Allow rtnl callbacks to support strict attribute checking. They can do so by
passing new RTNL_F_STRICT flag to rtnl_register_flags. The semantics of the
current rtnl_register and __rtnl_register functions were preserved in order
not to change almost hundred of the call sites.
Signed-off-by: Jiri Benc <jb...@redhat.com>
---
include/net/rtnetlink.h | 27 ++++++++++++++++++++++----
net/core/rtnetlink.c | 51 +++++++++++++++++++++++++++++++------------------
2 files changed, 55 insertions(+), 23 deletions(-)
diff --git a/include/net/rtnetlink.h b/include/net/rtnetlink.h
index aff6ceb891a9..58bf1f5ad6a1 100644
--- a/include/net/rtnetlink.h
+++ b/include/net/rtnetlink.h
@@ -8,13 +8,32 @@ typedef int (*rtnl_doit_func)(struct sk_buff *, struct
nlmsghdr *);
typedef int (*rtnl_dumpit_func)(struct sk_buff *, struct netlink_callback *);
typedef u16 (*rtnl_calcit_func)(struct sk_buff *, struct nlmsghdr *);
-int __rtnl_register(int protocol, int msgtype,
- rtnl_doit_func, rtnl_dumpit_func, rtnl_calcit_func);
-void rtnl_register(int protocol, int msgtype,
- rtnl_doit_func, rtnl_dumpit_func, rtnl_calcit_func);
+#define RTNL_F_STRICT 1
+
+int __rtnl_register_flags(int protocol, int msgtype,
+ rtnl_doit_func, rtnl_dumpit_func, rtnl_calcit_func,
+ unsigned int flags);
+void rtnl_register_flags(int protocol, int msgtype,
+ rtnl_doit_func, rtnl_dumpit_func, rtnl_calcit_func,
+ unsigned int flags);
int rtnl_unregister(int protocol, int msgtype);
void rtnl_unregister_all(int protocol);
+static inline int __rtnl_register(int protocol, int msgtype,
+ rtnl_doit_func doit, rtnl_dumpit_func dumpit,
+ rtnl_calcit_func calcit)
+{
+ return __rtnl_register_flags(protocol, msgtype,
+ doit, dumpit, calcit, 0);
+}
+
+static inline void rtnl_register(int protocol, int msgtype,
+ rtnl_doit_func doit, rtnl_dumpit_func dumpit,
+ rtnl_calcit_func calcit)
+{
+ rtnl_register_flags(protocol, msgtype, doit, dumpit, calcit, 0);
+}
+
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 afb41c7492b4..dedc539b960c 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -61,6 +61,7 @@ struct rtnl_link {
rtnl_doit_func doit;
rtnl_dumpit_func dumpit;
rtnl_calcit_func calcit;
+ unsigned int flags;
};
static DEFINE_MUTEX(rtnl_mutex);
@@ -119,7 +120,8 @@ static inline int rtm_msgindex(int msgtype)
return msgindex;
}
-static rtnl_doit_func rtnl_get_doit(int protocol, int msgindex)
+static rtnl_doit_func rtnl_get_doit(int protocol, int msgindex,
+ unsigned int *flags)
{
struct rtnl_link *tab;
@@ -131,6 +133,7 @@ static rtnl_doit_func rtnl_get_doit(int protocol, int
msgindex)
if (tab == NULL || tab[msgindex].doit == NULL)
tab = rtnl_msg_handlers[PF_UNSPEC];
+ *flags = tab[msgindex].flags;
return tab[msgindex].doit;
}
@@ -165,12 +168,13 @@ static rtnl_calcit_func rtnl_get_calcit(int protocol, int
msgindex)
}
/**
- * __rtnl_register - Register a rtnetlink message type
+ * __rtnl_register_flags - 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_F_ flags
*
* Registers the specified function pointers (at least one of them has
* to be non-NULL) to be called whenever a request message for the
@@ -182,9 +186,9 @@ static rtnl_calcit_func rtnl_get_calcit(int protocol, int
msgindex)
*
* Returns 0 on success or a negative error code.
*/
-int __rtnl_register(int protocol, int msgtype,
- rtnl_doit_func doit, rtnl_dumpit_func dumpit,
- rtnl_calcit_func calcit)
+int __rtnl_register_flags(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;
@@ -210,29 +214,32 @@ int __rtnl_register(int protocol, int msgtype,
if (calcit)
tab[msgindex].calcit = calcit;
+ tab[msgindex].flags = flags;
+
return 0;
}
-EXPORT_SYMBOL_GPL(__rtnl_register);
+EXPORT_SYMBOL_GPL(__rtnl_register_flags);
/**
- * rtnl_register - Register a rtnetlink message type
+ * rtnl_register_flags - Register a rtnetlink message type
*
- * Identical to __rtnl_register() but panics on failure. This is useful
- * as failure of this function is very unlikely, it can only happen due
- * to lack of memory when allocating the chain to store all message
- * handlers for a protocol. Meant for use in init functions where lack
- * of memory implies no sense in continuing.
+ * Identical to __rtnl_register_flags() but panics on failure. This is
+ * useful as failure of this function is very unlikely, it can only happen
+ * due to lack of memory when allocating the chain to store all message
+ * handlers for a protocol. Meant for use in init functions where lack of
+ * memory implies no sense in continuing.
*/
-void rtnl_register(int protocol, int msgtype,
- rtnl_doit_func doit, rtnl_dumpit_func dumpit,
- rtnl_calcit_func calcit)
+void rtnl_register_flags(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_flags(protocol, msgtype, doit, dumpit, calcit,
+ flags) < 0)
panic("Unable to register rtnetlink message handler, "
"protocol = %d, message type = %d\n",
protocol, msgtype);
}
-EXPORT_SYMBOL_GPL(rtnl_register);
+EXPORT_SYMBOL_GPL(rtnl_register_flags);
/**
* rtnl_unregister - Unregister a rtnetlink message type
@@ -3298,6 +3305,7 @@ static int rtnetlink_rcv_msg(struct sk_buff *skb, struct
nlmsghdr *nlh)
{
struct net *net = sock_net(skb->sk);
rtnl_doit_func doit;
+ unsigned int flags;
int sz_idx, kind;
int family;
int type;
@@ -3326,6 +3334,9 @@ static int rtnetlink_rcv_msg(struct sk_buff *skb, struct
nlmsghdr *nlh)
rtnl_calcit_func calcit;
u16 min_dump_alloc = 0;
+ if (nlh->nlmsg_flags & NLM_F_STRICT)
+ return -EPROTO;
+
dumpit = rtnl_get_dumpit(family, type);
if (dumpit == NULL)
return -EOPNOTSUPP;
@@ -3346,9 +3357,11 @@ static int rtnetlink_rcv_msg(struct sk_buff *skb, struct
nlmsghdr *nlh)
return err;
}
- doit = rtnl_get_doit(family, type);
+ doit = rtnl_get_doit(family, type, &flags);
if (doit == NULL)
return -EOPNOTSUPP;
+ if (!(flags & RTNL_F_STRICT) && (nlh->nlmsg_flags & NLM_F_STRICT))
+ return -EPROTO;
return doit(skb, nlh);
}
@@ -3356,7 +3369,7 @@ static int rtnetlink_rcv_msg(struct sk_buff *skb, struct
nlmsghdr *nlh)
static void rtnetlink_rcv(struct sk_buff *skb)
{
rtnl_lock();
- netlink_rcv_skb(skb, false, &rtnetlink_rcv_msg);
+ netlink_rcv_skb(skb, true, &rtnetlink_rcv_msg);
rtnl_unlock();
}
--
1.8.3.1
--
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