From: Daniel Salzman <daniel.salzman@nic.cz>
Date: Tue, 25 Feb 2020 10:49:42 +0000 (+0100)
Subject: libknot/xdp: extend filter configuration with DROP mode
X-Git-Tag: embedded_lmdb~35^2~41
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=f4d8d7c689cc6a05d9d719a882bef2a2e80cbbca;p=thirdparty%2Fknot-dns.git

libknot/xdp: extend filter configuration with DROP mode
---

diff --git a/src/libknot/xdp/af_xdp.c b/src/libknot/xdp/af_xdp.c
index 03a943f05b..e254535055 100644
--- a/src/libknot/xdp/af_xdp.c
+++ b/src/libknot/xdp/af_xdp.c
@@ -587,7 +587,7 @@ void knot_xsk_free_recvd(struct knot_xsk_socket *socket, const knot_xsk_msg_t ms
 
 _public_
 int knot_xsk_init(struct knot_xsk_socket **socket, const char *ifname, int if_queue,
-                  int listen_port, knot_xsk_load_bpf_t load_bpf)
+                  uint32_t listen_port, knot_xsk_load_bpf_t load_bpf)
 {
 	if (socket == NULL || *socket != NULL) {
 		return KNOT_EINVAL;
diff --git a/src/libknot/xdp/af_xdp.h b/src/libknot/xdp/af_xdp.h
index 0a0041926a..fe4a5657c1 100644
--- a/src/libknot/xdp/af_xdp.h
+++ b/src/libknot/xdp/af_xdp.h
@@ -21,6 +21,12 @@
 
 #include <sys/socket.h>
 
+enum {
+	KNOT_XDP_LISTEN_PORT_MASK = 0xFFFF0000, /*!< Listen port option mask. */
+	KNOT_XDP_LISTEN_PORT_ALL  = 1 << 16,    /*!< Listen on all ports. */
+	KNOT_XDP_LISTEN_PORT_DROP = 1 << 17,    /*!< Drop all incoming messages. */
+};
+
 /*! \brief A packet with src & dst MAC & IP addrs + UDP payload. */
 typedef struct {
 	struct sockaddr_storage ip_from;
@@ -52,13 +58,13 @@ struct knot_xsk_socket;
  * \param socket        Socket ctx; call with *socket == NULL.
  * \param ifname        Name of the net iface (e.g. eth0).
  * \param if_queue      Network card queue to be used (normally 1 socket per each queue).
- * \param listen_port   Port to listen on, or (1 << 16) to listen on all ports.
+ * \param listen_port   Port to listen on, or KNOT_XSK_LISTEN_PORT_ flag.
  * \param load_bpf      Insert BPF program into packet processing.
  *
  * \return KNOT_E*
  */
 int knot_xsk_init(struct knot_xsk_socket **socket, const char *ifname, int if_queue,
-                  int listen_port, knot_xsk_load_bpf_t load_bpf);
+                  uint32_t listen_port, knot_xsk_load_bpf_t load_bpf);
 
