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 <linux/slab.h>
  22 #include <net/llc_conn.h>
  23 #include <net/llc_sap.h>
  24 #include <net/sock.h>
  25 #include <net/llc_c_ev.h>
  26 #include <net/llc_c_ac.h>
  27 #include <net/llc_c_st.h>
  28 #include <net/llc_pdu.h>
  29 #include <net/llc.h>
  30
  31
  32 static int llc_conn_ac_inc_vs_by_1(struct sock *sk, struct sk_buff *skb);
  33 static void llc_process_tmr_ev(struct sock *sk, struct sk_buff *skb);
  34 static int llc_conn_ac_data_confirm(struct sock *sk, struct sk_buff *ev);
  35
  36 static int llc_conn_ac_inc_npta_value(struct sock *sk, struct sk_buff *skb);
  37
  38 static int llc_conn_ac_send_rr_rsp_f_set_ackpf(struct sock *sk,
  39                                                struct sk_buff *skb);
  40
  41 static int llc_conn_ac_set_p_flag_1(struct sock *sk, struct sk_buff *skb);
  42
  43 #define INCORRECT 0
  44
  45 int llc_conn_ac_clear_remote_busy(struct sock *sk, struct sk_buff *skb)
  46 {
  47         struct llc_sock *llc = llc_sk(sk);
  48
  49         if (llc->remote_busy_flag) {
  50                 u8 nr;
  51                 struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
  52
  53                 llc->remote_busy_flag = 0;
  54                 del_timer(&llc->busy_state_timer.timer);
  55                 nr = LLC_I_GET_NR(pdu);
  56                 llc_conn_resend_i_pdu_as_cmd(sk, nr, 0);
  57         }
  58         return 0;
  59 }
  60
  61 int llc_conn_ac_conn_ind(struct sock *sk, struct sk_buff *skb)
  62 {
  63         struct llc_conn_state_ev *ev = llc_conn_ev(skb);
  64
  65         ev->ind_prim = LLC_CONN_PRIM;
  66         return 0;
  67 }
  68
  69 int llc_conn_ac_conn_confirm(struct sock *sk, struct sk_buff *skb)
  70 {
  71         struct llc_conn_state_ev *ev = llc_conn_ev(skb);
  72
  73         ev->cfm_prim = LLC_CONN_PRIM;
  74         return 0;
  75 }
  76
  77 static int llc_conn_ac_data_confirm(struct sock *sk, struct sk_buff *skb)
  78 {
  79         struct llc_conn_state_ev *ev = llc_conn_ev(skb);
  80
  81         ev->cfm_prim = LLC_DATA_PRIM;
  82         return 0;
  83 }
  84
  85 int llc_conn_ac_data_ind(struct sock *sk, struct sk_buff *skb)
  86 {
  87         llc_conn_rtn_pdu(sk, skb);
  88         return 0;
  89 }
  90
  91 int llc_conn_ac_disc_ind(struct sock *sk, struct sk_buff *skb)
  92 {
  93         struct llc_conn_state_ev *ev = llc_conn_ev(skb);
  94         u8 reason = 0;
  95         int rc = 0;
  96
  97         if (ev->type == LLC_CONN_EV_TYPE_PDU) {
  98                 struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb);
  99
 100                 if (LLC_PDU_IS_RSP(pdu) &&
 101                     LLC_PDU_TYPE_IS_U(pdu) &&
 102                     LLC_U_PDU_RSP(pdu) == LLC_2_PDU_RSP_DM)
 103                         reason = LLC_DISC_REASON_RX_DM_RSP_PDU;
 104                 else if (LLC_PDU_IS_CMD(pdu) &&
 105                            LLC_PDU_TYPE_IS_U(pdu) &&
 106                            LLC_U_PDU_CMD(pdu) == LLC_2_PDU_CMD_DISC)
 107                         reason = LLC_DISC_REASON_RX_DISC_CMD_PDU;
 108         } else if (ev->type == LLC_CONN_EV_TYPE_ACK_TMR)
 109                 reason = LLC_DISC_REASON_ACK_TMR_EXP;
 110         else
 111                 rc = -EINVAL;
 112         if (!rc) {
 113                 ev->reason   = reason;
 114                 ev->ind_prim = LLC_DISC_PRIM;
 115         }
 116         return rc;
 117 }
 118
 119 int llc_conn_ac_disc_confirm(struct sock *sk, struct sk_buff *skb)
 120 {
 121         struct llc_conn_state_ev *ev = llc_conn_ev(skb);
 122
 123         ev->reason   = ev->status;
 124         ev->cfm_prim = LLC_DISC_PRIM;
 125         return 0;
 126 }
 127
 128 int llc_conn_ac_rst_ind(struct sock *sk, struct sk_buff *skb)
 129 {
 130         u8 reason = 0;
 131         int rc = 1;
 132         struct llc_conn_state_ev *ev = llc_conn_ev(skb);
 133         struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb);
 134         struct llc_sock *llc = llc_sk(sk);
 135
 136         switch (ev->type) {
 137         case LLC_CONN_EV_TYPE_PDU:
 138                 if (LLC_PDU_IS_RSP(pdu) &&
 139                     LLC_PDU_TYPE_IS_U(pdu) &&
 140                     LLC_U_PDU_RSP(pdu) == LLC_2_PDU_RSP_FRMR) {
 141                         reason = LLC_RESET_REASON_LOCAL;
 142                         rc = 0;
 143                 } else if (LLC_PDU_IS_CMD(pdu) &&
 144                            LLC_PDU_TYPE_IS_U(pdu) &&
 145                            LLC_U_PDU_CMD(pdu) == LLC_2_PDU_CMD_SABME) {
 146                         reason = LLC_RESET_REASON_REMOTE;
 147                         rc = 0;
 148                 }
 149                 break;
 150         case LLC_CONN_EV_TYPE_ACK_TMR:
 151         case LLC_CONN_EV_TYPE_P_TMR:
 152         case LLC_CONN_EV_TYPE_REJ_TMR:
 153         case LLC_CONN_EV_TYPE_BUSY_TMR:
 154                 if (llc->retry_count > llc->n2) {
 155                         reason = LLC_RESET_REASON_LOCAL;
 156                         rc = 0;
 157                 }
 158                 break;
 159         }
 160         if (!rc) {
 161                 ev->reason   = reason;
 162                 ev->ind_prim = LLC_RESET_PRIM;
 163         }
 164         return rc;
 165 }
 166
 167 int llc_conn_ac_rst_confirm(struct sock *sk, struct sk_buff *skb)
 168 {
 169         struct llc_conn_state_ev *ev = llc_conn_ev(skb);
 170
 171         ev->reason   = 0;
 172         ev->cfm_prim = LLC_RESET_PRIM;
 173         return 0;
 174 }
 175
 176 int llc_conn_ac_clear_remote_busy_if_f_eq_1(struct sock *sk,
 177                                             struct sk_buff *skb)
 178 {
 179         struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
 180
 181         if (LLC_PDU_IS_RSP(pdu) &&
 182             LLC_PDU_TYPE_IS_I(pdu) &&
 183             LLC_I_PF_IS_1(pdu) && llc_sk(sk)->ack_pf)
 184                 llc_conn_ac_clear_remote_busy(sk, skb);
 185         return 0;
 186 }
 187
 188 int llc_conn_ac_stop_rej_tmr_if_data_flag_eq_2(struct sock *sk,
 189                                                struct sk_buff *skb)
 190 {
 191         struct llc_sock *llc = llc_sk(sk);
 192
 193         if (llc->data_flag == 2)
 194                 del_timer(&llc->rej_sent_timer.timer);
 195         return 0;
 196 }
 197
 198 int llc_conn_ac_send_disc_cmd_p_set_x(struct sock *sk, struct sk_buff *skb)
 199 {
 200         int rc = -ENOBUFS;
 201         struct llc_sock *llc = llc_sk(sk);
 202         struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_U, 0);
