Support tc flower gtp enc opts

Author: daniel-noland

src/tc/filters/cls_flower.rs

@@ -198,7 +198,7 @@ pub enum EncOpts {
     Geneve(Vec<GeneveEncOpts>),
     Vxlan(Vec<VxlanEncOpts>),
     Erspan(Vec<ErspanEncOpts>),
-    // Gtp(Vec<u8>), // TODO: I don't know what this is well enough to
+    Gtp(Vec<GtpEncOpts>), // TODO: I don't know what this is well enough to
     // implement it confidently.
     Other(DefaultNla),
 }
@@ -209,7 +209,7 @@ impl Nla for EncOpts {
             Self::Geneve(opts) => opts.as_slice().buffer_len(),
             Self::Vxlan(opts) => opts.as_slice().buffer_len(),
             Self::Erspan(opts) => opts.as_slice().buffer_len(),
-            // Self::Gtp(v) => v.len(),
+            Self::Gtp(opts) => opts.as_slice().buffer_len(),
             Self::Other(nla) => nla.value_len(),
         }
     }
@@ -219,7 +219,7 @@ impl Nla for EncOpts {
             Self::Geneve(_) => TCA_FLOWER_KEY_ENC_OPTS_GENEVE,
             Self::Vxlan(_) => TCA_FLOWER_KEY_ENC_OPTS_VXLAN,
             Self::Erspan(_) => TCA_FLOWER_KEY_ENC_OPTS_ERSPAN,
-            // Self::Gtp(_) => TCA_FLOWER_KEY_ENC_OPTS_GTP,
+            Self::Gtp(_) => TCA_FLOWER_KEY_ENC_OPTS_GTP,
             Self::Other(nla) => nla.kind(),
         }
     }
@@ -229,7 +229,7 @@ impl Nla for EncOpts {
             Self::Geneve(opts) => opts.as_slice().emit(buffer),
             Self::Vxlan(opts) => opts.as_slice().emit(buffer),
             Self::Erspan(opts) => opts.as_slice().emit(buffer),
-            // Self::Gtp(v) => buffer.copy_from_slice(v),
+            Self::Gtp(opts) => opts.as_slice().emit(buffer),
             Self::Other(nla) => nla.emit_value(buffer),
         }
     }
@@ -2612,3 +2612,64 @@ impl<'a, T: AsRef<[u8]> + ?Sized> Parseable<NlaBuffer<&'a T>> for CfmAttribute {
         })
     }
 }
+
+const TCA_FLOWER_KEY_ENC_OPT_GTP_PDU_TYPE: u16 = 1;		/* u8 */
+const TCA_FLOWER_KEY_ENC_OPT_GTP_QFI: u16 = 2;			/* u8 */
+
+/// I don't have any real experience with GTP.
+/// It looks like the [spec for GTP `PduType`][1] is available
+/// but the number of codes is fairly large, and I am not sure
+/// more than `u8` is justified.
+/// I can implement all of those codes as an enum if needed.
+///
+/// [1]: https://www.etsi.org/deliver/etsi_ts/129000_129099/129060/12.06.00_60/ts_129060v120600p.pdf#page=22
+#[derive(Debug, PartialEq, Eq, Clone)]
+#[non_exhaustive]
+pub enum GtpEncOpts {
+    PduType(u8),
+    Qfi(u8),
+    Other(DefaultNla),
+}
+
+impl Nla for GtpEncOpts {
+    fn value_len(&self) -> usize {
+        1
+    }
+
+    fn kind(&self) -> u16 {
+        match self {
+            GtpEncOpts::PduType(_) => TCA_FLOWER_KEY_ENC_OPT_GTP_PDU_TYPE,
+            GtpEncOpts::Qfi(_) => TCA_FLOWER_KEY_ENC_OPT_GTP_QFI,
+            GtpEncOpts::Other(nla) => nla.kind(),
+        }
+    }
+
+    fn emit_value(&self, buffer: &mut [u8]) {
+        match self {
+            GtpEncOpts::PduType(pdu_type) => {
+                buffer[0] = *pdu_type;
+            }
+            GtpEncOpts::Qfi(qfi) => {
+                buffer[0] = *qfi;
+            }
+            GtpEncOpts::Other(nla) => nla.emit_value(buffer),
+        }
+    }
+}
+
+impl<'a, T: AsRef<[u8]> + ?Sized> Parseable<NlaBuffer<&'a T>> for GtpEncOpts {
+    fn parse(buf: &NlaBuffer<&'a T>) -> Result<Self, DecodeError> {
+        let payload = buf.value();
+        Ok(match buf.kind() {
+            TCA_FLOWER_KEY_ENC_OPT_GTP_PDU_TYPE => {
+                GtpEncOpts::PduType(parse_u8(payload)?)
+            }
+            TCA_FLOWER_KEY_ENC_OPT_GTP_QFI => {
+                GtpEncOpts::Qfi(parse_u8(payload)?)
+            }
+            _ => GtpEncOpts::Other(
+                DefaultNla::parse(buf).context("failed to parse gtp nla")?,
+            ),
+        })
+    }
+}

src/tc/filters/mod.rs

@@ -3,8 +3,8 @@
 pub use cls_flower::{
     CfmAttribute, ConnectionTrackingFlags, EncOpts, ErspanDir, ErspanEncOpts,
     ErspanHwid, ErspanIndex, ErspanVer, GeneveClass, GeneveData, GeneveEncOpts,
-    GeneveType, Gpb, L2Miss, Lse, LseOpts, MaintenanceDomainLevel, MplsOpts,
-    TcFilterFlower, TcFilterFlowerOption, TcpFlags, VxlanEncOpts,
+    GeneveType, Gpb, GtpEncOpts, L2Miss, Lse, LseOpts, MaintenanceDomainLevel,
+    MplsOpts, TcFilterFlower, TcFilterFlowerOption, TcpFlags, VxlanEncOpts,
 };
 pub use flower_flags::TcFlowerOptionFlags;
 pub use u32_flags::{TcU32OptionFlags, TcU32SelectorFlags};

src/tc/mod.rs

@@ -14,10 +14,10 @@ pub use self::actions::{
 };
 pub use self::attribute::TcAttribute;
 pub use self::filters::{
-    arp, icmpv4, icmpv6, CfmAttribute, ConnectionTrackingFlags, EncOpts, ErspanDir,
-    ErspanEncOpts, ErspanHwid, ErspanIndex, ErspanVer, GeneveClass, GeneveData,
-    GeneveEncOpts, GeneveType, Gpb, L2Miss, Lse, LseOpts, MplsOpts,
-    TcFilterFlower, TcFilterFlowerOption, TcFilterMatchAll,
+    arp, icmpv4, icmpv6, CfmAttribute, ConnectionTrackingFlags, EncOpts,
+    ErspanDir, ErspanEncOpts, ErspanHwid, ErspanIndex, ErspanVer, GeneveClass,
+    GeneveData, GeneveEncOpts, GeneveType, Gpb, GtpEncOpts, L2Miss, Lse,
+    LseOpts, MplsOpts, TcFilterFlower, TcFilterFlowerOption, TcFilterMatchAll,
     TcFilterMatchAllOption, TcFilterU32, TcFilterU32Option,
     TcFlowerOptionFlags, TcU32Key, TcU32OptionFlags, TcU32Selector,
     TcU32SelectorFlags, TcpFlags, VxlanEncOpts,