inet6_opt_finish() — Return the updated total length of extension header

Standards

Standards / Extensions	C or C++	Dependencies
RFC3542	both	z/OS® V1R7

Format

#define _OPEN_SYS_SOCK_IPV6
#include <netinet/in.h>

int inet6_opt_finish(void *extbuf, socklen_t extlen, int offset);

General description

inet6_opt_finish() returns the updated total length taking into account the final padding of the extension header to make it a multiple of 8 bytes. If extbuf is not NULL the function also initializes the option by inserting a Pad1 or PadN option of the proper length.

Returned value

If successful, inet6_opt_finish() returns the total length of the extension header including the final padding.

Upon failure, returns -1 and errno is set to one of the following:

EINVAL If one of the following is true:

extbuf is NULL and extlen is non-zero;
extbuf is non-NULL and extlen is not a positive multiple of 8;
extbuf is non-NULL and offset is greater than extlen;
offset is less than the size of the empty extension header.

Usage notes

offset should be the length returned by inet6_opt_init() or inet6_opt_append().