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| | /* SPDX-License-Identifier: GPL-2.0-or-later
* Copyright Red Hat
* Author: David Gibson <david@gibson.dropbear.id.au>
*
* Definitions for the global table of packet flows.
*/
#ifndef FLOW_TABLE_H
#define FLOW_TABLE_H
#include "tcp_conn.h"
/**
* struct flow_free_cluster - Information about a cluster of free entries
* @f: Generic flow information
* @n: Number of entries in the free cluster (including this one)
* @next: Index of next free cluster
*/
struct flow_free_cluster {
/* Must be first element */
struct flow_common f;
unsigned n;
unsigned next;
};
/**
* union flow - Descriptor for a logical packet flow (e.g. connection)
* @f: Fields common between all variants
* @tcp: Fields for non-spliced TCP connections
* @tcp_splice: Fields for spliced TCP connections
*/
union flow {
struct flow_common f;
struct flow_free_cluster free;
struct tcp_tap_conn tcp;
struct tcp_splice_conn tcp_splice;
};
/* Global Flow Table */
extern unsigned flow_first_free;
extern union flow flowtab[];
/** flow_idx - Index of flow from common structure
* @f: Common flow fields pointer
*
* Return: index of @f in the flow table
*/
static inline unsigned flow_idx(const struct flow_common *f)
{
return (union flow *)f - flowtab;
}
/** FLOW_IDX - Find the index of a flow
* @f_: Flow pointer, either union flow * or protocol specific
*
* Return: index of @f in the flow table
*/
#define FLOW_IDX(f_) (flow_idx(&(f_)->f))
/** FLOW - Flow entry at a given index
* @idx: Flow index
*
* Return: pointer to entry @idx in the flow table
*/
#define FLOW(idx) (&flowtab[(idx)])
/** flow_at_sidx - Flow entry for a given sidx
* @sidx: Flow & side index
*
* Return: pointer to the corresponding flow entry, or NULL
*/
static inline union flow *flow_at_sidx(flow_sidx_t sidx)
{
if (sidx.flow >= FLOW_MAX)
return NULL;
return FLOW(sidx.flow);
}
/** flow_sidx_t - Index of one side of a flow from common structure
* @f: Common flow fields pointer
* @side: Which side to refer to (0 or 1)
*
* Return: index of @f and @side in the flow table
*/
static inline flow_sidx_t flow_sidx(const struct flow_common *f,
int side)
{
/* cppcheck-suppress [knownConditionTrueFalse, unmatchedSuppression] */
ASSERT(side == !!side);
return (flow_sidx_t){
.side = side,
.flow = flow_idx(f),
};
}
/** FLOW_SIDX - Find the index of one side of a flow
* @f_: Flow pointer, either union flow * or protocol specific
* @side: Which side to index (0 or 1)
*
* Return: index of @f and @side in the flow table
*/
#define FLOW_SIDX(f_, side) (flow_sidx(&(f_)->f, (side)))
union flow *flow_alloc(void);
void flow_alloc_cancel(union flow *flow);
#endif /* FLOW_TABLE_H */
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