From: Shardul Bankar MPTCP_RST_EMPTCP (reset reason 1) is used as a catch-all for several distinct error conditions across subflow setup, authentication, and data-path validation. The existing MPRstTx/MPRstRx counters only track aggregate reset volume, making it difficult to diagnose which code path is triggering subflow resets in production. Add per-event MIB counters covering each MPTCP_RST_EMPTCP use site that is not already covered by an existing counter, named after the underlying event or condition rather than the reset action: MD5SigReset MD5SIG enabled on listener (incompatible) MPJoinSynAckNoMPJoin SYN/ACK missing MP_JOIN option MPJoinAckNoMPJoin server-side ACK missing MP_JOIN option (fallback path, MPJoin required) MPJoinAckNoCtx server-side ACK with no subflow context MPJoinNoIdFound MP_JOIN with a valid token but no PM local ID DssReset data mapping invalid (also fires on MAPPING_NODSS / EMIDDLEBOX path) MPJoinNotEstablished JOIN attempted on a not-fully-established msk MPJoinNoIdFound covers the second half of the no-msk MP_JOIN reset: the existing MPJoinNoTokenFound (MPTCP_MIB_JOINNOTOKEN) only counts the missing-token case in subflow_token_join_request(), while a JOIN that carries a valid token but for which the path manager returns no local id reaches the same MPTCP_RST_EMPTCP in subflow_check_req() uncounted. The aggregate MPRstTx/MPRstRx counters are unchanged. Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/511 Signed-off-by: Shardul Bankar Reviewed-by: Matthieu Baerts (NGI0) Signed-off-by: Matthieu Baerts (NGI0) --- net/mptcp/mib.c | 7 +++++++ net/mptcp/mib.h | 7 +++++++ net/mptcp/protocol.c | 1 + net/mptcp/subflow.c | 10 ++++++++++ 4 files changed, 25 insertions(+) diff --git a/net/mptcp/mib.c b/net/mptcp/mib.c index 2569385bab7c..608cb568897c 100644 --- a/net/mptcp/mib.c +++ b/net/mptcp/mib.c @@ -21,14 +21,19 @@ static const struct snmp_mib mptcp_snmp_list[] = { SNMP_MIB_ITEM("MPFallbackTokenInit", MPTCP_MIB_TOKENFALLBACKINIT), SNMP_MIB_ITEM("MPTCPRetrans", MPTCP_MIB_RETRANSSEGS), SNMP_MIB_ITEM("MPJoinNoTokenFound", MPTCP_MIB_JOINNOTOKEN), + SNMP_MIB_ITEM("MPJoinNoIdFound", MPTCP_MIB_MPJOINNOIDFOUND), SNMP_MIB_ITEM("MPJoinSynRx", MPTCP_MIB_JOINSYNRX), SNMP_MIB_ITEM("MPJoinSynBackupRx", MPTCP_MIB_JOINSYNBACKUPRX), SNMP_MIB_ITEM("MPJoinSynAckRx", MPTCP_MIB_JOINSYNACKRX), SNMP_MIB_ITEM("MPJoinSynAckBackupRx", MPTCP_MIB_JOINSYNACKBACKUPRX), SNMP_MIB_ITEM("MPJoinSynAckHMacFailure", MPTCP_MIB_JOINSYNACKMAC), + SNMP_MIB_ITEM("MPJoinSynAckNoMPJoin", MPTCP_MIB_MPJOINSYNACKNOMPJOIN), SNMP_MIB_ITEM("MPJoinAckRx", MPTCP_MIB_JOINACKRX), SNMP