# sockaddr.rs - source
Source of the Rust file `/home/runner/.cargo/registry/src/github.com-1ecc6299db9ec823/socket2-0.4.0/src/sockaddr.rs`.
Keywords: rust, rustlang, rust-lang

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    use std::mem::{self, size_of, MaybeUninit};
    use std::net::{SocketAddr, SocketAddrV4, SocketAddrV6};
    use std::{fmt, io};

    use crate::sys::{
        sa_family_t, sockaddr, sockaddr_in, sockaddr_in6, sockaddr_storage, socklen_t, AF_INET,
        AF_INET6,
    };
    #[cfg(windows)]
    use winapi::shared::ws2ipdef::SOCKADDR_IN6_LH_u;

    /// The address of a socket.
    ///
    /// `SockAddr`s may be constructed directly to and from the standard library
    /// `SocketAddr`, `SocketAddrV4`, and `SocketAddrV6` types.
    pub struct SockAddr {
        storage: sockaddr_storage,
        len: socklen_t,
    }

    impl SockAddr {
        /// Initialise a `SockAddr` by calling the function `init`.
        ///
        /// The type of the address storage and length passed to the function `init`
        /// is OS/architecture specific.
        ///
        /// # Safety
        ///
        /// Caller must initialise the provided address storage and set the length
        /// properly. The address is zeroed before `init` is called and is thus
        /// valid to dereference and read from. The length initialised to the
        /// maximum length of the storage.
        ///
        /// # Examples
        ///
        #[cfg_attr(unix, doc = "```")]
        #[cfg_attr(not(unix), doc = "```ignore")]
        /// use std::io;
        /// use std::os::unix::io::AsRawFd;
        ///
        /// use socket2::{SockAddr, Socket, Domain, Type};
        ///
        /// # fn main() -> io::Result<()> {
        /// let socket = Socket::new(Domain::IPV4, Type::STREAM, None)?;
        ///
        /// // Initialise a `SocketAddr` byte calling `getsockname(2)`.
        /// let (_, address) = unsafe {
        ///     SockAddr::init(|addr_storage, len| {
        ///         // The `getsockname(2)` system call will intiliase `storage` for
        ///         // us, setting `len` to the correct length.
        ///         if libc::getsockname(socket.as_raw_fd(), addr_storage.cast(), len) == -1 {
        ///             Err(io::Error::last_os_error())
        ///         } else {
        ///             Ok(())
        ///         }
        ///     })
        /// }?;
        /// # drop(address);
        /// # Ok(())
        /// # }
        /// ```
        pub unsafe fn init<F, T>(init: F) -> io::Result<(T, SockAddr)>
        where
            F: FnOnce(*mut sockaddr_storage, *mut socklen_t) -> io::Result<T>,
        {
            const STORAGE_SIZE: socklen_t = size_of::<sockaddr_storage>() as socklen_t;
            // NOTE: `SockAddr::unix` depends on the storage being zeroed before
            // calling `init`.
            // NOTE: calling `recvfrom` with an empty buffer also depends on the
            // storage being zeroed before calling `init` as the OS might not
            // initialise it.
            let mut storage = MaybeUninit::<sockaddr_storage>::zeroed();
            let mut len = STORAGE_SIZE;
            init(storage.as_mut_ptr(), &mut len).map(|res| {
                debug_assert!(len <= STORAGE_SIZE, "overflown address storage");
                let addr = SockAddr {
                    // Safety: zeroed-out `sockaddr_storage` is valid, caller must
                    // ensure at least `len` bytes are valid.
                    storage: storage.assume_init(),
                    len,
                };
                (res, addr)
            })
        }

        /// Returns this address's family.
        pub const fn family(&self) -> sa_family_t {
            self.storage.ss_family
        }

        /// Returns the size of this address in bytes.
        pub const fn len(&self) -> socklen_t {
            self.len
        }

        /// Returns a raw pointer to the address.
        pub const fn as_ptr(&self) -> *const sockaddr {
            &self.storage as *const _ as *const _
        }

