root/net/llc/llc_c_ac.c

/* [<][>][^][v][top][bottom][index][help] */

DEFINITIONS

This source file includes following definitions.
  1. llc_conn_ac_clear_remote_busy
  2. llc_conn_ac_conn_ind
  3. llc_conn_ac_conn_confirm
  4. llc_conn_ac_data_confirm
  5. llc_conn_ac_data_ind
  6. llc_conn_ac_disc_ind
  7. llc_conn_ac_disc_confirm
  8. llc_conn_ac_rst_ind
  9. llc_conn_ac_rst_confirm
  10. llc_conn_ac_clear_remote_busy_if_f_eq_1
  11. llc_conn_ac_stop_rej_tmr_if_data_flag_eq_2
  12. llc_conn_ac_send_disc_cmd_p_set_x
  13. llc_conn_ac_send_dm_rsp_f_set_p
  14. llc_conn_ac_send_dm_rsp_f_set_1
  15. llc_conn_ac_send_frmr_rsp_f_set_x
  16. llc_conn_ac_resend_frmr_rsp_f_set_0
  17. llc_conn_ac_resend_frmr_rsp_f_set_p
  18. llc_conn_ac_send_i_cmd_p_set_1
  19. llc_conn_ac_send_i_cmd_p_set_0
  20. llc_conn_ac_send_i_xxx_x_set_0
  21. llc_conn_ac_resend_i_xxx_x_set_0
  22. llc_conn_ac_resend_i_xxx_x_set_0_or_send_rr
  23. llc_conn_ac_resend_i_rsp_f_set_1
  24. llc_conn_ac_send_rej_cmd_p_set_1
  25. llc_conn_ac_send_rej_rsp_f_set_1
  26. llc_conn_ac_send_rej_xxx_x_set_0
  27. llc_conn_ac_send_rnr_cmd_p_set_1
  28. llc_conn_ac_send_rnr_rsp_f_set_1
  29. llc_conn_ac_send_rnr_xxx_x_set_0
  30. llc_conn_ac_set_remote_busy
  31. llc_conn_ac_opt_send_rnr_xxx_x_set_0
  32. llc_conn_ac_send_rr_cmd_p_set_1
  33. llc_conn_ac_send_rr_rsp_f_set_1
  34. llc_conn_ac_send_ack_rsp_f_set_1
  35. llc_conn_ac_send_rr_xxx_x_set_0
  36. llc_conn_ac_send_ack_xxx_x_set_0
  37. llc_conn_set_p_flag
  38. llc_conn_ac_send_sabme_cmd_p_set_x
  39. llc_conn_ac_send_ua_rsp_f_set_p
  40. llc_conn_ac_set_s_flag_0
  41. llc_conn_ac_set_s_flag_1
  42. llc_conn_ac_start_p_timer
  43. llc_conn_ac_send_ack_if_needed
  44. llc_conn_ac_rst_sendack_flag
  45. llc_conn_ac_send_i_rsp_f_set_ackpf
  46. llc_conn_ac_send_i_as_ack
  47. llc_conn_ac_send_rr_rsp_f_set_ackpf
  48. llc_conn_ac_inc_npta_value
  49. llc_conn_ac_adjust_npta_by_rr
  50. llc_conn_ac_adjust_npta_by_rnr
  51. llc_conn_ac_dec_tx_win_size
  52. llc_conn_ac_inc_tx_win_size
  53. llc_conn_ac_stop_all_timers
  54. llc_conn_ac_stop_other_timers
  55. llc_conn_ac_start_ack_timer
  56. llc_conn_ac_start_rej_timer
  57. llc_conn_ac_start_ack_tmr_if_not_running
  58. llc_conn_ac_stop_ack_timer
  59. llc_conn_ac_stop_p_timer
  60. llc_conn_ac_stop_rej_timer
  61. llc_conn_ac_upd_nr_received
  62. llc_conn_ac_upd_p_flag
  63. llc_conn_ac_set_data_flag_2
  64. llc_conn_ac_set_data_flag_0
  65. llc_conn_ac_set_data_flag_1
  66. llc_conn_ac_set_data_flag_1_if_data_flag_eq_0
  67. llc_conn_ac_set_p_flag_0
  68. llc_conn_ac_set_p_flag_1
  69. llc_conn_ac_set_remote_busy_0
  70. llc_conn_ac_set_cause_flag_0
  71. llc_conn_ac_set_cause_flag_1
  72. llc_conn_ac_set_retry_cnt_0
  73. llc_conn_ac_inc_retry_cnt_by_1
  74. llc_conn_ac_set_vr_0
  75. llc_conn_ac_inc_vr_by_1
  76. llc_conn_ac_set_vs_0
  77. llc_conn_ac_set_vs_nr
  78. llc_conn_ac_inc_vs_by_1
  79. llc_conn_tmr_common_cb
  80. llc_conn_pf_cycle_tmr_cb
  81. llc_conn_busy_tmr_cb
  82. llc_conn_ack_tmr_cb
  83. llc_conn_rej_tmr_cb
  84. llc_conn_ac_rst_vs
  85. llc_conn_ac_upd_vs
  86. llc_conn_disc
  87. llc_conn_reset
  88. llc_circular_between
  89. llc_process_tmr_ev
   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                 skb_get(skb);
 376                 llc_conn_send_pdu(sk, skb);
 377                 llc_conn_ac_inc_vs_by_1(sk, skb);
 378         }
 379         return rc;
 380 }
 381 
 382 static int llc_conn_ac_send_i_cmd_p_set_0(struct sock *sk, struct sk_buff *skb)
 383 {
 384         int rc;
 385         struct llc_sock *llc = llc_sk(sk);
 386         struct llc_sap *sap = llc->sap;
 387 
 388         llc_pdu_header_init(skb, LLC_PDU_TYPE_I, sap->laddr.lsap,
 389                             llc->daddr.lsap, LLC_PDU_CMD);
 390         llc_pdu_init_as_i_cmd(skb, 0, llc->vS, llc->vR);
 391         rc = llc_mac_hdr_init(skb, llc->dev->dev_addr, llc->daddr.mac);
 392         if (likely(!rc)) {
 393                 skb_get(skb);
 394                 llc_conn_send_pdu(sk, skb);
 395                 llc_conn_ac_inc_vs_by_1(sk, skb);
 396         }
 397         return rc;
 398 }
 399 
 400 int llc_conn_ac_send_i_xxx_x_set_0(struct sock *sk, struct sk_buff *skb)
 401 {
 402         int rc;
 403         struct llc_sock *llc = llc_sk(sk);
 404         struct llc_sap *sap = llc->sap;
 405 
 406         llc_pdu_header_init(skb, LLC_PDU_TYPE_I, sap->laddr.lsap,
 407                             llc->daddr.lsap, LLC_PDU_CMD);
