Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * llc_conn.c - Driver routines for connection component. |
| 3 | * |
| 4 | * Copyright (c) 1997 by Procom Technology, Inc. |
| 5 | * 2001-2003 by Arnaldo Carvalho de Melo <acme@conectiva.com.br> |
| 6 | * |
| 7 | * This program can be redistributed or modified under the terms of the |
| 8 | * GNU General Public License as published by the Free Software Foundation. |
| 9 | * This program is distributed without any warranty or implied warranty |
| 10 | * of merchantability or fitness for a particular purpose. |
| 11 | * |
| 12 | * See the GNU General Public License for more details. |
| 13 | */ |
| 14 | |
| 15 | #include <linux/init.h> |
Tejun Heo | 5a0e3ad | 2010-03-24 17:04:11 +0900 | [diff] [blame] | 16 | #include <linux/slab.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 17 | #include <net/llc_sap.h> |
| 18 | #include <net/llc_conn.h> |
| 19 | #include <net/sock.h> |
Arnaldo Carvalho de Melo | c752f07 | 2005-08-09 20:08:28 -0700 | [diff] [blame] | 20 | #include <net/tcp_states.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 21 | #include <net/llc_c_ev.h> |
| 22 | #include <net/llc_c_ac.h> |
| 23 | #include <net/llc_c_st.h> |
| 24 | #include <net/llc_pdu.h> |
| 25 | |
| 26 | #if 0 |
| 27 | #define dprintk(args...) printk(KERN_DEBUG args) |
| 28 | #else |
| 29 | #define dprintk(args...) |
| 30 | #endif |
| 31 | |
| 32 | static int llc_find_offset(int state, int ev_type); |
| 33 | static void llc_conn_send_pdus(struct sock *sk); |
| 34 | static int llc_conn_service(struct sock *sk, struct sk_buff *skb); |
| 35 | static int llc_exec_conn_trans_actions(struct sock *sk, |
| 36 | struct llc_conn_state_trans *trans, |
| 37 | struct sk_buff *ev); |
| 38 | static struct llc_conn_state_trans *llc_qualify_conn_ev(struct sock *sk, |
| 39 | struct sk_buff *skb); |
| 40 | |
| 41 | /* Offset table on connection states transition diagram */ |
| 42 | static int llc_offset_table[NBR_CONN_STATES][NBR_CONN_EV]; |
| 43 | |
Arnaldo Carvalho de Melo | 590232a | 2005-09-22 04:30:44 -0300 | [diff] [blame] | 44 | int sysctl_llc2_ack_timeout = LLC2_ACK_TIME * HZ; |
| 45 | int sysctl_llc2_p_timeout = LLC2_P_TIME * HZ; |
| 46 | int sysctl_llc2_rej_timeout = LLC2_REJ_TIME * HZ; |
| 47 | int sysctl_llc2_busy_timeout = LLC2_BUSY_TIME * HZ; |
| 48 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 49 | /** |
| 50 | * llc_conn_state_process - sends event to connection state machine |
| 51 | * @sk: connection |
| 52 | * @skb: occurred event |
| 53 | * |
| 54 | * Sends an event to connection state machine. After processing event |
| 55 | * (executing it's actions and changing state), upper layer will be |
| 56 | * indicated or confirmed, if needed. Returns 0 for success, 1 for |
| 57 | * failure. The socket lock has to be held before calling this function. |
| 58 | */ |
| 59 | int llc_conn_state_process(struct sock *sk, struct sk_buff *skb) |
| 60 | { |
| 61 | int rc; |
Arnaldo Carvalho de Melo | d389424 | 2005-09-22 07:57:21 -0300 | [diff] [blame] | 62 | struct llc_sock *llc = llc_sk(skb->sk); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 63 | struct llc_conn_state_ev *ev = llc_conn_ev(skb); |
| 64 | |
| 65 | /* |
| 66 | * We have to hold the skb, because llc_conn_service will kfree it in |
| 67 | * the sending path and we need to look at the skb->cb, where we encode |
| 68 | * llc_conn_state_ev. |
| 69 | */ |
| 70 | skb_get(skb); |
| 71 | ev->ind_prim = ev->cfm_prim = 0; |
Arnaldo Carvalho de Melo | d389424 | 2005-09-22 07:57:21 -0300 | [diff] [blame] | 72 | /* |
| 73 | * Send event to state machine |
| 74 | */ |
| 75 | rc = llc_conn_service(skb->sk, skb); |
Arnaldo Carvalho de Melo | af426d3 | 2005-09-22 03:59:22 -0300 | [diff] [blame] | 76 | if (unlikely(rc != 0)) { |
Harvey Harrison | 0dc4787 | 2008-03-05 20:47:47 -0800 | [diff] [blame] | 77 | printk(KERN_ERR "%s: llc_conn_service failed\n", __func__); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 78 | goto out_kfree_skb; |
| 79 | } |
| 80 | |
Arnaldo Carvalho de Melo | af426d3 | 2005-09-22 03:59:22 -0300 | [diff] [blame] | 81 | if (unlikely(!ev->ind_prim && !ev->cfm_prim)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 82 | /* indicate or confirm not required */ |
David S. Miller | 8728b83 | 2005-08-09 19:25:21 -0700 | [diff] [blame] | 83 | if (!skb->next) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 84 | goto out_kfree_skb; |
| 85 | goto out_skb_put; |
| 86 | } |
| 87 | |
Arnaldo Carvalho de Melo | af426d3 | 2005-09-22 03:59:22 -0300 | [diff] [blame] | 88 | if (unlikely(ev->ind_prim && ev->cfm_prim)) /* Paranoia */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 89 | skb_get(skb); |
| 90 | |
| 91 | switch (ev->ind_prim) { |
| 92 | case LLC_DATA_PRIM: |
Arnaldo Carvalho de Melo | 04e4223 | 2005-09-22 04:40:59 -0300 | [diff] [blame] | 93 | llc_save_primitive(sk, skb, LLC_DATA_PRIM); |
| 94 | if (unlikely(sock_queue_rcv_skb(sk, skb))) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 95 | /* |
| 96 | * shouldn't happen |
| 97 | */ |
| 98 | printk(KERN_ERR "%s: sock_queue_rcv_skb failed!\n", |
Harvey Harrison | 0dc4787 | 2008-03-05 20:47:47 -0800 | [diff] [blame] | 99 | __func__); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 100 | kfree_skb(skb); |
| 101 | } |
| 102 | break; |
Arnaldo Carvalho de Melo | d389424 | 2005-09-22 07:57:21 -0300 | [diff] [blame] | 103 | case LLC_CONN_PRIM: |
Arnaldo Carvalho de Melo | 04e4223 | 2005-09-22 04:40:59 -0300 | [diff] [blame] | 104 | /* |
Arnaldo Carvalho de Melo | d389424 | 2005-09-22 07:57:21 -0300 | [diff] [blame] | 105 | * Can't be sock_queue_rcv_skb, because we have to leave the |
| 106 | * skb->sk pointing to the newly created struct sock in |
| 107 | * llc_conn_handler. -acme |
Arnaldo Carvalho de Melo | 04e4223 | 2005-09-22 04:40:59 -0300 | [diff] [blame] | 108 | */ |
