struct ifinfomsg
{
unsigned char ifi_family; /* AF_UNSPEC */
unsigned short ifi_type; /* Device type */
int ifi_index; /* Interface index */
unsigned int ifi_flags; /* Device flags */
unsigned int ifi_change; /* change mask */
};

ifi_flags contains the device flags, see netdevice(7); ifi_index is the unique interface index, ifi_change is reserved for future use and should be always set to 0xFFFFFFFF.

struct ifaddrmsg
{
unsigned char ifa_family; /* Address type */
unsigned char ifa_prefixlen;/* Prefixlength of the address */
unsigned char ifa_flags; /* Address flags */
unsigned char ifa_scope; /* Address scope */
int ifa_index; /* Interface index */
};

ifa_family is the address family type (currently AF_INET or AF_INET6), ifa_prefixlen is the length of the address mask of the address if defined for the family (like for IPv4), ifa_scope is the address scope, ifa_index is the interface index of the interface the address is associated with. ifa_flags is a flag word of IFA_F_SECONDARY for secondary address (old alias interface), IFA_F_PERMANENT for a permanent address set by the user and other undocumented flags.

struct rtmsg
{
unsigned char rtm_family; /* Address family of route */
unsigned char rtm_dst_len; /* Length of source */
unsigned char rtm_src_len; /* Length of destination */
unsigned char rtm_tos;/* TOS filter */

unsigned char rtm_table; /* Routing table id */
unsigned char rtm_protocol;/* Routing protocol; see below */
unsigned char rtm_scope; /* See below */
unsigned char rtm_type; /* See below */

unsigned int rtm_flags;
};

Values larger than RTPROT_STATIC are not interpreted by the kernel, they are just for user information. They may be used to tag the source of a routing information or to distingush between multiple routing daemons. See <linux/rtnetlink.h> for the routing daemon identifiers which are already assigned.

rtm_scope is the distance to the destination:

The values between RT_SCOPE_UNIVERSE and RT_SCOPE_SITE are available to the user.

The rtm_flags have the following meanings:

rtm_table specifies the routing table

The user may assign arbitary values between RT_TABLE_UNSPEC and RT_TABLE_DEFAULT.

Fill these values in!

struct ndmsg
{
unsigned char ndm_family;
int ndm_ifindex; /* Interface index */
__u16ndm_state; /* State */
__u8 ndm_flags; /* Flags */
__u8 ndm_type;
};

struct nda_cacheinfo
{
__u32ndm_confirmed;
__u32ndm_used;
__u32ndm_updated;
__u32ndm_refcnt;
};

ndm_state is a bitmask of the following states:

Valid ndm_flags are:

document the members of the struct better

The rtaddr struct has the following meanings for the rta_type field:

If the rta_type field is NDA_CACHEINFO then a struct nda_cacheinfo header follows

struct tcmsg
{
unsigned char tcm_family;
int tcm_ifindex; /* interface index */
__u32tcm_handle; /* Qdisc handle */
__u32tcm_parent; /* Parent qdisc */
__u32tcm_info;
};

In addition various other qdisc module specific attributes are allowed. For more information see the appropriate include files.