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a0376db0f2
Do not convert endian back and forth. If the caller uses contant "mask" argument (and most callers do), we can omit runtime endian conversion here. Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org> Signed-off-by: David S. Miller <davem@davemloft.net>
53 lines
1.1 KiB
C
53 lines
1.1 KiB
C
/* include/net/dsfield.h - Manipulation of the Differentiated Services field */
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/* Written 1998-2000 by Werner Almesberger, EPFL ICA */
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#ifndef __NET_DSFIELD_H
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#define __NET_DSFIELD_H
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#include <linux/types.h>
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#include <linux/ip.h>
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#include <linux/ipv6.h>
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#include <asm/byteorder.h>
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static inline __u8 ipv4_get_dsfield(const struct iphdr *iph)
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{
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return iph->tos;
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}
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static inline __u8 ipv6_get_dsfield(const struct ipv6hdr *ipv6h)
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{
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return ntohs(*(const __be16 *)ipv6h) >> 4;
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}
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static inline void ipv4_change_dsfield(struct iphdr *iph,__u8 mask,
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__u8 value)
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{
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__u32 check = ntohs((__force __be16)iph->check);
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__u8 dsfield;
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dsfield = (iph->tos & mask) | value;
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check += iph->tos;
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if ((check+1) >> 16) check = (check+1) & 0xffff;
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check -= dsfield;
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check += check >> 16; /* adjust carry */
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iph->check = (__force __sum16)htons(check);
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iph->tos = dsfield;
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}
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static inline void ipv6_change_dsfield(struct ipv6hdr *ipv6h,__u8 mask,
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__u8 value)
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{
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__be16 *p = (__force __be16 *)ipv6h;
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*p = (*p & htons((((u16)mask << 4) | 0xf00f))) | htons((u16)value << 4);
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}
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#endif
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