Add support to priority code point (PCP) that is an 3-bit field

which refers to IEEE 802.1p class of service and maps to the frame
priority level.

Values in order of priority are: 1 (Background (lowest)),
0 (Best effort (default)), 2 (Excellent effort),
3 (Critical applications), 4 (Video, < 100ms latency),
5 (Video, < 10ms latency), 6 (Internetwork control) and
7 (Network control (highest)).

Example of usage:
root# ifconfig em0.1 create
root# ifconfig em0.1 vlanpcp 3

Note:
The review D801 includes the pf(4) part, but as discussed with kristof,
we won't commit the pf(4) bits for now.
The credits of the original code is from rwatson.

Differential Revision:	https://reviews.freebsd.org/D801
Reviewed by:	gnn, adrian, loos
Discussed with: rwatson, glebius, kristof
Tested by:	many including Matthew Grooms <mgrooms__shrew.net>
Obtained from:	pfSense
Relnotes:	Yes

1 files changed, 2 insertions, 0 deletions

diff --git a/sys/net/if.h b/sys/net/if.h
index 792704a..98ae0a8 100644
--- a/sys/net/if.h
+++ b/sys/net/if.h
@@ -393,6 +393,7 @@ struct	ifreq {
 		caddr_t	ifru_data;
 		int	ifru_cap[2];
 		u_int	ifru_fib;
+		u_char	ifru_vlan_pcp;
 	} ifr_ifru;
 #define	ifr_addr	ifr_ifru.ifru_addr	/* address */
 #define	ifr_dstaddr	ifr_ifru.ifru_dstaddr	/* other end of p-to-p link */
@@ -410,6 +411,7 @@ struct	ifreq {
 #define	ifr_curcap	ifr_ifru.ifru_cap[1]	/* current capabilities */
 #define	ifr_index	ifr_ifru.ifru_index	/* interface index */
 #define	ifr_fib		ifr_ifru.ifru_fib	/* interface fib */
+#define	ifr_vlan_pcp	ifr_ifru.ifru_vlan_pcp	/* VLAN priority */
 };
 
 #define	_SIZEOF_ADDR_IFREQ(ifr) \