Fix crash bug

src/dns.c

@@ -1586,6 +1586,10 @@ static int _dns_decode_an(struct dns_context *context, dns_rr_type type)
 		dns_set_OPT_payload_size(packet, qclass);
 	} break;
 	default:
+		if (_dns_left_len(context) < rr_len) {
+			tlog(TLOG_DEBUG, "length mitchmatch\n");
+			return -1;
+		}
 		context->ptr += rr_len;
 		tlog(TLOG_DEBUG, "DNS type = %d not supported", qtype);
 		break;
@@ -1661,41 +1665,46 @@ static int _dns_decode_body(struct dns_context *context)
 	struct dns_head *head = &packet->head;
 	int i = 0;
 	int ret = 0;
+	int count = 0;
 
-	for (i = 0; i < head->qdcount; i++) {
+	count = head->qdcount;
+	head->qdcount = 0;
+	for (i = 0; i < count; i++) {
 		ret = _dns_decode_qd(context);
 		if (ret < 0) {
 			tlog(TLOG_DEBUG, "decode qd failed.");
 			return -1;
 		}
-		head->qdcount--;
 	}
 
-	for (i = 0; i < head->ancount; i++) {
+	count = head->ancount;
+	head->ancount = 0;
+	for (i = 0; i < count; i++) {
 		ret = _dns_decode_an(context, DNS_RRS_AN);
 		if (ret < 0) {
 			tlog(TLOG_DEBUG, "decode an failed.");
 			return -1;
 		}
-		head->ancount--;
 	}
 
-	for (i = 0; i < head->nscount; i++) {
+	count = head->nscount;
+	head->nscount = 0;
+	for (i = 0; i < count; i++) {
 		ret = _dns_decode_an(context, DNS_RRS_NS);
 		if (ret < 0) {
 			tlog(TLOG_DEBUG, "decode ns failed.");
 			return -1;
 		}
-		head->nscount--;
 	}
 
-	for (i = 0; i < head->nrcount; i++) {
+	count = head->nrcount;
+	head->nrcount = 0;
+	for (i = 0; i < count; i++) {
 		ret = _dns_decode_an(context, DNS_RRS_NR);
 		if (ret < 0) {
 			tlog(TLOG_DEBUG, "decode nr failed.");
 			return -1;
 		}
-		head->nrcount--;
 	}
 
 	return 0;

src/dns_client.c

@@ -986,7 +986,7 @@ static int _dns_client_socket_ssl_send(SSL *ssl, const void *buf, int num)
 	}
 
 	ret = SSL_write(ssl, buf, num);
-	if (ret > 0) {
+	if (ret >= 0) {
 		return ret;
 	}
 
@@ -1131,7 +1131,7 @@ static int _dns_client_process_tcp(struct dns_server_info *server_info, struct e
 				goto errout;
 			}
 
-			tlog(TLOG_ERROR, "recv failed, %s, %d\n", strerror(errno), errno);
+			tlog(TLOG_ERROR, "recv failed, %s\n", strerror(errno));
 			goto errout;
 		}
 
@@ -1211,8 +1211,12 @@ static int _dns_client_process_tcp(struct dns_server_info *server_info, struct e
 			/* send data in send_buffer */
 			len = _dns_client_socket_send(server_info);
 			if (len < 0) {
+				if (errno == EAGAIN) {
+					pthread_mutex_unlock(&client.server_list_lock);
+					return 0;
+				}
 				pthread_mutex_unlock(&client.server_list_lock);
-				return -1;
+				goto errout;
 			}
 
 			server_info->send_buff.len -= len;
@@ -1233,7 +1237,7 @@ static int _dns_client_process_tcp(struct dns_server_info *server_info, struct e
 		event.data.ptr = server_info;
 		if (epoll_ctl(client.epoll_fd, EPOLL_CTL_MOD, server_info->fd, &event) != 0) {
 			tlog(TLOG_ERROR, "epoll ctl failed.");
-			return -1;
+			goto errout;
 		}
 
 		return 0;