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_result_to_errno(u8 result)
  32 {
  33         switch (result) {
  34         case NFC_HCI_ANY_OK:
  35                 return 0;
  36         case NFC_HCI_ANY_E_TIMEOUT:
  37                 return -ETIMEDOUT;
  38         default:
  39                 return -1;
  40         }
  41 }
  42
  43 static void nfc_hci_execute_cb(struct nfc_hci_dev *hdev, u8 result,
  44                                struct sk_buff *skb, void *cb_data)
  45 {
  46         struct hcp_exec_waiter *hcp_ew = (struct hcp_exec_waiter *)cb_data;
  47
  48         pr_debug("HCI Cmd completed with HCI result=%d\n", result);
  49
  50         hcp_ew->exec_result = nfc_hci_result_to_errno(result);
  51         if (hcp_ew->exec_result == 0)
  52                 hcp_ew->result_skb = skb;
  53         else
  54                 kfree_skb(skb);
  55         hcp_ew->exec_complete = true;
  56
  57         wake_up(hcp_ew->wq);
  58 }
  59
  60 static int nfc_hci_execute_cmd(struct nfc_hci_dev *hdev, u8 pipe, u8 cmd,
  61                                const u8 *param, size_t param_len,
  62                                struct sk_buff **skb)
  63 {
  64         DECLARE_WAIT_QUEUE_HEAD_ONSTACK(ew_wq);
  65         struct hcp_exec_waiter hcp_ew;
  66         hcp_ew.wq = &ew_wq;
  67         hcp_ew.exec_complete = false;
  68         hcp_ew.result_skb = NULL;
  69
  70         pr_debug("through pipe=%d, cmd=%d, plen=%zd\n", pipe, cmd, param_len);
  71
  72         /* TODO: Define hci cmd execution delay. Should it be the same
  73          * for all commands?
  74          */
  75         hcp_ew.exec_result = nfc_hci_hcp_message_tx(hdev, pipe,
  76                                                     NFC_HCI_HCP_COMMAND, cmd,
  77                                                     param, param_len,
  78                                                     nfc_hci_execute_cb, &hcp_ew,
  79                                                     3000);
  80         if (hcp_ew.exec_result < 0)
  81                 return hcp_ew.exec_result;
  82
  83         wait_event(ew_wq, hcp_ew.exec_complete == true);
  84
  85         if (hcp_ew.exec_result == 0) {
  86                 if (skb)
  87                         *skb = hcp_ew.result_skb;
  88                 else
  89                         kfree_skb(hcp_ew.result_skb);
  90         }
  91
  92         return hcp_ew.exec_result;
  93 }
  94
  95 int nfc_hci_send_event(struct nfc_hci_dev *hdev, u8 gate, u8 event,
  96                        const u8 *param, size_t param_len)
  97 {
  98         u8 pipe;
  99
 100         pr_debug("%d to gate %d\n", event, gate);
 101
 102         pipe = hdev->gate2pipe[gate];
 103         if (pipe == NFC_HCI_INVALID_PIPE)
 104                 return -EADDRNOTAVAIL;
 105
 106         return nfc_hci_hcp_message_tx(hdev, pipe, NFC_HCI_HCP_EVENT, event,
 107                                       param, param_len, NULL, NULL, 0);
 108 }
 109 EXPORT_SYMBOL(nfc_hci_send_event);
 110
 111 int nfc_hci_send_response(struct nfc_hci_dev *hdev, u8 gate, u8 response,
 112                           const u8 *param, size_t param_len)
 113 {
 114         u8 pipe;
 115
 116         pr_debug("\n");
 117
 118         pipe = hdev->gate2pipe[gate];
 119         if (pipe == NFC_HCI_INVALID_PIPE)
 120                 return -EADDRNOTAVAIL;
 121
 122         return nfc_hci_hcp_message_tx(hdev, pipe, NFC_HCI_HCP_RESPONSE,
 123                                       response, param, param_len, NULL, NULL,
 124                                       0);
 125 }
 126 EXPORT_SYMBOL(nfc_hci_send_response);
 127
 128 /*
 129  * Execute an hci command sent to gate.
 130  * skb will contain response data if success. skb can be NULL if you are not
 131  * interested by the response.
