[PATCH v14 net-next 13/23] net/tcp: Add TCP-AO segments counters

From: Dmitry Safonov
Date: Mon Oct 09 2023 - 19:08:44 EST

Next message: Dmitry Safonov: "[PATCH v14 net-next 12/23] net/tcp: Verify inbound TCP-AO signed segments"
Previous message: Dmitry Safonov: "[PATCH v14 net-next 11/23] net/tcp: Sign SYN-ACK segments with TCP-AO"
In reply to: Dmitry Safonov: "[PATCH v14 net-next 11/23] net/tcp: Sign SYN-ACK segments with TCP-AO"
Next in thread: Dmitry Safonov: "[PATCH v14 net-next 12/23] net/tcp: Verify inbound TCP-AO signed segments"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]

Introduce segment counters that are useful for troubleshooting/debugging
as well as for writing tests.
Now there are global snmp counters as well as per-socket and per-key.

Co-developed-by: Francesco Ruggeri <fruggeri@xxxxxxxxxx>
Signed-off-by: Francesco Ruggeri <fruggeri@xxxxxxxxxx>
Co-developed-by: Salam Noureddine <noureddine@xxxxxxxxxx>
Signed-off-by: Salam Noureddine <noureddine@xxxxxxxxxx>
Signed-off-by: Dmitry Safonov <dima@xxxxxxxxxx>
Acked-by: David Ahern <dsahern@xxxxxxxxxx>
---
include/net/dropreason-core.h | 15 +++++++++++----
include/net/tcp.h | 15 +++++++++++----
include/net/tcp_ao.h | 10 ++++++++++
include/uapi/linux/snmp.h | 4 ++++
include/uapi/linux/tcp.h | 8 +++++++-
net/ipv4/proc.c | 4 ++++
net/ipv4/tcp_ao.c | 30 +++++++++++++++++++++++++++---
net/ipv4/tcp_ipv4.c | 2 +-
net/ipv6/tcp_ipv6.c | 4 ++--
9 files changed, 77 insertions(+), 15 deletions(-)

diff --git a/include/net/dropreason-core.h b/include/net/dropreason-core.h
index a01e1860fe25..efb6ea5ffb1e 100644
--- a/include/net/dropreason-core.h
+++ b/include/net/dropreason-core.h
@@ -167,17 +167,24 @@ enum skb_drop_reason {
*/
SKB_DROP_REASON_TCP_MD5FAILURE,
/**
- * @SKB_DROP_REASON_TCP_AONOTFOUND: no TCP-AO hash and one was expected
+ * @SKB_DROP_REASON_TCP_AONOTFOUND: no TCP-AO hash and one was expected,
+ * corresponding to LINUX_MIB_TCPAOREQUIRED
*/
SKB_DROP_REASON_TCP_AONOTFOUND,
/**
* @SKB_DROP_REASON_TCP_AOUNEXPECTED: TCP-AO hash is present and it
- * was not expected.
+ * was not expected, corresponding to LINUX_MIB_TCPAOKEYNOTFOUND
*/
SKB_DROP_REASON_TCP_AOUNEXPECTED,
- /** @SKB_DROP_REASON_TCP_AOKEYNOTFOUND: TCP-AO key is unknown */
+ /**
+ * @SKB_DROP_REASON_TCP_AOKEYNOTFOUND: TCP-AO key is unknown,
+ * corresponding to LINUX_MIB_TCPAOKEYNOTFOUND
+ */
SKB_DROP_REASON_TCP_AOKEYNOTFOUND,
- /** @SKB_DROP_REASON_TCP_AOFAILURE: TCP-AO hash is wrong */
+ /**
+ * @SKB_DROP_REASON_TCP_AOFAILURE: TCP-AO hash is wrong,
+ * corresponding to LINUX_MIB_TCPAOBAD
+ */
SKB_DROP_REASON_TCP_AOFAILURE,
/**
* @SKB_DROP_REASON_SOCKET_BACKLOG: failed to add skb to socket backlog (
diff --git a/include/net/tcp.h b/include/net/tcp.h
index c5c7893c77cc..bda549703fd4 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -2674,7 +2674,7 @@ static inline int tcp_parse_auth_options(const struct tcphdr *th,
}