Arnaldo Carvalho de Melo | d389424 | 2005-09-22 07:57:21 -0300 | [diff] [blame] | 109 | skb_queue_tail(&sk->sk_receive_queue, skb); |
| 110 | sk->sk_state_change(sk); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 111 | break; |
| 112 | case LLC_DISC_PRIM: |
| 113 | sock_hold(sk); |
| 114 | if (sk->sk_type == SOCK_STREAM && |
| 115 | sk->sk_state == TCP_ESTABLISHED) { |
| 116 | sk->sk_shutdown = SHUTDOWN_MASK; |
| 117 | sk->sk_socket->state = SS_UNCONNECTED; |
| 118 | sk->sk_state = TCP_CLOSE; |
| 119 | if (!sock_flag(sk, SOCK_DEAD)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 120 | sock_set_flag(sk, SOCK_DEAD); |
Arnaldo Carvalho de Melo | 8420e1b | 2005-09-22 08:29:08 -0300 | [diff] [blame] | 121 | sk->sk_state_change(sk); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 122 | } |
| 123 | } |
| 124 | kfree_skb(skb); |
| 125 | sock_put(sk); |
| 126 | break; |
| 127 | case LLC_RESET_PRIM: |
| 128 | /* |
| 129 | * FIXME: |
| 130 | * RESET is not being notified to upper layers for now |
| 131 | */ |
Harvey Harrison | 0dc4787 | 2008-03-05 20:47:47 -0800 | [diff] [blame] | 132 | printk(KERN_INFO "%s: received a reset ind!\n", __func__); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 133 | kfree_skb(skb); |
| 134 | break; |
| 135 | default: |
| 136 | if (ev->ind_prim) { |
| 137 | printk(KERN_INFO "%s: received unknown %d prim!\n", |
Harvey Harrison | 0dc4787 | 2008-03-05 20:47:47 -0800 | [diff] [blame] | 138 | __func__, ev->ind_prim); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 139 | kfree_skb(skb); |
| 140 | } |
| 141 | /* No indication */ |
| 142 | break; |
| 143 | } |
| 144 | |
| 145 | switch (ev->cfm_prim) { |
| 146 | case LLC_DATA_PRIM: |
| 147 | if (!llc_data_accept_state(llc->state)) |
| 148 | sk->sk_write_space(sk); |
| 149 | else |
| 150 | rc = llc->failed_data_req = 1; |
| 151 | break; |
| 152 | case LLC_CONN_PRIM: |
| 153 | if (sk->sk_type == SOCK_STREAM && |
| 154 | sk->sk_state == TCP_SYN_SENT) { |
| 155 | if (ev->status) { |
| 156 | sk->sk_socket->state = SS_UNCONNECTED; |
| 157 | sk->sk_state = TCP_CLOSE; |
| 158 | } else { |
| 159 | sk->sk_socket->state = SS_CONNECTED; |
| 160 | sk->sk_state = TCP_ESTABLISHED; |
| 161 | } |
| 162 | sk->sk_state_change(sk); |
| 163 | } |
| 164 | break; |
| 165 | case LLC_DISC_PRIM: |
| 166 | sock_hold(sk); |
| 167 | if (sk->sk_type == SOCK_STREAM && sk->sk_state == TCP_CLOSING) { |
| 168 | sk->sk_socket->state = SS_UNCONNECTED; |
| 169 | sk->sk_state = TCP_CLOSE; |
| 170 | sk->sk_state_change(sk); |
| 171 | } |
| 172 | sock_put(sk); |
| 173 | break; |
| 174 | case LLC_RESET_PRIM: |
| 175 | /* |
| 176 | * FIXME: |
| 177 | * RESET is not being notified to upper layers for now |
| 178 | */ |
Harvey Harrison | 0dc4787 | 2008-03-05 20:47:47 -0800 | [diff] [blame] | 179 | printk(KERN_INFO "%s: received a reset conf!\n", __func__); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 180 | break; |
| 181 | default: |
| 182 | if (ev->cfm_prim) { |
| 183 | printk(KERN_INFO "%s: received unknown %d prim!\n", |
Harvey Harrison | 0dc4787 | 2008-03-05 20:47:47 -0800 | [diff] [blame] | 184 | __func__, ev->cfm_prim); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 185 | break; |
| 186 | } |
| 187 | goto out_skb_put; /* No confirmation */ |
| 188 | } |
| 189 | out_kfree_skb: |
| 190 | kfree_skb(skb); |
| 191 | out_skb_put: |
| 192 | kfree_skb(skb); |
| 193 | return rc; |
| 194 | } |
| 195 | |
| 196 | void llc_conn_send_pdu(struct sock *sk, struct sk_buff *skb) |
| 197 | { |
| 198 | /* queue PDU to send to MAC layer */ |
| 199 | skb_queue_tail(&sk->sk_write_queue, skb); |
| 200 | llc_conn_send_pdus(sk); |
| 201 | } |
| 202 | |
| 203 | /** |
| 204 | * llc_conn_rtn_pdu - sends received data pdu to upper layer |
| 205 | * @sk: Active connection |
| 206 | * @skb: Received data frame |
| 207 | * |
| 208 | * Sends received data pdu to upper layer (by using indicate function). |
| 209 | * Prepares service parameters (prim and prim_data). calling indication |
| 210 | * function will be done in llc_conn_state_process. |
| 211 | */ |
| 212 | void llc_conn_rtn_pdu(struct sock *sk, struct sk_buff *skb) |
| 213 | { |
| 214 | struct llc_conn_state_ev *ev = llc_conn_ev(skb); |
| 215 | |
| 216 | ev->ind_prim = LLC_DATA_PRIM; |
| 217 | } |
| 218 | |
| 219 | /** |
| 220 | * llc_conn_resend_i_pdu_as_cmd - resend all all unacknowledged I PDUs |
| 221 | * @sk: active connection |
| 222 | * @nr: NR |
| 223 | * @first_p_bit: p_bit value of first pdu |
| 224 | * |
| 225 | * Resend all unacknowledged I PDUs, starting with the NR; send first as |
| 226 | * command PDU with P bit equal first_p_bit; if more than one send |
| 227 | * subsequent as command PDUs with P bit equal zero (0). |
| 228 | */ |
| 229 | void llc_conn_resend_i_pdu_as_cmd(struct sock *sk, u8 nr, u8 first_p_bit) |
| 230 | { |
| 231 | struct sk_buff *skb; |
| 232 | struct llc_pdu_sn *pdu; |
| 233 | u16 nbr_unack_pdus; |
| 234 | struct llc_sock *llc; |
| 235 | u8 howmany_resend = 0; |
| 236 | |
| 237 | llc_conn_remove_acked_pdus(sk, nr, &nbr_unack_pdus); |
| 238 | if (!nbr_unack_pdus) |
| 239 | goto out; |
| 240 | /* |
| 241 | * Process unack PDUs only if unack queue is not empty; remove |
| 242 | * appropriate PDUs, fix them up, and put them on mac_pdu_q. |
| 243 | */ |
| 244 | llc = llc_sk(sk); |
| 245 | |
| 246 | while ((skb = skb_dequeue(&llc->pdu_unack_q)) != NULL) { |
| 247 | pdu = llc_pdu_sn_hdr(skb); |
| 248 | llc_pdu_set_cmd_rsp(skb, LLC_PDU_CMD); |
| 249 | llc_pdu_set_pf_bit(skb, first_p_bit); |
| 250 | skb_queue_tail(&sk->sk_write_queue, skb); |
| 251 | first_p_bit = 0; |
| 252 | llc->vS = LLC_I_GET_NS(pdu); |
| 253 | howmany_resend++; |
| 254 | } |
| 255 | if (howmany_resend > 0) |
| 256 | llc->vS = (llc->vS + 1) % LLC_2_SEQ_NBR_MODULO; |
| 257 | /* any PDUs to re-send are queued up; start sending to MAC */ |
