From: Neil Horman <nhorman@redhat.com>
Date: Tue, 7 Aug 2007 14:53:15 -0400
Subject: [net] ipv6: backport optimistic DAD
Message-id: 20070807185315.GI6353@hmsendeavour.rdu.redhat.com
O-Subject: [RHEL 5.2 PATCH] backport optimistic DAD for IPv6 (bz 246723)
Bugzilla: 246723
Hey all-
This is a backport of my upstream patch to support RFC 4429 Optimistic
Duplicate Address Detection for IPv6. The patch is almost identical to
upstream, save for one major point. Because upstream, optimistic dad can be
enabled per interface, the added devconf code is an ABI breaker in RHEL 5. I've
fixed that here by making optimistic dad a global sysctl instead. This is
required for our IPv6 stack by the DoD and satisfies BZ 246723
Regards
Neil
Acked-by: "David S. Miller" <davem@redhat.com>
Acked-by: Thomas Graf <tgraf@redhat.com>
diff --git a/include/linux/if_addr.h b/include/linux/if_addr.h
new file mode 100644
index 0000000..e99aa71
--- /dev/null
+++ b/include/linux/if_addr.h
@@ -0,0 +1,53 @@
+#ifndef __LINUX_IF_ADDR_H
+#define __LINUX_IF_ADDR_H
+
+#include <linux/netlink.h>
+
+struct ifaddrmsg
+{
+ __u8 ifa_family;
+ __u8 ifa_prefixlen; /* The prefix length */
+ __u8 ifa_flags; /* Flags */
+ __u8 ifa_scope; /* Address scope */
+ __u32 ifa_index; /* Link index */
+};
+
+/*
+ * Important comment:
+ * IFA_ADDRESS is prefix address, rather than local interface address.
+ * It makes no difference for normally configured broadcast interfaces,
+ * but for point-to-point IFA_ADDRESS is DESTINATION address,
+ * local address is supplied in IFA_LOCAL attribute.
+ */
+enum
+{
+ IFA_UNSPEC,
+ IFA_ADDRESS,
+ IFA_LOCAL,
+ IFA_LABEL,
+ IFA_BROADCAST,
+ IFA_ANYCAST,
+ IFA_CACHEINFO,
+ IFA_MULTICAST,
+ __IFA_MAX,
+};
+
+#define IFA_MAX (__IFA_MAX - 1)
+
+/* ifa_flags */
+#define IFA_F_SECONDARY 0x01
+#define IFA_F_TEMPORARY IFA_F_SECONDARY
+#define IFA_F_OPTIMISTIC 0x04
+#define IFA_F_DEPRECATED 0x20
+#define IFA_F_TENTATIVE 0x40
+#define IFA_F_PERMANENT 0x80
+
+struct ifa_cacheinfo
+{
+ __u32 ifa_prefered;
+ __u32 ifa_valid;
+ __u32 cstamp; /* created timestamp, hundredths of seconds */
+ __u32 tstamp; /* updated timestamp, hundredths of seconds */
+};
+
+#endif
diff --git a/include/linux/ipv6.h b/include/linux/ipv6.h
index 02d14a3..258c220 100644
--- a/include/linux/ipv6.h
+++ b/include/linux/ipv6.h
@@ -156,6 +156,8 @@ struct ipv6_devconf {
void *sysctl;
};
+extern int sysctl_ip6_odad;
+
/* index values for the variables in ipv6_devconf */
enum {
DEVCONF_FORWARDING = 0,
diff --git a/include/linux/rtnetlink.h b/include/linux/rtnetlink.h
index fd3650d..41b8df5 100644
--- a/include/linux/rtnetlink.h
+++ b/include/linux/rtnetlink.h
@@ -383,62 +383,6 @@ struct rta_session
};
-/*********************************************************
- * Interface address.
