1 /* SPDX-License-Identifier: GPL-2.0-or-later */ 2 #ifndef _TCP_AO_H 3 #define _TCP_AO_H 4 5 #define TCP_AO_KEY_ALIGN 1 6 #define __tcp_ao_key_align __aligned(TCP_AO_KEY_ALIGN) 7 8 union tcp_ao_addr { 9 struct in_addr a4; 10 #if IS_ENABLED(CONFIG_IPV6) 11 struct in6_addr a6; 12 #endif 13 }; 14 15 struct tcp_ao_hdr { 16 u8 kind; 17 u8 length; 18 u8 keyid; 19 u8 rnext_keyid; 20 }; 21 22 struct tcp_ao_counters { 23 atomic64_t pkt_good; 24 atomic64_t pkt_bad; 25 atomic64_t key_not_found; 26 atomic64_t ao_required; 27 atomic64_t dropped_icmp; 28 }; 29 30 struct tcp_ao_key { 31 struct hlist_node node; 32 union tcp_ao_addr addr; 33 u8 key[TCP_AO_MAXKEYLEN] __tcp_ao_key_align; 34 unsigned int tcp_sigpool_id; 35 unsigned int digest_size; 36 int l3index; 37 u8 prefixlen; 38 u8 family; 39 u8 keylen; 40 u8 keyflags; 41 u8 sndid; 42 u8 rcvid; 43 u8 maclen; 44 struct rcu_head rcu; 45 atomic64_t pkt_good; 46 atomic64_t pkt_bad; 47 u8 traffic_keys[]; 48 }; 49 50 static inline u8 *rcv_other_key(struct tcp_ao_key *key) 51 { 52 return key->traffic_keys; 53 } 54 55 static inline u8 *snd_other_key(struct tcp_ao_key *key) 56 { 57 return key->traffic_keys + key->digest_size; 58 } 59 60 static inline int tcp_ao_maclen(const struct tcp_ao_key *key) 61 { 62 return key->maclen; 63 } 64 65 /* Use tcp_ao_len_aligned() for TCP header calculations */ 66 static inline int tcp_ao_len(const struct tcp_ao_key *key) 67 { 68 return tcp_ao_maclen(key) + sizeof(struct tcp_ao_hdr); 69 } 70 71 static inline int tcp_ao_len_aligned(const struct tcp_ao_key *key) 72 { 73 return round_up(tcp_ao_len(key), 4); 74 } 75 76 static inline unsigned int tcp_ao_digest_size(struct tcp_ao_key *key) 77 { 78 return key->digest_size; 79 } 80 81 static inline int tcp_ao_sizeof_key(const struct tcp_ao_key *key) 82 { 83 return sizeof(struct tcp_ao_key) + (key->digest_size << 1); 84 } 85 86 struct tcp_ao_info { 87 /* List of tcp_ao_key's */ 88 struct hlist_head head; 89 /* current_key and rnext_key aren't maintained on listen sockets. 90 * Their purpose is to cache keys on established connections, 91 * saving needless lookups. Never dereference any of them from 92 * listen sockets. 93 * ::current_key may change in RX to the key that was requested by 94 * the peer, please use READ_ONCE()/WRITE_ONCE() in order to avoid 95 * load/store tearing. 96 * Do the same for ::rnext_key, if you don't hold socket lock 97 * (it's changed only by userspace request in setsockopt()). 98 */ 99 struct tcp_ao_key *current_key; 100 struct tcp_ao_key *rnext_key; 101 struct tcp_ao_counters counters; 102 u32 ao_required :1, 103 accept_icmps :1, 104 __unused :30; 105 __be32 lisn; 106 __be32 risn; 107 /* Sequence Number Extension (SNE) are upper 4 bytes for SEQ, 108 * that protect TCP-AO connection from replayed old TCP segments. 109 * See RFC5925 (6.2). 110 * In order to get correct SNE, there's a helper tcp_ao_compute_sne(). 111 * It needs SEQ basis to understand whereabouts are lower SEQ numbers. 112 * According to that basis vector, it can provide incremented SNE 113 * when SEQ rolls over or provide decremented SNE when there's 114 * a retransmitted segment from before-rolling over. 115 * - for request sockets such basis is rcv_isn/snt_isn, which seems 116 * good enough as it's unexpected to receive 4 Gbytes on reqsk. 