 408         llc_pdu_init_as_i_cmd(skb, 0, llc->vS, llc->vR);
 409         rc = llc_mac_hdr_init(skb, llc->dev->dev_addr, llc->daddr.mac);
 410         if (likely(!rc)) {
 411                 skb_get(skb);
 412                 llc_conn_send_pdu(sk, skb);
 413                 llc_conn_ac_inc_vs_by_1(sk, skb);
 414         }
 415         return 0;
 416 }
 417 
 418 int llc_conn_ac_resend_i_xxx_x_set_0(struct sock *sk, struct sk_buff *skb)
 419 {
 420         struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
 421         u8 nr = LLC_I_GET_NR(pdu);
 422 
 423         llc_conn_resend_i_pdu_as_cmd(sk, nr, 0);
 424         return 0;
 425 }
 426 
 427 int llc_conn_ac_resend_i_xxx_x_set_0_or_send_rr(struct sock *sk,
 428                                                 struct sk_buff *skb)
 429 {
 430         u8 nr;
 431         struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
 432         int rc = -ENOBUFS;
 433         struct llc_sock *llc = llc_sk(sk);
 434         struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_U, 0);
 435 
 436         if (nskb) {
 437                 struct llc_sap *sap = llc->sap;
 438 
 439                 llc_pdu_header_init(nskb, LLC_PDU_TYPE_U, sap->laddr.lsap,
 440                                     llc->daddr.lsap, LLC_PDU_RSP);
 441                 llc_pdu_init_as_rr_rsp(nskb, 0, llc->vR);
 442                 rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
 443                 if (likely(!rc))
 444                         llc_conn_send_pdu(sk, nskb);
 445                 else
 446                         kfree_skb(skb);
 447         }
 448         if (rc) {
 449                 nr = LLC_I_GET_NR(pdu);
 450                 rc = 0;
 451                 llc_conn_resend_i_pdu_as_cmd(sk, nr, 0);
 452         }
 453         return rc;
 454 }
 455 
 456 int llc_conn_ac_resend_i_rsp_f_set_1(struct sock *sk, struct sk_buff *skb)
 457 {
 458         struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
 459         u8 nr = LLC_I_GET_NR(pdu);
 460 
 461         llc_conn_resend_i_pdu_as_rsp(sk, nr, 1);
 462         return 0;
 463 }
 464 
 465 int llc_conn_ac_send_rej_cmd_p_set_1(struct sock *sk, struct sk_buff *skb)
 466 {
 467         int rc = -ENOBUFS;
 468         struct llc_sock *llc = llc_sk(sk);
 469         struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_S, 0);
 470 
 471         if (nskb) {
 472                 struct llc_sap *sap = llc->sap;
 473 
 474                 llc_pdu_header_init(nskb, LLC_PDU_TYPE_S, sap->laddr.lsap,
 475                                     llc->daddr.lsap, LLC_PDU_CMD);
 476                 llc_pdu_init_as_rej_cmd(nskb, 1, llc->vR);
 477                 rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
 478                 if (unlikely(rc))
 479                         goto free;
 480                 llc_conn_send_pdu(sk, nskb);
 481         }
 482 out:
 483         return rc;
 484 free:
 485         kfree_skb(nskb);
 486         goto out;
 487 }
 488 
 489 int llc_conn_ac_send_rej_rsp_f_set_1(struct sock *sk, struct sk_buff *skb)
 490 {
 491         int rc = -ENOBUFS;
 492         struct llc_sock *llc = llc_sk(sk);
 493         struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_S, 0);
 494 
 495         if (nskb) {
 496                 struct llc_sap *sap = llc->sap;
 497 
 498                 llc_pdu_header_init(nskb, LLC_PDU_TYPE_S, sap->laddr.lsap,
 499                                     llc->daddr.lsap, LLC_PDU_RSP);
 500                 llc_pdu_init_as_rej_rsp(nskb, 1, llc->vR);
 501                 rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
 502                 if (unlikely(rc))
 503                         goto free;
 504                 llc_conn_send_pdu(sk, nskb);
 505         }
 506 out:
 507         return rc;
 508 free:
 509         kfree_skb(nskb);
 510         goto out;
 511 }
 512 
 513 int llc_conn_ac_send_rej_xxx_x_set_0(struct sock *sk, struct sk_buff *skb)
 514 {
 515         int rc = -ENOBUFS;
 516         struct llc_sock *llc = llc_sk(sk);
 517         struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_S, 0);
 518 
 519         if (nskb) {
 520                 struct llc_sap *sap = llc->sap;
 521 
 522                 llc_pdu_header_init(nskb, LLC_PDU_TYPE_S, sap->laddr.lsap,
 523                                     llc->daddr.lsap, LLC_PDU_RSP);
 524                 llc_pdu_init_as_rej_rsp(nskb, 0, llc->vR);
