open syscall

src/sys/syscalls/open.c

@@ -0,0 +1,114 @@
+#include <kernel/syscalls.h>
+#include <kernel/sched.h>
+#include <arch/cls.h>
+#include <kernel/fd.h>
+#include <sys/types.h>
+#include <arch/spinlock.h>
+#include <errno.h>
+#include <kernel/alloc.h>
+#include <stddef.h>
+
+
+syscallret syscall_open(const char* pathname, int flags, mode_t mode){
+
+	syscallret retv;
+	retv.ret = -1;
+
+	if(pathname > USER_SPACE_END){
+		retv.errno = EFAULT;
+		return retv;
+	}
+
+	const char* name = alloc(strlen(pathname) + 1); // XXX use an user specific strlen func
+	if(!name){
+		retv.errno = ENOMEM;
+		return retv;
+	}
+
+	strcpy(name, pathname); // XXX use an user specific strcpy
+
+	proc_t* proc = arch_getcls()->thread->proc;
+	
+	spinlock_acquire(&proc->fdlock);
+
+	fd_t* fd = NULL;
+	
+	// find fd to use
+	
+	for(uintmax_t i = 0; i < proc->fdcount; ++i){
+		spinlock_acquire(&proc->fds[i].lock);
+		if(!proc->fds[i].node){
+			fd = &proc->fds[i].node;
+			break;
+		}
+		spinlock_release(&proc->fds[i].lock);
+	}
+
+	// resize table
+
+	if(!fd){
+		
+		fd_t* tmp = realloc(proc->fds, sizeof(fd_t)*proc->fdcount + 1);
+		
+		if(!tmp){
+			spinlock_release(&proc->fdlock);
+			retv.errno = ENOMEM;
+			return retv;
+		}
+
+		proc->fds = tmp;
+		
+		fd = &proc->fds[proc->fdcount];
+		++proc->fdcount;
+		spinlock_acquire(&fd->lock);
+
+	}
+
+	spinlock_release(&proc->fdlock);
+	
+	fd->flags = flags + 1; // 1 is added to make O_RDONLY etc easier to lookup
+	fd->offset = 0;
+	
+	vnode_t* file;
+
+	size_t ret = vfs_open(&file, 
+		*name == '/' ? proc->root : proc->cwd,
+		*name == '/' ? name + 1 : name
+	);
+
+	if(ret == ENOENT && (flags & O_CREAT)){
+		printf("O_CREAT NOT SUPPORTED YET!\n");
+		retv.errno = ENOENT;
+		goto _fail;
+	}
+	else if(ret){
+		retv.errno = ret;
+		goto _fail;
+	}
+	
+	if((flags & O_DIRECTORY) && (file->st.st_mode & MAKETYPE(TYPE_DIR)) == 0){
+		retv.errno = ENOTDIR;
+		goto _fail;
+	}
+
+	
+	fd->node = file;
+
+	spinlock_release(&fd->lock);
+
+	free(name);	
+	retv.errno = 0;
+	retv.ret = ((uintptr_t)fd - (uintptr_t)proc->fds) / sizeof(fd_t);
+
+	return retv;
+
+	_fail:
+
+	if(file)
+		vfs_close(file);
+	spinlock_release(&fd->lock);
+	fd->node = NULL;
+	free(name);
+	return retv;
+
+}