perf: use ncase memem

Signed-off-by: Zxilly <[email protected]>

src/ua2f.c

@@ -51,6 +51,33 @@ char *str = NULL;
 
 static struct ipset *Pipset;
 
+void *memncasemem(const void *l, size_t l_len, const void *s, size_t s_len) {
+    register char *cur, *last;
+    const char *cl = (const char *) l;
+    const char *cs = (const char *) s;
+
+    /* we need something to compare */
+    if (l_len == 0 || s_len == 0)
+        return NULL;
+
+    /* "s" must be smaller or equal to "l" */
+    if (l_len < s_len)
+        return NULL;
+
+    /* special case where s_len == 1 */
+    if (s_len == 1)
+        return memchr(l, (int) *cs, l_len);
+
+    /* the last position where its possible to find "s" in "l" */
+    last = (char *) cl + l_len - s_len;
+
+    for (cur = (char *) cl; cur <= last; cur++)
+        if (cur[0] == cs[0] && strncasecmp(cur, cs, s_len) == 0)
+            return cur;
+
+    return NULL;
+}
+
 static char *time2str(int sec) {
     memset(timestr, 0, sizeof(timestr));
     if (sec <= 60) {
@@ -258,15 +285,15 @@ static int queue_cb(const struct nlmsghdr *nlh, void *data) {
     tcppklen = nfq_tcp_get_payload_len(tcppkhdl, pktb); //获取 tcp长度
 
     if (tcppkpayload) {
-        char *uapointer = memmem(tcppkpayload, tcppklen, "\r\nUser", 6);
-        if (uapointer) {
+        char *uapointer = memncasemem(tcppkpayload, tcppklen, "\r\nUser-Agent:", 13);
+/*        if (uapointer) {
             uapointer = memmem(tcppkpayload, tcppklen, "\r\nUser-Agent:", 13);
             if (!uapointer) {
                 uapointer = memmem(tcppkpayload, tcppklen, "\r\nUser-agent:", 13);
             }
         } else {
             uapointer = memmem(tcppkpayload, tcppklen, "\r\nuser-agent:", 13);
-        }
+        }*/
 
         if (uapointer) {
             uaoffset = uapointer - tcppkpayload + 14;