| 258 | llc_conn_send_pdus(sk); |
| 259 | out:; |
| 260 | } |
| 261 | |
| 262 | /** |
| 263 | * llc_conn_resend_i_pdu_as_rsp - Resend all unacknowledged I PDUs |
| 264 | * @sk: active connection. |
| 265 | * @nr: NR |
| 266 | * @first_f_bit: f_bit value of first pdu. |
| 267 | * |
| 268 | * Resend all unacknowledged I PDUs, starting with the NR; send first as |
| 269 | * response PDU with F bit equal first_f_bit; if more than one send |
| 270 | * subsequent as response PDUs with F bit equal zero (0). |
| 271 | */ |
| 272 | void llc_conn_resend_i_pdu_as_rsp(struct sock *sk, u8 nr, u8 first_f_bit) |
| 273 | { |
| 274 | struct sk_buff *skb; |
| 275 | u16 nbr_unack_pdus; |
| 276 | struct llc_sock *llc = llc_sk(sk); |
| 277 | u8 howmany_resend = 0; |
| 278 | |
| 279 | llc_conn_remove_acked_pdus(sk, nr, &nbr_unack_pdus); |
| 280 | if (!nbr_unack_pdus) |
| 281 | goto out; |
| 282 | /* |
| 283 | * Process unack PDUs only if unack queue is not empty; remove |
| 284 | * appropriate PDUs, fix them up, and put them on mac_pdu_q |
| 285 | */ |
| 286 | while ((skb = skb_dequeue(&llc->pdu_unack_q)) != NULL) { |
| 287 | struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb); |
| 288 | |
| 289 | llc_pdu_set_cmd_rsp(skb, LLC_PDU_RSP); |
| 290 | llc_pdu_set_pf_bit(skb, first_f_bit); |
| 291 | skb_queue_tail(&sk->sk_write_queue, skb); |
| 292 | first_f_bit = 0; |
| 293 | llc->vS = LLC_I_GET_NS(pdu); |
| 294 | howmany_resend++; |
| 295 | } |
| 296 | if (howmany_resend > 0) |
| 297 | llc->vS = (llc->vS + 1) % LLC_2_SEQ_NBR_MODULO; |
| 298 | /* any PDUs to re-send are queued up; start sending to MAC */ |
| 299 | llc_conn_send_pdus(sk); |
| 300 | out:; |
| 301 | } |
| 302 | |
| 303 | /** |
| 304 | * llc_conn_remove_acked_pdus - Removes acknowledged pdus from tx queue |
| 305 | * @sk: active connection |
| 306 | * nr: NR |
| 307 | * how_many_unacked: size of pdu_unack_q after removing acked pdus |
| 308 | * |
| 309 | * Removes acknowledged pdus from transmit queue (pdu_unack_q). Returns |
| 310 | * the number of pdus that removed from queue. |
| 311 | */ |
| 312 | int llc_conn_remove_acked_pdus(struct sock *sk, u8 nr, u16 *how_many_unacked) |
| 313 | { |
| 314 | int pdu_pos, i; |
| 315 | struct sk_buff *skb; |
| 316 | struct llc_pdu_sn *pdu; |
| 317 | int nbr_acked = 0; |
| 318 | struct llc_sock *llc = llc_sk(sk); |
| 319 | int q_len = skb_queue_len(&llc->pdu_unack_q); |
| 320 | |
| 321 | if (!q_len) |
| 322 | goto out; |
| 323 | skb = skb_peek(&llc->pdu_unack_q); |
| 324 | pdu = llc_pdu_sn_hdr(skb); |
| 325 | |
| 326 | /* finding position of last acked pdu in queue */ |
| 327 | pdu_pos = ((int)LLC_2_SEQ_NBR_MODULO + (int)nr - |
| 328 | (int)LLC_I_GET_NS(pdu)) % LLC_2_SEQ_NBR_MODULO; |
| 329 | |
| 330 | for (i = 0; i < pdu_pos && i < q_len; i++) { |
| 331 | skb = skb_dequeue(&llc->pdu_unack_q); |
Wei Yongjun | c3431ea | 2009-02-25 00:42:22 +0000 | [diff] [blame] | 332 | kfree_skb(skb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 333 | nbr_acked++; |
| 334 | } |
| 335 | out: |
| 336 | *how_many_unacked = skb_queue_len(&llc->pdu_unack_q); |
| 337 | return nbr_acked; |
| 338 | } |
| 339 | |
| 340 | /** |
| 341 | * llc_conn_send_pdus - Sends queued PDUs |
| 342 | * @sk: active connection |
| 343 | * |
| 344 | * Sends queued pdus to MAC layer for transmission. |
| 345 | */ |
| 346 | static void llc_conn_send_pdus(struct sock *sk) |
| 347 | { |
| 348 | struct sk_buff *skb; |
| 349 | |
| 350 | while ((skb = skb_dequeue(&sk->sk_write_queue)) != NULL) { |
| 351 | struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb); |
| 352 | |
| 353 | if (LLC_PDU_TYPE_IS_I(pdu) && |
| 354 | !(skb->dev->flags & IFF_LOOPBACK)) { |
| 355 | struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC); |
| 356 | |
| 357 | skb_queue_tail(&llc_sk(sk)->pdu_unack_q, skb); |
| 358 | if (!skb2) |
| 359 | break; |
| 360 | skb = skb2; |
| 361 | } |
| 362 | dev_queue_xmit(skb); |
| 363 | } |
| 364 | } |
| 365 | |
| 366 | /** |
| 367 | * llc_conn_service - finds transition and changes state of connection |
| 368 | * @sk: connection |
| 369 | * @skb: happened event |
| 370 | * |
| 371 | * This function finds transition that matches with happened event, then |
| 372 | * executes related actions and finally changes state of connection. |
| 373 | * Returns 0 for success, 1 for failure. |
| 374 | */ |
| 375 | static int llc_conn_service(struct sock *sk, struct sk_buff *skb) |
| 376 | { |
| 377 | int rc = 1; |
| 378 | struct llc_sock *llc = llc_sk(sk); |
| 379 | struct llc_conn_state_trans *trans; |
| 380 | |
| 381 | if (llc->state > NBR_CONN_STATES) |
| 382 | goto out; |
| 383 | rc = 0; |
| 384 | trans = llc_qualify_conn_ev(sk, skb); |
| 385 | if (trans) { |
| 386 | rc = llc_exec_conn_trans_actions(sk, trans, skb); |
| 387 | if (!rc && trans->next_state != NO_STATE_CHANGE) { |
| 388 | llc->state = trans->next_state; |
| 389 | if (!llc_data_accept_state(llc->state)) |
| 390 | sk->sk_state_change(sk); |
| 391 | } |
| 392 | } |
| 393 | out: |
| 394 | return rc; |
| 395 | } |
| 396 | |
| 397 | /** |
| 398 | * llc_qualify_conn_ev - finds transition for event |
| 399 | * @sk: connection |
| 400 | * @skb: happened event |
| 401 | * |
| 402 | * This function finds transition that matches with happened event. |
| 403 | * Returns pointer to found transition on success, %NULL otherwise. |
| 404 | */ |
| 405 | static struct llc_conn_state_trans *llc_qualify_conn_ev(struct sock *sk, |
| 406 | struct sk_buff *skb) |
| 407 | { |
| 408 | struct llc_conn_state_trans **next_trans; |
Joe Perches | 9b37306 | 2014-12-10 09:43:57 -0800 | [diff] [blame] | 409 | const llc_conn_ev_qfyr_t *next_qualifier; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 410 | struct llc_conn_state_ev *ev = llc_conn_ev(skb); |
| 411 | struct llc_sock *llc = llc_sk(sk); |
| 412 | struct llc_conn_state *curr_state = |
| 413 | &llc_conn_state_table[llc->state - 1]; |
