From f6bca70d1129bed95b198593bf83f248ff132205 Mon Sep 17 00:00:00 2001
From: Marian Buschsieweke <marian.buschsieweke@ovgu.de>
Date: Wed, 29 Jul 2020 10:56:07 +0200
Subject: [PATCH] sys/net/gnrc/netif/ethernet: Support RX timestamp

---
 drivers/include/net/netdev/eth.h              | 19 +++++++++++++++++++
 .../gnrc/netif/ethernet/gnrc_netif_ethernet.c |  9 +++++++--
 2 files changed, 26 insertions(+), 2 deletions(-)

diff --git a/drivers/include/net/netdev/eth.h b/drivers/include/net/netdev/eth.h
index 318a1897f5..7b57fa7b7e 100644
--- a/drivers/include/net/netdev/eth.h
+++ b/drivers/include/net/netdev/eth.h
@@ -29,6 +29,25 @@
 extern "C" {
 #endif
 
+/**
+ * @name    Flags for use in @ref netdev_eth_rx_info_t::flags
+ * @{
+ */
+#define NETDEV_ETH_RX_INFO_FLAG_TIMESTAMP       (0x01)  /**< Timestamp valid */
+/** @} */
+
+/**
+ * @brief   Received frame status information for Ethernet devices
+ */
+typedef struct {
+    /**
+     * @brief   Time of the reception of the start of frame delimiter in
+     *          nanoseconds since epoch
+     */
+    uint64_t timestamp;
+    uint8_t flags;      /**< Flags e.g. used to mark other fields as valid */
+} netdev_eth_rx_info_t;
+
 /**
  * @brief   Fallback function for netdev ethernet devices' _get function
  *
diff --git a/sys/net/gnrc/netif/ethernet/gnrc_netif_ethernet.c b/sys/net/gnrc/netif/ethernet/gnrc_netif_ethernet.c
index 2a629852ea..bc159a8549 100644
--- a/sys/net/gnrc/netif/ethernet/gnrc_netif_ethernet.c
+++ b/sys/net/gnrc/netif/ethernet/gnrc_netif_ethernet.c
@@ -21,6 +21,7 @@
 #include "net/ethernet/hdr.h"
 #include "net/gnrc.h"
 #include "net/gnrc/netif/ethernet.h"
+#include "net/netdev/eth.h"
 #ifdef MODULE_GNRC_IPV6
 #include "net/ipv6/hdr.h"
 #endif
@@ -169,8 +170,9 @@ static int _send(gnrc_netif_t *netif, gnrc_pktsnip_t *pkt)
 static gnrc_pktsnip_t *_recv(gnrc_netif_t *netif)
 {
     netdev_t *dev = netif->dev;
-    int bytes_expected = dev->driver->recv(dev, NULL, 0, NULL);
     gnrc_pktsnip_t *pkt = NULL;
+    netdev_eth_rx_info_t rx_info = { .flags = 0 };
+    int bytes_expected = dev->driver->recv(dev, NULL, 0, NULL);
 
     if (bytes_expected > 0) {
         pkt = gnrc_pktbuf_add(NULL, NULL,
@@ -186,7 +188,7 @@ static gnrc_pktsnip_t *_recv(gnrc_netif_t *netif)
             goto out;
         }
 
-        int nread = dev->driver->recv(dev, pkt->data, bytes_expected, NULL);
+        int nread = dev->driver->recv(dev, pkt->data, bytes_expected, &rx_info);
         if (nread <= 0) {
             DEBUG("gnrc_netif_ethernet: read error.\n");
             goto safe_out;
@@ -245,6 +247,9 @@ static gnrc_pktsnip_t *_recv(gnrc_netif_t *netif)
         gnrc_netif_hdr_set_src_addr(netif_hdr->data, hdr->src, ETHERNET_ADDR_LEN);
         gnrc_netif_hdr_set_dst_addr(netif_hdr->data, hdr->dst, ETHERNET_ADDR_LEN);
         gnrc_netif_hdr_set_netif(netif_hdr->data, netif);
+        if (rx_info.flags & NETDEV_ETH_RX_INFO_FLAG_TIMESTAMP) {
+            gnrc_netif_hdr_set_timestamp(netif_hdr->data, rx_info.timestamp);
+        }
 
         gnrc_pktbuf_remove_snip(pkt, eth_hdr);
         pkt = gnrc_pkt_append(pkt, netif_hdr);