 /*! \brief De-init XDP socket. */
 void knot_xsk_deinit(struct knot_xsk_socket *socket);
diff --git a/src/libknot/xdp/bpf-kernel-obj.c b/src/libknot/xdp/bpf-kernel-obj.c
index a055759404..9fbbf4a853 100644
--- a/src/libknot/xdp/bpf-kernel-obj.c
+++ b/src/libknot/xdp/bpf-kernel-obj.c
@@ -7,13 +7,13 @@ unsigned char bpf_kernel_o[] = {
   0x07, 0x00, 0x01, 0x00, 0xb7, 0x00, 0x00, 0x00, 0x02, 0x00, 0x00, 0x00,
   0x61, 0x12, 0x04, 0x00, 0x00, 0x00, 0x00, 0x00, 0x61, 0x13, 0x00, 0x00,
   0x00, 0x00, 0x00, 0x00, 0xbf, 0x36, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-  0x07, 0x06, 0x00, 0x00, 0x0e, 0x00, 0x00, 0x00, 0x2d, 0x26, 0x3b, 0x00,
+  0x07, 0x06, 0x00, 0x00, 0x0e, 0x00, 0x00, 0x00, 0x2d, 0x26, 0x3f, 0x00,
   0x00, 0x00, 0x00, 0x00, 0x71, 0x35, 0x0c, 0x00, 0x00, 0x00, 0x00, 0x00,
   0x71, 0x34, 0x0d, 0x00, 0x00, 0x00, 0x00, 0x00, 0x67, 0x04, 0x00, 0x00,
   0x08, 0x00, 0x00, 0x00, 0x4f, 0x54, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-  0x15, 0x04, 0x0f, 0x00, 0x86, 0xdd, 0x00, 0x00, 0x55, 0x04, 0x35, 0x00,
+  0x15, 0x04, 0x0f, 0x00, 0x86, 0xdd, 0x00, 0x00, 0x55, 0x04, 0x39, 0x00,
   0x08, 0x00, 0x00, 0x00, 0xbf, 0x34, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-  0x07, 0x04, 0x00, 0x00, 0x22, 0x00, 0x00, 0x00, 0x2d, 0x24, 0x32, 0x00,
+  0x07, 0x04, 0x00, 0x00, 0x22, 0x00, 0x00, 0x00, 0x2d, 0x24, 0x36, 0x00,
   0x00, 0x00, 0x00, 0x00, 0xb7, 0x07, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
   0x69, 0x34, 0x14, 0x00, 0x00, 0x00, 0x00, 0x00, 0x47, 0x04, 0x00, 0x00,
   0x40, 0x00, 0x00, 0x00, 0x15, 0x04, 0x01, 0x00, 0x40, 0x00, 0x00, 0x00,
@@ -23,78 +23,78 @@ unsigned char bpf_kernel_o[] = {
   0x00, 0x00, 0x00, 0x00, 0x71, 0x34, 0x17, 0x00, 0x00, 0x00, 0x00, 0x00,
   0x05, 0x00, 0x0b, 0x00, 0x00, 0x00, 0x00, 0x00, 0xbf, 0x36, 0x00, 0x00,
   0x00, 0x00, 0x00, 0x00, 0x07, 0x06, 0x00, 0x00, 0x36, 0x00, 0x00, 0x00,
-  0x2d, 0x26, 0x24, 0x00, 0x00, 0x00, 0x00, 0x00, 0xb7, 0x07, 0x00, 0x00,
+  0x2d, 0x26, 0x28, 0x00, 0x00, 0x00, 0x00, 0x00, 0xb7, 0x07, 0x00, 0x00,
   0x00, 0x00, 0x00, 0x00, 0x71, 0x34, 0x14, 0x00, 0x00, 0x00, 0x00, 0x00,
   0x55, 0x04, 0x05, 0x00, 0x2c, 0x00, 0x00, 0x00, 0x07, 0x03, 0x00, 0x00,
-  0x3e, 0x00, 0x00, 0x00, 0x2d, 0x23, 0x1f, 0x00, 0x00, 0x00, 0x00, 0x00,
+  0x3e, 0x00, 0x00, 0x00, 0x2d, 0x23, 0x23, 0x00, 0x00, 0x00, 0x00, 0x00,
   0xb7, 0x07, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x71, 0x64, 0x00, 0x00,
   0x00, 0x00, 0x00, 0x00, 0xbf, 0x36, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-  0x55, 0x04, 0x1b, 0x00, 0x11, 0x00, 0x00, 0x00, 0xbf, 0x63, 0x00, 0x00,
+  0x55, 0x04, 0x1f, 0x00, 0x11, 0x00, 0x00, 0x00, 0xbf, 0x63, 0x00, 0x00,
   0x00, 0x00, 0x00, 0x00, 0x07, 0x03, 0x00, 0x00, 0x08, 0x00, 0x00, 0x00,
-  0x2d, 0x23, 0x18, 0x00, 0x00, 0x00, 0x00, 0x00, 0x61, 0x11, 0x10, 0x00,
+  0x2d, 0x23, 0x1c, 0x00, 0x00, 0x00, 0x00, 0x00, 0x61, 0x11, 0x10, 0x00,
   0x00, 0x00, 0x00, 0x00, 0x63, 0x1a, 0xfc, 0xff, 0x00, 0x00, 0x00, 0x00,
   0xbf, 0xa2, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x07, 0x02, 0x00, 0x00,
   0xfc, 0xff, 0xff, 0xff, 0x18, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
   0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x85, 0x00, 0x00, 0x00,
   0x01, 0x00, 0x00, 0x00, 0xbf, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-  0xb7, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x15, 0x01, 0x0e, 0x00,
-  0x00, 0x00, 0x00, 0x00, 0x61, 0x11, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-  0xbf, 0x12, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x57, 0x02, 0x00, 0x00,
-  0x00, 0x00, 0x01, 0x00, 0x55, 0x02, 0x03, 0x00, 0x00, 0x00, 0x00, 0x00,
-  0xb7, 0x00, 0x00, 0x00, 0x02, 0x00, 0x00, 0x00, 0x69, 0x62, 0x02, 0x00,
-  0x00, 0x00, 0x00, 0x00, 0x5d, 0x21, 0x07, 0x00, 0x00, 0x00, 0x00, 0x00,
-  0xb7, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x55, 0x07, 0x05, 0x00,
-  0x00, 0x00, 0x00, 0x00, 0x61, 0xa2, 0xfc, 0xff, 0x00, 0x00, 0x00, 0x00,
-  0x18, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-  0x00, 0x00, 0x00, 0x00, 0xb7, 0x03, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-  0x85, 0x00, 0x00, 0x00, 0x33, 0x00, 0x00, 0x00, 0x95, 0x00, 0x00, 0x00,
-  0x00, 0x00, 0x00, 0x00, 0x02, 0x00, 0x00, 0x00, 0x04, 0x00, 0x00, 0x00,
-  0x04, 0x00, 0x00, 0x00, 0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-  0x11, 0x00, 0x00, 0x00, 0x04, 0x00, 0x00, 0x00, 0x04, 0x00, 0x00, 0x00,
-  0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+  0xb7, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x15, 0x01, 0x12, 0x00,
+  0x00, 0x00, 0x00, 0x00, 0xb7, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00,