        /// Returns a raw pointer to the address storage.
        #[cfg(all(unix, not(target_os = "redox")))]
        pub(crate) const fn as_storage_ptr(&self) -> *const sockaddr_storage {
            &self.storage
        }

        /// Returns this address as a `SocketAddr` if it is in the `AF_INET` (IPv4)
        /// or `AF_INET6` (IPv6) family, otherwise returns `None`.
        pub fn as_socket(&self) -> Option<SocketAddr> {
            if self.storage.ss_family == AF_INET as sa_family_t {
                // Safety: if the ss_family field is AF_INET then storage must be a sockaddr_in.
                let addr = unsafe { &*(&self.storage as *const _ as *const sockaddr_in) };

                let ip = crate::sys::from_in_addr(addr.sin_addr);
                let port = u16::from_be(addr.sin_port);
                Some(SocketAddr::V4(SocketAddrV4::new(ip, port)))
            } else if self.storage.ss_family == AF_INET6 as sa_family_t {
                // Safety: if the ss_family field is AF_INET6 then storage must be a sockaddr_in6.
                let addr = unsafe { &*(&self.storage as *const _ as *const sockaddr_in6) };

                let ip = crate::sys::from_in6_addr(addr.sin6_addr);
                let port = u16::from_be(addr.sin6_port);
                Some(SocketAddr::V6(SocketAddrV6::new(
                    ip,
                    port,
                    addr.sin6_flowinfo,
                    #[cfg(unix)]
                    addr.sin6_scope_id,
                    #[cfg(windows)]
                    unsafe {
                        *addr.u.sin6_scope_id()
                    },
                )))
            } else {
                None
            }
        }

        /// Returns this address as a `SocketAddrV4` if it is in the `AF_INET`
        /// family.
        pub fn as_socket_ipv4(&self) -> Option<SocketAddrV4> {
            match self.as_socket() {
                Some(SocketAddr::V4(addr)) => Some(addr),
                _ => None,
            }
        }

        /// Returns this address as a `SocketAddrV6` if it is in the `AF_INET6`
        /// family.
        pub fn as_socket_ipv6(&self) -> Option<SocketAddrV6> {
            match self.as_socket() {
                Some(SocketAddr::V6(addr)) => Some(addr),
                _ => None,
            }
        }
    }

    impl From<SocketAddr> for SockAddr {
        fn from(addr: SocketAddr) -> SockAddr {
            match addr {
                SocketAddr::V4(addr) => addr.into(),
                SocketAddr::V6(addr) => addr.into(),
            }
        }
    }

    impl From<SocketAddrV4> for SockAddr {
        fn from(addr: SocketAddrV4) -> SockAddr {
            let sockaddr_in = sockaddr_in {
                sin_family: AF_INET as sa_family_t,
                sin_port: addr.port().to_be(),
                sin_addr: crate::sys::to_in_addr(&addr.ip()),
                sin_zero: Default::default(),
                #[cfg(any(
                    target_os = "dragonfly",
                    target_os = "freebsd",
                    target_os = "haiku",
                    target_os = "ios",
                    target_os = "macos",
                    target_os = "netbsd",
                    target_os = "openbsd"
                ))]
                sin_len: 0,
            };
            let mut storage = MaybeUninit::<sockaddr_storage>::zeroed();
            // Safety: A `sockaddr_in` is memory compatible with a `sockaddr_storage`
            unsafe { (storage.as_mut_ptr() as *mut sockaddr_in).write(sockaddr_in) };
            SockAddr {
                storage: unsafe { storage.assume_init() },
                len: mem::size_of::<sockaddr_in>() as socklen_t,
            }
        }
    }

    impl From<SocketAddrV6> for SockAddr {
        fn from(addr: SocketAddrV6) -> SockAddr {
            #[cfg(windows)]
            let u = unsafe {
                let mut u = mem::zeroed::<SOCKADDR_IN6_LH_u>();
                *u.sin6_scope_id_mut() = addr.scope_id();
                u
            };

