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-rw-r--r--Documentation/networking/ip-sysctl.txt9
-rw-r--r--include/linux/ipv6.h1
-rw-r--r--include/net/if_inet6.h1
-rw-r--r--include/net/ndisc.h5
-rw-r--r--include/uapi/linux/ipv6.h1
-rw-r--r--net/ipv6/addrconf.c22
-rw-r--r--net/ipv6/ndisc.c29
-rw-r--r--net/ipv6/route.c2
8 files changed, 64 insertions, 6 deletions
diff --git a/Documentation/networking/ip-sysctl.txt b/Documentation/networking/ip-sysctl.txt
index 5ca567fa6b8c..7dd65c9cf707 100644
--- a/Documentation/networking/ip-sysctl.txt
+++ b/Documentation/networking/ip-sysctl.txt
@@ -1734,6 +1734,15 @@ drop_unsolicited_na - BOOLEAN
By default this is turned off.
+enhanced_dad - BOOLEAN
+ Include a nonce option in the IPv6 neighbor solicitation messages used for
+ duplicate address detection per RFC7527. A received DAD NS will only signal
+ a duplicate address if the nonce is different. This avoids any false
+ detection of duplicates due to loopback of the NS messages that we send.
+ The nonce option will be sent on an interface unless both of
+ conf/{all,interface}/enhanced_dad are set to FALSE.
+ Default: TRUE
+
icmp/*:
ratelimit - INTEGER
Limit the maximal rates for sending ICMPv6 packets.
diff --git a/include/linux/ipv6.h b/include/linux/ipv6.h
index 3f95233b2733..671d014e6429 100644
--- a/include/linux/ipv6.h
+++ b/include/linux/ipv6.h
@@ -68,6 +68,7 @@ struct ipv6_devconf {
#ifdef CONFIG_IPV6_SEG6_HMAC
__s32 seg6_require_hmac;
#endif
+ __u32 enhanced_dad;
struct ctl_table_header *sysctl_header;
};
diff --git a/include/net/if_inet6.h b/include/net/if_inet6.h
index b0576cb2ab25..0fa4c324b713 100644
--- a/include/net/if_inet6.h
+++ b/include/net/if_inet6.h
@@ -55,6 +55,7 @@ struct inet6_ifaddr {
__u8 stable_privacy_retry;
__u16 scope;
+ __u64 dad_nonce;
unsigned long cstamp; /* created timestamp */
unsigned long tstamp; /* updated timestamp */
diff --git a/include/net/ndisc.h b/include/net/ndisc.h
index be1fe2283254..d562a2fe4860 100644
--- a/include/net/ndisc.h
+++ b/include/net/ndisc.h
@@ -31,6 +31,7 @@ enum {
ND_OPT_PREFIX_INFO = 3, /* RFC2461 */
ND_OPT_REDIRECT_HDR = 4, /* RFC2461 */
ND_OPT_MTU = 5, /* RFC2461 */
+ ND_OPT_NONCE = 14, /* RFC7527 */
__ND_OPT_ARRAY_MAX,
ND_OPT_ROUTE_INFO = 24, /* RFC4191 */
ND_OPT_RDNSS = 25, /* RFC5006 */
@@ -121,6 +122,7 @@ struct ndisc_options {
#define nd_opts_pi_end nd_opt_array[__ND_OPT_PREFIX_INFO_END]
#define nd_opts_rh nd_opt_array[ND_OPT_REDIRECT_HDR]
#define nd_opts_mtu nd_opt_array[ND_OPT_MTU]
+#define nd_opts_nonce nd_opt_array[ND_OPT_NONCE]
#define nd_802154_opts_src_lladdr nd_802154_opt_array[ND_OPT_SOURCE_LL_ADDR]
#define nd_802154_opts_tgt_lladdr nd_802154_opt_array[ND_OPT_TARGET_LL_ADDR]
@@ -398,7 +400,8 @@ void ndisc_cleanup(void);
int ndisc_rcv(struct sk_buff *skb);
void ndisc_send_ns(struct net_device *dev, const struct in6_addr *solicit,
- const struct in6_addr *daddr, const struct in6_addr *saddr);
