net/cor/cor.h

   1 /*
   2  *      Connection oriented routing
   3  *      Copyright (C) 2007-2008 Michael Blizek
   4  *
   5  *      This program is free software; you can redistribute it and/or
   6  *      modify it under the terms of the GNU General Public License
   7  *      as published by the Free Software Foundation; either version 2
   8  *      of the License, or (at your option) any later version.
   9  *
  10  *      This program is distributed in the hope that it will be useful,
  11  *      but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  *      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  *      GNU General Public License for more details.
  14  *
  15  *      You should have received a copy of the GNU General Public License
  16  *      along with this program; if not, write to the Free Software
  17  *      Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  18  *      02110-1301, USA.
  19  */
  20
  21 #include <asm/atomic.h>
  22
  23 #include <linux/types.h>
  24 #include <linux/netdevice.h>
  25 #include <linux/skbuff.h>
  26 #include <linux/spinlock.h>
  27 #include <linux/workqueue.h>
  28 #include <linux/kref.h>
  29
  30 #include "settings.h"
  31
  32
  33 /* options */
  34 #define PIDOUT_NEWCONN 16
  35 #define PIDOUT_SENDDEF_THRES 8
  36 #define PIDOUT_SENDDEF_COUNT 16
  37
  38
  39
  40 #define ETH_P_COR 0x1022
  41 #define AF_COR 37
  42 #define PF_COR AF_COR
  43
  44 #define SOCKADDRTYPE_PORT 1
  45 struct cor_sockaddr {
  46         int type;
  47
  48         union {
  49                 __be64 port;
  50         } addr;
  51 };
  52
  53 #define MAX_CONN_CMD_LEN 4096
  54
  55
  56 #define PACKET_TYPE_ANNOUNCE 1
  57 #define PACKET_TYPE_DATA 2
  58
  59 /*
  60  * Kernel packet data - these commands are sent by the neighbor
  61  * The end nodes may cause these commands to be sent, but they see them beyond
  62  * the first hop.
  63  */
  64
  65 /* KP_PADDING[1] */
  66 #define KP_PADDING 1
  67
  68 /*
  69  * KP_PING[1] cookie[4]
  70  * KP_PONG[1] cookie[4] respdelay[4]
  71  *
  72  * This is needed to find out whether the other node is reachable. After a new
  73  * neighbor is seen, ping requests are sent and the neighbor is only reachable
  74  * after a few pongs are received. These requests are also used to find out
  75  * whether a neighber is gone.
  76  *
  77  * respdelay:
  78  * The receiver of a ping may delay the sending of the pong e.g. to create
  79  * bigger kernel packets. The respdelay is the time in microseconds the packet
  80  * was delayed.
  81  */
  82 #define KP_PING 2
  83 #define KP_PONG 3
  84
  85 /* KP_ACK[1] sent_conn_id[4] seqno[4]
  86  *
  87  * sent_conn_id means that this is *not* the conn_id we use if we sent something
  88  * through this conn, but the conn_id that the neighbor used to send us the
  89  * packet
  90  */
  91 #define KP_ACK 4
  92
  93 /*
  94  * KP_SPEED[1] conn_id[4] speedinfo[2]
  95  *
  96  * speedinfo[2] =
  97  *     buffer_state_value = speedinfo % 181
  98  *     speed_value = speedinfo / 181
  99  *
 100  *     buffer_state = 1024 * pow(2, buffer_state_value/3.0)
 101  *     speed = 1024 * pow(2, speed_value/12.0)
 102  *   see the .0 ...
