From decde2586b34b99684faff1eab41e5c496c27fb6 Mon Sep 17 00:00:00 2001 From: Dmitry Safonov Date: Mon, 23 Oct 2023 20:22:01 +0100 Subject: net/tcp: Add TCP-AO sign to twsk Add support for sockets in time-wait state. ao_info as well as all keys are inherited on transition to time-wait socket. The lifetime of ao_info is now protected by ref counter, so that tcp_ao_destroy_sock() will destruct it only when the last user is gone. Co-developed-by: Francesco Ruggeri Signed-off-by: Francesco Ruggeri Co-developed-by: Salam Noureddine Signed-off-by: Salam Noureddine Signed-off-by: Dmitry Safonov Acked-by: David Ahern Signed-off-by: David S. Miller --- include/linux/tcp.h | 3 ++ include/net/tcp_ao.h | 11 ++++-- net/ipv4/tcp_ao.c | 49 +++++++++++++++++++++----- net/ipv4/tcp_ipv4.c | 92 ++++++++++++++++++++++++++++++++++++++---------- net/ipv4/tcp_minisocks.c | 4 ++- net/ipv4/tcp_output.c | 2 +- net/ipv6/tcp_ipv6.c | 72 +++++++++++++++++++++++++++---------- 7 files changed, 183 insertions(+), 50 deletions(-) diff --git a/include/linux/tcp.h b/include/linux/tcp.h index 64e7b560fa79..eec6e7e5312e 100644 --- a/include/linux/tcp.h +++ b/include/linux/tcp.h @@ -514,6 +514,9 @@ struct tcp_timewait_sock { #ifdef CONFIG_TCP_MD5SIG struct tcp_md5sig_key *tw_md5_key; #endif +#ifdef CONFIG_TCP_AO + struct tcp_ao_info __rcu *ao_info; +#endif }; static inline struct tcp_timewait_sock *tcp_twsk(const struct sock *sk) diff --git a/include/net/tcp_ao.h b/include/net/tcp_ao.h index 629ab0365b83..971d7edcda9c 100644 --- a/include/net/tcp_ao.h +++ b/include/net/tcp_ao.h @@ -85,6 +85,7 @@ struct tcp_ao_info { __unused :31; __be32 lisn; __be32 risn; + refcount_t refcnt; /* Protects twsk destruction */ struct rcu_head rcu; }; @@ -124,7 +125,8 @@ struct tcp_ao_key *tcp_ao_established_key(struct tcp_ao_info *ao, int sndid, int rcvid); 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); +void tcp_ao_destroy_sock(struct sock *sk, bool twsk); +void tcp_ao_time_wait(struct tcp_timewait_sock *tcptw, struct tcp_sock *tp); struct tcp_ao_key *tcp_ao_do_lookup(const struct sock *sk, const union tcp_ao_addr *addr, int family, int sndid, int rcvid); @@ -182,7 +184,7 @@ static inline struct tcp_ao_key *tcp_ao_do_lookup(const struct sock *sk, return NULL; } -static inline void tcp_ao_destroy_sock(struct sock *sk) +static inline void tcp_ao_destroy_sock(struct sock *sk, bool twsk) { } @@ -194,6 +196,11 @@ 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) { } diff --git a/net/ipv4/tcp_ao.c b/net/ipv4/tcp_ao.c index b8afe78ff057..7c4e2f42845a 100644 --- a/net/ipv4/tcp_ao.c +++ b/net/ipv4/tcp_ao.c @@ -159,6 +159,7 @@ static struct tcp_ao_info *tcp_ao_alloc_info(gfp_t flags) if (!ao) return NULL; INIT_HLIST_HEAD(&ao->head); + refcount_set(&ao->refcnt, 1); return ao; } @@ -176,27 +177,54 @@ static void tcp_ao_key_free_rcu(struct rcu_head *head) kfree_sensitive(key); } -void tcp_ao_destroy_sock(struct sock *sk) +void tcp_ao_destroy_sock(struct