Add rule match log

ReadMe.md

@@ -123,6 +123,7 @@ rtt min/avg/max/mdev = 5.954/6.133/6.313/0.195 ms
 
 openwrt系统CPU架构比较多，请查看CPU架构后下载，CPU架构可在路由器管理界面找到，查看方法：
 * 登录路由器，点击`System`->`Software`，点击`Configuration` Tab页面，在opkg安装源中可找到对应软件架构，下载路径中可找到，如下，架构为ar71xx
+
 ```
 src/gz chaos_calmer_base http://downloads.openwrt.org/chaos_calmer/15.05/ar71xx/generic/packages/base
 ```
@@ -133,20 +134,27 @@ src/gz chaos_calmer_base http://downloads.openwrt.org/chaos_calmer/15.05/ar71xx/
 --------------
 1. 安装
 下载配套安装包`smartdns.xxxxxxxx.armhf.deb`，并上传到Linux系统中。 执行如下命令安装
+
 ```
 dpkg -i smartdns.xxxxxxxx.armhf.deb
 ```
+
 2. 修改配置
 安装完成后，可配置smartdns的上游服务器信息。具体配置参数参考`配置参数`说明。  
 一般情况下，只需要增加`server [IP]:port`, `server-tcp [IP]:port`配置项
+尽可能配置多个上游DNS服务器，包括国内外的服务器。
+
 ```
 vi /etc/smartdns/smartdns.conf
 ```
+
 3. 启动服务
+
 ```
 systemctl enable smartdns
 systemctl start smartdns
 ```
+
 4. 将DNS请求转发的SmartDNS解析。  
 修改本地路由器的DNS服务器，将DNS服务器配置为SmartDNS。 
 * 登录到本地网络的路由器中，配置树莓派分配静态IP地址。
@@ -189,6 +197,7 @@ opkg install luci-app-smartdns.xxxxxxxx.xxxx.all.ipk
 
 4. 检测服务是否配置成功。  
 使用nslookup查询域名，看命令结果中的`服务器`项目是否显示为`Linux主机名`，如`smartdns`则表示生效  
+
 ```
 C:\Users\meikechong>nslookup www.baidu.com  
 服务器:  smartdns  
@@ -220,6 +229,7 @@ SSH登录用户名密码与管理界面相同。
 
 3. 安装SmartDNS
 将软件使用winscp上传到路由器的`/tmp/mnt/sda1`目录。（或网上邻居复制到sda1共享目录） 
+ 
 ```
 ipkg install smartdns.xxxxxxx.mipsbig.ipk
 ```

src/dns_server.c

@@ -741,11 +741,22 @@ errout:
 	return -1;
 }
 
+static void _dns_server_log_rule(char *domain, unsigned char *rule_key, int rule_key_len)
+{
+	char rule_name[DNS_MAX_CNAME_LEN];
+	reverse_string(rule_name, (char *)rule_key, rule_key_len);
+	rule_name[rule_key_len - 1] = 0;
+	tlog(TLOG_INFO, "RULE-MATCH, domain: %s, rule: %s", domain, rule_name);
+}
+
 static struct dns_address *_dns_server_get_address_by_domain(char *domain, int qtype)
 {
 	int domain_len;
 	char domain_key[DNS_MAX_CNAME_LEN];
 	char type = '4';
+	unsigned char matched_key[DNS_MAX_CNAME_LEN];
+	int matched_key_len = DNS_MAX_CNAME_LEN;
+	struct dns_address *address = NULL;
 
 	switch (qtype) {
 	case DNS_T_A:
@@ -763,7 +774,18 @@ static struct dns_address *_dns_server_get_address_by_domain(char *domain, int q
 	domain_key[0] = type;
 	domain_len++;
 
-	return art_substring(&dns_conf_address, (unsigned char *)domain_key, domain_len);
+	if (likely(dns_conf_log_level > TLOG_INFO)) {
+		return art_substring(&dns_conf_address, (unsigned char *)domain_key, domain_len, NULL, NULL);
+	} 
+		
+	address = art_substring(&dns_conf_address, (unsigned char *)domain_key, domain_len, matched_key, &matched_key_len);
+	if (address == NULL) {
+		return NULL;
+	}
+
+	_dns_server_log_rule(domain, matched_key, matched_key_len);
+
+	return address;
 }
 
 static int _dns_server_process_address(struct dns_request *request, struct dns_packet *packet)

src/include/art.h

@@ -193,7 +193,7 @@ void* art_search(const art_tree *t, const unsigned char *key, int key_len);
  * @return NULL if the item was not found, otherwise
  * the value pointer is returned.
  */
-void *art_substring(const art_tree *t, const unsigned char *str, int str_len);
+void *art_substring(const art_tree *t, const unsigned char *str, int str_len, unsigned char *key, int *key_len);
 
 /**
  * Returns the minimum valued leaf

src/lib/art.c

@@ -998,7 +998,20 @@ static int str_prefix_matches(const art_leaf *n, const unsigned char *str, int s
     return memcmp(str, n->key, n->key_len);
 }
 
-void *art_substring(const art_tree *t, const unsigned char *str, int str_len)
+static void art_copy_key(art_leaf *leaf, unsigned char *key, int *key_len)
+{
+	int len;
+
+    if (key == NULL || key_len == NULL) {
+		return;
+	}
+
+	len = leaf->key_len > *key_len ? *key_len : leaf->key_len;
+	memcpy(key, leaf->key, len);
+	*key_len = len;
+}
+
+void *art_substring(const art_tree *t, const unsigned char *str, int str_len, unsigned char *key, int *key_len)
 {
     art_node **child;
     art_node *n = t->root;
@@ -1013,6 +1026,7 @@ void *art_substring(const art_tree *t, const unsigned char *str, int str_len)
             // Check if the expanded path matches
             if (!str_prefix_matches((art_leaf*)n, str, str_len)) {
                 found = (art_leaf*)n;
+				art_copy_key(found, key, key_len);
 			}
             break;
         }
@@ -1025,6 +1039,7 @@ void *art_substring(const art_tree *t, const unsigned char *str, int str_len)
             // Check if the expanded path matches
             if (!str_prefix_matches((art_leaf*)m, str, str_len)) {
                 found = (art_leaf*)m;
+                art_copy_key(found, key, key_len);
             }
     	}