ongrep

commit 918cf7ce2514d73f545f84bbad5a6ca1fc7316cf
parent a98d946d5e7464b29c91c818ec5e50d7a8197c47
Author: Stephen Gregoratto <dev@sgregoratto.me>
Date:   Wed,  1 Jul 2020 10:36:32 +1000

bin_match_func: Replace rolling memcmp with memmem

Diffstat:
M
ngrep.c
 | 
19
+++++++++----------

1 file changed, 9 insertions(+), 10 deletions(-)
diff --git a/ngrep.c b/ngrep.c
@@ -910,24 +910,23 @@ bin_match_func(unsigned char *data, uint32_t len, uint16_t *mindex,
 	       uint16_t *msize)
 {
 	int32_t stop = len - match_len;
-	int32_t i = 0;
+	unsigned char *p;
 
 	if (stop < 0)
 		return 0;
 
-	while (i <= stop) {
-		if (!memcmp(data + (i++), bin_data, match_len)) {
-			matches++;
+	if ((p = memmem(data, len, bin_data, match_len)) != NULL) {
+		matches++;
 
-			if (match_after && keep_matching != match_after)
-				keep_matching = match_after;
+		if (match_after && keep_matching != match_after)
+			keep_matching = match_after;
 
-			*mindex = i - 1;
-			*msize = match_len;
+		*mindex = (uint16_t)(p - data);
+		*msize = match_len;
 
-			return 1;
-		}
+		return 1;
 	}
+
 	return 0;
 }