svn commit: r318504 - stable/11/sys/net

[Ravi Pokala]

Author: rpokala
Date: Thu May 18 23:41:18 2017
New Revision: 318504
URL: https://svnweb.freebsd.org/changeset/base/318504

Log:
  Persistently store NIC's hardware MAC address, and add a way to retrive it
  
  jhb pointed out that (struct ifnet) is part of the network driver KBI, and
  thus the offsets of internal fields must not change. Therefore, move the new
  "if_hw_addr" field to the end, and consume one of the "if_pspare"s; that's
  what they're there for. The new field replaces the *last* element of that
  array; that way, offsetof(if_pspare) and offsetof(if_ispare) are unchanged
  compared to before r318397.
  
  PR:		194386
  Reviewed by:	jhb
  Pointyhat to:	rpokala
  Sponsored by:	Panasas

Modified:
  stable/11/sys/net/if_var.h

Modified: stable/11/sys/net/if_var.h
==============================================================================
--- stable/11/sys/net/if_var.h	Thu May 18 22:50:16 2017	(r318503)
+++ stable/11/sys/net/if_var.h	Thu May 18 23:41:18 2017	(r318504)
@@ -241,7 +241,6 @@ struct ifnet {
 	struct	ifmultihead if_multiaddrs; /* multicast addresses configured */
 	int	if_amcount;		/* number of all-multicast requests */
 	struct	ifaddr	*if_addr;	/* pointer to link-level address */
-	void	*if_hw_addr;		/* hardware link-level address */
 	const u_int8_t *if_broadcastaddr; /* linklevel broadcast bytestring */
 	struct	rwlock if_afdata_lock;
 	void	*if_afdata[AF_MAX];
@@ -312,7 +311,8 @@ struct ifnet {
 	 * that structure can be enhanced without changing the kernel
 	 * binary interface.
 	 */
-	void	*if_pspare[4];		/* packet pacing / general use */
+	void	*if_pspare[3];		/* packet pacing / general use */
+	void	*if_hw_addr;		/* hardware link-level address */
 	int	if_ispare[4];		/* packet pacing / general use */
 };