From d08fdb8ddc7c88dec82da282f713e6a45e70f0d3 Mon Sep 17 00:00:00 2001
From: seladb <pcapplusplus@gmail.com>
Date: Tue, 5 Dec 2023 00:06:04 -0800
Subject: [PATCH] Check `pcap_dispatch` return value (#1252)

---
 Pcap++/src/PcapLiveDevice.cpp | 37 +++++++++++++++++++++++++++++++----
 1 file changed, 33 insertions(+), 4 deletions(-)

diff --git a/Pcap++/src/PcapLiveDevice.cpp b/Pcap++/src/PcapLiveDevice.cpp
index 2ee315112a..c799dc9aea 100644
--- a/Pcap++/src/PcapLiveDevice.cpp
+++ b/Pcap++/src/PcapLiveDevice.cpp
@@ -176,12 +176,24 @@ void PcapLiveDevice::captureThreadMain()
 	if (m_CaptureCallbackMode)
 	{
 		while (!m_StopThread)
-			pcap_dispatch(m_PcapDescriptor, -1, onPacketArrives, (uint8_t*)this);
+		{
+			if (pcap_dispatch(m_PcapDescriptor, -1, onPacketArrives, reinterpret_cast<uint8_t*>(this)) == -1)
+			{
+				PCPP_LOG_ERROR("pcap_dispatch returned an error: " << pcap_geterr(m_PcapDescriptor));
+				m_StopThread = true;
+			}
+		}
 	}
 	else
 	{
 		while (!m_StopThread)
-			pcap_dispatch(m_PcapDescriptor, 100, onPacketArrivesNoCallback, (uint8_t*)this);
+		{
+			if (pcap_dispatch(m_PcapDescriptor, 100, onPacketArrivesNoCallback, reinterpret_cast<uint8_t*>(this)) == -1)
+			{
+				PCPP_LOG_ERROR("pcap_dispatch returned an error: " << pcap_geterr(m_PcapDescriptor));
+				m_StopThread = true;
+			}
+		}
 	}
 	PCPP_LOG_DEBUG("Ended capture thread for device '" << m_Name << "'");
 }
@@ -496,11 +508,18 @@ int PcapLiveDevice::startCaptureBlockingMode(OnPacketArrivesStopBlocking onPacke
 	m_CaptureThreadStarted = true;
 	m_StopThread = false;
 
+	bool pcapDispatchError = false;
+
 	if (timeout <= 0)
 	{
 		while (!m_StopThread)
 		{
-			pcap_dispatch(m_PcapDescriptor, -1, onPacketArrivesBlockingMode, (uint8_t*)this);
+			if (pcap_dispatch(m_PcapDescriptor, -1, onPacketArrivesBlockingMode, reinterpret_cast<uint8_t*>(this)) == -1)
+			{
+				PCPP_LOG_ERROR("pcap_dispatch returned an error: " << pcap_geterr(m_PcapDescriptor));
+				pcapDispatchError = true;
+				m_StopThread = true;
+			}
 		}
 		curTimeSec = startTimeSec + timeout;
 	}
@@ -509,7 +528,12 @@ int PcapLiveDevice::startCaptureBlockingMode(OnPacketArrivesStopBlocking onPacke
 		while (!m_StopThread && curTimeSec <= (startTimeSec + timeout))
 		{
 			long curTimeNSec = 0;
-			pcap_dispatch(m_PcapDescriptor, -1, onPacketArrivesBlockingMode, (uint8_t*)this);
+			if (pcap_dispatch(m_PcapDescriptor, -1, onPacketArrivesBlockingMode, reinterpret_cast<uint8_t*>(this)) == -1)
+			{
+				PCPP_LOG_ERROR("pcap_dispatch returned an error: " << pcap_geterr(m_PcapDescriptor));
+				pcapDispatchError = true;
+				m_StopThread = true;
+			}
 			clockGetTime(curTimeSec, curTimeNSec);
 		}
 	}
@@ -521,6 +545,11 @@ int PcapLiveDevice::startCaptureBlockingMode(OnPacketArrivesStopBlocking onPacke
 	m_cbOnPacketArrivesBlockingMode = nullptr;
 	m_cbOnPacketArrivesBlockingModeUserCookie = nullptr;
 
+	if (pcapDispatchError)
+	{
+		return 0;
+	}
+
 	if (curTimeSec > (startTimeSec + timeout))
 		return -1;
 	return 1;