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         /* Don't forget to refcount it - should be NULL anyway */
  56         if(userdata)
  57                 skb_get(userdata);
  58
  59         ret = irlmp_connect_request(self->lsap, info->dlsap_sel,
  60                                     info->saddr, info->daddr, NULL, userdata);
  61         return ret;
  62 }
  63
  64 /*
  65  * Function ircomm_lmp_connect_response (self, skb)
  66  *
  67  *
  68  *
  69  */
  70 static int ircomm_lmp_connect_response(struct ircomm_cb *self,
  71                                        struct sk_buff *userdata)
  72 {
  73         struct sk_buff *tx_skb;
  74
  75         /* Any userdata supplied? */
  76         if (userdata == NULL) {
  77                 tx_skb = alloc_skb(LMP_MAX_HEADER, GFP_ATOMIC);
  78                 if (!tx_skb)
  79                         return -ENOMEM;
  80
  81                 /* Reserve space for MUX and LAP header */
  82                 skb_reserve(tx_skb, LMP_MAX_HEADER);
  83         } else {
  84                 /*
  85                  *  Check that the client has reserved enough space for
  86                  *  headers
  87                  */
  88                 IRDA_ASSERT(skb_headroom(userdata) >= LMP_MAX_HEADER,
  89                             return -1;);
  90
  91                 /* Don't forget to refcount it - should be NULL anyway */
  92                 skb_get(userdata);
  93                 tx_skb = userdata;
  94         }
  95
  96         return irlmp_connect_response(self->lsap, tx_skb);
  97 }
  98
  99 static int ircomm_lmp_disconnect_request(struct ircomm_cb *self,
 100                                          struct sk_buff *userdata,
 101                                          struct ircomm_info *info)
 102 {
 103         struct sk_buff *tx_skb;
 104         int ret;
 105
 106         if (!userdata) {
 107                 tx_skb = alloc_skb(LMP_MAX_HEADER, GFP_ATOMIC);
 108                 if (!tx_skb)
 109                         return -ENOMEM;
 110
 111                 /*  Reserve space for MUX and LAP header */
 112                 skb_reserve(tx_skb, LMP_MAX_HEADER);
 113                 userdata = tx_skb;
 114         } else {
 115                 /* Don't forget to refcount it - should be NULL anyway */
 116                 skb_get(userdata);
 117         }
 118
 119         ret = irlmp_disconnect_request(self->lsap, userdata);
 120
 121         return ret;
 122 }
 123
 124 /*
 125  * Function ircomm_lmp_flow_control (skb)
 126  *
 127  *    This function is called when a data frame we have sent to IrLAP has
 128  *    been deallocated. We do this to make sure we don't flood IrLAP with
 129  *    frames, since we are not using the IrTTP flow control mechanism
 130  */
 131 static void ircomm_lmp_flow_control(struct sk_buff *skb)
 132 {
 133         struct irda_skb_cb *cb;
 134         struct ircomm_cb *self;
 135         int line;
 136
 137         IRDA_ASSERT(skb != NULL, return;);
 138
 139         cb = (struct irda_skb_cb *) skb->cb;
 140
 141         line = cb->line;
 142
 143         self = (struct ircomm_cb *) hashbin_lock_find(ircomm, line, NULL);
 144         if (!self) {
 145                 pr_debug("%s(), didn't find myself\n", __func__);
 146                 return;
 147         }
 148
 149         IRDA_ASSERT(self != NULL, return;);
 150         IRDA_ASSERT(self->magic == IRCOMM_MAGIC, return;);
 151
 152         self->pkt_count--;
 153
 154         if ((self->pkt_count < 2) && (self->flow_status == FLOW_STOP)) {
 155                 pr_debug("%s(), asking TTY to start again!\n", __func__);
 156                 self->flow_status = FLOW_START;
 157                 if (self->notify.flow_indication)
 158                         self->notify.flow_indication(self->notify.instance,
 159                                                      self, FLOW_START);
 160         }
 161 }
 162
 163 /*
 164  * Function ircomm_lmp_data_request (self, userdata)
 165  *
 166  *    Send data frame to peer device
 167  *
 168  */
 169 static int ircomm_lmp_data_request(struct ircomm_cb *self,
 170                                    struct sk_buff *skb,
 171                                    int not_used)
 172 {
 173         struct irda_skb_cb *cb;
 174         int ret;
 175
 176         IRDA_ASSERT(skb != NULL, return -1;);
 177
 178         cb = (struct irda_skb_cb *) skb->cb;
 179
 180         cb->line = self->line;
 181
 182         pr_debug("%s(), sending frame\n", __func__);
 183
 184         /* Don't forget to refcount it - see ircomm_tty_do_softint() */
 185         skb_get(skb);
 186
 187         skb_orphan(skb);
 188         skb->destructor = ircomm_lmp_flow_control;
 189
 190         if ((self->pkt_count++ > 7) && (self->flow_status == FLOW_START)) {
 191                 pr_debug("%s(), asking TTY to slow down!\n", __func__);
 192                 self->flow_status = FLOW_STOP;
 193                 if (self->notify.flow_indication)
 194                         self->notify.flow_indication(self->notify.instance,
 195                                                      self, FLOW_STOP);
 196         }
 197         ret = irlmp_data_request(self->lsap, skb);
 198         if (ret) {
 199                 net_err_ratelimited("%s(), failed\n", __func__);
 200                 /* irlmp_data_request already free the packet */
 201         }
 202
 203         return ret;
 204 }
 205
 206 /*
 207  * Function ircomm_lmp_data_indication (instance, sap, skb)
 208  *
 209  *    Incoming data which we must deliver to the state machine, to check
 210  *    we are still connected.