 525                 rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
 526                 if (unlikely(rc))
 527                         goto free;
 528                 llc_conn_send_pdu(sk, nskb);
 529         }
 530 out:
 531         return rc;
 532 free:
 533         kfree_skb(nskb);
 534         goto out;
 535 }
 536 
 537 int llc_conn_ac_send_rnr_cmd_p_set_1(struct sock *sk, struct sk_buff *skb)
 538 {
 539         int rc = -ENOBUFS;
 540         struct llc_sock *llc = llc_sk(sk);
 541         struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_S, 0);
 542 
 543         if (nskb) {
 544                 struct llc_sap *sap = llc->sap;
 545 
 546                 llc_pdu_header_init(nskb, LLC_PDU_TYPE_S, sap->laddr.lsap,
 547                                     llc->daddr.lsap, LLC_PDU_CMD);
 548                 llc_pdu_init_as_rnr_cmd(nskb, 1, llc->vR);
 549                 rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
 550                 if (unlikely(rc))
 551                         goto free;
 552                 llc_conn_send_pdu(sk, nskb);
 553         }
 554 out:
 555         return rc;
 556 free:
 557         kfree_skb(nskb);
 558         goto out;
 559 }
 560 
 561 int llc_conn_ac_send_rnr_rsp_f_set_1(struct sock *sk, struct sk_buff *skb)
 562 {
 563         int rc = -ENOBUFS;
 564         struct llc_sock *llc = llc_sk(sk);
 565         struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_S, 0);
 566 
 567         if (nskb) {
 568                 struct llc_sap *sap = llc->sap;
 569 
 570                 llc_pdu_header_init(nskb, LLC_PDU_TYPE_S, sap->laddr.lsap,
 571                                     llc->daddr.lsap, LLC_PDU_RSP);
 572                 llc_pdu_init_as_rnr_rsp(nskb, 1, llc->vR);
 573                 rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
 574                 if (unlikely(rc))
 575                         goto free;
 576                 llc_conn_send_pdu(sk, nskb);
 577         }
 578 out:
 579         return rc;
 580 free:
 581         kfree_skb(nskb);
 582         goto out;
 583 }
 584 
 585 int llc_conn_ac_send_rnr_xxx_x_set_0(struct sock *sk, struct sk_buff *skb)
 586 {
 587         int rc = -ENOBUFS;
 588         struct llc_sock *llc = llc_sk(sk);
 589         struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_S, 0);
 590 
 591         if (nskb) {
 592                 struct llc_sap *sap = llc->sap;
 593 
 594                 llc_pdu_header_init(nskb, LLC_PDU_TYPE_S, sap->laddr.lsap,
 595                                     llc->daddr.lsap, LLC_PDU_RSP);
 596                 llc_pdu_init_as_rnr_rsp(nskb, 0, llc->vR);
 597                 rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
 598                 if (unlikely(rc))
 599                         goto free;
 600                 llc_conn_send_pdu(sk, nskb);
 601         }
 602 out:
 603         return rc;
 604 free:
 605         kfree_skb(nskb);
 606         goto out;
 607 }
 608 
 609 int llc_conn_ac_set_remote_busy(struct sock *sk, struct sk_buff *skb)
 610 {
 611         struct llc_sock *llc = llc_sk(sk);
 612 
 613         if (!llc->remote_busy_flag) {
 614                 llc->remote_busy_flag = 1;
 615                 mod_timer(&llc->busy_state_timer.timer,
 616                          jiffies + llc->busy_state_timer.expire);
 617         }
 618         return 0;
 619 }
 620 
 621 int llc_conn_ac_opt_send_rnr_xxx_x_set_0(struct sock *sk, struct sk_buff *skb)
 622 {
 623         int rc = -ENOBUFS;
 624         struct llc_sock *llc = llc_sk(sk);
 625         struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_S, 0);
 626 
 627         if (nskb) {
 628                 struct llc_sap *sap = llc->sap;
 629 
 630                 llc_pdu_header_init(nskb, LLC_PDU_TYPE_S, sap->laddr.lsap,
 631                                     llc->daddr.lsap, LLC_PDU_RSP);
 632                 llc_pdu_init_as_rnr_rsp(nskb, 0, llc->vR);
 633                 rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
 634                 if (unlikely(rc))
 635                         goto free;
 636                 llc_conn_send_pdu(sk, nskb);
 637         }
 638 out:
 639         return rc;
 640 free:
 641         kfree_skb(nskb);
 642         goto out;
 643 }
 644 
 645 int llc_conn_ac_send_rr_cmd_p_set_1(struct sock *sk, struct sk_buff *skb)
 646 {
 647         int rc = -ENOBUFS;
 648         struct llc_sock *llc = llc_sk(sk);
