net/llc/llc_c_ac.c

   1 /*
   2  * llc_c_ac.c - actions performed during connection state transition.
   3  *
   4  * Description:
   5  *   Functions in this module are implementation of connection component actions
   6  *   Details of actions can be found in IEEE-802.2 standard document.
   7  *   All functions have one connection and one event as input argument. All of
   8  *   them return 0 On success and 1 otherwise.
   9  *
  10  * Copyright (c) 1997 by Procom Technology, Inc.
  11  *               2001-2003 by Arnaldo Carvalho de Melo <acme@conectiva.com.br>
  12  *
  13  * This program can be redistributed or modified under the terms of the
  14  * GNU General Public License as published by the Free Software Foundation.
  15  * This program is distributed without any warranty or implied warranty
  16  * of merchantability or fitness for a particular purpose.
  17  *
  18  * See the GNU General Public License for more details.
  19  */
  20 #include <linux/netdevice.h>
  21 #include <net/llc_conn.h>
  22 #include <net/llc_sap.h>
  23 #include <net/sock.h>
  24 #include <net/llc_c_ev.h>
  25 #include <net/llc_c_ac.h>
  26 #include <net/llc_c_st.h>
  27 #include <net/llc_pdu.h>
  28 #include <net/llc.h>
  29
  30
  31 static int llc_conn_ac_inc_vs_by_1(struct sock *sk, struct sk_buff *skb);
  32 static void llc_process_tmr_ev(struct sock *sk, struct sk_buff *skb);
  33 static int llc_conn_ac_data_confirm(struct sock *sk, struct sk_buff *ev);
  34
  35 static int llc_conn_ac_inc_npta_value(struct sock *sk, struct sk_buff *skb);
  36
  37 static int llc_conn_ac_send_rr_rsp_f_set_ackpf(struct sock *sk,
  38                                                struct sk_buff *skb);
  39
  40 static int llc_conn_ac_set_p_flag_1(struct sock *sk, struct sk_buff *skb);
  41
  42 #define INCORRECT 0
  43
  44 int llc_conn_ac_clear_remote_busy(struct sock *sk, struct sk_buff *skb)
  45 {
  46         struct llc_sock *llc = llc_sk(sk);
  47
  48         if (llc->remote_busy_flag) {
  49                 u8 nr;
  50                 struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
  51
  52                 llc->remote_busy_flag = 0;
  53                 del_timer(&llc->busy_state_timer.timer);
  54                 nr = LLC_I_GET_NR(pdu);
  55                 llc_conn_resend_i_pdu_as_cmd(sk, nr, 0);
  56         }
  57         return 0;
  58 }
  59
  60 int llc_conn_ac_conn_ind(struct sock *sk, struct sk_buff *skb)
  61 {
  62         struct llc_conn_state_ev *ev = llc_conn_ev(skb);
  63
  64         ev->ind_prim = LLC_CONN_PRIM;
  65         return 0;
  66 }
  67
  68 int llc_conn_ac_conn_confirm(struct sock *sk, struct sk_buff *skb)
  69 {
  70         struct llc_conn_state_ev *ev = llc_conn_ev(skb);
  71
  72         ev->cfm_prim = LLC_CONN_PRIM;
  73         return 0;
  74 }
  75
  76 static int llc_conn_ac_data_confirm(struct sock *sk, struct sk_buff *skb)
  77 {
  78         struct llc_conn_state_ev *ev = llc_conn_ev(skb);
  79
  80         ev->cfm_prim = LLC_DATA_PRIM;
  81         return 0;
  82 }
  83
  84 int llc_conn_ac_data_ind(struct sock *sk, struct sk_buff *skb)
  85 {
  86         llc_conn_rtn_pdu(sk, skb);
  87         return 0;
  88 }
  89
  90 int llc_conn_ac_disc_ind(struct sock *sk, struct sk_buff *skb)
  91 {
  92         struct llc_conn_state_ev *ev = llc_conn_ev(skb);
  93         u8 reason = 0;
  94         int rc = 0;
  95
  96         if (ev->type == LLC_CONN_EV_TYPE_PDU) {
  97                 struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb);
  98
  99                 if (LLC_PDU_IS_RSP(pdu) &&
 100                     LLC_PDU_TYPE_IS_U(pdu) &&
 101                     LLC_U_PDU_RSP(pdu) == LLC_2_PDU_RSP_DM)
 102                         reason = LLC_DISC_REASON_RX_DM_RSP_PDU;
 103                 else if (LLC_PDU_IS_CMD(pdu) &&
 104                            LLC_PDU_TYPE_IS_U(pdu) &&
 105                            LLC_U_PDU_CMD(pdu) == LLC_2_PDU_CMD_DISC)
 106                         reason = LLC_DISC_REASON_RX_DISC_CMD_PDU;
 107         } else if (ev->type == LLC_CONN_EV_TYPE_ACK_TMR)
 108                 reason = LLC_DISC_REASON_ACK_TMR_EXP;
 109         else
 110                 rc = -EINVAL;
 111         if (!rc) {
 112                 ev->reason   = reason;
 113                 ev->ind_prim = LLC_DISC_PRIM;
 114         }
 115         return rc;
 116 }
 117
 118 int llc_conn_ac_disc_confirm(struct sock *sk, struct sk_buff *skb)
 119 {
 120         struct llc_conn_state_ev *ev = llc_conn_ev(skb);
 121
 122         ev->reason   = ev->status;
 123         ev->cfm_prim = LLC_DISC_PRIM;
 124         return 0;
 125 }
 126
 127 int llc_conn_ac_rst_ind(struct sock *sk, struct sk_buff *skb)
 128 {
 129         u8 reason = 0;
 130         int rc = 1;
 131         struct llc_conn_state_ev *ev = llc_conn_ev(skb);
 132         struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb);
 133         struct llc_sock *llc = llc_sk(sk);
 134
 135         switch (ev->type) {
 136         case LLC_CONN_EV_TYPE_PDU:
 137                 if (LLC_PDU_IS_RSP(pdu) &&
 138                     LLC_PDU_TYPE_IS_U(pdu) &&
 139                     LLC_U_PDU_RSP(pdu) == LLC_2_PDU_RSP_FRMR) {
 140                         reason = LLC_RESET_REASON_LOCAL;
 141                         rc = 0;
 142                 } else if (LLC_PDU_IS_CMD(pdu) &&
 143                            LLC_PDU_TYPE_IS_U(pdu) &&
 144                            LLC_U_PDU_CMD(pdu) == LLC_2_PDU_CMD_SABME) {
 145                         reason = LLC_RESET_REASON_REMOTE;
 146                         rc = 0;
 147                 }
 148                 break;
 149         case LLC_CONN_EV_TYPE_ACK_TMR:
 150         case LLC_CONN_EV_TYPE_P_TMR:
 151         case LLC_CONN_EV_TYPE_REJ_TMR:
 152         case LLC_CONN_EV_TYPE_BUSY_TMR:
 153                 if (llc->retry_count > llc->n2) {
 154                         reason = LLC_RESET_REASON_LOCAL;
 155                         rc = 0;
 156                 }
 157                 break;
 158         }
 159         if (!rc) {
 160                 ev->reason   = reason;
 161                 ev->ind_prim = LLC_RESET_PRIM;
 162         }
 163         return rc;
 164 }
 165
 166 int llc_conn_ac_rst_confirm(struct sock *sk, struct sk_buff *skb)
 167 {
 168         struct llc_conn_state_ev *ev = llc_conn_ev(skb);
 169
 170         ev->reason   = 0;
 171         ev->cfm_prim = LLC_RESET_PRIM;
 172         return 0;
 173 }
 174
 175 int llc_conn_ac_clear_remote_busy_if_f_eq_1(struct sock *sk,
 176                                             struct sk_buff *skb)
 177 {
