[PATCH net-next 04/10] net/tcp: Add tcp-md5 and tcp-ao tracepoints
From: Dmitry Safonov <hidden>
Date: 2024-02-24 09:04:50
Also in:
linux-kselftest, linux-trace-kernel, lkml
Subsystem:
networking [general], networking [tcp], the rest, tracing · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Neal Cardwell, Linus Torvalds, Steven Rostedt, Masami Hiramatsu
Instead of forcing userspace to parse dmesg (that's what currently is happening, at least in codebase of my current company), provide a better way, that can be enabled/disabled in runtime. Currently, there are already tcp events, add hashing related ones there, too. Rasdaemon currently exercises net_dev_xmit_timeout, devlink_health_report, but it'll be trivial to teach it to deal with failed hashes. Otherwise, BGP may trace/log them itself. Especially exciting for possible investigations is key rotation (RNext_key requests). Suggested-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Dmitry Safonov <redacted> --- include/trace/events/tcp.h | 317 +++++++++++++++++++++++++++++++++++++++++++++ net/ipv4/tcp.c | 7 + net/ipv4/tcp_ao.c | 13 ++ net/ipv4/tcp_input.c | 8 +- net/ipv4/tcp_output.c | 2 + 5 files changed, 345 insertions(+), 2 deletions(-)
diff --git a/include/trace/events/tcp.h b/include/trace/events/tcp.h
index 7b1ddffa3dfc..5065000aad93 100644
--- a/include/trace/events/tcp.h
+++ b/include/trace/events/tcp.h@@ -419,6 +419,323 @@ TRACE_EVENT(tcp_cong_state_set, __entry->cong_state) ); +DECLARE_EVENT_CLASS(tcp_hash_event, + + TP_PROTO(const struct sock *sk, const struct sk_buff *skb), + + TP_ARGS(sk, skb), + + TP_STRUCT__entry( + __field(__u64, net_cookie) + __field(const void *, skbaddr) + __field(const void *, skaddr) + __field(int, state) + + /* sockaddr_in6 is always bigger than sockaddr_in */ + __array(__u8, saddr, sizeof(struct sockaddr_in6)) + __array(__u8, daddr, sizeof(struct sockaddr_in6)) + __field(int, l3index) + + __field(__u16, sport) + __field(__u16, dport) + __field(__u16, family) + + __field(bool, fin) + __field(bool, syn) + __field(bool, rst) + __field(bool, psh) + __field(bool, ack) + ), + + TP_fast_assign( + const struct tcphdr *th = (const struct tcphdr *)skb->data; + + __entry->net_cookie = sock_net(sk)->net_cookie; + __entry->skbaddr = skb; + __entry->skaddr = sk; + __entry->state = sk->sk_state; + + memset(__entry->saddr, 0, sizeof(struct sockaddr_in6)); + memset(__entry->daddr, 0, sizeof(struct sockaddr_in6)); + TP_STORE_ADDR_PORTS_SKB(__entry, skb); + __entry->l3index = inet_sdif(skb) ? inet_iif(skb) : 0; + + /* For filtering use */ + __entry->sport = ntohs(th->source); + __entry->dport = ntohs(th->dest); + __entry->family = sk->sk_family; + + __entry->fin = th->fin; + __entry->syn = th->syn; + __entry->rst = th->rst; + __entry->psh = th->psh; + __entry->ack = th->ack; + ), + + TP_printk("net=%llu state=%s family=%s src=%pISpc dest=%pISpc L3index=%d [%c%c%c%c%c]", + __entry->net_cookie, + show_tcp_state_name(__entry->state), + show_family_name(__entry->family), + __entry->saddr, __entry->daddr, + __entry->l3index, + __entry->fin ? 'F' : ' ', + __entry->syn ? 'S' : ' ', + __entry->rst ? 'R' : ' ', + __entry->psh ? 