net/irda/ircomm/ircomm_lmp.c

   1 /*********************************************************************
   2  *
   3  * Filename:      ircomm_lmp.c
   4  * Version:       1.0
   5  * Description:   Interface between IrCOMM and IrLMP
   6  * Status:        Stable
   7  * Author:        Dag Brattli <dagb@cs.uit.no>
   8  * Created at:    Sun Jun  6 20:48:27 1999
   9  * Modified at:   Sun Dec 12 13:44:17 1999
  10  * Modified by:   Dag Brattli <dagb@cs.uit.no>
  11  * Sources:       Previous IrLPT work by Thomas Davis
  12  *
  13  *     Copyright (c) 1999 Dag Brattli, All Rights Reserved.
  14  *     Copyright (c) 2000-2003 Jean Tourrilhes <jt@hpl.hp.com>
  15  *
  16  *     This program is free software; you can redistribute it and/or
  17  *     modify it under the terms of the GNU General Public License as
  18  *     published by the Free Software Foundation; either version 2 of
  19  *     the License, or (at your option) any later version.
  20  *
  21  *     This program is distributed in the hope that it will be useful,
  22  *     but WITHOUT ANY WARRANTY; without even the implied warranty of
  23  *     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  24  *     GNU General Public License for more details.
  25  *
  26  *     You should have received a copy of the GNU General Public License
  27  *     along with this program; if not, see <http://www.gnu.org/licenses/>.
  28  *
  29  ********************************************************************/
  30
  31 #include <linux/init.h>
  32 #include <linux/gfp.h>
  33
  34 #include <net/irda/irda.h>
  35 #include <net/irda/irlmp.h>
  36 #include <net/irda/iriap.h>
  37 #include <net/irda/irda_device.h>       /* struct irda_skb_cb */
  38
  39 #include <net/irda/ircomm_event.h>
  40 #include <net/irda/ircomm_lmp.h>
  41
  42
  43 /*
  44  * Function ircomm_lmp_connect_request (self, userdata)
  45  *
  46  *
  47  *
  48  */
  49 static int ircomm_lmp_connect_request(struct ircomm_cb *self,
  50                                       struct sk_buff *userdata,
  51                                       struct ircomm_info *info)
  52 {
  53         int ret = 0;
  54
  55         IRDA_DEBUG(0, "%s()\n", __func__ );
  56
  57         /* Don't forget to refcount it - should be NULL anyway */
  58         if(userdata)
  59                 skb_get(userdata);
  60
  61         ret = irlmp_connect_request(self->lsap, info->dlsap_sel,
  62                                     info->saddr, info->daddr, NULL, userdata);
  63         return ret;
  64 }
  65
  66 /*
  67  * Function ircomm_lmp_connect_response (self, skb)
  68  *
  69  *
  70  *
  71  */
  72 static int ircomm_lmp_connect_response(struct ircomm_cb *self,
  73                                        struct sk_buff *userdata)
  74 {
  75         struct sk_buff *tx_skb;
  76
  77         IRDA_DEBUG(0, "%s()\n", __func__ );
  78
  79         /* Any userdata supplied? */
  80         if (userdata == NULL) {
  81                 tx_skb = alloc_skb(LMP_MAX_HEADER, GFP_ATOMIC);
  82                 if (!tx_skb)
  83                         return -ENOMEM;
  84
  85                 /* Reserve space for MUX and LAP header */
  86                 skb_reserve(tx_skb, LMP_MAX_HEADER);
  87         } else {
  88                 /*
  89                  *  Check that the client has reserved enough space for
  90                  *  headers
  91                  */
  92                 IRDA_ASSERT(skb_headroom(userdata) >= LMP_MAX_HEADER,
  93                             return -1;);
  94
  95                 /* Don't forget to refcount it - should be NULL anyway */
  96                 skb_get(userdata);
  97                 tx_skb = userdata;
  98         }
  99
 100         return irlmp_connect_response(self->lsap, tx_skb);
 101 }
 102
 103 static int ircomm_lmp_disconnect_request(struct ircomm_cb *self,
 104                                          struct sk_buff *userdata,
 105                                          struct ircomm_info *info)
