11da177e4SLinus Torvalds /* include/net/dsfield.h - Manipulation of the Differentiated Services field */ 21da177e4SLinus Torvalds 31da177e4SLinus Torvalds /* Written 1998-2000 by Werner Almesberger, EPFL ICA */ 41da177e4SLinus Torvalds 51da177e4SLinus Torvalds 61da177e4SLinus Torvalds #ifndef __NET_DSFIELD_H 71da177e4SLinus Torvalds #define __NET_DSFIELD_H 81da177e4SLinus Torvalds 91da177e4SLinus Torvalds #include <linux/types.h> 101da177e4SLinus Torvalds #include <linux/ip.h> 111da177e4SLinus Torvalds #include <linux/ipv6.h> 121da177e4SLinus Torvalds #include <asm/byteorder.h> 131da177e4SLinus Torvalds 141da177e4SLinus Torvalds 153c3f4866SJan Engelhardt static inline __u8 ipv4_get_dsfield(const struct iphdr *iph) 161da177e4SLinus Torvalds { 171da177e4SLinus Torvalds return iph->tos; 181da177e4SLinus Torvalds } 191da177e4SLinus Torvalds 201da177e4SLinus Torvalds 213c3f4866SJan Engelhardt static inline __u8 ipv6_get_dsfield(const struct ipv6hdr *ipv6h) 221da177e4SLinus Torvalds { 233c3f4866SJan Engelhardt return ntohs(*(const __be16 *)ipv6h) >> 4; 241da177e4SLinus Torvalds } 251da177e4SLinus Torvalds 261da177e4SLinus Torvalds 271da177e4SLinus Torvalds static inline void ipv4_change_dsfield(struct iphdr *iph,__u8 mask, 281da177e4SLinus Torvalds __u8 value) 291da177e4SLinus Torvalds { 305c78f275SAl Viro __u32 check = ntohs((__force __be16)iph->check); 311da177e4SLinus Torvalds __u8 dsfield; 321da177e4SLinus Torvalds 331da177e4SLinus Torvalds dsfield = (iph->tos & mask) | value; 341da177e4SLinus Torvalds check += iph->tos; 351da177e4SLinus Torvalds if ((check+1) >> 16) check = (check+1) & 0xffff; 361da177e4SLinus Torvalds check -= dsfield; 371da177e4SLinus Torvalds check += check >> 16; /* adjust carry */ 385c78f275SAl Viro iph->check = (__force __sum16)htons(check); 391da177e4SLinus Torvalds iph->tos = dsfield; 401da177e4SLinus Torvalds } 411da177e4SLinus Torvalds 421da177e4SLinus Torvalds 431da177e4SLinus Torvalds static inline void ipv6_change_dsfield(struct ipv6hdr *ipv6h,__u8 mask, 441da177e4SLinus Torvalds __u8 value) 451da177e4SLinus Torvalds { 461da177e4SLinus Torvalds __u16 tmp; 471da177e4SLinus Torvalds 488a9ae211SAl Viro tmp = ntohs(*(__be16 *) ipv6h); 491da177e4SLinus Torvalds tmp = (tmp & ((mask << 4) | 0xf00f)) | (value << 4); 508a9ae211SAl Viro *(__be16 *) ipv6h = htons(tmp); 511da177e4SLinus Torvalds } 521da177e4SLinus Torvalds 531da177e4SLinus Torvalds 541da177e4SLinus Torvalds #endif 55