'P' : ' ', + __entry->ack ? '.' : ' ') +); + +DEFINE_EVENT(tcp_hash_event, tcp_hash_bad_header, + + TP_PROTO(const struct sock *sk, const struct sk_buff *skb), + TP_ARGS(sk, skb) +); + +DEFINE_EVENT(tcp_hash_event, tcp_hash_md5_required, + + TP_PROTO(const struct sock *sk, const struct sk_buff *skb), + TP_ARGS(sk, skb) +); + +DEFINE_EVENT(tcp_hash_event, tcp_hash_md5_unexpected, + + TP_PROTO(const struct sock *sk, const struct sk_buff *skb), + TP_ARGS(sk, skb) +); + +DEFINE_EVENT(tcp_hash_event, tcp_hash_md5_mismatch, + + TP_PROTO(const struct sock *sk, const struct sk_buff *skb), + TP_ARGS(sk, skb) +); + +DEFINE_EVENT(tcp_hash_event, tcp_hash_ao_required, + + TP_PROTO(const struct sock *sk, const struct sk_buff *skb), + TP_ARGS(sk, skb) +); + +DECLARE_EVENT_CLASS(tcp_ao_event, + + TP_PROTO(const struct sock *sk, const struct sk_buff *skb, + const __u8 keyid, const __u8 rnext, const __u8 maclen), + + TP_ARGS(sk, skb, keyid, rnext, maclen), + + TP_STRUCT__entry( + __field(__u64, net_cookie) + __field(const void *, skbaddr) + __field(const void *, skaddr) + __field(int, state) + + /* sockaddr_in6 is always bigger than sockaddr_in */ + __array(__u8, saddr, sizeof(struct sockaddr_in6)) + __array(__u8, daddr, sizeof(struct sockaddr_in6)) + __field(int, l3index) + + __field(__u16, sport) + __field(__u16, dport) + __field(__u16, family) + + __field(bool, fin) + __field(bool, syn) + __field(bool, rst) + __field(bool, psh) + __field(bool, ack) + + __field(__u8, keyid) + __field(__u8, rnext) + __field(__u8, maclen) + ), + + TP_fast_assign( + const struct tcphdr *th = (const struct tcphdr *)skb->data; + + __entry->net_cookie = sock_net(sk)->net_cookie; + __entry->skbaddr = skb; + __entry->skaddr = sk; + __entry->state = sk->sk_state; + + memset(__entry->saddr, 0, sizeof(struct sockaddr_in6)); + memset(__entry->daddr, 0, sizeof(struct sockaddr_in6)); + TP_STORE_ADDR_PORTS_SKB(__entry, skb); + __entry->l3index = inet_sdif(skb) ? inet_iif(skb) : 0; + + /* For filtering use */ + __entry->sport = ntohs(th->source); + __entry->dport = ntohs(th->dest); + __entry->family = sk->sk_family; + + __entry->fin = th->fin; + __entry->syn = th->syn; + __entry->rst = th->rst; + __entry->psh = th->psh; + __entry->ack = th->ack; + + __entry->keyid = keyid; + __entry->rnext = rnext; + __entry->maclen = maclen; + ), + + TP_printk("net=%llu state=%s family=%s src=%pISpc dest=%pISpc L3index=%d [%c%c%c%c%c] keyid=%u rnext=%u maclen=%u", + __entry->net_cookie, + show_tcp_state_name(__entry->state), + show_family_name(__entry->family), + __entry->saddr, __entry->daddr, + __entry->l3index, + __entry->fin ? 'F' : ' ', + __entry->syn ? 'S' : ' ', + __entry->rst ? 'R' : ' ', + __entry->psh ? 'P' : ' ', + __entry->ack ? '.' : ' ', + __entry->keyid, __entry->rnext, __entry->maclen) +); + +DEFINE_EVENT(tcp_ao_event, tcp_ao_handshake_failure, + TP_PROTO(const struct sock *sk, const struct sk_buff *skb, + const __u8 keyid, const __u8 rnext, const __u8 maclen), + TP_ARGS(sk, skb, keyid, rnext, maclen) +); + +DEFINE_EVENT(tcp_ao_event, tcp_ao_wrong_maclen, + TP_PROTO(const struct sock *sk, const struct sk_buff *skb, + const __u8 keyid, const __u8 rnext, const __u8 maclen), + TP_ARGS(sk, skb, keyid, rnext, maclen) +); + +DEFINE_EVENT(tcp_ao_event, tcp_ao_mismatch, + TP_PROTO(const struct sock *sk, const struct sk_buff *skb, + const __u8 keyid, const __u8 rnext, const __u8 maclen), + TP_ARGS(sk, skb, keyid, rnext, maclen) +); + +DEFINE_EVENT(tcp_ao_event, tcp_ao_key_not_found, + TP_PROTO(const struct sock *sk, const struct sk_buff *skb, + const __u8 keyid, const __u8 rnext, const __u8 maclen), + TP_ARGS(sk, skb, keyid, rnext, maclen) +); + +DEFINE_EVENT(tcp_ao_event, tcp_ao_rnext_request, + TP_PROTO(const struct sock *sk, const struct sk_buff *skb, + const __u8 keyid, const __u8 rnext, const __u8 maclen), + TP_ARGS(sk, skb, keyid, rnext, maclen) +); + +DECLARE_EVENT_CLASS(tcp_ao_event_sk, + + TP_PROTO(const struct sock *sk, const __u8 keyid, const __u8 rnext), + + TP_ARGS(sk, keyid, rnext), + + TP_STRUCT__entry( + __field(__u64, net_cookie) + __field(const void *, skaddr) + __field(int, state) + + /* sockaddr_in6 is always bigger than sockaddr_in */ + __array(__u8, saddr, sizeof(struct sockaddr_in6)) + __array(__u8, daddr, sizeof(struct sockaddr_in6)) + + __field(__u16, sport) + __field(__u16, dport) + __field(__u16, family) + + __field(__u8, keyid) + __field(__u8, rnext) + ), + + TP_fast_assign( + const struct inet_sock *inet = inet_sk(sk); + + __entry->net_cookie = sock_net(sk)->net_cookie; + __entry->skaddr = sk; + __entry->state = sk->sk_state; + + memset(__entry->saddr, 0, sizeof(struct sockaddr_in6)); + memset(__entry->daddr, 0, sizeof(struct sockaddr_in6)); + TP_STORE_ADDR_PORTS(__entry, inet, sk); + + /* For filtering use */ + __entry->sport = ntohs(inet->inet_sport); + __entry->dport = ntohs(inet->inet_dport); + __entry->family = sk->sk_family; + + __entry->keyid = keyid; + __entry->rnext = rnext; + ), + + TP_printk("net=%llu state=%s family=%s src=%pISpc dest=%pISpc keyid=%u rnext=%u", + __entry->net_cookie, + show_tcp_state_name(__entry->state), + show_family_name(__entry->family), + __entry->saddr, __entry->daddr, + __entry->keyid, __entry->rnext) +); + +DEFINE_EVENT(tcp_ao_event_sk, tcp_ao_synack_no_key, + TP_PROTO(const struct sock *sk, const __u8 keyid, const __u8 rnext), + TP_ARGS(sk, keyid, rnext) +); + +DECLARE_EVENT_CLASS(tcp_ao_event_sne, + + TP_PROTO(const struct sock *sk, __u32 new_sne), + + TP_ARGS(sk, new_sne), + + TP_STRUCT__entry( + __field(__u64, net_cookie) + __field(const void *, skaddr) + __field(int, state) + + /* sockaddr_in6 is always bigger than sockaddr_in */ + __array(__u8, saddr, sizeof(struct sockaddr_in6)) + __array(__u8, daddr, sizeof(struct sockaddr_in6)) + + __field(__u16, sport) + __field(__u16, dport) + __field(__u16, family) + + __field(__u32, new_sne) + ), + + TP_fast_assign( + const struct inet_sock *inet = inet_sk(sk); + + __entry->net_cookie = sock_net(sk)->net_cookie; + __entry->skaddr = sk; + __entry->state = sk->sk_state; + + memset(__entry->saddr, 0, sizeof(struct sockaddr_in6)); + memset(__entry->daddr, 0, sizeof(struct sockaddr_in6)); + TP_STORE_ADDR_PORTS(__entry, inet, sk); + + /* For filtering use */ + __entry->sport = ntohs(inet->inet_sport); + __entry->dport = ntohs(inet->inet_dport); + __entry->family = sk->sk_family; + + __entry->new_sne = new_sne; + ), + + TP_printk("net=%llu state=%s family=%s src=%pISpc dest=%pISpc sne=%u", + __entry->net_cookie, + show_tcp_state_name(__entry->state), + show_family_name(__entry->family), + __entry->saddr, __entry->daddr, + __entry->new_sne) +); + +DEFINE_EVENT(tcp_ao_event_sne, tcp_ao_snd_sne_update, + TP_PROTO(const struct sock *sk, __u32 new_sne), + TP_ARGS(sk, new_sne) +); + +DEFINE_EVENT(tcp_ao_event_sne, tcp_ao_rcv_sne_update, + TP_PROTO(const struct sock *sk, __u32 new_sne), + TP_ARGS(sk, new_sne) +); + #endif /* _TRACE_TCP_H */ /* This part must be outside protection */
