Finds a specific option in an extension header.
    Format
      #include  <in6.h>
      int inet6_opt_find  ( void *extbuf, size_t extlen, int offset,
                          uint8_t type, size_t *lenp, void **databufp
                          );

1  –  Arguments

 extbuf
    Points to a buffer that contains an extension header.
 extlen
    Specifies the length, in bytes, of the extension header.
 offset
    Specifies the location in the extension header of an option.
    Valid values are either 0 (zero) for the first option or the
    length returned from a previous call to either inet6_opt_next()
    or inet6_opt_find().
 type
    Specifies the type of option to find.
 lenp
    Points to the length of the option found.
 databufp
    Points to the option data.

2  –  Description

    This function searches a received option extension header for an
    option specified by type. If it finds the specified option, it
    returns the option length and a pointer to the option data. It
    also returns an offset to the next option, which you can specify
    in the offset argument to subsequent calls to inet6_opt_next()
    in order to search for additional occurrences of the same option
    type.

3  –  Return Values

    x                  Upon successful completion, the inet6_opt_
                       find() function returns an offset from which
                       you can begin the next search in the data
                       buffer.
    -1                 Failure