            let sockaddr_in6 = sockaddr_in6 {
                sin6_family: AF_INET6 as sa_family_t,
                sin6_port: addr.port().to_be(),
                sin6_addr: crate::sys::to_in6_addr(addr.ip()),
                sin6_flowinfo: addr.flowinfo(),
                #[cfg(unix)]
                sin6_scope_id: addr.scope_id(),
                #[cfg(windows)]
                u,
                #[cfg(any(
                    target_os = "dragonfly",
                    target_os = "freebsd",
                    target_os = "haiku",
                    target_os = "ios",
                    target_os = "macos",
                    target_os = "netbsd",
                    target_os = "openbsd"
                ))]
                sin6_len: 0,
                #[cfg(any(target_os = "solaris", target_os = "illumos"))]
                __sin6_src_id: 0,
            };
            let mut storage = MaybeUninit::<sockaddr_storage>::zeroed();
            // Safety: A `sockaddr_in6` is memory compatible with a `sockaddr_storage`
            unsafe { (storage.as_mut_ptr() as *mut sockaddr_in6).write(sockaddr_in6) };
            SockAddr {
                storage: unsafe { storage.assume_init() },
                len: mem::size_of::<sockaddr_in6>() as socklen_t,
            }
        }
    }

    impl fmt::Debug for SockAddr {
        fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
            let mut f = fmt.debug_struct("SockAddr");
            #[cfg(any(
                target_os = "dragonfly",
                target_os = "freebsd",
                target_os = "haiku",
                target_os = "hermit",
                target_os = "ios",
                target_os = "macos",
                target_os = "netbsd",
                target_os = "openbsd",
                target_os = "vxworks",
            ))]
            f.field("ss_len", &self.storage.ss_len);
            f.field("ss_family", &self.storage.ss_family)
                .field("len", &self.len)
                .finish()
        }
    }

    #[test]
    fn ipv4() {
        use std::net::Ipv4Addr;
        let std = SocketAddrV4::new(Ipv4Addr::new(1, 2, 3, 4), 9876);
        let addr = SockAddr::from(std);
        assert_eq!(addr.family(), AF_INET as sa_family_t);
        assert_eq!(addr.len(), size_of::<sockaddr_in>() as socklen_t);
        assert_eq!(addr.as_socket(), Some(SocketAddr::V4(std)));
        assert_eq!(addr.as_socket_ipv4(), Some(std));
        assert!(addr.as_socket_ipv6().is_none());

        let addr = SockAddr::from(SocketAddr::from(std));
        assert_eq!(addr.family(), AF_INET as sa_family_t);
        assert_eq!(addr.len(), size_of::<sockaddr_in>() as socklen_t);
        assert_eq!(addr.as_socket(), Some(SocketAddr::V4(std)));
        assert_eq!(addr.as_socket_ipv4(), Some(std));
        assert!(addr.as_socket_ipv6().is_none());
    }

    #[test]
    fn ipv6() {
        use std::net::Ipv6Addr;
        let std = SocketAddrV6::new(Ipv6Addr::new(1, 2, 3, 4, 5, 6, 7, 8), 9876, 11, 12);
        let addr = SockAddr::from(std);
        assert_eq!(addr.family(), AF_INET6 as sa_family_t);
        assert_eq!(addr.len(), size_of::<sockaddr_in6>() as socklen_t);
        assert_eq!(addr.as_socket(), Some(SocketAddr::V6(std)));
        assert!(addr.as_socket_ipv4().is_none());
        assert_eq!(addr.as_socket_ipv6(), Some(std));

        let addr = SockAddr::from(SocketAddr::from(std));
        assert_eq!(addr.family(), AF_INET6 as sa_family_t);
        assert_eq!(addr.len(), size_of::<sockaddr_in6>() as socklen_t);
        assert_eq!(addr.as_socket(), Some(SocketAddr::V6(std)));
        assert!(addr.as_socket_ipv4().is_none());
        assert_eq!(addr.as_socket_ipv6(), Some(std));
    }