log: set default log path to /var/log/smartdns/ and auto create directory

ReadMe.md

@@ -563,11 +563,11 @@ rtt min/avg/max/mdev = 5.954/6.133/6.313/0.195 ms
 | rr-ttl-reply-max | 允许返回给客户端的最大 TTL 值 | 远程查询结果 | 大于 0 的数字 | rr-ttl-reply-max 60 |
 | max-reply-ip-num | 允许返回给客户的最大IP数量 | IP数量 | 大于 0 的数字 | max-reply-ip-num 1 |
 | log-level | 设置日志级别 | error | fatal、error、warn、notice、info 或 debug | log-level error |
-| log-file | 日志文件路径 | /var/log/smartdns.log | 合法路径字符串 | log-file /var/log/smartdns.log |
+| log-file | 日志文件路径 | /var/log/smartdns/smartdns.log | 合法路径字符串 | log-file /var/log/smartdns/smartdns.log |
 | log-size | 日志大小 | 128K | 数字 + K、M 或 G | log-size 128K |
 | log-num | 日志归档个数 | 2 | 大于等于 0 的数字 | log-num 2 |
 | audit-enable | 设置审计启用 | no | [yes\|no] | audit-enable yes |
-| audit-file | 审计文件路径 | /var/log/smartdns-audit.log | 合法路径字符串 | audit-file /var/log/smartdns-audit.log |
+| audit-file | 审计文件路径 | /var/log/smartdns/smartdns-audit.log | 合法路径字符串 | audit-file /var/log/smartdns/smartdns-audit.log |
 | audit-size | 审计大小 | 128K | 数字 + K、M 或 G | audit-size 128K |
 | audit-num | 审计归档个数 | 2 | 大于等于 0 的数字 | audit-num 2 |
 | conf-file | 附加配置文件 | 无 | 合法路径字符串 | conf-file /etc/smartdns/smartdns.more.conf |

ReadMe_en.md

@@ -501,11 +501,11 @@ Note: Merlin firmware is derived from ASUS firmware and can theoretically be use
 |rr-ttl-max|Domain name Maximum TTL|Remote query result|number greater than 0|rr-ttl-max 600
 |max-reply-ip-num|Maximum number of IPs returned to the client|8|number of IPs, 1~16 |max-reply-ip-num 1
 |log-level|log level|error|fatal,error,warn,notice,info,debug|log-level error
-|log-file|log path|/var/log/smartdns.log|File Pah|log-file /var/log/smartdns.log
+|log-file|log path|/var/log/smartdns/smartdns.log|File Pah|log-file /var/log/smartdns/smartdns.log
 |log-size|log size|128K|number+K,M,G|log-size 128K
 |log-num|archived log number|2|Integer|log-num 2
 |audit-enable|audit log enable|no|[yes\|no]|audit-enable yes
-|audit-file|audit log file|/var/log/smartdns-audit.log|File Path|audit-file /var/log/smartdns-audit.log
+|audit-file|audit log file|/var/log/smartdns/smartdns-audit.log|File Path|audit-file /var/log/smartdns/smartdns-audit.log
 |audit-size|audit log size|128K|number+K,M,G|audit-size 128K
 |audit-num|archived audit log number|2|Integer|audit-num 2
 |conf-file|additional conf file|None|File path|conf-file /etc/smartdns/smartdns.more.conf

etc/smartdns/smartdns.conf

@@ -4,7 +4,7 @@
 #   server-name smartdns
 #
 
-# dns server run ser
+# dns server run user
 # user [username]
 # example: run as nobody
 #   user nobody
@@ -126,7 +126,7 @@ cache-size 16384
 # log-size: size of each log file, support k,m,g
 # log-num: number of logs
 log-level info
-# log-file /var/log/smartdns.log
+# log-file /var/log/smartdns/smartdns.log
 # log-size 128k
 # log-num 2
 

src/dns_conf.h

@@ -49,8 +49,8 @@ extern "C" {
 #define DEFAULT_DNS_HTTPS_PORT 443
 #define DNS_MAX_CONF_CNAME_LEN 256
 #define SMARTDNS_CONF_FILE "/etc/smartdns/smartdns.conf"
-#define SMARTDNS_LOG_FILE "/var/log/smartdns.log"
-#define SMARTDNS_AUDIT_FILE "/var/log/smartdns-audit.log"
+#define SMARTDNS_LOG_FILE "/var/log/smartdns/smartdns.log"
+#define SMARTDNS_AUDIT_FILE "/var/log/smartdns/smartdns-audit.log"
 #define SMARTDNS_CACHE_FILE "/tmp/smartdns.cache"
 
 enum domain_rule {

src/smartdns.c

@@ -114,8 +114,8 @@ static int drop_root_privilege(void)
 	prctl(PR_SET_KEEPCAPS, 1, 0, 0, 0);
 	cap.effective |= (1 << CAP_NET_RAW | 1 << CAP_NET_ADMIN);
 	cap.permitted |= (1 << CAP_NET_RAW | 1 << CAP_NET_ADMIN);
-	unused = setuid(uid);
 	unused = setgid(gid);
+	unused = setuid(uid);
 	if (capset(&header, &cap) < 0) {
 		return -1;
 	}
@@ -323,15 +323,22 @@ static int _smartdns_destroy_ssl(void)
 	return 0;
 }
 
-static int _smartdns_init(void)
+static const char *_smartdns_log_path(void)
 {
-	int ret = 0;
 	char *logfile = SMARTDNS_LOG_FILE;
 
 	if (dns_conf_log_file[0] != 0) {
 		logfile = dns_conf_log_file;
 	}
 
+	return logfile;
+}
+
+static int _smartdns_init(void)
+{
+	int ret = 0;
+	const char *logfile = _smartdns_log_path();
+
 	ret = tlog_init(logfile, dns_conf_log_size, dns_conf_log_num, 0, 0);
 	if (ret != 0) {
 		tlog(TLOG_ERROR, "start tlog failed.\n");
@@ -463,6 +470,43 @@ static void _reg_signal(void)
 	}
 }
 
+static int _smartdns_create_logdir(void)
+{
+	int uid = 0;
+	int gid = 0;
+	char logdir[PATH_MAX] = {0};
+	safe_strncpy(logdir, _smartdns_log_path(), PATH_MAX);
+	dirname(logdir);
+
+	if (access(logdir, F_OK) == 0) {
+		return 0;
+	}
+
+	if (mkdir(logdir, 0750) != 0) {
+		if (errno == EEXIST) {
+			return 0;
+		}
+
+		return -1;
+	}
+
+	int unused __attribute__((unused)) = 0;
+
+	if (get_uid_gid(&uid, &gid) != 0) {
+		return -1;
+	}
+
+	chown(logdir, uid, gid);
+	return 0;
+}
+
+static int _smartdns_init_pre(void)
+{
+	_smartdns_create_logdir();
+
+	return 0;
+}
+
 int main(int argc, char *argv[])
 {
 	int ret = 0;
@@ -531,6 +575,11 @@ int main(int argc, char *argv[])
 	signal(SIGINT, _sig_exit);
 	signal(SIGTERM, _sig_exit);
 
+	if (_smartdns_init_pre() != 0) {
+		fprintf(stderr, "init failed.\n");
+		return 1;
+	}
+
 	drop_root_privilege();
 
 	ret = _smartdns_init();