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 5fd61ae6bcc9..81f22d6afe4a 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c@@ -279,6 +279,7 @@ #include <linux/uaccess.h> #include <asm/ioctls.h> #include <net/busy_poll.h> +#include <trace/events/tcp.h> /* Track pending CMSGs. */ enum {
@@ -4448,6 +4449,7 @@ tcp_inbound_md5_hash(const struct sock *sk, const struct sk_buff *skb, if (!key && hash_location) { NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMD5UNEXPECTED); tcp_hash_fail("Unexpected MD5 Hash found", family, skb, ""); + trace_tcp_hash_md5_unexpected(sk, skb); return SKB_DROP_REASON_TCP_MD5UNEXPECTED; }
@@ -4477,6 +4479,7 @@ tcp_inbound_md5_hash(const struct sock *sk, const struct sk_buff *skb, l3index); } } + trace_tcp_hash_md5_mismatch(sk, skb); return SKB_DROP_REASON_TCP_MD5FAILURE; } return SKB_NOT_DROPPED_YET;
@@ -4501,6 +4504,7 @@ tcp_inbound_hash(struct sock *sk, const struct request_sock *req, if (tcp_parse_auth_options(th, &md5_location, &aoh)) { tcp_hash_fail("TCP segment has incorrect auth options set", family, skb, ""); + trace_tcp_hash_bad_header(sk, skb); return SKB_DROP_REASON_TCP_AUTH_HDR; }
@@ -4520,6 +4524,7 @@ tcp_inbound_hash(struct sock *sk, const struct request_sock *req, tcp_hash_fail("TCP connection can't start/end using TCP-AO", family, skb, "%s", !aoh ? "missing AO" : "AO signed"); + trace_tcp_ao_handshake_failure(sk, skb, keyid, rnext, maclen); return SKB_DROP_REASON_TCP_AOFAILURE; } }
@@ -4539,12 +4544,14 @@ tcp_inbound_hash(struct sock *sk, const struct request_sock *req, if (tcp_ao_required(sk, saddr, family, l3index, true)) { tcp_hash_fail("AO hash is required, but not found", family, skb, "L3 index %d", l3index); + trace_tcp_hash_ao_required(sk, skb); 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); tcp_hash_fail("MD5 Hash not found", family, skb, "L3 index %d", l3index); + trace_tcp_hash_md5_required(sk, skb); return SKB_DROP_REASON_TCP_MD5NOTFOUND; } return SKB_NOT_DROPPED_YET;
diff --git a/net/ipv4/tcp_ao.c b/net/ipv4/tcp_ao.c
index 8726aa58e8b6..416cdeaccd07 100644
--- a/net/ipv4/tcp_ao.c
+++ b/net/ipv4/tcp_ao.c@@ -16,6 +16,7 @@ #include <net/tcp.h> #include <net/ipv6.h> #include <net/icmp.h> +#include <trace/events/tcp.h> DEFINE_STATIC_KEY_DEFERRED_FALSE(tcp_ao_needed, HZ);
@@ -895,6 +896,8 @@ tcp_ao_verify_hash(const struct sock *sk, const struct sk_buff *skb, tcp_hash_fail("AO hash wrong length", family, skb, "%u != %d L3index: %d", maclen, tcp_ao_maclen(key), l3index); + trace_tcp_ao_wrong_maclen(sk, skb, aoh->keyid, + aoh->rnext_keyid, maclen); return SKB_DROP_REASON_TCP_AOFAILURE; }
@@ -911,6 +914,8 @@ tcp_ao_verify_hash(const struct sock *sk, const struct sk_buff *skb, atomic64_inc(&key->pkt_bad); tcp_hash_fail("AO hash mismatch", family, skb, "L3index: %d", l3index); + trace_tcp_ao_mismatch(sk, skb, aoh->keyid, + aoh->rnext_keyid, maclen); kfree(hash_buf); return SKB_DROP_REASON_TCP_AOFAILURE; }
