dhcpclient now listens to netlink for link addition and removal

This commit is contained in:
Xnoe 2022-10-25 23:10:16 +01:00
parent f04132bfe1
commit 65b32a4be5
Signed by: xnoe
GPG Key ID: 45AC398F44F0DAFE
4 changed files with 504 additions and 65 deletions

4
Cargo.lock generated
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@ -31,9 +31,7 @@ checksum = "baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd"
[[package]] [[package]]
name = "dhcprs" name = "dhcprs"
version = "0.1.2" version = "0.1.3"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "fb5849fa01b515c56a6247af5121fa38bb22988e2c0f7216d93e5623417a57ea"
dependencies = [ dependencies = [
"eui48", "eui48",
] ]

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@ -6,7 +6,7 @@ edition = "2021"
# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
[dependencies] [dependencies]
dhcprs = "0.1.2" dhcprs = {version = "0.1.3", path = "../rust-dhcprs"}
nix = "0.25.0" nix = "0.25.0"
libc = "0.2.133" libc = "0.2.133"
eui48 = "1.1.0" eui48 = "1.1.0"

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@ -1,12 +1,22 @@
use nix::sys::socket::*; pub mod rtnetlink;
use std::net::Ipv4Addr;
use eui48::MacAddress; use eui48::MacAddress;
use nix::sys::socket::*;
use rand::prelude::*; use rand::prelude::*;
use std::net::Ipv4Addr;
use dhcprs::dhcp::DHCPOption;
use dhcprs::dhcp::DHCPMessageType; use dhcprs::dhcp::DHCPMessageType;
use dhcprs::dhcp::DHCPOption;
fn create_dhcp_packet(xid: u32, mac: MacAddress, source_ip: Option<Ipv4Addr>, dest_ip: Option<Ipv4Addr>, options: Vec<dhcprs::dhcp::DHCPOption>) -> dhcprs::udpbuilder::RawUDPPacket { use std::collections::HashMap;
fn create_dhcp_packet(
xid: u32,
mac: MacAddress,
source_ip: Option<Ipv4Addr>,
dest_ip: Option<Ipv4Addr>,
options: Vec<dhcprs::dhcp::DHCPOption>,
) -> dhcprs::udpbuilder::RawUDPPacket {
let options_bytes = dhcprs::dhcp::DHCPOption::to_bytes(options); let options_bytes = dhcprs::dhcp::DHCPOption::to_bytes(options);
let mut vend = [0; 312]; let mut vend = [0; 312];
vend[..options_bytes.len()].copy_from_slice(&options_bytes); vend[..options_bytes.len()].copy_from_slice(&options_bytes);
@ -24,15 +34,18 @@ fn create_dhcp_packet(xid: u32, mac: MacAddress, source_ip: Option<Ipv4Addr>, de
mac, mac,
[0; 64], [0; 64],
[0; 128], [0; 128],
vend vend,
); );
let udppacket = dhcprs::udpbuilder::UDPPacket::new( let udppacket = dhcprs::udpbuilder::UDPPacket::new(
source_ip.unwrap_or(Ipv4Addr::new(0,0,0,0)), source_ip.unwrap_or(Ipv4Addr::new(0, 0, 0, 0)),
dest_ip.unwrap_or(Ipv4Addr::new(255,255,255,255)), dest_ip.unwrap_or(Ipv4Addr::new(255, 255, 255, 255)),
68, 68,
67, 67,
dhcprs::bootp::RawBOOTPPacket::from(bootppacket).as_bytes().try_into().unwrap() dhcprs::bootp::RawBOOTPPacket::from(bootppacket)
.as_bytes()
.try_into()
.unwrap(),
); );
return dhcprs::udpbuilder::RawUDPPacket::from(udppacket); return dhcprs::udpbuilder::RawUDPPacket::from(udppacket);
@ -43,33 +56,46 @@ enum DHCPTransactionState {
WaitingAfterDiscover, WaitingAfterDiscover,
Request, Request,
WaitAfterRequest, WaitAfterRequest,
Renew,
WaitAfterRenew,
Rebind,
WaitafterRebind,
} }
fn dhcp_client(name: String, mac: LinkAddr) { fn dhcp_client(name: String, index: i32, mac: [u8; 6]) {
let mut rng = rand::thread_rng(); let mut rng = rand::thread_rng();
// Before we can do anything else, we need to construct an LinkAddr for the mac ff:ff:ff:ff:ff:ff // Before we can do anything else, we need to construct an LinkAddr for the mac ff:ff:ff:ff:ff:ff
