support clients that don't send a client identifier0.2.6

Uses the chaddr field to generate a client id based on the MAC address preceeded by 0x01. Increases compatibility with IoT devices.

5 files changed, 25 insertions, 27 deletions

diff --git a/Cargo.lock b/Cargo.lock
index ddc116e..e411266 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -531,7 +531,7 @@ dependencies = [
 
 [[package]]
 name = "rsdsl_dhcp4d"
-version = "0.2.5"
+version = "0.2.6"
 dependencies = [
  "dhcproto",
  "ipnet",
diff --git a/Cargo.toml b/Cargo.toml
index a35ebcf..f731b2e 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "rsdsl_dhcp4d"
-version = "0.2.5"
+version = "0.2.6"
 authors = ["HimbeerserverDE <himbeerserverde@gmail.com>"]
 license = "MIT"
 edition = "2021"
diff --git a/src/error.rs b/src/error.rs
index baa97cb..8d149ee 100644
--- a/src/error.rs
+++ b/src/error.rs
@@ -5,16 +5,12 @@ use thiserror::Error;
 
 #[derive(Debug, Error)]
 pub enum Error {
-    #[error("empty client id")]
-    EmptyClientId,
     #[error("unhandled or unknown message type {0:?}")]
     InvalidMsgType(MessageType),
     #[error("unhandled or unknown opcode {0:?}")]
     InvalidOpcode(Opcode),
     #[error("missing ip address in dhcprequest")]
     NoAddrRequested,
-    #[error("missing client id")]
-    NoClientId,
     #[error("no ipv4 address on interface {0}")]
     NoIpv4Addr(String),
     #[error("missing message type")]
diff --git a/src/main.rs b/src/main.rs
index e3b0629..0de6529 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,5 +1,5 @@
 use rsdsl_dhcp4d::lease::{LeaseFileManager, LeaseFileManagerConfig, LeaseManager};
-use rsdsl_dhcp4d::util::{format_client_id, local_ip, setsockopt};
+use rsdsl_dhcp4d::util::*;
 use rsdsl_dhcp4d::{Error, Result};
 
 use std::ffi::CString;
@@ -142,10 +142,8 @@ fn handle_request<T: LeaseManager>(
 
             match msg_type {
                 MessageType::Discover => {
-                    let client_id = match opts
-                        .get(OptionCode::ClientIdentifier)
-                        .ok_or(Error::NoClientId)?
-                    {
+                    let chid = gen_client_id(msg.chaddr());
+                    let client_id = match opts.get(OptionCode::ClientIdentifier).unwrap_or(&chid) {
                         DhcpOption::ClientIdentifier(id) => id,
                         _ => unreachable!(),
                     };
@@ -193,7 +191,7 @@ fn handle_request<T: LeaseManager>(
                         println!(
                             "[info] offer {} client id {} lease time {:?} on {}",
                             lease.address,
-                            format_client_id(client_id)?,
+                            format_client_id(client_id),
                             lease.lease_time,
                             link
                         );
@@ -204,10 +202,8 @@ fn handle_request<T: LeaseManager>(
                 MessageType::Request => {
                     let mut lease_mgr = lease_mgr.lock().unwrap();
 
-                    let client_id = match opts
-                        .get(OptionCode::ClientIdentifier)
-                        .ok_or(Error::NoClientId)?
-                    {
+                    let chid = gen_client_id(msg.chaddr());
+                    let client_id = match opts.get(OptionCode::ClientIdentifier).unwrap_or(&chid) {
                         DhcpOption::ClientIdentifier(id) => id,
                         _ => unreachable!(),
                     };
@@ -261,14 +257,14 @@ fn handle_request<T: LeaseManager>(
                             println!(
                                 "[info] nak {} client id {} on {} (renew)",
                                 requested_addr,
-                                format_client_id(client_id)?,
+                                format_client_id(client_id),
                                 link
                             );
                         } else {
                             println!(
                                 "[info] nak {} client id {} on {}",
                                 requested_addr,
-                                format_client_id(client_id)?,
+                                format_client_id(client_id),
                                 link
                             );
                         }
@@ -303,7 +299,7 @@ fn handle_request<T: LeaseManager>(
                             println!(
                                 "[info] ack {} client id {} lease time {:?} on {} (renew)",
                                 requested_addr,
-                                format_client_id(client_id)?,
+                                format_client_id(client_id),
                                 lease_time,
                                 link
                             );
@@ -311,7 +307,7 @@ fn handle_request<T: LeaseManager>(
                             println!(
                                 "[info] ack {} client id {} lease time {:?} on {}",
                                 requested_addr,
-                                format_client_id(client_id)?,
+                                format_client_id(client_id),
                                 lease_time,
                                 link
                             );
@@ -325,10 +321,8 @@ fn handle_request<T: LeaseManager>(
                     Ok(())
                 }
                 MessageType::Release => {
-                    let client_id = match opts
-                        .get(OptionCode::ClientIdentifier)
-                        .ok_or(Error::NoClientId)?
-                    {
+                    let chid = gen_client_id(msg.chaddr());
+                    let client_id = match opts.get(OptionCode::ClientIdentifier).unwrap_or(&chid) {
                         DhcpOption::ClientIdentifier(id) => id,
                         _ => unreachable!(),
                     };
@@ -344,7 +338,7 @@ fn handle_request<T: LeaseManager>(
                     println!(
                         "[info] release {} client id {} on {}",
                         released_pretty,
-                        format_client_id(client_id)?,
+                        format_client_id(client_id),
                         link
                     );
                     Ok(())
diff --git a/src/util.rs b/src/util.rs
index 26ac950..cd595dd 100644
--- a/src/util.rs
+++ b/src/util.rs
@@ -4,6 +4,7 @@ use std::ffi::{c_char, c_int};
 use std::io;
 use std::net::{IpAddr, Ipv4Addr};
 
+use dhcproto::v4::DhcpOption;
 use rsdsl_netlinklib::blocking::Connection;
 
 /// Helper macro to execute a system call that returns an `io::Result`.
@@ -19,12 +20,19 @@ macro_rules! syscall {
     }};
 }
 
-pub fn format_client_id(client_id: &[u8]) -> Result<String> {
+pub fn gen_client_id(hwaddr: &[u8]) -> DhcpOption {
+    let mut client_id = vec![0x01];
+    client_id.extend_from_slice(hwaddr);
+
+    DhcpOption::ClientIdentifier(client_id)
+}
+
+pub fn format_client_id(client_id: &[u8]) -> String {
     client_id
         .iter()
         .map(|octet| format!("{:02x}", octet))
         .reduce(|acc, octet| acc + ":" + &octet)
-        .ok_or(Error::EmptyClientId)
+        .unwrap_or(String::new())
 }
 
 pub fn local_ip(conn: &Connection, link: String) -> Result<Ipv4Addr> {