1 /* SPDX-License-Identifier: GPL-2.0 */ 1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _INET_ECN_H_ 2 #ifndef _INET_ECN_H_
3 #define _INET_ECN_H_ 3 #define _INET_ECN_H_
4 4
5 #include <linux/ip.h> 5 #include <linux/ip.h>
6 #include <linux/skbuff.h> 6 #include <linux/skbuff.h>
7 #include <linux/if_vlan.h> 7 #include <linux/if_vlan.h>
8 8
9 #include <net/inet_sock.h> 9 #include <net/inet_sock.h>
10 #include <net/dsfield.h> 10 #include <net/dsfield.h>
11 #include <net/checksum.h> 11 #include <net/checksum.h>
12 12
13 enum { 13 enum {
14 INET_ECN_NOT_ECT = 0, 14 INET_ECN_NOT_ECT = 0,
15 INET_ECN_ECT_1 = 1, 15 INET_ECN_ECT_1 = 1,
16 INET_ECN_ECT_0 = 2, 16 INET_ECN_ECT_0 = 2,
17 INET_ECN_CE = 3, 17 INET_ECN_CE = 3,
18 INET_ECN_MASK = 3, 18 INET_ECN_MASK = 3,
19 }; 19 };
20 20
21 extern int sysctl_tunnel_ecn_log; 21 extern int sysctl_tunnel_ecn_log;
22 22
23 static inline int INET_ECN_is_ce(__u8 dsfield) 23 static inline int INET_ECN_is_ce(__u8 dsfield)
24 { 24 {
25 return (dsfield & INET_ECN_MASK) == IN 25 return (dsfield & INET_ECN_MASK) == INET_ECN_CE;
26 } 26 }
27 27
28 static inline int INET_ECN_is_not_ect(__u8 dsf 28 static inline int INET_ECN_is_not_ect(__u8 dsfield)
29 { 29 {
30 return (dsfield & INET_ECN_MASK) == IN 30 return (dsfield & INET_ECN_MASK) == INET_ECN_NOT_ECT;
31 } 31 }
32 32
33 static inline int INET_ECN_is_capable(__u8 dsf 33 static inline int INET_ECN_is_capable(__u8 dsfield)
34 { 34 {
35 return dsfield & INET_ECN_ECT_0; 35 return dsfield & INET_ECN_ECT_0;
36 } 36 }
37 37
38 /* 38 /*
39 * RFC 3168 9.1.1 39 * RFC 3168 9.1.1
40 * The full-functionality option for ECN enca 40 * The full-functionality option for ECN encapsulation is to copy the
41 * ECN codepoint of the inside header to the 41 * ECN codepoint of the inside header to the outside header on
42 * encapsulation if the inside header is not- 42 * encapsulation if the inside header is not-ECT or ECT, and to set the
43 * ECN codepoint of the outside header to ECT 43 * ECN codepoint of the outside header to ECT(0) if the ECN codepoint of
44 * the inside header is CE. 44 * the inside header is CE.
45 */ 45 */
46 static inline __u8 INET_ECN_encapsulate(__u8 o 46 static inline __u8 INET_ECN_encapsulate(__u8 outer, __u8 inner)
47 { 47 {
48 outer &= ~INET_ECN_MASK; 48 outer &= ~INET_ECN_MASK;
49 outer |= !INET_ECN_is_ce(inner) ? (inn 49 outer |= !INET_ECN_is_ce(inner) ? (inner & INET_ECN_MASK) :
50 INET 50 INET_ECN_ECT_0;
51 return outer; 51 return outer;
52 } 52 }
53 53
54 static inline void INET_ECN_xmit(struct sock * 54 static inline void INET_ECN_xmit(struct sock *sk)
55 { 55 {
56 inet_sk(sk)->tos |= INET_ECN_ECT_0; 56 inet_sk(sk)->tos |= INET_ECN_ECT_0;
57 if (inet6_sk(sk) != NULL) 57 if (inet6_sk(sk) != NULL)
58 inet6_sk(sk)->tclass |= INET_E 58 inet6_sk(sk)->tclass |= INET_ECN_ECT_0;
59 } 59 }
60 60
61 static inline void INET_ECN_dontxmit(struct so 61 static inline void INET_ECN_dontxmit(struct sock *sk)
62 { 62 {
63 inet_sk(sk)->tos &= ~INET_ECN_MASK; 63 inet_sk(sk)->tos &= ~INET_ECN_MASK;
64 if (inet6_sk(sk) != NULL) 64 if (inet6_sk(sk) != NULL)
65 inet6_sk(sk)->tclass &= ~INET_ 65 inet6_sk(sk)->tclass &= ~INET_ECN_MASK;
66 } 66 }
67 67
