[PATCH net 2/2] ipv6: allow IPV6_PMTUDISC_INTERFACE generate fragments if packet size is larger than interface mtu
From: Hannes Frederic Sowa <hidden>
Date: 2014-02-25 00:58:16
Subsystem:
networking [general], networking [ipv4/ipv6], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, David Ahern, Ido Schimmel, Linus Torvalds
Following the changes of the IPv4 IP_PMTUDISC_INTERFACE logic, this
patch relax this option to allow generation of fragments if the packet
size exceeds only the interface mtu.
Fixes: 93b36cf3425b9b ("ipv6: support IPV6_PMTU_INTERFACE on sockets")
Cc: Florian Weimer <redacted>
Signed-off-by: Hannes Frederic Sowa <redacted>
---
include/net/ip6_route.h | 8 ++++++++
net/ipv6/ip6_output.c | 9 +++++----
2 files changed, 13 insertions(+), 4 deletions(-)
diff --git a/include/net/ip6_route.h b/include/net/ip6_route.h
index 017badb..f0dc32f 100644
--- a/include/net/ip6_route.h
+++ b/include/net/ip6_route.h@@ -174,6 +174,14 @@ static inline bool ip6_sk_accept_pmtu(const struct sock *sk) return inet6_sk(sk)->pmtudisc != IPV6_PMTUDISC_INTERFACE; } +static inline bool ip6_sk_allow_local_frag(const struct sock *sk) +{ + struct ipv6_pinfo *np = inet6_sk(sk); + + return np->pmtudisc != IPV6_PMTUDISC_DO && + np->pmtudisc != IPV6_PMTUDISC_PROBE; +} + static inline struct in6_addr *rt6_nexthop(struct rt6_info *rt) { return &rt->rt6i_gateway;
diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index 16f91a2..227b7b7 100644
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c@@ -1231,8 +1231,10 @@ int ip6_append_data(struct sock *sk, int getfrag(void *from, char *to, sizeof(struct frag_hdr) : 0) + rt->rt6i_nfheader_len; - maxnonfragsize = (np->pmtudisc >= IPV6_PMTUDISC_DO) ? - mtu : sizeof(struct ipv6hdr) + IPV6_MAXPLEN; + if (ip6_sk_allow_local_frag(sk)) + maxnonfragsize = sizeof(struct ipv6hdr) + IPV6_MAXPLEN; + else + maxnonfragsize = mtu; /* dontfrag active */ if ((cork->length + length > mtu - headersize) && dontfrag &&
@@ -1540,8 +1542,7 @@ int ip6_push_pending_frames(struct sock *sk) } /* Allow local fragmentation. */ - if (np->pmtudisc < IPV6_PMTUDISC_DO) - skb->local_df = 1; + skb->local_df = ip6_sk_allow_local_frag(sk); *final_dst = fl6->daddr; __skb_pull(skb, skb_network_header_len(skb));
--
1.8.5.3