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Diffstat (limited to 'net/core/rtnetlink.c')
-rw-r--r--net/core/rtnetlink.c249
1 files changed, 144 insertions, 105 deletions
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index 9201e3621351..a78fd61da0ec 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -62,7 +62,7 @@
struct rtnl_link {
rtnl_doit_func doit;
rtnl_dumpit_func dumpit;
- rtnl_calcit_func calcit;
+ unsigned int flags;
};
static DEFINE_MUTEX(rtnl_mutex);
@@ -127,7 +127,8 @@ bool lockdep_rtnl_is_held(void)
EXPORT_SYMBOL(lockdep_rtnl_is_held);
#endif /* #ifdef CONFIG_PROVE_LOCKING */
-static struct rtnl_link *rtnl_msg_handlers[RTNL_FAMILY_MAX + 1];
+static struct rtnl_link __rcu *rtnl_msg_handlers[RTNL_FAMILY_MAX + 1];
+static refcount_t rtnl_msg_handlers_ref[RTNL_FAMILY_MAX + 1];
static inline int rtm_msgindex(int msgtype)
{
@@ -143,58 +144,13 @@ static inline int rtm_msgindex(int msgtype)
return msgindex;
}
-static rtnl_doit_func rtnl_get_doit(int protocol, int msgindex)
-{
- struct rtnl_link *tab;
-
- if (protocol <= RTNL_FAMILY_MAX)
- tab = rtnl_msg_handlers[protocol];
- else
- tab = NULL;
-
- if (tab == NULL || tab[msgindex].doit == NULL)
- tab = rtnl_msg_handlers[PF_UNSPEC];
-
- return tab[msgindex].doit;
-}
-
-static rtnl_dumpit_func rtnl_get_dumpit(int protocol, int msgindex)
-{
- struct rtnl_link *tab;
-
- if (protocol <= RTNL_FAMILY_MAX)
- tab = rtnl_msg_handlers[protocol];
- else
- tab = NULL;
-
- if (tab == NULL || tab[msgindex].dumpit == NULL)
- tab = rtnl_msg_handlers[PF_UNSPEC];
-
- return tab[msgindex].dumpit;
-}
-
-static rtnl_calcit_func rtnl_get_calcit(int protocol, int msgindex)
-{
- struct rtnl_link *tab;
-
- if (protocol <= RTNL_FAMILY_MAX)
- tab = rtnl_msg_handlers[protocol];
- else
- tab = NULL;
-
- if (tab == NULL || tab[msgindex].calcit == NULL)
- tab = rtnl_msg_handlers[PF_UNSPEC];
-
- return tab[msgindex].calcit;
-}
-
/**
* __rtnl_register - Register a rtnetlink message type
* @protocol: Protocol family or PF_UNSPEC
* @msgtype: rtnetlink message type
* @doit: Function pointer called for each request message
* @dumpit: Function pointer called for each dump request (NLM_F_DUMP) message
- * @calcit: Function pointer to calc size of dump message
+ * @flags: rtnl_link_flags to modifiy behaviour of doit/dumpit functions
*
* Registers the specified function pointers (at least one of them has
* to be non-NULL) to be called whenever a request message for the
@@ -208,7 +164,7 @@ static rtnl_calcit_func rtnl_get_calcit(int protocol, int msgindex)
*/
int __rtnl_register(int protocol, int msgtype,
rtnl_doit_func doit, rtnl_dumpit_func dumpit,
- rtnl_calcit_func calcit)
+ unsigned int flags)
{
struct rtnl_link *tab;
int msgindex;
@@ -216,23 +172,20 @@ int __rtnl_register(int protocol, int msgtype,
BUG_ON(protocol < 0 || protocol > RTNL_FAMILY_MAX);
msgindex = rtm_msgindex(msgtype);
- tab = rtnl_msg_handlers[protocol];
+ tab = rcu_dereference_raw(rtnl_msg_handlers[protocol]);
if (tab == NULL) {
tab = kcalloc(RTM_NR_MSGTYPES, sizeof(*tab), GFP_KERNEL);
if (tab == NULL)
return -ENOBUFS;
- rtnl_msg_handlers[protocol] = tab;
+ rcu_assign_pointer(rtnl_msg_handlers[protocol], tab);
}
if (doit)
tab[msgindex].doit = doit;
-
if (dumpit)
tab[msgindex].dumpit = dumpit;
-
- if (calcit)
- tab[msgindex].calcit = calcit;
+ tab[msgindex].flags |= flags;
return 0;
}
@@ -249,9 +202,9 @@ EXPORT_SYMBOL_GPL(__rtnl_register);
