From efdc4817bb6f3a3dd58afa7cab8773482d4a8798 Mon Sep 17 00:00:00 2001
From: Bananymous <oskari.alaranta@bananymous.com>
Date: Sun, 25 Feb 2024 21:32:37 +0200
Subject: [PATCH] Kernel: Print to debug log ICMP unreachable messages

These messages should be forwarded to underlying sockets
---
 kernel/include/kernel/Networking/ICMP.h | 1 +
 kernel/kernel/Networking/IPv4Layer.cpp  | 7 +++++++
 2 files changed, 8 insertions(+)

diff --git a/kernel/include/kernel/Networking/ICMP.h b/kernel/include/kernel/Networking/ICMP.h
index 689bde47..ba766c52 100644
--- a/kernel/include/kernel/Networking/ICMP.h
+++ b/kernel/include/kernel/Networking/ICMP.h
@@ -18,6 +18,7 @@ namespace Kernel
 	enum ICMPType : uint8_t
 	{
 		EchoReply = 0x00,
+		DestinationUnreachable = 0x03,
 		EchoRequest = 0x08,
 	};
 
diff --git a/kernel/kernel/Networking/IPv4Layer.cpp b/kernel/kernel/Networking/IPv4Layer.cpp
index 42fca57a..00f2f217 100644
--- a/kernel/kernel/Networking/IPv4Layer.cpp
+++ b/kernel/kernel/Networking/IPv4Layer.cpp
@@ -212,6 +212,13 @@ namespace Kernel
 						TRY(interface.send_bytes(dst_mac, EtherType::IPv4, packet));
 						break;
 					}
+					case ICMPType::DestinationUnreachable:
+					{
+						auto& ipv4_header = ipv4_data.slice(sizeof(ICMPHeader)).as<const IPv4Header>();
+						dprintln("Destination '{}' unreachable, code {2H}", ipv4_header.dst_address, icmp_header.code);
+						// FIXME: inform the socket
+						break;
+					}
 					default:
 						dprintln("Unhandleded ICMP packet (type {2H})", icmp_header.type);
 						break;