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linux/net/irda/parameters.c

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/*********************************************************************
*
* Filename: parameters.c
* Version: 1.0
* Description: A more general way to handle (pi,pl,pv) parameters
* Status: Experimental.
* Author: Dag Brattli <dagb@cs.uit.no>
* Created at: Mon Jun 7 10:25:11 1999
* Modified at: Sun Jan 30 14:08:39 2000
* Modified by: Dag Brattli <dagb@cs.uit.no>
*
* Copyright (c) 1999-2000 Dag Brattli, All Rights Reserved.
*
* 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
*
********************************************************************/
#include <linux/types.h>
#include <linux/module.h>
#include <asm/unaligned.h>
#include <asm/byteorder.h>
#include <net/irda/irda.h>
#include <net/irda/parameters.h>
static int irda_extract_integer(void *self, __u8 *buf, int len, __u8 pi,
PV_TYPE type, PI_HANDLER func);
static int irda_extract_string(void *self, __u8 *buf, int len, __u8 pi,
PV_TYPE type, PI_HANDLER func);
static int irda_extract_octseq(void *self, __u8 *buf, int len, __u8 pi,
PV_TYPE type, PI_HANDLER func);
static int irda_extract_no_value(void *self, __u8 *buf, int len, __u8 pi,
PV_TYPE type, PI_HANDLER func);
static int irda_insert_integer(void *self, __u8 *buf, int len, __u8 pi,
PV_TYPE type, PI_HANDLER func);
static int irda_insert_no_value(void *self, __u8 *buf, int len, __u8 pi,
PV_TYPE type, PI_HANDLER func);
static int irda_param_unpack(__u8 *buf, char *fmt, ...);
/* Parameter value call table. Must match PV_TYPE */
static PV_HANDLER pv_extract_table[] = {
irda_extract_integer, /* Handler for any length integers */
irda_extract_integer, /* Handler for 8 bits integers */
irda_extract_integer, /* Handler for 16 bits integers */
irda_extract_string, /* Handler for strings */
irda_extract_integer, /* Handler for 32 bits integers */
irda_extract_octseq, /* Handler for octet sequences */
irda_extract_no_value /* Handler for no value parameters */
};
static PV_HANDLER pv_insert_table[] = {
irda_insert_integer, /* Handler for any length integers */
irda_insert_integer, /* Handler for 8 bits integers */
irda_insert_integer, /* Handler for 16 bits integers */
NULL, /* Handler for strings */
irda_insert_integer, /* Handler for 32 bits integers */
NULL, /* Handler for octet sequences */
irda_insert_no_value /* Handler for no value parameters */
};
/*
* Function irda_insert_no_value (self, buf, len, pi, type, func)
*/
static int irda_insert_no_value(void *self, __u8 *buf, int len, __u8 pi,
PV_TYPE type, PI_HANDLER func)
{
irda_param_t p;
int ret;
p.pi = pi;
p.pl = 0;
/* Call handler for this parameter */
ret = (*func)(self, &p, PV_GET);
/* Extract values anyway, since handler may need them */
irda_param_pack(buf, "bb", p.pi, p.pl);
if (ret < 0)
return ret;
return 2; /* Inserted pl+2 bytes */
}
/*
* Function irda_extract_no_value (self, buf, len, type, func)
*
* Extracts a parameter without a pv field (pl=0)
*
*/
static int irda_extract_no_value(void *self, __u8 *buf, int len, __u8 pi,
PV_TYPE type, PI_HANDLER func)
{
irda_param_t p;
int ret;
/* Extract values anyway, since handler may need them */
irda_param_unpack(buf, "bb", &p.pi, &p.pl);
/* Call handler for this parameter */
ret = (*func)(self, &p, PV_PUT);
if (ret < 0)
return ret;
return 2; /* Extracted pl+2 bytes */
}
/*
* Function irda_insert_integer (self, buf, len, pi, type, func)
*/
static int irda_insert_integer(void *self, __u8 *buf, int len, __u8 pi,
PV_TYPE type, PI_HANDLER func)
{
irda_param_t p;
int n = 0;
int err;
p.pi = pi; /* In case handler needs to know */
p.pl = type & PV_MASK; /* The integer type codes the length as well */
p.pv.i = 0; /* Clear value */
/* Call handler for this parameter */
err = (*func)(self, &p, PV_GET);
if (err < 0)
return err;
/*
* If parameter length is still 0, then (1) this is an any length
* integer, and (2) the handler function does not care which length
* we choose to use, so we pick the one the gives the fewest bytes.