- ****/
-
-struct ifaddrmsg
-{
- unsigned char ifa_family;
- unsigned char ifa_prefixlen; /* The prefix length */
- unsigned char ifa_flags; /* Flags */
- unsigned char ifa_scope; /* See above */
- int ifa_index; /* Link index */
-};
-
-enum
-{
- IFA_UNSPEC,
- IFA_ADDRESS,
- IFA_LOCAL,
- IFA_LABEL,
- IFA_BROADCAST,
- IFA_ANYCAST,
- IFA_CACHEINFO,
- IFA_MULTICAST,
- __IFA_MAX
-};
-
-#define IFA_MAX (__IFA_MAX - 1)
-
-/* ifa_flags */
-
-#define IFA_F_SECONDARY 0x01
-#define IFA_F_TEMPORARY IFA_F_SECONDARY
-
-#define IFA_F_DEPRECATED 0x20
-#define IFA_F_TENTATIVE 0x40
-#define IFA_F_PERMANENT 0x80
-
-struct ifa_cacheinfo
-{
- __u32 ifa_prefered;
- __u32 ifa_valid;
- __u32 cstamp; /* created timestamp, hundredths of seconds */
- __u32 tstamp; /* updated timestamp, hundredths of seconds */
-};
-
-
-#define IFA_RTA(r) ((struct rtattr*)(((char*)(r)) + NLMSG_ALIGN(sizeof(struct ifaddrmsg))))
-#define IFA_PAYLOAD(n) NLMSG_PAYLOAD(n,sizeof(struct ifaddrmsg))
-
-/*
- Important comment:
- IFA_ADDRESS is prefix address, rather than local interface address.
- It makes no difference for normally configured broadcast interfaces,
- but for point-to-point IFA_ADDRESS is DESTINATION address,
- local address is supplied in IFA_LOCAL attribute.
- */
/**************************************************************
* Neighbour discovery.
diff --git a/include/linux/sysctl.h b/include/linux/sysctl.h
index 909fd90..98bc8c9 100644
--- a/include/linux/sysctl.h
+++ b/include/linux/sysctl.h
@@ -528,6 +528,7 @@ enum {
NET_IPV6_IP6FRAG_TIME=23,
NET_IPV6_IP6FRAG_SECRET_INTERVAL=24,
NET_IPV6_MLD_MAX_MSF=25,
+ NET_IPV6_OPTIMISTIC_DAD=26,
};
enum {
diff --git a/include/net/addrconf.h b/include/net/addrconf.h
index 3d71251..ed399f5 100644
--- a/include/net/addrconf.h
+++ b/include/net/addrconf.h
@@ -70,7 +70,9 @@ extern int ipv6_get_saddr(struct dst_entry *dst,
extern int ipv6_dev_get_saddr(struct net_device *dev,
struct in6_addr *daddr,
struct in6_addr *saddr);
-extern int ipv6_get_lladdr(struct net_device *dev, struct in6_addr *);
+extern int ipv6_get_lladdr(struct net_device *dev,
+ struct in6_addr *addr,
+ unsigned char banned_flags);
extern int ipv6_rcv_saddr_equal(const struct sock *sk,
const struct sock *sk2);
extern void addrconf_join_solict(struct net_device *dev,
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index aa7cff2..3571203 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -35,6 +35,7 @@
#include <linux/init.h>
#include <linux/security.h>
#include <linux/mutex.h>
+#include <linux/if_addr.h>
#include <asm/uaccess.h>
#include <asm/system.h>
diff --git a/net/decnet/dn_dev.c b/net/decnet/dn_dev.c
index 9ab2e5b..88ea7a1 100644
--- a/net/decnet/dn_dev.c
+++ b/net/decnet/dn_dev.c
@@ -34,6 +34,7 @@
#include <linux/seq_file.h>
#include <linux/timer.h>
#include <linux/string.h>
+#include <linux/if_addr.h>
#include <linux/if_arp.h>
#include <linux/if_ether.h>
#include <linux/skbuff.h>
diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c
index 9f3ffbe..9466f82 100644
--- a/net/ipv4/devinet.c
+++ b/net/ipv4/devinet.c
