e79ec50b95
Parenthesize macro parameters. Signed-off-by: Jan Engelhardt <jengelh@computergmbh.de> Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
877 lines
19 KiB
C
877 lines
19 KiB
C
/****************************************************************************
|
|
* ip_conntrack_helper_h323_asn1.c - BER and PER decoding library for H.323
|
|
* conntrack/NAT module.
|
|
*
|
|
* Copyright (c) 2006 by Jing Min Zhao <zhaojingmin@users.sourceforge.net>
|
|
*
|
|
* This source code is licensed under General Public License version 2.
|
|
*
|
|
* See ip_conntrack_helper_h323_asn1.h for details.
|
|
*
|
|
****************************************************************************/
|
|
|
|
#ifdef __KERNEL__
|
|
#include <linux/kernel.h>
|
|
#else
|
|
#include <stdio.h>
|
|
#endif
|
|
#include <linux/netfilter/nf_conntrack_h323_asn1.h>
|
|
|
|
/* Trace Flag */
|
|
#ifndef H323_TRACE
|
|
#define H323_TRACE 0
|
|
#endif
|
|
|
|
#if H323_TRACE
|
|
#define TAB_SIZE 4
|
|
#define IFTHEN(cond, act) if(cond){act;}
|
|
#ifdef __KERNEL__
|
|
#define PRINT printk
|
|
#else
|
|
#define PRINT printf
|
|
#endif
|
|
#define FNAME(name) name,
|
|
#else
|
|
#define IFTHEN(cond, act)
|
|
#define PRINT(fmt, args...)
|
|
#define FNAME(name)
|
|
#endif
|
|
|
|
/* ASN.1 Types */
|
|
#define NUL 0
|
|
#define BOOL 1
|
|
#define OID 2
|
|
#define INT 3
|
|
#define ENUM 4
|
|
#define BITSTR 5
|
|
#define NUMSTR 6
|
|
#define NUMDGT 6
|
|
#define TBCDSTR 6
|
|
#define OCTSTR 7
|
|
#define PRTSTR 7
|
|
#define IA5STR 7
|
|
#define GENSTR 7
|
|
#define BMPSTR 8
|
|
#define SEQ 9
|
|
#define SET 9
|
|
#define SEQOF 10
|
|
#define SETOF 10
|
|
#define CHOICE 11
|
|
|
|
/* Constraint Types */
|
|
#define FIXD 0
|
|
/* #define BITS 1-8 */
|
|
#define BYTE 9
|
|
#define WORD 10
|
|
#define CONS 11
|
|
#define SEMI 12
|
|
#define UNCO 13
|
|
|
|
/* ASN.1 Type Attributes */
|
|
#define SKIP 0
|
|
#define STOP 1
|
|
#define DECODE 2
|
|
#define EXT 4
|
|
#define OPEN 8
|
|
#define OPT 16
|
|
|
|
|
|
/* ASN.1 Field Structure */
|
|
typedef struct field_t {
|
|
#if H323_TRACE
|
|
char *name;
|
|
#endif
|
|
unsigned char type;
|
|
unsigned char sz;
|
|
unsigned char lb;
|
|
unsigned char ub;
|
|
unsigned short attr;
|
|
unsigned short offset;
|
|
struct field_t *fields;
|
|
} field_t;
|
|
|
|
/* Bit Stream */
|
|
typedef struct {
|
|
unsigned char *buf;
|
|
unsigned char *beg;
|
|
unsigned char *end;
|
|
unsigned char *cur;
|
|
unsigned bit;
|
|
} bitstr_t;
|
|
|
|
/* Tool Functions */
|
|
#define INC_BIT(bs) if((++(bs)->bit)>7){(bs)->cur++;(bs)->bit=0;}
|
|
#define INC_BITS(bs,b) if(((bs)->bit+=(b))>7){(bs)->cur+=(bs)->bit>>3;(bs)->bit&=7;}
|
|
#define BYTE_ALIGN(bs) if((bs)->bit){(bs)->cur++;(bs)->bit=0;}
|
|
#define CHECK_BOUND(bs,n) if((bs)->cur+(n)>(bs)->end)return(H323_ERROR_BOUND)