*/
if (p.pl == 0) {
if (p.pv.i < 0xff) {
IRDA_DEBUG(2, "%s(), using 1 byte\n", __func__);
p.pl = 1;
} else if (p.pv.i < 0xffff) {
IRDA_DEBUG(2, "%s(), using 2 bytes\n", __func__);
p.pl = 2;
} else {
IRDA_DEBUG(2, "%s(), using 4 bytes\n", __func__);
p.pl = 4; /* Default length */
}
}
/* Check if buffer is long enough for insertion */
if (len < (2+p.pl)) {
IRDA_WARNING("%s: buffer too short for insertion!\n",
__func__);
return -1;
}
IRDA_DEBUG(2, "%s(), pi=%#x, pl=%d, pi=%d\n", __func__,
p.pi, p.pl, p.pv.i);
switch (p.pl) {
case 1:
n += irda_param_pack(buf, "bbb", p.pi, p.pl, (__u8) p.pv.i);
break;
case 2:
if (type & PV_BIG_ENDIAN)
p.pv.i = cpu_to_be16((__u16) p.pv.i);
else
p.pv.i = cpu_to_le16((__u16) p.pv.i);
n += irda_param_pack(buf, "bbs", p.pi, p.pl, (__u16) p.pv.i);
break;
case 4:
if (type & PV_BIG_ENDIAN)
cpu_to_be32s(&p.pv.i);
else
cpu_to_le32s(&p.pv.i);
n += irda_param_pack(buf, "bbi", p.pi, p.pl, p.pv.i);
break;
default:
IRDA_WARNING("%s: length %d not supported\n",
__func__, p.pl);
/* Skip parameter */
return -1;
}
return p.pl+2; /* Inserted pl+2 bytes */
}
/*
* Function irda_extract integer (self, buf, len, pi, type, func)
*
* Extract a possibly variable length integer from buffer, and call
* handler for processing of the parameter
*/
static int irda_extract_integer(void *self, __u8 *buf, int len, __u8 pi,
PV_TYPE type, PI_HANDLER func)
{
irda_param_t p;
int n = 0;
int extract_len; /* Real length we extract */
int err;
p.pi = pi; /* In case handler needs to know */
p.pl = buf[1]; /* Extract length of value */
p.pv.i = 0; /* Clear value */
extract_len = p.pl; /* Default : extract all */
/* Check if buffer is long enough for parsing */
if (len < (2+p.pl)) {
IRDA_WARNING("%s: buffer too short for parsing! "
"Need %d bytes, but len is only %d\n",
__func__, p.pl, len);
return -1;
}
/*
* Check that the integer length is what we expect it to be. If the
* handler want a 16 bits integer then a 32 bits is not good enough
* PV_INTEGER means that the handler is flexible.
*/
if (((type & PV_MASK) != PV_INTEGER) && ((type & PV_MASK) != p.pl)) {
IRDA_ERROR("%s: invalid parameter length! "
"Expected %d bytes, but value had %d bytes!\n",
__func__, type & PV_MASK, p.pl);
/* Most parameters are bit/byte fields or little endian,
* so it's ok to only extract a subset of it (the subset
* that the handler expect). This is necessary, as some
* broken implementations seems to add extra undefined bits.
