iptun: add support to ipip, ipip6 and ip6ip6 tunnels

All these tunnels use the IFLA_IPTUN_* netlink API. Therefore, both
IFLAN_INFO_KIND "ipip" and "ip6tnl" data is serialized using the IpTun
struct.

Unit tests added.

Author: ffmancera

src/link/link_info/info_data.rs

@@ -9,9 +9,9 @@ use netlink_packet_utils::{
 
 use super::super::{
     InfoBond, InfoBridge, InfoGeneve, InfoGreTap, InfoGreTap6, InfoGreTun,
-    InfoGreTun6, InfoGtp, InfoHsr, InfoIpVlan, InfoIpVtap, InfoIpoib, InfoKind,
-    InfoMacSec, InfoMacVlan, InfoMacVtap, InfoSitTun, InfoTun, InfoVeth,
-    InfoVlan, InfoVrf, InfoVti, InfoVxlan, InfoXfrm,
+    InfoGreTun6, InfoGtp, InfoHsr, InfoIpTun, InfoIpVlan, InfoIpVtap,
+    InfoIpoib, InfoKind, InfoMacSec, InfoMacVlan, InfoMacVtap, InfoSitTun,
+    InfoTun, InfoVeth, InfoVlan, InfoVrf, InfoVti, InfoVxlan, InfoXfrm,
 };
 
 const IFLA_INFO_DATA: u16 = 2;
@@ -42,6 +42,7 @@ pub enum InfoData {
     MacSec(Vec<InfoMacSec>),
     Hsr(Vec<InfoHsr>),
     Geneve(Vec<InfoGeneve>),
+    IpTun(Vec<InfoIpTun>),
     Other(Vec<u8>),
 }
 
@@ -71,6 +72,7 @@ impl Nla for InfoData {
             Self::Vti(nlas) => nlas.as_slice().buffer_len(),
             Self::Gtp(nlas) => nlas.as_slice().buffer_len(),
             Self::Geneve(nlas) => nlas.as_slice().buffer_len(),
+            Self::IpTun(nlas) => nlas.as_slice().buffer_len(),
             Self::Other(v) => v.len(),
         }
     }
@@ -100,6 +102,7 @@ impl Nla for InfoData {
             Self::Vti(nlas) => nlas.as_slice().emit(buffer),
             Self::Gtp(nlas) => nlas.as_slice().emit(buffer),
             Self::Geneve(nlas) => nlas.as_slice().emit(buffer),
+            Self::IpTun(nlas) => nlas.as_slice().emit(buffer),
             Self::Other(v) => buffer.copy_from_slice(v.as_slice()),
         }
     }
@@ -353,6 +356,17 @@ impl InfoData {
                 }
                 InfoData::Hsr(v)
             }
+            InfoKind::IpIp | InfoKind::Ip6Tnl => {
+                let mut v = Vec::new();
+                for nla in NlasIterator::new(payload) {
+                    let nla = &nla.context(format!(
+                        "invalid IFLA_INFO_DATA for {kind} {payload:?}"
+                    ))?;
+                    let parsed = InfoIpTun::parse(nla)?;
+                    v.push(parsed);
+                }
+                InfoData::IpTun(v)
+            }
             InfoKind::Geneve => {
                 let mut v = Vec::new();
                 for nla in NlasIterator::new(payload) {

src/link/link_info/infos.rs

@@ -31,6 +31,7 @@ const MACVTAP: &str = "macvtap";
 const GRETAP: &str = "gretap";
 const IP6GRETAP: &str = "ip6gretap";
 const IPIP: &str = "ipip";
+const IP6TNL: &str = "ip6tnl";
 const SIT: &str = "sit";
 const GRE: &str = "gre";
 const IP6GRE: &str = "ip6gre";
@@ -189,7 +190,8 @@ pub enum InfoKind {
     MacVtap,
     GreTap,
     GreTap6,
-    IpTun,
+    IpIp,
+    Ip6Tnl,
     SitTun,
     GreTun,
     GreTun6,
@@ -226,7 +228,8 @@ impl std::fmt::Display for InfoKind {
                 Self::MacVtap => MACVTAP,
                 Self::GreTap => GRETAP,
                 Self::GreTap6 => IP6GRETAP,
-                Self::IpTun => IPIP,
+                Self::IpIp => IPIP,
+                Self::Ip6Tnl => IP6TNL,
                 Self::SitTun => SIT,
                 Self::GreTun => GRE,
                 Self::GreTun6 => IP6GRE,
@@ -263,7 +266,8 @@ impl Nla for InfoKind {
             Self::MacVtap => MACVTAP.len(),
             Self::GreTap => GRETAP.len(),
             Self::GreTap6 => IP6GRETAP.len(),
-            Self::IpTun => IPIP.len(),
+            Self::IpIp => IPIP.len(),
+            Self::Ip6Tnl => IP6TNL.len(),
             Self::SitTun => SIT.len(),
             Self::GreTun => GRE.len(),
             Self::GreTun6 => IP6GRE.len(),
@@ -320,7 +324,8 @@ impl<'a, T: AsRef<[u8]> + ?Sized> Parseable<NlaBuffer<&'a T>> for InfoKind {
             MACVTAP => Self::MacVtap,
             GRETAP => Self::GreTap,
             IP6GRETAP => Self::GreTap6,
-            IPIP => Self::IpTun,
+            IPIP => Self::IpIp,
+            IP6TNL => Self::Ip6Tnl,
             SIT => Self::SitTun,
             GRE => Self::GreTun,
             IP6GRE => Self::GreTun6,