Ok, I'm still testing it, but heres a new patch for review. Significant changes
include the addition of a CONFIG_IPV6_OPTIMISTIC_DAD option that is dependent on
the inclusion of both IPPV6 and EXPERIMENTAL options, as well as a new method
for redirecting packets from optimistic sources to incomplete neighbors by
instead looking up a default router in ip6_dst_lookup_tail, as I described in my
previous note.
Thoughts and comments appreciated
Thanks & Regards
Neil
Signed-off-by: Neil Horman <[EMAIL PROTECTED]>
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 | 79 ++++++++++++++++++++++++++++++++++++++----------
net/ipv6/ip6_output.c | 32 ++++++++++++++++++-
net/ipv6/mcast.c | 4 +-
net/ipv6/ndisc.c | 79 +++++++++++++++++++++++++++++++++---------------
9 files changed, 171 insertions(+), 43 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 2a7e461..d00e3f6 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -593,7 +593,13 @@ ipv6_add_addr(struct inet6_dev *idev, const struct
in6_addr *addr, int pfxlen,
ifa->cstamp = ifa->tstamp = jiffies;
ifa->rt = rt;
-
+#ifdef CONFIG_IPV6_OPTIMISTIC_DAD
+ if (!idev->cnf.optimistic_dad || ipv6_devconf.forwarding ||
+ (ifa->rt->rt6i_nexthop == NULL))
+ ifa->flags &= ~IFA_F_OPTIMISTIC;
+#else
+ ifa->flags &= ~IFA_F_OPTIMISTIC;
+#endif
ifa->idev = idev;
in6_dev_hold(idev);
/* For caller */
@@ -830,7 +836,8 @@ retry:
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,
+ IFA_F_TEMPORARY|IFA_F_OPTIMISTIC) : NULL;
if (!ift || IS_ERR(ift)) {
in6_ifa_put(ifp);
in6_dev_put(idev);
@@ -962,13 +969,14 @@ 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 +1035,17 @@ int ipv6_dev_get_saddr(struct net_device *daddr_dev,
}
}
- /* Rule 3: Avoid deprecated address */
+ /* Rule 3: Avoid deprecated and optimistic address */
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 +1184,8 @@ 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 +1196,7 @@ 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;
@@ -1751,6 +1762,10 @@ ok:
update_lft = create = 1;
ifp->cstamp = jiffies;
+#ifdef CONFIG_IPV6_OPTIMISTIC_DAD
+ if (ifp->idev->cnf.optimistic_dad)
+ ifp->flags |= IFA_F_OPTIMISTIC;
+#endif
addrconf_dad_start(ifp, RTF_ADDRCONF|RTF_PREFIX_RT);
}
@@ -1945,7 +1960,11 @@ 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);
@@ -2123,7 +2142,8 @@ static void addrconf_add_linklocal(struct inet6_dev
*idev, struct in6_addr *addr
{
struct inet6_ifaddr * ifp;
- ifp = ipv6_add_addr(idev, addr, 64, IFA_LINK, IFA_F_PERMANENT);
+ ifp = ipv6_add_addr(idev, addr, 64, IFA_LINK,
+ IFA_F_PERMANENT|IFA_F_OPTIMISTIC);
if (!IS_ERR(ifp)) {
addrconf_dad_start(ifp, 0);
in6_ifa_put(ifp);
@@ -2190,7 +2210,7 @@ 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 +2547,11 @@ 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 +2577,7 @@ 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);
@@ -2573,6 +2597,14 @@ static void addrconf_dad_start(struct inet6_ifaddr *ifp,
u32 flags)
addrconf_dad_stop(ifp);
return;
}
+
+ /*
+ * Optimistic nodes need to join the anycast address
+ * right away
+ */
+ if (ifp->flags & IFA_F_OPTIMISTIC)
+ addrconf_join_anycast(ifp);
+
addrconf_dad_kick(ifp);
spin_unlock_bh(&ifp->lock);
out:
@@ -2597,7 +2629,7 @@ 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);
@@ -2627,6 +2659,9 @@ static void addrconf_dad_completed(struct inet6_ifaddr
*ifp)
* Configure the address for reception. Now it is valid.
