db_sqlite raw queries: Fix unnecessary lowercase restriction

The code was searching for the " from " string chunk in the query but
in a case-sensitive manner (??), causing formatted queries (e.g. " FROM
") to fail.

Credits to Eric Tamme (@etamme) for spotting and reporting the issue

Fixes #3409

(cherry picked from commit 388d4fa)

modules/db_sqlite/dbase.c

@@ -93,7 +93,7 @@ static inline int db_copy_rest_of_count(const str* _qh, str* count_query)
 	const str searched_str = {" from ", sizeof(" from ")-1};
 
 	count_query->len = sizeof(COUNT_QUERY)-1;
-	if ((found=str_strstr(_qh, &searched_str)) != NULL) {
+	if ((found=str_strcasestr(_qh, &searched_str)) != NULL) {
 		const int len=_qh->len-(found-_qh->s);
 		/* check for overflow */
 		if (len > COUNT_BUF_SIZE-(sizeof(COUNT_QUERY)-1)) {

test/test_ut.c

@@ -45,4 +45,37 @@ void test_ut(void)
 	ok(_is_e164(_str("+123456789012345"), 0, 15) == 1, "test-e164-17");
 	ok(_is_e164(_str("+1234567890123456"), 0, 15) == -1, "test-e164-18");
 	ok(_is_e164(_str("123456789x12345"), 0, 15) == -1, "test-e164-19");
+
+	/* str_strcasestr() tests */
+	{
+		struct {
+			str a;
+			str b;
+			int ok_offset;
+		} tests[] = {
+			{str_init(""), str_init(""), -1},
+			{str_init(""), str_init("x"), -1},
+			{str_init("x"), str_init(""), -1},
+			{str_init("x"), str_init("x"), 0},
+			{str_init("xy"), str_init("x"), 0},
+			{str_init("yx"), str_init("x"), 1},
+			{str_init("yxy"), str_init("x"), 1},
+			{str_init("foo"), str_init("bar"), -1},
+			{str_init("foobar"), str_init("BAR"), 3},
+			{str_init("fooBaRx"), str_init("bAr"), 3},
+			{str_init("fbaRx"), str_init("bar"), 1},
+			{str_init("barx"), str_init("Bar"), 0},
+			{str_init("Bar"), str_init("baR"), 0},
+			{str_init("foo"), str_init("foobar"), -1},
+		};
+		int i;
+
+		for (i = 0; i < sizeof(tests)/sizeof(tests[0]); i++) {
+			char *p = str_strcasestr(&tests[i].a, &tests[i].b);
+			if (tests[i].ok_offset < 0)
+				ok(!p, "test-str_strcasestr-%d", i);
+			else
+				ok(p == (tests[i].a.s + tests[i].ok_offset), "test-str_strcasestr-%d", i);
+		}
+	}
 }

ut.h

@@ -1176,6 +1176,48 @@ static inline char* str_strstr(const str *stra, const str *strb)
 	return NULL;
 }
 
+/*
+ * search @strb in @stra ignoring case of both, return pointer to 1st occurrence
+ */
+static inline char* str_strcasestr(const str *stra, const str *strb)
+{
+	int i;
+	int len;
+
+	if (stra==NULL || strb==NULL || stra->s==NULL || strb->s==NULL
+			|| stra->len<=0 || strb->len<=0) {
+#ifdef EXTRA_DEBUG
+		LM_DBG("bad parameters\n");
+#endif
+		return NULL;
+	}
+
+	if (strb->len > stra->len)
+		return NULL;
+
+	len=0;
+	while (stra->len-len >= strb->len){
+		if (tolower(stra->s[len]) != tolower(strb->s[0])) {
+			len++;
+			continue;
+		}
+
+		for (i=1; i<strb->len; i++)
+			if (tolower(stra->s[len+i])!=tolower(strb->s[i])) {
+				len++;
+				break;
+			}
+
+		if (i != strb->len)
+			continue;
+
+		return stra->s+len;
+	}
+
+
+	return NULL;
+}
+
 /*
  * case-insensitive compare n chars of two str's
  */