Sockets services

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bsd:u, bsd:s

This is "nn::socket::sf::IClient".

All the services commands but the first two return -1 on failure and set errno when that happens. Although Nintendo has the FreeBSD kernel's to socket stack, the errno macro definitions being in use actually come from Linux (and not from FreeBSD as one would expect!).

Cmd Name
0 RegisterClient (Initialize)
1 StartMonitoring
2 #Socket
3 #SocketExempt
4 #Open
5 Select
6 Poll
7 #Sysctl
8 Recv
9 RecvFrom
10 Send
11 SendTo
12 Accept
13 Bind
14 Connect
15 GetPeerName
16 GetSockName
17 GetSockOpt
18 Listen
19 #Ioctl
20 #Fcntl
21 SetSockOpt
22 Shutdown
23 ShutdownAllSockets
24 Write
25 Read
26 Close
27 #DuplicateSocket
28 GetResourceStatistics
29 [3.0.0+] RecvMMsg
30 [3.0.0+] SendMMsg

Initalize

Takes a #BsdBufferConfig (made-up name), the PID, the size of the transfer memory and a copy-handle of the latter.

BsdBufferConfig

/// Configuration structure for bsdInitalize
typedef struct  {
    u32 version;                ///< Observed 1 on 2.0 LibAppletWeb, 2 on 3.0.

    u32 tcp_tx_buf_size;        ///< Size of the TCP transfer (send) buffer (initial or fixed).
    u32 tcp_rx_buf_size;        ///< Size of the TCP recieve buffer (initial or fixed).
    u32 tcp_tx_buf_max_size;    ///< Maximum size of the TCP transfer (send) buffer. If it is 0, the size of the buffer is fixed to its initial value.
    u32 tcp_rx_buf_max_size;    ///< Maximum size of the TCP receive buffer. If it is 0, the size of the buffer is fixed to its initial value.

    u32 udp_tx_buf_size;        ///< Size of the UDP transfer (send) buffer (typically 0x2400 bytes).
    u32 udp_rx_buf_size;        ///< Size of the UDP receive buffer (typically 0xA500 bytes).

    u32 sb_efficiency;          ///< Number of buffers for each socket (standard values range from 1 to 8).
} BsdBufferConfig;


The transfer memory must be larger than a the computed size below. Should the transfer memory be smaller than that, the BSD sockets service would only send ZeroWindow packets (for TCP), resulting in a transfer rate not exceeding 1 byte/s.

static size_t _bsdGetTransferMemSizeForBufferConfig(const BsdBufferConfig *config)
{
    u32 tcp_tx_buf_max_size = config->tcp_tx_buf_max_size != 0 ? config->tcp_tx_buf_max_size : config->tcp_tx_buf_size;
    u32 tcp_rx_buf_max_size = config->tcp_rx_buf_max_size != 0 ? config->tcp_rx_buf_max_size : config->tcp_rx_buf_size;
    u32 sum = tcp_tx_buf_max_size + tcp_rx_buf_max_size + config->udp_tx_buf_size + config->udp_rx_buf_size;

    sum = ((sum + 0xFFF) >> 12) << 12; // page round-up
    return (size_t)(config->sb_efficiency * sum);
}

Socket

FreeBSD's socket command. bsd:u disallows the usage of the SOCK_SEQPACKET and SOCK_RAW types, with the exception of (AF_INET, SOCK_RAW, IPPROTO_ICMP) (IPv4 ping), bsd:s needs to be used for those.

The only registered domains are AF_INET and AF_ROUTE.

SocketExempt: same as socket but the socket is immediately shutdown (disconnected) on creation.

Open

FreeBSD's open command, limited to opening /dev/bpf. This can be used, for example, to enable promiscuous mode, see FreeBSD's /dev/bpf for more details.

Sysctl

FreeBSD's sysctl command. Privileged operations are reserved for bsd:s. CTL_NET, CTL_VM, CTL_KERN and CTL_DEBUG commands are implemented (?).

Ioctl

FreeBSD's ioctl function. The following ioctls are whitelisted, refer to FreeBSD's headers for more details: SIOCATMARK, BIOCGBLEN, BIOCSETF BIOCIMMEDIATE, BIOCSETIF, BIOCVERSION, FIONSPACE, FIONWRITE, FIONREAD, SIOCGETSGCNT, SIOCGIFMETRIC, SIOCSIFMETRIC, SIOCDIFADDR, SIOCGIFINDEX, SIOCGIFADDR, SIOCGIFCONF, SIOCGIFNETMASK, SIOCAIFADDR, SIOCGIFMTU, SIOCSIFMTU, SIOCGIFMEDIA, SIOCSIFLLADDR and SIOCGIFXMEDIA.

Nintendo use the following definition (hence changing all ioctls using this structure):

struct bpf_program {
	u_int bf_len;
	struct bpf_insn bf_insns[BPF_MAXINSNS]; // [512]. This is a pointer in the official structure
};

Fcntl

FreeBSD's fcntl, limited to F_GETFL and F_SETFL with O_NONBLOCK.

