flow: Remove unneeded index from foreach_* macros

The foreach macros are odd in that they take two loop counters: an integer
index, and a pointer to the flow.  We nearly always want the latter, not
the former, and we can get the index from the pointer trivially when we
need it.  So, rearrange the macros not to need the integer index.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>

1 files changed, 21 insertions, 23 deletions

diff --git a/flow.c b/flow.c
index c68f6bb..3fcdd9f 100644
--- a/flow.c
+++ b/flow.c
@@ -53,30 +53,28 @@ 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(i, flow, bound)					\
-	for ((i) = 0, (flow) = &flowtab[(i)];				\
-	     (i) < (bound);						\
-	     (i)++, (flow) = &flowtab[(i)])				\
+#define foreach_flow(flow, bound)					\
+	for ((flow) = flowtab; FLOW_IDX(flow) < (bound); (flow)++)	\
 		if ((flow)->f.state == FLOW_STATE_FREE)			\
-			(i) += (flow)->free.n - 1;			\
+			(flow) += (flow)->free.n - 1;			\
 		else
 
-#define foreach_active_flow(i, flow, bound)				\
-	foreach_flow((i), (flow), (bound))				\
+#define foreach_active_flow(flow, bound)				\
+	foreach_flow((flow), (bound))					\
 		if ((flow)->f.state != FLOW_STATE_ACTIVE)		\
 			/* NOLINTNEXTLINE(bugprone-branch-clone) */	\
 			continue;					\
 		else
 
-#define foreach_tcp_flow(i, flow, bound)				\
-	foreach_active_flow((i), (flow), (bound))			\
+#define foreach_tcp_flow(flow, bound)					\
+	foreach_active_flow((flow), (bound))				\
 		if ((flow)->f.type != FLOW_TCP)				\
 			/* NOLINTNEXTLINE(bugprone-branch-clone) */	\
 			continue;					\
 		else
 
-#define foreach_established_tcp_flow(i, flow, bound)			\
-	foreach_tcp_flow((i), (flow), (bound))				\
+#define foreach_established_tcp_flow(flow, bound)			\
+	foreach_tcp_flow((flow), (bound))				\
 		if (!tcp_flow_is_established(&(flow)->tcp))		\
 			/* NOLINTNEXTLINE(bugprone-branch-clone) */	\
 			continue;					\
@@ -918,11 +916,10 @@ static int flow_migrate_source_rollback(struct ctx *c, unsigned max_flow,
 					int ret)
 {
 	union flow *flow;
-	unsigned i;
 
 	debug("...roll back migration");
 
-	foreach_established_tcp_flow(i, flow, max_flow)
+	foreach_established_tcp_flow(flow, max_flow)
 		if (tcp_flow_repair_off(c, &flow->tcp))
 			die("Failed to roll back TCP_REPAIR mode");
 
@@ -942,10 +939,9 @@ static int flow_migrate_source_rollback(struct ctx *c, unsigned max_flow,
 static int flow_migrate_repair_all(struct ctx *c, bool enable)
 {
 	union flow *flow;
-	unsigned i;
 	int rc;
 
-	foreach_established_tcp_flow(i, flow, FLOW_MAX) {
+	foreach_established_tcp_flow(flow, FLOW_MAX) {
 		if (enable)
 			rc = tcp_flow_repair_on(c, &flow->tcp);
 		else
@@ -954,14 +950,15 @@ static int flow_migrate_repair_all(struct ctx *c, bool enable)
 		if (rc) {
 			debug("Can't %s repair mode: %s",
 			      enable ? "enable" : "disable", strerror_(-rc));
-			return flow_migrate_source_rollback(c, i, rc);
+			return flow_migrate_source_rollback(c, FLOW_IDX(flow),
+							    rc);
 		}
 	}
 
 	if ((rc = repair_flush(c))) {
 		debug("Can't %s repair mode: %s",
 		      enable ? "enable" : "disable", strerror_(-rc));
-		return flow_migrate_source_rollback(c, i, rc);
+		return flow_migrate_source_rollback(c, FLOW_IDX(flow), rc);
 	}
 
 	return 0;
@@ -1003,13 +1000,12 @@ int flow_migrate_source(struct ctx *c, const struct migrate_stage *stage,
 	uint32_t count = 0;
 	bool first = true;
 	union flow *flow;
-	unsigned i;
 	int rc;
 
 	(void)c;
 	(void)stage;
 
-	foreach_established_tcp_flow(i, flow, FLOW_MAX)
+	foreach_established_tcp_flow(flow, FLOW_MAX)
 		count++;
 
 	count = htonl(count);
@@ -1028,10 +1024,11 @@ int flow_migrate_source(struct ctx *c, const struct migrate_stage *stage,
 	 * stream might now be inconsistent, and we might have closed listening
 	 * TCP sockets, so just terminate.
 	 */
-	foreach_established_tcp_flow(i, flow, FLOW_MAX) {
+	foreach_established_tcp_flow(flow, FLOW_MAX) {
 		rc = tcp_flow_migrate_source(fd, &flow->tcp);
 		if (rc) {
-			err("Can't send data, flow %u: %s", i, strerror_(-rc));
+			err("Can't send data, flow %u: %s", FLOW_IDX(flow),
+			    strerror_(-rc));
 			if (!first)
 				die("Inconsistent migration state, exiting");
 
@@ -1054,10 +1051,11 @@ int flow_migrate_source(struct ctx *c, const struct migrate_stage *stage,
 	 * failures but not if the stream might be inconsistent (reported here
 	 * as EIO).
 	 */
-	foreach_established_tcp_flow(i, flow, FLOW_MAX) {
+	foreach_established_tcp_flow(flow, FLOW_MAX) {
 		rc = tcp_flow_migrate_source_ext(fd, &flow->tcp);
 		if (rc) {
-			err("Extended data for flow %u: %s", i, strerror_(-rc));
+			err("Extended data for flow %u: %s", FLOW_IDX(flow),
+			    strerror_(-rc));
 
 			if (rc == -EIO)
 				die("Inconsistent migration state, exiting");