Merge branch 'ipv6_stable_privacy_address'

Hannes Frederic Sowa says:

====================
ipv6: RFC7217 stable privacy addresses implementation

this is an implementation of basic support for RFC7217 stable privacy
addresses. Please review and consider for net-next.

v2:
* Correct references to RFC 7212 -> RFC 7217 in documentation patch (thanks, Eric!)
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Documentation/networking/ip-sysctl.txt

@@ -1220,6 +1220,17 @@ anycast_src_echo_reply - BOOLEAN
 	FALSE: disabled
 	Default: FALSE
 
+idgen_delay - INTEGER
+	Controls the delay in seconds after which time to retry
+	privacy stable address generation if a DAD conflict is
+	detected.
+	Default: 1 (as specified in RFC7217)
+
+idgen_retries - INTEGER
+	Controls the number of retries to generate a stable privacy
+	address if a DAD conflict is detected.
+	Default: 3 (as specified in RFC7217)
+
 mld_qrv - INTEGER
 	Controls the MLD query robustness variable (see RFC3810 9.1).
 	Default: 2 (as specified by RFC3810 9.1)
@@ -1540,6 +1551,20 @@ use_optimistic - BOOLEAN
 		0: disabled (default)
 		1: enabled
 
+stable_secret - IPv6 address
+	This IPv6 address will be used as a secret to generate IPv6
+	addresses for link-local addresses and autoconfigured
+	ones. All addresses generated after setting this secret will
+	be stable privacy ones by default. This can be changed via the
+	addrgenmode ip-link. conf/default/stable_secret is used as the
+	secret for the namespace, the interface specific ones can
+	overwrite that. Writes to conf/all/stable_secret are refused.
+
+	It is recommended to generate this secret during installation
+	of a system and keep it stable after that.
+
+	By default the stable secret is unset.
+
 icmp/*:
 ratelimit - INTEGER
 	Limit the maximal rates for sending ICMPv6 packets.

include/linux/ipv6.h

@@ -53,6 +53,10 @@ struct ipv6_devconf {
 	__s32           ndisc_notify;
 	__s32		suppress_frag_ndisc;
 	__s32		accept_ra_mtu;
+	struct ipv6_stable_secret {
+		bool initialized;
+		struct in6_addr secret;
+	} stable_secret;
 	void		*sysctl;
 };
 

include/net/if_inet6.h

@@ -47,12 +47,12 @@ struct inet6_ifaddr {
 	__u32			prefered_lft;
 	atomic_t		refcnt;
 	spinlock_t		lock;
-	spinlock_t		state_lock;
 
 	int			state;
 
 	__u32			flags;
 	__u8			dad_probes;
+	__u8			stable_privacy_retry;
 
 	__u16			scope;
 

include/net/netns/ipv6.h

@@ -32,6 +32,8 @@ struct netns_sysctl_ipv6 {
 	int icmpv6_time;
 	int anycast_src_echo_reply;
 	int fwmark_reflect;
+	int idgen_retries;
+	int idgen_delay;
 };
 
 struct netns_ipv6 {

include/uapi/linux/if_addr.h

@@ -51,6 +51,7 @@ enum {
 #define IFA_F_MANAGETEMPADDR	0x100
 #define IFA_F_NOPREFIXROUTE	0x200
 #define IFA_F_MCAUTOJOIN	0x400
+#define IFA_F_STABLE_PRIVACY	0x800
 
 struct ifa_cacheinfo {
 	__u32	ifa_prefered;

include/uapi/linux/if_link.h

@@ -216,6 +216,7 @@ enum {
 enum in6_addr_gen_mode {
 	IN6_ADDR_GEN_MODE_EUI64,
 	IN6_ADDR_GEN_MODE_NONE,
+	IN6_ADDR_GEN_MODE_STABLE_PRIVACY,
 };
 
 /* Bridge section */

include/uapi/linux/ipv6.h

@@ -170,6 +170,7 @@ enum {
 	DEVCONF_ACCEPT_RA_FROM_LOCAL,
 	DEVCONF_USE_OPTIMISTIC,
 	DEVCONF_ACCEPT_RA_MTU,
+	DEVCONF_STABLE_SECRET,
 	DEVCONF_MAX
 };
 

lib/sha1.c

@@ -198,3 +198,4 @@ void sha_init(__u32 *buf)
 	buf[3] = 0x10325476;
 	buf[4] = 0xc3d2e1f0;
 }
+EXPORT_SYMBOL(sha_init);

net/ipv6/af_inet6.c

@@ -766,6 +766,8 @@ static int __net_init inet6_net_init(struct net *net)
 	net->ipv6.sysctl.icmpv6_time = 1*HZ;
 	net->ipv6.sysctl.flowlabel_consistency = 1;
 	net->ipv6.sysctl.auto_flowlabels = 0;
+	net->ipv6.sysctl.idgen_retries = 3;
+	net->ipv6.sysctl.idgen_delay = 1 * HZ;
 	atomic_set(&net->ipv6.fib6_sernum, 1);
 
 	err = ipv6_init_mibs(net);

net/ipv6/sysctl_net_ipv6.c

@@ -54,6 +54,20 @@ static struct ctl_table ipv6_table_template[] = {
 		.mode		= 0644,
 		.proc_handler	= proc_dointvec
 	},
+	{
+		.procname	= "idgen_retries",
+		.data		= &init_net.ipv6.sysctl.idgen_retries,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec,
+	},
+	{
+		.procname	= "idgen_delay",
+		.data		= &init_net.ipv6.sysctl.idgen_delay,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec_jiffies,
+	},
 	{ }
 };
 
@@ -93,6 +107,8 @@ static int __net_init ipv6_sysctl_net_init(struct net *net)
 	ipv6_table[2].data = &net->ipv6.sysctl.flowlabel_consistency;
 	ipv6_table[3].data = &net->ipv6.sysctl.auto_flowlabels;
 	ipv6_table[4].data = &net->ipv6.sysctl.fwmark_reflect;
+	ipv6_table[5].data = &net->ipv6.sysctl.idgen_retries;
+	ipv6_table[6].data = &net->ipv6.sysctl.idgen_delay;
 
 	ipv6_route_table = ipv6_route_sysctl_init(net);
 	if (!ipv6_route_table)