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path: root/net/core/sock_diag.c
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Diffstat (limited to 'net/core/sock_diag.c')
-rw-r--r--net/core/sock_diag.c142
1 files changed, 80 insertions, 62 deletions
diff --git a/net/core/sock_diag.c b/net/core/sock_diag.c
index 3312a5849a97..026ce9bd9e5e 100644
--- a/net/core/sock_diag.c
+++ b/net/core/sock_diag.c
@@ -1,5 +1,6 @@
/* License: GPL */
+#include <linux/filter.h>
#include <linux/mutex.h>
#include <linux/socket.h>
#include <linux/skbuff.h>
@@ -11,25 +12,31 @@
#include <linux/tcp.h>
#include <linux/workqueue.h>
#include <linux/nospec.h>
-
+#include <linux/cookie.h>
#include <linux/inet_diag.h>
#include <linux/sock_diag.h>
-static const struct sock_diag_handler *sock_diag_handlers[AF_MAX];
-static int (*inet_rcv_compat)(struct sk_buff *skb, struct nlmsghdr *nlh);
-static DEFINE_MUTEX(sock_diag_table_mutex);
+static const struct sock_diag_handler __rcu *sock_diag_handlers[AF_MAX];
+
+static const struct sock_diag_inet_compat __rcu *inet_rcv_compat;
+
static struct workqueue_struct *broadcast_wq;
-u64 sock_gen_cookie(struct sock *sk)
+DEFINE_COOKIE(sock_cookie);
+
+u64 __sock_gen_cookie(struct sock *sk)
{
- while (1) {
- u64 res = atomic64_read(&sk->sk_cookie);
+ u64 res = atomic64_read(&sk->sk_cookie);
- if (res)
- return res;
- res = atomic64_inc_return(&sock_net(sk)->cookie_gen);
- atomic64_cmpxchg(&sk->sk_cookie, 0, res);
+ if (!res) {
+ u64 new = gen_cookie_next(&sock_cookie);
+
+ atomic64_cmpxchg(&sk->sk_cookie, res, new);
+
+ /* Another thread might have changed sk_cookie before us. */
+ res = atomic64_read(&sk->sk_cookie);
}
+ return res;
}
int sock_diag_check_cookie(struct sock *sk, const __u32 *cookie)
@@ -116,6 +123,24 @@ static size_t sock_diag_nlmsg_size(void)
+ nla_total_size_64bit(sizeof(struct tcp_info))); /* INET_DIAG_INFO */
}
+static const struct sock_diag_handler *sock_diag_lock_handler(int family)
+{
+ const struct sock_diag_handler *handler;
+
+ rcu_read_lock();
+ handler = rcu_dereference(sock_diag_handlers[family]);
+ if (handler && !try_module_get(handler->owner))
+ handler = NULL;
+ rcu_read_unlock();
+
+ return handler;
+}
+
+static void sock_diag_unlock_handler(const struct sock_diag_handler *handler)
+{
+ module_put(handler->owner);
+}
+
static void sock_diag_broadcast_destroy_work(struct work_struct *work)
{
struct broadcast_sk *bsk =
@@ -132,12 +157,12 @@ static void sock_diag_broadcast_destroy_work(struct work_struct *work)
if (!skb)
goto out;
- mutex_lock(&sock_diag_table_mutex);
- hndl = sock_diag_handlers[sk->sk_family];
- if (hndl && hndl->get_info)
- err = hndl->get_info(skb, sk);
- mutex_unlock(&sock_diag_table_mutex);
-
+ hndl = sock_diag_lock_handler(sk->sk_family);
+ if (hndl) {
+ if (hndl->get_info)
+ err = hndl->get_info(skb, sk);
+ sock_diag_unlock_handler(hndl);
+ }
if (!err)
nlmsg_multicast(sock_net(sk)->diag_nlsk, skb, 0, group,
GFP_KERNEL);
@@ -160,51 +185,43 @@ void sock_diag_broadcast_destroy(struct sock *sk)
queue_work(broadcast_wq, &bsk->work);
}
-void sock_diag_register_inet_compat(int (*fn)(struct sk_buff *skb, struct nlmsghdr *nlh))
+void sock_diag_register_inet_compat(const struct sock_diag_inet_compat *ptr)
{
- mutex_lock(&sock_diag_table_mutex);
- inet_rcv_compat = fn;
- mutex_unlock(&sock_diag_table_mutex);
+ xchg(&inet_rcv_compat, RCU_INITIALIZER(ptr));
}
EXPORT_SYMBOL_GPL(sock_diag_register_inet_compat);
-void sock_diag_unregister_inet_compat(int (*fn)(struct sk_buff *skb, struct nlmsghdr *nlh))
+void sock_diag_unregister_inet_compat(const struct sock_diag_inet_compat *ptr)
{
- mutex_lock(&sock_diag_table_mutex);
- inet_rcv_compat = NULL;
- mutex_unlock(&sock_diag_table_mutex);
+ const struct sock_diag_inet_compat *old;
+
+ old = unrcu_pointer(xchg(&inet_rcv_compat, NULL));
+ WARN_ON_ONCE(old != ptr);
}
EXPORT_SYMBOL_GPL(sock_diag_unregister_inet_compat);
int sock_diag_register(const struct sock_diag_handler *hndl)
