diff options
Diffstat (limited to 'include/net/dsfield.h')
-rw-r--r-- | include/net/dsfield.h | 53 |
1 files changed, 53 insertions, 0 deletions
diff --git a/include/net/dsfield.h b/include/net/dsfield.h new file mode 100644 index 000000000..a59a57ffc --- /dev/null +++ b/include/net/dsfield.h @@ -0,0 +1,53 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* include/net/dsfield.h - Manipulation of the Differentiated Services field */ + +/* Written 1998-2000 by Werner Almesberger, EPFL ICA */ + + +#ifndef __NET_DSFIELD_H +#define __NET_DSFIELD_H + +#include <linux/types.h> +#include <linux/ip.h> +#include <linux/ipv6.h> +#include <asm/byteorder.h> + + +static inline __u8 ipv4_get_dsfield(const struct iphdr *iph) +{ + return iph->tos; +} + + +static inline __u8 ipv6_get_dsfield(const struct ipv6hdr *ipv6h) +{ + return ntohs(*(__force const __be16 *)ipv6h) >> 4; +} + + +static inline void ipv4_change_dsfield(struct iphdr *iph,__u8 mask, + __u8 value) +{ + __u32 check = ntohs((__force __be16)iph->check); + __u8 dsfield; + + dsfield = (iph->tos & mask) | value; + check += iph->tos; + if ((check+1) >> 16) check = (check+1) & 0xffff; + check -= dsfield; + check += check >> 16; /* adjust carry */ + iph->check = (__force __sum16)htons(check); + iph->tos = dsfield; +} + + +static inline void ipv6_change_dsfield(struct ipv6hdr *ipv6h,__u8 mask, + __u8 value) +{ + __be16 *p = (__force __be16 *)ipv6h; + + *p = (*p & htons((((u16)mask << 4) | 0xf00f))) | htons((u16)value << 4); +} + + +#endif |