 203
 204         if (nskb) {
 205                 struct llc_sap *sap = llc->sap;
 206
 207                 llc_pdu_header_init(nskb, LLC_PDU_TYPE_U, sap->laddr.lsap,
 208                                     llc->daddr.lsap, LLC_PDU_CMD);
 209                 llc_pdu_init_as_disc_cmd(nskb, 1);
 210                 rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
 211                 if (unlikely(rc))
 212                         goto free;
 213                 llc_conn_send_pdu(sk, nskb);
 214                 llc_conn_ac_set_p_flag_1(sk, skb);
 215         }
 216 out:
 217         return rc;
 218 free:
 219         kfree_skb(nskb);
 220         goto out;
 221 }
 222
 223 int llc_conn_ac_send_dm_rsp_f_set_p(struct sock *sk, struct sk_buff *skb)
 224 {
 225         int rc = -ENOBUFS;
 226         struct llc_sock *llc = llc_sk(sk);
 227         struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_U, 0);
 228
 229         if (nskb) {
 230                 struct llc_sap *sap = llc->sap;
 231                 u8 f_bit;
 232
 233                 llc_pdu_decode_pf_bit(skb, &f_bit);
 234                 llc_pdu_header_init(nskb, LLC_PDU_TYPE_U, sap->laddr.lsap,
 235                                     llc->daddr.lsap, LLC_PDU_RSP);
 236                 llc_pdu_init_as_dm_rsp(nskb, f_bit);
 237                 rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
 238                 if (unlikely(rc))
 239                         goto free;
 240                 llc_conn_send_pdu(sk, nskb);
 241         }
 242 out:
 243         return rc;
 244 free:
 245         kfree_skb(nskb);
 246         goto out;
 247 }
 248
 249 int llc_conn_ac_send_dm_rsp_f_set_1(struct sock *sk, struct sk_buff *skb)
 250 {
 251         int rc = -ENOBUFS;
 252         struct llc_sock *llc = llc_sk(sk);
 253         struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_U, 0);
 254
 255         if (nskb) {
 256                 struct llc_sap *sap = llc->sap;
 257
 258                 llc_pdu_header_init(nskb, LLC_PDU_TYPE_U, sap->laddr.lsap,
 259                                     llc->daddr.lsap, LLC_PDU_RSP);
 260                 llc_pdu_init_as_dm_rsp(nskb, 1);
 261                 rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
 262                 if (unlikely(rc))
 263                         goto free;
 264                 llc_conn_send_pdu(sk, nskb);
 265         }
 266 out:
 267         return rc;
 268 free:
 269         kfree_skb(nskb);
 270         goto out;
 271 }
 272
 273 int llc_conn_ac_send_frmr_rsp_f_set_x(struct sock *sk, struct sk_buff *skb)
 274 {
 275         u8 f_bit;
 276         int rc = -ENOBUFS;
 277         struct sk_buff *nskb;
 278         struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
 279         struct llc_sock *llc = llc_sk(sk);
 280
 281         llc->rx_pdu_hdr = *((u32 *)pdu);
 282         if (LLC_PDU_IS_CMD(pdu))
 283                 llc_pdu_decode_pf_bit(skb, &f_bit);
 284         else
 285                 f_bit = 0;
 286         nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_U,
 287                                sizeof(struct llc_frmr_info));
 288         if (nskb) {
 289                 struct llc_sap *sap = llc->sap;
 290
 291                 llc_pdu_header_init(nskb, LLC_PDU_TYPE_U, sap->laddr.lsap,
 292                                     llc->daddr.lsap, LLC_PDU_RSP);
 293                 llc_pdu_init_as_frmr_rsp(nskb, pdu, f_bit, llc->vS,
 294                                          llc->vR, INCORRECT);
 295                 rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
 296                 if (unlikely(rc))
 297                         goto free;
 298                 llc_conn_send_pdu(sk, nskb);
 299         }
 300 out:
 301         return rc;
 302 free:
 303         kfree_skb(nskb);
 304         goto out;
 305 }
 306
 307 int llc_conn_ac_resend_frmr_rsp_f_set_0(struct sock *sk, struct sk_buff *skb)
 308 {
 309         int rc = -ENOBUFS;
 310         struct llc_sock *llc = llc_sk(sk);
 311         struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_U,
 312                                                sizeof(struct llc_frmr_info));
 313
 314         if (nskb) {
 315                 struct llc_sap *sap = llc->sap;
 316                 struct llc_pdu_sn *pdu = (struct llc_pdu_sn *)&llc->rx_pdu_hdr;
 317
 318                 llc_pdu_header_init(nskb, LLC_PDU_TYPE_U, sap->laddr.lsap,
 319                                     llc->daddr.lsap, LLC_PDU_RSP);
 320                 llc_pdu_init_as_frmr_rsp(nskb, pdu, 0, llc->vS,
 321                                          llc->vR, INCORRECT);
 322                 rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
 323                 if (unlikely(rc))
 324                         goto free;
 325                 llc_conn_send_pdu(sk, nskb);
 326         }
 327 out:
 328         return rc;
 329 free:
 330         kfree_skb(nskb);
 331         goto out;
 332 }
 333
 334 int llc_conn_ac_resend_frmr_rsp_f_set_p(struct sock *sk, struct sk_buff *skb)
 335 {
 336         u8 f_bit;
 337         int rc = -ENOBUFS;
 338         struct sk_buff *nskb;
 339         struct llc_sock *llc = llc_sk(sk);
 340
 341         llc_pdu_decode_pf_bit(skb, &f_bit);
 342         nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_U,
 343                                sizeof(struct llc_frmr_info));
 344         if (nskb) {
 345                 struct llc_sap *sap = llc->sap;
 346                 struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
 347
 348                 llc_pdu_header_init(nskb, LLC_PDU_TYPE_U, sap->laddr.lsap,
 349                                     llc->daddr.lsap, LLC_PDU_RSP);
 350                 llc_pdu_init_as_frmr_rsp(nskb, pdu, f_bit, llc->vS,
 351                                          llc->vR, INCORRECT);
 352                 rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
 353                 if (unlikely(rc))
 354                         goto free;
 355                 llc_conn_send_pdu(sk, nskb);
 356         }
 357 out:
 358         return rc;
 359 free:
 360         kfree_skb(nskb);
 361         goto out;
 362 }
 363
 364 int llc_conn_ac_send_i_cmd_p_set_1(struct sock *sk, struct sk_buff *skb)
 365 {
 366         int rc;
 367         struct llc_sock *llc = llc_sk(sk);
 368         struct llc_sap *sap = llc->sap;
 369
 370         llc_pdu_header_init(skb, LLC_PDU_TYPE_I, sap->laddr.lsap,
 371                             llc->daddr.lsap, LLC_PDU_CMD);
 372         llc_pdu_init_as_i_cmd(skb, 1, llc->vS, llc->vR);
