From 0866a0cd1e81600776d034334950390b3c07a734 Mon Sep 17 00:00:00 2001
From: brapru <brapru@pm.me>
Date: Fri, 29 Apr 2022 21:49:00 -0400
Subject: [PATCH] Kernel+route: Support global routing table deletion

---
 Kernel/Net/IPv4Socket.cpp    | 12 ++++++++++--
 Kernel/Net/Routing.cpp       | 10 +++++++++-
 Userland/Utilities/route.cpp |  7 ++-----
 3 files changed, 21 insertions(+), 8 deletions(-)

diff --git a/Kernel/Net/IPv4Socket.cpp b/Kernel/Net/IPv4Socket.cpp
index 264c7a34f5..76f851899b 100644
--- a/Kernel/Net/IPv4Socket.cpp
+++ b/Kernel/Net/IPv4Socket.cpp
@@ -639,8 +639,16 @@ ErrorOr<void> IPv4Socket::ioctl(OpenFileDescription&, unsigned request, Userspac
             return update_routing_table(destination, gateway, genmask, adapter, UpdateTable::Set);
         }
         case SIOCDELRT:
-            // FIXME: Support gateway deletion
-            return {};
+            if (!Process::current().is_superuser())
+                return EPERM;
+            if (route.rt_gateway.sa_family != AF_INET)
+                return EAFNOSUPPORT;
+
+            auto destination = IPv4Address(((sockaddr_in&)route.rt_dst).sin_addr.s_addr);
+            auto gateway = IPv4Address(((sockaddr_in&)route.rt_gateway).sin_addr.s_addr);
+            auto genmask = IPv4Address(((sockaddr_in&)route.rt_genmask).sin_addr.s_addr);
+
+            return update_routing_table(destination, gateway, genmask, adapter, UpdateTable::Delete);
         }
 
         return EINVAL;
diff --git a/Kernel/Net/Routing.cpp b/Kernel/Net/Routing.cpp
index feba06a32b..8c2396b3ad 100644
--- a/Kernel/Net/Routing.cpp
+++ b/Kernel/Net/Routing.cpp
@@ -142,7 +142,6 @@ ErrorOr<void> update_routing_table(IPv4Address const& destination, IPv4Address c
         return ENOMEM;
 
     TRY(routing_table().with([&](auto& table) -> ErrorOr<void> {
-        // TODO: Add support for deleting routing entries
         if (update == UpdateTable::Set) {
             for (auto const& route : table) {
                 if (route == *route_entry)
@@ -150,6 +149,15 @@ ErrorOr<void> update_routing_table(IPv4Address const& destination, IPv4Address c
             }
             table.append(*route_entry);
         }
+        if (update == UpdateTable::Delete) {
+            for (auto& route : table) {
+                if (route == *route_entry) {
+                    table.remove(route);
+                    return {};
+                }
+            }
+            return ESRCH;
+        }
         return {};
     }));
 
diff --git a/Userland/Utilities/route.cpp b/Userland/Utilities/route.cpp
index 2b41e0de1f..881268f513 100644
--- a/Userland/Utilities/route.cpp
+++ b/Userland/Utilities/route.cpp
@@ -179,11 +179,8 @@ ErrorOr<int> serenity_main(Main::Arguments arguments)
         if (action_add)
             TRY(Core::System::ioctl(fd, SIOCADDRT, &rt));
 
-        // FIXME: Add support for route deletion.
-        if (action_del) {
-            warnln("Route deletion currently not implemented.");
-            return 1;
-        }
+        if (action_del)
+            TRY(Core::System::ioctl(fd, SIOCDELRT, &rt));
     }
 
     return 0;