From e9ea342bf7453ad683fad7934023558beecce54d Mon Sep 17 00:00:00 2001
From: Kedar Sovani <kedars@gmail.com>
Date: Sun, 8 Jan 2023 11:13:12 +0530
Subject: [PATCH] mdns: Discriminator is a property of the 'commissionable'
 state

---
 matter/src/core.rs                |  8 ++++++--
 matter/src/mdns.rs                | 19 ++++++++-----------
 matter/src/secure_channel/core.rs | 10 ++++++++--
 3 files changed, 22 insertions(+), 15 deletions(-)

diff --git a/matter/src/core.rs b/matter/src/core.rs
index 0706413..c5eb5b0 100644
--- a/matter/src/core.rs
+++ b/matter/src/core.rs
@@ -62,7 +62,7 @@ impl Matter {
         dev_comm: CommissioningData,
     ) -> Result<Box<Matter>, Error> {
         let mdns = Mdns::get()?;
-        mdns.set_values(dev_det.vid, dev_det.pid, dev_comm.discriminator);
+        mdns.set_values(dev_det.vid, dev_det.pid);
 
         let fabric_mgr = Arc::new(FabricMgr::new()?);
         let acl_mgr = Arc::new(AclMgr::new()?);
@@ -78,7 +78,11 @@ impl Matter {
         matter.transport_mgr.register_protocol(interaction_model)?;
         let mut secure_channel = Box::new(SecureChannel::new(matter.fabric_mgr.clone()));
         if open_comm_window {
-            secure_channel.open_comm_window(&dev_comm.salt, dev_comm.passwd)?;
+            secure_channel.open_comm_window(
+                &dev_comm.salt,
+                dev_comm.passwd,
+                dev_comm.discriminator,
+            )?;
         }
 
         matter.transport_mgr.register_protocol(secure_channel)?;
diff --git a/matter/src/mdns.rs b/matter/src/mdns.rs
index f5aeb7c..287eece 100644
--- a/matter/src/mdns.rs
+++ b/matter/src/mdns.rs
@@ -30,8 +30,6 @@ pub struct MdnsInner {
     vid: u16,
     /// Product ID
     pid: u16,
-    /// Discriminator
-    discriminator: u16,
 }
 
 pub struct Mdns {
@@ -45,8 +43,10 @@ static mut G_MDNS: Option<Arc<Mdns>> = None;
 static INIT: Once = Once::new();
 
 pub enum ServiceMode {
+    /// The commissioned state
     Commissioned,
-    Commissionable,
+    /// The commissionable state with the discriminator that should be used
+    Commissionable(u16),
 }
 
 impl Mdns {
@@ -71,11 +71,10 @@ impl Mdns {
     /// Set mDNS service specific values
     /// Values like vid, pid, discriminator etc
     // TODO: More things like device-type etc can be added here
-    pub fn set_values(&self, vid: u16, pid: u16, discriminator: u16) {
+    pub fn set_values(&self, vid: u16, pid: u16) {
         let mut inner = self.inner.lock().unwrap();
         inner.vid = vid;
         inner.pid = pid;
-        inner.discriminator = discriminator;
     }
 
     /// Publish a mDNS service
@@ -86,13 +85,11 @@ impl Mdns {
             ServiceMode::Commissioned => {
                 sys_publish_service(name, "_matter._tcp", MATTER_PORT, &[])
             }
-            ServiceMode::Commissionable => {
-                let inner = self.inner.lock().unwrap();
-                let short =
-                    (inner.discriminator & SHORT_DISCRIMINATOR_MASK) >> SHORT_DISCRIMINATOR_SHIFT;
-                let serv_type = format!("_matterc._udp,_S{},_L{}", short, inner.discriminator);
+            ServiceMode::Commissionable(discriminator) => {
+                let short = (discriminator & SHORT_DISCRIMINATOR_MASK) >> SHORT_DISCRIMINATOR_SHIFT;
+                let serv_type = format!("_matterc._udp,_S{},_L{}", short, discriminator);
 
-                let str_discriminator = format!("{}", inner.discriminator);
+                let str_discriminator = format!("{}", discriminator);
                 let txt_kvs = [["D", &str_discriminator], ["CM", "1"]];
                 sys_publish_service(name, &serv_type, MATTER_PORT, &txt_kvs)
             }
diff --git a/matter/src/secure_channel/core.rs b/matter/src/secure_channel/core.rs
index 8a2774c..86ae55b 100644
--- a/matter/src/secure_channel/core.rs
+++ b/matter/src/secure_channel/core.rs
@@ -48,10 +48,16 @@ impl SecureChannel {
         }
     }
 
-    pub fn open_comm_window(&mut self, salt: &[u8; 16], passwd: u32) -> Result<(), Error> {
+    pub fn open_comm_window(
+        &mut self,
+        salt: &[u8; 16],
+        passwd: u32,
+        discriminator: u16,
+    ) -> Result<(), Error> {
         let name: u64 = rand::thread_rng().gen_range(0..0xFFFFFFFFFFFFFFFF);
         let name = format!("{:016X}", name);
-        let mdns = Mdns::get()?.publish_service(&name, mdns::ServiceMode::Commissionable)?;
+        let mdns = Mdns::get()?
+            .publish_service(&name, mdns::ServiceMode::Commissionable(discriminator))?;
         self.pake = Some((PAKE::new(salt, passwd), mdns));
         Ok(())
     }