HP-UX IPv6 Porting Guide (September 2004)

Configuring or Querying an Interface using IPv6 ioctl() Function Calls
Chapter 1356
calls, as defined in /usr/include/sys/ioctl.h, to determine the characteristics of the
network interfaces and their attributes.
All of the IPv4 SIOC* ioctl() function calls use the struct ifreq data structure (defined in
/usr/include/net/if.h) as one of the arguments for the SIOC* ioctl() function calls.
However, the ifreq data structure defined for IPv4 is not large enough to hold an IPv6 address.
Therefore, the existing IPv4 SIOC* and their associated data structures are not applicable for
IPv6 applications.
New ioctl() function calls for IPv6-applications-follow the SIOCSL* and SIOCGL* ioctl()
name format. IPv6 ioctl() function calls also use a larger data structure described below.
They are otherwise identical to the IPv4 ioctl() function calls.
NOTE The IPv6 SIOCSL* and SIOCGL* ioctl() function calls are not supported for
IPv4 applications.
Definitions for both IPv6 and IPv4 ioctl() function calls are in
/usr/include/sys/ioctl.h.
NOTE Use a larger data structure for IPv6 addresses. IPv6 addresses cannot fit into
the IPv4 struct ifreq data structure used by IPv4 SIOC* ioctl() function
calls. IPv6 applications pass, as a parameter to IPv6 ioctl()function calls, the
data structures struct if_laddrreq and struct if_laddrconf.
Both IPv6 and IPv4 ioctl() data structures are in /usr/include/net/if.h.