From: Guillaume Nault gnault@redhat.com
stable inclusion from stable-v5.10.96 commit 869f1704f1c29debabde2fa2a12c30f90b81f86b bugzilla: https://gitee.com/openeuler/kernel/issues/I55NWB
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...
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[ Upstream commit 36268983e90316b37000a005642af42234dabb36 ]
This reverts commit b75326c201242de9495ff98e5d5cff41d7fc0d9d.
This commit breaks Linux compatibility with USGv6 tests. The RFC this commit was based on is actually an expired draft: no published RFC currently allows the new behaviour it introduced.
Without full IETF endorsement, the flash renumbering scenario this patch was supposed to enable is never going to work, as other IPv6 equipements on the same LAN will keep the 2 hours limit.
Fixes: b75326c20124 ("ipv6: Honor all IPv6 PIO Valid Lifetime values") Signed-off-by: Guillaume Nault gnault@redhat.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Yu Liao liaoyu15@huawei.com Reviewed-by: Wei Li liwei391@huawei.com Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com --- include/net/addrconf.h | 2 ++ net/ipv6/addrconf.c | 27 ++++++++++++++++++++------- 2 files changed, 22 insertions(+), 7 deletions(-)
diff --git a/include/net/addrconf.h b/include/net/addrconf.h index 78ea3e332688..e7ce719838b5 100644 --- a/include/net/addrconf.h +++ b/include/net/addrconf.h @@ -6,6 +6,8 @@ #define RTR_SOLICITATION_INTERVAL (4*HZ) #define RTR_SOLICITATION_MAX_INTERVAL (3600*HZ) /* 1 hour */
+#define MIN_VALID_LIFETIME (2*3600) /* 2 hours */ + #define TEMP_VALID_LIFETIME (7*86400) #define TEMP_PREFERRED_LIFETIME (86400) #define REGEN_MAX_RETRY (3) diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c index f88023a34d0a..d9785ea78593 100644 --- a/net/ipv6/addrconf.c +++ b/net/ipv6/addrconf.c @@ -2581,7 +2581,7 @@ int addrconf_prefix_rcv_add_addr(struct net *net, struct net_device *dev, __u32 valid_lft, u32 prefered_lft) { struct inet6_ifaddr *ifp = ipv6_get_ifaddr(net, addr, dev, 1); - int create = 0; + int create = 0, update_lft = 0;
if (!ifp && valid_lft) { int max_addresses = in6_dev->cnf.max_addresses; @@ -2625,19 +2625,32 @@ int addrconf_prefix_rcv_add_addr(struct net *net, struct net_device *dev, unsigned long now; u32 stored_lft;
- /* Update lifetime (RFC4862 5.5.3 e) - * We deviate from RFC4862 by honoring all Valid Lifetimes to - * improve the reaction of SLAAC to renumbering events - * (draft-gont-6man-slaac-renum-06, Section 4.2) - */ + /* update lifetime (RFC2462 5.5.3 e) */ spin_lock_bh(&ifp->lock); now = jiffies; if (ifp->valid_lft > (now - ifp->tstamp) / HZ) stored_lft = ifp->valid_lft - (now - ifp->tstamp) / HZ; else stored_lft = 0; - if (!create && stored_lft) { + const u32 minimum_lft = min_t(u32, + stored_lft, MIN_VALID_LIFETIME); + valid_lft = max(valid_lft, minimum_lft); + + /* RFC4862 Section 5.5.3e: + * "Note that the preferred lifetime of the + * corresponding address is always reset to + * the Preferred Lifetime in the received + * Prefix Information option, regardless of + * whether the valid lifetime is also reset or + * ignored." + * + * So we should always update prefered_lft here. + */ + update_lft = 1; + } + + if (update_lft) { ifp->valid_lft = valid_lft; ifp->prefered_lft = prefered_lft; ifp->tstamp = now;