Socket Services

The socket sysmodule has a maximum limit of 64 sockets in total.

Socket user service "soc:U"

There can be up to 18 sessions of this service.

Command Header	Available since system-version	Description
0x00010044		InitializeSockets
0x000200C2		socket
0x00030082		listen
0x00040082		accept
0x00050084		bind
0x00060084		connect
0x00070104		recvfrom_other
0x00080102		recvfrom
0x00090106		sendto_other
0x000A0106		sendto
0x000B0042		close
0x000C0082		shutdown
0x000D0082		gethostbyname
0x000E00C2		gethostbyaddr
0x000F0106		getaddrinfo
0x00100102		getnameinfo
0x00110102		getsockopt
0x00120104		setsockopt
0x001300C2		fcntl
0x00140084		poll
0x00150042		sockatmark
0x00160000		gethostid
0x00170082		getsockname
0x00180082		getpeername
0x00190000		ShutdownSockets
0x001A00C0		GetNetworkOpt
0x001B0040		ICMPSocket
0x001C0104		ICMPPing
0x001D0040		ICMPCancel
0x001E0040		ICMPClose
0x001F0040		GetResolverInfo
0x00200146		SendToMultiple
0x00210002		CloseSockets
0x00220040		(int sockfd) Might be the inverse of command 0x00230040?
0x00230040		AddGlobalSocket
0x100100C0	?	?
0x10030142	?	?
0x10050084	?	?
0x10070102	?	?

Socket privileged service "soc:P"

There can be up to 3 sessions of this service.

Command Header	Description
0x00010084	InitializeSockets
0x00020000	FinalizeSockets
0x000300C2	SetNetworkOpt
0x00040040	CloseSocketsForProcess
0x000500C0
0x00060000	gethostid
0x00070000
0x00080000
0x00090000	StopInitializeSockets

struct sockaddr

Offset	Size	Description
0x0	0x1	Total size of the entire sockaddr buffer.
0x1	0x1	u8 sa_family
0x2	sockaddr_totalsize-0x2	sa_data[]

The total buffer size is 0x8, for family AF_INET value 2. AF_INET6 seems to be value 23, the total sockaddr size for this is 0x1C. The max sockaddr buffer size which the socket module can handle is size 0x1C.

These socket services(and defines/structures) seem to be based on the Wii sockets?

Socket module errors

Error	Description
0xC8A07004	This is returned when trying to use a socket descriptor from a different process.
0xC8A07009	Network dropped connection on reset? (Translated from ENETRESET error)
0xC8A0700B	SOCU:InitializeSockets returns this when the specified PID was already used with SOCU:InitializeSockets(since the PID was found in SOC module state table).
0xD860700A	SOCU:InitializeSockets returns this when the PID table is already full(32 processes max).
0xD8E07006	Not initialized. This is returned when SOCU:InitializeSockets has not been run.
0xD8E07007	The given socket descriptor does not exist.

Socket module static buffers

This is the list of the known thread static buffers in use for SOC:u and the commands using those.

buffer ID	commands
0	bind,connect
1	sendto_other,sendto
2	sendto
5-7	getaddrinfo
8	getnameinfo
9	setsockopt
10	poll

IPV6

It seems that Nintendo planned ahead and included IPv6 support to some extent in their code. Name resolution functions support IPv6 (such as getnameinfo), but socket doesn't.

The ipv6 sockaddr size is 0x1C and is required for some IPC commands, even when using sockaddr_in which in reality is of size 8. The sockaddr_in6 struct is the following:

struct in6_addr
{
	uint8_t s6_addr[16];
};

struct sockaddr_in6
{
    sa_family_t     sin6_family;
    in_port_t       sin6_port;
    struct in6_addr sin6_addr;
    u32             sin6_flowinfo; // Not confirmed
    u32             sin6_scope_id; // Not confirmed
};