010 | } |
| 1011 | } |
| 1012 | printk("\n"); |
| 1013 | } |
| 1014 | |
| 1015 | /* Queue the packet to IP for output */ |
Shan Wei | 4e15ed4 | 2010-04-15 16:43:08 +0000 | [diff] [blame] | 1016 | skb->local_df = 1; |
Benjamin LaHaise | d2cf336 | 2012-04-27 08:24:18 +0000 | [diff] [blame] | 1017 | #if IS_ENABLED(CONFIG_IPV6) |
| 1018 | if (skb->sk->sk_family == PF_INET6) |
| 1019 | error = inet6_csk_xmit(skb, NULL); |
| 1020 | else |
| 1021 | #endif |
| 1022 | error = ip_queue_xmit(skb, fl); |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1023 | |
| 1024 | /* Update stats */ |
| 1025 | if (error >= 0) { |
| 1026 | tunnel->stats.tx_packets++; |
| 1027 | tunnel->stats.tx_bytes += len; |
| 1028 | session->stats.tx_packets++; |
| 1029 | session->stats.tx_bytes += len; |
| 1030 | } else { |
| 1031 | tunnel->stats.tx_errors++; |
| 1032 | session->stats.tx_errors++; |
| 1033 | } |
| 1034 | |
| 1035 | return 0; |
| 1036 | } |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1037 | |
| 1038 | /* Automatically called when the skb is freed. |
| 1039 | */ |
| 1040 | static void l2tp_sock_wfree(struct sk_buff *skb) |
| 1041 | { |
| 1042 | sock_put(skb->sk); |
| 1043 | } |
| 1044 | |
| 1045 | /* For data skbs that we transmit, we associate with the tunnel socket |
| 1046 | * but don't do accounting. |
| 1047 | */ |
| 1048 | static inline void l2tp_skb_set_owner_w(struct sk_buff *skb, struct sock *sk) |
| 1049 | { |
| 1050 | sock_hold(sk); |
| 1051 | skb->sk = sk; |
| 1052 | skb->destructor = l2tp_sock_wfree; |
| 1053 | } |
| 1054 | |
Benjamin LaHaise | d2cf336 | 2012-04-27 08:24:18 +0000 | [diff] [blame] | 1055 | #if IS_ENABLED(CONFIG_IPV6) |
| 1056 | static void l2tp_xmit_ipv6_csum(struct sock *sk, struct sk_buff *skb, |
| 1057 | int udp_len) |
| 1058 | { |
| 1059 | struct ipv6_pinfo *np = inet6_sk(sk); |
| 1060 | struct udphdr *uh = udp_hdr(skb); |
| 1061 | |
| 1062 | if (!skb_dst(skb) || !skb_dst(skb)->dev || |
| 1063 | !(skb_dst(skb)->dev->features & NETIF_F_IPV6_CSUM)) { |
| 1064 | __wsum csum = skb_checksum(skb, 0, udp_len, 0); |
| 1065 | skb->ip_summed = CHECKSUM_UNNECESSARY; |
| 1066 | uh->check = csum_ipv6_magic(&np->saddr, &np->daddr, udp_len, |
| 1067 | IPPROTO_UDP, csum); |
| 1068 | if (uh->check == 0) |
| 1069 | uh->check = CSUM_MANGLED_0; |
| 1070 | } else { |
| 1071 | skb->ip_summed = CHECKSUM_PARTIAL; |
| 1072 | skb->csum_start = skb_transport_header(skb) - skb->head; |
| 1073 | skb->csum_offset = offsetof(struct udphdr, check); |
| 1074 | uh->check = ~csum_ipv6_magic(&np->saddr, &np->daddr, |
| 1075 | udp_len, IPPROTO_UDP, 0); |
| 1076 | } |
| 1077 | } |
| 1078 | #endif |
| 1079 | |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1080 | /* If caller requires the skb to have a ppp header, the header must be |
| 1081 | * inserted in the skb data before calling this function. |
| 1082 | */ |
| 1083 | int l2tp_xmit_skb(struct l2tp_session *session, struct sk_buff *skb, int hdr_len) |
| 1084 | { |
| 1085 | int data_len = skb->len; |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 1086 | struct l2tp_tunnel *tunnel = session->tunnel; |
| 1087 | struct sock *sk = tunnel->sock; |
David S. Miller | d9d8da8 | 2011-05-06 22:23:20 -0700 | [diff] [blame] | 1088 | struct flowi *fl; |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1089 | struct udphdr *uh; |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1090 | struct inet_sock *inet; |
| 1091 | __wsum csum; |
| 1092 | int old_headroom; |
| 1093 | int new_headroom; |
| 1094 | int headroom; |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 1095 | int uhlen = (tunnel->encap == L2TP_ENCAPTYPE_UDP) ? sizeof(struct udphdr) : 0; |
| 1096 | int udp_len; |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1097 | |
| 1098 | /* Check that there's enough headroom in the skb to insert IP, |
| 1099 | * UDP and L2TP headers. If not enough, expand it to |
| 1100 | * make room. Adjust truesize. |
| 1101 | */ |
| 1102 | headroom = NET_SKB_PAD + sizeof(struct iphdr) + |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 1103 | uhlen + hdr_len; |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1104 | old_headroom = skb_headroom(skb); |