| 414 | |
| 415 | /* search thru events for this state until |
| 416 | * list exhausted or until no more |
| 417 | */ |
| 418 | for (next_trans = curr_state->transitions + |
| 419 | llc_find_offset(llc->state - 1, ev->type); |
| 420 | (*next_trans)->ev; next_trans++) { |
| 421 | if (!((*next_trans)->ev)(sk, skb)) { |
| 422 | /* got POSSIBLE event match; the event may require |
| 423 | * qualification based on the values of a number of |
| 424 | * state flags; if all qualifications are met (i.e., |
| 425 | * if all qualifying functions return success, or 0, |
| 426 | * then this is THE event we're looking for |
| 427 | */ |
| 428 | for (next_qualifier = (*next_trans)->ev_qualifiers; |
| 429 | next_qualifier && *next_qualifier && |
| 430 | !(*next_qualifier)(sk, skb); next_qualifier++) |
| 431 | /* nothing */; |
| 432 | if (!next_qualifier || !*next_qualifier) |
| 433 | /* all qualifiers executed successfully; this is |
| 434 | * our transition; return it so we can perform |
| 435 | * the associated actions & change the state |
| 436 | */ |
| 437 | return *next_trans; |
| 438 | } |
| 439 | } |
| 440 | return NULL; |
| 441 | } |
| 442 | |
| 443 | /** |
| 444 | * llc_exec_conn_trans_actions - executes related actions |
| 445 | * @sk: connection |
| 446 | * @trans: transition that it's actions must be performed |
| 447 | * @skb: event |
| 448 | * |
| 449 | * Executes actions that is related to happened event. Returns 0 for |
| 450 | * success, 1 to indicate failure of at least one action. |
| 451 | */ |
| 452 | static int llc_exec_conn_trans_actions(struct sock *sk, |
| 453 | struct llc_conn_state_trans *trans, |
| 454 | struct sk_buff *skb) |
| 455 | { |
| 456 | int rc = 0; |
Joe Perches | 14b7d95 | 2014-12-10 08:18:50 -0800 | [diff] [blame] | 457 | const llc_conn_action_t *next_action; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 458 | |
| 459 | for (next_action = trans->ev_actions; |
| 460 | next_action && *next_action; next_action++) { |
| 461 | int rc2 = (*next_action)(sk, skb); |
| 462 | |
| 463 | if (rc2 == 2) { |
| 464 | rc = rc2; |
| 465 | break; |
| 466 | } else if (rc2) |
| 467 | rc = 1; |
| 468 | } |
| 469 | return rc; |
| 470 | } |
| 471 | |
Octavian Purdila | b76f5a8 | 2009-12-26 11:51:02 +0000 | [diff] [blame] | 472 | static inline bool llc_estab_match(const struct llc_sap *sap, |
| 473 | const struct llc_addr *daddr, |
| 474 | const struct llc_addr *laddr, |
| 475 | const struct sock *sk) |
| 476 | { |
| 477 | struct llc_sock *llc = llc_sk(sk); |
| 478 | |
| 479 | return llc->laddr.lsap == laddr->lsap && |
| 480 | llc->daddr.lsap == daddr->lsap && |
Joe Perches | 951fd87 | 2013-09-01 13:11:55 -0700 | [diff] [blame] | 481 | ether_addr_equal(llc->laddr.mac, laddr->mac) && |
| 482 | ether_addr_equal(llc->daddr.mac, daddr->mac); |
Octavian Purdila | b76f5a8 | 2009-12-26 11:51:02 +0000 | [diff] [blame] | 483 | } |
| 484 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 485 | /** |
Arnaldo Carvalho de Melo | d389424 | 2005-09-22 07:57:21 -0300 | [diff] [blame] | 486 | * __llc_lookup_established - Finds connection for the remote/local sap/mac |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 487 | * @sap: SAP |
| 488 | * @daddr: address of remote LLC (MAC + SAP) |
| 489 | * @laddr: address of local LLC (MAC + SAP) |
| 490 | * |
| 491 | * Search connection list of the SAP and finds connection using the remote |
| 492 | * mac, remote sap, local mac, and local sap. Returns pointer for |
| 493 | * connection found, %NULL otherwise. |
Arnaldo Carvalho de Melo | d389424 | 2005-09-22 07:57:21 -0300 | [diff] [blame] | 494 | * Caller has to make sure local_bh is disabled. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 495 | */ |
Arnaldo Carvalho de Melo | d389424 | 2005-09-22 07:57:21 -0300 | [diff] [blame] | 496 | static struct sock *__llc_lookup_established(struct llc_sap *sap, |
| 497 | struct llc_addr *daddr, |
| 498 | struct llc_addr *laddr) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 499 | { |
| 500 | struct sock *rc; |
Octavian Purdila | b76f5a8 | 2009-12-26 11:51:02 +0000 | [diff] [blame] | 501 | struct hlist_nulls_node *node; |
Octavian Purdila | 52d58ae | 2009-12-26 11:51:05 +0000 | [diff] [blame] | 502 | int slot = llc_sk_laddr_hashfn(sap, laddr); |
| 503 | struct hlist_nulls_head *laddr_hb = &sap->sk_laddr_hash[slot]; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 504 | |
Octavian Purdila | b76f5a8 | 2009-12-26 11:51:02 +0000 | [diff] [blame] | 505 | rcu_read_lock(); |
| 506 | again: |
Octavian Purdila | 52d58ae | 2009-12-26 11:51:05 +0000 | [diff] [blame] | 507 | sk_nulls_for_each_rcu(rc, node, laddr_hb) { |
Octavian Purdila | b76f5a8 | 2009-12-26 11:51:02 +0000 | [diff] [blame] | 508 | if (llc_estab_match(sap, daddr, laddr, rc)) { |
| 509 | /* Extra checks required by SLAB_DESTROY_BY_RCU */ |
| 510 | if (unlikely(!atomic_inc_not_zero(&rc->sk_refcnt))) |
| 511 | goto again; |
| 512 | if (unlikely(llc_sk(rc)->sap != sap || |
| 513 | !llc_estab_match(sap, daddr, laddr, rc))) { |
| 514 | sock_put(rc); |
| 515 | continue; |
| 516 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 517 | goto found; |
| 518 | } |
| 519 | } |
| 520 | rc = NULL; |
Octavian Purdila | 52d58ae | 2009-12-26 11:51:05 +0000 | [diff] [blame] | 521 | /* |
| 522 | * if the nulls value we got at the end of this lookup is |
| 523 | * not the expected one, we must restart lookup. |
| 524 | * We probably met an item that was moved to another chain. |
| 525 | */ |
| 526 | if (unlikely(get_nulls_value(node) != slot)) |
| 527 | goto again; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 528 | found: |
Octavian Purdila | b76f5a8 | 2009-12-26 11:51:02 +0000 | [diff] [blame] | 529 | rcu_read_unlock(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 530 | return rc; |
| 531 | } |
| 532 | |
