This code is responsible for routing between various hosts/guests as well as routing in nested scenarios.
Signed-off-by: Andrew Stiegmann (stieg) <[email protected]> --- drivers/misc/vmw_vmci/vmci_route.c | 234 ++++++++++++++++++++++++++++++++++++ drivers/misc/vmw_vmci/vmci_route.h | 34 +++++ 2 files changed, 268 insertions(+), 0 deletions(-) create mode 100644 drivers/misc/vmw_vmci/vmci_route.c create mode 100644 drivers/misc/vmw_vmci/vmci_route.h diff --git a/drivers/misc/vmw_vmci/vmci_route.c b/drivers/misc/vmw_vmci/vmci_route.c new file mode 100644 index 0000000..4c9183c --- /dev/null +++ b/drivers/misc/vmw_vmci/vmci_route.c @@ -0,0 +1,234 @@ +/* + * VMware VMCI Driver + * + * Copyright (C) 2012 VMware, Inc. All rights reserved. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the + * Free Software Foundation version 2 and no later version. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY + * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License + * for more details. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, write to the Free Software Foundation, Inc., + * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA + */ + +#include <linux/vmw_vmci_api.h> +#include <linux/vmw_vmci_defs.h> + +#include "vmci_common_int.h" +#include "vmci_context.h" +#include "vmci_driver.h" +#include "vmci_route.h" + +/* + *------------------------------------------------------------------------------ + * + * vmci_route -- + * + * Make a routing decision for the given source and destination handles. + * This will try to determine the route using the handles and the available + * devices. + * + * Result: + * A VMCIRoute value. + * + * Side effects: + * Sets the source context if it is invalid. + * + *------------------------------------------------------------------------------ + */ + +int vmci_route(struct vmci_handle *src, // IN/OUT + const struct vmci_handle *dst, // IN + bool fromGuest, // IN + enum vmci_route *route) // OUT +{ + bool hasHostDevice = vmci_host_code_active(); + bool hasGuestDevice = vmci_guest_code_active(); + + ASSERT(src); + ASSERT(dst); + ASSERT(route); + + *route = VMCI_ROUTE_NONE; + + /* + * "fromGuest" is only ever set to true by IOCTL_VMCI_DATAGRAM_SEND (or by + * the vmkernel equivalent), which comes from the VMX, so we know it is + * coming from a guest. + * + * To avoid inconsistencies, test these once. We will test them again + * when we do the actual send to ensure that we do not touch a non-existent + * device. + */ + + /* Must have a valid destination context. */ + if (VMCI_INVALID_ID == dst->context) + return VMCI_ERROR_INVALID_ARGS; + + /* Anywhere to hypervisor. */ + if (VMCI_HYPERVISOR_CONTEXT_ID == dst->context) { + + /* + * If this message already came from a guest then we cannot send it + * to the hypervisor. It must come from a local client. + */ + if (fromGuest) + return VMCI_ERROR_DST_UNREACHABLE; + + /* We must be acting as a guest in order to send to the hypervisor. */ + if (!hasGuestDevice) + return VMCI_ERROR_DEVICE_NOT_FOUND; + + /* And we cannot send if the source is the host context. */ + if (VMCI_HOST_CONTEXT_ID == src->context) + return VMCI_ERROR_INVALID_ARGS; + + /* + * If the client passed the ANON source handle then respect it (both + * context and resource are invalid). However, if they passed only + * an invalid context, then they probably mean ANY, in which case we + * should set the real context here before passing it down. + */ + if (VMCI_INVALID_ID == src->context && VMCI_INVALID_ID != src->resource) + src->context = VMCI_GetContextID(); + + /* Send from local client down to the hypervisor. */ + *route = VMCI_ROUTE_AS_GUEST; + return VMCI_SUCCESS; + } + + /* Anywhere to local client on host. */ + if (VMCI_HOST_CONTEXT_ID == dst->context) { + /* + * If it is not from a guest but we are acting as a guest, then we need + * to send it down to the host. Note that if we are also acting as a + * host then this will prevent us from sending from local client to + * local client, but we accept that restriction as a way to remove + * any ambiguity from the host context. + */ + if (src->context == VMCI_HYPERVISOR_CONTEXT_ID) { + /* + * If the hypervisor is the source, this is host local + * communication. The hypervisor may send vmci event + * datagrams to the