Eric Dumazet | 835acf5 | 2011-10-07 05:35:46 +0000 | [diff] [blame] | 1105 | if (skb_cow_head(skb, headroom)) { |
| 1106 | dev_kfree_skb(skb); |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1107 | goto abort; |
Eric Dumazet | 835acf5 | 2011-10-07 05:35:46 +0000 | [diff] [blame] | 1108 | } |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1109 | |
| 1110 | new_headroom = skb_headroom(skb); |
| 1111 | skb_orphan(skb); |
| 1112 | skb->truesize += new_headroom - old_headroom; |
| 1113 | |
| 1114 | /* Setup L2TP header */ |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 1115 | session->build_header(session, __skb_push(skb, hdr_len)); |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1116 | |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 1117 | /* Reset skb netfilter state */ |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1118 | memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt)); |
| 1119 | IPCB(skb)->flags &= ~(IPSKB_XFRM_TUNNEL_SIZE | IPSKB_XFRM_TRANSFORMED | |
| 1120 | IPSKB_REROUTED); |
| 1121 | nf_reset(skb); |
| 1122 | |
David S. Miller | 6af88da | 2011-05-08 13:45:20 -0700 | [diff] [blame] | 1123 | bh_lock_sock(sk); |
| 1124 | if (sock_owned_by_user(sk)) { |
| 1125 | dev_kfree_skb(skb); |
| 1126 | goto out_unlock; |
| 1127 | } |
| 1128 | |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1129 | /* Get routing info from the tunnel socket */ |
| 1130 | skb_dst_drop(skb); |
Florian Westphal | 71b1391 | 2011-11-25 06:47:16 +0000 | [diff] [blame] | 1131 | skb_dst_set(skb, dst_clone(__sk_dst_check(sk, 0))); |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1132 | |
David S. Miller | d9d8da8 | 2011-05-06 22:23:20 -0700 | [diff] [blame] | 1133 | inet = inet_sk(sk); |
| 1134 | fl = &inet->cork.fl; |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 1135 | switch (tunnel->encap) { |
| 1136 | case L2TP_ENCAPTYPE_UDP: |
| 1137 | /* Setup UDP header */ |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 1138 | __skb_push(skb, sizeof(*uh)); |
| 1139 | skb_reset_transport_header(skb); |
| 1140 | uh = udp_hdr(skb); |
| 1141 | uh->source = inet->inet_sport; |
| 1142 | uh->dest = inet->inet_dport; |
| 1143 | udp_len = uhlen + hdr_len + data_len; |
| 1144 | uh->len = htons(udp_len); |
| 1145 | uh->check = 0; |
| 1146 | |
| 1147 | /* Calculate UDP checksum if configured to do so */ |
Benjamin LaHaise | d2cf336 | 2012-04-27 08:24:18 +0000 | [diff] [blame] | 1148 | #if IS_ENABLED(CONFIG_IPV6) |
| 1149 | if (sk->sk_family == PF_INET6) |
| 1150 | l2tp_xmit_ipv6_csum(sk, skb, udp_len); |
| 1151 | else |
| 1152 | #endif |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 1153 | if (sk->sk_no_check == UDP_CSUM_NOXMIT) |
| 1154 | skb->ip_summed = CHECKSUM_NONE; |
| 1155 | else if ((skb_dst(skb) && skb_dst(skb)->dev) && |
| 1156 | (!(skb_dst(skb)->dev->features & NETIF_F_V4_CSUM))) { |
| 1157 | skb->ip_summed = CHECKSUM_COMPLETE; |
| 1158 | csum = skb_checksum(skb, 0, udp_len, 0); |
| 1159 | uh->check = csum_tcpudp_magic(inet->inet_saddr, |
| 1160 | inet->inet_daddr, |
| 1161 | udp_len, IPPROTO_UDP, csum); |
| 1162 | if (uh->check == 0) |
| 1163 | uh->check = CSUM_MANGLED_0; |
| 1164 | } else { |
| 1165 | skb->ip_summed = CHECKSUM_PARTIAL; |
| 1166 | skb->csum_start = skb_transport_header(skb) - skb->head; |
| 1167 | skb->csum_offset = offsetof(struct udphdr, check); |
| 1168 | uh->check = ~csum_tcpudp_magic(inet->inet_saddr, |
| 1169 | inet->inet_daddr, |
| 1170 | udp_len, IPPROTO_UDP, 0); |
| 1171 | } |
| 1172 | break; |
| 1173 | |
| 1174 | case L2TP_ENCAPTYPE_IP: |
| 1175 | break; |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1176 | } |
| 1177 | |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 1178 | l2tp_skb_set_owner_w(skb, sk); |
| 1179 | |
David S. Miller | d9d8da8 | 2011-05-06 22:23:20 -0700 | [diff] [blame] | 1180 | l2tp_xmit_core(session, skb, fl, data_len); |
David S. Miller | 6af88da | 2011-05-08 13:45:20 -0700 | [diff] [blame] | 1181 | out_unlock: |
| 1182 | bh_unlock_sock(sk); |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1183 | |
| 1184 | abort: |
| 1185 | return 0; |
| 1186 | } |
| 1187 | EXPORT_SYMBOL_GPL(l2tp_xmit_skb); |
| 1188 | |
| 1189 | /***************************************************************************** |
