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netfilter: nf_ct_h323: Convert CHECK_BOUND macro to function
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It is bad practive to return in a macro, this patch
moves the check into a function.

Signed-off-by: Eric Sesterhenn <eric.sesterhenn@x41-dsec.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
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Eric Sesterhenn authored and Pablo Neira Ayuso committed Nov 20, 2017
1 parent 613d077 commit bc7d811
Showing 1 changed file with 65 additions and 29 deletions.
94 changes: 65 additions & 29 deletions net/netfilter/nf_conntrack_h323_asn1.c
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Original file line number Diff line number Diff line change
Expand Up @@ -103,7 +103,6 @@ struct bitstr {
#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 int get_len(struct bitstr *bs);
static unsigned int get_bit(struct bitstr *bs);
static unsigned int get_bits(struct bitstr *bs, unsigned int b);
Expand Down Expand Up @@ -165,6 +164,14 @@ static unsigned int get_len(struct bitstr *bs)
return v;
}

static int nf_h323_error_boundary(struct bitstr *bs, size_t bytes)
{
if (*bs->cur + bytes > *bs->end)
return 1;

return 0;
}

/****************************************************************************/
static unsigned int get_bit(struct bitstr *bs)
{
Expand Down Expand Up @@ -280,7 +287,8 @@ static int decode_bool(struct bitstr *bs, const struct field_t *f,

INC_BIT(bs);

CHECK_BOUND(bs, 0);
if (nf_h323_error_boundary(bs, 0))
return H323_ERROR_BOUND;
return H323_ERROR_NONE;
}

Expand All @@ -293,11 +301,14 @@ static int decode_oid(struct bitstr *bs, const struct field_t *f,
PRINT("%*.s%s\n", level * TAB_SIZE, " ", f->name);

BYTE_ALIGN(bs);
CHECK_BOUND(bs, 1);
if (nf_h323_error_boundary(bs, 1))
return H323_ERROR_BOUND;

len = *bs->cur++;
bs->cur += len;
if (nf_h323_error_boundary(bs, 0))
return H323_ERROR_BOUND;

CHECK_BOUND(bs, 0);
return H323_ERROR_NONE;
}

Expand Down Expand Up @@ -330,7 +341,8 @@ static int decode_int(struct bitstr *bs, const struct field_t *f,
break;
case UNCO:
BYTE_ALIGN(bs);
CHECK_BOUND(bs, 2);
if (nf_h323_error_boundary(bs, 2))
return H323_ERROR_BOUND;
len = get_len(bs);
bs->cur += len;
break;
Expand All @@ -341,7 +353,8 @@ static int decode_int(struct bitstr *bs, const struct field_t *f,

PRINT("\n");

CHECK_BOUND(bs, 0);
if (nf_h323_error_boundary(bs, 0))
return H323_ERROR_BOUND;
return H323_ERROR_NONE;
}

Expand All @@ -357,7 +370,8 @@ static int decode_enum(struct bitstr *bs, const struct field_t *f,
INC_BITS(bs, f->sz);
}

CHECK_BOUND(bs, 0);
if (nf_h323_error_boundary(bs, 0))
return H323_ERROR_BOUND;
return H323_ERROR_NONE;
}

Expand All @@ -375,12 +389,14 @@ static int decode_bitstr(struct bitstr *bs, const struct field_t *f,
len = f->lb;
break;
case WORD: /* 2-byte length */
CHECK_BOUND(bs, 2);
if (nf_h323_error_boundary(bs, 2))
return H323_ERROR_BOUND;
len = (*bs->cur++) << 8;
len += (*bs->cur++) + f->lb;
break;
case SEMI:
CHECK_BOUND(bs, 2);
if (nf_h323_error_boundary(bs, 2))
return H323_ERROR_BOUND;
len = get_len(bs);
break;
default:
Expand All @@ -391,7 +407,8 @@ static int decode_bitstr(struct bitstr *bs, const struct field_t *f,
bs->cur += len >> 3;
bs->bit = len & 7;

CHECK_BOUND(bs, 0);
if (nf_h323_error_boundary(bs, 0))
return H323_ERROR_BOUND;
return H323_ERROR_NONE;
}

Expand All @@ -409,7 +426,8 @@ static int decode_numstr(struct bitstr *bs, const struct field_t *f,
BYTE_ALIGN(bs);
INC_BITS(bs, (len << 2));

CHECK_BOUND(bs, 0);
if (nf_h323_error_boundary(bs, 0))
return H323_ERROR_BOUND;
return H323_ERROR_NONE;
}

Expand Down Expand Up @@ -440,12 +458,14 @@ static int decode_octstr(struct bitstr *bs, const struct field_t *f,
break;
case BYTE: /* Range == 256 */
BYTE_ALIGN(bs);
CHECK_BOUND(bs, 1);
if (nf_h323_error_boundary(bs, 1))
return H323_ERROR_BOUND;
len = (*bs->cur++) + f->lb;
break;
case SEMI:
BYTE_ALIGN(bs);
CHECK_BOUND(bs, 2);
if (nf_h323_error_boundary(bs, 2))
return H323_ERROR_BOUND;
len = get_len(bs) + f->lb;
break;
default: /* 2 <= Range <= 255 */
Expand All @@ -458,7 +478,8 @@ static int decode_octstr(struct bitstr *bs, const struct field_t *f,

PRINT("\n");

CHECK_BOUND(bs, 0);
if (nf_h323_error_boundary(bs, 0))
return H323_ERROR_BOUND;
return H323_ERROR_NONE;
}