 103  *
 104  * This has to be done either with floating points (which is no so nice) or
 105  * you can calculate:
 106  *     buffer_state =  pow(2, value/3) *
 107  *         1024 * pow(pow(2, 1.0/3), buffer_state_value%3)
 108  *   where 1024 * pow(pow(2, 1.0/4), value%3) can be just a table lookup
 109  *   (the "1024" should be part of the value in the table, because it increases
 110  *   the accuracy)
 111  *
 112  *   you can do the same with the speed
 113  *
 114  *
 115  * Some values have special meanings:
 116  *   if speedinfo is the highest possible value(65535), it means both values
 117  *     are inifinite
 118  *   if buffer_state_value if > 91, you have to subtract 90 and make the
 119  *     resulting buffer_state negative
 120  */
 121 #define KP_SPEED 5
 122
 123 /* NOTE on connection ids:
 124  * connection ids we send are used for the receive channel
 125  * connection ids we receive are used for the send channel
 126  */
 127
 128 /*
 129  * incoming connection
 130  * KP_CONNECT[1] conn_id[4]
 131  */
 132 #define KP_CONNECT 6
 133
 134 /*
 135  * incoming connection successful,
 136  * the first conn_id is the same as previously sent/received in KP_CONNECT
 137  * the second conn_id is generated by us and used for the other direction
 138  * KP_CONNECT_SUCCESS[1] conn_id[4] conn_id[4]
 139  */
 140 #define KP_CONNECT_SUCCESS 7
 141
 142 /* KP_CONN_DATA[1] conn_id[4] seqno[4] length[2] data[length] */
 143 #define KP_CONN_DATA 8
 144
 145 /*
 146  * { KP_RESET_CONN[1] conn_id[4] }
 147  * We send this, if there is an established connection we want to close.
 148  */
 149 #define KP_RESET_CONN 9
 150
 151
 152 /*
 153  * Connection data which in interpreted when connection has no target yet
 154  * These commands are sent by the end node.
 155  *
 156  * Format:
 157  * cmd[2] length[4] parameter[length]
 158  * unrecogniced commands are ignored
 159  * parameters which are longer than expected are ignored as well
 160  */
 161
 162 /* outgoing connection: CD_CONNECT_NB[2] length[4]
 163  * addrtypelen[2] addrlen[2] addrtype[addrtypelen] addr[addrlen] */
 164 #define CD_CONNECT_NB 1
 165
 166 /* connection to local open part: CD_CONNECT_PORT[2] length[4] port[8] */
 167 #define CD_CONNECT_PORT 2
 168
 169 /*
 170  * CD_LIST_NEIGH sends CDR_BINDATA if the command was successful. The response
 171  * format is:
 172  *
 173  * totalneighs[4] response_rows[4]
 174  * for every row:
 175  *   numaddr[2] (addrtypelen[2] addrlen[2] addrtype[addrtypelen] addr[addrlen]
 176  *       )[numaddr]
 177  *
 178  * Neighbors have to be sorted by uptime, new neighbors first. This is so that
 179  * the routing daemon can easily find out whether there are new neighbors. It
 180  * only needs to send a query with offset 0. If the totalneighs stays the same
 181  * while new were added, a connection to another neighbor was lost.
 182  */
 183
 184 /* list connected neighbors: CD_LIST_NEIGH[2] length[4] limit[4] offset[4] */
 185 #define CD_LIST_NEIGH 3
 186
 187 /*
 188  * CD_SET_(FORWARD|BACKWARD)_TIMEOUT[2] length[4] timeout_ms[4]
 189  *
 190  * If there is no successful communication with the previous or neighbor for
 191  * this period, the connection will be reset. This value must be between
 192  * NB_STALL_TIME and NB_KILL_TIME. Otherwise it will silently behave as if it
 193  * was set to exactly one of these limits.
 194  */
 195 #define CD_SET_FORWARD_TIMEOUT 4
 196 #define CD_SET_BACKWARD_TIMEOUT 5
 197
 198 /*
 199  * Connection data response
 200  * Format is the same as with connection data
 201  */
 202
 203 /*
 204  * {CDR_EXECOK[2] || CDR_EXECFAILED[2]}
 205  * reasoncode[2] reasontextlength[2] reasontext[reasontextlength]
 206  * reasontextlength may be 0
 207  */
 208 #define CDR_EXECOK 32768
 209         #define CDR_EXECOK_OK 33024
 210
 211
 212 #define CDR_EXECFAILED 32769
 213         #define CDR_EXECFAILED_UNKNOWN_COMMAND 33280
 214         #define CDR_EXECFAILED_PERMISSION_DENIED 33281
 215         #define CDR_EXECFAILED_TEMPORARILY_OUT_OF_RESSOURCES 33282
 216         #define CDR_EXECFAILED_CMD_TOO_SHORT 33283
 217         #define CDR_EXECFAILED_CMD_TOO_LONG 33284
 218         #define CDR_EXECFAILED_TARGETADDRTYPE_UNKNOWN 33285
