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Message-ID: <49FEEE08.1090503@poczta.fm>
Date: Mon, 04 May 2009 15:30:48 +0200
From: Lukasz Stelmach <stlman@...zta.fm>
To: LKML <linux-kernel@...r.kernel.org>
Cc: netdev@...r.kernel.org, davem@...emloft.net,
yoshfuji@...ux-ipv6.org, ebiederm@...ssion.com
Subject: Re: [PATCH] Temporary IPv6 address asignment (v.1.1)
A fixed mechanism to create and recreate temporary addresses,
even for very short preferred lifetimes.
A new RFC-compliant DESYNC_FACTOR implemented as a sysctl
variable desync_factor which is assigned a random value
each time max_desync_factor is written to. Each interface
has its own desync_factor and max_desync_factor. Writes to
default/max_desync_factor influence only default values. Writes
to all/max_desync_factor influence "all" and default values but
not values of running interfaces.
The patch fixes issues described in bugs #13208 and #13221 at
http://bugzilla.kernel.org.
Signed-off-by: Łukasz Stelmach <stlman@...zta.fm>
diff --git a/include/linux/ipv6.h b/include/linux/ipv6.h
index 476d946..678687d 100644
--- a/include/linux/ipv6.h
+++ b/include/linux/ipv6.h
@@ -146,6 +146,7 @@ struct ipv6_devconf {
__s32 temp_prefered_lft;
__s32 regen_max_retry;
__s32 max_desync_factor;
+ __s32 desync_factor;
#endif
__s32 max_addresses;
__s32 accept_ra_defrtr;
@@ -201,6 +202,7 @@ enum {
DEVCONF_MC_FORWARDING,
DEVCONF_DISABLE_IPV6,
DEVCONF_ACCEPT_DAD,
+ DEVCONF_DESYNC_FACTOR,
DEVCONF_MAX
};
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index a8218bc..c883064 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -116,8 +116,6 @@ static inline void addrconf_sysctl_unregister(struct inet6_dev *idev)
static int __ipv6_regen_rndid(struct inet6_dev *idev);
static int __ipv6_try_regen_rndid(struct inet6_dev *idev, struct in6_addr *tmpaddr);
static void ipv6_regen_rndid(unsigned long data);
-
-static int desync_factor = MAX_DESYNC_FACTOR * HZ;
#endif
static int ipv6_generate_eui64(u8 *eui, struct net_device *dev);
@@ -172,6 +170,7 @@ static struct ipv6_devconf ipv6_devconf __read_mostly = {
.temp_prefered_lft = TEMP_PREFERRED_LIFETIME,
.regen_max_retry = REGEN_MAX_RETRY,
.max_desync_factor = MAX_DESYNC_FACTOR,
+ .desync_factor = MAX_DESYNC_FACTOR / 2,
#endif
.max_addresses = IPV6_MAX_ADDRESSES,
.accept_ra_defrtr = 1,
@@ -206,6 +205,7 @@ static struct ipv6_devconf ipv6_devconf_dflt __read_mostly = {
.temp_prefered_lft = TEMP_PREFERRED_LIFETIME,
.regen_max_retry = REGEN_MAX_RETRY,
.max_desync_factor = MAX_DESYNC_FACTOR,
+ .desync_factor = MAX_DESYNC_FACTOR / 2,
#endif
.max_addresses = IPV6_MAX_ADDRESSES,
.accept_ra_defrtr = 1,
@@ -831,11 +831,13 @@ static void ipv6_del_addr(struct inet6_ifaddr *ifp)
}
#ifdef CONFIG_IPV6_PRIVACY
-static int ipv6_create_tempaddr(struct inet6_ifaddr *ifp, struct inet6_ifaddr *ift)
+static int ipv6_create_tempaddr(struct inet6_ifaddr *ifp,
+ struct inet6_ifaddr *ift,
+ unsigned long now)
{
struct inet6_dev *idev = ifp->idev;
struct in6_addr addr, *tmpaddr;
- unsigned long tmp_prefered_lft, tmp_valid_lft, tmp_cstamp, tmp_tstamp;
+ unsigned long tmp_prefered_lft, tmp_valid_lft;
unsigned long regen_advance;
int tmp_plen;
int ret = 0;
@@ -890,11 +892,9 @@ retry:
idev->cnf.temp_valid_lft);
tmp_prefered_lft = min_t(__u32,
ifp->prefered_lft,
- idev->cnf.temp_prefered_lft - desync_factor / HZ);
+ idev->cnf.temp_prefered_lft - idev->cnf.desync_factor);
tmp_plen = ifp->prefix_len;
max_addresses = idev->cnf.max_addresses;
- tmp_cstamp = ifp->cstamp;
- tmp_tstamp = ifp->tstamp;
spin_unlock_bh(&ifp->lock);
regen_advance = idev->cnf.regen_max_retry *
@@ -938,8 +938,7 @@ retry:
ift->ifpub = ifp;
ift->valid_lft = tmp_valid_lft;
ift->prefered_lft = tmp_prefered_lft;
- ift->cstamp = tmp_cstamp;
- ift->tstamp = tmp_tstamp;
+ ift->cstamp = ift->tstamp = now;
spin_unlock_bh(&ift->lock);
addrconf_dad_start(ift, 0);
@@ -1388,7 +1387,7 @@ static void addrconf_dad_stop(struct inet6_ifaddr *ifp)
if (ifpub) {
in6_ifa_hold(ifpub);
spin_unlock_bh(&ifp->lock);
- ipv6_create_tempaddr(ifpub, ifp);
+ ipv6_create_tempaddr(ifpub, ifp, jiffies);
in6_ifa_put(ifpub);
} else {
spin_unlock_bh(&ifp->lock);
@@ -1624,7 +1623,8 @@ static void ipv6_regen_rndid(unsigned long data)
expires = jiffies +
idev->cnf.temp_prefered_lft * HZ -
- idev->cnf.regen_max_retry * idev->cnf.dad_transmits * idev->nd_parms->retrans_time - desync_factor;
+ idev->cnf.regen_max_retry * idev->cnf.dad_transmits * idev->nd_parms->retrans_time -
+ idev->cnf.desync_factor * HZ;
if (time_before(expires, jiffies)) {
printk(KERN_WARNING
"ipv6_regen_rndid(): too short regeneration interval; timer disabled for %s.\n",
@@ -1971,7 +1971,7 @@ ok:
* also create a new temporary address.
