[PATCH v7 22/22] net/tcp: Add TCP_AO_REPAIR
From: Dmitry Safonov
Date: Wed Jun 14 2023 - 19:12:32 EST
Add TCP_AO_REPAIR setsockopt(), getsockopt(). They let a user to repair
TCP-AO ISNs/SNEs. Also let the user hack around when (tp->repair) is on
and add ao_info on a socket in any supported state.
As SNEs now can be read/written at any moment, use
WRITE_ONCE()/READ_ONCE() to set/read them.
Signed-off-by: Dmitry Safonov <dima@xxxxxxxxxx>
---
include/net/tcp_ao.h | 14 ++++++
include/uapi/linux/tcp.h | 10 ++++
net/ipv4/tcp.c | 24 +++++++---
net/ipv4/tcp_ao.c | 100 ++++++++++++++++++++++++++++++++++++---
net/ipv4/tcp_input.c | 12 ++---
net/ipv4/tcp_ipv4.c | 4 +-
net/ipv4/tcp_output.c | 3 +-
net/ipv6/tcp_ipv6.c | 4 +-
8 files changed, 147 insertions(+), 24 deletions(-)
diff --git a/include/net/tcp_ao.h b/include/net/tcp_ao.h
index 3449d093143e..54eec4859b35 100644
--- a/include/net/tcp_ao.h
+++ b/include/net/tcp_ao.h
@@ -182,6 +182,8 @@ void tcp_ao_time_wait(struct tcp_timewait_sock *tcptw, struct tcp_sock *tp);
bool tcp_ao_ignore_icmp(struct sock *sk, 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,
@@ -303,6 +305,18 @@ static inline int tcp_ao_get_sock_info(struct sock *sk, sockptr_t optval, sockpt
{
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)
diff --git a/include/uapi/linux/tcp.h b/include/uapi/linux/tcp.h
index 979ff960fddb..a0dd4612a37c 100644
--- a/include/uapi/linux/tcp.h
+++ b/include/uapi/linux/tcp.h
@@ -133,6 +133,7 @@ enum {
#define TCP_AO_DEL_KEY 39 /* Delete MKT */
#define TCP_AO_INFO 40 /* Set/list TCP-AO per-socket options */
#define TCP_AO_GET_KEYS 41 /* List MKT(s) */
+#define TCP_AO_REPAIR 42 /* Get/Set SNEs and ISNs */
#define TCP_REPAIR_ON 1
#define TCP_REPAIR_OFF 0
@@ -445,6 +446,15 @@ struct tcp_ao_getsockopt { /* getsockopt(TCP_AO_GET_KEYS) */
__u64 pkt_bad; /* out: segments that failed verification */
} __attribute__((aligned(8)));
+struct tcp_ao_repair { /* {s,g}etsockopt(TCP_AO_REPAIR) */
+ __be32 snt_isn;
+ __be32 rcv_isn;
+ __u32 snd_sne;
+ __u32 snd_sne_seq;
+ __u32 rcv_sne;
+ __u32 rcv_sne_seq;
+} __attribute__((aligned(8)));
+
/* setsockopt(fd, IPPROTO_TCP, TCP_ZEROCOPY_RECEIVE, ...) */
#define TCP_RECEIVE_ZEROCOPY_FLAG_TLB_CLEAN_HINT 0x1
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index c4143b67a67b..b814a3ce9e69 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -3714,20 +3714,28 @@ int do_tcp_setsockopt(struct sock *sk, int level, int optname,
__tcp_sock_set_quickack(sk, val);
break;
+ case TCP_AO_REPAIR:
+ err = tcp_ao_set_repair(sk, optval, optlen);
+ break;
#ifdef CONFIG_TCP_AO
case TCP_AO_ADD_KEY:
case TCP_AO_DEL_KEY:
case TCP_AO_INFO: {
/* If this is the first TCP-AO setsockopt() on the socket,
- * sk_state has to be LISTEN or CLOSE
+ * sk_state has to be LISTEN or CLOSE. Allow TCP_REPAIR
+ * in any state.
