net/nfc/hci/command.c

   1 /*
   2  * Copyright (C) 2012  Intel Corporation. All rights reserved.
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation; either version 2 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the
  16  * Free Software Foundation, Inc.,
  17  * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  18  */
  19
  20 #define pr_fmt(fmt) "hci: %s: " fmt, __func__
  21
  22 #include <linux/init.h>
  23 #include <linux/kernel.h>
  24 #include <linux/sched.h>
  25 #include <linux/module.h>
  26
  27 #include <net/nfc/hci.h>
  28
  29 #include "hci.h"
  30
  31 static int nfc_hci_execute_cmd_async(struct nfc_hci_dev *hdev, u8 pipe, u8 cmd,
  32                                const u8 *param, size_t param_len,
  33                                data_exchange_cb_t cb, void *cb_context)
  34 {
  35         pr_debug("exec cmd async through pipe=%d, cmd=%d, plen=%zd\n", pipe,
  36                  cmd, param_len);
  37
  38         /* TODO: Define hci cmd execution delay. Should it be the same
  39          * for all commands?
  40          */
  41         return nfc_hci_hcp_message_tx(hdev, pipe, NFC_HCI_HCP_COMMAND, cmd,
  42                                       param, param_len, cb, cb_context, 3000);
  43 }
  44
  45 /*
  46  * HCI command execution completion callback.
  47  * err will be a standard linux error (may be converted from HCI response)
  48  * skb contains the response data and must be disposed, or may be NULL if
  49  * an error occured
  50  */
  51 static void nfc_hci_execute_cb(void *context, struct sk_buff *skb, int err)
  52 {
  53         struct hcp_exec_waiter *hcp_ew = (struct hcp_exec_waiter *)context;
  54
  55         pr_debug("HCI Cmd completed with result=%d\n", err);
  56
  57         hcp_ew->exec_result = err;
  58         if (hcp_ew->exec_result == 0)
  59                 hcp_ew->result_skb = skb;
  60         else
  61                 kfree_skb(skb);
  62         hcp_ew->exec_complete = true;
  63
  64         wake_up(hcp_ew->wq);
  65 }
  66
  67 static int nfc_hci_execute_cmd(struct nfc_hci_dev *hdev, u8 pipe, u8 cmd,
  68                                const u8 *param, size_t param_len,
  69                                struct sk_buff **skb)
  70 {
  71         DECLARE_WAIT_QUEUE_HEAD_ONSTACK(ew_wq);
  72         struct hcp_exec_waiter hcp_ew;
  73         hcp_ew.wq = &ew_wq;
  74         hcp_ew.exec_complete = false;
  75         hcp_ew.result_skb = NULL;
  76
  77         pr_debug("exec cmd sync through pipe=%d, cmd=%d, plen=%zd\n", pipe,
  78                  cmd, param_len);
  79
  80         /* TODO: Define hci cmd execution delay. Should it be the same
  81          * for all commands?
  82          */
  83         hcp_ew.exec_result = nfc_hci_hcp_message_tx(hdev, pipe,
  84                                                     NFC_HCI_HCP_COMMAND, cmd,
  85                                                     param, param_len,
  86                                                     nfc_hci_execute_cb, &hcp_ew,
  87                                                     3000);
  88         if (hcp_ew.exec_result < 0)
  89                 return hcp_ew.exec_result;
  90
  91         wait_event(ew_wq, hcp_ew.exec_complete == true);
  92
  93         if (hcp_ew.exec_result == 0) {
  94                 if (skb)
  95                         *skb = hcp_ew.result_skb;
  96                 else
  97                         kfree_skb(hcp_ew.result_skb);
  98         }
  99
 100         return hcp_ew.exec_result;
 101 }
 102
 103 int nfc_hci_send_event(struct nfc_hci_dev *hdev, u8 gate, u8 event,
 104                        const u8 *param, size_t param_len)
 105 {
 106         u8 pipe;
 107
 108         pr_debug("%d to gate %d\n", event, gate);
 109
 110         pipe = hdev->gate2pipe[gate];
 111         if (pipe == NFC_HCI_INVALID_PIPE)
 112                 return -EADDRNOTAVAIL;
 113
 114         return nfc_hci_hcp_message_tx(hdev, pipe, NFC_HCI_HCP_EVENT, event,
 115                                       param, param_len, NULL, NULL, 0);
 116 }
 117 EXPORT_SYMBOL(nfc_hci_send_event);
 118
 119 int nfc_hci_send_response(struct nfc_hci_dev *hdev, u8 gate, u8 response,
 120                           const u8 *param, size_t param_len)
 121 {
 122         u8 pipe;
 123
 124         pr_debug("\n");
 125
 126         pipe = hdev->gate2pipe[gate];
 127         if (pipe == NFC_HCI_INVALID_PIPE)
 128                 return -EADDRNOTAVAIL;
 129
 130         return nfc_hci_hcp_message_tx(hdev, pipe, NFC_HCI_HCP_RESPONSE,
 131                                       response, param, param_len, NULL, NULL,
 132                                       0);
 133 }
 134 EXPORT_SYMBOL(nfc_hci_send_response);
 135
 136 /*
 137  * Execute an hci command sent to gate.
