diff --git a/Documentation/networking/ip-sysctl.txt b/Documentation/networking/ip-sysctl.txt
index 9028b879a97baebc29832c42694896361ecfba03..368e3251c5535c3eb5a16baaa0d83733fdf85ad1 100644
--- a/Documentation/networking/ip-sysctl.txt
+++ b/Documentation/networking/ip-sysctl.txt
@@ -1460,6 +1460,19 @@ suppress_frag_ndisc - INTEGER
1 - (default) discard fragmented neighbor discovery packets
0 - allow fragmented neighbor discovery packets
+optimistic_dad - BOOLEAN
+ Whether to perform Optimistic Duplicate Address Detection (RFC 4429).
+ 0: disabled (default)
+ 1: enabled
+
+use_optimistic - BOOLEAN
+ If enabled, do not classify optimistic addresses as deprecated during
+ source address selection. Preferred addresses will still be chosen
+ before optimistic addresses, subject to other ranking in the source
+ address selection algorithm.
+ 0: disabled (default)
+ 1: enabled
+
icmp/*:
ratelimit - INTEGER
Limit the maximal rates for sending ICMPv6 packets.
diff --git a/include/linux/ipv6.h b/include/linux/ipv6.h
index ff560537dd61b334a3dfbfb559dfa0f1cff20f41..7121a2e97ce2ed5911a94b238f726919315673fb 100644
--- a/include/linux/ipv6.h
+++ b/include/linux/ipv6.h
@@ -42,6 +42,7 @@ struct ipv6_devconf {
__s32 accept_ra_from_local;
#ifdef CONFIG_IPV6_OPTIMISTIC_DAD
__s32 optimistic_dad;
+ __s32 use_optimistic;
#endif
#ifdef CONFIG_IPV6_MROUTE
__s32 mc_forwarding;
diff --git a/include/uapi/linux/ipv6.h b/include/uapi/linux/ipv6.h
index efa2666f4b8af10ca72c26206f82e527d7adc8e6..e863d088b9a5a54cfd18d1e507c6c6e758ba5516 100644
--- a/include/uapi/linux/ipv6.h
+++ b/include/uapi/linux/ipv6.h
@@ -164,6 +164,7 @@ enum {
DEVCONF_MLDV2_UNSOLICITED_REPORT_INTERVAL,
DEVCONF_SUPPRESS_FRAG_NDISC,
DEVCONF_ACCEPT_RA_FROM_LOCAL,
+ DEVCONF_USE_OPTIMISTIC,
DEVCONF_MAX
};
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 50b95b2db87c2887314076dcad3a0d64b10ffda1..8d12b7c7018f30fa1c9f704d26aa02e1a4d2b380 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -1170,6 +1170,9 @@ enum {
IPV6_SADDR_RULE_PRIVACY,
IPV6_SADDR_RULE_ORCHID,
IPV6_SADDR_RULE_PREFIX,
+#ifdef CONFIG_IPV6_OPTIMISTIC_DAD
+ IPV6_SADDR_RULE_NOT_OPTIMISTIC,
+#endif
IPV6_SADDR_RULE_MAX
};
@@ -1197,6 +1200,15 @@ static inline int ipv6_saddr_preferred(int type)
return 0;
}
+static inline bool ipv6_use_optimistic_addr(struct inet6_dev *idev)
+{
+#ifdef CONFIG_IPV6_OPTIMISTIC_DAD
+ return idev && idev->cnf.optimistic_dad && idev->cnf.use_optimistic;
+#else
+ return false;
+#endif
+}
+
static int ipv6_get_saddr_eval(struct net *net,
struct ipv6_saddr_score *score,
struct ipv6_saddr_dst *dst,
@@ -1257,10 +1269,16 @@ static int ipv6_get_saddr_eval(struct net *net,
score->scopedist = ret;
break;
case IPV6_SADDR_RULE_PREFERRED:
+ {
/* Rule 3: Avoid deprecated and optimistic addresses */
+ u8 avoid = IFA_F_DEPRECATED;
+
+ if (!ipv6_use_optimistic_addr(score->ifa->idev))
+ avoid |= IFA_F_OPTIMISTIC;
ret = ipv6_saddr_preferred(score->addr_type) ||
- !(score->ifa->flags & (IFA_F_DEPRECATED|IFA_F_OPTIMISTIC));
+ !(score->ifa->flags & avoid);
break;
+ }
#ifdef CONFIG_IPV6_MIP6
case IPV6_SADDR_RULE_HOA:
{
@@ -1306,6 +1324,14 @@ static int ipv6_get_saddr_eval(struct net *net,
ret = score->ifa->prefix_len;
score->matchlen = ret;
break;
+#ifdef CONFIG_IPV6_OPTIMISTIC_DAD
+ case IPV6_SADDR_RULE_NOT_OPTIMISTIC:
+ /* Optimistic addresses still have lower precedence than other
+ * preferred addresses.
+ */
+ ret = !(score->ifa->flags & IFA_F_OPTIMISTIC);
+ break;
+#endif
default:
ret = 0;
}
@@ -3222,8 +3248,15 @@ static void addrconf_dad_begin(struct inet6_ifaddr *ifp)
* Optimistic nodes can start receiving
* Frames right away
*/
- if (ifp->flags & IFA_F_OPTIMISTIC)
+ if (ifp->flags & IFA_F_OPTIMISTIC) {
ip6_ins_rt(ifp->rt);
+ if (ipv6_use_optimistic_addr(idev)) {
+ /* Because optimistic nodes can use this address,
+ * notify listeners. If DAD fails, RTM_DELADDR is sent.
+ */
+ ipv6_ifa_notify(RTM_NEWADDR, ifp);
+ }
+ }
addrconf_dad_kick(ifp);
out:
@@ -4330,6 +4363,7 @@ static inline void ipv6_store_devconf(struct ipv6_devconf *cnf,
array[DEVCONF_ACCEPT_SOURCE_ROUTE] = cnf->accept_source_route;
#ifdef CONFIG_IPV6_OPTIMISTIC_DAD
array[DEVCONF_OPTIMISTIC_DAD] = cnf->optimistic_dad;
+ array[DEVCONF_USE_OPTIMISTIC] = cnf->use_optimistic;
#endif
#ifdef CONFIG_IPV6_MROUTE
array[DEVCONF_MC_FORWARDING] = cnf->mc_forwarding;
@@ -5155,6 +5189,14 @@ static struct addrconf_sysctl_table
.proc_handler = proc_dointvec,
},
+ {
+ .procname = "use_optimistic",
+ .data = &ipv6_devconf.use_optimistic,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = proc_dointvec,
+
+ },
#endif
#ifdef CONFIG_IPV6_MROUTE
{