c693cc4676
All callers of these primitives will * discard anything we might've copied in case of error * ignore the csum value in case of error * always pass 0xffffffff as the initial sum, so the resulting csum value (in case of success, that is) will never be 0. That suggest the following calling conventions: * don't pass err_ptr - just return 0 on error. * don't bother with zeroing destination, etc. in case of error * don't pass the initial sum - just use 0xffffffff. This commit does the minimal conversion in the instances of csum_and_copy_...(); the changes of actual asm code behind them are done later in the series. Note that this asm code is often shared with csum_partial_copy_nocheck(); the difference is that csum_partial_copy_nocheck() passes 0 for initial sum while csum_and_copy_..._user() pass 0xffffffff. Fortunately, we are free to pass 0xffffffff in all cases and subsequent patches will use that freedom without any special comments. A part that could be split off: parisc and uml/i386 claimed to have csum_and_copy_to_user() instances of their own, but those were identical to the generic one, so we simply drop them. Not sure if it's worth a separate commit... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
75 lines
2.0 KiB
C
75 lines
2.0 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef _ALPHA_CHECKSUM_H
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#define _ALPHA_CHECKSUM_H
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#include <linux/in6.h>
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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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extern __sum16 ip_fast_csum(const void *iph, unsigned int ihl);
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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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__sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr,
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__u32 len, __u8 proto, __wsum sum);
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__wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr,
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__u32 len, __u8 proto, __wsum sum);
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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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extern __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
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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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#define _HAVE_ARCH_COPY_AND_CSUM_FROM_USER
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#define _HAVE_ARCH_CSUM_AND_COPY
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__wsum csum_and_copy_from_user(const void __user *src, void *dst, int len);
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__wsum csum_partial_copy_nocheck(const void *src, void *dst, int len);
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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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extern __sum16 ip_compute_csum(const void *buff, int len);
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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 csum)
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{
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u32 sum = (__force u32)csum;
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sum = (sum & 0xffff) + (sum >> 16);
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sum = (sum & 0xffff) + (sum >> 16);
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return (__force __sum16)~sum;
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}
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#define _HAVE_ARCH_IPV6_CSUM
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extern __sum16 csum_ipv6_magic(const struct in6_addr *saddr,
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const struct in6_addr *daddr,
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__u32 len, __u8 proto, __wsum sum);
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#endif
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