 138  * skb will contain response data if success. skb can be NULL if you are not
 139  * interested by the response.
 140  */
 141 int nfc_hci_send_cmd(struct nfc_hci_dev *hdev, u8 gate, u8 cmd,
 142                      const u8 *param, size_t param_len, struct sk_buff **skb)
 143 {
 144         u8 pipe;
 145
 146         pr_debug("\n");
 147
 148         pipe = hdev->gate2pipe[gate];
 149         if (pipe == NFC_HCI_INVALID_PIPE)
 150                 return -EADDRNOTAVAIL;
 151
 152         return nfc_hci_execute_cmd(hdev, pipe, cmd, param, param_len, skb);
 153 }
 154 EXPORT_SYMBOL(nfc_hci_send_cmd);
 155
 156 int nfc_hci_send_cmd_async(struct nfc_hci_dev *hdev, u8 gate, u8 cmd,
 157                            const u8 *param, size_t param_len,
 158                            data_exchange_cb_t cb, void *cb_context)
 159 {
 160         u8 pipe;
 161
 162         pr_debug("\n");
 163
 164         pipe = hdev->gate2pipe[gate];
 165         if (pipe == NFC_HCI_INVALID_PIPE)
 166                 return -EADDRNOTAVAIL;
 167
 168         return nfc_hci_execute_cmd_async(hdev, pipe, cmd, param, param_len,
 169                                          cb, cb_context);
 170 }
 171 EXPORT_SYMBOL(nfc_hci_send_cmd_async);
 172
 173 int nfc_hci_set_param(struct nfc_hci_dev *hdev, u8 gate, u8 idx,
 174                       const u8 *param, size_t param_len)
 175 {
 176         int r;
 177         u8 *tmp;
 178
 179         /* TODO ELa: reg idx must be inserted before param, but we don't want
 180          * to ask the caller to do it to keep a simpler API.
 181          * For now, just create a new temporary param buffer. This is far from
 182          * optimal though, and the plan is to modify APIs to pass idx down to
 183          * nfc_hci_hcp_message_tx where the frame is actually built, thereby
 184          * eliminating the need for the temp allocation-copy here.
 185          */
 186
 187         pr_debug("idx=%d to gate %d\n", idx, gate);
 188
 189         tmp = kmalloc(1 + param_len, GFP_KERNEL);
 190         if (tmp == NULL)
 191                 return -ENOMEM;
 192
 193         *tmp = idx;
 194         memcpy(tmp + 1, param, param_len);
 195
 196         r = nfc_hci_send_cmd(hdev, gate, NFC_HCI_ANY_SET_PARAMETER,
 197                              tmp, param_len + 1, NULL);
 198
 199         kfree(tmp);
 200
 201         return r;
 202 }
 203 EXPORT_SYMBOL(nfc_hci_set_param);
 204
 205 int nfc_hci_get_param(struct nfc_hci_dev *hdev, u8 gate, u8 idx,
 206                       struct sk_buff **skb)
 207 {
 208         pr_debug("gate=%d regidx=%d\n", gate, idx);
 209
 210         return nfc_hci_send_cmd(hdev, gate, NFC_HCI_ANY_GET_PARAMETER,
 211                                 &idx, 1, skb);
 212 }
 213 EXPORT_SYMBOL(nfc_hci_get_param);
 214
 215 static int nfc_hci_open_pipe(struct nfc_hci_dev *hdev, u8 pipe)
 216 {
 217         struct sk_buff *skb;
 218         int r;
 219
 220         pr_debug("pipe=%d\n", pipe);
 221
 222         r = nfc_hci_execute_cmd(hdev, pipe, NFC_HCI_ANY_OPEN_PIPE,
 223                                 NULL, 0, &skb);
 224         if (r == 0) {
 225                 /* dest host other than host controller will send
 226                  * number of pipes already open on this gate before
 227                  * execution. The number can be found in skb->data[0]
 228                  */
 229                 kfree_skb(skb);
 230         }
 231
 232         return r;
 233 }
 234
 235 static int nfc_hci_close_pipe(struct nfc_hci_dev *hdev, u8 pipe)
 236 {
 237         pr_debug("\n");
 238
 239         return nfc_hci_execute_cmd(hdev, pipe, NFC_HCI_ANY_CLOSE_PIPE,
 240                                    NULL, 0, NULL);
 241 }
 242
 243 static u8 nfc_hci_create_pipe(struct nfc_hci_dev *hdev, u8 dest_host,
 244                               u8 dest_gate, int *result)
 245 {
 246         struct sk_buff *skb;
 247         struct hci_create_pipe_params params;
 248         struct hci_create_pipe_resp *resp;
 249         u8 pipe;
 250
 251         pr_debug("gate=%d\n", dest_gate);
 252
 253         params.src_gate = NFC_HCI_ADMIN_GATE;
