+
+
+static struct termios oldtty;
+
+static void term_exit(void)
+{
+ tcsetattr(0, TCSANOW, &oldtty);
+}
+
+static void term_init(void)
+{
+ struct termios tty;
+
+ tcgetattr(0, &tty);
+ oldtty = tty;
+
+ tty.c_iflag &= ~(IGNBRK|BRKINT|PARMRK|ISTRIP
+ |INLCR|IGNCR|ICRNL|IXON);
+ tty.c_oflag |= OPOST;
+ tty.c_lflag &= ~(ECHO|ECHONL|ICANON|IEXTEN);
+ tty.c_cflag &= ~(CSIZE|PARENB);
+ tty.c_cflag |= CS8;
+ tty.c_cc[VMIN] = 1;
+ tty.c_cc[VTIME] = 0;
+
+ tcsetattr(0, TCSANOW, &tty);
+
+ atexit(term_exit);
+}
+
+int qemu_read_password(char *buf, int buf_size)
+{
+ uint8_t ch;
+ int i, ret;
+
+ printf("password: ");
+ fflush(stdout);
+ term_init();
+ i = 0;
+ for (;;) {
+ ret = read(0, &ch, 1);
+ if (ret == -1) {
+ if (errno == EAGAIN || errno == EINTR) {
+ continue;
+ } else {
+ break;
+ }
+ } else if (ret == 0) {
+ ret = -1;
+ break;
+ } else {
+ if (ch == '\r' ||
+ ch == '\n') {
+ ret = 0;
+ break;
+ }
+ if (i < (buf_size - 1)) {
+ buf[i++] = ch;
+ }
+ }
+ }
+ term_exit();
+ buf[i] = '\0';
+ printf("\n");
+ return ret;
+}
+
+
+pid_t qemu_fork(Error **errp)
+{
+ sigset_t oldmask, newmask;
+ struct sigaction sig_action;
+ int saved_errno;
+ pid_t pid;
+
+ /*
+ * Need to block signals now, so that child process can safely
+ * kill off caller's signal handlers without a race.
+ */
+ sigfillset(&newmask);
+ if (pthread_sigmask(SIG_SETMASK, &newmask, &oldmask) != 0) {
+ error_setg_errno(errp, errno,
+ "cannot block signals");
+ return -1;
+ }
+
+ pid = fork();
+ saved_errno = errno;
+
+ if (pid < 0) {
+ /* attempt to restore signal mask, but ignore failure, to
+ * avoid obscuring the fork failure */
+ (void)pthread_sigmask(SIG_SETMASK, &oldmask, NULL);
+ error_setg_errno(errp, saved_errno,
+ "cannot fork child process");
+ errno = saved_errno;
+ return -1;
+ } else if (pid) {
+ /* parent process */
+
+ /* Restore our original signal mask now that the child is
+ * safely running. Only documented failures are EFAULT (not
+ * possible, since we are using just-grabbed mask) or EINVAL
+ * (not possible, since we are using correct arguments). */
+ (void)pthread_sigmask(SIG_SETMASK, &oldmask, NULL);
+ } else {
+ /* child process */
+ size_t i;
+
+ /* Clear out all signal handlers from parent so nothing
+ * unexpected can happen in our child once we unblock
+ * signals */
+ sig_action.sa_handler = SIG_DFL;
+ sig_action.sa_flags = 0;
+ sigemptyset(&sig_action.sa_mask);
+
+ for (i = 1; i < NSIG; i++) {
+ /* Only possible errors are EFAULT or EINVAL The former
+ * won't happen, the latter we expect, so no need to check
+ * return value */
+ (void)sigaction(i, &sig_action, NULL);
+ }
+
+ /* Unmask all signals in child, since we've no idea what the
+ * caller's done with their signal mask and don't want to
+ * propagate that to children */
+ sigemptyset(&newmask);
+ if (pthread_sigmask(SIG_SETMASK, &newmask, NULL) != 0) {
+ Error *local_err = NULL;
+ error_setg_errno(&local_err, errno,
+ "cannot unblock signals");
+ error_report_err(local_err);
+ _exit(1);
+ }
+ }
+ return pid;
+}
projects / qemu.git / blobdiff