SAFE public projects git trees. - safe/jmp/linux-2.6/blob - net/l2tp/l2tp_core.h

   1 /*
   2  * L2TP internal definitions.
   3  *
   4  * Copyright (c) 2008,2009 Katalix Systems Ltd
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 as
   8  * published by the Free Software Foundation.
   9  */
  10
  11 #ifndef _L2TP_CORE_H_
  12 #define _L2TP_CORE_H_
  13
  14 /* Just some random numbers */
  15 #define L2TP_TUNNEL_MAGIC       0x42114DDA
  16 #define L2TP_SESSION_MAGIC      0x0C04EB7D
  17
  18 /* Per tunnel, session hash table size */
  19 #define L2TP_HASH_BITS  4
  20 #define L2TP_HASH_SIZE  (1 << L2TP_HASH_BITS)
  21
  22 /* System-wide, session hash table size */
  23 #define L2TP_HASH_BITS_2        8
  24 #define L2TP_HASH_SIZE_2        (1 << L2TP_HASH_BITS_2)
  25
  26 /* Debug message categories for the DEBUG socket option */
  27 enum {
  28         L2TP_MSG_DEBUG          = (1 << 0),     /* verbose debug (if
  29                                                  * compiled in) */
  30         L2TP_MSG_CONTROL        = (1 << 1),     /* userspace - kernel
  31                                                  * interface */
  32         L2TP_MSG_SEQ            = (1 << 2),     /* sequence numbers */
  33         L2TP_MSG_DATA           = (1 << 3),     /* data packets */
  34 };
  35
  36 enum l2tp_pwtype {
  37         L2TP_PWTYPE_NONE = 0x0000,
  38         L2TP_PWTYPE_ETH_VLAN = 0x0004,
  39         L2TP_PWTYPE_ETH = 0x0005,
  40         L2TP_PWTYPE_PPP = 0x0007,
  41         L2TP_PWTYPE_PPP_AC = 0x0008,
  42         L2TP_PWTYPE_IP = 0x000b,
  43         __L2TP_PWTYPE_MAX
  44 };
  45
  46 enum l2tp_l2spec_type {
  47         L2TP_L2SPECTYPE_NONE,
  48         L2TP_L2SPECTYPE_DEFAULT,
  49 };
  50
  51 enum l2tp_encap_type {
  52         L2TP_ENCAPTYPE_UDP,
  53         L2TP_ENCAPTYPE_IP,
  54 };
  55
  56 struct sk_buff;
  57
  58 struct l2tp_stats {
  59         u64                     tx_packets;
  60         u64                     tx_bytes;
  61         u64                     tx_errors;
  62         u64                     rx_packets;
  63         u64                     rx_bytes;
  64         u64                     rx_seq_discards;
  65         u64                     rx_oos_packets;
  66         u64                     rx_errors;
  67         u64                     rx_cookie_discards;
  68 };
  69
  70 struct l2tp_tunnel;
  71
  72 /* Describes a session. Contains information to determine incoming
  73  * packets and transmit outgoing ones.
  74  */
  75 struct l2tp_session_cfg {
  76         enum l2tp_pwtype        pw_type;
  77         unsigned                data_seq:2;     /* data sequencing level
  78                                                  * 0 => none, 1 => IP only,
  79                                                  * 2 => all
  80                                                  */
  81         unsigned                recv_seq:1;     /* expect receive packets with
  82                                                  * sequence numbers? */
  83         unsigned                send_seq:1;     /* send packets with sequence
  84                                                  * numbers? */
  85         unsigned                lns_mode:1;     /* behave as LNS? LAC enables
  86                                                  * sequence numbers under
  87                                                  * control of LNS. */
  88         int                     debug;          /* bitmask of debug message
  89                                                  * categories */
  90         u16                     offset;         /* offset to payload */
  91         u16                     l2specific_len; /* Layer 2 specific length */
  92         u16                     l2specific_type; /* Layer 2 specific type */
  93         u8                      cookie[8];      /* optional cookie */
  94         int                     cookie_len;     /* 0, 4 or 8 bytes */
  95         u8                      peer_cookie[8]; /* peer's cookie */
  96         int                     peer_cookie_len; /* 0, 4 or 8 bytes */
  97         int                     reorder_timeout; /* configured reorder timeout
  98                                                   * (in jiffies) */
  99         int                     mtu;
 100         int                     mru;
 101 };
 102
 103 struct l2tp_session {
 104         int                     magic;          /* should be
 105                                                  * L2TP_SESSION_MAGIC */
 106
 107         struct l2tp_tunnel      *tunnel;        /* back pointer to tunnel
 108                                                  * context */
 109         u32                     session_id;
