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01cfbad79a
This patch updates all instances of csum_tcpudp_magic and csum_tcpudp_nofold to reflect the types that are usually used as the source inputs. For example the protocol field is populated based on nexthdr which is actually an unsigned 8 bit value. The length is usually populated based on skb->len which is an unsigned integer. This addresses an issue in which the IPv6 function csum_ipv6_magic was generating a checksum using the full 32b of skb->len while csum_tcpudp_magic was only using the lower 16 bits. As a result we could run into issues when attempting to adjust the checksum as there was no protocol agnostic way to update it. With this change the value is still truncated as many architectures use "(len + proto) << 8", however this truncation only occurs for values greater than 16776960 in length and as such is unlikely to occur as we stop the inner headers at ~64K in size. I did have to make a few minor changes in the arm, mn10300, nios2, and score versions of the function in order to support these changes as they were either using things such as an OR to combine the protocol and length, or were using ntohs to convert the length which would have truncated the value. I also updated a few spots in terms of whitespace and type differences for the addresses. Most of this was just to make sure all of the definitions were in sync going forward. Signed-off-by: Alexander Duyck <aduyck@mirantis.com> Signed-off-by: David S. Miller <davem@davemloft.net>
153 lines
3.7 KiB
C
153 lines
3.7 KiB
C
/*
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* arch/arm/include/asm/checksum.h
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*
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* IP checksum routines
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*
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* Copyright (C) Original authors of ../asm-i386/checksum.h
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* Copyright (C) 1996-1999 Russell King
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*/
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#ifndef __ASM_ARM_CHECKSUM_H
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#define __ASM_ARM_CHECKSUM_H
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#include <linux/in6.h>
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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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*
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* returns a 32-bit number suitable for feeding into itself
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* or csum_tcpudp_magic
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*
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* this function must be called with even lengths, except
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* for the last fragment, which may be odd
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*
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* it's best to have buff aligned on a 32-bit boundary
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*/
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__wsum csum_partial(const void *buff, int len, __wsum sum);
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/*
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* the same as csum_partial, but copies from src while it
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* checksums, and handles user-space pointer exceptions correctly, when needed.
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*
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* here even more important to align src and dst on a 32-bit (or even
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* better 64-bit) boundary
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*/
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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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__wsum
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csum_partial_copy_from_user(const void __user *src, void *dst, int len, __wsum sum, int *err_ptr);
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/*
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* Fold a partial checksum without adding pseudo headers
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*/
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static inline __sum16 csum_fold(__wsum sum)
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{
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__asm__(
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"add %0, %1, %1, ror #16 @ csum_fold"
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: "=r" (sum)
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: "r" (sum)
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: "cc");
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return (__force __sum16)(~(__force u32)sum >> 16);
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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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static inline __sum16
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ip_fast_csum(const void *iph, unsigned int ihl)
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{
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unsigned int tmp1;
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__wsum sum;
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__asm__ __volatile__(
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"ldr %0, [%1], #4 @ ip_fast_csum \n\
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ldr %3, [%1], #4 \n\
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sub %2, %2, #5 \n\
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adds %0, %0, %3 \n\
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ldr %3, [%1], #4 \n\
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adcs %0, %0, %3 \n\
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ldr %3, [%1], #4 \n\
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1: adcs %0, %0, %3 \n\
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ldr %3, [%1], #4 \n\
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tst %2, #15 @ do this carefully \n\
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subne %2, %2, #1 @ without destroying \n\
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bne 1b @ the carry flag \n\
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adcs %0, %0, %3 \n\
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adc %0, %0, #0"
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: "=r" (sum), "=r" (iph), "=r" (ihl), "=r" (tmp1)
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: "1" (iph), "2" (ihl)
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: "cc", "memory");
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return csum_fold(sum);
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}
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static inline __wsum
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csum_tcpudp_nofold(__be32 saddr, __be32 daddr, __u32 len,
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__u8 proto, __wsum sum)
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{
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u32 lenprot = len + proto;
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if (__builtin_constant_p(sum) && sum == 0) {
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__asm__(
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"adds %0, %1, %2 @ csum_tcpudp_nofold0 \n\t"
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#ifdef __ARMEB__
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"adcs %0, %0, %3 \n\t"
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#else
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"adcs %0, %0, %3, ror #8 \n\t"
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#endif
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"adc %0, %0, #0"
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: "=&r" (sum)
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: "r" (daddr), "r" (saddr), "r" (lenprot)
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: "cc");
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} else {
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__asm__(
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"adds %0, %1, %2 @ csum_tcpudp_nofold \n\t"
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"adcs %0, %0, %3 \n\t"
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#ifdef __ARMEB__
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"adcs %0, %0, %4 \n\t"
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#else
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"adcs %0, %0, %4, ror #8 \n\t"
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#endif
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"adc %0, %0, #0"
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: "=&r"(sum)
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: "r" (sum), "r" (daddr), "r" (saddr), "r" (lenprot)
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: "cc");
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}
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return sum;
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}
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/*
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* computes the checksum of the TCP/UDP pseudo-header
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* returns a 16-bit checksum, already complemented
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*/
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static inline __sum16
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csum_tcpudp_magic(__be32 saddr, __be32 daddr, __u32 len,
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__u8 proto, __wsum sum)
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{
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return csum_fold(csum_tcpudp_nofold(saddr, daddr, len, proto, sum));
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}
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/*
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* this routine is used for miscellaneous IP-like checksums, mainly
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* in icmp.c
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*/
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static inline __sum16
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ip_compute_csum(const void *buff, int len)
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{
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return csum_fold(csum_partial(buff, len, 0));
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}
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#define _HAVE_ARCH_IPV6_CSUM
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extern __wsum
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__csum_ipv6_magic(const struct in6_addr *saddr, const struct in6_addr *daddr, __be32 len,
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__be32 proto, __wsum sum);
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static inline __sum16
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csum_ipv6_magic(const struct in6_addr *saddr, const struct in6_addr *daddr, __u32 len,
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unsigned short proto, __wsum sum)
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{
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return csum_fold(__csum_ipv6_magic(saddr, daddr, htonl(len),
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htonl(proto), sum));
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}
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#endif
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