@@ -43,6 +43,7 @@
#include <linux/in.h>
#include <linux/errno.h>
#include <linux/interrupt.h>
+#include <linux/if_addr.h>
#include <linux/if_ether.h>
#include <linux/inet.h>
#include <linux/netdevice.h>
diff --git a/net/ipv4/fib_frontend.c b/net/ipv4/fib_frontend.c
index 277706c..02b6ea9 100644
--- a/net/ipv4/fib_frontend.c
+++ b/net/ipv4/fib_frontend.c
@@ -32,6 +32,7 @@
#include <linux/inet.h>
#include <linux/inetdevice.h>
#include <linux/netdevice.h>
+#include <linux/if_addr.h>
#include <linux/if_arp.h>
#include <linux/skbuff.h>
#include <linux/netlink.h>
diff --git a/net/ipv4/netfilter/ip_conntrack_netbios_ns.c b/net/ipv4/netfilter/ip_conntrack_netbios_ns.c
index a566a81..8d31b60 100644
--- a/net/ipv4/netfilter/ip_conntrack_netbios_ns.c
+++ b/net/ipv4/netfilter/ip_conntrack_netbios_ns.c
@@ -20,6 +20,7 @@
#include <linux/init.h>
#include <linux/skbuff.h>
#include <linux/netdevice.h>
+#include <linux/if_addr.h>
#include <linux/inetdevice.h>
#include <linux/in.h>
#include <linux/ip.h>
diff --git a/net/ipv6/Kconfig b/net/ipv6/Kconfig
index 652f61a..5127d6d 100644
--- a/net/ipv6/Kconfig
+++ b/net/ipv6/Kconfig
@@ -57,6 +57,16 @@ config IPV6_ROUTE_INFO
If unsure, say N.
+config IPV6_OPTIMISTIC_DAD
+ bool "IPv6: Enable RFC 4429 Optimistic DAD (EXPERIMENTAL)"
+ depends on IPV6 && EXPERIMENTAL
+ ---help---
+ This is experimental support for optimistic Duplicate
+ Address Detection. It allows for autoconfigured addresses
+ to be used more quickly.
+
+ If unsure, say N.
+
config INET6_AH
tristate "IPv6: AH transformation"
depends on IPV6
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 464eaff..0fa6008 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -48,6 +48,7 @@
#include <linux/net.h>
#include <linux/in6.h>
#include <linux/netdevice.h>
+#include <linux/if_addr.h>
#include <linux/if_arp.h>
#include <linux/if_arcnet.h>
#include <linux/if_infiniband.h>
@@ -205,6 +206,8 @@ static struct ipv6_devconf ipv6_devconf_dflt = {
#endif
};
+int sysctl_ip6_odad = 0;
+
/* IPv6 Wildcard Address and Loopback Address defined by RFC2553 */
#if 0
const struct in6_addr in6addr_any = IN6ADDR_ANY_INIT;
@@ -583,6 +586,16 @@ ipv6_add_addr(struct inet6_dev *idev, const struct in6_addr *addr, int pfxlen,
ifa->rt = rt;
+ /*
+ * part one of RFC 4429, section 3.3
+ * We should not configure an address as
+ * optimistic if we do not yet know the link
+ * layer address of our nexhop router
+ */
+
+ if (rt->rt6i_nexthop == NULL)
+ ifa->flags &= ~IFA_F_OPTIMISTIC;
+
ifa->idev = idev;
in6_dev_hold(idev);
/* For caller */
@@ -759,6 +772,7 @@ static int ipv6_create_tempaddr(struct inet6_ifaddr *ifp, struct inet6_ifaddr *i
int tmp_plen;
int ret = 0;
int max_addresses;
+ u32 addr_flags;
write_lock(&idev->lock);
if (ift) {
@@ -816,10 +830,17 @@ retry:
spin_unlock_bh(&ifp->lock);
write_unlock(&idev->lock);
+
+ addr_flags = IFA_F_TEMPORARY;
+ /* set in addrconf_prefix_rcv() */
+ if (ifp->flags & IFA_F_OPTIMISTIC)
+ addr_flags |= IFA_F_OPTIMISTIC;
+
ift = !max_addresses ||
ipv6_count_addresses(idev) < max_addresses ?
