Implement VFS syscalls

kernel/syscall/syscall.c

@@ -248,7 +248,7 @@ DEFINE_SYSCALL (sys_exec) {
   if (!path_parse (path, mountpoint, &subpath))
     return SYSRESULT (-ST_BAD_PATH);
 
-  struct proc* new = proc_from_file (mountpoint, subpath);
+  struct proc* new = proc_from_file (proc->procgroup, mountpoint, subpath);
 
   if (new == NULL)
     return SYSRESULT (-ST_EXEC_ERROR);
@@ -261,6 +261,125 @@ DEFINE_SYSCALL (sys_exec) {
   return SYSRESULT (pid);
 }
 
+/* int open (char* path) */
+DEFINE_SYSCALL (sys_open) {
+  uintptr_t uvaddr_path = a1;
+
+  struct limine_hhdm_response* hhdm = limine_hhdm_request.response;
+
+  uintptr_t out_paddr;
+
+  spin_lock (&proc->procgroup->lock);
+  out_paddr = mm_v2p (&proc->procgroup->pd, uvaddr_path);
+  spin_unlock (&proc->procgroup->lock);
+
+  if (out_paddr == 0)
+    return SYSRESULT (-ST_BAD_ADDRESS_SPACE);
+
+  const char* path = (const char*)((uintptr_t)hhdm->offset + out_paddr);
+
+  char mountpoint[fieldsizeof (struct vfs_mountpoint, key)];
+  const char* subpath = NULL;
+
+  if (!path_parse (path, mountpoint, &subpath))
+    return SYSRESULT (-ST_BAD_PATH);
+
+  return SYSRESULT (vfs_open (proc->procgroup, mountpoint, subpath));
+}
+
+/* int close (char* path) */
+DEFINE_SYSCALL (sys_close) {
+  uintptr_t uvaddr_path = a1;
+
+  struct limine_hhdm_response* hhdm = limine_hhdm_request.response;
+
+  uintptr_t out_paddr;
+
+  spin_lock (&proc->procgroup->lock);
+  out_paddr = mm_v2p (&proc->procgroup->pd, uvaddr_path);
+  spin_unlock (&proc->procgroup->lock);
+
+  if (out_paddr == 0)
+    return SYSRESULT (-ST_BAD_ADDRESS_SPACE);
+
+  const char* path = (const char*)((uintptr_t)hhdm->offset + out_paddr);
+
+  char mountpoint[fieldsizeof (struct vfs_mountpoint, key)];
+  const char* subpath = NULL;
+
+  if (!path_parse (path, mountpoint, &subpath))
+    return SYSRESULT (-ST_BAD_PATH);
+
+  return SYSRESULT (vfs_close (proc->procgroup, mountpoint, subpath));
+}
+
+/* int read (char* path, size_t off, uint8_t* buffer, size_t size) */
+DEFINE_SYSCALL (sys_read) {
+  uintptr_t uvaddr_path = a1;
+  size_t off = (size_t)a2;
+  uintptr_t uvaddr_buffer = a3;
+  size_t size = (size_t)a4;
+
+  uint8_t* buffer = sys_get_user_buffer (proc, uvaddr_buffer, size);
+
+  if (buffer == NULL)
+    return SYSRESULT (-ST_BAD_ADDRESS_SPACE);
+
+  struct limine_hhdm_response* hhdm = limine_hhdm_request.response;
+
+  uintptr_t out_paddr;
+
+  spin_lock (&proc->procgroup->lock);
+  out_paddr = mm_v2p (&proc->procgroup->pd, uvaddr_path);
+  spin_unlock (&proc->procgroup->lock);
+
+  if (out_paddr == 0)
+    return SYSRESULT (-ST_BAD_ADDRESS_SPACE);
+
+  const char* path = (const char*)((uintptr_t)hhdm->offset + out_paddr);
+
+  char mountpoint[fieldsizeof (struct vfs_mountpoint, key)];
+  const char* subpath = NULL;
+
+  if (!path_parse (path, mountpoint, &subpath))
+    return SYSRESULT (-ST_BAD_PATH);
+
+  return SYSRESULT (vfs_read (proc->procgroup, mountpoint, subpath, buffer, off, size));
+}
+
+/* int describe (char* path, struct fs_desc_buffer* desc) */
+DEFINE_SYSCALL (sys_describe) {
+  uintptr_t uvaddr_path = a1;
+  uintptr_t uvaddr_desc = a2;
+
+  struct fs_desc_buffer* desc =
+      sys_get_user_buffer (proc, uvaddr_desc, sizeof (struct fs_desc_buffer));
+
+  if (desc == NULL)
+    return SYSRESULT (-ST_BAD_ADDRESS_SPACE);
+
+  struct limine_hhdm_response* hhdm = limine_hhdm_request.response;
+
+  uintptr_t out_paddr;
+
+  spin_lock (&proc->procgroup->lock);
+  out_paddr = mm_v2p (&proc->procgroup->pd, uvaddr_path);
+  spin_unlock (&proc->procgroup->lock);
+
+  if (out_paddr == 0)
+    return SYSRESULT (-ST_BAD_ADDRESS_SPACE);
+
+  const char* path = (const char*)((uintptr_t)hhdm->offset + out_paddr);
+
+  char mountpoint[fieldsizeof (struct vfs_mountpoint, key)];
+  const char* subpath = NULL;
+
+  if (!path_parse (path, mountpoint, &subpath))
+    return SYSRESULT (-ST_BAD_PATH);
+
+  return SYSRESULT (vfs_describe (proc->procgroup, mountpoint, subpath, desc));
+}
+
 static syscall_handler_func_t handler_table[] = {
     [SYS_QUIT] = &sys_quit,
     [SYS_TEST] = &sys_test,
@@ -275,6 +394,10 @@ static syscall_handler_func_t handler_table[] = {
     [SYS_MUTEX_UNLOCK] = &sys_mutex_unlock,
     [SYS_DEVICE_DO] = &sys_device_do,
     [SYS_EXEC] = &sys_exec,
+    [SYS_OPEN] = &sys_open,
+    [SYS_CLOSE] = &sys_close,
+    [SYS_READ] = &sys_read,
+    [SYS_DESCRIBE] = &sys_describe,
 };
 
 syscall_handler_func_t syscall_find_handler (int syscall_num) {