From 65e317a8fca4eaf9efbfe642cc7e4322c56aa1f7 Mon Sep 17 00:00:00 2001
From: David Gibson <david@gibson.dropbear.id.au>
Date: Wed, 19 Feb 2025 13:28:36 +1100
Subject: [PATCH] flow: Clean up and generalise flow traversal macros
The migration code introduced a number of 'foreach' macros to traverse the
flow table. These aren't inherently tied to migration, so polish up their
naming, move them to flow_table.h and also use in flow_defer_handler()
which is the other place we need to traverse the whole table.
For now we keep foreach_established_tcp_flow() as is.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
---
flow.c | 36 ++++++++----------------------------
flow_table.h | 36 ++++++++++++++++++++++++++++++++++++
2 files changed, 44 insertions(+), 28 deletions(-)
diff --git a/flow.c b/flow.c
index 602fea7..bb5dcc3 100644
--- a/flow.c
+++ b/flow.c
@@ -53,28 +53,8 @@ const uint8_t flow_proto[] = {
static_assert(ARRAY_SIZE(flow_proto) == FLOW_NUM_TYPES,
"flow_proto[] doesn't match enum flow_type");
-#define foreach_flow(flow) \
- for ((flow) = flowtab; FLOW_IDX(flow) < FLOW_MAX; (flow)++) \
- if ((flow)->f.state == FLOW_STATE_FREE) \
- (flow) += (flow)->free.n - 1; \
- else
-
-#define foreach_active_flow(flow) \
- foreach_flow((flow)) \
- if ((flow)->f.state != FLOW_STATE_ACTIVE) \
- /* NOLINTNEXTLINE(bugprone-branch-clone) */ \
- continue; \
- else
-
-#define foreach_tcp_flow(flow) \
- foreach_active_flow((flow)) \
- if ((flow)->f.type != FLOW_TCP) \
- /* NOLINTNEXTLINE(bugprone-branch-clone) */ \
- continue; \
- else
-
#define foreach_established_tcp_flow(flow) \
- foreach_tcp_flow((flow)) \
+ flow_foreach_of_type((flow), FLOW_TCP) \
if (!tcp_flow_is_established(&(flow)->tcp)) \
/* NOLINTNEXTLINE(bugprone-branch-clone) */ \
continue; \
@@ -801,7 +781,7 @@ void flow_defer_handler(const struct ctx *c, const struct timespec *now)
struct flow_free_cluster *free_head = NULL;
unsigned *last_next = &flow_first_free;
bool timer = false;
- unsigned idx;
+ union flow *flow;
if (timespec_diff_ms(now, &flow_timer_run) >= FLOW_TIMER_INTERVAL) {
timer = true;
@@ -810,8 +790,7 @@ void flow_defer_handler(const struct ctx *c, const struct timespec *now)
ASSERT(!flow_new_entry); /* Incomplete flow at end of cycle */
- for (idx = 0; idx < FLOW_MAX; idx++) {
- union flow *flow = &flowtab[idx];
+ flow_foreach_slot(flow) {
bool closed = false;
switch (flow->f.state) {
@@ -828,12 +807,12 @@ void flow_defer_handler(const struct ctx *c, const struct timespec *now)
} else {
/* New free cluster, add to chain */
free_head = &flow->free;
- *last_next = idx;
+ *last_next = FLOW_IDX(flow);
last_next = &free_head->next;
}
/* Skip remaining empty entries */
- idx += skip - 1;
+ flow += skip - 1;
continue;
}
@@ -886,14 +865,15 @@ void flow_defer_handler(const struct ctx *c, const struct timespec *now)
if (free_head) {
/* Add slot to current free cluster */
- ASSERT(idx == FLOW_IDX(free_head) + free_head->n);
+ ASSERT(FLOW_IDX(flow) ==
+ FLOW_IDX(free_head) + free_head->n);
free_head->n++;
flow->free.n = flow->free.next = 0;
} else {
/* Create new free cluster */
free_head = &flow->free;
free_head->n = 1;
- *last_next = idx;
+ *last_next = FLOW_IDX(flow);
last_next = &free_head->next;
}
} else {
diff --git a/flow_table.h b/flow_table.h
index 9a2ff24..fd2c57b 100644
--- a/flow_table.h
+++ b/flow_table.h
@@ -50,6 +50,42 @@ extern union flow flowtab[];
#define flow_foreach_sidei(sidei_) \
for ((sidei_) = INISIDE; (sidei_) < SIDES; (sidei_)++)
+
+/**
+ * flow_foreach_slot() - Step through each flow table entry
+ * @flow: Takes values of pointer to each flow table entry
+ *
+ * Includes FREE slots.
+ */
+#define flow_foreach_slot(flow) \
+ for ((flow) = flowtab; FLOW_IDX(flow) < FLOW_MAX; (flow)++)
+
+/**
+ * flow_foreach() - Step through each active flow
+ * @flow: Takes values of pointer to each active flow
+ */
+#define flow_foreach(flow) \
+ flow_foreach_slot((flow)) \
+ if ((flow)->f.state == FLOW_STATE_FREE) \
+ (flow) += (flow)->free.n - 1; \
+ else if ((flow)->f.state != FLOW_STATE_ACTIVE) { \
+ flow_err((flow), "Bad flow state during traversal"); \
+ continue; \
+ } else
+
+/**
+ * flow_foreach_of_type() - Step through each active flow of given type
+ * @flow: Takes values of pointer to each flow
+ * @type_: Type of flow to traverse
+ */
+#define flow_foreach_of_type(flow, type_) \
+ flow_foreach((flow)) \
+ if ((flow)->f.type != (type_)) \
+ /* NOLINTNEXTLINE(bugprone-branch-clone) */ \
+ continue; \
+ else
+
+
/** flow_idx() - Index of flow from common structure
* @f: Common flow fields pointer
*