 649         struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_S, 0);
 650 
 651         if (nskb) {
 652                 struct llc_sap *sap = llc->sap;
 653 
 654                 llc_pdu_header_init(nskb, LLC_PDU_TYPE_S, sap->laddr.lsap,
 655                                     llc->daddr.lsap, LLC_PDU_CMD);
 656                 llc_pdu_init_as_rr_cmd(nskb, 1, llc->vR);
 657                 rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
 658                 if (unlikely(rc))
 659                         goto free;
 660                 llc_conn_send_pdu(sk, nskb);
 661         }
 662 out:
 663         return rc;
 664 free:
 665         kfree_skb(nskb);
 666         goto out;
 667 }
 668 
 669 int llc_conn_ac_send_rr_rsp_f_set_1(struct sock *sk, struct sk_buff *skb)
 670 {
 671         int rc = -ENOBUFS;
 672         struct llc_sock *llc = llc_sk(sk);
 673         struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_S, 0);
 674 
 675         if (nskb) {
 676                 struct llc_sap *sap = llc->sap;
 677                 u8 f_bit = 1;
 678 
 679                 llc_pdu_header_init(nskb, LLC_PDU_TYPE_S, sap->laddr.lsap,
 680                                     llc->daddr.lsap, LLC_PDU_RSP);
 681                 llc_pdu_init_as_rr_rsp(nskb, f_bit, llc->vR);
 682                 rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
 683                 if (unlikely(rc))
 684                         goto free;
 685                 llc_conn_send_pdu(sk, nskb);
 686         }
 687 out:
 688         return rc;
 689 free:
 690         kfree_skb(nskb);
 691         goto out;
 692 }
 693 
 694 int llc_conn_ac_send_ack_rsp_f_set_1(struct sock *sk, struct sk_buff *skb)
 695 {
 696         int rc = -ENOBUFS;
 697         struct llc_sock *llc = llc_sk(sk);
 698         struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_S, 0);
 699 
 700         if (nskb) {
 701                 struct llc_sap *sap = llc->sap;
 702 
 703                 llc_pdu_header_init(nskb, LLC_PDU_TYPE_S, sap->laddr.lsap,
 704                                     llc->daddr.lsap, LLC_PDU_RSP);
 705                 llc_pdu_init_as_rr_rsp(nskb, 1, llc->vR);
 706                 rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
 707                 if (unlikely(rc))
 708                         goto free;
 709                 llc_conn_send_pdu(sk, nskb);
 710         }
 711 out:
 712         return rc;
 713 free:
 714         kfree_skb(nskb);
 715         goto out;
 716 }
 717 
 718 int llc_conn_ac_send_rr_xxx_x_set_0(struct sock *sk, struct sk_buff *skb)
 719 {
 720         int rc = -ENOBUFS;
 721         struct llc_sock *llc = llc_sk(sk);
 722         struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_S, 0);
 723 
 724         if (nskb) {
 725                 struct llc_sap *sap = llc->sap;
 726 
 727                 llc_pdu_header_init(nskb, LLC_PDU_TYPE_S, sap->laddr.lsap,
 728                                     llc->daddr.lsap, LLC_PDU_RSP);
 729                 llc_pdu_init_as_rr_rsp(nskb, 0, llc->vR);
 730                 rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
 731                 if (unlikely(rc))
 732                         goto free;
 733                 llc_conn_send_pdu(sk, nskb);
 734         }
 735 out:
 736         return rc;
 737 free:
 738         kfree_skb(nskb);
 739         goto out;
 740 }
 741 
 742 int llc_conn_ac_send_ack_xxx_x_set_0(struct sock *sk, struct sk_buff *skb)
 743 {
 744         int rc = -ENOBUFS;
 745         struct llc_sock *llc = llc_sk(sk);
 746         struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_S, 0);
 747 
 748         if (nskb) {
 749                 struct llc_sap *sap = llc->sap;
 750 
 751                 llc_pdu_header_init(nskb, LLC_PDU_TYPE_S, sap->laddr.lsap,
 752                                     llc->daddr.lsap, LLC_PDU_RSP);
 753                 llc_pdu_init_as_rr_rsp(nskb, 0, llc->vR);
 754                 rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
 755                 if (unlikely(rc))
 756                         goto free;
 757                 llc_conn_send_pdu(sk, nskb);
 758         }
 759 out:
 760         return rc;
 761 free:
 762         kfree_skb(nskb);
 763         goto out;
 764 }
 765 
 766 void llc_conn_set_p_flag(struct sock *sk, u8 value)
 767 {
 768         int state_changed = llc_sk(sk)->p_flag && !value;
 769 
 770         llc_sk(sk)->p_flag = value;
 771 