 254         params.dest_host = dest_host;
 255         params.dest_gate = dest_gate;
 256
 257         *result = nfc_hci_execute_cmd(hdev, NFC_HCI_ADMIN_PIPE,
 258                                       NFC_HCI_ADM_CREATE_PIPE,
 259                                       (u8 *) &params, sizeof(params), &skb);
 260         if (*result == 0) {
 261                 resp = (struct hci_create_pipe_resp *)skb->data;
 262                 pipe = resp->pipe;
 263                 kfree_skb(skb);
 264
 265                 pr_debug("pipe created=%d\n", pipe);
 266
 267                 return pipe;
 268         } else
 269                 return NFC_HCI_INVALID_PIPE;
 270 }
 271
 272 static int nfc_hci_delete_pipe(struct nfc_hci_dev *hdev, u8 pipe)
 273 {
 274         pr_debug("\n");
 275
 276         return nfc_hci_execute_cmd(hdev, NFC_HCI_ADMIN_PIPE,
 277                                    NFC_HCI_ADM_DELETE_PIPE, &pipe, 1, NULL);
 278 }
 279
 280 static int nfc_hci_clear_all_pipes(struct nfc_hci_dev *hdev)
 281 {
 282         int r;
 283
 284         u8 param[2];
 285
 286         /* TODO: Find out what the identity reference data is
 287          * and fill param with it. HCI spec 6.1.3.5 */
 288
 289         pr_debug("\n");
 290
 291         r = nfc_hci_execute_cmd(hdev, NFC_HCI_ADMIN_PIPE,
 292                                 NFC_HCI_ADM_CLEAR_ALL_PIPE, param, 2, NULL);
 293
 294         return 0;
 295 }
 296
 297 int nfc_hci_disconnect_gate(struct nfc_hci_dev *hdev, u8 gate)
 298 {
 299         int r;
 300         u8 pipe = hdev->gate2pipe[gate];
 301
 302         pr_debug("\n");
 303
 304         if (pipe == NFC_HCI_INVALID_PIPE)
 305                 return -EADDRNOTAVAIL;
 306
 307         r = nfc_hci_close_pipe(hdev, pipe);
 308         if (r < 0)
 309                 return r;
 310
 311         if (pipe != NFC_HCI_LINK_MGMT_PIPE && pipe != NFC_HCI_ADMIN_PIPE) {
 312                 r = nfc_hci_delete_pipe(hdev, pipe);
 313                 if (r < 0)
 314                         return r;
 315         }
 316
 317         hdev->gate2pipe[gate] = NFC_HCI_INVALID_PIPE;
 318
 319         return 0;
 320 }
 321 EXPORT_SYMBOL(nfc_hci_disconnect_gate);
 322
 323 int nfc_hci_disconnect_all_gates(struct nfc_hci_dev *hdev)
 324 {
 325         int r;
 326
 327         pr_debug("\n");
 328
 329         r = nfc_hci_clear_all_pipes(hdev);
 330         if (r < 0)
 331                 return r;
 332
 333         memset(hdev->gate2pipe, NFC_HCI_INVALID_PIPE, sizeof(hdev->gate2pipe));
 334
 335         return 0;
 336 }
 337 EXPORT_SYMBOL(nfc_hci_disconnect_all_gates);
 338
 339 int nfc_hci_connect_gate(struct nfc_hci_dev *hdev, u8 dest_host, u8 dest_gate,
 340                          u8 pipe)
 341 {
 342         bool pipe_created = false;
 343         int r;
 344
 345         pr_debug("\n");
 346
 347         if (hdev->gate2pipe[dest_gate] != NFC_HCI_INVALID_PIPE)
 348                 return -EADDRINUSE;
 349
 350         if (pipe != NFC_HCI_INVALID_PIPE)
 351                 goto pipe_is_open;
 352
 353         switch (dest_gate) {
 354         case NFC_HCI_LINK_MGMT_GATE:
 355                 pipe = NFC_HCI_LINK_MGMT_PIPE;
 356                 break;
 357         case NFC_HCI_ADMIN_GATE:
 358                 pipe = NFC_HCI_ADMIN_PIPE;
 359                 break;
 360         default:
 361                 pipe = nfc_hci_create_pipe(hdev, dest_host, dest_gate, &r);
 362                 if (pipe == NFC_HCI_INVALID_PIPE)
 363                         return r;
 364                 pipe_created = true;
 365                 break;
 366         }
 367
 368         r = nfc_hci_open_pipe(hdev, pipe);
 369         if (r < 0) {
 370                 if (pipe_created)
 371                         if (nfc_hci_delete_pipe(hdev, pipe) < 0) {
 372                                 /* TODO: Cannot clean by deleting pipe...
 373                                  * -> inconsistent state */
 374                         }
 375                 return r;
 376         }
 377
 378 pipe_is_open:
 379         hdev->gate2pipe[dest_gate] = pipe;
 380
 381         return 0;
 382 }
 383 EXPORT_SYMBOL(nfc_hci_connect_gate);