{
- int err = 0;
+ int family = hndl->family;
- if (hndl->family >= AF_MAX)
+ if (family >= AF_MAX)
return -EINVAL;
- mutex_lock(&sock_diag_table_mutex);
- if (sock_diag_handlers[hndl->family])
- err = -EBUSY;
- else
- sock_diag_handlers[hndl->family] = hndl;
- mutex_unlock(&sock_diag_table_mutex);
-
- return err;
+ return !cmpxchg((const struct sock_diag_handler **)
+ &sock_diag_handlers[family],
+ NULL, hndl) ? 0 : -EBUSY;
}
EXPORT_SYMBOL_GPL(sock_diag_register);
-void sock_diag_unregister(const struct sock_diag_handler *hnld)
+void sock_diag_unregister(const struct sock_diag_handler *hndl)
{
- int family = hnld->family;
+ int family = hndl->family;
if (family >= AF_MAX)
return;
- mutex_lock(&sock_diag_table_mutex);
- BUG_ON(sock_diag_handlers[family] != hnld);
- sock_diag_handlers[family] = NULL;
- mutex_unlock(&sock_diag_table_mutex);
+ xchg((const struct sock_diag_handler **)&sock_diag_handlers[family],
+ NULL);
}
EXPORT_SYMBOL_GPL(sock_diag_unregister);
@@ -221,20 +238,20 @@ static int __sock_diag_cmd(struct sk_buff *skb, struct nlmsghdr *nlh)
return -EINVAL;
req->sdiag_family = array_index_nospec(req->sdiag_family, AF_MAX);
- if (sock_diag_handlers[req->sdiag_family] == NULL)
+ if (!rcu_access_pointer(sock_diag_handlers[req->sdiag_family]))
sock_load_diag_module(req->sdiag_family, 0);
- mutex_lock(&sock_diag_table_mutex);
- hndl = sock_diag_handlers[req->sdiag_family];
+ hndl = sock_diag_lock_handler(req->sdiag_family);
if (hndl == NULL)
- err = -ENOENT;
- else if (nlh->nlmsg_type == SOCK_DIAG_BY_FAMILY)
+ return -ENOENT;
+
+ if (nlh->nlmsg_type == SOCK_DIAG_BY_FAMILY)
err = hndl->dump(skb, nlh);
else if (nlh->nlmsg_type == SOCK_DESTROY && hndl->destroy)
err = hndl->destroy(skb, nlh);
else
err = -EOPNOTSUPP;
- mutex_unlock(&sock_diag_table_mutex);
+ sock_diag_unlock_handler(hndl);
return err;
}
@@ -242,20 +259,25 @@ static int __sock_diag_cmd(struct sk_buff *skb, struct nlmsghdr *nlh)
static int sock_diag_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh,
struct netlink_ext_ack *extack)
{
+ const struct sock_diag_inet_compat *ptr;
int ret;
switch (nlh->nlmsg_type) {
case TCPDIAG_GETSOCK:
- case DCCPDIAG_GETSOCK:
- if (inet_rcv_compat == NULL)
+ if (!rcu_access_pointer(inet_rcv_compat))
sock_load_diag_module(AF_INET, 0);
- mutex_lock(&sock_diag_table_mutex);
- if (inet_rcv_compat != NULL)
- ret = inet_rcv_compat(skb, nlh);
- else
- ret = -EOPNOTSUPP;
- mutex_unlock(&sock_diag_table_mutex);
+ rcu_read_lock();
+ ptr = rcu_dereference(inet_rcv_compat);
+ if (ptr && !try_module_get(ptr->owner))
+ ptr = NULL;
+ rcu_read_unlock();
+
+ ret = -EOPNOTSUPP;
+ if (ptr) {
+ ret = ptr->fn(skb, nlh);
+ module_put(ptr->owner);
+ }
return ret;
case SOCK_DIAG_BY_FAMILY:
@@ -266,13 +288,9 @@ static int sock_diag_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh,
}
}
-static DEFINE_MUTEX(sock_diag_mutex);
-
static void sock_diag_rcv(struct sk_buff *skb)
{
- mutex_lock(&sock_diag_mutex);
netlink_rcv_skb(skb, &sock_diag_rcv_msg);
- mutex_unlock(&sock_diag_mutex);
}
static int sock_diag_bind(struct net *net, int group)
@@ -280,12 +298,12 @@ static int sock_diag_bind(struct net *net, int group)
switch (group) {
case SKNLGRP_INET_TCP_DESTROY:
case SKNLGRP_INET_UDP_DESTROY:
- if (!sock_diag_handlers[AF_INET])
+ if (!rcu_access_pointer(sock_diag_handlers[AF_INET]))
sock_load_diag_module(AF_INET, 0);
break;
case SKNLGRP_INET6_TCP_DESTROY:
case SKNLGRP_INET6_UDP_DESTROY:
- if (!sock_diag_handlers[AF_INET6])
+ if (!rcu_access_pointer(sock_diag_handlers[AF_INET6]))
sock_load_diag_module(AF_INET6, 0);
break;
}
@@ -330,7 +348,7 @@ static struct pernet_operations diag_net_ops = {
static int __init sock_diag_init(void)
{
- broadcast_wq = alloc_workqueue("sock_diag_events", 0, 0);
+ broadcast_wq = alloc_workqueue("sock_diag_events", WQ_PERCPU, 0);
BUG_ON(!broadcast_wq);
return register_pernet_subsys(&diag_net_ops);
}
generated by cgit (git 2.34.1) at 2025-12-24 20:56:46 +0000