+  0x61, 0x11, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x18, 0x03, 0x00, 0x00,
+  0x00, 0x00, 0xff, 0xff, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+  0xbf, 0x12, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x5f, 0x32, 0x00, 0x00,
+  0x00, 0x00, 0x00, 0x00, 0x15, 0x02, 0x04, 0x00, 0x00, 0x00, 0x01, 0x00,
+  0x15, 0x02, 0x0a, 0x00, 0x00, 0x00, 0x02, 0x00, 0xb7, 0x00, 0x00, 0x00,
+  0x02, 0x00, 0x00, 0x00, 0x69, 0x62, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00,
+  0x5d, 0x21, 0x07, 0x00, 0x00, 0x00, 0x00, 0x00, 0xb7, 0x00, 0x00, 0x00,
+  0x01, 0x00, 0x00, 0x00, 0x55, 0x07, 0x05, 0x00, 0x00, 0x00, 0x00, 0x00,
+  0x61, 0xa2, 0xfc, 0xff, 0x00, 0x00, 0x00, 0x00, 0x18, 0x01, 0x00, 0x00,
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+  0xb7, 0x03, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x85, 0x00, 0x00, 0x00,
+  0x33, 0x00, 0x00, 0x00, 0x95, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
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-  0x11, 0x00, 0x05, 0x00, 0x14, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
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-  0x70, 0x5f, 0x72, 0x65, 0x64, 0x69, 0x72, 0x65, 0x63, 0x74, 0x5f, 0x75,
-  0x64, 0x70, 0x5f, 0x66, 0x75, 0x6e, 0x63, 0x00, 0x62, 0x70, 0x66, 0x2d,
-  0x6b, 0x65, 0x72, 0x6e, 0x65, 0x6c, 0x2e, 0x63, 0x00, 0x2e, 0x73, 0x74,
-  0x72, 0x74, 0x61, 0x62, 0x00, 0x2e, 0x73, 0x79, 0x6d, 0x74, 0x61, 0x62,
-  0x00, 0x4c, 0x42, 0x42, 0x30, 0x5f, 0x31, 0x38, 0x00, 0x4c, 0x42, 0x42,
-  0x30, 0x5f, 0x37, 0x00, 0x4c, 0x42, 0x42, 0x30, 0x5f, 0x36, 0x00, 0x4c,
-  0x42, 0x42, 0x30, 0x5f, 0x31, 0x36, 0x00, 0x4c, 0x42, 0x42, 0x30, 0x5f,
-  0x31, 0x31, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x59, 0x00, 0x00, 0x00,
   0x03, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x88, 0x03, 0x00, 0x00,
-  0x00, 0x00, 0x00, 0x00, 0x8f, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x90, 0x03, 0x00, 0x00,
+  0x00, 0x00, 0x00, 0x00, 0x82, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
   0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00,
   0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
   0x01, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x06, 0x00, 0x00, 0x00,
@@ -105,24 +105,24 @@ unsigned char bpf_kernel_o[] = {
   0x00, 0x00, 0x00, 0x00, 0x10, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00,
   0x06, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
   0x00, 0x00, 0x00, 0x00, 0x40, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-  0x10, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+  0x30, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
   0x00, 0x00, 0x00, 0x00, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
   0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x0c, 0x00, 0x00, 0x00,
   0x09, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x68, 0x03, 0x00, 0x00,
+  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x70, 0x03, 0x00, 0x00,
   0x00, 0x00, 0x00, 0x00, 0x20, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
   0x06, 0x00, 0x00, 0x00, 0x03, 0x00, 0x00, 0x00, 0x08, 0x00, 0x00, 0x00,
   0x00, 0x00, 0x00, 0x00, 0x10, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
   0x07, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x03, 0x00, 0x00, 0x00,
   0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-  0x50, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x28, 0x00, 0x00, 0x00,
+  0x70, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x28, 0x00, 0x00, 0x00,
   0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
   0x04, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-  0x00, 0x00, 0x00, 0x00, 0x61, 0x00, 0x00, 0x00, 0x02, 0x00, 0x00, 0x00,
+  0x00, 0x00, 0x00, 0x00, 0x54, 0x00, 0x00, 0x00, 0x02, 0x00, 0x00, 0x00,
   0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-  0x00, 0x00, 0x00, 0x00, 0x78, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-  0xf0, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00,
-  0x07, 0x00, 0x00, 0x00, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+  0x00, 0x00, 0x00, 0x00, 0x98, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+  0xd8, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00,
+  0x06, 0x00, 0x00, 0x00, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
   0x18, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
 };
 unsigned int bpf_kernel_o_len = 1496;
diff --git a/src/libknot/xdp/bpf-kernel.c b/src/libknot/xdp/bpf-kernel.c
index 74e1d5163c..485b081ce0 100644
--- a/src/libknot/xdp/bpf-kernel.c
+++ b/src/libknot/xdp/bpf-kernel.c
@@ -46,16 +46,17 @@ struct ipv6_frag_hdr {
 	unsigned char whatever[7];
 } __attribute__((packed));
 
