kernel+libc: Add chown and chmod

kernel/src/sys/id.cpp

@@ -1,3 +1,4 @@
+#include "memory/MemoryManager.h"
 #include "sys/Syscall.h"
 #include "thread/Scheduler.h"
 
@@ -90,3 +91,36 @@ Result<u64> sys_setegid(Registers*, SyscallArgs args)
 
     return 0;
 }
+
+Result<u64> sys_chmod(Registers*, SyscallArgs args)
+{
+    auto path = TRY(MemoryManager::strdup_from_user(args[0]));
+    mode_t mode = (mode_t)args[1];
+
+    Credentials& auth = Scheduler::current()->auth;
+
+    auto inode = TRY(VFS::resolve_path(path.chars(), auth));
+
+    if (auth.euid != 0 && auth.euid != inode->uid()) return err(EPERM);
+
+    TRY(inode->chmod(mode));
+
+    return 0;
+}
+
+Result<u64> sys_chown(Registers*, SyscallArgs args)
+{
+    auto path = TRY(MemoryManager::strdup_from_user(args[0]));
+    u32 uid = (u32)args[1];
+    u32 gid = (u32)args[2];
+
+    Credentials& auth = Scheduler::current()->auth;
+
+    auto inode = TRY(VFS::resolve_path(path.chars(), auth));
+
+    if (auth.euid != 0) return err(EPERM);
+
+    TRY(inode->chown(uid == (u32)-1 ? inode->uid() : uid, gid == (u32)-1 ? inode->gid() : gid));
+
+    return 0;
+}

libc/include/unistd.h

@@ -52,6 +52,12 @@ extern "C"
     /* Set the current process' effective group ID. */
     int setegid(gid_t gid);
 
+    /* Change the mode bits of a file. */
+    int chmod(const char* path, mode_t mode);
+
+    /* Change the owner and group of a file. */
+    int chown(const char* path, uid_t uid, gid_t gid);
+
     /* Replace the current process with another one. On success, does not return. */
     int execv(const char* path, char* const* argv);
 

libc/src/unistd.cpp

@@ -75,6 +75,18 @@ extern "C"
         __errno_return(rc, int);
     }
 
+    int chmod(const char* path, mode_t mode)
+    {
+        long rc = syscall(SYS_chmod, path, mode);
+        __errno_return(rc, int);
+    }
+
+    int chown(const char* path, uid_t uid, gid_t gid)
+    {
+        long rc = syscall(SYS_chown, path, uid, gid);
+        __errno_return(rc, int);
+    }
+
     int execv(const char* path, char* const* argv)
     {
         return execve(path, argv, environ);

libluna/include/luna/Syscall.h

@@ -3,7 +3,7 @@
 #define enumerate_syscalls(_e)                                                                                         \
     _e(exit) _e(clock_gettime) _e(mmap) _e(munmap) _e(usleep) _e(open) _e(close) _e(read) _e(getpid) _e(write)         \
         _e(lseek) _e(mkdir) _e(execve) _e(mknod) _e(fork) _e(waitpid) _e(getppid) _e(fcntl) _e(getdents) _e(getuid)    \
-            _e(geteuid) _e(getgid) _e(getegid) _e(setuid) _e(setgid) _e(seteuid) _e(setegid)
+            _e(geteuid) _e(getgid) _e(getegid) _e(setuid) _e(setgid) _e(seteuid) _e(setegid) _e(chmod) _e(chown)
 
 enum Syscalls
 {