| 1190 | * Tinnel and session create/destroy. |
| 1191 | *****************************************************************************/ |
| 1192 | |
| 1193 | /* Tunnel socket destruct hook. |
| 1194 | * The tunnel context is deleted only when all session sockets have been |
| 1195 | * closed. |
| 1196 | */ |
stephen hemminger | fc13084 | 2010-10-21 07:50:46 +0000 | [diff] [blame] | 1197 | static void l2tp_tunnel_destruct(struct sock *sk) |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1198 | { |
| 1199 | struct l2tp_tunnel *tunnel; |
| 1200 | |
| 1201 | tunnel = sk->sk_user_data; |
| 1202 | if (tunnel == NULL) |
| 1203 | goto end; |
| 1204 | |
| 1205 | PRINTK(tunnel->debug, L2TP_MSG_CONTROL, KERN_INFO, |
| 1206 | "%s: closing...\n", tunnel->name); |
| 1207 | |
| 1208 | /* Close all sessions */ |
| 1209 | l2tp_tunnel_closeall(tunnel); |
| 1210 | |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 1211 | switch (tunnel->encap) { |
| 1212 | case L2TP_ENCAPTYPE_UDP: |
| 1213 | /* No longer an encapsulation socket. See net/ipv4/udp.c */ |
| 1214 | (udp_sk(sk))->encap_type = 0; |
| 1215 | (udp_sk(sk))->encap_rcv = NULL; |
| 1216 | break; |
| 1217 | case L2TP_ENCAPTYPE_IP: |
| 1218 | break; |
| 1219 | } |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1220 | |
| 1221 | /* Remove hooks into tunnel socket */ |
| 1222 | tunnel->sock = NULL; |
| 1223 | sk->sk_destruct = tunnel->old_sk_destruct; |
| 1224 | sk->sk_user_data = NULL; |
| 1225 | |
| 1226 | /* Call the original destructor */ |
| 1227 | if (sk->sk_destruct) |
| 1228 | (*sk->sk_destruct)(sk); |
| 1229 | |
| 1230 | /* We're finished with the socket */ |
| 1231 | l2tp_tunnel_dec_refcount(tunnel); |
| 1232 | |
| 1233 | end: |
| 1234 | return; |
| 1235 | } |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1236 | |
| 1237 | /* When the tunnel is closed, all the attached sessions need to go too. |
| 1238 | */ |
stephen hemminger | fc13084 | 2010-10-21 07:50:46 +0000 | [diff] [blame] | 1239 | static void l2tp_tunnel_closeall(struct l2tp_tunnel *tunnel) |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1240 | { |
| 1241 | int hash; |
| 1242 | struct hlist_node *walk; |
| 1243 | struct hlist_node *tmp; |
| 1244 | struct l2tp_session *session; |
| 1245 | |
| 1246 | BUG_ON(tunnel == NULL); |
| 1247 | |
| 1248 | PRINTK(tunnel->debug, L2TP_MSG_CONTROL, KERN_INFO, |
| 1249 | "%s: closing all sessions...\n", tunnel->name); |
| 1250 | |
| 1251 | write_lock_bh(&tunnel->hlist_lock); |
| 1252 | for (hash = 0; hash < L2TP_HASH_SIZE; hash++) { |
| 1253 | again: |
| 1254 | hlist_for_each_safe(walk, tmp, &tunnel->session_hlist[hash]) { |
| 1255 | session = hlist_entry(walk, struct l2tp_session, hlist); |
| 1256 | |
| 1257 | PRINTK(session->debug, L2TP_MSG_CONTROL, KERN_INFO, |
| 1258 | "%s: closing session\n", session->name); |
| 1259 | |
| 1260 | hlist_del_init(&session->hlist); |
| 1261 | |
| 1262 | /* Since we should hold the sock lock while |
| 1263 | * doing any unbinding, we need to release the |
| 1264 | * lock we're holding before taking that lock. |
| 1265 | * Hold a reference to the sock so it doesn't |
| 1266 | * disappear as we're jumping between locks. |
| 1267 | */ |
| 1268 | if (session->ref != NULL) |
| 1269 | (*session->ref)(session); |
| 1270 | |
| 1271 | write_unlock_bh(&tunnel->hlist_lock); |
| 1272 | |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 1273 | if (tunnel->version != L2TP_HDR_VER_2) { |
| 1274 | struct l2tp_net *pn = l2tp_pernet(tunnel->l2tp_net); |
| 1275 | |
James Chapman | e02d494 | 2010-04-02 06:19:16 +0000 | [diff] [blame] | 1276 | spin_lock_bh(&pn->l2tp_session_hlist_lock); |
| 1277 | hlist_del_init_rcu(&session->global_hlist); |
| 1278 | spin_unlock_bh(&pn->l2tp_session_hlist_lock); |
| 1279 | synchronize_rcu(); |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 1280 | } |
| 1281 | |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1282 | if (session->session_close != NULL) |
| 1283 | (*session->session_close)(session); |
| 1284 | |
| 1285 | if (session->deref != NULL) |
| 1286 | (*session->deref)(session); |
| 1287 | |
| 1288 | write_lock_bh(&tunnel->hlist_lock); |
| 1289 | |
| 1290 | /* Now restart from the beginning of this hash |
