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