diff options
Diffstat (limited to 'net/sunrpc/xdr.c')
| -rw-r--r-- | net/sunrpc/xdr.c | 65 |
1 files changed, 41 insertions, 24 deletions
diff --git a/net/sunrpc/xdr.c b/net/sunrpc/xdr.c index 48c93b9e525e..14ba9e72a204 100644 --- a/net/sunrpc/xdr.c +++ b/net/sunrpc/xdr.c @@ -560,7 +560,7 @@ EXPORT_SYMBOL_GPL(xdr_init_encode); * required at the end of encoding, or any other time when the xdr_buf * data might be read. */ -void xdr_commit_encode(struct xdr_stream *xdr) +inline void xdr_commit_encode(struct xdr_stream *xdr) { int shift = xdr->scratch.iov_len; void *page; @@ -1236,43 +1236,60 @@ xdr_encode_word(struct xdr_buf *buf, unsigned int base, u32 obj) } EXPORT_SYMBOL_GPL(xdr_encode_word); -/* If the netobj starting offset bytes from the start of xdr_buf is contained - * entirely in the head or the tail, set object to point to it; otherwise - * try to find space for it at the end of the tail, copy it there, and - * set obj to point to it. */ -int xdr_buf_read_netobj(struct xdr_buf *buf, struct xdr_netobj *obj, unsigned int offset) +/** + * xdr_buf_read_mic() - obtain the address of the GSS mic from xdr buf + * @buf: pointer to buffer containing a mic + * @mic: on success, returns the address of the mic + * @offset: the offset in buf where mic may be found + * + * This function may modify the xdr buf if the mic is found to be straddling + * a boundary between head, pages, and tail. On success the mic can be read + * from the address returned. There is no need to free the mic. + * + * Return: Success returns 0, otherwise an integer error. + */ +int xdr_buf_read_mic(struct xdr_buf *buf, struct xdr_netobj *mic, unsigned int offset) { struct xdr_buf subbuf; + unsigned int boundary; - if (xdr_decode_word(buf, offset, &obj->len)) + if (xdr_decode_word(buf, offset, &mic->len)) return -EFAULT; - if (xdr_buf_subsegment(buf, &subbuf, offset + 4, obj->len)) + offset += 4; + + /* Is the mic partially in the head? */ + boundary = buf->head[0].iov_len; + if (offset < boundary && (offset + mic->len) > boundary) + xdr_shift_buf(buf, boundary - offset); + + /* Is the mic partially in the pages? */ + boundary += buf->page_len; + if (offset < boundary && (offset + mic->len) > boundary) + xdr_shrink_pagelen(buf, boundary - offset); + + if (xdr_buf_subsegment(buf, &subbuf, offset, mic->len)) return -EFAULT; - /* Is the obj contained entirely in the head? */ - obj->data = subbuf.head[0].iov_base; - if (subbuf.head[0].iov_len == obj->len) + /* Is the mic contained entirely in the head? */ + mic->data = subbuf.head[0].iov_base; + if (subbuf.head[0].iov_len == mic->len) return 0; - /* ..or is the obj contained entirely in the tail? */ - obj->data = subbuf.tail[0].iov_base; - if (subbuf.tail[0].iov_len == obj->len) + /* ..or is the mic contained entirely in the tail? */ + mic->data = subbuf.tail[0].iov_base; + if (subbuf.tail[0].iov_len == mic->len) return 0; - /* use end of tail as storage for obj: - * (We don't copy to the beginning because then we'd have - * to worry about doing a potentially overlapping copy. - * This assumes the object is at most half the length of the - * tail.) */ - if (obj->len > buf->buflen - buf->len) + /* Find a contiguous area in @buf to hold all of @mic */ + if (mic->len > buf->buflen - buf->len) return -ENOMEM; if (buf->tail[0].iov_len != 0) - obj->data = buf->tail[0].iov_base + buf->tail[0].iov_len; + mic->data = buf->tail[0].iov_base + buf->tail[0].iov_len; else - obj->data = buf->head[0].iov_base + buf->head[0].iov_len; - __read_bytes_from_xdr_buf(&subbuf, obj->data, obj->len); + mic->data = buf->head[0].iov_base + buf->head[0].iov_len; + __read_bytes_from_xdr_buf(&subbuf, mic->data, mic->len); return 0; } -EXPORT_SYMBOL_GPL(xdr_buf_read_netobj); +EXPORT_SYMBOL_GPL(xdr_buf_read_mic); /* Returns 0 on success, or else a negative error code. */ static int |