sock *sk, bool twsk) { struct tcp_ao_info *ao; struct tcp_ao_key *key; struct hlist_node *n; - ao = rcu_dereference_protected(tcp_sk(sk)->ao_info, 1); - tcp_sk(sk)->ao_info = NULL; + if (twsk) { + ao = rcu_dereference_protected(tcp_twsk(sk)->ao_info, 1); + tcp_twsk(sk)->ao_info = NULL; + } else { + ao = rcu_dereference_protected(tcp_sk(sk)->ao_info, 1); + tcp_sk(sk)->ao_info = NULL; + } - if (!ao) + if (!ao || !refcount_dec_and_test(&ao->refcnt)) return; hlist_for_each_entry_safe(key, n, &ao->head, node) { hlist_del_rcu(&key->node); - atomic_sub(tcp_ao_sizeof_key(key), &sk->sk_omem_alloc); + if (!twsk) + atomic_sub(tcp_ao_sizeof_key(key), &sk->sk_omem_alloc); call_rcu(&key->rcu, tcp_ao_key_free_rcu); } kfree_rcu(ao, rcu); } +void tcp_ao_time_wait(struct tcp_timewait_sock *tcptw, struct tcp_sock *tp) +{ + struct tcp_ao_info *ao_info = rcu_dereference_protected(tp->ao_info, 1); + + if (ao_info) { + struct tcp_ao_key *key; + struct hlist_node *n; + int omem = 0; + + hlist_for_each_entry_safe(key, n, &ao_info->head, node) { + omem += tcp_ao_sizeof_key(key); + } + + refcount_inc(&ao_info->refcnt); + atomic_sub(omem, &(((struct sock *)tp)->sk_omem_alloc)); + rcu_assign_pointer(tcptw->ao_info, ao_info); + } else { + tcptw->ao_info = NULL; + } +} + /* 4 tuple and ISNs are expected in NBO */ static int tcp_v4_ao_calc_key(struct tcp_ao_key *mkt, u8 *key, __be32 saddr, __be32 daddr, @@ -514,11 +542,13 @@ int tcp_ao_prepare_reset(const struct sock *sk, struct sk_buff *skb, if (!sk) return -ENOTCONN; - if ((1 << sk->sk_state) & - (TCPF_LISTEN | TCPF_NEW_SYN_RECV | TCPF_TIME_WAIT)) + if ((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_NEW_SYN_RECV)) { return -1; - ao_info = rcu_dereference(tcp_sk(sk)->ao_info); + if (sk->sk_state == TCP_TIME_WAIT) + ao_info = rcu_dereference(tcp_twsk(sk)->ao_info); + else + ao_info = rcu_dereference(tcp_sk(sk)->ao_info); if (!ao_info) return -ENOENT; @@ -910,6 +940,9 @@ static struct tcp_ao_info *setsockopt_ao_info(struct sock *sk) if (sk_fullsock(sk)) { return rcu_dereference_protected(tcp_sk(sk)->ao_info, lockdep_sock_is_held(sk)); + } else if (sk->sk_state == TCP_TIME_WAIT) { + return rcu_dereference_protected(tcp_twsk(sk)->ao_info, + lockdep_sock_is_held(sk)); } return ERR_PTR(-ESOCKTNOSUPPORT); } diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index 71e1cbb0020b..a78112d78d06 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -911,17 +911,13 @@ out: static void tcp_v4_send_ack(const struct sock *sk, struct sk_buff *skb, u32 seq, u32 ack, u32 win, u32 tsval, u32 tsecr, int oif, - struct tcp_md5sig_key *key, + struct tcp_key *key, int reply_flags, u8 tos, u32 txhash) { const struct tcphdr *th = tcp_hdr(skb); struct { struct tcphdr th; - __be32 opt[(TCPOLEN_TSTAMP_ALIGNED >> 2) -#ifdef CONFIG_TCP_MD5SIG - + (TCPOLEN_MD5SIG_ALIGNED >> 2) -#endif - ]; + __be32 opt[(MAX_TCP_OPTION_SPACE >> 2)]; } rep; struct net *net = sock_net(sk); struct ip_reply_arg arg; @@ -952,7 +948,7 @@ static void tcp_v4_send_ack(const struct sock *sk, rep.th.window = htons(win); #ifdef CONFIG_TCP_MD5SIG - if (key) { + if (tcp_key_is_md5(key)) { int offset = (tsecr) ? 