temporary undoing of renaming

1 files changed, 150 insertions, 0 deletions

diff --git a/pk/file.c b/pk/file.c
new file mode 100644
index 0000000..cf370b5
--- /dev/null
+++ b/pk/file.c
@@ -0,0 +1,150 @@
+#include <string.h>
+#include <errno.h>
+#include "file.h"
+#include "pk.h"
+#include "frontend.h"
+#include "pcr.h"
+
+#define MAX_FDS 32
+file_t* fds[MAX_FDS];
+#define MAX_FILES 32
+file_t files[MAX_FILES] = {[0 ... MAX_FILES-1] = {-1,{0}}};
+file_t *stdout, *stdin, *stderr;
+
+static void file_incref(file_t* f)
+{
+  atomic_add(&f->refcnt,1);
+}
+
+void file_decref(file_t* f)
+{
+  if(atomic_add(&f->refcnt,-1) == 2)
+  {
+    if(f->kfd != -1)
+    {
+      frontend_syscall(SYS_close,f->kfd,0,0,0);
+      f->kfd = -1;
+    }
+    atomic_add(&f->refcnt,-1); // I think this could just be atomic_set(..,0)
+  }
+}
+
+static file_t* file_get_free()
+{
+  for(int i = 0; i < MAX_FILES; i++)
+  {
+    if(atomic_read(&files[i].refcnt) == 0)
+    {
+      if(atomic_add(&files[i].refcnt,1) == 0)
+      {
+        atomic_add(&files[i].refcnt,1);
+        return &files[i];
+      }
+      file_decref(&files[i]);
+    }
+  }
+  return NULL;
+}
+
+static int fd_get_free()
+{
+  for(int i = 0; i < MAX_FDS; i++)
+    if(fds[i] == NULL)
+      return i;
+  return -1;
+}
+
+int file_dup(file_t* f)
+{
+  int fd = fd_get_free();
+  if(fd == -1)
+    return -1;
+  file_incref(f);
+  fds[fd] = f;
+  return fd;
+}
+
+void file_init()
+{
+  stdin = file_get_free();
+  stdout = file_get_free();
+  stderr = file_get_free();
+
+  stdin->kfd = 0;
+  stdout->kfd = 1;
+  stderr->kfd = 2;
+
+  // create user FDs 0, 1, and 2
+  file_dup(stdin);
+  file_dup(stdout);
+  file_dup(stderr);
+}
+
+file_t* file_get(int fd)
+{
+  return fd < 0 || fd >= MAX_FDS ? NULL : fds[fd];
+}
+
+sysret_t file_open(const char* fn, size_t len, int flags, int mode)
+{
+  file_t* f = file_get_free();
+  if(!f)
+    return (sysret_t){-1,ENOMEM};
+
+  sysret_t ret = frontend_syscall(SYS_open,(long)fn,len,flags,mode);
+  if(ret.result != -1)
+  {
+    f->kfd = ret.result;
+    ret.result = (long)f;
+  }
+  else
+    file_decref(f);
+
+  return ret;
+}
+
+int fd_close(int fd)
+{
+  file_t* f = file_get(fd);
+  if(!f)
+    return -1;
+  fds[fd] = NULL;
+  file_decref(f);
+  return 0;
+}
+
+sysret_t file_read(file_t* f, char* buf, size_t size)
+{
+  return frontend_syscall(SYS_read,f->kfd,(long)buf,size,0);
+}
+
+sysret_t file_pread(file_t* f, char* buf, size_t size, off_t offset)
+{
+  return frontend_syscall(SYS_pread,f->kfd,(long)buf,size,offset);
+}
+
+sysret_t file_write(file_t* f, const char* buf, size_t size)
+{
+  if(f->kfd == 1 || f->kfd == 2)
+  {
+    for(size_t i = 0; i < size; i++)
+      mtpcr(PCR_CONSOLE,buf[i]);
+  }
+
+  return frontend_syscall(SYS_write,f->kfd,(long)buf,size,0);
+}
+
+sysret_t file_pwrite(file_t* f, const char* buf, size_t size, off_t offset)
+{
+  return frontend_syscall(SYS_pwrite,f->kfd,(long)buf,size,offset);
+}
+
+sysret_t file_stat(file_t* f, struct stat* s)
+{
+  return frontend_syscall(SYS_fstat,f->kfd,(long)s,0,0);
+}
+
+sysret_t file_lseek(file_t* f, size_t ptr, int dir)
+{
+  return frontend_syscall(SYS_lseek,f->kfd,ptr,dir,0);
+}