![Nick Andrew](/assets/img/avatar_default.png)
Fix incorrect use of loose in c-checksum.c It should be 'lose', not 'loose'. Signed-off-by: Nick Andrew <nick@nick-andrew.net> Signed-off-by: Paul Mundt <lethal@linux-sh.org>
215 lines
5 KiB
C
215 lines
5 KiB
C
/*
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* arch/sh/lib64/c-checksum.c
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*
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* This file contains network checksum routines that are better done
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* in an architecture-specific manner due to speed..
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*/
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#include <linux/string.h>
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#include <linux/errno.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <asm/byteorder.h>
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#include <asm/uaccess.h>
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static inline unsigned short from64to16(unsigned long long x)
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{
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/* add up 32-bit words for 33 bits */
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x = (x & 0xffffffff) + (x >> 32);
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/* add up 16-bit and 17-bit words for 17+c bits */
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x = (x & 0xffff) + (x >> 16);
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/* add up 16-bit and 2-bit for 16+c bit */
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x = (x & 0xffff) + (x >> 16);
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/* add up carry.. */
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x = (x & 0xffff) + (x >> 16);
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return x;
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}
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static inline unsigned short foldto16(unsigned long x)
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{
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/* add up 16-bit for 17 bits */
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x = (x & 0xffff) + (x >> 16);
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/* add up carry.. */
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x = (x & 0xffff) + (x >> 16);
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return x;
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}
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static inline unsigned short myfoldto16(unsigned long long x)
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{
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/* Fold down to 32-bits so we don't lose in the typedef-less
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network stack. */
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/* 64 to 33 */
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x = (x & 0xffffffff) + (x >> 32);
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/* 33 to 32 */
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x = (x & 0xffffffff) + (x >> 32);
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/* add up 16-bit for 17 bits */
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x = (x & 0xffff) + (x >> 16);
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/* add up carry.. */
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x = (x & 0xffff) + (x >> 16);
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return x;
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}
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#define odd(x) ((x)&1)
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#define U16(x) ntohs(x)
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static unsigned long do_csum(const unsigned char *buff, int len)
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{
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int odd, count;
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unsigned long result = 0;
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pr_debug("do_csum buff %p, len %d (0x%x)\n", buff, len, len);
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#ifdef DEBUG
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for (i = 0; i < len; i++) {
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if ((i % 26) == 0)
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printk("\n");
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printk("%02X ", buff[i]);
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}
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#endif
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if (len <= 0)
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goto out;
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odd = 1 & (unsigned long) buff;
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if (odd) {
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result = *buff << 8;
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len--;
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buff++;
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}
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count = len >> 1; /* nr of 16-bit words.. */
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if (count) {
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if (2 & (unsigned long) buff) {
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result += *(unsigned short *) buff;
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count--;
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len -= 2;
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buff += 2;
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}
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count >>= 1; /* nr of 32-bit words.. */
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if (count) {
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unsigned long carry = 0;
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do {
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unsigned long w = *(unsigned long *) buff;
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buff += 4;
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count--;
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result += carry;
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result += w;
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carry = (w > result);
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} while (count);
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result += carry;
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result = (result & 0xffff) + (result >> 16);
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}
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if (len & 2) {
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result += *(unsigned short *) buff;
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buff += 2;
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}
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}
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if (len & 1)
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result += *buff;
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result = foldto16(result);
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if (odd)
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result = ((result >> 8) & 0xff) | ((result & 0xff) << 8);
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pr_debug("\nCHECKSUM is 0x%lx\n", result);
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out:
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return result;
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}
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/* computes the checksum of a memory block at buff, length len,
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and adds in "sum" (32-bit) */
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__wsum csum_partial(const void *buff, int len, __wsum sum)
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{
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unsigned long long result = do_csum(buff, len);
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/* add in old sum, and carry.. */
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result += (__force u32)sum;
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/* 32+c bits -> 32 bits */
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result = (result & 0xffffffff) + (result >> 32);
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pr_debug("csum_partial, buff %p len %d sum 0x%x result=0x%016Lx\n",
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buff, len, sum, result);
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return (__force __wsum)result;
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}
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/* Copy while checksumming, otherwise like csum_partial. */
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__wsum
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csum_partial_copy_nocheck(const void *src, void *dst, int len, __wsum sum)
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{
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sum = csum_partial(src, len, sum);
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memcpy(dst, src, len);
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return sum;
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}
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/* Copy from userspace and compute checksum. If we catch an exception
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then zero the rest of the buffer. */
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__wsum
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csum_partial_copy_from_user(const void __user *src, void *dst, int len,
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__wsum sum, int *err_ptr)
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{
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int missing;
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pr_debug
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("csum_partial_copy_from_user src %p, dest %p, len %d, sum %08x, err_ptr %p\n",
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src, dst, len, sum, err_ptr);
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missing = copy_from_user(dst, src, len);
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pr_debug(" access_ok %d\n", __access_ok((unsigned long) src, len));
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pr_debug(" missing %d\n", missing);
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if (missing) {
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memset(dst + len - missing, 0, missing);
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*err_ptr = -EFAULT;
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}
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return csum_partial(dst, len, sum);
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}
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/* Copy to userspace and compute checksum. */
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__wsum
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csum_partial_copy_to_user(const unsigned char *src, unsigned char *dst, int len,
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__wsum sum, int *err_ptr)
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{
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sum = csum_partial(src, len, sum);
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if (copy_to_user(dst, src, len))
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*err_ptr = -EFAULT;
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return sum;
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}
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/*
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* This is a version of ip_compute_csum() optimized for IP headers,
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* which always checksum on 4 octet boundaries.
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*/
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__sum16 ip_fast_csum(const void *iph, unsigned int ihl)
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{
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pr_debug("ip_fast_csum %p,%d\n", iph, ihl);
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return (__force __sum16)~do_csum(iph, ihl * 4);
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}
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__wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr,
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unsigned short len,
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unsigned short proto, __wsum sum)
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{
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unsigned long long result;
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pr_debug("ntohs(0x%x)=0x%x\n", 0xdead, ntohs(0xdead));
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pr_debug("htons(0x%x)=0x%x\n", 0xdead, htons(0xdead));
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result = (__force u64) saddr + (__force u64) daddr +
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(__force u64) sum + ((len + proto) << 8);
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/* Fold down to 32-bits so we don't lose in the typedef-less
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network stack. */
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/* 64 to 33 */
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result = (result & 0xffffffff) + (result >> 32);
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/* 33 to 32 */
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result = (result & 0xffffffff) + (result >> 32);
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pr_debug("%s saddr %x daddr %x len %x proto %x sum %x result %08Lx\n",
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__func__, saddr, daddr, len, proto, sum, result);
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return (__wsum)result;
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}
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EXPORT_SYMBOL(csum_tcpudp_nofold);
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