Arnaldo Carvalho de Melo | d389424 | 2005-09-22 07:57:21 -0300 | [diff] [blame] | 533 | struct sock *llc_lookup_established(struct llc_sap *sap, |
| 534 | struct llc_addr *daddr, |
| 535 | struct llc_addr *laddr) |
| 536 | { |
| 537 | struct sock *sk; |
| 538 | |
| 539 | local_bh_disable(); |
| 540 | sk = __llc_lookup_established(sap, daddr, laddr); |
| 541 | local_bh_enable(); |
| 542 | return sk; |
| 543 | } |
| 544 | |
Octavian Purdila | b76f5a8 | 2009-12-26 11:51:02 +0000 | [diff] [blame] | 545 | static inline bool llc_listener_match(const struct llc_sap *sap, |
| 546 | const struct llc_addr *laddr, |
| 547 | const struct sock *sk) |
| 548 | { |
| 549 | struct llc_sock *llc = llc_sk(sk); |
| 550 | |
| 551 | return sk->sk_type == SOCK_STREAM && sk->sk_state == TCP_LISTEN && |
| 552 | llc->laddr.lsap == laddr->lsap && |
Joe Perches | 951fd87 | 2013-09-01 13:11:55 -0700 | [diff] [blame] | 553 | ether_addr_equal(llc->laddr.mac, laddr->mac); |
Octavian Purdila | 52d58ae | 2009-12-26 11:51:05 +0000 | [diff] [blame] | 554 | } |
| 555 | |
| 556 | static struct sock *__llc_lookup_listener(struct llc_sap *sap, |
| 557 | struct llc_addr *laddr) |
| 558 | { |
| 559 | struct sock *rc; |
| 560 | struct hlist_nulls_node *node; |
| 561 | int slot = llc_sk_laddr_hashfn(sap, laddr); |
| 562 | struct hlist_nulls_head *laddr_hb = &sap->sk_laddr_hash[slot]; |
| 563 | |
| 564 | rcu_read_lock(); |
| 565 | again: |
| 566 | sk_nulls_for_each_rcu(rc, node, laddr_hb) { |
| 567 | if (llc_listener_match(sap, laddr, rc)) { |
| 568 | /* Extra checks required by SLAB_DESTROY_BY_RCU */ |
| 569 | if (unlikely(!atomic_inc_not_zero(&rc->sk_refcnt))) |
| 570 | goto again; |
| 571 | if (unlikely(llc_sk(rc)->sap != sap || |
| 572 | !llc_listener_match(sap, laddr, rc))) { |
| 573 | sock_put(rc); |
| 574 | continue; |
| 575 | } |
| 576 | goto found; |
| 577 | } |
| 578 | } |
| 579 | rc = NULL; |
| 580 | /* |
| 581 | * if the nulls value we got at the end of this lookup is |
| 582 | * not the expected one, we must restart lookup. |
| 583 | * We probably met an item that was moved to another chain. |
| 584 | */ |
| 585 | if (unlikely(get_nulls_value(node) != slot)) |
| 586 | goto again; |
| 587 | found: |
| 588 | rcu_read_unlock(); |
| 589 | return rc; |
Octavian Purdila | b76f5a8 | 2009-12-26 11:51:02 +0000 | [diff] [blame] | 590 | } |
| 591 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 592 | /** |
| 593 | * llc_lookup_listener - Finds listener for local MAC + SAP |
| 594 | * @sap: SAP |
| 595 | * @laddr: address of local LLC (MAC + SAP) |
| 596 | * |
| 597 | * Search connection list of the SAP and finds connection listening on |
| 598 | * local mac, and local sap. Returns pointer for parent socket found, |
| 599 | * %NULL otherwise. |
Arnaldo Carvalho de Melo | d389424 | 2005-09-22 07:57:21 -0300 | [diff] [blame] | 600 | * Caller has to make sure local_bh is disabled. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 601 | */ |
| 602 | static struct sock *llc_lookup_listener(struct llc_sap *sap, |
| 603 | struct llc_addr *laddr) |
| 604 | { |
Octavian Purdila | 52d58ae | 2009-12-26 11:51:05 +0000 | [diff] [blame] | 605 | static struct llc_addr null_addr; |
| 606 | struct sock *rc = __llc_lookup_listener(sap, laddr); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 607 | |
Octavian Purdila | 52d58ae | 2009-12-26 11:51:05 +0000 | [diff] [blame] | 608 | if (!rc) |
| 609 | rc = __llc_lookup_listener(sap, &null_addr); |
| 610 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 611 | return rc; |
| 612 | } |
| 613 | |
Arnaldo Carvalho de Melo | d389424 | 2005-09-22 07:57:21 -0300 | [diff] [blame] | 614 | static struct sock *__llc_lookup(struct llc_sap *sap, |
| 615 | struct llc_addr *daddr, |
| 616 | struct llc_addr *laddr) |
| 617 | { |
| 618 | struct sock *sk = __llc_lookup_established(sap, daddr, laddr); |
| 619 | |
| 620 | return sk ? : llc_lookup_listener(sap, laddr); |
| 621 | } |
| 622 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 623 | /** |
| 624 | * llc_data_accept_state - designates if in this state data can be sent. |
| 625 | * @state: state of connection. |
| 626 | * |
| 627 | * Returns 0 if data can be sent, 1 otherwise. |
| 628 | */ |
| 629 | u8 llc_data_accept_state(u8 state) |
| 630 | { |
| 631 | return state != LLC_CONN_STATE_NORMAL && state != LLC_CONN_STATE_BUSY && |
| 632 | state != LLC_CONN_STATE_REJ; |
| 633 | } |
| 634 | |
| 635 | /** |
Arnaldo Carvalho de Melo | 0eb8017 | 2005-09-22 03:57:55 -0300 | [diff] [blame] | 636 | * llc_find_next_offset - finds offset for next category of transitions |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 637 | * @state: state table. |
| 638 | * @offset: start offset. |
| 639 | * |
| 640 | * Finds offset of next category of transitions in transition table. |
| 641 | * Returns the start index of next category. |
| 642 | */ |
Arnaldo Carvalho de Melo | 0eb8017 | 2005-09-22 03:57:55 -0300 | [diff] [blame] | 643 | static u16 __init llc_find_next_offset(struct llc_conn_state *state, u16 offset) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 644 | { |
| 645 | u16 cnt = 0; |
| 646 | struct llc_conn_state_trans **next_trans; |
| 647 | |
| 648 | for (next_trans = state->transitions + offset; |
| 649 | (*next_trans)->ev; next_trans++) |
| 650 | ++cnt; |
| 651 | return cnt; |
| 652 | } |
| 653 | |
| 654 | /** |
| 655 | * llc_build_offset_table - builds offset table of connection |
| 656 | * |
| 657 | * Fills offset table of connection state transition table |
| 658 | * (llc_offset_table). |
| 659 | */ |
| 660 | void __init llc_build_offset_table(void) |
| 661 | { |
| 662 | struct llc_conn_state *curr_state; |
| 663 | int state, ev_type, next_offset; |
| 664 | |
| 665 | for (state = 0; state < NBR_CONN_STATES; state++) { |
| 666 | curr_state = &llc_conn_state_table[state]; |
| 667 | next_offset = 0; |