static inline bool tcp_ao_required(struct sock *sk, const void *saddr,
- int family)
+ int family, bool stat_inc)
{
#ifdef CONFIG_TCP_AO
struct tcp_ao_info *ao_info;
@@ -2686,8 +2686,13 @@ static inline bool tcp_ao_required(struct sock *sk, const void *saddr,
return false;

ao_key = tcp_ao_do_lookup(sk, saddr, family, -1, -1);
- if (ao_info->ao_required || ao_key)
+ if (ao_info->ao_required || ao_key) {
+ if (stat_inc) {
+ NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPAOREQUIRED);
+ atomic64_inc(&ao_info->counters.ao_required);
+ }
return true;
+ }
#endif
return false;
}
@@ -2709,8 +2714,10 @@ tcp_inbound_hash(struct sock *sk, const struct request_sock *req,
return SKB_DROP_REASON_TCP_AUTH_HDR;

if (req) {
- if (tcp_rsk_used_ao(req) != !!aoh)
+ if (tcp_rsk_used_ao(req) != !!aoh) {
+ NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPAOBAD);
return SKB_DROP_REASON_TCP_AOFAILURE;
+ }
}

/* sdif set, means packet ingressed via a device
@@ -2725,7 +2732,7 @@ tcp_inbound_hash(struct sock *sk, const struct request_sock *req,
* the last key is impossible to remove, so there's
* always at least one current_key.
*/
- if (tcp_ao_required(sk, saddr, family))
+ if (tcp_ao_required(sk, saddr, family, true))
return SKB_DROP_REASON_TCP_AONOTFOUND;
if (unlikely(tcp_md5_do_lookup(sk, l3index, saddr, family))) {
NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMD5NOTFOUND);
diff --git a/include/net/tcp_ao.h b/include/net/tcp_ao.h
index 6e62235c7cae..b34b9a37c81b 100644
--- a/include/net/tcp_ao.h
+++ b/include/net/tcp_ao.h
@@ -19,6 +19,13 @@ struct tcp_ao_hdr {
u8 rnext_keyid;
};

+struct tcp_ao_counters {
+ atomic64_t pkt_good;
+ atomic64_t pkt_bad;
+ atomic64_t key_not_found;
+ atomic64_t ao_required;
+};
+
struct tcp_ao_key {
struct hlist_node node;
union tcp_ao_addr addr;
@@ -33,6 +40,8 @@ struct tcp_ao_key {
u8 rcvid;
u8 maclen;
struct rcu_head rcu;
+ atomic64_t pkt_good;
+ atomic64_t pkt_bad;
u8 traffic_keys[];
};

@@ -81,6 +90,7 @@ struct tcp_ao_info {
*/
struct tcp_ao_key *current_key;
struct tcp_ao_key *rnext_key;
+ struct tcp_ao_counters counters;
u32 ao_required :1,
__unused :31;
__be32 lisn;
diff --git a/include/uapi/linux/snmp.h b/include/uapi/linux/snmp.h
index 26f33a4c253d..06ddf4cd295c 100644
--- a/include/uapi/linux/snmp.h
+++ b/include/uapi/linux/snmp.h
@@ -296,6 +296,10 @@ enum
LINUX_MIB_TCPMIGRATEREQSUCCESS, /* TCPMigrateReqSuccess */
LINUX_MIB_TCPMIGRATEREQFAILURE, /* TCPMigrateReqFailure */
LINUX_MIB_TCPPLBREHASH, /* TCPPLBRehash */
+ LINUX_MIB_TCPAOREQUIRED, /* TCPAORequired */
+ LINUX_MIB_TCPAOBAD, /* TCPAOBad */
+ LINUX_MIB_TCPAOKEYNOTFOUND, /* TCPAOKeyNotFound */
+ LINUX_MIB_TCPAOGOOD, /* TCPAOGood */
__LINUX_MIB_MAX
};