 178         struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
 179
 180         if (LLC_PDU_IS_RSP(pdu) &&
 181             LLC_PDU_TYPE_IS_I(pdu) &&
 182             LLC_I_PF_IS_1(pdu) && llc_sk(sk)->ack_pf)
 183                 llc_conn_ac_clear_remote_busy(sk, skb);
 184         return 0;
 185 }
 186
 187 int llc_conn_ac_stop_rej_tmr_if_data_flag_eq_2(struct sock *sk,
 188                                                struct sk_buff *skb)
 189 {
 190         struct llc_sock *llc = llc_sk(sk);
 191
 192         if (llc->data_flag == 2)
 193                 del_timer(&llc->rej_sent_timer.timer);
 194         return 0;
 195 }
 196
 197 int llc_conn_ac_send_disc_cmd_p_set_x(struct sock *sk, struct sk_buff *skb)
 198 {
 199         int rc = -ENOBUFS;
 200         struct llc_sock *llc = llc_sk(sk);
 201         struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_U, 0);
 202
 203         if (nskb) {
 204                 struct llc_sap *sap = llc->sap;
 205
 206                 llc_pdu_header_init(nskb, LLC_PDU_TYPE_U, sap->laddr.lsap,
 207                                     llc->daddr.lsap, LLC_PDU_CMD);
 208                 llc_pdu_init_as_disc_cmd(nskb, 1);
 209                 rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
 210                 if (unlikely(rc))
 211                         goto free;
 212                 llc_conn_send_pdu(sk, nskb);
 213                 llc_conn_ac_set_p_flag_1(sk, skb);
 214         }
 215 out:
 216         return rc;
 217 free:
 218         kfree_skb(nskb);
 219         goto out;
 220 }
 221
 222 int llc_conn_ac_send_dm_rsp_f_set_p(struct sock *sk, struct sk_buff *skb)
 223 {
 224         int rc = -ENOBUFS;
 225         struct llc_sock *llc = llc_sk(sk);
 226         struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_U, 0);
 227
 228         if (nskb) {
 229                 struct llc_sap *sap = llc->sap;
 230                 u8 f_bit;
 231
 232                 llc_pdu_decode_pf_bit(skb, &f_bit);
 233                 llc_pdu_header_init(nskb, LLC_PDU_TYPE_U, sap->laddr.lsap,
 234                                     llc->daddr.lsap, LLC_PDU_RSP);
 235                 llc_pdu_init_as_dm_rsp(nskb, f_bit);
 236                 rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
 237                 if (unlikely(rc))
 238                         goto free;
 239                 llc_conn_send_pdu(sk, nskb);
 240         }
 241 out:
 242         return rc;
 243 free:
 244         kfree_skb(nskb);
 245         goto out;
 246 }
 247
 248 int llc_conn_ac_send_dm_rsp_f_set_1(struct sock *sk, struct sk_buff *skb)
 249 {
 250         int rc = -ENOBUFS;
 251         struct llc_sock *llc = llc_sk(sk);
 252         struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_U, 0);
 253
 254         if (nskb) {
 255                 struct llc_sap *sap = llc->sap;
 256
 257                 llc_pdu_header_init(nskb, LLC_PDU_TYPE_U, sap->laddr.lsap,
 258                                     llc->daddr.lsap, LLC_PDU_RSP);
 259                 llc_pdu_init_as_dm_rsp(nskb, 1);
 260                 rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
 261                 if (unlikely(rc))
 262                         goto free;
 263                 llc_conn_send_pdu(sk, nskb);
 264         }
 265 out:
 266         return rc;
 267 free:
 268         kfree_skb(nskb);
 269         goto out;
 270 }
 271
 272 int llc_conn_ac_send_frmr_rsp_f_set_x(struct sock *sk, struct sk_buff *skb)
 273 {
 274         u8 f_bit;
 275         int rc = -ENOBUFS;
 276         struct sk_buff *nskb;
 277         struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
 278         struct llc_sock *llc = llc_sk(sk);
 279
 280         llc->rx_pdu_hdr = *((u32 *)pdu);
 281         if (LLC_PDU_IS_CMD(pdu))
 282                 llc_pdu_decode_pf_bit(skb, &f_bit);
 283         else
 284                 f_bit = 0;
 285         nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_U,
 286                                sizeof(struct llc_frmr_info));
 287         if (nskb) {
 288                 struct llc_sap *sap = llc->sap;
 289
 290                 llc_pdu_header_init(nskb, LLC_PDU_TYPE_U, sap->laddr.lsap,
 291                                     llc->daddr.lsap, LLC_PDU_RSP);
 292                 llc_pdu_init_as_frmr_rsp(nskb, pdu, f_bit, llc->vS,
 293                                          llc->vR, INCORRECT);
 294                 rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
 295                 if (unlikely(rc))
 296                         goto free;
 297                 llc_conn_send_pdu(sk, nskb);
 298         }
 299 out:
 300         return rc;
 301 free:
 302         kfree_skb(nskb);
 303         goto out;
 304 }
 305
 306 int llc_conn_ac_resend_frmr_rsp_f_set_0(struct sock *sk, struct sk_buff *skb)
 307 {
 308         int rc = -ENOBUFS;
 309         struct llc_sock *llc = llc_sk(sk);
 310         struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_U,
 311                                                sizeof(struct llc_frmr_info));
 312
 313         if (nskb) {
 314                 struct llc_sap *sap = llc->sap;
 315                 struct llc_pdu_sn *pdu = (struct llc_pdu_sn *)&llc->rx_pdu_hdr;
 316
 317                 llc_pdu_header_init(nskb, LLC_PDU_TYPE_U, sap->laddr.lsap,
 318                                     llc->daddr.lsap, LLC_PDU_RSP);
 319                 llc_pdu_init_as_frmr_rsp(nskb, pdu, 0, llc->vS,
 320                                          llc->vR, INCORRECT);
 321                 rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
 322                 if (unlikely(rc))
 323                         goto free;
 324                 llc_conn_send_pdu(sk, nskb);
 325         }
 326 out:
 327         return rc;
 328 free:
 329         kfree_skb(nskb);
 330         goto out;
 331 }
 332
 333 int llc_conn_ac_resend_frmr_rsp_f_set_p(struct sock *sk, struct sk_buff *skb)
 334 {
 335         u8 f_bit;
 336         int rc = -ENOBUFS;
 337         struct sk_buff *nskb;
 338         struct llc_sock *llc = llc_sk(sk);
 339
 340         llc_pdu_decode_pf_bit(skb, &f_bit);
 341         nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_U,
 342                                sizeof(struct llc_frmr_info));
 343         if (nskb) {
 344                 struct llc_sap *sap = llc->sap;
 345                 struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
 346
 347                 llc_pdu_header_init(nskb, LLC_PDU_TYPE_U, sap->laddr.lsap,
 348                                     llc->daddr.lsap, LLC_PDU_RSP);
 349                 llc_pdu_init_as_frmr_rsp(nskb, pdu, f_bit, llc->vS,