 772         if (state_changed)
 773                 sk->sk_state_change(sk);
 774 }
 775 
 776 int llc_conn_ac_send_sabme_cmd_p_set_x(struct sock *sk, struct sk_buff *skb)
 777 {
 778         int rc = -ENOBUFS;
 779         struct llc_sock *llc = llc_sk(sk);
 780         struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_U, 0);
 781 
 782         if (nskb) {
 783                 struct llc_sap *sap = llc->sap;
 784                 u8 *dmac = llc->daddr.mac;
 785 
 786                 if (llc->dev->flags & IFF_LOOPBACK)
 787                         dmac = llc->dev->dev_addr;
 788                 llc_pdu_header_init(nskb, LLC_PDU_TYPE_U, sap->laddr.lsap,
 789                                     llc->daddr.lsap, LLC_PDU_CMD);
 790                 llc_pdu_init_as_sabme_cmd(nskb, 1);
 791                 rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, dmac);
 792                 if (unlikely(rc))
 793                         goto free;
 794                 llc_conn_send_pdu(sk, nskb);
 795                 llc_conn_set_p_flag(sk, 1);
 796         }
 797 out:
 798         return rc;
 799 free:
 800         kfree_skb(nskb);
 801         goto out;
 802 }
 803 
 804 int llc_conn_ac_send_ua_rsp_f_set_p(struct sock *sk, struct sk_buff *skb)
 805 {
 806         u8 f_bit;
 807         int rc = -ENOBUFS;
 808         struct llc_sock *llc = llc_sk(sk);
 809         struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_U, 0);
 810 
 811         llc_pdu_decode_pf_bit(skb, &f_bit);
 812         if (nskb) {
 813                 struct llc_sap *sap = llc->sap;
 814 
 815                 nskb->dev = llc->dev;
 816                 llc_pdu_header_init(nskb, LLC_PDU_TYPE_U, sap->laddr.lsap,
 817                                     llc->daddr.lsap, LLC_PDU_RSP);
 818                 llc_pdu_init_as_ua_rsp(nskb, f_bit);
 819                 rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
 820                 if (unlikely(rc))
 821                         goto free;
 822                 llc_conn_send_pdu(sk, nskb);
 823         }
 824 out:
 825         return rc;
 826 free:
 827         kfree_skb(nskb);
 828         goto out;
 829 }
 830 
 831 int llc_conn_ac_set_s_flag_0(struct sock *sk, struct sk_buff *skb)
 832 {
 833         llc_sk(sk)->s_flag = 0;
 834         return 0;
 835 }
 836 
 837 int llc_conn_ac_set_s_flag_1(struct sock *sk, struct sk_buff *skb)
 838 {
 839         llc_sk(sk)->s_flag = 1;
 840         return 0;
 841 }
 842 
 843 int llc_conn_ac_start_p_timer(struct sock *sk, struct sk_buff *skb)
 844 {
 845         struct llc_sock *llc = llc_sk(sk);
 846 
 847         llc_conn_set_p_flag(sk, 1);
 848         mod_timer(&llc->pf_cycle_timer.timer,
 849                   jiffies + llc->pf_cycle_timer.expire);
 850         return 0;
 851 }
 852 
 853 /**
 854  *      llc_conn_ac_send_ack_if_needed - check if ack is needed
 855  *      @sk: current connection structure
 856  *      @skb: current event
 857  *
 858  *      Checks number of received PDUs which have not been acknowledged, yet,
 859  *      If number of them reaches to "npta"(Number of PDUs To Acknowledge) then
 860  *      sends an RR response as acknowledgement for them.  Returns 0 for
 861  *      success, 1 otherwise.
 862  */
 863 int llc_conn_ac_send_ack_if_needed(struct sock *sk, struct sk_buff *skb)
 864 {
 865         u8 pf_bit;
 866         struct llc_sock *llc = llc_sk(sk);
 867 
 868         llc_pdu_decode_pf_bit(skb, &pf_bit);
 869         llc->ack_pf |= pf_bit & 1;
 870         if (!llc->ack_must_be_send) {
 871                 llc->first_pdu_Ns = llc->vR;
 872                 llc->ack_must_be_send = 1;
 873                 llc->ack_pf = pf_bit & 1;
 874         }
 875         if (((llc->vR - llc->first_pdu_Ns + 1 + LLC_2_SEQ_NBR_MODULO)
 876                         % LLC_2_SEQ_NBR_MODULO) >= llc->npta) {
 877                 llc_conn_ac_send_rr_rsp_f_set_ackpf(sk, skb);
 878                 llc->ack_must_be_send   = 0;
 879                 llc->ack_pf             = 0;
 880                 llc_conn_ac_inc_npta_value(sk, skb);
 881         }
 882         return 0;
 883 }
 884 
 885 /**
 886  *      llc_conn_ac_rst_sendack_flag - resets ack_must_be_send flag
 887  *      @sk: current connection structure
 888  *      @skb: current event
 889  *
 890  *      This action resets ack_must_be_send flag of given connection, this flag
 891  *      indicates if there is any PDU which has not been acknowledged yet.
