| Message ID | 20241004222358.79129-2-kuniyu@amazon.com (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | rtnetlink: Handle error of rtnl_register_module(). | expand |
On Sat, Oct 5, 2024 at 12:24 AM Kuniyuki Iwashima <kuniyu@amazon.com> wrote: > > Before commit addf9b90de22 ("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> > --- > include/net/rtnetlink.h | 19 +++++++++++++++++++ > net/core/rtnetlink.c | 30 ++++++++++++++++++++++++++++++ > 2 files changed, 49 insertions(+) > > diff --git a/include/net/rtnetlink.h b/include/net/rtnetlink.h > index b45d57b5968a..b6b91898dc13 100644 > --- a/include/net/rtnetlink.h > +++ b/include/net/rtnetlink.h > @@ -29,6 +29,14 @@ static inline enum rtnl_kinds rtnl_msgtype_kind(int msgtype) > return msgtype & RTNL_KIND_MASK; > } > > +struct rtnl_msg_handler { Since we add a structure, we could stick here a 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 +44,17 @@ 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(struct module *owner, > + struct rtnl_msg_handler *handlers, int n); > +void __rtnl_unregister_many(struct rtnl_msg_handler *handlers, int n); > + > +#define rtnl_register_many(handlers) \ > + __rtnl_register_many(NULL, handlers, ARRAY_SIZE(handlers)) > +#define rtnl_register_module_many(handlers) \ > + __rtnl_register_many(THIS_MODULE, handlers, ARRAY_SIZE(handlers)) This would allow a simpler api, no need for rtnl_register_module_many()
From: Eric Dumazet <edumazet@google.com> Date: Sat, 5 Oct 2024 10:25:20 +0200 > On Sat, Oct 5, 2024 at 12:24 AM Kuniyuki Iwashima <kuniyu@amazon.com> wrote: > > > > Before commit addf9b90de22 ("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> > > --- > > include/net/rtnetlink.h | 19 +++++++++++++++++++ > > net/core/rtnetlink.c | 30 ++++++++++++++++++++++++++++++ > > 2 files changed, 49 insertions(+) > > > > diff --git a/include/net/rtnetlink.h b/include/net/rtnetlink.h > > index b45d57b5968a..b6b91898dc13 100644 > > --- a/include/net/rtnetlink.h > > +++ b/include/net/rtnetlink.h > > @@ -29,6 +29,14 @@ static inline enum rtnl_kinds rtnl_msgtype_kind(int msgtype) > > return msgtype & RTNL_KIND_MASK; > > } > > > > +struct rtnl_msg_handler { > > Since we add a structure, we could stick here a > > struct module *owner; Will add it and remove _module version in v3. Thanks! > > > + 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 +44,17 @@ 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(struct module *owner, > > + struct rtnl_msg_handler *handlers, int n); > > +void __rtnl_unregister_many(struct rtnl_msg_handler *handlers, int n); > > + > > +#define rtnl_register_many(handlers) \ > > + __rtnl_register_many(NULL, handlers, ARRAY_SIZE(handlers)) > > +#define rtnl_register_module_many(handlers) \ > > + __rtnl_register_many(THIS_MODULE, handlers, ARRAY_SIZE(handlers)) > > > This would allow a simpler api, no need for rtnl_register_module_many()
diff --git a/include/net/rtnetlink.h b/include/net/rtnetlink.h index b45d57b5968a..b6b91898dc13 100644 --- a/include/net/rtnetlink.h +++ b/include/net/rtnetlink.h @@ -29,6 +29,14 @@ static inline enum rtnl_kinds rtnl_msgtype_kind(int msgtype) return msgtype & RTNL_KIND_MASK; } +struct rtnl_msg_handler { + 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 +44,17 @@ 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(struct module *owner, + struct rtnl_msg_handler *handlers, int n); +void __rtnl_unregister_many(struct rtnl_msg_handler *handlers, int n); + +#define rtnl_register_many(handlers) \ + __rtnl_register_many(NULL, handlers, ARRAY_SIZE(handlers)) +#define rtnl_register_module_many(handlers) \ + __rtnl_register_many(THIS_MODULE, 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)) diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c index f0a520987085..1fac9e786315 100644 --- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -384,6 +384,36 @@ void rtnl_unregister_all(int protocol) } EXPORT_SYMBOL_GPL(rtnl_unregister_all); +int __rtnl_register_many(struct module *owner, + struct rtnl_msg_handler *handlers, int n) +{ + struct rtnl_msg_handler *handler; + int i, err; + + for (i = 0, handler = handlers; i < n; i++, handler++) { + err = rtnl_register_internal(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(struct rtnl_msg_handler *handlers, int n) +{ + 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)
Before commit addf9b90de22 ("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> --- include/net/rtnetlink.h | 19 +++++++++++++++++++ net/core/rtnetlink.c | 30 ++++++++++++++++++++++++++++++ 2 files changed, 49 insertions(+)