1 /* include/net/dsfield.h - Manipulation of the Differentiated Services field */ 2 3 /* Written 1998-2000 by Werner Almesberger, EPFL ICA */ 4 5 6 #ifndef __NET_DSFIELD_H 7 #define __NET_DSFIELD_H 8 9 #include <linux/types.h> 10 #include <linux/ip.h> 11 #include <linux/ipv6.h> 12 #include <asm/byteorder.h> 13 14 15 static inline __u8 ipv4_get_dsfield(const struct iphdr *iph) 16 { 17 return iph->tos; 18 } 19 20 21 static inline __u8 ipv6_get_dsfield(const struct ipv6hdr *ipv6h) 22 { 23 return ntohs(*(const __be16 *)ipv6h) >> 4; 24 } 25 26 27 static inline void ipv4_change_dsfield(struct iphdr *iph,__u8 mask, 28 __u8 value) 29 { 30 __u32 check = ntohs((__force __be16)iph->check); 31 __u8 dsfield; 32 33 dsfield = (iph->tos & mask) | value; 34 check += iph->tos; 35 if ((check+1) >> 16) check = (check+1) & 0xffff; 36 check -= dsfield; 37 check += check >> 16; /* adjust carry */ 38 iph->check = (__force __sum16)htons(check); 39 iph->tos = dsfield; 40 } 41 42 43 static inline void ipv6_change_dsfield(struct ipv6hdr *ipv6h,__u8 mask, 44 __u8 value) 45 { 46 __u16 tmp; 47 48 tmp = ntohs(*(__be16 *) ipv6h); 49 tmp = (tmp & ((mask << 4) | 0xf00f)) | (value << 4); 50 *(__be16 *) ipv6h = htons(tmp); 51 } 52 53 54 #endif 55