68 #define IP6_ECN_flow_init(label) do { 68 #define IP6_ECN_flow_init(label) do { \
69 (label) &= ~htonl(INET_ECN_MASK << 20); 69 (label) &= ~htonl(INET_ECN_MASK << 20); \
70 } while (0) 70 } while (0)
71 71
72 #define IP6_ECN_flow_xmit(sk, label) do { 72 #define IP6_ECN_flow_xmit(sk, label) do { \
73 if (INET_ECN_is_capable(inet6_sk(sk)-> 73 if (INET_ECN_is_capable(inet6_sk(sk)->tclass)) \
74 (label) |= htonl(INET_ECN_ECT_ 74 (label) |= htonl(INET_ECN_ECT_0 << 20); \
75 } while (0) 75 } while (0)
76 76
77 static inline int IP_ECN_set_ce(struct iphdr * 77 static inline int IP_ECN_set_ce(struct iphdr *iph)
78 { 78 {
79 u32 ecn = (iph->tos + 1) & INET_ECN_MA 79 u32 ecn = (iph->tos + 1) & INET_ECN_MASK;
80 __be16 check_add; 80 __be16 check_add;
81 81
82 /* 82 /*
83 * After the last operation we have (i 83 * After the last operation we have (in binary):
84 * INET_ECN_NOT_ECT => 01 84 * INET_ECN_NOT_ECT => 01
85 * INET_ECN_ECT_1 => 10 85 * INET_ECN_ECT_1 => 10
86 * INET_ECN_ECT_0 => 11 86 * INET_ECN_ECT_0 => 11
87 * INET_ECN_CE => 00 87 * INET_ECN_CE => 00
88 */ 88 */
89 if (!(ecn & 2)) 89 if (!(ecn & 2))
90 return !ecn; 90 return !ecn;
91 91
92 /* 92 /*
93 * The following gives us: 93 * The following gives us:
94 * INET_ECN_ECT_1 => check += htons(0x 94 * INET_ECN_ECT_1 => check += htons(0xFFFD)
95 * INET_ECN_ECT_0 => check += htons(0x 95 * INET_ECN_ECT_0 => check += htons(0xFFFE)
96 */ 96 */
97 check_add = (__force __be16)((__force 97 check_add = (__force __be16)((__force u16)htons(0xFFFB) +
98 (__force 98 (__force u16)htons(ecn));
99 99
100 iph->check = csum16_add(iph->check, ch 100 iph->check = csum16_add(iph->check, check_add);
101 iph->tos |= INET_ECN_CE; 101 iph->tos |= INET_ECN_CE;
102 return 1; 102 return 1;
103 } 103 }
104 104
105 static inline int IP_ECN_set_ect1(struct iphdr 105 static inline int IP_ECN_set_ect1(struct iphdr *iph)
106 { 106 {
107 if ((iph->tos & INET_ECN_MASK) != INET 107 if ((iph->tos & INET_ECN_MASK) != INET_ECN_ECT_0)
108 return 0; 108 return 0;
109 109
110 iph->check = csum16_add(iph->check, ht 110 iph->check = csum16_add(iph->check, htons(0x1));
111 iph->tos ^= INET_ECN_MASK; 111 iph->tos ^= INET_ECN_MASK;
112 return 1; 112 return 1;
113 } 113 }
114 114
115 static inline void IP_ECN_clear(struct iphdr * 115 static inline void IP_ECN_clear(struct iphdr *iph)
116 { 116 {
117 iph->tos &= ~INET_ECN_MASK; 117 iph->tos &= ~INET_ECN_MASK;
118 } 118 }
119 119
120 static inline void ipv4_copy_dscp(unsigned int 120 static inline void ipv4_copy_dscp(unsigned int dscp, struct iphdr *inner)
121 { 121 {
122 dscp &= ~INET_ECN_MASK; 122 dscp &= ~INET_ECN_MASK;
123 ipv4_change_dsfield(inner, INET_ECN_MA 123 ipv4_change_dsfield(inner, INET_ECN_MASK, dscp);
124 } 124 }
125 125
126 struct ipv6hdr; 126 struct ipv6hdr;
127 127
128 /* Note: 128 /* Note:
129 * IP_ECN_set_ce() has to tweak IPV4 checksum 129 * IP_ECN_set_ce() has to tweak IPV4 checksum when setting CE,
130 * meaning both changes have no effect on skb- 130 * meaning both changes have no effect on skb->csum if/when CHECKSUM_COMPLETE
131 * In IPv6 case, no checksum compensates the c 131 * In IPv6 case, no checksum compensates the change in IPv6 header,
132 * so we have to update skb->csum. 132 * so we have to update skb->csum.
