diff options
Diffstat (limited to 'libgo/go/net/dial.go')
| -rw-r--r-- | libgo/go/net/dial.go | 168 |
1 files changed, 107 insertions, 61 deletions
diff --git a/libgo/go/net/dial.go b/libgo/go/net/dial.go index 50bba5a49e4..f8b4aa22742 100644 --- a/libgo/go/net/dial.go +++ b/libgo/go/net/dial.go @@ -7,6 +7,7 @@ package net import ( "context" "internal/nettrace" + "internal/poll" "time" ) @@ -22,8 +23,8 @@ type Dialer struct { // // The default is no timeout. // - // When dialing a name with multiple IP addresses, the timeout - // may be divided between them. + // When using TCP and dialing a host name with multiple IP + // addresses, the timeout may be divided between them. // // With or without a timeout, the operating system may impose // its own earlier timeout. For instance, TCP timeouts are @@ -42,10 +43,11 @@ type Dialer struct { // If nil, a local address is automatically chosen. LocalAddr Addr - // DualStack enables RFC 6555-compliant "Happy Eyeballs" dialing - // when the network is "tcp" and the destination is a host name - // with both IPv4 and IPv6 addresses. This allows a client to - // tolerate networks where one address family is silently broken. + // DualStack enables RFC 6555-compliant "Happy Eyeballs" + // dialing when the network is "tcp" and the host in the + // address parameter resolves to both IPv4 and IPv6 addresses. + // This allows a client to tolerate networks where one address + // family is silently broken. DualStack bool // FallbackDelay specifies the length of time to wait before @@ -110,7 +112,7 @@ func partialDeadline(now, deadline time.Time, addrsRemaining int) (time.Time, er } timeRemaining := deadline.Sub(now) if timeRemaining <= 0 { - return time.Time{}, errTimeout + return time.Time{}, poll.ErrTimeout } // Tentatively allocate equal time to each remaining address. timeout := timeRemaining / time.Duration(addrsRemaining) @@ -134,23 +136,26 @@ func (d *Dialer) fallbackDelay() time.Duration { } } -func parseNetwork(ctx context.Context, net string) (afnet string, proto int, err error) { - i := last(net, ':') +func parseNetwork(ctx context.Context, network string, needsProto bool) (afnet string, proto int, err error) { + i := last(network, ':') if i < 0 { // no colon - switch net { + switch network { case "tcp", "tcp4", "tcp6": case "udp", "udp4", "udp6": case "ip", "ip4", "ip6": + if needsProto { + return "", 0, UnknownNetworkError(network) + } case "unix", "unixgram", "unixpacket": default: - return "", 0, UnknownNetworkError(net) + return "", 0, UnknownNetworkError(network) } - return net, 0, nil + return network, 0, nil } - afnet = net[:i] + afnet = network[:i] switch afnet { case "ip", "ip4", "ip6": - protostr := net[i+1:] + protostr := network[i+1:] proto, i, ok := dtoi(protostr) if !ok || i != len(protostr) { proto, err = lookupProtocol(ctx, protostr) @@ -160,14 +165,14 @@ func parseNetwork(ctx context.Context, net string) (afnet string, proto int, err } return afnet, proto, nil } - return "", 0, UnknownNetworkError(net) + return "", 0, UnknownNetworkError(network) } // resolveAddrList resolves addr using hint and returns a list of // addresses. The result contains at least one address when error is // nil. func (r *Resolver) resolveAddrList(ctx context.Context, op, network, addr string, hint Addr) (addrList, error) { - afnet, _, err := parseNetwork(ctx, network) + afnet, _, err := parseNetwork(ctx, network, true) if err != nil { return nil, err } @@ -242,39 +247,60 @@ func (r *Resolver) resolveAddrList(ctx context.Context, op, network, addr string // (IPv4-only), "ip6" (IPv6-only), "unix", "unixgram" and // "unixpacket". // -// For TCP and UDP networks, addresses have the form host:port. -// If host is a literal IPv6 address it must be enclosed -// in square brackets as in "[::1]:80" or "[ipv6-host%zone]:80". -// The functions JoinHostPort and SplitHostPort manipulate addresses -// in this form. -// If the host is empty, as in ":80", the local system is assumed. +// For TCP and UDP networks, the address has the form "host:port". +// The