diff options
Diffstat (limited to 'include/net/tcp_ao.h')
| -rw-r--r-- | include/net/tcp_ao.h | 389 |
1 files changed, 389 insertions, 0 deletions
diff --git a/include/net/tcp_ao.h b/include/net/tcp_ao.h new file mode 100644 index 0000000000..b04afced4c --- /dev/null +++ b/include/net/tcp_ao.h @@ -0,0 +1,389 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +#ifndef _TCP_AO_H +#define _TCP_AO_H + +#define TCP_AO_KEY_ALIGN 1 +#define __tcp_ao_key_align __aligned(TCP_AO_KEY_ALIGN) + +union tcp_ao_addr { + struct in_addr a4; +#if IS_ENABLED(CONFIG_IPV6) + struct in6_addr a6; +#endif +}; + +struct tcp_ao_hdr { + u8 kind; + u8 length; + u8 keyid; + u8 rnext_keyid; +}; + +struct tcp_ao_counters { + atomic64_t pkt_good; + atomic64_t pkt_bad; + atomic64_t key_not_found; + atomic64_t ao_required; + atomic64_t dropped_icmp; +}; + +struct tcp_ao_key { + struct hlist_node node; + union tcp_ao_addr addr; + u8 key[TCP_AO_MAXKEYLEN] __tcp_ao_key_align; + unsigned int tcp_sigpool_id; + unsigned int digest_size; + int l3index; + u8 prefixlen; + u8 family; + u8 keylen; + u8 keyflags; + u8 sndid; + u8 rcvid; + u8 maclen; + struct rcu_head rcu; + atomic64_t pkt_good; + atomic64_t pkt_bad; + u8 traffic_keys[]; +}; + +static inline u8 *rcv_other_key(struct tcp_ao_key *key) +{ + return key->traffic_keys; +} + +static inline u8 *snd_other_key(struct tcp_ao_key *key) +{ + return key->traffic_keys + key->digest_size; +} + +static inline int tcp_ao_maclen(const struct tcp_ao_key *key) +{ + return key->maclen; +} + +/* Use tcp_ao_len_aligned() for TCP header calculations */ +static inline int tcp_ao_len(const struct tcp_ao_key *key) +{ + return tcp_ao_maclen(key) + sizeof(struct tcp_ao_hdr); +} + +static inline int tcp_ao_len_aligned(const struct tcp_ao_key *key) +{ + return round_up(tcp_ao_len(key), 4); +} + +static inline unsigned int tcp_ao_digest_size(struct tcp_ao_key *key) +{ + return key->digest_size; +} + +static inline int tcp_ao_sizeof_key(const struct tcp_ao_key *key) +{ + return sizeof(struct tcp_ao_key) + (key->digest_size << 1); +} + +struct tcp_ao_info { + /* List of tcp_ao_key's */ + struct hlist_head head; + /* current_key and rnext_key aren't maintained on listen sockets. + * Their purpose is to cache keys on established connections, + * saving needless lookups. Never dereference any of them from + * listen sockets. + * ::current_key may change in RX to the key that was requested by + * the peer, please use READ_ONCE()/WRITE_ONCE() in order to avoid + * load/store tearing. + * Do the same for ::rnext_key, if you don't hold socket lock + * (it's changed only by userspace request in setsockopt()). + */ + struct tcp_ao_key *current_key; + struct tcp_ao_key *rnext_key; + struct tcp_ao_counters counters; + u32 ao_required :1, + accept_icmps :1, + __unused :30; + __be32 lisn; + __be32 risn; + /* Sequence Number Extension (SNE) are upper 4 bytes for SEQ, + * that protect TCP-AO connection from replayed old TCP segments. + * See RFC5925 (6.2). + * In order to get correct SNE, there's a helper tcp_ao_compute_sne(). + * It needs SEQ basis to understand whereabouts are lower SEQ numbers. + * According to that basis vector, it can provide incremented SNE + * when SEQ rolls over or provide decremented SNE when there's + * a retransmitted segment from before-rolling over. + * - for request sockets such basis is rcv_isn/snt_isn, which seems + * good enough as it's unexpected to receive 4 Gbytes on reqsk. + * - for full sockets the basis is rcv_nxt/snd_una. snd_una is + * taken instead of snd_nxt as currently it's easier to track + * in tcp_snd_una_update(), rather than updating SNE in all + * WRITE_ONCE(tp->snd_nxt, ...) + * - for time-wait sockets the basis is tw_rcv_nxt/tw_snd_nxt. + * tw_snd_nxt is not expected to change, while tw_rcv_nxt may. + */ + u32 snd_sne; + u32 rcv_sne; + refcount_t refcnt; /* Protects twsk destruction */ + struct rcu_head rcu; +}; + +#ifdef CONFIG_TCP_MD5SIG +#include <linux/jump_label.h> +extern struct static_key_false_deferred tcp_md5_needed; +#define static_branch_tcp_md5() static_branch_unlikely(&tcp_md5_needed.key) +#else +#define static_branch_tcp_md5() false +#endif +#ifdef CONFIG_TCP_AO +/* TCP-AO structures and functions */ +#include <linux/jump_label.h> +extern struct static_key_false_deferred tcp_ao_needed; +#define static_branch_tcp_ao() static_branch_unlikely(&tcp_ao_needed.key) +#else +#define static_branch_tcp_ao() false +#endif + +static inline bool tcp_hash_should_produce_warnings(void) +{ + return static_branch_tcp_md5() || static_branch_tcp_ao(); +} + +#define tcp_hash_fail(msg, family, skb, fmt, ...) \ +do { \ + const struct tcphdr *th = tcp_hdr(skb); \ + char hdr_flags[6]; \ + char *f = hdr_flags; \ + \ + if (!tcp_hash_should_produce_warnings()) \ + break; \ + if (th->fin) \ + *f++ = 'F'; \ + if (th->syn) \ + *f++ = 'S'; \ + if (th->rst) \ + *f++ = 'R'; \ + if (th->psh) \ + *f++ = 'P'; \ + if (th->ack) \ + *f++ = '.'; \ + *f = 0; \ + if ((family) == AF_INET) { \ + net_info_ratelimited("%s for %pI4.%d->%pI4.%d [%s] " fmt "\n", \ + msg, &ip_hdr(skb)->saddr, ntohs(th->source), \ + &ip_hdr(skb)->daddr, ntohs(th->dest), \ + hdr_flags, ##__VA_ARGS__); \ + } else { \ + net_info_ratelimited("%s for [%pI6c].%d->[%pI6c].%d [%s]" fmt "\n", \ + msg, &ipv6_hdr(skb)->saddr, ntohs(th->source), \ + &ipv6_hdr(skb)->daddr, ntohs(th->dest), \ + hdr_flags, ##__VA_ARGS__); \ + } \ +} while (0) + +#ifdef CONFIG_TCP_AO +/* TCP-AO structures and functions */ +struct tcp4_ao_context { + __be32 saddr; + __be32 daddr; + __be16 sport; + __be16 dport; + __be32 sisn; + __be32 disn; +}; + +struct tcp6_ao_context { + struct in6_addr saddr; + struct in6_addr daddr; + __be16 sport; + __be16 dport; + __be32 sisn; + __be32 disn; +}; + +struct tcp_sigpool; +#define TCP_AO_ESTABLISHED (TCPF_ESTABLISHED | TCPF_FIN_WAIT1 | TCPF_FIN_WAIT2 | \ + TCPF_CLOSE | TCPF_CLOSE_WAIT | \ + TCPF_LAST_ACK | TCPF_CLOSING) + +int tcp_ao_transmit_skb(struct sock *sk, struct sk_buff *skb, + struct tcp_ao_key *key, struct tcphdr *th, + __u8 *hash_location); +int tcp_ao_hash_skb(unsigned short int family, + char *ao_hash, struct tcp_ao_key *key, + const struct sock *sk, const struct sk_buff *skb, + const u8 *tkey, int hash_offset, u32 sne); +int