_MIB_ITEM("MPJoinAckHMacFailure", MPTCP_MIB_JOINACKMAC), + SNMP_MIB_ITEM("MPJoinAckNoMPJoin", MPTCP_MIB_MPJOINACKNOMPJOIN), + SNMP_MIB_ITEM("MPJoinAckNoCtx", MPTCP_MIB_MPJOINACKNOCTX), SNMP_MIB_ITEM("MPJoinRejected", MPTCP_MIB_JOINREJECTED), + SNMP_MIB_ITEM("MPJoinNotEstablished", MPTCP_MIB_MPJOINNOTESTABLISHED), SNMP_MIB_ITEM("MPJoinSynTx", MPTCP_MIB_JOINSYNTX), SNMP_MIB_ITEM("MPJoinSynTxCreatSkErr", MPTCP_MIB_JOINSYNTXCREATSKERR), SNMP_MIB_ITEM("MPJoinSynTxBindErr", MPTCP_MIB_JOINSYNTXBINDERR), @@ -81,7 +86,9 @@ static const struct snmp_mib mptcp_snmp_list[] = { SNMP_MIB_ITEM("Blackhole", MPTCP_MIB_BLACKHOLE), SNMP_MIB_ITEM("MPCapableDataFallback", MPTCP_MIB_MPCAPABLEDATAFALLBACK), SNMP_MIB_ITEM("MD5SigFallback", MPTCP_MIB_MD5SIGFALLBACK), + SNMP_MIB_ITEM("MD5SigReset", MPTCP_MIB_MD5SIGRESET), SNMP_MIB_ITEM("DssFallback", MPTCP_MIB_DSSFALLBACK), + SNMP_MIB_ITEM("DssReset", MPTCP_MIB_DSSRESET), SNMP_MIB_ITEM("SimultConnectFallback", MPTCP_MIB_SIMULTCONNFALLBACK), SNMP_MIB_ITEM("FallbackFailed", MPTCP_MIB_FALLBACKFAILED), SNMP_MIB_ITEM("WinProbe", MPTCP_MIB_WINPROBE), diff --git a/net/mptcp/mib.h b/net/mptcp/mib.h index 3a3425e258a7..1ebdb55e9534 100644 --- a/net/mptcp/mib.h +++ b/net/mptcp/mib.h @@ -16,14 +16,19 @@ enum linux_mptcp_mib_field { MPTCP_MIB_TOKENFALLBACKINIT, /* Could not init/allocate token */ MPTCP_MIB_RETRANSSEGS, /* Segments retransmitted at the MPTCP-level */ MPTCP_MIB_JOINNOTOKEN, /* Received MP_JOIN but the token was not found */ + MPTCP_MIB_MPJOINNOIDFOUND, /* Received MP_JOIN but no local ID was found */ MPTCP_MIB_JOINSYNRX, /* Received a SYN + MP_JOIN */ MPTCP_MIB_JOINSYNBACKUPRX, /* Received a SYN + MP_JOIN + backup flag */ MPTCP_MIB_JOINSYNACKRX, /* Received a SYN/ACK + MP_JOIN */ MPTCP_MIB_JOINSYNACKBACKUPRX, /* Received a SYN/ACK + MP_JOIN + backup flag */ MPTCP_MIB_JOINSYNACKMAC, /* HMAC was wrong on SYN/ACK + MP_JOIN */ + MPTCP_MIB_MPJOINSYNACKNOMPJOIN, /* MP_RST: missing MP_JOIN in SYN/ACK */ MPTCP_MIB_JOINACKRX, /* Received an ACK + MP_JOIN */ MPTCP_MIB_JOINACKMAC, /* HMAC was wrong on ACK + MP_JOIN */ + MPTCP_MIB_MPJOINACKNOMPJOIN, /* MP_RST: missing MP_JOIN in ACK */ + MPTCP_MIB_MPJOINACKNOCTX, /* MP_RST: no subflow context on ACK */ MPTCP_MIB_JOINREJECTED, /* The PM rejected the JOIN request */ + MPTCP_MIB_MPJOINNOTESTABLISHED, /* MP_RST: JOIN on not-fully-established msk */ MPTCP_MIB_JOINSYNTX, /* Sending a SYN + MP_JOIN */ MPTCP_MIB_JOINSYNTXCREATSKERR, /* Not able to create a socket when sending a SYN + MP_JOIN */ MPTCP_MIB_JOINSYNTXBINDERR, /* Not able to bind() the address when sending a SYN + MP_JOIN */ @@ -84,7 +89,9 @@ enum linux_mptcp_mib_field { * established packet */ MPTCP_MIB_MD5SIGFALLBACK, /* Conflicting TCP option enabled */ + MPTCP_MIB_MD5SIGRESET, /* MP_RST: MD5SIG enabled on listener */ MPTCP_MIB_DSSFALLBACK, /* Bad or missing DSS */ + MPTCP_MIB_DSSRESET, /* MP_RST: bad data mapping */ MPTCP_MIB_SIMULTCONNFALLBACK, /* Simultaneous connect */ MPTCP_MIB_FALLBACKFAILED, /* Can't fallback due to msk status */ MPTCP_MIB_WINPROBE, /* MPTCP-level zero window probe */ diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index 8f074d757743..b474d03620a7 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -4002,6 +4002,7 @@ bool mptcp_finish_join(struct sock *ssk) /* mptcp socket already closing? */ if (!mptcp_is_fully_established(parent)) { + MPTCP_INC_STATS(sock_net(parent), MPTCP_MIB_MPJOINNOTESTABLISHED); subflow->reset_reason = MPTCP_RST_EMPTCP; return false; } diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c index e1f20ff8fdb4..af81ad5e699d 100644 --- a/net/mptcp/subflow.c +++ b/net/mptcp/subflow.c @@ -96,6 +96,7 @@ static struct mptcp_sock *subflow_token_join_request(struct request_sock *req) local_id = mptcp_pm_get_local_id(msk, (struct sock_common *)req); if (local_id < 0) { + SUBFLOW_REQ_INC_STATS(req, MPTCP_MIB_MPJOINNOIDFOUND); sock_put((struct sock *)msk); return NULL; } @@ -160,6 +161,7 @@ static int subflow_check_req(struct request_sock *req, * TCP option space. */ if (rcu_access_pointer(tcp_sk(sk_listener)->md5sig_info)) { + MPTCP_INC_STATS(sock_net(sk_listener), MPTCP_MIB_MD5SIGRESET); subflow_add_reset_reason(skb, MPTCP_RST_EMPTCP); return -EINVAL; } @@ -563,6 +565,7 @@ static void subflow_finish_connect(struct sock *sk, const struct sk_buff *skb) u8 hmac[SHA256_DIGEST_SIZE]; if (!(mp_opt.suboptions & OPTION_MPTCP_MPJ_SYNACK)) { + MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_MPJOINSYNACKNOMPJOIN); subflow->reset_reason = MPTCP_RST_EMPTCP; goto do_reset; } @@ -865,6 +868,12 @@ static struct sock *subflow_syn_recv_sock(const struct sock *sk, */ if (!ctx || fallback) { if (fallback_is_fatal) { + if (!ctx) + MPTCP_INC_STATS(sock_net(sk), + MPTCP_MIB_MPJOINACKNOCTX); + else + MPTCP_INC_STATS(sock_net(sk), + MPTCP_MIB_MPJOINACKNOMPJOIN); subflow_add_reset_reason(skb, MPTCP_RST_EMPTCP); goto dispose_child; } @@ -1416,6 +1425,7 @@ static bool subflow_check_data_avail(struct sock *ssk) * subflow_error_report() will introduce the appropriate barriers */ subflow->reset_transient = 0; + MPTCP_INC_STATS(sock_net(ssk), MPTCP_MIB_DSSRESET); subflow->reset_reason = status == MAPPING_NODSS ? MPTCP_RST_EMIDDLEBOX : MPTCP_RST_EMPTCP; -- 2.53.0