host must be a literal IP address, or a host name that can be +// resolved to IP addresses. +// The port must be a literal port number or a service name. +// If the host is a literal IPv6 address it must be enclosed in square +// brackets, as in "[2001:db8::1]:80" or "[fe80::1%zone]:80". +// The zone specifies the scope of the literal IPv6 address as defined +// in RFC 4007. +// The functions JoinHostPort and SplitHostPort manipulate a pair of +// host and port in this form. +// When using TCP, and the host resolves to multiple IP addresses, +// Dial will try each IP address in order until one succeeds. // // Examples: -// Dial("tcp", "192.0.2.1:80") // Dial("tcp", "golang.org:http") -// Dial("tcp", "[2001:db8::1]:http") -// Dial("tcp", "[fe80::1%lo0]:80") +// Dial("tcp", "192.0.2.1:http") +// Dial("tcp", "198.51.100.1:80") +// Dial("udp", "[2001:db8::1]:domain") +// Dial("udp", "[fe80::1%lo0]:53") // Dial("tcp", ":80") // // For IP networks, the network must be "ip", "ip4" or "ip6" followed -// by a colon and a protocol number or name and the addr must be a -// literal IP address. +// by a colon and a literal protocol number or a protocol name, and +// the address has the form "host". The host must be a literal IP +// address or a literal IPv6 address with zone. +// It depends on each operating system how the operating system +// behaves with a non-well known protocol number such as "0" or "255". // // Examples: // Dial("ip4:1", "192.0.2.1") // Dial("ip6:ipv6-icmp", "2001:db8::1") +// Dial("ip6:58", "fe80::1%lo0") // -// For Unix networks, the address must be a file system path. +// For TCP, UDP and IP networks, if the host is empty or a literal +// unspecified IP address, as in ":80", "0.0.0.0:80" or "[::]:80" for +// TCP and UDP, "", "0.0.0.0" or "::" for IP, the local system is +// assumed. // -// If the host is resolved to multiple addresses, -// Dial will try each address in order until one succeeds. +// For Unix networks, the address must be a file system path. func Dial(network, address string) (Conn, error) { var d Dialer return d.Dial(network, address) } // DialTimeout acts like Dial but takes a timeout. +// // The timeout includes name resolution, if required. +// When using TCP, and the host in the address parameter resolves to +// multiple IP addresses, the timeout is spread over each consecutive +// dial, such that each is given an appropriate fraction of the time +// to connect. +// +// See func Dial for a description of the network and address +// parameters. func DialTimeout(network, address string, timeout time.Duration) (Conn, error) { d := Dialer{Timeout: timeout} return d.Dial(network, address) @@ -537,29 +563,37 @@ func dialSingle(ctx context.Context, dp *dialParam, ra Addr) (c Conn, err error) return c, nil } -// Listen announces on the local network address laddr. -// The network net must be a stream-oriented network: "tcp", "tcp4", -// "tcp6", "unix" or "unixpacket". -// For TCP and UDP, the syntax of laddr is "host:port", like "127.0.0.1:8080". -// If host is omitted, as in ":8080", Listen listens on all available interfaces -// instead of just the interface with the given host address. -// See Dial for more details about address syntax. +// Listen announces on the local network address. +// +// The network must be "tcp", "tcp4", "tcp6", "unix" or "unixpacket". // -// Listening on a hostname is not recommended because this creates a socket -// for at most one of its IP addresses. -func Listen(net, laddr string) (Listener, error) { - addrs, err := DefaultResolver.resolveAddrList(context.Background(), "listen", net, laddr, nil) +// For TCP networks, if the host in the address parameter is empty or +// a literal unspecified IP address, Listen listens on all available +// unicast and anycast IP addresses of the local system. +// To only use IPv4, use network "tcp4". +// The address can use a host name, but this is not recommended, +// because it will create a listener for at most one of the host's IP +// addresses. +// If the port in the address