3 : 0; rep.opt[offset++] = htonl((TCPOPT_NOP << 24) | @@ -963,9 +959,27 @@ static void tcp_v4_send_ack(const struct sock *sk, rep.th.doff = arg.iov[0].iov_len/4; tcp_v4_md5_hash_hdr((__u8 *) &rep.opt[offset], - key, ip_hdr(skb)->saddr, + key->md5_key, ip_hdr(skb)->saddr, ip_hdr(skb)->daddr, &rep.th); } +#endif +#ifdef CONFIG_TCP_AO + if (tcp_key_is_ao(key)) { + int offset = (tsecr) ? 3 : 0; + + rep.opt[offset++] = htonl((TCPOPT_AO << 24) | + (tcp_ao_len(key->ao_key) << 16) | + (key->ao_key->sndid << 8) | + key->rcv_next); + arg.iov[0].iov_len += round_up(tcp_ao_len(key->ao_key), 4); + rep.th.doff = arg.iov[0].iov_len / 4; + + tcp_ao_hash_hdr(AF_INET, (char *)&rep.opt[offset], + key->ao_key, key->traffic_key, + (union tcp_ao_addr *)&ip_hdr(skb)->saddr, + (union tcp_ao_addr *)&ip_hdr(skb)->daddr, + &rep.th, key->sne); + } #endif arg.flags = reply_flags; arg.csum = csum_tcpudp_nofold(ip_hdr(skb)->daddr, @@ -999,18 +1013,50 @@ static void tcp_v4_timewait_ack(struct sock *sk, struct sk_buff *skb) { struct inet_timewait_sock *tw = inet_twsk(sk); struct tcp_timewait_sock *tcptw = tcp_twsk(sk); + struct tcp_key key = {}; +#ifdef CONFIG_TCP_AO + struct tcp_ao_info *ao_info; + + /* FIXME: the segment to-be-acked is not verified yet */ + ao_info = rcu_dereference(tcptw->ao_info); + if (ao_info) { + const struct tcp_ao_hdr *aoh; + + if (tcp_parse_auth_options(tcp_hdr(skb), NULL, &aoh)) { + inet_twsk_put(tw); + return; + } + + if (aoh) + key.ao_key = tcp_ao_established_key(ao_info, aoh->rnext_keyid, -1); + } + if (key.ao_key) { + struct tcp_ao_key *rnext_key; + + key.traffic_key = snd_other_key(key.ao_key); + rnext_key = READ_ONCE(ao_info->rnext_key); + key.rcv_next = rnext_key->rcvid; + key.type = TCP_KEY_AO; +#else + if (0) { +#endif +#ifdef CONFIG_TCP_MD5SIG + } else if (static_branch_unlikely(&tcp_md5_needed.key)) { + key.md5_key = tcp_twsk_md5_key(tcptw); + if (key.md5_key) + key.type = TCP_KEY_MD5; +#endif + } tcp_v4_send_ack(sk, skb, tcptw->tw_snd_nxt, tcptw->tw_rcv_nxt, tcptw->tw_rcv_wnd >> tw->tw_rcv_wscale, tcp_tw_tsval(tcptw), tcptw->tw_ts_recent, - tw->tw_bound_dev_if, - tcp_twsk_md5_key(tcptw), + tw->tw_bound_dev_if, &key, tw->tw_transparent ? IP_REPLY_ARG_NOSRCCHECK : 0, tw->tw_tos, - tw->tw_txhash - ); + tw->tw_txhash); inet_twsk_put(tw); } @@ -1018,8 +1064,7 @@ static void tcp_v4_timewait_ack(struct sock *sk, struct sk_buff *skb) static void tcp_v4_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb, struct request_sock *req) { - const union tcp_md5_addr *addr; - int l3index; + struct tcp_key key = {}; /* sk->sk_state == TCP_LISTEN -> for regular TCP_SYN_RECV * sk->sk_state == TCP_SYN_RECV -> for Fast Open. @@ -1032,15 +1077,24 @@ static void tcp_v4_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb, * exception