 219         #define CDR_EXECFAILED_TARGETADDR_DOESNTEXIST 33286
 220         #define CDR_EXECFAILED_TARGETADDR_PORTCLOSED 33287
 221         #define CDR_EXECFAILED_LISTENERQUEUE_FULL 33288
 222         #define CDR_EXECFAILED_ILLEGAL_COMMAND 33289
 223
 224 /*
 225  * must be sent after CDR_EXEC{OK|FAILED}
 226  * CDR_EXEOK_BINDATA[2] bindatalen[4] bindata[bindatalen] */
 227 #define CDR_BINDATA 32770
 228
 229
 230 /* result codes for rcv.c/proc_packet */
 231 #define RC_DROP 0
 232 #define RC_FINISHED 1
 233
 234 #define RC_RCV1_ANNOUNCE 2
 235 #define RC_RCV1_KERNEL 3
 236 #define RC_RCV1_CONN 4
 237
 238 struct htab_entry{
 239         /* start of next element, *not* next htab_entry */
 240         void *next;
 241 };
 242
 243 struct htable{
 244         struct htab_entry **htable;
 245         __u32 htable_size;
 246         __u32 cell_size;
 247         __u32 num_elements;
 248
 249         int (*matches)(void *htentry, void *searcheditem);
 250         __u32 key_offset;
 251         __u32 entry_offset;
 252         __u32 kref_offset;
 253 };
 254
 255 struct ping_cookie{
 256         unsigned long time;
 257         __u32 cookie;
 258         __u8 pongs; /* count of pongs for pings sent after this one */
 259 };
 260
 261 #define NEIGHBOR_STATE_INITIAL 0
 262 #define NEIGHBOR_STATE_ACTIVE 1
 263 #define NEIGHBOR_STATE_STALLED 2
 264 #define NEIGHBOR_STATE_KILLED 3
 265
 266 struct neighbor{
 267         struct list_head nb_list;
 268
 269         struct kref ref;
 270
 271         struct net_device *dev;
 272         char mac[MAX_ADDR_LEN];
 273
 274         char *addr;
 275         __u16 addrlen;
 276
 277         struct delayed_work cmsg_timer;
 278         struct mutex cmsg_lock;
 279         struct list_head control_msgs_out;
 280         /**
 281          * urgent messages; These are sent even if the neighbor state is not
 282          * active. If the queue gets full, the oldest ones are dropped. It thus
 283          * may only contain messages which are allowed to be dropped.
 284          */
 285         struct list_head ucontrol_msgs_out;
 286         __u64 timeout;
 287         __u32 cmlength;
 288         __u32 ucmlength;
 289
 290
 291         unsigned long last_ping_time; /* protected by cmsg_lock */
 292         __u32 noping_cnt;/* protected by cmsg_lock */
 293
 294         struct mutex pingcookie_lock;
 295         __u32 ping_intransit;
 296         struct ping_cookie cookies[PING_COOKIES_PER_NEIGH];
 297         __u32 lastcookie;
 298         atomic_t latency; /* microsecs */
 299
 300         spinlock_t state_lock;
 301         union {
 302                 __u64 last_state_change;/* initial state */
 303                 /**
 304                  * last_roundtrip:
 305                  * time of the last sent packet which has been acked or
 306                  * otherwise responded to (e.g. pong)
 307                  */
 308                 unsigned long last_roundtrip;/* active/stalled state */
 309         }state_time;
 310         __u8 state;
 311         __u16 ping_success;
 312
 313         struct delayed_work stalltimeout_timer;
 314         __u8 str_timer_pending;
 315
 316
 317         atomic_t kpacket_seqno;
 318         atomic_t ooo_packets;
 319
 320         /*
 321          * connecions which receive data from/send data to this node
 322          * used when terminating all connections of a neighbor
 323          */
 324         struct mutex conn_list_lock;
 325         struct list_head rcv_conn_list;
 326         struct list_head snd_conn_list;
 327
 328         /*
 329          * the timer has to be inited when adding the neighbor
 330          * init_timer(struct timer_list * timer);
 331          * add_timer(struct timer_list * timer);
 332          */
 333         spinlock_t retrans_lock;
 334         struct timer_list retrans_timer;
 335         __u8 retrans_timer_running;
 336
 337         /*
 338          * next_retransmit are linked with
 339          * skb_procstate->funcstate.retransmit_queue
 340          * because the sk_buff next/prev fields are needed by the hashtable
 341          */
 342         struct sk_buff_head retrans_list;
 343
 344         struct conn *firstboundconn;