+/* NOTE: this implementation expects little-endian byte ordering! */
 SEC("xdp_redirect_udp")
 int xdp_redirect_udp_func(struct xdp_md *ctx)
 {
-	void *data = (void *)(long)ctx->data;
-	void *data_end = (void *)(long)ctx->data_end;
+	const void *data = (void *)(long)ctx->data;
+	const void *data_end = (void *)(long)ctx->data_end;
 
-	struct ethhdr *eth = data;
-	struct iphdr *ip4;
-	struct ipv6hdr *ip6;
-	struct udphdr *udp;
+	const struct ethhdr *eth = data;
+	const struct iphdr *ip4;
+	const struct ipv6hdr *ip6;
+	const struct udphdr *udp;
 
 	__u8 ip_proto;
 	__u8 fragmented = 0;
@@ -88,7 +89,7 @@ int xdp_redirect_udp_func(struct xdp_md *ctx)
 			data += sizeof(*ip6);
 			if (ip_proto == IPPROTO_FRAGMENT) {
 				fragmented = 1;
-				struct ipv6_frag_hdr *frag = data;
+				const struct ipv6_frag_hdr *frag = data;
 				if ((void *)frag + sizeof(*frag) > data_end) {
 					return XDP_PASS;
 				}
@@ -117,10 +118,17 @@ int xdp_redirect_udp_func(struct xdp_md *ctx)
 		return XDP_ABORTED;
 	}
 
