rfcomm.c

blue tooth protocol stack source code

/*
 * rfcomm.c -- Implementation of Bluetooth RFCOMM with TS 07.10, 
 *             Serial Port Emulation
 *
 * Copyright (C) 2000, 2001  Axis Communications AB
 *
 * Author: Mats Friden <[e-mail]>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 *
 * Exceptionally, Axis Communications AB grants discretionary and
 * conditional permissions for additional use of the text contained
 * in the company's release of the AXIS OpenBT Stack under the
 * provisions set forth hereunder.
 *
 * Provided that, if you use the AXIS OpenBT Stack with other files,
 * that do not implement functionality as specified in the Bluetooth
 * System specification, to produce an executable, this does not by
 * itself cause the resulting executable to be covered by the GNU
 * General Public License. Your use of that executable is in no way
 * restricted on account of using the AXIS OpenBT Stack code with it.
 *
 * This exception does not however invalidate any other reasons why
 * the executable file might be covered by the provisions of the GNU
* General Public License.
 *
 * $Id: rfcomm.c,v 1.127 2001/10/18 15:49:25 pkj Exp $
 *
 */

/****************** INCLUDE FILES SECTION ***********************************/

#define __NO_VERSION__ /* don't define kernel_version in module.h */

#ifdef __KERNEL__ 
#include <linux/config.h>
#include <linux/bluetooth/sysdep-2.1.h>
#include <linux/malloc.h>
#include <linux/types.h>
#include <linux/string.h>
#include <linux/sched.h>

#include <asm/unaligned.h>

#include <linux/bluetooth/rfcomm.h>
#include <linux/bluetooth/rfcomm_sec.h>
#include <linux/bluetooth/btmem.h>
#include <linux/bluetooth/l2cap.h>
#include <linux/bluetooth/bluetooth.h>
#include <linux/bluetooth/btconfig.h>
#include <linux/bluetooth/bt_errno.h>
#else
#include <stdlib.h>
#include <string.h>
#include <errno.h>

#include <asm/unaligned.h>

#include "include/rfcomm.h"
#include "include/rfcomm_sec.h"
#include "include/btmem.h"
#include "include/l2cap.h"
#include "include/bluetooth.h"
#include "include/local.h"
#include "include/bt_errno.h"
#endif

/****************** DEBUG CONSTANT AND MACRO SECTION ************************/

/* Defines for the debug macros */

#if DEBUG_RFCOMM_RECEIVE_FLOW
#define D_REC(fmt...) printk(RFCOMM_DBG_STR fmt)
#else
#define D_REC(fmt...) 
#endif

#if DEBUG_RFCOMM_SEND_PROCESS
#define D_SND(fmt...) printk(RFCOMM_DBG_STR fmt)
#else
#define D_SND(fmt...)
#endif

#if DEBUG_RFCOMM_INTERNAL_SIGNALING
#define D_CTRL(fmt...) printk(RFCOMM_DBG_STR fmt)
#else
#define D_CTRL(fmt...)
#endif

#if PRINT_DATA_ENABLE
#define RF_DATA(str, data, len) print_data(str, data, len)
#else
#define RF_DATA(str, data, len)
#endif

#define FNC __FUNCTION__ ": "

/****************** CONSTANT AND MACRO SECTION ******************************/

#define SET_PF(ctr) ((ctr) | (1 << 4)) 
/* Sets the P/F-bit in the control field */
#define CLR_PF(ctr) ((ctr) & 0xef)
/* clears the P/F-bit in the control field */
#define GET_PF(ctr) (((ctr) >> 4) & 0x1)
/* Returns the P/F bit */

#define SHORT_CRC_CHECK 2
/* Used for uih packets */
#define LONG_CRC_CHECK 3
/* Used for all packet exepts for the uih packets */
#define SHORT_HDR 2
/* Short header for short uih packets */
#define LONG_HDR 3
/* and long header for long uih packets */

/* FIXME: Should thsi one be define here? */
#define SHORT_PAYLOAD_SIZE 127
#define EA 1
/* Used for setting the EA field in different packets,  really neccessary? */
#define FCS_SIZE 1
/* Yes the FCS size is only one byte */

#define RFCOMM_MAX_HDR_SIZE 5

#define MAX_CREDITS   30
#define START_CREDITS 7
#define MIN_CREDITS   15

#define DEF_RFCOMM_MTU 127

/* The values in the control field when sending ordinary rfcomm packets */
#define SABM      0x2f
#define SABM_SIZE 4
#define UA        0x63
#define UA_SIZE   4
#define DM        0x0f
#define DISC      0x43
#define UIH       0xef

/* The values in the type field in a multiplexer command packet */
#define TEST  0x08
#define FCON  0x28
#define FCOFF 0x18
#define MSC   0x38
#define RPN   0x24
#define RLS   0x14
#define PN    0x20
#define NSC   0x04

/* Define of some V.24 signals modem control signals in RFCOMM */
#define FC  0x02
#define RTC 0x04
#define RTR 0x08
#define DV  0x80

