On Wed, Jul 11, 2012 at 7:01 AM, Alex Elder <elder@xxxxxxxxxxx> wrote:
> This adds a new utility routine which will return a dynamically-
> allocated buffer containing a string that has been decoded from ceph
> over-the-wire format. It also returns the length of the string
> if the address of a size variable is supplied to receive it.
>
> For now, no gfp_flags parameter is defined (GFP_KERNEL is used) but
> it could be easily be added if needed.
>
I'd rather have it upfront, will help avoiding future errors.
> Signed-off-by: Alex Elder <elder@xxxxxxxxxxx>
> ---
> include/linux/ceph/decode.h | 29 +++++++++++++++++++++++++++++
> 1 files changed, 29 insertions(+), 0 deletions(-)
>
> diff --git a/include/linux/ceph/decode.h b/include/linux/ceph/decode.h
> index 7ead11fc..7759164 100644
> --- a/include/linux/ceph/decode.h
> +++ b/include/linux/ceph/decode.h
> @@ -80,6 +80,35 @@ static inline size_t ceph_decode_string(void **p,
> char *s, size_t size)
> }
>
> /*
> + * Allocate a buffer big enough to hold the wire-encoded string, and
> + * decode the string into it. The resulting string will always be
> + * terminated with '\0'. If successful, *p will be advanced
> + * past the decoded data. Also, if lenp is not a null pointer, the
> + * length (not including the terminating '\0') will be recorded in
> + * it. Note that a zero-length string is a valid return value.
> + *
> + * Returns a pointer to the newly-allocated string buffer, or a
> + * null pointer if memory could not be allocated for the result.
> + * Neither of the arguments is updated if NULL is returned.
> + */
> +static inline char *ceph_extract_encoded_string(void **p, size_t *lenp)
> +{
> + size_t len;
> + char *buf;
> +
> + len = ceph_decode_string(p, NULL, 0);
> + buf = kmalloc(len + 1, GFP_KERNEL);
> + if (!buf)
> + return NULL;
> +
> + (void) ceph_decode_string(p, buf, len + 1);
> + if (lenp)
> + *lenp = len;
> +
> + return buf;
> +}
> +
> +/*
We don't make an effort here to check whether encoded string buffer is
valid. While we may be checking it somewhere up the stack, this seem
like a generic enough function that could be naively used. Either make
it clear that it's an internal function, or make it check p bounds.
> * bounds check input.
> */
> static inline int ceph_has_room(void **p, void *end, size_t n)
> --
> 1.7.5.4
>
> --
> To unsubscribe from this list: send the line "unsubscribe ceph-devel" in
> the body of a message to majordomo@xxxxxxxxxxxxxxx
> More majordomo info at http://vger.kernel.org/majordomo-info.html
--
To unsubscribe from this list: send the line "unsubscribe ceph-devel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
