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+/* Copyright (C) 2007-2022 Open Information Security Foundation
+ *
+ * You can copy, redistribute or modify this Program under the terms of
+ * the GNU General Public License version 2 as published by the Free
+ * Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * version 2 along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ */
+
+/**
+ * \file
+ *
+ * \author Victor Julien <victor@inliniac.net>
+ *
+ * Memcmp implementations for SSE3, SSE4.1, SSE4.2.
+ *
+ * Both SCMemcmp and SCMemcmpLowercase return 0 on a exact match,
+ * 1 on a failed match.
+ */
+
+#ifndef __UTIL_MEMCMP_H__
+#define __UTIL_MEMCMP_H__
+
+#include "suricata-common.h"
+#include "util-optimize.h"
+
+/** \brief compare two patterns, converting the 2nd to lowercase
+ * \warning *ONLY* the 2nd pattern is converted to lowercase
+ */
+static inline int SCMemcmpLowercase(const void *, const void *, size_t);
+
+void MemcmpRegisterTests(void);
+
+static inline int
+MemcmpLowercase(const void *s1, const void *s2, size_t n)
+{
+ for (size_t i = 0; i < n; i++) {
+ if (((uint8_t *)s1)[i] != u8_tolower(((uint8_t *)s2)[i]))
+ return 1;
+ }
+
+ return 0;
+}
+
+#if defined(__SSE4_2__)
+#include <nmmintrin.h>
+#define SCMEMCMP_BYTES 16
+
+static inline int SCMemcmp(const void *s1, const void *s2, size_t n)
+{
+ int r = 0;
+ /* counter for how far we already matched in the buffer */
+ size_t m = 0;
+ do {
+ if (likely(n - m < SCMEMCMP_BYTES)) {
+ return memcmp(s1, s2, n - m) ? 1 : 0;
+ }
+
+ /* load the buffers into the 128bit vars */
+ __m128i b1 = _mm_loadu_si128((const __m128i *)s1);
+ __m128i b2 = _mm_loadu_si128((const __m128i *)s2);
+
+ /* do the actual compare: _mm_cmpestri() returns the number of matching bytes */
+ r = _mm_cmpestri(b1, SCMEMCMP_BYTES, b2, SCMEMCMP_BYTES,
+ _SIDD_CMP_EQUAL_EACH | _SIDD_MASKED_NEGATIVE_POLARITY);
+ m += r;
+ s1 += SCMEMCMP_BYTES;
+ s2 += SCMEMCMP_BYTES;
+ } while (r == SCMEMCMP_BYTES);
+
+ return ((m == n) ? 0 : 1);
+}
+
+/* Range of values of uppercase characters. We only use the first 2 bytes. */
+static char scmemcmp_uppercase[16] __attribute__((aligned(16))) = {
+ 'A', 'Z', 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, };
+
+/** \brief compare two buffers in a case insensitive way
+ * \param s1 buffer already in lowercase
+ * \param s2 buffer with mixed upper and lowercase
+ */
+static inline int SCMemcmpLowercase(const void *s1, const void *s2, size_t n)
+{
+ /* counter for how far we already matched in the buffer */
+ size_t m = 0;
+ int r = 0;
+ __m128i ucase = _mm_load_si128((const __m128i *) scmemcmp_uppercase);
+ __m128i uplow = _mm_set1_epi8(0x20);
+
+ do {
+ const size_t len = n - m;
+ if (likely(len < SCMEMCMP_BYTES)) {
+ return MemcmpLowercase(s1, s2, len);
+ }
+
+ __m128i b1 = _mm_loadu_si128((const __m128i *)s1);
+ __m128i b2 = _mm_loadu_si128((const __m128i *)s2);