133 */ 133 */
134 static inline int IP6_ECN_set_ce(struct sk_buf 134 static inline int IP6_ECN_set_ce(struct sk_buff *skb, struct ipv6hdr *iph)
135 { 135 {
136 __be32 from, to; 136 __be32 from, to;
137 137
138 if (INET_ECN_is_not_ect(ipv6_get_dsfie 138 if (INET_ECN_is_not_ect(ipv6_get_dsfield(iph)))
139 return 0; 139 return 0;
140 140
141 from = *(__be32 *)iph; 141 from = *(__be32 *)iph;
142 to = from | htonl(INET_ECN_CE << 20); 142 to = from | htonl(INET_ECN_CE << 20);
143 *(__be32 *)iph = to; 143 *(__be32 *)iph = to;
144 if (skb->ip_summed == CHECKSUM_COMPLET 144 if (skb->ip_summed == CHECKSUM_COMPLETE)
145 skb->csum = csum_add(csum_sub( 145 skb->csum = csum_add(csum_sub(skb->csum, (__force __wsum)from),
146 (__force 146 (__force __wsum)to);
147 return 1; 147 return 1;
148 } 148 }
149 149
150 static inline int IP6_ECN_set_ect1(struct sk_b 150 static inline int IP6_ECN_set_ect1(struct sk_buff *skb, struct ipv6hdr *iph)
151 { 151 {
152 __be32 from, to; 152 __be32 from, to;
153 153
154 if ((ipv6_get_dsfield(iph) & INET_ECN_ 154 if ((ipv6_get_dsfield(iph) & INET_ECN_MASK) != INET_ECN_ECT_0)
155 return 0; 155 return 0;
156 156
157 from = *(__be32 *)iph; 157 from = *(__be32 *)iph;
158 to = from ^ htonl(INET_ECN_MASK << 20) 158 to = from ^ htonl(INET_ECN_MASK << 20);
159 *(__be32 *)iph = to; 159 *(__be32 *)iph = to;
160 if (skb->ip_summed == CHECKSUM_COMPLET 160 if (skb->ip_summed == CHECKSUM_COMPLETE)
161 skb->csum = csum_add(csum_sub( 161 skb->csum = csum_add(csum_sub(skb->csum, (__force __wsum)from),
162 (__force 162 (__force __wsum)to);
163 return 1; 163 return 1;
164 } 164 }
165 165
166 static inline void ipv6_copy_dscp(unsigned int 166 static inline void ipv6_copy_dscp(unsigned int dscp, struct ipv6hdr *inner)
167 { 167 {
168 dscp &= ~INET_ECN_MASK; 168 dscp &= ~INET_ECN_MASK;
169 ipv6_change_dsfield(inner, INET_ECN_MA 169 ipv6_change_dsfield(inner, INET_ECN_MASK, dscp);
170 } 170 }
171 171
172 static inline int INET_ECN_set_ce(struct sk_bu 172 static inline int INET_ECN_set_ce(struct sk_buff *skb)
173 { 173 {
174 switch (skb_protocol(skb, true)) { 174 switch (skb_protocol(skb, true)) {
175 case cpu_to_be16(ETH_P_IP): 175 case cpu_to_be16(ETH_P_IP):
176 if (skb_network_header(skb) + 176 if (skb_network_header(skb) + sizeof(struct iphdr) <=
177 skb_tail_pointer(skb)) 177 skb_tail_pointer(skb))
178 return IP_ECN_set_ce(i 178 return IP_ECN_set_ce(ip_hdr(skb));
179 break; 179 break;
180 180
181 case cpu_to_be16(ETH_P_IPV6): 181 case cpu_to_be16(ETH_P_IPV6):
182 if (skb_network_header(skb) + 182 if (skb_network_header(skb) + sizeof(struct ipv6hdr) <=
183 skb_tail_pointer(skb)) 183 skb_tail_pointer(skb))
184 return IP6_ECN_set_ce( 184 return IP6_ECN_set_ce(skb, ipv6_hdr(skb));
185 break; 185 break;
186 } 186 }
187 187
188 return 0; 188 return 0;
189 } 189 }
190 190
191 static inline int skb_get_dsfield(struct sk_bu <<
192 { <<
193 switch (skb_protocol(skb, true)) { <<
194 case cpu_to_be16(ETH_P_IP): <<
195 if (!pskb_network_may_pull(skb <<
196 break; <<
