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