 350                                          llc->vR, INCORRECT);
 351                 rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
 352                 if (unlikely(rc))
 353                         goto free;
 354                 llc_conn_send_pdu(sk, nskb);
 355         }
 356 out:
 357         return rc;
 358 free:
 359         kfree_skb(nskb);
 360         goto out;
 361 }
 362
 363 int llc_conn_ac_send_i_cmd_p_set_1(struct sock *sk, struct sk_buff *skb)
 364 {
 365         int rc;
 366         struct llc_sock *llc = llc_sk(sk);
 367         struct llc_sap *sap = llc->sap;
 368
 369         llc_pdu_header_init(skb, LLC_PDU_TYPE_I, sap->laddr.lsap,
 370                             llc->daddr.lsap, LLC_PDU_CMD);
 371         llc_pdu_init_as_i_cmd(skb, 1, llc->vS, llc->vR);
 372         rc = llc_mac_hdr_init(skb, llc->dev->dev_addr, llc->daddr.mac);
 373         if (likely(!rc)) {
 374                 llc_conn_send_pdu(sk, skb);
 375                 llc_conn_ac_inc_vs_by_1(sk, skb);
 376         }
 377         return rc;
 378 }
 379
 380 static int llc_conn_ac_send_i_cmd_p_set_0(struct sock *sk, struct sk_buff *skb)
 381 {
 382         int rc;
 383         struct llc_sock *llc = llc_sk(sk);
 384         struct llc_sap *sap = llc->sap;
 385
 386         llc_pdu_header_init(skb, LLC_PDU_TYPE_I, sap->laddr.lsap,
 387                             llc->daddr.lsap, LLC_PDU_CMD);
 388         llc_pdu_init_as_i_cmd(skb, 0, llc->vS, llc->vR);
 389         rc = llc_mac_hdr_init(skb, llc->dev->dev_addr, llc->daddr.mac);
 390         if (likely(!rc)) {
 391                 llc_conn_send_pdu(sk, skb);
 392                 llc_conn_ac_inc_vs_by_1(sk, skb);
 393         }
 394         return rc;
 395 }
 396
 397 int llc_conn_ac_send_i_xxx_x_set_0(struct sock *sk, struct sk_buff *skb)
 398 {
 399         int rc;
 400         struct llc_sock *llc = llc_sk(sk);
 401         struct llc_sap *sap = llc->sap;
 402
 403         llc_pdu_header_init(skb, LLC_PDU_TYPE_I, sap->laddr.lsap,
 404                             llc->daddr.lsap, LLC_PDU_CMD);
 405         llc_pdu_init_as_i_cmd(skb, 0, llc->vS, llc->vR);
 406         rc = llc_mac_hdr_init(skb, llc->dev->dev_addr, llc->daddr.mac);
 407         if (likely(!rc)) {
 408                 llc_conn_send_pdu(sk, skb);
 409                 llc_conn_ac_inc_vs_by_1(sk, skb);
 410         }
 411         return 0;
 412 }
 413
 414 int llc_conn_ac_resend_i_xxx_x_set_0(struct sock *sk, struct sk_buff *skb)
 415 {
 416         struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
 417         u8 nr = LLC_I_GET_NR(pdu);
 418
 419         llc_conn_resend_i_pdu_as_cmd(sk, nr, 0);
 420         return 0;
 421 }
 422
 423 int llc_conn_ac_resend_i_xxx_x_set_0_or_send_rr(struct sock *sk,
 424                                                 struct sk_buff *skb)
 425 {
 426         u8 nr;
 427         struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
 428         int rc = -ENOBUFS;
 429         struct llc_sock *llc = llc_sk(sk);
 430         struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_U, 0);
 431
 432         if (nskb) {
 433                 struct llc_sap *sap = llc->sap;
 434
 435                 llc_pdu_header_init(nskb, LLC_PDU_TYPE_U, sap->laddr.lsap,
 436                                     llc->daddr.lsap, LLC_PDU_RSP);
 437                 llc_pdu_init_as_rr_rsp(nskb, 0, llc->vR);
 438                 rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
 439                 if (likely(!rc))
 440                         llc_conn_send_pdu(sk, nskb);
 441                 else
 442                         kfree_skb(skb);
 443         }
 444         if (rc) {
 445                 nr = LLC_I_GET_NR(pdu);
 446                 rc = 0;
 447                 llc_conn_resend_i_pdu_as_cmd(sk, nr, 0);
 448         }
 449         return rc;
 450 }
 451
 452 int llc_conn_ac_resend_i_rsp_f_set_1(struct sock *sk, struct sk_buff *skb)
 453 {
 454         struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
 455         u8 nr = LLC_I_GET_NR(pdu);
 456
 457         llc_conn_resend_i_pdu_as_rsp(sk, nr, 1);
 458         return 0;
 459 }
 460
 461 int llc_conn_ac_send_rej_cmd_p_set_1(struct sock *sk, struct sk_buff *skb)
 462 {
 463         int rc = -ENOBUFS;
 464         struct llc_sock *llc = llc_sk(sk);
 465         struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_S, 0);
 466
 467         if (nskb) {
 468                 struct llc_sap *sap = llc->sap;
 469
 470                 llc_pdu_header_init(nskb, LLC_PDU_TYPE_S, sap->laddr.lsap,
 471                                     llc->daddr.lsap, LLC_PDU_CMD);
 472                 llc_pdu_init_as_rej_cmd(nskb, 1, llc->vR);
 473                 rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
 474                 if (unlikely(rc))
 475                         goto free;
 476                 llc_conn_send_pdu(sk, nskb);
 477         }
 478 out:
 479         return rc;
 480 free:
 481         kfree_skb(nskb);
 482         goto out;
 483 }
 484
 485 int llc_conn_ac_send_rej_rsp_f_set_1(struct sock *sk, struct sk_buff *skb)
 486 {
 487         int rc = -ENOBUFS;
 488         struct llc_sock *llc = llc_sk(sk);
 489         struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_S, 0);
 490
 491         if (nskb) {
 492                 struct llc_sap *sap = llc->sap;
 493
 494                 llc_pdu_header_init(nskb, LLC_PDU_TYPE_S, sap->laddr.lsap,
 495                                     llc->daddr.lsap, LLC_PDU_RSP);
 496                 llc_pdu_init_as_rej_rsp(nskb, 1, llc->vR);
 497                 rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
 498                 if (unlikely(rc))
 499                         goto free;
 500                 llc_conn_send_pdu(sk, nskb);
 501         }
 502 out:
 503         return rc;
 504 free:
 505         kfree_skb(nskb);
 506         goto out;
 507 }
 508
 509 int llc_conn_ac_send_rej_xxx_x_set_0(struct sock *sk, struct sk_buff *skb)
 510 {
 511         int rc = -ENOBUFS;
 512         struct llc_sock *llc = llc_sk(sk);
 513         struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_S, 0);
 514
 515         if (nskb) {
 516                 struct llc_sap *sap = llc->sap;
 517
 518                 llc_pdu_header_init(nskb, LLC_PDU_TYPE_S, sap->laddr.lsap,
 519                                     llc->daddr.lsap, LLC_PDU_RSP);
 520                 llc_pdu_init_as_rej_rsp(nskb, 0, llc->vR);
 521                 rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
 522                 if (unlikely(rc))
