static int usb_serial_handle_data(USBDevice *dev, USBPacket *p) { USBSerialState *s = (USBSerialState *)dev; int i, ret = 0; uint8_t devep = p->devep; struct iovec *iov; uint8_t header[2]; int first_len, len; switch (p->pid) { case USB_TOKEN_OUT: if (devep != 2) goto fail; for (i = 0; i < p->iov.niov; i++) { iov = p->iov.iov + i; qemu_chr_fe_write(s->cs, iov->iov_base, iov->iov_len); } break; case USB_TOKEN_IN: if (devep != 1) goto fail; first_len = RECV_BUF - s->recv_ptr; len = p->iov.size; if (len <= 2) { ret = USB_RET_NAK; break; } header[0] = usb_get_modem_lines(s) | 1; /* We do not have the uart details */ /* handle serial break */ if (s->event_trigger && s->event_trigger & FTDI_BI) { s->event_trigger &= ~FTDI_BI; header[1] = FTDI_BI; usb_packet_copy(p, header, 2); ret = 2; break; } else { header[1] = 0; } len -= 2; if (len > s->recv_used) len = s->recv_used; if (!len) { ret = USB_RET_NAK; break; } if (first_len > len) first_len = len; usb_packet_copy(p, header, 2); usb_packet_copy(p, s->recv_buf + s->recv_ptr, first_len); if (len > first_len) usb_packet_copy(p, s->recv_buf, len - first_len); s->recv_used -= len; s->recv_ptr = (s->recv_ptr + len) % RECV_BUF; ret = len + 2; break; default: DPRINTF("Bad token\n"); fail: ret = USB_RET_STALL; break; } return ret; }