[UNIKRAFT/LIBLWIP PATCH v3 2/3] lib/lwip: Fetch features supported on the netdev

[Sharan Santhanam <sharan.santhanam@xxxxxxxxx>]

Signed-off-by: Sharan Santhanam <sharan.santhanam@xxxxxxxxx>
---
 uknetdev.c | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/uknetdev.c b/uknetdev.c
index 7047352..fe679e9 100644
--- a/uknetdev.c
+++ b/uknetdev.c
@@ -62,6 +62,10 @@
 #define UKNETDEV_NETIF_NAME0 'e'
 #define UKNETDEV_NETIF_NAME1 'n'
 
+struct lwip_netdev_data {
+       uint32_t features;
+};
+
 /*
  * Global headroom settings for buffer allocations used on receive
  * and transmit. We are taking the maximum of all uknetdev devices as
@@ -372,6 +376,7 @@ err_t uknetdev_init(struct netif *nf)
        struct uk_netdev_rxqueue_conf rxq_conf;
        struct uk_netdev_txqueue_conf txq_conf;
        struct uk_netdev_info info;
+       struct lwip_netdev_data *lwip_data;
        const struct uk_hwaddr *hwaddr;
        unsigned int i;
        int ret;
@@ -379,6 +384,21 @@ err_t uknetdev_init(struct netif *nf)
        UK_ASSERT(nf);
        dev = netif_to_uknetdev(nf);
        UK_ASSERT(dev);
+#if CONFIG_UK_NETDEV_SCRATCH_SIZE < CONFIG_LWIP_UKNETDEV_SCRATCH 
+/**
+ * CONFIG_UK_NETDEV_SCRATCH_SIZE is configured as the max of all scratch pad
+ * requirements by the Makefile.uk macro uknetdev_scratch_mem. This value
+ * should atleast be greater CONFIG_LWIP_UKNETDEV_SCRATCH
+ */
+#error "Insufficient Scratch memory"
+#endif
+
+       /**
+        * Make sure the CONFIG_LWIP_UKNETDEV_SCRATCH is still sufficient to
+        * store lwip_data.
+        */
+       UK_ASSERT(sizeof(*lwip_data) <= CONFIG_LWIP_UKNETDEV_SCRATCH);
+       lwip_data = (struct lwip_netdev_data *)dev->scratch_pad;
 
        LWIP_ASSERT("uknetdev needs an input callback (netif_input or 
tcpip_input)",
                    nf->input != NULL);
@@ -411,6 +431,7 @@ err_t uknetdev_init(struct netif *nf)
        uk_netdev_info_get(dev, &info);
        if (!info.max_rx_queues || !info.max_tx_queues)
                return ERR_IF;
+       lwip_data->features = info.features;
 
        /*
         * Update our global (rx|tx)_headroom setting that we use for
-- 
2.7.4