 523                         goto free;
 524                 llc_conn_send_pdu(sk, nskb);
 525         }
 526 out:
 527         return rc;
 528 free:
 529         kfree_skb(nskb);
 530         goto out;
 531 }
 532
 533 int llc_conn_ac_send_rnr_cmd_p_set_1(struct sock *sk, struct sk_buff *skb)
 534 {
 535         int rc = -ENOBUFS;
 536         struct llc_sock *llc = llc_sk(sk);
 537         struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_S, 0);
 538
 539         if (nskb) {
 540                 struct llc_sap *sap = llc->sap;
 541
 542                 llc_pdu_header_init(nskb, LLC_PDU_TYPE_S, sap->laddr.lsap,
 543                                     llc->daddr.lsap, LLC_PDU_CMD);
 544                 llc_pdu_init_as_rnr_cmd(nskb, 1, llc->vR);
 545                 rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
 546                 if (unlikely(rc))
 547                         goto free;
 548                 llc_conn_send_pdu(sk, nskb);
 549         }
 550 out:
 551         return rc;
 552 free:
 553         kfree_skb(nskb);
 554         goto out;
 555 }
 556
 557 int llc_conn_ac_send_rnr_rsp_f_set_1(struct sock *sk, struct sk_buff *skb)
 558 {
 559         int rc = -ENOBUFS;
 560         struct llc_sock *llc = llc_sk(sk);
 561         struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_S, 0);
 562
 563         if (nskb) {
 564                 struct llc_sap *sap = llc->sap;
 565
 566                 llc_pdu_header_init(nskb, LLC_PDU_TYPE_S, sap->laddr.lsap,
 567                                     llc->daddr.lsap, LLC_PDU_RSP);
 568                 llc_pdu_init_as_rnr_rsp(nskb, 1, llc->vR);
 569                 rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
 570                 if (unlikely(rc))
 571                         goto free;
 572                 llc_conn_send_pdu(sk, nskb);
 573         }
 574 out:
 575         return rc;
 576 free:
 577         kfree_skb(nskb);
 578         goto out;
 579 }
 580
 581 int llc_conn_ac_send_rnr_xxx_x_set_0(struct sock *sk, struct sk_buff *skb)
 582 {
 583         int rc = -ENOBUFS;
 584         struct llc_sock *llc = llc_sk(sk);
 585         struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_S, 0);
 586
 587         if (nskb) {
 588                 struct llc_sap *sap = llc->sap;
 589
 590                 llc_pdu_header_init(nskb, LLC_PDU_TYPE_S, sap->laddr.lsap,
 591                                     llc->daddr.lsap, LLC_PDU_RSP);
 592                 llc_pdu_init_as_rnr_rsp(nskb, 0, llc->vR);
 593                 rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
 594                 if (unlikely(rc))
 595                         goto free;
 596                 llc_conn_send_pdu(sk, nskb);
 597         }
 598 out:
 599         return rc;
 600 free:
 601         kfree_skb(nskb);
 602         goto out;
 603 }
 604
 605 int llc_conn_ac_set_remote_busy(struct sock *sk, struct sk_buff *skb)
 606 {
 607         struct llc_sock *llc = llc_sk(sk);
 608
 609         if (!llc->remote_busy_flag) {
 610                 llc->remote_busy_flag = 1;
 611                 mod_timer(&llc->busy_state_timer.timer,
 612                          jiffies + llc->busy_state_timer.expire);
 613         }
 614         return 0;
 615 }
 616
 617 int llc_conn_ac_opt_send_rnr_xxx_x_set_0(struct sock *sk, struct sk_buff *skb)
 618 {
 619         int rc = -ENOBUFS;
 620         struct llc_sock *llc = llc_sk(sk);
 621         struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_S, 0);
 622
 623         if (nskb) {
 624                 struct llc_sap *sap = llc->sap;
 625
 626                 llc_pdu_header_init(nskb, LLC_PDU_TYPE_S, sap->laddr.lsap,
 627                                     llc->daddr.lsap, LLC_PDU_RSP);
 628                 llc_pdu_init_as_rnr_rsp(nskb, 0, llc->vR);
 629                 rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
 630                 if (unlikely(rc))
 631                         goto free;
 632                 llc_conn_send_pdu(sk, nskb);
 633         }
 634 out:
 635         return rc;
 636 free:
 637         kfree_skb(nskb);
 638         goto out;
 639 }
 640
 641 int llc_conn_ac_send_rr_cmd_p_set_1(struct sock *sk, struct sk_buff *skb)
 642 {
 643         int rc = -ENOBUFS;
 644         struct llc_sock *llc = llc_sk(sk);
 645         struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_S, 0);
 646
 647         if (nskb) {
 648                 struct llc_sap *sap = llc->sap;
 649
 650                 llc_pdu_header_init(nskb, LLC_PDU_TYPE_S, sap->laddr.lsap,
 651                                     llc->daddr.lsap, LLC_PDU_CMD);
 652                 llc_pdu_init_as_rr_cmd(nskb, 1, llc->vR);
 653                 rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
 654                 if (unlikely(rc))
 655                         goto free;
 656                 llc_conn_send_pdu(sk, nskb);
 657         }
 658 out:
 659         return rc;
 660 free:
 661         kfree_skb(nskb);
 662         goto out;
 663 }
 664
 665 int llc_conn_ac_send_rr_rsp_f_set_1(struct sock *sk, struct sk_buff *skb)
 666 {
 667         int rc = -ENOBUFS;
 668         struct llc_sock *llc = llc_sk(sk);
 669         struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_S, 0);
 670
 671         if (nskb) {
 672                 struct llc_sap *sap = llc->sap;
 673                 u8 f_bit = 1;
 674
 675                 llc_pdu_header_init(nskb, LLC_PDU_TYPE_S, sap->laddr.lsap,
 676                                     llc->daddr.lsap, LLC_PDU_RSP);
 677                 llc_pdu_init_as_rr_rsp(nskb, f_bit, llc->vR);
 678                 rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
 679                 if (unlikely(rc))
 680                         goto free;
 681                 llc_conn_send_pdu(sk, nskb);
 682         }
 683 out:
 684         return rc;
 685 free:
 686         kfree_skb(nskb);
 687         goto out;
 688 }
 689
 690 int llc_conn_ac_send_ack_rsp_f_set_1(struct sock *sk, struct sk_buff *skb)
 691 {
 692         int rc = -ENOBUFS;
 693         struct llc_sock *llc = llc_sk(sk);
 694         struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_S, 0);
 695
 696         if (nskb) {
 697                 struct llc_sap *sap = llc->sap;
 698
 699                 llc_pdu_header_init(nskb, LLC_PDU_TYPE_S, sap->laddr.lsap,
 700                                     llc->daddr.lsap, LLC_PDU_RSP);
 701                 llc_pdu_init_as_rr_rsp(nskb, 1, llc->vR);
 702                 rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
 703                 if (unlikely(rc))
 704                         goto free;