ipv6_add_addr(idev, &addr, tmp_plen,
- ipv6_addr_type(&addr)&IPV6_ADDR_SCOPE_MASK, IFA_F_TEMPORARY) : NULL;
+ ipv6_addr_type(&addr)&IPV6_ADDR_SCOPE_MASK,
+ addr_flags) : NULL;
if (!ift || IS_ERR(ift)) {
in6_ifa_put(ifp);
in6_dev_put(idev);
@@ -837,7 +858,11 @@ retry:
ift->cstamp = tmp_cstamp;
ift->tstamp = tmp_tstamp;
spin_unlock_bh(&ift->lock);
-
+ /*
+ * Note that section 3.1 of RFC 4429 indicates
+ * that the Optimistic flag should not be set for
+ * manually configured addresses
+ */
addrconf_dad_start(ift, 0);
in6_ifa_put(ift);
in6_dev_put(idev);
@@ -951,13 +976,14 @@ int ipv6_dev_get_saddr(struct net_device *daddr_dev,
* - Tentative Address (RFC2462 section 5.4)
* - A tentative address is not considered
* "assigned to an interface" in the traditional
- * sense.
+ * sense, unless it is also flagged as optimistic.
* - Candidate Source Address (section 4)
* - In any case, anycast addresses, multicast
* addresses, and the unspecified address MUST
* NOT be included in a candidate set.
*/
- if (ifa->flags & IFA_F_TENTATIVE)
+ if ((ifa->flags & IFA_F_TENTATIVE) &&
+ (!(ifa->flags & IFA_F_OPTIMISTIC)))
continue;
if (unlikely(score.addr_type == IPV6_ADDR_ANY ||
score.addr_type & IPV6_ADDR_MULTICAST)) {
@@ -1016,15 +1042,17 @@ int ipv6_dev_get_saddr(struct net_device *daddr_dev,
}
}
- /* Rule 3: Avoid deprecated address */
+ /* Rule 3: Avoid deprecated and optimistic addresses */
if (hiscore.rule < 3) {
if (ipv6_saddr_preferred(hiscore.addr_type) ||
- !(ifa_result->flags & IFA_F_DEPRECATED))
+ (((ifa_result->flags &
+ (IFA_F_DEPRECATED|IFA_F_OPTIMISTIC)) == 0)))
hiscore.attrs |= IPV6_SADDR_SCORE_PREFERRED;
hiscore.rule++;
}
if (ipv6_saddr_preferred(score.addr_type) ||
- !(ifa->flags & IFA_F_DEPRECATED)) {
+ (((ifa_result->flags &
+ (IFA_F_DEPRECATED|IFA_F_OPTIMISTIC)) == 0))) {
score.attrs |= IPV6_SADDR_SCORE_PREFERRED;
if (!(hiscore.attrs & IPV6_SADDR_SCORE_PREFERRED)) {
score.rule = 3;
@@ -1145,7 +1173,8 @@ int ipv6_get_saddr(struct dst_entry *dst,
}
-int ipv6_get_lladdr(struct net_device *dev, struct in6_addr *addr)
+int ipv6_get_lladdr(struct net_device *dev, struct in6_addr *addr,
+ unsigned char banned_flags)
{
struct inet6_dev *idev;
int err = -EADDRNOTAVAIL;
@@ -1156,7 +1185,7 @@ int ipv6_get_lladdr(struct net_device *dev, struct in6_addr *addr)
read_lock_bh(&idev->lock);
for (ifp=idev->addr_list; ifp; ifp=ifp->if_next) {
- if (ifp->scope == IFA_LINK && !(ifp->flags&IFA_F_TENTATIVE)) {
+ if (ifp->scope == IFA_LINK && !(ifp->flags & banned_flags)) {
ipv6_addr_copy(addr, &ifp->addr);
err = 0;
break;
@@ -1705,6 +1734,13 @@ ok:
if (ifp == NULL && valid_lft) {
int max_addresses = in6_dev->cnf.max_addresses;
+ u32 addr_flags = 0;
+
+#ifdef CONFIG_IPV6_OPTIMISTIC_DAD
+ if (sysctl_ip6_odad &&
+ !ipv6_devconf.forwarding)
+ addr_flags = IFA_F_OPTIMISTIC;
+#endif
/* Do not allow to create too much of autoconfigured
* addresses; this would be too easy way to crash kernel.
