flow: Add helper to determine a flow's protocol

Each flow already has a type field.  This implies the protocol the
flow represents, but also has more information: we have two ways to
represent TCP flows, "tap" and "spliced".  In order to generalise some
of the flow mechanics, we'll need to determine a flow's protocol in
terms of the IP (L4) protocol number.

Introduce a constant table and helper macro to derive this from the flow
type.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
This commit is contained in:
David Gibson 2024-02-28 22:25:07 +11:00 committed by Stefano Brivio
parent bb9bf0bb8f
commit 76c7e1dca3
2 changed files with 11 additions and 0 deletions

7
flow.c
View file

@ -25,6 +25,13 @@ const char *flow_type_str[] = {
static_assert(ARRAY_SIZE(flow_type_str) == FLOW_NUM_TYPES,
"flow_type_str[] doesn't match enum flow_type");
const uint8_t flow_proto[] = {
[FLOW_TCP] = IPPROTO_TCP,
[FLOW_TCP_SPLICE] = IPPROTO_TCP,
};
static_assert(ARRAY_SIZE(flow_proto) == FLOW_NUM_TYPES,
"flow_proto[] doesn't match enum flow_type");
/* Global Flow Table */
/**

4
flow.h
View file

@ -27,6 +27,10 @@ extern const char *flow_type_str[];
#define FLOW_TYPE(f) \
((f)->type < FLOW_NUM_TYPES ? flow_type_str[(f)->type] : "?")
extern const uint8_t flow_proto[];
#define FLOW_PROTO(f) \
((f)->type < FLOW_NUM_TYPES ? flow_proto[(f)->type] : 0)
/**
* struct flow_common - Common fields for packet flows
* @type: Type of packet flow