|
|
static unsigned get_len(bitstr_t * bs);
|
|
static unsigned get_bit(bitstr_t * bs);
|
|
static unsigned get_bits(bitstr_t * bs, unsigned b);
|
|
static unsigned get_bitmap(bitstr_t * bs, unsigned b);
|
|
static unsigned get_uint(bitstr_t * bs, int b);
|
|
|
|
/* Decoder Functions */
|
|
static int decode_nul(bitstr_t * bs, field_t * f, char *base, int level);
|
|
static int decode_bool(bitstr_t * bs, field_t * f, char *base, int level);
|
|
static int decode_oid(bitstr_t * bs, field_t * f, char *base, int level);
|
|
static int decode_int(bitstr_t * bs, field_t * f, char *base, int level);
|
|
static int decode_enum(bitstr_t * bs, field_t * f, char *base, int level);
|
|
static int decode_bitstr(bitstr_t * bs, field_t * f, char *base, int level);
|
|
static int decode_numstr(bitstr_t * bs, field_t * f, char *base, int level);
|
|
static int decode_octstr(bitstr_t * bs, field_t * f, char *base, int level);
|
|
static int decode_bmpstr(bitstr_t * bs, field_t * f, char *base, int level);
|
|
static int decode_seq(bitstr_t * bs, field_t * f, char *base, int level);
|
|
static int decode_seqof(bitstr_t * bs, field_t * f, char *base, int level);
|
|
static int decode_choice(bitstr_t * bs, field_t * f, char *base, int level);
|
|
|
|
/* Decoder Functions Vector */
|
|
typedef int (*decoder_t) (bitstr_t *, field_t *, char *, int);
|
|
static decoder_t Decoders[] = {
|
|
decode_nul,
|
|
decode_bool,
|
|
decode_oid,
|
|
decode_int,
|
|
decode_enum,
|
|
decode_bitstr,
|
|
decode_numstr,
|
|
decode_octstr,
|
|
decode_bmpstr,
|
|
decode_seq,
|
|
decode_seqof,
|
|
decode_choice,
|
|
};
|
|
|
|
/****************************************************************************
|
|
* H.323 Types
|
|
****************************************************************************/
|
|
#include "nf_conntrack_h323_types.c"
|
|
|
|
/****************************************************************************
|
|
* Functions
|
|
****************************************************************************/
|
|
/* Assume bs is aligned && v < 16384 */
|
|
unsigned get_len(bitstr_t * bs)
|
|
{
|
|
unsigned v;
|
|
|
|
v = *bs->cur++;
|
|
|
|
if (v & 0x80) {
|
|
v &= 0x3f;
|
|
v <<= 8;
|
|
v += *bs->cur++;
|
|
}
|
|
|
|
return v;
|
|
}
|
|
|
|
/****************************************************************************/
|
|
unsigned get_bit(bitstr_t * bs)
|
|
{
|
|
unsigned b = (*bs->cur) & (0x80 >> bs->bit);
|
|
|
|
INC_BIT(bs);
|
|
|
|
return b;
|
|
}
|
|
|
|
/****************************************************************************/
|
|
/* Assume b <= 8 */
|
|
unsigned get_bits(bitstr_t * bs, unsigned b)
|
|
{
|
|
unsigned v, l;
|
|
|
|
v = (*bs->cur) & (0xffU >> bs->bit);
|
|
l = b + bs->bit;
|
|
|
|
if (l < 8) {
|
|
v >>= 8 - l;