* If the parameter is shorter than we expect or is big
* endian, we can't play those tricks. Jean II */
if((p.pl < (type & PV_MASK)) || (type & PV_BIG_ENDIAN)) {
/* Skip parameter */
return p.pl+2;
} else {
/* Extract subset of it, fallthrough */
extract_len = type & PV_MASK;
}
}
switch (extract_len) {
case 1:
n += irda_param_unpack(buf+2, "b", &p.pv.i);
break;
case 2:
n += irda_param_unpack(buf+2, "s", &p.pv.i);
if (type & PV_BIG_ENDIAN)
p.pv.i = be16_to_cpu((__u16) p.pv.i);
else
p.pv.i = le16_to_cpu((__u16) p.pv.i);
break;
case 4:
n += irda_param_unpack(buf+2, "i", &p.pv.i);
if (type & PV_BIG_ENDIAN)
be32_to_cpus(&p.pv.i);
else
le32_to_cpus(&p.pv.i);
break;
default:
IRDA_WARNING("%s: length %d not supported\n",
__func__, p.pl);
/* Skip parameter */
return p.pl+2;
}
IRDA_DEBUG(2, "%s(), pi=%#x, pl=%d, pi=%d\n", __func__,
p.pi, p.pl, p.pv.i);
/* Call handler for this parameter */
err = (*func)(self, &p, PV_PUT);
if (err < 0)
return err;
return p.pl+2; /* Extracted pl+2 bytes */
}
/*
* Function irda_extract_string (self, buf, len, type, func)
*/
static int irda_extract_string(void *self, __u8 *buf, int len, __u8 pi,
PV_TYPE type, PI_HANDLER func)
{
char str[33];
irda_param_t p;
int err;
IRDA_DEBUG(2, "%s()\n", __func__);
p.pi = pi; /* In case handler needs to know */
p.pl = buf[1]; /* Extract length of value */
if (p.pl > 32)
p.pl = 32;
IRDA_DEBUG(2, "%s(), pi=%#x, pl=%d\n", __func__,
p.pi, p.pl);
/* Check if buffer is long enough for parsing */
if (len < (2+p.pl)) {
IRDA_WARNING("%s: buffer too short for parsing! "
"Need %d bytes, but len is only %d\n",
__func__, p.pl, len);
return -1;
}
/* Should be safe to copy string like this since we have already
* checked that the buffer is long enough */
strncpy(str, buf+2, p.pl);
IRDA_DEBUG(2, "%s(), str=0x%02x 0x%02x\n", __func__,
(__u8) str[0], (__u8) str[1]);
/* Null terminate string */
str[p.pl] = '\0';
p.pv.c = str; /* Handler will need to take a copy */
/* Call handler for this parameter */
err = (*func)(self, &p, PV_PUT);
if (err < 0)
return err;
return p.pl+2; /* Extracted pl+2 bytes */
}
/*
* Function irda_extract_octseq (self, buf, len, type, func)
*/
static int irda_extract_octseq(void *self, __u8 *buf, int len, __u8 pi,
PV_TYPE type, PI_HANDLER func)
{
irda_param_t p;
p.pi = pi; /* In case handler needs to know */
p.pl = buf[1]; /* Extract length of value */
/* Check if buffer is long enough for parsing */
if (len < (2+p.pl)) {
IRDA_WARNING("%s: buffer too short for parsing! "
"Need %d bytes, but len is only %d\n",
__func__, p.pl, len);
return -1;
}
IRDA_DEBUG(0, "%s(), not impl\n", __func__);
return p.pl+2; /* Extracted pl+2 bytes */
}
/*
* Function irda_param_pack (skb, fmt, ...)
*
* Format:
* 'i' = 32 bits integer
* 's' = string
*
*/
int irda_param_pack(__u8 *buf, char *fmt, ...)
{
irda_pv_t arg;
va_list args;
char *p;
int n = 0;
va_start(args, fmt);
for (p = fmt; *p != '\0'; p++) {
switch (*p) {
case 'b': /* 8 bits unsigned byte */
buf[n++] = (__u8)va_arg(args, int);
break;
case 's': /* 16 bits unsigned short */
arg.i = (__u16)va_arg(args, int);
put_unaligned((__u16)arg.i, (__u16 *)(buf+n)); n+=2;
break;
case 'i': /* 32 bits unsigned integer */
arg.i = va_arg(args, __u32);
put_unaligned(arg.i, (__u32 *)(buf+n)); n+=4;
break;
#if 0
case 'c': /* \0 terminated string */
arg.c = va_arg(args, char *);
strcpy(buf+n, arg.c);
n += strlen(arg.c) + 1;
break;
#endif
default:
va_end(args);
return -1;
}
}
va_end(args);
return 0;
}
EXPORT_SYMBOL(irda_param_pack);
/*
* Function irda_param_unpack (skb, fmt, ...)
*/
static int irda_param_unpack(__u8 *buf, char *fmt, ...)