+ const struct in6_addr *daddr, const struct in6_addr *saddr,
+ u64 nonce);
void ndisc_send_rs(struct net_device *dev,
const struct in6_addr *saddr, const struct in6_addr *daddr);
diff --git a/include/uapi/linux/ipv6.h b/include/uapi/linux/ipv6.h
index 53561be1ac21..eaf65dc82e22 100644
--- a/include/uapi/linux/ipv6.h
+++ b/include/uapi/linux/ipv6.h
@@ -181,6 +181,7 @@ enum {
DEVCONF_RTR_SOLICIT_MAX_INTERVAL,
DEVCONF_SEG6_ENABLED,
DEVCONF_SEG6_REQUIRE_HMAC,
+ DEVCONF_ENHANCED_DAD,
DEVCONF_MAX
};
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 4c387dc338e3..c1e124bc8e1e 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -242,6 +242,7 @@ static struct ipv6_devconf ipv6_devconf __read_mostly = {
#ifdef CONFIG_IPV6_SEG6_HMAC
.seg6_require_hmac = 0,
#endif
+ .enhanced_dad = 1,
};
static struct ipv6_devconf ipv6_devconf_dflt __read_mostly = {
@@ -292,6 +293,7 @@ static struct ipv6_devconf ipv6_devconf_dflt __read_mostly = {
#ifdef CONFIG_IPV6_SEG6_HMAC
.seg6_require_hmac = 0,
#endif
+ .enhanced_dad = 1,
};
/* Check if a valid qdisc is available */
@@ -3735,12 +3737,21 @@ static void addrconf_dad_kick(struct inet6_ifaddr *ifp)
{
unsigned long rand_num;
struct inet6_dev *idev = ifp->idev;
+ u64 nonce;
if (ifp->flags & IFA_F_OPTIMISTIC)
rand_num = 0;
else
rand_num = prandom_u32() % (idev->cnf.rtr_solicit_delay ? : 1);
+ nonce = 0;
+ if (idev->cnf.enhanced_dad ||
+ dev_net(idev->dev)->ipv6.devconf_all->enhanced_dad) {
+ do
+ get_random_bytes(&nonce, 6);
+ while (nonce == 0);
+ }
+ ifp->dad_nonce = nonce;
ifp->dad_probes = idev->cnf.dad_transmits;
addrconf_mod_dad_work(ifp, rand_num);
}
@@ -3918,7 +3929,8 @@ static void addrconf_dad_work(struct work_struct *w)
/* send a neighbour solicitation for our addr */
addrconf_addr_solict_mult(&ifp->addr, &mcaddr);
- ndisc_send_ns(ifp->idev->dev, &ifp->addr, &mcaddr, &in6addr_any);
+ ndisc_send_ns(ifp->idev->dev, &ifp->addr, &mcaddr, &in6addr_any,
+ ifp->dad_nonce);
out:
in6_ifa_put(ifp);
rtnl_unlock();
@@ -4962,6 +4974,7 @@ static inline void ipv6_store_devconf(struct ipv6_devconf *cnf,
#ifdef CONFIG_IPV6_SEG6_HMAC
array[DEVCONF_SEG6_REQUIRE_HMAC] = cnf->seg6_require_hmac;
#endif
+ array[DEVCONF_ENHANCED_DAD] = cnf->enhanced_dad;
}
static inline size_t inet6_ifla6_size(void)
@@ -6070,6 +6083,13 @@ static const struct ctl_table addrconf_sysctl[] = {
},
#endif
{
+ .procname = "enhanced_dad",
+ .data = &ipv6_devconf.enhanced_dad,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = proc_dointvec,
+ },
+ {
/* sentinel */
}
};
diff --git a/net/ipv6/ndisc.c b/net/ipv6/ndisc.c
index d8e671457d10..7ebac630d3c6 100644
--- a/net/ipv6/ndisc.c
+++ b/net/ipv6/ndisc.c
@@ -233,6 +233,7 @@ struct ndisc_options *ndisc_parse_options(const struct net_device *dev,
case ND_OPT_SOURCE_LL_ADDR:
case ND_OPT_TARGET_LL_ADDR:
case ND_OPT_MTU:
+ case ND_OPT_NONCE:
case ND_OPT_REDIRECT_HDR:
if (ndopts->nd_opt_array[nd_opt->nd_opt_type]) {