 705                 llc_conn_send_pdu(sk, nskb);
 706         }
 707 out:
 708         return rc;
 709 free:
 710         kfree_skb(nskb);
 711         goto out;
 712 }
 713
 714 int llc_conn_ac_send_rr_xxx_x_set_0(struct sock *sk, struct sk_buff *skb)
 715 {
 716         int rc = -ENOBUFS;
 717         struct llc_sock *llc = llc_sk(sk);
 718         struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_S, 0);
 719
 720         if (nskb) {
 721                 struct llc_sap *sap = llc->sap;
 722
 723                 llc_pdu_header_init(nskb, LLC_PDU_TYPE_S, sap->laddr.lsap,
 724                                     llc->daddr.lsap, LLC_PDU_RSP);
 725                 llc_pdu_init_as_rr_rsp(nskb, 0, llc->vR);
 726                 rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
 727                 if (unlikely(rc))
 728                         goto free;
 729                 llc_conn_send_pdu(sk, nskb);
 730         }
 731 out:
 732         return rc;
 733 free:
 734         kfree_skb(nskb);
 735         goto out;
 736 }
 737
 738 int llc_conn_ac_send_ack_xxx_x_set_0(struct sock *sk, struct sk_buff *skb)
 739 {
 740         int rc = -ENOBUFS;
 741         struct llc_sock *llc = llc_sk(sk);
 742         struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_S, 0);
 743
 744         if (nskb) {
 745                 struct llc_sap *sap = llc->sap;
 746
 747                 llc_pdu_header_init(nskb, LLC_PDU_TYPE_S, sap->laddr.lsap,
 748                                     llc->daddr.lsap, LLC_PDU_RSP);
 749                 llc_pdu_init_as_rr_rsp(nskb, 0, llc->vR);
 750                 rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
 751                 if (unlikely(rc))
 752                         goto free;
 753                 llc_conn_send_pdu(sk, nskb);
 754         }
 755 out:
 756         return rc;
 757 free:
 758         kfree_skb(nskb);
 759         goto out;
 760 }
 761
 762 void llc_conn_set_p_flag(struct sock *sk, u8 value)
 763 {
 764         int state_changed = llc_sk(sk)->p_flag && !value;
 765
 766         llc_sk(sk)->p_flag = value;
 767
 768         if (state_changed)
 769                 sk->sk_state_change(sk);
 770 }
 771
 772 int llc_conn_ac_send_sabme_cmd_p_set_x(struct sock *sk, struct sk_buff *skb)
 773 {
 774         int rc = -ENOBUFS;
 775         struct llc_sock *llc = llc_sk(sk);
 776         struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_U, 0);
 777
 778         if (nskb) {
 779                 struct llc_sap *sap = llc->sap;
 780                 u8 *dmac = llc->daddr.mac;
 781
 782                 if (llc->dev->flags & IFF_LOOPBACK)
 783                         dmac = llc->dev->dev_addr;
 784                 llc_pdu_header_init(nskb, LLC_PDU_TYPE_U, sap->laddr.lsap,
 785                                     llc->daddr.lsap, LLC_PDU_CMD);
 786                 llc_pdu_init_as_sabme_cmd(nskb, 1);
 787                 rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, dmac);
 788                 if (unlikely(rc))
 789                         goto free;
 790                 llc_conn_send_pdu(sk, nskb);
 791                 llc_conn_set_p_flag(sk, 1);
 792         }
 793 out:
 794         return rc;
 795 free:
 796         kfree_skb(nskb);
 797         goto out;
 798 }
 799
 800 int llc_conn_ac_send_ua_rsp_f_set_p(struct sock *sk, struct sk_buff *skb)
 801 {
 802         u8 f_bit;
 803         int rc = -ENOBUFS;
 804         struct llc_sock *llc = llc_sk(sk);
 805         struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_U, 0);
 806
 807         llc_pdu_decode_pf_bit(skb, &f_bit);
 808         if (nskb) {
 809                 struct llc_sap *sap = llc->sap;
 810
 811                 nskb->dev = llc->dev;
 812                 llc_pdu_header_init(nskb, LLC_PDU_TYPE_U, sap->laddr.lsap,
 813                                     llc->daddr.lsap, LLC_PDU_RSP);
 814                 llc_pdu_init_as_ua_rsp(nskb, f_bit);
 815                 rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
 816                 if (unlikely(rc))
 817                         goto free;
 818                 llc_conn_send_pdu(sk, nskb);
 819         }
 820 out:
 821         return rc;
 822 free:
 823         kfree_skb(nskb);
 824         goto out;
 825 }
 826
 827 int llc_conn_ac_set_s_flag_0(struct sock *sk, struct sk_buff *skb)
 828 {
 829         llc_sk(sk)->s_flag = 0;
 830         return 0;
 831 }
 832
 833 int llc_conn_ac_set_s_flag_1(struct sock *sk, struct sk_buff *skb)
 834 {
 835         llc_sk(sk)->s_flag = 1;
 836         return 0;
 837 }
 838
 839 int llc_conn_ac_start_p_timer(struct sock *sk, struct sk_buff *skb)
 840 {
 841         struct llc_sock *llc = llc_sk(sk);
 842
 843         llc_conn_set_p_flag(sk, 1);
 844         mod_timer(&llc->pf_cycle_timer.timer,
 845                   jiffies + llc->pf_cycle_timer.expire);
 846         return 0;
 847 }
 848
 849 /**
 850  *      llc_conn_ac_send_ack_if_needed - check if ack is needed
 851  *      @sk: current connection structure
 852  *      @skb: current event
 853  *
 854  *      Checks number of received PDUs which have not been acknowledged, yet,
 855  *      If number of them reaches to "npta"(Number of PDUs To Acknowledge) then
 856  *      sends an RR response as acknowledgement for them.  Returns 0 for
 857  *      success, 1 otherwise.
 858  */
 859 int llc_conn_ac_send_ack_if_needed(struct sock *sk, struct sk_buff *skb)
 860 {
 861         u8 pf_bit;
 862         struct llc_sock *llc = llc_sk(sk);
 863
 864         llc_pdu_decode_pf_bit(skb, &pf_bit);
 865         llc->ack_pf |= pf_bit & 1;
 866         if (!llc->ack_must_be_send) {
 867                 llc->first_pdu_Ns = llc->vR;
 868                 llc->ack_must_be_send = 1;
 869                 llc->ack_pf = pf_bit & 1;
 870         }
 871         if (((llc->vR - llc->first_pdu_Ns + 1 + LLC_2_SEQ_NBR_MODULO)
 872                         % LLC_2_SEQ_NBR_MODULO) >= llc->npta) {
 873                 llc_conn_ac_send_rr_rsp_f_set_ackpf(sk, skb);
 874                 llc->ack_must_be_send   = 0;
 875                 llc->ack_pf             = 0;
 876                 llc_conn_ac_inc_npta_value(sk, skb);
 877         }
 878         return 0;
 879 }
 880
 881 /**
 882  *      llc_conn_ac_rst_sendack_flag - resets ack_must_be_send flag
 883  *      @sk: current connection structure
 884  *      @skb: current event
 885  *
 886  *      This action resets ack_must_be_send flag of given connection, this flag
 887  *      indicates if there is any PDU which has not been acknowledged yet.
 888  *      Returns 0 for success, 1 otherwise.
