EXPORT_SYMBOL_GPL(tcp_unregister_congestion_control);
/* Assign choice of congestion control. */
-void tcp_init_congestion_control(struct sock *sk)
+void tcp_assign_congestion_control(struct sock *sk)
{
struct inet_connection_sock *icsk = inet_csk(sk);
struct tcp_congestion_ops *ca;
- /* if no choice made yet assign the current value set as default */
- if (icsk->icsk_ca_ops == &tcp_init_congestion_ops) {
- rcu_read_lock();
- list_for_each_entry_rcu(ca, &tcp_cong_list, list) {
- if (try_module_get(ca->owner)) {
- icsk->icsk_ca_ops = ca;
- break;
- }
-
- /* fallback to next available */
+ rcu_read_lock();
+ list_for_each_entry_rcu(ca, &tcp_cong_list, list) {
+ if (likely(try_module_get(ca->owner))) {
+ icsk->icsk_ca_ops = ca;
+ goto out;
}
- rcu_read_unlock();
+ /* Fallback to next available. The last really
+ * guaranteed fallback is Reno from this list.
+ */
}
+out:
+ rcu_read_unlock();
+
+ /* Clear out private data before diag gets it and
+ * the ca has not been initialized.
+ */
+ if (ca->get_info)
+ memset(icsk->icsk_ca_priv, 0, sizeof(icsk->icsk_ca_priv));
+}
+
+void tcp_init_congestion_control(struct sock *sk)
+{
+ const struct inet_connection_sock *icsk = inet_csk(sk);
if (icsk->icsk_ca_ops->init)
icsk->icsk_ca_ops->init(sk);
}
late_initcall(tcp_congestion_default);
-
/* Build string with list of available congestion control values */
void tcp_get_available_congestion_control(char *buf, size_t maxlen)
{
offs += snprintf(buf + offs, maxlen - offs,
"%s%s",
offs == 0 ? "" : " ", ca->name);
-
}
rcu_read_unlock();
}
offs += snprintf(buf + offs, maxlen - offs,
"%s%s",
offs == 0 ? "" : " ", ca->name);
-
}
rcu_read_unlock();
}
return ret;
}
-
/* Change congestion control for socket */
int tcp_set_congestion_control(struct sock *sk, const char *name)
{
u32 tcp_reno_ssthresh(struct sock *sk)
{
const struct tcp_sock *tp = tcp_sk(sk);
+
return max(tp->snd_cwnd >> 1U, 2U);
}
EXPORT_SYMBOL_GPL(tcp_reno_ssthresh);
.ssthresh = tcp_reno_ssthresh,
.cong_avoid = tcp_reno_cong_avoid,
};
-
-/* Initial congestion control used (until SYN)
- * really reno under another name so we can tell difference
- * during tcp_set_default_congestion_control
- */
-struct tcp_congestion_ops tcp_init_congestion_ops = {
- .name = "",
- .owner = THIS_MODULE,
- .ssthresh = tcp_reno_ssthresh,
- .cong_avoid = tcp_reno_cong_avoid,
-};
-EXPORT_SYMBOL_GPL(tcp_init_congestion_ops);