From c700d9f714f49a00fce4040755cd9b87734a90ea Mon Sep 17 00:00:00 2001
From: Bananymous <oskari.alaranta@bananymous.com>
Date: Wed, 12 Nov 2025 03:34:16 +0200
Subject: [PATCH] Kernel: Implement connect for UDP socket

---
 kernel/include/kernel/Networking/UDPSocket.h |  4 +++
 kernel/kernel/Networking/UDPSocket.cpp       | 26 +++++++++++++++++++-
 2 files changed, 29 insertions(+), 1 deletion(-)

diff --git a/kernel/include/kernel/Networking/UDPSocket.h b/kernel/include/kernel/Networking/UDPSocket.h
index 83e6ed0b..f5791025 100644
--- a/kernel/include/kernel/Networking/UDPSocket.h
+++ b/kernel/include/kernel/Networking/UDPSocket.h
@@ -33,6 +33,7 @@ namespace Kernel
 	protected:
 		virtual void receive_packet(BAN::ConstByteSpan, const sockaddr* sender, socklen_t sender_len) override;
 
+		virtual BAN::ErrorOr<void> connect_impl(const sockaddr*, socklen_t) override;
 		virtual BAN::ErrorOr<void> bind_impl(const sockaddr* address, socklen_t address_len) override;
 		virtual BAN::ErrorOr<size_t> recvmsg_impl(msghdr& message, int flags) override;
 		virtual BAN::ErrorOr<size_t> sendmsg_impl(const msghdr& message, int flags) override;
@@ -63,6 +64,9 @@ namespace Kernel
 		SpinLock							m_packet_lock;
 		ThreadBlocker						m_packet_thread_blocker;
 
+		sockaddr_storage					m_peer_address {};
+		socklen_t							m_peer_address_len { 0 };
+
 		friend class BAN::RefPtr<UDPSocket>;
 	};
 
diff --git a/kernel/kernel/Networking/UDPSocket.cpp b/kernel/kernel/Networking/UDPSocket.cpp
index 34680a37..caf94682 100644
--- a/kernel/kernel/Networking/UDPSocket.cpp
+++ b/kernel/kernel/Networking/UDPSocket.cpp
@@ -79,6 +79,15 @@ namespace Kernel
 		m_packet_thread_blocker.unblock();
 	}
 
+	BAN::ErrorOr<void> UDPSocket::connect_impl(const sockaddr* address, socklen_t address_len)
+	{
+		if (address_len > static_cast<socklen_t>(sizeof(m_peer_address)))
+			address_len = sizeof(m_peer_address);
+		memcpy(&m_peer_address, address, address_len);
+		m_peer_address_len = address_len;
+		return {};
+	}
+
 	BAN::ErrorOr<void> UDPSocket::bind_impl(const sockaddr* address, socklen_t address_len)
 	{
 		if (is_bound())
@@ -187,7 +196,22 @@ namespace Kernel
 			offset += message.msg_iov[i].iov_len;
 		}
 
-		return TRY(m_network_layer.sendto(*this, buffer.span(), static_cast<sockaddr*>(message.msg_name), message.msg_namelen));
+		sockaddr* address;
+		socklen_t address_len;
+		if (!message.msg_name || message.msg_namelen == 0)
+		{
+			if (m_peer_address_len == 0)
+				return BAN::Error::from_errno(EDESTADDRREQ);
+			address = reinterpret_cast<sockaddr*>(&m_peer_address);
+			address_len = m_peer_address_len;
+		}
+		else
+		{
+			address = static_cast<sockaddr*>(message.msg_name);
+			address_len = message.msg_namelen;
+		}
+
+		return TRY(m_network_layer.sendto(*this, buffer.span(), address, address_len));
 	}
 
 	BAN::ErrorOr<long> UDPSocket::ioctl_impl(int request, void* argument)