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authorLorenzo Colitti <lorenzo@google.com>2011-07-26 13:50:49 +0000
committerDavid S. Miller <davem@davemloft.net>2011-08-01 18:05:00 -0700
commit76f793e3a47139d340185cbc1a314740c09b13d3 (patch)
tree9abd3f1753cb10d328cc87db365910ef2181ea69 /net
parentnet/smsc911x: add device tree probe support (diff)
downloadlinux-dev-76f793e3a47139d340185cbc1a314740c09b13d3.tar.xz
linux-dev-76f793e3a47139d340185cbc1a314740c09b13d3.zip
ipv6: updates to privacy addresses per RFC 4941.
Update the code to handle some of the differences between RFC 3041 and RFC 4941, which obsoletes it. Also a couple of janitorial fixes. - Allow router advertisements to increase the lifetime of temporary addresses. This was not allowed by RFC 3041, but is specified by RFC 4941. It is useful when RA lifetimes are lower than TEMP_{VALID,PREFERRED}_LIFETIME: in this case, the previous code would delete or deprecate addresses prematurely. - Change the default of MAX_RETRY to 3 per RFC 4941. - Add a comment to clarify that the preferred and valid lifetimes in inet6_ifaddr are relative to the timestamp. - Shorten lines to 80 characters in a couple of places. Signed-off-by: Lorenzo Colitti <lorenzo@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r--net/ipv6/addrconf.c69
1 files changed, 48 insertions, 21 deletions
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index a55500cc0b29..9a852156a8f3 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -824,12 +824,13 @@ static int ipv6_create_tempaddr(struct inet6_ifaddr *ifp, struct inet6_ifaddr *i
{
struct inet6_dev *idev = ifp->idev;
struct in6_addr addr, *tmpaddr;
- unsigned long tmp_prefered_lft, tmp_valid_lft, tmp_cstamp, tmp_tstamp, age;
+ unsigned long tmp_prefered_lft, tmp_valid_lft, tmp_tstamp, age;
unsigned long regen_advance;
int tmp_plen;
int ret = 0;
int max_addresses;
u32 addr_flags;
+ unsigned long now = jiffies;
write_lock(&idev->lock);
if (ift) {
@@ -874,7 +875,7 @@ retry:
goto out;
}
memcpy(&addr.s6_addr[8], idev->rndid, 8);
- age = (jiffies - ifp->tstamp) / HZ;
+ age = (now - ifp->tstamp) / HZ;
tmp_valid_lft = min_t(__u32,
ifp->valid_lft,
idev->cnf.temp_valid_lft + age);
@@ -884,7 +885,6 @@ retry:
idev->cnf.max_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);
@@ -929,7 +929,7 @@ retry:
ift->ifpub = ifp;
ift->valid_lft = tmp_valid_lft;
ift->prefered_lft = tmp_prefered_lft;
- ift->cstamp = tmp_cstamp;
+ ift->cstamp = now;
ift->tstamp = tmp_tstamp;
spin_unlock_bh(&ift->lock);
@@ -1999,25 +1999,50 @@ ok:
#ifdef CONFIG_IPV6_PRIVACY
read_lock_bh(&in6_dev->lock);
/* update all temporary addresses in the list */
- list_for_each_entry(ift, &in6_dev->tempaddr_list, tmp_list) {
- /*
- * When adjusting the lifetimes of an existing
- * temporary address, only lower the lifetimes.
- * Implementations must not increase the
- * lifetimes of an existing temporary address
- * when processing a Prefix Information Option.
- */
+ list_for_each_entry(ift, &in6_dev->tempaddr_list,
+ tmp_list) {
+ int age, max_valid, max_prefered;
+
if (ifp != ift->ifpub)
continue;
+ /*
+ * RFC 4941 section 3.3:
+ * If a received option will extend the lifetime
+ * of a public address, the lifetimes of
+ * temporary addresses should be extended,
+ * subject to the overall constraint that no
+ * temporary addresses should ever remain
+ * "valid" or "preferred" for a time longer than
+ * (TEMP_VALID_LIFETIME) or
+ * (TEMP_PREFERRED_LIFETIME - DESYNC_FACTOR),
+ * respectively.
+ */
+ age = (now - ift->cstamp) / HZ;
+ max_valid = in6_dev->cnf.temp_valid_lft - age;
+ if (max_valid < 0)
+ max_valid = 0;
+
+ max_prefered = in6_dev->cnf.temp_prefered_lft -
+ in6_dev->cnf.max_desync_factor -
+ age;
+ if (max_prefered < 0)
+ max_prefered = 0;
+
+ if (valid_lft > max_valid)
+ valid_lft = max_valid;
+
+ if (prefered_lft > max_prefered)
+ prefered_lft = max_prefered;
+
spin_lock(&ift->lock);
flags = ift->flags;
- if (ift->valid_lft > valid_lft &&
- ift->valid_lft - valid_lft > (jiffies - ift->tstamp) / HZ)
- ift->valid_lft = valid_lft + (jiffies - ift->tstamp) / HZ;
- if (ift->prefered_lft > prefered_lft &&
- ift->prefered_lft - prefered_lft > (jiffies - ift->tstamp) / HZ)
- ift->prefered_lft = prefered_lft + (jiffies - ift->tstamp) / HZ;
+ ift->valid_lft = valid_lft;
+ ift->prefered_lft = prefered_lft;
+ ift->tstamp = now;
+ if (prefered_lft > 0)
+ ift->flags &= ~IFA_F_DEPRECATED;
+
spin_unlock(&ift->lock);
if (!(flags&IFA_F_TENTATIVE))
ipv6_ifa_notify(0, ift);
@@ -2025,9 +2050,11 @@ ok:
if ((create || list_empty(&in6_dev->tempaddr_list)) && in6_dev->cnf.use_tempaddr > 0) {
/*
- * When a new public address is created as described in [ADDRCONF],
- * also create a new temporary address. Also create a temporary
- * address if it's enabled but no temporary address currently exists.
+ * When a new public address is created as
+ * described in [ADDRCONF], also create a new
+ * temporary address. Also create a temporary
+ * address if it's enabled but no temporary
+ * address currently exists.
*/
read_unlock_bh(&in6_dev->lock);
ipv6_create_tempaddr(ifp, NULL);