-	/* Treat destination (DNS) port only. */
+	/* Treat specified destination ports only. */
 	__u32 port_info = *qidconf;
-	if (!(port_info & (1 << 16)) && udp->dest != port_info) {
-		return XDP_PASS;
+	switch (port_info & 0xFFFF0000) {
+	case (1 << 17):
+		return XDP_DROP;
+	case (1 << 16):
+		break;
+	default:
+		if (udp->dest != port_info) {
+			return XDP_PASS;
+		}
 	}
 
 	/* Drop fragmented UDP datagrams. */
diff --git a/src/utils/xdp-gun/main.c b/src/utils/xdp-gun/main.c
index 641717af04..d7d921a3f7 100644
--- a/src/utils/xdp-gun/main.c
+++ b/src/utils/xdp-gun/main.c
@@ -51,6 +51,8 @@ uint64_t global_size_recv = 0;
 #define LOCAL_PORT_MIN  1024
 #define LOCAL_PORT_MAX 65535
 
+#define LISTEN_PORT	KNOT_XDP_LISTEN_PORT_ALL
+
 typedef struct {
 	char		dev[IFNAMSIZ];
 	uint64_t	qps, duration;
@@ -140,12 +142,12 @@ void *dns_xdp_gun_thread(void *_ctx)
 	uint64_t tot_sent = 0, tot_recv = 0, tot_size = 0;
 	uint64_t duration = 0;
 
-	int ret = knot_xsk_init(&xsk, ctx->dev, ctx->thread_id, (1 << 16), ctx->thread_id == 0);
+	int ret = knot_xsk_init(&xsk, ctx->dev, ctx->thread_id, LISTEN_PORT, ctx->thread_id == 0);
 	if (ret != KNOT_EOK) {
 		printf("failed to init XDP socket#%u: %s\n", ctx->thread_id, knot_strerror(ret));
 		return NULL;
 	}
-	
+
 	struct pollfd pfd = { knot_xsk_get_poll_fd(xsk), POLLIN, 0 };
 
 	while (!dns_xdp_trigger) {
@@ -159,7 +161,7 @@ void *dns_xdp_gun_thread(void *_ctx)
 	timer_start(&timer);
 
 	while (duration < ctx->duration + 1000000) {
-		
+
 		// sending part
 		if (duration < ctx->duration) {
 			ret = alloc_pkts(pkts, ctx->at_once, xsk, ctx, tick, &payload_ptr);
@@ -199,7 +201,7 @@ void *dns_xdp_gun_thread(void *_ctx)
 			if (!pfd.revents) {
 				break;
 			}
-			
+
 			uint32_t recvd = 0;
 			ret = knot_xsk_recvmmsg(xsk, pkts, ctx->at_once, &recvd);
 			if (ret != KNOT_EOK) {
@@ -247,7 +249,7 @@ static int dev2mac(const char *dev, uint8_t *mac)
 		return -errno;
 	}
 	strncpy(ifr.ifr_name, dev, IFNAMSIZ);
-	
+
 	int ret = ioctl(fd, SIOCGIFHWADDR, &ifr);
 	if (ret >= 0) {
 		memcpy(mac, ifr.ifr_hwaddr.sa_data, 6);
@@ -375,7 +377,7 @@ int main(int argc, char *argv[])
 		} else {
 			goto pusage;
 		}
-		
+
 		double argf = atof(argv[2]);
 		if (argf > 0) {
 			ctx.duration = argf * 1000000.0;
@@ -457,7 +459,7 @@ int main(int argc, char *argv[])
 	} else {
 		goto pusage;
 	}
-	
+
 	struct rlimit no_limit = { RLIM_INFINITY, RLIM_INFINITY };
 	int ret = setrlimit(RLIMIT_MEMLOCK, &no_limit);
 	if (ret) {