*/
- if (((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE)) ||
- rcu_dereference_protected(tcp_sk(sk)->ao_info,
+ if ((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE))
+ goto ao_parse;
+ if (rcu_dereference_protected(tcp_sk(sk)->ao_info,
lockdep_sock_is_held(sk)))
- err = tp->af_specific->ao_parse(sk, optname, optval,
- optlen);
- else
- err = -EISCONN;
+ goto ao_parse;
+ if (tp->repair)
+ goto ao_parse;
+ err = -EISCONN;
+ break;
+ao_parse:
+ err = tp->af_specific->ao_parse(sk, optname, optval, optlen);
break;
}
#endif
@@ -4394,6 +4402,8 @@ int do_tcp_getsockopt(struct sock *sk, int level,
return err;
}
#endif
+ case TCP_AO_REPAIR:
+ return tcp_ao_get_repair(sk, optval, optlen);
case TCP_AO_GET_KEYS:
case TCP_AO_INFO: {
int err;
diff --git a/net/ipv4/tcp_ao.c b/net/ipv4/tcp_ao.c
index d8a02cf0ba3c..6fe745e0b04c 100644
--- a/net/ipv4/tcp_ao.c
+++ b/net/ipv4/tcp_ao.c
@@ -1061,8 +1061,8 @@ void tcp_ao_finish_connect(struct sock *sk, struct sk_buff *skb)
ao->risn = tcp_hdr(skb)->seq;
- ao->rcv_sne = 0;
- ao->rcv_sne_seq = ntohl(tcp_hdr(skb)->seq);
+ WRITE_ONCE(ao->rcv_sne, 0);
+ WRITE_ONCE(ao->rcv_sne_seq, ntohl(tcp_hdr(skb)->seq));
hlist_for_each_entry_rcu(key, &ao->head, node) {
tcp_ao_cache_traffic_keys(sk, ao, key);
@@ -1452,6 +1452,16 @@ static struct tcp_ao_info *setsockopt_ao_info(struct sock *sk)
return ERR_PTR(-ESOCKTNOSUPPORT);
}
+static struct tcp_ao_info *getsockopt_ao_info(struct sock *sk)
+{
+ if (sk_fullsock(sk))
+ return rcu_dereference(tcp_sk(sk)->ao_info);
+ else if (sk->sk_state == TCP_TIME_WAIT)
+ return rcu_dereference(tcp_twsk(sk)->ao_info);
+
+ return ERR_PTR(-ESOCKTNOSUPPORT);
+}
+
#define TCP_AO_KEYF_ALL (TCP_AO_KEYF_IFINDEX | TCP_AO_KEYF_EXCLUDE_OPT)
#define TCP_AO_GET_KEYF_VALID (TCP_AO_KEYF_IFINDEX)
@@ -1586,11 +1596,13 @@ static int tcp_ao_add_cmd(struct sock *sk, unsigned short int family,
if (ret < 0)
goto err_free_sock;
- /* Change this condition if we allow adding keys in states
- * like close_wait, syn_sent or fin_wait...
- */
- if (sk->sk_state == TCP_ESTABLISHED)
+ if (!((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE))) {
tcp_ao_cache_traffic_keys(sk, ao_info, key);
+ if (first) {
+ ao_info->current_key = key;
+ ao_info->rnext_key = key;
+ }
+ }
tcp_ao_link_mkt(ao_info, key);
if (first) {
@@ -1837,6 +1849,8 @@ static int tcp_ao_info_cmd(struct sock *sk, unsigned short int family,
if (IS_ERR(ao_info))
return PTR_ERR(ao_info);
if (!ao_info) {
+ if (!((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE)))
+ return -EINVAL;
ao_info = tcp_ao_alloc_info(GFP_KERNEL);
if (!ao_info)
return -ENOMEM;
@@ -2219,3 +2233,77 @@ int tcp_ao_get_sock_info(struct sock *sk, sockptr_t optval, sockptr_t optlen)
return 0;
}
+int tcp_ao_set_repair(struct sock *sk, sockptr_t optval, unsigned int optlen)
+{
+ struct tcp_sock *tp = tcp_sk(sk);
+ struct tcp_ao_repair cmd;
+ struct tcp_ao_key *key;
+ struct tcp_ao_info *ao;
+ int err;
+
+ if (optlen < sizeof(cmd))
+ return -EINVAL;
+
+ err = copy_struct_from_sockptr(&cmd, sizeof(cmd), optval, optlen);
+ if (err)
+ return err;
+
+ if (!tp->repair)
+ return -EPERM;
+
+ ao = setsockopt_ao_info(sk);
+ if (IS_ERR(ao))
+ return PTR_ERR(ao);
+ if (!ao)
+ return -ENOENT;
+
+ WRITE_ONCE(ao->lisn, cmd.snt_isn);
+ WRITE_ONCE(ao->risn, cmd.rcv_isn);
+ WRITE_ONCE(ao->snd_sne, cmd.snd_sne);
+ WRITE_ONCE(ao->snd_sne_seq, cmd.snd_sne_seq);
+ WRITE_ONCE(ao->rcv_sne, cmd.rcv_sne);
+ WRITE_ONCE(ao->rcv_sne_seq, cmd.rcv_sne_seq);
+
+ hlist_for_each_entry_rcu(key, &ao->head, node)