{
irda_pv_t arg;
va_list args;
char *p;
int n = 0;
va_start(args, fmt);
for (p = fmt; *p != '\0'; p++) {
switch (*p) {
case 'b': /* 8 bits byte */
arg.ip = va_arg(args, __u32 *);
*arg.ip = buf[n++];
break;
case 's': /* 16 bits short */
arg.ip = va_arg(args, __u32 *);
*arg.ip = get_unaligned((__u16 *)(buf+n)); n+=2;
break;
case 'i': /* 32 bits unsigned integer */
arg.ip = va_arg(args, __u32 *);
*arg.ip = get_unaligned((__u32 *)(buf+n)); n+=4;
break;
#if 0
case 'c': /* \0 terminated string */
arg.c = va_arg(args, char *);
strcpy(arg.c, buf+n);
n += strlen(arg.c) + 1;
break;
#endif
default:
va_end(args);
return -1;
}
}
va_end(args);
return 0;
}
/*
* Function irda_param_insert (self, pi, buf, len, info)
*
* Insert the specified parameter (pi) into buffer. Returns number of
* bytes inserted
*/
int irda_param_insert(void *self, __u8 pi, __u8 *buf, int len,
pi_param_info_t *info)
{
pi_minor_info_t *pi_minor_info;
__u8 pi_minor;
__u8 pi_major;
int type;
int ret = -1;
int n = 0;
IRDA_ASSERT(buf != NULL, return ret;);
IRDA_ASSERT(info != NULL, return ret;);
pi_minor = pi & info->pi_mask;
pi_major = pi >> info->pi_major_offset;
/* Check if the identifier value (pi) is valid */
if ((pi_major > info->len-1) ||
(pi_minor > info->tables[pi_major].len-1))
{
IRDA_DEBUG(0, "%s(), no handler for parameter=0x%02x\n",
__func__, pi);
/* Skip this parameter */
return -1;
}
/* Lookup the info on how to parse this parameter */
pi_minor_info = &info->tables[pi_major].pi_minor_call_table[pi_minor];
/* Find expected data type for this parameter identifier (pi)*/
type = pi_minor_info->type;
/* Check if handler has been implemented */
if (!pi_minor_info->func) {
IRDA_MESSAGE("%s: no handler for pi=%#x\n", __func__, pi);
/* Skip this parameter */
return -1;
}
/* Insert parameter value */
ret = (*pv_insert_table[type & PV_MASK])(self, buf+n, len, pi, type,
pi_minor_info->func);
return ret;
}
EXPORT_SYMBOL(irda_param_insert);
/*
* Function irda_param_extract (self, buf, len, info)
*
* Parse all parameters. If len is correct, then everything should be
* safe. Returns the number of bytes that was parsed
*
*/
static int irda_param_extract(void *self, __u8 *buf, int len,
pi_param_info_t *info)
{
pi_minor_info_t *pi_minor_info;
__u8 pi_minor;
__u8 pi_major;
int type;
int ret = -1;
int n = 0;
IRDA_ASSERT(buf != NULL, return ret;);
IRDA_ASSERT(info != NULL, return ret;);
pi_minor = buf[n] & info->pi_mask;
pi_major = buf[n] >> info->pi_major_offset;
/* Check if the identifier value (pi) is valid */
if ((pi_major > info->len-1) ||
(pi_minor > info->tables[pi_major].len-1))
{
IRDA_DEBUG(0, "%s(), no handler for parameter=0x%02x\n",
__func__, buf[0]);
/* Skip this parameter */
return 2 + buf[n + 1]; /* Continue */
}
/* Lookup the info on how to parse this parameter */
pi_minor_info = &info->tables[pi_major].pi_minor_call_table[pi_minor];
/* Find expected data type for this parameter identifier (pi)*/
type = pi_minor_info->type;
IRDA_DEBUG(3, "%s(), pi=[%d,%d], type=%d\n", __func__,
pi_major, pi_minor, type);
/* Check if handler has been implemented */
if (!pi_minor_info->func) {
IRDA_MESSAGE("%s: no handler for pi=%#x\n",
__func__, buf[n]);
/* Skip this parameter */
return 2 + buf[n + 1]; /* Continue */
}
/* Parse parameter value */
ret = (*pv_extract_table[type & PV_MASK])(self, buf+n, len, buf[n],
type, pi_minor_info->func);
return ret;
}
/*
* Function irda_param_extract_all (self, buf, len, info)
*
* Parse all parameters. If len is correct, then everything should be
* safe. Returns the number of bytes that was parsed
*
*/
int irda_param_extract_all(void *self, __u8 *buf, int len,
pi_param_info_t *info)
{
int ret = -1;
int n = 0;
IRDA_ASSERT(buf != NULL, return ret;);
IRDA_ASSERT(info != NULL, return ret;);
/*
* Parse all parameters. Each parameter must be at least two bytes
* long or else there is no point in trying to parse it
*/
while (len > 2) {
ret = irda_param_extract(self, buf+n, len, info);
if (ret < 0)
return ret;
n += ret;
len -= ret;
}
return n;
}
EXPORT_SYMBOL(irda_param_extract_all);
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