From b3b5981f7ab71e08746480cf6ac4f1465195b311 Mon Sep 17 00:00:00 2001
From: Matheus <matheusuky@gmail.com>
Date: Sat, 20 Aug 2022 12:18:54 -0300
Subject: [PATCH] isatty syscall

---
 src/arch/x86_64/syscall.asm |  4 +++-
 src/fs/vfs.c                |  9 +++++++++
 src/include/kernel/devman.h |  2 ++
 src/include/kernel/vfs.h    |  1 +
 src/sys/devman.c            |  9 +++++++++
 src/sys/syscalls/isatty.c   | 38 +++++++++++++++++++++++++++++++++++++
 6 files changed, 62 insertions(+), 1 deletion(-)
 create mode 100644 src/sys/syscalls/isatty.c

diff --git a/src/arch/x86_64/syscall.asm b/src/arch/x86_64/syscall.asm
index db797d31..e44e6b06 100644
--- a/src/arch/x86_64/syscall.asm
+++ b/src/arch/x86_64/syscall.asm
@@ -9,7 +9,8 @@ extern syscall_open
 extern syscall_read
 extern syscall_lseek
 extern syscall_close
-func_count equ 8
+extern syscall_isatty
+func_count equ 9
 
 
 func_table:
@@ -21,6 +22,7 @@ func_table:
 	dq syscall_read
 	dq syscall_lseek
 	dq syscall_close
+	dq syscall_isatty
 section .text
 global asm_syscall_entry
 
diff --git a/src/fs/vfs.c b/src/fs/vfs.c
index 133499a8..7b071863 100644
--- a/src/fs/vfs.c
+++ b/src/fs/vfs.c
@@ -78,6 +78,15 @@ int vfs_write(int* error, vnode_t* node, void* buff, size_t count, size_t offset
 	
 }
 
+int vfs_isatty(vnode_t* node){
+	
+	if(GETTYPE(node->st.st_mode) != TYPE_CHARDEV)
+		return ENOTTY;
+	
+	return devman_isatty(node->st.st_rdev);
+	
+}
+
 int vfs_read(int* error, vnode_t* node, void* buff, size_t count, size_t offset){
 	
 	int type = GETTYPE(node->st.st_mode);
diff --git a/src/include/kernel/devman.h b/src/include/kernel/devman.h
index 900f7ca2..e0ccfddf 100644
--- a/src/include/kernel/devman.h
+++ b/src/include/kernel/devman.h
@@ -7,11 +7,13 @@
 typedef struct{
 	int (*read)(int* error, int minor, void* buff, size_t count, size_t offset);
 	int (*write)(int* error, int minor, void* buff, size_t count, size_t offset);
+	int (*isatty)(int minor);
 } devcalls;
 
 int devman_read(int *error, int dev, void* buff, size_t count, size_t offset);
 int devman_write(int *error, int dev, void* buff, size_t count, size_t offset);
 int devman_newdevice(char* name, int type, int major, int minor, devcalls* calls);
+int devman_isatty(int dev);
 void devman_init();
 
 #endif
diff --git a/src/include/kernel/vfs.h b/src/include/kernel/vfs.h
index 191231a8..c7212187 100644
--- a/src/include/kernel/vfs.h
+++ b/src/include/kernel/vfs.h
@@ -67,6 +67,7 @@ int vfs_mkdir(dirnode_t* ref, char* path, mode_t mode);
 int vfs_create(dirnode_t* ref, char* path, mode_t mode);
 int vfs_write(int* error, vnode_t* node, void* buff, size_t count, size_t offset);
 int vfs_read(int* error, vnode_t* node, void* buff, size_t count, size_t offset);
+int vfs_isatty(vnode_t* node);
 
 void vfs_init();
 dirnode_t* vfs_root();
diff --git a/src/sys/devman.c b/src/sys/devman.c
index bc1fd766..e7c05459 100644
--- a/src/sys/devman.c
+++ b/src/sys/devman.c
@@ -47,6 +47,15 @@ int devman_read(int *error, int dev, void* buff, size_t count, size_t offset){
 
 }
 
+int devman_isatty(int dev){
+	
+	if(major(dev) > highestmajor)
+		return ENOTTY;
+	
+	return majorcalls[major(dev)]->isatty(minor(dev));
+	
+}
+
 void devman_init(){
 	
 	devfs_init();
diff --git a/src/sys/syscalls/isatty.c b/src/sys/syscalls/isatty.c
new file mode 100644
index 00000000..89bec527
--- /dev/null
+++ b/src/sys/syscalls/isatty.c
@@ -0,0 +1,38 @@
+#include <kernel/syscalls.h>
+#include <kernel/fd.h>
+#include <kernel/vfs.h>
+#include <arch/cls.h>
+#include <kernel/sched.h>
+#include <arch/spinlock.h>
+
+syscallret syscall_isatty(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){
+                spinlock_release(&proc->fdlock);
+                retv.errno = EBADF;
+                return retv;
+        }
+
+        spinlock_acquire(&fd->lock);
+        spinlock_release(&proc->fdlock);
+
+	int ret = vfs_isatty(fd->node);
+	
+	retv.errno = ret;
+
+	retv.ret = retv.errno == ENOTTY ? 0 : 1;
+
+	spinlock_release(&fd->lock);
+
+	return retv;
+	
+}