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Message-ID: <20070208193210.GC27267@hmsreliant.homelinux.net>
Date: Thu, 8 Feb 2007 14:32:10 -0500
From: Neil Horman <nhorman@...driver.com>
To: YOSHIFUJI Hideaki / 吉藤英明
<yoshfuji@...ux-ipv6.org>
Cc: vladislav.yasevich@...com, sri@...ibm.com, davem@...emloft.net,
kuznet@....inr.ac.ru, pekkas@...core.fi, jmorris@...ei.org,
kaber@...eworks.de, netdev@...r.kernel.org
Subject: Re: [PATCH] IPv6: Implement RFC 4429 Optimistic Duplicate Address Detection
On Fri, Feb 09, 2007 at 02:10:37AM +0900, YOSHIFUJI Hideaki / 吉藤英明 wrote:
> In article <20070208164151.GB27267@...reliant.homelinux.net> (at Thu, 8 Feb 2007 11:41:52 -0500), Neil Horman <nhorman@...driver.com> says:
>
><snip>
> These should be placed
>
> > }
>
> here. No?
>
Yes, you're right. After re-reading the logic, its pretty evident that you want
to do the optimistic dad checks regardless of weather the flows initial source
address is the anycast address.
><snip>
>
> Still leaking ifp. Something like this?
>
> int send_sllao = dev->addr_len;
>
> #ifdef CONFIG_IPV6_OPTIMISTIC_DAD
> if (send_sllao) {
> struct inet6_ifaddr *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
>
Yeah, definately another leak. You're fix looks good to me.
New patch attached with these fixes included
Thanks & Regards
Neil
Signed-off-by: Neil Horman <nhorman@...driver.com>
include/linux/if_addr.h | 1
include/linux/ipv6.h | 4 ++
include/linux/sysctl.h | 1
include/net/addrconf.h | 4 +-
net/ipv6/Kconfig | 10 +++++
net/ipv6/addrconf.c | 90 ++++++++++++++++++++++++++++++++++++++++--------
net/ipv6/ip6_output.c | 35 ++++++++++++++++++
net/ipv6/mcast.c | 4 +-
net/ipv6/ndisc.c | 84 ++++++++++++++++++++++++++++++++------------
9 files changed, 192 insertions(+), 41 deletions(-)
diff --git a/include/linux/if_addr.h b/include/linux/if_addr.h
index d557e4c..43f3bed 100644
--- a/include/linux/if_addr.h
+++ b/include/linux/if_addr.h
@@ -39,6 +39,7 @@ enum
#define IFA_F_TEMPORARY IFA_F_SECONDARY
#define IFA_F_NODAD 0x02
+#define IFA_F_OPTIMISTIC 0x04
#define IFA_F_HOMEADDRESS 0x10
#define IFA_F_DEPRECATED 0x20
#define IFA_F_TENTATIVE 0x40
diff --git a/include/linux/ipv6.h b/include/linux/ipv6.h
index f824113..bf93c1b 100644
--- a/include/linux/ipv6.h
+++ b/include/linux/ipv6.h
@@ -177,6 +177,9 @@ struct ipv6_devconf {
#endif
#endif
__s32 proxy_ndp;
+#ifdef CONFIG_IPV6_OPTIMISTIC_DAD
+ __s32 optimistic_dad;
+#endif
void *sysctl;
};
@@ -205,6 +208,7 @@ enum {
DEVCONF_RTR_PROBE_INTERVAL,
DEVCONF_ACCEPT_RA_RT_INFO_MAX_PLEN,
DEVCONF_PROXY_NDP,
+ DEVCONF_OPTIMISTIC_DAD,
DEVCONF_MAX
};
diff --git a/include/linux/sysctl.h b/include/linux/sysctl.h
index 81480e6..972a33a 100644
--- a/include/linux/sysctl.h
+++ b/include/linux/sysctl.h
@@ -570,6 +570,7 @@ enum {
NET_IPV6_RTR_PROBE_INTERVAL=21,
NET_IPV6_ACCEPT_RA_RT_INFO_MAX_PLEN=22,
NET_IPV6_PROXY_NDP=23,
+ NET_IPV6_OPTIMISTIC_DAD=24,
__NET_IPV6_MAX
};
diff --git a/include/net/addrconf.h b/include/net/addrconf.h
index 88df8fc..d248a19 100644
--- a/include/net/addrconf.h
+++ b/include/net/addrconf.h
@@ -73,7 +73,9 @@ 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 *,
+ 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/ipv6/Kconfig b/net/ipv6/Kconfig
index deb4101..822d3eb 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 e385469..c884eeb 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -594,6 +594,16 @@ 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 */
@@ -770,6 +780,7 @@ 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) {
@@ -827,10 +838,17 @@ 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);
@@ -962,13 +980,14 @@ 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)) {
@@ -1027,15 +1046,17 @@ 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;
@@ -1174,7 +1195,8 @@ 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;
@@ -1185,7 +1207,7 @@ 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;
@@ -1735,6 +1757,13 @@ ok:
if (ifp == NULL && valid_lft) {
int max_addresses = in6_dev->cnf.max_addresses;
+ u32 addr_flags = 0;
+
+#ifdef CONFIG_IPV6_OPTIMISTIC_DAD
+ if (in6_dev->cnf.optimistic_dad &&
+ !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.