println!("Starting DHCP on interface {}", name);
let sockaddr_ll = libc::sockaddr_ll { let sockaddr_ll = libc::sockaddr_ll {
sll_family: libc::AF_PACKET as u16, sll_family: libc::AF_PACKET as u16,
sll_halen: mac.halen() as u8, sll_halen: 6,
sll_hatype: mac.hatype(), sll_hatype: 1,
sll_ifindex: mac.ifindex() as i32, sll_ifindex: index,
sll_addr: [0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0, 0], sll_addr: [0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0, 0],
sll_pkttype: mac.pkttype(), sll_pkttype: 0,
sll_protocol: 0x0008 sll_protocol: 0x0008,
}; };
let mut linkaddr = unsafe {LinkAddr::from_raw(&sockaddr_ll as *const libc::sockaddr_ll as *const libc::sockaddr, Some(20)).expect("Failed to create linkaddr!")}; let mut linkaddr = unsafe {
LinkAddr::from_raw(
&sockaddr_ll as *const libc::sockaddr_ll as *const libc::sockaddr,
Some(20),
)
.expect("Failed to create linkaddr!")
};
// Create and bind the socket // Create and bind the socket
let socket = socket(AddressFamily::Packet, SockType::Datagram, SockFlag::empty(), SockProtocol::Udp).expect("Failed to create socket! Permission issue?"); let socket = socket(
AddressFamily::Packet,
SockType::Datagram,
SockFlag::empty(),
SockProtocol::Udp,
)
.expect("Failed to create socket! Permission issue?");
assert!(setsockopt(socket, sockopt::Broadcast, &true).is_ok()); assert!(setsockopt(socket, sockopt::Broadcast, &true).is_ok());
assert!(bind(socket, &linkaddr).is_ok()); assert!(bind(socket, &linkaddr).is_ok());
let client_mac = MacAddress::from_bytes(&mac.addr().unwrap()).unwrap(); let client_mac = MacAddress::from_bytes(&mac).unwrap();
let mut client_addr: Option<Ipv4Addr> = None; let mut client_addr: Option<Ipv4Addr> = None;
let mut server_addr: Option<Ipv4Addr> = None; let mut server_addr: Option<Ipv4Addr> = None;
@ -84,10 +110,30 @@ fn dhcp_client(name: String, mac: LinkAddr) {
match &dhcp_state { match &dhcp_state {
DHCPTransactionState::Discover => { DHCPTransactionState::Discover => {
println!("Sent DHCPDiscover on {}", name); println!("Sent DHCPDiscover on {}", name);
let _ = sendto(socket, create_dhcp_packet(xid, client_mac, None, None, vec![ loop {
DHCPOption::DHCPMessageType(DHCPMessageType::DHCPDiscover), match sendto(
DHCPOption::End socket,
]).as_bytes(), &linkaddr, MsgFlags::empty()).unwrap(); create_dhcp_packet(
xid,
client_mac,
None,
None,
vec![
DHCPOption::DHCPMessageType(DHCPMessageType::DHCPDiscover),
DHCPOption::End,
],
)
.as_bytes(),
&linkaddr,
MsgFlags::empty(),
) {
Ok(_) => break,
Err(nix::errno::Errno::ENETDOWN) => {
unsafe { libc::sleep(3) };
}
Err(_) => panic!("")
}
}
dhcp_state = DHCPTransactionState::WaitingAfterDiscover; dhcp_state = DHCPTransactionState::WaitingAfterDiscover;
} }
@ -97,15 +143,17 @@ fn dhcp_client(name: String, mac: LinkAddr) {
println!("Received {} bytes on {}", bytes, name); println!("Received {} bytes on {}", bytes, name);
let udppacet_raw: dhcprs::udpbuilder::RawUDPPacket = unsafe {std::ptr::read(packet.as_ptr() as *const _)}; let udppacket_raw: dhcprs::udpbuilder::RawUDPPacket =
let udppacket: dhcprs::udpbuilder::UDPPacket = udppacet_raw.into(); unsafe { std::ptr::read(packet.as_ptr() as *const _) };
let udppacket: dhcprs::udpbuilder::UDPPacket = udppacket_raw.into();
if udppacket.source_port != 67 { if udppacket.source_port != 67 {
// Not a BOOTP reply, get the next packet. // Not a BOOTP reply, get the next packet.