 106 {
 107         struct sk_buff *tx_skb;
 108         int ret;
 109
 110         IRDA_DEBUG(0, "%s()\n", __func__ );
 111
 112         if (!userdata) {
 113                 tx_skb = alloc_skb(LMP_MAX_HEADER, GFP_ATOMIC);
 114                 if (!tx_skb)
 115                         return -ENOMEM;
 116
 117                 /*  Reserve space for MUX and LAP header */
 118                 skb_reserve(tx_skb, LMP_MAX_HEADER);
 119                 userdata = tx_skb;
 120         } else {
 121                 /* Don't forget to refcount it - should be NULL anyway */
 122                 skb_get(userdata);
 123         }
 124
 125         ret = irlmp_disconnect_request(self->lsap, userdata);
 126
 127         return ret;
 128 }
 129
 130 /*
 131  * Function ircomm_lmp_flow_control (skb)
 132  *
 133  *    This function is called when a data frame we have sent to IrLAP has
 134  *    been deallocated. We do this to make sure we don't flood IrLAP with
 135  *    frames, since we are not using the IrTTP flow control mechanism
 136  */
 137 static void ircomm_lmp_flow_control(struct sk_buff *skb)
 138 {
 139         struct irda_skb_cb *cb;
 140         struct ircomm_cb *self;
 141         int line;
 142
 143         IRDA_ASSERT(skb != NULL, return;);
 144
 145         cb = (struct irda_skb_cb *) skb->cb;
 146
 147         IRDA_DEBUG(2, "%s()\n", __func__ );
 148
 149         line = cb->line;
 150
 151         self = (struct ircomm_cb *) hashbin_lock_find(ircomm, line, NULL);
 152         if (!self) {
 153                 IRDA_DEBUG(2, "%s(), didn't find myself\n", __func__ );
 154                 return;
 155         }
 156
 157         IRDA_ASSERT(self != NULL, return;);
 158         IRDA_ASSERT(self->magic == IRCOMM_MAGIC, return;);
 159
 160         self->pkt_count--;
 161
 162         if ((self->pkt_count < 2) && (self->flow_status == FLOW_STOP)) {
 163                 IRDA_DEBUG(2, "%s(), asking TTY to start again!\n", __func__ );
 164                 self->flow_status = FLOW_START;
 165                 if (self->notify.flow_indication)
 166                         self->notify.flow_indication(self->notify.instance,
 167                                                      self, FLOW_START);
 168         }
 169 }
 170
 171 /*
 172  * Function ircomm_lmp_data_request (self, userdata)
 173  *
 174  *    Send data frame to peer device
 175  *
 176  */
 177 static int ircomm_lmp_data_request(struct ircomm_cb *self,
 178                                    struct sk_buff *skb,
 179                                    int not_used)
 180 {
 181         struct irda_skb_cb *cb;
 182         int ret;
 183
 184         IRDA_ASSERT(skb != NULL, return -1;);
 185
 186         cb = (struct irda_skb_cb *) skb->cb;
 187
 188         cb->line = self->line;
 189
 190         IRDA_DEBUG(4, "%s(), sending frame\n", __func__ );
 191
 192         /* Don't forget to refcount it - see ircomm_tty_do_softint() */
 193         skb_get(skb);
 194
 195         skb_orphan(skb);
 196         skb->destructor = ircomm_lmp_flow_control;
 197
 198         if ((self->pkt_count++ > 7) && (self->flow_status == FLOW_START)) {
 199                 IRDA_DEBUG(2, "%s(), asking TTY to slow down!\n", __func__ );
 200                 self->flow_status = FLOW_STOP;
 201                 if (self->notify.flow_indication)
 202                         self->notify.flow_indication(self->notify.instance,
 203                                                      self, FLOW_STOP);
 204         }
 205         ret = irlmp_data_request(self->lsap, skb);
 206         if (ret) {
 207                 IRDA_ERROR("%s(), failed\n", __func__);
 208                 /* irlmp_data_request already free the packet */
 209         }
 210
 211         return ret;
 212 }
 213
 214 /*
 215  * Function ircomm_lmp_data_indication (instance, sap, skb)
 216  *
 217  *    Incoming data which we must deliver to the state machine, to check
 218  *    we are still connected.
