sync with OpenBSD -current

regress/sys/kern/pledge/generic/pty.c

@@ -0,0 +1,103 @@
+/*	$OpenBSD: pty.c,v 1.1 2024/06/03 08:02:22 anton Exp $	*/
+
+#include <sys/ioctl.h>
+
+#include <err.h>
+#include <fcntl.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+#include "pty.h"
+
+int
+pty_open(struct pty *pty)
+{
+	int master, slave;
+
+	master = posix_openpt(O_RDWR);
+	if (master == -1) {
+		warn("posix_openpt");
+		return 1;
+	}
+	if (grantpt(master) == -1) {
+		warn("grantpt");
+		return 1;
+	}
+	if (unlockpt(master) == -1) {
+		warn("unlockpt");
+		return 1;
+	}
+
+	slave = open(ptsname(master), O_RDWR);
+	if (slave == -1) {
+		warn("%s", ptsname(master));
+		return 1;
+	}
+
+	pty->master = master;
+	pty->slave = slave;
+	return 0;
+}
+
+void
+pty_close(struct pty *pty)
+{
+	close(pty->slave);
+	close(pty->master);
+}
+
+/*
+ * Disconnect the controlling tty, if present.
+ */
+int
+pty_detach(struct pty *pty)
+{
+	int fd;
+
+	fd = open("/dev/tty", O_RDWR | O_NOCTTY);
+	if (fd >= 0) {
+		(void)ioctl(fd, TIOCNOTTY, NULL);
+		close(fd);
+	}
+	return 0;
+}
+
+/*
+ * Connect the slave as the controlling tty.
+ */
+int
+pty_attach(struct pty *pty)
+{
+	if (ioctl(pty->slave, TIOCSCTTY, NULL) == -1) {
+		warn("TIOCSCTTY");
+		return 1;
+	}
+	return 0;
+}
+
+int
+pty_drain(struct pty *pty)
+{
+	for (;;) {
+		char *buf = &pty->buf.storage[pty->buf.len];
+		size_t bufsize = sizeof(pty->buf.storage) - pty->buf.len;
+		ssize_t n;
+
+		n = read(pty->master, buf, bufsize);
+		if (n == -1) {
+			warn("read");
+			return 1;
+		}
+		if (n == 0)
+			break;
+
+		/* Ensure space for NUL-terminator. */
+		if ((size_t)n >= bufsize) {
+			warnx("pty buffer too small");
+			return 1;
+		}
+		pty->buf.len += n;
+	}
+
+	return 0;
+}