| #ifndef _INET_ECN_H_ |
| #define _INET_ECN_H_ |
| |
| #include <linux/ip.h> |
| #include <linux/skbuff.h> |
| |
| #include <net/inet_sock.h> |
| #include <net/dsfield.h> |
| |
| enum { |
| INET_ECN_NOT_ECT = 0, |
| INET_ECN_ECT_1 = 1, |
| INET_ECN_ECT_0 = 2, |
| INET_ECN_CE = 3, |
| INET_ECN_MASK = 3, |
| }; |
| |
| static inline int INET_ECN_is_ce(__u8 dsfield) |
| { |
| return (dsfield & INET_ECN_MASK) == INET_ECN_CE; |
| } |
| |
| static inline int INET_ECN_is_not_ect(__u8 dsfield) |
| { |
| return (dsfield & INET_ECN_MASK) == INET_ECN_NOT_ECT; |
| } |
| |
| static inline int INET_ECN_is_capable(__u8 dsfield) |
| { |
| return (dsfield & INET_ECN_ECT_0); |
| } |
| |
| static inline __u8 INET_ECN_encapsulate(__u8 outer, __u8 inner) |
| { |
| outer &= ~INET_ECN_MASK; |
| outer |= !INET_ECN_is_ce(inner) ? (inner & INET_ECN_MASK) : |
| INET_ECN_ECT_0; |
| return outer; |
| } |
| |
| #define INET_ECN_xmit(sk) do { inet_sk(sk)->tos |= INET_ECN_ECT_0; } while (0) |
| #define INET_ECN_dontxmit(sk) \ |
| do { inet_sk(sk)->tos &= ~INET_ECN_MASK; } while (0) |
| |
| #define IP6_ECN_flow_init(label) do { \ |
| (label) &= ~htonl(INET_ECN_MASK << 20); \ |
| } while (0) |
| |
| #define IP6_ECN_flow_xmit(sk, label) do { \ |
| if (INET_ECN_is_capable(inet_sk(sk)->tos)) \ |
| (label) |= htonl(INET_ECN_ECT_0 << 20); \ |
| } while (0) |
| |
| static inline int IP_ECN_set_ce(struct iphdr *iph) |
| { |
| u32 check = (__force u32)iph->check; |
| u32 ecn = (iph->tos + 1) & INET_ECN_MASK; |
| |
| /* |
| * After the last operation we have (in binary): |
| * INET_ECN_NOT_ECT => 01 |
| * INET_ECN_ECT_1 => 10 |
| * INET_ECN_ECT_0 => 11 |
| * INET_ECN_CE => 00 |
| */ |
| if (!(ecn & 2)) |
| return !ecn; |
| |
| /* |
| * The following gives us: |
| * INET_ECN_ECT_1 => check += htons(0xFFFD) |
| * INET_ECN_ECT_0 => check += htons(0xFFFE) |
| */ |
| check += (__force u16)htons(0xFFFB) + (__force u16)htons(ecn); |
| |
| iph->check = (__force __sum16)(check + (check>=0xFFFF)); |
| iph->tos |= INET_ECN_CE; |
| return 1; |
| } |
| |
| static inline void IP_ECN_clear(struct iphdr *iph) |
| { |
| iph->tos &= ~INET_ECN_MASK; |
| } |
| |
| static inline void ipv4_copy_dscp(struct iphdr *outer, struct iphdr *inner) |
| { |
| u32 dscp = ipv4_get_dsfield(outer) & ~INET_ECN_MASK; |
| ipv4_change_dsfield(inner, INET_ECN_MASK, dscp); |
| } |
| |
| struct ipv6hdr; |
| |
| static inline int IP6_ECN_set_ce(struct ipv6hdr *iph) |
| { |
| if (INET_ECN_is_not_ect(ipv6_get_dsfield(iph))) |
| return 0; |
| *(__be32*)iph |= htonl(INET_ECN_CE << 20); |
| return 1; |
| } |
| |
| static inline void IP6_ECN_clear(struct ipv6hdr *iph) |
| { |
| *(__be32*)iph &= ~htonl(INET_ECN_MASK << 20); |
| } |
| |
| static inline void ipv6_copy_dscp(struct ipv6hdr *outer, struct ipv6hdr *inner) |
| { |
| u32 dscp = ipv6_get_dsfield(outer) & ~INET_ECN_MASK; |
| ipv6_change_dsfield(inner, INET_ECN_MASK, dscp); |
| } |
| |
| static inline int INET_ECN_set_ce(struct sk_buff *skb) |
| { |
| switch (skb->protocol) { |
| case __constant_htons(ETH_P_IP): |
| if (skb_network_header(skb) + sizeof(struct iphdr) <= |
| skb->tail) |
| return IP_ECN_set_ce(skb->nh.iph); |
| break; |
| |
| case __constant_htons(ETH_P_IPV6): |
| if (skb_network_header(skb) + sizeof(struct ipv6hdr) <= |
| skb->tail) |
| return IP6_ECN_set_ce(skb->nh.ipv6h); |
| break; |
| } |
| |
| return 0; |
| } |
| |
| #endif |