*/
read_unlock_bh(&in6_dev->lock);
- ipv6_create_tempaddr(ifp, NULL);
+ ipv6_create_tempaddr(ifp, NULL, jiffies);
} else {
read_unlock_bh(&in6_dev->lock);
}
@@ -2809,6 +2809,11 @@ static void addrconf_dad_timer(unsigned long data)
read_unlock_bh(&idev->lock);
addrconf_dad_completed(ifp);
+ /*
+ * Required to expire properly temporary addresses
+ * with preferred lifetimes < ADDR_CHECK_FREQUENCY
+ */
+ addrconf_verify(0);
goto out;
}
@@ -3121,7 +3126,7 @@ restart:
spin_lock(&ifpub->lock);
ifpub->regen_count = 0;
spin_unlock(&ifpub->lock);
- ipv6_create_tempaddr(ifpub, ifp);
+ ipv6_create_tempaddr(ifpub, ifp, now);
in6_ifa_put(ifpub);
in6_ifa_put(ifp);
goto restart;
@@ -3638,6 +3643,7 @@ static inline void ipv6_store_devconf(struct ipv6_devconf *cnf,
array[DEVCONF_TEMP_PREFERED_LFT] = cnf->temp_prefered_lft;
array[DEVCONF_REGEN_MAX_RETRY] = cnf->regen_max_retry;
array[DEVCONF_MAX_DESYNC_FACTOR] = cnf->max_desync_factor;
+ array[DEVCONF_DESYNC_FACTOR] = cnf->desync_factor;
#endif
array[DEVCONF_MAX_ADDRESSES] = cnf->max_addresses;
array[DEVCONF_ACCEPT_RA_DEFRTR] = cnf->accept_ra_defrtr;
@@ -3935,6 +3941,43 @@ static void ipv6_ifa_notify(int event, struct inet6_ifaddr *ifp)
}
#ifdef CONFIG_SYSCTL
+#ifdef CONFIG_IPV6_PRIVACY
+static int addrconf_sysctl_desync(ctl_table *ctl, int write,
+ struct file *filp, void __user *buffer,
+ size_t *lenp, loff_t *ppos)
+{
+ int ret;
+
+ ret = proc_dointvec(ctl, write, filp, buffer, lenp, ppos);
+
+ if (write) {
+ __s32 df;
+ int *valp = ctl->data;
+ struct ipv6_devconf *all, *dflt;
+ struct inet6_dev *idev = ctl->extra1;
+ struct net *net = ctl->extra2;
+ all = net->ipv6.devconf_all;
+ dflt = net->ipv6.devconf_dflt;
+
+ get_random_bytes(&df, sizeof(df));
+ /* The global abs() casts to int. */;
+ df = ((df) < 0 ? -(df) : df) % (*valp)
+
+ /* XXX How about some locking? */
+ if(idev)
+ idev->cnf.desync_factor = df;
+ else if (valp == &dflt->max_desync_factor)
+ dflt->desync_factor = df;
+ else if (valp == &all->max_desync_factor) {
+ all->desync_factor = df;
+ dflt->max_desync_factor = all->max_desync_factor;
+ dflt->desync_factor = df;
+ }
+
+ }
+ return ret;
+}
+#endif
static
int addrconf_sysctl_forward(ctl_table *ctl, int write, struct file * filp,
@@ -4124,6 +4167,14 @@ static struct addrconf_sysctl_table
.data = &ipv6_devconf.max_desync_factor,
.maxlen = sizeof(int),
.mode = 0644,
+ .proc_handler = addrconf_sysctl_desync,
+ },
+ {
+ .ctl_name = CTL_UNNUMBERED,
+ .procname = "desync_factor",
+ .data = &ipv6_devconf.desync_factor,
+ .maxlen = sizeof(int),
+ .mode = 0444,
.proc_handler = proc_dointvec,
},
#endif
@@ -4449,6 +4500,11 @@ int __init addrconf_init(void)
rtnl_unlock();
if (err)
goto errlo;
+#ifdef CONFIG_IPV6_PRIVACY
+ get_random_bytes(&ipv6_devconf.desync_factor, sizeof(ipv6_devconf.desync_factor));
+ ipv6_devconf.desync_factor = abs(ipv6_devconf.desync_factor) % ipv6_devconf.max_desync_factor;
+ ipv6_devconf_dflt.desync_factor = ipv6_devconf.desync_factor;
+#endif
register_netdevice_notifier(&ipv6_dev_notf);
--
Było mi bardzo miło. Czwarta pospolita klęska, [...]
>Łukasz< Już nie katolicka lecz złodziejska. (c)PP
----------------------------------------------------------------------
Dzwonki na komork!
Sprawdz >> http://link.interia.pl/f2152
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