diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
---|---|---|
committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /include/net/checksum.h | |
download | kernel_samsung_espresso10-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.zip kernel_samsung_espresso10-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.gz kernel_samsung_espresso10-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.bz2 |
Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'include/net/checksum.h')
-rw-r--r-- | include/net/checksum.h | 87 |
1 files changed, 87 insertions, 0 deletions
diff --git a/include/net/checksum.h b/include/net/checksum.h new file mode 100644 index 0000000..e3ea7cc --- /dev/null +++ b/include/net/checksum.h @@ -0,0 +1,87 @@ +/* + * INET An implementation of the TCP/IP protocol suite for the LINUX + * operating system. INET is implemented using the BSD Socket + * interface as the means of communication with the user level. + * + * Checksumming functions for IP, TCP, UDP and so on + * + * Authors: Jorge Cwik, <jorge@laser.satlink.net> + * Arnt Gulbrandsen, <agulbra@nvg.unit.no> + * Borrows very liberally from tcp.c and ip.c, see those + * files for more names. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + */ + +#ifndef _CHECKSUM_H +#define _CHECKSUM_H + +#include <linux/errno.h> +#include <asm/types.h> +#include <asm/byteorder.h> +#include <asm/uaccess.h> +#include <asm/checksum.h> + +#ifndef _HAVE_ARCH_COPY_AND_CSUM_FROM_USER +static inline +unsigned int csum_and_copy_from_user (const unsigned char __user *src, unsigned char *dst, + int len, int sum, int *err_ptr) +{ + if (access_ok(VERIFY_READ, src, len)) + return csum_partial_copy_from_user(src, dst, len, sum, err_ptr); + + if (len) + *err_ptr = -EFAULT; + + return sum; +} +#endif + +#ifndef HAVE_CSUM_COPY_USER +static __inline__ unsigned int csum_and_copy_to_user +(const unsigned char *src, unsigned char __user *dst, int len, unsigned int sum, int *err_ptr) +{ + sum = csum_partial(src, len, sum); + + if (access_ok(VERIFY_WRITE, dst, len)) { + if (copy_to_user(dst, src, len) == 0) + return sum; + } + if (len) + *err_ptr = -EFAULT; + + return -1; /* invalid checksum */ +} +#endif + +static inline unsigned int csum_add(unsigned int csum, unsigned int addend) +{ + csum += addend; + return csum + (csum < addend); +} + +static inline unsigned int csum_sub(unsigned int csum, unsigned int addend) +{ + return csum_add(csum, ~addend); +} + +static inline unsigned int +csum_block_add(unsigned int csum, unsigned int csum2, int offset) +{ + if (offset&1) + csum2 = ((csum2&0xFF00FF)<<8)+((csum2>>8)&0xFF00FF); + return csum_add(csum, csum2); +} + +static inline unsigned int +csum_block_sub(unsigned int csum, unsigned int csum2, int offset) +{ + if (offset&1) + csum2 = ((csum2&0xFF00FF)<<8)+((csum2>>8)&0xFF00FF); + return csum_sub(csum, csum2); +} + +#endif |