diff options
Diffstat (limited to 'include')
| -rw-r--r-- | include/net/netlink.h | 21 | ||||
| -rw-r--r-- | include/uapi/linux/netlink.h | 2 |
2 files changed, 23 insertions, 0 deletions
diff --git a/include/net/netlink.h b/include/net/netlink.h index 4418b1981e31..784b4688fc6f 100644 --- a/include/net/netlink.h +++ b/include/net/netlink.h @@ -932,6 +932,27 @@ static inline struct nlmsghdr *nlmsg_put(struct sk_buff *skb, u32 portid, u32 se } /** + * nlmsg_append - Add more data to a nlmsg in a skb + * @skb: socket buffer to store message in + * @size: length of message payload + * + * Append data to an existing nlmsg, used when constructing a message + * with multiple fixed-format headers (which is rare). + * Returns NULL if the tailroom of the skb is insufficient to store + * the extra payload. + */ +static inline void *nlmsg_append(struct sk_buff *skb, u32 size) +{ + if (unlikely(skb_tailroom(skb) < NLMSG_ALIGN(size))) + return NULL; + + if (NLMSG_ALIGN(size) - size) + memset(skb_tail_pointer(skb) + size, 0, + NLMSG_ALIGN(size) - size); + return __skb_put(skb, NLMSG_ALIGN(size)); +} + +/** * nlmsg_put_answer - Add a new callback based netlink message to an skb * @skb: socket buffer to store message in * @cb: netlink callback diff --git a/include/uapi/linux/netlink.h b/include/uapi/linux/netlink.h index e2ae82e3f9f7..5da0da59bf01 100644 --- a/include/uapi/linux/netlink.h +++ b/include/uapi/linux/netlink.h @@ -48,6 +48,7 @@ struct sockaddr_nl { * @nlmsg_flags: Additional flags * @nlmsg_seq: Sequence number * @nlmsg_pid: Sending process port ID + * @nlmsg_data: Message payload */ struct nlmsghdr { __u32 nlmsg_len; @@ -55,6 +56,7 @@ struct nlmsghdr { __u16 nlmsg_flags; __u32 nlmsg_seq; __u32 nlmsg_pid; + __u8 nlmsg_data[]; }; /* Flags values */ |