[PATCH net-next 07/10] genetlink: add genlmsg_iput() API
From: Jakub Kicinski <kuba@kernel.org>
Date: 2023-08-09 18:26:59
Subsystem:
networking [general], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
Add some APIs and helpers required for convenient construction of replies and notifications based on struct genl_info. Signed-off-by: Jakub Kicinski <kuba@kernel.org> --- include/net/genetlink.h | 50 ++++++++++++++++++++++++++++++++++++++++- 1 file changed, 49 insertions(+), 1 deletion(-)
diff --git a/include/net/genetlink.h b/include/net/genetlink.h
index 6b858c4cba5b..53f403b8efa9 100644
--- a/include/net/genetlink.h
+++ b/include/net/genetlink.h@@ -113,7 +113,7 @@ struct genl_info { struct netlink_ext_ack *extack; }; -static inline struct net *genl_info_net(struct genl_info *info) +static inline struct net *genl_info_net(const struct genl_info *info) { return read_pnet(&info->_net); }
@@ -270,6 +270,31 @@ genl_info_dump(struct netlink_callback *cb) return &genl_dumpit_info(cb)->info; } +#ifdef __LITTLE_ENDIAN +#define __GENL_PTR_LOW(byte) ((void *)(unsigned long)(byte)) +#else +#define __GENL_PTR_LOW(byte) \ + ((void *)((unsigned long)(byte) << (BITS_PER_LONG - 8))) +#endif + +/** + * GENL_INFO_NTF() - define genl_info for notifications + * @__name: name of declared variable + * @__family: pointer to the genetlink family + * @__cmd: command to be used in the notification + */ +#define GENL_INFO_NTF(__name, __family, __cmd) \ + struct genl_info __name = { \ + .family = (__family), \ + .genlhdr = (void *)&(__name.user_ptr[0]), \ + .user_ptr[0] = __GENL_PTR_LOW(__cmd), \ + } + +static inline bool genl_info_is_ntf(const struct genl_info *info) +{ + return !info->nlhdr; +} + int genl_register_family(struct genl_family *family); int genl_unregister_family(const struct genl_family *family); void genl_notify(const struct genl_family *family, struct sk_buff *skb,
@@ -278,6 +303,29 @@ void genl_notify(const struct genl_family *family, struct sk_buff *skb, void *genlmsg_put(struct sk_buff *skb, u32 portid, u32 seq, const struct genl_family *family, int flags, u8 cmd); +static inline void * +__genlmsg_iput(struct sk_buff *skb, const struct genl_info *info, int flags) +{ + return genlmsg_put(skb, info->snd_portid, info->snd_seq, info->family, + flags, info->genlhdr->cmd); +} + +/** + * genlmsg_iput - start genetlink message based on genl_info + * @skb: skb in which message header will be placed + * @info: genl_info as provided to do/dump handlers + * + * Convenience wrapper which starts a genetlink message based on + * information in user request (or info constructed with GENL_INFO_NTF()). + * + * Returns pointer to new genetlink header. + */ +static inline void * +genlmsg_iput(struct sk_buff *skb, const struct genl_info *info) +{ + return __genlmsg_iput(skb, info, 0); +} + /** * genlmsg_nlhdr - Obtain netlink header from user specified header * @user_hdr: user header as returned from genlmsg_put()
--
2.41.0