 373         rc = llc_mac_hdr_init(skb, llc->dev->dev_addr, llc->daddr.mac);
 374         if (likely(!rc)) {
 375                 llc_conn_send_pdu(sk, skb);
 376                 llc_conn_ac_inc_vs_by_1(sk, skb);
 377         }
 378         return rc;
 379 }
 380
 381 static int llc_conn_ac_send_i_cmd_p_set_0(struct sock *sk, struct sk_buff *skb)
 382 {
 383         int rc;
 384         struct llc_sock *llc = llc_sk(sk);
 385         struct llc_sap *sap = llc->sap;
 386
 387         llc_pdu_header_init(skb, LLC_PDU_TYPE_I, sap->laddr.lsap,
 388                             llc->daddr.lsap, LLC_PDU_CMD);
 389         llc_pdu_init_as_i_cmd(skb, 0, llc->vS, llc->vR);
 390         rc = llc_mac_hdr_init(skb, llc->dev->dev_addr, llc->daddr.mac);
 391         if (likely(!rc)) {
 392                 llc_conn_send_pdu(sk, skb);
 393                 llc_conn_ac_inc_vs_by_1(sk, skb);
 394         }
 395         return rc;
 396 }
 397
 398 int llc_conn_ac_send_i_xxx_x_set_0(struct sock *sk, struct sk_buff *skb)
 399 {
 400         int rc;
 401         struct llc_sock *llc = llc_sk(sk);
 402         struct llc_sap *sap = llc->sap;
 403
 404         llc_pdu_header_init(skb, LLC_PDU_TYPE_I, sap->laddr.lsap,
 405                             llc->daddr.lsap, LLC_PDU_CMD);
 406         llc_pdu_init_as_i_cmd(skb, 0, llc->vS, llc->vR);
 407         rc = llc_mac_hdr_init(skb, llc->dev->dev_addr, llc->daddr.mac);
 408         if (likely(!rc)) {
 409                 llc_conn_send_pdu(sk, skb);
 410                 llc_conn_ac_inc_vs_by_1(sk, skb);
 411         }
 412         return 0;
 413 }
 414
 415 int llc_conn_ac_resend_i_xxx_x_set_0(struct sock *sk, struct sk_buff *skb)
 416 {
 417         struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
 418         u8 nr = LLC_I_GET_NR(pdu);
 419
 420         llc_conn_resend_i_pdu_as_cmd(sk, nr, 0);
 421         return 0;
 422 }
 423
 424 int llc_conn_ac_resend_i_xxx_x_set_0_or_send_rr(struct sock *sk,
 425                                                 struct sk_buff *skb)
 426 {
 427         u8 nr;
 428         struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
 429         int rc = -ENOBUFS;
 430         struct llc_sock *llc = llc_sk(sk);
 431         struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_U, 0);
 432
 433         if (nskb) {
 434                 struct llc_sap *sap = llc->sap;
 435
 436                 llc_pdu_header_init(nskb, LLC_PDU_TYPE_U, sap->laddr.lsap,
 437                                     llc->daddr.lsap, LLC_PDU_RSP);
 438                 llc_pdu_init_as_rr_rsp(nskb, 0, llc->vR);
 439                 rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
 440                 if (likely(!rc))
 441                         llc_conn_send_pdu(sk, nskb);
 442                 else
 443                         kfree_skb(skb);
 444         }
 445         if (rc) {
 446                 nr = LLC_I_GET_NR(pdu);
 447                 rc = 0;
 448                 llc_conn_resend_i_pdu_as_cmd(sk, nr, 0);
 449         }
 450         return rc;
 451 }
 452
 453 int llc_conn_ac_resend_i_rsp_f_set_1(struct sock *sk, struct sk_buff *skb)
 454 {
 455         struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
 456         u8 nr = LLC_I_GET_NR(pdu);
 457
 458         llc_conn_resend_i_pdu_as_rsp(sk, nr, 1);
 459         return 0;
 460 }
 461
 462 int llc_conn_ac_send_rej_cmd_p_set_1(struct sock *sk, struct sk_buff *skb)
 463 {
 464         int rc = -ENOBUFS;
 465         struct llc_sock *llc = llc_sk(sk);
 466         struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_S, 0);
 467
 468         if (nskb) {
 469                 struct llc_sap *sap = llc->sap;
 470
 471                 llc_pdu_header_init(nskb, LLC_PDU_TYPE_S, sap->laddr.lsap,
 472                                     llc->daddr.lsap, LLC_PDU_CMD);
 473                 llc_pdu_init_as_rej_cmd(nskb, 1, llc->vR);
 474                 rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
 475                 if (unlikely(rc))
 476                         goto free;
 477                 llc_conn_send_pdu(sk, nskb);
 478         }
 479 out:
 480         return rc;
 481 free:
 482         kfree_skb(nskb);
 483         goto out;
 484 }
 485
 486 int llc_conn_ac_send_rej_rsp_f_set_1(struct sock *sk, struct sk_buff *skb)
 487 {
 488         int rc = -ENOBUFS;
 489         struct llc_sock *llc = llc_sk(sk);
 490         struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_S, 0);
 491
 492         if (nskb) {
 493                 struct llc_sap *sap = llc->sap;
 494
 495                 llc_pdu_header_init(nskb, LLC_PDU_TYPE_S, sap->laddr.lsap,
 496                                     llc->daddr.lsap, LLC_PDU_RSP);
 497                 llc_pdu_init_as_rej_rsp(nskb, 1, llc->vR);
 498                 rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
 499                 if (unlikely(rc))
 500                         goto free;
 501                 llc_conn_send_pdu(sk, nskb);
 502         }
 503 out:
 504         return rc;
 505 free:
 506         kfree_skb(nskb);
 507         goto out;
 508 }
 509
 510 int llc_conn_ac_send_rej_xxx_x_set_0(struct sock *sk, struct sk_buff *skb)
 511 {
 512         int rc = -ENOBUFS;
 513         struct llc_sock *llc = llc_sk(sk);
 514         struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_S, 0);
 515
 516         if (nskb) {
 517                 struct llc_sap *sap = llc->sap;
 518
 519                 llc_pdu_header_init(nskb, LLC_PDU_TYPE_S, sap->laddr.lsap,
 520                                     llc->daddr.lsap, LLC_PDU_RSP);
 521                 llc_pdu_init_as_rej_rsp(nskb, 0, llc->vR);
 522                 rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
 523                 if (unlikely(rc))
 524                         goto free;
 525                 llc_conn_send_pdu(sk, nskb);
 526         }
 527 out:
 528         return rc;
 529 free:
 530         kfree_skb(nskb);
 531         goto out;
 532 }
 533
 534 int llc_conn_ac_send_rnr_cmd_p_set_1(struct sock *sk, struct sk_buff *skb)
 535 {
 536         int rc = -ENOBUFS;
 537         struct llc_sock *llc = llc_sk(sk);
 538         struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_S, 0);
 539
 540         if (nskb) {
 541                 struct llc_sap *sap = llc->sap;
 542
 543                 llc_pdu_header_init(nskb, LLC_PDU_TYPE_S, sap->laddr.lsap,
 544                                     llc->daddr.lsap, LLC_PDU_CMD);
 545                 llc_pdu_init_as_rnr_cmd(nskb, 1, llc->vR);
