added list_network_interfaces function

1 files changed, 56 insertions, 0 deletions

diff --git a/src/main.rs b/src/main.rs
index 07e4eec..321b5ea 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -6,6 +6,8 @@ pub mod wire;
 use std::io::{BufRead, Cursor, Read, Result, Write};
 use std::net::{Ipv4Addr, SocketAddr, SocketAddrV4, UdpSocket};
 
+use ipnet::Ipv4Net;
+
 const FLAG_BROADCAST: u16 = 1 << 15;
 
 const OPTION_CODE_PAD: u8 = 0;
@@ -347,6 +349,60 @@ fn write_boot_ack(xid: u32, chaddr: [u8; 16], client_uuid: Option<Vec<u8>>) -> R
     Ok(writer)
 }
 
+#[derive(Debug, Clone)]
+struct InterfaceAddr {
+    interface: String,
+    address: Ipv4Addr,
+    network: Ipv4Net,
+}
+
+fn list_network_interfaces() -> Result<Vec<InterfaceAddr>> {
+    unsafe {
+        let mut ifap: *mut libc::ifaddrs = std::ptr::null_mut();
+
+        if libc::getifaddrs(&mut ifap) != 0 {
+            return Err(std::io::Error::last_os_error());
+        }
+
+        let mut interfaces = Vec::new();
+        let mut current = ifap;
+
+        while !current.is_null() {
+            let ifa = &*current;
+
+            if !ifa.ifa_addr.is_null() {
+                let addr_family = (*ifa.ifa_addr).sa_family;
+                let name = std::ffi::CStr::from_ptr(ifa.ifa_name)
+                    .to_string_lossy()
+                    .into_owned();
+
+                match addr_family as i32 {
+                    libc::AF_INET => {
+                        let addr = ifa.ifa_addr as *const libc::sockaddr_in;
+                        let mask = ifa.ifa_netmask as *const libc::sockaddr_in;
+
+                        let addr = Ipv4Addr::from((*addr).sin_addr.s_addr.to_ne_bytes());
+                        let mask = Ipv4Addr::from((*mask).sin_addr.s_addr.to_ne_bytes());
+                        let network = Ipv4Net::with_netmask(addr, mask).unwrap().trunc();
+
+                        interfaces.push(InterfaceAddr {
+                            interface: name,
+                            address: addr,
+                            network,
+                        });
+                    }
+                    _ => {}
+                }
+            }
+
+            current = ifa.ifa_next;
+        }
+
+        libc::freeifaddrs(ifap);
+        Ok(interfaces)
+    }
+}
+
 fn main() {
     let socket67 = UdpSocket::bind("0.0.0.0:67").unwrap();
     socket67.set_broadcast(true).unwrap();