| Message ID | 1611959267-20536-1-git-send-email-vfedorenko@novek.ru (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 28e104d00281ade30250b24e098bf50887671ea4 |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [RESEND,net,v3] net: ip_tunnel: fix mtu calculation | expand |
| Context | Check | Description |
|---|---|---|
| netdev/cover_letter | success | Link |
| netdev/fixes_present | success | Link |
| netdev/patch_count | success | Link |
| netdev/tree_selection | success | Clearly marked for net |
| netdev/subject_prefix | success | Link |
| netdev/cc_maintainers | warning | 6 maintainers not CCed: xiyou.wangcong@gmail.com willemb@google.com yoshfuji@linux-ipv6.org xie.he.0141@gmail.com davem@davemloft.net dsahern@kernel.org |
| netdev/source_inline | success | Was 0 now: 0 |
| netdev/verify_signedoff | success | Link |
| netdev/module_param | success | Was 0 now: 0 |
| netdev/build_32bit | success | Errors and warnings before: 0 this patch: 0 |
| netdev/kdoc | success | Errors and warnings before: 0 this patch: 0 |
| netdev/verify_fixes | success | Link |
| netdev/checkpatch | warning | WARNING: line length of 82 exceeds 80 columns |
| netdev/build_allmodconfig_warn | success | Errors and warnings before: 0 this patch: 0 |
| netdev/header_inline | success | Link |
| netdev/stable | success | Stable not CCed |
On Fri, Jan 29, 2021 at 2:30 PM Vadim Fedorenko <vfedorenko@novek.ru> wrote: > > dev->hard_header_len for tunnel interface is set only when header_ops > are set too and already contains full overhead of any tunnel encapsulation. > That's why there is not need to use this overhead twice in mtu calc. > > Fixes: fdafed459998 ("ip_gre: set dev->hard_header_len and dev->needed_headroom properly") > Reported-by: Slava Bacherikov <mail@slava.cc> > Signed-off-by: Vadim Fedorenko <vfedorenko@novek.ru> I have no objection, just please double check this does not break other IP tunnels as you touch the core ip tunnel code, especially those using ip_tunnel_header_ops. Thanks.
Hello: This patch was applied to netdev/net.git (refs/heads/master): On Sat, 30 Jan 2021 01:27:47 +0300 you wrote: > dev->hard_header_len for tunnel interface is set only when header_ops > are set too and already contains full overhead of any tunnel encapsulation. > That's why there is not need to use this overhead twice in mtu calc. > > Fixes: fdafed459998 ("ip_gre: set dev->hard_header_len and dev->needed_headroom properly") > Reported-by: Slava Bacherikov <mail@slava.cc> > Signed-off-by: Vadim Fedorenko <vfedorenko@novek.ru> > > [...] Here is the summary with links: - [RESEND,net,v3] net: ip_tunnel: fix mtu calculation https://git.kernel.org/netdev/net/c/28e104d00281 You are awesome, thank you! -- Deet-doot-dot, I am a bot. https://korg.docs.kernel.org/patchwork/pwbot.html
diff --git a/net/ipv4/ip_tunnel.c b/net/ipv4/ip_tunnel.c index 64594aa..76a420c 100644 --- a/net/ipv4/ip_tunnel.c +++ b/net/ipv4/ip_tunnel.c @@ -317,7 +317,7 @@ static int ip_tunnel_bind_dev(struct net_device *dev) } dev->needed_headroom = t_hlen + hlen; - mtu -= (dev->hard_header_len + t_hlen); + mtu -= t_hlen; if (mtu < IPV4_MIN_MTU) mtu = IPV4_MIN_MTU; @@ -347,7 +347,7 @@ static struct ip_tunnel *ip_tunnel_create(struct net *net, nt = netdev_priv(dev); t_hlen = nt->hlen + sizeof(struct iphdr); dev->min_mtu = ETH_MIN_MTU; - dev->max_mtu = IP_MAX_MTU - dev->hard_header_len - t_hlen; + dev->max_mtu = IP_MAX_MTU - t_hlen; ip_tunnel_add(itn, nt); return nt; @@ -488,11 +488,10 @@ static int tnl_update_pmtu(struct net_device *dev, struct sk_buff *skb, int mtu; tunnel_hlen = md ? tunnel_hlen : tunnel->hlen; - pkt_size = skb->len - tunnel_hlen - dev->hard_header_len; + pkt_size = skb->len - tunnel_hlen; if (df) - mtu = dst_mtu(&rt->dst) - dev->hard_header_len - - sizeof(struct iphdr) - tunnel_hlen; + mtu = dst_mtu(&rt->dst) - (sizeof(struct iphdr) + tunnel_hlen); else mtu = skb_valid_dst(skb) ? dst_mtu(skb_dst(skb)) : dev->mtu; @@ -972,7 +971,7 @@ int __ip_tunnel_change_mtu(struct net_device *dev, int new_mtu, bool strict) { struct ip_tunnel *tunnel = netdev_priv(dev); int t_hlen = tunnel->hlen + sizeof(struct iphdr); - int max_mtu = IP_MAX_MTU - dev->hard_header_len - t_hlen; + int max_mtu = IP_MAX_MTU - t_hlen; if (new_mtu < ETH_MIN_MTU) return -EINVAL; @@ -1149,10 +1148,9 @@ int ip_tunnel_newlink(struct net_device *dev, struct nlattr *tb[], mtu = ip_tunnel_bind_dev(dev); if (tb[IFLA_MTU]) { - unsigned int max = IP_MAX_MTU - dev->hard_header_len - nt->hlen; + unsigned int max = IP_MAX_MTU - (nt->hlen + sizeof(struct iphdr)); - mtu = clamp(dev->mtu, (unsigned int)ETH_MIN_MTU, - (unsigned int)(max - sizeof(struct iphdr))); + mtu = clamp(dev->mtu, (unsigned int)ETH_MIN_MTU, max); } err = dev_set_mtu(dev, mtu);
dev->hard_header_len for tunnel interface is set only when header_ops are set too and already contains full overhead of any tunnel encapsulation. That's why there is not need to use this overhead twice in mtu calc. Fixes: fdafed459998 ("ip_gre: set dev->hard_header_len and dev->needed_headroom properly") Reported-by: Slava Bacherikov <mail@slava.cc> Signed-off-by: Vadim Fedorenko <vfedorenko@novek.ru> --- net/ipv4/ip_tunnel.c | 16 +++++++--------- 1 file changed, 7 insertions(+), 9 deletions(-)