1b2441318SGreg Kroah-Hartman /* SPDX-License-Identifier: GPL-2.0 */ 21da177e4SLinus Torvalds /* include/net/dsfield.h - Manipulation of the Differentiated Services field */ 31da177e4SLinus Torvalds 41da177e4SLinus Torvalds /* Written 1998-2000 by Werner Almesberger, EPFL ICA */ 51da177e4SLinus Torvalds 61da177e4SLinus Torvalds 71da177e4SLinus Torvalds #ifndef __NET_DSFIELD_H 81da177e4SLinus Torvalds #define __NET_DSFIELD_H 91da177e4SLinus Torvalds 101da177e4SLinus Torvalds #include <linux/types.h> 111da177e4SLinus Torvalds #include <linux/ip.h> 121da177e4SLinus Torvalds #include <linux/ipv6.h> 131da177e4SLinus Torvalds #include <asm/byteorder.h> 141da177e4SLinus Torvalds 151da177e4SLinus Torvalds ipv4_get_dsfield(const struct iphdr * iph)163c3f4866SJan Engelhardtstatic inline __u8 ipv4_get_dsfield(const struct iphdr *iph) 171da177e4SLinus Torvalds { 181da177e4SLinus Torvalds return iph->tos; 191da177e4SLinus Torvalds } 201da177e4SLinus Torvalds 211da177e4SLinus Torvalds ipv6_get_dsfield(const struct ipv6hdr * ipv6h)223c3f4866SJan Engelhardtstatic inline __u8 ipv6_get_dsfield(const struct ipv6hdr *ipv6h) 231da177e4SLinus Torvalds { 24*1f1c1d7cSSven Eckelmann return ntohs(*(__force const __be16 *)ipv6h) >> 4; 251da177e4SLinus Torvalds } 261da177e4SLinus Torvalds 271da177e4SLinus Torvalds ipv4_change_dsfield(struct iphdr * iph,__u8 mask,__u8 value)281da177e4SLinus Torvaldsstatic inline void ipv4_change_dsfield(struct iphdr *iph,__u8 mask, 291da177e4SLinus Torvalds __u8 value) 301da177e4SLinus Torvalds { 315c78f275SAl Viro __u32 check = ntohs((__force __be16)iph->check); 321da177e4SLinus Torvalds __u8 dsfield; 331da177e4SLinus Torvalds 341da177e4SLinus Torvalds dsfield = (iph->tos & mask) | value; 351da177e4SLinus Torvalds check += iph->tos; 361da177e4SLinus Torvalds if ((check+1) >> 16) check = (check+1) & 0xffff; 371da177e4SLinus Torvalds check -= dsfield; 381da177e4SLinus Torvalds check += check >> 16; /* adjust carry */ 395c78f275SAl Viro iph->check = (__force __sum16)htons(check); 401da177e4SLinus Torvalds iph->tos = dsfield; 411da177e4SLinus Torvalds } 421da177e4SLinus Torvalds 431da177e4SLinus Torvalds ipv6_change_dsfield(struct ipv6hdr * ipv6h,__u8 mask,__u8 value)441da177e4SLinus Torvaldsstatic inline void ipv6_change_dsfield(struct ipv6hdr *ipv6h,__u8 mask, 451da177e4SLinus Torvalds __u8 value) 461da177e4SLinus Torvalds { 47a0376db0SYOSHIFUJI Hideaki / 吉藤英明 __be16 *p = (__force __be16 *)ipv6h; 481da177e4SLinus Torvalds 49a0376db0SYOSHIFUJI Hideaki / 吉藤英明 *p = (*p & htons((((u16)mask << 4) | 0xf00f))) | htons((u16)value << 4); 501da177e4SLinus Torvalds } 511da177e4SLinus Torvalds 521da177e4SLinus Torvalds 531da177e4SLinus Torvalds #endif 54