netfilter: nf_ct_h323: Convert CHECK_BOUND macro to function

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>

diff --git a/net/netfilter/nf_conntrack_h323_asn1.c b/net/netfilter/nf_conntrack_h323_asn1.c
index cf1bf26..3d9a009 100644 (file)
--- a/net/netfilter/nf_conntrack_h323_asn1.c
+++ b/net/netfilter/nf_conntrack_h323_asn1.c
@@ -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);
@@ -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)
 {
@@ -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;
 }
 
@@ -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;
 }
 
@@ -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;
@@ -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;
 }
 
@@ -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;
 }
 
@@ -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:
@@ -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;
 }
 
@@ -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;
 }
 
@@ -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 */
@@ -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;
 }
 
@@ -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 */
@@ -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;
 }
 
@@ -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);
@@ -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)
@@ -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;
                }
@@ -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);
@@ -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:
@@ -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);
@@ -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;
        }
@@ -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);