BadVPN – Rev 1
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/**
* @file PacketPassFairQueue.h
* @author Ambroz Bizjak <ambrop7@gmail.com>
*
* @section LICENSE
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the author nor the
* names of its contributors may be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* @section DESCRIPTION
*
* Fair queue using {@link PacketPassInterface}.
*/
#ifndef BADVPN_FLOW_PACKETPASSFAIRQUEUE_H
#define BADVPN_FLOW_PACKETPASSFAIRQUEUE_H
#include <stdint.h>
#include <misc/debug.h>
#include <misc/debugcounter.h>
#include <structure/SAvl.h>
#include <structure/LinkedList1.h>
#include <base/DebugObject.h>
#include <base/BPending.h>
#include <flow/PacketPassInterface.h>
// reduce this to test time overflow handling
#define FAIRQUEUE_MAX_TIME UINT64_MAX
typedef void (*PacketPassFairQueue_handler_busy) (void *user);
struct PacketPassFairQueueFlow_s;
#include "PacketPassFairQueue_tree.h"
#include <structure/SAvl_decl.h>
typedef struct PacketPassFairQueueFlow_s {
struct PacketPassFairQueue_s *m;
PacketPassFairQueue_handler_busy handler_busy;
void *user;
PacketPassInterface input;
uint64_t time;
LinkedList1Node list_node;
int is_queued;
struct {
PacketPassFairQueue__TreeNode tree_node;
uint8_t *data;
int data_len;
} queued;
DebugObject d_obj;
} PacketPassFairQueueFlow;
/**
* Fair queue using {@link PacketPassInterface}.
*/
typedef struct PacketPassFairQueue_s {
PacketPassInterface *output;
BPendingGroup *pg;
int use_cancel;
int packet_weight;
struct PacketPassFairQueueFlow_s *sending_flow;
int sending_len;
struct PacketPassFairQueueFlow_s *previous_flow;
PacketPassFairQueue__Tree queued_tree;
LinkedList1 flows_list;
int freeing;
BPending schedule_job;
DebugObject d_obj;
DebugCounter d_ctr;
} PacketPassFairQueue;
/**
* Initializes the queue.
*
* @param m the object
* @param output output interface
* @param pg pending group
* @param use_cancel whether cancel functionality is required. Must be 0 or 1.
* If 1, output must support cancel functionality.
* @param packet_weight additional weight a packet bears. Must be >0, to keep
* the queue fair for zero size packets.
* @return 1 on success, 0 on failure (because output MTU is too large)
*/
int PacketPassFairQueue_Init (PacketPassFairQueue *m, PacketPassInterface *output, BPendingGroup *pg, int use_cancel, int packet_weight) WARN_UNUSED;
/**
* Frees the queue.
* All flows must have been freed.
*
* @param m the object
*/
void PacketPassFairQueue_Free (PacketPassFairQueue *m);
/**
* Prepares for freeing the entire queue. Must be called to allow freeing
* the flows in the process of freeing the entire queue.
* After this function is called, flows and the queue must be freed
* before any further I/O.
* May be called multiple times.
* The queue enters freeing state.
*
* @param m the object
*/
void PacketPassFairQueue_PrepareFree (PacketPassFairQueue *m);
/**
* Returns the MTU of the queue.
*
* @param m the object
*/
int PacketPassFairQueue_GetMTU (PacketPassFairQueue *m);
/**
* Initializes a queue flow.
* Queue must not be in freeing state.
* Must not be called from queue calls to output.
*
* @param flow the object
* @param m queue to attach to
*/
void PacketPassFairQueueFlow_Init (PacketPassFairQueueFlow *flow, PacketPassFairQueue *m);
/**
* Frees a queue flow.
* Unless the queue is in freeing state:
* - The flow must not be busy as indicated by {@link PacketPassFairQueueFlow_IsBusy}.
* - Must not be called from queue calls to output.
*
* @param flow the object
*/
void PacketPassFairQueueFlow_Free (PacketPassFairQueueFlow *flow);
/**
* Does nothing.
* It must be possible to free the flow (see {@link PacketPassFairQueueFlow_Free}).
*
* @param flow the object
*/
void PacketPassFairQueueFlow_AssertFree (PacketPassFairQueueFlow *flow);
/**
* Determines if the flow is busy. If the flow is considered busy, it must not
* be freed. At any given time, at most one flow will be indicated as busy.
* Queue must not be in freeing state.
* Must not be called from queue calls to output.
*
* @param flow the object
* @return 0 if not busy, 1 is busy
*/
int PacketPassFairQueueFlow_IsBusy (PacketPassFairQueueFlow *flow);
/**
* Requests the output to stop processing the current packet as soon as possible.
* Cancel functionality must be enabled for the queue.
* The flow must be busy as indicated by {@link PacketPassFairQueueFlow_IsBusy}.
* Queue must not be in freeing state.
*
* @param flow the object
*/
void PacketPassFairQueueFlow_RequestCancel (PacketPassFairQueueFlow *flow);
/**
* Sets up a callback to be called when the flow is no longer busy.
* The handler will be called as soon as the flow is no longer busy, i.e. it is not
* possible that this flow is no longer busy before the handler is called.
* The flow must be busy as indicated by {@link PacketPassFairQueueFlow_IsBusy}.
* Queue must not be in freeing state.
* Must not be called from queue calls to output.
*
* @param flow the object
* @param handler callback function. NULL to disable.
* @param user value passed to callback function. Ignored if handler is NULL.
*/
void PacketPassFairQueueFlow_SetBusyHandler (PacketPassFairQueueFlow *flow, PacketPassFairQueue_handler_busy handler, void *user);
/**
* Returns the input interface of the flow.
*
* @param flow the object
* @return input interface
*/
PacketPassInterface * PacketPassFairQueueFlow_GetInput (PacketPassFairQueueFlow *flow);
#endif