continue 'dhcp_message_loop; continue 'dhcp_message_loop;
}; };
let bootppacket_raw: dhcprs::bootp::RawBOOTPPacket = unsafe {std::ptr::read(udppacket.get_data().as_ptr() as *const _)}; let bootppacket_raw: dhcprs::bootp::RawBOOTPPacket =
unsafe { std::ptr::read(udppacket.get_data().as_ptr() as *const _) };
let bootppacket: dhcprs::bootp::BOOTPPacket = bootppacket_raw.into(); let bootppacket: dhcprs::bootp::BOOTPPacket = bootppacket_raw.into();
if bootppacket.xid != xid { if bootppacket.xid != xid {
@ -113,9 +161,20 @@ fn dhcp_client(name: String, mac: LinkAddr) {
continue 'dhcp_message_loop; continue 'dhcp_message_loop;
}; };
let options = dhcprs::dhcp::DHCPOption::from_bytes(&bootppacket.get_vend()[4..]); let options =
dhcprs::dhcp::DHCPOption::from_bytes(&bootppacket.get_vend()[4..]);
if !options.iter().find(|&x| if let DHCPOption::DHCPMessageType(DHCPMessageType::DHCPOffer) = x {true} else {false}).is_some() { if !options
.iter()
.find(|&x| {
if let DHCPOption::DHCPMessageType(DHCPMessageType::DHCPOffer) = x {
true
} else {
false
}
})
.is_some()
{
// We got a response but it wasn't the expected message, try again with another transaction. // We got a response but it wasn't the expected message, try again with another transaction.
continue 'dhcp_transaction; continue 'dhcp_transaction;
} }
@ -125,8 +184,14 @@ fn dhcp_client(name: String, mac: LinkAddr) {
client_addr = bootppacket.yiaddr; client_addr = bootppacket.yiaddr;
server_addr = bootppacket.siaddr; server_addr = bootppacket.siaddr;
println!("Got client address: {}", client_addr.unwrap_or(Ipv4Addr::new(0,0,0,0))); println!(
println!("Got server address: {}", server_addr.unwrap_or(Ipv4Addr::new(0,0,0,0))); "Got client address: {}",
client_addr.unwrap_or(Ipv4Addr::new(0, 0, 0, 0))
);
println!(
"Got server address: {}",
server_addr.unwrap_or(Ipv4Addr::new(0, 0, 0, 0))
);
// Update the linkaddr to be the server's actual hardware address rather than the broadcast MAC. // Update the linkaddr to be the server's actual hardware address rather than the broadcast MAC.
let mut mac: [u8; 8] = [0; 8]; let mut mac: [u8; 8] = [0; 8];
@ -138,21 +203,41 @@ fn dhcp_client(name: String, mac: LinkAddr) {
sll_ifindex: sockaddr_ll.sll_ifindex, sll_ifindex: sockaddr_ll.sll_ifindex,
sll_addr: mac, sll_addr: mac,
sll_pkttype: sockaddr_ll.sll_pkttype, sll_pkttype: sockaddr_ll.sll_pkttype,
sll_protocol: sockaddr_ll.sll_protocol sll_protocol: sockaddr_ll.sll_protocol,
}; };
linkaddr = unsafe {LinkAddr::from_raw(&new_sockaddr_ll as *const libc::sockaddr_ll as *const libc::sockaddr, Some(20)).expect("Failed to update linkaddr to server's hardware address!")}; linkaddr = unsafe {
LinkAddr::from_raw(
&new_sockaddr_ll as *const libc::sockaddr_ll as *const libc::sockaddr,
Some(20),
)
.expect("Failed to update linkaddr to server's hardware address!")
