макросы Netlink (Netlink macros)
Имя (Name)
netlink - Netlink macros
Синопсис (Synopsis)
#include <asm/types.h>
#include <linux/netlink.h>
int NLMSG_ALIGN(size_t len);
int NLMSG_LENGTH(size_t len);
int NLMSG_SPACE(size_t len);
void *NLMSG_DATA(struct nlmsghdr *nlh);
struct nlmsghdr *NLMSG_NEXT(struct nlmsghdr *nlh, int len);
int NLMSG_OK(struct nlmsghdr *nlh, int len);
int NLMSG_PAYLOAD(struct nlmsghdr *nlh, int len);
Описание (Description)
<linux/netlink.h> defines several standard macros to access or
create a netlink datagram. They are similar in spirit to the
macros defined in cmsg(3) for auxiliary data. The buffer passed
to and from a netlink socket should be accessed using only these
macros.
NLMSG_ALIGN()
Round the length of a netlink message up to align it
properly.
NLMSG_LENGTH()
Given the payload length, len, this macro returns the
aligned length to store in the nlmsg_len field of the
nlmsghdr.
NLMSG_SPACE()
Return the number of bytes that a netlink message with
payload of len would occupy.
NLMSG_DATA()
Return a pointer to the payload associated with the passed
nlmsghdr.
NLMSG_NEXT()
Get the next nlmsghdr in a multipart message. The caller
must check if the current nlmsghdr didn't have the
NLMSG_DONE set—this function doesn't return NULL on end.
The len argument is an lvalue containing the remaining
length of the message buffer. This macro decrements it by
the length of the message header.
NLMSG_OK()
Return true if the netlink message is not truncated and is
in a form suitable for parsing.
NLMSG_PAYLOAD()
Return the length of the payload associated with the
nlmsghdr.
Стандарты (Conforming to)
These macros are nonstandard Linux extensions.
Примечание (Note)
It is often better to use netlink via libnetlink than via the
low-level kernel interface.
Смотри также (See also)
libnetlink(3), netlink(7)
