fixup! iptunnel: add support to ipip, ipip6 and ip6ip6 tunnels

Author: liangwen12year

src/link/link_info/iptunnel.rs

@@ -166,14 +166,26 @@ impl<'a, T: AsRef<[u8]> + ?Sized>
                 parse_u32(payload).context("invalid IFLA_IPTUN_LINK value")?,
             ),
             IFLA_IPTUN_LOCAL => {
-                let ip = parse_ip_addr(payload)
-                    .context("invalid IFLA_IPTUN_LOCAL")?;
-                Self::Local(ip)
+                match parse_ip_addr(payload) {
+                    Ok(ip) => Local(ip),
+                    Err(_) => {
+                        // Fallback for malformed IP addresses in SIT tunnels
+                        Other(DefaultNla::parse(buf).context(
+                            "failed to parse IFLA_IPTUN_LOCAL as fallback",
+                        )?)
+                    }
+                }
             }
             IFLA_IPTUN_REMOTE => {
-                let ip = parse_ip_addr(payload)
-                    .context("invalid IFLA_IPTUN_REMOTE")?;
-                Self::Remote(ip)
+                match parse_ip_addr(payload) {
+                    Ok(ip) => Remote(ip),
+                    Err(_) => {
+                        // Fallback for malformed IP addresses in SIT tunnels
+                        Other(DefaultNla::parse(buf).context(
+                            "failed to parse IFLA_IPTUN_REMOTE as fallback",
+                        )?)
+                    }
+                }
             }
             IFLA_IPTUN_TTL => {
                 Ttl(parse_u8(payload)
@@ -221,25 +233,26 @@ impl<'a, T: AsRef<[u8]> + ?Sized>
             IFLA_IPTUN_6RD_PREFIX => {
                 if payload.len() == 16 {
                     let mut data = [0u8; 16];
-                    data.copy_from_slice(&payload[0..16]);
+                    data.copy_from_slice(payload);
                     Self::Ipv6RdPrefix(Ipv6Addr::from(data))
                 } else {
-                    return Err(DecodeError::from(format!(
-                        "Invalid IFLA_IPTUN_6RD_PREFIX, got unexpected length \
-                         of IPv6 address payload {payload:?}"
-                    )));
+                    // Fallback for malformed 6RD prefix data
+                    Other(DefaultNla::parse(buf).context(
+                        "failed to parse IFLA_IPTUN_6RD_PREFIX as fallback",
+                    )?)
                 }
             }
             IFLA_IPTUN_6RD_RELAY_PREFIX => {
                 if payload.len() == 16 {
                     let mut data = [0u8; 16];
-                    data.copy_from_slice(&payload[0..16]);
+                    data.copy_from_slice(payload);
                     Self::Ipv6RdRelayPrefix(Ipv6Addr::from(data))
                 } else {
-                    return Err(DecodeError::from(format!(
-                        "Invalid IFLA_IPTUN_6RD_RELAY_PREFIX, got unexpected \
-                         length of IPv6 address payload {payload:?}"
-                    )));
+                    // Fallback for malformed 6RD relay prefix data
+                    Other(
+                        DefaultNla::parse(buf)
+                            .context("failed to parse IFLA_IPTUN_6RD_RELAY_PREFIX as fallback")?,
+                    )
                 }
             }
             IFLA_IPTUN_6RD_PREFIXLEN => Ipv6RdPrefixLen(