+/*
+ * Shall we try to damage output packets if routing dev changes?
+ */
+
+int sysctl_ip_dynaddr __read_mostly;
+
+static int inet_sk_reselect_saddr(struct sock *sk)
+{
+ struct inet_sock *inet = inet_sk(sk);
+ int err;
+ struct rtable *rt;
+ __be32 old_saddr = inet->saddr;
+ __be32 new_saddr;
+ __be32 daddr = inet->daddr;
+
+ if (inet->opt && inet->opt->srr)
+ daddr = inet->opt->faddr;
+
+ /* Query new route. */
+ err = ip_route_connect(&rt, daddr, 0,
+ RT_CONN_FLAGS(sk),
+ sk->sk_bound_dev_if,
+ sk->sk_protocol,
+ inet->sport, inet->dport, sk);
+ if (err)
+ return err;
+
+ sk_setup_caps(sk, &rt->u.dst);
+
+ new_saddr = rt->rt_src;
+
+ if (new_saddr == old_saddr)
+ return 0;
+
+ if (sysctl_ip_dynaddr > 1) {
+ printk(KERN_INFO "%s(): shifting inet->"
+ "saddr from %d.%d.%d.%d to %d.%d.%d.%d\n",
+ __FUNCTION__,
+ NIPQUAD(old_saddr),
+ NIPQUAD(new_saddr));
+ }
+
+ inet->saddr = inet->rcv_saddr = new_saddr;
+
+ /*
+ * XXX The only one ugly spot where we need to
+ * XXX really change the sockets identity after
+ * XXX it has entered the hashes. -DaveM
+ *
+ * Besides that, it does not check for connection
+ * uniqueness. Wait for troubles.
+ */
+ __sk_prot_rehash(sk);
+ return 0;
+}
+
+int inet_sk_rebuild_header(struct sock *sk)
+{
+ struct inet_sock *inet = inet_sk(sk);
+ struct rtable *rt = (struct rtable *)__sk_dst_check(sk, 0);
+ __be32 daddr;
+ int err;
+
+ /* Route is OK, nothing to do. */
+ if (rt)
+ return 0;
+
+ /* Reroute. */
+ daddr = inet->daddr;
+ if (inet->opt && inet->opt->srr)
+ daddr = inet->opt->faddr;
+{
+ struct flowi fl = {
+ .oif = sk->sk_bound_dev_if,
+ .nl_u = {
+ .ip4_u = {
+ .daddr = daddr,
+ .saddr = inet->saddr,
+ .tos = RT_CONN_FLAGS(sk),
+ },
+ },
+ .proto = sk->sk_protocol,
+ .uli_u = {
+ .ports = {
+ .sport = inet->sport,
+ .dport = inet->dport,
+ },
+ },
+ };
+
+ security_sk_classify_flow(sk, &fl);
+ err = ip_route_output_flow(&rt, &fl, sk, 0);
+}
+ if (!err)
+ sk_setup_caps(sk, &rt->u.dst);
+ else {
+ /* Routing failed... */
+ sk->sk_route_caps = 0;
+ /*
+ * Other protocols have to map its equivalent state to TCP_SYN_SENT.
+ * DCCP maps its DCCP_REQUESTING state to TCP_SYN_SENT. -acme
+ */
+ if (!sysctl_ip_dynaddr ||
+ sk->sk_state != TCP_SYN_SENT ||
+ (sk->sk_userlocks & SOCK_BINDADDR_LOCK) ||
+ (err = inet_sk_reselect_saddr(sk)) != 0)
+ sk->sk_err_soft = -err;
+ }
+
+ return err;
+}
+
+EXPORT_SYMBOL(inet_sk_rebuild_header);
+
+static int inet_gso_send_check(struct sk_buff *skb)
+{
+ struct iphdr *iph;
+ struct net_protocol *ops;
+ int proto;
+ int ihl;
+ int err = -EINVAL;
+
+ if (unlikely(!pskb_may_pull(skb, sizeof(*iph))))
+ goto out;
+
+ iph = skb->nh.iph;
+ ihl = iph->ihl * 4;
+ if (ihl < sizeof(*iph))
+ goto out;
+
+ if (unlikely(!pskb_may_pull(skb, ihl)))
+ goto out;
+
+ skb->h.raw = __skb_pull(skb, ihl);
+ iph = skb->nh.iph;
+ proto = iph->protocol & (MAX_INET_PROTOS - 1);
+ err = -EPROTONOSUPPORT;
+
+ rcu_read_lock();
+ ops = rcu_dereference(inet_protos[proto]);
+ if (likely(ops && ops->gso_send_check))
+ err = ops->gso_send_check(skb);
+ rcu_read_unlock();
+
+out:
+ return err;
+}
+
+static struct sk_buff *inet_gso_segment(struct sk_buff *skb, int features)
+{
+ struct sk_buff *segs = ERR_PTR(-EINVAL);
+ struct iphdr *iph;
+ struct net_protocol *ops;
+ int proto;
+ int ihl;
+ int id;
+
+ if (unlikely(skb_shinfo(skb)->gso_type &
+ ~(SKB_GSO_TCPV4 |
+ SKB_GSO_UDP |
+ SKB_GSO_DODGY |
+ SKB_GSO_TCP_ECN |
+ 0)))
+ goto out;
+
+ if (unlikely(!pskb_may_pull(skb, sizeof(*iph))))
+ goto out;
+
+ iph = skb->nh.iph;
+ ihl = iph->ihl * 4;
+ if (ihl < sizeof(*iph))
+ goto out;
+
+ if (unlikely(!pskb_may_pull(skb, ihl)))
+ goto out;
+
+ skb->h.raw = __skb_pull(skb, ihl);
+ iph = skb->nh.iph;
+ id = ntohs(iph->id);
+ proto = iph->protocol & (MAX_INET_PROTOS - 1);
+ segs = ERR_PTR(-EPROTONOSUPPORT);
+
+ rcu_read_lock();
+ ops = rcu_dereference(inet_protos[proto]);
+ if (likely(ops && ops->gso_segment))
+ segs = ops->gso_segment(skb, features);
+ rcu_read_unlock();
+
+ if (!segs || unlikely(IS_ERR(segs)))
+ goto out;
+
+ skb = segs;
+ do {
+ iph = skb->nh.iph;
+ iph->id = htons(id++);
+ iph->tot_len = htons(skb->len - skb->mac_len);
+ iph->check = 0;
+ iph->check = ip_fast_csum(skb->nh.raw, iph->ihl);
+ } while ((skb = skb->next));
+
+out:
+ return segs;
+}
+