 546                 rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
 547                 if (unlikely(rc))
 548                         goto free;
 549                 llc_conn_send_pdu(sk, nskb);
 550         }
 551 out:
 552         return rc;
 553 free:
 554         kfree_skb(nskb);
 555         goto out;
 556 }
 557
 558 int llc_conn_ac_send_rnr_rsp_f_set_1(struct sock *sk, struct sk_buff *skb)
 559 {
 560         int rc = -ENOBUFS;
 561         struct llc_sock *llc = llc_sk(sk);
 562         struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_S, 0);
 563
 564         if (nskb) {
 565                 struct llc_sap *sap = llc->sap;
 566
 567                 llc_pdu_header_init(nskb, LLC_PDU_TYPE_S, sap->laddr.lsap,
 568                                     llc->daddr.lsap, LLC_PDU_RSP);
 569                 llc_pdu_init_as_rnr_rsp(nskb, 1, llc->vR);
 570                 rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
 571                 if (unlikely(rc))
 572                         goto free;
 573                 llc_conn_send_pdu(sk, nskb);
 574         }
 575 out:
 576         return rc;
 577 free:
 578         kfree_skb(nskb);
 579         goto out;
 580 }
 581
 582 int llc_conn_ac_send_rnr_xxx_x_set_0(struct sock *sk, struct sk_buff *skb)
 583 {
 584         int rc = -ENOBUFS;
 585         struct llc_sock *llc = llc_sk(sk);
 586         struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_S, 0);
 587
 588         if (nskb) {
 589                 struct llc_sap *sap = llc->sap;
 590
 591                 llc_pdu_header_init(nskb, LLC_PDU_TYPE_S, sap->laddr.lsap,
 592                                     llc->daddr.lsap, LLC_PDU_RSP);
 593                 llc_pdu_init_as_rnr_rsp(nskb, 0, llc->vR);
 594                 rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
 595                 if (unlikely(rc))
 596                         goto free;
 597                 llc_conn_send_pdu(sk, nskb);
 598         }
 599 out:
 600         return rc;
 601 free:
 602         kfree_skb(nskb);
 603         goto out;
 604 }
 605
 606 int llc_conn_ac_set_remote_busy(struct sock *sk, struct sk_buff *skb)
 607 {
 608         struct llc_sock *llc = llc_sk(sk);
 609
 610         if (!llc->remote_busy_flag) {
 611                 llc->remote_busy_flag = 1;
 612                 mod_timer(&llc->busy_state_timer.timer,
 613                          jiffies + llc->busy_state_timer.expire);
 614         }
 615         return 0;
 616 }
 617
 618 int llc_conn_ac_opt_send_rnr_xxx_x_set_0(struct sock *sk, struct sk_buff *skb)
 619 {
 620         int rc = -ENOBUFS;
 621         struct llc_sock *llc = llc_sk(sk);
 622         struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_S, 0);
 623
 624         if (nskb) {
 625                 struct llc_sap *sap = llc->sap;
 626
 627                 llc_pdu_header_init(nskb, LLC_PDU_TYPE_S, sap->laddr.lsap,
 628                                     llc->daddr.lsap, LLC_PDU_RSP);
 629                 llc_pdu_init_as_rnr_rsp(nskb, 0, llc->vR);
 630                 rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
 631                 if (unlikely(rc))
 632                         goto free;
 633                 llc_conn_send_pdu(sk, nskb);
 634         }
 635 out:
 636         return rc;
 637 free:
 638         kfree_skb(nskb);
 639         goto out;
 640 }
 641
 642 int llc_conn_ac_send_rr_cmd_p_set_1(struct sock *sk, struct sk_buff *skb)
 643 {
 644         int rc = -ENOBUFS;
 645         struct llc_sock *llc = llc_sk(sk);
 646         struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_S, 0);
 647
 648         if (nskb) {
 649                 struct llc_sap *sap = llc->sap;
 650
 651                 llc_pdu_header_init(nskb, LLC_PDU_TYPE_S, sap->laddr.lsap,
 652                                     llc->daddr.lsap, LLC_PDU_CMD);
 653                 llc_pdu_init_as_rr_cmd(nskb, 1, llc->vR);
 654                 rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
 655                 if (unlikely(rc))
 656                         goto free;
 657                 llc_conn_send_pdu(sk, nskb);
 658         }
 659 out:
 660         return rc;
 661 free:
 662         kfree_skb(nskb);
 663         goto out;
 664 }
 665
 666 int llc_conn_ac_send_rr_rsp_f_set_1(struct sock *sk, struct sk_buff *skb)
 667 {
 668         int rc = -ENOBUFS;
 669         struct llc_sock *llc = llc_sk(sk);
 670         struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_S, 0);
 671
 672         if (nskb) {
 673                 struct llc_sap *sap = llc->sap;
 674                 u8 f_bit = 1;
 675
 676                 llc_pdu_header_init(nskb, LLC_PDU_TYPE_S, sap->laddr.lsap,
 677                                     llc->daddr.lsap, LLC_PDU_RSP);
 678                 llc_pdu_init_as_rr_rsp(nskb, f_bit, llc->vR);
 679                 rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
 680                 if (unlikely(rc))
 681                         goto free;
 682                 llc_conn_send_pdu(sk, nskb);
 683         }
 684 out:
 685         return rc;
 686 free:
 687         kfree_skb(nskb);
 688         goto out;
 689 }
 690
 691 int llc_conn_ac_send_ack_rsp_f_set_1(struct sock *sk, struct sk_buff *skb)
 692 {
 693         int rc = -ENOBUFS;
 694         struct llc_sock *llc = llc_sk(sk);
 695         struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_S, 0);
 696
 697         if (nskb) {
 698                 struct llc_sap *sap = llc->sap;
 699
 700                 llc_pdu_header_init(nskb, LLC_PDU_TYPE_S, sap->laddr.lsap,
 701                                     llc->daddr.lsap, LLC_PDU_RSP);
 702                 llc_pdu_init_as_rr_rsp(nskb, 1, llc->vR);
 703                 rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
 704                 if (unlikely(rc))
 705                         goto free;
 706                 llc_conn_send_pdu(sk, nskb);
 707         }
 708 out:
 709         return rc;
 710 free:
 711         kfree_skb(nskb);
 712         goto out;
 713 }
 714
 715 int llc_conn_ac_send_rr_xxx_x_set_0(struct sock *sk, struct sk_buff *skb)
 716 {
 717         int rc = -ENOBUFS;
 718         struct llc_sock *llc = llc_sk(sk);
 719         struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_S, 0);
 720
 721         if (nskb) {
 722                 struct llc_sap *sap = llc->sap;
 723
 724                 llc_pdu_header_init(nskb, LLC_PDU_TYPE_S, sap->laddr.lsap,
 725                                     llc->daddr.lsap, LLC_PDU_RSP);
 726                 llc_pdu_init_as_rr_rsp(nskb, 0, llc->vR);