tcp_parse_ao(struct sock *sk, int cmd, unsigned short int family, + sockptr_t optval, int optlen); +struct tcp_ao_key *tcp_ao_established_key(struct tcp_ao_info *ao, + int sndid, int rcvid); +int tcp_ao_copy_all_matching(const struct sock *sk, struct sock *newsk, + struct request_sock *req, struct sk_buff *skb, + int family); +int tcp_ao_calc_traffic_key(struct tcp_ao_key *mkt, u8 *key, void *ctx, + unsigned int len, struct tcp_sigpool *hp); +void tcp_ao_destroy_sock(struct sock *sk, bool twsk); +void tcp_ao_time_wait(struct tcp_timewait_sock *tcptw, struct tcp_sock *tp); +bool tcp_ao_ignore_icmp(const struct sock *sk, int family, int type, int code); +int tcp_ao_get_mkts(struct sock *sk, sockptr_t optval, sockptr_t optlen); +int tcp_ao_get_sock_info(struct sock *sk, sockptr_t optval, sockptr_t optlen); +int tcp_ao_get_repair(struct sock *sk, sockptr_t optval, sockptr_t optlen); +int tcp_ao_set_repair(struct sock *sk, sockptr_t optval, unsigned int optlen); +enum skb_drop_reason tcp_inbound_ao_hash(struct sock *sk, + const struct sk_buff *skb, unsigned short int family, + const struct request_sock *req, int l3index, + const struct tcp_ao_hdr *aoh); +u32 tcp_ao_compute_sne(u32 next_sne, u32 next_seq, u32 seq); +struct tcp_ao_key *tcp_ao_do_lookup(const struct sock *sk, int l3index, + const union tcp_ao_addr *addr, + int family, int sndid, int rcvid); +int tcp_ao_hash_hdr(unsigned short family, char *ao_hash, + struct tcp_ao_key *key, const u8 *tkey, + const union tcp_ao_addr *daddr, + const union tcp_ao_addr *saddr, + const struct tcphdr *th, u32 sne); +int tcp_ao_prepare_reset(const struct sock *sk, struct sk_buff *skb, + const struct tcp_ao_hdr *aoh, int l3index, u32 seq, + struct tcp_ao_key **key, char **traffic_key, + bool *allocated_traffic_key, u8 *keyid, u32 *sne); + +/* ipv4 specific functions */ +int tcp_v4_parse_ao(struct sock *sk, int cmd, sockptr_t optval, int optlen); +struct tcp_ao_key *tcp_v4_ao_lookup(const struct sock *sk, struct sock *addr_sk, + int sndid, int rcvid); +int tcp_v4_ao_synack_hash(char *ao_hash, struct tcp_ao_key *mkt, + struct request_sock *req, const struct sk_buff *skb, + int hash_offset, u32 sne); +int tcp_v4_ao_calc_key_sk(struct tcp_ao_key *mkt, u8 *key, + const struct sock *sk, + __be32 sisn, __be32 disn, bool send); +int tcp_v4_ao_calc_key_rsk(struct tcp_ao_key *mkt, u8 *key, + struct request_sock *req); +struct tcp_ao_key *tcp_v4_ao_lookup_rsk(const struct sock *sk, + struct request_sock *req, + int sndid, int rcvid); +int tcp_v4_ao_hash_skb(char *ao_hash, struct tcp_ao_key *key, + const struct sock *sk, const struct sk_buff *skb, + const u8 *tkey, int hash_offset, u32 sne); +/* ipv6 specific functions */ +int tcp_v6_ao_hash_pseudoheader(struct tcp_sigpool *hp, + const struct in6_addr *daddr, + const struct in6_addr *saddr, int nbytes); +int tcp_v6_ao_calc_key_skb(struct tcp_ao_key *mkt, u8 *key, + const struct sk_buff *skb, __be32 sisn, __be32 disn); +int tcp_v6_ao_calc_key_sk(struct tcp_ao_key *mkt, u8 *key, + const struct sock *sk, __be32 sisn, + __be32 disn, bool send); +int tcp_v6_ao_calc_key_rsk(struct tcp_ao_key *mkt, u8 *key, + struct request_sock *req); +struct tcp_ao_key *tcp_v6_ao_lookup(const struct sock *sk, + struct sock *addr_sk, int sndid, int rcvid); +struct tcp_ao_key *tcp_v6_ao_lookup_rsk(const struct sock *sk, + struct request_sock *req, + int sndid, int rcvid); +int tcp_v6_ao_hash_skb(char *ao_hash, struct tcp_ao_key *key, + const struct sock *sk, const struct sk_buff *skb, + const u8 *tkey, int hash_offset, u32 sne); +int tcp_v6_parse_ao(struct sock *sk, int cmd, sockptr_t optval, int optlen); +int tcp_v6_ao_synack_hash(char *ao_hash, struct tcp_ao_key *ao_key, + struct request_sock *req, const struct sk_buff *skb, + int hash_offset, u32 sne); +void tcp_ao_established(struct sock *sk); +void tcp_ao_finish_connect(struct sock *sk, struct sk_buff *skb); +void tcp_ao_connect_init(struct sock *sk); +void tcp_ao_syncookie(struct sock *sk, const struct sk_buff *skb, + struct tcp_request_sock *treq, + unsigned short int family, int l3index); +#else /* CONFIG_TCP_AO */ + +static inline int tcp_ao_transmit_skb(struct sock *sk, struct sk_buff *skb, + struct tcp_ao_key *key, struct tcphdr *th, + __u8 *hash_location) +{ + return 0; +} + +static inline void tcp_ao_syncookie(struct sock *sk, const struct sk_buff *skb, + struct tcp_request_sock *treq, + unsigned short int family, int l3index) +{ +} + +static inline bool tcp_ao_ignore_icmp(const struct sock *sk, int family, + int type, int code) +{ + return false; +} + +static inline enum skb_drop_reason tcp_inbound_ao_hash(struct sock *sk, + const struct sk_buff *skb, unsigned short int family, + const struct request_sock *req, int l3index, + const struct tcp_ao_hdr *aoh) +{ + return SKB_NOT_DROPPED_YET; +} + +static inline struct tcp_ao_key *tcp_ao_do_lookup(const struct sock *sk, + int l3index, const union tcp_ao_addr *addr, + int family, int sndid, int rcvid) +{ + return NULL; +} + +static inline void tcp_ao_destroy_sock(struct sock *sk, bool twsk) +{ +} + +static inline void tcp_ao_established(struct sock *sk) +{ +} + +static inline void tcp_ao_finish_connect(struct sock *sk, struct sk_buff *skb) +{ +} + +static inline void tcp_ao_time_wait(struct tcp_timewait_sock *tcptw, + struct tcp_sock *tp) +{ +} + +static inline void tcp_ao_connect_init(struct sock *sk) +{ +} + +static inline int tcp_ao_get_mkts(struct sock *sk, sockptr_t optval, sockptr_t optlen) +{ + return -ENOPROTOOPT; +} + +static inline int tcp_ao_get_sock_info(struct sock *sk, sockptr_t optval, sockptr_t optlen) +{ + return -ENOPROTOOPT; +} + +static inline int tcp_ao_get_repair(struct sock *sk, + sockptr_t optval, sockptr_t optlen) +{ + return -ENOPROTOOPT; +} + +static inline int tcp_ao_set_repair(struct sock *sk, + sockptr_t optval, unsigned int optlen) +{ + return -ENOPROTOOPT; +} +#endif + +#if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO) +int tcp_do_parse_auth_options(const struct tcphdr *th, + const u8 **md5_hash, const u8 **ao_hash); +#else +static inline int tcp_do_parse_auth_options(const struct tcphdr *th, + const u8 **md5_hash, const u8 **ao_hash) +{ + *md5_hash = NULL; + *ao_hash = NULL; + return 0; +} +#endif + +#endif /* _TCP_AO_H */ |