 132  */
 133 int nfc_hci_send_cmd(struct nfc_hci_dev *hdev, u8 gate, u8 cmd,
 134                      const u8 *param, size_t param_len, struct sk_buff **skb)
 135 {
 136         u8 pipe;
 137
 138         pr_debug("\n");
 139
 140         pipe = hdev->gate2pipe[gate];
 141         if (pipe == NFC_HCI_INVALID_PIPE)
 142                 return -EADDRNOTAVAIL;
 143
 144         return nfc_hci_execute_cmd(hdev, pipe, cmd, param, param_len, skb);
 145 }
 146 EXPORT_SYMBOL(nfc_hci_send_cmd);
 147
 148 int nfc_hci_set_param(struct nfc_hci_dev *hdev, u8 gate, u8 idx,
 149                       const u8 *param, size_t param_len)
 150 {
 151         int r;
 152         u8 *tmp;
 153
 154         /* TODO ELa: reg idx must be inserted before param, but we don't want
 155          * to ask the caller to do it to keep a simpler API.
 156          * For now, just create a new temporary param buffer. This is far from
 157          * optimal though, and the plan is to modify APIs to pass idx down to
 158          * nfc_hci_hcp_message_tx where the frame is actually built, thereby
 159          * eliminating the need for the temp allocation-copy here.
 160          */
 161
 162         pr_debug("idx=%d to gate %d\n", idx, gate);
 163
 164         tmp = kmalloc(1 + param_len, GFP_KERNEL);
 165         if (tmp == NULL)
 166                 return -ENOMEM;
 167
 168         *tmp = idx;
 169         memcpy(tmp + 1, param, param_len);
 170
 171         r = nfc_hci_send_cmd(hdev, gate, NFC_HCI_ANY_SET_PARAMETER,
 172                              tmp, param_len + 1, NULL);
 173
 174         kfree(tmp);
 175
 176         return r;
 177 }
 178 EXPORT_SYMBOL(nfc_hci_set_param);
 179
 180 int nfc_hci_get_param(struct nfc_hci_dev *hdev, u8 gate, u8 idx,
 181                       struct sk_buff **skb)
 182 {
 183         pr_debug("gate=%d regidx=%d\n", gate, idx);
 184
 185         return nfc_hci_send_cmd(hdev, gate, NFC_HCI_ANY_GET_PARAMETER,
 186                                 &idx, 1, skb);
 187 }
 188 EXPORT_SYMBOL(nfc_hci_get_param);
 189
 190 static int nfc_hci_open_pipe(struct nfc_hci_dev *hdev, u8 pipe)
 191 {
 192         struct sk_buff *skb;
 193         int r;
 194
 195         pr_debug("pipe=%d\n", pipe);
 196
 197         r = nfc_hci_execute_cmd(hdev, pipe, NFC_HCI_ANY_OPEN_PIPE,
 198                                 NULL, 0, &skb);
 199         if (r == 0) {
 200                 /* dest host other than host controller will send
 201                  * number of pipes already open on this gate before
 202                  * execution. The number can be found in skb->data[0]
 203                  */
 204                 kfree_skb(skb);
 205         }
 206
 207         return r;
 208 }
 209
 210 static int nfc_hci_close_pipe(struct nfc_hci_dev *hdev, u8 pipe)
 211 {
 212         pr_debug("\n");
 213
 214         return nfc_hci_execute_cmd(hdev, pipe, NFC_HCI_ANY_CLOSE_PIPE,
 215                                    NULL, 0, NULL);
 216 }
 217
 218 static u8 nfc_hci_create_pipe(struct nfc_hci_dev *hdev, u8 dest_host,
 219                               u8 dest_gate, int *result)
 220 {
 221         struct sk_buff *skb;
 222         struct hci_create_pipe_params params;
 223         struct hci_create_pipe_resp *resp;
 224         u8 pipe;
 225
 226         pr_debug("gate=%d\n", dest_gate);
 227
 228         params.src_gate = NFC_HCI_ADMIN_GATE;
 229         params.dest_host = dest_host;
 230         params.dest_gate = dest_gate;
 231
 232         *result = nfc_hci_execute_cmd(hdev, NFC_HCI_ADMIN_PIPE,
 233                                       NFC_HCI_ADM_CREATE_PIPE,
 234                                       (u8 *) &params, sizeof(params), &skb);
 235         if (*result == 0) {
