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