|
|
bs->bit = l;
|
|
} else if (l == 8) {
|
|
bs->cur++;
|
|
bs->bit = 0;
|
|
} else { /* l > 8 */
|
|
|
|
v <<= 8;
|
|
v += *(++bs->cur);
|
|
v >>= 16 - l;
|
|
bs->bit = l - 8;
|
|
}
|
|
|
|
return v;
|
|
}
|
|
|
|
/****************************************************************************/
|
|
/* Assume b <= 32 */
|
|
unsigned get_bitmap(bitstr_t * bs, unsigned b)
|
|
{
|
|
unsigned v, l, shift, bytes;
|
|
|
|
if (!b)
|
|
return 0;
|
|
|
|
l = bs->bit + b;
|
|
|
|
if (l < 8) {
|
|
v = (unsigned) (*bs->cur) << (bs->bit + 24);
|
|
bs->bit = l;
|
|
} else if (l == 8) {
|
|
v = (unsigned) (*bs->cur++) << (bs->bit + 24);
|
|
bs->bit = 0;
|
|
} else {
|
|
for (bytes = l >> 3, shift = 24, v = 0; bytes;
|
|
bytes--, shift -= 8)
|
|
v |= (unsigned) (*bs->cur++) << shift;
|
|
|
|
if (l < 32) {
|
|
v |= (unsigned) (*bs->cur) << shift;
|
|
v <<= bs->bit;
|
|
} else if (l > 32) {
|
|
v <<= bs->bit;
|
|
v |= (*bs->cur) >> (8 - bs->bit);
|
|
}
|
|
|
|
bs->bit = l & 0x7;
|
|
}
|
|
|
|
v &= 0xffffffff << (32 - b);
|
|
|
|
return v;
|
|
}
|
|
|
|
/****************************************************************************
|
|
* Assume bs is aligned and sizeof(unsigned int) == 4
|
|
****************************************************************************/
|
|
unsigned get_uint(bitstr_t * bs, int b)
|
|
{
|
|
unsigned v = 0;
|
|
|
|
switch (b) {
|
|
case 4:
|
|
v |= *bs->cur++;
|
|
v <<= 8;
|
|
case 3:
|
|
v |= *bs->cur++;
|
|
v <<= 8;
|
|
case 2:
|
|
v |= *bs->cur++;
|
|
v <<= 8;
|
|
case 1:
|
|
v |= *bs->cur++;
|
|
break;
|
|
}
|
|
return v;
|
|
}
|
|
|
|
/****************************************************************************/
|
|
int decode_nul(bitstr_t * bs, field_t * f, char *base, int level)
|
|
{
|
|
PRINT("%*.s%s\n", level * TAB_SIZE, " ", f->name);
|
|
|
|
return H323_ERROR_NONE;
|
|
}
|
|
|
|
/****************************************************************************/
|
|
int decode_bool(bitstr_t * bs, field_t * f, char *base, int level)
|
|
{
|
|
PRINT("%*.s%s\n", level * TAB_SIZE, " ", f->name);
|
|
|
|
INC_BIT(bs);
|
|
|
|
CHECK_BOUND(bs, 0);
|
|
return H323_ERROR_NONE;
|
|
}
|
|
|
|
/****************************************************************************/
|
|
int decode_oid(bitstr_t * bs, field_t * f, char *base, int level)
|
|
{
|
|
int len;
|
|
|
|
PRINT("%*.s%s\n", level * TAB_SIZE, " ", f->name);
|
|
|
|
BYTE_ALIGN(bs);
|
|
CHECK_BOUND(bs, 1);
|
|
len = *bs->cur++;
|
|
bs->cur += len;
|
|
|
|
CHECK_BOUND(bs, 0);
|
|
return H323_ERROR_NONE;
|
|
}
|
|
|
|
/****************************************************************************/
|
|
int decode_int(bitstr_t * bs, field_t * f, char *base, int level)
|
|
{
|
|
unsigned len;
|
|
|
|
PRINT("%*.s%s", level * TAB_SIZE, " ", f->name);
|
|
|
|
switch (f->sz) {