 892  *      Returns 0 for success, 1 otherwise.
 893  */
 894 int llc_conn_ac_rst_sendack_flag(struct sock *sk, struct sk_buff *skb)
 895 {
 896         llc_sk(sk)->ack_must_be_send = llc_sk(sk)->ack_pf = 0;
 897         return 0;
 898 }
 899 
 900 /**
 901  *      llc_conn_ac_send_i_rsp_f_set_ackpf - acknowledge received PDUs
 902  *      @sk: current connection structure
 903  *      @skb: current event
 904  *
 905  *      Sends an I response PDU with f-bit set to ack_pf flag as acknowledge to
 906  *      all received PDUs which have not been acknowledged, yet. ack_pf flag is
 907  *      set to one if one PDU with p-bit set to one is received.  Returns 0 for
 908  *      success, 1 otherwise.
 909  */
 910 static int llc_conn_ac_send_i_rsp_f_set_ackpf(struct sock *sk,
 911                                               struct sk_buff *skb)
 912 {
 913         int rc;
 914         struct llc_sock *llc = llc_sk(sk);
 915         struct llc_sap *sap = llc->sap;
 916 
 917         llc_pdu_header_init(skb, LLC_PDU_TYPE_I, sap->laddr.lsap,
 918                             llc->daddr.lsap, LLC_PDU_RSP);
 919         llc_pdu_init_as_i_cmd(skb, llc->ack_pf, llc->vS, llc->vR);
 920         rc = llc_mac_hdr_init(skb, llc->dev->dev_addr, llc->daddr.mac);
 921         if (likely(!rc)) {
 922                 skb_get(skb);
 923                 llc_conn_send_pdu(sk, skb);
 924                 llc_conn_ac_inc_vs_by_1(sk, skb);
 925         }
 926         return rc;
 927 }
 928 
 929 /**
 930  *      llc_conn_ac_send_i_as_ack - sends an I-format PDU to acknowledge rx PDUs
 931  *      @sk: current connection structure.
 932  *      @skb: current event.
 933  *
 934  *      This action sends an I-format PDU as acknowledge to received PDUs which
 935  *      have not been acknowledged, yet, if there is any. By using of this
 936  *      action number of acknowledgements decreases, this technic is called
 937  *      piggy backing. Returns 0 for success, 1 otherwise.
 938  */
 939 int llc_conn_ac_send_i_as_ack(struct sock *sk, struct sk_buff *skb)
 940 {
 941         struct llc_sock *llc = llc_sk(sk);
 942         int ret;
 943 
 944         if (llc->ack_must_be_send) {
 945                 ret = llc_conn_ac_send_i_rsp_f_set_ackpf(sk, skb);
 946                 llc->ack_must_be_send = 0 ;
 947                 llc->ack_pf = 0;
 948         } else {
 949                 ret = llc_conn_ac_send_i_cmd_p_set_0(sk, skb);
 950         }
 951 
 952         return ret;
 953 }
 954 
 955 /**
 956  *      llc_conn_ac_send_rr_rsp_f_set_ackpf - ack all rx PDUs not yet acked
 957  *      @sk: current connection structure.
 958  *      @skb: current event.
 959  *
 960  *      This action sends an RR response with f-bit set to ack_pf flag as
 961  *      acknowledge to all received PDUs which have not been acknowledged, yet,
 962  *      if there is any. ack_pf flag indicates if a PDU has been received with
 963  *      p-bit set to one. Returns 0 for success, 1 otherwise.
 964  */
 965 static int llc_conn_ac_send_rr_rsp_f_set_ackpf(struct sock *sk,
 966                                                struct sk_buff *skb)
 967 {
 968         int rc = -ENOBUFS;
 969         struct llc_sock *llc = llc_sk(sk);
 970         struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_S, 0);
 971 
 972         if (nskb) {
 973                 struct llc_sap *sap = llc->sap;
 974 
 975                 llc_pdu_header_init(nskb, LLC_PDU_TYPE_S, sap->laddr.lsap,
 976                                     llc->daddr.lsap, LLC_PDU_RSP);
 977                 llc_pdu_init_as_rr_rsp(nskb, llc->ack_pf, llc->vR);
 978                 rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
 979                 if (unlikely(rc))
 980                         goto free;
 981                 llc_conn_send_pdu(sk, nskb);
 982         }
 983 out:
 984         return rc;
 985 free:
 986         kfree_skb(nskb);
 987         goto out;
 988 }
 989 
 990 /**
 991  *      llc_conn_ac_inc_npta_value - tries to make value of npta greater
 992  *      @sk: current connection structure.
