Hi,
David Turner wrote:
> If the full hostname doesn't fit in the buffer supplied to
> gethostname, POSIX does not specify whether the buffer will be
> null-terminated, so to be safe, we should do it ourselves.
[...]
> +++ b/wrapper.c
> @@ -655,3 +655,16 @@ void sleep_millisec(int millisec)
> {
> poll(NULL, 0, millisec);
> }
> +
> +int xgethostname(char *buf, size_t len)
> +{
> + /*
> + * If the full hostname doesn't fit in buf, POSIX does not
> + * specify whether the buffer will be null-terminated, so to
> + * be safe, do it ourselves.
> + */
> + int ret = gethostname(buf, len);
> + if (!ret)
> + buf[len - 1] = 0;
> + return ret;
I wonder if after null-terminating we would want to report this as
an error, instead of silently using a truncated result. I.e. something
like
> + if (!ret)
> + buf[len - 1] = 0;
> + if (strlen(buf) >= len - 1) {
> + errno = ENAMETOOLONG;
> + return -1;
> + }
(or EINVAL --- either is equally descriptive).
Also POSIX requires that hostnames are <= 255 bytes. Maybe we can
force the buffer to be large enough.
Thoughts?
Jonathan