@@ -1712,7 +1748,8 @@ ok:
if (!max_addresses ||
ipv6_count_addresses(in6_dev) < max_addresses)
ifp = ipv6_add_addr(in6_dev, &addr, pinfo->prefix_len,
- addr_type&IPV6_ADDR_SCOPE_MASK, 0);
+ addr_type&IPV6_ADDR_SCOPE_MASK,
+ addr_flags);
if (!ifp || IS_ERR(ifp)) {
in6_dev_put(in6_dev);
@@ -2092,8 +2129,16 @@ static void init_loopback(struct net_device *dev)
static void addrconf_add_linklocal(struct inet6_dev *idev, struct in6_addr *addr)
{
struct inet6_ifaddr * ifp;
+ u32 addr_flags = IFA_F_PERMANENT;
+
+#ifdef CONFIG_IPV6_OPTIMISTIC_DAD
+ if (sysctl_ip6_odad &&
+ !ipv6_devconf.forwarding)
+ addr_flags |= IFA_F_OPTIMISTIC;
+#endif
- ifp = ipv6_add_addr(idev, addr, 64, IFA_LINK, IFA_F_PERMANENT);
+
+ ifp = ipv6_add_addr(idev, addr, 64, IFA_LINK, addr_flags);
if (!IS_ERR(ifp)) {
addrconf_dad_start(ifp, 0);
in6_ifa_put(ifp);
@@ -2158,7 +2203,7 @@ ipv6_inherit_linklocal(struct inet6_dev *idev, struct net_device *link_dev)
{
struct in6_addr lladdr;
- if (!ipv6_get_lladdr(link_dev, &lladdr)) {
+ if (!ipv6_get_lladdr(link_dev, &lladdr, IFA_F_TENTATIVE)) {
addrconf_add_linklocal(idev, &lladdr);
return 0;
}
@@ -2493,7 +2538,11 @@ static void addrconf_dad_kick(struct inet6_ifaddr *ifp)
unsigned long rand_num;
struct inet6_dev *idev = ifp->idev;
- rand_num = net_random() % (idev->cnf.rtr_solicit_delay ? : 1);
+ if (ifp->flags & IFA_F_OPTIMISTIC)
+ rand_num = 0;
+ else
+ rand_num = net_random() % (idev->cnf.rtr_solicit_delay ? : 1);
+
ifp->probes = idev->cnf.dad_transmits;
addrconf_mod_timer(ifp, AC_DAD, rand_num);
}
@@ -2519,7 +2568,7 @@ static void addrconf_dad_start(struct inet6_ifaddr *ifp, u32 flags)
if (dev->flags&(IFF_NOARP|IFF_LOOPBACK) ||
!(dev->flags&IFF_MULTICAST) ||
!(ifp->flags&IFA_F_TENTATIVE)) {
- ifp->flags &= ~IFA_F_TENTATIVE;
+ ifp->flags &= ~(IFA_F_TENTATIVE|IFA_F_OPTIMISTIC);
spin_unlock_bh(&ifp->lock);
read_unlock_bh(&idev->lock);
@@ -2539,6 +2588,14 @@ static void addrconf_dad_start(struct inet6_ifaddr *ifp, u32 flags)
addrconf_dad_stop(ifp);
return;
}
+
+ /*
+ * Optimistic nodes can start receiving
+ * Frames right away
+ */
+ if(ifp->flags & IFA_F_OPTIMISTIC)
+ ip6_ins_rt(ifp->rt, NULL, NULL, NULL);
+
addrconf_dad_kick(ifp);
spin_unlock_bh(&ifp->lock);
out:
@@ -2563,7 +2620,7 @@ static void addrconf_dad_timer(unsigned long data)
* DAD was successful
*/
- ifp->flags &= ~IFA_F_TENTATIVE;
+ ifp->flags &= ~(IFA_F_TENTATIVE|IFA_F_OPTIMISTIC);
spin_unlock_bh(&ifp->lock);
read_unlock_bh(&idev->lock);