|
|
case BYTE: /* Range == 256 */
|
|
BYTE_ALIGN(bs);
|
|
bs->cur++;
|
|
break;
|
|
case WORD: /* 257 <= Range <= 64K */
|
|
BYTE_ALIGN(bs);
|
|
bs->cur += 2;
|
|
break;
|
|
case CONS: /* 64K < Range < 4G */
|
|
len = get_bits(bs, 2) + 1;
|
|
BYTE_ALIGN(bs);
|
|
if (base && (f->attr & DECODE)) { /* timeToLive */
|
|
unsigned v = get_uint(bs, len) + f->lb;
|
|
PRINT(" = %u", v);
|
|
*((unsigned *) (base + f->offset)) = v;
|
|
}
|
|
bs->cur += len;
|
|
break;
|
|
case UNCO:
|
|
BYTE_ALIGN(bs);
|
|
CHECK_BOUND(bs, 2);
|
|
len = get_len(bs);
|
|
bs->cur += len;
|
|
break;
|
|
default: /* 2 <= Range <= 255 */
|
|
INC_BITS(bs, f->sz);
|
|
break;
|
|
}
|
|
|
|
PRINT("\n");
|
|
|
|
CHECK_BOUND(bs, 0);
|
|
return H323_ERROR_NONE;
|
|
}
|
|
|
|
/****************************************************************************/
|
|
int decode_enum(bitstr_t * bs, field_t * f, char *base, int level)
|
|
{
|
|
PRINT("%*.s%s\n", level * TAB_SIZE, " ", f->name);
|
|
|
|
if ((f->attr & EXT) && get_bit(bs)) {
|
|
INC_BITS(bs, 7);
|
|
} else {
|
|
INC_BITS(bs, f->sz);
|
|
}
|
|
|
|
CHECK_BOUND(bs, 0);
|
|
return H323_ERROR_NONE;
|
|
}
|
|
|
|
/****************************************************************************/
|
|
int decode_bitstr(bitstr_t * bs, field_t * f, char *base, int level)
|
|
{
|
|
unsigned len;
|
|
|
|
PRINT("%*.s%s\n", level * TAB_SIZE, " ", f->name);
|
|
|
|
BYTE_ALIGN(bs);
|
|
switch (f->sz) {
|
|
case FIXD: /* fixed length > 16 */
|
|
len = f->lb;
|
|
break;
|
|
case WORD: /* 2-byte length */
|
|
CHECK_BOUND(bs, 2);
|
|
len = (*bs->cur++) << 8;
|
|
len += (*bs->cur++) + f->lb;
|
|
break;
|
|
case SEMI:
|
|
CHECK_BOUND(bs, 2);
|
|
len = get_len(bs);
|
|
break;
|
|
default:
|
|
len = 0;
|
|
break;
|
|
}
|
|
|
|
bs->cur += len >> 3;
|
|
bs->bit = len & 7;
|
|
|
|
CHECK_BOUND(bs, 0);
|
|
return H323_ERROR_NONE;
|
|
}
|
|
|
|
/****************************************************************************/
|
|
int decode_numstr(bitstr_t * bs, field_t * f, char *base, int level)
|
|
{
|
|
unsigned len;
|
|
|
|
PRINT("%*.s%s\n", level * TAB_SIZE, " ", f->name);
|
|
|
|
/* 2 <= Range <= 255 */
|
|
len = get_bits(bs, f->sz) + f->lb;
|
|
|
|
BYTE_ALIGN(bs);
|
|
INC_BITS(bs, (len << 2));
|
|
|
|
CHECK_BOUND(bs, 0);
|
|
return H323_ERROR_NONE;
|
|
}
|
|
|
|
/****************************************************************************/
|
|
int decode_octstr(bitstr_t * bs, field_t * f, char *base, int level)
|
|
{
|
|
unsigned len;
|
|
|
|
PRINT("%*.s%s", level * TAB_SIZE, " ", f->name);
|
|
|
|
switch (f->sz) {
|
|
case FIXD: /* Range == 1 */
|
|
if (f->lb > 2) {
|
|
BYTE_ALIGN(bs);
|
|
if (base && (f->attr & DECODE)) {
|
|
/* The IP Address */
|
|
IFTHEN(f->lb == 4,
|
|
PRINT(" = %d.%d.%d.%d:%d",
|
|
bs->cur[0], bs->cur[1],
|
|
