diff options
Diffstat (limited to 'net/ipv4/ip_forward.c')
| -rw-r--r-- | net/ipv4/ip_forward.c | 18 |
1 files changed, 11 insertions, 7 deletions
diff --git a/net/ipv4/ip_forward.c b/net/ipv4/ip_forward.c index 367448494..2d3aa408f 100644 --- a/net/ipv4/ip_forward.c +++ b/net/ipv4/ip_forward.c @@ -39,17 +39,21 @@ #include <net/route.h> #include <net/xfrm.h> -static bool ip_may_fragment(const struct sk_buff *skb) -{ - return unlikely((ip_hdr(skb)->frag_off & htons(IP_DF)) == 0) || - skb->ignore_df; -} - static bool ip_exceeds_mtu(const struct sk_buff *skb, unsigned int mtu) { if (skb->len <= mtu) return false; + if (unlikely((ip_hdr(skb)->frag_off & htons(IP_DF)) == 0)) + return false; + + /* original fragment exceeds mtu and DF is set */ + if (unlikely(IPCB(skb)->frag_max_size > mtu)) + return true; + + if (skb->ignore_df) + return false; + if (skb_is_gso(skb) && skb_gso_network_seglen(skb) <= mtu) return false; @@ -114,7 +118,7 @@ int ip_forward(struct sk_buff *skb) IPCB(skb)->flags |= IPSKB_FORWARDED; mtu = ip_dst_mtu_maybe_forward(&rt->dst, true); - if (!ip_may_fragment(skb) && ip_exceeds_mtu(skb, mtu)) { + if (ip_exceeds_mtu(skb, mtu)) { IP_INC_STATS(dev_net(rt->dst.dev), IPSTATS_MIB_FRAGFAILS); icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, htonl(mtu)); |