+ tcp_ao_cache_traffic_keys(sk, ao, key);
+
+ return 0;
+}
+
+int tcp_ao_get_repair(struct sock *sk, sockptr_t optval, sockptr_t optlen)
+{
+ struct tcp_sock *tp = tcp_sk(sk);
+ struct tcp_ao_repair opt;
+ struct tcp_ao_info *ao;
+ int len;
+
+ if (copy_from_sockptr(&len, optlen, sizeof(int)))
+ return -EFAULT;
+
+ if (len <= 0)
+ return -EINVAL;
+
+ if (!tp->repair)
+ return -EPERM;
+
+ rcu_read_lock();
+ ao = getsockopt_ao_info(sk);
+ if (IS_ERR(ao))
+ return PTR_ERR(ao);
+ if (!ao) {
+ rcu_read_unlock();
+ return -ENOENT;
+ }
+
+ opt.snt_isn = ao->lisn;
+ opt.rcv_isn = ao->risn;
+ opt.snd_sne = READ_ONCE(ao->snd_sne);
+ opt.snd_sne_seq = READ_ONCE(ao->snd_sne_seq);
+ opt.rcv_sne = READ_ONCE(ao->rcv_sne);
+ opt.rcv_sne_seq = READ_ONCE(ao->rcv_sne_seq);
+ rcu_read_unlock();
+
+ if (copy_to_sockptr(optval, &opt, len))
+ return -EFAULT;
+ return 0;
+}
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index c0c18b05fd1c..1bd47cb8fb9a 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -3536,8 +3536,8 @@ static void tcp_snd_sne_update(struct tcp_sock *tp, u32 ack)
lockdep_sock_is_held((struct sock *)tp));
if (ao) {
if (ack < ao->snd_sne_seq)
- ao->snd_sne++;
- ao->snd_sne_seq = ack;
+ WRITE_ONCE(ao->snd_sne, ao->snd_sne + 1);
+ WRITE_ONCE(ao->snd_sne_seq, ack);
}
#endif
}
@@ -3565,8 +3565,8 @@ static void tcp_rcv_sne_update(struct tcp_sock *tp, u32 seq)
lockdep_sock_is_held((struct sock *)tp));
if (ao) {
if (seq < ao->rcv_sne_seq)
- ao->rcv_sne++;
- ao->rcv_sne_seq = seq;
+ WRITE_ONCE(ao->rcv_sne, ao->rcv_sne + 1);
+ WRITE_ONCE(ao->rcv_sne_seq, seq);
}
#endif
}
@@ -6416,8 +6416,8 @@ static int tcp_rcv_synsent_state_process(struct sock *sk, struct sk_buff *skb,
lockdep_sock_is_held(sk));
if (ao) {
ao->risn = th->seq;
- ao->rcv_sne = 0;
- ao->rcv_sne_seq = ntohl(th->seq);
+ WRITE_ONCE(ao->rcv_sne, 0);
+ WRITE_ONCE(ao->rcv_sne_seq, ntohl(th->seq));
}
#endif
tcp_set_state(sk, TCP_SYN_RECV);
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 211d0edd6eea..229317e38a5e 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -1040,8 +1040,8 @@ static void tcp_v4_timewait_ack(struct sock *sk, struct sk_buff *skb)
* below since sne probably doesn't change once we are
* in timewait state.
*/
- ao_sne = tcp_ao_compute_sne(ao_info->snd_sne,
- ao_info->snd_sne_seq,
+ ao_sne = tcp_ao_compute_sne(READ_ONCE(ao_info->snd_sne),
+ READ_ONCE(ao_info->snd_sne_seq),
tcptw->tw_snd_nxt);
rnext_key = READ_ONCE(ao_info->rnext_key);
rcv_next = rnext_key->rcvid;
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index f055ef225c37..e68ae7b896b7 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -1455,7 +1455,8 @@ static int __tcp_transmit_skb(struct sock *sk, struct sk_buff *skb,
} else {
traffic_key = snd_other_key(ao_key);
}
- sne = tcp_ao_compute_sne(ao->snd_sne, ao->snd_sne_seq,
+ sne = tcp_ao_compute_sne(READ_ONCE(ao->snd_sne),
+ READ_ONCE(ao->snd_sne_seq),
ntohl(th->seq));
tp->af_specific->calc_ao_hash(opts.hash_location, ao_key, sk, skb,
traffic_key,
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index 6b39da6c477e..ba9d4571b265 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -1190,8 +1190,8 @@ static void tcp_v6_timewait_ack(struct sock *sk, struct sk_buff *skb)
/* rcv_next switches to our rcv_next */
rnext_key = READ_ONCE(ao_info->rnext_key);
rcv_next = rnext_key->rcvid;
- ao_sne = tcp_ao_compute_sne(ao_info->snd_sne,
- ao_info->snd_sne_seq,
+ ao_sne = tcp_ao_compute_sne(READ_ONCE(ao_info->snd_sne),
+ READ_ONCE(ao_info->snd_sne_seq),
tcptw->tw_snd_nxt);
}
#endif
--
2.40.0