@@ -3544,7 +3601,15 @@ static void __ipv6_ifa_notify(int event, struct inet6_ifaddr *ifp)
switch (event) {
case RTM_NEWADDR:
- ip6_ins_rt(ifp->rt, NULL, NULL, NULL);
+ /*
+ * If the address was optimistic
+ * we inserted the route at the start of
+ * our DAD process, so we don't need
+ * to do it again
+ */
+ if (!(ifp->rt->rt6i_node))
+ ip6_ins_rt(ifp->rt, NULL, NULL,NULL );
+
if (ifp->idev->cnf.forwarding)
addrconf_join_anycast(ifp);
break;
diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index a0e1980..c9cebb5 100644
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -39,6 +39,7 @@
#include <linux/tcp.h>
#include <linux/route.h>
#include <linux/module.h>
+#include <linux/if_addr.h>
#include <linux/netfilter.h>
#include <linux/netfilter_ipv6.h>
@@ -791,6 +792,41 @@ static int ip6_dst_lookup_tail(struct sock *sk,
goto out_err_release;
}
+#ifdef CONFIG_IPV6_OPTIMISTIC_DAD
+ /*
+ * Here if the dst entry we've looked up
+ * has a neighbour entry that is in the INCOMPLETE
+ * state and the src address from the flow is
+ * marked as OPTIMISTIC, we release the found
+ * dst entry and replace it instead with the
+ * dst entry of the nexthop router
+ */
+ if (!((*dst)->neighbour->nud_state & NUD_VALID)) {
+ struct inet6_ifaddr *ifp;
+ struct flowi fl_gw;
+ int redirect;
+
+ ifp = ipv6_get_ifaddr(&fl->fl6_src, (*dst)->dev, 1);
+
+ redirect = (ifp && ifp->flags & IFA_F_OPTIMISTIC);
+ if (ifp)
+ in6_ifa_put(ifp);
+
+ if (redirect) {
+ /*
+ * We need to get the dst entry for the
+ * default router instead
+ */
+ dst_release(*dst);
+ memcpy(&fl_gw, fl, sizeof(struct flowi));
+ memset(&fl_gw.fl6_dst, 0, sizeof(struct in6_addr));
+ *dst = ip6_route_output(sk, &fl_gw);
+ if ((err = (*dst)->error))
+ goto out_err_release;
+ }
+ }
+#endif
+
return 0;
out_err_release:
diff --git a/net/ipv6/mcast.c b/net/ipv6/mcast.c
index dc81880..c070724 100644
--- a/net/ipv6/mcast.c
+++ b/net/ipv6/mcast.c
@@ -45,6 +45,7 @@
#include <linux/init.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
+#include <linux/if_addr.h>
#include <linux/netfilter.h>
#include <linux/netfilter_ipv6.h>
@@ -1411,7 +1412,7 @@ static struct sk_buff *mld_newpack(struct net_device *dev, int size)
skb_reserve(skb, LL_RESERVED_SPACE(dev));
- if (ipv6_get_lladdr(dev, &addr_buf)) {
+ if (ipv6_get_lladdr(dev, &addr_buf, IFA_F_TENTATIVE)) {
/* <draft-ietf-magma-mld-source-05.txt>:
* use unspecified address as the source address
* when a valid link-local address is not available.