 889  */
 890 int llc_conn_ac_rst_sendack_flag(struct sock *sk, struct sk_buff *skb)
 891 {
 892         llc_sk(sk)->ack_must_be_send = llc_sk(sk)->ack_pf = 0;
 893         return 0;
 894 }
 895
 896 /**
 897  *      llc_conn_ac_send_i_rsp_f_set_ackpf - acknowledge received PDUs
 898  *      @sk: current connection structure
 899  *      @skb: current event
 900  *
 901  *      Sends an I response PDU with f-bit set to ack_pf flag as acknowledge to
 902  *      all received PDUs which have not been acknowledged, yet. ack_pf flag is
 903  *      set to one if one PDU with p-bit set to one is received.  Returns 0 for
 904  *      success, 1 otherwise.
 905  */
 906 static int llc_conn_ac_send_i_rsp_f_set_ackpf(struct sock *sk,
 907                                               struct sk_buff *skb)
 908 {
 909         int rc;
 910         struct llc_sock *llc = llc_sk(sk);
 911         struct llc_sap *sap = llc->sap;
 912
 913         llc_pdu_header_init(skb, LLC_PDU_TYPE_I, sap->laddr.lsap,
 914                             llc->daddr.lsap, LLC_PDU_RSP);
 915         llc_pdu_init_as_i_cmd(skb, llc->ack_pf, llc->vS, llc->vR);
 916         rc = llc_mac_hdr_init(skb, llc->dev->dev_addr, llc->daddr.mac);
 917         if (likely(!rc)) {
 918                 llc_conn_send_pdu(sk, skb);
 919                 llc_conn_ac_inc_vs_by_1(sk, skb);
 920         }
 921         return rc;
 922 }
 923
 924 /**
 925  *      llc_conn_ac_send_i_as_ack - sends an I-format PDU to acknowledge rx PDUs
 926  *      @sk: current connection structure.
 927  *      @skb: current event.
 928  *
 929  *      This action sends an I-format PDU as acknowledge to received PDUs which
 930  *      have not been acknowledged, yet, if there is any. By using of this
 931  *      action number of acknowledgements decreases, this technic is called
 932  *      piggy backing. Returns 0 for success, 1 otherwise.
 933  */
 934 int llc_conn_ac_send_i_as_ack(struct sock *sk, struct sk_buff *skb)
 935 {
 936         struct llc_sock *llc = llc_sk(sk);
 937
 938         if (llc->ack_must_be_send) {
 939                 llc_conn_ac_send_i_rsp_f_set_ackpf(sk, skb);
 940                 llc->ack_must_be_send = 0 ;
 941                 llc->ack_pf = 0;
 942         } else
 943                 llc_conn_ac_send_i_cmd_p_set_0(sk, skb);
 944         return 0;
 945 }
 946
 947 /**
 948  *      llc_conn_ac_send_rr_rsp_f_set_ackpf - ack all rx PDUs not yet acked
 949  *      @sk: current connection structure.
 950  *      @skb: current event.
 951  *
 952  *      This action sends an RR response with f-bit set to ack_pf flag as
 953  *      acknowledge to all received PDUs which have not been acknowledged, yet,
 954  *      if there is any. ack_pf flag indicates if a PDU has been received with
 955  *      p-bit set to one. Returns 0 for success, 1 otherwise.
 956  */
 957 static int llc_conn_ac_send_rr_rsp_f_set_ackpf(struct sock *sk,
 958                                                struct sk_buff *skb)
 959 {
 960         int rc = -ENOBUFS;
 961         struct llc_sock *llc = llc_sk(sk);
 962         struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_S, 0);
 963
 964         if (nskb) {
 965                 struct llc_sap *sap = llc->sap;
 966
 967                 llc_pdu_header_init(nskb, LLC_PDU_TYPE_S, sap->laddr.lsap,
 968                                     llc->daddr.lsap, LLC_PDU_RSP);
 969                 llc_pdu_init_as_rr_rsp(nskb, llc->ack_pf, llc->vR);
 970                 rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
 971                 if (unlikely(rc))
 972                         goto free;
 973                 llc_conn_send_pdu(sk, nskb);
 974         }
 975 out:
 976         return rc;
 977 free:
 978         kfree_skb(nskb);
 979         goto out;
 980 }
 981
 982 /**
 983  *      llc_conn_ac_inc_npta_value - tries to make value of npta greater
 984  *      @sk: current connection structure.
 985  *      @skb: current event.
 986  *
 987  *      After "inc_cntr" times calling of this action, "npta" increase by one.
 988  *      this action tries to make vale of "npta" greater as possible; number of
 989  *      acknowledgements decreases by increasing of "npta". Returns 0 for
 990  *      success, 1 otherwise.
 991  */
 992 static int llc_conn_ac_inc_npta_value(struct sock *sk, struct sk_buff *skb)
 993 {
 994         struct llc_sock *llc = llc_sk(sk);
 995
 996         if (!llc->inc_cntr) {
 997                 llc->dec_step = 0;
 998                 llc->dec_cntr = llc->inc_cntr = 2;
 999                 ++llc->npta;
1000                 if (llc->npta > (u8) ~LLC_2_SEQ_NBR_MODULO)
1001                         llc->npta = (u8) ~LLC_2_SEQ_NBR_MODULO;
1002         } else
1003                 --llc->inc_cntr;
1004         return 0;
1005 }
1006
1007 /**
1008  *      llc_conn_ac_adjust_npta_by_rr - decreases "npta" by one
1009  *      @sk: current connection structure.
1010  *      @skb: current event.
1011  *
1012  *      After receiving "dec_cntr" times RR command, this action decreases
1013  *      "npta" by one. Returns 0 for success, 1 otherwise.
1014  */
1015 int llc_conn_ac_adjust_npta_by_rr(struct sock *sk, struct sk_buff *skb)
1016 {
1017         struct llc_sock *llc = llc_sk(sk);
1018
1019         if (!llc->connect_step && !llc->remote_busy_flag) {
1020                 if (!llc->dec_step) {
1021                         if (!llc->dec_cntr) {
1022                                 llc->inc_cntr = llc->dec_cntr = 2;
1023                                 if (llc->npta > 0)
1024                                         llc->npta = llc->npta - 1;
1025                         } else
1026                                 llc->dec_cntr -=1;
1027                 }
1028         } else
1029                 llc->connect_step = 0 ;
1030         return 0;
1031 }
1032
1033 /**
1034  *      llc_conn_ac_adjust_npta_by_rnr - decreases "npta" by one
1035  *      @sk: current connection structure.
1036  *      @skb: current event.
1037  *
1038  *      After receiving "dec_cntr" times RNR command, this action decreases
1039  *      "npta" by one. Returns 0 for success, 1 otherwise.
1040  */
1041 int llc_conn_ac_adjust_npta_by_rnr(struct sock *sk, struct sk_buff *skb)
1042 {
1043         struct llc_sock *llc = llc_sk(sk);
1044
1045         if (llc->remote_busy_flag)
1046                 if (!llc->dec_step) {
1047                         if (!llc->dec_cntr) {
1048                                 llc->inc_cntr = llc->dec_cntr = 2;
1049                                 if (llc->npta > 0)
1050                                         --llc->npta;
1051                         } else
1052                                 --llc->dec_cntr;
1053                 }
1054         return 0;
1055 }
1056
1057 /**
1058  *      llc_conn_ac_dec_tx_win_size - decreases tx window size
1059  *      @sk: current connection structure.
1060  *      @skb: current event.
1061  *
1062  *      After receiving of a REJ command or response, transmit window size is
1063  *      decreased by number of PDUs which are outstanding yet. Returns 0 for
1064  *      success, 1 otherwise.