diff --git a/include/uapi/linux/tcp.h b/include/uapi/linux/tcp.h
index 8285300f95c9..62543f7c5523 100644
--- a/include/uapi/linux/tcp.h
+++ b/include/uapi/linux/tcp.h
@@ -403,9 +403,15 @@ struct tcp_ao_info_opt { /* setsockopt(TCP_AO_INFO) */
__u32 set_current :1, /* corresponding ::current_key */
set_rnext :1, /* corresponding ::rnext */
ao_required :1, /* don't accept non-AO connects */
- reserved :29; /* must be 0 */
+ set_counters :1, /* set/clear ::pkt_* counters */
+ reserved :28; /* must be 0 */
+ __u16 reserved2; /* padding, must be 0 */
__u8 current_key; /* KeyID to set as Current_key */
__u8 rnext; /* KeyID to set as Rnext_key */
+ __u64 pkt_good; /* verified segments */
+ __u64 pkt_bad; /* failed verification */
+ __u64 pkt_key_not_found; /* could not find a key to verify */
+ __u64 pkt_ao_required; /* segments missing TCP-AO sign */
} __attribute__((aligned(8)));

/* setsockopt(fd, IPPROTO_TCP, TCP_ZEROCOPY_RECEIVE, ...) */
diff --git a/net/ipv4/proc.c b/net/ipv4/proc.c
index eaf1d3113b62..3f643cd29cfe 100644
--- a/net/ipv4/proc.c
+++ b/net/ipv4/proc.c
@@ -298,6 +298,10 @@ static const struct snmp_mib snmp4_net_list[] = {
SNMP_MIB_ITEM("TCPMigrateReqSuccess", LINUX_MIB_TCPMIGRATEREQSUCCESS),
SNMP_MIB_ITEM("TCPMigrateReqFailure", LINUX_MIB_TCPMIGRATEREQFAILURE),
SNMP_MIB_ITEM("TCPPLBRehash", LINUX_MIB_TCPPLBREHASH),
+ SNMP_MIB_ITEM("TCPAORequired", LINUX_MIB_TCPAOREQUIRED),
+ SNMP_MIB_ITEM("TCPAOBad", LINUX_MIB_TCPAOBAD),
+ SNMP_MIB_ITEM("TCPAOKeyNotFound", LINUX_MIB_TCPAOKEYNOTFOUND),
+ SNMP_MIB_ITEM("TCPAOGood", LINUX_MIB_TCPAOGOOD),
SNMP_MIB_SENTINEL
};

diff --git a/net/ipv4/tcp_ao.c b/net/ipv4/tcp_ao.c
index 4813b9283c55..f7ee2aecf8fc 100644
--- a/net/ipv4/tcp_ao.c
+++ b/net/ipv4/tcp_ao.c
@@ -182,6 +182,8 @@ static struct tcp_ao_key *tcp_ao_copy_key(struct sock *sk,
*new_key = *key;
INIT_HLIST_NODE(&new_key->node);
tcp_sigpool_get(new_key->tcp_sigpool_id);
+ atomic64_set(&new_key->pkt_good, 0);
+ atomic64_set(&new_key->pkt_bad, 0);

return new_key;
}
@@ -771,8 +773,12 @@ tcp_ao_verify_hash(const struct sock *sk, const struct sk_buff *skb,
const struct tcphdr *th = tcp_hdr(skb);
void *hash_buf = NULL;

- if (maclen != tcp_ao_maclen(key))
+ if (maclen != tcp_ao_maclen(key)) {
+ NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPAOBAD);
+ atomic64_inc(&info->counters.pkt_bad);
+ atomic64_inc(&key->pkt_bad);
return SKB_DROP_REASON_TCP_AOFAILURE;
+ }

hash_buf = kmalloc(tcp_ao_digest_size(key), GFP_ATOMIC);
if (!hash_buf)
@@ -782,9 +788,15 @@ tcp_ao_verify_hash(const struct sock *sk, const struct sk_buff *skb,
tcp_ao_hash_skb(family, hash_buf, key, sk, skb, traffic_key,
(phash - (u8 *)th), sne);
if (memcmp(phash, hash_buf, maclen)) {
+ NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPAOBAD);
+ atomic64_inc(&info->counters.pkt_bad);
+ atomic64_inc(&key->pkt_bad);
kfree(hash_buf);
return SKB_DROP_REASON_TCP_AOFAILURE;
}
+ NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPAOGOOD);
+ atomic64_inc(&info->counters.pkt_good);
+ atomic64_inc(&key->pkt_good);
kfree(hash_buf);
return SKB_NOT_DROPPED_YET;
}
@@ -804,8 +816,10 @@ tcp_inbound_ao_hash(struct sock *sk, const struct sk_buff *skb,
u32 sne = 0;