@@ -1785,7 +1786,7 @@ static void igmp6_send(struct in6_addr *addr, struct net_device *dev, int type)
skb_reserve(skb, LL_RESERVED_SPACE(dev));
- if (ipv6_get_lladdr(dev, &addr_buf)) {
+ if (ipv6_get_lladdr(dev, &addr_buf, IFA_F_TENTATIVE)) {
/* <draft-ietf-magma-mld-source-05.txt>:
* use unspecified address as the source address
* when a valid link-local address is not available.
diff --git a/net/ipv6/ndisc.c b/net/ipv6/ndisc.c
index ad7fb18..36e6bbf 100644
--- a/net/ipv6/ndisc.c
+++ b/net/ipv6/ndisc.c
@@ -62,6 +62,7 @@
#include <linux/sysctl.h>
#endif
+#include <linux/if_addr.h>
#include <linux/if_arp.h>
#include <linux/ipv6.h>
#include <linux/icmpv6.h>
@@ -446,6 +447,8 @@ static void ndisc_send_na(struct net_device *dev, struct neighbour *neigh,
ifp = ipv6_get_ifaddr(solicited_addr, dev, 1);
if (ifp) {
src_addr = solicited_addr;
+ if (ifp->flags & IFA_F_OPTIMISTIC)
+ override = 0;
in6_ifa_put(ifp);
} else {
if (ipv6_dev_get_saddr(dev, daddr, &tmpaddr))
@@ -539,7 +542,8 @@ void ndisc_send_ns(struct net_device *dev, struct neighbour *neigh,
int send_llinfo;
if (saddr == NULL) {
- if (ipv6_get_lladdr(dev, &addr_buf))
+ if (ipv6_get_lladdr(dev, &addr_buf,
+ (IFA_F_TENTATIVE|IFA_F_OPTIMISTIC)))
return;
saddr = &addr_buf;
}
@@ -617,9 +621,32 @@ void ndisc_send_rs(struct net_device *dev, struct in6_addr *saddr,
struct sk_buff *skb;
struct icmp6hdr *hdr;
__u8 * opt;
+ struct inet6_ifaddr *ifp;
+ int send_sllao = dev->addr_len;
int len;
int err;
-
+
+ #ifdef CONFIG_IPV6_OPTIMISTIC_DAD
+ /*
+ * According to section 2.2 of RFC 4429, we must not
+ * send router solicitations with a sllao from
+ * optimistic addresses, but we may send the solicitation
+ * if we don't include the sllao. So here we check
+ * if our address is optimistic, and if so, we
+ * supress the inclusion of the sllao.
+ */
+ if (send_sllao) {
+ ifp = ipv6_get_ifaddr(saddr, dev, 1);
+ if (ifp) {
+ if (ifp->flags & IFA_F_OPTIMISTIC) {
+ send_sllao=0;
+ in6_ifa_put(ifp);
+ }
+ } else {
+ send_sllao = 0;
+ }
+ }
+#endif
ndisc_flow_init(&fl, NDISC_ROUTER_SOLICITATION, saddr, daddr,
dev->ifindex);
@@ -632,7 +659,7 @@ void ndisc_send_rs(struct net_device *dev, struct in6_addr *saddr,
return;
len = sizeof(struct icmp6hdr);
- if (dev->addr_len)
+ if (send_sllao)
len += ndisc_opt_addr_space(dev);
skb = sock_alloc_send_skb(sk, MAX_HEADER + len + LL_RESERVED_SPACE(dev),
@@ -657,7 +684,7 @@ void ndisc_send_rs(struct net_device *dev, struct in6_addr *saddr,
opt = (u8*) (hdr + 1);
- if (dev->addr_len)
+ if (send_sllao)
ndisc_fill_addr_option(opt, ND_OPT_SOURCE_LL_ADDR, dev->dev_addr,
dev->addr_len, dev->type);
@@ -787,30 +814,39 @@ static void ndisc_recv_ns(struct sk_buff *skb)
inc = ipv6_addr_is_multicast(daddr);
if ((ifp = ipv6_get_ifaddr(&msg->target, dev, 1)) != NULL) {
- if (ifp->flags & IFA_F_TENTATIVE) {
- /* Address is tentative. If the source
- is unspecified address, it is someone
- does DAD, otherwise we ignore solicitations
- until DAD timer expires.
