/*
* Copyright (c) 2015 Cisco and/or its affiliates.
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at:
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/*
Copyright (c) 2001-2005 Eliot Dresselhaus
Permission is hereby granted, free of charge, to any person obtaining
a copy of this software and associated documentation files (the
"Software"), to deal in the Software without restriction, including
without limitation the rights to use, copy, modify, merge, publish,
distribute, sublicense, and/or sell copies of the Software, and to
permit persons to whom the Software is furnished to do so, subject to
the following conditions:
The above copyright notice and this permission notice shall be
included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
#include <vppinfra/hash.h>
#include <vppinfra/error.h>
#include <vppinfra/mem.h>
#include <vppinfra/byte_order.h> /* for clib_arch_is_big_endian */
always_inline void
zero_pair (hash_t * h, hash_pair_t * p)
{
clib_memset (p, 0, hash_pair_bytes (h));
}
always_inline void
init_pair (hash_t * h, hash_pair_t * p)
{
clib_memset (p->value, ~0, hash_value_bytes (h));
}
always_inline hash_pair_union_t *
get_pair (void *v, uword i)
{
hash_t *h = hash_header (v);
hash_pair_t *p;
ASSERT (i < vec_len (v));
p = v;
p += i << h->log2_pair_size;
return (hash_pair_union_t *) p;
}
always_inline void
set_is_user (void *v, uword i, uword is_user)
{
hash_t *h = hash_header (v);
uword i0 = i / BITS (h->is_user[0]);
uword i1 = (uword) 1 << (i % BITS (h->is_user[0]));
if (is_user)
h->is_user[i0] |= i1;
else
h->is_user[i0] &= ~i1;
}
static u8 *hash_format_pair_default (u8 * s, va_list * args);
#if uword_bits == 64
static inline u64
zap64 (u64 x, word n)
{
#define _(n) (((u64) 1 << (u64) (8*(n))) - (u64) 1)
static u64 masks_little_endian[] = {
0, _(1), _(2), _(3), _(4), _(5), _(6), _(7),
};
static u64 masks_big_endian[] = {
0, ~_(7), ~_(6), ~_(5), ~_(4), ~_(3), ~_(2), ~_(1),
};
#undef _
if (clib_arch_is_big_endian)
return x & masks_big_endian[n];
else
return x & masks_little_endian[n];
}
/**
* make address-sanitizer skip this:
* clib_mem_unaligned + zap64 casts its input as u64, computes a mask
* according to the input length, and returns the casted maked value.
* Therefore all the 8 Bytes of the u64 are systematically read, which
* rightfully causes address-sanitizer to raise an error on smaller inputs.
*
* However the invalid Bytes are discarded within zap64(), which is why
* this can be silenced safely.
*
* The above is true *unless* the extra bytes cross a page boundary
* into unmapped or no-access space, hence the boundary crossing check.
*/
static inline u64
hash_memory64 (void *p, word n_bytes, u64 state)
{
u64 *q = p;
u64 a, b, c, n;
int page_boundary_crossing;
u64 start_addr, end_addr;
union
{
u8 as_u8[8];
u64 as_u64;
} tmp;
/*
* If the request crosses a 4k boundary, it's not OK to assume
* that the zap64 game is safe. 4k is the minimum known page size.
