Reviewed-by: Yehuda Sadeh <yehuda@xxxxxxxxxxx>
On Wed, Jul 11, 2012 at 7:00 AM, Alex Elder <elder@xxxxxxxxxxx> wrote:
> There is no string decoding function defined in <decode.h>, so this
> defines one.
>
> This function is a little different from the others in that the
> length of the encoded string is not known a priori. So the
> interface is defined a bit like snprintf(), where the value returned
> indicates the space required--even if it's more than the space
> allotted.
>
> Signed-off-by: Alex Elder <elder@xxxxxxxxxxx>
> ---
> include/linux/ceph/decode.h | 36 ++++++++++++++++++++++++++++++++++++
> 1 files changed, 36 insertions(+), 0 deletions(-)
>
> diff --git a/include/linux/ceph/decode.h b/include/linux/ceph/decode.h
> index bcbd66c..7ead11fc 100644
> --- a/include/linux/ceph/decode.h
> +++ b/include/linux/ceph/decode.h
> @@ -44,6 +44,42 @@ static inline void ceph_decode_copy(void **p, void
> *pv, size_t n)
> }
>
> /*
> + * Decode the wire-encoded string at *p into the buffer "s"
> + * provided, whose size is indicated by "size". Note that "s" can
> + * be a null pointer if size is 0. If it fits, the resulting string
> + * will always be terminated with '\0'; otherwise the buffer will
> + * be unchanged.
> + *
> + * Returns the length of the encoded string (which may be greater
> + * than or equal to the buffer size). The return value does not
> + * include the terminating '\0'.
> + *
> + * If the the return value is less than the size provided, *p will
> + * be advanced past the decoded data; otherwise it is unchanged.
> + * This allows for a two call sequence to be used to allocate
> + * sufficient space for the string.
> + *
> + * NB It is assumed that *p refers to a block of valid memory
> + * sufficient to hold the length field followed by the number
> + * of bytes indicated by that field.
> + */
> +static inline size_t ceph_decode_string(void **p, char *s, size_t size)
> +{
> + size_t len;
> +
> + len = get_unaligned_le32(*p);
> + if (size < len + 1)
> + return len;
> +
> + if (len)
> + memcpy(s, (char *) *p + sizeof (u32), len);
> + *(s + len) = '\0';
> + *p += sizeof (u32) + len;
> +
> + return len;
> +}
> +
> +/*
> * 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
