diff options
Diffstat (limited to 'net/ipv4/ip_output.c')
| -rw-r--r-- | net/ipv4/ip_output.c | 29 |
1 files changed, 21 insertions, 8 deletions
diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c index 451b009..f5f5ef1 100644 --- a/net/ipv4/ip_output.c +++ b/net/ipv4/ip_output.c @@ -84,6 +84,7 @@ int sysctl_ip_default_ttl __read_mostly = IPDEFTTL; EXPORT_SYMBOL(sysctl_ip_default_ttl); static int ip_fragment(struct sock *sk, struct sk_buff *skb, + unsigned int mtu, int (*output)(struct sock *, struct sk_buff *)); /* Generate a checksum for an outgoing IP datagram. */ @@ -219,7 +220,8 @@ static inline int ip_finish_output2(struct sock *sk, struct sk_buff *skb) return -EINVAL; } -static int ip_finish_output_gso(struct sock *sk, struct sk_buff *skb) +static int ip_finish_output_gso(struct sock *sk, struct sk_buff *skb, + unsigned int mtu) { netdev_features_t features; struct sk_buff *segs; @@ -227,7 +229,7 @@ static int ip_finish_output_gso(struct sock *sk, struct sk_buff *skb) /* common case: locally created skb or seglen is <= mtu */ if (((IPCB(skb)->flags & IPSKB_FORWARDED) == 0) || - skb_gso_network_seglen(skb) <= ip_skb_dst_mtu(skb)) + skb_gso_network_seglen(skb) <= mtu) return ip_finish_output2(sk, skb); /* Slowpath - GSO segment length is exceeding the dst MTU. @@ -251,7 +253,7 @@ static int ip_finish_output_gso(struct sock *sk, struct sk_buff *skb) int err; segs->next = NULL; - err = ip_fragment(sk, segs, ip_finish_output2); + err = ip_fragment(sk, segs, mtu, ip_finish_output2); if (err && ret == 0) ret = err; @@ -263,6 +265,8 @@ static int ip_finish_output_gso(struct sock *sk, struct sk_buff *skb) static int ip_finish_output(struct sock *sk, struct sk_buff *skb) { + unsigned int mtu; + #if defined(CONFIG_NETFILTER) && defined(CONFIG_XFRM) /* Policy lookup after SNAT yielded a new policy */ if (skb_dst(skb)->xfrm) { @@ -270,11 +274,12 @@ static int ip_finish_output(struct sock *sk, struct sk_buff *skb) return dst_output_sk(sk, skb); } #endif + mtu = ip_skb_dst_mtu(skb); if (skb_is_gso(skb)) - return ip_finish_output_gso(sk, skb); + return ip_finish_output_gso(sk, skb, mtu); - if (skb->len > ip_skb_dst_mtu(skb)) - return ip_fragment(sk, skb, ip_finish_output2); + if (skb->len > mtu || (IPCB(skb)->flags & IPSKB_FRAG_PMTU)) + return ip_fragment(sk, skb, mtu, ip_finish_output2); return ip_finish_output2(sk, skb); } @@ -482,12 +487,15 @@ static void ip_copy_metadata(struct sk_buff *to, struct sk_buff *from) } static int ip_fragment(struct sock *sk, struct sk_buff *skb, + unsigned int mtu, int (*output)(struct sock *, struct sk_buff *)) { struct iphdr *iph = ip_hdr(skb); - unsigned int mtu = ip_skb_dst_mtu(skb); - if (unlikely(((iph->frag_off & htons(IP_DF)) && !skb->ignore_df) || + if ((iph->frag_off & htons(IP_DF)) == 0) + return ip_do_fragment(sk, skb, output); + + if (unlikely(!skb->ignore_df || (IPCB(skb)->frag_max_size && IPCB(skb)->frag_max_size > mtu))) { struct rtable *rt = skb_rtable(skb); @@ -532,6 +540,8 @@ int ip_do_fragment(struct sock *sk, struct sk_buff *skb, iph = ip_hdr(skb); mtu = ip_skb_dst_mtu(skb); + if (IPCB(skb)->frag_max_size && IPCB(skb)->frag_max_size < mtu) + mtu = IPCB(skb)->frag_max_size; /* * Setup starting values. @@ -727,6 +737,9 @@ slow_path: iph = ip_hdr(skb2); iph->frag_off = htons((offset >> 3)); + if (IPCB(skb)->flags & IPSKB_FRAG_PMTU) + iph->frag_off |= htons(IP_DF); + /* ANK: dirty, but effective trick. Upgrade options only if * the segment to be fragmented was THE FIRST (otherwise, * options are already fixed) and make it ONCE |
