static int nbd_negotiate_options(NBDClient *client, Error **errp) { uint32_t flags; bool fixedNewstyle = false; /* Client sends: [ 0 .. 3] client flags [ 0 .. 7] NBD_OPTS_MAGIC [ 8 .. 11] NBD option [12 .. 15] Data length ... Rest of request [ 0 .. 7] NBD_OPTS_MAGIC [ 8 .. 11] Second NBD option [12 .. 15] Data length ... Rest of request */ if (nbd_read(client->ioc, &flags, sizeof(flags), errp) < 0) { error_prepend(errp, "read failed: "); return -EIO; } trace_nbd_negotiate_options_flags(); be32_to_cpus(&flags); if (flags & NBD_FLAG_C_FIXED_NEWSTYLE) { trace_nbd_negotiate_options_newstyle(); fixedNewstyle = true; flags &= ~NBD_FLAG_C_FIXED_NEWSTYLE; } if (flags & NBD_FLAG_C_NO_ZEROES) { trace_nbd_negotiate_options_no_zeroes(); client->no_zeroes = true; flags &= ~NBD_FLAG_C_NO_ZEROES; } if (flags != 0) { error_setg(errp, "Unknown client flags 0x%" PRIx32 " received", flags); return -EIO; } while (1) { int ret; uint32_t option, length; uint64_t magic; if (nbd_read(client->ioc, &magic, sizeof(magic), errp) < 0) { error_prepend(errp, "read failed: "); return -EINVAL; } magic = be64_to_cpu(magic); trace_nbd_negotiate_options_check_magic(magic); if (magic != NBD_OPTS_MAGIC) { error_setg(errp, "Bad magic received"); return -EINVAL; } if (nbd_read(client->ioc, &option, sizeof(option), errp) < 0) { error_prepend(errp, "read failed: "); return -EINVAL; } option = be32_to_cpu(option); if (nbd_read(client->ioc, &length, sizeof(length), errp) < 0) { error_prepend(errp, "read failed: "); return -EINVAL; } length = be32_to_cpu(length); trace_nbd_negotiate_options_check_option(option); if (client->tlscreds && client->ioc == (QIOChannel *)client->sioc) { QIOChannel *tioc; if (!fixedNewstyle) { error_setg(errp, "Unsupported option 0x%" PRIx32, option); return -EINVAL; } switch (option) { case NBD_OPT_STARTTLS: tioc = nbd_negotiate_handle_starttls(client, length, errp); if (!tioc) { return -EIO; } object_unref(OBJECT(client->ioc)); client->ioc = QIO_CHANNEL(tioc); break; case NBD_OPT_EXPORT_NAME: /* No way to return an error to client, so drop connection */ error_setg(errp, "Option 0x%x not permitted before TLS", option); return -EINVAL; default: if (nbd_drop(client->ioc, length, errp) < 0) { return -EIO; } ret = nbd_negotiate_send_rep_err(client->ioc, NBD_REP_ERR_TLS_REQD, option, errp, "Option 0x%" PRIx32 "not permitted before TLS", option); if (ret < 0) { return ret; } /* Let the client keep trying, unless they asked to * quit. In this mode, we've already sent an error, so * we can't ack the abort. */ if (option == NBD_OPT_ABORT) { return 1; } break; } } else if (fixedNewstyle) { switch (option) { case NBD_OPT_LIST: ret = nbd_negotiate_handle_list(client, length, errp); if (ret < 0) { return ret; } break; case NBD_OPT_ABORT: /* NBD spec says we must try to reply before * disconnecting, but that we must also tolerate * guests that don't wait for our reply. */ nbd_negotiate_send_rep(client->ioc, NBD_REP_ACK, option, NULL); return 1; case NBD_OPT_EXPORT_NAME: return nbd_negotiate_handle_export_name(client, length, errp); case NBD_OPT_STARTTLS: if (nbd_drop(client->ioc, length, errp) < 0) { return -EIO; } if (client->tlscreds) { ret = nbd_negotiate_send_rep_err(client->ioc, NBD_REP_ERR_INVALID, option, errp, "TLS already enabled"); } else { ret = nbd_negotiate_send_rep_err(client->ioc, NBD_REP_ERR_POLICY, option, errp, "TLS not configured"); } if (ret < 0) { return ret; } break; default: if (nbd_drop(client->ioc, length, errp) < 0) { return -EIO; } ret = nbd_negotiate_send_rep_err(client->ioc, NBD_REP_ERR_UNSUP, option, errp, "Unsupported option 0x%" PRIx32, option); if (ret < 0) { return ret; } break; } } else { /* * If broken new-style we should drop the connection * for anything except NBD_OPT_EXPORT_NAME */ switch (option) { case NBD_OPT_EXPORT_NAME: return nbd_negotiate_handle_export_name(client, length, errp); default: error_setg(errp, "Unsupported option 0x%" PRIx32, option); return -EINVAL; } } } }