RE: [PATCH RFC 1/3] net: Add dev_set_env_hdr_len to accept envelope frames
flat view
From: Mintz, Yuval <hidden>
Date: 2016-09-27 14:39:18
quoted hunk ↗ jump to hunk
+/* return envelope header length */ +static inline int netif_get_env_hdr_len(struct net_device *dev) { + if (dev->netdev_ops->ndo_set_env_hdr_len) + return dev->env_hdr_len; + + if (netif_reduces_vlan_mtu(dev)) + return 0; + + return 4; /* VLAN_HLEN */ +}
Why claim that `4' is the default? What's the benefit of propagating this value to userspace if driver doesn't actually support it? Assuming this *is* a good default [meaning your analysis indicated basically every driver has at least so many octets reserved] perhaps we should consider initializing the env_hdr_len in some common function [e.g., in setup_ether() next to the mtu] to this value?