/* endian-swapping macros for structs */
#define swap_long_frame(x) ((x)->h.length.val = le16_to_cpu((x)->h.length.val))
#define swap_mcc_long_frame(x) (swap_long_frame(x))

#define RFCOMM_CON_TIMEOUT (5*HZ)

/****************** TYPE DEFINITION SECTION *********************************/

/* Typedefinitions of stuctures used for creating and parsing packets, for a
   further description of the structures please se the bluetooth core
   specification part F:1 and the ETSI TS 07.10 specification  */

#include <asm/byteorder.h>
#ifdef __LITTLE_ENDIAN_BITFIELD

typedef struct address_field {
	u8 ea:1;
	u8 cr:1;
	u8 d:1;
	u8 server_chn:5;
} __attribute__ ((packed)) address_field;

typedef struct short_length {
	u8 ea:1;
	u8 len:7;
} __attribute__ ((packed)) short_length;

typedef union long_length {
	struct bits {
		u16 ea:1;
		u16 len:15;
	} __attribute__ ((packed)) bits;
	u16 val;
} __attribute__ ((packed)) long_length;

typedef struct short_frame_head {
	address_field addr;
	u8 control;
	short_length length;
} __attribute__ ((packed)) short_frame_head;

typedef struct short_frame {
	short_frame_head h;
	u8 data[0];
} __attribute__ ((packed)) short_frame;

typedef struct long_frame_head {
	address_field addr;
	u8 control;
	long_length length;
	u8 data[0];
} __attribute__ ((packed)) long_frame_head;

typedef struct long_frame {
	long_frame_head h;
	u8 data[0];
} __attribute__ ((packed)) long_frame;

/* Typedefinitions for structures used for the multiplexer commands */
typedef struct mcc_type {
	u8 ea:1;
	u8 cr:1;
	u8 type:6;
} __attribute__ ((packed)) mcc_type;

typedef struct mcc_short_frame_head {
	mcc_type type;
	short_length length;
	u8 value[0];
} __attribute__ ((packed)) mcc_short_frame_head;

typedef struct mcc_short_frame {
	mcc_short_frame_head h;
	u8 value[0];
} __attribute__ ((packed)) mcc_short_frame;

typedef struct mcc_long_frame_head {
	mcc_type type;
	long_length length;
	u8 value[0];
} __attribute__ ((packed)) mcc_long_frame_head;

typedef struct mcc_long_frame {
	mcc_long_frame_head h;
	u8 value[0];
} __attribute__ ((packed)) mcc_long_frame;

/* MSC command */
typedef struct v24_signals {
	u8 ea:1;
	u8 fc:1;
	u8 rtc:1;
	u8 rtr:1;
	u8 reserved:2;
	u8 ic:1;
	u8 dv:1;
} __attribute__ ((packed)) v24_sigs;

typedef struct brk_sigs {
	u8 ea:1;
	u8 b1:1;
	u8 b2:1;
	u8 b3:1;
	u8 len:4;
} __attribute__ ((packed)) brk_sigs;

typedef struct msc_msg {
	short_frame_head s_head;
	mcc_short_frame_head mcc_s_head;
	address_field dlci;
	u8 v24_sigs;
//	brk_sigs break_signals;
	u8 fcs;
} __attribute__ ((packed)) msc_msg;

/* RPN command */
typedef struct rpn_msg {
	short_frame_head s_head;
	mcc_short_frame_head mcc_s_head;
	address_field dlci;
	rpn_values rpn_val;
	u8 fcs;
} __attribute__ ((packed)) rpn_msg;

/* RLS command */  
typedef struct rls_msg {
	short_frame_head s_head;
	mcc_short_frame_head mcc_s_head;
	address_field dlci;
	u8 error:4;
	u8 res:4;
	u8 fcs;
} __attribute__ ((packed)) rls_msg;

/* PN command */
typedef struct pn_msg {
	short_frame_head s_head;
	mcc_short_frame_head mcc_s_head;
/* The res1, res2 and res3 values have to be set to 0 by the sender */
	u8 dlci:6;
	u8 res1:2;
	u8 frame_type:4;
	u8 credit_flow:4;
	u8 prior:6;
	u8 res2:2;
	u8 ack_timer;
	u16 frame_size;
	u8 max_nbrof_retrans;
	u8 credits;
	u8 fcs;
} __attribute__ ((packed)) pn_msg;

/* NSC-command */
typedef struct nsc_msg {
	short_frame_head s_head;
	mcc_short_frame_head mcc_s_head;
	mcc_type command_type;
	u8 fcs;
} __attribute__ ((packed)) nsc_msg;

