/* * Helpers for getting linearized buffers from iov / filling buffers into iovs * * Copyright IBM, Corp. 2007, 2008 * Copyright (C) 2010 Red Hat, Inc. * * Author(s): * Anthony Liguori <aliguori@us.ibm.com> * Amit Shah <amit.shah@redhat.com> * * This work is licensed under the terms of the GNU GPL, version 2. See * the COPYING file in the top-level directory. */ #include "iov.h" size_t iov_from_buf(struct iovec *iov, unsigned int iov_cnt, const void *buf, size_t iov_off, size_t size) { size_t iovec_off, buf_off; unsigned int i; iovec_off = 0; buf_off = 0; for (i = 0; i < iov_cnt && size; i++) { if (iov_off < (iovec_off + iov[i].iov_len)) { size_t len = MIN((iovec_off + iov[i].iov_len) - iov_off, size); memcpy(iov[i].iov_base + (iov_off - iovec_off), buf + buf_off, len); buf_off += len; iov_off += len; size -= len; } iovec_off += iov[i].iov_len; } return buf_off; } size_t iov_to_buf(const struct iovec *iov, const unsigned int iov_cnt, void *buf, size_t iov_off, size_t size) { uint8_t *ptr; size_t iovec_off, buf_off; unsigned int i; ptr = buf; iovec_off = 0; buf_off = 0; for (i = 0; i < iov_cnt && size; i++) { if (iov_off < (iovec_off + iov[i].iov_len)) { size_t len = MIN((iovec_off + iov[i].iov_len) - iov_off , size); memcpy(ptr + buf_off, iov[i].iov_base + (iov_off - iovec_off), len); buf_off += len; iov_off += len; size -= len; } iovec_off += iov[i].iov_len; } return buf_off; } size_t iov_size(const struct iovec *iov, const unsigned int iov_cnt) { size_t len; unsigned int i; len = 0; for (i = 0; i < iov_cnt; i++) { len += iov[i].iov_len; } return len; }