of segments, MUST be right-shifted by * Rcv.Wind.Shift bits: */ - addr = (union tcp_md5_addr *)&ip_hdr(skb)->saddr; - l3index = tcp_v4_sdif(skb) ? inet_iif(skb) : 0; +#ifdef CONFIG_TCP_MD5SIG + if (static_branch_unlikely(&tcp_md5_needed.key)) { + const union tcp_md5_addr *addr; + int l3index; + + addr = (union tcp_md5_addr *)&ip_hdr(skb)->saddr; + l3index = tcp_v4_sdif(skb) ? inet_iif(skb) : 0; + key.md5_key = tcp_md5_do_lookup(sk, l3index, addr, AF_INET); + if (key.md5_key) + key.type = TCP_KEY_MD5; + } +#endif tcp_v4_send_ack(sk, skb, seq, tcp_rsk(req)->rcv_nxt, req->rsk_rcv_wnd >> inet_rsk(req)->rcv_wscale, tcp_rsk_tsval(tcp_rsk(req)), READ_ONCE(req->ts_recent), - 0, - tcp_md5_do_lookup(sk, l3index, addr, AF_INET), + 0, &key, inet_rsk(req)->no_srccheck ? IP_REPLY_ARG_NOSRCCHECK : 0, ip_hdr(skb)->tos, READ_ONCE(tcp_rsk(req)->txhash)); @@ -2404,7 +2458,7 @@ void tcp_v4_destroy_sock(struct sock *sk) rcu_assign_pointer(tp->md5sig_info, NULL); } #endif - tcp_ao_destroy_sock(sk); + tcp_ao_destroy_sock(sk, false); /* Clean up a referenced TCP bind bucket. */ if (inet_csk(sk)->icsk_bind_hash) diff --git a/net/ipv4/tcp_minisocks.c b/net/ipv4/tcp_minisocks.c index 3dcb3fc36e64..6810cf65a322 100644 --- a/net/ipv4/tcp_minisocks.c +++ b/net/ipv4/tcp_minisocks.c @@ -279,7 +279,7 @@ out_free: void tcp_time_wait(struct sock *sk, int state, int timeo) { const struct inet_connection_sock *icsk = inet_csk(sk); - const struct tcp_sock *tp = tcp_sk(sk); + struct tcp_sock *tp = tcp_sk(sk); struct net *net = sock_net(sk); struct inet_timewait_sock *tw; @@ -316,6 +316,7 @@ void tcp_time_wait(struct sock *sk, int state, int timeo) #endif tcp_time_wait_init(sk, tcptw); + tcp_ao_time_wait(tcptw, tp); /* Get the TIME_WAIT timeout firing. */ if (timeo < rto) @@ -370,6 +371,7 @@ void tcp_twsk_destructor(struct sock *sk) call_rcu(&twsk->tw_md5_key->rcu, tcp_md5_twsk_free_rcu); } #endif + tcp_ao_destroy_sock(sk, true); } EXPORT_SYMBOL_GPL(tcp_twsk_destructor); diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index fa3a630f3629..de546313a214 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -3997,7 +3997,7 @@ int tcp_connect(struct sock *sk) * then free up ao_info if allocated. */ if (needs_md5) { - tcp_ao_destroy_sock(sk); + tcp_ao_destroy_sock(sk, false); } else if (needs_ao) { tcp_clear_md5_list(sk); kfree(rcu_replace_pointer(tp->md5sig_info, NULL, diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c index 45b81e230438..e6c3617976f0 100644 --- a/net/ipv6/tcp_ipv6.c +++ b/net/ipv6/tcp_ipv6.c @@ -778,13 +778,6 @@ clear_hash_nostart: memset(md5_hash, 0, 16); return 1; } -#else /* CONFIG_TCP_MD5SIG */ -static struct tcp_md5sig_key *tcp_v6_md5_do_lookup(const struct sock *sk, - const struct in6_addr *addr, - int l3index) -{ - return NULL; -} #endif static void tcp_v6_init_req(struct request_sock *req, @@ -1134,39 +1127,81 @@ out: static void tcp_v6_send_ack(const struct sock *sk, struct sk_buff *skb, u32 seq, u32 ack, u32 win, u32 tsval, u32 tsecr, int oif, - struct tcp_md5sig_key *md5_key, u8 tclass, + struct tcp_key *key, u8 tclass, __be32 label, u32 priority, u32 txhash) { - struct tcp_key key = { - .md5_key = md5_key, - .type = md5_key ? TCP_KEY_MD5 : TCP_KEY_NONE, - }; - tcp_v6_send_response(sk, skb, seq, ack, win, tsval, tsecr, oif, 0, - tclass, label, priority, txhash, &key); + tclass, label, priority, txhash, key); } static void tcp_v6_timewait_ack(struct sock *sk, struct sk_buff *skb) { struct inet_timewait_sock *tw = inet_twsk(sk); struct tcp_timewait_sock *tcptw = tcp_twsk(sk); + struct tcp_key key = {}; +#ifdef CONFIG_TCP_AO + struct tcp_ao_info *ao_info; + + /* FIXME: the segment to-be-acked is not verified yet */ + ao_info = rcu_dereference(tcptw->ao_info); + if (ao_info) { + const struct tcp_ao_hdr *aoh; + + /* Invalid TCP option size or twice included auth */ + if (tcp_parse_auth_options(tcp_hdr(skb), NULL, &aoh)) + goto out; + if (aoh) { + key.ao_key = tcp_ao_established_key(ao_info, + aoh->rnext_keyid, -1); + } + } + if (key.ao_key) { + struct tcp_ao_key *rnext_key; + + key.traffic_key = snd_other_key(key.ao_key); + /* rcv_next switches to our rcv_next */ + rnext_key = READ_ONCE(ao_info->rnext_key); + key.rcv_next = rnext_key->rcvid; + key.type = TCP_KEY_AO; +#else + if (0) { +#endif +#ifdef CONFIG_TCP_MD5SIG + } else if (static_branch_unlikely(&tcp_md5_needed.key)) { + key.md5_key = tcp_twsk_md5_key(tcptw); + if (key.md5_key) + key.type = TCP_KEY_MD5; +#endif + } tcp_v6_send_ack(sk, skb, tcptw->tw_snd_nxt, tcptw->tw_rcv_nxt, tcptw->tw_rcv_wnd >> tw->tw_rcv_wscale, tcp_tw_tsval(tcptw), - tcptw->tw_ts_recent, tw->tw_bound_dev_if, tcp_twsk_md5_key(tcptw), + tcptw->tw_ts_recent, tw->tw_bound_dev_if, &key, tw->tw_tclass, cpu_to_be32(tw->tw_flowlabel), tw->tw_priority, tw->tw_txhash); +#ifdef CONFIG_TCP_AO +out: +#endif inet_twsk_put(tw); } static void tcp_v6_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb, struct request_sock *req) { - int l3index; + struct tcp_key key = {}; + +#ifdef CONFIG_TCP_MD5SIG + if (static_branch_unlikely(&tcp_md5_needed.key)) { + int l3index = tcp_v6_sdif(skb) ? tcp_v6_iif_l3_slave(skb) : 0; - l3index = tcp_v6_sdif(skb) ? tcp_v6_iif_l3_slave(skb) : 0; + key.md5_key = tcp_v6_md5_do_lookup(sk, &ipv6_hdr(skb)->saddr, + l3index); + if (key.md5_key) + key.type = TCP_KEY_MD5; + } +#endif /* sk->sk_state == TCP_LISTEN -> for regular TCP_SYN_RECV * sk->sk_state == TCP_SYN_RECV -> for Fast Open. @@ -1182,8 +1217,7 @@ static void tcp_v6_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb, req->rsk_rcv_wnd >> inet_rsk(req)->rcv_wscale, tcp_rsk_tsval(tcp_rsk(req)), READ_ONCE(req->ts_recent), sk->sk_bound_dev_if, - tcp_v6_md5_do_lookup(sk, &ipv6_hdr(skb)->saddr, l3index), - ipv6_get_dsfield(ipv6_hdr(skb)), 0, + &key, ipv6_get_dsfield(ipv6_hdr(skb)), 0, READ_ONCE(sk->sk_priority), READ_ONCE(tcp_rsk(req)->txhash)); } -- cgit