From 1f07a7ea97bdb6067dedd723fe14c4b15e1cc526 Mon Sep 17 00:00:00 2001
From: Nick Peng <pymumu@gmail.com>
Date: Tue, 28 Jun 2022 22:01:14 +0800
Subject: [PATCH] log: make log happy when receiving malformd packet

---
 src/dns_server.c | 18 ++++++++++++------
 src/util.c       | 22 ++++++++++++++++++++++
 src/util.h       |  2 ++
 3 files changed, 36 insertions(+), 6 deletions(-)

diff --git a/src/dns_server.c b/src/dns_server.c
index a26d8c8..f4725dc 100644
--- a/src/dns_server.c
+++ b/src/dns_server.c
@@ -62,6 +62,7 @@
 #define RECV_ERROR_OK 0
 #define RECV_ERROR_FAIL -1
 #define RECV_ERROR_CLOSE -2
+#define RECV_ERROR_INVALID_PACKET -3
 
 typedef enum {
 	DNS_CONN_TYPE_UDP_SERVER = 0,
@@ -4000,11 +4001,12 @@ static int _dns_server_recv(struct dns_server_conn_head *conn, unsigned char *in
 	struct dns_request *request = NULL;
 
 	/* decode packet */
-	tlog(TLOG_DEBUG, "recv query packet from %s, len = %d",
-		 gethost_by_addr(name, sizeof(name), (struct sockaddr *)from), inpacket_len);
+	tlog(TLOG_DEBUG, "recv query packet from %s, len = %d, type = %d",
+		 gethost_by_addr(name, sizeof(name), (struct sockaddr *)from), inpacket_len, conn->type);
 	decode_len = dns_decode(packet, DNS_PACKSIZE, inpacket, inpacket_len);
 	if (decode_len < 0) {
 		tlog(TLOG_DEBUG, "decode failed.\n");
+		ret = RECV_ERROR_INVALID_PACKET;
 		goto errout;
 	}
 
@@ -4306,10 +4308,10 @@ static int _dns_server_tcp_process_one_request(struct dns_server_conn_tcp_client
 		request_data = (unsigned char *)(tcpclient->recvbuff.buf + proceed_len + sizeof(unsigned short));
 
 		/* process one record */
-		if (_dns_server_recv(&tcpclient->head, request_data, request_len, &tcpclient->localaddr,
-							 tcpclient->localaddr_len, &tcpclient->addr, tcpclient->addr_len) != 0) {
-			tlog(TLOG_ERROR, "process tcp request failed.");
-			return RECV_ERROR_FAIL;
+		ret = _dns_server_recv(&tcpclient->head, request_data, request_len, &tcpclient->localaddr,
+							   tcpclient->localaddr_len, &tcpclient->addr, tcpclient->addr_len);
+		if (ret != 0) {
+			return ret;
 		}
 
 		proceed_len += sizeof(unsigned short) + request_len;
@@ -4446,6 +4448,10 @@ static int _dns_server_process(struct dns_server_conn_head *conn, struct epoll_e
 	}
 	_dns_server_conn_release(conn);
 
+	if (ret == RECV_ERROR_INVALID_PACKET) {
+		ret = 0;
+	}
+
 	return ret;
 }
 
diff --git a/src/util.c b/src/util.c
index 79cec32..1fb0730 100644
--- a/src/util.c
+++ b/src/util.c
@@ -1098,3 +1098,25 @@ void print_stack(void)
 		tlog(TLOG_FATAL, "#%.2d: %p %s from %s+%p", idx + 1, addr, symbol, info.dli_fname, offset);
 	}
 }
+
+int write_file(const char *filename, void *data, int data_len)
+{
+	int fd = open(filename, O_WRONLY|O_CREAT, 0644);
+	if (fd < 0) {
+		return -1;
+	}
+
+	int len = write(fd, data, data_len);
+	if (len < 0) {
+		goto errout;
+	}
+
+	close(fd);
+	return 0;
+errout:
+	if (fd > 0) {
+		close(fd);
+	}
+
+	return -1;
+}
\ No newline at end of file
diff --git a/src/util.h b/src/util.h
index 7aa945b..98abbb6 100644
--- a/src/util.h
+++ b/src/util.h
@@ -112,6 +112,8 @@ uint64_t get_free_space(const char *path);
 
 void print_stack(void);
 
+int write_file(const char *filename, void *data, int data_len);
+
 #ifdef __cplusplus
 }
 #endif /*__cplusplus */