std/nativesockets

This module implements a low-level cross-platform sockets interface. Look at the net module for the higher-level version.

Imports

os, options, since, strbasics, winlean

Types

Domain = enum
  AF_UNSPEC = 0, ## unspecified domain (can be detected automatically by
                  ## some procedures, such as getaddrinfo)
  AF_UNIX = 1,              ## for local socket (using a file). Unsupported on Windows.
  AF_INET = 2,              ## for network protocol IPv4 or
  AF_INET6 = 23

domain, which specifies the protocol family of the created socket. Other domains than those that are listed here are unsupported. Source Edit

Hostent = object
  name*: string
  aliases*: seq[string]
  addrtype*: Domain
  length*: int
  addrList*: seq[string]

information about a given host Source Edit

Port = distinct uint16

port type Source Edit

Protocol = enum
  IPPROTO_TCP = 6,          ## Transmission control protocol.
  IPPROTO_UDP = 17,         ## User datagram protocol.
  IPPROTO_IP,               ## Internet protocol.
  IPPROTO_IPV6,             ## Internet Protocol Version 6.
  IPPROTO_RAW,              ## Raw IP Packets Protocol. Unsupported on Windows.
  IPPROTO_ICMP,             ## Internet Control message protocol.
  IPPROTO_ICMPV6             ## Internet Control message protocol for IPv6.

third argument to socket proc Source Edit

Servent = object
  name*: string
  aliases*: seq[string]
  port*: Port
  proto*: string

information about a service Source Edit

SockType = enum
  SOCK_STREAM = 1,          ## reliable stream-oriented service or Stream Sockets
  SOCK_DGRAM = 2,           ## datagram service or Datagram Sockets
  SOCK_RAW = 3,             ## raw protocols atop the network layer.
  SOCK_SEQPACKET = 5         ## reliable sequenced packet service

second argument to socket proc Source Edit

Lets

osInvalidSocket = INVALID_SOCKET

Source Edit

Consts

FIONBIO = -2147195266'i32

Source Edit

IOC_IN = -2147483648

Source Edit

IOCPARM_MASK = 127

Source Edit

IPPROTO_NONE = IPPROTO_IP

Use this if your socket type requires a protocol value of zero (e.g. Unix sockets). Source Edit

Procs

proc `$`(p: Port): string {.borrow, ...raises: [], tags: [], forbids: [].}

Returns the port number as a string Source Edit

proc `==`(a, b: Port): bool {.borrow, ...raises: [], tags: [], forbids: [].}

== for ports. Source Edit

proc accept(fd: SocketHandle; inheritable = defined(nimInheritHandles)): (
    SocketHandle, string) {....raises: [], tags: [], forbids: [].}

Accepts a new client connection.

inheritable decides if the resulting SocketHandle can be inherited by child processes.

Returns (osInvalidSocket, "") if an error occurred.

Source Edit

proc bindAddr(socket: SocketHandle; name: ptr SockAddr; namelen: SockLen): cint {.
    ...raises: [], tags: [], forbids: [].}

Source Edit

proc close(socket: SocketHandle) {....raises: [], tags: [], forbids: [].}

Closes a socket. Source Edit

proc createNativeSocket(domain: cint; sockType: cint; protocol: cint;
                        inheritable: bool = defined(nimInheritHandles)): SocketHandle {.
    ...raises: [], tags: [], forbids: [].}

Creates a new socket; returns osInvalidSocket if an error occurs.

inheritable decides if the resulting SocketHandle can be inherited by child processes.

Use this overload if one of the enums specified above does not contain what you need.

Source Edit

proc createNativeSocket(domain: Domain = AF_INET;
                        sockType: SockType = SOCK_STREAM;
                        protocol: Protocol = IPPROTO_TCP;
                        inheritable: bool = defined(nimInheritHandles)): SocketHandle {.
    ...raises: [], tags: [], forbids: [].}

Creates a new socket; returns osInvalidSocket if an error occurs.

inheritable decides if the resulting SocketHandle can be inherited by child processes.

Source Edit

proc getAddrInfo(address: string; port: Port; domain: Domain = AF_INET;
                 sockType: SockType = SOCK_STREAM;
                 protocol: Protocol = IPPROTO_TCP): ptr AddrInfo {.
    ...raises: [OSError], tags: [], forbids: [].}

Warning: The resulting ptr AddrInfo must be freed using freeAddrInfo!

Source Edit

proc getAddrString(sockAddr: ptr SockAddr): string {.
    ...raises: [Exception, OSError, IOError], tags: [], forbids: [].}

Returns the string representation of address within sockAddr Source Edit

proc getAddrString(sockAddr: ptr SockAddr; strAddress: var string) {.
    ...raises: [Exception, OSError, IOError], tags: [], forbids: [].}

Stores in strAddress the string representation of the address inside sockAddr

Note

• strAddress must be initialized to 46 in length.

Source Edit

proc getHostByAddr(ip: string): Hostent {....tags: [ReadIOEffect],
    raises: [OSError, IOError, Exception], forbids: [].}

This function will lookup the hostname of an IP Address. Source Edit

proc getHostByName(name: string): Hostent {....tags: [ReadIOEffect],
    raises: [OSError], forbids: [].}

This function will lookup the IP address of a hostname. Source Edit

proc getHostname(): string {....tags: [ReadIOEffect], raises: [OSError],
                             forbids: [].}

Returns the local hostname (not the FQDN) Source Edit

proc getLocalAddr(socket: SocketHandle; domain: Domain): (string, Port) {.
    ...raises: [OSError, Exception], tags: [], forbids: [].}

Returns the socket's local address and port number.

