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/* 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 are maintained on sockets
* in TCP_AO_ESTABLISHED states.
* 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;
/* Established states are fast-path and there always is current_key/rnext_key */
#define TCP_AO_ESTABLISHED (TCPF_ESTABLISHED | TCPF_FIN_WAIT1 | TCPF_FIN_WAIT2 | \
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(const struct sock *sk,
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 request_sock *req, unsigned short int family);
#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 request_sock *req, unsigned short int family)
{
}
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 */
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