 993  *      @skb: current event.
 994  *
 995  *      After "inc_cntr" times calling of this action, "npta" increase by one.
 996  *      this action tries to make vale of "npta" greater as possible; number of
 997  *      acknowledgements decreases by increasing of "npta". Returns 0 for
 998  *      success, 1 otherwise.
 999  */
1000 static int llc_conn_ac_inc_npta_value(struct sock *sk, struct sk_buff *skb)
1001 {
1002         struct llc_sock *llc = llc_sk(sk);
1003 
1004         if (!llc->inc_cntr) {
1005                 llc->dec_step = 0;
1006                 llc->dec_cntr = llc->inc_cntr = 2;
1007                 ++llc->npta;
1008                 if (llc->npta > (u8) ~LLC_2_SEQ_NBR_MODULO)
1009                         llc->npta = (u8) ~LLC_2_SEQ_NBR_MODULO;
1010         } else
1011                 --llc->inc_cntr;
1012         return 0;
1013 }
1014 
1015 /**
1016  *      llc_conn_ac_adjust_npta_by_rr - decreases "npta" by one
1017  *      @sk: current connection structure.
1018  *      @skb: current event.
1019  *
1020  *      After receiving "dec_cntr" times RR command, this action decreases
1021  *      "npta" by one. Returns 0 for success, 1 otherwise.
1022  */
1023 int llc_conn_ac_adjust_npta_by_rr(struct sock *sk, struct sk_buff *skb)
1024 {
1025         struct llc_sock *llc = llc_sk(sk);
1026 
1027         if (!llc->connect_step && !llc->remote_busy_flag) {
1028                 if (!llc->dec_step) {
1029                         if (!llc->dec_cntr) {
1030                                 llc->inc_cntr = llc->dec_cntr = 2;
1031                                 if (llc->npta > 0)
1032                                         llc->npta = llc->npta - 1;
1033                         } else
1034                                 llc->dec_cntr -=1;
1035                 }
1036         } else
1037                 llc->connect_step = 0 ;
1038         return 0;
1039 }
1040 
1041 /**
1042  *      llc_conn_ac_adjust_npta_by_rnr - decreases "npta" by one
1043  *      @sk: current connection structure.
1044  *      @skb: current event.
1045  *
1046  *      After receiving "dec_cntr" times RNR command, this action decreases
1047  *      "npta" by one. Returns 0 for success, 1 otherwise.
1048  */
1049 int llc_conn_ac_adjust_npta_by_rnr(struct sock *sk, struct sk_buff *skb)
1050 {
1051         struct llc_sock *llc = llc_sk(sk);
1052 
1053         if (llc->remote_busy_flag)
1054                 if (!llc->dec_step) {
1055                         if (!llc->dec_cntr) {
1056                                 llc->inc_cntr = llc->dec_cntr = 2;
1057                                 if (llc->npta > 0)
1058                                         --llc->npta;
1059                         } else
1060                                 --llc->dec_cntr;
1061                 }
1062         return 0;
1063 }
1064 
1065 /**
1066  *      llc_conn_ac_dec_tx_win_size - decreases tx window size
1067  *      @sk: current connection structure.
1068  *      @skb: current event.
1069  *
1070  *      After receiving of a REJ command or response, transmit window size is
1071  *      decreased by number of PDUs which are outstanding yet. Returns 0 for
1072  *      success, 1 otherwise.
1073  */
1074 int llc_conn_ac_dec_tx_win_size(struct sock *sk, struct sk_buff *skb)
1075 {
1076         struct llc_sock *llc = llc_sk(sk);
1077         u8 unacked_pdu = skb_queue_len(&llc->pdu_unack_q);
1078 
1079         if (llc->k - unacked_pdu < 1)
1080                 llc->k = 1;
1081         else
1082                 llc->k -= unacked_pdu;
1083         return 0;
1084 }
1085 
1086 /**
1087  *      llc_conn_ac_inc_tx_win_size - tx window size is inc by 1
1088  *      @sk: current connection structure.
1089  *      @skb: current event.
1090  *
1091  *      After receiving an RR response with f-bit set to one, transmit window
1092  *      size is increased by one. Returns 0 for success, 1 otherwise.
