mount /dev/console

Author: elijah-wright

vminitd/Sources/vmexec/Mount.swift

@@ -18,6 +18,9 @@ import ContainerizationOCI
 import ContainerizationOS
 import Foundation
 import Musl
+#if canImport(Glibc)
+import Glibc
+#endif
 
 struct ContainerMount {
     private let mounts: [ContainerizationOCI.Mount]
@@ -35,7 +38,7 @@ struct ContainerMount {
         }
     }
 
-    func configureConsole() throws {
+    func configureConsole(process: ContainerizationOCI.Process) throws {
         let ptmx = self.rootfs.standardizingPath.appendingPathComponent("/dev/ptmx")
 
         guard remove(ptmx) == 0 else {
@@ -44,6 +47,29 @@ struct ContainerMount {
         guard symlink("pts/ptmx", ptmx) == 0 else {
             throw App.Errno(stage: "symlink(pts/ptmx)")
         }
+
+        if process.terminal {
+            var buf = [CChar](repeating: 0, count: 4096)
+            let len = readlink("/proc/self/fd/0", &buf, buf.count - 1)
+            if len != -1 {
+                buf[Int(len)] = 0
+                let ptyPath = String(cString: buf)
+
+                let console = self.rootfs.standardizingPath.appendingPathComponent("/dev/console")
+
+                if access(console, F_OK) != 0 {
+                    let fd = open(console, O_RDWR | O_CREAT, mode_t(UInt16(0o600)))
+                    if fd == -1 {
+                        throw App.erno(stage: "open(/dev/console)")
+                    }
+                    close(fd)
+                }
+
+                if mount(ptyPath, console, "", UInt(MS_BIND), nil) != 0 {
+                    throw App.Errno(stage: "mount(/dev/console)")
+                }
+            }
+        }
     }
 
     private func mkdirAll(_ name: String, _ perm: Int16) throws {

vminitd/Sources/vmexec/RunCommand.swift

@@ -39,10 +39,10 @@ struct RunCommand: ParsableCommand {
         try execInNamespace(spec: ociSpec, log: log)
     }
 
-    private func childRootSetup(rootfs: ContainerizationOCI.Root, mounts: [ContainerizationOCI.Mount], log: Logger) throws {
+    private func childRootSetup(rootfs: ContainerizationOCI.Root, mounts: [ContainerizationOCI.Mount], process: ContainerizationOCI.Process, log: Logger) throws {
         // setup rootfs
         try prepareRoot(rootfs: rootfs.path)
-        try mountRootfs(rootfs: rootfs.path, mounts: mounts)
+        try mountRootfs(rootfs: rootfs.path, mounts: mounts, process: process)
         try setDevSymlinks(rootfs: rootfs.path)
 
         try pivotRoot(rootfs: rootfs.path)
@@ -90,7 +90,7 @@ struct RunCommand: ParsableCommand {
                 throw App.Errno(stage: "setsid()")
             }
 
-            try childRootSetup(rootfs: root, mounts: spec.mounts, log: log)
+            try childRootSetup(rootfs: root, mounts: spec.mounts, log: log, process: process)
 
             if !spec.hostname.isEmpty {
                 let errCode = spec.hostname.withCString { ptr in
@@ -138,10 +138,10 @@ struct RunCommand: ParsableCommand {
         }
     }
 
-    private func mountRootfs(rootfs: String, mounts: [ContainerizationOCI.Mount]) throws {
+    private func mountRootfs(rootfs: String, mounts: [ContainerizationOCI.Mount], process: ContainerizationOCI.Process) throws {
         let containerMount = ContainerMount(rootfs: rootfs, mounts: mounts)
         try containerMount.mountToRootfs()
-        try containerMount.configureConsole()
+        try containerMount.configureConsole(process)
     }
 
     private func prepareRoot(rootfs: String) throws {