 727                 rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
 728                 if (unlikely(rc))
 729                         goto free;
 730                 llc_conn_send_pdu(sk, nskb);
 731         }
 732 out:
 733         return rc;
 734 free:
 735         kfree_skb(nskb);
 736         goto out;
 737 }
 738
 739 int llc_conn_ac_send_ack_xxx_x_set_0(struct sock *sk, struct sk_buff *skb)
 740 {
 741         int rc = -ENOBUFS;
 742         struct llc_sock *llc = llc_sk(sk);
 743         struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_S, 0);
 744
 745         if (nskb) {
 746                 struct llc_sap *sap = llc->sap;
 747
 748                 llc_pdu_header_init(nskb, LLC_PDU_TYPE_S, sap->laddr.lsap,
 749                                     llc->daddr.lsap, LLC_PDU_RSP);
 750                 llc_pdu_init_as_rr_rsp(nskb, 0, llc->vR);
 751                 rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
 752                 if (unlikely(rc))
 753                         goto free;
 754                 llc_conn_send_pdu(sk, nskb);
 755         }
 756 out:
 757         return rc;
 758 free:
 759         kfree_skb(nskb);
 760         goto out;
 761 }
 762
 763 void llc_conn_set_p_flag(struct sock *sk, u8 value)
 764 {
 765         int state_changed = llc_sk(sk)->p_flag && !value;
 766
 767         llc_sk(sk)->p_flag = value;
 768
 769         if (state_changed)
 770                 sk->sk_state_change(sk);
 771 }
 772
 773 int llc_conn_ac_send_sabme_cmd_p_set_x(struct sock *sk, struct sk_buff *skb)
 774 {
 775         int rc = -ENOBUFS;
 776         struct llc_sock *llc = llc_sk(sk);
 777         struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_U, 0);
 778
 779         if (nskb) {
 780                 struct llc_sap *sap = llc->sap;
 781                 u8 *dmac = llc->daddr.mac;
 782
 783                 if (llc->dev->flags & IFF_LOOPBACK)
 784                         dmac = llc->dev->dev_addr;
 785                 llc_pdu_header_init(nskb, LLC_PDU_TYPE_U, sap->laddr.lsap,
 786                                     llc->daddr.lsap, LLC_PDU_CMD);
 787                 llc_pdu_init_as_sabme_cmd(nskb, 1);
 788                 rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, dmac);
 789                 if (unlikely(rc))
 790                         goto free;
 791                 llc_conn_send_pdu(sk, nskb);
 792                 llc_conn_set_p_flag(sk, 1);
 793         }
 794 out:
 795         return rc;
 796 free:
 797         kfree_skb(nskb);
 798         goto out;
 799 }
 800
 801 int llc_conn_ac_send_ua_rsp_f_set_p(struct sock *sk, struct sk_buff *skb)
 802 {
 803         u8 f_bit;
 804         int rc = -ENOBUFS;
 805         struct llc_sock *llc = llc_sk(sk);
 806         struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_U, 0);
 807
 808         llc_pdu_decode_pf_bit(skb, &f_bit);
 809         if (nskb) {
 810                 struct llc_sap *sap = llc->sap;
 811
 812                 nskb->dev = llc->dev;
 813                 llc_pdu_header_init(nskb, LLC_PDU_TYPE_U, sap->laddr.lsap,
 814                                     llc->daddr.lsap, LLC_PDU_RSP);
 815                 llc_pdu_init_as_ua_rsp(nskb, f_bit);
 816                 rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
 817                 if (unlikely(rc))
 818                         goto free;
 819                 llc_conn_send_pdu(sk, nskb);
 820         }
 821 out:
 822         return rc;
 823 free:
 824         kfree_skb(nskb);
 825         goto out;
 826 }
 827
 828 int llc_conn_ac_set_s_flag_0(struct sock *sk, struct sk_buff *skb)
 829 {
 830         llc_sk(sk)->s_flag = 0;
 831         return 0;
 832 }
 833
 834 int llc_conn_ac_set_s_flag_1(struct sock *sk, struct sk_buff *skb)
 835 {
 836         llc_sk(sk)->s_flag = 1;
 837         return 0;
 838 }
 839
 840 int llc_conn_ac_start_p_timer(struct sock *sk, struct sk_buff *skb)
 841 {
 842         struct llc_sock *llc = llc_sk(sk);
 843
 844         llc_conn_set_p_flag(sk, 1);
 845         mod_timer(&llc->pf_cycle_timer.timer,
 846                   jiffies + llc->pf_cycle_timer.expire);
 847         return 0;
 848 }
 849
 850 /**
 851  *      llc_conn_ac_send_ack_if_needed - check if ack is needed
 852  *      @sk: current connection structure
 853  *      @skb: current event
 854  *
 855  *      Checks number of received PDUs which have not been acknowledged, yet,
 856  *      If number of them reaches to "npta"(Number of PDUs To Acknowledge) then
 857  *      sends an RR response as acknowledgement for them.  Returns 0 for
 858  *      success, 1 otherwise.
 859  */
 860 int llc_conn_ac_send_ack_if_needed(struct sock *sk, struct sk_buff *skb)
 861 {
 862         u8 pf_bit;
 863         struct llc_sock *llc = llc_sk(sk);
 864
 865         llc_pdu_decode_pf_bit(skb, &pf_bit);
 866         llc->ack_pf |= pf_bit & 1;
 867         if (!llc->ack_must_be_send) {
 868                 llc->first_pdu_Ns = llc->vR;
 869                 llc->ack_must_be_send = 1;
 870                 llc->ack_pf = pf_bit & 1;
 871         }
 872         if (((llc->vR - llc->first_pdu_Ns + 1 + LLC_2_SEQ_NBR_MODULO)
 873                         % LLC_2_SEQ_NBR_MODULO) >= llc->npta) {
 874                 llc_conn_ac_send_rr_rsp_f_set_ackpf(sk, skb);
 875                 llc->ack_must_be_send   = 0;
 876                 llc->ack_pf             = 0;
 877                 llc_conn_ac_inc_npta_value(sk, skb);
 878         }
 879         return 0;
 880 }
 881
 882 /**
 883  *      llc_conn_ac_rst_sendack_flag - resets ack_must_be_send flag
 884  *      @sk: current connection structure
 885  *      @skb: current event
 886  *
 887  *      This action resets ack_must_be_send flag of given connection, this flag
 888  *      indicates if there is any PDU which has not been acknowledged yet.
 889  *      Returns 0 for success, 1 otherwise.
 890  */
 891 int llc_conn_ac_rst_sendack_flag(struct sock *sk, struct sk_buff *skb)
 892 {
 893         llc_sk(sk)->ack_must_be_send = llc_sk(sk)->ack_pf = 0;
 894         return 0;
 895 }
 896
 897 /**
 898  *      llc_conn_ac_send_i_rsp_f_set_ackpf - acknowledge received PDUs
 899  *      @sk: current connection structure
 900  *      @skb: current event
 901  *
 902  *      Sends an I response PDU with f-bit set to ack_pf flag as acknowledge to
 903  *      all received PDUs which have not been acknowledged, yet. ack_pf flag is
 904  *      set to one if one PDU with p-bit set to one is received.  Returns 0 for
 905  *      success, 1 otherwise.
