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Diffstat (limited to 'src/sys/os/os_filedes.c')
-rw-r--r--src/sys/os/os_filedes.c88
1 files changed, 69 insertions, 19 deletions
diff --git a/src/sys/os/os_filedes.c b/src/sys/os/os_filedes.c
index 95452af..3eaee0d 100644
--- a/src/sys/os/os_filedes.c
+++ b/src/sys/os/os_filedes.c
@@ -44,16 +44,9 @@
#define STDOUT_FILENO 1
/*
- * Allocate a file descriptor from a specific process's
- * file descriptor table
- *
- * @procp: Process to allocate fd from
- * @fd_res: Result pointer is written here
- *
- * Returns zero on success, otherwise a less than
- * zero value upon failure
+ * Allocate a file descriptor
*/
-static int
+int
fd_alloc(struct proc *procp, struct filedesc **fd_res)
{
struct filedesc *fd;
@@ -91,16 +84,9 @@ fd_alloc(struct proc *procp, struct filedesc **fd_res)
}
/*
- * Look up a file descriptor that belongs to a specific
- * process by using its fd number
- *
- * @procp: Process to look up
- * @fd: File descriptor number
- *
- * Returns the file descriptor pointer on success,
- * otherwise a less than zero value on failure
+ * Get a file descriptor
*/
-static struct filedesc *
+struct filedesc *
fd_get(struct proc *procp, int fd)
{
struct filedesc *fdp;
@@ -160,8 +146,10 @@ fd_open(const char *path, mode_t mode)
{
struct filedesc *fd;
struct nameidata nd;
+ struct vop_create_args creat_args;
struct proc *self = proc_self();
struct vnode *vp;
+ uint32_t namei_flags = 0;
int error;
/* We need the current proc */
@@ -180,12 +168,21 @@ fd_open(const char *path, mode_t mode)
}
/*
+ * If we are creating a new file, we'll need to
+ * get the parent vnode so that we can use the
+ * create vop.
+ */
+ if (ISSET(mode, O_CREAT)) {
+ namei_flags |= NAMEI_CREATE;
+ }
+
+ /*
* Now we try to do the lookup, we'll need
* the vnode for file references to be
* useful
*/
nd.path = path;
- nd.flags = 0;
+ nd.flags = namei_flags;
nd.vp_res = &vp;
error = namei(&nd);
if (error < 0) {
@@ -348,6 +345,44 @@ read(int fd, void *buf, size_t count)
return retval;
}
+off_t
+lseek(int fd, off_t offset, int whence)
+{
+ struct filedesc *fdp;
+ struct proc *self = proc_self();
+ struct vattr attr;
+ int error;
+
+ if (fd < 0) {
+ return -EBADF;
+ }
+
+ fdp = fd_get(self, fd);
+ if (fdp == NULL) {
+ return -EBADF;
+ }
+
+ /* Could not get vnode attributes */
+ error = vop_getattr(fdp->vp, &attr);
+ if (error < 0) {
+ return 0;
+ }
+
+ switch (whence) {
+ case SEEK_SET:
+ fdp->off = offset;
+ break;
+ case SEEK_CUR:
+ fdp->off += offset;
+ break;
+ case SEEK_END:
+ fdp->off = attr.size;
+ break;
+ }
+
+ return fdp->off;
+}
+
/*
* ARG0: Path
* ARG1: Mode
@@ -367,3 +402,18 @@ sys_open(struct syscall_args *scargs)
return fd_open(pathbuf, mode);
}
+
+/*
+ * ARG0: Fd
+ * ARG1: Offset
+ * ARG2: Whence
+ */
+scret_t
+sys_lseek(struct syscall_args *scargs)
+{
+ int fd = SCARG(scargs, int, 0);
+ off_t off = SCARG(scargs, off_t, 1);
+ int whence = SCARG(scargs, int, 2);
+
+ return lseek(fd, off, whence);
+}