};
dhcp_state = DHCPTransactionState::Request; dhcp_state = DHCPTransactionState::Request;
} }
DHCPTransactionState::Request => { DHCPTransactionState::Request => {
println!("Sent DHCPRequest on {}", name); println!("Sent DHCPRequest on {}", name);
let _ = sendto(socket, create_dhcp_packet(xid, client_mac, client_addr, server_addr, vec![ let _ = sendto(
DHCPOption::DHCPMessageType(DHCPMessageType::DHCPRequest), socket,
DHCPOption::ParameterRequest(vec![1, 3, 6, 28]), create_dhcp_packet(
DHCPOption::End xid,
]).as_bytes(), &linkaddr, MsgFlags::empty()); client_mac,
None,
None,
vec![
DHCPOption::DHCPMessageType(DHCPMessageType::DHCPRequest),
DHCPOption::RequestIPAddress(client_addr.unwrap()),
DHCPOption::ServerIdentifier(server_addr.unwrap()),
DHCPOption::ParameterRequest(vec![1, 3, 6, 28, 121]),
DHCPOption::End,
],
)
.as_bytes(),
&linkaddr,
MsgFlags::empty(),
);
dhcp_state = DHCPTransactionState::WaitAfterRequest; dhcp_state = DHCPTransactionState::WaitAfterRequest;
} }
@ -161,15 +246,17 @@ fn dhcp_client(name: String, mac: LinkAddr) {
let (bytes, _) = recvfrom::<LinkAddr>(socket, &mut packet).unwrap(); let (bytes, _) = recvfrom::<LinkAddr>(socket, &mut packet).unwrap();
println!("Received {} bytes on {}", bytes, name); println!("Received {} bytes on {}", bytes, name);
let udppacet_raw: dhcprs::udpbuilder::RawUDPPacket = unsafe {std::ptr::read(packet.as_ptr() as *const _)}; let udppacket_raw: dhcprs::udpbuilder::RawUDPPacket =
let udppacket: dhcprs::udpbuilder::UDPPacket = udppacet_raw.into(); unsafe { std::ptr::read(packet.as_ptr() as *const _) };
let udppacket: dhcprs::udpbuilder::UDPPacket = udppacket_raw.into();
if udppacket.source_port != 67 { if udppacket.source_port != 67 {
// Not a BOOTP reply, get the next packet. // Not a BOOTP reply, get the next packet.
continue 'dhcp_message_loop; continue 'dhcp_message_loop;
}; };
let bootppacket_raw: dhcprs::bootp::RawBOOTPPacket = unsafe {std::ptr::read(udppacket.get_data().as_ptr() as *const _)}; let bootppacket_raw: dhcprs::bootp::RawBOOTPPacket =
unsafe { std::ptr::read(udppacket.get_data().as_ptr() as *const _) };
let bootppacket: dhcprs::bootp::BOOTPPacket = bootppacket_raw.into(); let bootppacket: dhcprs::bootp::BOOTPPacket = bootppacket_raw.into();
if bootppacket.xid != xid { if bootppacket.xid != xid {
@ -177,9 +264,20 @@ fn dhcp_client(name: String, mac: LinkAddr) {
continue 'dhcp_message_loop; continue 'dhcp_message_loop;
}; };
let options = dhcprs::dhcp::DHCPOption::from_bytes(&bootppacket.get_vend()[4..]); let options =
dhcprs::dhcp::DHCPOption::from_bytes(&bootppacket.get_vend()[4..]);
if !options.iter().find(|&x| if let DHCPOption::DHCPMessageType(DHCPMessageType::DHCPACK) = x {true} else {false}).is_some() { if !options
.iter()
.find(|&x| {
if let DHCPOption::DHCPMessageType(DHCPMessageType::DHCPACK) = x {
true
} else {
false
}
})
.is_some()
{
// Wasn't an ACK, probably NAK, try again. // Wasn't an ACK, probably NAK, try again.
