From 0ea9d5e3e0e03a63b11392f5613378977dae7eca Mon Sep 17 00:00:00 2001 From: Hannes Frederic Sowa Date: Tue, 13 Aug 2013 04:35:58 +0200 Subject: [PATCH] xfrm: introduce helper for safe determination of mtu skb->sk socket can be of AF_INET or AF_INET6 address family. Thus we always have to make sure we a referring to the correct interpretation of skb->sk. We only depend on header defines to query the mtu, so we don't introduce a new dependency to ipv6 by this change. Cc: Steffen Klassert Signed-off-by: Hannes Frederic Sowa Signed-off-by: Steffen Klassert --- include/net/route.h | 8 ++++++++ include/net/xfrm.h | 12 ++++++++++++ net/ipv4/ip_output.c | 8 -------- net/ipv4/xfrm4_output.c | 4 +--- net/ipv6/xfrm6_output.c | 5 ++++- 5 files changed, 25 insertions(+), 12 deletions(-) diff --git a/include/net/route.h b/include/net/route.h index 2ea40c1b5e0..afdeeb5bec2 100644 --- a/include/net/route.h +++ b/include/net/route.h @@ -317,4 +317,12 @@ static inline int ip4_dst_hoplimit(const struct dst_entry *dst) return hoplimit; } +static inline int ip_skb_dst_mtu(struct sk_buff *skb) +{ + struct inet_sock *inet = skb->sk ? inet_sk(skb->sk) : NULL; + + return (inet && inet->pmtudisc == IP_PMTUDISC_PROBE) ? + skb_dst(skb)->dev->mtu : dst_mtu(skb_dst(skb)); +} + #endif /* _ROUTE_H */ diff --git a/include/net/xfrm.h b/include/net/xfrm.h index e823786e7c6..b41d2d10ff0 100644 --- a/include/net/xfrm.h +++ b/include/net/xfrm.h @@ -20,6 +20,7 @@ #include #include #include +#include #include #include @@ -1723,4 +1724,15 @@ static inline int xfrm_mark_put(struct sk_buff *skb, const struct xfrm_mark *m) return ret; } +static inline int xfrm_skb_dst_mtu(struct sk_buff *skb) +{ + struct sock *sk = skb->sk; + + if (sk && sk->sk_family == AF_INET6) + return ip6_skb_dst_mtu(skb); + else if (sk && sk->sk_family == AF_INET) + return ip_skb_dst_mtu(skb); + return dst_mtu(skb_dst(skb)); +} + #endif /* _NET_XFRM_H */ diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c index 4bcabf3ab4c..9ee17e3d11c 100644 --- a/net/ipv4/ip_output.c +++ b/net/ipv4/ip_output.c @@ -211,14 +211,6 @@ static inline int ip_finish_output2(struct sk_buff *skb) return -EINVAL; } -static inline int ip_skb_dst_mtu(struct sk_buff *skb) -{ - struct inet_sock *inet = skb->sk ? inet_sk(skb->sk) : NULL; - - return (inet && inet->pmtudisc == IP_PMTUDISC_PROBE) ? - skb_dst(skb)->dev->mtu : dst_mtu(skb_dst(skb)); -} - static int ip_finish_output(struct sk_buff *skb) { #if defined(CONFIG_NETFILTER) && defined(CONFIG_XFRM) diff --git a/net/ipv4/xfrm4_output.c b/net/ipv4/xfrm4_output.c index 7a5491ffa4d..80baf4a3b1b 100644 --- a/net/ipv4/xfrm4_output.c +++ b/net/ipv4/xfrm4_output.c @@ -21,7 +21,6 @@ static int xfrm4_tunnel_check_size(struct sk_buff *skb) { int mtu, ret = 0; - struct dst_entry *dst; if (IPCB(skb)->flags & IPSKB_XFRM_TUNNEL_SIZE) goto out; @@ -29,8 +28,7 @@ static int xfrm4_tunnel_check_size(struct sk_buff *skb) if (!(ip_hdr(skb)->frag_off & htons(IP_DF)) || skb->local_df) goto out; - dst = skb_dst(skb); - mtu = dst_mtu(dst); + mtu = xfrm_skb_dst_mtu(skb); if (skb->len > mtu) { if (skb->sk) xfrm_local_error(skb, mtu); diff --git a/net/ipv6/xfrm6_output.c b/net/ipv6/xfrm6_output.c index b64fff30eb0..3ac5ab264fe 100644 --- a/net/ipv6/xfrm6_output.c +++ b/net/ipv6/xfrm6_output.c @@ -138,7 +138,10 @@ static int __xfrm6_output(struct sk_buff *skb) { struct dst_entry *dst = skb_dst(skb); struct xfrm_state *x = dst->xfrm; - int mtu = ip6_skb_dst_mtu(skb); + int mtu = xfrm_skb_dst_mtu(skb); + + if (mtu < IPV6_MIN_MTU) + mtu = IPV6_MIN_MTU; if (skb->len > mtu && xfrm6_local_dontfrag(skb)) { xfrm6_local_rxpmtu(skb, mtu); -- 2.41.0