sftp.c

OpenSSH 是 SSH （Secure SHell） 协议的免费开源实现。它用安全、加密的网络连接工具代替了 telnet、ftp、 rlogin、rsh 和 rcp 工具。OpenSSH 支持

		break;
	case I_MKDIR:
		path1 = make_absolute(path1, *pwd);
		attrib_clear(&a);
		a.flags |= SSH2_FILEXFER_ATTR_PERMISSIONS;
		a.perm = 0777;
		err = do_mkdir(conn, path1, &a);
		break;
	case I_RMDIR:
		path1 = make_absolute(path1, *pwd);
		err = do_rmdir(conn, path1);
		break;
	case I_CHDIR:
		path1 = make_absolute(path1, *pwd);
		if ((tmp = do_realpath(conn, path1)) == NULL) {
			err = 1;
			break;
		}
		if ((aa = do_stat(conn, tmp, 0)) == NULL) {
			xfree(tmp);
			err = 1;
			break;
		}
		if (!(aa->flags & SSH2_FILEXFER_ATTR_PERMISSIONS)) {
			error("Can't change directory: Can't check target");
			xfree(tmp);
			err = 1;
			break;
		}
		if (!S_ISDIR(aa->perm)) {
			error("Can't change directory: \"%s\" is not "
			    "a directory", tmp);
			xfree(tmp);
			err = 1;
			break;
		}
		xfree(*pwd);
		*pwd = tmp;
		break;
	case I_LS:
		if (!path1) {
			do_globbed_ls(conn, *pwd, *pwd, lflag);
			break;
		}

		/* Strip pwd off beginning of non-absolute paths */
		tmp = NULL;
		if (*path1 != '/')
			tmp = *pwd;

		path1 = make_absolute(path1, *pwd);
		err = do_globbed_ls(conn, path1, tmp, lflag);
		break;
	case I_LCHDIR:
		if (chdir(path1) == -1) {
			error("Couldn't change local directory to "
			    "\"%s\": %s", path1, strerror(errno));
			err = 1;
		}
		break;
	case I_LMKDIR:
		if (mkdir(path1, 0777) == -1) {
			error("Couldn't create local directory "
			    "\"%s\": %s", path1, strerror(errno));
			err = 1;
		}
		break;
	case I_LLS:
		local_do_ls(cmd);
		break;
	case I_SHELL:
		local_do_shell(cmd);
		break;
	case I_LUMASK:
		umask(n_arg);
		printf("Local umask: %03lo\n", n_arg);
		break;
	case I_CHMOD:
		path1 = make_absolute(path1, *pwd);
		attrib_clear(&a);
		a.flags |= SSH2_FILEXFER_ATTR_PERMISSIONS;
		a.perm = n_arg;
		remote_glob(conn, path1, GLOB_NOCHECK, NULL, &g);
		for (i = 0; g.gl_pathv[i] && !interrupted; i++) {
			printf("Changing mode on %s\n", g.gl_pathv[i]);
			err = do_setstat(conn, g.gl_pathv[i], &a);
			if (err != 0 && err_abort)
				break;
		}
		break;
	case I_CHOWN:
	case I_CHGRP:
		path1 = make_absolute(path1, *pwd);
		remote_glob(conn, path1, GLOB_NOCHECK, NULL, &g);
		for (i = 0; g.gl_pathv[i] && !interrupted; i++) {
			if (!(aa = do_stat(conn, g.gl_pathv[i], 0))) {
				if (err != 0 && err_abort)
					break;
				else
					continue;
			}
			if (!(aa->flags & SSH2_FILEXFER_ATTR_UIDGID)) {
				error("Can't get current ownership of "
				    "remote file \"%s\"", g.gl_pathv[i]);
				if (err != 0 && err_abort)
					break;
				else
					continue;
			}
			aa->flags &= SSH2_FILEXFER_ATTR_UIDGID;
			if (cmdnum == I_CHOWN) {
				printf("Changing owner on %s\n", g.gl_pathv[i]);
				aa->uid = n_arg;
			} else {
				printf("Changing group on %s\n", g.gl_pathv[i]);
				aa->gid = n_arg;
			}
			err = do_setstat(conn, g.gl_pathv[i], aa);
			if (err != 0 && err_abort)
				break;
		}
		break;
	case I_PWD:
		printf("Remote working directory: %s\n", *pwd);
		break;
	case I_LPWD:
		if (!getcwd(path_buf, sizeof(path_buf))) {
			error("Couldn't get local cwd: %s", strerror(errno));
			err = -1;
			break;
		}
		printf("Local working directory: %s\n", path_buf);
		break;
	case I_QUIT:
		/* Processed below */
		break;
	case I_HELP:
		help();
		break;
	case I_VERSION:
		printf("SFTP protocol version %u\n", sftp_proto_version(conn));
		break;
	case I_PROGRESS:
		showprogress = !showprogress;
		if (showprogress)
			printf("Progress meter enabled\n");
		else
			printf("Progress meter disabled\n");
		break;
	default:
		fatal("%d is not implemented", cmdnum);
	}