- */
- if (!dad)
- goto out;
- if (dev->type == ARPHRD_IEEE802_TR) {
- unsigned char *sadr = skb->mac.raw;
- if (((sadr[8] ^ dev->dev_addr[0]) & 0x7f) == 0 &&
- sadr[9] == dev->dev_addr[1] &&
- sadr[10] == dev->dev_addr[2] &&
- sadr[11] == dev->dev_addr[3] &&
- sadr[12] == dev->dev_addr[4] &&
- sadr[13] == dev->dev_addr[5]) {
- /* looped-back to us */
- goto out;
+ if (ifp->flags & (IFA_F_TENTATIVE|IFA_F_OPTIMISTIC)) {
+ if (dad) {
+ if (dev->type == ARPHRD_IEEE802_TR) {
+ unsigned char *sadr = skb->mac.raw;
+ if (((sadr[8] ^ dev->dev_addr[0]) & 0x7f) == 0 &&
+ sadr[9] == dev->dev_addr[1] &&
+ sadr[10] == dev->dev_addr[2] &&
+ sadr[11] == dev->dev_addr[3] &&
+ sadr[12] == dev->dev_addr[4] &&
+ sadr[13] == dev->dev_addr[5]) {
+ /* looped-back to us */
+ goto out;
+ }
}
+
+ /*
+ * We are colliding with another node
+ * who is doing DAD
+ * so fail our DAD process
+ */
+ addrconf_dad_failure(ifp);
+ goto out;
+ } else {
+ /*
+ * This is not a dad solicitation.
+ * If we are an optimistic node,
+ * we should respond.
+ * Otherwise, we should ignore it.
+ */
+ if (!(ifp->flags & IFA_F_OPTIMISTIC))
+ goto out;
}
- addrconf_dad_failure(ifp);
- return;
}
-
idev = ifp->idev;
} else {
idev = in6_dev_get(dev);
@@ -1380,7 +1416,7 @@ void ndisc_send_redirect(struct sk_buff *skb, struct neighbour *neigh,
dev = skb->dev;
- if (ipv6_get_lladdr(dev, &saddr_buf)) {
+ if (ipv6_get_lladdr(dev, &saddr_buf, IFA_F_TENTATIVE)) {
ND_PRINTK2(KERN_WARNING
"ICMPv6 Redirect: no link-local address on %s\n",
dev->name);
diff --git a/net/ipv6/sysctl_net_ipv6.c b/net/ipv6/sysctl_net_ipv6.c
index 7a4639d..8d09102 100644
--- a/net/ipv6/sysctl_net_ipv6.c
+++ b/net/ipv6/sysctl_net_ipv6.c
@@ -80,6 +80,14 @@ static ctl_table ipv6_table[] = {
.mode = 0644,
.proc_handler = &proc_dointvec
},
+ {
+ .ctl_name = NET_IPV6_OPTIMISTIC_DAD,
+ .procname = "optimistic_dad",
+ .data = &sysctl_ip6_odad,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = &proc_dointvec
+ },
{ .ctl_name = 0 }
};
distrib
>
Scientific%20Linux
>
5x
>
x86_64
>
by-pkgid
>
fc11cd6e1c513a17304da94a5390f3cd
>
files
>
2242