 345 };
 346
 347 struct cor_sched_data{
 348         spinlock_t lock;
 349         struct list_head conn_list;
 350         struct sk_buff_head requeue_queue;
 351 };
 352
 353 #define TYPE_BUF 0
 354 #define TYPE_SKB 1
 355
 356 struct data_buf_item{
 357         struct list_head buf_list;
 358
 359         union {
 360                 struct {
 361                         char *buf;
 362                         __u32 datalen;
 363
 364                 }buf;
 365
 366                 struct sk_buff *skb;
 367         }data;
 368
 369         __u8 type;
 370 };
 371
 372 struct data_buf{
 373         struct list_head items;
 374         struct data_buf_item *lastread;
 375         __u64 first_offset;
 376         __u64 read_offset;
 377
 378         __u32 totalsize;
 379         __u32 read_remaining;
 380
 381         __u16 last_read_offset;
 382
 383         __u16 last_buflen;
 384 };
 385
 386 struct connlistener;
 387
 388 struct bindnode{
 389         struct list_head lh;
 390         struct connlistener *owner;
 391         __be64 port;
 392 };
 393
 394 #define SOCKSTATE_LISTENER 1
 395 #define SOCKSTATE_CONN 2
 396
 397 struct sock_hdr {
 398         /* The first member of connlistener/conn (see sock.c) */
 399         __u8 sockstate;
 400 };
 401
 402 struct connlistener {
 403         /* The first member has to be the same as in conn (see sock.c) */
 404         __u8 sockstate;
 405         struct bindnode *bn;
 406         struct mutex lock;
 407         int queue_maxlen;
 408         int queue_len;
 409         struct list_head conn_queue;
 410         wait_queue_head_t wait;
 411
 412 };
 413
 414 /*
 415  * There are 2 conn objects per bi-directional connection. They refer to each
 416  * other with in the reversedir field. To distinguish them, the variables on
 417  * the stack are usually called rconn and sconn. rconn refers to the conn object
 418  * which has received a command. sconn is the other conn object. This means that
 419  * in send functions rconn means the connection we want to send the command to.
 420  */
 421
 422 struct conn{
 423         /* The first member has to be the same as in connlistener (see sock.c)*/
 424         __u8 sockstate;
 425
 426 #define SOURCE_NONE 0
 427 #define SOURCE_IN 1
 428 #define SOURCE_SOCK 2
 429
 430 #define TARGET_UNCONNECTED 0
 431 #define TARGET_OUT 1
 432 #define TARGET_SOCK 2
 433
 434         __u8    sourcetype:4,
 435                 targettype:4;
 436         __u8 isreset;
 437         __u8 qdisc_active;
 438         struct list_head queue_list;
 439
 440         struct kref ref;
 441
 442         struct mutex rcv_lock;
 443
 444         /* state */
 445         __u32 credits;
 446         /* credit rate */
 447         __s32 sender_crate;
 448         __s32 resp_crate;
 449
 450         union{
 451                 struct{
 452                         struct neighbor *nb;
 453                         /* list of all connections from this neighbor */
 454                         struct list_head nb_list;
 455
 456                         struct sk_buff_head reorder_queue;
 457
 458                         struct htab_entry htab_entry;
 459                         __u32 conn_id;
 460                         __u32 next_seqno;
 461                         __u32 ooo_packets;
 462                 }in;
 463
 464                 struct{
 465                         struct list_head cl_list;
 466                         wait_queue_head_t wait;
 467                         struct socket *sock;
 468                         int flags;
 469                 }sock;
 470         }source;
 471
 472         union{
 473                 struct{
 474                         __u32 paramlen;
 475                         __u32 cmdread;
 476                         __u16 cmd;
 477                         __u8 *cmdparams;
 478
 479                         __u32 stall_timeout_ms;
 480                 }unconnected;
 481
 482                 struct{
 483                         /* has to be first (because it is first in target
 484                          * kernel too)
 485                          */
 486                         struct neighbor *nb;