 219  */
 220 static int ircomm_lmp_data_indication(void *instance, void *sap,
 221                                       struct sk_buff *skb)
 222 {
 223         struct ircomm_cb *self = (struct ircomm_cb *) instance;
 224
 225         IRDA_DEBUG(4, "%s()\n", __func__ );
 226
 227         IRDA_ASSERT(self != NULL, return -1;);
 228         IRDA_ASSERT(self->magic == IRCOMM_MAGIC, return -1;);
 229         IRDA_ASSERT(skb != NULL, return -1;);
 230
 231         ircomm_do_event(self, IRCOMM_LMP_DATA_INDICATION, skb, NULL);
 232
 233         /* Drop reference count - see ircomm_tty_data_indication(). */
 234         dev_kfree_skb(skb);
 235
 236         return 0;
 237 }
 238
 239 /*
 240  * Function ircomm_lmp_connect_confirm (instance, sap, qos, max_sdu_size,
 241  *                                       max_header_size, skb)
 242  *
 243  *    Connection has been confirmed by peer device
 244  *
 245  */
 246 static void ircomm_lmp_connect_confirm(void *instance, void *sap,
 247                                        struct qos_info *qos,
 248                                        __u32 max_seg_size,
 249                                        __u8 max_header_size,
 250                                        struct sk_buff *skb)
 251 {
 252         struct ircomm_cb *self = (struct ircomm_cb *) instance;
 253         struct ircomm_info info;
 254
 255         IRDA_DEBUG(0, "%s()\n", __func__ );
 256
 257         IRDA_ASSERT(self != NULL, return;);
 258         IRDA_ASSERT(self->magic == IRCOMM_MAGIC, return;);
 259         IRDA_ASSERT(skb != NULL, return;);
 260         IRDA_ASSERT(qos != NULL, return;);
 261
 262         info.max_data_size = max_seg_size;
 263         info.max_header_size = max_header_size;
 264         info.qos = qos;
 265
 266         ircomm_do_event(self, IRCOMM_LMP_CONNECT_CONFIRM, skb, &info);
 267
 268         /* Drop reference count - see ircomm_tty_connect_confirm(). */
 269         dev_kfree_skb(skb);
 270 }
 271
 272 /*
 273  * Function ircomm_lmp_connect_indication (instance, sap, qos, max_sdu_size,
 274  *                                         max_header_size, skb)
 275  *
 276  *    Peer device wants to make a connection with us
 277  *
 278  */
 279 static void ircomm_lmp_connect_indication(void *instance, void *sap,
 280                                           struct qos_info *qos,
 281                                           __u32 max_seg_size,
 282                                           __u8 max_header_size,
 283                                           struct sk_buff *skb)
 284 {
 285         struct ircomm_cb *self = (struct ircomm_cb *)instance;
 286         struct ircomm_info info;
 287
 288         IRDA_DEBUG(0, "%s()\n", __func__ );
 289
 290         IRDA_ASSERT(self != NULL, return;);
 291         IRDA_ASSERT(self->magic == IRCOMM_MAGIC, return;);
 292         IRDA_ASSERT(skb != NULL, return;);
 293         IRDA_ASSERT(qos != NULL, return;);
 294
 295         info.max_data_size = max_seg_size;
 296         info.max_header_size = max_header_size;
 297         info.qos = qos;
 298
 299         ircomm_do_event(self, IRCOMM_LMP_CONNECT_INDICATION, skb, &info);
 300
 301         /* Drop reference count - see ircomm_tty_connect_indication(). */
 302         dev_kfree_skb(skb);
 303 }
 304
 305 /*
 306  * Function ircomm_lmp_disconnect_indication (instance, sap, reason, skb)
 307  *
 308  *    Peer device has closed the connection, or the link went down for some
 309  *    other reason
 310  */
 311 static void ircomm_lmp_disconnect_indication(void *instance, void *sap,
 312                                              LM_REASON reason,
 313                                              struct sk_buff *skb)
 314 {
 315         struct ircomm_cb *self = (struct ircomm_cb *) instance;
 316         struct ircomm_info info;
 317
 318         IRDA_DEBUG(0, "%s()\n", __func__ );
 319
 320         IRDA_ASSERT(self != NULL, return;);
 321         IRDA_ASSERT(self->magic == IRCOMM_MAGIC, return;);
 322
 323         info.reason = reason;
 324
 325         ircomm_do_event(self, IRCOMM_LMP_DISCONNECT_INDICATION, skb, &info);
 326
 327         /* Drop reference count - see ircomm_tty_disconnect_indication(). */
 328         if(skb)
 329                 dev_kfree_skb(skb);
 330 }
 331 /*
 332  * Function ircomm_open_lsap (self)
 333  *
 334  *    Open LSAP. This function will only be used when using "raw" services
 335  *
 336  */
 337 int ircomm_open_lsap(struct ircomm_cb *self)
 338 {
 339         notify_t notify;
 340
 341         IRDA_DEBUG(0, "%s()\n", __func__ );
 342
 343         /* Register callbacks */
 344         irda_notify_init(&notify);
 345         notify.data_indication       = ircomm_lmp_data_indication;
 346         notify.connect_confirm       = ircomm_lmp_connect_confirm;
 347         notify.connect_indication    = ircomm_lmp_connect_indication;
 348         notify.disconnect_indication = ircomm_lmp_disconnect_indication;
 349         notify.instance = self;
 350         strlcpy(notify.name, "IrCOMM", sizeof(notify.name));
 351
 352         self->lsap = irlmp_open_lsap(LSAP_ANY, &notify, 0);
 353         if (!self->lsap) {
 354                 IRDA_DEBUG(0,"%sfailed to allocate tsap\n", __func__ );
 355                 return -1;
 356         }
 357         self->slsap_sel = self->lsap->slsap_sel;
 358
 359         /*
 360          *  Initialize the call-table for issuing commands
 361          */
 362         self->issue.data_request       = ircomm_lmp_data_request;
 363         self->issue.connect_request    = ircomm_lmp_connect_request;
 364         self->issue.connect_response   = ircomm_lmp_connect_response;
 365         self->issue.disconnect_request = ircomm_lmp_disconnect_request;
 366
 367         return 0;
 368 }