Merge branch 'manipulate-exprs' into 'master'

Add functions to iterate over the expressions of existing rules

See merge request rustwall/rustables!3

1 files changed, 36 insertions, 3 deletions

diff --git a/rustables/src/expr/counter.rs b/rustables/src/expr/counter.rs
index c2a0b5d..099e7fa 100644
--- a/rustables/src/expr/counter.rs
+++ b/rustables/src/expr/counter.rs
@@ -1,13 +1,46 @@
-use super::{Expression, Rule};
+use super::{DeserializationError, Expression, Rule};
 use rustables_sys as sys;
 use std::os::raw::c_char;
 
 /// A counter expression adds a counter to the rule that is incremented to count number of packets
 /// and number of bytes for all packets that has matched the rule.
-pub struct Counter;
+#[derive(Debug, PartialEq)]
+pub struct Counter {
+    pub nb_bytes: u64,
+    pub nb_packets: u64,
+}
+
+impl Counter {
+    pub fn new() -> Self {
+        Self {
+            nb_bytes: 0,
+            nb_packets: 0,
+        }
+    }
+}
 
 impl Expression for Counter {
+    fn get_raw_name() -> *const c_char {
+        b"counter\0" as *const _ as *const c_char
+    }
+
+    fn from_expr(expr: *const sys::nftnl_expr) -> Result<Self, DeserializationError> {
+        unsafe {
+            let nb_bytes = sys::nftnl_expr_get_u64(expr, sys::NFTNL_EXPR_CTR_BYTES as u16);
+            let nb_packets = sys::nftnl_expr_get_u64(expr, sys::NFTNL_EXPR_CTR_PACKETS as u16);
+            Ok(Counter {
+                nb_bytes,
+                nb_packets,
+            })
+        }
+    }
+
     fn to_expr(&self, _rule: &Rule) -> *mut sys::nftnl_expr {
-        try_alloc!(unsafe { sys::nftnl_expr_alloc(b"counter\0" as *const _ as *const c_char) })
+        unsafe {
+            let expr = try_alloc!(sys::nftnl_expr_alloc(Self::get_raw_name()));
+            sys::nftnl_expr_set_u64(expr, sys::NFTNL_EXPR_CTR_BYTES as u16, self.nb_bytes);
+            sys::nftnl_expr_set_u64(expr, sys::NFTNL_EXPR_CTR_PACKETS as u16, self.nb_packets);
+            expr
+        }
     }
 }