diff options
Diffstat (limited to 'net/sunrpc/xdr.c')
| -rw-r--r-- | net/sunrpc/xdr.c | 45 |
1 files changed, 45 insertions, 0 deletions
diff --git a/net/sunrpc/xdr.c b/net/sunrpc/xdr.c index c607744b3ea8..757560a3b06b 100644 --- a/net/sunrpc/xdr.c +++ b/net/sunrpc/xdr.c @@ -1408,6 +1408,51 @@ int xdr_buf_subsegment(const struct xdr_buf *buf, struct xdr_buf *subbuf, EXPORT_SYMBOL_GPL(xdr_buf_subsegment); /** + * xdr_stream_subsegment - set @subbuf to a portion of @xdr + * @xdr: an xdr_stream set up for decoding + * @subbuf: the result buffer + * @nbytes: length of @xdr to extract, in bytes + * + * Sets up @subbuf to represent a portion of @xdr. The portion + * starts at the current offset in @xdr, and extends for a length + * of @nbytes. If this is successful, @xdr is advanced to the next + * position following that portion. + * + * Return values: + * %true: @subbuf has been initialized, and @xdr has been advanced. + * %false: a bounds error has occurred + */ +bool xdr_stream_subsegment(struct xdr_stream *xdr, struct xdr_buf *subbuf, + unsigned int nbytes) +{ + unsigned int remaining, offset, len; + + if (xdr_buf_subsegment(xdr->buf, subbuf, xdr_stream_pos(xdr), nbytes)) + return false; + + if (subbuf->head[0].iov_len) + if (!__xdr_inline_decode(xdr, subbuf->head[0].iov_len)) + return false; + + remaining = subbuf->page_len; + offset = subbuf->page_base; + while (remaining) { + len = min_t(unsigned int, remaining, PAGE_SIZE) - offset; + + if (xdr->p == xdr->end && !xdr_set_next_buffer(xdr)) + return false; + if (!__xdr_inline_decode(xdr, len)) + return false; + + remaining -= len; + offset = 0; + } + + return true; +} +EXPORT_SYMBOL_GPL(xdr_stream_subsegment); + +/** * xdr_buf_trim - lop at most "len" bytes off the end of "buf" * @buf: buf to be trimmed * @len: number of bytes to reduce "buf" by |