diff options
Diffstat (limited to 'net/sunrpc/xdr.c')
-rw-r--r-- | net/sunrpc/xdr.c | 96 |
1 files changed, 41 insertions, 55 deletions
diff --git a/net/sunrpc/xdr.c b/net/sunrpc/xdr.c index e5497dc2475b..6f7d82fb1eb0 100644 --- a/net/sunrpc/xdr.c +++ b/net/sunrpc/xdr.c @@ -1150,6 +1150,47 @@ xdr_buf_subsegment(struct xdr_buf *buf, struct xdr_buf *subbuf, } EXPORT_SYMBOL_GPL(xdr_buf_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 + * + * Trim an xdr_buf by the given number of bytes by fixing up the lengths. Note + * that it's possible that we'll trim less than that amount if the xdr_buf is + * too small, or if (for instance) it's all in the head and the parser has + * already read too far into it. + */ +void xdr_buf_trim(struct xdr_buf *buf, unsigned int len) +{ + size_t cur; + unsigned int trim = len; + + if (buf->tail[0].iov_len) { + cur = min_t(size_t, buf->tail[0].iov_len, trim); + buf->tail[0].iov_len -= cur; + trim -= cur; + if (!trim) + goto fix_len; + } + + if (buf->page_len) { + cur = min_t(unsigned int, buf->page_len, trim); + buf->page_len -= cur; + trim -= cur; + if (!trim) + goto fix_len; + } + + if (buf->head[0].iov_len) { + cur = min_t(size_t, buf->head[0].iov_len, trim); + buf->head[0].iov_len -= cur; + trim -= cur; + } +fix_len: + buf->len -= (len - trim); +} +EXPORT_SYMBOL_GPL(xdr_buf_trim); + static void __read_bytes_from_xdr_buf(struct xdr_buf *subbuf, void *obj, unsigned int len) { unsigned int this_len; @@ -1235,61 +1276,6 @@ xdr_encode_word(struct xdr_buf *buf, unsigned int base, u32 obj) } EXPORT_SYMBOL_GPL(xdr_encode_word); -/** - * 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, &mic->len)) - return -EFAULT; - 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 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 mic contained entirely in the tail? */ - mic->data = subbuf.tail[0].iov_base; - if (subbuf.tail[0].iov_len == mic->len) - return 0; - - /* 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) - mic->data = buf->tail[0].iov_base + buf->tail[0].iov_len; - else - 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_mic); - /* Returns 0 on success, or else a negative error code. */ static int xdr_xcode_array2(struct xdr_buf *buf, unsigned int base, |