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passt/flow.h
David Gibson b43e4483ed flow, tcp: Add flow-centric dispatch for deferred flow handling
tcp_defer_handler(), amongst other things, scans the flow table and does
some processing for each TCP connection.  When we add other protocols to
the flow table, they're likely to want some similar scanning.  It makes
more sense for cache friendliness to perform a single scan of the flow
table and dispatch to the protocol specific handlers, rather than having
each protocol separately scan the table.

To that end, add a new flow_defer_handler() handling all flow-linked
deferred operations.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2024-01-22 23:35:17 +01:00

87 lines
2.2 KiB
C

/* SPDX-License-Identifier: GPL-2.0-or-later
* Copyright Red Hat
* Author: David Gibson <david@gibson.dropbear.id.au>
*
* Tracking for logical "flows" of packets.
*/
#ifndef FLOW_H
#define FLOW_H
/**
* enum flow_type - Different types of packet flows we track
*/
enum flow_type {
/* Represents an invalid or unused flow */
FLOW_TYPE_NONE = 0,
/* A TCP connection between a socket and tap interface */
FLOW_TCP,
/* A TCP connection between a host socket and ns socket */
FLOW_TCP_SPLICE,
FLOW_NUM_TYPES,
};
extern const char *flow_type_str[];
#define FLOW_TYPE(f) \
((f)->type < FLOW_NUM_TYPES ? flow_type_str[(f)->type] : "?")
/**
* struct flow_common - Common fields for packet flows
* @type: Type of packet flow
*/
struct flow_common {
uint8_t type;
};
#define FLOW_INDEX_BITS 17 /* 128k - 1 */
#define FLOW_MAX MAX_FROM_BITS(FLOW_INDEX_BITS)
#define FLOW_TABLE_PRESSURE 30 /* % of FLOW_MAX */
#define FLOW_FILE_PRESSURE 30 /* % of c->nofile */
/**
* struct flow_sidx - ID for one side of a specific flow
* @side: Side referenced (0 or 1)
* @flow: Index of flow referenced
*/
typedef struct flow_sidx {
unsigned side :1;
unsigned flow :FLOW_INDEX_BITS;
} flow_sidx_t;
static_assert(sizeof(flow_sidx_t) <= sizeof(uint32_t),
"flow_sidx_t must fit within 32 bits");
#define FLOW_SIDX_NONE ((flow_sidx_t){ .flow = FLOW_MAX })
/**
* flow_sidx_eq() - Test if two sidx values are equal
* @a, @b: sidx values
*
* Return: true iff @a and @b refer to the same side of the same flow
*/
static inline bool flow_sidx_eq(flow_sidx_t a, flow_sidx_t b)
{
return (a.flow == b.flow) && (a.side == b.side);
}
union flow;
void flow_table_compact(struct ctx *c, union flow *hole);
void flow_defer_handler(struct ctx *c);
void flow_log_(const struct flow_common *f, int pri, const char *fmt, ...)
__attribute__((format(printf, 3, 4)));
#define flow_log(f_, pri, ...) flow_log_(&(f_)->f, (pri), __VA_ARGS__)
#define flow_dbg(f, ...) flow_log((f), LOG_DEBUG, __VA_ARGS__)
#define flow_err(f, ...) flow_log((f), LOG_ERR, __VA_ARGS__)
#define flow_trace(f, ...) \
do { \
if (log_trace) \
flow_dbg((f), __VA_ARGS__); \
} while (0)
#endif /* FLOW_H */