ND_PRINTK(2, warn,
@@ -568,7 +569,8 @@ static void ndisc_send_unsol_na(struct net_device *dev)
}
void ndisc_send_ns(struct net_device *dev, const struct in6_addr *solicit,
- const struct in6_addr *daddr, const struct in6_addr *saddr)
+ const struct in6_addr *daddr, const struct in6_addr *saddr,
+ u64 nonce)
{
struct sk_buff *skb;
struct in6_addr addr_buf;
@@ -588,6 +590,8 @@ void ndisc_send_ns(struct net_device *dev, const struct in6_addr *solicit,
if (inc_opt)
optlen += ndisc_opt_addr_space(dev,
NDISC_NEIGHBOUR_SOLICITATION);
+ if (nonce != 0)
+ optlen += 8;
skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
if (!skb)
@@ -605,6 +609,13 @@ void ndisc_send_ns(struct net_device *dev, const struct in6_addr *solicit,
ndisc_fill_addr_option(skb, ND_OPT_SOURCE_LL_ADDR,
dev->dev_addr,
NDISC_NEIGHBOUR_SOLICITATION);
+ if (nonce != 0) {
+ u8 *opt = skb_put(skb, 8);
+
+ opt[0] = ND_OPT_NONCE;
+ opt[1] = 8 >> 3;
+ memcpy(opt + 2, &nonce, 6);
+ }
ndisc_send_skb(skb, daddr, saddr);
}
@@ -693,12 +704,12 @@ static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb)
"%s: trying to ucast probe in NUD_INVALID: %pI6\n",
__func__, target);
}
- ndisc_send_ns(dev, target, target, saddr);
+ ndisc_send_ns(dev, target, target, saddr, 0);
} else if ((probes -= NEIGH_VAR(neigh->parms, APP_PROBES)) < 0) {
neigh_app_ns(neigh);
} else {
addrconf_addr_solict_mult(target, &mcaddr);
- ndisc_send_ns(dev, target, &mcaddr, saddr);
+ ndisc_send_ns(dev, target, &mcaddr, saddr, 0);
}
}
@@ -742,6 +753,7 @@ static void ndisc_recv_ns(struct sk_buff *skb)
int dad = ipv6_addr_any(saddr);
bool inc;
int is_router = -1;
+ u64 nonce = 0;
if (skb->len < sizeof(struct nd_msg)) {
ND_PRINTK(2, warn, "NS: packet too short\n");
@@ -786,6 +798,8 @@ static void ndisc_recv_ns(struct sk_buff *skb)
return;
}
}
+ if (ndopts.nd_opts_nonce)
+ memcpy(&nonce, (u8 *)(ndopts.nd_opts_nonce + 1), 6);
inc = ipv6_addr_is_multicast(daddr);
@@ -794,6 +808,15 @@ static void ndisc_recv_ns(struct sk_buff *skb)
have_ifp:
if (ifp->flags & (IFA_F_TENTATIVE|IFA_F_OPTIMISTIC)) {
if (dad) {
+ if (nonce != 0 && ifp->dad_nonce == nonce) {
+ u8 *np = (u8 *)&nonce;
+ /* Matching nonce if looped back */
+ ND_PRINTK(2, notice,
+ "%s: IPv6 DAD loopback for address %pI6c nonce %pM ignored\n",
+ ifp->idev->dev->name,
+ &ifp->addr, np);
+ goto out;
+ }
/*
* We are colliding with another node
* who is doing DAD
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index b317bb135ed4..aac7818e2e0f 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -527,7 +527,7 @@ static void rt6_probe_deferred(struct work_struct *w)
container_of(w, struct __rt6_probe_work, work);
addrconf_addr_solict_mult(&work->target, &mcaddr);
- ndisc_send_ns(work->dev, &work->target, &mcaddr, NULL);
+ ndisc_send_ns(work->dev, &work->target, &mcaddr, NULL, 0);
dev_put(work->dev);
kfree(work);
}
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-12 04:32:49 +0000