@@ -927,6 +932,7 @@ tcp_inbound_ao_hash(struct sock *sk, const struct sk_buff *skb, int l3index, const struct tcp_ao_hdr *aoh) { const struct tcphdr *th = tcp_hdr(skb); + u8 maclen = tcp_ao_hdr_maclen(aoh); u8 *phash = (u8 *)(aoh + 1); /* hash goes just after the header */ struct tcp_ao_info *info; enum skb_drop_reason ret;
@@ -940,6 +946,8 @@ tcp_inbound_ao_hash(struct sock *sk, const struct sk_buff *skb, NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPAOKEYNOTFOUND); tcp_hash_fail("AO key not found", family, skb, "keyid: %u L3index: %d", aoh->keyid, l3index); + trace_tcp_ao_key_not_found(sk, skb, aoh->keyid, + aoh->rnext_keyid, maclen); return SKB_DROP_REASON_TCP_AOUNEXPECTED; }
@@ -979,6 +987,9 @@ tcp_inbound_ao_hash(struct sock *sk, const struct sk_buff *skb, current_key = READ_ONCE(info->current_key); /* Key rotation: the peer asks us to use new key (RNext) */ if (unlikely(aoh->rnext_keyid != current_key->sndid)) { + trace_tcp_ao_rnext_request(sk, skb, current_key->sndid, + aoh->rnext_keyid, + tcp_ao_hdr_maclen(aoh)); /* If the key is not found we do nothing. */ key = tcp_ao_established_key(info, aoh->rnext_keyid, -1); if (key)
@@ -1043,6 +1054,8 @@ tcp_inbound_ao_hash(struct sock *sk, const struct sk_buff *skb, atomic64_inc(&info->counters.key_not_found); tcp_hash_fail("Requested by the peer AO key id not found", family, skb, "L3index: %d", l3index); + trace_tcp_ao_key_not_found(sk, skb, aoh->keyid, + aoh->rnext_keyid, maclen); return SKB_DROP_REASON_TCP_AOKEYNOTFOUND; }
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 74c03f0a6c0c..11f4da3aa827 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c@@ -3575,8 +3575,10 @@ static void tcp_snd_sne_update(struct tcp_sock *tp, u32 ack) ao = rcu_dereference_protected(tp->ao_info, lockdep_sock_is_held((struct sock *)tp)); - if (ao && ack < tp->snd_una) + if (ao && ack < tp->snd_una) { ao->snd_sne++; + trace_tcp_ao_snd_sne_update((struct sock *)tp, ao->snd_sne); + } #endif }
@@ -3601,8 +3603,10 @@ static void tcp_rcv_sne_update(struct tcp_sock *tp, u32 seq) ao = rcu_dereference_protected(tp->ao_info, lockdep_sock_is_held((struct sock *)tp)); - if (ao && seq < tp->rcv_nxt) + if (ao && seq < tp->rcv_nxt) { ao->rcv_sne++; + trace_tcp_ao_rcv_sne_update((struct sock *)tp, ao->rcv_sne); + } #endif }
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index e3167ad96567..dcdaf3229de9 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c@@ -3727,6 +3727,7 @@ struct sk_buff *tcp_make_synack(const struct sock *sk, struct dst_entry *dst, #ifdef CONFIG_TCP_AO struct tcp_ao_key *ao_key = NULL; u8 keyid = tcp_rsk(req)->ao_keyid; + u8 rnext = tcp_rsk(req)->ao_rcv_next; ao_key = tcp_sk(sk)->af_specific->ao_lookup(sk, req_to_sk(req), keyid, -1);
@@ -3736,6 +3737,7 @@ struct sk_buff *tcp_make_synack(const struct sock *sk, struct dst_entry *dst, * ao_keyid (RFC5925 RNextKeyID), so let's keep it simple here. */ if (unlikely(!ao_key)) { + trace_tcp_ao_synack_no_key(sk, keyid, rnext); rcu_read_unlock(); kfree_skb(skb); net_warn_ratelimited("TCP-AO: the keyid %u from SYN packet is not present - not sending SYNACK\n",
--
2.43.0