| 1291 | * chain. We always remove a session from the |
| 1292 | * list so we are guaranteed to make forward |
| 1293 | * progress. |
| 1294 | */ |
| 1295 | goto again; |
| 1296 | } |
| 1297 | } |
| 1298 | write_unlock_bh(&tunnel->hlist_lock); |
| 1299 | } |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1300 | |
| 1301 | /* Really kill the tunnel. |
| 1302 | * Come here only when all sessions have been cleared from the tunnel. |
| 1303 | */ |
stephen hemminger | fc13084 | 2010-10-21 07:50:46 +0000 | [diff] [blame] | 1304 | static void l2tp_tunnel_free(struct l2tp_tunnel *tunnel) |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1305 | { |
| 1306 | struct l2tp_net *pn = l2tp_pernet(tunnel->l2tp_net); |
| 1307 | |
| 1308 | BUG_ON(atomic_read(&tunnel->ref_count) != 0); |
| 1309 | BUG_ON(tunnel->sock != NULL); |
| 1310 | |
| 1311 | PRINTK(tunnel->debug, L2TP_MSG_CONTROL, KERN_INFO, |
| 1312 | "%s: free...\n", tunnel->name); |
| 1313 | |
| 1314 | /* Remove from tunnel list */ |
James Chapman | e02d494 | 2010-04-02 06:19:16 +0000 | [diff] [blame] | 1315 | spin_lock_bh(&pn->l2tp_tunnel_list_lock); |
| 1316 | list_del_rcu(&tunnel->list); |
| 1317 | spin_unlock_bh(&pn->l2tp_tunnel_list_lock); |
| 1318 | synchronize_rcu(); |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1319 | |
| 1320 | atomic_dec(&l2tp_tunnel_count); |
| 1321 | kfree(tunnel); |
| 1322 | } |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1323 | |
James Chapman | 789a4a2 | 2010-04-02 06:19:40 +0000 | [diff] [blame] | 1324 | /* Create a socket for the tunnel, if one isn't set up by |
| 1325 | * userspace. This is used for static tunnels where there is no |
| 1326 | * managing L2TP daemon. |
| 1327 | */ |
| 1328 | static int l2tp_tunnel_sock_create(u32 tunnel_id, u32 peer_tunnel_id, struct l2tp_tunnel_cfg *cfg, struct socket **sockp) |
| 1329 | { |
| 1330 | int err = -EINVAL; |
| 1331 | struct sockaddr_in udp_addr; |
| 1332 | struct sockaddr_l2tpip ip_addr; |
Eric Dumazet | 7bddd0d | 2010-04-04 01:02:46 -0700 | [diff] [blame] | 1333 | struct socket *sock = NULL; |
James Chapman | 789a4a2 | 2010-04-02 06:19:40 +0000 | [diff] [blame] | 1334 | |
| 1335 | switch (cfg->encap) { |
| 1336 | case L2TP_ENCAPTYPE_UDP: |
| 1337 | err = sock_create(AF_INET, SOCK_DGRAM, 0, sockp); |
| 1338 | if (err < 0) |
| 1339 | goto out; |
| 1340 | |
| 1341 | sock = *sockp; |
| 1342 | |
| 1343 | memset(&udp_addr, 0, sizeof(udp_addr)); |
| 1344 | udp_addr.sin_family = AF_INET; |
| 1345 | udp_addr.sin_addr = cfg->local_ip; |
| 1346 | udp_addr.sin_port = htons(cfg->local_udp_port); |
| 1347 | err = kernel_bind(sock, (struct sockaddr *) &udp_addr, sizeof(udp_addr)); |
| 1348 | if (err < 0) |
| 1349 | goto out; |
| 1350 | |
| 1351 | udp_addr.sin_family = AF_INET; |
| 1352 | udp_addr.sin_addr = cfg->peer_ip; |
| 1353 | udp_addr.sin_port = htons(cfg->peer_udp_port); |
| 1354 | err = kernel_connect(sock, (struct sockaddr *) &udp_addr, sizeof(udp_addr), 0); |
| 1355 | if (err < 0) |
| 1356 | goto out; |
| 1357 | |
| 1358 | if (!cfg->use_udp_checksums) |
| 1359 | sock->sk->sk_no_check = UDP_CSUM_NOXMIT; |
| 1360 | |
| 1361 | break; |
| 1362 | |
| 1363 | case L2TP_ENCAPTYPE_IP: |
| 1364 | err = sock_create(AF_INET, SOCK_DGRAM, IPPROTO_L2TP, sockp); |
| 1365 | if (err < 0) |
| 1366 | goto out; |
| 1367 | |
| 1368 | sock = *sockp; |
| 1369 | |
| 1370 | memset(&ip_addr, 0, sizeof(ip_addr)); |
| 1371 | ip_addr.l2tp_family = AF_INET; |
| 1372 | ip_addr.l2tp_addr = cfg->local_ip; |
| 1373 | ip_addr.l2tp_conn_id = tunnel_id; |
| 1374 | err = kernel_bind(sock, (struct sockaddr *) &ip_addr, sizeof(ip_addr)); |
| 1375 | if (err < 0) |
| 1376 | goto out; |
| 1377 | |
| 1378 | ip_addr.l2tp_family = AF_INET; |
| 1379 | ip_addr.l2tp_addr = cfg->peer_ip; |
| 1380 | ip_addr.l2tp_conn_id = peer_tunnel_id; |
| 1381 | err = kernel_connect(sock, (struct sockaddr *) &ip_addr, sizeof(ip_addr), 0); |
| 1382 | if (err < 0) |
| 1383 | goto out; |
| 1384 | |
| 1385 | break; |
| 1386 | |
| 1387 | default: |
| 1388 | goto out; |
| 1389 | } |
| 1390 | |
| 1391 | out: |
| 1392 | if ((err < 0) && sock) { |
| 1393 | sock_release(sock); |
| 1394 | *sockp = NULL; |
| 1395 | } |
| 1396 | |
| 1397 | return err; |
| 1398 | } |
