From 1708ebc9636a249e104b83c6d105f15244825281 Mon Sep 17 00:00:00 2001 From: Nikolay Aleksandrov Date: Tue, 3 Jan 2017 12:13:39 +0100 Subject: [PATCH] ipmr, ip6mr: add RTNH_F_UNRESOLVED flag to unresolved cache entries While working with ipmr, we noticed that it is impossible to determine if an entry is actually unresolved or its IIF interface has disappeared (e.g. virtual interface got deleted). These entries look almost identical to user-space when dumping or receiving notifications. So in order to recognize them add a new RTNH_F_UNRESOLVED flag which is set when sending an unresolved cache entry to user-space. Suggested-by: Roopa Prabhu Signed-off-by: Nikolay Aleksandrov Signed-off-by: David S. Miller --- include/uapi/linux/rtnetlink.h | 1 + net/ipv4/ipmr.c | 4 +++- net/ipv6/ip6mr.c | 4 +++- 3 files changed, 7 insertions(+), 2 deletions(-) diff --git a/include/uapi/linux/rtnetlink.h b/include/uapi/linux/rtnetlink.h index e14377f..8c93ad1 100644 --- a/include/uapi/linux/rtnetlink.h +++ b/include/uapi/linux/rtnetlink.h @@ -350,6 +350,7 @@ struct rtnexthop { #define RTNH_F_ONLINK 4 /* Gateway is forced on link */ #define RTNH_F_OFFLOAD 8 /* offloaded route */ #define RTNH_F_LINKDOWN 16 /* carrier-down on nexthop */ +#define RTNH_F_UNRESOLVED 32 /* The entry is unresolved (ipmr) */ #define RTNH_COMPARE_MASK (RTNH_F_DEAD | RTNH_F_LINKDOWN | RTNH_F_OFFLOAD) diff --git a/net/ipv4/ipmr.c b/net/ipv4/ipmr.c index efc1e76..b35dda5 100644 --- a/net/ipv4/ipmr.c +++ b/net/ipv4/ipmr.c @@ -2091,8 +2091,10 @@ static int __ipmr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb, int ct; /* If cache is unresolved, don't try to parse IIF and OIF */ - if (c->mfc_parent >= MAXVIFS) + if (c->mfc_parent >= MAXVIFS) { + rtm->rtm_flags |= RTNH_F_UNRESOLVED; return -ENOENT; + } if (VIF_EXISTS(mrt, c->mfc_parent) && nla_put_u32(skb, RTA_IIF, mrt->vif_table[c->mfc_parent].dev->ifindex) < 0) diff --git a/net/ipv6/ip6mr.c b/net/ipv6/ip6mr.c index 604d8953..e275077 100644 --- a/net/ipv6/ip6mr.c +++ b/net/ipv6/ip6mr.c @@ -2243,8 +2243,10 @@ static int __ip6mr_fill_mroute(struct mr6_table *mrt, struct sk_buff *skb, int ct; /* If cache is unresolved, don't try to parse IIF and OIF */ - if (c->mf6c_parent >= MAXMIFS) + if (c->mf6c_parent >= MAXMIFS) { + rtm->rtm_flags |= RTNH_F_UNRESOLVED; return -ENOENT; + } if (MIF_EXISTS(mrt, c->mf6c_parent) && nla_put_u32(skb, RTA_IIF, mrt->vif6_table[c->mf6c_parent].dev->ifindex) < 0) -- 2.7.4