	if (g.gl_pathc)
		globfree(&g);
	if (path1)
		xfree(path1);
	if (path2)
		xfree(path2);

	/* If an unignored error occurs in batch mode we should abort. */
	if (err_abort && err != 0)
		return (-1);
	else if (cmdnum == I_QUIT)
		return (1);

	return (0);
}

#ifdef USE_LIBEDIT
static char *
prompt(EditLine *el)
{
	return ("sftp> ");
}
#endif

int
interactive_loop(int fd_in, int fd_out, char *file1, char *file2)
{
	char *pwd;
	char *dir = NULL;
	char cmd[2048];
	struct sftp_conn *conn;
	int err;
	EditLine *el = NULL;
#ifdef USE_LIBEDIT
	History *hl = NULL;
	HistEvent hev;
	extern char *__progname;

	if (!batchmode && isatty(STDIN_FILENO)) {
		if ((el = el_init(__progname, stdin, stdout, stderr)) == NULL)
			fatal("Couldn't initialise editline");
		if ((hl = history_init()) == NULL)
			fatal("Couldn't initialise editline history");
		history(hl, &hev, H_SETSIZE, 100);
		el_set(el, EL_HIST, history, hl);

		el_set(el, EL_PROMPT, prompt);
		el_set(el, EL_EDITOR, "emacs");
		el_set(el, EL_TERMINAL, NULL);
		el_set(el, EL_SIGNAL, 1);
		el_source(el, NULL);
	}
#endif /* USE_LIBEDIT */

	conn = do_init(fd_in, fd_out, copy_buffer_len, num_requests);
	if (conn == NULL)
		fatal("Couldn't initialise connection to server");

	pwd = do_realpath(conn, ".");
	if (pwd == NULL)
		fatal("Need cwd");

	if (file1 != NULL) {
		dir = xstrdup(file1);
		dir = make_absolute(dir, pwd);

		if (remote_is_dir(conn, dir) && file2 == NULL) {
			printf("Changing to: %s\n", dir);
			snprintf(cmd, sizeof cmd, "cd \"%s\"", dir);
			if (parse_dispatch_command(conn, cmd, &pwd, 1) != 0) {
				xfree(dir);
				xfree(pwd);
				return (-1);
			}
		} else {
			if (file2 == NULL)
				snprintf(cmd, sizeof cmd, "get %s", dir);
			else
				snprintf(cmd, sizeof cmd, "get %s %s", dir,
				    file2);

			err = parse_dispatch_command(conn, cmd, &pwd, 1);
			xfree(dir);
			xfree(pwd);
			return (err);
		}
		xfree(dir);
	}

