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Diffstat (limited to 'net/ipv4/tcp_cong.c')
-rw-r--r--net/ipv4/tcp_cong.c76
1 files changed, 36 insertions, 40 deletions
diff --git a/net/ipv4/tcp_cong.c b/net/ipv4/tcp_cong.c
index 2f26124fd160..bc6c02f16243 100644
--- a/net/ipv4/tcp_cong.c
+++ b/net/ipv4/tcp_cong.c
@@ -33,9 +33,11 @@ static struct tcp_congestion_ops *tcp_ca_find(const char *name)
}
/* Must be called with rcu lock held */
-static const struct tcp_congestion_ops *__tcp_ca_find_autoload(const char *name)
+static struct tcp_congestion_ops *tcp_ca_find_autoload(struct net *net,
+ const char *name)
{
- const struct tcp_congestion_ops *ca = tcp_ca_find(name);
+ struct tcp_congestion_ops *ca = tcp_ca_find(name);
+
#ifdef CONFIG_MODULES
if (!ca && capable(CAP_NET_ADMIN)) {
rcu_read_unlock();
@@ -115,7 +117,7 @@ void tcp_unregister_congestion_control(struct tcp_congestion_ops *ca)
}
EXPORT_SYMBOL_GPL(tcp_unregister_congestion_control);
-u32 tcp_ca_get_key_by_name(const char *name, bool *ecn_ca)
+u32 tcp_ca_get_key_by_name(struct net *net, const char *name, bool *ecn_ca)
{
const struct tcp_congestion_ops *ca;
u32 key = TCP_CA_UNSPEC;
@@ -123,7 +125,7 @@ u32 tcp_ca_get_key_by_name(const char *name, bool *ecn_ca)
might_sleep();
rcu_read_lock();
- ca = __tcp_ca_find_autoload(name);
+ ca = tcp_ca_find_autoload(net, name);
if (ca) {
key = ca->key;
*ecn_ca = ca->flags & TCP_CONG_NEEDS_ECN;
@@ -153,23 +155,18 @@ EXPORT_SYMBOL_GPL(tcp_ca_get_name_by_key);
/* Assign choice of congestion control. */
void tcp_assign_congestion_control(struct sock *sk)
{
+ struct net *net = sock_net(sk);
struct inet_connection_sock *icsk = inet_csk(sk);
- struct tcp_congestion_ops *ca;
+ const struct tcp_congestion_ops *ca;
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;
- }
- /* Fallback to next available. The last really
- * guaranteed fallback is Reno from this list.
- */
- }
-out:
+ ca = rcu_dereference(net->ipv4.tcp_congestion_control);
+ if (unlikely(!try_module_get(ca->owner)))
+ ca = &tcp_reno;
+ icsk->icsk_ca_ops = ca;
rcu_read_unlock();
- memset(icsk->icsk_ca_priv, 0, sizeof(icsk->icsk_ca_priv));
+ memset(icsk->icsk_ca_priv, 0, sizeof(icsk->icsk_ca_priv));
if (ca->flags & TCP_CONG_NEEDS_ECN)
INET_ECN_xmit(sk);
else
@@ -214,29 +211,27 @@ void tcp_cleanup_congestion_control(struct sock *sk)
}
/* Used by sysctl to change default congestion control */
-int tcp_set_default_congestion_control(const char *name)
+int tcp_set_default_congestion_control(struct net *net, const char *name)
{
struct tcp_congestion_ops *ca;
- int ret = -ENOENT;
-
- spin_lock(&tcp_cong_list_lock);
- ca = tcp_ca_find(name);
-#ifdef CONFIG_MODULES
- if (!ca && capable(CAP_NET_ADMIN)) {
- spin_unlock(&tcp_cong_list_lock);
+ const struct tcp_congestion_ops *prev;
+ int ret;
- request_module("tcp_%s", name);
- spin_lock(&tcp_cong_list_lock);
- ca = tcp_ca_find(name);
- }
-#endif
+ rcu_read_lock();
+ ca = tcp_ca_find_autoload(net, name);
+ if (!ca) {
+ ret = -ENOENT;
+ } else if (!try_module_get(ca->owner)) {
+ ret = -EBUSY;
+ } else {
+ prev = xchg(&net->ipv4.tcp_congestion_control, ca);
+ if (prev)
+ module_put(prev->owner);
- if (ca) {
- ca->flags |= TCP_CONG_NON_RESTRICTED; /* default is always allowed */
- list_move(&ca->list, &tcp_cong_list);
+ ca->flags |= TCP_CONG_NON_RESTRICTED;
ret = 0;
}
- spin_unlock(&tcp_cong_list_lock);
+ rcu_read_unlock();
return ret;
}
@@ -244,7 +239,8 @@ int tcp_set_default_congestion_control(const char *name)
/* Set default value from kernel configuration at bootup */
static int __init tcp_congestion_default(void)
{
- return tcp_set_default_congestion_control(CONFIG_DEFAULT_TCP_CONG);
+ return tcp_set_default_congestion_control(&init_net,
+ CONFIG_DEFAULT_TCP_CONG);
}
late_initcall(tcp_congestion_default);
@@ -264,14 +260,12 @@ void tcp_get_available_congestion_control(char *buf, size_t maxlen)
}
/* Get current default congestion control */
-void tcp_get_default_congestion_control(char *name)
+void tcp_get_default_congestion_control(struct net *net, char *name)
{
- struct tcp_congestion_ops *ca;
- /* We will always have reno... */
- BUG_ON(list_empty(&tcp_cong_list));
+ const struct tcp_congestion_ops *ca;
rcu_read_lock();
- ca = list_entry(tcp_cong_list.next, struct tcp_congestion_ops, list);
+ ca = rcu_dereference(net->ipv4.tcp_congestion_control);
strncpy(name, ca->name, TCP_CA_NAME_MAX);
rcu_read_unlock();
}
@@ -351,12 +345,14 @@ int tcp_set_congestion_control(struct sock *sk, const char *name, bool load, boo
if (!load)
ca = tcp_ca_find(name);
else
- ca = __tcp_ca_find_autoload(name);
+ ca = tcp_ca_find_autoload(sock_net(sk), name);
+
/* No change asking for existing value */
if (ca == icsk->icsk_ca_ops) {
icsk->icsk_ca_setsockopt = 1;
goto out;
}
+
if (!ca) {
err = -ENOENT;
} else if (!load) {