parameter is empty or "0", as in +// "127.0.0.1:" or "[::1]:0", a port number is automatically chosen. +// The Addr method of Listener can be used to discover the chosen +// port. +// +// See func Dial for a description of the network and address +// parameters. +func Listen(network, address string) (Listener, error) { + addrs, err := DefaultResolver.resolveAddrList(context.Background(), "listen", network, address, nil) if err != nil { - return nil, &OpError{Op: "listen", Net: net, Source: nil, Addr: nil, Err: err} + return nil, &OpError{Op: "listen", Net: network, Source: nil, Addr: nil, Err: err} } var l Listener switch la := addrs.first(isIPv4).(type) { case *TCPAddr: - l, err = ListenTCP(net, la) + l, err = ListenTCP(network, la) case *UnixAddr: - l, err = ListenUnix(net, la) + l, err = ListenUnix(network, la) default: - return nil, &OpError{Op: "listen", Net: net, Source: nil, Addr: la, Err: &AddrError{Err: "unexpected address type", Addr: laddr}} + return nil, &OpError{Op: "listen", Net: network, Source: nil, Addr: la, Err: &AddrError{Err: "unexpected address type", Addr: address}} } if err != nil { return nil, err // l is non-nil interface containing nil pointer @@ -567,31 +601,43 @@ func Listen(net, laddr string) (Listener, error) { return l, nil } -// ListenPacket announces on the local network address laddr. -// The network net must be a packet-oriented network: "udp", "udp4", -// "udp6", "ip", "ip4", "ip6" or "unixgram". -// For TCP and UDP, the syntax of laddr is "host:port", like "127.0.0.1:8080". -// If host is omitted, as in ":8080", ListenPacket listens on all available interfaces -// instead of just the interface with the given host address. -// See Dial for the syntax of laddr. +// ListenPacket announces on the local network address. +// +// The network must be "udp", "udp4", "udp6", "unixgram", or an IP +// transport. The IP transports are "ip", "ip4", or "ip6" followed by +// a colon and a literal protocol number or a protocol name, as in +// "ip:1" or "ip:icmp". // -// Listening on a hostname is not recommended because this creates a socket -// for at most one of its IP addresses. -func ListenPacket(net, laddr string) (PacketConn, error) { - addrs, err := DefaultResolver.resolveAddrList(context.Background(), "listen", net, laddr, nil) +// For UDP and IP networks, if the host in the address parameter is +// empty or a literal unspecified IP address, ListenPacket listens on +// all available IP addresses of the local system except multicast IP +// addresses. +// To only use IPv4, use network "udp4" or "ip4:proto". +// The address can use a host name, but this is not recommended, +// because it will create a listener for at most one of the host's IP +// addresses. +// If the port in the address parameter is empty or "0", as in +// "127.0.0.1:" or "[::1]:0", a port number is automatically chosen. +// The LocalAddr method of PacketConn can be used to discover the +// chosen port. +// +// See func Dial for a description of the network and address +// parameters. +func ListenPacket(network, address string) (PacketConn, error) { + addrs, err := DefaultResolver.resolveAddrList(context.Background(), "listen", network, address, nil) if err != nil { - return nil, &OpError{Op: "listen", Net: net, Source: nil, Addr: nil, Err: err} + return nil, &OpError{Op: "listen", Net: network, Source: nil, Addr: nil, Err: err} } var l PacketConn switch la := addrs.first(isIPv4).(type) { case *UDPAddr: - l, err = ListenUDP(net, la) + l, err = ListenUDP(network, la) case *IPAddr: - l, err = ListenIP(net, la) + l, err = ListenIP(network, la) case *UnixAddr: - l, err = ListenUnixgram(net, la) + l, err = ListenUnixgram(network, la) default: - return nil, &OpError{Op: "listen", Net: net, Source: nil, Addr: la, Err: &AddrError{Err: "unexpected address type", Addr: laddr}} + return nil, &OpError{Op: "listen", Net: network, Source: nil, Addr: la, Err: &AddrError{Err: "unexpected address type", Addr: address}} } if err != nil { return nil, err // l is non-nil interface containing nil pointer |