197 return ipv4_get_dsfield(ip_hdr <<
198 <<
199 case cpu_to_be16(ETH_P_IPV6): <<
200 if (!pskb_network_may_pull(skb <<
201 break; <<
202 return ipv6_get_dsfield(ipv6_h <<
203 } <<
204 <<
205 return -1; <<
206 } <<
207 <<
208 static inline int INET_ECN_set_ect1(struct sk_ 191 static inline int INET_ECN_set_ect1(struct sk_buff *skb)
209 { 192 {
210 switch (skb_protocol(skb, true)) { 193 switch (skb_protocol(skb, true)) {
211 case cpu_to_be16(ETH_P_IP): 194 case cpu_to_be16(ETH_P_IP):
212 if (skb_network_header(skb) + 195 if (skb_network_header(skb) + sizeof(struct iphdr) <=
213 skb_tail_pointer(skb)) 196 skb_tail_pointer(skb))
214 return IP_ECN_set_ect1 197 return IP_ECN_set_ect1(ip_hdr(skb));
215 break; 198 break;
216 199
217 case cpu_to_be16(ETH_P_IPV6): 200 case cpu_to_be16(ETH_P_IPV6):
218 if (skb_network_header(skb) + 201 if (skb_network_header(skb) + sizeof(struct ipv6hdr) <=
219 skb_tail_pointer(skb)) 202 skb_tail_pointer(skb))
220 return IP6_ECN_set_ect 203 return IP6_ECN_set_ect1(skb, ipv6_hdr(skb));
221 break; 204 break;
222 } 205 }
223 206
224 return 0; 207 return 0;
225 } 208 }
226 209
227 /* 210 /*
228 * RFC 6040 4.2 211 * RFC 6040 4.2
229 * To decapsulate the inner header at the tun 212 * To decapsulate the inner header at the tunnel egress, a compliant
230 * tunnel egress MUST set the outgoing ECN fi 213 * tunnel egress MUST set the outgoing ECN field to the codepoint at the
231 * intersection of the appropriate arriving i 214 * intersection of the appropriate arriving inner header (row) and outer
232 * header (column) in Figure 4 215 * header (column) in Figure 4
233 * 216 *
234 * +---------+--------------------------- 217 * +---------+------------------------------------------------+
235 * |Arriving | Arriving Outer 218 * |Arriving | Arriving Outer Header |
236 * | Inner +---------+------------+---- 219 * | Inner +---------+------------+------------+------------+
237 * | Header | Not-ECT | ECT(0) | ECT 220 * | Header | Not-ECT | ECT(0) | ECT(1) | CE |
238 * +---------+---------+------------+---- 221 * +---------+---------+------------+------------+------------+
239 * | Not-ECT | Not-ECT |Not-ECT(!!!)|Not- 222 * | Not-ECT | Not-ECT |Not-ECT(!!!)|Not-ECT(!!!)| <drop>(!!!)|
240 * | ECT(0) | ECT(0) | ECT(0) | ECT 223 * | ECT(0) | ECT(0) | ECT(0) | ECT(1) | CE |
241 * | ECT(1) | ECT(1) | ECT(1) (!) | ECT 224 * | ECT(1) | ECT(1) | ECT(1) (!) | ECT(1) | CE |
242 * | CE | CE | CE | 225 * | CE | CE | CE | CE(!!!)| CE |
243 * +---------+---------+------------+---- 226 * +---------+---------+------------+------------+------------+
244 * 227 *
245 * Figure 4: New IP in IP Decapsul 228 * Figure 4: New IP in IP Decapsulation Behaviour
246 * 229 *
247 * returns 0 on success 230 * returns 0 on success
248 * 1 if something is broken and shoul 231 * 1 if something is broken and should be logged (!!! above)
249 * 2 if packet should be dropped 232 * 2 if packet should be dropped
250 */ 233 */