| 1399 | |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1400 | 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) |
| 1401 | { |
| 1402 | struct l2tp_tunnel *tunnel = NULL; |
| 1403 | int err; |
| 1404 | struct socket *sock = NULL; |
| 1405 | struct sock *sk = NULL; |
| 1406 | struct l2tp_net *pn; |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 1407 | enum l2tp_encap_type encap = L2TP_ENCAPTYPE_UDP; |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1408 | |
| 1409 | /* Get the tunnel socket from the fd, which was opened by |
James Chapman | 789a4a2 | 2010-04-02 06:19:40 +0000 | [diff] [blame] | 1410 | * the userspace L2TP daemon. If not specified, create a |
| 1411 | * kernel socket. |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1412 | */ |
James Chapman | 789a4a2 | 2010-04-02 06:19:40 +0000 | [diff] [blame] | 1413 | if (fd < 0) { |
| 1414 | err = l2tp_tunnel_sock_create(tunnel_id, peer_tunnel_id, cfg, &sock); |
| 1415 | if (err < 0) |
| 1416 | goto err; |
| 1417 | } else { |
| 1418 | err = -EBADF; |
| 1419 | sock = sockfd_lookup(fd, &err); |
| 1420 | if (!sock) { |
| 1421 | printk(KERN_ERR "tunl %hu: sockfd_lookup(fd=%d) returned %d\n", |
| 1422 | tunnel_id, fd, err); |
| 1423 | goto err; |
| 1424 | } |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1425 | } |
| 1426 | |
| 1427 | sk = sock->sk; |
| 1428 | |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 1429 | if (cfg != NULL) |
| 1430 | encap = cfg->encap; |
| 1431 | |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1432 | /* Quick sanity checks */ |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 1433 | switch (encap) { |
| 1434 | case L2TP_ENCAPTYPE_UDP: |
| 1435 | err = -EPROTONOSUPPORT; |
| 1436 | if (sk->sk_protocol != IPPROTO_UDP) { |
| 1437 | printk(KERN_ERR "tunl %hu: fd %d wrong protocol, got %d, expected %d\n", |
| 1438 | tunnel_id, fd, sk->sk_protocol, IPPROTO_UDP); |
| 1439 | goto err; |
| 1440 | } |
| 1441 | break; |
| 1442 | case L2TP_ENCAPTYPE_IP: |
| 1443 | err = -EPROTONOSUPPORT; |
| 1444 | if (sk->sk_protocol != IPPROTO_L2TP) { |
| 1445 | printk(KERN_ERR "tunl %hu: fd %d wrong protocol, got %d, expected %d\n", |
| 1446 | tunnel_id, fd, sk->sk_protocol, IPPROTO_L2TP); |
| 1447 | goto err; |
| 1448 | } |
| 1449 | break; |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1450 | } |
| 1451 | |
| 1452 | /* Check if this socket has already been prepped */ |
| 1453 | tunnel = (struct l2tp_tunnel *)sk->sk_user_data; |
| 1454 | if (tunnel != NULL) { |
| 1455 | /* This socket has already been prepped */ |
| 1456 | err = -EBUSY; |
| 1457 | goto err; |
| 1458 | } |
| 1459 | |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1460 | tunnel = kzalloc(sizeof(struct l2tp_tunnel), GFP_KERNEL); |
| 1461 | if (tunnel == NULL) { |
| 1462 | err = -ENOMEM; |
| 1463 | goto err; |
| 1464 | } |
| 1465 | |
| 1466 | tunnel->version = version; |
| 1467 | tunnel->tunnel_id = tunnel_id; |
| 1468 | tunnel->peer_tunnel_id = peer_tunnel_id; |
| 1469 | tunnel->debug = L2TP_DEFAULT_DEBUG_FLAGS; |
| 1470 | |
| 1471 | tunnel->magic = L2TP_TUNNEL_MAGIC; |
| 1472 | sprintf(&tunnel->name[0], "tunl %u", tunnel_id); |
| 1473 | rwlock_init(&tunnel->hlist_lock); |
| 1474 | |
| 1475 | /* The net we belong to */ |
| 1476 | tunnel->l2tp_net = net; |
| 1477 | pn = l2tp_pernet(net); |
| 1478 | |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 1479 | if (cfg != NULL) |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1480 | tunnel->debug = cfg->debug; |
| 1481 | |
| 1482 | /* Mark socket as an encapsulation socket. See net/ipv4/udp.c */ |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 1483 | tunnel->encap = encap; |
| 1484 | if (encap == L2TP_ENCAPTYPE_UDP) { |
| 1485 | /* Mark socket as an encapsulation socket. See net/ipv4/udp.c */ |
| 1486 | udp_sk(sk)->encap_type = UDP_ENCAP_L2TPINUDP; |
| 1487 | udp_sk(sk)->encap_rcv = l2tp_udp_encap_recv; |
Benjamin LaHaise | d2cf336 | 2012-04-27 08:24:18 +0000 | [diff] [blame] | 1488 | #if IS_ENABLED(CONFIG_IPV6) |
| 1489 | if (sk->sk_family == PF_INET6) |
| 1490 | udpv6_encap_enable(); |
| 1491 | else |
| 1492 | #endif |
Eric Dumazet | 447167b | 2012-04-11 23:05:28 +0000 | [diff] [blame] | 1493 | udp_encap_enable(); |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 1494 | } |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1495 | |
