lcd/nullnet: Fix offsets that need to be passed

Signed-off-by: Vikram Narayanan <vikram186@gmail.com>

lcd-domains/test_mods/nullnet/dummy_lcd/glue/nullnet_caller.c

@@ -826,7 +826,7 @@ int ndo_start_xmit_callee(struct fipc_message *request, struct thc_channel *chan
 	unsigned long skb_ord, skb_off;
 	unsigned long skbd_ord, skbd_off;
 	gva_t skb_gva, skbd_gva;
-	unsigned int head_off;
+	unsigned int data_off;
 	request_cookie = thc_get_request_cookie(request);
 
 	ret = glue_cap_lookup_net_device_type(c_cspace, __cptr(fipc_get_reg1(request)), &net_dev_container);
@@ -860,7 +860,7 @@ int ndo_start_xmit_callee(struct fipc_message *request, struct thc_channel *chan
 	skb_off = lcd_r1();
 	skbd_ord = lcd_r2();
 	skbd_off = lcd_r3();
-	head_off = lcd_r4();
+	data_off = lcd_r4();
 
 	sync_ret = lcd_map_virt(skb_cptr, skb_ord, &skb_gva);
 	if (sync_ret) {
@@ -875,8 +875,8 @@ int ndo_start_xmit_callee(struct fipc_message *request, struct thc_channel *chan
 	}
 
 	skb = (void*)(gva_val(skb_gva) + skb_off);
-	skb->data = (void*)(gva_val(skbd_gva) + skbd_off);
-	skb->head = skb->data - head_off;
+	skb->head = (void*)(gva_val(skbd_gva) + skbd_off);
+	skb->data = skb->head + data_off;
 
 	ret = net_dev_container->net_device.netdev_ops->ndo_start_xmit(skb, &net_dev_container->net_device);
 

lcd-domains/test_mods/nullnet/net_klcd/glue/nullnet_callee.c

@@ -416,9 +416,9 @@ int ndo_start_xmit_user(struct sk_buff *skb, struct net_device *dev, struct tram
 
 	net_dev_container = container_of(dev, struct net_device_container, net_device);
 
-	ret = sync_setup_memory(skb, skb->truesize, &skb_ord, &skb_cptr, &skb_off);
+	ret = sync_setup_memory(skb, sizeof(struct sk_buff), &skb_ord, &skb_cptr, &skb_off);
 
-	ret = sync_setup_memory(skb->data, skb_headlen(skb), &skbd_ord, &skbd_cptr, &skbd_off);
+	ret = sync_setup_memory(skb->head, skb_end_offset(skb) + sizeof(struct skb_shared_info), &skbd_ord, &skbd_cptr, &skbd_off);
 
 	ret = async_msg_blocking_send_start(hidden_args->async_chnl, &request);
 	if (ret) {
@@ -451,7 +451,7 @@ int ndo_start_xmit_user(struct sk_buff *skb, struct net_device *dev, struct tram
 			skb->data, skb->len, false);
 	}
 
-	LIBLCD_MSG("r4 tail_off 0x%X |  r5 end off 0x%X | r6 head off 0x%X", skb->tail - (unsigned long)skb->data, skb->end - (unsigned long)skb->data, skb->data - skb->head);
+	LIBLCD_MSG("r4 data_off 0x%X | %d", skb->data - skb->head);
 	ret = lcd_sync_send(sync_end);
 	lcd_set_cr0(CAP_CPTR_NULL);
 	lcd_set_cr1(CAP_CPTR_NULL);