Merge tag 'kvm-s390-kernel-access' from emailed bundle

[linux-2.6-microblaze.git] / net / ipv4 / ip_output.c

diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c
index 57c1d84..139cec2 100644 (file)
--- a/net/ipv4/ip_output.c
+++ b/net/ipv4/ip_output.c
@@ -162,12 +162,19 @@ int ip_build_and_send_pkt(struct sk_buff *skb, const struct sock *sk,
        iph->daddr    = (opt && opt->opt.srr ? opt->opt.faddr : daddr);
        iph->saddr    = saddr;
        iph->protocol = sk->sk_protocol;
-       if (ip_dont_fragment(sk, &rt->dst)) {
+       /* Do not bother generating IPID for small packets (eg SYNACK) */
+       if (skb->len <= IPV4_MIN_MTU || ip_dont_fragment(sk, &rt->dst)) {
                iph->frag_off = htons(IP_DF);
                iph->id = 0;
        } else {
                iph->frag_off = 0;
-               __ip_select_ident(net, iph, 1);
+               /* TCP packets here are SYNACK with fat IPv4/TCP options.
+                * Avoid using the hashed IP ident generator.
+                */
+               if (sk->sk_protocol == IPPROTO_TCP)
+                       iph->id = (__force __be16)prandom_u32();
+               else
+                       __ip_select_ident(net, iph, 1);
        }
 
        if (opt && opt->opt.optlen) {
@@ -825,15 +832,24 @@ int ip_do_fragment(struct net *net, struct sock *sk, struct sk_buff *skb,
                /* Everything is OK. Generate! */
                ip_fraglist_init(skb, iph, hlen, &iter);
 
-               if (iter.frag)
-                       ip_options_fragment(iter.frag);
-
                for (;;) {
                        /* Prepare header of the next frame,
                         * before previous one went down. */
                        if (iter.frag) {
+                               bool first_frag = (iter.offset == 0);
+
                                IPCB(iter.frag)->flags = IPCB(skb)->flags;
                                ip_fraglist_prepare(skb, &iter);
+                               if (first_frag && IPCB(skb)->opt.optlen) {
+                                       /* ipcb->opt is not populated for frags
+                                        * coming from __ip_make_skb(),
+                                        * ip_options_fragment() needs optlen
+                                        */
+                                       IPCB(iter.frag)->opt.optlen =
+                                               IPCB(skb)->opt.optlen;
+                                       ip_options_fragment(iter.frag);
+                                       ip_send_check(iter.iph);
+                               }
                        }
 
                        skb->tstamp = tstamp;