bond: support xmit_hash_policy=vlan+srcmac

bond: support xmit_hash_policy=vlan+srcmac

There's a new transmit hash policy being added to the bonding driver that
is a simple XOR of vlan ID and source MAC, xmit_hash_policy vlan+srcmac.
This trivial patch makes it configurable and queryable via iproute2.

$ sudo modprobe bonding mode=2 max_bonds=1 xmit_hash_policy=0

$ sudo ip link set bond0 type bond xmit_hash_policy vlan+srcmac

$ ip -d link show bond0
11: bond0: <BROADCAST,MULTICAST,MASTER> mtu 1500 qdisc noop state DOWN mode DEFAULT group default qlen 1000
    link/ether ce:85:5e:24:ce:90 brd ff:ff:ff:ff:ff:ff promiscuity 0 minmtu 68 maxmtu 65535
    bond mode balance-xor miimon 0 updelay 0 downdelay 0 peer_notify_delay 0 use_carrier 1 arp_interval 0 arp_validate none arp_all_targets any
primary_reselect always fail_over_mac none xmit_hash_policy vlan+srcmac resend_igmp 1 num_grat_arp 1 all_slaves_active 0 min_links 0 lp_interval 1
packets_per_slave 1 lacp_rate slow ad_select stable tlb_dynamic_lb 1 addrgenmode eui64 numtxqueues 16 numrxqueues 16 gso_max_size 65536 gso_max_segs
65535

$ grep Hash /proc/net/bonding/bond0
Transmit Hash Policy: vlan+srcmac (5)

$ sudo ip link add test type bond help
Usage: ... bond [ mode BONDMODE ] [ active_slave SLAVE_DEV ]
                [ clear_active_slave ] [ miimon MIIMON ]
                [ updelay UPDELAY ] [ downdelay DOWNDELAY ]
                [ peer_notify_delay DELAY ]
                [ use_carrier USE_CARRIER ]
                [ arp_interval ARP_INTERVAL ]
                [ arp_validate ARP_VALIDATE ]
                [ arp_all_targets ARP_ALL_TARGETS ]
                [ arp_ip_target [ ARP_IP_TARGET, ... ] ]
                [ primary SLAVE_DEV ]
                [ primary_reselect PRIMARY_RESELECT ]
                [ fail_over_mac FAIL_OVER_MAC ]
                [ xmit_hash_policy XMIT_HASH_POLICY ]
                [ resend_igmp RESEND_IGMP ]
                [ num_grat_arp|num_unsol_na NUM_GRAT_ARP|NUM_UNSOL_NA ]
                [ all_slaves_active ALL_SLAVES_ACTIVE ]
                [ min_links MIN_LINKS ]
                [ lp_interval LP_INTERVAL ]
                [ packets_per_slave PACKETS_PER_SLAVE ]
                [ tlb_dynamic_lb TLB_DYNAMIC_LB ]
                [ lacp_rate LACP_RATE ]
                [ ad_select AD_SELECT ]
                [ ad_user_port_key PORTKEY ]
                [ ad_actor_sys_prio SYSPRIO ]
                [ ad_actor_system LLADDR ]

BONDMODE := balance-rr|active-backup|balance-xor|broadcast|802.3ad|balance-tlb|balance-alb
ARP_VALIDATE := none|active|backup|all
ARP_ALL_TARGETS := any|all
PRIMARY_RESELECT := always|better|failure
FAIL_OVER_MAC := none|active|follow
XMIT_HASH_POLICY := layer2|layer2+3|layer3+4|encap2+3|encap3+4|vlan+srcmac
LACP_RATE := slow|fast
AD_SELECT := stable|bandwidth|count

Cc: Stephen Hemminger <stephen@networkplumber.org>
Cc: Jay Vosburgh <j.vosburgh@gmail.com>
Signed-off-by: Jarod Wilson <jarod@redhat.com>
Signed-off-by: David Ahern <dsahern@kernel.org>