Similar to POSIX's getsockname.

Source Edit

proc getPeerAddr(socket: SocketHandle; domain: Domain): (string, Port) {.
    ...raises: [OSError, Exception], tags: [], forbids: [].}

Returns the socket's peer address and port number.

Similar to POSIX's getpeername

Source Edit

proc getProtoByName(name: string): int {....raises: [OSError], tags: [],
    forbids: [].}

Returns a protocol code from the database that matches the protocol name. Source Edit

proc getServByName(name, proto: string): Servent {....tags: [ReadIOEffect],
    raises: [OSError], forbids: [].}

Searches the database from the beginning and finds the first entry for which the service name specified by name matches the s_name member and the protocol name specified by proto matches the s_proto member.

On posix this will search through the /etc/services file.

Source Edit

proc getServByPort(port: Port; proto: string): Servent {....tags: [ReadIOEffect],
    raises: [OSError], forbids: [].}

Searches the database from the beginning and finds the first entry for which the port specified by port matches the s_port member and the protocol name specified by proto matches the s_proto member.

On posix this will search through the /etc/services file.

Source Edit

proc getSockDomain(socket: SocketHandle): Domain {....raises: [OSError, IOError],
    tags: [], forbids: [].}

Returns the socket's domain (AF_INET or AF_INET6). Source Edit

proc getSockName(socket: SocketHandle): Port {....raises: [OSError], tags: [],
    forbids: [].}

Returns the socket's associated port number. Source Edit

proc getSockOptInt(socket: SocketHandle; level, optname: int): int {.
    ...tags: [ReadIOEffect], raises: [OSError], forbids: [].}

getsockopt for integer options. Source Edit

proc ioctlsocket(s: SocketHandle; cmd: clong; argptr: ptr clong): cint {.
    stdcall, importc: "ioctlsocket", dynlib: "ws2_32.dll", ...raises: [], tags: [],
    forbids: [].}

Source Edit

proc listen(socket: SocketHandle; backlog = SOMAXCONN): cint {.
    ...tags: [ReadIOEffect], raises: [], forbids: [].}

Marks socket as accepting connections. Backlog specifies the maximum length of the queue of pending connections. Source Edit

proc ntohl(x: uint32): uint32 {....raises: [], tags: [], forbids: [].}

Converts 32-bit unsigned integers from network to host byte order. On machines where the host byte order is the same as network byte order, this is a no-op; otherwise, it performs a 4-byte swap operation. Source Edit

proc ntohs(x: uint16): uint16 {....raises: [], tags: [], forbids: [].}

Converts 16-bit unsigned integers from network to host byte order. On machines where the host byte order is the same as network byte order, this is a no-op; otherwise, it performs a 2-byte swap operation. Source Edit

proc selectRead(readfds: var seq[SocketHandle]; timeout = 500): int {.
    ...raises: [], tags: [], forbids: [].}

When a socket in readfds is ready to be read from then a non-zero value will be returned specifying the count of the sockets which can be read from. The sockets which cannot be read from will also be removed from readfds.

timeout is specified in milliseconds and -1 can be specified for an unlimited time.

Source Edit

proc selectWrite(writefds: var seq[SocketHandle]; timeout = 500): int {.
    ...tags: [ReadIOEffect], raises: [], forbids: [].}

When a socket in writefds is ready to be written to then a non-zero value will be returned specifying the count of the sockets which can be written to. The sockets which cannot be written to will also be removed from writefds.

timeout is specified in milliseconds and -1 can be specified for an unlimited time.

Source Edit

proc setBlocking(s: SocketHandle; blocking: bool) {....raises: [OSError], tags: [],
    forbids: [].}

Sets blocking mode on socket.

Raises OSError on error.

Source Edit

proc setInheritable(s: SocketHandle; inheritable: bool): bool {.inline,
    ...raises: [], tags: [], forbids: [].}

Set whether a socket is inheritable by child processes. Returns true on success.

This function is not implemented on all platform, test for availability with declared() <system.html#declared,untyped>.

Source Edit

proc setSockOptInt(socket: SocketHandle; level, optname, optval: int) {.
    ...tags: [WriteIOEffect], raises: [OSError], forbids: [].}

setsockopt for integer options. Source Edit

proc toInt(domain: Domain): cint {....raises: [], tags: [], forbids: [].}

Converts the Domain enum to a platform-dependent cint. Source Edit

proc toInt(p: Protocol): cint {....raises: [], tags: [], forbids: [].}

Converts the Protocol enum to a platform-dependent cint. Source Edit

proc toInt(typ: SockType): cint {....raises: [], tags: [], forbids: [].}

Converts the SockType enum to a platform-dependent cint. Source Edit

proc toKnownDomain(family: cint): Option[Domain] {....raises: [], tags: [],
    forbids: [].}

Converts the platform-dependent cint to the Domain or none(), if the cint is not known. Source Edit

proc toSockType(protocol: Protocol): SockType {....raises: [], tags: [],
    forbids: [].}

Source Edit

Templates

template htonl(x: uint32): untyped

Converts 32-bit unsigned integers from host to network byte order. On machines where the host byte order is the same as network byte order, this is a no-op; otherwise, it performs a 4-byte swap operation. Source Edit

template htons(x: uint16): untyped

Converts 16-bit unsigned integers from host to network byte order. On machines where the host byte order is the same as network byte order, this is a no-op; otherwise, it performs a 2-byte swap operation. Source Edit