diff --git a/library/std/src/net/udp.rs b/library/std/src/net/udp.rs index 227e418b70992..60347a11da9c5 100644 --- a/library/std/src/net/udp.rs +++ b/library/std/src/net/udp.rs @@ -99,6 +99,16 @@ impl UdpSocket { /// /// let socket = UdpSocket::bind("127.0.0.1:0").unwrap(); /// ``` + /// + /// Note that `bind` declares the scope of your network connection. + /// You can only receive datagrams from and send datagrams to + /// participants in that view of the network. + /// For instance, binding to a loopback address as in the example + /// above will prevent you from sending datagrams to another device + /// in your local network. + /// + /// In order to limit your view of the network the least, `bind` to + /// [`Ipv4Addr::UNSPECIFIED`] or [`Ipv6Addr::UNSPECIFIED`]. #[stable(feature = "rust1", since = "1.0.0")] pub fn bind(addr: A) -> io::Result { super::each_addr(addr, net_imp::UdpSocket::bind).map(UdpSocket) @@ -157,7 +167,9 @@ impl UdpSocket { } /// Sends data on the socket to the given address. On success, returns the - /// number of bytes written. + /// number of bytes written. Note that the operating system may refuse + /// buffers larger than 65507. However, partial writes are not possible + /// until buffer sizes above `i32::MAX`. /// /// Address type can be any implementor of [`ToSocketAddrs`] trait. See its /// documentation for concrete examples. @@ -652,12 +664,19 @@ impl UdpSocket { /// function of a UDP socket is not a useful thing to do: The OS will be /// unable to determine whether something is listening on the remote /// address without the application sending data. + /// + /// If your first `connect` is to a loopback address, subsequent + /// `connect`s to non-loopback addresses might fail, depending + /// on the platform. #[stable(feature = "net2_mutators", since = "1.9.0")] pub fn connect(&self, addr: A) -> io::Result<()> { super::each_addr(addr, |addr| self.0.connect(addr)) } /// Sends data on the socket to the remote address to which it is connected. + /// On success, returns the number of bytes written. Note that the operating + /// system may refuse buffers larger than 65507. However, partial writes are + /// not possible until buffer sizes above `i32::MAX`. /// /// [`UdpSocket::connect`] will connect this socket to a remote address. This /// method will fail if the socket is not connected.