| 668 | for (ev_type = 0; ev_type < NBR_CONN_EV; ev_type++) { |
| 669 | llc_offset_table[state][ev_type] = next_offset; |
Arnaldo Carvalho de Melo | 0eb8017 | 2005-09-22 03:57:55 -0300 | [diff] [blame] | 670 | next_offset += llc_find_next_offset(curr_state, |
| 671 | next_offset) + 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 672 | } |
| 673 | } |
| 674 | } |
| 675 | |
| 676 | /** |
| 677 | * llc_find_offset - finds start offset of category of transitions |
| 678 | * @state: state of connection |
| 679 | * @ev_type: type of happened event |
| 680 | * |
| 681 | * Finds start offset of desired category of transitions. Returns the |
| 682 | * desired start offset. |
| 683 | */ |
| 684 | static int llc_find_offset(int state, int ev_type) |
| 685 | { |
| 686 | int rc = 0; |
| 687 | /* at this stage, llc_offset_table[..][2] is not important. it is for |
| 688 | * init_pf_cycle and I don't know what is it. |
| 689 | */ |
| 690 | switch (ev_type) { |
| 691 | case LLC_CONN_EV_TYPE_PRIM: |
| 692 | rc = llc_offset_table[state][0]; break; |
| 693 | case LLC_CONN_EV_TYPE_PDU: |
| 694 | rc = llc_offset_table[state][4]; break; |
| 695 | case LLC_CONN_EV_TYPE_SIMPLE: |
| 696 | rc = llc_offset_table[state][1]; break; |
| 697 | case LLC_CONN_EV_TYPE_P_TMR: |
| 698 | case LLC_CONN_EV_TYPE_ACK_TMR: |
| 699 | case LLC_CONN_EV_TYPE_REJ_TMR: |
| 700 | case LLC_CONN_EV_TYPE_BUSY_TMR: |
| 701 | rc = llc_offset_table[state][3]; break; |
| 702 | } |
| 703 | return rc; |
| 704 | } |
| 705 | |
| 706 | /** |
| 707 | * llc_sap_add_socket - adds a socket to a SAP |
| 708 | * @sap: SAP |
| 709 | * @sk: socket |
| 710 | * |
Octavian Purdila | 52d58ae | 2009-12-26 11:51:05 +0000 | [diff] [blame] | 711 | * This function adds a socket to the hash tables of a SAP. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 712 | */ |
| 713 | void llc_sap_add_socket(struct llc_sap *sap, struct sock *sk) |
| 714 | { |
Octavian Purdila | 6d2e3ea | 2009-12-26 11:51:04 +0000 | [diff] [blame] | 715 | struct llc_sock *llc = llc_sk(sk); |
| 716 | struct hlist_head *dev_hb = llc_sk_dev_hash(sap, llc->dev->ifindex); |
Octavian Purdila | 52d58ae | 2009-12-26 11:51:05 +0000 | [diff] [blame] | 717 | struct hlist_nulls_head *laddr_hb = llc_sk_laddr_hash(sap, &llc->laddr); |
Octavian Purdila | 6d2e3ea | 2009-12-26 11:51:04 +0000 | [diff] [blame] | 718 | |
Arnaldo Carvalho de Melo | 6e2144b | 2005-09-22 04:43:05 -0300 | [diff] [blame] | 719 | llc_sap_hold(sap); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 720 | llc_sk(sk)->sap = sap; |
Octavian Purdila | 6d2e3ea | 2009-12-26 11:51:04 +0000 | [diff] [blame] | 721 | |
| 722 | spin_lock_bh(&sap->sk_lock); |
Octavian Purdila | 52d58ae | 2009-12-26 11:51:05 +0000 | [diff] [blame] | 723 | sap->sk_count++; |
| 724 | sk_nulls_add_node_rcu(sk, laddr_hb); |
Octavian Purdila | 6d2e3ea | 2009-12-26 11:51:04 +0000 | [diff] [blame] | 725 | hlist_add_head(&llc->dev_hash_node, dev_hb); |
Octavian Purdila | b76f5a8 | 2009-12-26 11:51:02 +0000 | [diff] [blame] | 726 | spin_unlock_bh(&sap->sk_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 727 | } |
| 728 | |
| 729 | /** |
| 730 | * llc_sap_remove_socket - removes a socket from SAP |
| 731 | * @sap: SAP |
| 732 | * @sk: socket |
| 733 | * |
Octavian Purdila | 52d58ae | 2009-12-26 11:51:05 +0000 | [diff] [blame] | 734 | * This function removes a connection from the hash tables of a SAP if |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 735 | * the connection was in this list. |
| 736 | */ |
| 737 | void llc_sap_remove_socket(struct llc_sap *sap, struct sock *sk) |
| 738 | { |
Octavian Purdila | 6d2e3ea | 2009-12-26 11:51:04 +0000 | [diff] [blame] | 739 | struct llc_sock *llc = llc_sk(sk); |
| 740 | |
Octavian Purdila | b76f5a8 | 2009-12-26 11:51:02 +0000 | [diff] [blame] | 741 | spin_lock_bh(&sap->sk_lock); |
| 742 | sk_nulls_del_node_init_rcu(sk); |
Octavian Purdila | 6d2e3ea | 2009-12-26 11:51:04 +0000 | [diff] [blame] | 743 | hlist_del(&llc->dev_hash_node); |
Octavian Purdila | 52d58ae | 2009-12-26 11:51:05 +0000 | [diff] [blame] | 744 | sap->sk_count--; |
Octavian Purdila | b76f5a8 | 2009-12-26 11:51:02 +0000 | [diff] [blame] | 745 | spin_unlock_bh(&sap->sk_lock); |
Arnaldo Carvalho de Melo | 6e2144b | 2005-09-22 04:43:05 -0300 | [diff] [blame] | 746 | llc_sap_put(sap); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 747 | } |
| 748 | |
| 749 | /** |
| 750 | * llc_conn_rcv - sends received pdus to the connection state machine |
| 751 | * @sk: current connection structure. |
| 752 | * @skb: received frame. |
| 753 | * |
| 754 | * Sends received pdus to the connection state machine. |
| 755 | */ |
Weilong Chen | 3cdba60 | 2013-12-20 11:14:59 +0800 | [diff] [blame] | 756 | static int llc_conn_rcv(struct sock *sk, struct sk_buff *skb) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 757 | { |
| 758 | struct llc_conn_state_ev *ev = llc_conn_ev(skb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 759 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 760 | ev->type = LLC_CONN_EV_TYPE_PDU; |
| 761 | ev->reason = 0; |
| 762 | return llc_conn_state_process(sk, skb); |
| 763 | } |
| 764 | |
Arnaldo Carvalho de Melo | d389424 | 2005-09-22 07:57:21 -0300 | [diff] [blame] | 765 | static struct sock *llc_create_incoming_sock(struct sock *sk, |
| 766 | struct net_device *dev, |
| 767 | struct llc_addr *saddr, |
| 768 | struct llc_addr *daddr) |
| 769 | { |
YOSHIFUJI Hideaki | 3b1e0a6 | 2008-03-26 02:26:21 +0900 | [diff] [blame] | 770 | struct sock *newsk = llc_sk_alloc(sock_net(sk), sk->sk_family, GFP_ATOMIC, |
Arnaldo Carvalho de Melo | d389424 | 2005-09-22 07:57:21 -0300 | [diff] [blame] | 771 | sk->sk_prot); |
| 772 | struct llc_sock *newllc, *llc = llc_sk(sk); |
| 773 | |
| 774 | if (!newsk) |
| 775 | goto out; |
| 776 | newllc = llc_sk(newsk); |
| 777 | memcpy(&newllc->laddr, daddr, sizeof(newllc->laddr)); |