| 1496 | sk->sk_user_data = tunnel; |
| 1497 | |
| 1498 | /* Hook on the tunnel socket destructor so that we can cleanup |
| 1499 | * if the tunnel socket goes away. |
| 1500 | */ |
| 1501 | tunnel->old_sk_destruct = sk->sk_destruct; |
| 1502 | sk->sk_destruct = &l2tp_tunnel_destruct; |
| 1503 | tunnel->sock = sk; |
| 1504 | sk->sk_allocation = GFP_ATOMIC; |
| 1505 | |
| 1506 | /* Add tunnel to our list */ |
| 1507 | INIT_LIST_HEAD(&tunnel->list); |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1508 | atomic_inc(&l2tp_tunnel_count); |
| 1509 | |
| 1510 | /* Bump the reference count. The tunnel context is deleted |
Eric Dumazet | 1769192 | 2011-05-11 18:22:36 +0000 | [diff] [blame] | 1511 | * only when this drops to zero. Must be done before list insertion |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1512 | */ |
| 1513 | l2tp_tunnel_inc_refcount(tunnel); |
Eric Dumazet | 1769192 | 2011-05-11 18:22:36 +0000 | [diff] [blame] | 1514 | spin_lock_bh(&pn->l2tp_tunnel_list_lock); |
| 1515 | list_add_rcu(&tunnel->list, &pn->l2tp_tunnel_list); |
| 1516 | spin_unlock_bh(&pn->l2tp_tunnel_list_lock); |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1517 | |
| 1518 | err = 0; |
| 1519 | err: |
| 1520 | if (tunnelp) |
| 1521 | *tunnelp = tunnel; |
| 1522 | |
James Chapman | 789a4a2 | 2010-04-02 06:19:40 +0000 | [diff] [blame] | 1523 | /* If tunnel's socket was created by the kernel, it doesn't |
| 1524 | * have a file. |
| 1525 | */ |
| 1526 | if (sock && sock->file) |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1527 | sockfd_put(sock); |
| 1528 | |
| 1529 | return err; |
| 1530 | } |
| 1531 | EXPORT_SYMBOL_GPL(l2tp_tunnel_create); |
| 1532 | |
James Chapman | 309795f | 2010-04-02 06:19:10 +0000 | [diff] [blame] | 1533 | /* This function is used by the netlink TUNNEL_DELETE command. |
| 1534 | */ |
| 1535 | int l2tp_tunnel_delete(struct l2tp_tunnel *tunnel) |
| 1536 | { |
| 1537 | int err = 0; |
James Chapman | 789a4a2 | 2010-04-02 06:19:40 +0000 | [diff] [blame] | 1538 | struct socket *sock = tunnel->sock ? tunnel->sock->sk_socket : NULL; |
James Chapman | 309795f | 2010-04-02 06:19:10 +0000 | [diff] [blame] | 1539 | |
| 1540 | /* Force the tunnel socket to close. This will eventually |
| 1541 | * cause the tunnel to be deleted via the normal socket close |
| 1542 | * mechanisms when userspace closes the tunnel socket. |
| 1543 | */ |
James Chapman | 789a4a2 | 2010-04-02 06:19:40 +0000 | [diff] [blame] | 1544 | if (sock != NULL) { |
| 1545 | err = inet_shutdown(sock, 2); |
| 1546 | |
| 1547 | /* If the tunnel's socket was created by the kernel, |
| 1548 | * close the socket here since the socket was not |
| 1549 | * created by userspace. |
| 1550 | */ |
| 1551 | if (sock->file == NULL) |
| 1552 | err = inet_release(sock); |
| 1553 | } |
James Chapman | 309795f | 2010-04-02 06:19:10 +0000 | [diff] [blame] | 1554 | |
| 1555 | return err; |
| 1556 | } |
| 1557 | EXPORT_SYMBOL_GPL(l2tp_tunnel_delete); |
| 1558 | |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1559 | /* Really kill the session. |
| 1560 | */ |
| 1561 | void l2tp_session_free(struct l2tp_session *session) |
| 1562 | { |
| 1563 | struct l2tp_tunnel *tunnel; |
| 1564 | |
| 1565 | BUG_ON(atomic_read(&session->ref_count) != 0); |
| 1566 | |
| 1567 | tunnel = session->tunnel; |
| 1568 | if (tunnel != NULL) { |
| 1569 | BUG_ON(tunnel->magic != L2TP_TUNNEL_MAGIC); |
| 1570 | |
| 1571 | /* Delete the session from the hash */ |
| 1572 | write_lock_bh(&tunnel->hlist_lock); |
| 1573 | hlist_del_init(&session->hlist); |
| 1574 | write_unlock_bh(&tunnel->hlist_lock); |
| 1575 | |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 1576 | /* Unlink from the global hash if not L2TPv2 */ |
| 1577 | if (tunnel->version != L2TP_HDR_VER_2) { |
| 1578 | struct l2tp_net *pn = l2tp_pernet(tunnel->l2tp_net); |
| 1579 | |
James Chapman | e02d494 | 2010-04-02 06:19:16 +0000 | [diff] [blame] | 1580 | spin_lock_bh(&pn->l2tp_session_hlist_lock); |
| 1581 | hlist_del_init_rcu(&session->global_hlist); |
| 1582 | spin_unlock_bh(&pn->l2tp_session_hlist_lock); |
| 1583 | synchronize_rcu(); |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 1584 | } |
