libc+apps: Start implementing POSIX-compliant termios.h wrappers around tty ioctls

apps/login.cpp

@@ -1,10 +1,9 @@
-#include <bits/termios.h>
 #include <luna/String.h>
 #include <os/ArgumentParser.h>
 #include <os/File.h>
 #include <signal.h>
 #include <stdio.h>
-#include <sys/ioctl.h>
+#include <termios.h>
 #include <unistd.h>
 
 Result<int> luna_main(int argc, char** argv)
@@ -31,11 +30,7 @@ Result<int> luna_main(int argc, char** argv)
     {
         signal(SIGTTOU, SIG_IGN);
 
-        if (isatty(STDIN_FILENO))
-        {
-            pid_t pgid = getpgid(0);
-            ioctl(STDIN_FILENO, TIOCSPGRP, &pgid);
-        }
+        if (isatty(STDIN_FILENO)) tcsetpgrp(STDIN_FILENO, getpgid(0));
 
         auto input = os::File::standard_input();
 

apps/sh.cpp

@@ -1,4 +1,3 @@
-#include <bits/termios.h>
 #include <errno.h>
 #include <luna/String.h>
 #include <luna/Vector.h>
@@ -12,8 +11,8 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
-#include <sys/ioctl.h>
 #include <sys/utsname.h>
+#include <termios.h>
 #include <unistd.h>
 
 using os::File;
@@ -85,8 +84,7 @@ Result<int> luna_main(int argc, char** argv)
         signal(SIGTTOU, SIG_IGN);
         signal(SIGINT, sigint_handler);
 
-        pid_t pgid = getpgid(0);
-        ioctl(STDIN_FILENO, TIOCSPGRP, &pgid);
+        tcsetpgrp(STDIN_FILENO, getpgid(0));
     }
 
     while (1)
@@ -138,8 +136,7 @@ Result<int> luna_main(int argc, char** argv)
             if (interactive)
             {
                 setpgid(0, 0);
-                pid_t pgid = getpgid(0);
-                ioctl(STDIN_FILENO, TIOCSPGRP, &pgid);
+                tcsetpgrp(STDIN_FILENO, getpid());
             }
             TRY(execute_command(cmd.view()));
         }
@@ -147,11 +144,7 @@ Result<int> luna_main(int argc, char** argv)
         int status;
         TRY(os::Process::wait(child, &status));
 
-        if (interactive)
-        {
-            pid_t pgid = getpgid(0);
-            ioctl(STDIN_FILENO, TIOCSPGRP, &pgid);
-        }
+        if (interactive) tcsetpgrp(STDIN_FILENO, getpgid(0));
 
         if (WIFSIGNALED(status))
         {

apps/su.cpp

@@ -1,17 +1,16 @@
-#include <bits/termios.h>
 #include <os/ArgumentParser.h>
 #include <pwd.h>
 #include <signal.h>
 #include <stdio.h>
 #include <stdlib.h>
-#include <sys/ioctl.h>
+#include <termios.h>
 #include <unistd.h>
 
 static struct termios orig;
 
 void restore_terminal()
 {
-    ioctl(fileno(stdin), TCSETS, &orig);
+    tcsetattr(STDIN_FILENO, TCSANOW, &orig);
 }
 
 void signal_handler(int signo)
@@ -29,14 +28,13 @@ char* getpass()
         return nullptr;
     }
 
-    pid_t pgid = getpgid(0);
-    ioctl(STDIN_FILENO, TIOCSPGRP, &pgid);
+    tcsetpgrp(STDIN_FILENO, getpgid(0));
 
     fputs("Password: ", stdout);
 
-    if (ioctl(fileno(stdin), TCGETS, &orig) < 0)
+    if (tcgetattr(STDIN_FILENO, &orig) < 0)
     {
-        perror("ioctl(TCGETS)");
+        perror("tcgetattr");
         return nullptr;
     }
 