@@ -1742,7 +1771,8 @@ 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);
@@ -1945,7 +1975,11 @@ static int inet6_addr_add(int ifindex, struct in6_addr *pfx, int plen,
ifp->prefered_lft = prefered_lft;
ifp->tstamp = jiffies;
spin_unlock_bh(&ifp->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(ifp, 0);
in6_ifa_put(ifp);
addrconf_verify(0);
@@ -2122,8 +2156,16 @@ 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;
- ifp = ipv6_add_addr(idev, addr, 64, IFA_LINK, IFA_F_PERMANENT);
+#ifdef CONFIG_IPV6_OPTIMISTIC_DAD
+ if (idev->cnf.optimistic_dad &&
+ !ipv6_devconf.forwarding)
+ addr_flags |= IFA_F_OPTIMISTIC;
+#endif
+
+
+ ifp = ipv6_add_addr(idev, addr, 64, IFA_LINK, addr_flags);
if (!IS_ERR(ifp)) {
addrconf_dad_start(ifp, 0);
in6_ifa_put(ifp);
@@ -2190,7 +2232,7 @@ 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;
}
@@ -2527,7 +2569,11 @@ 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);
}
@@ -2553,7 +2599,7 @@ static void addrconf_dad_start(struct inet6_ifaddr *ifp, u32 flags)
if (dev->flags&(IFF_NOARP|IFF_LOOPBACK) ||
!(ifp->flags&IFA_F_TENTATIVE) ||
ifp->flags & IFA_F_NODAD) {
- ifp->flags &= ~IFA_F_TENTATIVE;
+ ifp->flags &= ~(IFA_F_TENTATIVE|IFA_F_OPTIMISTIC);
spin_unlock_bh(&ifp->lock);
read_unlock_bh(&idev->lock);
@@ -2597,7 +2643,7 @@ 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);
@@ -3398,6 +3444,9 @@ static void inline ipv6_store_devconf(struct ipv6_devconf *cnf,
#endif
#endif
array[DEVCONF_PROXY_NDP] = cnf->proxy_ndp;
+#ifdef CONFIG_IPV6_OPTIMISTIC_DAD
+ array[DEVCONF_OPTIMISTIC_DAD] = cnf->optimistic_dad;
+#endif
}
static inline size_t inet6_if_nlmsg_size(void)
@@ -3917,6 +3966,17 @@ static struct addrconf_sysctl_table
.mode = 0644,
.proc_handler = &proc_dointvec,
},
+#ifdef CONFIG_IPV6_OPTIMISTIC_DAD
+ {
+ .ctl_name = NET_IPV6_OPTIMISTIC_DAD,
+ .procname = "optimistic_dad",
+ .data = &ipv6_devconf.optimistic_dad,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = &proc_dointvec,
+
+ },
+#endif
{
.ctl_name = 0, /* sentinel */
}
diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index 7b7bd44..df13fc8 100644
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -861,6 +861,41 @@ 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 882cde4..9c5273c 100644
--- a/net/ipv6/mcast.c
+++ b/net/ipv6/mcast.c
@@ -1411,7 +1411,7 @@ 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.
@@ -1789,7 +1789,7 @@ 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 39bb658..98913c4 100644
--- a/net/ipv6/ndisc.c
+++ b/net/ipv6/ndisc.c
@@ -447,6 +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))
@@ -542,7 +544,8 @@ 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;
}
@@ -622,9 +625,33 @@ 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);
@@ -637,7 +664,7 @@ 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,
@@ -664,7 +691,7 @@ 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);
@@ -796,28 +823,39 @@ 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)
+
+ 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;
- 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 */
+ } 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;
@@ -1406,7 +1444,7 @@ 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);
-
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