117 * - for full sockets the basis is rcv_nxt/snd_una. snd_una is 118 * taken instead of snd_nxt as currently it's easier to track 119 * in tcp_snd_una_update(), rather than updating SNE in all 120 * WRITE_ONCE(tp->snd_nxt, ...) 121 * - for time-wait sockets the basis is tw_rcv_nxt/tw_snd_nxt. 122 * tw_snd_nxt is not expected to change, while tw_rcv_nxt may. 123 */ 124 u32 snd_sne; 125 u32 rcv_sne; 126 refcount_t refcnt; /* Protects twsk destruction */ 127 struct rcu_head rcu; 128 }; 129 130 #ifdef CONFIG_TCP_MD5SIG 131 #include <linux/jump_label.h> 132 extern struct static_key_false_deferred tcp_md5_needed; 133 #define static_branch_tcp_md5() static_branch_unlikely(&tcp_md5_needed.key) 134 #else 135 #define static_branch_tcp_md5() false 136 #endif 137 #ifdef CONFIG_TCP_AO 138 /* TCP-AO structures and functions */ 139 #include <linux/jump_label.h> 140 extern struct static_key_false_deferred tcp_ao_needed; 141 #define static_branch_tcp_ao() static_branch_unlikely(&tcp_ao_needed.key) 142 #else 143 #define static_branch_tcp_ao() false 144 #endif 145 146 static inline bool tcp_hash_should_produce_warnings(void) 147 { 148 return static_branch_tcp_md5() || static_branch_tcp_ao(); 149 } 150 151 #define tcp_hash_fail(msg, family, skb, fmt, ...) \ 152 do { \ 153 const struct tcphdr *th = tcp_hdr(skb); \ 154 char hdr_flags[6]; \ 155 char *f = hdr_flags; \ 156 \ 157 if (!tcp_hash_should_produce_warnings()) \ 158 break; \ 159 if (th->fin) \ 160 *f++ = 'F'; \ 161 if (th->syn) \ 162 *f++ = 'S'; \ 163 if (th->rst) \ 164 *f++ = 'R'; \ 165 if (th->psh) \ 166 *f++ = 'P'; \ 167 if (th->ack) \ 168 *f++ = '.'; \ 169 *f = 0; \ 170 if ((family) == AF_INET) { \ 171 net_info_ratelimited("%s for %pI4.%d->%pI4.%d [%s] " fmt "\n", \ 172 msg, &ip_hdr(skb)->saddr, ntohs(th->source), \ 173 &ip_hdr(skb)->daddr, ntohs(th->dest), \ 174 hdr_flags, ##__VA_ARGS__); \ 175 } else { \ 176 net_info_ratelimited("%s for [%pI6c].%d->[%pI6c].%d [%s]" fmt "\n", \ 177 msg, &ipv6_hdr(skb)->saddr, ntohs(th->source), \ 178 &ipv6_hdr(skb)->daddr, ntohs(th->dest), \ 179 hdr_flags, ##__VA_ARGS__); \ 180 } \ 181 } while (0) 182 183 #ifdef CONFIG_TCP_AO 184 /* TCP-AO structures and functions */ 185 struct tcp4_ao_context { 186 __be32 saddr; 187 __be32 daddr; 188 __be16 sport; 189 __be16 dport; 190 __be32 sisn; 191 __be32 disn; 192 }; 193 194 struct tcp6_ao_context { 195 struct in6_addr saddr; 196 struct in6_addr daddr; 197 __be16 sport; 198 __be16 dport; 199 __be32 sisn; 200 __be32 disn; 201 }; 202 203 struct tcp_sigpool; 204 #define TCP_AO_ESTABLISHED (TCPF_ESTABLISHED | TCPF_FIN_WAIT1 | TCPF_FIN_WAIT2 | \ 205 TCPF_CLOSE | TCPF_CLOSE_WAIT | \ 206 TCPF_LAST_ACK | TCPF_CLOSING) 207 208 int tcp_ao_transmit_skb(struct sock *sk, struct sk_buff *skb, 209 struct tcp_ao_key *key, struct tcphdr *th, 210 __u8 *hash_location); 211 int tcp_ao_hash_skb(unsigned short int family, 212 char *ao_hash, struct tcp_ao_key *key, 213 const struct sock *sk, const struct sk_buff *skb, 214 const u8 *tkey, int hash_offset, u32 sne); 215 int tcp_parse_ao(struct sock *sk, int cmd, unsigned short int family, 216 sockptr_t optval, int optlen); 217 struct tcp_ao_key *tcp_ao_established_key(struct tcp_ao_info *ao, 218 int sndid, int rcvid); 219 int tcp_ao_copy_all_matching(const struct sock *sk, struct sock *newsk, 220 struct request_sock *req, struct sk_buff *skb, 221 int family); 222 int tcp_ao_calc_traffic_key(struct tcp_ao_key *mkt, u8 *key, void *ctx, 223 unsigned int len, struct tcp_sigpool *hp); 224 void tcp_ao_destroy_sock(struct sock *sk, bool twsk); 225 void tcp_ao_time_wait(struct tcp_timewait_sock *tcptw, struct tcp_sock *tp); 226 bool tcp_ao_ignore_icmp(const struct sock *sk, int family, int type, int code); 227 int tcp_ao_get_mkts(struct sock *sk, sockptr_t optval, sockptr_t optlen); 228 int tcp_ao_get_sock_info(struct sock *sk, sockptr_t optval, sockptr_t optlen); 229 int tcp_ao_get_repair(struct sock *sk, sockptr_t optval, sockptr_t optlen); 230 int tcp_ao_set_repair(struct sock *sk, sockptr_t optval, unsigned int optlen); 231 enum skb_drop_reason tcp_inbound_ao_hash(struct sock *sk, 232 const struct sk_buff *skb, unsigned short int family, 233 const struct request_sock *req, int l3index, 234 const struct tcp_ao_hdr *aoh); 235 u32 tcp_ao_compute_sne(u32 next_sne, u32 next_seq, u32 seq); 236 struct tcp_ao_key *tcp_ao_do_lookup(const struct sock *sk, int l3index, 237 const union tcp_ao_addr *addr, 238 int family, int sndid, int rcvid); 239 int tcp_ao_hash_hdr(unsigned short family, char *ao_hash, 240 struct tcp_ao_key *key, const u8 *tkey, 241 const union tcp_ao_addr *daddr, 242 const union tcp_ao_addr *saddr, 243 const struct tcphdr *th, u32 sne); 244 int tcp_ao_prepare_reset(const struct sock *sk, struct sk_buff *skb, 245 const struct tcp_ao_hdr *aoh, int l3index, u32 seq, 246 struct tcp_ao_key **key, char **traffic_key, 247 bool *allocated_traffic_key, u8 *keyid, u32 *sne); 248 249 /* ipv4 specific functions */ 250 int tcp_v4_parse_ao(struct sock *sk, int cmd, sockptr_t optval, int optlen); 251 struct tcp_ao_key *tcp_v4_ao_lookup(const struct sock *sk, struct sock *addr_sk, 252 int sndid, int rcvid); 253 int tcp_v4_ao_synack_hash(char *ao_hash, struct tcp_ao_key *mkt, 254 struct request_sock *req, const struct sk_buff *skb, 255 int hash_offset, u32 sne); 256 int tcp_v4_ao_calc_key_sk(struct tcp_ao_key *mkt, u8 *key, 257 const struct sock *sk, 258 __be32 sisn, __be32 disn, bool send); 259 int tcp_v4_ao_calc_key_rsk(struct tcp_ao_key *mkt, u8 *key, 260 struct request_sock *req); 261 struct tcp_ao_key *tcp_v4_ao_lookup_rsk(const struct sock *sk, 262 struct request_sock *req, 263 int sndid, int rcvid); 264 int tcp_v4_ao_hash_skb(char *ao_hash, struct tcp_ao_key *key, 265 const struct sock *sk, const struct sk_buff *skb, 266 const u8 *tkey, int hash_offset, u32 sne); 267 /* ipv6 specific functions */ 268 int tcp_v6_ao_hash_pseudoheader(struct tcp_sigpool *hp, 269 const struct in6_addr *daddr, 270 const struct in6_addr *saddr, int nbytes); 271 int tcp_v6_ao_calc_key_skb(struct tcp_ao_key *mkt, u8 *key, 272 const struct sk_buff *skb, __be32 sisn, __be32 disn); 273 int tcp_v6_ao_calc_key_sk(struct tcp_ao_key *mkt, u8 *key, 274 const struct sock *sk, __be32 sisn, 275 __be32 disn, bool send); 276 int tcp_v6_ao_calc_key_rsk(struct tcp_ao_key *mkt, u8 *key, 277 struct request_sock *req); 278 struct tcp_ao_key *tcp_v6_ao_lookup(const struct sock *sk, 279 struct sock *addr_sk, int