println!("Did not receive ACK from DHCPRequest, sleeping for 10secs before continuing."); println!("Did not receive ACK from DHCPRequest, sleeping for 10secs before continuing.");
std::thread::sleep(core::time::Duration::new(10, 0)); std::thread::sleep(core::time::Duration::new(10, 0));
@ -192,11 +290,9 @@ fn dhcp_client(name: String, mac: LinkAddr) {
println!("Received: {:?}", option); println!("Received: {:?}", option);
match option { match option {
DHCPOption::IPAddressLeaseTime(n) => { DHCPOption::IPAddressLeaseTime(n) => sleep_time = n,
sleep_time = n
}
_ => () _ => (),
} }
} }
@ -204,22 +300,75 @@ fn dhcp_client(name: String, mac: LinkAddr) {
std::thread::sleep(core::time::Duration::new(sleep_time.into(), 0)); std::thread::sleep(core::time::Duration::new(sleep_time.into(), 0));
} }
_ => () _ => panic!("Fail!"),
} }
} }
} }
} }
fn main() { fn zascii(slice: &[libc::c_char]) -> String {
let threads: Vec<std::thread::JoinHandle<()>> = nix::ifaddrs::getifaddrs().unwrap() String::from_iter(
.filter(|x| x.address.is_some()) slice
.filter(|x| x.address.unwrap().as_link_addr().is_some()) .iter()
.filter(|x| x.address.unwrap().as_link_addr().unwrap().hatype() == 1) // Only perform DHCP on Ethernet interfaces. .take_while(|c| **c != 0)
.map(|x| (x.interface_name, *x.address.unwrap().as_link_addr().unwrap())) .map(|c| *c as u8 as char),
.map(|(name, mac)| std::thread::spawn(move || { dhcp_client(name, mac)} )) )
.collect(); }
for thread in threads { fn main() {
let _ = thread.join(); let mut thread_map: HashMap<[u8; 6], libc::c_int> = HashMap::new();
let iterator = rtnetlink::new_interface_iterator().unwrap();
for message in iterator {
let interface: rtnetlink::InterfaceDetails;
match message {
rtnetlink::MessageType::NewLink(i) => {
interface = i;
let name = zascii(&interface.name);
println!("New Link");
if let None = thread_map.get(&interface.hwaddr) {
println!("Starting DHCP on {}", name);
unsafe {
match libc::fork() {
x if x < 0 => panic!("Failed to fork!"),
0 => dhcp_client(name, interface.index, interface.hwaddr),
pid => {
println!("Started DHCP on {} PID {}", name, pid);
thread_map.insert(interface.hwaddr, pid);
}
}
}
}
}
rtnetlink::MessageType::DelLink(i) => {
interface = i;
let name = zascii(&interface.name);
println!("Del Link");
if let Some(pid) = thread_map.get(&interface.hwaddr) {
println!("Stopping DHCP on {}", name);
unsafe {
libc::kill(*pid, libc::SIGTERM);
}
thread_map.remove(&interface.hwaddr);
}
}
}
let name = zascii(&interface.name);
println!("Name: {}", name);
println!(
"MAC: {:02X}:{:02X}:{:02X}:{:02X}:{:02X}:{:02X}",
interface.hwaddr[0],
interface.hwaddr[1],
interface.hwaddr[2],
interface.hwaddr[3],
interface.hwaddr[4],
interface.hwaddr[5]
);
println!("Index: {}", interface.index);
} }
} }

292
src/rtnetlink.rs Normal file
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@ -0,0 +1,292 @@
use eui48::MacAddress;
#[repr(C)]
struct ifinfomsg {
ifi_family: libc::__u8,
ifi_pad: libc::__u8,
ifi_type: libc::__u16,
ifi_index: libc::c_int,
ifi_flags: libc::__u32,
ifi_change: libc::__u32,
}
const nlmsg_alignto: u32 = 4;
macro_rules! nlmsg_align {
($len:expr) => {
($len as u32 + (nlmsg_alignto - 1)) & !(nlmsg_alignto - 1)
};
}
const nlmsg_hdrlen: usize = nlmsg_align!(std::mem::size_of::<libc::nlmsghdr>()) as usize;
macro_rules! nlmsg_length {
($len:expr) => {
$len as u32 + nlmsg_hdrlen as u32