1093  */
1094 int llc_conn_ac_inc_tx_win_size(struct sock *sk, struct sk_buff *skb)
1095 {
1096         struct llc_sock *llc = llc_sk(sk);
1097 
1098         llc->k += 1;
1099         if (llc->k > (u8) ~LLC_2_SEQ_NBR_MODULO)
1100                 llc->k = (u8) ~LLC_2_SEQ_NBR_MODULO;
1101         return 0;
1102 }
1103 
1104 int llc_conn_ac_stop_all_timers(struct sock *sk, struct sk_buff *skb)
1105 {
1106         llc_sk_stop_all_timers(sk, false);
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(struct sock *sk, u8 type)
1322 {
1323         struct sk_buff *skb = alloc_skb(0, GFP_ATOMIC);
1324 
1325         bh_lock_sock(sk);
1326         if (skb) {
1327                 struct llc_conn_state_ev *ev = llc_conn_ev(skb);
1328 
1329                 skb_set_owner_r(skb, sk);
1330                 ev->type = type;
1331                 llc_process_tmr_ev(sk, skb);
1332         }
1333         bh_unlock_sock(sk);
1334 }
1335 
1336 void llc_conn_pf_cycle_tmr_cb(struct timer_list *t)
1337 {
1338         struct llc_sock *llc = from_timer(llc, t, pf_cycle_timer.timer);
1339 
1340         llc_conn_tmr_common_cb(&llc->sk, LLC_CONN_EV_TYPE_P_TMR);
1341 }
1342 
1343 void llc_conn_busy_tmr_cb(struct timer_list *t)
1344 {
1345         struct llc_sock *llc = from_timer(llc, t, busy_state_timer.timer);
1346 
1347         llc_conn_tmr_common_cb(&llc->sk, LLC_CONN_EV_TYPE_BUSY_TMR);
1348 }
1349 
1350 void llc_conn_ack_tmr_cb(struct timer_list *t)
1351 {
1352         struct llc_sock *llc = from_timer(llc, t, ack_timer.timer);
1353 
1354         llc_conn_tmr_common_cb(&llc->sk, LLC_CONN_EV_TYPE_ACK_TMR);
1355 }
1356 
1357 void llc_conn_rej_tmr_cb(struct timer_list *t)
1358 {
1359         struct llc_sock *llc = from_timer(llc, t, rej_sent_timer.timer);
1360 
1361         llc_conn_tmr_common_cb(&llc->sk, LLC_CONN_EV_TYPE_REJ_TMR);
1362 }
1363 
1364 int llc_conn_ac_rst_vs(struct sock *sk, struct sk_buff *skb)
1365 {
1366         llc_sk(sk)->X = llc_sk(sk)->vS;
1367         llc_conn_ac_set_vs_nr(sk, skb);
1368         return 0;
1369 }
1370 
1371 int llc_conn_ac_upd_vs(struct sock *sk, struct sk_buff *skb)
1372 {
1373         struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
1374         u8 nr = PDU_SUPV_GET_Nr(pdu);
1375 
1376         if (llc_circular_between(llc_sk(sk)->vS, nr, llc_sk(sk)->X))
1377                 llc_conn_ac_set_vs_nr(sk, skb);
1378         return 0;
1379 }
1380 
1381 /*
1382  * Non-standard actions; these not contained in IEEE specification; for
1383  * our own usage
1384  */
1385 /**
1386  *      llc_conn_disc - removes connection from SAP list and frees it
1387  *      @sk: closed connection
1388  *      @skb: occurred event
1389  */
1390 int llc_conn_disc(struct sock *sk, struct sk_buff *skb)
1391 {
1392         /* FIXME: this thing seems to want to die */
1393         return 0;
1394 }
1395 
1396 /**
1397  *      llc_conn_reset - resets connection
1398  *      @sk : reseting connection.
1399  *      @skb: occurred event.
1400  *
1401  *      Stop all timers, empty all queues and reset all flags.
1402  */
1403 int llc_conn_reset(struct sock *sk, struct sk_buff *skb)
1404 {
1405         llc_sk_reset(sk);
1406         return 0;
1407 }
1408 
1409 /**
1410  *      llc_circular_between - designates that b is between a and c or not
1411  *      @a: lower bound
1412  *      @b: element to see if is between a and b
1413  *      @c: upper bound
1414  *
1415  *      This function designates that b is between a and c or not (for example,
1416  *      0 is between 127 and 1). Returns 1 if b is between a and c, 0
1417  *      otherwise.
1418  */
1419 u8 llc_circular_between(u8 a, u8 b, u8 c)
1420 {
1421         b = b - a;
1422         c = c - a;
1423         return b <= c;
1424 }
1425 
1426 /**
1427  *      llc_process_tmr_ev - timer backend
1428  *      @sk: active connection
1429  *      @skb: occurred event
1430  *
1431  *      This function is called from timer callback functions. When connection
1432  *      is busy (during sending a data frame) timer expiration event must be
1433  *      queued. Otherwise this event can be sent to connection state machine.
1434  *      Queued events will process by llc_backlog_rcv function after sending
1435  *      data frame.
1436  */
1437 static void llc_process_tmr_ev(struct sock *sk, struct sk_buff *skb)
1438 {
1439         if (llc_sk(sk)->state == LLC_CONN_OUT_OF_SVC) {
1440                 printk(KERN_WARNING "%s: timer called on closed connection\n",
1441                        __func__);
1442                 kfree_skb(skb);
1443         } else {
1444                 if (!sock_owned_by_user(sk))
1445                         llc_conn_state_process(sk, skb);
1446                 else {
1447                         llc_set_backlog_type(skb, LLC_EVENT);
1448                         __sk_add_backlog(sk, skb);
1449                 }
1450         }
1451 }
/* [<][>][^][v][top][bottom][index][help] */