info = rcu_dereference(tcp_sk(sk)->ao_info);
- if (!info)
+ if (!info) {
+ NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPAOKEYNOTFOUND);
return SKB_DROP_REASON_TCP_AOUNEXPECTED;
+ }

if (unlikely(th->syn)) {
sisn = th->seq;
@@ -900,6 +914,8 @@ tcp_inbound_ao_hash(struct sock *sk, const struct sk_buff *skb,
return ret;

key_not_found:
+ NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPAOKEYNOTFOUND);
+ atomic64_inc(&info->counters.key_not_found);
return SKB_DROP_REASON_TCP_AOKEYNOTFOUND;
}

@@ -1480,6 +1496,8 @@ static int tcp_ao_add_cmd(struct sock *sk, unsigned short int family,
key->keyflags = cmd.keyflags;
key->sndid = cmd.sndid;
key->rcvid = cmd.rcvid;
+ atomic64_set(&key->pkt_good, 0);
+ atomic64_set(&key->pkt_bad, 0);

ret = tcp_ao_parse_crypto(&cmd, key);
if (ret < 0)
@@ -1696,7 +1714,7 @@ static int tcp_ao_info_cmd(struct sock *sk, unsigned short int family,
return -EINVAL;
}

- if (cmd.reserved != 0)
+ if (cmd.reserved != 0 || cmd.reserved2 != 0)
return -EINVAL;

ao_info = setsockopt_ao_info(sk);
@@ -1731,6 +1749,12 @@ static int tcp_ao_info_cmd(struct sock *sk, unsigned short int family,
goto out;
}
}
+ if (cmd.set_counters) {
+ atomic64_set(&ao_info->counters.pkt_good, cmd.pkt_good);
+ atomic64_set(&ao_info->counters.pkt_bad, cmd.pkt_bad);
+ atomic64_set(&ao_info->counters.key_not_found, cmd.pkt_key_not_found);
+ atomic64_set(&ao_info->counters.ao_required, cmd.pkt_ao_required);
+ }

ao_info->ao_required = cmd.ao_required;
if (new_current)
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 1b1ad6da5929..1e714b26d9ce 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -1530,7 +1530,7 @@ static int tcp_v4_parse_md5_keys(struct sock *sk, int optname,
/* Don't allow keys for peers that have a matching TCP-AO key.
* See the comment in tcp_ao_add_cmd()
*/
- if (tcp_ao_required(sk, addr, AF_INET))
+ if (tcp_ao_required(sk, addr, AF_INET, false))
return -EKEYREJECTED;

return tcp_md5_do_add(sk, addr, AF_INET, prefixlen, l3index, flags,
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index aefe0825532e..d022659f40e8 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -660,7 +660,7 @@ static int tcp_v6_parse_md5_keys(struct sock *sk, int optname,
/* Don't allow keys for peers that have a matching TCP-AO key.
* See the comment in tcp_ao_add_cmd()
*/
- if (tcp_ao_required(sk, addr, AF_INET))
+ if (tcp_ao_required(sk, addr, AF_INET, false))
return -EKEYREJECTED;
return tcp_md5_do_add(sk, addr,
AF_INET, prefixlen, l3index, flags,
@@ -672,7 +672,7 @@ static int tcp_v6_parse_md5_keys(struct sock *sk, int optname,
/* Don't allow keys for peers that have a matching TCP-AO key.
* See the comment in tcp_ao_add_cmd()
*/
- if (tcp_ao_required(sk, addr, AF_INET6))
+ if (tcp_ao_required(sk, addr, AF_INET6, false))
return -EKEYREJECTED;

return tcp_md5_do_add(sk, addr, AF_INET6, prefixlen, l3index, flags,
--
2.42.0

Next message: Dmitry Safonov: "[PATCH v14 net-next 12/23] net/tcp: Verify inbound TCP-AO signed segments"
Previous message: Dmitry Safonov: "[PATCH v14 net-next 11/23] net/tcp: Sign SYN-ACK segments with TCP-AO"
In reply to: Dmitry Safonov: "[PATCH v14 net-next 11/23] net/tcp: Sign SYN-ACK segments with TCP-AO"
Next in thread: Dmitry Safonov: "[PATCH v14 net-next 12/23] net/tcp: Verify inbound TCP-AO signed segments"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]