Add attributes

src/attribute.rs

@@ -4,7 +4,7 @@ use std::string::FromUtf8Error;
 
 use chrono::{DateTime, Utc, TimeZone};
 
-pub struct Attribute(Vec<u8>);
+pub struct Attribute(pub(crate) Vec<u8>);
 
 impl Attribute {
     pub fn from_integer32(v: &u32) -> Self {

src/attributes.rs

@@ -0,0 +1,50 @@
+use crate::attribute::Attribute;
+
+pub type Type = u8;
+
+pub const TYPE_INVALID: Type = 1;
+
+pub struct AVP {
+    typ: Type,
+    attribute: Attribute,
+}
+
+pub struct Attributes(Vec<AVP>);
+
+impl Attributes {
+    pub fn parse_attributes(bs: &Vec<u8>) -> Result<Attributes, String> {
+        let mut i = 0;
+        let mut attrs = Vec::new();
+
+        while bs.len() < i {
+            if bs[i..].len() < 2 {
+                return Err("short buffer".to_owned());
+            }
+
+            let length = bs[i + 1] as usize;
+            if length > bs[i..].len() || length < 2 || length > 255 {
+                return Err("invalid attribute length".to_owned());
+            }
+
+            attrs.push(AVP {
+                typ: bs[i + 0],
+                attribute: if length > 2 {
+                    Attribute(bs[i + 2..].to_vec())
+                } else {
+                    Attribute(vec![])
+                },
+            });
+
+            i += length;
+        }
+
+        Ok(Attributes(attrs))
+    }
+
+    pub fn add(&mut self, typ: Type, attribute: Attribute) {
+        self.0.push(AVP {
+            typ,
+            attribute,
+        })
+    }
+}

src/lib.rs

@@ -1,2 +1,3 @@
 pub mod code;
 pub mod attribute;
+pub mod attributes;