valid_utf8_hostname.c

[詳解]

/*++
/* NAME
/*  valid_utf8_hostname 3
/* SUMMARY
/*  validate (maybe UTF-8) domain name
/* SYNOPSIS
/*  #include <valid_utf8_hostname.h>
/*
/*  int valid_utf8_hostname(
/*  int enable_utf8,
/*  const char *domain,
/*  int gripe)
/* DESCRIPTION
/*  valid_utf8_hostname() is a wrapper around valid_hostname().
/*  If EAI support is compiled in, and enable_utf8 is true, the
/*  name is converted from UTF-8 to ASCII per IDNA rules, before
/*  invoking valid_hostname().
/* SEE ALSO
/*  valid_hostname(3) STD3 hostname validation.
/* DIAGNOSTICS
/*  Fatal errors: memory allocation problem.
/*  Warnings: malformed domain name.
/* LICENSE
/* .ad
/* .fi
/*  The Secure Mailer license must be distributed with this software.
/* AUTHOR(S)
/*  Wietse Venema
/*  IBM T.J. Watson Research
/*  P.O. Box 704
/*  Yorktown Heights, NY 10598, USA
/*--*/

 /*
  * System library.
  */
#include <sys_defs.h>

 /*
  * Utility library.
  */
#include <msg.h>
#include <mymalloc.h>
#include <stringops.h>
#include <valid_hostname.h>
#include <midna_domain.h>
#include <valid_utf8_hostname.h>

/* valid_utf8_hostname - validate internationalized domain name */

int     valid_utf8_hostname(int enable_utf8, const char *name, int gripe)
{
    static const char myname[] = "valid_utf8_hostname";

    /*
     * Trivial cases first.
     */
    if (*name == 0) {
    if (gripe)
        msg_warn("%s: empty domain name", myname);
    return (0);
    }

    /*
     * Convert non-ASCII domain name to ASCII and validate the result per
     * STD3. midna_domain_to_ascii() applies valid_hostname() to the result.
     * Propagate the gripe parameter for better diagnostics (note that
     * midna_domain_to_ascii() logs a problem only when the result is not
     * cached).
     */
#ifndef NO_EAI
    if (enable_utf8 && !allascii(name)) {
    if (midna_domain_to_ascii(name) == 0) {
        if (gripe)
        msg_warn("%s: malformed UTF-8 domain name", myname);
        return (0);
    } else {
        return (1);
    }
    }
#endif

    /*
     * Validate ASCII name per STD3.
     */
    return (valid_hostname(name, gripe));
}