#if HAVE_SETVBUF
	setvbuf(stdout, NULL, _IOLBF, 0);
	setvbuf(infile, NULL, _IOLBF, 0);
#else
       setlinebuf(stdout);
       setlinebuf(infile);
#endif

	err = 0;
	for (;;) {
		char *cp;

		signal(SIGINT, SIG_IGN);

		if (el == NULL) {
			printf("sftp> ");
			if (fgets(cmd, sizeof(cmd), infile) == NULL) {
				printf("\n");
				break;
			}
			if (batchmode) /* Echo command */
				printf("%s", cmd);
		} else {
#ifdef USE_LIBEDIT
			const char *line;
			int count = 0;

			if ((line = el_gets(el, &count)) == NULL || count <= 0)
				break;
			history(hl, &hev, H_ENTER, line);
			if (strlcpy(cmd, line, sizeof(cmd)) >= sizeof(cmd)) {
				fprintf(stderr, "Error: input line too long\n");
				continue;
			}
#endif /* USE_LIBEDIT */
		}

		cp = strrchr(cmd, '\n');
		if (cp)
			*cp = '\0';

		/* Handle user interrupts gracefully during commands */
		interrupted = 0;
		signal(SIGINT, cmd_interrupt);

		err = parse_dispatch_command(conn, cmd, &pwd, batchmode);
		if (err != 0)
			break;
	}
	xfree(pwd);

	/* err == 1 signifies normal "quit" exit */
	return (err >= 0 ? 0 : -1);
}

static void
connect_to_server(char *path, char **args, int *in, int *out)
{
	int c_in, c_out;

#ifdef USE_PIPES
	int pin[2], pout[2];

	if ((pipe(pin) == -1) || (pipe(pout) == -1))
		fatal("pipe: %s", strerror(errno));
	*in = pin[0];
	*out = pout[1];
	c_in = pout[0];
	c_out = pin[1];
#else /* USE_PIPES */
	int inout[2];

	if (socketpair(AF_UNIX, SOCK_STREAM, 0, inout) == -1)
		fatal("socketpair: %s", strerror(errno));
	*in = *out = inout[0];
	c_in = c_out = inout[1];
#endif /* USE_PIPES */

	if ((sshpid = fork()) == -1)
		fatal("fork: %s", strerror(errno));
	else if (sshpid == 0) {
		if ((dup2(c_in, STDIN_FILENO) == -1) ||
		    (dup2(c_out, STDOUT_FILENO) == -1)) {
			fprintf(stderr, "dup2: %s\n", strerror(errno));
			_exit(1);
		}
		close(*in);
		close(*out);
		close(c_in);
		close(c_out);

		/*
		 * The underlying ssh is in the same process group, so we must
		 * ignore SIGINT if we want to gracefully abort commands,
		 * otherwise the signal will make it to the ssh process and
		 * kill it too
		 */
		signal(SIGINT, SIG_IGN);
		execvp(path, args);
		fprintf(stderr, "exec: %s: %s\n", path, strerror(errno));
		_exit(1);
	}

	signal(SIGTERM, killchild);
	signal(SIGINT, killchild);
	signal(SIGHUP, killchild);
	close(c_in);
	close(c_out);
}

static void
usage(void)
{
	extern char *__progname;

	fprintf(stderr,
	    "usage: %s [-1Cv] [-B buffer_size] [-b batchfile] [-F ssh_config]\n"
	    "            [-o ssh_option] [-P sftp_server_path] [-R num_requests]\n"
	    "            [-S program] [-s subsystem | sftp_server] host\n"
	    "       %s [[user@]host[:file [file]]]\n"
	    "       %s [[user@]host[:dir[/]]]\n"
	    "       %s -b batchfile [user@]host\n", __progname, __progname, __progname, __progname);
	exit(1);
}

int
main(int argc, char **argv)
{
	int in, out, ch, err;
	char *host, *userhost, *cp, *file2 = NULL;
	int debug_level = 0, sshver = 2;
	char *file1 = NULL, *sftp_server = NULL;
	char *ssh_program = _PATH_SSH_PROGRAM, *sftp_direct = NULL;
	LogLevel ll = SYSLOG_LEVEL_INFO;
	arglist args;
	extern int optind;
	extern char *optarg;

