Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Berkeley style UIO structures - Alan Cox 1994. |
| 3 | * |
| 4 | * This program is free software; you can redistribute it and/or |
| 5 | * modify it under the terms of the GNU General Public License |
| 6 | * as published by the Free Software Foundation; either version |
| 7 | * 2 of the License, or (at your option) any later version. |
| 8 | */ |
David Howells | 607ca46 | 2012-10-13 10:46:48 +0100 | [diff] [blame] | 9 | #ifndef __LINUX_UIO_H |
| 10 | #define __LINUX_UIO_H |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 11 | |
David Howells | 607ca46 | 2012-10-13 10:46:48 +0100 | [diff] [blame] | 12 | #include <uapi/linux/uio.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 13 | |
Jiri Slaby | 812ed03 | 2009-07-29 15:04:19 -0700 | [diff] [blame] | 14 | |
| 15 | struct kvec { |
| 16 | void *iov_base; /* and that should *never* hold a userland pointer */ |
| 17 | size_t iov_len; |
| 18 | }; |
| 19 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 20 | /* |
| 21 | * Total number of bytes covered by an iovec. |
| 22 | * |
| 23 | * NOTE that it is not safe to use this function until all the iovec's |
| 24 | * segment lengths have been validated. Because the individual lengths can |
| 25 | * overflow a size_t when added together. |
| 26 | */ |
| 27 | static inline size_t iov_length(const struct iovec *iov, unsigned long nr_segs) |
| 28 | { |
| 29 | unsigned long seg; |
| 30 | size_t ret = 0; |
| 31 | |
| 32 | for (seg = 0; seg < nr_segs; seg++) |
| 33 | ret += iov[seg].iov_len; |
| 34 | return ret; |
| 35 | } |
| 36 | |
| 37 | unsigned long iov_shorten(struct iovec *iov, unsigned long nr_segs, size_t to); |
Jiri Slaby | 812ed03 | 2009-07-29 15:04:19 -0700 | [diff] [blame] | 38 | #endif |