From 789a5c8e37baeb7b041447419a869aca42e8aac6 Mon Sep 17 00:00:00 2001
From: Delio Brignoli <dbrignoli@audioscience.com>
Date: Mon, 18 Mar 2013 17:08:22 +0100
Subject: [PATCH] Add support for FT_BAD_PEER_NETWORK

Handle reception of >=3 sequential multiple pdelay responses from
distinct peers as a fault of type FT_BAD_PEER_NETWORK.

Signed-off-by: Delio Brignoli <dbrignoli@audioscience.com>
---
 config.c | 10 ++++++++++
 fault.c  |  1 +
 fault.h  |  1 +
 port.c   | 25 ++++++++++++++++++++++++-
 ptp4l.8  |  7 +++++++
 5 files changed, 43 insertions(+), 1 deletion(-)

diff --git a/config.c b/config.c
index 0b3abb4..afb2e6b 100644
--- a/config.c
+++ b/config.c
@@ -112,6 +112,16 @@ static enum parser_result parse_pod_setting(const char *option,
 			return BAD_VALUE;
 		pod->neighborPropDelayThresh = val;
 
+	} else if (!strcmp(option, "fault_badpeernet_interval")) {
+		pod->flt_interval_pertype[FT_BAD_PEER_NETWORK].type = FTMO_LINEAR_SECONDS;
+		if (!strcasecmp("ASAP", value)) {
+			pod->flt_interval_pertype[FT_BAD_PEER_NETWORK].val = 0;
+		} else if (1 != sscanf(value, "%d", &val)) {
+			pod->flt_interval_pertype[FT_BAD_PEER_NETWORK].val = val;
+		} else {
+			return BAD_VALUE;
+		}
+
 	} else if (!strcmp(option, "fault_reset_interval")) {
 		pod->flt_interval_pertype[FT_UNSPECIFIED].type = FTMO_LOG2_SECONDS;
 		if (!strcasecmp("ASAP", value)) {
diff --git a/fault.c b/fault.c
index 6f48169..7fcf019 100644
--- a/fault.c
+++ b/fault.c
@@ -20,6 +20,7 @@
 
 static const char *fault_type_str[FT_CNT] = {
 	"FT_UNSPECIFIED",
+	"FT_BAD_PEER_NETWORK",
 };
 
 const char *ft_str(enum fault_type ft)
diff --git a/fault.h b/fault.h
index d7ac2b6..8d62c38 100644
--- a/fault.h
+++ b/fault.h
@@ -20,6 +20,7 @@
 
 enum fault_type {
 	FT_UNSPECIFIED = 0,
+	FT_BAD_PEER_NETWORK,
 	FT_CNT,
 };
 
diff --git a/port.c b/port.c
index e47f276..d922047 100644
--- a/port.c
+++ b/port.c
@@ -73,6 +73,8 @@ struct port {
 	int log_sync_interval;
 	struct nrate_estimator nrate;
 	unsigned int pdr_missing;
+	unsigned int multiple_seq_pdr_count;
+	unsigned int multiple_pdr_detected;
 	/* portDS */
 	struct port_defaults pod;
 	struct PortIdentity portIdentity;
@@ -430,6 +432,13 @@ static int port_capable(struct port *p)
 		goto not_capable;
 	}
 
+	if (p->multiple_seq_pdr_count) {
+		if (p->asCapable)
+			pr_debug("port %hu: multiple sequential peer delay resp, "
+				"resetting asCapable", portnum(p));
+		goto not_capable;
+	}
+
 	if (!p->peer_portid_valid) {
 		if (p->asCapable)
 			pr_debug("port %hu: invalid peer port id, "
@@ -838,6 +847,11 @@ static int port_pdelay_request(struct port *p)
 	struct ptp_message *msg;
 	int cnt, pdulen;
 
+	/* If multiple pdelay resp were not detected the counter can be reset */
+	if (!p->multiple_pdr_detected)
+		p->multiple_seq_pdr_count = 0;
+	p->multiple_pdr_detected = 0;
+
 	msg = msg_allocate();
 	if (!msg)
 		return -1;
@@ -1144,6 +1158,8 @@ static int port_initialize(struct port *p)
 {
 	int fd[N_TIMER_FDS], i;
 
+	p->multiple_seq_pdr_count  = 0;
+	p->multiple_pdr_detected   = 0;
 	p->last_fault_type         = FT_UNSPECIFIED;
 	p->logMinDelayReqInterval  = p->pod.logMinDelayReqInterval;
 	p->peerMeanPathDelay       = 0;
@@ -1583,7 +1599,14 @@ static int process_pdelay_resp(struct port *p, struct ptp_message *m)
 	if (p->peer_delay_resp) {
 		if (!source_pid_eq(p->peer_delay_resp, m)) {
 			pr_err("port %hu: multiple peer responses", portnum(p));
-			return -1;
+			if (!p->multiple_pdr_detected) {
+				p->multiple_pdr_detected = 1;
+				p->multiple_seq_pdr_count++;
+			}
+			if (p->multiple_seq_pdr_count >= 3) {
+				p->last_fault_type = FT_BAD_PEER_NETWORK;
+				return -1;
+			}
 		}
 	}
 	if (!p->peer_delay_req) {
diff --git a/ptp4l.8 b/ptp4l.8
index be0d3a6..98a7674 100644
--- a/ptp4l.8
+++ b/ptp4l.8
@@ -188,6 +188,13 @@ value to -128 or to the special key word "ASAP" will let the fault be
 reset immediately.
 The default is 4 (16 seconds).
 .TP
+.B fault_badpeernet_interval
+The time in seconds between the detection of a peer network misconfiguration
+and the fault being reset. The port is disabled for the duration of the
+interval. The value is in seconds and the special key word ASAP will let
+the fault be reset immediately.
+The default is 16 seconds.
+.TP
 .B delay_mechanism
 Select the delay mechanism. Possible values are E2E, P2P and Auto.
 The default is E2E.