| 1585 | |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1586 | if (session->session_id != 0) |
| 1587 | atomic_dec(&l2tp_session_count); |
| 1588 | |
| 1589 | sock_put(tunnel->sock); |
| 1590 | |
| 1591 | /* This will delete the tunnel context if this |
| 1592 | * is the last session on the tunnel. |
| 1593 | */ |
| 1594 | session->tunnel = NULL; |
| 1595 | l2tp_tunnel_dec_refcount(tunnel); |
| 1596 | } |
| 1597 | |
| 1598 | kfree(session); |
| 1599 | |
| 1600 | return; |
| 1601 | } |
| 1602 | EXPORT_SYMBOL_GPL(l2tp_session_free); |
| 1603 | |
James Chapman | 309795f | 2010-04-02 06:19:10 +0000 | [diff] [blame] | 1604 | /* This function is used by the netlink SESSION_DELETE command and by |
| 1605 | pseudowire modules. |
| 1606 | */ |
| 1607 | int l2tp_session_delete(struct l2tp_session *session) |
| 1608 | { |
| 1609 | if (session->session_close != NULL) |
| 1610 | (*session->session_close)(session); |
| 1611 | |
| 1612 | l2tp_session_dec_refcount(session); |
| 1613 | |
| 1614 | return 0; |
| 1615 | } |
| 1616 | EXPORT_SYMBOL_GPL(l2tp_session_delete); |
| 1617 | |
| 1618 | |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 1619 | /* We come here whenever a session's send_seq, cookie_len or |
| 1620 | * l2specific_len parameters are set. |
| 1621 | */ |
stephen hemminger | fc13084 | 2010-10-21 07:50:46 +0000 | [diff] [blame] | 1622 | 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] | 1623 | { |
| 1624 | if (version == L2TP_HDR_VER_2) { |
| 1625 | session->hdr_len = 6; |
| 1626 | if (session->send_seq) |
| 1627 | session->hdr_len += 4; |
| 1628 | } else { |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 1629 | session->hdr_len = 4 + session->cookie_len + session->l2specific_len + session->offset; |
| 1630 | if (session->tunnel->encap == L2TP_ENCAPTYPE_UDP) |
| 1631 | session->hdr_len += 4; |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 1632 | } |
| 1633 | |
| 1634 | } |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 1635 | |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1636 | 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) |
| 1637 | { |
| 1638 | struct l2tp_session *session; |
| 1639 | |
| 1640 | session = kzalloc(sizeof(struct l2tp_session) + priv_size, GFP_KERNEL); |
| 1641 | if (session != NULL) { |
| 1642 | session->magic = L2TP_SESSION_MAGIC; |
| 1643 | session->tunnel = tunnel; |
| 1644 | |
| 1645 | session->session_id = session_id; |
| 1646 | session->peer_session_id = peer_session_id; |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 1647 | session->nr = 1; |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1648 | |
| 1649 | sprintf(&session->name[0], "sess %u/%u", |
| 1650 | tunnel->tunnel_id, session->session_id); |
| 1651 | |
| 1652 | skb_queue_head_init(&session->reorder_q); |
| 1653 | |
| 1654 | INIT_HLIST_NODE(&session->hlist); |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 1655 | INIT_HLIST_NODE(&session->global_hlist); |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1656 | |
| 1657 | /* Inherit debug options from tunnel */ |
| 1658 | session->debug = tunnel->debug; |
| 1659 | |
| 1660 | if (cfg) { |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 1661 | session->pwtype = cfg->pw_type; |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1662 | session->debug = cfg->debug; |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1663 | session->mtu = cfg->mtu; |
| 1664 | session->mru = cfg->mru; |
| 1665 | session->send_seq = cfg->send_seq; |
| 1666 | session->recv_seq = cfg->recv_seq; |
| 1667 | session->lns_mode = cfg->lns_mode; |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 1668 | session->reorder_timeout = cfg->reorder_timeout; |
| 1669 | session->offset = cfg->offset; |
| 1670 | session->l2specific_type = cfg->l2specific_type; |
| 1671 | session->l2specific_len = cfg->l2specific_len; |
| 1672 | session->cookie_len = cfg->cookie_len; |
| 1673 | memcpy(&session->cookie[0], &cfg->cookie[0], cfg->cookie_len); |
| 1674 | session->peer_cookie_len = cfg->peer_cookie_len; |
| 1675 | 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] | 1676 | } |
| 1677 | |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 1678 | if (tunnel->version == L2TP_HDR_VER_2) |
