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