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Diffstat (limited to 'net/ipv4/tcp_cong.c')
-rw-r--r--net/ipv4/tcp_cong.c91
1 files changed, 90 insertions, 1 deletions
diff --git a/net/ipv4/tcp_cong.c b/net/ipv4/tcp_cong.c
index 1e2982f..5ca7723 100644
--- a/net/ipv4/tcp_cong.c
+++ b/net/ipv4/tcp_cong.c
@@ -113,7 +113,7 @@ int tcp_set_default_congestion_control(const char *name)
spin_lock(&tcp_cong_list_lock);
ca = tcp_ca_find(name);
#ifdef CONFIG_KMOD
- if (!ca) {
+ if (!ca && capable(CAP_SYS_MODULE)) {
spin_unlock(&tcp_cong_list_lock);
request_module("tcp_%s", name);
@@ -123,6 +123,7 @@ int tcp_set_default_congestion_control(const char *name)
#endif
if (ca) {
+ ca->non_restricted = 1; /* default is always allowed */
list_move(&ca->list, &tcp_cong_list);
ret = 0;
}
@@ -139,6 +140,22 @@ static int __init tcp_congestion_default(void)
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)
+{
+ struct tcp_congestion_ops *ca;
+ size_t offs = 0;
+
+ rcu_read_lock();
+ list_for_each_entry_rcu(ca, &tcp_cong_list, list) {
+ offs += snprintf(buf + offs, maxlen - offs,
+ "%s%s",
+ offs == 0 ? "" : " ", ca->name);
+
+ }
+ rcu_read_unlock();
+}
+
/* Get current default congestion control */
void tcp_get_default_congestion_control(char *name)
{
@@ -152,6 +169,64 @@ void tcp_get_default_congestion_control(char *name)
rcu_read_unlock();
}
+/* Built list of non-restricted congestion control values */
+void tcp_get_allowed_congestion_control(char *buf, size_t maxlen)
+{
+ struct tcp_congestion_ops *ca;
+ size_t offs = 0;
+
+ *buf = '\0';
+ rcu_read_lock();
+ list_for_each_entry_rcu(ca, &tcp_cong_list, list) {
+ if (!ca->non_restricted)
+ continue;
+ offs += snprintf(buf + offs, maxlen - offs,
+ "%s%s",
+ offs == 0 ? "" : " ", ca->name);
+
+ }
+ rcu_read_unlock();
+}
+
+/* Change list of non-restricted congestion control */
+int tcp_set_allowed_congestion_control(char *val)
+{
+ struct tcp_congestion_ops *ca;
+ char *clone, *name;
+ int ret = 0;
+
+ clone = kstrdup(val, GFP_USER);
+ if (!clone)
+ return -ENOMEM;
+
+ spin_lock(&tcp_cong_list_lock);
+ /* pass 1 check for bad entries */
+ while ((name = strsep(&clone, " ")) && *name) {
+ ca = tcp_ca_find(name);
+ if (!ca) {
+ ret = -ENOENT;
+ goto out;
+ }
+ }
+
+ /* pass 2 clear */
+ list_for_each_entry_rcu(ca, &tcp_cong_list, list)
+ ca->non_restricted = 0;
+
+ /* pass 3 mark as allowed */
+ while ((name = strsep(&val, " ")) && *name) {
+ ca = tcp_ca_find(name);
+ WARN_ON(!ca);
+ if (ca)
+ ca->non_restricted = 1;
+ }
+out:
+ spin_unlock(&tcp_cong_list_lock);
+
+ return ret;
+}
+
+
/* Change congestion control for socket */
int tcp_set_congestion_control(struct sock *sk, const char *name)
{
@@ -161,12 +236,25 @@ int tcp_set_congestion_control(struct sock *sk, const char *name)
rcu_read_lock();
ca = tcp_ca_find(name);
+ /* no change asking for existing value */
if (ca == icsk->icsk_ca_ops)
goto out;
+#ifdef CONFIG_KMOD
+ /* not found attempt to autoload module */
+ if (!ca && capable(CAP_SYS_MODULE)) {
+ rcu_read_unlock();
+ request_module("tcp_%s", name);
+ rcu_read_lock();
+ ca = tcp_ca_find(name);
+ }
+#endif
if (!ca)
err = -ENOENT;
+ else if (!(ca->non_restricted || capable(CAP_NET_ADMIN)))
+ err = -EPERM;
+
else if (!try_module_get(ca->owner))
err = -EBUSY;
@@ -268,6 +356,7 @@ EXPORT_SYMBOL_GPL(tcp_reno_min_cwnd);
struct tcp_congestion_ops tcp_reno = {
.name = "reno",
+ .non_restricted = 1,
.owner = THIS_MODULE,
.ssthresh = tcp_reno_ssthresh,
.cong_avoid = tcp_reno_cong_avoid,
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