| 1679 | session->build_header = l2tp_build_l2tpv2_header; |
| 1680 | else |
| 1681 | session->build_header = l2tp_build_l2tpv3_header; |
| 1682 | |
| 1683 | l2tp_session_set_header_len(session, tunnel->version); |
| 1684 | |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1685 | /* Bump the reference count. The session context is deleted |
| 1686 | * only when this drops to zero. |
| 1687 | */ |
| 1688 | l2tp_session_inc_refcount(session); |
| 1689 | l2tp_tunnel_inc_refcount(tunnel); |
| 1690 | |
| 1691 | /* Ensure tunnel socket isn't deleted */ |
| 1692 | sock_hold(tunnel->sock); |
| 1693 | |
| 1694 | /* Add session to the tunnel's hash list */ |
| 1695 | write_lock_bh(&tunnel->hlist_lock); |
| 1696 | hlist_add_head(&session->hlist, |
| 1697 | l2tp_session_id_hash(tunnel, session_id)); |
| 1698 | write_unlock_bh(&tunnel->hlist_lock); |
| 1699 | |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 1700 | /* And to the global session list if L2TPv3 */ |
| 1701 | if (tunnel->version != L2TP_HDR_VER_2) { |
| 1702 | struct l2tp_net *pn = l2tp_pernet(tunnel->l2tp_net); |
| 1703 | |
James Chapman | e02d494 | 2010-04-02 06:19:16 +0000 | [diff] [blame] | 1704 | spin_lock_bh(&pn->l2tp_session_hlist_lock); |
| 1705 | hlist_add_head_rcu(&session->global_hlist, |
| 1706 | l2tp_session_id_hash_2(pn, session_id)); |
| 1707 | spin_unlock_bh(&pn->l2tp_session_hlist_lock); |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 1708 | } |
| 1709 | |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1710 | /* Ignore management session in session count value */ |
| 1711 | if (session->session_id != 0) |
| 1712 | atomic_inc(&l2tp_session_count); |
| 1713 | } |
| 1714 | |
| 1715 | return session; |
| 1716 | } |
| 1717 | EXPORT_SYMBOL_GPL(l2tp_session_create); |
| 1718 | |
| 1719 | /***************************************************************************** |
| 1720 | * Init and cleanup |
| 1721 | *****************************************************************************/ |
| 1722 | |
| 1723 | static __net_init int l2tp_init_net(struct net *net) |
| 1724 | { |
Jiri Pirko | e773aaf | 2010-04-23 00:53:39 +0000 | [diff] [blame] | 1725 | struct l2tp_net *pn = net_generic(net, l2tp_net_id); |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 1726 | int hash; |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1727 | |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1728 | INIT_LIST_HEAD(&pn->l2tp_tunnel_list); |
James Chapman | e02d494 | 2010-04-02 06:19:16 +0000 | [diff] [blame] | 1729 | spin_lock_init(&pn->l2tp_tunnel_list_lock); |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1730 | |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 1731 | for (hash = 0; hash < L2TP_HASH_SIZE_2; hash++) |
| 1732 | INIT_HLIST_HEAD(&pn->l2tp_session_hlist[hash]); |
| 1733 | |
James Chapman | e02d494 | 2010-04-02 06:19:16 +0000 | [diff] [blame] | 1734 | spin_lock_init(&pn->l2tp_session_hlist_lock); |
James Chapman | f7faffa | 2010-04-02 06:18:49 +0000 | [diff] [blame] | 1735 | |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1736 | return 0; |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1737 | } |
| 1738 | |
| 1739 | static struct pernet_operations l2tp_net_ops = { |
| 1740 | .init = l2tp_init_net, |
James Chapman | fd558d1 | 2010-04-02 06:18:33 +0000 | [diff] [blame] | 1741 | .id = &l2tp_net_id, |
| 1742 | .size = sizeof(struct l2tp_net), |
| 1743 | }; |
| 1744 | |
| 1745 | static int __init l2tp_init(void) |
| 1746 | { |
| 1747 | int rc = 0; |
| 1748 | |
| 1749 | rc = register_pernet_device(&l2tp_net_ops); |
| 1750 | if (rc) |
| 1751 | goto out; |
| 1752 | |
| 1753 | printk(KERN_INFO "L2TP core driver, %s\n", L2TP_DRV_VERSION); |
| 1754 | |
| 1755 | out: |
| 1756 | return rc; |
| 1757 | } |
| 1758 | |
| 1759 | static void __exit l2tp_exit(void) |
| 1760 | { |
| 1761 | unregister_pernet_device(&l2tp_net_ops); |
| 1762 | } |
| 1763 | |
| 1764 | module_init(l2tp_init); |
| 1765 | module_exit(l2tp_exit); |
| 1766 | |
| 1767 | MODULE_AUTHOR("James Chapman <jchapman@katalix.com>"); |
| 1768 | MODULE_DESCRIPTION("L2TP core"); |
| 1769 | MODULE_LICENSE("GPL"); |
| 1770 | MODULE_VERSION(L2TP_DRV_VERSION); |
| 1771 | |