};
}
macro_rules! nlmsg_space {
($len:expr) => {
nlmsg_align!(nlmsg_length!($len))
};
}
#[inline]
unsafe fn nlmsg_data(nlh: *const libc::nlmsghdr) -> *const u8 {
return (nlh as *const u8).offset(nlmsg_hdrlen as isize);
}
#[inline]
unsafe fn nlmsg_next(nlh: *const libc::nlmsghdr, len: &mut u32) -> *const libc::nlmsghdr {
*len -= nlmsg_align!((*nlh).nlmsg_len);
return (nlh as *const u8).offset(nlmsg_align!((*nlh).nlmsg_len) as isize)
as *const libc::nlmsghdr;
}
#[inline]
unsafe fn nlmsg_ok(nlh: *const libc::nlmsghdr, len: &mut u32) -> bool {
return *len >= std::mem::size_of::<libc::nlmsghdr>() as u32
&& (*nlh).nlmsg_len >= std::mem::size_of::<libc::nlmsghdr>() as u32
&& (*nlh).nlmsg_len <= *len;
}
#[inline]
unsafe fn nlmsg_payload(nlh: *const libc::nlmsghdr, len: &mut u32) -> u32 {
return (*nlh).nlmsg_len - nlmsg_space!(*len);
}
#[repr(C)]
struct rtattr {
rta_len: libc::c_ushort,
rta_type: libc::c_ushort,
}
const rta_alignto: u32 = 4;
macro_rules! rta_align {
($len:expr) => {
($len as u32 + (rta_alignto - 1)) & !(rta_alignto - 1)
};
}
#[inline]
unsafe fn rta_ok(rta: *const rtattr, len: &mut u32) -> bool {
return *len >= std::mem::size_of::<rtattr>() as u32
&& (*rta).rta_len >= std::mem::size_of::<rtattr>() as libc::c_ushort
&& (*rta).rta_len <= *len as libc::c_ushort;
}
#[inline]
unsafe fn rta_next(rta: *const rtattr, len: &mut u32) -> *const rtattr {
*len -= rta_align!((*rta).rta_len);
return (rta as *const u8).offset(nlmsg_align!((*rta).rta_len) as isize) as *const rtattr;
}
#[inline]
fn rta_length(len: u32) -> u32 {
return std::mem::size_of::<rtattr>() as u32 + len;
}
#[inline]
fn rta_space(len: u32) -> u32 {
rta_align!(rta_length(len))
}
#[inline]
unsafe fn rta_data(rta: *const rtattr) -> *const u8 {
return (rta as *const u8).offset(rta_length(0) as isize);
}
struct RtAttrs {
current_attr: *const rtattr,
current_size: u32,
}
impl Iterator for RtAttrs {
type Item = *const rtattr;
fn next(&mut self) -> Option<Self::Item> {
unsafe {
if rta_ok(self.current_attr, &mut self.current_size) {
let hdr = self.current_attr;
self.current_attr = rta_next(self.current_attr, &mut self.current_size);
return Some(hdr);
} else {
None
}
}
}
}
#[inline]
unsafe fn ifla_rta(r: *const ifinfomsg) -> *const rtattr {
return (r as *const u8).offset(nlmsg_align!(std::mem::size_of::<ifinfomsg>()) as isize)
as *const rtattr;
}
pub struct InterfaceIterator {
socket: libc::c_int,
src_addr: libc::sockaddr_nl,
dest_addr: libc::sockaddr_nl,
subscribed: bool,
buffer: [u8; 4096],
current_header: Option<*const libc::nlmsghdr>,
current_len: u32,
}
pub fn new_interface_iterator() -> Result<InterfaceIterator, String> {
let socket;
let mut src_addr = unsafe { std::mem::zeroed::<libc::sockaddr_nl>() };
let mut dest_addr = unsafe { std::mem::zeroed::<libc::sockaddr_nl>() };
src_addr.nl_family = libc::AF_NETLINK as u16;
src_addr.nl_groups = libc::RTMGRP_LINK as u32;
src_addr.nl_pid = unsafe { libc::getpid() } as u32;
dest_addr.nl_family = libc::AF_NETLINK as u16;
unsafe {
socket = libc::socket(libc::AF_NETLINK, libc::SOCK_RAW, libc::NETLINK_ROUTE);
if socket == -1 {
return Err("Failed to create AF_NETLINK socket!".to_string());
}
if libc::bind(
socket,
&src_addr as *const libc::sockaddr_nl as *const libc::sockaddr,
std::mem::size_of::<libc::sockaddr>() as u32,
) == -1
{
return Err("Failed to bind to AF_NETLINK socket!".to_string());
}
}