251 static inline int __INET_ECN_decapsulate(__u8 234 static inline int __INET_ECN_decapsulate(__u8 outer, __u8 inner, bool *set_ce)
252 { 235 {
253 if (INET_ECN_is_not_ect(inner)) { 236 if (INET_ECN_is_not_ect(inner)) {
254 switch (outer & INET_ECN_MASK) 237 switch (outer & INET_ECN_MASK) {
255 case INET_ECN_NOT_ECT: 238 case INET_ECN_NOT_ECT:
256 return 0; 239 return 0;
257 case INET_ECN_ECT_0: 240 case INET_ECN_ECT_0:
258 case INET_ECN_ECT_1: 241 case INET_ECN_ECT_1:
259 return 1; 242 return 1;
260 case INET_ECN_CE: 243 case INET_ECN_CE:
261 return 2; 244 return 2;
262 } 245 }
263 } 246 }
264 247
265 *set_ce = INET_ECN_is_ce(outer); 248 *set_ce = INET_ECN_is_ce(outer);
266 return 0; 249 return 0;
267 } 250 }
268 251
269 static inline int INET_ECN_decapsulate(struct 252 static inline int INET_ECN_decapsulate(struct sk_buff *skb,
270 __u8 ou 253 __u8 outer, __u8 inner)
271 { 254 {
272 bool set_ce = false; 255 bool set_ce = false;
273 int rc; 256 int rc;
274 257
275 rc = __INET_ECN_decapsulate(outer, inn 258 rc = __INET_ECN_decapsulate(outer, inner, &set_ce);
276 if (!rc) { 259 if (!rc) {
277 if (set_ce) 260 if (set_ce)
278 INET_ECN_set_ce(skb); 261 INET_ECN_set_ce(skb);
279 else if ((outer & INET_ECN_MAS 262 else if ((outer & INET_ECN_MASK) == INET_ECN_ECT_1)
280 INET_ECN_set_ect1(skb) 263 INET_ECN_set_ect1(skb);
281 } 264 }
282 265
283 return rc; 266 return rc;
284 } 267 }
285 268
286 static inline int IP_ECN_decapsulate(const str 269 static inline int IP_ECN_decapsulate(const struct iphdr *oiph,
287 struct sk 270 struct sk_buff *skb)
288 { 271 {
289 __u8 inner; 272 __u8 inner;
290 273
291 switch (skb_protocol(skb, true)) { 274 switch (skb_protocol(skb, true)) {
292 case htons(ETH_P_IP): 275 case htons(ETH_P_IP):
293 inner = ip_hdr(skb)->tos; 276 inner = ip_hdr(skb)->tos;
294 break; 277 break;
295 case htons(ETH_P_IPV6): 278 case htons(ETH_P_IPV6):
296 inner = ipv6_get_dsfield(ipv6_ 279 inner = ipv6_get_dsfield(ipv6_hdr(skb));
297 break; 280 break;
298 default: 281 default:
299 return 0; 282 return 0;
300 } 283 }
301 284
302 return INET_ECN_decapsulate(skb, oiph- 285 return INET_ECN_decapsulate(skb, oiph->tos, inner);
303 } 286 }
304 287
305 static inline int IP6_ECN_decapsulate(const st 288 static inline int IP6_ECN_decapsulate(const struct ipv6hdr *oipv6h,
306 struct s 289 struct sk_buff *skb)
307 { 290 {
308 __u8 inner; 291 __u8 inner;
309 292
310 switch (skb_protocol(skb, true)) { 293 switch (skb_protocol(skb, true)) {
311 case htons(ETH_P_IP): 294 case htons(ETH_P_IP):
312 inner = ip_hdr(skb)->tos; 295 inner = ip_hdr(skb)->tos;
313 break; 296 break;
314 case htons(ETH_P_IPV6): 297 case htons(ETH_P_IPV6):
315 inner = ipv6_get_dsfield(ipv6_ 298 inner = ipv6_get_dsfield(ipv6_hdr(skb));
316 break; 299 break;
317 default: 300 default:
318 return 0; 301 return 0;
319 } 302 }
320 303
321 return INET_ECN_decapsulate(skb, ipv6_ 304 return INET_ECN_decapsulate(skb, ipv6_get_dsfield(oipv6h), inner);
322 } 305 }
323 #endif 306 #endif
324 307
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