Function SysOpen

Kernel/src/arch/x86_64/syscalls.cpp:297–367

* SysOpen (path, flags) - Opens file at specified path with flags * path - Path of file * flags - flags of opened file descriptor * * On success: return file descriptor * On failure: return -1 */

 * On failure: return -1
 */
long SysOpen(regs64_t* r){
	char* filepath = (char*)kmalloc(strlen((char*)SC_ARG0(r)) + 1);
	strcpy(filepath, (char*)SC_ARG0(r));
	FsNode* root = fs::GetRoot();

	uint64_t flags = SC_ARG1(r);

	process_t* proc = Scheduler::GetCurrentProcess();

	//Log::Info("Opening: %s", filepath);
	long fd;
	if(strcmp(filepath,"/") == 0){
		fd = proc->fileDescriptors.get_length();
		proc->fileDescriptors.add_back(fs::Open(root, 0));
		return fd;
	}

open:
	FsNode* node = fs::ResolvePath(filepath, proc->workingDir, !(flags & O_NOFOLLOW));

	if(!node){
		if(flags & O_CREAT){
			FsNode* parent = fs::ResolveParent(filepath, proc->workingDir);
			char* basename = fs::BaseName(filepath);

			Log::Info("sys_open: Creating %s", basename);

			if(!parent) {
				Log::Warning("sys_open: Could not resolve parent directory of new file %s", basename);
				return -ENOENT;
			}

			DirectoryEntry ent;
			strcpy(ent.name, basename);
			parent->Create(&ent, flags);

			kfree(basename);

			flags &= ~O_CREAT;
			goto open;
		} else {
			Log::Warning("sys_open: Failed to open file %s", filepath);
			return -ENOENT;
		}
	}

	if(flags & O_DIRECTORY && ((node->flags & FS_NODE_TYPE) != FS_NODE_DIRECTORY)){
		return -ENOTDIR;
	}

	if(flags & O_TRUNC && ((flags & O_ACCESS) == O_RDWR || (flags & O_ACCESS) == O_WRONLY)){
		node->Truncate(0);
	}

	fs_fd_t* handle = fs::Open(node, SC_ARG1(r));

	if(!handle){
		Log::Warning("SysOpen: Error retrieving file handle for node. Dangling symlink?");