 487                         /* list of all connections to this neighbor */
 488                         struct list_head nb_list;
 489
 490                         __u32 conn_id;
 491                         __u32 seqno;
 492
 493                         __u32 stall_timeout_ms;
 494                 }out;
 495
 496                 struct{
 497                         wait_queue_head_t wait;
 498                 }sock;
 499         }target;
 500
 501         struct data_buf buf;
 502
 503         struct conn *reversedir;
 504 };
 505
 506 /* inside skb->cb */
 507 struct skb_procstate{
 508         struct conn *rconn;
 509
 510         union{
 511                 struct{
 512                         struct work_struct work;
 513                 }rcv;
 514
 515                 struct{
 516                         __u32 offset;
 517                 }announce;
 518
 519                 struct{
 520                         __u32 conn_id;
 521                         __u32 seqno;
 522                 }rcv2;
 523
 524                 struct{
 525                         struct htab_entry htab_entry;
 526                         struct kref ref;
 527                         unsigned long timeout;
 528                         __u32 conn_id;
 529                         __u32 seqno;
 530                         struct neighbor *nb;
 531                 }retransmit_queue;
 532         }funcstate;
 533 };
 534
 535
 536 /* common.c */
 537 extern char *htable_get(struct htable *ht, __u32 key, void *searcheditem);
 538
 539 extern int htable_delete(struct htable *ht, __u32 key, void *searcheditem,
 540                 void (*free) (struct kref *ref));
 541
 542 extern void htable_insert(struct htable *ht, char *newelement, __u32 key);
 543
 544 extern void htable_init(struct htable *ht, int (*matches)(void *htentry,
 545                 void *searcheditem), __u32 entry_offset,
 546                 __u32 kref_offset);
 547
 548 extern struct conn *get_conn(__u32 conn_id);
 549
 550 extern void free_conn(struct kref *ref);
 551
 552 extern int conn_init_out(struct conn *rconn, struct neighbor *nb);
 553
 554 extern void conn_init_sock_source(struct conn *conn);
 555 extern void conn_init_sock_target(struct conn *conn);
 556
 557 extern void close_port(struct connlistener *listener);
 558
 559 extern struct connlistener *open_port(__be64 port);
 560
 561 extern int connect_port(struct conn *rconn, __be64 port);
 562
 563 extern int connect_neigh(struct conn *rconn,
 564                 __u16 addrtypelen, __u8 *addrtype,
 565                 __u16 addrlen, __u8 *addr);
 566
 567 extern struct conn* alloc_conn(gfp_t allocflags);
 568
 569 extern void reset_conn(struct conn *conn);
 570
 571 /* neighbor.c */
 572 extern void neighbor_free(struct kref *ref);
 573
 574 extern struct neighbor *get_neigh_by_mac(struct sk_buff *skb);
 575
 576 extern struct neighbor *find_neigh(__u16 addrtypelen, __u8 *addrtype,
 577                 __u16 addrlen, __u8 *addr);
 578
 579 extern __u32 generate_neigh_list(char *buf, __u32 buflen, __u32 limit,
 580                 __u32 offset);
 581
 582 extern int get_neigh_state(struct neighbor *nb);
 583
 584 extern void ping_resp(struct neighbor *nb, __u32 cookie, __u32 respdelay);
 585
 586 extern __u32 add_ping_req(struct neighbor *nb);
 587
 588 extern int time_to_send_ping(struct neighbor *nb);
 589
 590 extern int force_ping(struct neighbor *nb);
 591
 592 extern void rcv_announce(struct sk_buff *skb);
 593
 594 extern int __init cor_neighbor_init(void);
 595
 596 /* rcv.c */
 597 extern void drain_ooo_queue(struct conn *rconn);
 598
 599 extern void conn_rcv_buildskb(char *data, __u32 datalen, __u32 conn_id,
 600                 __u32 seqno);
 601
 602 extern int __init cor_rcv_init(void);
 603
 604 /* kpacket_parse.c */
 605 extern void kernel_packet(struct neighbor *nb, struct sk_buff *skb, __u32 seqno);
 606
 607 /* kpacket_gen.c */
 608 extern void schedule_controlmsg_timerfunc(struct neighbor *nb);
 609
 610 struct control_msg_out;
 611
 612 extern struct control_msg_out *alloc_control_msg(void);
 613
 614 extern void free_control_msg(struct control_msg_out *cm);
 615
 616 extern void send_pong(struct control_msg_out *cm, struct neighbor *nb,