 906  */
 907 static int llc_conn_ac_send_i_rsp_f_set_ackpf(struct sock *sk,
 908                                               struct sk_buff *skb)
 909 {
 910         int rc;
 911         struct llc_sock *llc = llc_sk(sk);
 912         struct llc_sap *sap = llc->sap;
 913
 914         llc_pdu_header_init(skb, LLC_PDU_TYPE_I, sap->laddr.lsap,
 915                             llc->daddr.lsap, LLC_PDU_RSP);
 916         llc_pdu_init_as_i_cmd(skb, llc->ack_pf, llc->vS, llc->vR);
 917         rc = llc_mac_hdr_init(skb, llc->dev->dev_addr, llc->daddr.mac);
 918         if (likely(!rc)) {
 919                 llc_conn_send_pdu(sk, skb);
 920                 llc_conn_ac_inc_vs_by_1(sk, skb);
 921         }
 922         return rc;
 923 }
 924
 925 /**
 926  *      llc_conn_ac_send_i_as_ack - sends an I-format PDU to acknowledge rx PDUs
 927  *      @sk: current connection structure.
 928  *      @skb: current event.
 929  *
 930  *      This action sends an I-format PDU as acknowledge to received PDUs which
 931  *      have not been acknowledged, yet, if there is any. By using of this
 932  *      action number of acknowledgements decreases, this technic is called
 933  *      piggy backing. Returns 0 for success, 1 otherwise.
 934  */
 935 int llc_conn_ac_send_i_as_ack(struct sock *sk, struct sk_buff *skb)
 936 {
 937         struct llc_sock *llc = llc_sk(sk);
 938
 939         if (llc->ack_must_be_send) {
 940                 llc_conn_ac_send_i_rsp_f_set_ackpf(sk, skb);
 941                 llc->ack_must_be_send = 0 ;
 942                 llc->ack_pf = 0;
 943         } else
 944                 llc_conn_ac_send_i_cmd_p_set_0(sk, skb);
 945         return 0;
 946 }
 947
 948 /**
 949  *      llc_conn_ac_send_rr_rsp_f_set_ackpf - ack all rx PDUs not yet acked
 950  *      @sk: current connection structure.
 951  *      @skb: current event.
 952  *
 953  *      This action sends an RR response with f-bit set to ack_pf flag as
 954  *      acknowledge to all received PDUs which have not been acknowledged, yet,
 955  *      if there is any. ack_pf flag indicates if a PDU has been received with
 956  *      p-bit set to one. Returns 0 for success, 1 otherwise.
 957  */
 958 static int llc_conn_ac_send_rr_rsp_f_set_ackpf(struct sock *sk,
 959                                                struct sk_buff *skb)
 960 {
 961         int rc = -ENOBUFS;
 962         struct llc_sock *llc = llc_sk(sk);
 963         struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_S, 0);
 964
 965         if (nskb) {
 966                 struct llc_sap *sap = llc->sap;
 967
 968                 llc_pdu_header_init(nskb, LLC_PDU_TYPE_S, sap->laddr.lsap,
 969                                     llc->daddr.lsap, LLC_PDU_RSP);
 970                 llc_pdu_init_as_rr_rsp(nskb, llc->ack_pf, llc->vR);
 971                 rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
 972                 if (unlikely(rc))
 973                         goto free;
 974                 llc_conn_send_pdu(sk, nskb);
 975         }
 976 out:
 977         return rc;
 978 free:
 979         kfree_skb(nskb);
 980         goto out;
 981 }
 982
 983 /**
 984  *      llc_conn_ac_inc_npta_value - tries to make value of npta greater
 985  *      @sk: current connection structure.
 986  *      @skb: current event.
 987  *
 988  *      After "inc_cntr" times calling of this action, "npta" increase by one.
 989  *      this action tries to make vale of "npta" greater as possible; number of
 990  *      acknowledgements decreases by increasing of "npta". Returns 0 for
 991  *      success, 1 otherwise.
 992  */
 993 static int llc_conn_ac_inc_npta_value(struct sock *sk, struct sk_buff *skb)
 994 {
 995         struct llc_sock *llc = llc_sk(sk);
 996
 997         if (!llc->inc_cntr) {
 998                 llc->dec_step = 0;
 999                 llc->dec_cntr = llc->inc_cntr = 2;
1000                 ++llc->npta;
1001                 if (llc->npta > (u8) ~LLC_2_SEQ_NBR_MODULO)
1002                         llc->npta = (u8) ~LLC_2_SEQ_NBR_MODULO;
1003         } else
1004                 --llc->inc_cntr;
1005         return 0;
1006 }
1007
1008 /**
1009  *      llc_conn_ac_adjust_npta_by_rr - decreases "npta" by one
1010  *      @sk: current connection structure.
1011  *      @skb: current event.
1012  *
1013  *      After receiving "dec_cntr" times RR command, this action decreases
1014  *      "npta" by one. Returns 0 for success, 1 otherwise.
1015  */
1016 int llc_conn_ac_adjust_npta_by_rr(struct sock *sk, struct sk_buff *skb)
1017 {
1018         struct llc_sock *llc = llc_sk(sk);
1019
1020         if (!llc->connect_step && !llc->remote_busy_flag) {
1021                 if (!llc->dec_step) {
1022                         if (!llc->dec_cntr) {
1023                                 llc->inc_cntr = llc->dec_cntr = 2;
1024                                 if (llc->npta > 0)
1025                                         llc->npta = llc->npta - 1;
1026                         } else
1027                                 llc->dec_cntr -=1;
1028                 }
1029         } else
1030                 llc->connect_step = 0 ;
1031         return 0;
1032 }
1033
1034 /**
1035  *      llc_conn_ac_adjust_npta_by_rnr - decreases "npta" by one
1036  *      @sk: current connection structure.
1037  *      @skb: current event.
1038  *
1039  *      After receiving "dec_cntr" times RNR command, this action decreases
1040  *      "npta" by one. Returns 0 for success, 1 otherwise.
1041  */
1042 int llc_conn_ac_adjust_npta_by_rnr(struct sock *sk, struct sk_buff *skb)
1043 {
1044         struct llc_sock *llc = llc_sk(sk);
1045
1046         if (llc->remote_busy_flag)
1047                 if (!llc->dec_step) {
1048                         if (!llc->dec_cntr) {
1049                                 llc->inc_cntr = llc->dec_cntr = 2;
1050                                 if (llc->npta > 0)
1051                                         --llc->npta;
1052                         } else
1053                                 --llc->dec_cntr;
1054                 }
1055         return 0;
1056 }
1057
1058 /**
1059  *      llc_conn_ac_dec_tx_win_size - decreases tx window size
1060  *      @sk: current connection structure.
1061  *      @skb: current event.
1062  *
1063  *      After receiving of a REJ command or response, transmit window size is
1064  *      decreased by number of PDUs which are outstanding yet. Returns 0 for
1065  *      success, 1 otherwise.
