From fab307311f6e1e87f1c3580b03c5a3e36d1b2645 Mon Sep 17 00:00:00 2001
From: Ian Moffett <ian@osmora.org>
Date: Tue, 29 Oct 2024 18:34:24 -0400
Subject: kernel: syscall: Add SYS_stat

Signed-off-by: Ian Moffett <ian@osmora.org>
---
 sys/kern/kern_syscall.c |  1 +
 sys/kern/vfs_syscalls.c | 61 +++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 62 insertions(+)

(limited to 'sys/kern')

diff --git a/sys/kern/kern_syscall.c b/sys/kern/kern_syscall.c
index b36c6af..f4d9cb8 100644
--- a/sys/kern/kern_syscall.c
+++ b/sys/kern/kern_syscall.c
@@ -38,6 +38,7 @@ scret_t(*g_sctab[])(struct syscall_args *) = {
     sys_open,   /* SYS_open */
     sys_read,   /* SYS_read */
     sys_close,  /* SYS_close */
+    sys_stat,   /* SYS_stat */
 };
 
 const size_t MAX_SYSCALLS = NELEM(g_sctab);
diff --git a/sys/kern/vfs_syscalls.c b/sys/kern/vfs_syscalls.c
index f4c5c59..0ef3d42 100644
--- a/sys/kern/vfs_syscalls.c
+++ b/sys/kern/vfs_syscalls.c
@@ -28,10 +28,61 @@
  */
 
 #include <sys/vfs.h>
+#include <sys/vnode.h>
+#include <sys/systm.h>
+#include <sys/device.h>
+#include <sys/namei.h>
+#include <sys/stat.h>
+#include <sys/limits.h>
+#include <sys/errno.h>
 #include <sys/types.h>
 #include <sys/filedesc.h>
 #include <string.h>
 
+static int
+vfs_dostat(const char *path, struct stat *sbuf)
+{
+    char pathbuf[PATH_MAX];
+    struct vattr *attr;
+    struct stat st;
+    struct vnode *vp;
+    struct vop_getattr_args gattr;
+    struct nameidata nd;
+    int error;
+
+    if (sbuf == NULL || path == NULL) {
+        return -EINVAL;
+    }
+
+    if ((copyinstr(path, pathbuf, sizeof(path))) < 0) {
+        return -EFAULT;
+    }
+
+    nd.path = path;
+    nd.flags = 0;
+
+    if ((error = namei(&nd)) != 0) {
+        return error;
+    }
+
+    vp = nd.vp;
+    gattr.vp = vp;
+    error = vfs_vop_getattr(vp, &gattr);
+
+    if (error != 0) {
+        return error;
+    }
+
+    attr = gattr.res;
+    memset(&st, VNOVAL, sizeof(st));
+
+    /* Copy stat data to userspace statbuf */
+    st.st_mode = attr->mode;
+    st.st_size = attr->size;
+    copyout(&st, sbuf, sizeof(*sbuf));
+    return 0;
+}
+
 /*
  * arg0: pathname
  * arg1: oflags
@@ -64,3 +115,13 @@ sys_read(struct syscall_args *scargs)
     return fd_read(scargs->arg0, (void *)scargs->arg1,
         scargs->arg2);
 }
+
+/*
+ * arg0: path
+ * arg1: buf
+ */
+scret_t
+sys_stat(struct syscall_args *scargs)
+{
+    return vfs_dostat((const char *)scargs->arg0, (void *)scargs->arg1);
+}
-- 
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