From: Thomas Markwalder <tmark@isc.org>
Date: Thu, 20 Nov 2025 15:33:50 +0000 (-0500)
Subject: [#4221] Start reader in ping channel open
X-Git-Tag: Kea-3.1.4~33
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=511115da8ff64a5c19d48f77183c229d0da94aa8;p=thirdparty%2Fkea.git

[#4221] Start reader in ping channel open

/src/hooks/dhcp/ping_check/ping_channel.cc
    PingChannel::open()  - add call to startRead() to
    ensure we always handle read ready and avoid
    ICMP socket build up when not actively ping checking
---

diff --git a/changelog_unreleased/4221-ping-check-hook-can-break-dhcp-service-in-one-edge-case b/changelog_unreleased/4221-ping-check-hook-can-break-dhcp-service-in-one-edge-case
new file mode 100644
index 0000000000..d0eb6d0989
--- /dev/null
+++ b/changelog_unreleased/4221-ping-check-hook-can-break-dhcp-service-in-one-edge-case
@@ -0,0 +1,5 @@
+[bug]		tmark
+	Corrected an issue in the ping-check hook library that
+	could result in the ICMP socket stuck in the read ready
+	state.
+	(Gitlab #4221)
diff --git a/src/hooks/dhcp/ping_check/ping_channel.cc b/src/hooks/dhcp/ping_check/ping_channel.cc
index 1e495fc958..e0f08d4504 100644
--- a/src/hooks/dhcp/ping_check/ping_channel.cc
+++ b/src/hooks/dhcp/ping_check/ping_channel.cc
@@ -101,6 +101,9 @@ PingChannel::open() {
         isc_throw(Unexpected, "PingChannel::open failed:" << ex.what());
     }
 
+    // Start reader now so unexpected ICMP traffic won't go unhandled and pile up.
+    startRead();
+
     LOG_DEBUG(ping_check_logger, isc::log::DBGLVL_TRACE_BASIC, PING_CHECK_CHANNEL_SOCKET_OPENED);
 }