Commit 07cc7b0b authored by Kuniyuki Iwashima's avatar Kuniyuki Iwashima Committed by Paolo Abeni
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rtnetlink: Add bulk registration helpers for rtnetlink message handlers. 



Before commit addf9b90 ("net: rtnetlink: use rcu to free rtnl message
handlers"), once rtnl_msg_handlers[protocol] was allocated, the following
rtnl_register_module() for the same protocol never failed.

However, after the commit, rtnl_msg_handler[protocol][msgtype] needs to
be allocated in each rtnl_register_module(), so each call could fail.

Many callers of rtnl_register_module() do not handle the returned error,
and we need to add many error handlings.

To handle that easily, let's add wrapper functions for bulk registration
of rtnetlink message handlers.

Signed-off-by: default avatarKuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: default avatarPaolo Abeni <pabeni@redhat.com>
parent 9a3cd877

include/net/rtnetlink.h

+17 −0
Original line number Diff line number Diff line
@@ -29,6 +29,15 @@ static inline enum rtnl_kinds rtnl_msgtype_kind(int msgtype) 
	return msgtype & RTNL_KIND_MASK;

}



struct rtnl_msg_handler {

	struct module *owner;

	int protocol;

	int msgtype;

	rtnl_doit_func doit;

	rtnl_dumpit_func dumpit;

	int flags;

};



void rtnl_register(int protocol, int msgtype,

		   rtnl_doit_func, rtnl_dumpit_func, unsigned int flags);

int rtnl_register_module(struct module *owner, int protocol, int msgtype,
@@ -36,6 +45,14 @@ int rtnl_register_module(struct module *owner, int protocol, int msgtype, 
int rtnl_unregister(int protocol, int msgtype);

void rtnl_unregister_all(int protocol);



int __rtnl_register_many(const struct rtnl_msg_handler *handlers, int n);

void __rtnl_unregister_many(const struct rtnl_msg_handler *handlers, int n);



#define rtnl_register_many(handlers)				\

	__rtnl_register_many(handlers, ARRAY_SIZE(handlers))

#define rtnl_unregister_many(handlers)				\

	__rtnl_unregister_many(handlers, ARRAY_SIZE(handlers))



static inline int rtnl_msg_family(const struct nlmsghdr *nlh)

{

	if (nlmsg_len(nlh) >= sizeof(struct rtgenmsg))

net/core/rtnetlink.c

+29 −0
Original line number Diff line number Diff line
@@ -384,6 +384,35 @@ void rtnl_unregister_all(int protocol) 
}

EXPORT_SYMBOL_GPL(rtnl_unregister_all);



int __rtnl_register_many(const struct rtnl_msg_handler *handlers, int n)

{

	const struct rtnl_msg_handler *handler;

	int i, err;



	for (i = 0, handler = handlers; i < n; i++, handler++) {

		err = rtnl_register_internal(handler->owner, handler->protocol,

					     handler->msgtype, handler->doit,

					     handler->dumpit, handler->flags);

		if (err) {

			__rtnl_unregister_many(handlers, i);

			break;

		}

	}



	return err;

}

EXPORT_SYMBOL_GPL(__rtnl_register_many);



void __rtnl_unregister_many(const struct rtnl_msg_handler *handlers, int n)

{

	const struct rtnl_msg_handler *handler;

	int i;



	for (i = n - 1, handler = handlers + n - 1; i >= 0; i--, handler--)

		rtnl_unregister(handler->protocol, handler->msgtype);

}

EXPORT_SYMBOL_GPL(__rtnl_unregister_many);



static LIST_HEAD(link_ops);



static const struct rtnl_link_ops *rtnl_link_ops_get(const char *kind)