rtrequest Kernel Service

Purpose

Carries out a request to change the routing table.

Syntax

#include <sys/types.h>
#include <sys/errno.h>
#include <sys/mbuf.h>
#include <net/if.h>
#include <net/af.h>
#include <net/route.h>

int rtrequest ( req, dst, gateway, netmask, flags, ret_nrt) int req; struct sockaddr *dst, *gateway, *netmask; int flags; struct rtentry **ret_nrt;

Parameters

Item	Description
req	Specifies a request to add or delete a route.
dst	Specifies the destination part of the route.
gateway	Specifies the gateway part of the route.
netmask	Specifies the network mask to apply to the route.
flags	Identifies routing flags, as defined in the /usr/include/net/route.h file.
ret_nrt	Specifies to return the resultant route.

Description

The rtrequest kernel service carries out a request to change the routing table. Interfaces call the rtrequest service at boot time to make their local routes known for routing table ioctl operations. Interfaces also call the rtrequest service as the result of routing redirects. The request is either to add (if the req parameter has a value of RMT_ADD) or delete (the req parameter is a value of RMT_DELETE) the route.

Execution Environment

The rtrequest kernel service can be called from either the process or interrupt environment.

Return Values

Item	Description
0	Indicates a successful operation.
ESRCH	Indicates that the route was not there to delete.
EEXIST	Indicates that the entry the rtrequest service tried to add already exists.
ENETUNREACH	Indicates that the rtrequest service cannot find the interface for the route.
ENOBUFS	Indicates that the rtrequest service cannot get an mbuf structure to add an entry.

Example

To carry out a request to change the routing table, invoke the rtrequest kernel service as follows:

rtrequest(RTM_ADD, dst, gateway, netmask, flags, &rtp);