bs->cur[2], bs->cur[3],
|
|
bs->cur[4] * 256 + bs->cur[5]));
|
|
*((unsigned *) (base + f->offset)) =
|
|
bs->cur - bs->buf;
|
|
}
|
|
}
|
|
len = f->lb;
|
|
break;
|
|
case BYTE: /* Range == 256 */
|
|
BYTE_ALIGN(bs);
|
|
CHECK_BOUND(bs, 1);
|
|
len = (*bs->cur++) + f->lb;
|
|
break;
|
|
case SEMI:
|
|
BYTE_ALIGN(bs);
|
|
CHECK_BOUND(bs, 2);
|
|
len = get_len(bs) + f->lb;
|
|
break;
|
|
default: /* 2 <= Range <= 255 */
|
|
len = get_bits(bs, f->sz) + f->lb;
|
|
BYTE_ALIGN(bs);
|
|
break;
|
|
}
|
|
|
|
bs->cur += len;
|
|
|
|
PRINT("\n");
|
|
|
|
CHECK_BOUND(bs, 0);
|
|
return H323_ERROR_NONE;
|
|
}
|
|
|
|
/****************************************************************************/
|
|
int decode_bmpstr(bitstr_t * bs, field_t * f, char *base, int level)
|
|
{
|
|
unsigned len;
|
|
|
|
PRINT("%*.s%s\n", level * TAB_SIZE, " ", f->name);
|
|
|
|
switch (f->sz) {
|
|
case BYTE: /* Range == 256 */
|
|
BYTE_ALIGN(bs);
|
|
CHECK_BOUND(bs, 1);
|
|
len = (*bs->cur++) + f->lb;
|
|
break;
|
|
default: /* 2 <= Range <= 255 */
|
|
len = get_bits(bs, f->sz) + f->lb;
|
|
BYTE_ALIGN(bs);
|
|
break;
|
|
}
|
|
|
|
bs->cur += len << 1;
|
|
|
|
CHECK_BOUND(bs, 0);
|
|
return H323_ERROR_NONE;
|
|
}
|
|
|
|
/****************************************************************************/
|
|
int decode_seq(bitstr_t * bs, field_t * f, char *base, int level)
|
|
{
|
|
unsigned ext, bmp, i, opt, len = 0, bmp2, bmp2_len;
|
|
int err;
|
|
field_t *son;
|
|
unsigned char *beg = NULL;
|
|
|
|
PRINT("%*.s%s\n", level * TAB_SIZE, " ", f->name);
|
|
|
|
/* Decode? */
|
|
base = (base && (f->attr & DECODE)) ? base + f->offset : NULL;
|
|
|
|
/* Extensible? */
|
|
ext = (f->attr & EXT) ? get_bit(bs) : 0;
|
|
|
|
/* Get fields bitmap */
|
|
bmp = get_bitmap(bs, f->sz);
|
|
if (base)
|
|
*(unsigned *) base = bmp;
|
|
|
|
/* Decode the root components */
|
|
for (i = opt = 0, son = f->fields; i < f->lb; i++, son++) {
|
|
if (son->attr & STOP) {
|
|
PRINT("%*.s%s\n", (level + 1) * TAB_SIZE, " ",
|
|
son->name);
|
|
return H323_ERROR_STOP;
|
|
}
|
|
|
|
if (son->attr & OPT) { /* Optional component */
|
|
if (!((0x80000000U >> (opt++)) & bmp)) /* Not exist */
|
|
continue;
|
|
}
|
|
|
|
/* Decode */
|
|
if (son->attr & OPEN) { /* Open field */
|
|
CHECK_BOUND(bs, 2);
|
|
len = get_len(bs);
|
|
CHECK_BOUND(bs, len);
|
|
if (!base || !(son->attr & DECODE)) {
|
|
PRINT("%*.s%s\n", (level + 1) * TAB_SIZE,
|
|
" ", son->name);
|
|
bs->cur += len;
|
|
continue;
|
|
}
|
|
beg = bs->cur;
|
|
|
|
/* Decode */
|
|
if ((err = (Decoders[son->type]) (bs, son, base,
|
|
level + 1)) <
|
|
H323_ERROR_NONE)
|
|
return err;
|
|
|
|
bs->cur = beg + len;
|
|
bs->bit = 0;
|
|
} else if ((err = (Decoders[son->type]) (bs, son, base,
|
|
level + 1)) <
|
|
H323_ERROR_NONE)
|
|
return err;
|
|
}
|
|