let mut request = unsafe { std::mem::zeroed::<(libc::nlmsghdr, ifinfomsg)>() };
request.0.nlmsg_len = nlmsg_length!(std::mem::size_of::<ifinfomsg>());
request.0.nlmsg_type = libc::RTM_GETLINK;
request.0.nlmsg_flags = (libc::NLM_F_REQUEST | libc::NLM_F_DUMP) as u16;
request.1.ifi_family = libc::AF_NETLINK as u8;
let mut iov = libc::iovec {
iov_base: &mut request as *mut _ as *mut libc::c_void,
iov_len: request.0.nlmsg_len as usize,
};
let mut msg = unsafe { std::mem::zeroed::<libc::msghdr>() };
msg.msg_name = &mut dest_addr as *mut _ as *mut libc::c_void;
msg.msg_namelen = std::mem::size_of::<libc::sockaddr_nl>() as u32;
msg.msg_iov = &mut iov as *mut libc::iovec;
msg.msg_iovlen = 1;
if unsafe { libc::sendmsg(socket, &msg as *const libc::msghdr, 0) } < 0 {
return Err("Failed to send interface request!".to_string());
}
Ok(InterfaceIterator {
socket: socket,
src_addr: src_addr,
dest_addr: dest_addr,
subscribed: true,
buffer: [0; 4096],
current_header: None,
current_len: 0,
})
}
pub struct InterfaceDetails {
pub index: i32,
pub name: [libc::c_char; libc::IFNAMSIZ],
pub hwaddr: [u8; 6],
}
pub enum MessageType {
NewLink(InterfaceDetails),
DelLink(InterfaceDetails),
}
impl Iterator for InterfaceIterator {
type Item = MessageType;
fn next(&mut self) -> Option<Self::Item> {
loop {
if let None = self.current_header {
let mut recv_iov = libc::iovec {
iov_base: &mut self.buffer as *mut _ as *mut libc::c_void,
iov_len: 4096,
};
let mut msg = unsafe { std::mem::zeroed::<libc::msghdr>() };
msg.msg_name = &mut self.dest_addr as *mut _ as *mut libc::c_void;
msg.msg_namelen = std::mem::size_of::<libc::sockaddr_nl>() as u32;
msg.msg_iov = &mut recv_iov as *mut libc::iovec;
msg.msg_iovlen = 1;
let n = unsafe { libc::recvmsg(self.socket, &mut msg as *mut libc::msghdr, 0) };
if n < 0 {
panic!("Failed to receive on AF_NETLINK socket!");
}
self.current_header = Some(&self.buffer as *const _ as *const libc::nlmsghdr);
self.current_len = n as u32;
}
if unsafe { !nlmsg_ok(self.current_header.unwrap(), &mut self.current_len) } {
self.current_header = None;
continue;
}
if unsafe { (*self.current_header.unwrap()).nlmsg_type } == libc::NLMSG_DONE as u16 {
self.current_header = None;
continue;
}
let hdr = self.current_header.unwrap();
self.current_header =
Some(unsafe { nlmsg_next(self.current_header.unwrap(), &mut self.current_len) });
let ifi = unsafe { std::ptr::read(nlmsg_data(hdr) as *const ifinfomsg) };
if ifi.ifi_type != 1 {
continue;
}
let mut addr: [u8; 6] = [0; 6];
let mut name: [libc::c_char; libc::IFNAMSIZ] = [0; libc::IFNAMSIZ];
for attr in (RtAttrs {
current_attr: unsafe { ifla_rta(nlmsg_data(hdr) as *const ifinfomsg) },
current_size: unsafe { (*hdr).nlmsg_len }
- std::mem::size_of::<libc::nlmsghdr>() as u32,
}) {
match unsafe { (*attr).rta_type } {
libc::IFLA_ADDRESS => {
addr = unsafe { std::ptr::read(rta_data(attr) as *const [u8; 6]) };
}
libc::IFLA_IFNAME => {
name = unsafe {
std::ptr::read(rta_data(attr) as *const [libc::c_char; libc::IFNAMSIZ])
};
}
_ => (),
}
}
let interfacedetails = InterfaceDetails {
index: ifi.ifi_index,
name: name,
hwaddr: addr,
};
match unsafe { (*hdr).nlmsg_type } {
libc::RTM_NEWLINK => return Some(MessageType::NewLink(interfacedetails)),
libc::RTM_DELLINK => return Some(MessageType::DelLink(interfacedetails)),
_ => panic!("Unknown Message Received! {}", unsafe { (*hdr).nlmsg_type }),
}
}
}
}