Add support for getifaddrs. Closes: #650.

src/ifaddrs.rs

@@ -0,0 +1,153 @@
+//! Query network interface addresses
+//!
+//! Uses the Linux and/or BSD specific function `getifaddrs` to query the list
+//! of interfaces and their associated addresses.
+
+use std::ffi;
+use std::fmt;
+use std::iter::Iterator;
+use std::mem;
+use std::option::Option;
+
+use libc;
+
+use {Result, Errno};
+use sys::socket::SockAddr;
+use net::if_::*;
+
+/// Describes a single address for an interface as returned by `getifaddrs`.
+#[derive(Clone, Eq, Hash, PartialEq)]
+pub struct InterfaceAddress {
+ /// Name of the network interface
+ pub interface_name: String,
+ /// Flags as from `SIOCGIFFLAGS` ioctl
+ pub flags: InterfaceFlags,
+ /// Network address of this interface
+ pub address: Option<SockAddr>,
+ /// Netmask of this interface
+ pub netmask: Option<SockAddr>,
+ /// Broadcast address of this interface, if applicable
+ pub broadcast: Option<SockAddr>,
+ /// Point-to-point destination address
+ pub destination: Option<SockAddr>,
+}
+
+impl fmt::Debug for InterfaceAddress {
+ fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+ write!(f, "InterfaceAddress ({:?})", self.interface_name)
+ }
+}
+
+cfg_if! {
+ if #[cfg(any(target_os = "emscripten", target_os = "fuchsia", target_os = "linux"))] {
+ fn get_ifu_from_sockaddr(info: &libc::ifaddrs) -> *const libc::sockaddr {
+ info.ifa_ifu
+ }
+ } else {
+ fn get_ifu_from_sockaddr(info: &libc::ifaddrs) -> *const libc::sockaddr {
+ info.ifa_dstaddr
+ }
+ }
+}
+
+impl InterfaceAddress {
+ /// Create an `InterfaceAddress` from the libc struct.
+ fn from_libc_ifaddrs(info: &libc::ifaddrs) -> InterfaceAddress {
+ let ifname = unsafe { ffi::CStr::from_ptr(info.ifa_name) };
+ let address = unsafe { SockAddr::from_libc_sockaddr(info.ifa_addr) };
+ let netmask = unsafe { SockAddr::from_libc_sockaddr(info.ifa_netmask) };
+ let mut addr = InterfaceAddress {
+ interface_name: ifname.to_string_lossy().to_string(),
+ flags: InterfaceFlags::from_bits_truncate(info.ifa_flags as i32),
+ address: address,
+ netmask: netmask,
+ broadcast: None,
+ destination: None,
+ };
+
+ let ifu = get_ifu_from_sockaddr(info);
+ if addr.flags.contains(InterfaceFlags::IFF_POINTOPOINT) {
+ addr.destination = unsafe { SockAddr::from_libc_sockaddr(ifu) };
+ } else if addr.flags.contains(InterfaceFlags::IFF_BROADCAST) {
+ addr.broadcast = unsafe { SockAddr::from_libc_sockaddr(ifu) };
+ }
+
+ addr
+ }
+}
+
+/// Holds the results of `getifaddrs`.
+///
+/// Use the function `getifaddrs` to create this Iterator. Note that the
+/// actual list of interfaces can be iterated once and will be freed as
+/// soon as the Iterator goes out of scope.
+#[derive(Debug, Eq, Hash, PartialEq)]
+pub struct InterfaceAddressIterator {
+ base: *mut libc::ifaddrs,
+ next: *mut libc::ifaddrs,
+}
+
+impl Drop for InterfaceAddressIterator {
+ fn drop(&mut self) {
+ unsafe { libc::freeifaddrs(self.base) };
+ }
+}
+
+impl Iterator for InterfaceAddressIterator {
+ type Item = InterfaceAddress;
+ fn next(&mut self) -> Option<<Self as Iterator>::Item> {
+ match unsafe { self.next.as_ref() } {
+ Some(ifaddr) => {
+ self.next = ifaddr.ifa_next;
+ Some(InterfaceAddress::from_libc_ifaddrs(ifaddr))
+ }
+ None => None,
+ }
+ }
+}
+
+/// Get interface addresses using libc's `getifaddrs`
+///
+/// Note that the underlying implementation differs between OSes. Only the
+/// most common address families are supported by the nix crate (due to
+/// lack of time and complexity of testing). The address family is encoded
+/// in the specific variant of `SockAddr` returned for the fields `address`,
+/// `netmask`, `broadcast`, and `destination`. For any entry not supported,
+/// the returned list will contain a `None` entry.
+///
+/// # Example
+/// ```
+/// let addrs = nix::ifaddrs::getifaddrs().unwrap();
+/// for ifaddr in addrs {
+/// match ifaddr.address {
+/// Some(address) => {
+/// println!("interface {} address {}",
+/// ifaddr.interface_name, address);
+/// },
+/// None => {
+/// println!("interface {} with unsupported address family",
+/// ifaddr.interface_name);
+/// }
+/// }
+/// }
+/// ```
+pub fn getifaddrs() -> Result<InterfaceAddressIterator> {
+ let mut addrs: *mut libc::ifaddrs = unsafe { mem::uninitialized() };
+ Errno::result(unsafe { libc::getifaddrs(&mut addrs) }).map(|_| {
+ InterfaceAddressIterator {
+ base: addrs,
+ next: addrs,
+ }
+ })
+}
+
+#[cfg(test)]
+mod tests {
+ use super::*;
+
+ // Only checks if `getifaddrs` can be invoked without panicking.
+ #[test]
+ fn test_getifaddrs() {
+ let _ = getifaddrs();
+ }
+}

src/lib.rs

@@ -43,6 +43,15 @@ pub mod poll;
 
 pub mod net;
 
+#[cfg(any(target_os = "dragonfly",
+ target_os = "freebsd",
+ target_os = "ios",
+ target_os = "linux",
+ target_os = "macos",
+ target_os = "netbsd",
+ target_os = "openbsd"))]
+pub mod ifaddrs;
+
 #[cfg(any(target_os = "linux", target_os = "android"))]
 pub mod sched;