| 778 | memcpy(&newllc->daddr, saddr, sizeof(newllc->daddr)); |
| 779 | newllc->dev = dev; |
| 780 | dev_hold(dev); |
| 781 | llc_sap_add_socket(llc->sap, newsk); |
| 782 | llc_sap_hold(llc->sap); |
| 783 | out: |
| 784 | return newsk; |
| 785 | } |
| 786 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 787 | void llc_conn_handler(struct llc_sap *sap, struct sk_buff *skb) |
| 788 | { |
| 789 | struct llc_addr saddr, daddr; |
| 790 | struct sock *sk; |
| 791 | |
| 792 | llc_pdu_decode_sa(skb, saddr.mac); |
| 793 | llc_pdu_decode_ssap(skb, &saddr.lsap); |
| 794 | llc_pdu_decode_da(skb, daddr.mac); |
| 795 | llc_pdu_decode_dsap(skb, &daddr.lsap); |
| 796 | |
Arnaldo Carvalho de Melo | d389424 | 2005-09-22 07:57:21 -0300 | [diff] [blame] | 797 | sk = __llc_lookup(sap, &saddr, &daddr); |
| 798 | if (!sk) |
| 799 | goto drop; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 800 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 801 | bh_lock_sock(sk); |
Arnaldo Carvalho de Melo | d389424 | 2005-09-22 07:57:21 -0300 | [diff] [blame] | 802 | /* |
| 803 | * This has to be done here and not at the upper layer ->accept |
| 804 | * method because of the way the PROCOM state machine works: |
| 805 | * it needs to set several state variables (see, for instance, |
| 806 | * llc_adm_actions_2 in net/llc/llc_c_st.c) and send a packet to |
| 807 | * the originator of the new connection, and this state has to be |
| 808 | * in the newly created struct sock private area. -acme |
| 809 | */ |
| 810 | if (unlikely(sk->sk_state == TCP_LISTEN)) { |
| 811 | struct sock *newsk = llc_create_incoming_sock(sk, skb->dev, |
| 812 | &saddr, &daddr); |
| 813 | if (!newsk) |
| 814 | goto drop_unlock; |
| 815 | skb_set_owner_r(skb, newsk); |
| 816 | } else { |
| 817 | /* |
| 818 | * Can't be skb_set_owner_r, this will be done at the |
| 819 | * llc_conn_state_process function, later on, when we will use |
| 820 | * skb_queue_rcv_skb to send it to upper layers, this is |
| 821 | * another trick required to cope with how the PROCOM state |
| 822 | * machine works. -acme |
| 823 | */ |
| 824 | skb->sk = sk; |
| 825 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 826 | if (!sock_owned_by_user(sk)) |
| 827 | llc_conn_rcv(sk, skb); |
| 828 | else { |
Harvey Harrison | 0dc4787 | 2008-03-05 20:47:47 -0800 | [diff] [blame] | 829 | dprintk("%s: adding to backlog...\n", __func__); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 830 | llc_set_backlog_type(skb, LLC_PACKET); |
Eric Dumazet | f545a38 | 2012-04-22 23:34:26 +0000 | [diff] [blame] | 831 | if (sk_add_backlog(sk, skb, sk->sk_rcvbuf)) |
Zhu Yi | 79545b6 | 2010-03-04 18:01:43 +0000 | [diff] [blame] | 832 | goto drop_unlock; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 833 | } |
Arnaldo Carvalho de Melo | d389424 | 2005-09-22 07:57:21 -0300 | [diff] [blame] | 834 | out: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 835 | bh_unlock_sock(sk); |
| 836 | sock_put(sk); |
| 837 | return; |
| 838 | drop: |
| 839 | kfree_skb(skb); |
Arnaldo Carvalho de Melo | d389424 | 2005-09-22 07:57:21 -0300 | [diff] [blame] | 840 | return; |
| 841 | drop_unlock: |
| 842 | kfree_skb(skb); |
| 843 | goto out; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 844 | } |
| 845 | |
| 846 | #undef LLC_REFCNT_DEBUG |
| 847 | #ifdef LLC_REFCNT_DEBUG |
| 848 | static atomic_t llc_sock_nr; |
| 849 | #endif |
| 850 | |
| 851 | /** |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 852 | * llc_backlog_rcv - Processes rx frames and expired timers. |
| 853 | * @sk: LLC sock (p8022 connection) |
| 854 | * @skb: queued rx frame or event |
| 855 | * |
| 856 | * This function processes frames that has received and timers that has |
| 857 | * expired during sending an I pdu (refer to data_req_handler). frames |
| 858 | * queue by llc_rcv function (llc_mac.c) and timers queue by timer |
| 859 | * callback functions(llc_c_ac.c). |
| 860 | */ |
| 861 | static int llc_backlog_rcv(struct sock *sk, struct sk_buff *skb) |
| 862 | { |
| 863 | int rc = 0; |
| 864 | struct llc_sock *llc = llc_sk(sk); |
| 865 | |
Arnaldo Carvalho de Melo | af426d3 | 2005-09-22 03:59:22 -0300 | [diff] [blame] | 866 | if (likely(llc_backlog_type(skb) == LLC_PACKET)) { |
| 867 | if (likely(llc->state > 1)) /* not closed */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 868 | rc = llc_conn_rcv(sk, skb); |
| 869 | else |
| 870 | goto out_kfree_skb; |
| 871 | } else if (llc_backlog_type(skb) == LLC_EVENT) { |
| 872 | /* timer expiration event */ |
Arnaldo Carvalho de Melo | af426d3 | 2005-09-22 03:59:22 -0300 | [diff] [blame] | 873 | if (likely(llc->state > 1)) /* not closed */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 874 | rc = llc_conn_state_process(sk, skb); |
| 875 | else |
| 876 | goto out_kfree_skb; |
| 877 | } else { |
Harvey Harrison | 0dc4787 | 2008-03-05 20:47:47 -0800 | [diff] [blame] | 878 | printk(KERN_ERR "%s: invalid skb in backlog\n", __func__); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 879 | goto out_kfree_skb; |
| 880 | } |
| 881 | out: |
| 882 | return rc; |
| 883 | out_kfree_skb: |
| 884 | kfree_skb(skb); |
| 885 | goto out; |
| 886 | } |
| 887 | |
| 888 | /** |
| 889 | * llc_sk_init - Initializes a socket with default llc values. |
| 890 | * @sk: socket to initialize. |
| 891 | * |
| 892 | * Initializes a socket with default llc values. |
| 893 | */ |
Weilong Chen | 3cdba60 | 2013-12-20 11:14:59 +0800 | [diff] [blame] | 894 | static void llc_sk_init(struct sock *sk) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 895 | { |
| 896 | struct llc_sock *llc = llc_sk(sk); |
| 897 | |
| 898 | llc->state = LLC_CONN_STATE_ADM; |
| 899 | llc->inc_cntr = llc->dec_cntr = 2; |
| 900 | llc->dec_step = llc->connect_step = 1; |
| 901 | |
Pavel Emelyanov | b24b8a2 | 2008-01-23 21:20:07 -0800 | [diff] [blame] | 902 | setup_timer(&llc->ack_timer.timer, llc_conn_ack_tmr_cb, |