 110         u32                     peer_session_id;
 111         u8                      cookie[8];
 112         int                     cookie_len;
 113         u8                      peer_cookie[8];
 114         int                     peer_cookie_len;
 115         u16                     offset;         /* offset from end of L2TP header
 116                                                    to beginning of data */
 117         u16                     l2specific_len;
 118         u16                     l2specific_type;
 119         u16                     hdr_len;
 120         u32                     nr;             /* session NR state (receive) */
 121         u32                     ns;             /* session NR state (send) */
 122         struct sk_buff_head     reorder_q;      /* receive reorder queue */
 123         struct hlist_node       hlist;          /* Hash list node */
 124         atomic_t                ref_count;
 125
 126         char                    name[32];       /* for logging */
 127         unsigned                data_seq:2;     /* data sequencing level
 128                                                  * 0 => none, 1 => IP only,
 129                                                  * 2 => all
 130                                                  */
 131         unsigned                recv_seq:1;     /* expect receive packets with
 132                                                  * sequence numbers? */
 133         unsigned                send_seq:1;     /* send packets with sequence
 134                                                  * numbers? */
 135         unsigned                lns_mode:1;     /* behave as LNS? LAC enables
 136                                                  * sequence numbers under
 137                                                  * control of LNS. */
 138         int                     debug;          /* bitmask of debug message
 139                                                  * categories */
 140         int                     reorder_timeout; /* configured reorder timeout
 141                                                   * (in jiffies) */
 142         int                     mtu;
 143         int                     mru;
 144         enum l2tp_pwtype        pwtype;
 145         struct l2tp_stats       stats;
 146         struct hlist_node       global_hlist;   /* Global hash list node */
 147
 148         int (*build_header)(struct l2tp_session *session, void *buf);
 149         void (*recv_skb)(struct l2tp_session *session, struct sk_buff *skb, int data_len);
 150         void (*session_close)(struct l2tp_session *session);
 151         void (*ref)(struct l2tp_session *session);
 152         void (*deref)(struct l2tp_session *session);
 153
 154         uint8_t                 priv[0];        /* private data */
 155 };
 156
 157 /* Describes the tunnel. It contains info to track all the associated
 158  * sessions so incoming packets can be sorted out
 159  */
 160 struct l2tp_tunnel_cfg {
 161         int                     debug;          /* bitmask of debug message
 162                                                  * categories */
 163         enum l2tp_encap_type    encap;
 164 };
 165
 166 struct l2tp_tunnel {
 167         int                     magic;          /* Should be L2TP_TUNNEL_MAGIC */
 168         rwlock_t                hlist_lock;     /* protect session_hlist */
 169         struct hlist_head       session_hlist[L2TP_HASH_SIZE];
 170                                                 /* hashed list of sessions,
 171                                                  * hashed by id */
 172         u32                     tunnel_id;
 173         u32                     peer_tunnel_id;
 174         int                     version;        /* 2=>L2TPv2, 3=>L2TPv3 */
 175
 176         char                    name[20];       /* for logging */
 177         int                     debug;          /* bitmask of debug message
 178                                                  * categories */
 179         enum l2tp_encap_type    encap;
 180         struct l2tp_stats       stats;
 181
 182         struct list_head        list;           /* Keep a list of all tunnels */
 183         struct net              *l2tp_net;      /* the net we belong to */
 184
 185         atomic_t                ref_count;
 186
 187         int (*recv_payload_hook)(struct sk_buff *skb);
 188         void (*old_sk_destruct)(struct sock *);
 189         struct sock             *sock;          /* Parent socket */
 190         int                     fd;
 191
 192         uint8_t                 priv[0];        /* private data */
 193 };
 194
 195 static inline void *l2tp_tunnel_priv(struct l2tp_tunnel *tunnel)