+ /* The first step is creating a mask that is FF for all uppercase
+ * characters, 00 for all others */
+ __m128i mask = _mm_cmpestrm(ucase, 2, b2, len, _SIDD_CMP_RANGES | _SIDD_UNIT_MASK);
+ /* Next we use that mask to create a new: this one has 0x20 for
+ * the uppercase chars, 00 for all other. */
+ mask = _mm_and_si128(uplow, mask);
+ /* finally, merge the mask and the buffer converting the
+ * uppercase to lowercase */
+ b2 = _mm_add_epi8(b2, mask);
+
+ /* search using our converted buffer, return number of matching bytes */
+ r = _mm_cmpestri(b1, SCMEMCMP_BYTES, b2, SCMEMCMP_BYTES,
+ _SIDD_CMP_EQUAL_EACH | _SIDD_MASKED_NEGATIVE_POLARITY);
+ m += r;
+ s1 += SCMEMCMP_BYTES;
+ s2 += SCMEMCMP_BYTES;
+ } while (r == SCMEMCMP_BYTES);
+
+ return ((m == n) ? 0 : 1);
+}
+
+#elif defined(__SSE4_1__)
+#include <smmintrin.h>
+#define SCMEMCMP_BYTES 16
+
+static inline int SCMemcmp(const void *s1, const void *s2, size_t len)
+{
+ size_t offset = 0;
+ do {
+ if (likely(len - offset < SCMEMCMP_BYTES)) {
+ return memcmp(s1, s2, len - offset) ? 1 : 0;
+ }
+
+ /* unaligned loads */
+ __m128i b1 = _mm_loadu_si128((const __m128i *)s1);
+ __m128i b2 = _mm_loadu_si128((const __m128i *)s2);
+ __m128i c = _mm_cmpeq_epi8(b1, b2);
+
+ if (_mm_movemask_epi8(c) != 0x0000FFFF) {
+ return 1;
+ }
+
+ offset += SCMEMCMP_BYTES;
+ s1 += SCMEMCMP_BYTES;
+ s2 += SCMEMCMP_BYTES;
+ } while (len > offset);
+
+ return 0;
+}
+
+#define UPPER_LOW 0x40 /* "A" - 1 */
+#define UPPER_HIGH 0x5B /* "Z" + 1 */
+
+static inline int SCMemcmpLowercase(const void *s1, const void *s2, size_t len)
+{
+ size_t offset = 0;
+ __m128i b1, b2, mask1, mask2, upper1, upper2, uplow;
+
+ /* setup registers for upper to lower conversion */
+ upper1 = _mm_set1_epi8(UPPER_LOW);
+ upper2 = _mm_set1_epi8(UPPER_HIGH);
+ uplow = _mm_set1_epi8(0x20);
+
+ do {
+ if (likely(len - offset < SCMEMCMP_BYTES)) {
+ return MemcmpLowercase(s1, s2, len - offset);
+ }
+
+ /* unaligned loading of the bytes to compare */
+ b1 = _mm_loadu_si128((const __m128i *) s1);
+ b2 = _mm_loadu_si128((const __m128i *) s2);
+
+ /* mark all chars bigger than upper1 */
+ mask1 = _mm_cmpgt_epi8(b2, upper1);
+ /* mark all chars lower than upper2 */
+ mask2 = _mm_cmplt_epi8(b2, upper2);
+ /* merge the two, leaving only those that are true in both */
+ mask1 = _mm_cmpeq_epi8(mask1, mask2);
+ /* Next we use that mask to create a new: this one has 0x20 for
+ * the uppercase chars, 00 for all other. */
+ mask1 = _mm_and_si128(uplow, mask1);
+ /* add to b2, converting uppercase to lowercase */
+ b2 = _mm_add_epi8(b2, mask1);
+ /* now all is lowercase, let's do the actual compare (reuse mask1 reg) */
+ mask1 = _mm_cmpeq_epi8(b1, b2);
+
+ if (_mm_movemask_epi8(mask1) != 0x0000FFFF) {
+ return 1;
+ }
+
+ offset += SCMEMCMP_BYTES;
+ s1 += SCMEMCMP_BYTES;
+ s2 += SCMEMCMP_BYTES;
+ } while (len > offset);