1065  */
1066 int llc_conn_ac_dec_tx_win_size(struct sock *sk, struct sk_buff *skb)
1067 {
1068         struct llc_sock *llc = llc_sk(sk);
1069         u8 unacked_pdu = skb_queue_len(&llc->pdu_unack_q);
1070
1071         if (llc->k - unacked_pdu < 1)
1072                 llc->k = 1;
1073         else
1074                 llc->k -= unacked_pdu;
1075         return 0;
1076 }
1077
1078 /**
1079  *      llc_conn_ac_inc_tx_win_size - tx window size is inc by 1
1080  *      @sk: current connection structure.
1081  *      @skb: current event.
1082  *
1083  *      After receiving an RR response with f-bit set to one, transmit window
1084  *      size is increased by one. Returns 0 for success, 1 otherwise.
1085  */
1086 int llc_conn_ac_inc_tx_win_size(struct sock *sk, struct sk_buff *skb)
1087 {
1088         struct llc_sock *llc = llc_sk(sk);
1089
1090         llc->k += 1;
1091         if (llc->k > (u8) ~LLC_2_SEQ_NBR_MODULO)
1092                 llc->k = (u8) ~LLC_2_SEQ_NBR_MODULO;
1093         return 0;
1094 }
1095
1096 int llc_conn_ac_stop_all_timers(struct sock *sk, struct sk_buff *skb)
1097 {
1098         struct llc_sock *llc = llc_sk(sk);
1099
1100         del_timer(&llc->pf_cycle_timer.timer);
1101         del_timer(&llc->ack_timer.timer);
1102         del_timer(&llc->rej_sent_timer.timer);
1103         del_timer(&llc->busy_state_timer.timer);
1104         llc->ack_must_be_send = 0;
1105         llc->ack_pf = 0;
1106         return 0;
1107 }
1108
1109 int llc_conn_ac_stop_other_timers(struct sock *sk, struct sk_buff *skb)
1110 {
1111         struct llc_sock *llc = llc_sk(sk);
1112
1113         del_timer(&llc->rej_sent_timer.timer);
1114         del_timer(&llc->pf_cycle_timer.timer);
1115         del_timer(&llc->busy_state_timer.timer);
1116         llc->ack_must_be_send = 0;
1117         llc->ack_pf = 0;
1118         return 0;
1119 }
1120
1121 int llc_conn_ac_start_ack_timer(struct sock *sk, struct sk_buff *skb)
1122 {
1123         struct llc_sock *llc = llc_sk(sk);
1124
1125         mod_timer(&llc->ack_timer.timer, jiffies + llc->ack_timer.expire);
1126         return 0;
1127 }
1128
1129 int llc_conn_ac_start_rej_timer(struct sock *sk, struct sk_buff *skb)
1130 {
1131         struct llc_sock *llc = llc_sk(sk);
1132
1133         mod_timer(&llc->rej_sent_timer.timer,
1134                   jiffies + llc->rej_sent_timer.expire);
1135         return 0;
1136 }
1137
1138 int llc_conn_ac_start_ack_tmr_if_not_running(struct sock *sk,
1139                                              struct sk_buff *skb)
1140 {
1141         struct llc_sock *llc = llc_sk(sk);
1142
1143         if (!timer_pending(&llc->ack_timer.timer))
1144                 mod_timer(&llc->ack_timer.timer,
1145                           jiffies + llc->ack_timer.expire);
1146         return 0;
1147 }
1148
1149 int llc_conn_ac_stop_ack_timer(struct sock *sk, struct sk_buff *skb)
1150 {
1151         del_timer(&llc_sk(sk)->ack_timer.timer);
1152         return 0;
1153 }
1154
1155 int llc_conn_ac_stop_p_timer(struct sock *sk, struct sk_buff *skb)
1156 {
1157         struct llc_sock *llc = llc_sk(sk);
1158
1159         del_timer(&llc->pf_cycle_timer.timer);
1160         llc_conn_set_p_flag(sk, 0);
1161         return 0;
1162 }
1163
1164 int llc_conn_ac_stop_rej_timer(struct sock *sk, struct sk_buff *skb)
1165 {
1166         del_timer(&llc_sk(sk)->rej_sent_timer.timer);
1167         return 0;
1168 }
1169
1170 int llc_conn_ac_upd_nr_received(struct sock *sk, struct sk_buff *skb)
1171 {
1172         int acked;
1173         u16 unacked = 0;
1174         struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
1175         struct llc_sock *llc = llc_sk(sk);
1176
1177         llc->last_nr = PDU_SUPV_GET_Nr(pdu);
1178         acked = llc_conn_remove_acked_pdus(sk, llc->last_nr, &unacked);
1179         /* On loopback we don't queue I frames in unack_pdu_q queue. */
1180         if (acked > 0 || (llc->dev->flags & IFF_LOOPBACK)) {
1181                 llc->retry_count = 0;
1182                 del_timer(&llc->ack_timer.timer);
1183                 if (llc->failed_data_req) {
1184                         /* already, we did not accept data from upper layer
1185                          * (tx_window full or unacceptable state). Now, we
1186                          * can send data and must inform to upper layer.
1187                          */
1188                         llc->failed_data_req = 0;
1189                         llc_conn_ac_data_confirm(sk, skb);
1190                 }
1191                 if (unacked)
1192                         mod_timer(&llc->ack_timer.timer,
1193                                   jiffies + llc->ack_timer.expire);
1194         } else if (llc->failed_data_req) {
1195                 u8 f_bit;
1196
1197                 llc_pdu_decode_pf_bit(skb, &f_bit);
1198                 if (f_bit == 1) {
1199                         llc->failed_data_req = 0;
1200                         llc_conn_ac_data_confirm(sk, skb);
1201                 }
1202         }
1203         return 0;
1204 }
1205
1206 int llc_conn_ac_upd_p_flag(struct sock *sk, struct sk_buff *skb)
1207 {
1208         struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
1209
1210         if (LLC_PDU_IS_RSP(pdu)) {
1211                 u8 f_bit;
1212
1213                 llc_pdu_decode_pf_bit(skb, &f_bit);
1214                 if (f_bit) {
1215                         llc_conn_set_p_flag(sk, 0);
1216                         llc_conn_ac_stop_p_timer(sk, skb);
1217                 }
1218         }
1219         return 0;
1220 }
1221
1222 int llc_conn_ac_set_data_flag_2(struct sock *sk, struct sk_buff *skb)
1223 {
1224         llc_sk(sk)->data_flag = 2;
1225         return 0;
1226 }
1227
1228 int llc_conn_ac_set_data_flag_0(struct sock *sk, struct sk_buff *skb)
1229 {
1230         llc_sk(sk)->data_flag = 0;
1231         return 0;
1232 }
1233
1234 int llc_conn_ac_set_data_flag_1(struct sock *sk, struct sk_buff *skb)
1235 {
1236         llc_sk(sk)->data_flag = 1;
1237         return 0;
1238 }
1239
1240 int llc_conn_ac_set_data_flag_1_if_data_flag_eq_0(struct sock *sk,
1241                                                   struct sk_buff *skb)
1242 {
1243         if (!llc_sk(sk)->data_flag)
