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nzrdhcp: make it actually work

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* Check the DHCP options for the requested IPv4 address
* Update yiaddr, not siaddr or ciaddr
* Read the RFC a tenth time. I think I've got it now
This commit is contained in:
snow flurry 2024-08-10 01:33:31 -07:00
parent 9ca1b0c821
commit 3d0ea1f2ef
2 changed files with 81 additions and 43 deletions
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3
nzrd/src/ctx.rs
View file

@ -3,6 +3,7 @@ use diesel::{
SqliteConnection,
};
use diesel_migrations::{embed_migrations, EmbeddedMigrations, MigrationHarness};
use log::trace;
use nzr_virt::{vol, Connection};
use std::ops::Deref;
use thiserror::Error;
@ -64,6 +65,7 @@ impl InnerCtx {
baseimg: conn.get_pool(&config.storage.base_image_pool).await?,
};
trace!("Connecting to database");
let db_uri = config.db_uri.clone();
let sqldb = tokio::task::spawn_blocking(|| {
let manager = ConnectionManager::<SqliteConnection>::new(db_uri);
@ -74,6 +76,7 @@ impl InnerCtx {
.unwrap()?;
{
trace!("Running pending migrations");
let mut conn = sqldb.get()?;
tokio::task::spawn_blocking(move || {
conn.run_pending_migrations(MIGRATIONS)

121
nzrdhcp/src/main.rs
View file

@ -5,7 +5,7 @@ use std::{net::Ipv4Addr, process::ExitCode};
use ctx::Context;
use dhcproto::{
v4::{DhcpOption, Message, MessageType, Opcode, OptionCode},
Decodable, Decoder,
Decodable, Decoder, Encodable, Encoder,
};
use nzr_api::{config::Config, net::mac::MacAddr};
use std::net::SocketAddr;
@ -16,9 +16,9 @@ const DEFAULT_LEASE: u32 = 86400;
fn make_reply(msg: &Message, msg_type: MessageType, lease_addr: Option<Ipv4Addr>) -> Message {
let mut resp = Message::new(
EMPTY_V4,
EMPTY_V4,
lease_addr.unwrap_or(EMPTY_V4),
EMPTY_V4,
msg.giaddr(),
msg.chaddr(),
);
@ -46,6 +46,7 @@ async fn handle_message(ctx: &Context, from: SocketAddr, msg: &Message) {
tracing::info!("Received DHCP payload with invalid addr (different media type?)");
return;
};
tracing::debug!("Client MAC is {client_mac}!!!");
let instance = match ctx.instance_by_mac(client_mac).await {
Ok(Some(i)) => i,
@ -59,6 +60,11 @@ async fn handle_message(ctx: &Context, from: SocketAddr, msg: &Message) {
}
};
tracing::info!(
"Recieved {msg_type:?} from {client_mac} (assuming {})",
&instance.name
);
let mut lease_time = None;
let mut nak = false;
@ -68,12 +74,18 @@ async fn handle_message(ctx: &Context, from: SocketAddr, msg: &Message) {
make_reply(msg, MessageType::Offer, Some(instance.lease.addr.addr))
}
MessageType::Request => {
if msg.ciaddr() != instance.lease.addr.addr {
if let Some(DhcpOption::RequestedIpAddress(addr)) =
msg.opts().get(OptionCode::RequestedIpAddress)
{
if *addr == instance.lease.addr.addr {
make_reply(msg, MessageType::Ack, Some(instance.lease.addr.addr))
} else {
nak = true;
make_reply(msg, MessageType::Nak, None)
}
} else {
nak = true;
make_reply(msg, MessageType::Nak, None)
} else {
lease_time = Some(DEFAULT_LEASE);
make_reply(msg, MessageType::Ack, Some(instance.lease.addr.addr))
}
}
MessageType::Decline => {
@ -86,57 +98,80 @@ async fn handle_message(ctx: &Context, from: SocketAddr, msg: &Message) {
}
MessageType::Release => {
// We only provide static leases
tracing::trace!("Ignoring DHCPRELEASE");
tracing::debug!("Ignoring DHCPRELEASE");
return;
}
MessageType::Inform => make_reply(msg, MessageType::Ack, None),
other => {
tracing::trace!("Received unhandled message {other:?}");
tracing::info!("Received unhandled message {other:?}");
return;
}
};
let opts = response.opts_mut();
let giaddr = if msg.giaddr().is_unspecified() {
todo!("no relay??")
} else {
msg.giaddr()
};
opts.insert(DhcpOption::ServerIdentifier(giaddr));
if let Some(time) = lease_time {
opts.insert(DhcpOption::AddressLeaseTime(time));
}
if !nak {
// Get general networking info
let subnet = match ctx.get_subnet(&instance.lease.subnet).await {
Ok(Some(net)) => net,
Ok(None) => {
tracing::error!("nzrd says '{}' isn't a subnet", &instance.lease.subnet);
return;
}
Err(err) => {
tracing::error!("Error getting subnet: {err}");
return;
}
{
let opts = response.opts_mut();
let giaddr = if msg.giaddr().is_unspecified() {
todo!("no relay??")
} else {
msg.giaddr()
};
opts.insert(DhcpOption::Hostname(instance.name.clone()));
if !subnet.dns.is_empty() {
opts.insert(DhcpOption::DomainNameServer(subnet.dns));
opts.insert(DhcpOption::ServerIdentifier(giaddr));
if let Some(time) = lease_time {
opts.insert(DhcpOption::AddressLeaseTime(time));
}
if let Some(name) = subnet.domain_name {
opts.insert(DhcpOption::DomainName(name.to_utf8()));
}
if !nak {
// Get general networking info
let subnet = match ctx.get_subnet(&instance.lease.subnet).await {
Ok(Some(net)) => net,
Ok(None) => {
tracing::error!("nzrd says '{}' isn't a subnet", &instance.lease.subnet);
return;
}
Err(err) => {
tracing::error!("Error getting subnet: {err}");
return;
}
};
if let Some(gw) = subnet.gateway4 {
opts.insert(DhcpOption::Router(Vec::from(&[gw])));
}
opts.insert(DhcpOption::Hostname(instance.name.clone()));
opts.insert(DhcpOption::SubnetMask(instance.lease.addr.netmask()));
if !subnet.dns.is_empty() {
opts.insert(DhcpOption::DomainNameServer(subnet.dns));
}
if let Some(name) = subnet.domain_name {
opts.insert(DhcpOption::DomainName(name.to_utf8()));
}
if let Some(gw) = subnet.gateway4 {
opts.insert(DhcpOption::Router(Vec::from(&[gw])));
}
opts.insert(DhcpOption::SubnetMask(instance.lease.addr.netmask()));
}
}
tracing::info!(
"Sending message {:?} with yiaddr {}",
response
.opts()
.get(OptionCode::MessageType)
.unwrap_or(&DhcpOption::End),
response.yiaddr()
);
// unicast it back
let mut resp_buf = Vec::new();
let mut enc = Encoder::new(&mut resp_buf);
if let Err(err) = response.encode(&mut enc) {
tracing::error!("Couldn't encode response: {err}");
return;
}
if let Err(err) = ctx.sock().send_to(&resp_buf, from).await {
tracing::error!("Couldn't send response: {err}");
}
}