*/
start_addr = (u64) p;
end_addr = start_addr + n_bytes + 7;
page_boundary_crossing = (start_addr >> 12) != (end_addr >> 12);
a = b = 0x9e3779b97f4a7c13LL;
c = state;
n = n_bytes;
while (n >= 3 * sizeof (u64))
{
a += clib_mem_unaligned (q + 0, u64);
b += clib_mem_unaligned (q + 1, u64);
c += clib_mem_unaligned (q + 2, u64);
hash_mix64 (a, b, c);
n -= 3 * sizeof (u64);
q += 3;
}
c += n_bytes;
switch (n / sizeof (u64))
{
case 2:
a += clib_mem_unaligned (q + 0, u64);
b += clib_mem_unaligned (q + 1, u64);
if (n % sizeof (u64))
{
if (PREDICT_TRUE (page_boundary_crossing == 0))
c +=
zap64 (CLIB_MEM_OVERFLOW
(clib_mem_unaligned (q + 2, u64), q + 2, sizeof (u64)),
n % sizeof (u64)) << 8;
else
{
clib_memcpy_fast (tmp.as_u8, q + 2, n % sizeof (u64));
c += zap64 (tmp.as_u64, n % sizeof (u64)) << 8;
}
}
break;
case 1:
a += clib_mem_unaligned (q + 0, u64);
if (n % sizeof (u64))
{
if (PREDICT_TRUE (page_boundary_crossing == 0))
b +=
zap64 (CLIB_MEM_OVERFLOW
(clib_mem_unaligned (q + 1, u64), q + 1, sizeof (u64)),
n % sizeof (u64));
else
{
clib_memcpy_fast (tmp.as_u8, q + 1, n % sizeof (u64));
b += zap64 (tmp.as_u64, n % sizeof (u64));
}
}
break;
case 0:
if (n % sizeof (u64))
{
if (PREDICT_TRUE (page_boundary_crossing == 0))
a +=
zap64 (CLIB_MEM_OVERFLOW
(clib_mem_unaligned (q + 0, u64), q + 0, sizeof (u64)),
n % sizeof (u64));
else
{
clib_memcpy_fast (tmp.as_u8, q, n % sizeof (u64));
a += zap64 (tmp.as_u64, n % sizeof (u64));
}
}
break;
}
hash_mix64 (a, b, c);
return c;
}
#else /* if uword_bits == 64 */
static inline u32
zap32 (u32 x, word n)
{
#define _(n) (((u32) 1 << (u32) (8*(n))) - (u32) 1)
static u32 masks_little_endian[] = {
0, _(1), _(2), _(3),
};
static u32 masks_big_endian[] = {
0, ~_(3), ~_(2), ~_(1),
};
#undef _
if (clib_arch_is_big_endian)
return x & masks_big_endian[n];
else
return x & masks_little_endian[n];
}
static inline u32
hash_memory32 (void *p, word n_bytes, u32 state)
{
u32 *q = p;
u32 a, b, c, n;
a = b = 0x9e3779b9;
c = state;
n = n_bytes;
while (n >= 3 * sizeof (u32))
{
a += clib_mem_unaligned (q + 0, u32);
b += clib_mem_unaligned (q + 1, u32);
c += clib_mem_unaligned (q + 2, u32);
hash_mix32 (a, b, c);
n -= 3 * sizeof (u32);
q += 3;
}
c += n_bytes;
switch (n / sizeof (u32))
{
case 2:
a += clib_mem_unaligned (q + 0, u32);
b += clib_mem_unaligned (q + 1, u32);
if (n % sizeof (u32))
c += zap32 (clib_mem_unaligned (q + 2, u32), n % sizeof (u32)) << 8;
break;
case 1:
a += clib_mem_unaligned (q + 0, u32);
if (n % sizeof (u32))
b += zap32 (clib_mem_unaligned (q + 1, u32), n % sizeof (u32));
break;
case 0:
if (n % sizeof (u32))
a += zap32 (clib_mem_unaligned (q + 0, u32), n % sizeof (u32));
break;
}
hash_mix32 (a, b, c);
return c;
}
#endif
__clib_export uword
hash_memory (void *p, word n_bytes, uword state)
{
uword *q = p;
#if uword_bits == 64
return hash_memory64 (q, n_bytes, state);
#else
return hash_memory32 (q, n_bytes, state);
#endif
}
#if uword_bits == 64
always_inline uword
hash_uword (uword x)
{
u64 a, b, c;
a = b = 0x9e3779b97f4a7c13LL;
c = 0;
a += x;
hash_mix64 (a,