1066  */
1067 int llc_conn_ac_dec_tx_win_size(struct sock *sk, struct sk_buff *skb)
1068 {
1069         struct llc_sock *llc = llc_sk(sk);
1070         u8 unacked_pdu = skb_queue_len(&llc->pdu_unack_q);
1071
1072         if (llc->k - unacked_pdu < 1)
1073                 llc->k = 1;
1074         else
1075                 llc->k -= unacked_pdu;
1076         return 0;
1077 }
1078
1079 /**
1080  *      llc_conn_ac_inc_tx_win_size - tx window size is inc by 1
1081  *      @sk: current connection structure.
1082  *      @skb: current event.
1083  *
1084  *      After receiving an RR response with f-bit set to one, transmit window
1085  *      size is increased by one. Returns 0 for success, 1 otherwise.
1086  */
1087 int llc_conn_ac_inc_tx_win_size(struct sock *sk, struct sk_buff *skb)
1088 {
1089         struct llc_sock *llc = llc_sk(sk);
1090
1091         llc->k += 1;
1092         if (llc->k > (u8) ~LLC_2_SEQ_NBR_MODULO)
1093                 llc->k = (u8) ~LLC_2_SEQ_NBR_MODULO;
1094         return 0;
1095 }
1096
1097 int llc_conn_ac_stop_all_timers(struct sock *sk, struct sk_buff *skb)
1098 {
1099         struct llc_sock *llc = llc_sk(sk);
1100
1101         del_timer(&llc->pf_cycle_timer.timer);
1102         del_timer(&llc->ack_timer.timer);
1103         del_timer(&llc->rej_sent_timer.timer);
1104         del_timer(&llc->busy_state_timer.timer);
1105         llc->ack_must_be_send = 0;
1106         llc->ack_pf = 0;
1107         return 0;
1108 }
1109
1110 int llc_conn_ac_stop_other_timers(struct sock *sk, struct sk_buff *skb)
1111 {
1112         struct llc_sock *llc = llc_sk(sk);
1113
1114         del_timer(&llc->rej_sent_timer.timer);
1115         del_timer(&llc->pf_cycle_timer.timer);
1116         del_timer(&llc->busy_state_timer.timer);
1117         llc->ack_must_be_send = 0;
1118         llc->ack_pf = 0;
1119         return 0;
1120 }
1121
1122 int llc_conn_ac_start_ack_timer(struct sock *sk, struct sk_buff *skb)
1123 {
1124         struct llc_sock *llc = llc_sk(sk);
1125
1126         mod_timer(&llc->ack_timer.timer, jiffies + llc->ack_timer.expire);
1127         return 0;
1128 }
1129
1130 int llc_conn_ac_start_rej_timer(struct sock *sk, struct sk_buff *skb)
1131 {
1132         struct llc_sock *llc = llc_sk(sk);
1133
1134         mod_timer(&llc->rej_sent_timer.timer,
1135                   jiffies + llc->rej_sent_timer.expire);
1136         return 0;
1137 }
1138
1139 int llc_conn_ac_start_ack_tmr_if_not_running(struct sock *sk,
1140                                              struct sk_buff *skb)
1141 {
1142         struct llc_sock *llc = llc_sk(sk);
1143
1144         if (!timer_pending(&llc->ack_timer.timer))
1145                 mod_timer(&llc->ack_timer.timer,
1146                           jiffies + llc->ack_timer.expire);
1147         return 0;
1148 }
1149
1150 int llc_conn_ac_stop_ack_timer(struct sock *sk, struct sk_buff *skb)
1151 {
1152         del_timer(&llc_sk(sk)->ack_timer.timer);
1153         return 0;
1154 }
1155
1156 int llc_conn_ac_stop_p_timer(struct sock *sk, struct sk_buff *skb)
1157 {
1158         struct llc_sock *llc = llc_sk(sk);
1159
1160         del_timer(&llc->pf_cycle_timer.timer);
1161         llc_conn_set_p_flag(sk, 0);
1162         return 0;
1163 }
1164
1165 int llc_conn_ac_stop_rej_timer(struct sock *sk, struct sk_buff *skb)
1166 {
1167         del_timer(&llc_sk(sk)->rej_sent_timer.timer);
1168         return 0;
1169 }
1170
1171 int llc_conn_ac_upd_nr_received(struct sock *sk, struct sk_buff *skb)
1172 {
1173         int acked;
1174         u16 unacked = 0;
1175         struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
1176         struct llc_sock *llc = llc_sk(sk);
1177
1178         llc->last_nr = PDU_SUPV_GET_Nr(pdu);
1179         acked = llc_conn_remove_acked_pdus(sk, llc->last_nr, &unacked);
1180         /* On loopback we don't queue I frames in unack_pdu_q queue. */
1181         if (acked > 0 || (llc->dev->flags & IFF_LOOPBACK)) {
1182                 llc->retry_count = 0;
1183                 del_timer(&llc->ack_timer.timer);
1184                 if (llc->failed_data_req) {
1185                         /* already, we did not accept data from upper layer
1186                          * (tx_window full or unacceptable state). Now, we
1187                          * can send data and must inform to upper layer.
1188                          */
1189                         llc->failed_data_req = 0;
1190                         llc_conn_ac_data_confirm(sk, skb);
1191                 }
1192                 if (unacked)
1193                         mod_timer(&llc->ack_timer.timer,
1194                                   jiffies + llc->ack_timer.expire);
1195         } else if (llc->failed_data_req) {
1196                 u8 f_bit;
1197
1198                 llc_pdu_decode_pf_bit(skb, &f_bit);
1199                 if (f_bit == 1) {
1200                         llc->failed_data_req = 0;
1201                         llc_conn_ac_data_confirm(sk, skb);
1202                 }
1203         }
1204         return 0;
1205 }
1206
1207 int llc_conn_ac_upd_p_flag(struct sock *sk, struct sk_buff *skb)
1208 {
1209         struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
1210
1211         if (LLC_PDU_IS_RSP(pdu)) {
1212                 u8 f_bit;
1213
1214                 llc_pdu_decode_pf_bit(skb, &f_bit);
1215                 if (f_bit) {
1216                         llc_conn_set_p_flag(sk, 0);
1217                         llc_conn_ac_stop_p_timer(sk, skb);
1218                 }
1219         }
1220         return 0;
1221 }
1222
1223 int llc_conn_ac_set_data_flag_2(struct sock *sk, struct sk_buff *skb)
1224 {
1225         llc_sk(sk)->data_flag = 2;
1226         return 0;
1227 }
1228
1229 int llc_conn_ac_set_data_flag_0(struct sock *sk, struct sk_buff *skb)
1230 {
1231         llc_sk(sk)->data_flag = 0;
1232         return 0;
1233 }
1234
1235 int llc_conn_ac_set_data_flag_1(struct sock *sk, struct sk_buff *skb)
1236 {
1237         llc_sk(sk)->data_flag = 1;
1238         return 0;
1239 }
1240
1241 int llc_conn_ac_set_data_flag_1_if_data_flag_eq_0(struct sock *sk,
1242                                                   struct sk_buff *skb)
1243 {
1244         if (!llc_sk(sk)->data_flag)