 211  */
 212 static int ircomm_lmp_data_indication(void *instance, void *sap,
 213                                       struct sk_buff *skb)
 214 {
 215         struct ircomm_cb *self = (struct ircomm_cb *) instance;
 216
 217         IRDA_ASSERT(self != NULL, return -1;);
 218         IRDA_ASSERT(self->magic == IRCOMM_MAGIC, return -1;);
 219         IRDA_ASSERT(skb != NULL, return -1;);
 220
 221         ircomm_do_event(self, IRCOMM_LMP_DATA_INDICATION, skb, NULL);
 222
 223         /* Drop reference count - see ircomm_tty_data_indication(). */
 224         dev_kfree_skb(skb);
 225
 226         return 0;
 227 }
 228
 229 /*
 230  * Function ircomm_lmp_connect_confirm (instance, sap, qos, max_sdu_size,
 231  *                                       max_header_size, skb)
 232  *
 233  *    Connection has been confirmed by peer device
 234  *
 235  */
 236 static void ircomm_lmp_connect_confirm(void *instance, void *sap,
 237                                        struct qos_info *qos,
 238                                        __u32 max_seg_size,
 239                                        __u8 max_header_size,
 240                                        struct sk_buff *skb)
 241 {
 242         struct ircomm_cb *self = (struct ircomm_cb *) instance;
 243         struct ircomm_info info;
 244
 245         IRDA_ASSERT(self != NULL, return;);
 246         IRDA_ASSERT(self->magic == IRCOMM_MAGIC, return;);
 247         IRDA_ASSERT(skb != NULL, return;);
 248         IRDA_ASSERT(qos != NULL, return;);
 249
 250         info.max_data_size = max_seg_size;
 251         info.max_header_size = max_header_size;
 252         info.qos = qos;
 253
 254         ircomm_do_event(self, IRCOMM_LMP_CONNECT_CONFIRM, skb, &info);
 255
 256         /* Drop reference count - see ircomm_tty_connect_confirm(). */
 257         dev_kfree_skb(skb);
 258 }
 259
 260 /*
 261  * Function ircomm_lmp_connect_indication (instance, sap, qos, max_sdu_size,
 262  *                                         max_header_size, skb)
 263  *
 264  *    Peer device wants to make a connection with us
 265  *
 266  */
 267 static void ircomm_lmp_connect_indication(void *instance, void *sap,
 268                                           struct qos_info *qos,
 269                                           __u32 max_seg_size,
 270                                           __u8 max_header_size,
 271                                           struct sk_buff *skb)
 272 {
 273         struct ircomm_cb *self = (struct ircomm_cb *)instance;
 274         struct ircomm_info info;
 275
 276         IRDA_ASSERT(self != NULL, return;);
 277         IRDA_ASSERT(self->magic == IRCOMM_MAGIC, return;);
 278         IRDA_ASSERT(skb != NULL, return;);
 279         IRDA_ASSERT(qos != NULL, return;);
 280
 281         info.max_data_size = max_seg_size;
 282         info.max_header_size = max_header_size;
 283         info.qos = qos;
 284
 285         ircomm_do_event(self, IRCOMM_LMP_CONNECT_INDICATION, skb, &info);
 286
 287         /* Drop reference count - see ircomm_tty_connect_indication(). */
 288         dev_kfree_skb(skb);
 289 }
 290
 291 /*
 292  * Function ircomm_lmp_disconnect_indication (instance, sap, reason, skb)
 293  *
 294  *    Peer device has closed the connection, or the link went down for some
 295  *    other reason
 296  */
 297 static void ircomm_lmp_disconnect_indication(void *instance, void *sap,
 298                                              LM_REASON reason,
 299                                              struct sk_buff *skb)
 300 {
 301         struct ircomm_cb *self = (struct ircomm_cb *) instance;
 302         struct ircomm_info info;
 303
 304         IRDA_ASSERT(self != NULL, return;);
 305         IRDA_ASSERT(self->magic == IRCOMM_MAGIC, return;);
 306
 307         info.reason = reason;
 308
 309         ircomm_do_event(self, IRCOMM_LMP_DISCONNECT_INDICATION, skb, &info);
 310
 311         /* Drop reference count - see ircomm_tty_disconnect_indication(). */
 312         if(skb)
 313                 dev_kfree_skb(skb);
 314 }
 315 /*
 316  * Function ircomm_open_lsap (self)
 317  *
 318  *    Open LSAP. This function will only be used when using "raw" services
 319  *
 320  */
 321 int ircomm_open_lsap(struct ircomm_cb *self)
 322 {
 323         notify_t notify;
 324
 325         /* Register callbacks */
 326         irda_notify_init(&notify);
 327         notify.data_indication       = ircomm_lmp_data_indication;
 328         notify.connect_confirm       = ircomm_lmp_connect_confirm;
 329         notify.connect_indication    = ircomm_lmp_connect_indication;
 330         notify.disconnect_indication = ircomm_lmp_disconnect_indication;
 331         notify.instance = self;
 332         strlcpy(notify.name, "IrCOMM", sizeof(notify.name));
 333
 334         self->lsap = irlmp_open_lsap(LSAP_ANY, &notify, 0);
 335         if (!self->lsap) {
 336                 pr_debug("%sfailed to allocate tsap\n", __func__);
 337                 return -1;
 338         }
 339         self->slsap_sel = self->lsap->slsap_sel;
 340
 341         /*
 342          *  Initialize the call-table for issuing commands
 343          */
 344         self->issue.data_request       = ircomm_lmp_data_request;
 345         self->issue.connect_request    = ircomm_lmp_connect_request;
 346         self->issue.connect_response   = ircomm_lmp_connect_response;
 347         self->issue.disconnect_request = ircomm_lmp_disconnect_request;
 348
 349         return 0;
 350 }