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-rw-r--r--include/net/tcp_ao.h389
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 */