@@ -52,9 +50,9 @@ char* getpass()
 
     struct termios tc = orig;
     tc.c_lflag &= ~ECHO;
-    if (ioctl(fileno(stdin), TCSETS, &tc) < 0)
+    if (tcsetattr(STDIN_FILENO, TCSANOW, &tc) < 0)
     {
-        perror("ioctl(TCSETS)");
+        perror("tcsetattr");
         return nullptr;
     }
 

kernel/src/fs/devices/ConsoleDevice.cpp

@@ -193,6 +193,11 @@ Result<u64> ConsoleDevice::ioctl(int request, void* arg)
         g_foreground_process_group = pgid;
         return 0;
     }
+    case TIOCGPGRP: {
+        pid_t pgid = g_foreground_process_group.value_or((pid_t)next_thread_id());
+        if (!MemoryManager::copy_to_user_typed((pid_t*)arg, &pgid)) return err(EFAULT);
+        return 0;
+    }
     default: return err(EINVAL);
     }
 }

kernel/src/thread/Thread.cpp

@@ -28,6 +28,11 @@ Result<Thread*> new_thread()
     return thread;
 }
 
+u64 next_thread_id()
+{
+    return g_next_id.load();
+}
+
 Result<int> Thread::allocate_fd(int min)
 {
     if (min < 0 || min >= FD_MAX) return err(EINVAL);

kernel/src/thread/Thread.h

@@ -159,4 +159,6 @@ bool is_in_kernel(Registers* regs);
 
 Result<Thread*> new_thread();
 
+u64 next_thread_id();
+
 extern LinkedList<Thread> g_threads;

libc/CMakeLists.txt

@@ -22,6 +22,7 @@ set(SOURCES
     src/locale.cpp
     src/scanf.cpp
     src/signal.cpp
+    src/termios.cpp
     src/sys/stat.cpp
     src/sys/mman.cpp
     src/sys/wait.cpp

libc/include/bits/termios.h

@@ -19,5 +19,6 @@ struct termios
 #define TCGETS 0
 #define TCSETS 1
 #define TIOCSPGRP 2
+#define TIOCGPGRP 3
 
 #endif

libc/include/termios.h

@@ -0,0 +1,26 @@
+/* termios.h: Terminal device control. */
+
+#ifndef _TERMIOS_H
+#define _TERMIOS_H
+
+#include <bits/termios.h>
+#include <sys/types.h>
+
+#define TCSANOW 0
+
+#ifdef __cplusplus
+extern "C"
+{
+#endif
+
+    /* Fetch attributes associated with a terminal file descriptor. */
+    int tcgetattr(int fd, struct termios* termp);
+
+    /* Set attributes associated with a terminal file descriptor. */
+    int tcsetattr(int fd, int act, const struct termios* termp);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif

libc/include/unistd.h

@@ -174,6 +174,12 @@ extern "C"
     /* Check whether a file descriptor refers to a terminal device. */
     int isatty(int fd);
 
+    /* Fetch the process group associated with a terminal file descriptor. */
+    pid_t tcgetpgrp(int fd);
+
+    /* Set the process group associated with a terminal file descriptor. */
+    int tcsetpgrp(int fd, pid_t pgrp);
+
 #ifdef __cplusplus
 }
 #endif

libc/src/termios.cpp

@@ -0,0 +1,17 @@
+#include <luna/Check.h>
+#include <sys/ioctl.h>
+#include <termios.h>
+
+extern "C"
+{
+    int tcgetattr(int fd, struct termios* termp)
+    {
+        return ioctl(fd, TCGETS, termp);
+    }
+
+    int tcsetattr(int fd, int act, const struct termios* termp)
+    {
+        check(act == TCSANOW);
+        return ioctl(fd, TCSETS, termp);
+    }
+}

libc/src/unistd.cpp

@@ -1,4 +1,5 @@
 #include <bits/errno-return.h>
+#include <bits/termios.h>
 #include <fcntl.h>
 #include <luna/StringBuilder.h>
 #include <luna/Vector.h>
@@ -6,6 +7,7 @@
 #include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <sys/ioctl.h>
 #include <sys/stat.h>
 #include <sys/syscall.h>
 #include <sys/utsname.h>
@@ -484,4 +486,16 @@ extern "C"
         }
         return (int)rc;
     }
+
+    pid_t tcgetpgrp(int fd)
+    {
+        pid_t pgid;
+        if (ioctl(fd, TIOCGPGRP, &pgid) < 0) return -1;
+        return pgid;
+    }
+
+    int tcsetpgrp(int fd, pid_t pgid)
+    {
+        return ioctl(fd, TIOCSPGRP, &pgid);
+    }
 }