|
|
/* No extension? */
|
|
if (!ext)
|
|
return H323_ERROR_NONE;
|
|
|
|
/* Get the extension bitmap */
|
|
bmp2_len = get_bits(bs, 7) + 1;
|
|
CHECK_BOUND(bs, (bmp2_len + 7) >> 3);
|
|
bmp2 = get_bitmap(bs, bmp2_len);
|
|
bmp |= bmp2 >> f->sz;
|
|
if (base)
|
|
*(unsigned *) base = bmp;
|
|
BYTE_ALIGN(bs);
|
|
|
|
/* Decode the extension components */
|
|
for (opt = 0; opt < bmp2_len; opt++, i++, son++) {
|
|
/* Check Range */
|
|
if (i >= f->ub) { /* Newer Version? */
|
|
CHECK_BOUND(bs, 2);
|
|
len = get_len(bs);
|
|
CHECK_BOUND(bs, len);
|
|
bs->cur += len;
|
|
continue;
|
|
}
|
|
|
|
if (son->attr & STOP) {
|
|
PRINT("%*.s%s\n", (level + 1) * TAB_SIZE, " ",
|
|
son->name);
|
|
return H323_ERROR_STOP;
|
|
}
|
|
|
|
if (!((0x80000000 >> opt) & bmp2)) /* Not present */
|
|
continue;
|
|
|
|
CHECK_BOUND(bs, 2);
|
|
len = get_len(bs);
|
|
CHECK_BOUND(bs, len);
|
|
if (!base || !(son->attr & DECODE)) {
|
|
PRINT("%*.s%s\n", (level + 1) * TAB_SIZE, " ",
|
|
son->name);
|
|
bs->cur += len;
|
|
continue;
|
|
}
|
|
beg = bs->cur;
|
|
|
|
if ((err = (Decoders[son->type]) (bs, son, base,
|
|
level + 1)) <
|
|
H323_ERROR_NONE)
|
|
return err;
|
|
|
|
bs->cur = beg + len;
|
|
bs->bit = 0;
|
|
}
|
|
return H323_ERROR_NONE;
|
|
}
|
|
|
|
/****************************************************************************/
|
|
int decode_seqof(bitstr_t * bs, field_t * f, char *base, int level)
|
|
{
|
|
unsigned count, effective_count = 0, i, len = 0;
|
|
int err;
|
|
field_t *son;
|
|
unsigned char *beg = NULL;
|
|
|
|
PRINT("%*.s%s\n", level * TAB_SIZE, " ", f->name);
|
|
|
|
/* Decode? */
|
|
base = (base && (f->attr & DECODE)) ? base + f->offset : NULL;
|
|
|
|
/* Decode item count */
|
|
switch (f->sz) {
|
|
case BYTE:
|
|
BYTE_ALIGN(bs);
|
|
CHECK_BOUND(bs, 1);
|
|
count = *bs->cur++;
|
|
break;
|
|
case WORD:
|
|
BYTE_ALIGN(bs);
|
|
CHECK_BOUND(bs, 2);
|
|
count = *bs->cur++;
|
|
count <<= 8;
|
|
count = *bs->cur++;
|
|
break;
|
|
case SEMI:
|
|
BYTE_ALIGN(bs);
|
|
CHECK_BOUND(bs, 2);
|
|
count = get_len(bs);
|
|
break;
|
|
default:
|
|
count = get_bits(bs, f->sz);
|
|
break;
|
|
}
|
|
count += f->lb;
|
|
|
|
/* Write Count */
|
|
if (base) {
|
|
effective_count = count > f->ub ? f->ub : count;
|
|
*(unsigned *) base = effective_count;
|
|
base += sizeof(unsigned);
|
|
}
|
|
|
|
/* Decode nested field */
|
|
son = f->fields;
|
|
if (base)
|
|
base -= son->offset;
|
|
for (i = 0; i < count; i++) {
|
|
if (son->attr & OPEN) {
|
|
BYTE_ALIGN(bs);
|
|
len = get_len(bs);
|
|
CHECK_BOUND(bs, len);
|
|
if (!base || !(son->attr & DECODE)) {
|
|
PRINT("%*.s%s\n", (level + 1) * TAB_SIZE,
|
|
" ", son->name);
|
|
bs->cur += len;
|
|
continue;
|
|
}
|
|
beg = bs->cur;
|
|
|
|
if ((err = (Decoders[son->type]) (bs, son,
|
|
i <
|
|
effective_count ?