	__progname = ssh_get_progname(argv[0]);
	args.list = NULL;
	addargs(&args, "ssh");		/* overwritten with ssh_program */
	addargs(&args, "-oForwardX11 no");
	addargs(&args, "-oForwardAgent no");
	addargs(&args, "-oClearAllForwardings yes");

	ll = SYSLOG_LEVEL_INFO;
	infile = stdin;

	while ((ch = getopt(argc, argv, "1hvCo:s:S:b:B:F:P:R:")) != -1) {
		switch (ch) {
		case 'C':
			addargs(&args, "-C");
			break;
		case 'v':
			if (debug_level < 3) {
				addargs(&args, "-v");
				ll = SYSLOG_LEVEL_DEBUG1 + debug_level;
			}
			debug_level++;
			break;
		case 'F':
		case 'o':
			addargs(&args, "-%c%s", ch, optarg);
			break;
		case '1':
			sshver = 1;
			if (sftp_server == NULL)
				sftp_server = _PATH_SFTP_SERVER;
			break;
		case 's':
			sftp_server = optarg;
			break;
		case 'S':
			ssh_program = optarg;
			break;
		case 'b':
			if (batchmode)
				fatal("Batch file already specified.");

			/* Allow "-" as stdin */
			if (strcmp(optarg, "-") != 0 &&
			   (infile = fopen(optarg, "r")) == NULL)
				fatal("%s (%s).", strerror(errno), optarg);
			showprogress = 0;
			batchmode = 1;
			addargs(&args, "-obatchmode yes");
			break;
		case 'P':
			sftp_direct = optarg;
			break;
		case 'B':
			copy_buffer_len = strtol(optarg, &cp, 10);
			if (copy_buffer_len == 0 || *cp != '\0')
				fatal("Invalid buffer size \"%s\"", optarg);
			break;
		case 'R':
			num_requests = strtol(optarg, &cp, 10);
			if (num_requests == 0 || *cp != '\0')
				fatal("Invalid number of requests \"%s\"",
				    optarg);
			break;
		case 'h':
		default:
			usage();
		}
	}

	if (!isatty(STDERR_FILENO))
		showprogress = 0;

	log_init(argv[0], ll, SYSLOG_FACILITY_USER, 1);

	if (sftp_direct == NULL) {
		if (optind == argc || argc > (optind + 2))
			usage();

		userhost = xstrdup(argv[optind]);
		file2 = argv[optind+1];

		if ((host = strrchr(userhost, '@')) == NULL)
			host = userhost;
		else {
			*host++ = '\0';
			if (!userhost[0]) {
				fprintf(stderr, "Missing username\n");
				usage();
			}
			addargs(&args, "-l%s",userhost);
		}

		if ((cp = colon(host)) != NULL) {
			*cp++ = '\0';
			file1 = cp;
		}

		host = cleanhostname(host);
		if (!*host) {
			fprintf(stderr, "Missing hostname\n");
			usage();
		}

		addargs(&args, "-oProtocol %d", sshver);

		/* no subsystem if the server-spec contains a '/' */
		if (sftp_server == NULL || strchr(sftp_server, '/') == NULL)
			addargs(&args, "-s");

		addargs(&args, "%s", host);
		addargs(&args, "%s", (sftp_server != NULL ?
		    sftp_server : "sftp"));
		args.list[0] = ssh_program;

		if (!batchmode)
			fprintf(stderr, "Connecting to %s...\n", host);
		connect_to_server(ssh_program, args.list, &in, &out);
	} else {
		args.list = NULL;
		addargs(&args, "sftp-server");

		if (!batchmode)
			fprintf(stderr, "Attaching to %s...\n", sftp_direct);
		connect_to_server(sftp_direct, args.list, &in, &out);
	}

	err = interactive_loop(in, out, file1, file2);

#if !defined(USE_PIPES)
       shutdown(in, SHUT_RDWR);
       shutdown(out, SHUT_RDWR);
#endif

	close(in);
	close(out);
	if (batchmode)
		fclose(infile);

	while (waitpid(sshpid, NULL, 0) == -1)
		if (errno != EINTR)
			fatal("Couldn't wait for ssh process: %s",
			    strerror(errno));

	exit(err == 0 ? 0 : 1);
}