2 files changed, 81 insertions, 0 deletions
diff --git a/src/chain_methods.rs b/src/chain_methods.rs
new file mode 100644
index 0000000..81b5fd1
--- /dev/null
+++ b/src/chain_methods.rs
@@ -0,0 +1,78 @@
+use crate::{Batch, Chain, Hook, MsgType, Policy, Table};
+use std::ffi::{CString, NulError};
+use std::rc::Rc;
+
+use serde::{Deserialize, Serialize};
+
+/// A helper trait over [`rustables::Chain`].
+pub trait ChainMethods {
+    /// Create a new Chain instance from a [`Direction`] over a [`rustables::Table`].
+    fn from_direction(direction: &Direction, table: Rc<Table>) -> Result<Self, NulError> where Self: std::marker::Sized;
+    /// Add a [`Verdict`] to the current Chain.
+    fn verdict(self, verdict: &Verdict) -> Self;
+    fn add_to_batch(self, batch: &mut Batch) -> Self;
+}
+
+impl ChainMethods for Chain {
+    fn from_direction(direction: &Direction, table: Rc<Table>) -> Result<Self, NulError> {
+        let chain_name = CString::new(direction.display())?;
+        let mut chain = Chain::new(&chain_name, table);
+        chain.set_hook(direction.get_hook(), 0);
+        Ok(chain)
+    }
+    fn verdict(mut self, verdict: &Verdict) -> Self {
+        self.set_policy(verdict.get());
+        self
+    }
+    fn add_to_batch(self, batch: &mut Batch) -> Self {
+        batch.add(&self, MsgType::Add);
+        self
+    }
+}
+
+/// A Serializable wrapper type around [`rustables::Hook`].
+#[derive(Serialize, Deserialize, Debug, Clone, Eq, PartialEq, Hash)]
+#[serde(rename_all = "snake_case")]
+pub enum Direction {
+    Inbound,
+    Outbound,
+    Forward
+}
+impl Direction {
+    /// Return the Direction's [`rustables::Hook`], ie its representation inside rustables. Note that
+    /// there are Hooks not represented here, namely Prerouting and Postrouting. File a bug if
+    /// you need those.
+    pub fn get_hook(&self) -> Hook {
+        match self {
+            Direction::Inbound => Hook::In,
+            Direction::Outbound => Hook::Out,
+            Direction::Forward => Hook::Forward,
+        }
+    }
+    /// Return a string representation of the Direction.
+    pub fn display(&self) -> String {
+        let s = match self {
+            Direction::Inbound => "inbound",
+            Direction::Outbound => "outbound",
+            Direction::Forward => "forward",
+        };
+        s.to_string()
+    }
+}
+/// A Serializable wrapper type around [`rustables::Policy`].
+#[derive(Serialize, Deserialize, Debug, Clone)]
+#[serde(rename_all = "snake_case")]
+pub enum Verdict {
+    Accept,
+    Drop
+}
+impl Verdict {
+    /// Return the rustables representation of a Verdict (ie, a [`rustables::Policy`]).
+    pub fn get(&self) -> Policy {
+        match self {
+            Verdict::Accept => Policy::Accept,
+            Verdict::Drop => Policy::Drop,
+        }
+    }
+}
+
diff --git a/src/lib.rs b/src/lib.rs
index 33bf12c..511b0ba 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -109,6 +109,9 @@ mod chain;
 pub use chain::{get_chains_cb, list_chains_for_table};
 pub use chain::{Chain, ChainType, Hook, Policy, Priority};
 
+mod chain_methods;
+pub use chain_methods::{ChainMethods, Direction, Verdict};
+
 pub mod query;
 
 mod rule;