Commit 990c3049 authored by Patrick Rohr's avatar Patrick Rohr Committed by David S. Miller
Browse files

Add support for PIO p flag 



draft-ietf-6man-pio-pflag is adding a new flag to the Prefix Information
Option to signal that the network can allocate a unique IPv6 prefix per
client via DHCPv6-PD (see draft-ietf-v6ops-dhcp-pd-per-device).

When ra_honor_pio_pflag is enabled, the presence of a P-flag causes
SLAAC autoconfiguration to be disabled for that particular PIO.

An automated test has been added in Android (r.android.com/3195335) to
go along with this change.

Cc: Maciej Żenczykowski <maze@google.com>
Cc: Lorenzo Colitti <lorenzo@google.com>
Cc: David Lamparter <equinox@opensourcerouting.org>
Cc: Simon Horman <horms@kernel.org>
Signed-off-by: default avatarPatrick Rohr <prohr@google.com>
Reviewed-by: default avatarMaciej Żenczykowski <maze@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 59f72657

Documentation/networking/ip-sysctl.rst

+14 −0
Original line number Diff line number Diff line
@@ -2362,6 +2362,20 @@ ra_honor_pio_life - BOOLEAN 


	Default: 0 (disabled)



ra_honor_pio_pflag - BOOLEAN

	The Prefix Information Option P-flag indicates the network can

	allocate a unique IPv6 prefix per client using DHCPv6-PD.

	This sysctl can be enabled when a userspace DHCPv6-PD client

	is running to cause the P-flag to take effect: i.e. the

	P-flag suppresses any effects of the A-flag within the same

	PIO. For a given PIO, P=1 and A=1 is treated as A=0.



	- If disabled, the P-flag is ignored.

	- If enabled, the P-flag will disable SLAAC autoconfiguration

	  for the given Prefix Information Option.



	Default: 0 (disabled)



accept_ra_rt_info_min_plen - INTEGER

	Minimum prefix length of Route Information in RA.

include/linux/ipv6.h

+1 −0
Original line number Diff line number Diff line
@@ -89,6 +89,7 @@ struct ipv6_devconf { 
	__u8		ioam6_enabled;

	__u8		ndisc_evict_nocarrier;

	__u8		ra_honor_pio_life;

	__u8		ra_honor_pio_pflag;



	struct ctl_table_header *sysctl_header;

};

include/net/addrconf.h

+7 −3
Original line number Diff line number Diff line
@@ -38,9 +38,13 @@ struct prefix_info { 
#if defined(__BIG_ENDIAN_BITFIELD)

			__u8	onlink : 1,

				autoconf : 1,

				reserved : 6;

				routeraddr : 1,

				preferpd : 1,

				reserved : 4;

#elif defined(__LITTLE_ENDIAN_BITFIELD)

			__u8	reserved : 6,

			__u8	reserved : 4,

				preferpd : 1,

				routeraddr : 1,

				autoconf : 1,

				onlink : 1;

#else

net/ipv6/addrconf.c

+14 −1
Original line number Diff line number Diff line
@@ -239,6 +239,7 @@ static struct ipv6_devconf ipv6_devconf __read_mostly = { 
	.ioam6_id_wide		= IOAM6_DEFAULT_IF_ID_WIDE,

	.ndisc_evict_nocarrier	= 1,

	.ra_honor_pio_life	= 0,

	.ra_honor_pio_pflag	= 0,

};



static struct ipv6_devconf ipv6_devconf_dflt __read_mostly = {
@@ -302,6 +303,7 @@ static struct ipv6_devconf ipv6_devconf_dflt __read_mostly = { 
	.ioam6_id_wide		= IOAM6_DEFAULT_IF_ID_WIDE,

	.ndisc_evict_nocarrier	= 1,

	.ra_honor_pio_life	= 0,

	.ra_honor_pio_pflag	= 0,

};



/* Check if link is ready: is it up and is a valid qdisc available */
@@ -2762,6 +2764,7 @@ void addrconf_prefix_rcv(struct net_device *dev, u8 *opt, int len, bool sllao) 
	u32 addr_flags = 0;

	struct inet6_dev *in6_dev;

	struct net *net = dev_net(dev);

	bool ignore_autoconf = false;



	pinfo = (struct prefix_info *) opt;
@@ -2864,7 +2867,8 @@ void addrconf_prefix_rcv(struct net_device *dev, u8 *opt, int len, bool sllao) 


	/* Try to figure out our local address for this prefix */



	if (pinfo->autoconf && in6_dev->cnf.autoconf) {

	ignore_autoconf = READ_ONCE(in6_dev->cnf.ra_honor_pio_pflag) && pinfo->preferpd;

	if (pinfo->autoconf && in6_dev->cnf.autoconf && !ignore_autoconf) {

		struct in6_addr addr;

		bool tokenized = false, dev_addr_generated = false;
@@ -6926,6 +6930,15 @@ static const struct ctl_table addrconf_sysctl[] = { 
		.extra1		= SYSCTL_ZERO,

		.extra2		= SYSCTL_ONE,

	},

	{

		.procname	= "ra_honor_pio_pflag",

		.data		= &ipv6_devconf.ra_honor_pio_pflag,

		.maxlen		= sizeof(u8),

		.mode		= 0644,

		.proc_handler	= proc_dou8vec_minmax,

		.extra1		= SYSCTL_ZERO,

		.extra2		= SYSCTL_ONE,

	},

#ifdef CONFIG_IPV6_ROUTER_PREF

	{

		.procname	= "accept_ra_rtr_pref",