|
|
base : NULL,
|
|
level + 1)) <
|
|
H323_ERROR_NONE)
|
|
return err;
|
|
|
|
bs->cur = beg + len;
|
|
bs->bit = 0;
|
|
} else
|
|
if ((err = (Decoders[son->type]) (bs, son,
|
|
i <
|
|
effective_count ?
|
|
base : NULL,
|
|
level + 1)) <
|
|
H323_ERROR_NONE)
|
|
return err;
|
|
|
|
if (base)
|
|
base += son->offset;
|
|
}
|
|
|
|
return H323_ERROR_NONE;
|
|
}
|
|
|
|
|
|
/****************************************************************************/
|
|
int decode_choice(bitstr_t * bs, field_t * f, char *base, int level)
|
|
{
|
|
unsigned type, ext, len = 0;
|
|
int err;
|
|
field_t *son;
|
|
unsigned char *beg = NULL;
|
|
|
|
PRINT("%*.s%s\n", level * TAB_SIZE, " ", f->name);
|
|
|
|
/* Decode? */
|
|
base = (base && (f->attr & DECODE)) ? base + f->offset : NULL;
|
|
|
|
/* Decode the choice index number */
|
|
if ((f->attr & EXT) && get_bit(bs)) {
|
|
ext = 1;
|
|
type = get_bits(bs, 7) + f->lb;
|
|
} else {
|
|
ext = 0;
|
|
type = get_bits(bs, f->sz);
|
|
if (type >= f->lb)
|
|
return H323_ERROR_RANGE;
|
|
}
|
|
|
|
/* Write Type */
|
|
if (base)
|
|
*(unsigned *) base = type;
|
|
|
|
/* Check Range */
|
|
if (type >= f->ub) { /* Newer version? */
|
|
BYTE_ALIGN(bs);
|
|
len = get_len(bs);
|
|
CHECK_BOUND(bs, len);
|
|
bs->cur += len;
|
|
return H323_ERROR_NONE;
|
|
}
|
|
|
|
/* Transfer to son level */
|
|
son = &f->fields[type];
|
|
if (son->attr & STOP) {
|
|
PRINT("%*.s%s\n", (level + 1) * TAB_SIZE, " ", son->name);
|
|
return H323_ERROR_STOP;
|
|
}
|
|
|
|
if (ext || (son->attr & OPEN)) {
|
|
BYTE_ALIGN(bs);
|
|
len = get_len(bs);
|
|
CHECK_BOUND(bs, len);
|
|
if (!base || !(son->attr & DECODE)) {
|
|
PRINT("%*.s%s\n", (level + 1) * TAB_SIZE, " ",
|
|
son->name);
|
|
bs->cur += len;
|
|
return H323_ERROR_NONE;
|
|
}
|
|
beg = bs->cur;
|
|
|
|
if ((err = (Decoders[son->type]) (bs, son, base, level + 1)) <
|
|
H323_ERROR_NONE)
|
|
return err;
|
|
|
|
bs->cur = beg + len;
|
|
bs->bit = 0;
|
|
} else if ((err = (Decoders[son->type]) (bs, son, base, level + 1)) <
|
|
H323_ERROR_NONE)
|
|
return err;
|
|
|
|
return H323_ERROR_NONE;
|
|
}
|
|
|
|
/****************************************************************************/
|
|
int DecodeRasMessage(unsigned char *buf, size_t sz, RasMessage * ras)
|
|
{
|
|
static field_t ras_message = {
|
|
FNAME("RasMessage") CHOICE, 5, 24, 32, DECODE | EXT,
|
|
0, _RasMessage
|
|
};
|
|
bitstr_t bs;
|
|
|
|
bs.buf = bs.beg = bs.cur = buf;
|
|
bs.end = buf + sz;
|
|
bs.bit = 0;
|
|
|
|