*/
void rtnl_register(int protocol, int msgtype,
rtnl_doit_func doit, rtnl_dumpit_func dumpit,
- rtnl_calcit_func calcit)
+ unsigned int flags)
{
- if (__rtnl_register(protocol, msgtype, doit, dumpit, calcit) < 0)
+ if (__rtnl_register(protocol, msgtype, doit, dumpit, flags) < 0)
panic("Unable to register rtnetlink message handler, "
"protocol = %d, message type = %d\n",
protocol, msgtype);
@@ -267,17 +220,23 @@ EXPORT_SYMBOL_GPL(rtnl_register);
*/
int rtnl_unregister(int protocol, int msgtype)
{
+ struct rtnl_link *handlers;
int msgindex;
BUG_ON(protocol < 0 || protocol > RTNL_FAMILY_MAX);
msgindex = rtm_msgindex(msgtype);
- if (rtnl_msg_handlers[protocol] == NULL)
+ rtnl_lock();
+ handlers = rtnl_dereference(rtnl_msg_handlers[protocol]);
+ if (!handlers) {
+ rtnl_unlock();
return -ENOENT;
+ }
- rtnl_msg_handlers[protocol][msgindex].doit = NULL;
- rtnl_msg_handlers[protocol][msgindex].dumpit = NULL;
- rtnl_msg_handlers[protocol][msgindex].calcit = NULL;
+ handlers[msgindex].doit = NULL;
+ handlers[msgindex].dumpit = NULL;
+ handlers[msgindex].flags = 0;
+ rtnl_unlock();
return 0;
}
@@ -292,10 +251,20 @@ EXPORT_SYMBOL_GPL(rtnl_unregister);
*/
void rtnl_unregister_all(int protocol)
{
+ struct rtnl_link *handlers;
+
BUG_ON(protocol < 0 || protocol > RTNL_FAMILY_MAX);
- kfree(rtnl_msg_handlers[protocol]);
- rtnl_msg_handlers[protocol] = NULL;
+ rtnl_lock();
+ handlers = rtnl_dereference(rtnl_msg_handlers[protocol]);
+ RCU_INIT_POINTER(rtnl_msg_handlers[protocol], NULL);
+ rtnl_unlock();
+
+ synchronize_net();
+
+ while (refcount_read(&rtnl_msg_handlers_ref[protocol]) > 1)
+ schedule();
+ kfree(handlers);
}
EXPORT_SYMBOL_GPL(rtnl_unregister_all);
@@ -433,16 +402,24 @@ static size_t rtnl_link_get_slave_info_data_size(const struct net_device *dev)
{
struct net_device *master_dev;
const struct rtnl_link_ops *ops;
+ size_t size = 0;
- master_dev = netdev_master_upper_dev_get((struct net_device *) dev);
+ rcu_read_lock();
+
+ master_dev = netdev_master_upper_dev_get_rcu((struct net_device *)dev);
if (!master_dev)
- return 0;
+ goto out;
+
ops = master_dev->rtnl_link_ops;
if (!ops || !ops->get_slave_size)
- return 0;
+ goto out;
/* IFLA_INFO_SLAVE_DATA + nested data */
- return nla_total_size(sizeof(struct nlattr)) +
+ size = nla_total_size(sizeof(struct nlattr)) +
ops->get_slave_size(master_dev, dev);
+
+out:
+ rcu_read_unlock();
+ return size;
}
static size_t rtnl_link_get_size(const struct net_device *dev)
@@ -1644,8 +1621,6 @@ static int rtnl_dump_ifinfo(struct sk_buff *skb, struct netlink_callback *cb)
s_h = cb->args[0];
s_idx = cb->args[1];
- cb->seq = net->dev_base_seq;
-
/* A hack to preserve kernel<->userspace interface.
* The correct header is ifinfomsg. It is consistent with rtnl_getlink.
* However, before Linux v3.9 the code here assumed rtgenmsg and that's
@@ -1691,8 +1666,6 @@ static int rtnl_dump_ifinfo(struct sk_buff *skb, struct netlink_callback *cb)
goto out_err;
}
-
- nl_dump_check_consistent(cb, nlmsg_hdr(skb));
cont:
idx++;
}
@@ -1702,6 +1675,8 @@ out:
out_err:
cb->args[1] = idx;
cb->args[0] = h;
+ cb->seq = net->dev_base_seq;
+ nl_dump_check_consistent(cb, nlmsg_hdr(skb));
return err;
}
@@ -2831,11 +2806,13 @@ static u16 rtnl_calcit(struct sk_buff *skb, struct nlmsghdr *nlh)
* traverse the list of net devices and compute the minimum
* buffer size based upon the filter mask.
