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| author | Jakub Kicinski <kuba@kernel.org> | 2022-03-18 14:06:58 -0700 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2022-03-18 14:06:59 -0700 |
| commit | 03e2777c1a01cdc072193b72ff6a96a0147944cd (patch) | |
| tree | ed392f6ddd3fceed9b25794b834a743d34d547b0 /net | |
| parent | 6bd0c76bd70447aedfeafa9e1fcc249991d6c678 (diff) | |
| parent | ec730c3e1f0e3a80612a9be2beb00e2b4f93fe70 (diff) | |
Merge branch 'ipv4-handle-tos-and-scope-properly-for-icmp-redirects-and-pmtu-updates'
Guillaume Nault says:
====================
ipv4: Handle TOS and scope properly for ICMP redirects and PMTU updates
ICMPv4 PMTU and redirect handlers didn't properly initialise the
struct flowi4 they used for route lookups:
* ECN bits sometimes weren't cleared from ->flowi4_tos.
* The RTO_ONLINK flag wasn't taken into account for ->flowi4_scope.
In some special cases, this resulted in ICMP redirects and PMTU updates
not being taken into account because fib_lookup() couldn't retrieve the
correct route.
====================
Link: https://lore.kernel.org/r/cover.1647519748.git.gnault@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'net')
| -rw-r--r-- | net/ipv4/route.c | 18 |
1 files changed, 14 insertions, 4 deletions
diff --git a/net/ipv4/route.c b/net/ipv4/route.c index f33ad1f383b6..d5d058de3664 100644 --- a/net/ipv4/route.c +++ b/net/ipv4/route.c @@ -499,6 +499,15 @@ void __ip_select_ident(struct net *net, struct iphdr *iph, int segs) } EXPORT_SYMBOL(__ip_select_ident); +static void ip_rt_fix_tos(struct flowi4 *fl4) +{ + __u8 tos = RT_FL_TOS(fl4); + + fl4->flowi4_tos = tos & IPTOS_RT_MASK; + fl4->flowi4_scope = tos & RTO_ONLINK ? + RT_SCOPE_LINK : RT_SCOPE_UNIVERSE; +} + static void __build_flow_key(const struct net *net, struct flowi4 *fl4, const struct sock *sk, const struct iphdr *iph, @@ -824,6 +833,7 @@ static void ip_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_buf rt = (struct rtable *) dst; __build_flow_key(net, &fl4, sk, iph, oif, tos, prot, mark, 0); + ip_rt_fix_tos(&fl4); __ip_do_redirect(rt, skb, &fl4, true); } @@ -1048,6 +1058,7 @@ static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk, struct flowi4 fl4; ip_rt_build_flow_key(&fl4, sk, skb); + ip_rt_fix_tos(&fl4); /* Don't make lookup fail for bridged encapsulations */ if (skb && netif_is_any_bridge_port(skb->dev)) @@ -1122,6 +1133,8 @@ void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu) goto out; new = true; + } else { + ip_rt_fix_tos(&fl4); } __ip_rt_update_pmtu((struct rtable *)xfrm_dst_path(&rt->dst), &fl4, mtu); @@ -2603,7 +2616,6 @@ add: struct rtable *ip_route_output_key_hash(struct net *net, struct flowi4 *fl4, const struct sk_buff *skb) { - __u8 tos = RT_FL_TOS(fl4); struct fib_result res = { .type = RTN_UNSPEC, .fi = NULL, @@ -2613,9 +2625,7 @@ struct rtable *ip_route_output_key_hash(struct net *net, struct flowi4 *fl4, struct rtable *rth; fl4->flowi4_iif = LOOPBACK_IFINDEX; - fl4->flowi4_tos = tos & IPTOS_RT_MASK; - fl4->flowi4_scope = ((tos & RTO_ONLINK) ? - RT_SCOPE_LINK : RT_SCOPE_UNIVERSE); + ip_rt_fix_tos(fl4); rcu_read_lock(); rth = ip_route_output_key_hash_rcu(net, fl4, &res, skb); |