host itself, but it will never send + * datagrams to an "outer host" through the guest device. + */ + + if (hasHostDevice) { + *route = VMCI_ROUTE_AS_HOST; + return VMCI_SUCCESS; + } else { + return VMCI_ERROR_DEVICE_NOT_FOUND; + } + } + + if (!fromGuest && hasGuestDevice) { + /* If no source context then use the current. */ + if (VMCI_INVALID_ID == src->context) + src->context = VMCI_GetContextID(); + + /* Send it from local client down to the host. */ + *route = VMCI_ROUTE_AS_GUEST; + return VMCI_SUCCESS; + } + + /* + * Otherwise we already received it from a guest and it is destined + * for a local client on this host, or it is from another local client + * on this host. We must be acting as a host to service it. + */ + if (!hasHostDevice) + return VMCI_ERROR_DEVICE_NOT_FOUND; + + if (VMCI_INVALID_ID == src->context) { + /* + * If it came from a guest then it must have a valid context. + * Otherwise we can use the host context. + */ + + if (fromGuest) + return VMCI_ERROR_INVALID_ARGS; + + src->context = VMCI_HOST_CONTEXT_ID; + } + + /* Route to local client. */ + *route = VMCI_ROUTE_AS_HOST; + return VMCI_SUCCESS; + } + + /* If we are acting as a host then this might be destined for a guest. */ + if (hasHostDevice) { + /* It will have a context if it is meant for a guest. */ + if (vmci_ctx_exists(dst->context)) { + if (VMCI_INVALID_ID == src->context) { + /* + * If it came from a guest then it must have a valid context. + * Otherwise we can use the host context. + */ + + if (fromGuest) + return VMCI_ERROR_INVALID_ARGS; + + src->context = VMCI_HOST_CONTEXT_ID; + } else if (VMCI_CONTEXT_IS_VM(src->context) && + src->context != dst->context) { + /* + * VM to VM communication is not allowed. Since we catch + * all communication destined for the host above, this + * must be destined for a VM since there is a valid + * context. + */ + + ASSERT(VMCI_CONTEXT_IS_VM(dst->context)); + + return VMCI_ERROR_DST_UNREACHABLE; + } + + /* Pass it up to the guest. */ + *route = VMCI_ROUTE_AS_HOST; + return VMCI_SUCCESS; + } else if (!hasGuestDevice) { + /* + * The host is attempting to reach a CID without an active context, and + * we can't send it down, since we have no guest device. + */ + + return VMCI_ERROR_DST_UNREACHABLE; + } + } + + /* + * We must be a guest trying to send to another guest, which means + * we need to send it down to the host. We do not filter out VM to + * VM communication here, since we want to be able to use the guest + * driver on older versions that do support VM to VM communication. + */ + if (!hasGuestDevice) { + /* + * Ending up here means we have neither guest nor host device. That + * shouldn't happen, since any VMCI client in the kernel should have done + * a successful VMCI_DeviceGet. + */ + + ASSERT(false); + return VMCI_ERROR_DEVICE_NOT_FOUND; + } + + /* If no source context then use the current context. */ + if (VMCI_INVALID_ID == src->context) + src->context = VMCI_GetContextID(); + + /* + * Send it from local client down to the host, which will route it to + * the other guest for us. + */ + *route = VMCI_ROUTE_AS_GUEST; + return VMCI_SUCCESS; +} diff --git a/drivers/misc/vmw_vmci/vmci_route.h b/drivers/misc/vmw_vmci/vmci_route.h new file mode 100644 index 0000000..c53f86e --- /dev/null +++ b/drivers/misc/vmw_vmci/vmci_route.h @@ -0,0 +1,34 @@ +/* + * VMware VMCI Driver + * + * Copyright (C) 2012 VMware, Inc. All rights reserved. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the + * Free Software Foundation version 2 and no later version. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY + * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License + * for more details. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, write to the Free Software Foundation, Inc., + * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA + */ + +#ifndef _VMCI_ROUTE_H_ +#define _VMCI_ROUTE_H_ + +#include <linux/vmw_vmci_defs.h> + +enum vmci_route { + VMCI_ROUTE_NONE, + VMCI_ROUTE_AS_HOST, + VMCI_ROUTE_AS_GUEST, +}; + +int vmci_route(struct vmci_handle *src, const struct vmci_handle *dst, + bool fromGuest, enum vmci_route *route); + +#endif // _VMCI_ROUTE_H_ -- 1.7.0.4 _______________________________________________ Virtualization mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/virtualization
