src/tools/procfs.rs: implement read_proc_net_ipv6_route()

Signed-off-by: Christian Ebner <c.ebner@proxmox.com>

src/tools/procfs.rs

@@ -1,10 +1,11 @@
 use failure::*;
 
+use std::u32;
 use std::fs::OpenOptions;
 use std::io::{BufRead, BufReader};
 use std::collections::HashSet;
 use std::process;
-use std::net::Ipv4Addr;
+use std::net::{Ipv4Addr, Ipv6Addr};
 use crate::tools;
 use lazy_static::lazy_static;
 use regex::Regex;
@@ -277,7 +278,7 @@ fn hex_nibble(c: u8) -> Result<u8, Error> {
 fn hexstr_to_ipv4addr<T: AsRef<[u8]>>(hex: T) -> Result<Ipv4Addr, Error> {
     let hex = hex.as_ref();
     if hex.len() != 8 {
-	bail!("Error while converting hex string to IP address: unexpected string length");
+	bail!("Error while converting hex string to IPv4 address: unexpected string length");
     }
 
     let mut addr: [u8; 4] = unsafe { std::mem::uninitialized() };
@@ -329,3 +330,80 @@ pub fn read_proc_net_route() -> Result<Vec<ProcFsNetRoute>, Error> {
 
     Ok(result)
 }
+
+fn hexstr_to_ipv6addr<T: AsRef<[u8]>>(hex: T) -> Result<Ipv6Addr, Error> {
+    let hex = hex.as_ref();
+    if hex.len() != 32 {
+	bail!("Error while converting hex string to IPv6 address: unexpected string length");
+    }
+
+    let mut addr: [u8; 16] = unsafe { std::mem::uninitialized() };
+    for i in 0..16 {
+	addr[i] = (hex_nibble(hex[i * 2])? << 4) + hex_nibble(hex[i * 2 + 1])?;
+    }
+
+    Ok(Ipv6Addr::from(addr))
+}
+
+fn hexstr_to_u8<T: AsRef<[u8]>>(hex: T) -> Result<u8, Error> {
+    let hex = hex.as_ref();
+    if hex.len() != 2 {
+	bail!("Error while converting hex string to u8: unexpected string length");
+    }
+
+    Ok((hex_nibble(hex[0])? << 4) + hex_nibble(hex[1])?)
+}
+
+fn hexstr_to_u32<T: AsRef<[u8]>>(hex: T) -> Result<u32, Error> {
+    let hex = hex.as_ref();
+    if hex.len() != 8 {
+	bail!("Error while converting hex string to u32: unexpected string length");
+    }
+
+    let mut bytes: [u8; 4] = unsafe { std::mem::uninitialized() };
+    for i in 0..4 {
+	bytes[i] = (hex_nibble(hex[i * 2])? << 4) + hex_nibble(hex[i * 2 + 1])?;
+    }
+
+    Ok(u32::from_be_bytes(bytes))
+}
+
+#[derive(Debug)]
+pub struct ProcFsNetIPv6Route {
+    pub dest: Ipv6Addr,
+    pub prefix: u8,
+    pub gateway: Ipv6Addr,
+    pub metric: u32,
+    pub iface: String,
+}
+
+pub fn read_proc_net_ipv6_route() -> Result<Vec<ProcFsNetIPv6Route>, Error> {
+    let path = "/proc/net/ipv6_route";
+    let file = OpenOptions::new().read(true).open(&path)?;
+    let err = "Error while parsing '/proc/net/ipv6_route";
+
+    let mut result = Vec::new();
+    for line in BufReader::new(&file).lines() {
+	let content = line?;
+	if content.is_empty() { continue; }
+	let mut iter = content.split_whitespace();
+
+	let dest = iter.next().ok_or(format_err!("{}", err))?;
+	let dest_prefix_len = iter.next().ok_or(format_err!("{}", err))?;
+	for _ in 0..2 { iter.next(); }
+	let nexthop = iter.next().ok_or(format_err!("{}", err))?;
+	let metric = iter.next().ok_or(format_err!("{}", err))?;
+	for _ in 0..3 { iter.next(); }
+	let iface = iter.next().ok_or(format_err!("{}", err))?;
+
+	result.push(ProcFsNetIPv6Route {
+	    dest: hexstr_to_ipv6addr(dest)?,
+	    prefix: hexstr_to_u8(dest_prefix_len)?,
+	    gateway: hexstr_to_ipv6addr(nexthop)?,
+	    metric: hexstr_to_u32(metric)?,
+	    iface: iface.to_string(),
+	});
+    }
+
+    Ok(result)
+}