 617                 __u32 cookie);
 618
 619 extern void send_reset_conn(struct control_msg_out *cm, struct neighbor *nb,
 620                 __u32 conn_id);
 621
 622 extern void send_ack(struct control_msg_out *cm, struct neighbor *nb,
 623                 __u32 conn_id, __u32 seqno);
 624
 625 extern void send_connect_success(struct control_msg_out *cm,
 626                 struct neighbor *nb, __u32 rcvd_conn_id, __u32 gen_conn_id);
 627
 628 extern void send_connect_nb(struct control_msg_out *cm, struct neighbor *nb,
 629                 __u32 conn_id);
 630
 631 extern void send_conndata(struct control_msg_out *cm, struct neighbor *nb,
 632                 __u32 connid, __u32 seqno, char *data_orig, char *data,
 633                 __u32 datalen);
 634
 635 /* cpacket_parse.c */
 636 extern void parse(struct conn *rconn);
 637
 638 /* snd.c */
 639 extern void retransmit_timerfunc(unsigned long arg);
 640
 641 extern struct sk_buff *create_packet_conn(struct conn *target, int size,
 642                 gfp_t alloc_flags);
 643
 644 extern struct sk_buff *create_packet_kernel(struct neighbor *nb, int size,
 645                 gfp_t alloc_flags);
 646
 647 extern void send_conn_flushdata(struct conn *rconn, char *data, __u32 datalen);
 648
 649 extern void send_packet(struct sk_buff *skb, struct neighbor *nb,
 650                 int retransmit);
 651
 652 extern void ack_received(struct neighbor *nb, __u32 conn_id, __u32 seqno);
 653
 654 extern void flush_out(struct conn *rconn);
 655
 656 extern int __init cor_snd_init(void);
 657
 658 /* forward.c */
 659 extern void databuf_pull(struct data_buf *data, char *dst, int len);
 660
 661 extern size_t databuf_pulluser(struct conn *sconn, struct msghdr *msg);
 662
 663 extern void databuf_ack(struct data_buf *buf, __u64 pos);
 664
 665 extern void databuf_ackread(struct data_buf *buf);
 666
 667 extern int databuf_maypush(struct data_buf *buf);
 668
 669 extern void databuf_free(struct data_buf *data);
 670
 671 extern void databuf_init(struct data_buf *data);
 672
 673 extern int receive_userbuf(struct conn *rconn, struct msghdr *msg);
 674
 675 extern void receive_buf(struct conn *rconn, char *buf, int len);
 676
 677 extern int receive_skb(struct conn *rconn, struct sk_buff *skb);
 678
 679 extern void wake_sender(struct conn *rconn);
 680
 681 extern void forward_init(void);
 682
 683
 684
 685 static inline struct skb_procstate *skb_pstate(struct sk_buff *skb)
 686 {
 687         return (struct skb_procstate *) &(skb->cb[0]);
 688 }
 689
 690 static inline struct sk_buff *skb_from_pstate(struct skb_procstate *ps)
 691 {
 692         return (struct sk_buff *) (((char *)ps) - offsetof(struct sk_buff,cb));
 693 }
 694
 695
 696 static inline __u32 mss(struct neighbor *nb)
 697 {
 698         return nb->dev->mtu - LL_RESERVED_SPACE(nb->dev) - 9;
 699 }
 700
 701
 702 static inline void put_u64(char *dst, __u64 value, int convbo)
 703 {
 704         char *p_value = (char *) &value;
 705
 706         if (convbo)
 707                 value = cpu_to_be64(value);
 708
 709         dst[0] = p_value[0];
 710         dst[1] = p_value[1];
 711         dst[2] = p_value[2];
 712         dst[3] = p_value[3];
 713         dst[4] = p_value[4];
 714         dst[5] = p_value[5];
 715         dst[6] = p_value[6];
 716         dst[7] = p_value[7];
 717 }
 718
 719 static inline void put_u32(char *dst, __u32 value, int convbo)
 720 {
 721         char *p_value = (char *) &value;
 722
 723         if (convbo)
 724                 value = cpu_to_be32(value);
 725
 726         dst[0] = p_value[0];
 727         dst[1] = p_value[1];
 728         dst[2] = p_value[2];
 729         dst[3] = p_value[3];
 730 }
 731
 732 static inline void put_u16(char *dst, __u16 value, int convbo)
 733 {
 734         char *p_value = (char *) &value;
 735
 736         if (convbo)
 737                 value = cpu_to_be16(value);
 738
 739         dst[0] = p_value[0];
 740         dst[1] = p_value[1];
 741 }
 742
 743 static inline char *cor_pull_skb(struct sk_buff *skb, unsigned int len)
 744 {
 745         char *ptr = skb_pull(skb, len);
 746
 747         if(ptr == 0)
 748                 return 0;
 749
 750         return ptr - len;
 751 }