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rtnetlink: Add bulk registration helpers for rtnetlink message handlers.

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Before commit addf9b90de ("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: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
This commit is contained in:
Kuniyuki Iwashima 2024-10-08 11:47:32 -07:00 committed by Paolo Abeni
parent 9a3cd877dc
commit 07cc7b0b94
2 changed files with 46 additions and 0 deletions
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17
include/net/rtnetlink.h
View File

@ -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))

29
net/core/rtnetlink.c
View File

@ -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)