+
+ return 0;
+}
+
+#elif defined(__SSE3__)
+#include <pmmintrin.h> /* for SSE3 */
+#define SCMEMCMP_BYTES 16
+
+static inline int SCMemcmp(const void *s1, const void *s2, size_t len)
+{
+ size_t offset = 0;
+ __m128i b1, b2, c;
+
+ do {
+ if (likely(len - offset < SCMEMCMP_BYTES)) {
+ return memcmp(s1, s2, len - offset) ? 1 : 0;
+ }
+
+ /* unaligned loads */
+ b1 = _mm_loadu_si128((const __m128i *) s1);
+ b2 = _mm_loadu_si128((const __m128i *) s2);
+ c = _mm_cmpeq_epi8(b1, b2);
+
+ if (_mm_movemask_epi8(c) != 0x0000FFFF) {
+ return 1;
+ }
+
+ offset += SCMEMCMP_BYTES;
+ s1 += SCMEMCMP_BYTES;
+ s2 += SCMEMCMP_BYTES;
+ } while (len > offset);
+
+ return 0;
+}
+
+#define UPPER_LOW 0x40 /* "A" - 1 */
+#define UPPER_HIGH 0x5B /* "Z" + 1 */
+#define UPPER_DELTA 0xDF /* 0xFF - 0x20 */
+
+static inline int SCMemcmpLowercase(const void *s1, const void *s2, size_t len)
+{
+ size_t offset = 0;
+ __m128i b1, b2, mask1, mask2, upper1, upper2, delta;
+
+ /* setup registers for upper to lower conversion */
+ upper1 = _mm_set1_epi8(UPPER_LOW);
+ upper2 = _mm_set1_epi8(UPPER_HIGH);
+ delta = _mm_set1_epi8(UPPER_DELTA);
+
+ do {
+ if (likely(len - offset < SCMEMCMP_BYTES)) {
+ return MemcmpLowercase(s1, s2, len - offset);
+ }
+
+ /* unaligned loading of the bytes to compare */
+ b1 = _mm_loadu_si128((const __m128i *) s1);
+ b2 = _mm_loadu_si128((const __m128i *) s2);
+
+ /* mark all chars bigger than upper1 */
+ mask1 = _mm_cmpgt_epi8(b2, upper1);
+ /* mark all chars lower than upper2 */
+ mask2 = _mm_cmplt_epi8(b2, upper2);
+ /* merge the two, leaving only those that are true in both */
+ mask1 = _mm_cmpeq_epi8(mask1, mask2);
+ /* sub delta leaves 0x20 only for uppercase positions, the
+ rest is 0x00 due to the saturation (reuse mask1 reg)*/
+ mask1 = _mm_subs_epu8(mask1, delta);
+ /* add to b2, converting uppercase to lowercase */
+ b2 = _mm_add_epi8(b2, mask1);
+
+ /* now all is lowercase, let's do the actual compare (reuse mask1 reg) */
+ mask1 = _mm_cmpeq_epi8(b1, b2);
+
+ if (_mm_movemask_epi8(mask1) != 0x0000FFFF) {
+ return 1;
+ }
+
+ offset += SCMEMCMP_BYTES;
+ s1 += SCMEMCMP_BYTES;
+ s2 += SCMEMCMP_BYTES;
+ } while (len > offset);
+
+ return 0;
+}
+
+#else
+
+/* No SIMD support, fall back to plain memcmp and a home grown lowercase one */
+
+/* wrapper around memcmp to match the retvals of the SIMD implementations */
+#define SCMemcmp(a,b,c) ({ \
+ memcmp((a), (b), (c)) ? 1 : 0; \
+})
+
+static inline int SCMemcmpLowercase(const void *s1, const void *s2, size_t len)
+{
+ return MemcmpLowercase(s1, s2, len);
+}
+
+#endif /* SIMD */
+
+static inline int SCBufferCmp(const void *s1, size_t len1, const void *s2, size_t len2)
+{
+ if (len1 == len2) {
+ return SCMemcmp(s1, s2, len1);
+ } else if (len1 < len2) {
+ return -1;
+ }
+ return 1;
+}
+
+#endif /* __UTIL_MEMCMP_H__ */
+
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