UDP is broken

[niansa]

Bug Report

What's the issue you encountered?

When creating a UDP socket, the socket fails to receive any data. bind() calls return no error (returning 0), but select() then recv() or recvfrom() never returns data.

• ICMP pings are answered
• TCP servers work fine
• UDP sockets silently drop packets

How can the issue be reproduced?

1. Create a UDP socket:

int sock = socket(AF_INET, SOCK_DGRAM, 0);

2. Bind the socket:

sockaddr_in sa{};
sa.sin_family = AF_INET;
sa.sin_port = htons(5055);
sa.sin_addr.s_addr = htonl(INADDR_ANY);
bind(sock, (struct sockaddr*)&sa, sizeof(sa));

3. Send UDP packets from a PC to the DS's IP address on port 5055
4. Call recvfrom() on the DS
5. No data is received

Environment?

• What host OS are you using? Debian 13 on amd64
• Official release or unofficial/self-compiled build: official release from devkitpros package manager

Additional context?

I also noticed that passing IPPROTO_UDP to socket() instead of 0 causes socket to error.