1245                 llc_sk(sk)->data_flag = 1;
1246         return 0;
1247 }
1248
1249 int llc_conn_ac_set_p_flag_0(struct sock *sk, struct sk_buff *skb)
1250 {
1251         llc_conn_set_p_flag(sk, 0);
1252         return 0;
1253 }
1254
1255 static int llc_conn_ac_set_p_flag_1(struct sock *sk, struct sk_buff *skb)
1256 {
1257         llc_conn_set_p_flag(sk, 1);
1258         return 0;
1259 }
1260
1261 int llc_conn_ac_set_remote_busy_0(struct sock *sk, struct sk_buff *skb)
1262 {
1263         llc_sk(sk)->remote_busy_flag = 0;
1264         return 0;
1265 }
1266
1267 int llc_conn_ac_set_cause_flag_0(struct sock *sk, struct sk_buff *skb)
1268 {
1269         llc_sk(sk)->cause_flag = 0;
1270         return 0;
1271 }
1272
1273 int llc_conn_ac_set_cause_flag_1(struct sock *sk, struct sk_buff *skb)
1274 {
1275         llc_sk(sk)->cause_flag = 1;
1276         return 0;
1277 }
1278
1279 int llc_conn_ac_set_retry_cnt_0(struct sock *sk, struct sk_buff *skb)
1280 {
1281         llc_sk(sk)->retry_count = 0;
1282         return 0;
1283 }
1284
1285 int llc_conn_ac_inc_retry_cnt_by_1(struct sock *sk, struct sk_buff *skb)
1286 {
1287         llc_sk(sk)->retry_count++;
1288         return 0;
1289 }
1290
1291 int llc_conn_ac_set_vr_0(struct sock *sk, struct sk_buff *skb)
1292 {
1293         llc_sk(sk)->vR = 0;
1294         return 0;
1295 }
1296
1297 int llc_conn_ac_inc_vr_by_1(struct sock *sk, struct sk_buff *skb)
1298 {
1299         llc_sk(sk)->vR = PDU_GET_NEXT_Vr(llc_sk(sk)->vR);
1300         return 0;
1301 }
1302
1303 int llc_conn_ac_set_vs_0(struct sock *sk, struct sk_buff *skb)
1304 {
1305         llc_sk(sk)->vS = 0;
1306         return 0;
1307 }
1308
1309 int llc_conn_ac_set_vs_nr(struct sock *sk, struct sk_buff *skb)
1310 {
1311         llc_sk(sk)->vS = llc_sk(sk)->last_nr;
1312         return 0;
1313 }
1314
1315 static int llc_conn_ac_inc_vs_by_1(struct sock *sk, struct sk_buff *skb)
1316 {
1317         llc_sk(sk)->vS = (llc_sk(sk)->vS + 1) % LLC_2_SEQ_NBR_MODULO;
1318         return 0;
1319 }
1320
1321 static void llc_conn_tmr_common_cb(unsigned long timeout_data, u8 type)
1322 {
1323         struct sock *sk = (struct sock *)timeout_data;
1324         struct sk_buff *skb = alloc_skb(0, GFP_ATOMIC);
1325
1326         bh_lock_sock(sk);
1327         if (skb) {
1328                 struct llc_conn_state_ev *ev = llc_conn_ev(skb);
1329
1330                 skb_set_owner_r(skb, sk);
1331                 ev->type = type;
1332                 llc_process_tmr_ev(sk, skb);
1333         }
1334         bh_unlock_sock(sk);
1335 }
1336
1337 void llc_conn_pf_cycle_tmr_cb(unsigned long timeout_data)
1338 {
1339         llc_conn_tmr_common_cb(timeout_data, LLC_CONN_EV_TYPE_P_TMR);
1340 }
1341
1342 void llc_conn_busy_tmr_cb(unsigned long timeout_data)
1343 {
1344         llc_conn_tmr_common_cb(timeout_data, LLC_CONN_EV_TYPE_BUSY_TMR);
1345 }
1346
1347 void llc_conn_ack_tmr_cb(unsigned long timeout_data)
1348 {
1349         llc_conn_tmr_common_cb(timeout_data, LLC_CONN_EV_TYPE_ACK_TMR);
1350 }
1351
1352 void llc_conn_rej_tmr_cb(unsigned long timeout_data)
1353 {
1354         llc_conn_tmr_common_cb(timeout_data, LLC_CONN_EV_TYPE_REJ_TMR);
1355 }
1356
1357 int llc_conn_ac_rst_vs(struct sock *sk, struct sk_buff *skb)
1358 {
1359         llc_sk(sk)->X = llc_sk(sk)->vS;
1360         llc_conn_ac_set_vs_nr(sk, skb);
1361         return 0;
1362 }
1363
1364 int llc_conn_ac_upd_vs(struct sock *sk, struct sk_buff *skb)
1365 {
1366         struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
1367         u8 nr = PDU_SUPV_GET_Nr(pdu);
1368
1369         if (llc_circular_between(llc_sk(sk)->vS, nr, llc_sk(sk)->X))
1370                 llc_conn_ac_set_vs_nr(sk, skb);
1371         return 0;
1372 }
1373
1374 /*
1375  * Non-standard actions; these not contained in IEEE specification; for
1376  * our own usage
1377  */
1378 /**
1379  *      llc_conn_disc - removes connection from SAP list and frees it
1380  *      @sk: closed connection
1381  *      @skb: occurred event
1382  */
1383 int llc_conn_disc(struct sock *sk, struct sk_buff *skb)
1384 {
1385         /* FIXME: this thing seems to want to die */
1386         return 0;
1387 }
1388
1389 /**
1390  *      llc_conn_reset - resets connection
1391  *      @sk : reseting connection.
1392  *      @skb: occurred event.
1393  *
1394  *      Stop all timers, empty all queues and reset all flags.
1395  */
1396 int llc_conn_reset(struct sock *sk, struct sk_buff *skb)
1397 {
1398         llc_sk_reset(sk);
1399         return 0;
1400 }
1401
1402 /**
1403  *      llc_circular_between - designates that b is between a and c or not
1404  *      @a: lower bound
1405  *      @b: element to see if is between a and b
1406  *      @c: upper bound
1407  *
1408  *      This function designates that b is between a and c or not (for example,
1409  *      0 is between 127 and 1). Returns 1 if b is between a and c, 0
1410  *      otherwise.
1411  */
1412 u8 llc_circular_between(u8 a, u8 b, u8 c)
1413 {
1414         b = b - a;
1415         c = c - a;
1416         return b <= c;
1417 }
1418
1419 /**
1420  *      llc_process_tmr_ev - timer backend
1421  *      @sk: active connection
1422  *      @skb: occurred event
1423  *
1424  *      This function is called from timer callback functions. When connection
1425  *      is busy (during sending a data frame) timer expiration event must be
1426  *      queued. Otherwise this event can be sent to connection state machine.
1427  *      Queued events will process by llc_backlog_rcv function after sending
1428  *      data frame.
1429  */
1430 static void llc_process_tmr_ev(struct sock *sk, struct sk_buff *skb)
1431 {
1432         if (llc_sk(sk)->state == LLC_CONN_OUT_OF_SVC) {
1433                 printk(KERN_WARNING "%s: timer called on closed connection\n",
1434                        __func__);
1435                 kfree_skb(skb);
1436         } else {
1437                 if (!sock_owned_by_user(sk))
1438                         llc_conn_state_process(sk, skb);
1439                 else {
1440                         llc_set_backlog_type(skb, LLC_EVENT);
1441                         __sk_add_backlog(sk, skb);
1442                 }
1443         }
1444 }