 196 {
 197         return &tunnel->priv[0];
 198 }
 199
 200 static inline void *l2tp_session_priv(struct l2tp_session *session)
 201 {
 202         return &session->priv[0];
 203 }
 204
 205 static inline struct l2tp_tunnel *l2tp_sock_to_tunnel(struct sock *sk)
 206 {
 207         struct l2tp_tunnel *tunnel;
 208
 209         if (sk == NULL)
 210                 return NULL;
 211
 212         sock_hold(sk);
 213         tunnel = (struct l2tp_tunnel *)(sk->sk_user_data);
 214         if (tunnel == NULL) {
 215                 sock_put(sk);
 216                 goto out;
 217         }
 218
 219         BUG_ON(tunnel->magic != L2TP_TUNNEL_MAGIC);
 220
 221 out:
 222         return tunnel;
 223 }
 224
 225 extern struct l2tp_session *l2tp_session_find(struct net *net, struct l2tp_tunnel *tunnel, u32 session_id);
 226 extern struct l2tp_session *l2tp_session_find_nth(struct l2tp_tunnel *tunnel, int nth);
 227 extern struct l2tp_tunnel *l2tp_tunnel_find(struct net *net, u32 tunnel_id);
 228 extern struct l2tp_tunnel *l2tp_tunnel_find_nth(struct net *net, int nth);
 229
 230 extern 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);
 231 extern 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);
 232 extern void l2tp_tunnel_free(struct l2tp_tunnel *tunnel);
 233 extern void l2tp_session_free(struct l2tp_session *session);
 234 extern void l2tp_recv_common(struct l2tp_session *session, struct sk_buff *skb, unsigned char *ptr, unsigned char *optr, u16 hdrflags, int length, int (*payload_hook)(struct sk_buff *skb));
 235 extern int l2tp_udp_recv_core(struct l2tp_tunnel *tunnel, struct sk_buff *skb, int (*payload_hook)(struct sk_buff *skb));
 236 extern int l2tp_udp_encap_recv(struct sock *sk, struct sk_buff *skb);
 237
 238 extern int l2tp_xmit_core(struct l2tp_session *session, struct sk_buff *skb, size_t data_len);
 239 extern int l2tp_xmit_skb(struct l2tp_session *session, struct sk_buff *skb, int hdr_len);
 240 extern void l2tp_tunnel_destruct(struct sock *sk);
 241 extern void l2tp_tunnel_closeall(struct l2tp_tunnel *tunnel);
 242 extern void l2tp_session_set_header_len(struct l2tp_session *session, int version);
 243
 244 /* Tunnel reference counts. Incremented per session that is added to
 245  * the tunnel.
 246  */
 247 static inline void l2tp_tunnel_inc_refcount_1(struct l2tp_tunnel *tunnel)
 248 {
 249         atomic_inc(&tunnel->ref_count);
 250 }
 251
 252 static inline void l2tp_tunnel_dec_refcount_1(struct l2tp_tunnel *tunnel)
 253 {
 254         if (atomic_dec_and_test(&tunnel->ref_count))
 255                 l2tp_tunnel_free(tunnel);
 256 }
 257 #ifdef L2TP_REFCNT_DEBUG
 258 #define l2tp_tunnel_inc_refcount(_t) do { \
 259                 printk(KERN_DEBUG "l2tp_tunnel_inc_refcount: %s:%d %s: cnt=%d\n", __func__, __LINE__, (_t)->name, atomic_read(&_t->ref_count)); \
 260                 l2tp_tunnel_inc_refcount_1(_t);                         \
 261         } while (0)
 262 #define l2tp_tunnel_dec_refcount(_t) do { \
 263                 printk(KERN_DEBUG "l2tp_tunnel_dec_refcount: %s:%d %s: cnt=%d\n", __func__, __LINE__, (_t)->name, atomic_read(&_t->ref_count)); \
 264                 l2tp_tunnel_dec_refcount_1(_t);                         \
 265         } while (0)
 266 #else
 267 #define l2tp_tunnel_inc_refcount(t) l2tp_tunnel_inc_refcount_1(t)
 268 #define l2tp_tunnel_dec_refcount(t) l2tp_tunnel_dec_refcount_1(t)
 269 #endif
 270
 271 /* Session reference counts. Incremented when code obtains a reference
 272  * to a session.
 273  */
 274 static inline void l2tp_session_inc_refcount_1(struct l2tp_session *session)
 275 {
 276         atomic_inc(&session->ref_count);
 277 }
 278
 279 static inline void l2tp_session_dec_refcount_1(struct l2tp_session *session)
 280 {
 281         if (atomic_dec_and_test(&session->ref_count))
 282                 l2tp_session_free(session);
 283 }
 284
 285 #ifdef L2TP_REFCNT_DEBUG
 286 #define l2tp_session_inc_refcount(_s) do { \
 287                 printk(KERN_DEBUG "l2tp_session_inc_refcount: %s:%d %s: cnt=%d\n", __func__, __LINE__, (_s)->name, atomic_read(&_s->ref_count)); \
 288                 l2tp_session_inc_refcount_1(_s);                                \
 289         } while (0)
 290 #define l2tp_session_dec_refcount(_s) do { \
 291                 printk(KERN_DEBUG "l2tp_session_dec_refcount: %s:%d %s: cnt=%d\n", __func__, __LINE__, (_s)->name, atomic_read(&_s->ref_count)); \
 292                 l2tp_session_dec_refcount_1(_s);                                \
 293         } while (0)
 294 #else
 295 #define l2tp_session_inc_refcount(s) l2tp_session_inc_refcount_1(s)
 296 #define l2tp_session_dec_refcount(s) l2tp_session_dec_refcount_1(s)
 297 #endif
 298
 299 #endif /* _L2TP_CORE_H_ */