*/
+ if (ifp->flags & IFA_F_OPTIMISTIC)
+ addrconf_leave_anycast(ifp);
+
ipv6_ifa_notify(RTM_NEWADDR, ifp);
/* If added prefix is link local and forwarding is off,
@@ -3398,6 +3433,9 @@ 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 +3955,17 @@ 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..cf32b50 100644
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -848,13 +848,43 @@ static int ip6_dst_lookup_tail(struct sock *sk,
struct dst_entry **dst, struct flowi *fl)
{
int err;
-
+#ifdef CONFIG_IPV6_OPTIMISTIC_DAD
+ struct inet6_ifaddr *ifp;
+ struct flowi gateway_fl;
+#endif
if (*dst == NULL)
*dst = ip6_route_output(sk, fl);
if ((err = (*dst)->error))
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_INCOMPLETE) ||
+ ((*dst)->neighbour->nud_state == NUD_FAILED)) {
+ ifp = ipv6_get_ifaddr(&fl->fl6_src, (*dst)->dev, 1);
+
+ if (ifp && ifp->flags & IFA_F_OPTIMISTIC) {
+ /*
+ * We need to get the dst entry for the
+ * default router instead
+ */
+ dst_release(*dst);
+ memcpy(&gateway_fl, fl, sizeof(struct flowi));
+ memset(&gateway_fl.fl6_dst, 0, sizeof(struct in6_addr));
+ *dst = ip6_route_output(sk, &gateway_fl);
+ if ((err = (*dst)->error))
+ goto out_err_release;
+ }
+ }
+#endif
if (ipv6_addr_any(&fl->fl6_src)) {
err = ipv6_get_saddr(*dst, &fl->fl6_dst, &fl->fl6_src);
if (err)
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 6a9f616..90404d8 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))
@@ -498,7 +500,8 @@ static void ndisc_send_na(struct net_device *dev, struct
neighbour *neigh,
msg->icmph.icmp6_unused = 0;
msg->icmph.icmp6_router = router;
msg->icmph.icmp6_solicited = solicited;
- msg->icmph.icmp6_override = override;
+ msg->icmph.icmp6_override = override;
+
/* Set the target address. */
ipv6_addr_copy(&msg->target, solicited_addr);
@@ -540,13 +543,16 @@ void ndisc_send_ns(struct net_device *dev, struct
neighbour *neigh,
int len;
int err;
int send_llinfo;
+ unsigned char *lladdr = NULL;
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;
}
+
ndisc_flow_init(&fl, NDISC_NEIGHBOUR_SOLICITATION, saddr, daddr,
dev->ifindex);
@@ -559,7 +565,8 @@ void ndisc_send_ns(struct net_device *dev, struct neighbour
*neigh,
return;
len = sizeof(struct icmp6hdr) + sizeof(struct in6_addr);
- send_llinfo = dev->addr_len && !ipv6_addr_any(saddr);
+ send_llinfo = (dev->addr_len && !ipv6_addr_any(saddr));
+
if (send_llinfo)
len += ndisc_opt_addr_space(dev);
@@ -622,9 +629,21 @@ 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 include_sllao_option = 1;
int len;
int err;
+ /*
+ * Check the source address. If its OPTIMISTIC
+ * and addr_len is non-zero (implying the sllao option)
+ * then don't send the RS (RFC 4429, section 2.2)
+ */
+ ifp = ipv6_get_ifaddr(saddr, dev, 1);
+
+ if ((!ifp) || ((ifp->flags & IFA_F_OPTIMISTIC) && dev->addr_len))
+ include_sllao_option=0;
+
ndisc_flow_init(&fl, NDISC_ROUTER_SOLICITATION, saddr, daddr,
dev->ifindex);
@@ -664,7 +683,7 @@ void ndisc_send_rs(struct net_device *dev, struct in6_addr
*saddr,
opt = (u8*) (hdr + 1);
- if (dev->addr_len)
+ if (dev->addr_len && include_sllao_option)
ndisc_fill_addr_option(opt, ND_OPT_SOURCE_LL_ADDR,
dev->dev_addr,
dev->addr_len, dev->type);
@@ -746,6 +765,7 @@ static void ndisc_recv_ns(struct sk_buff *skb)
int dad = ipv6_addr_any(saddr);
int inc;
int is_router;
+ int type;
if (ipv6_addr_is_multicast(&msg->target)) {
ND_PRINTK2(KERN_WARNING
@@ -796,28 +816,39 @@ 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 +1437,7 @@ 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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