| 903 | (unsigned long)sk); |
Arnaldo Carvalho de Melo | 590232a | 2005-09-22 04:30:44 -0300 | [diff] [blame] | 904 | llc->ack_timer.expire = sysctl_llc2_ack_timeout; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 905 | |
Pavel Emelyanov | b24b8a2 | 2008-01-23 21:20:07 -0800 | [diff] [blame] | 906 | setup_timer(&llc->pf_cycle_timer.timer, llc_conn_pf_cycle_tmr_cb, |
| 907 | (unsigned long)sk); |
Arnaldo Carvalho de Melo | 590232a | 2005-09-22 04:30:44 -0300 | [diff] [blame] | 908 | llc->pf_cycle_timer.expire = sysctl_llc2_p_timeout; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 909 | |
Pavel Emelyanov | b24b8a2 | 2008-01-23 21:20:07 -0800 | [diff] [blame] | 910 | setup_timer(&llc->rej_sent_timer.timer, llc_conn_rej_tmr_cb, |
| 911 | (unsigned long)sk); |
Arnaldo Carvalho de Melo | 590232a | 2005-09-22 04:30:44 -0300 | [diff] [blame] | 912 | llc->rej_sent_timer.expire = sysctl_llc2_rej_timeout; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 913 | |
Pavel Emelyanov | b24b8a2 | 2008-01-23 21:20:07 -0800 | [diff] [blame] | 914 | setup_timer(&llc->busy_state_timer.timer, llc_conn_busy_tmr_cb, |
| 915 | (unsigned long)sk); |
Arnaldo Carvalho de Melo | 590232a | 2005-09-22 04:30:44 -0300 | [diff] [blame] | 916 | llc->busy_state_timer.expire = sysctl_llc2_busy_timeout; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 917 | |
| 918 | llc->n2 = 2; /* max retransmit */ |
| 919 | llc->k = 2; /* tx win size, will adjust dynam */ |
| 920 | llc->rw = 128; /* rx win size (opt and equal to |
YOSHIFUJI Hideaki | d57b186 | 2007-02-09 23:25:01 +0900 | [diff] [blame] | 921 | * tx_win of remote LLC) */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 922 | skb_queue_head_init(&llc->pdu_unack_q); |
| 923 | sk->sk_backlog_rcv = llc_backlog_rcv; |
| 924 | } |
| 925 | |
| 926 | /** |
| 927 | * llc_sk_alloc - Allocates LLC sock |
| 928 | * @family: upper layer protocol family |
| 929 | * @priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc) |
| 930 | * |
| 931 | * Allocates a LLC sock and initializes it. Returns the new LLC sock |
| 932 | * or %NULL if there's no memory available for one |
| 933 | */ |
Eric W. Biederman | 1b8d7ae | 2007-10-08 23:24:22 -0700 | [diff] [blame] | 934 | struct sock *llc_sk_alloc(struct net *net, int family, gfp_t priority, struct proto *prot) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 935 | { |
Pavel Emelyanov | 6257ff2 | 2007-11-01 00:39:31 -0700 | [diff] [blame] | 936 | struct sock *sk = sk_alloc(net, family, priority, prot); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 937 | |
| 938 | if (!sk) |
| 939 | goto out; |
| 940 | llc_sk_init(sk); |
| 941 | sock_init_data(NULL, sk); |
| 942 | #ifdef LLC_REFCNT_DEBUG |
| 943 | atomic_inc(&llc_sock_nr); |
| 944 | printk(KERN_DEBUG "LLC socket %p created in %s, now we have %d alive\n", sk, |
Harvey Harrison | 0dc4787 | 2008-03-05 20:47:47 -0800 | [diff] [blame] | 945 | __func__, atomic_read(&llc_sock_nr)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 946 | #endif |
| 947 | out: |
| 948 | return sk; |
| 949 | } |
| 950 | |
| 951 | /** |
| 952 | * llc_sk_free - Frees a LLC socket |
| 953 | * @sk - socket to free |
| 954 | * |
| 955 | * Frees a LLC socket |
| 956 | */ |
| 957 | void llc_sk_free(struct sock *sk) |
| 958 | { |
| 959 | struct llc_sock *llc = llc_sk(sk); |
| 960 | |
| 961 | llc->state = LLC_CONN_OUT_OF_SVC; |
| 962 | /* Stop all (possibly) running timers */ |
| 963 | llc_conn_ac_stop_all_timers(sk, NULL); |
| 964 | #ifdef DEBUG_LLC_CONN_ALLOC |
Harvey Harrison | 0dc4787 | 2008-03-05 20:47:47 -0800 | [diff] [blame] | 965 | printk(KERN_INFO "%s: unackq=%d, txq=%d\n", __func__, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 966 | skb_queue_len(&llc->pdu_unack_q), |
| 967 | skb_queue_len(&sk->sk_write_queue)); |
| 968 | #endif |
| 969 | skb_queue_purge(&sk->sk_receive_queue); |
| 970 | skb_queue_purge(&sk->sk_write_queue); |
| 971 | skb_queue_purge(&llc->pdu_unack_q); |
| 972 | #ifdef LLC_REFCNT_DEBUG |
| 973 | if (atomic_read(&sk->sk_refcnt) != 1) { |
| 974 | printk(KERN_DEBUG "Destruction of LLC sock %p delayed in %s, cnt=%d\n", |
Harvey Harrison | 0dc4787 | 2008-03-05 20:47:47 -0800 | [diff] [blame] | 975 | sk, __func__, atomic_read(&sk->sk_refcnt)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 976 | printk(KERN_DEBUG "%d LLC sockets are still alive\n", |
| 977 | atomic_read(&llc_sock_nr)); |
| 978 | } else { |
| 979 | atomic_dec(&llc_sock_nr); |
| 980 | printk(KERN_DEBUG "LLC socket %p released in %s, %d are still alive\n", sk, |
Harvey Harrison | 0dc4787 | 2008-03-05 20:47:47 -0800 | [diff] [blame] | 981 | __func__, atomic_read(&llc_sock_nr)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 982 | } |
| 983 | #endif |
| 984 | sock_put(sk); |
| 985 | } |
| 986 | |
| 987 | /** |
| 988 | * llc_sk_reset - resets a connection |
| 989 | * @sk: LLC socket to reset |
| 990 | * |
| 991 | * Resets a connection to the out of service state. Stops its timers |
| 992 | * and frees any frames in the queues of the connection. |
| 993 | */ |
| 994 | void llc_sk_reset(struct sock *sk) |
| 995 | { |
| 996 | struct llc_sock *llc = llc_sk(sk); |
| 997 | |
| 998 | llc_conn_ac_stop_all_timers(sk, NULL); |
| 999 | skb_queue_purge(&sk->sk_write_queue); |
| 1000 | skb_queue_purge(&llc->pdu_unack_q); |
| 1001 | llc->remote_busy_flag = 0; |
| 1002 | llc->cause_flag = 0; |
| 1003 | llc->retry_count = 0; |
| 1004 | llc_conn_set_p_flag(sk, 0); |
| 1005 | llc->f_flag = 0; |
| 1006 | llc->s_flag = 0; |
| 1007 | llc->ack_pf = 0; |
| 1008 | llc->first_pdu_Ns = 0; |
| 1009 | llc->ack_must_be_send = 0; |
| 1010 | llc->dec_step = 1; |
| 1011 | llc->inc_cntr = 2; |
| 1012 | llc->dec_cntr = 2; |
| 1013 | llc->X = 0; |
| 1014 | llc->failed_data_req = 0 ; |
| 1015 | llc->last_nr = 0; |
| 1016 | } |