*/
- list_for_each_entry(dev, &net->dev_base_head, dev_list) {
+ rcu_read_lock();
+ for_each_netdev_rcu(net, dev) {
min_ifinfo_dump_size = max_t(u16, min_ifinfo_dump_size,
if_nlmsg_size(dev,
ext_filter_mask));
}
+ rcu_read_unlock();
return nlmsg_total_size(min_ifinfo_dump_size);
}
@@ -2847,19 +2824,29 @@ static int rtnl_dump_all(struct sk_buff *skb, struct netlink_callback *cb)
if (s_idx == 0)
s_idx = 1;
+
for (idx = 1; idx <= RTNL_FAMILY_MAX; idx++) {
int type = cb->nlh->nlmsg_type-RTM_BASE;
+ struct rtnl_link *handlers;
+ rtnl_dumpit_func dumpit;
+
if (idx < s_idx || idx == PF_PACKET)
continue;
- if (rtnl_msg_handlers[idx] == NULL ||
- rtnl_msg_handlers[idx][type].dumpit == NULL)
+
+ handlers = rtnl_dereference(rtnl_msg_handlers[idx]);
+ if (!handlers)
continue;
+
+ dumpit = READ_ONCE(handlers[type].dumpit);
+ if (!dumpit)
+ continue;
+
if (idx > s_idx) {
memset(&cb->args[0], 0, sizeof(cb->args));
cb->prev_seq = 0;
cb->seq = 0;
}
- if (rtnl_msg_handlers[idx][type].dumpit(skb, cb))
+ if (dumpit(skb, cb))
break;
}
cb->family = idx;
@@ -4162,11 +4149,13 @@ static int rtnetlink_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh,
struct netlink_ext_ack *extack)
{
struct net *net = sock_net(skb->sk);
+ struct rtnl_link *handlers;
+ int err = -EOPNOTSUPP;
rtnl_doit_func doit;
+ unsigned int flags;
int kind;
int family;
int type;
- int err;
type = nlh->nlmsg_type;
if (type > RTM_MAX)
@@ -4184,20 +4173,40 @@ static int rtnetlink_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh,
if (kind != 2 && !netlink_net_capable(skb, CAP_NET_ADMIN))
return -EPERM;
+ if (family >= ARRAY_SIZE(rtnl_msg_handlers))
+ family = PF_UNSPEC;
+
+ rcu_read_lock();
+ handlers = rcu_dereference(rtnl_msg_handlers[family]);
+ if (!handlers) {
+ family = PF_UNSPEC;
+ handlers = rcu_dereference(rtnl_msg_handlers[family]);
+ }
+
if (kind == 2 && nlh->nlmsg_flags&NLM_F_DUMP) {
struct sock *rtnl;
rtnl_dumpit_func dumpit;
- rtnl_calcit_func calcit;
u16 min_dump_alloc = 0;
- dumpit = rtnl_get_dumpit(family, type);
- if (dumpit == NULL)
- return -EOPNOTSUPP;
- calcit = rtnl_get_calcit(family, type);
- if (calcit)
- min_dump_alloc = calcit(skb, nlh);
+ dumpit = READ_ONCE(handlers[type].dumpit);
+ if (!dumpit) {
+ family = PF_UNSPEC;
+ handlers = rcu_dereference(rtnl_msg_handlers[PF_UNSPEC]);
+ if (!handlers)
+ goto err_unlock;
+
+ dumpit = READ_ONCE(handlers[type].dumpit);
+ if (!dumpit)
+ goto err_unlock;
+ }
+
+ refcount_inc(&rtnl_msg_handlers_ref[family]);
+
+ if (type == RTM_GETLINK - RTM_BASE)
+ min_dump_alloc = rtnl_calcit(skb, nlh);
+
+ rcu_read_unlock();
- __rtnl_unlock();
rtnl = net->rtnl;
{
struct netlink_dump_control c = {
@@ -4206,22 +4215,47 @@ static int rtnetlink_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh,
};
err = netlink_dump_start(rtnl, skb, nlh, &c);
}
- rtnl_lock();
+ refcount_dec(&rtnl_msg_handlers_ref[family]);
return err;
}
- doit = rtnl_get_doit(family, type);
- if (doit == NULL)
- return -EOPNOTSUPP;
+ doit = READ_ONCE(handlers[type].doit);
+ if (!doit) {
+ family = PF_UNSPEC;
+ handlers = rcu_dereference(rtnl_msg_handlers[family]);