DuplicateSocket

Takes a socket file descriptor and an unused u64. Duplicates the socket (FreeBSD's dup). Reserved to bsd:s.

bsdcfg

This is "nn::bsdsocket::cfg::ServerInterface".

Cmd Name
0 SetIfUp
1 SetIfUpWithEvent
2 CancelIf
3 SetIfDown
4 GetIfState
5 DhcpRenew
6 AddStaticArpEntry
7 RemoveArpEntry
8 LookupArpEntry
9 LookupArpEntry2
10 ClearArpEntries
11 ClearArpEntries2
12 PrintArpEntries

ethc:c

This is "nn::eth::sf::IEthInterface".

Cmd Name
0 Initialize
1 Cancel
2 GetResult
3 GetMediaList
4 SetMediaType
5 GetMediaType

ethc:i

This is "nn::eth::sf::IEthInterfaceGroup".

Cmd Name
0 GetReadableHandle
1 Cancel
2 GetResult
3 GetInterfaceList
4 GetInterfaceCount

sfdnsres

This is "nn::socket::resolver::IResolver".

This service uses bionic/libc/dns to perform its tasks.

Cmd Name
0 SetDnsAddressesPrivate (stubbed, returns 0x7FE03)
1 GetDnsAddressPrivate (stubbed, returns 0x7FE03)
2 GetHostByName
3 GetHostByAddr
4 GetHostStringError
5 GetGaiStringError
6 #GetAddrInfo
7 GetNameInfo
8 RequestCancelHandle
9 CancelSocketCall
10 ?
11 #ClearDnsIpServerAddressArray (made-up name)

GetAddrInfo

Takes three type 5 buffers (host, port, and hints), and a type 6 buffer (the output addrinfos). Also takes a u8 (padded to 4 bytes so the next raw parameter can align), a u32, and a u64. The u8 is a boolean for whether to enable "nsd resolve" (1) or not (0). Not sure what the u32 is. It seems to either come from a parameter to GetAddrInfo or be zero. The u64 is most likely a placeholder for the server to copy the PID into and should be zero. Both hints and the output buffer contain serialized addrinfo chains. The hints buffer is sized 0x400 bytes long by default, and the output buffer 0x1000 bytes.

Addrinfo Serialization Format

Each struct addrinfo in the linked list is serialized according to this format and then written to the buffer. All numbers are in network byte order.

Size (bytes) Name Notes
4 Magic Needs to be 0xBEEFCAFE. Seriously.
4 ai_flags
4 ai_family
4 ai_socktype
4 ai_protocol
4 ai_addrlen
ai_addrlen ? ai_addrlen : 4 ai_addr
null-terminated string ai_canonname

If ai_addrlen is zero, ai_addr will occupy 4 bytes.

Size (bytes) Name Notes
4 ai_addr

If ai_family is recognized as AF_INET6 (28) or AF_INET (2), ai_addr is read as struct sockaddr_in or struct sockaddr_in6. Otherwise, it's just read as u8[ai_addrlen].

The list should be terminated with a sentinel four-byte zero value.

ClearDnsIpServerAddressArray

This function clears nn::socket::resolver::g_DnsIpServerAddressArray, setting its length to 0 as well. The array initially contains IPs filled by bsdconfig, a privileged service handling DHCP and such.

Takes no arguments, doesn't return anything, never fails.

nsd:u, nsd:a

This is "nn::nsd::detail::IManager".

Cmd Name
10 GetSettingName
11 #GetEnvironmentIdentifier
12 GetDeviceId
13 DeleteSettings
14 ImportSettings
20 Resolve
21 ResolveEx
30 GetNasServiceSetting
31 GetNasServiceSettingEx
40 GetNasRequestFqdn
41 GetNasRequestFqdnEx
42 GetNasApiFqdn
43 GetNasApiFqdnEx
50 GetCurrentSetting
60 #ReadSaveDataFromFsForTest
61 #WriteSaveDataToFsForTest
62 #DeleteSaveDataOfFsForTest

GetEnvironmentIdentifier

Takes a type-0x16 buffer with size 8. Returns a string.

The output string is used by NIM for the "eid:%s" in the User-Agent strings.

This is the "lp1" string also used in domains.

ReadSaveDataFromFsForTest

Requires the nsd!test_mode setting to be equal to 1.

Mounts the system save data for bsdsockets as nsdsave and reads from nsd:/file to the specified buffer, at the specified size and offset with no checks whatsoever. nsdsave is then unmounted.

WriteSaveDataToFsForTest

Requires the nsd!test_mode setting to be equal to 1.

Mounts the system save data for bsdsockets as nsdsave and writes to nsd:/file (appending is allowed) using the specified buffer, at the specified size and offset, with no checks whatsoever. nsdsave is then commited and unmounted.

DeleteSaveDataOfFsForTest

Requires the nsd!test_mode setting to be equal to 1.

Deletes the system save data for bsdsockets.