bitmap: Introduce bitmap_cut(): cut bits and shift remaining

The new bitmap function bitmap_cut() copies bits from source to
destination by removing the region specified by parameters first
and cut, and remapping the bits above the cut region by right
shifting them.

Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This commit is contained in:
Stefano Brivio
2020-01-22 00:17:54 +01:00
committed by Pablo Neira Ayuso
parent f3a2181e16
commit 2092767168
2 changed files with 70 additions and 0 deletions

View File

@@ -53,6 +53,7 @@
* bitmap_find_next_zero_area_off(buf, len, pos, n, mask) as above
* bitmap_shift_right(dst, src, n, nbits) *dst = *src >> n
* bitmap_shift_left(dst, src, n, nbits) *dst = *src << n
* bitmap_cut(dst, src, first, n, nbits) Cut n bits from first, copy rest
* bitmap_replace(dst, old, new, mask, nbits) *dst = (*old & ~(*mask)) | (*new & *mask)
* bitmap_remap(dst, src, old, new, nbits) *dst = map(old, new)(src)
* bitmap_bitremap(oldbit, old, new, nbits) newbit = map(old, new)(oldbit)
@@ -133,6 +134,9 @@ extern void __bitmap_shift_right(unsigned long *dst, const unsigned long *src,
unsigned int shift, unsigned int nbits);
extern void __bitmap_shift_left(unsigned long *dst, const unsigned long *src,
unsigned int shift, unsigned int nbits);
extern void bitmap_cut(unsigned long *dst, const unsigned long *src,
unsigned int first, unsigned int cut,
unsigned int nbits);
extern int __bitmap_and(unsigned long *dst, const unsigned long *bitmap1,
const unsigned long *bitmap2, unsigned int nbits);
extern void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1,