+ }
+
+ flags = READ_ONCE(handlers[type].flags);
+ if (flags & RTNL_FLAG_DOIT_UNLOCKED) {
+ refcount_inc(&rtnl_msg_handlers_ref[family]);
+ doit = READ_ONCE(handlers[type].doit);
+ rcu_read_unlock();
+ if (doit)
+ err = doit(skb, nlh, extack);
+ refcount_dec(&rtnl_msg_handlers_ref[family]);
+ return err;
+ }
- return doit(skb, nlh, extack);
+ rcu_read_unlock();
+
+ rtnl_lock();
+ handlers = rtnl_dereference(rtnl_msg_handlers[family]);
+ if (handlers) {
+ doit = READ_ONCE(handlers[type].doit);
+ if (doit)
+ err = doit(skb, nlh, extack);
+ }
+ rtnl_unlock();
+ return err;
+
+err_unlock:
+ rcu_read_unlock();
+ return -EOPNOTSUPP;
}
static void rtnetlink_rcv(struct sk_buff *skb)
{
- rtnl_lock();
netlink_rcv_skb(skb, &rtnetlink_rcv_msg);
- rtnl_unlock();
}
static int rtnetlink_bind(struct net *net, int group)
@@ -4294,29 +4328,34 @@ static struct pernet_operations rtnetlink_net_ops = {
void __init rtnetlink_init(void)
{
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(rtnl_msg_handlers_ref); i++)
+ refcount_set(&rtnl_msg_handlers_ref[i], 1);
+
if (register_pernet_subsys(&rtnetlink_net_ops))
panic("rtnetlink_init: cannot initialize rtnetlink\n");
register_netdevice_notifier(&rtnetlink_dev_notifier);
rtnl_register(PF_UNSPEC, RTM_GETLINK, rtnl_getlink,
- rtnl_dump_ifinfo, rtnl_calcit);
- rtnl_register(PF_UNSPEC, RTM_SETLINK, rtnl_setlink, NULL, NULL);
- rtnl_register(PF_UNSPEC, RTM_NEWLINK, rtnl_newlink, NULL, NULL);
- rtnl_register(PF_UNSPEC, RTM_DELLINK, rtnl_dellink, NULL, NULL);
+ rtnl_dump_ifinfo, 0);
+ rtnl_register(PF_UNSPEC, RTM_SETLINK, rtnl_setlink, NULL, 0);
+ rtnl_register(PF_UNSPEC, RTM_NEWLINK, rtnl_newlink, NULL, 0);
+ rtnl_register(PF_UNSPEC, RTM_DELLINK, rtnl_dellink, NULL, 0);
- rtnl_register(PF_UNSPEC, RTM_GETADDR, NULL, rtnl_dump_all, NULL);
- rtnl_register(PF_UNSPEC, RTM_GETROUTE, NULL, rtnl_dump_all, NULL);
- rtnl_register(PF_UNSPEC, RTM_GETNETCONF, NULL, rtnl_dump_all, NULL);
+ rtnl_register(PF_UNSPEC, RTM_GETADDR, NULL, rtnl_dump_all, 0);
+ rtnl_register(PF_UNSPEC, RTM_GETROUTE, NULL, rtnl_dump_all, 0);
+ rtnl_register(PF_UNSPEC, RTM_GETNETCONF, NULL, rtnl_dump_all, 0);
- rtnl_register(PF_BRIDGE, RTM_NEWNEIGH, rtnl_fdb_add, NULL, NULL);
- rtnl_register(PF_BRIDGE, RTM_DELNEIGH, rtnl_fdb_del, NULL, NULL);
- rtnl_register(PF_BRIDGE, RTM_GETNEIGH, NULL, rtnl_fdb_dump, NULL);
+ rtnl_register(PF_BRIDGE, RTM_NEWNEIGH, rtnl_fdb_add, NULL, 0);
+ rtnl_register(PF_BRIDGE, RTM_DELNEIGH, rtnl_fdb_del, NULL, 0);
+ rtnl_register(PF_BRIDGE, RTM_GETNEIGH, NULL, rtnl_fdb_dump, 0);
- rtnl_register(PF_BRIDGE, RTM_GETLINK, NULL, rtnl_bridge_getlink, NULL);
- rtnl_register(PF_BRIDGE, RTM_DELLINK, rtnl_bridge_dellink, NULL, NULL);
- rtnl_register(PF_BRIDGE, RTM_SETLINK, rtnl_bridge_setlink, NULL, NULL);
+ rtnl_register(PF_BRIDGE, RTM_GETLINK, NULL, rtnl_bridge_getlink, 0);
+ rtnl_register(PF_BRIDGE, RTM_DELLINK, rtnl_bridge_dellink, NULL, 0);
+ rtnl_register(PF_BRIDGE, RTM_SETLINK, rtnl_bridge_setlink, NULL, 0);
rtnl_register(PF_UNSPEC, RTM_GETSTATS, rtnl_stats_get, rtnl_stats_dump,
- NULL);
+ 0);
}