From fc7986e5be2148d68d627f633e440d19e310bce3 Mon Sep 17 00:00:00 2001
From: Matheus <matheusuky@gmail.com>
Date: Fri, 19 Aug 2022 22:54:07 -0300
Subject: [PATCH] close syscall

---
 src/arch/x86_64/syscall.asm |  4 +++-
 src/fs/tmpfs.c              |  2 +-
 src/sys/syscalls/close.c    | 46 +++++++++++++++++++++++++++++++++++++
 3 files changed, 50 insertions(+), 2 deletions(-)
 create mode 100644 src/sys/syscalls/close.c

diff --git a/src/arch/x86_64/syscall.asm b/src/arch/x86_64/syscall.asm
index c75e911a..db797d31 100644
--- a/src/arch/x86_64/syscall.asm
+++ b/src/arch/x86_64/syscall.asm
@@ -8,7 +8,8 @@ extern syscall_gettid
 extern syscall_open
 extern syscall_read
 extern syscall_lseek
-func_count equ 6
+extern syscall_close
+func_count equ 8
 
 
 func_table:
@@ -19,6 +20,7 @@ func_table:
 	dq syscall_open
 	dq syscall_read
 	dq syscall_lseek
+	dq syscall_close
 section .text
 global asm_syscall_entry
 
diff --git a/src/fs/tmpfs.c b/src/fs/tmpfs.c
index aa360977..9ae20f49 100644
--- a/src/fs/tmpfs.c
+++ b/src/fs/tmpfs.c
@@ -69,7 +69,7 @@ static int tmpfs_read(int *error, vnode_t* node, void* buff, size_t count, size_
 
 static int tmpfs_unmount(fs_t* fs) UNIMPLEMENTED
 static int tmpfs_open(dirnode_t* parent, char* name){ return ENOENT;} // tmpfs open should never be called if a file exists
-static int tmpfs_close(vnode_t* node) UNIMPLEMENTED
+static int tmpfs_close(vnode_t* node){return 0;} // nothing to do really
 
 static int tmpfs_mkdir(dirnode_t* parent, char* name, mode_t mode){
 	
diff --git a/src/sys/syscalls/close.c b/src/sys/syscalls/close.c
new file mode 100644
index 00000000..330d5149
--- /dev/null
+++ b/src/sys/syscalls/close.c
@@ -0,0 +1,46 @@
+#include <kernel/syscalls.h>
+#include <kernel/fd.h>
+#include <arch/cls.h>
+#include <kernel/vfs.h>
+#include <arch/spinlock.h>
+
+syscallret syscall_close(int ifd){
+
+        syscallret retv;
+        retv.ret = -1;
+
+        proc_t* proc = arch_getcls()->thread->proc;
+
+        fd_t* fd = proc->fds + ifd;
+
+        spinlock_acquire(&proc->fdlock);
+
+        if(proc->fdcount <= ifd || fd->node == NULL || (fd->flags & FD_FLAGS_READ) == 0){
+                spinlock_release(&proc->fdlock);
+                retv.errno = EBADF;
+                return retv;
+        }
+
+        spinlock_acquire(&fd->lock);
+        spinlock_release(&proc->fdlock);
+	
+	int ret = vfs_close(fd->node);
+	
+	if(ret){
+		retv.errno = ret;
+		goto _ret;
+	}
+
+	// the fd table isn't resized on a close
+	// although that can be added if it becomes an issue
+	
+	fd->node = NULL;
+
+	retv.ret = 0;
+	retv.errno = 0;
+
+	_ret:
+
+	spinlock_release(&fd->lock);
+	return retv;
+}