1244                 llc_sk(sk)->data_flag = 1;
1245         return 0;
1246 }
1247
1248 int llc_conn_ac_set_p_flag_0(struct sock *sk, struct sk_buff *skb)
1249 {
1250         llc_conn_set_p_flag(sk, 0);
1251         return 0;
1252 }
1253
1254 static int llc_conn_ac_set_p_flag_1(struct sock *sk, struct sk_buff *skb)
1255 {
1256         llc_conn_set_p_flag(sk, 1);
1257         return 0;
1258 }
1259
1260 int llc_conn_ac_set_remote_busy_0(struct sock *sk, struct sk_buff *skb)
1261 {
1262         llc_sk(sk)->remote_busy_flag = 0;
1263         return 0;
1264 }
1265
1266 int llc_conn_ac_set_cause_flag_0(struct sock *sk, struct sk_buff *skb)
1267 {
1268         llc_sk(sk)->cause_flag = 0;
1269         return 0;
1270 }
1271
1272 int llc_conn_ac_set_cause_flag_1(struct sock *sk, struct sk_buff *skb)
1273 {
1274         llc_sk(sk)->cause_flag = 1;
1275         return 0;
1276 }
1277
1278 int llc_conn_ac_set_retry_cnt_0(struct sock *sk, struct sk_buff *skb)
1279 {
1280         llc_sk(sk)->retry_count = 0;
1281         return 0;
1282 }
1283
1284 int llc_conn_ac_inc_retry_cnt_by_1(struct sock *sk, struct sk_buff *skb)
1285 {
1286         llc_sk(sk)->retry_count++;
1287         return 0;
1288 }
1289
1290 int llc_conn_ac_set_vr_0(struct sock *sk, struct sk_buff *skb)
1291 {
1292         llc_sk(sk)->vR = 0;
1293         return 0;
1294 }
1295
1296 int llc_conn_ac_inc_vr_by_1(struct sock *sk, struct sk_buff *skb)
1297 {
1298         llc_sk(sk)->vR = PDU_GET_NEXT_Vr(llc_sk(sk)->vR);
1299         return 0;
1300 }
1301
1302 int llc_conn_ac_set_vs_0(struct sock *sk, struct sk_buff *skb)
1303 {
1304         llc_sk(sk)->vS = 0;
1305         return 0;
1306 }
1307
1308 int llc_conn_ac_set_vs_nr(struct sock *sk, struct sk_buff *skb)
1309 {
1310         llc_sk(sk)->vS = llc_sk(sk)->last_nr;
1311         return 0;
1312 }
1313
1314 static int llc_conn_ac_inc_vs_by_1(struct sock *sk, struct sk_buff *skb)
1315 {
1316         llc_sk(sk)->vS = (llc_sk(sk)->vS + 1) % LLC_2_SEQ_NBR_MODULO;
1317         return 0;
1318 }
1319
1320 static void llc_conn_tmr_common_cb(unsigned long timeout_data, u8 type)
1321 {
1322         struct sock *sk = (struct sock *)timeout_data;
1323         struct sk_buff *skb = alloc_skb(0, GFP_ATOMIC);
1324
1325         bh_lock_sock(sk);
1326         if (skb) {
1327                 struct llc_conn_state_ev *ev = llc_conn_ev(skb);
1328
1329                 skb_set_owner_r(skb, sk);
1330                 ev->type = type;
1331                 llc_process_tmr_ev(sk, skb);
1332         }
1333         bh_unlock_sock(sk);
1334 }
1335
1336 void llc_conn_pf_cycle_tmr_cb(unsigned long timeout_data)
1337 {
1338         llc_conn_tmr_common_cb(timeout_data, LLC_CONN_EV_TYPE_P_TMR);
1339 }
1340
1341 void llc_conn_busy_tmr_cb(unsigned long timeout_data)
1342 {
1343         llc_conn_tmr_common_cb(timeout_data, LLC_CONN_EV_TYPE_BUSY_TMR);
1344 }
1345
1346 void llc_conn_ack_tmr_cb(unsigned long timeout_data)
1347 {
1348         llc_conn_tmr_common_cb(timeout_data, LLC_CONN_EV_TYPE_ACK_TMR);
1349 }
1350
1351 void llc_conn_rej_tmr_cb(unsigned long timeout_data)
1352 {
1353         llc_conn_tmr_common_cb(timeout_data, LLC_CONN_EV_TYPE_REJ_TMR);
1354 }
1355
1356 int llc_conn_ac_rst_vs(struct sock *sk, struct sk_buff *skb)
1357 {
1358         llc_sk(sk)->X = llc_sk(sk)->vS;
1359         llc_conn_ac_set_vs_nr(sk, skb);
1360         return 0;
1361 }
1362
1363 int llc_conn_ac_upd_vs(struct sock *sk, struct sk_buff *skb)
1364 {
1365         struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
1366         u8 nr = PDU_SUPV_GET_Nr(pdu);
1367
1368         if (llc_circular_between(llc_sk(sk)->vS, nr, llc_sk(sk)->X))
1369                 llc_conn_ac_set_vs_nr(sk, skb);
1370         return 0;
1371 }
1372
1373 /*
1374  * Non-standard actions; these not contained in IEEE specification; for
1375  * our own usage
1376  */
1377 /**
1378  *      llc_conn_disc - removes connection from SAP list and frees it
1379  *      @sk: closed connection
1380  *      @skb: occurred event
1381  */
1382 int llc_conn_disc(struct sock *sk, struct sk_buff *skb)
1383 {
1384         /* FIXME: this thing seems to want to die */
1385         return 0;
1386 }
1387
1388 /**
1389  *      llc_conn_reset - resets connection
1390  *      @sk : reseting connection.
1391  *      @skb: occurred event.
1392  *
1393  *      Stop all timers, empty all queues and reset all flags.
1394  */
1395 int llc_conn_reset(struct sock *sk, struct sk_buff *skb)
1396 {
1397         llc_sk_reset(sk);
1398         return 0;
1399 }
1400
1401 /**
1402  *      llc_circular_between - designates that b is between a and c or not
1403  *      @a: lower bound
1404  *      @b: element to see if is between a and b
1405  *      @c: upper bound
1406  *
1407  *      This function designates that b is between a and c or not (for example,
1408  *      0 is between 127 and 1). Returns 1 if b is between a and c, 0
1409  *      otherwise.
1410  */
1411 u8 llc_circular_between(u8 a, u8 b, u8 c)
1412 {
1413         b = b - a;
1414         c = c - a;
1415         return b <= c;
1416 }
1417
1418 /**
1419  *      llc_process_tmr_ev - timer backend
1420  *      @sk: active connection
1421  *      @skb: occurred event
1422  *
1423  *      This function is called from timer callback functions. When connection
1424  *      is busy (during sending a data frame) timer expiration event must be
1425  *      queued. Otherwise this event can be sent to connection state machine.
1426  *      Queued events will process by llc_backlog_rcv function after sending
1427  *      data frame.
1428  */
1429 static void llc_process_tmr_ev(struct sock *sk, struct sk_buff *skb)
1430 {
1431         if (llc_sk(sk)->state == LLC_CONN_OUT_OF_SVC) {
1432                 printk(KERN_WARNING "%s: timer called on closed connection\n",
1433                        __func__);
1434                 kfree_skb(skb);
1435         } else {
1436                 if (!sock_owned_by_user(sk))
1437                         llc_conn_state_process(sk, skb);
1438                 else {
1439                         llc_set_backlog_type(skb, LLC_EVENT);
1440                         __sk_add_backlog(sk, skb);
1441                 }
1442         }
1443 }