 236                 resp = (struct hci_create_pipe_resp *)skb->data;
 237                 pipe = resp->pipe;
 238                 kfree_skb(skb);
 239
 240                 pr_debug("pipe created=%d\n", pipe);
 241
 242                 return pipe;
 243         } else
 244                 return NFC_HCI_INVALID_PIPE;
 245 }
 246
 247 static int nfc_hci_delete_pipe(struct nfc_hci_dev *hdev, u8 pipe)
 248 {
 249         pr_debug("\n");
 250
 251         return nfc_hci_execute_cmd(hdev, NFC_HCI_ADMIN_PIPE,
 252                                    NFC_HCI_ADM_DELETE_PIPE, &pipe, 1, NULL);
 253 }
 254
 255 static int nfc_hci_clear_all_pipes(struct nfc_hci_dev *hdev)
 256 {
 257         int r;
 258
 259         u8 param[2];
 260
 261         /* TODO: Find out what the identity reference data is
 262          * and fill param with it. HCI spec 6.1.3.5 */
 263
 264         pr_debug("\n");
 265
 266         r = nfc_hci_execute_cmd(hdev, NFC_HCI_ADMIN_PIPE,
 267                                 NFC_HCI_ADM_CLEAR_ALL_PIPE, param, 2, NULL);
 268
 269         return 0;
 270 }
 271
 272 int nfc_hci_disconnect_gate(struct nfc_hci_dev *hdev, u8 gate)
 273 {
 274         int r;
 275         u8 pipe = hdev->gate2pipe[gate];
 276
 277         pr_debug("\n");
 278
 279         if (pipe == NFC_HCI_INVALID_PIPE)
 280                 return -EADDRNOTAVAIL;
 281
 282         r = nfc_hci_close_pipe(hdev, pipe);
 283         if (r < 0)
 284                 return r;
 285
 286         if (pipe != NFC_HCI_LINK_MGMT_PIPE && pipe != NFC_HCI_ADMIN_PIPE) {
 287                 r = nfc_hci_delete_pipe(hdev, pipe);
 288                 if (r < 0)
 289                         return r;
 290         }
 291
 292         hdev->gate2pipe[gate] = NFC_HCI_INVALID_PIPE;
 293
 294         return 0;
 295 }
 296 EXPORT_SYMBOL(nfc_hci_disconnect_gate);
 297
 298 int nfc_hci_disconnect_all_gates(struct nfc_hci_dev *hdev)
 299 {
 300         int r;
 301
 302         pr_debug("\n");
 303
 304         r = nfc_hci_clear_all_pipes(hdev);
 305         if (r < 0)
 306                 return r;
 307
 308         memset(hdev->gate2pipe, NFC_HCI_INVALID_PIPE, sizeof(hdev->gate2pipe));
 309
 310         return 0;
 311 }
 312 EXPORT_SYMBOL(nfc_hci_disconnect_all_gates);
 313
 314 int nfc_hci_connect_gate(struct nfc_hci_dev *hdev, u8 dest_host, u8 dest_gate)
 315 {
 316         u8 pipe = NFC_HCI_INVALID_PIPE;
 317         bool pipe_created = false;
 318         int r;
 319
 320         pr_debug("\n");
 321
 322         if (hdev->gate2pipe[dest_gate] != NFC_HCI_INVALID_PIPE)
 323                 return -EADDRINUSE;
 324
 325         switch (dest_gate) {
 326         case NFC_HCI_LINK_MGMT_GATE:
 327                 pipe = NFC_HCI_LINK_MGMT_PIPE;
 328                 break;
 329         case NFC_HCI_ADMIN_GATE:
 330                 pipe = NFC_HCI_ADMIN_PIPE;
 331                 break;
 332         default:
 333                 pipe = nfc_hci_create_pipe(hdev, dest_host, dest_gate, &r);
 334                 if (pipe == NFC_HCI_INVALID_PIPE)
 335                         return r;
 336                 pipe_created = true;
 337                 break;
 338         }
 339
 340         r = nfc_hci_open_pipe(hdev, pipe);
 341         if (r < 0) {
 342                 if (pipe_created)
 343                         if (nfc_hci_delete_pipe(hdev, pipe) < 0) {
 344                                 /* TODO: Cannot clean by deleting pipe...
 345                                  * -> inconsistent state */
 346                         }
 347                 return r;
 348         }
 349
 350         hdev->gate2pipe[dest_gate] = pipe;
 351
 352         return 0;
 353 }
 354 EXPORT_SYMBOL(nfc_hci_connect_gate);