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// Copyright (c) 2014-2016 Robert Clipsham <robert@octarineparrot.com> // // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your // option. This file may not be copied, modified, or distributed // except according to those terms. //! Support for sending and receiving data link layer packets extern crate libc; use packet::ethernet::{EtherType, EthernetPacket, MutableEthernetPacket}; use sockets; use std::io; use std::option::Option; use std::time::Duration; use util::MacAddr; use ipnetwork::IpNetwork; #[cfg(windows)] #[path = "winpcap.rs"] mod backend; #[cfg(windows)] pub mod winpcap; #[cfg(all(not(feature = "netmap"), target_os = "linux" ) )] #[path = "linux.rs"] mod backend; #[cfg(target_os = "linux")] pub mod linux; #[cfg(all(not(feature = "netmap"), any(target_os = "freebsd", target_os = "macos") ) )] #[path = "bpf.rs"] mod backend; #[cfg(any(target_os = "freebsd", target_os = "macos"))] pub mod bpf; #[cfg(feature = "netmap")] #[path = "netmap.rs"] mod backend; #[cfg(feature = "netmap")] pub mod netmap; #[cfg(feature = "pcap")] pub mod pcap; pub mod dummy; /// Type of data link channel to present (Linux only) #[derive(Clone, Copy, Debug, Eq, Hash, PartialEq)] pub enum ChannelType { /// Send and receive layer 2 packets directly, including headers Layer2, /// Send and receive "cooked" packets - send and receive network layer packets Layer3(EtherType), } /// A channel for sending and receiving at the data link layer /// /// NOTE: It is important to always include a catch-all variant in match statements using this /// enum, since new variants may be added. For example: /// /// ```ignore /// match some_channel { /// Ethernet(tx, rx) => { /* Handle Ethernet packets */ }, /// _ => panic!("Unhandled channel type") /// } /// ``` pub enum Channel { /// A datalink channel which sends and receives Ethernet packets Ethernet(Box<EthernetDataLinkSender>, Box<EthernetDataLinkReceiver>), /// This variant should never be used /// /// Including it allows new variants to be added to `Channel` without breaking existing code. PleaseIncludeACatchAllVariantWhenMatchingOnThisEnum, } /// A generic configuration type, encapsulating all options supported by each backend /// /// Each option should be treated as a hint - each backend is free to ignore any and all /// options which don't apply to it. #[derive(Clone, Copy, Debug, Eq, Hash, PartialEq)] pub struct Config { /// The size of buffer to use when writing packets. Defaults to 4096 pub write_buffer_size: usize, /// The size of buffer to use when reading packets. Defaults to 4096 pub read_buffer_size: usize, /// Linux/BPF/Netmap only: The read timeout. Defaults to None. pub read_timeout: Option<Duration>, /// Linux/BPF/Netmap only: The write timeout. Defaults to None. pub write_timeout: Option<Duration>, /// Linux only: Specifies whether to read packets at the datalink layer or network layer. /// Defaults to Layer2 pub channel_type: ChannelType, /// BPF/OS X only: The number of /dev/bpf* file descriptors to attempt before failing. Defaults /// to: 1000 pub bpf_fd_attempts: usize, } impl Default for Config { fn default() -> Config { Config { write_buffer_size: 4096, read_buffer_size: 4096, channel_type: ChannelType::Layer2, bpf_fd_attempts: 1000, read_timeout: None, write_timeout: None, } } } /// Create a new datalink channel for sending and receiving data /// /// This allows for sending and receiving packets at the data link layer. /// /// A list of network interfaces can be retrieved using datalink::interfaces(). /// /// The configuration serves as a hint to the backend - some or all of it may be used or ignored, /// depending on which backend is used. /// /// When matching on the returned channel, make sure to include a catch-all so that code doesn't /// break when new channel types are added. #[inline] pub fn channel(network_interface: &NetworkInterface, configuration: Config) -> io::Result<Channel> { backend::channel(network_interface, (&configuration).into()) } macro_rules! dls { ($name:ident, $mut_packet:ident, $packet:ident) => { /// Trait to enable sending $packet packets pub trait $name : Send { /// Create and send a number of packets /// /// This will call `func` `num_packets` times. The function will be provided with a /// mutable packet to manipulate, which will then be sent. This allows packets to be /// built in-place, avoiding the copy required for `send`. If there is not sufficient /// capacity in the buffer, None will be returned. #[inline] fn build_and_send(&mut self, num_packets: usize, packet_size: usize, func: &mut FnMut($mut_packet)) -> Option<io::Result<()>>; /// Send a packet /// /// This may require an additional copy compared to `build_and_send`, depending on the /// operating system being used. The second parameter is currently ignored, however /// `None` should be passed. #[inline] fn send_to(&mut self, packet: &$packet, dst: Option<NetworkInterface>) -> Option<io::Result<()>>; } } } dls!(EthernetDataLinkSender, MutableEthernetPacket, EthernetPacket); macro_rules! dlr { ($recv_name:ident, $iter_name:ident, $packet:ident) => { /// Structure for receiving packets at the data link layer. Should be constructed using /// datalink_channel(). pub trait $recv_name : Send { /// Returns an iterator over `EthernetPacket`s. /// /// This will likely be removed once other layer two types are supported. #[inline] fn iter<'a>(&'a mut self) -> Box<$iter_name + 'a>; } /// An iterator over data link layer packets pub trait $iter_name<'a> { /// Get the next EthernetPacket in the channel #[inline] fn next(&mut self) -> io::Result<$packet>; } } } dlr!(EthernetDataLinkReceiver, EthernetDataLinkChannelIterator, EthernetPacket); /// Represents a network interface and its associated addresses #[derive(Clone, PartialEq, Eq, Debug, Hash)] pub struct NetworkInterface { /// The name of the interface pub name: String, /// The interface index (operating system specific) pub index: u32, /// A MAC address for the interface pub mac: Option<MacAddr>, /// IP addresses and netmasks for the interface pub ips: Vec<IpNetwork>, /// Operating system specific flags for the interface pub flags: u32, } impl NetworkInterface { /// Retrieve the MAC address associated with the interface pub fn mac_address(&self) -> MacAddr { self.mac.unwrap() } /// Is the interface a loopback interface? pub fn is_loopback(&self) -> bool { self.flags & (sockets::IFF_LOOPBACK as u32) != 0 } } /// Get a list of available network interfaces for the current machine. pub fn interfaces() -> Vec<NetworkInterface> { backend::interfaces() }