sndid, int rcvid); 280 struct tcp_ao_key *tcp_v6_ao_lookup_rsk(const struct sock *sk, 281 struct request_sock *req, 282 int sndid, int rcvid); 283 int tcp_v6_ao_hash_skb(char *ao_hash, struct tcp_ao_key *key, 284 const struct sock *sk, const struct sk_buff *skb, 285 const u8 *tkey, int hash_offset, u32 sne); 286 int tcp_v6_parse_ao(struct sock *sk, int cmd, sockptr_t optval, int optlen); 287 int tcp_v6_ao_synack_hash(char *ao_hash, struct tcp_ao_key *ao_key, 288 struct request_sock *req, const struct sk_buff *skb, 289 int hash_offset, u32 sne); 290 void tcp_ao_established(struct sock *sk); 291 void tcp_ao_finish_connect(struct sock *sk, struct sk_buff *skb); 292 void tcp_ao_connect_init(struct sock *sk); 293 void tcp_ao_syncookie(struct sock *sk, const struct sk_buff *skb, 294 struct request_sock *req, unsigned short int family); 295 #else /* CONFIG_TCP_AO */ 296 297 static inline int tcp_ao_transmit_skb(struct sock *sk, struct sk_buff *skb, 298 struct tcp_ao_key *key, struct tcphdr *th, 299 __u8 *hash_location) 300 { 301 return 0; 302 } 303 304 static inline void tcp_ao_syncookie(struct sock *sk, const struct sk_buff *skb, 305 struct request_sock *req, unsigned short int family) 306 { 307 } 308 309 static inline bool tcp_ao_ignore_icmp(const struct sock *sk, int family, 310 int type, int code) 311 { 312 return false; 313 } 314 315 static inline enum skb_drop_reason tcp_inbound_ao_hash(struct sock *sk, 316 const struct sk_buff *skb, unsigned short int family, 317 const struct request_sock *req, int l3index, 318 const struct tcp_ao_hdr *aoh) 319 { 320 return SKB_NOT_DROPPED_YET; 321 } 322 323 static inline struct tcp_ao_key *tcp_ao_do_lookup(const struct sock *sk, 324 int l3index, const union tcp_ao_addr *addr, 325 int family, int sndid, int rcvid) 326 { 327 return NULL; 328 } 329 330 static inline void tcp_ao_destroy_sock(struct sock *sk, bool twsk) 331 { 332 } 333 334 static inline void tcp_ao_established(struct sock *sk) 335 { 336 } 337 338 static inline void tcp_ao_finish_connect(struct sock *sk, struct sk_buff *skb) 339 { 340 } 341 342 static inline void tcp_ao_time_wait(struct tcp_timewait_sock *tcptw, 343 struct tcp_sock *tp) 344 { 345 } 346 347 static inline void tcp_ao_connect_init(struct sock *sk) 348 { 349 } 350 351 static inline int tcp_ao_get_mkts(struct sock *sk, sockptr_t optval, sockptr_t optlen) 352 { 353 return -ENOPROTOOPT; 354 } 355 356 static inline int tcp_ao_get_sock_info(struct sock *sk, sockptr_t optval, sockptr_t optlen) 357 { 358 return -ENOPROTOOPT; 359 } 360 361 static inline int tcp_ao_get_repair(struct sock *sk, 362 sockptr_t optval, sockptr_t optlen) 363 { 364 return -ENOPROTOOPT; 365 } 366 367 static inline int tcp_ao_set_repair(struct sock *sk, 368 sockptr_t optval, unsigned int optlen) 369 { 370 return -ENOPROTOOPT; 371 } 372 #endif 373 374 #if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO) 375 int tcp_do_parse_auth_options(const struct tcphdr *th, 376 const u8 **md5_hash, const u8 **ao_hash); 377 #else 378 static inline int tcp_do_parse_auth_options(const struct tcphdr *th, 379 const u8 **md5_hash, const u8 **ao_hash) 380 { 381 *md5_hash = NULL; 382 *ao_hash = NULL; 383 return 0; 384 } 385 #endif 386 387 #endif /* _TCP_AO_H */ 388