#elif defined(__BIG_ENDIAN_BITFIELD)

typedef struct address_field {
	u8 server_chn:5;
	u8 d:1;
	u8 cr:1;
	u8 ea:1;
} __attribute__ ((packed)) address_field;

typedef struct short_length {
	u8 len:7;
	u8 ea:1;
} __attribute__ ((packed)) short_length;

typedef union long_length {
	struct bits {
		u16 len:15;
		u16 ea:1;
	} __attribute__ ((packed)) bits;
	u16 val;
} __attribute__ ((packed)) long_length;

typedef struct short_frame_head { 
	address_field addr;
	u8 control;
	short_length length;
} __attribute__ ((packed)) short_frame_head;

typedef struct short_frame {
	short_frame_head h;
	u8 data[0];
} __attribute__ ((packed)) short_frame;

typedef struct long_frame_head { 
	address_field addr;
	u8 control;
	long_length length;
	u8 data[0];
} __attribute__ ((packed)) long_frame_head;

typedef struct long_frame { 
	long_frame_head h;
	u8 data[0];
} __attribute__ ((packed)) long_frame;

/* Typedefinitions for structures used for the multiplexer commands */
typedef struct mcc_type { 
	u8 type:6;
	u8 cr:1;
	u8 ea:1;
} __attribute__ ((packed)) mcc_type;

typedef struct mcc_short_frame_head { 
	mcc_type type;
	short_length length;
	u8 value[0];
} __attribute__ ((packed)) mcc_short_frame_head;

typedef struct mcc_short_frame { 
	mcc_short_frame_head h;
	u8 value[0];
} __attribute__ ((packed)) mcc_short_frame;

typedef struct mcc_long_frame_head { 
	mcc_type type;
	long_length length;
	u8 value[0];
} __attribute__ ((packed)) mcc_long_frame_head;

typedef struct mcc_long_frame { 
	mcc_long_frame_head h;
	u8 value[0];
} __attribute__ ((packed)) mcc_long_frame;

/* MSC command */
typedef struct v24_signals { 
	u8 dv:1;
	u8 ic:1;
	u8 reserved:2;
	u8 rtr:1;
	u8 rtc:1;
	u8 fc:1;
	u8 ea:1;
} __attribute__ ((packed)) v24_sigs;

typedef struct brk_sigs { 
	u8 len:4;
	u8 b3:1;
	u8 b2:1;
	u8 b1:1;
	u8 ea:1;
} __attribute__ ((packed)) brk_sigs;

typedef struct msc_msg { 
	short_frame_head s_head;
	mcc_short_frame_head mcc_s_head;
	address_field dlci;
	u8 v24_sigs;
//	brk_sigs break_signals;
	u8 fcs;
} __attribute__ ((packed)) msc_msg;

/* RPN command */
typedef struct rpn_msg { 
	short_frame_head s_head;
	mcc_short_frame_head mcc_s_head;
	address_field dlci;
	rpn_values rpn_val;
	u8 fcs;
} __attribute__ ((packed)) rpn_msg;

/* RLS command */  
typedef struct rls_msg { 
	short_frame_head s_head;
	mcc_short_frame_head mcc_s_head;
	address_field dlci;
	u8 res:4;
	u8 error:4;
	u8 fcs;
} __attribute__ ((packed)) rls_msg;

/* PN command */
typedef struct pn_msg { 
	short_frame_head s_head;
	mcc_short_frame_head mcc_s_head;
/* The res1, res2 and res3 values have to be set to 0 by the sender */
	u8 res1:2;
	u8 dlci:6;
	u8 credit_flow:4;
	u8 frame_type:4;
	u8 res2:2;
	u8 prior:6;
	u8 ack_timer;
	u16 frame_size;
	u8 max_nbrof_retrans;
	u8 credits;
	u8 fcs;
} __attribute__ ((packed)) pn_msg;

/* NSC-command */
typedef struct nsc_msg { 
	short_frame_head s_head;
	mcc_short_frame_head mcc_s_head;
	mcc_type command_type;
	u8 fcs;
} __attribute__ ((packed)) nsc_msg;

#else /* __XXX_ENDIAN */
#error Processor endianness unknown!
#endif /* __XXX_ENDIAN */

/****************** LOCAL FUNCTION DECLARATION SECTION **********************/

static void process_mcc(u8* data, u32 len, rfcomm_con *rfcomm, s32 long_pkt);
static s32 send_ua(rfcomm_con *rfcomm, u8 dlci);
static s32 send_dm(rfcomm_con *rfcomm, u8 dlci);
static s32 send_sabm(rfcomm_con *rfcomm, u8 dlci);
static s32 send_disc(rfcomm_con *rfcomm, u8 dlci);
static s32 send_uih(u8 *data, u32 len, rfcomm_con *rfcomm, u8 dlci);

static s32 send_pn_msg(rfcomm_con *rfcomm, u8 prior, u32 frame_size, u8 credit_flow, u8 credits, u8 dlci, u8 cr);
static s32 send_nsc_msg(rfcomm_con *rfcomm, mcc_type cmd, u8 cr);
static void set_uih_hdr(short_frame *uih_pkt, u8 dlci, u32 len, u8 cr);
static u32 crc_check(u8 *data, u32 length, u8 check_sum);
static u8 crc_calc(u8 *data, u32 length);