Expand All @@ -473,7 +494,8 @@ static int decode_bmpstr(struct bitstr *bs, const struct field_t *f,
switch (f->sz) {
case BYTE: /* Range == 256 */
BYTE_ALIGN(bs);
CHECK_BOUND(bs, 1);
if (nf_h323_error_boundary(bs, 1))
return H323_ERROR_BOUND;
len = (*bs->cur++) + f->lb;
break;
default: /* 2 <= Range <= 255 */
Expand All @@ -484,7 +506,8 @@ static int decode_bmpstr(struct bitstr *bs, const struct field_t *f,

bs->cur += len << 1;

CHECK_BOUND(bs, 0);
if (nf_h323_error_boundary(bs, 0))
return H323_ERROR_BOUND;
return H323_ERROR_NONE;
}

Expand Down Expand Up @@ -525,9 +548,11 @@ static int decode_seq(struct bitstr *bs, const struct field_t *f,

/* Decode */
if (son->attr & OPEN) { /* Open field */
CHECK_BOUND(bs, 2);
if (nf_h323_error_boundary(bs, 2))
return H323_ERROR_BOUND;
len = get_len(bs);
CHECK_BOUND(bs, len);
if (nf_h323_error_boundary(bs, len))
return H323_ERROR_BOUND;
if (!base || !(son->attr & DECODE)) {
PRINT("%*.s%s\n", (level + 1) * TAB_SIZE,
" ", son->name);
Expand Down Expand Up @@ -556,7 +581,8 @@ static int decode_seq(struct bitstr *bs, const struct field_t *f,

/* Get the extension bitmap */
bmp2_len = get_bits(bs, 7) + 1;
CHECK_BOUND(bs, (bmp2_len + 7) >> 3);
if (nf_h323_error_boundary(bs, (bmp2_len + 7) >> 3))
return H323_ERROR_BOUND;
bmp2 = get_bitmap(bs, bmp2_len);
bmp |= bmp2 >> f->sz;
if (base)
Expand All @@ -567,9 +593,11 @@ static int decode_seq(struct bitstr *bs, const struct field_t *f,
for (opt = 0; opt < bmp2_len; opt++, i++, son++) {
/* Check Range */
if (i >= f->ub) { /* Newer Version? */
CHECK_BOUND(bs, 2);
if (nf_h323_error_boundary(bs, 2))
return H323_ERROR_BOUND;
len = get_len(bs);
CHECK_BOUND(bs, len);
if (nf_h323_error_boundary(bs, len))
return H323_ERROR_BOUND;
bs->cur += len;
continue;
}
Expand All @@ -583,9 +611,11 @@ static int decode_seq(struct bitstr *bs, const struct field_t *f,
if (!((0x80000000 >> opt) & bmp2)) /* Not present */
continue;

CHECK_BOUND(bs, 2);
if (nf_h323_error_boundary(bs, 2))
return H323_ERROR_BOUND;
len = get_len(bs);
CHECK_BOUND(bs, len);
if (nf_h323_error_boundary(bs, len))
return H323_ERROR_BOUND;
if (!base || !(son->attr & DECODE)) {
PRINT("%*.s%s\n", (level + 1) * TAB_SIZE, " ",
son->name);
Expand Down Expand Up @@ -623,19 +653,22 @@ static int decode_seqof(struct bitstr *bs, const struct field_t *f,
switch (f->sz) {
case BYTE:
BYTE_ALIGN(bs);
CHECK_BOUND(bs, 1);
if (nf_h323_error_boundary(bs, 1))
return H323_ERROR_BOUND;
count = *bs->cur++;
break;
case WORD:
BYTE_ALIGN(bs);
CHECK_BOUND(bs, 2);
if (nf_h323_error_boundary(bs, 2))
return H323_ERROR_BOUND;
count = *bs->cur++;
count <<= 8;
count += *bs->cur++;
break;
case SEMI:
BYTE_ALIGN(bs);
CHECK_BOUND(bs, 2);
if (nf_h323_error_boundary(bs, 2))
return H323_ERROR_BOUND;
count = get_len(bs);
break;
default:
Expand All @@ -659,7 +692,8 @@ static int decode_seqof(struct bitstr *bs, const struct field_t *f,
if (son->attr & OPEN) {
BYTE_ALIGN(bs);
len = get_len(bs);
CHECK_BOUND(bs, len);
if (nf_h323_error_boundary(bs, len))
return H323_ERROR_BOUND;
if (!base || !(son->attr & DECODE)) {
PRINT("%*.s%s\n", (level + 1) * TAB_SIZE,
" ", son->name);
Expand Down Expand Up @@ -728,7 +762,8 @@ static int decode_choice(struct bitstr *bs, const struct field_t *f,
if (type >= f->ub) { /* Newer version? */
BYTE_ALIGN(bs);
len = get_len(bs);
CHECK_BOUND(bs, len);
if (nf_h323_error_boundary(bs, len))
return H323_ERROR_BOUND;
bs->cur += len;
return H323_ERROR_NONE;
}
Expand All @@ -743,7 +778,8 @@ static int decode_choice(struct bitstr *bs, const struct field_t *f,
if (ext || (son->attr & OPEN)) {
BYTE_ALIGN(bs);
len = get_len(bs);
CHECK_BOUND(bs, len);
if (nf_h323_error_boundary(bs, len))
return H323_ERROR_BOUND;
if (!base || !(son->attr & DECODE)) {
PRINT("%*.s%s\n", (level + 1) * TAB_SIZE, " ",
son->name);
Expand Down

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