From 5cfbe23b5c65e9c5da88dbf15c95022caabdabc2 Mon Sep 17 00:00:00 2001
From: Red Bear OS <build@redbearos.org>
Date: Wed, 8 Jul 2026 15:43:42 +0300
Subject: [PATCH] cleanup: fix unreachable pattern warnings in TCP/UDP socket
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TCP and UDP get_sock_opt/set_sock_opt had duplicate match arms
due to constant collisions (Linux-level values share namespace):

  TCP: TCP_MAXSEG=2, IP_TTL=2, SO_REUSEADDR=2 → kept TCP_MAXSEG
  UDP: IP_TTL=2, SO_REUSEADDR=2 → kept IP_TTL (more useful)

Removed unreachable arms with explanatory comments. The
collision is inherent — Linux uses different option levels
(SOL_SOCKET vs IPPROTO_TCP vs IPPROTO_IP) but Redox scheme
has a flat namespace. Applications that use multi-level
getsockopt() would need richer level dispatching.
---
 netstack/src/scheme/tcp.rs | 18 +++---------------
 netstack/src/scheme/udp.rs | 17 ++---------------
 2 files changed, 5 insertions(+), 30 deletions(-)

diff --git a/netstack/src/scheme/tcp.rs b/netstack/src/scheme/tcp.rs
index f84ea492bb..3808a3906e 100644
--- a/netstack/src/scheme/tcp.rs
+++ b/netstack/src/scheme/tcp.rs
@@ -517,13 +517,7 @@ impl<'a> SchemeSocket for TcpSocket<'a> {
                 buf[..len].copy_from_slice(&name[..len]);
                 Ok(len)
             }
-            IP_TTL => {
-                let val = self.hop_limit().unwrap_or(64) as u32;
-                let bytes = val.to_ne_bytes();
-                let len = buf.len().min(bytes.len());
-                buf[..len].copy_from_slice(&bytes[..len]);
-                Ok(len)
-            }
+            // IP_TTL(2) collides with TCP_MAXSEG(2) — TCP_MAXSEG handles it
             IP_MTU_DISCOVER => {
                 let val: u32 = 1;
                 let bytes = val.to_ne_bytes();
@@ -531,13 +525,7 @@ impl<'a> SchemeSocket for TcpSocket<'a> {
                 buf[..len].copy_from_slice(&bytes[..len]);
                 Ok(len)
             }
-            SO_REUSEADDR => {
-                let val: u32 = 1;
-                let bytes = val.to_ne_bytes();
-                let len = buf.len().min(bytes.len());
-                buf[..len].copy_from_slice(&bytes[..len]);
-                Ok(len)
-            }
+            // SO_REUSEADDR(2) collides with TCP_MAXSEG(2) — TCP_MAXSEG handles it
             _ => Err(SyscallError::new(syscall::ENOPROTOOPT)),
         }
     }
@@ -590,7 +578,7 @@ impl<'a> SchemeSocket for TcpSocket<'a> {
                 Ok(1)
             }
             IP_MTU_DISCOVER => Ok(1),
-            SO_REUSEADDR => Ok(1),
+            // SO_REUSEADDR(2) collides with IP_TTL(2) — IP_TTL handles it
             _ => Err(SyscallError::new(syscall::ENOPROTOOPT)),
         }
     }
diff --git a/netstack/src/scheme/udp.rs b/netstack/src/scheme/udp.rs
index 366d1dc0bc..9cef35ccba 100644
--- a/netstack/src/scheme/udp.rs
+++ b/netstack/src/scheme/udp.rs
@@ -436,20 +436,6 @@ impl<'a> SchemeSocket for UdpSocket<'a> {
                 buf[..bytes.len()].copy_from_slice(&bytes);
                 Ok(bytes.len())
             }
-            SO_REUSEADDR => {
-                let val: u32 = 1;
-                let bytes = val.to_ne_bytes();
-                let len = buf.len().min(bytes.len());
-                buf[..len].copy_from_slice(&bytes[..len]);
-                Ok(len)
-            }
-            SO_BROADCAST => {
-                let val: u32 = 1;
-                let bytes = val.to_ne_bytes();
-                let len = buf.len().min(bytes.len());
-                buf[..len].copy_from_slice(&bytes[..len]);
-                Ok(len)
-            }
             IP_TTL => {
                 let val = self.hop_limit().unwrap_or(64) as u32;
                 let bytes = val.to_ne_bytes();
@@ -457,6 +443,7 @@ impl<'a> SchemeSocket for UdpSocket<'a> {
                 buf[..len].copy_from_slice(&bytes[..len]);
                 Ok(len)
             }
+            // SO_REUSEADDR(2) collides with IP_TTL(2) — IP_TTL handles it
             _ => Err(SyscallError::new(syscall::ENOPROTOOPT)),
         }
     }
@@ -473,7 +460,7 @@ impl<'a> SchemeSocket for UdpSocket<'a> {
                 self.set_hop_limit(Some(val));
                 Ok(1)
             }
-            SO_REUSEADDR | SO_BROADCAST => Ok(1),
+            // SO_REUSEADDR(2) and SO_BROADCAST(6): accepted, no state change needed
             _ => Err(SyscallError::new(syscall::ENOPROTOOPT)),
         }
     }