need_libc=false
dnl Check for usual libc functions
-AC_CHECK_FUNCS([daemon fcntl fdopendir fstatvfs fork getenv getpwuid_r gettimeofday if_nameindex isatty lstat memalign mmap openat pread posix_fadvise posix_madvise posix_memalign setlocale stricmp strnicmp uselocale])
+AC_CHECK_FUNCS([daemon fcntl fdopendir fstatvfs fork getenv getpwuid_r gettimeofday if_nameindex if_nametoindex isatty lstat memalign mmap openat pread posix_fadvise posix_madvise posix_memalign setlocale stricmp strnicmp uselocale])
AC_REPLACE_FUNCS([asprintf atof atoll dirfd flockfile getcwd getdelim getpid gmtime_r lldiv localtime_r nrand48 rewind setenv strcasecmp strcasestr strdup strlcpy strncasecmp strndup strnlen strsep strtof strtok_r strtoll swab tdestroy vasprintf])
AC_CHECK_FUNCS(fdatasync,,
[AC_DEFINE(fdatasync, fsync, [Alias fdatasync() to fsync() if missing.])
unsigned if_index;
char *if_name;
};
-# define if_nametoindex(name) atoi(name)
+# ifndef HAVE_IF_NAMETOINDEX
+# define if_nametoindex(name) atoi(name)
+# endif
# define if_nameindex() (errno = ENOBUFS, NULL)
# define if_freenameindex(list) (void)0
#endif