static ssize_t qio_channel_websock_decode_payload(QIOChannelWebsock *ioc, Error **errp) { size_t i; size_t payload_len; uint32_t *payload32; if (!ioc->payload_remain) { error_setg(errp, "Decoding payload but no bytes of payload remain"); return -1; } /* If we aren't at the end of the payload, then drop * off the last bytes, so we're always multiple of 4 * for purpose of unmasking, except at end of payload */ if (ioc->encinput.offset < ioc->payload_remain) { payload_len = ioc->encinput.offset - (ioc->encinput.offset % 4); } else { payload_len = ioc->payload_remain; } if (payload_len == 0) { return QIO_CHANNEL_ERR_BLOCK; } ioc->payload_remain -= payload_len; /* unmask frame */ /* process 1 frame (32 bit op) */ payload32 = (uint32_t *)ioc->encinput.buffer; for (i = 0; i < payload_len / 4; i++) { payload32[i] ^= ioc->mask.u; } /* process the remaining bytes (if any) */ for (i *= 4; i < payload_len; i++) { ioc->encinput.buffer[i] ^= ioc->mask.c[i % 4]; } buffer_reserve(&ioc->rawinput, payload_len); buffer_append(&ioc->rawinput, ioc->encinput.buffer, payload_len); buffer_advance(&ioc->encinput, payload_len); return payload_len; }