Merge pull request #19 from nicholaschiasson/minor/support-superset-check-feature

Add support to check if fcidr is superset of a cidr

Author: nicholaschiasson

README.md

@@ -38,6 +38,7 @@ Usage: fcidr [CIDR] <COMMAND>
 Commands:
   complement  Compute the complement of the input CIDR(s) [aliases: !, not]
   difference  Compute the set difference between the input CIDR(s) and another CIDR [aliases: -, exclude, minus]
+  superset    Exits successfully if the input CIDR(s) is a superset of another CIDR [aliases: >, contains]
   union       Compute the set union of the input CIDR(s) and another CIDR [aliases: +, include, plus]
   help        Print this message or the help of the given subcommand(s)
 
@@ -119,6 +120,16 @@ fcidr 10.0.0.0/8 + 127.0.0.0/16 | fcidr - 10.64.0.0/16 | fcidr !
 128.0.0.0/1
 ```
 
+```
+fcidr 255.0.0.0/16 contains "255.0.1.2/32" && echo Woohoo!
+Woohoo!
+```
+
+```
+echo 255.0.0.0/16 | fcidr contains "255.1.1.2/32" && echo Woohoo!
+Error: "not a superset of 255.1.1.2/32"
+```
+
 ## Development
 
 ### Prerequisites

src/cidr.rs

@@ -140,14 +140,20 @@ impl Display for Cidr {
     }
 }
 
-impl TryFrom<Ipv4Addr> for Cidr {
-    type Error = Error;
-
-    fn try_from(value: Ipv4Addr) -> Result<Self, Self::Error> {
-        Self::new(value, u32::BITS as u8)
+impl From<Ipv4Addr> for Cidr {
+    fn from(value: Ipv4Addr) -> Self {
+        Self::new(value, u32::BITS as u8).expect("convert from Ipv4Addr")
     }
 }
 
+// impl TryFrom<Ipv4Addr> for Cidr {
+//     type Error = Error;
+
+//     fn try_from(value: Ipv4Addr) -> Result<Self, Self::Error> {
+//         Self::new(value, u32::BITS as u8)
+//     }
+// }
+
 impl FromStr for Cidr {
     type Err = Error;
 

src/fcidr.rs

@@ -72,6 +72,23 @@ impl CidrNode {
         }
         self
     }
+
+    fn contains(&self, cidr: Cidr) -> bool {
+        if cidr.prefix() < self.cidr.prefix() {
+            return false;
+        }
+        match &self.inclusion {
+            Inclusion::Excluded => false,
+            Inclusion::Included => self.cidr.contains(cidr),
+            Inclusion::Subnets([left, right]) => {
+                if cidr.network() < self.cidr.mid() {
+                    left.borrow().contains(cidr)
+                } else {
+                    right.borrow().contains(cidr)
+                }
+            }
+        }
+    }
 }
 
 #[derive(Clone, Debug, Default, Eq, Ord, PartialEq, PartialOrd)]
@@ -139,6 +156,10 @@ impl Fcidr {
         self
     }
 
+    pub fn is_superset(&self, cidr: Cidr) -> bool {
+        self.cidr.borrow().contains(cidr)
+    }
+
     pub fn union(&mut self, cidr: Cidr) -> &mut Self {
         self.cidr
             .borrow_mut()

src/main.rs

@@ -32,8 +32,11 @@ enum FcidrCommand {
         /// The second CIDR range operand for the difference function
         cidr: Cidr,
     },
-    #[command(visible_alias = "+", visible_alias = "include", visible_alias = "plus")]
+    /// Exits successfully if the input CIDR(s) is a superset of another CIDR
+    #[command(visible_alias = ">", visible_alias = "contains")]
+    Superset { cidr: Cidr },
     /// Compute the set union of the input CIDR(s) and another CIDR
+    #[command(visible_alias = "+", visible_alias = "include", visible_alias = "plus")]
     Union {
         /// The second CIDR range operand for the union function
         cidr: Cidr,
@@ -65,6 +68,12 @@ fn main() -> Result<(), Box<dyn Error>> {
     match cli.command {
         FcidrCommand::Complement => fcidr.complement(),
         FcidrCommand::Difference { cidr } => fcidr.difference(cidr),
+        FcidrCommand::Superset { cidr } => {
+            if fcidr.is_superset(cidr) {
+                return Ok(());
+            }
+            return Err(format!("not a superset of {cidr}").into());
+        }
         FcidrCommand::Union { cidr } => fcidr.union(cidr),
     };