return decode_choice(&bs, &ras_message, (char *) ras, 0);
|
|
}
|
|
|
|
/****************************************************************************/
|
|
static int DecodeH323_UserInformation(unsigned char *buf, unsigned char *beg,
|
|
size_t sz, H323_UserInformation * uuie)
|
|
{
|
|
static field_t h323_userinformation = {
|
|
FNAME("H323-UserInformation") SEQ, 1, 2, 2, DECODE | EXT,
|
|
0, _H323_UserInformation
|
|
};
|
|
bitstr_t bs;
|
|
|
|
bs.buf = buf;
|
|
bs.beg = bs.cur = beg;
|
|
bs.end = beg + sz;
|
|
bs.bit = 0;
|
|
|
|
return decode_seq(&bs, &h323_userinformation, (char *) uuie, 0);
|
|
}
|
|
|
|
/****************************************************************************/
|
|
int DecodeMultimediaSystemControlMessage(unsigned char *buf, size_t sz,
|
|
MultimediaSystemControlMessage *
|
|
mscm)
|
|
{
|
|
static field_t multimediasystemcontrolmessage = {
|
|
FNAME("MultimediaSystemControlMessage") CHOICE, 2, 4, 4,
|
|
DECODE | EXT, 0, _MultimediaSystemControlMessage
|
|
};
|
|
bitstr_t bs;
|
|
|
|
bs.buf = bs.beg = bs.cur = buf;
|
|
bs.end = buf + sz;
|
|
bs.bit = 0;
|
|
|
|
return decode_choice(&bs, &multimediasystemcontrolmessage,
|
|
(char *) mscm, 0);
|
|
}
|
|
|
|
/****************************************************************************/
|
|
int DecodeQ931(unsigned char *buf, size_t sz, Q931 * q931)
|
|
{
|
|
unsigned char *p = buf;
|
|
int len;
|
|
|
|
if (!p || sz < 1)
|
|
return H323_ERROR_BOUND;
|
|
|
|
/* Protocol Discriminator */
|
|
if (*p != 0x08) {
|
|
PRINT("Unknown Protocol Discriminator\n");
|
|
return H323_ERROR_RANGE;
|
|
}
|
|
p++;
|
|
sz--;
|
|
|
|
/* CallReferenceValue */
|
|
if (sz < 1)
|
|
return H323_ERROR_BOUND;
|
|
len = *p++;
|
|
sz--;
|
|
if (sz < len)
|
|
return H323_ERROR_BOUND;
|
|
p += len;
|
|
sz -= len;
|
|
|
|
/* Message Type */
|
|
if (sz < 1)
|
|
return H323_ERROR_BOUND;
|
|
q931->MessageType = *p++;
|
|
PRINT("MessageType = %02X\n", q931->MessageType);
|
|
if (*p & 0x80) {
|
|
p++;
|
|
sz--;
|
|
}
|
|
|
|
/* Decode Information Elements */
|
|
while (sz > 0) {
|
|
if (*p == 0x7e) { /* UserUserIE */
|
|
if (sz < 3)
|
|
break;
|
|
p++;
|
|
len = *p++ << 8;
|
|
len |= *p++;
|
|
sz -= 3;
|
|
if (sz < len)
|
|
break;
|
|
p++;
|
|
len--;
|
|
return DecodeH323_UserInformation(buf, p, len,
|
|
&q931->UUIE);
|
|
}
|
|
p++;
|
|
sz--;
|
|
if (sz < 1)
|
|
break;
|
|
len = *p++;
|
|
if (sz < len)
|
|
break;
|
|
p += len;
|
|
sz -= len;
|
|
}
|
|
|
|
PRINT("Q.931 UUIE not found\n");
|
|
|
|
return H323_ERROR_BOUND;
|
|
}
|